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xattr.c

/* -*- mode: c; c-basic-offset: 8; -*-
 * vim: noexpandtab sw=8 ts=8 sts=0:
 *
 * xattr.c
 *
 * Copyright (C) 2004, 2008 Oracle.  All rights reserved.
 *
 * CREDITS:
 * Lots of code in this file is copy from linux/fs/ext3/xattr.c.
 * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public
 * License version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 */

#include <linux/capability.h>
#include <linux/fs.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/highmem.h>
#include <linux/pagemap.h>
#include <linux/uio.h>
#include <linux/sched.h>
#include <linux/splice.h>
#include <linux/mount.h>
#include <linux/writeback.h>
#include <linux/falloc.h>
#include <linux/sort.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/string.h>
#include <linux/security.h>

#define MLOG_MASK_PREFIX ML_XATTR
#include <cluster/masklog.h>

#include "ocfs2.h"
#include "alloc.h"
#include "blockcheck.h"
#include "dlmglue.h"
#include "file.h"
#include "symlink.h"
#include "sysfile.h"
#include "inode.h"
#include "journal.h"
#include "ocfs2_fs.h"
#include "suballoc.h"
#include "uptodate.h"
#include "buffer_head_io.h"
#include "super.h"
#include "xattr.h"


00060 struct ocfs2_xattr_def_value_root {
      struct ocfs2_xattr_value_root xv;
      struct ocfs2_extent_rec       er;
};

00065 struct ocfs2_xattr_bucket {
      /* The inode these xattrs are associated with */
      struct inode *bu_inode;

      /* The actual buffers that make up the bucket */
      struct buffer_head *bu_bhs[OCFS2_XATTR_MAX_BLOCKS_PER_BUCKET];

      /* How many blocks make up one bucket for this filesystem */
      int bu_blocks;
};

00076 struct ocfs2_xattr_set_ctxt {
      handle_t *handle;
      struct ocfs2_alloc_context *meta_ac;
      struct ocfs2_alloc_context *data_ac;
      struct ocfs2_cached_dealloc_ctxt dealloc;
};

#define OCFS2_XATTR_ROOT_SIZE (sizeof(struct ocfs2_xattr_def_value_root))
#define OCFS2_XATTR_INLINE_SIZE     80
#define OCFS2_XATTR_HEADER_GAP      4
#define OCFS2_XATTR_FREE_IN_IBODY   (OCFS2_MIN_XATTR_INLINE_SIZE \
                               - sizeof(struct ocfs2_xattr_header) \
                               - OCFS2_XATTR_HEADER_GAP)
#define OCFS2_XATTR_FREE_IN_BLOCK(ptr)    ((ptr)->i_sb->s_blocksize \
                               - sizeof(struct ocfs2_xattr_block) \
                               - sizeof(struct ocfs2_xattr_header) \
                               - OCFS2_XATTR_HEADER_GAP)

static struct ocfs2_xattr_def_value_root def_xv = {
      .xv.xr_list.l_count = cpu_to_le16(1),
};

struct xattr_handler *ocfs2_xattr_handlers[] = {
      &ocfs2_xattr_user_handler,
#ifdef CONFIG_OCFS2_FS_POSIX_ACL
      &ocfs2_xattr_acl_access_handler,
      &ocfs2_xattr_acl_default_handler,
#endif
      &ocfs2_xattr_trusted_handler,
      &ocfs2_xattr_security_handler,
      NULL
};

static struct xattr_handler *ocfs2_xattr_handler_map[OCFS2_XATTR_MAX] = {
      [OCFS2_XATTR_INDEX_USER]      = &ocfs2_xattr_user_handler,
#ifdef CONFIG_OCFS2_FS_POSIX_ACL
      [OCFS2_XATTR_INDEX_POSIX_ACL_ACCESS]
                              = &ocfs2_xattr_acl_access_handler,
      [OCFS2_XATTR_INDEX_POSIX_ACL_DEFAULT]
                              = &ocfs2_xattr_acl_default_handler,
#endif
      [OCFS2_XATTR_INDEX_TRUSTED]   = &ocfs2_xattr_trusted_handler,
      [OCFS2_XATTR_INDEX_SECURITY]  = &ocfs2_xattr_security_handler,
};

00121 struct ocfs2_xattr_info {
      int name_index;
      const char *name;
      const void *value;
      size_t value_len;
};

00128 struct ocfs2_xattr_search {
      struct buffer_head *inode_bh;
      /*
       * xattr_bh point to the block buffer head which has extended attribute
       * when extended attribute in inode, xattr_bh is equal to inode_bh.
       */
      struct buffer_head *xattr_bh;
      struct ocfs2_xattr_header *header;
      struct ocfs2_xattr_bucket *bucket;
      void *base;
      void *end;
      struct ocfs2_xattr_entry *here;
      int not_found;
};

static int ocfs2_xattr_bucket_get_name_value(struct inode *inode,
                                   struct ocfs2_xattr_header *xh,
                                   int index,
                                   int *block_off,
                                   int *new_offset);

static int ocfs2_xattr_block_find(struct inode *inode,
                          int name_index,
                          const char *name,
                          struct ocfs2_xattr_search *xs);
static int ocfs2_xattr_index_block_find(struct inode *inode,
                              struct buffer_head *root_bh,
                              int name_index,
                              const char *name,
                              struct ocfs2_xattr_search *xs);

static int ocfs2_xattr_tree_list_index_block(struct inode *inode,
                              struct ocfs2_xattr_tree_root *xt,
                              char *buffer,
                              size_t buffer_size);

static int ocfs2_xattr_create_index_block(struct inode *inode,
                                struct ocfs2_xattr_search *xs,
                                struct ocfs2_xattr_set_ctxt *ctxt);

static int ocfs2_xattr_set_entry_index_block(struct inode *inode,
                                   struct ocfs2_xattr_info *xi,
                                   struct ocfs2_xattr_search *xs,
                                   struct ocfs2_xattr_set_ctxt *ctxt);

static int ocfs2_delete_xattr_index_block(struct inode *inode,
                                struct buffer_head *xb_bh);
static int ocfs2_mv_xattr_buckets(struct inode *inode, handle_t *handle,
                          u64 src_blk, u64 last_blk, u64 to_blk,
                          unsigned int start_bucket,
                          u32 *first_hash);

static inline u16 ocfs2_xattr_buckets_per_cluster(struct ocfs2_super *osb)
{
      return (1 << osb->s_clustersize_bits) / OCFS2_XATTR_BUCKET_SIZE;
}

static inline u16 ocfs2_blocks_per_xattr_bucket(struct super_block *sb)
{
      return OCFS2_XATTR_BUCKET_SIZE / (1 << sb->s_blocksize_bits);
}

static inline u16 ocfs2_xattr_max_xe_in_bucket(struct super_block *sb)
{
      u16 len = sb->s_blocksize -
             offsetof(struct ocfs2_xattr_header, xh_entries);

      return len / sizeof(struct ocfs2_xattr_entry);
}

#define bucket_blkno(_b) ((_b)->bu_bhs[0]->b_blocknr)
#define bucket_block(_b, _n) ((_b)->bu_bhs[(_n)]->b_data)
#define bucket_xh(_b) ((struct ocfs2_xattr_header *)bucket_block((_b), 0))

static struct ocfs2_xattr_bucket *ocfs2_xattr_bucket_new(struct inode *inode)
{
      struct ocfs2_xattr_bucket *bucket;
      int blks = ocfs2_blocks_per_xattr_bucket(inode->i_sb);

      BUG_ON(blks > OCFS2_XATTR_MAX_BLOCKS_PER_BUCKET);

      bucket = kzalloc(sizeof(struct ocfs2_xattr_bucket), GFP_NOFS);
      if (bucket) {
            bucket->bu_inode = inode;
            bucket->bu_blocks = blks;
      }

      return bucket;
}

static void ocfs2_xattr_bucket_relse(struct ocfs2_xattr_bucket *bucket)
{
      int i;

      for (i = 0; i < bucket->bu_blocks; i++) {
            brelse(bucket->bu_bhs[i]);
            bucket->bu_bhs[i] = NULL;
      }
}

static void ocfs2_xattr_bucket_free(struct ocfs2_xattr_bucket *bucket)
{
      if (bucket) {
            ocfs2_xattr_bucket_relse(bucket);
            bucket->bu_inode = NULL;
            kfree(bucket);
      }
}

/*
 * A bucket that has never been written to disk doesn't need to be
 * read.  We just need the buffer_heads.  Don't call this for
 * buckets that are already on disk.  ocfs2_read_xattr_bucket() initializes
 * them fully.
 */
static int ocfs2_init_xattr_bucket(struct ocfs2_xattr_bucket *bucket,
                           u64 xb_blkno)
{
      int i, rc = 0;

      for (i = 0; i < bucket->bu_blocks; i++) {
            bucket->bu_bhs[i] = sb_getblk(bucket->bu_inode->i_sb,
                                    xb_blkno + i);
            if (!bucket->bu_bhs[i]) {
                  rc = -EIO;
                  mlog_errno(rc);
                  break;
            }

            if (!ocfs2_buffer_uptodate(bucket->bu_inode,
                                 bucket->bu_bhs[i]))
                  ocfs2_set_new_buffer_uptodate(bucket->bu_inode,
                                          bucket->bu_bhs[i]);
      }

      if (rc)
            ocfs2_xattr_bucket_relse(bucket);
      return rc;
}

/* Read the xattr bucket at xb_blkno */
static int ocfs2_read_xattr_bucket(struct ocfs2_xattr_bucket *bucket,
                           u64 xb_blkno)
{
      int rc;

      rc = ocfs2_read_blocks(bucket->bu_inode, xb_blkno,
                         bucket->bu_blocks, bucket->bu_bhs, 0,
                         NULL);
      if (!rc) {
            spin_lock(&OCFS2_SB(bucket->bu_inode->i_sb)->osb_xattr_lock);
            rc = ocfs2_validate_meta_ecc_bhs(bucket->bu_inode->i_sb,
                                     bucket->bu_bhs,
                                     bucket->bu_blocks,
                                     &bucket_xh(bucket)->xh_check);
            spin_unlock(&OCFS2_SB(bucket->bu_inode->i_sb)->osb_xattr_lock);
            if (rc)
                  mlog_errno(rc);
      }

      if (rc)
            ocfs2_xattr_bucket_relse(bucket);
      return rc;
}

static int ocfs2_xattr_bucket_journal_access(handle_t *handle,
                                   struct ocfs2_xattr_bucket *bucket,
                                   int type)
{
      int i, rc = 0;

      for (i = 0; i < bucket->bu_blocks; i++) {
            rc = ocfs2_journal_access(handle, bucket->bu_inode,
                                bucket->bu_bhs[i], type);
            if (rc) {
                  mlog_errno(rc);
                  break;
            }
      }

      return rc;
}

static void ocfs2_xattr_bucket_journal_dirty(handle_t *handle,
                                   struct ocfs2_xattr_bucket *bucket)
{
      int i;

      spin_lock(&OCFS2_SB(bucket->bu_inode->i_sb)->osb_xattr_lock);
      ocfs2_compute_meta_ecc_bhs(bucket->bu_inode->i_sb,
                           bucket->bu_bhs, bucket->bu_blocks,
                           &bucket_xh(bucket)->xh_check);
      spin_unlock(&OCFS2_SB(bucket->bu_inode->i_sb)->osb_xattr_lock);

      for (i = 0; i < bucket->bu_blocks; i++)
            ocfs2_journal_dirty(handle, bucket->bu_bhs[i]);
}

static void ocfs2_xattr_bucket_copy_data(struct ocfs2_xattr_bucket *dest,
                               struct ocfs2_xattr_bucket *src)
{
      int i;
      int blocksize = src->bu_inode->i_sb->s_blocksize;

      BUG_ON(dest->bu_blocks != src->bu_blocks);
      BUG_ON(dest->bu_inode != src->bu_inode);

      for (i = 0; i < src->bu_blocks; i++) {
            memcpy(bucket_block(dest, i), bucket_block(src, i),
                   blocksize);
      }
}

static int ocfs2_validate_xattr_block(struct super_block *sb,
                              struct buffer_head *bh)
{
      int rc;
      struct ocfs2_xattr_block *xb =
            (struct ocfs2_xattr_block *)bh->b_data;

      mlog(0, "Validating xattr block %llu\n",
           (unsigned long long)bh->b_blocknr);

      BUG_ON(!buffer_uptodate(bh));

      /*
       * If the ecc fails, we return the error but otherwise
       * leave the filesystem running.  We know any error is
       * local to this block.
       */
      rc = ocfs2_validate_meta_ecc(sb, bh->b_data, &xb->xb_check);
      if (rc)
            return rc;

      /*
       * Errors after here are fatal
       */

      if (!OCFS2_IS_VALID_XATTR_BLOCK(xb)) {
            ocfs2_error(sb,
                      "Extended attribute block #%llu has bad "
                      "signature %.*s",
                      (unsigned long long)bh->b_blocknr, 7,
                      xb->xb_signature);
            return -EINVAL;
      }

      if (le64_to_cpu(xb->xb_blkno) != bh->b_blocknr) {
            ocfs2_error(sb,
                      "Extended attribute block #%llu has an "
                      "invalid xb_blkno of %llu",
                      (unsigned long long)bh->b_blocknr,
                      (unsigned long long)le64_to_cpu(xb->xb_blkno));
            return -EINVAL;
      }

      if (le32_to_cpu(xb->xb_fs_generation) != OCFS2_SB(sb)->fs_generation) {
            ocfs2_error(sb,
                      "Extended attribute block #%llu has an invalid "
                      "xb_fs_generation of #%u",
                      (unsigned long long)bh->b_blocknr,
                      le32_to_cpu(xb->xb_fs_generation));
            return -EINVAL;
      }

      return 0;
}

static int ocfs2_read_xattr_block(struct inode *inode, u64 xb_blkno,
                          struct buffer_head **bh)
{
      int rc;
      struct buffer_head *tmp = *bh;

      rc = ocfs2_read_block(inode, xb_blkno, &tmp,
                        ocfs2_validate_xattr_block);

      /* If ocfs2_read_block() got us a new bh, pass it up. */
      if (!rc && !*bh)
            *bh = tmp;

      return rc;
}

static inline const char *ocfs2_xattr_prefix(int name_index)
{
      struct xattr_handler *handler = NULL;

      if (name_index > 0 && name_index < OCFS2_XATTR_MAX)
            handler = ocfs2_xattr_handler_map[name_index];

      return handler ? handler->prefix : NULL;
}

static u32 ocfs2_xattr_name_hash(struct inode *inode,
                         const char *name,
                         int name_len)
{
      /* Get hash value of uuid from super block */
      u32 hash = OCFS2_SB(inode->i_sb)->uuid_hash;
      int i;

      /* hash extended attribute name */
      for (i = 0; i < name_len; i++) {
            hash = (hash << OCFS2_HASH_SHIFT) ^
                   (hash >> (8*sizeof(hash) - OCFS2_HASH_SHIFT)) ^
                   *name++;
      }

      return hash;
}

/*
 * ocfs2_xattr_hash_entry()
 *
 * Compute the hash of an extended attribute.
 */
static void ocfs2_xattr_hash_entry(struct inode *inode,
                           struct ocfs2_xattr_header *header,
                           struct ocfs2_xattr_entry *entry)
{
      u32 hash = 0;
      char *name = (char *)header + le16_to_cpu(entry->xe_name_offset);

      hash = ocfs2_xattr_name_hash(inode, name, entry->xe_name_len);
      entry->xe_name_hash = cpu_to_le32(hash);

      return;
}

static int ocfs2_xattr_entry_real_size(int name_len, size_t value_len)
{
      int size = 0;

      if (value_len <= OCFS2_XATTR_INLINE_SIZE)
            size = OCFS2_XATTR_SIZE(name_len) + OCFS2_XATTR_SIZE(value_len);
      else
            size = OCFS2_XATTR_SIZE(name_len) + OCFS2_XATTR_ROOT_SIZE;
      size += sizeof(struct ocfs2_xattr_entry);

      return size;
}

int ocfs2_calc_security_init(struct inode *dir,
                       struct ocfs2_security_xattr_info *si,
                       int *want_clusters,
                       int *xattr_credits,
                       struct ocfs2_alloc_context **xattr_ac)
{
      int ret = 0;
      struct ocfs2_super *osb = OCFS2_SB(dir->i_sb);
      int s_size = ocfs2_xattr_entry_real_size(strlen(si->name),
                                     si->value_len);

      /*
       * The max space of security xattr taken inline is
       * 256(name) + 80(value) + 16(entry) = 352 bytes,
       * So reserve one metadata block for it is ok.
       */
      if (dir->i_sb->s_blocksize == OCFS2_MIN_BLOCKSIZE ||
          s_size > OCFS2_XATTR_FREE_IN_IBODY) {
            ret = ocfs2_reserve_new_metadata_blocks(osb, 1, xattr_ac);
            if (ret) {
                  mlog_errno(ret);
                  return ret;
            }
            *xattr_credits += OCFS2_XATTR_BLOCK_CREATE_CREDITS;
      }

      /* reserve clusters for xattr value which will be set in B tree*/
      if (si->value_len > OCFS2_XATTR_INLINE_SIZE) {
            int new_clusters = ocfs2_clusters_for_bytes(dir->i_sb,
                                              si->value_len);

            *xattr_credits += ocfs2_clusters_to_blocks(dir->i_sb,
                                             new_clusters);
            *want_clusters += new_clusters;
      }
      return ret;
}

int ocfs2_calc_xattr_init(struct inode *dir,
                    struct buffer_head *dir_bh,
                    int mode,
                    struct ocfs2_security_xattr_info *si,
                    int *want_clusters,
                    int *xattr_credits,
                    int *want_meta)
{
      int ret = 0;
      struct ocfs2_super *osb = OCFS2_SB(dir->i_sb);
      int s_size = 0, a_size = 0, acl_len = 0, new_clusters;

      if (si->enable)
            s_size = ocfs2_xattr_entry_real_size(strlen(si->name),
                                         si->value_len);

      if (osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) {
            acl_len = ocfs2_xattr_get_nolock(dir, dir_bh,
                              OCFS2_XATTR_INDEX_POSIX_ACL_DEFAULT,
                              "", NULL, 0);
            if (acl_len > 0) {
                  a_size = ocfs2_xattr_entry_real_size(0, acl_len);
                  if (S_ISDIR(mode))
                        a_size <<= 1;
            } else if (acl_len != 0 && acl_len != -ENODATA) {
                  mlog_errno(ret);
                  return ret;
            }
      }

      if (!(s_size + a_size))
            return ret;

      /*
       * The max space of security xattr taken inline is
       * 256(name) + 80(value) + 16(entry) = 352 bytes,
       * The max space of acl xattr taken inline is
       * 80(value) + 16(entry) * 2(if directory) = 192 bytes,
       * when blocksize = 512, may reserve one more cluser for
       * xattr bucket, otherwise reserve one metadata block
       * for them is ok.
       * If this is a new directory with inline data,
       * we choose to reserve the entire inline area for
       * directory contents and force an external xattr block.
       */
      if (dir->i_sb->s_blocksize == OCFS2_MIN_BLOCKSIZE ||
          (S_ISDIR(mode) && ocfs2_supports_inline_data(osb)) ||
          (s_size + a_size) > OCFS2_XATTR_FREE_IN_IBODY) {
            *want_meta = *want_meta + 1;
            *xattr_credits += OCFS2_XATTR_BLOCK_CREATE_CREDITS;
      }

      if (dir->i_sb->s_blocksize == OCFS2_MIN_BLOCKSIZE &&
          (s_size + a_size) > OCFS2_XATTR_FREE_IN_BLOCK(dir)) {
            *want_clusters += 1;
            *xattr_credits += ocfs2_blocks_per_xattr_bucket(dir->i_sb);
      }

      /*
       * reserve credits and clusters for xattrs which has large value
       * and have to be set outside
       */
      if (si->enable && si->value_len > OCFS2_XATTR_INLINE_SIZE) {
            new_clusters = ocfs2_clusters_for_bytes(dir->i_sb,
                                          si->value_len);
            *xattr_credits += ocfs2_clusters_to_blocks(dir->i_sb,
                                             new_clusters);
            *want_clusters += new_clusters;
      }
      if (osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL &&
          acl_len > OCFS2_XATTR_INLINE_SIZE) {
            /* for directory, it has DEFAULT and ACCESS two types of acls */
            new_clusters = (S_ISDIR(mode) ? 2 : 1) *
                        ocfs2_clusters_for_bytes(dir->i_sb, acl_len);
            *xattr_credits += ocfs2_clusters_to_blocks(dir->i_sb,
                                             new_clusters);
            *want_clusters += new_clusters;
      }

      return ret;
}

static int ocfs2_xattr_extend_allocation(struct inode *inode,
                               u32 clusters_to_add,
                               struct ocfs2_xattr_value_buf *vb,
                               struct ocfs2_xattr_set_ctxt *ctxt)
{
      int status = 0;
      handle_t *handle = ctxt->handle;
      enum ocfs2_alloc_restarted why;
      struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
      u32 prev_clusters, logical_start = le32_to_cpu(vb->vb_xv->xr_clusters);
      struct ocfs2_extent_tree et;

      mlog(0, "(clusters_to_add for xattr= %u)\n", clusters_to_add);

      ocfs2_init_xattr_value_extent_tree(&et, inode, vb);

      status = vb->vb_access(handle, inode, vb->vb_bh,
                        OCFS2_JOURNAL_ACCESS_WRITE);
      if (status < 0) {
            mlog_errno(status);
            goto leave;
      }

      prev_clusters = le32_to_cpu(vb->vb_xv->xr_clusters);
      status = ocfs2_add_clusters_in_btree(osb,
                                   inode,
                                   &logical_start,
                                   clusters_to_add,
                                   0,
                                   &et,
                                   handle,
                                   ctxt->data_ac,
                                   ctxt->meta_ac,
                                   &why);
      if (status < 0) {
            mlog_errno(status);
            goto leave;
      }

      status = ocfs2_journal_dirty(handle, vb->vb_bh);
      if (status < 0) {
            mlog_errno(status);
            goto leave;
      }

      clusters_to_add -= le32_to_cpu(vb->vb_xv->xr_clusters) - prev_clusters;

      /*
       * We should have already allocated enough space before the transaction,
       * so no need to restart.
       */
      BUG_ON(why != RESTART_NONE || clusters_to_add);

leave:

      return status;
}

static int __ocfs2_remove_xattr_range(struct inode *inode,
                              struct ocfs2_xattr_value_buf *vb,
                              u32 cpos, u32 phys_cpos, u32 len,
                              struct ocfs2_xattr_set_ctxt *ctxt)
{
      int ret;
      u64 phys_blkno = ocfs2_clusters_to_blocks(inode->i_sb, phys_cpos);
      handle_t *handle = ctxt->handle;
      struct ocfs2_extent_tree et;

      ocfs2_init_xattr_value_extent_tree(&et, inode, vb);

      ret = vb->vb_access(handle, inode, vb->vb_bh,
                      OCFS2_JOURNAL_ACCESS_WRITE);
      if (ret) {
            mlog_errno(ret);
            goto out;
      }

      ret = ocfs2_remove_extent(inode, &et, cpos, len, handle, ctxt->meta_ac,
                          &ctxt->dealloc);
      if (ret) {
            mlog_errno(ret);
            goto out;
      }

      le32_add_cpu(&vb->vb_xv->xr_clusters, -len);

      ret = ocfs2_journal_dirty(handle, vb->vb_bh);
      if (ret) {
            mlog_errno(ret);
            goto out;
      }

      ret = ocfs2_cache_cluster_dealloc(&ctxt->dealloc, phys_blkno, len);
      if (ret)
            mlog_errno(ret);

out:
      return ret;
}

static int ocfs2_xattr_shrink_size(struct inode *inode,
                           u32 old_clusters,
                           u32 new_clusters,
                           struct ocfs2_xattr_value_buf *vb,
                           struct ocfs2_xattr_set_ctxt *ctxt)
{
      int ret = 0;
      u32 trunc_len, cpos, phys_cpos, alloc_size;
      u64 block;

      if (old_clusters <= new_clusters)
            return 0;

      cpos = new_clusters;
      trunc_len = old_clusters - new_clusters;
      while (trunc_len) {
            ret = ocfs2_xattr_get_clusters(inode, cpos, &phys_cpos,
                                     &alloc_size,
                                     &vb->vb_xv->xr_list);
            if (ret) {
                  mlog_errno(ret);
                  goto out;
            }

            if (alloc_size > trunc_len)
                  alloc_size = trunc_len;

            ret = __ocfs2_remove_xattr_range(inode, vb, cpos,
                                     phys_cpos, alloc_size,
                                     ctxt);
            if (ret) {
                  mlog_errno(ret);
                  goto out;
            }

            block = ocfs2_clusters_to_blocks(inode->i_sb, phys_cpos);
            ocfs2_remove_xattr_clusters_from_cache(inode, block,
                                           alloc_size);
            cpos += alloc_size;
            trunc_len -= alloc_size;
      }

out:
      return ret;
}

static int ocfs2_xattr_value_truncate(struct inode *inode,
                              struct ocfs2_xattr_value_buf *vb,
                              int len,
                              struct ocfs2_xattr_set_ctxt *ctxt)
{
      int ret;
      u32 new_clusters = ocfs2_clusters_for_bytes(inode->i_sb, len);
      u32 old_clusters = le32_to_cpu(vb->vb_xv->xr_clusters);

      if (new_clusters == old_clusters)
            return 0;

      if (new_clusters > old_clusters)
            ret = ocfs2_xattr_extend_allocation(inode,
                                        new_clusters - old_clusters,
                                        vb, ctxt);
      else
            ret = ocfs2_xattr_shrink_size(inode,
                                    old_clusters, new_clusters,
                                    vb, ctxt);

      return ret;
}

static int ocfs2_xattr_list_entry(char *buffer, size_t size,
                          size_t *result, const char *prefix,
                          const char *name, int name_len)
{
      char *p = buffer + *result;
      int prefix_len = strlen(prefix);
      int total_len = prefix_len + name_len + 1;

      *result += total_len;

      /* we are just looking for how big our buffer needs to be */
      if (!size)
            return 0;

      if (*result > size)
            return -ERANGE;

      memcpy(p, prefix, prefix_len);
      memcpy(p + prefix_len, name, name_len);
      p[prefix_len + name_len] = '\0';

      return 0;
}

static int ocfs2_xattr_list_entries(struct inode *inode,
                            struct ocfs2_xattr_header *header,
                            char *buffer, size_t buffer_size)
{
      size_t result = 0;
      int i, type, ret;
      const char *prefix, *name;

      for (i = 0 ; i < le16_to_cpu(header->xh_count); i++) {
            struct ocfs2_xattr_entry *entry = &header->xh_entries[i];
            type = ocfs2_xattr_get_type(entry);
            prefix = ocfs2_xattr_prefix(type);

            if (prefix) {
                  name = (const char *)header +
                        le16_to_cpu(entry->xe_name_offset);

                  ret = ocfs2_xattr_list_entry(buffer, buffer_size,
                                         &result, prefix, name,
                                         entry->xe_name_len);
                  if (ret)
                        return ret;
            }
      }

      return result;
}

static int ocfs2_xattr_ibody_list(struct inode *inode,
                          struct ocfs2_dinode *di,
                          char *buffer,
                          size_t buffer_size)
{
      struct ocfs2_xattr_header *header = NULL;
      struct ocfs2_inode_info *oi = OCFS2_I(inode);
      int ret = 0;

      if (!(oi->ip_dyn_features & OCFS2_INLINE_XATTR_FL))
            return ret;

      header = (struct ocfs2_xattr_header *)
             ((void *)di + inode->i_sb->s_blocksize -
             le16_to_cpu(di->i_xattr_inline_size));

      ret = ocfs2_xattr_list_entries(inode, header, buffer, buffer_size);

      return ret;
}

static int ocfs2_xattr_block_list(struct inode *inode,
                          struct ocfs2_dinode *di,
                          char *buffer,
                          size_t buffer_size)
{
      struct buffer_head *blk_bh = NULL;
      struct ocfs2_xattr_block *xb;
      int ret = 0;

      if (!di->i_xattr_loc)
            return ret;

      ret = ocfs2_read_xattr_block(inode, le64_to_cpu(di->i_xattr_loc),
                             &blk_bh);
      if (ret < 0) {
            mlog_errno(ret);
            return ret;
      }

      xb = (struct ocfs2_xattr_block *)blk_bh->b_data;
      if (!(le16_to_cpu(xb->xb_flags) & OCFS2_XATTR_INDEXED)) {
            struct ocfs2_xattr_header *header = &xb->xb_attrs.xb_header;
            ret = ocfs2_xattr_list_entries(inode, header,
                                     buffer, buffer_size);
      } else {
            struct ocfs2_xattr_tree_root *xt = &xb->xb_attrs.xb_root;
            ret = ocfs2_xattr_tree_list_index_block(inode, xt,
                                       buffer, buffer_size);
      }

      brelse(blk_bh);

      return ret;
}

ssize_t ocfs2_listxattr(struct dentry *dentry,
                  char *buffer,
                  size_t size)
{
      int ret = 0, i_ret = 0, b_ret = 0;
      struct buffer_head *di_bh = NULL;
      struct ocfs2_dinode *di = NULL;
      struct ocfs2_inode_info *oi = OCFS2_I(dentry->d_inode);

      if (!ocfs2_supports_xattr(OCFS2_SB(dentry->d_sb)))
            return -EOPNOTSUPP;

      if (!(oi->ip_dyn_features & OCFS2_HAS_XATTR_FL))
            return ret;

      ret = ocfs2_inode_lock(dentry->d_inode, &di_bh, 0);
      if (ret < 0) {
            mlog_errno(ret);
            return ret;
      }

      di = (struct ocfs2_dinode *)di_bh->b_data;

      down_read(&oi->ip_xattr_sem);
      i_ret = ocfs2_xattr_ibody_list(dentry->d_inode, di, buffer, size);
      if (i_ret < 0)
            b_ret = 0;
      else {
            if (buffer) {
                  buffer += i_ret;
                  size -= i_ret;
            }
            b_ret = ocfs2_xattr_block_list(dentry->d_inode, di,
                                     buffer, size);
            if (b_ret < 0)
                  i_ret = 0;
      }
      up_read(&oi->ip_xattr_sem);
      ocfs2_inode_unlock(dentry->d_inode, 0);

      brelse(di_bh);

      return i_ret + b_ret;
}

static int ocfs2_xattr_find_entry(int name_index,
                          const char *name,
                          struct ocfs2_xattr_search *xs)
{
      struct ocfs2_xattr_entry *entry;
      size_t name_len;
      int i, cmp = 1;

      if (name == NULL)
            return -EINVAL;

      name_len = strlen(name);
      entry = xs->here;
      for (i = 0; i < le16_to_cpu(xs->header->xh_count); i++) {
            cmp = name_index - ocfs2_xattr_get_type(entry);
            if (!cmp)
                  cmp = name_len - entry->xe_name_len;
            if (!cmp)
                  cmp = memcmp(name, (xs->base +
                             le16_to_cpu(entry->xe_name_offset)),
                             name_len);
            if (cmp == 0)
                  break;
            entry += 1;
      }
      xs->here = entry;

      return cmp ? -ENODATA : 0;
}

static int ocfs2_xattr_get_value_outside(struct inode *inode,
                               struct ocfs2_xattr_value_root *xv,
                               void *buffer,
                               size_t len)
{
      u32 cpos, p_cluster, num_clusters, bpc, clusters;
      u64 blkno;
      int i, ret = 0;
      size_t cplen, blocksize;
      struct buffer_head *bh = NULL;
      struct ocfs2_extent_list *el;

      el = &xv->xr_list;
      clusters = le32_to_cpu(xv->xr_clusters);
      bpc = ocfs2_clusters_to_blocks(inode->i_sb, 1);
      blocksize = inode->i_sb->s_blocksize;

      cpos = 0;
      while (cpos < clusters) {
            ret = ocfs2_xattr_get_clusters(inode, cpos, &p_cluster,
                                     &num_clusters, el);
            if (ret) {
                  mlog_errno(ret);
                  goto out;
            }

            blkno = ocfs2_clusters_to_blocks(inode->i_sb, p_cluster);
            /* Copy ocfs2_xattr_value */
            for (i = 0; i < num_clusters * bpc; i++, blkno++) {
                  ret = ocfs2_read_block(inode, blkno, &bh, NULL);
                  if (ret) {
                        mlog_errno(ret);
                        goto out;
                  }

                  cplen = len >= blocksize ? blocksize : len;
                  memcpy(buffer, bh->b_data, cplen);
                  len -= cplen;
                  buffer += cplen;

                  brelse(bh);
                  bh = NULL;
                  if (len == 0)
                        break;
            }
            cpos += num_clusters;
      }
out:
      return ret;
}

static int ocfs2_xattr_ibody_get(struct inode *inode,
                         int name_index,
                         const char *name,
                         void *buffer,
                         size_t buffer_size,
                         struct ocfs2_xattr_search *xs)
{
      struct ocfs2_inode_info *oi = OCFS2_I(inode);
      struct ocfs2_dinode *di = (struct ocfs2_dinode *)xs->inode_bh->b_data;
      struct ocfs2_xattr_value_root *xv;
      size_t size;
      int ret = 0;

      if (!(oi->ip_dyn_features & OCFS2_INLINE_XATTR_FL))
            return -ENODATA;

      xs->end = (void *)di + inode->i_sb->s_blocksize;
      xs->header = (struct ocfs2_xattr_header *)
                  (xs->end - le16_to_cpu(di->i_xattr_inline_size));
      xs->base = (void *)xs->header;
      xs->here = xs->header->xh_entries;

      ret = ocfs2_xattr_find_entry(name_index, name, xs);
      if (ret)
            return ret;
      size = le64_to_cpu(xs->here->xe_value_size);
      if (buffer) {
            if (size > buffer_size)
                  return -ERANGE;
            if (ocfs2_xattr_is_local(xs->here)) {
                  memcpy(buffer, (void *)xs->base +
                         le16_to_cpu(xs->here->xe_name_offset) +
                         OCFS2_XATTR_SIZE(xs->here->xe_name_len), size);
            } else {
                  xv = (struct ocfs2_xattr_value_root *)
                        (xs->base + le16_to_cpu(
                         xs->here->xe_name_offset) +
                        OCFS2_XATTR_SIZE(xs->here->xe_name_len));
                  ret = ocfs2_xattr_get_value_outside(inode, xv,
                                              buffer, size);
                  if (ret < 0) {
                        mlog_errno(ret);
                        return ret;
                  }
            }
      }

      return size;
}

static int ocfs2_xattr_block_get(struct inode *inode,
                         int name_index,
                         const char *name,
                         void *buffer,
                         size_t buffer_size,
                         struct ocfs2_xattr_search *xs)
{
      struct ocfs2_xattr_block *xb;
      struct ocfs2_xattr_value_root *xv;
      size_t size;
      int ret = -ENODATA, name_offset, name_len, i;
      int uninitialized_var(block_off);

      xs->bucket = ocfs2_xattr_bucket_new(inode);
      if (!xs->bucket) {
            ret = -ENOMEM;
            mlog_errno(ret);
            goto cleanup;
      }

      ret = ocfs2_xattr_block_find(inode, name_index, name, xs);
      if (ret) {
            mlog_errno(ret);
            goto cleanup;
      }

      if (xs->not_found) {
            ret = -ENODATA;
            goto cleanup;
      }

      xb = (struct ocfs2_xattr_block *)xs->xattr_bh->b_data;
      size = le64_to_cpu(xs->here->xe_value_size);
      if (buffer) {
            ret = -ERANGE;
            if (size > buffer_size)
                  goto cleanup;

            name_offset = le16_to_cpu(xs->here->xe_name_offset);
            name_len = OCFS2_XATTR_SIZE(xs->here->xe_name_len);
            i = xs->here - xs->header->xh_entries;

            if (le16_to_cpu(xb->xb_flags) & OCFS2_XATTR_INDEXED) {
                  ret = ocfs2_xattr_bucket_get_name_value(inode,
                                                bucket_xh(xs->bucket),
                                                i,
                                                &block_off,
                                                &name_offset);
                  xs->base = bucket_block(xs->bucket, block_off);
            }
            if (ocfs2_xattr_is_local(xs->here)) {
                  memcpy(buffer, (void *)xs->base +
                         name_offset + name_len, size);
            } else {
                  xv = (struct ocfs2_xattr_value_root *)
                        (xs->base + name_offset + name_len);
                  ret = ocfs2_xattr_get_value_outside(inode, xv,
                                              buffer, size);
                  if (ret < 0) {
                        mlog_errno(ret);
                        goto cleanup;
                  }
            }
      }
      ret = size;
cleanup:
      ocfs2_xattr_bucket_free(xs->bucket);

      brelse(xs->xattr_bh);
      xs->xattr_bh = NULL;
      return ret;
}

int ocfs2_xattr_get_nolock(struct inode *inode,
                     struct buffer_head *di_bh,
                     int name_index,
                     const char *name,
                     void *buffer,
                     size_t buffer_size)
{
      int ret;
      struct ocfs2_dinode *di = NULL;
      struct ocfs2_inode_info *oi = OCFS2_I(inode);
      struct ocfs2_xattr_search xis = {
            .not_found = -ENODATA,
      };
      struct ocfs2_xattr_search xbs = {
            .not_found = -ENODATA,
      };

      if (!ocfs2_supports_xattr(OCFS2_SB(inode->i_sb)))
            return -EOPNOTSUPP;

      if (!(oi->ip_dyn_features & OCFS2_HAS_XATTR_FL))
            ret = -ENODATA;

      xis.inode_bh = xbs.inode_bh = di_bh;
      di = (struct ocfs2_dinode *)di_bh->b_data;

      down_read(&oi->ip_xattr_sem);
      ret = ocfs2_xattr_ibody_get(inode, name_index, name, buffer,
                            buffer_size, &xis);
      if (ret == -ENODATA && di->i_xattr_loc)
            ret = ocfs2_xattr_block_get(inode, name_index, name, buffer,
                                  buffer_size, &xbs);
      up_read(&oi->ip_xattr_sem);

      return ret;
}

/* ocfs2_xattr_get()
 *
 * Copy an extended attribute into the buffer provided.
 * Buffer is NULL to compute the size of buffer required.
 */
static int ocfs2_xattr_get(struct inode *inode,
                     int name_index,
                     const char *name,
                     void *buffer,
                     size_t buffer_size)
{
      int ret;
      struct buffer_head *di_bh = NULL;

      ret = ocfs2_inode_lock(inode, &di_bh, 0);
      if (ret < 0) {
            mlog_errno(ret);
            return ret;
      }
      ret = ocfs2_xattr_get_nolock(inode, di_bh, name_index,
                             name, buffer, buffer_size);

      ocfs2_inode_unlock(inode, 0);

      brelse(di_bh);

      return ret;
}

static int __ocfs2_xattr_set_value_outside(struct inode *inode,
                                 handle_t *handle,
                                 struct ocfs2_xattr_value_root *xv,
                                 const void *value,
                                 int value_len)
{
      int ret = 0, i, cp_len;
      u16 blocksize = inode->i_sb->s_blocksize;
      u32 p_cluster, num_clusters;
      u32 cpos = 0, bpc = ocfs2_clusters_to_blocks(inode->i_sb, 1);
      u32 clusters = ocfs2_clusters_for_bytes(inode->i_sb, value_len);
      u64 blkno;
      struct buffer_head *bh = NULL;

      BUG_ON(clusters > le32_to_cpu(xv->xr_clusters));

      while (cpos < clusters) {
            ret = ocfs2_xattr_get_clusters(inode, cpos, &p_cluster,
                                     &num_clusters, &xv->xr_list);
            if (ret) {
                  mlog_errno(ret);
                  goto out;
            }

            blkno = ocfs2_clusters_to_blocks(inode->i_sb, p_cluster);

            for (i = 0; i < num_clusters * bpc; i++, blkno++) {
                  ret = ocfs2_read_block(inode, blkno, &bh, NULL);
                  if (ret) {
                        mlog_errno(ret);
                        goto out;
                  }

                  ret = ocfs2_journal_access(handle,
                                       inode,
                                       bh,
                                       OCFS2_JOURNAL_ACCESS_WRITE);
                  if (ret < 0) {
                        mlog_errno(ret);
                        goto out;
                  }

                  cp_len = value_len > blocksize ? blocksize : value_len;
                  memcpy(bh->b_data, value, cp_len);
                  value_len -= cp_len;
                  value += cp_len;
                  if (cp_len < blocksize)
                        memset(bh->b_data + cp_len, 0,
                               blocksize - cp_len);

                  ret = ocfs2_journal_dirty(handle, bh);
                  if (ret < 0) {
                        mlog_errno(ret);
                        goto out;
                  }
                  brelse(bh);
                  bh = NULL;

                  /*
                   * XXX: do we need to empty all the following
                   * blocks in this cluster?
                   */
                  if (!value_len)
                        break;
            }
            cpos += num_clusters;
      }
out:
      brelse(bh);

      return ret;
}

static int ocfs2_xattr_cleanup(struct inode *inode,
                         handle_t *handle,
                         struct ocfs2_xattr_info *xi,
                         struct ocfs2_xattr_search *xs,
                         struct ocfs2_xattr_value_buf *vb,
                         size_t offs)
{
      int ret = 0;
      size_t name_len = strlen(xi->name);
      void *val = xs->base + offs;
      size_t size = OCFS2_XATTR_SIZE(name_len) + OCFS2_XATTR_ROOT_SIZE;

      ret = vb->vb_access(handle, inode, vb->vb_bh,
                      OCFS2_JOURNAL_ACCESS_WRITE);
      if (ret) {
            mlog_errno(ret);
            goto out;
      }
      /* Decrease xattr count */
      le16_add_cpu(&xs->header->xh_count, -1);
      /* Remove the xattr entry and tree root which has already be set*/
      memset((void *)xs->here, 0, sizeof(struct ocfs2_xattr_entry));
      memset(val, 0, size);

      ret = ocfs2_journal_dirty(handle, vb->vb_bh);
      if (ret < 0)
            mlog_errno(ret);
out:
      return ret;
}

static int ocfs2_xattr_update_entry(struct inode *inode,
                            handle_t *handle,
                            struct ocfs2_xattr_info *xi,
                            struct ocfs2_xattr_search *xs,
                            struct ocfs2_xattr_value_buf *vb,
                            size_t offs)
{
      int ret;

      ret = vb->vb_access(handle, inode, vb->vb_bh,
                      OCFS2_JOURNAL_ACCESS_WRITE);
      if (ret) {
            mlog_errno(ret);
            goto out;
      }

      xs->here->xe_name_offset = cpu_to_le16(offs);
      xs->here->xe_value_size = cpu_to_le64(xi->value_len);
      if (xi->value_len <= OCFS2_XATTR_INLINE_SIZE)
            ocfs2_xattr_set_local(xs->here, 1);
      else
            ocfs2_xattr_set_local(xs->here, 0);
      ocfs2_xattr_hash_entry(inode, xs->header, xs->here);

      ret = ocfs2_journal_dirty(handle, vb->vb_bh);
      if (ret < 0)
            mlog_errno(ret);
out:
      return ret;
}

/*
 * ocfs2_xattr_set_value_outside()
 *
 * Set large size value in B tree.
 */
static int ocfs2_xattr_set_value_outside(struct inode *inode,
                               struct ocfs2_xattr_info *xi,
                               struct ocfs2_xattr_search *xs,
                               struct ocfs2_xattr_set_ctxt *ctxt,
                               struct ocfs2_xattr_value_buf *vb,
                               size_t offs)
{
      size_t name_len = strlen(xi->name);
      void *val = xs->base + offs;
      struct ocfs2_xattr_value_root *xv = NULL;
      size_t size = OCFS2_XATTR_SIZE(name_len) + OCFS2_XATTR_ROOT_SIZE;
      int ret = 0;

      memset(val, 0, size);
      memcpy(val, xi->name, name_len);
      xv = (struct ocfs2_xattr_value_root *)
            (val + OCFS2_XATTR_SIZE(name_len));
      xv->xr_clusters = 0;
      xv->xr_last_eb_blk = 0;
      xv->xr_list.l_tree_depth = 0;
      xv->xr_list.l_count = cpu_to_le16(1);
      xv->xr_list.l_next_free_rec = 0;
      vb->vb_xv = xv;

      ret = ocfs2_xattr_value_truncate(inode, vb, xi->value_len, ctxt);
      if (ret < 0) {
            mlog_errno(ret);
            return ret;
      }
      ret = ocfs2_xattr_update_entry(inode, ctxt->handle, xi, xs, vb, offs);
      if (ret < 0) {
            mlog_errno(ret);
            return ret;
      }
      ret = __ocfs2_xattr_set_value_outside(inode, ctxt->handle, vb->vb_xv,
                                    xi->value, xi->value_len);
      if (ret < 0)
            mlog_errno(ret);

      return ret;
}

/*
 * ocfs2_xattr_set_entry_local()
 *
 * Set, replace or remove extended attribute in local.
 */
static void ocfs2_xattr_set_entry_local(struct inode *inode,
                              struct ocfs2_xattr_info *xi,
                              struct ocfs2_xattr_search *xs,
                              struct ocfs2_xattr_entry *last,
                              size_t min_offs)
{
      size_t name_len = strlen(xi->name);
      int i;

      if (xi->value && xs->not_found) {
            /* Insert the new xattr entry. */
            le16_add_cpu(&xs->header->xh_count, 1);
            ocfs2_xattr_set_type(last, xi->name_index);
            ocfs2_xattr_set_local(last, 1);
            last->xe_name_len = name_len;
      } else {
            void *first_val;
            void *val;
            size_t offs, size;

            first_val = xs->base + min_offs;
            offs = le16_to_cpu(xs->here->xe_name_offset);
            val = xs->base + offs;

            if (le64_to_cpu(xs->here->xe_value_size) >
                OCFS2_XATTR_INLINE_SIZE)
                  size = OCFS2_XATTR_SIZE(name_len) +
                        OCFS2_XATTR_ROOT_SIZE;
            else
                  size = OCFS2_XATTR_SIZE(name_len) +
                  OCFS2_XATTR_SIZE(le64_to_cpu(xs->here->xe_value_size));

            if (xi->value && size == OCFS2_XATTR_SIZE(name_len) +
                        OCFS2_XATTR_SIZE(xi->value_len)) {
                  /* The old and the new value have the
                     same size. Just replace the value. */
                  ocfs2_xattr_set_local(xs->here, 1);
                  xs->here->xe_value_size = cpu_to_le64(xi->value_len);
                  /* Clear value bytes. */
                  memset(val + OCFS2_XATTR_SIZE(name_len),
                         0,
                         OCFS2_XATTR_SIZE(xi->value_len));
                  memcpy(val + OCFS2_XATTR_SIZE(name_len),
                         xi->value,
                         xi->value_len);
                  return;
            }
            /* Remove the old name+value. */
            memmove(first_val + size, first_val, val - first_val);
            memset(first_val, 0, size);
            xs->here->xe_name_hash = 0;
            xs->here->xe_name_offset = 0;
            ocfs2_xattr_set_local(xs->here, 1);
            xs->here->xe_value_size = 0;

            min_offs += size;

            /* Adjust all value offsets. */
            last = xs->header->xh_entries;
            for (i = 0 ; i < le16_to_cpu(xs->header->xh_count); i++) {
                  size_t o = le16_to_cpu(last->xe_name_offset);

                  if (o < offs)
                        last->xe_name_offset = cpu_to_le16(o + size);
                  last += 1;
            }

            if (!xi->value) {
                  /* Remove the old entry. */
                  last -= 1;
                  memmove(xs->here, xs->here + 1,
                        (void *)last - (void *)xs->here);
                  memset(last, 0, sizeof(struct ocfs2_xattr_entry));
                  le16_add_cpu(&xs->header->xh_count, -1);
            }
      }
      if (xi->value) {
            /* Insert the new name+value. */
            size_t size = OCFS2_XATTR_SIZE(name_len) +
                        OCFS2_XATTR_SIZE(xi->value_len);
            void *val = xs->base + min_offs - size;

            xs->here->xe_name_offset = cpu_to_le16(min_offs - size);
            memset(val, 0, size);
            memcpy(val, xi->name, name_len);
            memcpy(val + OCFS2_XATTR_SIZE(name_len),
                   xi->value,
                   xi->value_len);
            xs->here->xe_value_size = cpu_to_le64(xi->value_len);
            ocfs2_xattr_set_local(xs->here, 1);
            ocfs2_xattr_hash_entry(inode, xs->header, xs->here);
      }

      return;
}

/*
 * ocfs2_xattr_set_entry()
 *
 * Set extended attribute entry into inode or block.
 *
 * If extended attribute value size > OCFS2_XATTR_INLINE_SIZE,
 * We first insert tree root(ocfs2_xattr_value_root) with set_entry_local(),
 * then set value in B tree with set_value_outside().
 */
static int ocfs2_xattr_set_entry(struct inode *inode,
                         struct ocfs2_xattr_info *xi,
                         struct ocfs2_xattr_search *xs,
                         struct ocfs2_xattr_set_ctxt *ctxt,
                         int flag)
{
      struct ocfs2_xattr_entry *last;
      struct ocfs2_inode_info *oi = OCFS2_I(inode);
      struct ocfs2_dinode *di = (struct ocfs2_dinode *)xs->inode_bh->b_data;
      size_t min_offs = xs->end - xs->base, name_len = strlen(xi->name);
      size_t size_l = 0;
      handle_t *handle = ctxt->handle;
      int free, i, ret;
      struct ocfs2_xattr_info xi_l = {
            .name_index = xi->name_index,
            .name = xi->name,
            .value = xi->value,
            .value_len = xi->value_len,
      };
      struct ocfs2_xattr_value_buf vb = {
            .vb_bh = xs->xattr_bh,
            .vb_access = ocfs2_journal_access_di,
      };

      if (!(flag & OCFS2_INLINE_XATTR_FL)) {
            BUG_ON(xs->xattr_bh == xs->inode_bh);
            vb.vb_access = ocfs2_journal_access_xb;
      } else
            BUG_ON(xs->xattr_bh != xs->inode_bh);

      /* Compute min_offs, last and free space. */
      last = xs->header->xh_entries;

      for (i = 0 ; i < le16_to_cpu(xs->header->xh_count); i++) {
            size_t offs = le16_to_cpu(last->xe_name_offset);
            if (offs < min_offs)
                  min_offs = offs;
            last += 1;
      }

      free = min_offs - ((void *)last - xs->base) - OCFS2_XATTR_HEADER_GAP;
      if (free < 0)
            return -EIO;

      if (!xs->not_found) {
            size_t size = 0;
            if (ocfs2_xattr_is_local(xs->here))
                  size = OCFS2_XATTR_SIZE(name_len) +
                  OCFS2_XATTR_SIZE(le64_to_cpu(xs->here->xe_value_size));
            else
                  size = OCFS2_XATTR_SIZE(name_len) +
                        OCFS2_XATTR_ROOT_SIZE;
            free += (size + sizeof(struct ocfs2_xattr_entry));
      }
      /* Check free space in inode or block */
      if (xi->value && xi->value_len > OCFS2_XATTR_INLINE_SIZE) {
            if (free < sizeof(struct ocfs2_xattr_entry) +
                     OCFS2_XATTR_SIZE(name_len) +
                     OCFS2_XATTR_ROOT_SIZE) {
                  ret = -ENOSPC;
                  goto out;
            }
            size_l = OCFS2_XATTR_SIZE(name_len) + OCFS2_XATTR_ROOT_SIZE;
            xi_l.value = (void *)&def_xv;
            xi_l.value_len = OCFS2_XATTR_ROOT_SIZE;
      } else if (xi->value) {
            if (free < sizeof(struct ocfs2_xattr_entry) +
                     OCFS2_XATTR_SIZE(name_len) +
                     OCFS2_XATTR_SIZE(xi->value_len)) {
                  ret = -ENOSPC;
                  goto out;
            }
      }

      if (!xs->not_found) {
            /* For existing extended attribute */
            size_t size = OCFS2_XATTR_SIZE(name_len) +
                  OCFS2_XATTR_SIZE(le64_to_cpu(xs->here->xe_value_size));
            size_t offs = le16_to_cpu(xs->here->xe_name_offset);
            void *val = xs->base + offs;

            if (ocfs2_xattr_is_local(xs->here) && size == size_l) {
                  /* Replace existing local xattr with tree root */
                  ret = ocfs2_xattr_set_value_outside(inode, xi, xs,
                                              ctxt, &vb, offs);
                  if (ret < 0)
                        mlog_errno(ret);
                  goto out;
            } else if (!ocfs2_xattr_is_local(xs->here)) {
                  /* For existing xattr which has value outside */
                  vb.vb_xv = (struct ocfs2_xattr_value_root *)
                        (val + OCFS2_XATTR_SIZE(name_len));

                  if (xi->value_len > OCFS2_XATTR_INLINE_SIZE) {
                        /*
                         * If new value need set outside also,
                         * first truncate old value to new value,
                         * then set new value with set_value_outside().
                         */
                        ret = ocfs2_xattr_value_truncate(inode,
                                                 &vb,
                                                 xi->value_len,
                                                 ctxt);
                        if (ret < 0) {
                              mlog_errno(ret);
                              goto out;
                        }

                        ret = ocfs2_xattr_update_entry(inode,
                                                 handle,
                                                 xi,
                                                 xs,
                                                 &vb,
                                                 offs);
                        if (ret < 0) {
                              mlog_errno(ret);
                              goto out;
                        }

                        ret = __ocfs2_xattr_set_value_outside(inode,
                                                handle,
                                                vb.vb_xv,
                                                xi->value,
                                                xi->value_len);
                        if (ret < 0)
                              mlog_errno(ret);
                        goto out;
                  } else {
                        /*
                         * If new value need set in local,
                         * just trucate old value to zero.
                         */
                         ret = ocfs2_xattr_value_truncate(inode,
                                                  &vb,
                                                  0,
                                                  ctxt);
                        if (ret < 0)
                              mlog_errno(ret);
                  }
            }
      }

      ret = ocfs2_journal_access_di(handle, inode, xs->inode_bh,
                              OCFS2_JOURNAL_ACCESS_WRITE);
      if (ret) {
            mlog_errno(ret);
            goto out;
      }

      if (!(flag & OCFS2_INLINE_XATTR_FL)) {
            ret = vb.vb_access(handle, inode, vb.vb_bh,
                           OCFS2_JOURNAL_ACCESS_WRITE);
            if (ret) {
                  mlog_errno(ret);
                  goto out;
            }
      }

      /*
       * Set value in local, include set tree root in local.
       * This is the first step for value size >INLINE_SIZE.
       */
      ocfs2_xattr_set_entry_local(inode, &xi_l, xs, last, min_offs);

      if (!(flag & OCFS2_INLINE_XATTR_FL)) {
            ret = ocfs2_journal_dirty(handle, xs->xattr_bh);
            if (ret < 0) {
                  mlog_errno(ret);
                  goto out;
            }
      }

      if (!(oi->ip_dyn_features & OCFS2_INLINE_XATTR_FL) &&
          (flag & OCFS2_INLINE_XATTR_FL)) {
            struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
            unsigned int xattrsize = osb->s_xattr_inline_size;

            /*
             * Adjust extent record count or inline data size
             * to reserve space for extended attribute.
             */
            if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
                  struct ocfs2_inline_data *idata = &di->id2.i_data;
                  le16_add_cpu(&idata->id_count, -xattrsize);
            } else if (!(ocfs2_inode_is_fast_symlink(inode))) {
                  struct ocfs2_extent_list *el = &di->id2.i_list;
                  le16_add_cpu(&el->l_count, -(xattrsize /
                              sizeof(struct ocfs2_extent_rec)));
            }
            di->i_xattr_inline_size = cpu_to_le16(xattrsize);
      }
      /* Update xattr flag */
      spin_lock(&oi->ip_lock);
      oi->ip_dyn_features |= flag;
      di->i_dyn_features = cpu_to_le16(oi->ip_dyn_features);
      spin_unlock(&oi->ip_lock);

      ret = ocfs2_journal_dirty(handle, xs->inode_bh);
      if (ret < 0)
            mlog_errno(ret);

      if (!ret && xi->value_len > OCFS2_XATTR_INLINE_SIZE) {
            /*
             * Set value outside in B tree.
             * This is the second step for value size > INLINE_SIZE.
             */
            size_t offs = le16_to_cpu(xs->here->xe_name_offset);
            ret = ocfs2_xattr_set_value_outside(inode, xi, xs, ctxt,
                                        &vb, offs);
            if (ret < 0) {
                  int ret2;

                  mlog_errno(ret);
                  /*
                   * If set value outside failed, we have to clean
                   * the junk tree root we have already set in local.
                   */
                  ret2 = ocfs2_xattr_cleanup(inode, ctxt->handle,
                                       xi, xs, &vb, offs);
                  if (ret2 < 0)
                        mlog_errno(ret2);
            }
      }
out:
      return ret;
}

static int ocfs2_remove_value_outside(struct inode*inode,
                              struct ocfs2_xattr_value_buf *vb,
                              struct ocfs2_xattr_header *header)
{
      int ret = 0, i;
      struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
      struct ocfs2_xattr_set_ctxt ctxt = { NULL, NULL, };

      ocfs2_init_dealloc_ctxt(&ctxt.dealloc);

      ctxt.handle = ocfs2_start_trans(osb,
                              ocfs2_remove_extent_credits(osb->sb));
      if (IS_ERR(ctxt.handle)) {
            ret = PTR_ERR(ctxt.handle);
            mlog_errno(ret);
            goto out;
      }

      for (i = 0; i < le16_to_cpu(header->xh_count); i++) {
            struct ocfs2_xattr_entry *entry = &header->xh_entries[i];

            if (!ocfs2_xattr_is_local(entry)) {
                  void *val;

                  val = (void *)header +
                        le16_to_cpu(entry->xe_name_offset);
                  vb->vb_xv = (struct ocfs2_xattr_value_root *)
                        (val + OCFS2_XATTR_SIZE(entry->xe_name_len));
                  ret = ocfs2_xattr_value_truncate(inode, vb, 0, &ctxt);
                  if (ret < 0) {
                        mlog_errno(ret);
                        break;
                  }
            }
      }

      ocfs2_commit_trans(osb, ctxt.handle);
      ocfs2_schedule_truncate_log_flush(osb, 1);
      ocfs2_run_deallocs(osb, &ctxt.dealloc);
out:
      return ret;
}

static int ocfs2_xattr_ibody_remove(struct inode *inode,
                            struct buffer_head *di_bh)
{

      struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
      struct ocfs2_xattr_header *header;
      int ret;
      struct ocfs2_xattr_value_buf vb = {
            .vb_bh = di_bh,
            .vb_access = ocfs2_journal_access_di,
      };

      header = (struct ocfs2_xattr_header *)
             ((void *)di + inode->i_sb->s_blocksize -
             le16_to_cpu(di->i_xattr_inline_size));

      ret = ocfs2_remove_value_outside(inode, &vb, header);

      return ret;
}

static int ocfs2_xattr_block_remove(struct inode *inode,
                            struct buffer_head *blk_bh)
{
      struct ocfs2_xattr_block *xb;
      int ret = 0;
      struct ocfs2_xattr_value_buf vb = {
            .vb_bh = blk_bh,
            .vb_access = ocfs2_journal_access_xb,
      };

      xb = (struct ocfs2_xattr_block *)blk_bh->b_data;
      if (!(le16_to_cpu(xb->xb_flags) & OCFS2_XATTR_INDEXED)) {
            struct ocfs2_xattr_header *header = &(xb->xb_attrs.xb_header);
            ret = ocfs2_remove_value_outside(inode, &vb, header);
      } else
            ret = ocfs2_delete_xattr_index_block(inode, blk_bh);

      return ret;
}

static int ocfs2_xattr_free_block(struct inode *inode,
                          u64 block)
{
      struct inode *xb_alloc_inode;
      struct buffer_head *xb_alloc_bh = NULL;
      struct buffer_head *blk_bh = NULL;
      struct ocfs2_xattr_block *xb;
      struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
      handle_t *handle;
      int ret = 0;
      u64 blk, bg_blkno;
      u16 bit;

      ret = ocfs2_read_xattr_block(inode, block, &blk_bh);
      if (ret < 0) {
            mlog_errno(ret);
            goto out;
      }

      ret = ocfs2_xattr_block_remove(inode, blk_bh);
      if (ret < 0) {
            mlog_errno(ret);
            goto out;
      }

      xb = (struct ocfs2_xattr_block *)blk_bh->b_data;
      blk = le64_to_cpu(xb->xb_blkno);
      bit = le16_to_cpu(xb->xb_suballoc_bit);
      bg_blkno = ocfs2_which_suballoc_group(blk, bit);

      xb_alloc_inode = ocfs2_get_system_file_inode(osb,
                        EXTENT_ALLOC_SYSTEM_INODE,
                        le16_to_cpu(xb->xb_suballoc_slot));
      if (!xb_alloc_inode) {
            ret = -ENOMEM;
            mlog_errno(ret);
            goto out;
      }
      mutex_lock(&xb_alloc_inode->i_mutex);

      ret = ocfs2_inode_lock(xb_alloc_inode, &xb_alloc_bh, 1);
      if (ret < 0) {
            mlog_errno(ret);
            goto out_mutex;
      }

      handle = ocfs2_start_trans(osb, OCFS2_SUBALLOC_FREE);
      if (IS_ERR(handle)) {
            ret = PTR_ERR(handle);
            mlog_errno(ret);
            goto out_unlock;
      }

      ret = ocfs2_free_suballoc_bits(handle, xb_alloc_inode, xb_alloc_bh,
                               bit, bg_blkno, 1);
      if (ret < 0)
            mlog_errno(ret);

      ocfs2_commit_trans(osb, handle);
out_unlock:
      ocfs2_inode_unlock(xb_alloc_inode, 1);
      brelse(xb_alloc_bh);
out_mutex:
      mutex_unlock(&xb_alloc_inode->i_mutex);
      iput(xb_alloc_inode);
out:
      brelse(blk_bh);
      return ret;
}

/*
 * ocfs2_xattr_remove()
 *
 * Free extended attribute resources associated with this inode.
 */
int ocfs2_xattr_remove(struct inode *inode, struct buffer_head *di_bh)
{
      struct ocfs2_inode_info *oi = OCFS2_I(inode);
      struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
      handle_t *handle;
      int ret;

      if (!ocfs2_supports_xattr(OCFS2_SB(inode->i_sb)))
            return 0;

      if (!(oi->ip_dyn_features & OCFS2_HAS_XATTR_FL))
            return 0;

      if (oi->ip_dyn_features & OCFS2_INLINE_XATTR_FL) {
            ret = ocfs2_xattr_ibody_remove(inode, di_bh);
            if (ret < 0) {
                  mlog_errno(ret);
                  goto out;
            }
      }

      if (di->i_xattr_loc) {
            ret = ocfs2_xattr_free_block(inode,
                                   le64_to_cpu(di->i_xattr_loc));
            if (ret < 0) {
                  mlog_errno(ret);
                  goto out;
            }
      }

      handle = ocfs2_start_trans((OCFS2_SB(inode->i_sb)),
                           OCFS2_INODE_UPDATE_CREDITS);
      if (IS_ERR(handle)) {
            ret = PTR_ERR(handle);
            mlog_errno(ret);
            goto out;
      }
      ret = ocfs2_journal_access_di(handle, inode, di_bh,
                              OCFS2_JOURNAL_ACCESS_WRITE);
      if (ret) {
            mlog_errno(ret);
            goto out_commit;
      }

      di->i_xattr_loc = 0;

      spin_lock(&oi->ip_lock);
      oi->ip_dyn_features &= ~(OCFS2_INLINE_XATTR_FL | OCFS2_HAS_XATTR_FL);
      di->i_dyn_features = cpu_to_le16(oi->ip_dyn_features);
      spin_unlock(&oi->ip_lock);

      ret = ocfs2_journal_dirty(handle, di_bh);
      if (ret < 0)
            mlog_errno(ret);
out_commit:
      ocfs2_commit_trans(OCFS2_SB(inode->i_sb), handle);
out:
      return ret;
}

static int ocfs2_xattr_has_space_inline(struct inode *inode,
                              struct ocfs2_dinode *di)
{
      struct ocfs2_inode_info *oi = OCFS2_I(inode);
      unsigned int xattrsize = OCFS2_SB(inode->i_sb)->s_xattr_inline_size;
      int free;

      if (xattrsize < OCFS2_MIN_XATTR_INLINE_SIZE)
            return 0;

      if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
            struct ocfs2_inline_data *idata = &di->id2.i_data;
            free = le16_to_cpu(idata->id_count) - le64_to_cpu(di->i_size);
      } else if (ocfs2_inode_is_fast_symlink(inode)) {
            free = ocfs2_fast_symlink_chars(inode->i_sb) -
                  le64_to_cpu(di->i_size);
      } else {
            struct ocfs2_extent_list *el = &di->id2.i_list;
            free = (le16_to_cpu(el->l_count) -
                  le16_to_cpu(el->l_next_free_rec)) *
                  sizeof(struct ocfs2_extent_rec);
      }
      if (free >= xattrsize)
            return 1;

      return 0;
}

/*
 * ocfs2_xattr_ibody_find()
 *
 * Find extended attribute in inode block and
 * fill search info into struct ocfs2_xattr_search.
 */
static int ocfs2_xattr_ibody_find(struct inode *inode,
                          int name_index,
                          const char *name,
                          struct ocfs2_xattr_search *xs)
{
      struct ocfs2_inode_info *oi = OCFS2_I(inode);
      struct ocfs2_dinode *di = (struct ocfs2_dinode *)xs->inode_bh->b_data;
      int ret;
      int has_space = 0;

      if (inode->i_sb->s_blocksize == OCFS2_MIN_BLOCKSIZE)
            return 0;

      if (!(oi->ip_dyn_features & OCFS2_INLINE_XATTR_FL)) {
            down_read(&oi->ip_alloc_sem);
            has_space = ocfs2_xattr_has_space_inline(inode, di);
            up_read(&oi->ip_alloc_sem);
            if (!has_space)
                  return 0;
      }

      xs->xattr_bh = xs->inode_bh;
      xs->end = (void *)di + inode->i_sb->s_blocksize;
      if (oi->ip_dyn_features & OCFS2_INLINE_XATTR_FL)
            xs->header = (struct ocfs2_xattr_header *)
                  (xs->end - le16_to_cpu(di->i_xattr_inline_size));
      else
            xs->header = (struct ocfs2_xattr_header *)
                  (xs->end - OCFS2_SB(inode->i_sb)->s_xattr_inline_size);
      xs->base = (void *)xs->header;
      xs->here = xs->header->xh_entries;

      /* Find the named attribute. */
      if (oi->ip_dyn_features & OCFS2_INLINE_XATTR_FL) {
            ret = ocfs2_xattr_find_entry(name_index, name, xs);
            if (ret && ret != -ENODATA)
                  return ret;
            xs->not_found = ret;
      }

      return 0;
}

/*
 * ocfs2_xattr_ibody_set()
 *
 * Set, replace or remove an extended attribute into inode block.
 *
 */
static int ocfs2_xattr_ibody_set(struct inode *inode,
                         struct ocfs2_xattr_info *xi,
                         struct ocfs2_xattr_search *xs,
                         struct ocfs2_xattr_set_ctxt *ctxt)
{
      struct ocfs2_inode_info *oi = OCFS2_I(inode);
      struct ocfs2_dinode *di = (struct ocfs2_dinode *)xs->inode_bh->b_data;
      int ret;

      if (inode->i_sb->s_blocksize == OCFS2_MIN_BLOCKSIZE)
            return -ENOSPC;

      down_write(&oi->ip_alloc_sem);
      if (!(oi->ip_dyn_features & OCFS2_INLINE_XATTR_FL)) {
            if (!ocfs2_xattr_has_space_inline(inode, di)) {
                  ret = -ENOSPC;
                  goto out;
            }
      }

      ret = ocfs2_xattr_set_entry(inode, xi, xs, ctxt,
                        (OCFS2_INLINE_XATTR_FL | OCFS2_HAS_XATTR_FL));
out:
      up_write(&oi->ip_alloc_sem);

      return ret;
}

/*
 * ocfs2_xattr_block_find()
 *
 * Find extended attribute in external block and
 * fill search info into struct ocfs2_xattr_search.
 */
static int ocfs2_xattr_block_find(struct inode *inode,
                          int name_index,
                          const char *name,
                          struct ocfs2_xattr_search *xs)
{
      struct ocfs2_dinode *di = (struct ocfs2_dinode *)xs->inode_bh->b_data;
      struct buffer_head *blk_bh = NULL;
      struct ocfs2_xattr_block *xb;
      int ret = 0;

      if (!di->i_xattr_loc)
            return ret;

      ret = ocfs2_read_xattr_block(inode, le64_to_cpu(di->i_xattr_loc),
                             &blk_bh);
      if (ret < 0) {
            mlog_errno(ret);
            return ret;
      }

      xs->xattr_bh = blk_bh;
      xb = (struct ocfs2_xattr_block *)blk_bh->b_data;

      if (!(le16_to_cpu(xb->xb_flags) & OCFS2_XATTR_INDEXED)) {
            xs->header = &xb->xb_attrs.xb_header;
            xs->base = (void *)xs->header;
            xs->end = (void *)(blk_bh->b_data) + blk_bh->b_size;
            xs->here = xs->header->xh_entries;

            ret = ocfs2_xattr_find_entry(name_index, name, xs);
      } else
            ret = ocfs2_xattr_index_block_find(inode, blk_bh,
                                       name_index,
                                       name, xs);

      if (ret && ret != -ENODATA) {
            xs->xattr_bh = NULL;
            goto cleanup;
      }
      xs->not_found = ret;
      return 0;
cleanup:
      brelse(blk_bh);

      return ret;
}

/*
 * ocfs2_xattr_block_set()
 *
 * Set, replace or remove an extended attribute into external block.
 *
 */
static int ocfs2_xattr_block_set(struct inode *inode,
                         struct ocfs2_xattr_info *xi,
                         struct ocfs2_xattr_search *xs,
                         struct ocfs2_xattr_set_ctxt *ctxt)
{
      struct buffer_head *new_bh = NULL;
      struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
      struct ocfs2_dinode *di =  (struct ocfs2_dinode *)xs->inode_bh->b_data;
      handle_t *handle = ctxt->handle;
      struct ocfs2_xattr_block *xblk = NULL;
      u16 suballoc_bit_start;
      u32 num_got;
      u64 first_blkno;
      int ret;

      if (!xs->xattr_bh) {
            ret = ocfs2_journal_access_di(handle, inode, xs->inode_bh,
                                    OCFS2_JOURNAL_ACCESS_CREATE);
            if (ret < 0) {
                  mlog_errno(ret);
                  goto end;
            }

            ret = ocfs2_claim_metadata(osb, handle, ctxt->meta_ac, 1,
                                 &suballoc_bit_start, &num_got,
                                 &first_blkno);
            if (ret < 0) {
                  mlog_errno(ret);
                  goto end;
            }

            new_bh = sb_getblk(inode->i_sb, first_blkno);
            ocfs2_set_new_buffer_uptodate(inode, new_bh);

            ret = ocfs2_journal_access_xb(handle, inode, new_bh,
                                    OCFS2_JOURNAL_ACCESS_CREATE);
            if (ret < 0) {
                  mlog_errno(ret);
                  goto end;
            }

            /* Initialize ocfs2_xattr_block */
            xs->xattr_bh = new_bh;
            xblk = (struct ocfs2_xattr_block *)new_bh->b_data;
            memset(xblk, 0, inode->i_sb->s_blocksize);
            strcpy((void *)xblk, OCFS2_XATTR_BLOCK_SIGNATURE);
            xblk->xb_suballoc_slot = cpu_to_le16(osb->slot_num);
            xblk->xb_suballoc_bit = cpu_to_le16(suballoc_bit_start);
            xblk->xb_fs_generation = cpu_to_le32(osb->fs_generation);
            xblk->xb_blkno = cpu_to_le64(first_blkno);

            xs->header = &xblk->xb_attrs.xb_header;
            xs->base = (void *)xs->header;
            xs->end = (void *)xblk + inode->i_sb->s_blocksize;
            xs->here = xs->header->xh_entries;

            ret = ocfs2_journal_dirty(handle, new_bh);
            if (ret < 0) {
                  mlog_errno(ret);
                  goto end;
            }
            di->i_xattr_loc = cpu_to_le64(first_blkno);
            ocfs2_journal_dirty(handle, xs->inode_bh);
      } else
            xblk = (struct ocfs2_xattr_block *)xs->xattr_bh->b_data;

      if (!(le16_to_cpu(xblk->xb_flags) & OCFS2_XATTR_INDEXED)) {
            /* Set extended attribute into external block */
            ret = ocfs2_xattr_set_entry(inode, xi, xs, ctxt,
                                  OCFS2_HAS_XATTR_FL);
            if (!ret || ret != -ENOSPC)
                  goto end;

            ret = ocfs2_xattr_create_index_block(inode, xs, ctxt);
            if (ret)
                  goto end;
      }

      ret = ocfs2_xattr_set_entry_index_block(inode, xi, xs, ctxt);

end:

      return ret;
}

/* Check whether the new xattr can be inserted into the inode. */
static int ocfs2_xattr_can_be_in_inode(struct inode *inode,
                               struct ocfs2_xattr_info *xi,
                               struct ocfs2_xattr_search *xs)
{
      u64 value_size;
      struct ocfs2_xattr_entry *last;
      int free, i;
      size_t min_offs = xs->end - xs->base;

      if (!xs->header)
            return 0;

      last = xs->header->xh_entries;

      for (i = 0; i < le16_to_cpu(xs->header->xh_count); i++) {
            size_t offs = le16_to_cpu(last->xe_name_offset);
            if (offs < min_offs)
                  min_offs = offs;
            last += 1;
      }

      free = min_offs - ((void *)last - xs->base) - OCFS2_XATTR_HEADER_GAP;
      if (free < 0)
            return 0;

      BUG_ON(!xs->not_found);

      if (xi->value_len > OCFS2_XATTR_INLINE_SIZE)
            value_size = OCFS2_XATTR_ROOT_SIZE;
      else
            value_size = OCFS2_XATTR_SIZE(xi->value_len);

      if (free >= sizeof(struct ocfs2_xattr_entry) +
               OCFS2_XATTR_SIZE(strlen(xi->name)) + value_size)
            return 1;

      return 0;
}

static int ocfs2_calc_xattr_set_need(struct inode *inode,
                             struct ocfs2_dinode *di,
                             struct ocfs2_xattr_info *xi,
                             struct ocfs2_xattr_search *xis,
                             struct ocfs2_xattr_search *xbs,
                             int *clusters_need,
                             int *meta_need,
                             int *credits_need)
{
      int ret = 0, old_in_xb = 0;
      int clusters_add = 0, meta_add = 0, credits = 0;
      struct buffer_head *bh = NULL;
      struct ocfs2_xattr_block *xb = NULL;
      struct ocfs2_xattr_entry *xe = NULL;
      struct ocfs2_xattr_value_root *xv = NULL;
      char *base = NULL;
      int name_offset, name_len = 0;
      u32 new_clusters = ocfs2_clusters_for_bytes(inode->i_sb,
                                        xi->value_len);
      u64 value_size;

      /*
       * Calculate the clusters we need to write.
       * No matter whether we replace an old one or add a new one,
       * we need this for writing.
       */
      if (xi->value_len > OCFS2_XATTR_INLINE_SIZE)
            credits += new_clusters *
                     ocfs2_clusters_to_blocks(inode->i_sb, 1);

      if (xis->not_found && xbs->not_found) {
            credits += ocfs2_blocks_per_xattr_bucket(inode->i_sb);

            if (xi->value_len > OCFS2_XATTR_INLINE_SIZE) {
                  clusters_add += new_clusters;
                  credits += ocfs2_calc_extend_credits(inode->i_sb,
                                          &def_xv.xv.xr_list,
                                          new_clusters);
            }

            goto meta_guess;
      }

      if (!xis->not_found) {
            xe = xis->here;
            name_offset = le16_to_cpu(xe->xe_name_offset);
            name_len = OCFS2_XATTR_SIZE(xe->xe_name_len);
            base = xis->base;
            credits += OCFS2_INODE_UPDATE_CREDITS;
      } else {
            int i, block_off = 0;
            xb = (struct ocfs2_xattr_block *)xbs->xattr_bh->b_data;
            xe = xbs->here;
            name_offset = le16_to_cpu(xe->xe_name_offset);
            name_len = OCFS2_XATTR_SIZE(xe->xe_name_len);
            i = xbs->here - xbs->header->xh_entries;
            old_in_xb = 1;

            if (le16_to_cpu(xb->xb_flags) & OCFS2_XATTR_INDEXED) {
                  ret = ocfs2_xattr_bucket_get_name_value(inode,
                                          bucket_xh(xbs->bucket),
                                          i, &block_off,
                                          &name_offset);
                  base = bucket_block(xbs->bucket, block_off);
                  credits += ocfs2_blocks_per_xattr_bucket(inode->i_sb);
            } else {
                  base = xbs->base;
                  credits += OCFS2_XATTR_BLOCK_UPDATE_CREDITS;
            }
      }

      /*
       * delete a xattr doesn't need metadata and cluster allocation.
       * so just calculate the credits and return.
       *
       * The credits for removing the value tree will be extended
       * by ocfs2_remove_extent itself.
       */
      if (!xi->value) {
            if (!ocfs2_xattr_is_local(xe))
                  credits += ocfs2_remove_extent_credits(inode->i_sb);

            goto out;
      }

      /* do cluster allocation guess first. */
      value_size = le64_to_cpu(xe->xe_value_size);

      if (old_in_xb) {
            /*
             * In xattr set, we always try to set the xe in inode first,
             * so if it can be inserted into inode successfully, the old
             * one will be removed from the xattr block, and this xattr
             * will be inserted into inode as a new xattr in inode.
             */
            if (ocfs2_xattr_can_be_in_inode(inode, xi, xis)) {
                  clusters_add += new_clusters;
                  credits += ocfs2_remove_extent_credits(inode->i_sb) +
                            OCFS2_INODE_UPDATE_CREDITS;
                  if (!ocfs2_xattr_is_local(xe))
                        credits += ocfs2_calc_extend_credits(
                                          inode->i_sb,
                                          &def_xv.xv.xr_list,
                                          new_clusters);
                  goto out;
            }
      }

      if (xi->value_len > OCFS2_XATTR_INLINE_SIZE) {
            /* the new values will be stored outside. */
            u32 old_clusters = 0;

            if (!ocfs2_xattr_is_local(xe)) {
                  old_clusters =    ocfs2_clusters_for_bytes(inode->i_sb,
                                                 value_size);
                  xv = (struct ocfs2_xattr_value_root *)
                       (base + name_offset + name_len);
                  value_size = OCFS2_XATTR_ROOT_SIZE;
            } else
                  xv = &def_xv.xv;

            if (old_clusters >= new_clusters) {
                  credits += ocfs2_remove_extent_credits(inode->i_sb);
                  goto out;
            } else {
                  meta_add += ocfs2_extend_meta_needed(&xv->xr_list);
                  clusters_add += new_clusters - old_clusters;
                  credits += ocfs2_calc_extend_credits(inode->i_sb,
                                               &xv->xr_list,
                                               new_clusters -
                                               old_clusters);
                  if (value_size >= OCFS2_XATTR_ROOT_SIZE)
                        goto out;
            }
      } else {
            /*
             * Now the new value will be stored inside. So if the new
             * value is smaller than the size of value root or the old
             * value, we don't need any allocation, otherwise we have
             * to guess metadata allocation.
             */
            if ((ocfs2_xattr_is_local(xe) && value_size >= xi->value_len) ||
                (!ocfs2_xattr_is_local(xe) &&
                 OCFS2_XATTR_ROOT_SIZE >= xi->value_len))
                  goto out;
      }

meta_guess:
      /* calculate metadata allocation. */
      if (di->i_xattr_loc) {
            if (!xbs->xattr_bh) {
                  ret = ocfs2_read_xattr_block(inode,
                                         le64_to_cpu(di->i_xattr_loc),
                                         &bh);
                  if (ret) {
                        mlog_errno(ret);
                        goto out;
                  }

                  xb = (struct ocfs2_xattr_block *)bh->b_data;
            } else
                  xb = (struct ocfs2_xattr_block *)xbs->xattr_bh->b_data;

            /*
             * If there is already an xattr tree, good, we can calculate
             * like other b-trees. Otherwise we may have the chance of
             * create a tree, the credit calculation is borrowed from
             * ocfs2_calc_extend_credits with root_el = NULL. And the
             * new tree will be cluster based, so no meta is needed.
             */
            if (le16_to_cpu(xb->xb_flags) & OCFS2_XATTR_INDEXED) {
                  struct ocfs2_extent_list *el =
                         &xb->xb_attrs.xb_root.xt_list;
                  meta_add += ocfs2_extend_meta_needed(el);
                  credits += ocfs2_calc_extend_credits(inode->i_sb,
                                               el, 1);
            } else
                  credits += OCFS2_SUBALLOC_ALLOC + 1;

            /*
             * This cluster will be used either for new bucket or for
             * new xattr block.
             * If the cluster size is the same as the bucket size, one
             * more is needed since we may need to extend the bucket
             * also.
             */
            clusters_add += 1;
            credits += ocfs2_blocks_per_xattr_bucket(inode->i_sb);
            if (OCFS2_XATTR_BUCKET_SIZE ==
                  OCFS2_SB(inode->i_sb)->s_clustersize) {
                  credits += ocfs2_blocks_per_xattr_bucket(inode->i_sb);
                  clusters_add += 1;
            }
      } else {
            meta_add += 1;
            credits += OCFS2_XATTR_BLOCK_CREATE_CREDITS;
      }
out:
      if (clusters_need)
            *clusters_need = clusters_add;
      if (meta_need)
            *meta_need = meta_add;
      if (credits_need)
            *credits_need = credits;
      brelse(bh);
      return ret;
}

static int ocfs2_init_xattr_set_ctxt(struct inode *inode,
                             struct ocfs2_dinode *di,
                             struct ocfs2_xattr_info *xi,
                             struct ocfs2_xattr_search *xis,
                             struct ocfs2_xattr_search *xbs,
                             struct ocfs2_xattr_set_ctxt *ctxt,
                             int *credits)
{
      int clusters_add, meta_add, ret;
      struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);

      memset(ctxt, 0, sizeof(struct ocfs2_xattr_set_ctxt));

      ocfs2_init_dealloc_ctxt(&ctxt->dealloc);

      ret = ocfs2_calc_xattr_set_need(inode, di, xi, xis, xbs,
                              &clusters_add, &meta_add, credits);
      if (ret) {
            mlog_errno(ret);
            return ret;
      }

      mlog(0, "Set xattr %s, reserve meta blocks = %d, clusters = %d, "
           "credits = %d\n", xi->name, meta_add, clusters_add, *credits);

      if (meta_add) {
            ret = ocfs2_reserve_new_metadata_blocks(osb, meta_add,
                                          &ctxt->meta_ac);
            if (ret) {
                  mlog_errno(ret);
                  goto out;
            }
      }

      if (clusters_add) {
            ret = ocfs2_reserve_clusters(osb, clusters_add, &ctxt->data_ac);
            if (ret)
                  mlog_errno(ret);
      }
out:
      if (ret) {
            if (ctxt->meta_ac) {
                  ocfs2_free_alloc_context(ctxt->meta_ac);
                  ctxt->meta_ac = NULL;
            }

            /*
             * We cannot have an error and a non null ctxt->data_ac.
             */
      }

      return ret;
}

static int __ocfs2_xattr_set_handle(struct inode *inode,
                            struct ocfs2_dinode *di,
                            struct ocfs2_xattr_info *xi,
                            struct ocfs2_xattr_search *xis,
                            struct ocfs2_xattr_search *xbs,
                            struct ocfs2_xattr_set_ctxt *ctxt)
{
      int ret = 0, credits, old_found;

      if (!xi->value) {
            /* Remove existing extended attribute */
            if (!xis->not_found)
                  ret = ocfs2_xattr_ibody_set(inode, xi, xis, ctxt);
            else if (!xbs->not_found)
                  ret = ocfs2_xattr_block_set(inode, xi, xbs, ctxt);
      } else {
            /* We always try to set extended attribute into inode first*/
            ret = ocfs2_xattr_ibody_set(inode, xi, xis, ctxt);
            if (!ret && !xbs->not_found) {
                  /*
                   * If succeed and that extended attribute existing in
                   * external block, then we will remove it.
                   */
                  xi->value = NULL;
                  xi->value_len = 0;

                  old_found = xis->not_found;
                  xis->not_found = -ENODATA;
                  ret = ocfs2_calc_xattr_set_need(inode,
                                          di,
                                          xi,
                                          xis,
                                          xbs,
                                          NULL,
                                          NULL,
                                          &credits);
                  xis->not_found = old_found;
                  if (ret) {
                        mlog_errno(ret);
                        goto out;
                  }

                  ret = ocfs2_extend_trans(ctxt->handle, credits +
                              ctxt->handle->h_buffer_credits);
                  if (ret) {
                        mlog_errno(ret);
                        goto out;
                  }
                  ret = ocfs2_xattr_block_set(inode, xi, xbs, ctxt);
            } else if (ret == -ENOSPC) {
                  if (di->i_xattr_loc && !xbs->xattr_bh) {
                        ret = ocfs2_xattr_block_find(inode,
                                               xi->name_index,
                                               xi->name, xbs);
                        if (ret)
                              goto out;

                        old_found = xis->not_found;
                        xis->not_found = -ENODATA;
                        ret = ocfs2_calc_xattr_set_need(inode,
                                                di,
                                                xi,
                                                xis,
                                                xbs,
                                                NULL,
                                                NULL,
                                                &credits);
                        xis->not_found = old_found;
                        if (ret) {
                              mlog_errno(ret);
                              goto out;
                        }

                        ret = ocfs2_extend_trans(ctxt->handle, credits +
                              ctxt->handle->h_buffer_credits);
                        if (ret) {
                              mlog_errno(ret);
                              goto out;
                        }
                  }
                  /*
                   * If no space in inode, we will set extended attribute
                   * into external block.
                   */
                  ret = ocfs2_xattr_block_set(inode, xi, xbs, ctxt);
                  if (ret)
                        goto out;
                  if (!xis->not_found) {
                        /*
                         * If succeed and that extended attribute
                         * existing in inode, we will remove it.
                         */
                        xi->value = NULL;
                        xi->value_len = 0;
                        xbs->not_found = -ENODATA;
                        ret = ocfs2_calc_xattr_set_need(inode,
                                                di,
                                                xi,
                                                xis,
                                                xbs,
                                                NULL,
                                                NULL,
                                                &credits);
                        if (ret) {
                              mlog_errno(ret);
                              goto out;
                        }

                        ret = ocfs2_extend_trans(ctxt->handle, credits +
                                    ctxt->handle->h_buffer_credits);
                        if (ret) {
                              mlog_errno(ret);
                              goto out;
                        }
                        ret = ocfs2_xattr_ibody_set(inode, xi,
                                              xis, ctxt);
                  }
            }
      }

      if (!ret) {
            /* Update inode ctime. */
            ret = ocfs2_journal_access_di(ctxt->handle, inode,
                                    xis->inode_bh,
                                    OCFS2_JOURNAL_ACCESS_WRITE);
            if (ret) {
                  mlog_errno(ret);
                  goto out;
            }

            inode->i_ctime = CURRENT_TIME;
            di->i_ctime = cpu_to_le64(inode->i_ctime.tv_sec);
            di->i_ctime_nsec = cpu_to_le32(inode->i_ctime.tv_nsec);
            ocfs2_journal_dirty(ctxt->handle, xis->inode_bh);
      }
out:
      return ret;
}

/*
 * This function only called duing creating inode
 * for init security/acl xattrs of the new inode.
 * All transanction credits have been reserved in mknod.
 */
int ocfs2_xattr_set_handle(handle_t *handle,
                     struct inode *inode,
                     struct buffer_head *di_bh,
                     int name_index,
                     const char *name,
                     const void *value,
                     size_t value_len,
                     int flags,
                     struct ocfs2_alloc_context *meta_ac,
                     struct ocfs2_alloc_context *data_ac)
{
      struct ocfs2_dinode *di;
      int ret;

      struct ocfs2_xattr_info xi = {
            .name_index = name_index,
            .name = name,
            .value = value,
            .value_len = value_len,
      };

      struct ocfs2_xattr_search xis = {
            .not_found = -ENODATA,
      };

      struct ocfs2_xattr_search xbs = {
            .not_found = -ENODATA,
      };

      struct ocfs2_xattr_set_ctxt ctxt = {
            .handle = handle,
            .meta_ac = meta_ac,
            .data_ac = data_ac,
      };

      if (!ocfs2_supports_xattr(OCFS2_SB(inode->i_sb)))
            return -EOPNOTSUPP;

      /*
       * In extreme situation, may need xattr bucket when
       * block size is too small. And we have already reserved
       * the credits for bucket in mknod.
       */
      if (inode->i_sb->s_blocksize == OCFS2_MIN_BLOCKSIZE) {
            xbs.bucket = ocfs2_xattr_bucket_new(inode);
            if (!xbs.bucket) {
                  mlog_errno(-ENOMEM);
                  return -ENOMEM;
            }
      }

      xis.inode_bh = xbs.inode_bh = di_bh;
      di = (struct ocfs2_dinode *)di_bh->b_data;

      down_write(&OCFS2_I(inode)->ip_xattr_sem);

      ret = ocfs2_xattr_ibody_find(inode, name_index, name, &xis);
      if (ret)
            goto cleanup;
      if (xis.not_found) {
            ret = ocfs2_xattr_block_find(inode, name_index, name, &xbs);
            if (ret)
                  goto cleanup;
      }

      ret = __ocfs2_xattr_set_handle(inode, di, &xi, &xis, &xbs, &ctxt);

cleanup:
      up_write(&OCFS2_I(inode)->ip_xattr_sem);
      brelse(xbs.xattr_bh);
      ocfs2_xattr_bucket_free(xbs.bucket);

      return ret;
}

/*
 * ocfs2_xattr_set()
 *
 * Set, replace or remove an extended attribute for this inode.
 * value is NULL to remove an existing extended attribute, else either
 * create or replace an extended attribute.
 */
int ocfs2_xattr_set(struct inode *inode,
                int name_index,
                const char *name,
                const void *value,
                size_t value_len,
                int flags)
{
      struct buffer_head *di_bh = NULL;
      struct ocfs2_dinode *di;
      int ret, credits;
      struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
      struct inode *tl_inode = osb->osb_tl_inode;
      struct ocfs2_xattr_set_ctxt ctxt = { NULL, NULL, };

      struct ocfs2_xattr_info xi = {
            .name_index = name_index,
            .name = name,
            .value = value,
            .value_len = value_len,
      };

      struct ocfs2_xattr_search xis = {
            .not_found = -ENODATA,
      };

      struct ocfs2_xattr_search xbs = {
            .not_found = -ENODATA,
      };

      if (!ocfs2_supports_xattr(OCFS2_SB(inode->i_sb)))
            return -EOPNOTSUPP;

      /*
       * Only xbs will be used on indexed trees.  xis doesn't need a
       * bucket.
       */
      xbs.bucket = ocfs2_xattr_bucket_new(inode);
      if (!xbs.bucket) {
            mlog_errno(-ENOMEM);
            return -ENOMEM;
      }

      ret = ocfs2_inode_lock(inode, &di_bh, 1);
      if (ret < 0) {
            mlog_errno(ret);
            goto cleanup_nolock;
      }
      xis.inode_bh = xbs.inode_bh = di_bh;
      di = (struct ocfs2_dinode *)di_bh->b_data;

      down_write(&OCFS2_I(inode)->ip_xattr_sem);
      /*
       * Scan inode and external block to find the same name
       * extended attribute and collect search infomation.
       */
      ret = ocfs2_xattr_ibody_find(inode, name_index, name, &xis);
      if (ret)
            goto cleanup;
      if (xis.not_found) {
            ret = ocfs2_xattr_block_find(inode, name_index, name, &xbs);
            if (ret)
                  goto cleanup;
      }

      if (xis.not_found && xbs.not_found) {
            ret = -ENODATA;
            if (flags & XATTR_REPLACE)
                  goto cleanup;
            ret = 0;
            if (!value)
                  goto cleanup;
      } else {
            ret = -EEXIST;
            if (flags & XATTR_CREATE)
                  goto cleanup;
      }


      mutex_lock(&tl_inode->i_mutex);

      if (ocfs2_truncate_log_needs_flush(osb)) {
            ret = __ocfs2_flush_truncate_log(osb);
            if (ret < 0) {
                  mutex_unlock(&tl_inode->i_mutex);
                  mlog_errno(ret);
                  goto cleanup;
            }
      }
      mutex_unlock(&tl_inode->i_mutex);

      ret = ocfs2_init_xattr_set_ctxt(inode, di, &xi, &xis,
                              &xbs, &ctxt, &credits);
      if (ret) {
            mlog_errno(ret);
            goto cleanup;
      }

      /* we need to update inode's ctime field, so add credit for it. */
      credits += OCFS2_INODE_UPDATE_CREDITS;
      ctxt.handle = ocfs2_start_trans(osb, credits);
      if (IS_ERR(ctxt.handle)) {
            ret = PTR_ERR(ctxt.handle);
            mlog_errno(ret);
            goto cleanup;
      }

      ret = __ocfs2_xattr_set_handle(inode, di, &xi, &xis, &xbs, &ctxt);

      ocfs2_commit_trans(osb, ctxt.handle);

      if (ctxt.data_ac)
            ocfs2_free_alloc_context(ctxt.data_ac);
      if (ctxt.meta_ac)
            ocfs2_free_alloc_context(ctxt.meta_ac);
      if (ocfs2_dealloc_has_cluster(&ctxt.dealloc))
            ocfs2_schedule_truncate_log_flush(osb, 1);
      ocfs2_run_deallocs(osb, &ctxt.dealloc);
cleanup:
      up_write(&OCFS2_I(inode)->ip_xattr_sem);
      ocfs2_inode_unlock(inode, 1);
cleanup_nolock:
      brelse(di_bh);
      brelse(xbs.xattr_bh);
      ocfs2_xattr_bucket_free(xbs.bucket);

      return ret;
}

/*
 * Find the xattr extent rec which may contains name_hash.
 * e_cpos will be the first name hash of the xattr rec.
 * el must be the ocfs2_xattr_header.xb_attrs.xb_root.xt_list.
 */
static int ocfs2_xattr_get_rec(struct inode *inode,
                         u32 name_hash,
                         u64 *p_blkno,
                         u32 *e_cpos,
                         u32 *num_clusters,
                         struct ocfs2_extent_list *el)
{
      int ret = 0, i;
      struct buffer_head *eb_bh = NULL;
      struct ocfs2_extent_block *eb;
      struct ocfs2_extent_rec *rec = NULL;
      u64 e_blkno = 0;

      if (el->l_tree_depth) {
            ret = ocfs2_find_leaf(inode, el, name_hash, &eb_bh);
            if (ret) {
                  mlog_errno(ret);
                  goto out;
            }

            eb = (struct ocfs2_extent_block *) eb_bh->b_data;
            el = &eb->h_list;

            if (el->l_tree_depth) {
                  ocfs2_error(inode->i_sb,
                            "Inode %lu has non zero tree depth in "
                            "xattr tree block %llu\n", inode->i_ino,
                            (unsigned long long)eb_bh->b_blocknr);
                  ret = -EROFS;
                  goto out;
            }
      }

      for (i = le16_to_cpu(el->l_next_free_rec) - 1; i >= 0; i--) {
            rec = &el->l_recs[i];

            if (le32_to_cpu(rec->e_cpos) <= name_hash) {
                  e_blkno = le64_to_cpu(rec->e_blkno);
                  break;
            }
      }

      if (!e_blkno) {
            ocfs2_error(inode->i_sb, "Inode %lu has bad extent "
                      "record (%u, %u, 0) in xattr", inode->i_ino,
                      le32_to_cpu(rec->e_cpos),
                      ocfs2_rec_clusters(el, rec));
            ret = -EROFS;
            goto out;
      }

      *p_blkno = le64_to_cpu(rec->e_blkno);
      *num_clusters = le16_to_cpu(rec->e_leaf_clusters);
      if (e_cpos)
            *e_cpos = le32_to_cpu(rec->e_cpos);
out:
      brelse(eb_bh);
      return ret;
}

typedef int (xattr_bucket_func)(struct inode *inode,
                        struct ocfs2_xattr_bucket *bucket,
                        void *para);

static int ocfs2_find_xe_in_bucket(struct inode *inode,
                           struct ocfs2_xattr_bucket *bucket,
                           int name_index,
                           const char *name,
                           u32 name_hash,
                           u16 *xe_index,
                           int *found)
{
      int i, ret = 0, cmp = 1, block_off, new_offset;
      struct ocfs2_xattr_header *xh = bucket_xh(bucket);
      size_t name_len = strlen(name);
      struct ocfs2_xattr_entry *xe = NULL;
      char *xe_name;

      /*
       * We don't use binary search in the bucket because there
       * may be multiple entries with the same name hash.
       */
      for (i = 0; i < le16_to_cpu(xh->xh_count); i++) {
            xe = &xh->xh_entries[i];

            if (name_hash > le32_to_cpu(xe->xe_name_hash))
                  continue;
            else if (name_hash < le32_to_cpu(xe->xe_name_hash))
                  break;

            cmp = name_index - ocfs2_xattr_get_type(xe);
            if (!cmp)
                  cmp = name_len - xe->xe_name_len;
            if (cmp)
                  continue;

            ret = ocfs2_xattr_bucket_get_name_value(inode,
                                          xh,
                                          i,
                                          &block_off,
                                          &new_offset);
            if (ret) {
                  mlog_errno(ret);
                  break;
            }


            xe_name = bucket_block(bucket, block_off) + new_offset;
            if (!memcmp(name, xe_name, name_len)) {
                  *xe_index = i;
                  *found = 1;
                  ret = 0;
                  break;
            }
      }

      return ret;
}

/*
 * Find the specified xattr entry in a series of buckets.
 * This series start from p_blkno and last for num_clusters.
 * The ocfs2_xattr_header.xh_num_buckets of the first bucket contains
 * the num of the valid buckets.
 *
 * Return the buffer_head this xattr should reside in. And if the xattr's
 * hash is in the gap of 2 buckets, return the lower bucket.
 */
static int ocfs2_xattr_bucket_find(struct inode *inode,
                           int name_index,
                           const char *name,
                           u32 name_hash,
                           u64 p_blkno,
                           u32 first_hash,
                           u32 num_clusters,
                           struct ocfs2_xattr_search *xs)
{
      int ret, found = 0;
      struct ocfs2_xattr_header *xh = NULL;
      struct ocfs2_xattr_entry *xe = NULL;
      u16 index = 0;
      u16 blk_per_bucket = ocfs2_blocks_per_xattr_bucket(inode->i_sb);
      int low_bucket = 0, bucket, high_bucket;
      struct ocfs2_xattr_bucket *search;
      u32 last_hash;
      u64 blkno, lower_blkno = 0;

      search = ocfs2_xattr_bucket_new(inode);
      if (!search) {
            ret = -ENOMEM;
            mlog_errno(ret);
            goto out;
      }

      ret = ocfs2_read_xattr_bucket(search, p_blkno);
      if (ret) {
            mlog_errno(ret);
            goto out;
      }

      xh = bucket_xh(search);
      high_bucket = le16_to_cpu(xh->xh_num_buckets) - 1;
      while (low_bucket <= high_bucket) {
            ocfs2_xattr_bucket_relse(search);

            bucket = (low_bucket + high_bucket) / 2;
            blkno = p_blkno + bucket * blk_per_bucket;
            ret = ocfs2_read_xattr_bucket(search, blkno);
            if (ret) {
                  mlog_errno(ret);
                  goto out;
            }

            xh = bucket_xh(search);
            xe = &xh->xh_entries[0];
            if (name_hash < le32_to_cpu(xe->xe_name_hash)) {
                  high_bucket = bucket - 1;
                  continue;
            }

            /*
             * Check whether the hash of the last entry in our
             * bucket is larger than the search one. for an empty
             * bucket, the last one is also the first one.
             */
            if (xh->xh_count)
                  xe = &xh->xh_entries[le16_to_cpu(xh->xh_count) - 1];

            last_hash = le32_to_cpu(xe->xe_name_hash);

            /* record lower_blkno which may be the insert place. */
            lower_blkno = blkno;

            if (name_hash > le32_to_cpu(xe->xe_name_hash)) {
                  low_bucket = bucket + 1;
                  continue;
            }

            /* the searched xattr should reside in this bucket if exists. */
            ret = ocfs2_find_xe_in_bucket(inode, search,
                                    name_index, name, name_hash,
                                    &index, &found);
            if (ret) {
                  mlog_errno(ret);
                  goto out;
            }
            break;
      }

      /*
       * Record the bucket we have found.
       * When the xattr's hash value is in the gap of 2 buckets, we will
       * always set it to the previous bucket.
       */
      if (!lower_blkno)
            lower_blkno = p_blkno;

      /* This should be in cache - we just read it during the search */
      ret = ocfs2_read_xattr_bucket(xs->bucket, lower_blkno);
      if (ret) {
            mlog_errno(ret);
            goto out;
      }

      xs->header = bucket_xh(xs->bucket);
      xs->base = bucket_block(xs->bucket, 0);
      xs->end = xs->base + inode->i_sb->s_blocksize;

      if (found) {
            xs->here = &xs->header->xh_entries[index];
            mlog(0, "find xattr %s in bucket %llu, entry = %u\n", name,
                 (unsigned long long)bucket_blkno(xs->bucket), index);
      } else
            ret = -ENODATA;

out:
      ocfs2_xattr_bucket_free(search);
      return ret;
}

static int ocfs2_xattr_index_block_find(struct inode *inode,
                              struct buffer_head *root_bh,
                              int name_index,
                              const char *name,
                              struct ocfs2_xattr_search *xs)
{
      int ret;
      struct ocfs2_xattr_block *xb =
                  (struct ocfs2_xattr_block *)root_bh->b_data;
      struct ocfs2_xattr_tree_root *xb_root = &xb->xb_attrs.xb_root;
      struct ocfs2_extent_list *el = &xb_root->xt_list;
      u64 p_blkno = 0;
      u32 first_hash, num_clusters = 0;
      u32 name_hash = ocfs2_xattr_name_hash(inode, name, strlen(name));

      if (le16_to_cpu(el->l_next_free_rec) == 0)
            return -ENODATA;

      mlog(0, "find xattr %s, hash = %u, index = %d in xattr tree\n",
           name, name_hash, name_index);

      ret = ocfs2_xattr_get_rec(inode, name_hash, &p_blkno, &first_hash,
                          &num_clusters, el);
      if (ret) {
            mlog_errno(ret);
            goto out;
      }

      BUG_ON(p_blkno == 0 || num_clusters == 0 || first_hash > name_hash);

      mlog(0, "find xattr extent rec %u clusters from %llu, the first hash "
           "in the rec is %u\n", num_clusters, (unsigned long long)p_blkno,
           first_hash);

      ret = ocfs2_xattr_bucket_find(inode, name_index, name, name_hash,
                              p_blkno, first_hash, num_clusters, xs);

out:
      return ret;
}

static int ocfs2_iterate_xattr_buckets(struct inode *inode,
                               u64 blkno,
                               u32 clusters,
                               xattr_bucket_func *func,
                               void *para)
{
      int i, ret = 0;
      u32 bpc = ocfs2_xattr_buckets_per_cluster(OCFS2_SB(inode->i_sb));
      u32 num_buckets = clusters * bpc;
      struct ocfs2_xattr_bucket *bucket;

      bucket = ocfs2_xattr_bucket_new(inode);
      if (!bucket) {
            mlog_errno(-ENOMEM);
            return -ENOMEM;
      }

      mlog(0, "iterating xattr buckets in %u clusters starting from %llu\n",
           clusters, (unsigned long long)blkno);

      for (i = 0; i < num_buckets; i++, blkno += bucket->bu_blocks) {
            ret = ocfs2_read_xattr_bucket(bucket, blkno);
            if (ret) {
                  mlog_errno(ret);
                  break;
            }

            /*
             * The real bucket num in this series of blocks is stored
             * in the 1st bucket.
             */
            if (i == 0)
                  num_buckets = le16_to_cpu(bucket_xh(bucket)->xh_num_buckets);

            mlog(0, "iterating xattr bucket %llu, first hash %u\n",
                 (unsigned long long)blkno,
                 le32_to_cpu(bucket_xh(bucket)->xh_entries[0].xe_name_hash));
            if (func) {
                  ret = func(inode, bucket, para);
                  if (ret && ret != -ERANGE)
                        mlog_errno(ret);
                  /* Fall through to bucket_relse() */
            }

            ocfs2_xattr_bucket_relse(bucket);
            if (ret)
                  break;
      }

      ocfs2_xattr_bucket_free(bucket);
      return ret;
}

03172 struct ocfs2_xattr_tree_list {
      char *buffer;
      size_t buffer_size;
      size_t result;
};

static int ocfs2_xattr_bucket_get_name_value(struct inode *inode,
                                   struct ocfs2_xattr_header *xh,
                                   int index,
                                   int *block_off,
                                   int *new_offset)
{
      u16 name_offset;

      if (index < 0 || index >= le16_to_cpu(xh->xh_count))
            return -EINVAL;

      name_offset = le16_to_cpu(xh->xh_entries[index].xe_name_offset);

      *block_off = name_offset >> inode->i_sb->s_blocksize_bits;
      *new_offset = name_offset % inode->i_sb->s_blocksize;

      return 0;
}

static int ocfs2_list_xattr_bucket(struct inode *inode,
                           struct ocfs2_xattr_bucket *bucket,
                           void *para)
{
      int ret = 0, type;
      struct ocfs2_xattr_tree_list *xl = (struct ocfs2_xattr_tree_list *)para;
      int i, block_off, new_offset;
      const char *prefix, *name;

      for (i = 0 ; i < le16_to_cpu(bucket_xh(bucket)->xh_count); i++) {
            struct ocfs2_xattr_entry *entry = &bucket_xh(bucket)->xh_entries[i];
            type = ocfs2_xattr_get_type(entry);
            prefix = ocfs2_xattr_prefix(type);

            if (prefix) {
                  ret = ocfs2_xattr_bucket_get_name_value(inode,
                                                bucket_xh(bucket),
                                                i,
                                                &block_off,
                                                &new_offset);
                  if (ret)
                        break;

                  name = (const char *)bucket_block(bucket, block_off) +
                        new_offset;
                  ret = ocfs2_xattr_list_entry(xl->buffer,
                                         xl->buffer_size,
                                         &xl->result,
                                         prefix, name,
                                         entry->xe_name_len);
                  if (ret)
                        break;
            }
      }

      return ret;
}

static int ocfs2_xattr_tree_list_index_block(struct inode *inode,
                                   struct ocfs2_xattr_tree_root *xt,
                                   char *buffer,
                                   size_t buffer_size)
{
      struct ocfs2_extent_list *el = &xt->xt_list;
      int ret = 0;
      u32 name_hash = UINT_MAX, e_cpos = 0, num_clusters = 0;
      u64 p_blkno = 0;
      struct ocfs2_xattr_tree_list xl = {
            .buffer = buffer,
            .buffer_size = buffer_size,
            .result = 0,
      };

      if (le16_to_cpu(el->l_next_free_rec) == 0)
            return 0;

      while (name_hash > 0) {
            ret = ocfs2_xattr_get_rec(inode, name_hash, &p_blkno,
                                &e_cpos, &num_clusters, el);
            if (ret) {
                  mlog_errno(ret);
                  goto out;
            }

            ret = ocfs2_iterate_xattr_buckets(inode, p_blkno, num_clusters,
                                      ocfs2_list_xattr_bucket,
                                      &xl);
            if (ret) {
                  if (ret != -ERANGE)
                        mlog_errno(ret);
                  goto out;
            }

            if (e_cpos == 0)
                  break;

            name_hash = e_cpos - 1;
      }

      ret = xl.result;
out:
      return ret;
}

static int cmp_xe(const void *a, const void *b)
{
      const struct ocfs2_xattr_entry *l = a, *r = b;
      u32 l_hash = le32_to_cpu(l->xe_name_hash);
      u32 r_hash = le32_to_cpu(r->xe_name_hash);

      if (l_hash > r_hash)
            return 1;
      if (l_hash < r_hash)
            return -1;
      return 0;
}

static void swap_xe(void *a, void *b, int size)
{
      struct ocfs2_xattr_entry *l = a, *r = b, tmp;

      tmp = *l;
      memcpy(l, r, sizeof(struct ocfs2_xattr_entry));
      memcpy(r, &tmp, sizeof(struct ocfs2_xattr_entry));
}

/*
 * When the ocfs2_xattr_block is filled up, new bucket will be created
 * and all the xattr entries will be moved to the new bucket.
 * The header goes at the start of the bucket, and the names+values are
 * filled from the end.  This is why *target starts as the last buffer.
 * Note: we need to sort the entries since they are not saved in order
 * in the ocfs2_xattr_block.
 */
static void ocfs2_cp_xattr_block_to_bucket(struct inode *inode,
                                 struct buffer_head *xb_bh,
                                 struct ocfs2_xattr_bucket *bucket)
{
      int i, blocksize = inode->i_sb->s_blocksize;
      int blks = ocfs2_blocks_per_xattr_bucket(inode->i_sb);
      u16 offset, size, off_change;
      struct ocfs2_xattr_entry *xe;
      struct ocfs2_xattr_block *xb =
                        (struct ocfs2_xattr_block *)xb_bh->b_data;
      struct ocfs2_xattr_header *xb_xh = &xb->xb_attrs.xb_header;
      struct ocfs2_xattr_header *xh = bucket_xh(bucket);
      u16 count = le16_to_cpu(xb_xh->xh_count);
      char *src = xb_bh->b_data;
      char *target = bucket_block(bucket, blks - 1);

      mlog(0, "cp xattr from block %llu to bucket %llu\n",
           (unsigned long long)xb_bh->b_blocknr,
           (unsigned long long)bucket_blkno(bucket));

      for (i = 0; i < blks; i++)
            memset(bucket_block(bucket, i), 0, blocksize);

      /*
       * Since the xe_name_offset is based on ocfs2_xattr_header,
       * there is a offset change corresponding to the change of
       * ocfs2_xattr_header's position.
       */
      off_change = offsetof(struct ocfs2_xattr_block, xb_attrs.xb_header);
      xe = &xb_xh->xh_entries[count - 1];
      offset = le16_to_cpu(xe->xe_name_offset) + off_change;
      size = blocksize - offset;

      /* copy all the names and values. */
      memcpy(target + offset, src + offset, size);

      /* Init new header now. */
      xh->xh_count = xb_xh->xh_count;
      xh->xh_num_buckets = cpu_to_le16(1);
      xh->xh_name_value_len = cpu_to_le16(size);
      xh->xh_free_start = cpu_to_le16(OCFS2_XATTR_BUCKET_SIZE - size);

      /* copy all the entries. */
      target = bucket_block(bucket, 0);
      offset = offsetof(struct ocfs2_xattr_header, xh_entries);
      size = count * sizeof(struct ocfs2_xattr_entry);
      memcpy(target + offset, (char *)xb_xh + offset, size);

      /* Change the xe offset for all the xe because of the move. */
      off_change = OCFS2_XATTR_BUCKET_SIZE - blocksize +
             offsetof(struct ocfs2_xattr_block, xb_attrs.xb_header);
      for (i = 0; i < count; i++)
            le16_add_cpu(&xh->xh_entries[i].xe_name_offset, off_change);

      mlog(0, "copy entry: start = %u, size = %u, offset_change = %u\n",
           offset, size, off_change);

      sort(target + offset, count, sizeof(struct ocfs2_xattr_entry),
           cmp_xe, swap_xe);
}

/*
 * After we move xattr from block to index btree, we have to
 * update ocfs2_xattr_search to the new xe and base.
 *
 * When the entry is in xattr block, xattr_bh indicates the storage place.
 * While if the entry is in index b-tree, "bucket" indicates the
 * real place of the xattr.
 */
static void ocfs2_xattr_update_xattr_search(struct inode *inode,
                                  struct ocfs2_xattr_search *xs,
                                  struct buffer_head *old_bh)
{
      char *buf = old_bh->b_data;
      struct ocfs2_xattr_block *old_xb = (struct ocfs2_xattr_block *)buf;
      struct ocfs2_xattr_header *old_xh = &old_xb->xb_attrs.xb_header;
      int i;

      xs->header = bucket_xh(xs->bucket);
      xs->base = bucket_block(xs->bucket, 0);
      xs->end = xs->base + inode->i_sb->s_blocksize;

      if (xs->not_found)
            return;

      i = xs->here - old_xh->xh_entries;
      xs->here = &xs->header->xh_entries[i];
}

static int ocfs2_xattr_create_index_block(struct inode *inode,
                                struct ocfs2_xattr_search *xs,
                                struct ocfs2_xattr_set_ctxt *ctxt)
{
      int ret;
      u32 bit_off, len;
      u64 blkno;
      handle_t *handle = ctxt->handle;
      struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
      struct ocfs2_inode_info *oi = OCFS2_I(inode);
      struct buffer_head *xb_bh = xs->xattr_bh;
      struct ocfs2_xattr_block *xb =
                  (struct ocfs2_xattr_block *)xb_bh->b_data;
      struct ocfs2_xattr_tree_root *xr;
      u16 xb_flags = le16_to_cpu(xb->xb_flags);

      mlog(0, "create xattr index block for %llu\n",
           (unsigned long long)xb_bh->b_blocknr);

      BUG_ON(xb_flags & OCFS2_XATTR_INDEXED);
      BUG_ON(!xs->bucket);

      /*
       * XXX:
       * We can use this lock for now, and maybe move to a dedicated mutex
       * if performance becomes a problem later.
       */
      down_write(&oi->ip_alloc_sem);

      ret = ocfs2_journal_access_xb(handle, inode, xb_bh,
                              OCFS2_JOURNAL_ACCESS_WRITE);
      if (ret) {
            mlog_errno(ret);
            goto out;
      }

      ret = __ocfs2_claim_clusters(osb, handle, ctxt->data_ac,
                             1, 1, &bit_off, &len);
      if (ret) {
            mlog_errno(ret);
            goto out;
      }

      /*
       * The bucket may spread in many blocks, and
       * we will only touch the 1st block and the last block
       * in the whole bucket(one for entry and one for data).
       */
      blkno = ocfs2_clusters_to_blocks(inode->i_sb, bit_off);

      mlog(0, "allocate 1 cluster from %llu to xattr block\n",
           (unsigned long long)blkno);

      ret = ocfs2_init_xattr_bucket(xs->bucket, blkno);
      if (ret) {
            mlog_errno(ret);
            goto out;
      }

      ret = ocfs2_xattr_bucket_journal_access(handle, xs->bucket,
                                    OCFS2_JOURNAL_ACCESS_CREATE);
      if (ret) {
            mlog_errno(ret);
            goto out;
      }

      ocfs2_cp_xattr_block_to_bucket(inode, xb_bh, xs->bucket);
      ocfs2_xattr_bucket_journal_dirty(handle, xs->bucket);

      ocfs2_xattr_update_xattr_search(inode, xs, xb_bh);

      /* Change from ocfs2_xattr_header to ocfs2_xattr_tree_root */
      memset(&xb->xb_attrs, 0, inode->i_sb->s_blocksize -
             offsetof(struct ocfs2_xattr_block, xb_attrs));

      xr = &xb->xb_attrs.xb_root;
      xr->xt_clusters = cpu_to_le32(1);
      xr->xt_last_eb_blk = 0;
      xr->xt_list.l_tree_depth = 0;
      xr->xt_list.l_count = cpu_to_le16(ocfs2_xattr_recs_per_xb(inode->i_sb));
      xr->xt_list.l_next_free_rec = cpu_to_le16(1);

      xr->xt_list.l_recs[0].e_cpos = 0;
      xr->xt_list.l_recs[0].e_blkno = cpu_to_le64(blkno);
      xr->xt_list.l_recs[0].e_leaf_clusters = cpu_to_le16(1);

      xb->xb_flags = cpu_to_le16(xb_flags | OCFS2_XATTR_INDEXED);

      ocfs2_journal_dirty(handle, xb_bh);

out:
      up_write(&oi->ip_alloc_sem);

      return ret;
}

static int cmp_xe_offset(const void *a, const void *b)
{
      const struct ocfs2_xattr_entry *l = a, *r = b;
      u32 l_name_offset = le16_to_cpu(l->xe_name_offset);
      u32 r_name_offset = le16_to_cpu(r->xe_name_offset);

      if (l_name_offset < r_name_offset)
            return 1;
      if (l_name_offset > r_name_offset)
            return -1;
      return 0;
}

/*
 * defrag a xattr bucket if we find that the bucket has some
 * holes beteen name/value pairs.
 * We will move all the name/value pairs to the end of the bucket
 * so that we can spare some space for insertion.
 */
static int ocfs2_defrag_xattr_bucket(struct inode *inode,
                             handle_t *handle,
                             struct ocfs2_xattr_bucket *bucket)
{
      int ret, i;
      size_t end, offset, len, value_len;
      struct ocfs2_xattr_header *xh;
      char *entries, *buf, *bucket_buf = NULL;
      u64 blkno = bucket_blkno(bucket);
      u16 xh_free_start;
      size_t blocksize = inode->i_sb->s_blocksize;
      struct ocfs2_xattr_entry *xe;

      /*
       * In order to make the operation more efficient and generic,
       * we copy all the blocks into a contiguous memory and do the
       * defragment there, so if anything is error, we will not touch
       * the real block.
       */
      bucket_buf = kmalloc(OCFS2_XATTR_BUCKET_SIZE, GFP_NOFS);
      if (!bucket_buf) {
            ret = -EIO;
            goto out;
      }

      buf = bucket_buf;
      for (i = 0; i < bucket->bu_blocks; i++, buf += blocksize)
            memcpy(buf, bucket_block(bucket, i), blocksize);

      ret = ocfs2_xattr_bucket_journal_access(handle, bucket,
                                    OCFS2_JOURNAL_ACCESS_WRITE);
      if (ret < 0) {
            mlog_errno(ret);
            goto out;
      }

      xh = (struct ocfs2_xattr_header *)bucket_buf;
      entries = (char *)xh->xh_entries;
      xh_free_start = le16_to_cpu(xh->xh_free_start);

      mlog(0, "adjust xattr bucket in %llu, count = %u, "
           "xh_free_start = %u, xh_name_value_len = %u.\n",
           (unsigned long long)blkno, le16_to_cpu(xh->xh_count),
           xh_free_start, le16_to_cpu(xh->xh_name_value_len));

      /*
       * sort all the entries by their offset.
       * the largest will be the first, so that we can
       * move them to the end one by one.
       */
      sort(entries, le16_to_cpu(xh->xh_count),
           sizeof(struct ocfs2_xattr_entry),
           cmp_xe_offset, swap_xe);

      /* Move all name/values to the end of the bucket. */
      xe = xh->xh_entries;
      end = OCFS2_XATTR_BUCKET_SIZE;
      for (i = 0; i < le16_to_cpu(xh->xh_count); i++, xe++) {
            offset = le16_to_cpu(xe->xe_name_offset);
            if (ocfs2_xattr_is_local(xe))
                  value_len = OCFS2_XATTR_SIZE(
                              le64_to_cpu(xe->xe_value_size));
            else
                  value_len = OCFS2_XATTR_ROOT_SIZE;
            len = OCFS2_XATTR_SIZE(xe->xe_name_len) + value_len;

            /*
             * We must make sure that the name/value pair
             * exist in the same block. So adjust end to
             * the previous block end if needed.
             */
            if (((end - len) / blocksize !=
                  (end - 1) / blocksize))
                  end = end - end % blocksize;

            if (end > offset + len) {
                  memmove(bucket_buf + end - len,
                        bucket_buf + offset, len);
                  xe->xe_name_offset = cpu_to_le16(end - len);
            }

            mlog_bug_on_msg(end < offset + len, "Defrag check failed for "
                        "bucket %llu\n", (unsigned long long)blkno);

            end -= len;
      }

      mlog_bug_on_msg(xh_free_start > end, "Defrag check failed for "
                  "bucket %llu\n", (unsigned long long)blkno);

      if (xh_free_start == end)
            goto out;

      memset(bucket_buf + xh_free_start, 0, end - xh_free_start);
      xh->xh_free_start = cpu_to_le16(end);

      /* sort the entries by their name_hash. */
      sort(entries, le16_to_cpu(xh->xh_count),
           sizeof(struct ocfs2_xattr_entry),
           cmp_xe, swap_xe);

      buf = bucket_buf;
      for (i = 0; i < bucket->bu_blocks; i++, buf += blocksize)
            memcpy(bucket_block(bucket, i), buf, blocksize);
      ocfs2_xattr_bucket_journal_dirty(handle, bucket);

out:
      kfree(bucket_buf);
      return ret;
}

/*
 * prev_blkno points to the start of an existing extent.  new_blkno
 * points to a newly allocated extent.  Because we know each of our
 * clusters contains more than bucket, we can easily split one cluster
 * at a bucket boundary.  So we take the last cluster of the existing
 * extent and split it down the middle.  We move the last half of the
 * buckets in the last cluster of the existing extent over to the new
 * extent.
 *
 * first_bh is the buffer at prev_blkno so we can update the existing
 * extent's bucket count.  header_bh is the bucket were we were hoping
 * to insert our xattr.  If the bucket move places the target in the new
 * extent, we'll update first_bh and header_bh after modifying the old
 * extent.
 *
 * first_hash will be set as the 1st xe's name_hash in the new extent.
 */
static int ocfs2_mv_xattr_bucket_cross_cluster(struct inode *inode,
                                     handle_t *handle,
                                     struct ocfs2_xattr_bucket *first,
                                     struct ocfs2_xattr_bucket *target,
                                     u64 new_blkno,
                                     u32 num_clusters,
                                     u32 *first_hash)
{
      int ret;
      struct super_block *sb = inode->i_sb;
      int blks_per_bucket = ocfs2_blocks_per_xattr_bucket(sb);
      int num_buckets = ocfs2_xattr_buckets_per_cluster(OCFS2_SB(sb));
      int to_move = num_buckets / 2;
      u64 src_blkno;
      u64 last_cluster_blkno = bucket_blkno(first) +
            ((num_clusters - 1) * ocfs2_clusters_to_blocks(sb, 1));

      BUG_ON(le16_to_cpu(bucket_xh(first)->xh_num_buckets) < num_buckets);
      BUG_ON(OCFS2_XATTR_BUCKET_SIZE == OCFS2_SB(sb)->s_clustersize);

      mlog(0, "move half of xattrs in cluster %llu to %llu\n",
           (unsigned long long)last_cluster_blkno, (unsigned long long)new_blkno);

      ret = ocfs2_mv_xattr_buckets(inode, handle, bucket_blkno(first),
                             last_cluster_blkno, new_blkno,
                             to_move, first_hash);
      if (ret) {
            mlog_errno(ret);
            goto out;
      }

      /* This is the first bucket that got moved */
      src_blkno = last_cluster_blkno + (to_move * blks_per_bucket);

      /*
       * If the target bucket was part of the moved buckets, we need to
       * update first and target.
       */
      if (bucket_blkno(target) >= src_blkno) {
            /* Find the block for the new target bucket */
            src_blkno = new_blkno +
                  (bucket_blkno(target) - src_blkno);

            ocfs2_xattr_bucket_relse(first);
            ocfs2_xattr_bucket_relse(target);

            /*
             * These shouldn't fail - the buffers are in the
             * journal from ocfs2_cp_xattr_bucket().
             */
            ret = ocfs2_read_xattr_bucket(first, new_blkno);
            if (ret) {
                  mlog_errno(ret);
                  goto out;
            }
            ret = ocfs2_read_xattr_bucket(target, src_blkno);
            if (ret)
                  mlog_errno(ret);

      }

out:
      return ret;
}

/*
 * Find the suitable pos when we divide a bucket into 2.
 * We have to make sure the xattrs with the same hash value exist
 * in the same bucket.
 *
 * If this ocfs2_xattr_header covers more than one hash value, find a
 * place where the hash value changes.  Try to find the most even split.
 * The most common case is that all entries have different hash values,
 * and the first check we make will find a place to split.
 */
static int ocfs2_xattr_find_divide_pos(struct ocfs2_xattr_header *xh)
{
      struct ocfs2_xattr_entry *entries = xh->xh_entries;
      int count = le16_to_cpu(xh->xh_count);
      int delta, middle = count / 2;

      /*
       * We start at the middle.  Each step gets farther away in both
       * directions.  We therefore hit the change in hash value
       * nearest to the middle.  Note that this loop does not execute for
       * count < 2.
       */
      for (delta = 0; delta < middle; delta++) {
            /* Let's check delta earlier than middle */
            if (cmp_xe(&entries[middle - delta - 1],
                     &entries[middle - delta]))
                  return middle - delta;

            /* For even counts, don't walk off the end */
            if ((middle + delta + 1) == count)
                  continue;

            /* Now try delta past middle */
            if (cmp_xe(&entries[middle + delta],
                     &entries[middle + delta + 1]))
                  return middle + delta + 1;
      }

      /* Every entry had the same hash */
      return count;
}

/*
 * Move some xattrs in old bucket(blk) to new bucket(new_blk).
 * first_hash will record the 1st hash of the new bucket.
 *
 * Normally half of the xattrs will be moved.  But we have to make
 * sure that the xattrs with the same hash value are stored in the
 * same bucket. If all the xattrs in this bucket have the same hash
 * value, the new bucket will be initialized as an empty one and the
 * first_hash will be initialized as (hash_value+1).
 */
static int ocfs2_divide_xattr_bucket(struct inode *inode,
                            handle_t *handle,
                            u64 blk,
                            u64 new_blk,
                            u32 *first_hash,
                            int new_bucket_head)
{
      int ret, i;
      int count, start, len, name_value_len = 0, xe_len, name_offset = 0;
      struct ocfs2_xattr_bucket *s_bucket = NULL, *t_bucket = NULL;
      struct ocfs2_xattr_header *xh;
      struct ocfs2_xattr_entry *xe;
      int blocksize = inode->i_sb->s_blocksize;

      mlog(0, "move some of xattrs from bucket %llu to %llu\n",
           (unsigned long long)blk, (unsigned long long)new_blk);

      s_bucket = ocfs2_xattr_bucket_new(inode);
      t_bucket = ocfs2_xattr_bucket_new(inode);
      if (!s_bucket || !t_bucket) {
            ret = -ENOMEM;
            mlog_errno(ret);
            goto out;
      }

      ret = ocfs2_read_xattr_bucket(s_bucket, blk);
      if (ret) {
            mlog_errno(ret);
            goto out;
      }

      ret = ocfs2_xattr_bucket_journal_access(handle, s_bucket,
                                    OCFS2_JOURNAL_ACCESS_WRITE);
      if (ret) {
            mlog_errno(ret);
            goto out;
      }

      /*
       * Even if !new_bucket_head, we're overwriting t_bucket.  Thus,
       * there's no need to read it.
       */
      ret = ocfs2_init_xattr_bucket(t_bucket, new_blk);
      if (ret) {
            mlog_errno(ret);
            goto out;
      }

      /*
       * Hey, if we're overwriting t_bucket, what difference does
       * ACCESS_CREATE vs ACCESS_WRITE make?  See the comment in the
       * same part of ocfs2_cp_xattr_bucket().
       */
      ret = ocfs2_xattr_bucket_journal_access(handle, t_bucket,
                                    new_bucket_head ?
                                    OCFS2_JOURNAL_ACCESS_CREATE :
                                    OCFS2_JOURNAL_ACCESS_WRITE);
      if (ret) {
            mlog_errno(ret);
            goto out;
      }

      xh = bucket_xh(s_bucket);
      count = le16_to_cpu(xh->xh_count);
      start = ocfs2_xattr_find_divide_pos(xh);

      if (start == count) {
            xe = &xh->xh_entries[start-1];

            /*
             * initialized a new empty bucket here.
             * The hash value is set as one larger than
             * that of the last entry in the previous bucket.
             */
            for (i = 0; i < t_bucket->bu_blocks; i++)
                  memset(bucket_block(t_bucket, i), 0, blocksize);

            xh = bucket_xh(t_bucket);
            xh->xh_free_start = cpu_to_le16(blocksize);
            xh->xh_entries[0].xe_name_hash = xe->xe_name_hash;
            le32_add_cpu(&xh->xh_entries[0].xe_name_hash, 1);

            goto set_num_buckets;
      }

      /* copy the whole bucket to the new first. */
      ocfs2_xattr_bucket_copy_data(t_bucket, s_bucket);

      /* update the new bucket. */
      xh = bucket_xh(t_bucket);

      /*
       * Calculate the total name/value len and xh_free_start for
       * the old bucket first.
       */
      name_offset = OCFS2_XATTR_BUCKET_SIZE;
      name_value_len = 0;
      for (i = 0; i < start; i++) {
            xe = &xh->xh_entries[i];
            xe_len = OCFS2_XATTR_SIZE(xe->xe_name_len);
            if (ocfs2_xattr_is_local(xe))
                  xe_len +=
                     OCFS2_XATTR_SIZE(le64_to_cpu(xe->xe_value_size));
            else
                  xe_len += OCFS2_XATTR_ROOT_SIZE;
            name_value_len += xe_len;
            if (le16_to_cpu(xe->xe_name_offset) < name_offset)
                  name_offset = le16_to_cpu(xe->xe_name_offset);
      }

      /*
       * Now begin the modification to the new bucket.
       *
       * In the new bucket, We just move the xattr entry to the beginning
       * and don't touch the name/value. So there will be some holes in the
       * bucket, and they will be removed when ocfs2_defrag_xattr_bucket is
       * called.
       */
      xe = &xh->xh_entries[start];
      len = sizeof(struct ocfs2_xattr_entry) * (count - start);
      mlog(0, "mv xattr entry len %d from %d to %d\n", len,
           (int)((char *)xe - (char *)xh),
           (int)((char *)xh->xh_entries - (char *)xh));
      memmove((char *)xh->xh_entries, (char *)xe, len);
      xe = &xh->xh_entries[count - start];
      len = sizeof(struct ocfs2_xattr_entry) * start;
      memset((char *)xe, 0, len);

      le16_add_cpu(&xh->xh_count, -start);
      le16_add_cpu(&xh->xh_name_value_len, -name_value_len);

      /* Calculate xh_free_start for the new bucket. */
      xh->xh_free_start = cpu_to_le16(OCFS2_XATTR_BUCKET_SIZE);
      for (i = 0; i < le16_to_cpu(xh->xh_count); i++) {
            xe = &xh->xh_entries[i];
            xe_len = OCFS2_XATTR_SIZE(xe->xe_name_len);
            if (ocfs2_xattr_is_local(xe))
                  xe_len +=
                     OCFS2_XATTR_SIZE(le64_to_cpu(xe->xe_value_size));
            else
                  xe_len += OCFS2_XATTR_ROOT_SIZE;
            if (le16_to_cpu(xe->xe_name_offset) <
                le16_to_cpu(xh->xh_free_start))
                  xh->xh_free_start = xe->xe_name_offset;
      }

set_num_buckets:
      /* set xh->xh_num_buckets for the new xh. */
      if (new_bucket_head)
            xh->xh_num_buckets = cpu_to_le16(1);
      else
            xh->xh_num_buckets = 0;

      ocfs2_xattr_bucket_journal_dirty(handle, t_bucket);

      /* store the first_hash of the new bucket. */
      if (first_hash)
            *first_hash = le32_to_cpu(xh->xh_entries[0].xe_name_hash);

      /*
       * Now only update the 1st block of the old bucket.  If we
       * just added a new empty bucket, there is no need to modify
       * it.
       */
      if (start == count)
            goto out;

      xh = bucket_xh(s_bucket);
      memset(&xh->xh_entries[start], 0,
             sizeof(struct ocfs2_xattr_entry) * (count - start));
      xh->xh_count = cpu_to_le16(start);
      xh->xh_free_start = cpu_to_le16(name_offset);
      xh->xh_name_value_len = cpu_to_le16(name_value_len);

      ocfs2_xattr_bucket_journal_dirty(handle, s_bucket);

out:
      ocfs2_xattr_bucket_free(s_bucket);
      ocfs2_xattr_bucket_free(t_bucket);

      return ret;
}

/*
 * Copy xattr from one bucket to another bucket.
 *
 * The caller must make sure that the journal transaction
 * has enough space for journaling.
 */
static int ocfs2_cp_xattr_bucket(struct inode *inode,
                         handle_t *handle,
                         u64 s_blkno,
                         u64 t_blkno,
                         int t_is_new)
{
      int ret;
      struct ocfs2_xattr_bucket *s_bucket = NULL, *t_bucket = NULL;

      BUG_ON(s_blkno == t_blkno);

      mlog(0, "cp bucket %llu to %llu, target is %d\n",
           (unsigned long long)s_blkno, (unsigned long long)t_blkno,
           t_is_new);

      s_bucket = ocfs2_xattr_bucket_new(inode);
      t_bucket = ocfs2_xattr_bucket_new(inode);
      if (!s_bucket || !t_bucket) {
            ret = -ENOMEM;
            mlog_errno(ret);
            goto out;
      }

      ret = ocfs2_read_xattr_bucket(s_bucket, s_blkno);
      if (ret)
            goto out;

      /*
       * Even if !t_is_new, we're overwriting t_bucket.  Thus,
       * there's no need to read it.
       */
      ret = ocfs2_init_xattr_bucket(t_bucket, t_blkno);
      if (ret)
            goto out;

      /*
       * Hey, if we're overwriting t_bucket, what difference does
       * ACCESS_CREATE vs ACCESS_WRITE make?  Well, if we allocated a new
       * cluster to fill, we came here from
       * ocfs2_mv_xattr_buckets(), and it is really new -
       * ACCESS_CREATE is required.  But we also might have moved data
       * out of t_bucket before extending back into it.
       * ocfs2_add_new_xattr_bucket() can do this - its call to
       * ocfs2_add_new_xattr_cluster() may have created a new extent
       * and copied out the end of the old extent.  Then it re-extends
       * the old extent back to create space for new xattrs.  That's
       * how we get here, and the bucket isn't really new.
       */
      ret = ocfs2_xattr_bucket_journal_access(handle, t_bucket,
                                    t_is_new ?
                                    OCFS2_JOURNAL_ACCESS_CREATE :
                                    OCFS2_JOURNAL_ACCESS_WRITE);
      if (ret)
            goto out;

      ocfs2_xattr_bucket_copy_data(t_bucket, s_bucket);
      ocfs2_xattr_bucket_journal_dirty(handle, t_bucket);

out:
      ocfs2_xattr_bucket_free(t_bucket);
      ocfs2_xattr_bucket_free(s_bucket);

      return ret;
}

/*
 * src_blk points to the start of an existing extent.  last_blk points to
 * last cluster in that extent.  to_blk points to a newly allocated
 * extent.  We copy the buckets from the cluster at last_blk to the new
 * extent.  If start_bucket is non-zero, we skip that many buckets before
 * we start copying.  The new extent's xh_num_buckets gets set to the
 * number of buckets we copied.  The old extent's xh_num_buckets shrinks
 * by the same amount.
 */
static int ocfs2_mv_xattr_buckets(struct inode *inode, handle_t *handle,
                          u64 src_blk, u64 last_blk, u64 to_blk,
                          unsigned int start_bucket,
                          u32 *first_hash)
{
      int i, ret, credits;
      struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
      int blks_per_bucket = ocfs2_blocks_per_xattr_bucket(inode->i_sb);
      int num_buckets = ocfs2_xattr_buckets_per_cluster(osb);
      struct ocfs2_xattr_bucket *old_first, *new_first;

      mlog(0, "mv xattrs from cluster %llu to %llu\n",
           (unsigned long long)last_blk, (unsigned long long)to_blk);

      BUG_ON(start_bucket >= num_buckets);
      if (start_bucket) {
            num_buckets -= start_bucket;
            last_blk += (start_bucket * blks_per_bucket);
      }

      /* The first bucket of the original extent */
      old_first = ocfs2_xattr_bucket_new(inode);
      /* The first bucket of the new extent */
      new_first = ocfs2_xattr_bucket_new(inode);
      if (!old_first || !new_first) {
            ret = -ENOMEM;
            mlog_errno(ret);
            goto out;
      }

      ret = ocfs2_read_xattr_bucket(old_first, src_blk);
      if (ret) {
            mlog_errno(ret);
            goto out;
      }

      /*
       * We need to update the first bucket of the old extent and all
       * the buckets going to the new extent.
       */
      credits = ((num_buckets + 1) * blks_per_bucket) +
            handle->h_buffer_credits;
      ret = ocfs2_extend_trans(handle, credits);
      if (ret) {
            mlog_errno(ret);
            goto out;
      }

      ret = ocfs2_xattr_bucket_journal_access(handle, old_first,
                                    OCFS2_JOURNAL_ACCESS_WRITE);
      if (ret) {
            mlog_errno(ret);
            goto out;
      }

      for (i = 0; i < num_buckets; i++) {
            ret = ocfs2_cp_xattr_bucket(inode, handle,
                                  last_blk + (i * blks_per_bucket),
                                  to_blk + (i * blks_per_bucket),
                                  1);
            if (ret) {
                  mlog_errno(ret);
                  goto out;
            }
      }

      /*
       * Get the new bucket ready before we dirty anything
       * (This actually shouldn't fail, because we already dirtied
       * it once in ocfs2_cp_xattr_bucket()).
       */
      ret = ocfs2_read_xattr_bucket(new_first, to_blk);
      if (ret) {
            mlog_errno(ret);
            goto out;
      }
      ret = ocfs2_xattr_bucket_journal_access(handle, new_first,
                                    OCFS2_JOURNAL_ACCESS_WRITE);
      if (ret) {
            mlog_errno(ret);
            goto out;
      }

      /* Now update the headers */
      le16_add_cpu(&bucket_xh(old_first)->xh_num_buckets, -num_buckets);
      ocfs2_xattr_bucket_journal_dirty(handle, old_first);

      bucket_xh(new_first)->xh_num_buckets = cpu_to_le16(num_buckets);
      ocfs2_xattr_bucket_journal_dirty(handle, new_first);

      if (first_hash)
            *first_hash = le32_to_cpu(bucket_xh(new_first)->xh_entries[0].xe_name_hash);

out:
      ocfs2_xattr_bucket_free(new_first);
      ocfs2_xattr_bucket_free(old_first);
      return ret;
}

/*
 * Move some xattrs in this cluster to the new cluster.
 * This function should only be called when bucket size == cluster size.
 * Otherwise ocfs2_mv_xattr_bucket_cross_cluster should be used instead.
 */
static int ocfs2_divide_xattr_cluster(struct inode *inode,
                              handle_t *handle,
                              u64 prev_blk,
                              u64 new_blk,
                              u32 *first_hash)
{
      u16 blk_per_bucket = ocfs2_blocks_per_xattr_bucket(inode->i_sb);
      int ret, credits = 2 * blk_per_bucket + handle->h_buffer_credits;

      BUG_ON(OCFS2_XATTR_BUCKET_SIZE < OCFS2_SB(inode->i_sb)->s_clustersize);

      ret = ocfs2_extend_trans(handle, credits);
      if (ret) {
            mlog_errno(ret);
            return ret;
      }

      /* Move half of the xattr in start_blk to the next bucket. */
      return  ocfs2_divide_xattr_bucket(inode, handle, prev_blk,
                                new_blk, first_hash, 1);
}

/*
 * Move some xattrs from the old cluster to the new one since they are not
 * contiguous in ocfs2 xattr tree.
 *
 * new_blk starts a new separate cluster, and we will move some xattrs from
 * prev_blk to it. v_start will be set as the first name hash value in this
 * new cluster so that it can be used as e_cpos during tree insertion and
 * don't collide with our original b-tree operations. first_bh and header_bh
 * will also be updated since they will be used in ocfs2_extend_xattr_bucket
 * to extend the insert bucket.
 *
 * The problem is how much xattr should we move to the new one and when should
 * we update first_bh and header_bh?
 * 1. If cluster size > bucket size, that means the previous cluster has more
 *    than 1 bucket, so just move half nums of bucket into the new cluster and
 *    update the first_bh and header_bh if the insert bucket has been moved
 *    to the new cluster.
 * 2. If cluster_size == bucket_size:
 *    a) If the previous extent rec has more than one cluster and the insert
 *       place isn't in the last cluster, copy the entire last cluster to the
 *       new one. This time, we don't need to upate the first_bh and header_bh
 *       since they will not be moved into the new cluster.
 *    b) Otherwise, move the bottom half of the xattrs in the last cluster into
 *       the new one. And we set the extend flag to zero if the insert place is
 *       moved into the new allocated cluster since no extend is needed.
 */
static int ocfs2_adjust_xattr_cross_cluster(struct inode *inode,
                                  handle_t *handle,
                                  struct ocfs2_xattr_bucket *first,
                                  struct ocfs2_xattr_bucket *target,
                                  u64 new_blk,
                                  u32 prev_clusters,
                                  u32 *v_start,
                                  int *extend)
{
      int ret;

      mlog(0, "adjust xattrs from cluster %llu len %u to %llu\n",
           (unsigned long long)bucket_blkno(first), prev_clusters,
           (unsigned long long)new_blk);

      if (ocfs2_xattr_buckets_per_cluster(OCFS2_SB(inode->i_sb)) > 1) {
            ret = ocfs2_mv_xattr_bucket_cross_cluster(inode,
                                            handle,
                                            first, target,
                                            new_blk,
                                            prev_clusters,
                                            v_start);
            if (ret)
                  mlog_errno(ret);
      } else {
            /* The start of the last cluster in the first extent */
            u64 last_blk = bucket_blkno(first) +
                  ((prev_clusters - 1) *
                   ocfs2_clusters_to_blocks(inode->i_sb, 1));

            if (prev_clusters > 1 && bucket_blkno(target) != last_blk) {
                  ret = ocfs2_mv_xattr_buckets(inode, handle,
                                         bucket_blkno(first),
                                         last_blk, new_blk, 0,
                                         v_start);
                  if (ret)
                        mlog_errno(ret);
            } else {
                  ret = ocfs2_divide_xattr_cluster(inode, handle,
                                           last_blk, new_blk,
                                           v_start);
                  if (ret)
                        mlog_errno(ret);

                  if ((bucket_blkno(target) == last_blk) && extend)
                        *extend = 0;
            }
      }

      return ret;
}

/*
 * Add a new cluster for xattr storage.
 *
 * If the new cluster is contiguous with the previous one, it will be
 * appended to the same extent record, and num_clusters will be updated.
 * If not, we will insert a new extent for it and move some xattrs in
 * the last cluster into the new allocated one.
 * We also need to limit the maximum size of a btree leaf, otherwise we'll
 * lose the benefits of hashing because we'll have to search large leaves.
 * So now the maximum size is OCFS2_MAX_XATTR_TREE_LEAF_SIZE(or clustersize,
 * if it's bigger).
 *
 * first_bh is the first block of the previous extent rec and header_bh
 * indicates the bucket we will insert the new xattrs. They will be updated
 * when the header_bh is moved into the new cluster.
 */
static int ocfs2_add_new_xattr_cluster(struct inode *inode,
                               struct buffer_head *root_bh,
                               struct ocfs2_xattr_bucket *first,
                               struct ocfs2_xattr_bucket *target,
                               u32 *num_clusters,
                               u32 prev_cpos,
                               int *extend,
                               struct ocfs2_xattr_set_ctxt *ctxt)
{
      int ret;
      u16 bpc = ocfs2_clusters_to_blocks(inode->i_sb, 1);
      u32 prev_clusters = *num_clusters;
      u32 clusters_to_add = 1, bit_off, num_bits, v_start = 0;
      u64 block;
      handle_t *handle = ctxt->handle;
      struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
      struct ocfs2_extent_tree et;

      mlog(0, "Add new xattr cluster for %llu, previous xattr hash = %u, "
           "previous xattr blkno = %llu\n",
           (unsigned long long)OCFS2_I(inode)->ip_blkno,
           prev_cpos, (unsigned long long)bucket_blkno(first));

      ocfs2_init_xattr_tree_extent_tree(&et, inode, root_bh);

      ret = ocfs2_journal_access_xb(handle, inode, root_bh,
                              OCFS2_JOURNAL_ACCESS_WRITE);
      if (ret < 0) {
            mlog_errno(ret);
            goto leave;
      }

      ret = __ocfs2_claim_clusters(osb, handle, ctxt->data_ac, 1,
                             clusters_to_add, &bit_off, &num_bits);
      if (ret < 0) {
            if (ret != -ENOSPC)
                  mlog_errno(ret);
            goto leave;
      }

      BUG_ON(num_bits > clusters_to_add);

      block = ocfs2_clusters_to_blocks(osb->sb, bit_off);
      mlog(0, "Allocating %u clusters at block %u for xattr in inode %llu\n",
           num_bits, bit_off, (unsigned long long)OCFS2_I(inode)->ip_blkno);

      if (bucket_blkno(first) + (prev_clusters * bpc) == block &&
          (prev_clusters + num_bits) << osb->s_clustersize_bits <=
           OCFS2_MAX_XATTR_TREE_LEAF_SIZE) {
            /*
             * If this cluster is contiguous with the old one and
             * adding this new cluster, we don't surpass the limit of
             * OCFS2_MAX_XATTR_TREE_LEAF_SIZE, cool. We will let it be
             * initialized and used like other buckets in the previous
             * cluster.
             * So add it as a contiguous one. The caller will handle
             * its init process.
             */
            v_start = prev_cpos + prev_clusters;
            *num_clusters = prev_clusters + num_bits;
            mlog(0, "Add contiguous %u clusters to previous extent rec.\n",
                 num_bits);
      } else {
            ret = ocfs2_adjust_xattr_cross_cluster(inode,
                                           handle,
                                           first,
                                           target,
                                           block,
                                           prev_clusters,
                                           &v_start,
                                           extend);
            if (ret) {
                  mlog_errno(ret);
                  goto leave;
            }
      }

      mlog(0, "Insert %u clusters at block %llu for xattr at %u\n",
           num_bits, (unsigned long long)block, v_start);
      ret = ocfs2_insert_extent(osb, handle, inode, &et, v_start, block,
                          num_bits, 0, ctxt->meta_ac);
      if (ret < 0) {
            mlog_errno(ret);
            goto leave;
      }

      ret = ocfs2_journal_dirty(handle, root_bh);
      if (ret < 0)
            mlog_errno(ret);

leave:
      return ret;
}

/*
 * We are given an extent.  'first' is the bucket at the very front of
 * the extent.  The extent has space for an additional bucket past
 * bucket_xh(first)->xh_num_buckets.  'target_blkno' is the block number
 * of the target bucket.  We wish to shift every bucket past the target
 * down one, filling in that additional space.  When we get back to the
 * target, we split the target between itself and the now-empty bucket
 * at target+1 (aka, target_blkno + blks_per_bucket).
 */
static int ocfs2_extend_xattr_bucket(struct inode *inode,
                             handle_t *handle,
                             struct ocfs2_xattr_bucket *first,
                             u64 target_blk,
                             u32 num_clusters)
{
      int ret, credits;
      struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
      u16 blk_per_bucket = ocfs2_blocks_per_xattr_bucket(inode->i_sb);
      u64 end_blk;
      u16 new_bucket = le16_to_cpu(bucket_xh(first)->xh_num_buckets);

      mlog(0, "extend xattr bucket in %llu, xattr extend rec starting "
           "from %llu, len = %u\n", (unsigned long long)target_blk,
           (unsigned long long)bucket_blkno(first), num_clusters);

      /* The extent must have room for an additional bucket */
      BUG_ON(new_bucket >=
             (num_clusters * ocfs2_xattr_buckets_per_cluster(osb)));

      /* end_blk points to the last existing bucket */
      end_blk = bucket_blkno(first) + ((new_bucket - 1) * blk_per_bucket);

      /*
       * end_blk is the start of the last existing bucket.
       * Thus, (end_blk - target_blk) covers the target bucket and
       * every bucket after it up to, but not including, the last
       * existing bucket.  Then we add the last existing bucket, the
       * new bucket, and the first bucket (3 * blk_per_bucket).
       */
      credits = (end_blk - target_blk) + (3 * blk_per_bucket) +
              handle->h_buffer_credits;
      ret = ocfs2_extend_trans(handle, credits);
      if (ret) {
            mlog_errno(ret);
            goto out;
      }

      ret = ocfs2_xattr_bucket_journal_access(handle, first,
                                    OCFS2_JOURNAL_ACCESS_WRITE);
      if (ret) {
            mlog_errno(ret);
            goto out;
      }

      while (end_blk != target_blk) {
            ret = ocfs2_cp_xattr_bucket(inode, handle, end_blk,
                                  end_blk + blk_per_bucket, 0);
            if (ret)
                  goto out;
            end_blk -= blk_per_bucket;
      }

      /* Move half of the xattr in target_blkno to the next bucket. */
      ret = ocfs2_divide_xattr_bucket(inode, handle, target_blk,
                              target_blk + blk_per_bucket, NULL, 0);

      le16_add_cpu(&bucket_xh(first)->xh_num_buckets, 1);
      ocfs2_xattr_bucket_journal_dirty(handle, first);

out:
      return ret;
}

/*
 * Add new xattr bucket in an extent record and adjust the buckets
 * accordingly.  xb_bh is the ocfs2_xattr_block, and target is the
 * bucket we want to insert into.
 *
 * In the easy case, we will move all the buckets after target down by
 * one. Half of target's xattrs will be moved to the next bucket.
 *
 * If current cluster is full, we'll allocate a new one.  This may not
 * be contiguous.  The underlying calls will make sure that there is
 * space for the insert, shifting buckets around if necessary.
 * 'target' may be moved by those calls.
 */
static int ocfs2_add_new_xattr_bucket(struct inode *inode,
                              struct buffer_head *xb_bh,
                              struct ocfs2_xattr_bucket *target,
                              struct ocfs2_xattr_set_ctxt *ctxt)
{
      struct ocfs2_xattr_block *xb =
                  (struct ocfs2_xattr_block *)xb_bh->b_data;
      struct ocfs2_xattr_tree_root *xb_root = &xb->xb_attrs.xb_root;
      struct ocfs2_extent_list *el = &xb_root->xt_list;
      u32 name_hash =
            le32_to_cpu(bucket_xh(target)->xh_entries[0].xe_name_hash);
      struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
      int ret, num_buckets, extend = 1;
      u64 p_blkno;
      u32 e_cpos, num_clusters;
      /* The bucket at the front of the extent */
      struct ocfs2_xattr_bucket *first;

      mlog(0, "Add new xattr bucket starting from %llu\n",
           (unsigned long long)bucket_blkno(target));

      /* The first bucket of the original extent */
      first = ocfs2_xattr_bucket_new(inode);
      if (!first) {
            ret = -ENOMEM;
            mlog_errno(ret);
            goto out;
      }

      ret = ocfs2_xattr_get_rec(inode, name_hash, &p_blkno, &e_cpos,
                          &num_clusters, el);
      if (ret) {
            mlog_errno(ret);
            goto out;
      }

      ret = ocfs2_read_xattr_bucket(first, p_blkno);
      if (ret) {
            mlog_errno(ret);
            goto out;
      }

      num_buckets = ocfs2_xattr_buckets_per_cluster(osb) * num_clusters;
      if (num_buckets == le16_to_cpu(bucket_xh(first)->xh_num_buckets)) {
            /*
             * This can move first+target if the target bucket moves
             * to the new extent.
             */
            ret = ocfs2_add_new_xattr_cluster(inode,
                                      xb_bh,
                                      first,
                                      target,
                                      &num_clusters,
                                      e_cpos,
                                      &extend,
                                      ctxt);
            if (ret) {
                  mlog_errno(ret);
                  goto out;
            }
      }

      if (extend) {
            ret = ocfs2_extend_xattr_bucket(inode,
                                    ctxt->handle,
                                    first,
                                    bucket_blkno(target),
                                    num_clusters);
            if (ret)
                  mlog_errno(ret);
      }

out:
      ocfs2_xattr_bucket_free(first);

      return ret;
}

static inline char *ocfs2_xattr_bucket_get_val(struct inode *inode,
                              struct ocfs2_xattr_bucket *bucket,
                              int offs)
{
      int block_off = offs >> inode->i_sb->s_blocksize_bits;

      offs = offs % inode->i_sb->s_blocksize;
      return bucket_block(bucket, block_off) + offs;
}

/*
 * Handle the normal xattr set, including replace, delete and new.
 *
 * Note: "local" indicates the real data's locality. So we can't
 * just its bucket locality by its length.
 */
static void ocfs2_xattr_set_entry_normal(struct inode *inode,
                               struct ocfs2_xattr_info *xi,
                               struct ocfs2_xattr_search *xs,
                               u32 name_hash,
                               int local)
{
      struct ocfs2_xattr_entry *last, *xe;
      int name_len = strlen(xi->name);
      struct ocfs2_xattr_header *xh = xs->header;
      u16 count = le16_to_cpu(xh->xh_count), start;
      size_t blocksize = inode->i_sb->s_blocksize;
      char *val;
      size_t offs, size, new_size;

      last = &xh->xh_entries[count];
      if (!xs->not_found) {
            xe = xs->here;
            offs = le16_to_cpu(xe->xe_name_offset);
            if (ocfs2_xattr_is_local(xe))
                  size = OCFS2_XATTR_SIZE(name_len) +
                  OCFS2_XATTR_SIZE(le64_to_cpu(xe->xe_value_size));
            else
                  size = OCFS2_XATTR_SIZE(name_len) +
                  OCFS2_XATTR_SIZE(OCFS2_XATTR_ROOT_SIZE);

            /*
             * If the new value will be stored outside, xi->value has been
             * initalized as an empty ocfs2_xattr_value_root, and the same
             * goes with xi->value_len, so we can set new_size safely here.
             * See ocfs2_xattr_set_in_bucket.
             */
            new_size = OCFS2_XATTR_SIZE(name_len) +
                     OCFS2_XATTR_SIZE(xi->value_len);

            le16_add_cpu(&xh->xh_name_value_len, -size);
            if (xi->value) {
                  if (new_size > size)
                        goto set_new_name_value;

                  /* Now replace the old value with new one. */
                  if (local)
                        xe->xe_value_size = cpu_to_le64(xi->value_len);
                  else
                        xe->xe_value_size = 0;

                  val = ocfs2_xattr_bucket_get_val(inode,
                                           xs->bucket, offs);
                  memset(val + OCFS2_XATTR_SIZE(name_len), 0,
                         size - OCFS2_XATTR_SIZE(name_len));
                  if (OCFS2_XATTR_SIZE(xi->value_len) > 0)
                        memcpy(val + OCFS2_XATTR_SIZE(name_len),
                               xi->value, xi->value_len);

                  le16_add_cpu(&xh->xh_name_value_len, new_size);
                  ocfs2_xattr_set_local(xe, local);
                  return;
            } else {
                  /*
                   * Remove the old entry if there is more than one.
                   * We don't remove the last entry so that we can
                   * use it to indicate the hash value of the empty
                   * bucket.
                   */
                  last -= 1;
                  le16_add_cpu(&xh->xh_count, -1);
                  if (xh->xh_count) {
                        memmove(xe, xe + 1,
                              (void *)last - (void *)xe);
                        memset(last, 0,
                               sizeof(struct ocfs2_xattr_entry));
                  } else
                        xh->xh_free_start =
                              cpu_to_le16(OCFS2_XATTR_BUCKET_SIZE);

                  return;
            }
      } else {
            /* find a new entry for insert. */
            int low = 0, high = count - 1, tmp;
            struct ocfs2_xattr_entry *tmp_xe;

            while (low <= high && count) {
                  tmp = (low + high) / 2;
                  tmp_xe = &xh->xh_entries[tmp];

                  if (name_hash > le32_to_cpu(tmp_xe->xe_name_hash))
                        low = tmp + 1;
                  else if (name_hash <
                         le32_to_cpu(tmp_xe->xe_name_hash))
                        high = tmp - 1;
                  else {
                        low = tmp;
                        break;
                  }
            }

            xe = &xh->xh_entries[low];
            if (low != count)
                  memmove(xe + 1, xe, (void *)last - (void *)xe);

            le16_add_cpu(&xh->xh_count, 1);
            memset(xe, 0, sizeof(struct ocfs2_xattr_entry));
            xe->xe_name_hash = cpu_to_le32(name_hash);
            xe->xe_name_len = name_len;
            ocfs2_xattr_set_type(xe, xi->name_index);
      }

set_new_name_value:
      /* Insert the new name+value. */
      size = OCFS2_XATTR_SIZE(name_len) + OCFS2_XATTR_SIZE(xi->value_len);

      /*
       * We must make sure that the name/value pair
       * exists in the same block.
       */
      offs = le16_to_cpu(xh->xh_free_start);
      start = offs - size;

      if (start >> inode->i_sb->s_blocksize_bits !=
          (offs - 1) >> inode->i_sb->s_blocksize_bits) {
            offs = offs - offs % blocksize;
            xh->xh_free_start = cpu_to_le16(offs);
      }

      val = ocfs2_xattr_bucket_get_val(inode, xs->bucket, offs - size);
      xe->xe_name_offset = cpu_to_le16(offs - size);

      memset(val, 0, size);
      memcpy(val, xi->name, name_len);
      memcpy(val + OCFS2_XATTR_SIZE(name_len), xi->value, xi->value_len);

      xe->xe_value_size = cpu_to_le64(xi->value_len);
      ocfs2_xattr_set_local(xe, local);
      xs->here = xe;
      le16_add_cpu(&xh->xh_free_start, -size);
      le16_add_cpu(&xh->xh_name_value_len, size);

      return;
}

/*
 * Set the xattr entry in the specified bucket.
 * The bucket is indicated by xs->bucket and it should have the enough
 * space for the xattr insertion.
 */
static int ocfs2_xattr_set_entry_in_bucket(struct inode *inode,
                                 handle_t *handle,
                                 struct ocfs2_xattr_info *xi,
                                 struct ocfs2_xattr_search *xs,
                                 u32 name_hash,
                                 int local)
{
      int ret;
      u64 blkno;

      mlog(0, "Set xattr entry len = %lu index = %d in bucket %llu\n",
           (unsigned long)xi->value_len, xi->name_index,
           (unsigned long long)bucket_blkno(xs->bucket));

      if (!xs->bucket->bu_bhs[1]) {
            blkno = bucket_blkno(xs->bucket);
            ocfs2_xattr_bucket_relse(xs->bucket);
            ret = ocfs2_read_xattr_bucket(xs->bucket, blkno);
            if (ret) {
                  mlog_errno(ret);
                  goto out;
            }
      }

      ret = ocfs2_xattr_bucket_journal_access(handle, xs->bucket,
                                    OCFS2_JOURNAL_ACCESS_WRITE);
      if (ret < 0) {
            mlog_errno(ret);
            goto out;
      }

      ocfs2_xattr_set_entry_normal(inode, xi, xs, name_hash, local);
      ocfs2_xattr_bucket_journal_dirty(handle, xs->bucket);

out:
      return ret;
}

/*
 * Truncate the specified xe_off entry in xattr bucket.
 * bucket is indicated by header_bh and len is the new length.
 * Both the ocfs2_xattr_value_root and the entry will be updated here.
 *
 * Copy the new updated xe and xe_value_root to new_xe and new_xv if needed.
 */
static int ocfs2_xattr_bucket_value_truncate(struct inode *inode,
                                   struct ocfs2_xattr_bucket *bucket,
                                   int xe_off,
                                   int len,
                                   struct ocfs2_xattr_set_ctxt *ctxt)
{
      int ret, offset;
      u64 value_blk;
      struct ocfs2_xattr_entry *xe;
      struct ocfs2_xattr_header *xh = bucket_xh(bucket);
      size_t blocksize = inode->i_sb->s_blocksize;
      struct ocfs2_xattr_value_buf vb = {
            .vb_access = ocfs2_journal_access,
      };

      xe = &xh->xh_entries[xe_off];

      BUG_ON(!xe || ocfs2_xattr_is_local(xe));

      offset = le16_to_cpu(xe->xe_name_offset) +
             OCFS2_XATTR_SIZE(xe->xe_name_len);

      value_blk = offset / blocksize;

      /* We don't allow ocfs2_xattr_value to be stored in different block. */
      BUG_ON(value_blk != (offset + OCFS2_XATTR_ROOT_SIZE - 1) / blocksize);

      vb.vb_bh = bucket->bu_bhs[value_blk];
      BUG_ON(!vb.vb_bh);

      vb.vb_xv = (struct ocfs2_xattr_value_root *)
            (vb.vb_bh->b_data + offset % blocksize);

      /*
       * From here on out we have to dirty the bucket.  The generic
       * value calls only modify one of the bucket's bhs, but we need
       * to send the bucket at once.  So if they error, they *could* have
       * modified something.  We have to assume they did, and dirty
       * the whole bucket.  This leaves us in a consistent state.
       */
      mlog(0, "truncate %u in xattr bucket %llu to %d bytes.\n",
           xe_off, (unsigned long long)bucket_blkno(bucket), len);
      ret = ocfs2_xattr_value_truncate(inode, &vb, len, ctxt);
      if (ret) {
            mlog_errno(ret);
            goto out;
      }

      ret = ocfs2_xattr_bucket_journal_access(ctxt->handle, bucket,
                                    OCFS2_JOURNAL_ACCESS_WRITE);
      if (ret) {
            mlog_errno(ret);
            goto out;
      }

      xe->xe_value_size = cpu_to_le64(len);

      ocfs2_xattr_bucket_journal_dirty(ctxt->handle, bucket);

out:
      return ret;
}

static int ocfs2_xattr_bucket_value_truncate_xs(struct inode *inode,
                              struct ocfs2_xattr_search *xs,
                              int len,
                              struct ocfs2_xattr_set_ctxt *ctxt)
{
      int ret, offset;
      struct ocfs2_xattr_entry *xe = xs->here;
      struct ocfs2_xattr_header *xh = (struct ocfs2_xattr_header *)xs->base;

      BUG_ON(!xs->bucket->bu_bhs[0] || !xe || ocfs2_xattr_is_local(xe));

      offset = xe - xh->xh_entries;
      ret = ocfs2_xattr_bucket_value_truncate(inode, xs->bucket,
                                    offset, len, ctxt);
      if (ret)
            mlog_errno(ret);

      return ret;
}

static int ocfs2_xattr_bucket_set_value_outside(struct inode *inode,
                                    handle_t *handle,
                                    struct ocfs2_xattr_search *xs,
                                    char *val,
                                    int value_len)
{
      int ret, offset, block_off;
      struct ocfs2_xattr_value_root *xv;
      struct ocfs2_xattr_entry *xe = xs->here;
      struct ocfs2_xattr_header *xh = bucket_xh(xs->bucket);
      void *base;

      BUG_ON(!xs->base || !xe || ocfs2_xattr_is_local(xe));

      ret = ocfs2_xattr_bucket_get_name_value(inode, xh,
                                    xe - xh->xh_entries,
                                    &block_off,
                                    &offset);
      if (ret) {
            mlog_errno(ret);
            goto out;
      }

      base = bucket_block(xs->bucket, block_off);
      xv = (struct ocfs2_xattr_value_root *)(base + offset +
             OCFS2_XATTR_SIZE(xe->xe_name_len));

      ret = __ocfs2_xattr_set_value_outside(inode, handle,
                                    xv, val, value_len);
      if (ret)
            mlog_errno(ret);
out:
      return ret;
}

static int ocfs2_rm_xattr_cluster(struct inode *inode,
                          struct buffer_head *root_bh,
                          u64 blkno,
                          u32 cpos,
                          u32 len)
{
      int ret;
      struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
      struct inode *tl_inode = osb->osb_tl_inode;
      handle_t *handle;
      struct ocfs2_xattr_block *xb =
                  (struct ocfs2_xattr_block *)root_bh->b_data;
      struct ocfs2_alloc_context *meta_ac = NULL;
      struct ocfs2_cached_dealloc_ctxt dealloc;
      struct ocfs2_extent_tree et;

      ocfs2_init_xattr_tree_extent_tree(&et, inode, root_bh);

      ocfs2_init_dealloc_ctxt(&dealloc);

      mlog(0, "rm xattr extent rec at %u len = %u, start from %llu\n",
           cpos, len, (unsigned long long)blkno);

      ocfs2_remove_xattr_clusters_from_cache(inode, blkno, len);

      ret = ocfs2_lock_allocators(inode, &et, 0, 1, NULL, &meta_ac);
      if (ret) {
            mlog_errno(ret);
            return ret;
      }

      mutex_lock(&tl_inode->i_mutex);

      if (ocfs2_truncate_log_needs_flush(osb)) {
            ret = __ocfs2_flush_truncate_log(osb);
            if (ret < 0) {
                  mlog_errno(ret);
                  goto out;
            }
      }

      handle = ocfs2_start_trans(osb, ocfs2_remove_extent_credits(osb->sb));
      if (IS_ERR(handle)) {
            ret = -ENOMEM;
            mlog_errno(ret);
            goto out;
      }

      ret = ocfs2_journal_access_xb(handle, inode, root_bh,
                              OCFS2_JOURNAL_ACCESS_WRITE);
      if (ret) {
            mlog_errno(ret);
            goto out_commit;
      }

      ret = ocfs2_remove_extent(inode, &et, cpos, len, handle, meta_ac,
                          &dealloc);
      if (ret) {
            mlog_errno(ret);
            goto out_commit;
      }

      le32_add_cpu(&xb->xb_attrs.xb_root.xt_clusters, -len);

      ret = ocfs2_journal_dirty(handle, root_bh);
      if (ret) {
            mlog_errno(ret);
            goto out_commit;
      }

      ret = ocfs2_truncate_log_append(osb, handle, blkno, len);
      if (ret)
            mlog_errno(ret);

out_commit:
      ocfs2_commit_trans(osb, handle);
out:
      ocfs2_schedule_truncate_log_flush(osb, 1);

      mutex_unlock(&tl_inode->i_mutex);

      if (meta_ac)
            ocfs2_free_alloc_context(meta_ac);

      ocfs2_run_deallocs(osb, &dealloc);

      return ret;
}

static void ocfs2_xattr_bucket_remove_xs(struct inode *inode,
                               handle_t *handle,
                               struct ocfs2_xattr_search *xs)
{
      struct ocfs2_xattr_header *xh = bucket_xh(xs->bucket);
      struct ocfs2_xattr_entry *last = &xh->xh_entries[
                                    le16_to_cpu(xh->xh_count) - 1];
      int ret = 0;

      ret = ocfs2_xattr_bucket_journal_access(handle, xs->bucket,
                                    OCFS2_JOURNAL_ACCESS_WRITE);
      if (ret) {
            mlog_errno(ret);
            return;
      }

      /* Remove the old entry. */
      memmove(xs->here, xs->here + 1,
            (void *)last - (void *)xs->here);
      memset(last, 0, sizeof(struct ocfs2_xattr_entry));
      le16_add_cpu(&xh->xh_count, -1);

      ocfs2_xattr_bucket_journal_dirty(handle, xs->bucket);
}

/*
 * Set the xattr name/value in the bucket specified in xs.
 *
 * As the new value in xi may be stored in the bucket or in an outside cluster,
 * we divide the whole process into 3 steps:
 * 1. insert name/value in the bucket(ocfs2_xattr_set_entry_in_bucket)
 * 2. truncate of the outside cluster(ocfs2_xattr_bucket_value_truncate_xs)
 * 3. Set the value to the outside cluster(ocfs2_xattr_bucket_set_value_outside)
 * 4. If the clusters for the new outside value can't be allocated, we need
 *    to free the xattr we allocated in set.
 */
static int ocfs2_xattr_set_in_bucket(struct inode *inode,
                             struct ocfs2_xattr_info *xi,
                             struct ocfs2_xattr_search *xs,
                             struct ocfs2_xattr_set_ctxt *ctxt)
{
      int ret, local = 1;
      size_t value_len;
      char *val = (char *)xi->value;
      struct ocfs2_xattr_entry *xe = xs->here;
      u32 name_hash = ocfs2_xattr_name_hash(inode, xi->name,
                                    strlen(xi->name));

      if (!xs->not_found && !ocfs2_xattr_is_local(xe)) {
            /*
             * We need to truncate the xattr storage first.
             *
             * If both the old and new value are stored to
             * outside block, we only need to truncate
             * the storage and then set the value outside.
             *
             * If the new value should be stored within block,
             * we should free all the outside block first and
             * the modification to the xattr block will be done
             * by following steps.
             */
            if (xi->value_len > OCFS2_XATTR_INLINE_SIZE)
                  value_len = xi->value_len;
            else
                  value_len = 0;

            ret = ocfs2_xattr_bucket_value_truncate_xs(inode, xs,
                                             value_len,
                                             ctxt);
            if (ret)
                  goto out;

            if (value_len)
                  goto set_value_outside;
      }

      value_len = xi->value_len;
      /* So we have to handle the inside block change now. */
      if (value_len > OCFS2_XATTR_INLINE_SIZE) {
            /*
             * If the new value will be stored outside of block,
             * initalize a new empty value root and insert it first.
             */
            local = 0;
            xi->value = &def_xv;
            xi->value_len = OCFS2_XATTR_ROOT_SIZE;
      }

      ret = ocfs2_xattr_set_entry_in_bucket(inode, ctxt->handle, xi, xs,
                                    name_hash, local);
      if (ret) {
            mlog_errno(ret);
            goto out;
      }

      if (value_len <= OCFS2_XATTR_INLINE_SIZE)
            goto out;

      /* allocate the space now for the outside block storage. */
      ret = ocfs2_xattr_bucket_value_truncate_xs(inode, xs,
                                       value_len, ctxt);
      if (ret) {
            mlog_errno(ret);

            if (xs->not_found) {
                  /*
                   * We can't allocate enough clusters for outside
                   * storage and we have allocated xattr already,
                   * so need to remove it.
                   */
                  ocfs2_xattr_bucket_remove_xs(inode, ctxt->handle, xs);
            }
            goto out;
      }

set_value_outside:
      ret = ocfs2_xattr_bucket_set_value_outside(inode, ctxt->handle,
                                       xs, val, value_len);
out:
      return ret;
}

/*
 * check whether the xattr bucket is filled up with the same hash value.
 * If we want to insert the xattr with the same hash, return -ENOSPC.
 * If we want to insert a xattr with different hash value, go ahead
 * and ocfs2_divide_xattr_bucket will handle this.
 */
static int ocfs2_check_xattr_bucket_collision(struct inode *inode,
                                    struct ocfs2_xattr_bucket *bucket,
                                    const char *name)
{
      struct ocfs2_xattr_header *xh = bucket_xh(bucket);
      u32 name_hash = ocfs2_xattr_name_hash(inode, name, strlen(name));

      if (name_hash != le32_to_cpu(xh->xh_entries[0].xe_name_hash))
            return 0;

      if (xh->xh_entries[le16_to_cpu(xh->xh_count) - 1].xe_name_hash ==
          xh->xh_entries[0].xe_name_hash) {
            mlog(ML_ERROR, "Too much hash collision in xattr bucket %llu, "
                 "hash = %u\n",
                 (unsigned long long)bucket_blkno(bucket),
                 le32_to_cpu(xh->xh_entries[0].xe_name_hash));
            return -ENOSPC;
      }

      return 0;
}

static int ocfs2_xattr_set_entry_index_block(struct inode *inode,
                                   struct ocfs2_xattr_info *xi,
                                   struct ocfs2_xattr_search *xs,
                                   struct ocfs2_xattr_set_ctxt *ctxt)
{
      struct ocfs2_xattr_header *xh;
      struct ocfs2_xattr_entry *xe;
      u16 count, header_size, xh_free_start;
      int free, max_free, need, old;
      size_t value_size = 0, name_len = strlen(xi->name);
      size_t blocksize = inode->i_sb->s_blocksize;
      int ret, allocation = 0;

      mlog_entry("Set xattr %s in xattr index block\n", xi->name);

try_again:
      xh = xs->header;
      count = le16_to_cpu(xh->xh_count);
      xh_free_start = le16_to_cpu(xh->xh_free_start);
      header_size = sizeof(struct ocfs2_xattr_header) +
                  count * sizeof(struct ocfs2_xattr_entry);
      max_free = OCFS2_XATTR_BUCKET_SIZE - header_size -
            le16_to_cpu(xh->xh_name_value_len) - OCFS2_XATTR_HEADER_GAP;

      mlog_bug_on_msg(header_size > blocksize, "bucket %llu has header size "
                  "of %u which exceed block size\n",
                  (unsigned long long)bucket_blkno(xs->bucket),
                  header_size);

      if (xi->value && xi->value_len > OCFS2_XATTR_INLINE_SIZE)
            value_size = OCFS2_XATTR_ROOT_SIZE;
      else if (xi->value)
            value_size = OCFS2_XATTR_SIZE(xi->value_len);

      if (xs->not_found)
            need = sizeof(struct ocfs2_xattr_entry) +
                  OCFS2_XATTR_SIZE(name_len) + value_size;
      else {
            need = value_size + OCFS2_XATTR_SIZE(name_len);

            /*
             * We only replace the old value if the new length is smaller
             * than the old one. Otherwise we will allocate new space in the
             * bucket to store it.
             */
            xe = xs->here;
            if (ocfs2_xattr_is_local(xe))
                  old = OCFS2_XATTR_SIZE(le64_to_cpu(xe->xe_value_size));
            else
                  old = OCFS2_XATTR_SIZE(OCFS2_XATTR_ROOT_SIZE);

            if (old >= value_size)
                  need = 0;
      }

      free = xh_free_start - header_size - OCFS2_XATTR_HEADER_GAP;
      /*
       * We need to make sure the new name/value pair
       * can exist in the same block.
       */
      if (xh_free_start % blocksize < need)
            free -= xh_free_start % blocksize;

      mlog(0, "xs->not_found = %d, in xattr bucket %llu: free = %d, "
           "need = %d, max_free = %d, xh_free_start = %u, xh_name_value_len ="
           " %u\n", xs->not_found,
           (unsigned long long)bucket_blkno(xs->bucket),
           free, need, max_free, le16_to_cpu(xh->xh_free_start),
           le16_to_cpu(xh->xh_name_value_len));

      if (free < need ||
          (xs->not_found &&
           count == ocfs2_xattr_max_xe_in_bucket(inode->i_sb))) {
            if (need <= max_free &&
                count < ocfs2_xattr_max_xe_in_bucket(inode->i_sb)) {
                  /*
                   * We can create the space by defragment. Since only the
                   * name/value will be moved, the xe shouldn't be changed
                   * in xs.
                   */
                  ret = ocfs2_defrag_xattr_bucket(inode, ctxt->handle,
                                          xs->bucket);
                  if (ret) {
                        mlog_errno(ret);
                        goto out;
                  }

                  xh_free_start = le16_to_cpu(xh->xh_free_start);
                  free = xh_free_start - header_size
                        - OCFS2_XATTR_HEADER_GAP;
                  if (xh_free_start % blocksize < need)
                        free -= xh_free_start % blocksize;

                  if (free >= need)
                        goto xattr_set;

                  mlog(0, "Can't get enough space for xattr insert by "
                       "defragment. Need %u bytes, but we have %d, so "
                       "allocate new bucket for it.\n", need, free);
            }

            /*
             * We have to add new buckets or clusters and one
             * allocation should leave us enough space for insert.
             */
            BUG_ON(allocation);

            /*
             * We do not allow for overlapping ranges between buckets. And
             * the maximum number of collisions we will allow for then is
             * one bucket's worth, so check it here whether we need to
             * add a new bucket for the insert.
             */
            ret = ocfs2_check_xattr_bucket_collision(inode,
                                           xs->bucket,
                                           xi->name);
            if (ret) {
                  mlog_errno(ret);
                  goto out;
            }

            ret = ocfs2_add_new_xattr_bucket(inode,
                                     xs->xattr_bh,
                                     xs->bucket,
                                     ctxt);
            if (ret) {
                  mlog_errno(ret);
                  goto out;
            }

            /*
             * ocfs2_add_new_xattr_bucket() will have updated
             * xs->bucket if it moved, but it will not have updated
             * any of the other search fields.  Thus, we drop it and
             * re-search.  Everything should be cached, so it'll be
             * quick.
             */
            ocfs2_xattr_bucket_relse(xs->bucket);
            ret = ocfs2_xattr_index_block_find(inode, xs->xattr_bh,
                                       xi->name_index,
                                       xi->name, xs);
            if (ret && ret != -ENODATA)
                  goto out;
            xs->not_found = ret;
            allocation = 1;
            goto try_again;
      }

xattr_set:
      ret = ocfs2_xattr_set_in_bucket(inode, xi, xs, ctxt);
out:
      mlog_exit(ret);
      return ret;
}

static int ocfs2_delete_xattr_in_bucket(struct inode *inode,
                              struct ocfs2_xattr_bucket *bucket,
                              void *para)
{
      int ret = 0;
      struct ocfs2_xattr_header *xh = bucket_xh(bucket);
      u16 i;
      struct ocfs2_xattr_entry *xe;
      struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
      struct ocfs2_xattr_set_ctxt ctxt = {NULL, NULL,};
      int credits = ocfs2_remove_extent_credits(osb->sb) +
            ocfs2_blocks_per_xattr_bucket(inode->i_sb);


      ocfs2_init_dealloc_ctxt(&ctxt.dealloc);

      for (i = 0; i < le16_to_cpu(xh->xh_count); i++) {
            xe = &xh->xh_entries[i];
            if (ocfs2_xattr_is_local(xe))
                  continue;

            ctxt.handle = ocfs2_start_trans(osb, credits);
            if (IS_ERR(ctxt.handle)) {
                  ret = PTR_ERR(ctxt.handle);
                  mlog_errno(ret);
                  break;
            }

            ret = ocfs2_xattr_bucket_value_truncate(inode, bucket,
                                          i, 0, &ctxt);

            ocfs2_commit_trans(osb, ctxt.handle);
            if (ret) {
                  mlog_errno(ret);
                  break;
            }
      }

      ocfs2_schedule_truncate_log_flush(osb, 1);
      ocfs2_run_deallocs(osb, &ctxt.dealloc);
      return ret;
}

static int ocfs2_delete_xattr_index_block(struct inode *inode,
                                struct buffer_head *xb_bh)
{
      struct ocfs2_xattr_block *xb =
                  (struct ocfs2_xattr_block *)xb_bh->b_data;
      struct ocfs2_extent_list *el = &xb->xb_attrs.xb_root.xt_list;
      int ret = 0;
      u32 name_hash = UINT_MAX, e_cpos, num_clusters;
      u64 p_blkno;

      if (le16_to_cpu(el->l_next_free_rec) == 0)
            return 0;

      while (name_hash > 0) {
            ret = ocfs2_xattr_get_rec(inode, name_hash, &p_blkno,
                                &e_cpos, &num_clusters, el);
            if (ret) {
                  mlog_errno(ret);
                  goto out;
            }

            ret = ocfs2_iterate_xattr_buckets(inode, p_blkno, num_clusters,
                                      ocfs2_delete_xattr_in_bucket,
                                      NULL);
            if (ret) {
                  mlog_errno(ret);
                  goto out;
            }

            ret = ocfs2_rm_xattr_cluster(inode, xb_bh,
                                   p_blkno, e_cpos, num_clusters);
            if (ret) {
                  mlog_errno(ret);
                  break;
            }

            if (e_cpos == 0)
                  break;

            name_hash = e_cpos - 1;
      }

out:
      return ret;
}

/*
 * 'security' attributes support
 */
static size_t ocfs2_xattr_security_list(struct inode *inode, char *list,
                              size_t list_size, const char *name,
                              size_t name_len)
{
      const size_t prefix_len = XATTR_SECURITY_PREFIX_LEN;
      const size_t total_len = prefix_len + name_len + 1;

      if (list && total_len <= list_size) {
            memcpy(list, XATTR_SECURITY_PREFIX, prefix_len);
            memcpy(list + prefix_len, name, name_len);
            list[prefix_len + name_len] = '\0';
      }
      return total_len;
}

static int ocfs2_xattr_security_get(struct inode *inode, const char *name,
                            void *buffer, size_t size)
{
      if (strcmp(name, "") == 0)
            return -EINVAL;
      return ocfs2_xattr_get(inode, OCFS2_XATTR_INDEX_SECURITY, name,
                         buffer, size);
}

static int ocfs2_xattr_security_set(struct inode *inode, const char *name,
                            const void *value, size_t size, int flags)
{
      if (strcmp(name, "") == 0)
            return -EINVAL;

      return ocfs2_xattr_set(inode, OCFS2_XATTR_INDEX_SECURITY, name, value,
                         size, flags);
}

int ocfs2_init_security_get(struct inode *inode,
                      struct inode *dir,
                      struct ocfs2_security_xattr_info *si)
{
      /* check whether ocfs2 support feature xattr */
      if (!ocfs2_supports_xattr(OCFS2_SB(dir->i_sb)))
            return -EOPNOTSUPP;
      return security_inode_init_security(inode, dir, &si->name, &si->value,
                                  &si->value_len);
}

int ocfs2_init_security_set(handle_t *handle,
                      struct inode *inode,
                      struct buffer_head *di_bh,
                      struct ocfs2_security_xattr_info *si,
                      struct ocfs2_alloc_context *xattr_ac,
                      struct ocfs2_alloc_context *data_ac)
{
      return ocfs2_xattr_set_handle(handle, inode, di_bh,
                             OCFS2_XATTR_INDEX_SECURITY,
                             si->name, si->value, si->value_len, 0,
                             xattr_ac, data_ac);
}

struct xattr_handler ocfs2_xattr_security_handler = {
      .prefix     = XATTR_SECURITY_PREFIX,
      .list = ocfs2_xattr_security_list,
      .get  = ocfs2_xattr_security_get,
      .set  = ocfs2_xattr_security_set,
};

/*
 * 'trusted' attributes support
 */
static size_t ocfs2_xattr_trusted_list(struct inode *inode, char *list,
                               size_t list_size, const char *name,
                               size_t name_len)
{
      const size_t prefix_len = XATTR_TRUSTED_PREFIX_LEN;
      const size_t total_len = prefix_len + name_len + 1;

      if (list && total_len <= list_size) {
            memcpy(list, XATTR_TRUSTED_PREFIX, prefix_len);
            memcpy(list + prefix_len, name, name_len);
            list[prefix_len + name_len] = '\0';
      }
      return total_len;
}

static int ocfs2_xattr_trusted_get(struct inode *inode, const char *name,
                           void *buffer, size_t size)
{
      if (strcmp(name, "") == 0)
            return -EINVAL;
      return ocfs2_xattr_get(inode, OCFS2_XATTR_INDEX_TRUSTED, name,
                         buffer, size);
}

static int ocfs2_xattr_trusted_set(struct inode *inode, const char *name,
                           const void *value, size_t size, int flags)
{
      if (strcmp(name, "") == 0)
            return -EINVAL;

      return ocfs2_xattr_set(inode, OCFS2_XATTR_INDEX_TRUSTED, name, value,
                         size, flags);
}

struct xattr_handler ocfs2_xattr_trusted_handler = {
      .prefix     = XATTR_TRUSTED_PREFIX,
      .list = ocfs2_xattr_trusted_list,
      .get  = ocfs2_xattr_trusted_get,
      .set  = ocfs2_xattr_trusted_set,
};

/*
 * 'user' attributes support
 */
static size_t ocfs2_xattr_user_list(struct inode *inode, char *list,
                            size_t list_size, const char *name,
                            size_t name_len)
{
      const size_t prefix_len = XATTR_USER_PREFIX_LEN;
      const size_t total_len = prefix_len + name_len + 1;
      struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);

      if (osb->s_mount_opt & OCFS2_MOUNT_NOUSERXATTR)
            return 0;

      if (list && total_len <= list_size) {
            memcpy(list, XATTR_USER_PREFIX, prefix_len);
            memcpy(list + prefix_len, name, name_len);
            list[prefix_len + name_len] = '\0';
      }
      return total_len;
}

static int ocfs2_xattr_user_get(struct inode *inode, const char *name,
                        void *buffer, size_t size)
{
      struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);

      if (strcmp(name, "") == 0)
            return -EINVAL;
      if (osb->s_mount_opt & OCFS2_MOUNT_NOUSERXATTR)
            return -EOPNOTSUPP;
      return ocfs2_xattr_get(inode, OCFS2_XATTR_INDEX_USER, name,
                         buffer, size);
}

static int ocfs2_xattr_user_set(struct inode *inode, const char *name,
                        const void *value, size_t size, int flags)
{
      struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);

      if (strcmp(name, "") == 0)
            return -EINVAL;
      if (osb->s_mount_opt & OCFS2_MOUNT_NOUSERXATTR)
            return -EOPNOTSUPP;

      return ocfs2_xattr_set(inode, OCFS2_XATTR_INDEX_USER, name, value,
                         size, flags);
}

struct xattr_handler ocfs2_xattr_user_handler = {
      .prefix     = XATTR_USER_PREFIX,
      .list = ocfs2_xattr_user_list,
      .get  = ocfs2_xattr_user_get,
      .set  = ocfs2_xattr_user_set,
};

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