[Ocfs2-tools-devel] [PATCH 5/7] libocfs2: add set and get xattr operations

Tiger Yang tiger.yang at oracle.com
Tue Oct 20 01:42:01 PDT 2009


This patch implement set and get xattr in libocfs2,
they are very similiar with the functions in kernel.

Signed-off-by: Tiger Yang <tiger.yang at oracle.com>
---
 include/ocfs2/ocfs2.h |    7 +
 libocfs2/ocfs2_err.et |    6 +
 libocfs2/xattr.c      | 2655 ++++++++++++++++++++++++++++++++++++++++++++++++-
 libocfs2/xattr.h      |   15 +
 4 files changed, 2678 insertions(+), 5 deletions(-)

diff --git a/include/ocfs2/ocfs2.h b/include/ocfs2/ocfs2.h
index 046a2f2..20d391e 100644
--- a/include/ocfs2/ocfs2.h
+++ b/include/ocfs2/ocfs2.h
@@ -1331,5 +1331,12 @@ errcode_t ocfs2_xattr_get_clusters(ocfs2_cached_inode *cinode,
 errcode_t ocfs2_xattr_value_shrink(ocfs2_filesys *fs,
 				   struct ocfs2_xattr_value_root *xv,
 				   uint32_t new_clusters);
+const char *ocfs2_xattr_get_prefix(int name_index);
+errcode_t ocfs2_xattr_get(ocfs2_cached_inode *ci, const char *name,
+			  char *buf, size_t count, size_t *got);
+errcode_t ocfs2_xattr_set(ocfs2_cached_inode *ci,
+			  const char *name,
+			  const char *buf,
+			  size_t count);
 
 #endif  /* _FILESYS_H */
diff --git a/libocfs2/ocfs2_err.et b/libocfs2/ocfs2_err.et
index 13b03c4..9566b5c 100644
--- a/libocfs2/ocfs2_err.et
+++ b/libocfs2/ocfs2_err.et
@@ -180,6 +180,12 @@ ec	OCFS2_ET_BAD_DIR_BLOCK_MAGIC,
 ec	OCFS2_ET_BAD_XATTR_BLOCK_MAGIC,
 	"Bad magic number in xattr block"
 
+ec	OCFS2_ET_XATTR_NODATA,
+	"No xattr data available"
+
+ec	OCFS2_ET_XATTR_NOSPC,
+	"No space left for xattr"
+
 ec	OCFS2_ET_UNKNOWN_FEATURE,
 	"Unknown feature"
 
diff --git a/libocfs2/xattr.c b/libocfs2/xattr.c
index 0c1c68e..d3285c8 100644
--- a/libocfs2/xattr.c
+++ b/libocfs2/xattr.c
@@ -14,18 +14,82 @@
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * General Public License for more details.
  */
+#include <stdlib.h>
 #include <string.h>
 #include <inttypes.h>
+#include <assert.h>
 
 #include "ocfs2/byteorder.h"
 #include "ocfs2/ocfs2.h"
+#include "xattr.h"
+#include "extent_tree.h"
+
+#define DEBUG_XATTR 1
+#ifdef DEBUG_XATTR
+#define DEBUG(...) printf(__VA_ARGS__)
+#define ASSERT assert
+#else
+#define DEBUG(...)
+#define ASSERT
+#endif
+
+#define OCFS2_XATTR_ROOT_SIZE	(sizeof(struct ocfs2_xattr_def_value_root))
+#define OCFS2_XATTR_HEADER_GAP	4
+#define HEADER_SIZE     (sizeof(struct ocfs2_xattr_header))
+#define ENTRY_SIZE      (sizeof(struct ocfs2_xattr_entry))
+#define bucket_xh(_b)	((struct ocfs2_xattr_header *)(_b)->xb_buf)
 
 struct ocfs2_xattr_def_value_root {
 	struct ocfs2_xattr_value_root   xv;
 	struct ocfs2_extent_rec         er;
 };
 
-#define OCFS2_XATTR_ROOT_SIZE	(sizeof(struct ocfs2_xattr_def_value_root))
+static struct ocfs2_xattr_def_value_root def_xv = {
+	.xv.xr_list.l_count = 1,
+};
+
+static const char *ocfs2_xattr_prefix[OCFS2_XATTR_MAX] = {
+	[OCFS2_XATTR_INDEX_USER]	= "user.",
+	[OCFS2_XATTR_INDEX_POSIX_ACL_ACCESS]
+					= "system.posix_acl_access",
+	[OCFS2_XATTR_INDEX_POSIX_ACL_DEFAULT]
+					= "system.posix_acl_default",
+	[OCFS2_XATTR_INDEX_TRUSTED]	= "trusted.",
+	[OCFS2_XATTR_INDEX_SECURITY]	= "security.",
+};
+
+struct ocfs2_xattr_info {
+	int name_index;
+	const char *name;
+	const char *value;
+	size_t value_len;
+};
+
+struct ocfs2_xattr_buf {
+	char *xb_buf;
+	uint64_t xb_blkno;
+};
+
+struct ocfs2_xattr_search {
+	/*
+	 * blkbuf point to the block buffer which contains EAs.
+	 * this block may point to a inode block,
+	 * a xattr block or the first block of a bucket.
+	 */
+	char *blkbuf;
+	uint64_t blkno;
+	struct ocfs2_xattr_header *header;
+	struct ocfs2_xattr_entry *here;
+	char *base;
+	char *end;
+	int32_t not_found;
+};
+
+struct ocfs2_xattr_search_info {
+	struct ocfs2_xattr_search *xi_inode;
+	struct ocfs2_xattr_search *xi_block;
+	struct ocfs2_xattr_search *xi_bucket;
+};
 
 uint32_t ocfs2_xattr_uuid_hash(unsigned char *uuid)
 {
@@ -40,8 +104,8 @@ uint32_t ocfs2_xattr_uuid_hash(unsigned char *uuid)
 }
 
 uint32_t ocfs2_xattr_name_hash(uint32_t uuid_hash,
-			 const char *name,
-			 int name_len)
+			       const char *name,
+			       int name_len)
 {
 	/* Get hash value of uuid from super block */
 	uint32_t hash = uuid_hash;
@@ -67,6 +131,14 @@ uint16_t ocfs2_blocks_per_xattr_bucket(ocfs2_filesys *fs)
 	return OCFS2_XATTR_BUCKET_SIZE / fs->fs_blocksize;
 }
 
+static inline uint16_t ocfs2_xattr_max_xe_in_bucket(ocfs2_filesys *fs)
+{
+	uint16_t len = fs->fs_blocksize -
+		 offsetof(struct ocfs2_xattr_header, xh_entries);
+
+	return len / ENTRY_SIZE;
+}
+
 static void ocfs2_swap_xattr_entry(struct ocfs2_xattr_entry *xe)
 {
 	xe->xe_name_hash	= bswap_32(xe->xe_name_hash);
@@ -387,8 +459,7 @@ errcode_t ocfs2_xattr_get_rec(ocfs2_filesys *fs,
 	if (e_cpos)
 		*e_cpos = rec->e_cpos;
 out:
-	if (eb_buf)
-		ocfs2_free(&eb_buf);
+	ocfs2_free(&eb_buf);
 	return ret;
 }
 
@@ -505,3 +576,2577 @@ errcode_t ocfs2_write_xattr_bucket(ocfs2_filesys *fs,
 	ocfs2_free(&bucket);
 	return ret;
 }
+
+const char *ocfs2_xattr_get_prefix(int name_index)
+{
+	if (name_index > 0 && name_index < OCFS2_XATTR_MAX)
+		return ocfs2_xattr_prefix[name_index];
+	else
+		return NULL;
+}
+
+static int ocfs2_xattr_has_space_inline(ocfs2_cached_inode *ci,
+					struct ocfs2_dinode *di)
+{
+	int free = 0;
+	ocfs2_filesys *fs = ci->ci_fs;
+	uint32_t xattrsize = OCFS2_RAW_SB(fs->fs_super)->s_xattr_inline_size;
+
+	if (xattrsize < OCFS2_MIN_XATTR_INLINE_SIZE)
+		return 0;
+
+	if (di->i_dyn_features & OCFS2_INLINE_DATA_FL) {
+		struct ocfs2_inline_data *idata = &di->id2.i_data;
+		free = idata->id_count - di->i_size;
+	} else if (S_ISLNK(di->i_mode) && di->i_clusters == 0) {
+		free = ocfs2_fast_symlink_chars(fs->fs_blocksize) - di->i_size;
+	} else {
+		struct ocfs2_extent_list *el = &di->id2.i_list;
+		free = (el->l_count - el->l_next_free_rec) *
+			sizeof(struct ocfs2_extent_rec);
+	}
+	if (free >= xattrsize)
+		return 1;
+
+	return 0;
+}
+
+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 OCFS2_ET_INVALID_ARGUMENT;
+
+	name_len = strlen(name);
+	entry = xs->here;
+	for (i = 0; i < 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 + entry->xe_name_offset,
+				     name_len);
+		if (cmp == 0)
+			break;
+		entry += 1;
+	}
+	xs->here = entry;
+
+	return cmp ? OCFS2_ET_XATTR_NODATA : 0;
+}
+
+static errcode_t __ocfs2_xattr_set_value_outside(ocfs2_cached_inode *ci,
+					struct ocfs2_xattr_value_root *xv,
+					char *blkbuf,
+					uint64_t blkno,
+					const char *value,
+					int value_len)
+{
+	errcode_t ret = 0;
+	int cp_len;
+	ocfs2_filesys *fs = ci->ci_fs;
+	uint16_t blocksize = fs->fs_blocksize;
+	uint16_t clustersize = fs->fs_clustersize;
+	uint32_t p_cluster, num_clusters;
+	uint32_t cpos = 0;
+	uint32_t clusters = ocfs2_clusters_in_bytes(fs, value_len);
+	uint64_t p_blkno;
+	char *blks = NULL;
+	uint32_t max_blocks = OCFS2_MAX_XATTR_TREE_LEAF_SIZE / blocksize;
+
+	ASSERT(clusters <= xv->xr_clusters);
+
+	ret = ocfs2_malloc_blocks(fs->fs_io, max_blocks, &blks);
+	if (ret)
+		return ret;
+	memset(blks, 0, OCFS2_MAX_XATTR_TREE_LEAF_SIZE);
+
+	while (cpos < clusters) {
+		ret = ocfs2_xattr_get_clusters(ci, cpos, &p_cluster,
+					       &num_clusters,
+					       &xv->xr_list,
+					       blkno, blkbuf);
+		if (ret)
+			goto out;
+
+		p_blkno = ocfs2_clusters_to_blocks(fs, p_cluster);
+		cp_len = value_len > num_clusters * clustersize ?
+			 num_clusters * clustersize : value_len;
+		memcpy(blks, value, cp_len);
+		ret = io_write_block(fs->fs_io, p_blkno,
+				     (cp_len + blocksize - 1) / blocksize,
+				     blks);
+		if (ret)
+			goto out;
+		value_len -= cp_len;
+		value += cp_len;
+		blks += cp_len;
+		cpos += num_clusters;
+	}
+out:
+	ocfs2_free(&blks);
+
+	return ret;
+}
+
+static errcode_t ocfs2_xattr_value_truncate(ocfs2_cached_inode *ci,
+					    struct ocfs2_xattr_value_root *xv,
+					    char *blkbuf,
+					    uint64_t blkno,
+					    int len)
+{
+	errcode_t ret;
+	ocfs2_filesys *fs = ci->ci_fs;
+	uint32_t new_clusters = ocfs2_clusters_in_bytes(fs, len);
+	uint32_t old_clusters = xv->xr_clusters;
+
+	if (new_clusters == old_clusters)
+		return 0;
+
+	if (new_clusters > old_clusters) {
+		struct ocfs2_extent_tree et;
+
+		ocfs2_init_xattr_value_extent_tree(&et, fs, blkbuf, blkno, xv);
+		ret = ocfs2_tree_extend_allocation(fs,
+						   new_clusters - old_clusters,
+						   &et);
+	} else
+		ret = ocfs2_xattr_value_shrink(fs, xv, new_clusters);
+
+	return ret;
+}
+
+/*
+ * ocfs2_xattr_hash_entry()
+ *
+ * Compute the hash of an extended attribute.
+ */
+static void ocfs2_xattr_hash_entry(ocfs2_cached_inode *ci,
+				   struct ocfs2_xattr_header *header,
+				   struct ocfs2_xattr_entry *entry)
+{
+	uint32_t hash = 0;
+	uint32_t uuid_hash = ci->ci_fs->fs_super->id2.i_super.s_uuid_hash;
+	char *name = (char *)header + entry->xe_name_offset;
+
+	hash = ocfs2_xattr_name_hash(uuid_hash, name, entry->xe_name_len);
+	entry->xe_name_hash = hash;
+
+	return;
+}
+
+static inline void ocfs2_xattr_update_entry(ocfs2_cached_inode *ci,
+					    struct ocfs2_xattr_info *xi,
+					    struct ocfs2_xattr_search *xs,
+					    size_t offs)
+{
+	xs->here->xe_name_offset = offs;
+	xs->here->xe_value_size = 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(ci, xs->header, xs->here);
+}
+
+
+static errcode_t ocfs2_xattr_set_value_outside(ocfs2_cached_inode *ci,
+					       struct ocfs2_xattr_info *xi,
+					       struct ocfs2_xattr_search *xs,
+					       size_t offs)
+{
+	size_t name_len = strlen(xi->name);
+	char *val = xs->base + offs;
+	struct ocfs2_xattr_value_root *xv = NULL;
+	size_t size = OCFS2_XATTR_SIZE(name_len) + OCFS2_XATTR_ROOT_SIZE;
+	errcode_t 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 = 1;
+	xv->xr_list.l_next_free_rec = 0;
+
+	ret = ocfs2_xattr_value_truncate(ci, xv, xs->blkbuf, xs->blkno,
+					 xi->value_len);
+	if (ret)
+		return ret;
+
+	ocfs2_xattr_update_entry(ci, xi, xs, offs);
+
+	ret = __ocfs2_xattr_set_value_outside(ci, xv, xs->blkbuf, xs->blkno,
+					      xi->value, xi->value_len);
+	return ret;
+}
+
+/*
+ * ocfs2_xattr_set_entry_local()
+ *
+ * Set, replace or remove extended attribute in local.
+ */
+static void ocfs2_xattr_set_entry_local(ocfs2_cached_inode *ci,
+					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. */
+		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 = xs->here->xe_name_offset;
+		val = xs->base + offs;
+
+		if (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(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 = 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 < xs->header->xh_count; i++) {
+			size_t o = last->xe_name_offset;
+
+			if (o < offs)
+				last->xe_name_offset = 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, ENTRY_SIZE);
+			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 = 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 = xi->value_len;
+		ocfs2_xattr_set_local(xs->here, 1);
+		ocfs2_xattr_hash_entry(ci, xs->header, xs->here);
+	}
+
+	return;
+}
+
+static errcode_t ocfs2_xattr_set_entry(ocfs2_cached_inode *ci,
+				       struct ocfs2_xattr_info *xi,
+				       struct ocfs2_xattr_search *xs,
+				       int flag)
+{
+	errcode_t ret = 0;
+	ocfs2_filesys *fs = ci->ci_fs;
+	struct ocfs2_dinode *di = ci->ci_inode;
+	struct ocfs2_xattr_entry *last;
+	size_t min_offs = xs->end - xs->base;
+	size_t name_len = strlen(xi->name);
+	size_t size_l = 0;
+	int free, i;
+	struct ocfs2_xattr_info xi_l = {
+		.name_index = xi->name_index,
+		.name = xi->name,
+		.value = xi->value,
+		.value_len = xi->value_len,
+	};
+
+	/* Compute min_offs, last and free space. */
+	last = xs->header->xh_entries;
+
+	for (i = 0 ; i < xs->header->xh_count; i++) {
+		size_t offs = last->xe_name_offset;
+		if (offs < min_offs)
+			min_offs = offs;
+		last += 1;
+	}
+
+	free = min_offs - ((char *)last - xs->base) - OCFS2_XATTR_HEADER_GAP;
+	if (free < 0)
+		return OCFS2_ET_IO;
+
+	if (!xs->not_found) {
+		size_t size = 0;
+		if (ocfs2_xattr_is_local(xs->here))
+			size = OCFS2_XATTR_SIZE(name_len) +
+			OCFS2_XATTR_SIZE(xs->here->xe_value_size);
+		else
+			size = OCFS2_XATTR_SIZE(name_len) +
+				OCFS2_XATTR_ROOT_SIZE;
+		free += (size + ENTRY_SIZE);
+	}
+
+	/* Check free space in inode or block */
+	if (xi->value && xi->value_len > OCFS2_XATTR_INLINE_SIZE) {
+		if (free < ENTRY_SIZE + OCFS2_XATTR_SIZE(name_len) +
+			   OCFS2_XATTR_ROOT_SIZE) {
+			ret = OCFS2_ET_XATTR_NOSPC;
+			goto out;
+		}
+		size_l = OCFS2_XATTR_SIZE(name_len) + OCFS2_XATTR_ROOT_SIZE;
+		xi_l.value = (const char *)&def_xv;
+		xi_l.value_len = OCFS2_XATTR_ROOT_SIZE;
+	} else if (xi->value) {
+		if (free < ENTRY_SIZE + OCFS2_XATTR_SIZE(name_len) +
+			   OCFS2_XATTR_SIZE(xi->value_len)) {
+			ret = OCFS2_ET_XATTR_NOSPC;
+			goto out;
+		}
+	}
+
+	if (!xs->not_found) {
+		/* For existing extended attribute */
+		size_t size = OCFS2_XATTR_SIZE(name_len) +
+			OCFS2_XATTR_SIZE(xs->here->xe_value_size);
+		size_t offs = 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(ci, xi, xs,
+							    offs);
+			goto out;
+		} else if (!ocfs2_xattr_is_local(xs->here)) {
+			/* For existing xattr which has value outside */
+			struct ocfs2_xattr_value_root *xv;
+
+			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(ci,
+								 xv,
+								 xs->blkbuf,
+								 xs->blkno,
+								 xi->value_len);
+				if (ret < 0)
+					goto out;
+
+				ocfs2_xattr_update_entry(ci, xi, xs, offs);
+
+				ret = __ocfs2_xattr_set_value_outside(ci,
+								xv,
+								xs->blkbuf,
+								xs->blkno,
+								xi->value,
+								xi->value_len);
+				goto out;
+			} else {
+				/*
+				 * If new value need set in local,
+				 * just trucate old value to zero.
+				 */
+				 ret = ocfs2_xattr_value_truncate(ci,
+								  xv,
+								  xs->blkbuf,
+								  xs->blkno,
+								  0);
+			}
+		}
+	}
+	/*
+	 * 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(ci, &xi_l, xs, last, min_offs);
+
+
+	if (!(di->i_dyn_features & OCFS2_INLINE_XATTR_FL) &&
+	    (flag & OCFS2_INLINE_XATTR_FL)) {
+		uint32_t xattrsize = OCFS2_RAW_SB(fs->fs_super)->
+				     s_xattr_inline_size;
+
+		/*
+		 * Adjust extent record count or inline data size
+		 * to reserve space for extended attribute.
+		 */
+		if (di->i_dyn_features & OCFS2_INLINE_DATA_FL) {
+			struct ocfs2_inline_data *idata = &di->id2.i_data;
+			idata->id_count -= xattrsize;
+		} else if (!(S_ISLNK(di->i_mode) && di->i_clusters == 0)) {
+			struct ocfs2_extent_list *el = &di->id2.i_list;
+			el->l_count -= (xattrsize /
+					sizeof(struct ocfs2_extent_rec));
+		}
+		di->i_xattr_inline_size = xattrsize;
+	}
+	/* Update xattr flag */
+	di->i_dyn_features |= flag;
+
+	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 = xs->here->xe_name_offset;
+		ret = ocfs2_xattr_set_value_outside(ci, xi, xs, offs);
+		if (ret < 0) {
+			/*
+			 * If set value outside failed, we have to clean
+			 * the junk tree root we have already set in local.
+			 */
+			size_t name_len = strlen(xi->name);
+			void *val = xs->base + offs;
+			size_t size = OCFS2_XATTR_SIZE(name_len) +
+				      OCFS2_XATTR_ROOT_SIZE;
+			/* Decrease xattr count */
+			xs->header->xh_count -= 1;
+			/*
+			 * Remove the xattr entry and tree root
+			 * which has already be set
+			 */
+			memset(xs->here, 0, ENTRY_SIZE);
+			memset(val, 0, size);
+		}
+	}
+out:
+	return ret;
+}
+
+static errcode_t ocfs2_xattr_ibody_find(ocfs2_cached_inode *ci,
+					int name_index,
+					const char *name,
+					struct ocfs2_xattr_search *xs)
+{
+	struct ocfs2_dinode *di = ci->ci_inode;
+	ocfs2_filesys *fs = ci->ci_fs;
+	errcode_t ret = 0;
+
+	if (fs->fs_blocksize == OCFS2_MIN_BLOCKSIZE)
+		return 0;
+
+	if (!(di->i_dyn_features & OCFS2_INLINE_XATTR_FL) &&
+	    !ocfs2_xattr_has_space_inline(ci, di))
+		return 0;
+
+	xs->end = (char *)di + fs->fs_blocksize;
+	if (di->i_dyn_features & OCFS2_INLINE_XATTR_FL)
+		xs->header = (struct ocfs2_xattr_header *)
+			(xs->end - di->i_xattr_inline_size);
+	else
+		xs->header = (struct ocfs2_xattr_header *)(xs->end -
+			OCFS2_RAW_SB(fs->fs_super)->s_xattr_inline_size);
+	xs->base = (char *)xs->header;
+	xs->here = xs->header->xh_entries;
+
+	/* Find the named attribute. */
+	if (di->i_dyn_features & OCFS2_INLINE_XATTR_FL) {
+		ret = ocfs2_xattr_find_entry(name_index, name, xs);
+		if (ret && ret != OCFS2_ET_XATTR_NODATA)
+			return ret;
+		xs->not_found = ret;
+	}
+
+	return 0;
+}
+
+/*
+ * ocfs2_xattr_ibody_set()
+ *
+ * Set, replace or remove an extended attribute into inode block.
+ *
+ */
+static errcode_t ocfs2_xattr_ibody_set(ocfs2_cached_inode *ci,
+				       struct ocfs2_xattr_info *xi,
+				       struct ocfs2_xattr_search *xs)
+{
+	errcode_t ret;
+	struct ocfs2_dinode *di = ci->ci_inode;
+
+	if (ci->ci_fs->fs_blocksize == OCFS2_MIN_BLOCKSIZE)
+		return OCFS2_ET_XATTR_NOSPC;
+
+
+	if (!(di->i_dyn_features & OCFS2_INLINE_XATTR_FL) &&
+	    !ocfs2_xattr_has_space_inline(ci, di))
+		return 0;
+
+	ret = ocfs2_xattr_set_entry(ci, xi, xs, (OCFS2_INLINE_XATTR_FL |
+				    OCFS2_HAS_XATTR_FL));
+	if (!ret)
+		ret = ocfs2_write_cached_inode(ci->ci_fs, ci);
+	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.
+ */
+static errcode_t ocfs2_xattr_bucket_find(ocfs2_cached_inode *ci,
+					 int name_index,
+					 const char *name,
+					 uint32_t name_hash,
+					 uint64_t p_blkno,
+					 uint32_t num_clusters,
+					 struct ocfs2_xattr_search *xbks)
+{
+	int i;
+	char *bucket = xbks->blkbuf;
+	struct ocfs2_xattr_header *xh = NULL;
+	ocfs2_filesys *fs = ci->ci_fs;
+	uint16_t bpb = ocfs2_blocks_per_xattr_bucket(fs);
+	uint32_t num_buckets = ocfs2_xattr_buckets_per_cluster(fs);
+	uint64_t blk = 0;
+	errcode_t ret = 0;
+
+	blk = p_blkno;
+	for (i = 0; i < num_buckets; i++, blk += bpb) {
+		struct ocfs2_xattr_entry *first_xe;
+		struct ocfs2_xattr_entry *last_xe;
+
+		ret = ocfs2_read_xattr_bucket(fs, blk, bucket);
+		if (ret)
+			goto out;
+		xh = (struct ocfs2_xattr_header *)bucket;
+		xbks->blkno = blk;
+		xbks->header = xh;
+		xbks->base = (char *)xh;
+		xbks->end = xbks->base + fs->fs_blocksize;
+		xbks->here = xbks->header->xh_entries;
+		if (i == 0)
+			num_buckets = xh->xh_num_buckets;
+
+		last_xe = first_xe = xh->xh_entries;
+		if (xh->xh_count)
+			last_xe = &xh->xh_entries[xh->xh_count - 1];
+
+		if (name_hash > last_xe->xe_name_hash)
+			continue;
+		ret = ocfs2_xattr_find_entry(name_index, name, xbks);
+		if (ret && ret != OCFS2_ET_XATTR_NODATA)
+			goto out;
+		xbks->not_found = ret;
+		return 0;
+	}
+out:
+	return ret;
+}
+
+static errcode_t ocfs2_xattr_index_block_find(ocfs2_cached_inode *ci,
+					int name_index,
+					const char *name,
+					struct ocfs2_xattr_search_info *xsi)
+{
+	errcode_t ret;
+	struct ocfs2_xattr_block *xb = (struct ocfs2_xattr_block *)
+					xsi->xi_block->blkbuf;
+	struct ocfs2_xattr_tree_root *xb_root = &xb->xb_attrs.xb_root;
+	struct ocfs2_extent_list *el = &xb_root->xt_list;
+	uint64_t p_blkno = 0;
+	uint32_t first_hash, num_clusters = 0;
+	uint32_t uuid_hash, name_hash;
+
+	if (el->l_next_free_rec == 0) {
+		xsi->xi_bucket->not_found = OCFS2_ET_XATTR_NODATA;
+		return 0;
+	}
+
+	uuid_hash = ci->ci_fs->fs_super->id2.i_super.s_uuid_hash;
+	name_hash = ocfs2_xattr_name_hash(uuid_hash, name, strlen(name));
+	DEBUG("try to find xattr %s, hash = %u, index = %d in xattr tree.\n",
+	      name, name_hash, name_index);
+
+	ret = ocfs2_xattr_get_rec(ci->ci_fs, xb, name_hash, &p_blkno,
+				  &first_hash, &num_clusters);
+	if (ret)
+		return ret;
+
+	ASSERT(p_blkno != 0 || num_clusters != 0 || first_hash < name_hash);
+
+	DEBUG("find xattr extent rec %u clusters from #%"PRIu64", the first"
+	      " hash in the rec is %u\n", num_clusters, p_blkno, first_hash);
+
+	return ocfs2_xattr_bucket_find(ci, name_index, name, name_hash,
+				       p_blkno, num_clusters, xsi->xi_bucket);
+}
+
+
+/*
+ * ocfs2_xattr_block_find()
+ *
+ * Find extended attribute in external block and
+ * fill search info into struct ocfs2_xattr_search.
+ */
+static errcode_t ocfs2_xattr_block_find(ocfs2_cached_inode *ci,
+					int name_index,
+					const char *name,
+					struct ocfs2_xattr_search_info *xsi)
+{
+	ocfs2_filesys *fs = ci->ci_fs;
+	struct ocfs2_dinode *di = ci->ci_inode;
+	struct ocfs2_xattr_block *xb = NULL;
+	char *blk = xsi->xi_block->blkbuf;
+	errcode_t ret = 0;
+
+	if (!di->i_xattr_loc)
+		return 0;
+
+	ret = ocfs2_read_xattr_block(fs, di->i_xattr_loc, blk);
+	if (ret)
+		return ret;
+
+	xsi->xi_block->blkno = di->i_xattr_loc;
+
+	xb = (struct ocfs2_xattr_block *)blk;
+
+	if (xb->xb_flags & OCFS2_XATTR_INDEXED) {
+		ret = ocfs2_xattr_index_block_find(ci, name_index, name, xsi);
+	} else {
+		xsi->xi_block->header = &xb->xb_attrs.xb_header;
+		xsi->xi_block->base = (char *)xsi->xi_block->header;
+		xsi->xi_block->end = blk + fs->fs_blocksize;
+		xsi->xi_block->here = xsi->xi_block->header->xh_entries;
+		ret = ocfs2_xattr_find_entry(name_index, name, xsi->xi_block);
+		if (ret && ret != OCFS2_ET_XATTR_NODATA)
+			goto out;
+		xsi->xi_block->not_found = ret;
+		return 0;
+	}
+out:
+	return ret;
+}
+
+static errcode_t ocfs2_xattr_get_value_outside(ocfs2_cached_inode *ci,
+					struct ocfs2_xattr_value_root *xv,
+					struct ocfs2_xattr_search *xs,
+					void *buffer,
+					size_t value_len)
+{
+	uint32_t cpos, p_cluster, num_clusters;
+	uint64_t p_blkno;
+	size_t cp_len;
+	char *buf = NULL;
+	ocfs2_filesys *fs = ci->ci_fs;
+	size_t blocksize = fs->fs_blocksize;
+	uint16_t clustersize = fs->fs_clustersize;
+	uint32_t clusters = xv->xr_clusters;
+	uint32_t bpc = ocfs2_clusters_to_blocks(fs, 1);
+	uint32_t max_blocks = OCFS2_MAX_XATTR_TREE_LEAF_SIZE / blocksize;
+	errcode_t ret = 0;
+
+
+	ret = ocfs2_malloc_blocks(fs->fs_io, max_blocks, &buf);
+	if (ret)
+		return ret;
+
+	cpos = 0;
+	while (cpos < clusters) {
+		ret = ocfs2_xattr_get_clusters(ci, cpos, &p_cluster,
+					       &num_clusters,
+					       &xv->xr_list,
+					       xs->blkno, xs->blkbuf);
+		if (ret)
+			goto out;
+
+		p_blkno = ocfs2_clusters_to_blocks(fs, p_cluster);
+		memset(buf, 0, OCFS2_MAX_XATTR_TREE_LEAF_SIZE);
+
+		ret = io_read_block(fs->fs_io, p_blkno,
+				    num_clusters * bpc, buf);
+		if (ret)
+			goto out;
+
+		cp_len = value_len > num_clusters * clustersize ?
+			 num_clusters * clustersize : value_len;
+		memcpy(buffer, buf, cp_len);
+
+		value_len -= cp_len;
+		cpos += num_clusters;
+	}
+out:
+	ocfs2_free(&buf);
+	return ret;
+}
+
+
+static int ocfs2_xattr_ibody_get(ocfs2_cached_inode *ci,
+				 int name_index,
+				 const char *name,
+				 char *buffer,
+				 size_t buffer_size,
+				 struct ocfs2_xattr_search *xs,
+				 size_t *got)
+{
+	struct ocfs2_xattr_value_root *xv;
+	size_t size;
+	struct ocfs2_dinode *di = ci->ci_inode;
+	ocfs2_filesys *fs = ci->ci_fs;
+	errcode_t ret = 0;
+
+	if (!(di->i_dyn_features & OCFS2_INLINE_XATTR_FL))
+		return OCFS2_ET_XATTR_NODATA;
+
+	xs->end = (void *)di + fs->fs_blocksize;
+	xs->header = (struct ocfs2_xattr_header *)
+			(xs->end - 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 = xs->here->xe_value_size;
+	if (buffer) {
+		if (size > buffer_size)
+			return OCFS2_ET_XATTR_NOSPC;
+		if (ocfs2_xattr_is_local(xs->here)) {
+			memcpy(buffer, (void *)xs->base +
+			       xs->here->xe_name_offset +
+			       OCFS2_XATTR_SIZE(xs->here->xe_name_len), size);
+		} else {
+			xv = (struct ocfs2_xattr_value_root *)
+				(xs->base + xs->here->xe_name_offset +
+				OCFS2_XATTR_SIZE(xs->here->xe_name_len));
+			ret = ocfs2_xattr_get_value_outside(ci, xv, xs,
+							    buffer, size);
+			if (ret < 0)
+				return ret;
+		}
+	}
+
+	return size;
+}
+
+static errcode_t ocfs2_xattr_block_get(ocfs2_cached_inode *ci,
+					int name_index,
+					const char *name,
+					char *buffer,
+					size_t buffer_size,
+					struct ocfs2_xattr_search_info *xsi,
+					size_t *got)
+{
+	struct ocfs2_xattr_value_root *xv;
+	size_t size;
+	struct ocfs2_xattr_search *xs = NULL;
+	errcode_t ret = 0;
+
+	ret = ocfs2_xattr_block_find(ci, name_index, name, xsi);
+	if (ret)
+		return ret;
+
+	if (xsi->xi_block->not_found && xsi->xi_bucket->not_found)
+		return OCFS2_ET_XATTR_NODATA;
+
+	if (!xsi->xi_block->not_found) {
+		size = xsi->xi_block->here->xe_value_size;
+		xs = xsi->xi_block;
+	} else {
+		size = xsi->xi_bucket->here->xe_value_size;
+		xs = xsi->xi_bucket;
+	}
+
+	if (buffer) {
+		if (size > buffer_size)
+			return OCFS2_ET_XATTR_NOSPC;
+
+		if (ocfs2_xattr_is_local(xs->here)) {
+			memcpy(buffer, (void *)xs->base +
+			       xs->here->xe_name_offset +
+			       OCFS2_XATTR_SIZE(xs->here->xe_name_len), size);
+		} else {
+			xv = (struct ocfs2_xattr_value_root *)
+				(xs->base + xs->here->xe_name_offset +
+				OCFS2_XATTR_SIZE(xs->here->xe_name_len));
+			ret = ocfs2_xattr_get_value_outside(ci, xv, xs,
+							    buffer, size);
+			if (ret < 0)
+				return ret;
+		}
+	}
+	return size;
+}
+
+static errcode_t ocfs2_xattr_get_generic(ocfs2_cached_inode *ci,
+					 int name_index,
+					 const char *name,
+					 char *buffer,
+					 size_t buffer_size,
+					 size_t *got)
+{
+	errcode_t ret = 0;
+	struct ocfs2_dinode *di = ci->ci_inode;
+	ocfs2_filesys *fs = ci->ci_fs;
+	int bpb = ocfs2_blocks_per_xattr_bucket(fs);
+	struct ocfs2_xattr_search xis = {
+		.blkbuf = (char *)ci->ci_inode,
+		.blkno = ci->ci_blkno,
+		.not_found = OCFS2_ET_XATTR_NODATA,
+	};
+	struct ocfs2_xattr_search xbs = {.not_found = OCFS2_ET_XATTR_NODATA,};
+	struct ocfs2_xattr_search xbks = {.not_found = OCFS2_ET_XATTR_NODATA,};
+	struct ocfs2_xattr_search_info xsi = {
+		.xi_inode = &xis,
+		.xi_block = &xbs,
+		.xi_bucket = &xbks,
+	};
+
+	/* alloc block buffer for xattr block */
+	ret = ocfs2_malloc_block(fs->fs_io, &xbs.blkbuf);
+	if (ret)
+		return ret;
+
+	/* alloc block buffer for xattr bucket */
+	ret = ocfs2_malloc_blocks(fs->fs_io, bpb, &xbks.blkbuf);
+	if (ret)
+		return ret;
+
+
+	ret = ocfs2_xattr_ibody_get(ci, name_index, name, buffer,
+				    buffer_size, &xis, got);
+	if (ret == OCFS2_ET_XATTR_NODATA && di->i_xattr_loc)
+		ret = ocfs2_xattr_block_get(ci, name_index, name, buffer,
+					    buffer_size, &xsi, got);
+
+	if (xbs.blkbuf)
+		ocfs2_free(&xbs.blkbuf);
+	if (xbks.blkbuf)
+		ocfs2_free(&xbks.blkbuf);
+	return ret;
+}
+
+static int cmp_xe(const void *a, const void *b)
+{
+	const struct ocfs2_xattr_entry *l = a, *r = b;
+	uint32_t l_hash = l->xe_name_hash;
+	uint32_t r_hash = r->xe_name_hash;
+
+	if (l_hash > r_hash)
+		return 1;
+	if (l_hash < r_hash)
+		return -1;
+	return 0;
+}
+
+static int cmp_xe_offset(const void *a, const void *b)
+{
+	const struct ocfs2_xattr_entry *l = a, *r = b;
+	uint32_t l_name_offset = l->xe_name_offset;
+	uint32_t r_name_offset = r->xe_name_offset;
+
+	if (l_name_offset < r_name_offset)
+		return 1;
+	if (l_name_offset > r_name_offset)
+		return -1;
+	return 0;
+}
+
+/*
+ * 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(ocfs2_cached_inode *ci,
+					   char *block_buf,
+					   char *bucket_buf)
+{
+	int i, blocksize = ci->ci_fs->fs_blocksize;
+	int blks = ocfs2_blocks_per_xattr_bucket(ci->ci_fs);
+	uint16_t offset, size, off_change;
+	struct ocfs2_xattr_entry *xe;
+	struct ocfs2_xattr_block *xb = (struct ocfs2_xattr_block *)block_buf;
+	struct ocfs2_xattr_header *xb_xh = &xb->xb_attrs.xb_header;
+	struct ocfs2_xattr_header *xh = (struct ocfs2_xattr_header *)bucket_buf;
+	uint16_t count = xb_xh->xh_count;
+	char *src = block_buf;
+	char *target = bucket_buf + (blks - 1) * blocksize;
+
+	DEBUG("cp xattr from block #%"PRIu64" to bucket.\n", xb->xb_blkno);
+
+	memset(bucket_buf, 0, OCFS2_XATTR_BUCKET_SIZE);
+
+	/*
+	 * 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 = 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 = 1;
+	xh->xh_name_value_len = size;
+	xh->xh_free_start = OCFS2_XATTR_BUCKET_SIZE - size;
+
+	/* copy all the entries. */
+	target = bucket_buf;
+	offset = offsetof(struct ocfs2_xattr_header, xh_entries);
+	size = count * ENTRY_SIZE;
+	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++)
+		xh->xh_entries[i].xe_name_offset += off_change;
+
+	DEBUG("copy entry: start = %u, size = %u, offset_change = %u\n",
+	      offset, size, off_change);
+
+	qsort(target + offset, count, ENTRY_SIZE, cmp_xe);
+}
+
+static errcode_t ocfs2_xattr_create_index_block(ocfs2_cached_inode *ci,
+					struct ocfs2_xattr_search_info *xsi)
+{
+	errcode_t ret;
+	uint32_t len;
+	uint64_t blkno;
+	ocfs2_filesys *fs = ci->ci_fs;
+	struct ocfs2_xattr_block *xb = (struct ocfs2_xattr_block *)
+					xsi->xi_block->blkbuf;
+	uint16_t xb_flags = xb->xb_flags;
+	struct ocfs2_xattr_tree_root *xr = NULL;
+	char *bucket = xsi->xi_bucket->blkbuf;
+	size_t offs;
+
+	DEBUG("create xattr index block for #%"PRIu64"\n", xb->xb_blkno);
+
+	ASSERT(!(xb_flags & OCFS2_XATTR_INDEXED));
+
+	ret = ocfs2_new_clusters(fs, 1, 1, &blkno, &len);
+	if (ret)
+		return ret;
+
+	DEBUG("allocate 1 cluster from #%"PRIu64" to xattr block\n", blkno);
+
+	ocfs2_cp_xattr_block_to_bucket(ci, (char *)xb, bucket);
+
+	/* update xattr search info for xattr block and xattr bucket*/
+	offs = (char *)xsi->xi_block->here - (char *)xsi->xi_block->header;
+	xsi->xi_block->header = NULL;
+	xsi->xi_block->base = NULL;
+	xsi->xi_block->end = NULL;
+	xsi->xi_block->here = NULL;
+
+	xsi->xi_bucket->blkno = blkno;
+	xsi->xi_bucket->header = (struct ocfs2_xattr_header *)bucket;
+	xsi->xi_bucket->base = bucket;
+	xsi->xi_bucket->end = xsi->xi_bucket->base + fs->fs_blocksize;
+	xsi->xi_bucket->here = (struct ocfs2_xattr_entry *)(bucket + offs);
+
+	/* Change from ocfs2_xattr_header to ocfs2_xattr_tree_root */
+	memset(&xb->xb_attrs, 0, fs->fs_blocksize -
+	       offsetof(struct ocfs2_xattr_block, xb_attrs));
+
+	xr = &xb->xb_attrs.xb_root;
+	xr->xt_clusters = 1;
+	xr->xt_last_eb_blk = 0;
+	xr->xt_list.l_tree_depth = 0;
+	xr->xt_list.l_count = ocfs2_xattr_recs_per_xb(fs->fs_blocksize);
+	xr->xt_list.l_next_free_rec = 1;
+
+	xr->xt_list.l_recs[0].e_cpos = 0;
+	xr->xt_list.l_recs[0].e_blkno = blkno;
+	xr->xt_list.l_recs[0].e_leaf_clusters = 1;
+
+	xb->xb_flags = xb_flags | OCFS2_XATTR_INDEXED;
+
+	ret = ocfs2_write_xattr_bucket(fs, blkno, bucket);
+	if (ret)
+		return ret;
+
+	ret = ocfs2_write_xattr_block(fs, xsi->xi_block->blkno,
+				      xsi->xi_block->blkbuf);
+	return ret;
+}
+
+/*
+ * 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 errcode_t ocfs2_defrag_xattr_bucket(ocfs2_cached_inode  *ci,
+					   char *blkbuf,
+					   uint64_t blkno)
+{
+	errcode_t ret;
+	int i;
+	size_t end, offset, len, value_len;
+	char *entries = NULL;
+	char *bucket_buf = NULL;
+	uint16_t xh_free_start;
+	ocfs2_filesys *fs = ci->ci_fs;
+	size_t blocksize = fs->fs_blocksize;
+	struct ocfs2_xattr_entry *xe;
+	struct ocfs2_xattr_header *xh;
+	uint16_t bpb = ocfs2_blocks_per_xattr_bucket(fs);
+	/*
+	 * 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.
+	 */
+	ret = ocfs2_malloc_blocks(fs->fs_io, bpb, &bucket_buf);
+	if (ret)
+		goto out;
+
+	memcpy(bucket_buf, blkbuf, OCFS2_XATTR_BUCKET_SIZE);
+
+	xh = (struct ocfs2_xattr_header *)bucket_buf;
+	entries = (char *)xh->xh_entries;
+	xh_free_start = xh->xh_free_start;
+
+	DEBUG("Adjust xattr bucket in #%"PRIu64", count = %u,"
+	      " xh_free_start = %u, xh_name_value_len = %u.\n",
+	      blkno, xh->xh_count, xh_free_start,
+	      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.
+	 */
+	qsort(entries, xh->xh_count, ENTRY_SIZE, cmp_xe_offset);
+
+	/* Move all name/values to the end of the bucket. */
+	xe = xh->xh_entries;
+	end = OCFS2_XATTR_BUCKET_SIZE;
+	for (i = 0; i < xh->xh_count; i++, xe++) {
+		offset = xe->xe_name_offset;
+		if (ocfs2_xattr_is_local(xe))
+			value_len = OCFS2_XATTR_SIZE(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 = end - len;
+		}
+
+		if (end < offset + len) {
+			DEBUG("Defrag check failed for bucket #%"PRIu64"\n",
+			      blkno);
+			ASSERT(end >= offset + len);
+		}
+		end -= len;
+	}
+
+	if (xh_free_start > end) {
+		DEBUG("Defrag check failed for bucket #%"PRIu64"\n", blkno);
+		ASSERT(xh_free_start <= end);
+	}
+
+	if (xh_free_start == end)
+		goto out;
+
+	memset(bucket_buf + xh_free_start, 0, end - xh_free_start);
+	xh->xh_free_start = end;
+
+	/* sort the entries by their name_hash. */
+	qsort(entries, xh->xh_count, ENTRY_SIZE, cmp_xe);
+
+	memcpy(blkbuf, bucket_buf, OCFS2_XATTR_BUCKET_SIZE);
+	ret = ocfs2_write_xattr_bucket(fs, blkno, blkbuf);
+
+out:
+	if (bucket_buf)
+		ocfs2_free(&bucket_buf);
+	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 XATTR_NOSPC.
+ * If we want to insert a xattr with different hash value, go ahead
+ * and ocfs2_divide_xattr_bucket will handle this.
+ */
+static errcode_t ocfs2_check_xattr_bucket_collision(ocfs2_cached_inode *ci,
+						    char *blkbuf,
+						    uint64_t blkno,
+						    const char *name)
+{
+	struct ocfs2_xattr_header *xh = (struct ocfs2_xattr_header *)blkbuf;
+	uint32_t uuid_hash = ci->ci_fs->fs_super->id2.i_super.s_uuid_hash;
+	uint32_t name_hash = ocfs2_xattr_name_hash(uuid_hash,
+						   name, strlen(name));
+
+	if (name_hash != xh->xh_entries[0].xe_name_hash)
+		return 0;
+
+	if (xh->xh_entries[xh->xh_count - 1].xe_name_hash ==
+	    xh->xh_entries[0].xe_name_hash) {
+		DEBUG("Too much hash collision in xattr bucket #%"PRIu64","
+		      "hash = %u\n", blkno, xh->xh_entries[0].xe_name_hash);
+		return OCFS2_ET_XATTR_NOSPC;
+	}
+
+	return 0;
+}
+
+/*
+ * Copy xattr from one bucket to another bucket.
+ */
+static errcode_t ocfs2_cp_xattr_bucket(ocfs2_cached_inode *ci,
+				       uint64_t s_blkno,
+				       uint64_t t_blkno)
+{
+	errcode_t ret;
+	ocfs2_filesys *fs = ci->ci_fs;
+	int bpb = ocfs2_blocks_per_xattr_bucket(fs);
+	struct ocfs2_xattr_buf s_bucket = {
+		.xb_buf = NULL,
+		.xb_blkno = 0,
+	};
+	struct ocfs2_xattr_buf t_bucket = {
+		.xb_buf = NULL,
+		.xb_blkno = 0,
+	};
+
+	ASSERT(s_blkno != t_blkno);
+
+	DEBUG("cp bucket #%"PRIu64" to #%"PRIu64"\n", s_blkno, t_blkno);
+
+
+	ret = ocfs2_malloc_blocks(fs->fs_io, bpb, &s_bucket.xb_buf);
+	if (ret)
+		return ret;
+	ret = ocfs2_malloc_blocks(fs->fs_io, bpb, &t_bucket.xb_buf);
+	if (ret)
+		goto cleanup;
+
+	ret = ocfs2_read_xattr_bucket(fs, s_blkno, s_bucket.xb_buf);
+	if (ret)
+		goto cleanup;
+
+	memcpy(t_bucket.xb_buf, s_bucket.xb_buf, OCFS2_XATTR_BUCKET_SIZE);
+	ret = ocfs2_write_xattr_bucket(fs, t_blkno, t_bucket.xb_buf);
+
+cleanup:
+	if (s_bucket.xb_buf)
+		ocfs2_free(&s_bucket.xb_buf);
+	if (t_bucket.xb_buf)
+		ocfs2_free(&t_bucket.xb_buf);
+
+	return ret;
+}
+
+/*
+ * old_first_blkno 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 errcode_t ocfs2_mv_xattr_buckets(ocfs2_cached_inode *ci,
+					uint64_t old_first_blkno,
+					struct ocfs2_xattr_buf *target,
+					uint64_t last_blk,
+					uint64_t to_blk,
+					uint32_t start_bucket,
+					uint32_t *first_hash)
+{
+	errcode_t ret;
+	int i;
+	ocfs2_filesys *fs = ci->ci_fs;
+	int bpb = ocfs2_blocks_per_xattr_bucket(fs);
+	int num_buckets = ocfs2_xattr_buckets_per_cluster(fs);
+	char *old_first = NULL;
+	char *new_first = NULL;
+	struct ocfs2_xattr_header *xh = NULL;
+
+	DEBUG("mv xattrs from cluster #%"PRIu64" to #%"PRIu64"\n",
+	      last_blk, to_blk);
+
+	ASSERT(start_bucket < num_buckets);
+	if (start_bucket) {
+		num_buckets -= start_bucket;
+		last_blk += (start_bucket * bpb);
+	}
+
+	/*
+	 * We need to update the first bucket of the old extent and all
+	 * the buckets going to the new extent.
+	 */
+	for (i = 0; i < num_buckets; i++) {
+		ret = ocfs2_cp_xattr_bucket(ci, last_blk + (i * bpb),
+					    to_blk + (i * bpb));
+		if (ret)
+			goto cleanup;
+	}
+
+	if (old_first_blkno == target->xb_blkno)
+		old_first = target->xb_buf;
+	else {
+		ret = ocfs2_malloc_blocks(fs->fs_io, bpb, &old_first);
+		if (ret)
+			goto cleanup;
+		ret = ocfs2_read_xattr_bucket(fs, old_first_blkno, old_first);
+		if (ret)
+			goto cleanup;
+	}
+
+	/* The first bucket of the new extent */
+	ret = ocfs2_malloc_blocks(fs->fs_io, bpb, &new_first);
+	if (ret)
+		goto cleanup;
+	ret = ocfs2_read_xattr_bucket(fs, to_blk, new_first);
+	if (ret)
+		goto cleanup;
+
+	/* Now update the headers */
+	xh = (struct ocfs2_xattr_header *)old_first;
+	xh->xh_num_buckets -= num_buckets;
+	ret = ocfs2_write_xattr_bucket(fs, old_first_blkno, old_first);
+	if (ret)
+		goto cleanup;
+
+	xh = (struct ocfs2_xattr_header *)new_first;
+	xh->xh_num_buckets = num_buckets;
+	ret = ocfs2_write_xattr_bucket(fs, to_blk, new_first);
+
+	if (first_hash)
+		*first_hash = xh->xh_entries[0].xe_name_hash;
+
+cleanup:
+	if (old_first_blkno != target->xb_blkno)
+		ocfs2_free(&old_first);
+	if (new_first)
+		ocfs2_free(&new_first);
+	return ret;
+}
+
+/*
+ * First_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_blkno indecates to the first bucket so we can update the
+ * existing extent's bucket count. Target point to the bucket buffer
+ * which we were hoping to insert our xattr. If the bucket move places
+ * the target in the new extent, we'll update first bucket and
+ * target bucket after modifying the old extent.
+ *
+ * First_hash will be set as the 1st xe's name_hash in the new extent.
+ */
+static errcode_t ocfs2_mv_xattr_bucket_cross_cluster(ocfs2_cached_inode *ci,
+						uint64_t *first_blkno,
+						struct ocfs2_xattr_buf *target,
+						uint64_t new_blkno,
+						uint32_t num_clusters,
+						uint32_t *first_hash)
+{
+	errcode_t ret;
+	ocfs2_filesys *fs = ci->ci_fs;
+	int bpb = ocfs2_blocks_per_xattr_bucket(fs);
+	int num_buckets = ocfs2_xattr_buckets_per_cluster(fs);
+	int to_move = num_buckets / 2;
+	uint64_t src_blkno;
+	uint64_t last_cluster_blkno = *first_blkno +
+		((num_clusters - 1) * ocfs2_clusters_to_blocks(fs, 1));
+
+	ASSERT(OCFS2_XATTR_BUCKET_SIZE != fs->fs_clustersize);
+
+	DEBUG("move half of xattrs in cluster #%"PRIu64" to #%"PRIu64"\n",
+	      last_cluster_blkno, new_blkno);
+
+	ret = ocfs2_mv_xattr_buckets(ci, *first_blkno, target,
+				     last_cluster_blkno,
+				     new_blkno, to_move, first_hash);
+	if (ret)
+		goto out;
+
+	/* This is the first bucket that got moved */
+	src_blkno = last_cluster_blkno + (to_move * bpb);
+
+	/*
+	 * If the target bucket was part of the moved buckets, we need to
+	 * update first and target.
+	 */
+	if (target->xb_blkno >= src_blkno) {
+		/* Find the block for the new target bucket */
+		src_blkno = new_blkno + target->xb_blkno - src_blkno;
+
+		ret = ocfs2_read_xattr_bucket(fs, src_blkno, target->xb_buf);
+		if (ret)
+			goto out;
+		target->xb_blkno = src_blkno;
+		*first_blkno = new_blkno;
+	}
+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 = 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 errcode_t ocfs2_divide_xattr_bucket(ocfs2_cached_inode *ci,
+					   struct ocfs2_xattr_buf *s_bucket,
+					   uint64_t new_blk,
+					   uint32_t *first_hash,
+					   uint32_t is_new)
+{
+	errcode_t ret;
+	int i;
+	ocfs2_filesys *fs = ci->ci_fs;
+	int count, start, len, name_value_len = 0, xe_len, name_offset = 0;
+	uint16_t bpb = ocfs2_blocks_per_xattr_bucket(fs);
+	struct ocfs2_xattr_header *xh;
+	struct ocfs2_xattr_entry *xe;
+	char *temp = NULL;
+
+	DEBUG("move some of xattrs from bucket #%"PRIu64" to #%"PRIu64"\n",
+	      s_bucket->xb_blkno, new_blk);
+
+	ret = ocfs2_malloc_blocks(fs->fs_io, bpb, &temp);
+	if (ret)
+		return ret;
+
+	xh = bucket_xh(s_bucket);
+	count = xh->xh_count;
+	start = ocfs2_xattr_find_divide_pos(xh);
+	DEBUG("count = %d, start = %d\n", count, start);
+
+	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.
+		 */
+		memset(temp, 0, OCFS2_XATTR_BUCKET_SIZE);
+
+		xh = (struct ocfs2_xattr_header *)temp;
+		xh->xh_free_start = fs->fs_blocksize;
+		xh->xh_entries[0].xe_name_hash = xe->xe_name_hash;
+		xh->xh_entries[0].xe_name_hash += 1;
+
+		goto set_num_buckets;
+	}
+
+	/* copy the whole bucket to the new first. */
+	memcpy(temp, s_bucket->xb_buf, OCFS2_XATTR_BUCKET_SIZE);
+
+	/* update the new bucket. */
+	xh = (struct ocfs2_xattr_header *)temp;
+
+	/*
+	 * 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(xe->xe_value_size);
+		else
+			xe_len += OCFS2_XATTR_ROOT_SIZE;
+		name_value_len += xe_len;
+		if (xe->xe_name_offset < name_offset)
+			name_offset = 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);
+	DEBUG("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);
+
+	xh->xh_count -= start;
+	xh->xh_name_value_len -= name_value_len;
+
+	/* Calculate xh_free_start for the new bucket. */
+	xh->xh_free_start = OCFS2_XATTR_BUCKET_SIZE;
+	for (i = 0; i < 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(xe->xe_value_size);
+		else
+			xe_len += OCFS2_XATTR_ROOT_SIZE;
+		if (xe->xe_name_offset < 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 (is_new)
+		xh->xh_num_buckets = 1;
+	else
+		xh->xh_num_buckets = 0;
+
+	ret = ocfs2_write_xattr_bucket(fs, new_blk, temp);
+	if (ret)
+		goto out;
+
+	/* store the first_hash of the new bucket. */
+	if (first_hash)
+		*first_hash = 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 = start;
+	xh->xh_free_start = name_offset;
+	xh->xh_name_value_len = name_value_len;
+
+	ret = ocfs2_write_xattr_bucket(fs, s_bucket->xb_blkno,
+					s_bucket->xb_buf);
+	xh = (struct ocfs2_xattr_header *)s_bucket->xb_buf;
+out:
+	ocfs2_free(&temp);
+
+	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 errcode_t ocfs2_divide_xattr_cluster(ocfs2_cached_inode *ci,
+					    struct ocfs2_xattr_buf *target,
+					    uint64_t new_blk,
+					    uint32_t *first_hash)
+{
+	/* Move half of the xattr in start_blk to the next bucket. */
+	return  ocfs2_divide_xattr_bucket(ci, target,
+					  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 and target buckets
+ * 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 and target buckets?
+ * 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 and target buckets 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 and target buckets
+ *       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 errcode_t ocfs2_adjust_xattr_cross_cluster(ocfs2_cached_inode *ci,
+						uint64_t *first_blkno,
+						struct ocfs2_xattr_buf *target,
+						uint64_t new_blk,
+						uint32_t prev_clusters,
+						uint32_t *v_start,
+						int *extend)
+{
+	errcode_t ret;
+	uint64_t last_blk = *first_blkno + ((prev_clusters - 1) *
+			    ocfs2_clusters_to_blocks(ci->ci_fs, 1));
+
+	DEBUG("adjust xattrs from cluster #%"PRIu64" len %u to #%"PRIu64
+	      "first bucket at #%"PRIu64"\n",
+	      target->xb_blkno, prev_clusters, new_blk, *first_blkno);
+
+	if (ocfs2_xattr_buckets_per_cluster(ci->ci_fs) > 1)
+		return ocfs2_mv_xattr_bucket_cross_cluster(ci, first_blkno,
+							   target,
+							   new_blk,
+							   prev_clusters,
+							   v_start);
+
+	/* The start of the last cluster in the first extent */
+	if (prev_clusters > 1 && target->xb_blkno != last_blk) {
+		ret = ocfs2_mv_xattr_buckets(ci, *first_blkno, target, last_blk,
+					     new_blk, 0, v_start);
+	} else {
+		ret = ocfs2_divide_xattr_cluster(ci, target,
+						 new_blk, v_start);
+		if (target->xb_blkno == 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_blkno indicates the first bucket of the previous extent rec and target
+ * indicates the bucket we will insert the new xattrs. They will be updated
+ * when the target bucket is moved into the new cluster.
+ */
+static errcode_t ocfs2_add_new_xattr_cluster(ocfs2_cached_inode *ci,
+					     struct ocfs2_xattr_buf *block,
+					     uint64_t *first_blkno,
+					     struct ocfs2_xattr_buf *target,
+					     uint32_t *num_clusters,
+					     uint32_t prev_cpos,
+					     int *extend)
+{
+	int ret;
+	uint16_t bpc = ocfs2_clusters_to_blocks(ci->ci_fs, 1);
+	uint32_t prev_clusters = *num_clusters;
+	uint32_t num_bits, v_start = 0;
+	uint64_t blkno;
+	struct ocfs2_extent_tree et;
+	DEBUG("Add new xattr cluster for inode #%"PRIu64", previous xattr hash"
+	      " = %u, previous xattr blkno #%"PRIu64"\n", ci->ci_blkno,
+	      prev_cpos, *first_blkno);
+
+	ocfs2_init_xattr_tree_extent_tree(&et, ci->ci_fs, block->xb_buf,
+					  block->xb_blkno);
+	ret = ocfs2_new_clusters(ci->ci_fs, 1, 1, &blkno, &num_bits);
+	if (ret)
+		return ret;
+	DEBUG("Allocating %u clusters at block #%"PRIu64" for xattr in"
+	      " inode #%"PRIu64"\n", num_bits, blkno, ci->ci_blkno);
+
+	if (*first_blkno + (prev_clusters * bpc) == blkno &&
+	    (prev_clusters + num_bits) * ci->ci_fs->fs_clustersize <=
+	     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;
+		DEBUG("Add contiguous %u clusters to previous extent rec.\n",
+		      num_bits);
+	} else {
+		ret = ocfs2_adjust_xattr_cross_cluster(ci,
+						       first_blkno,
+						       target,
+						       blkno,
+						       prev_clusters,
+						       &v_start,
+						       extend);
+		if (ret)
+			return ret;
+	}
+
+	DEBUG("Insert %u clusters at block #%"PRIu64" for xattr at %u\n",
+	      num_bits, blkno, v_start);
+	ret = ocfs2_tree_insert_extent(ci->ci_fs, &et, v_start, blkno,
+					num_bits, 0);
+	if (ret)
+		return ret;
+	ret = ocfs2_write_xattr_block(ci->ci_fs, block->xb_blkno,
+				      block->xb_buf);
+
+	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 errcode_t ocfs2_extend_xattr_bucket(ocfs2_cached_inode *ci,
+					   uint64_t first_blkno,
+					   struct ocfs2_xattr_buf *target,
+					   uint32_t num_clusters)
+{
+	errcode_t ret;
+	ocfs2_filesys *fs = ci->ci_fs;
+	uint16_t bpb = ocfs2_blocks_per_xattr_bucket(fs);
+	uint64_t end_blk;
+	char *first_bucket = NULL;
+	uint16_t new_bucket;
+	struct ocfs2_xattr_header *xh = NULL;
+
+	DEBUG("extend xattr bucket in #%"PRIu64", xattr extend rec starting"
+	      " from #%"PRIu64", len = %u\n", target->xb_blkno,
+	      first_blkno, num_clusters);
+
+	if (first_blkno == target->xb_blkno)
+		first_bucket = target->xb_buf;
+	else {
+		ret = ocfs2_malloc_blocks(fs->fs_io, bpb, &first_bucket);
+		if (ret)
+			return ret;
+		ret = ocfs2_read_xattr_bucket(fs, first_blkno, first_bucket);
+		if (ret)
+			goto out;
+	}
+
+	xh = (struct ocfs2_xattr_header *)first_bucket;
+	new_bucket = xh->xh_num_buckets;
+	/* The extent must have room for an additional bucket */
+	ASSERT(new_bucket <
+	      (num_clusters * ocfs2_xattr_buckets_per_cluster(fs)));
+
+	/* end_blk points to the last existing bucket */
+	end_blk = first_blkno + ((new_bucket - 1) * bpb);
+
+	/*
+	 * 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).
+	 */
+
+	while (end_blk != target->xb_blkno) {
+		ret = ocfs2_cp_xattr_bucket(ci, end_blk, end_blk + bpb);
+		if (ret)
+			goto out;
+		end_blk -= bpb;
+	}
+
+	/* Move half of the xattr in target_blkno to the next bucket. */
+	ret = ocfs2_divide_xattr_bucket(ci, target, target->xb_blkno + bpb,
+					NULL, 0);
+	if (ret)
+		goto out;
+
+	xh->xh_num_buckets += 1;
+	ret = ocfs2_write_xattr_bucket(fs, first_blkno, first_bucket);
+
+out:
+	if (first_bucket)
+		ocfs2_free(&first_bucket);
+	return ret;
+}
+
+static errcode_t ocfs2_add_new_xattr_bucket(ocfs2_cached_inode *ci,
+					    struct ocfs2_xattr_buf *block,
+					    struct ocfs2_xattr_buf *target)
+{
+	errcode_t ret;
+	int extend = 1;
+	struct ocfs2_xattr_block *xb =
+			(struct ocfs2_xattr_block *)block->xb_buf;
+	uint32_t name_hash = bucket_xh(target)->xh_entries[0].xe_name_hash;
+	uint32_t e_cpos, num_clusters;
+	ocfs2_filesys *fs = ci->ci_fs;
+	uint16_t bpb = ocfs2_blocks_per_xattr_bucket(fs);
+	char *first_bucket = NULL;
+	uint64_t first_blkno;
+	uint16_t num_buckets, first_num_buckets;
+
+	DEBUG("Add new xattr bucket starting from #%"PRIu64"\n",
+	      target->xb_blkno);
+
+	ret = ocfs2_xattr_get_rec(fs, xb, name_hash, &first_blkno, &e_cpos,
+				  &num_clusters);
+	if (ret)
+		return ret;
+
+	if (first_blkno == target->xb_blkno) {
+		first_num_buckets = bucket_xh(target)->xh_num_buckets;
+	} else {
+		ret = ocfs2_malloc_blocks(fs->fs_io, bpb, &first_bucket);
+		if (ret)
+			return ret;
+
+		ret = ocfs2_read_xattr_bucket(ci->ci_fs, first_blkno,
+					      first_bucket);
+		if (ret)
+			goto out;
+		first_num_buckets = ((struct ocfs2_xattr_header *)first_bucket)
+				    ->xh_num_buckets;
+	}
+
+	num_buckets = ocfs2_xattr_buckets_per_cluster(fs) * num_clusters;
+	if (num_buckets == first_num_buckets) {
+		/*
+		 * This can move first+target if the target bucket moves
+		 * to the new extent.
+		 */
+		ret = ocfs2_add_new_xattr_cluster(ci,
+						  block,
+						  &first_blkno,
+						  target,
+						  &num_clusters,
+						  e_cpos,
+						  &extend);
+		if (ret)
+			goto out;
+	}
+
+	if (extend) {
+		ret = ocfs2_extend_xattr_bucket(ci,
+						first_blkno,
+						target,
+						num_clusters);
+	}
+
+out:
+	if (first_bucket)
+		ocfs2_free(&first_bucket);
+
+	return ret;
+}
+
+static int ocfs2_xattr_bucket_value_truncate(ocfs2_cached_inode *ci,
+					     struct ocfs2_xattr_search *xs,
+					     int len)
+{
+	int ret, offset;
+	uint64_t value_blk;
+	size_t blocksize = ci->ci_fs->fs_blocksize;
+	struct ocfs2_xattr_value_root *xv;
+
+	offset = xs->here->xe_name_offset +
+		 OCFS2_XATTR_SIZE(xs->here->xe_name_len);
+
+	value_blk = offset / blocksize;
+
+	/* We don't allow ocfs2_xattr_value to be stored in different block. */
+	ASSERT(value_blk == (offset + OCFS2_XATTR_ROOT_SIZE - 1) / blocksize);
+
+	xv = (struct ocfs2_xattr_value_root *)(xs->blkbuf + offset);
+
+	DEBUG("truncate in xattr bucket #%"PRIu64" to %d bytes.\n",
+	      xs->blkno, len);
+	ret = ocfs2_xattr_value_truncate(ci, xv, xs->blkbuf, xs->blkno, len);
+	if (ret)
+		goto out;
+
+	xs->here->xe_value_size = len;
+	ret = ocfs2_write_xattr_bucket(ci->ci_fs, xs->blkno, xs->blkbuf);
+
+out:
+	return ret;
+}
+
+static void ocfs2_xattr_set_entry_normal(ocfs2_cached_inode *ci,
+					 struct ocfs2_xattr_info *xi,
+					 struct ocfs2_xattr_search *xs,
+					 uint32_t name_hash,
+					 int local)
+{
+	struct ocfs2_xattr_entry *last, *xe;
+	int name_len = strlen(xi->name);
+	struct ocfs2_xattr_header *xh = xs->header;
+	uint16_t count = xh->xh_count, start;
+	size_t blocksize = ci->ci_fs->fs_blocksize;
+	char *val;
+	size_t offs, size, new_size;
+
+	last = &xh->xh_entries[count];
+	if (!xs->not_found) {
+		xe = xs->here;
+		offs = xe->xe_name_offset;
+		if (ocfs2_xattr_is_local(xe))
+			size = OCFS2_XATTR_SIZE(name_len) +
+			OCFS2_XATTR_SIZE(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);
+
+		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 = xi->value_len;
+			else
+				xe->xe_value_size = 0;
+
+			val = xs->blkbuf + 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);
+
+			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;
+			xh->xh_count -= 1;
+			if (xh->xh_count) {
+				memmove(xe, xe + 1,
+					(void *)last - (void *)xe);
+				memset(last, 0, ENTRY_SIZE);
+			} else
+				xh->xh_free_start =
+					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 > tmp_xe->xe_name_hash)
+				low = tmp + 1;
+			else if (name_hash <
+				 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);
+
+		xh->xh_count += 1;
+		memset(xe, 0, ENTRY_SIZE);
+		xe->xe_name_hash = 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 = xh->xh_free_start;
+	start = offs - size;
+
+	if (start / ci->ci_fs->fs_blocksize !=
+	    (offs - 1) / ci->ci_fs->fs_blocksize) {
+		offs = offs - offs % blocksize;
+		xh->xh_free_start = offs;
+	}
+
+	val = xs->blkbuf + offs - size;
+	xe->xe_name_offset = 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 = xi->value_len;
+	ocfs2_xattr_set_local(xe, local);
+	xs->here = xe;
+	xh->xh_free_start -= size;
+	xh->xh_name_value_len += size;
+
+	return;
+}
+
+static errcode_t ocfs2_xattr_bucket_remove_xs(ocfs2_cached_inode *ci,
+					      struct ocfs2_xattr_search *xs)
+{
+	struct ocfs2_xattr_header *xh =	(struct ocfs2_xattr_header *)
+					xs->blkbuf;
+	struct ocfs2_xattr_entry *last = &xh->xh_entries[xh->xh_count - 1];
+
+	/* Remove the old entry. */
+	memmove(xs->here, xs->here + 1,
+		(void *)last - (void *)xs->here);
+	memset(last, 0, ENTRY_SIZE);
+	xh->xh_count -= 1;
+
+	return ocfs2_write_xattr_bucket(ci->ci_fs, xs->blkno, xs->blkbuf);
+}
+
+
+static int ocfs2_xattr_bucket_set_value_outside(ocfs2_cached_inode *ci,
+						struct ocfs2_xattr_search *xs,
+						char *val,
+						int value_len)
+{
+	struct ocfs2_xattr_value_root *xv;
+
+	xv = (struct ocfs2_xattr_value_root *)(xs->blkbuf +
+	     xs->here->xe_name_offset +
+	     OCFS2_XATTR_SIZE(xs->here->xe_name_len));
+
+	return  __ocfs2_xattr_set_value_outside(ci, xv, xs->blkbuf, xs->blkno,
+						val, value_len);
+}
+
+/*
+ * 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 errcode_t ocfs2_xattr_set_in_bucket(ocfs2_cached_inode *ci,
+					   struct ocfs2_xattr_info *xi,
+					   struct ocfs2_xattr_search *xs)
+{
+	errcode_t ret = 0;
+	int local = 1;
+	size_t value_len;
+	char *val = (char *)xi->value;
+	struct ocfs2_xattr_entry *xe = xs->here;
+	uint32_t uuid_hash = ci->ci_fs->fs_super->id2.i_super.s_uuid_hash;
+	uint32_t name_hash = ocfs2_xattr_name_hash(uuid_hash, 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(ci, xs, value_len);
+		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 = (const char *)&def_xv;
+		xi->value_len = OCFS2_XATTR_ROOT_SIZE;
+	}
+
+	ocfs2_xattr_set_entry_normal(ci, xi, xs, name_hash, local);
+	ret = ocfs2_write_xattr_bucket(ci->ci_fs, xs->blkno, xs->blkbuf);
+	if (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(ci, xs, value_len);
+	if (ret) {
+		errcode_t ret2;
+		if (xs->not_found) {
+			/*
+			 * We can't allocate enough clusters for outside
+			 * storage and we have allocated xattr already,
+			 * so need to remove it.
+			 */
+			ret2 = ocfs2_xattr_bucket_remove_xs(ci, xs);
+		}
+		goto out;
+	}
+
+set_value_outside:
+	ret = ocfs2_xattr_bucket_set_value_outside(ci, xs, val, value_len);
+out:
+	return ret;
+}
+
+
+static errcode_t ocfs2_xattr_set_entry_index_block(ocfs2_cached_inode *ci,
+						struct ocfs2_xattr_info *xi,
+					struct ocfs2_xattr_search_info *xsi)
+{
+	struct ocfs2_xattr_header *xh;
+	struct ocfs2_xattr_entry *xe;
+	uint16_t count, header_size, xh_free_start;
+	int free, max_free, need, old;
+	size_t value_size = 0, name_len = strlen(xi->name);
+	ocfs2_filesys *fs = ci->ci_fs;
+	size_t blocksize = fs->fs_blocksize;
+	int allocation = 0;
+	errcode_t ret = 0;
+	struct ocfs2_xattr_search *xbks = NULL;
+	struct ocfs2_xattr_buf bucket;
+	struct ocfs2_xattr_buf block = {
+		.xb_buf = xsi->xi_block->blkbuf,
+		.xb_blkno = xsi->xi_block->blkno,
+	};
+
+	DEBUG("Set xattr %s in xattr index block\n", xi->name);
+
+try_again:
+	xbks = xsi->xi_bucket;
+	bucket.xb_buf = xbks->blkbuf;
+	bucket.xb_blkno = xbks->blkno;
+
+	xh = xbks->header;
+	count = xh->xh_count;
+	xh_free_start = xh->xh_free_start;
+	header_size = HEADER_SIZE + count * ENTRY_SIZE;
+	max_free = OCFS2_XATTR_BUCKET_SIZE - header_size -
+		   xh->xh_name_value_len - OCFS2_XATTR_HEADER_GAP;
+
+	if (header_size > blocksize) {
+		DEBUG("bucket #%"PRIu64" has header size of %u which exceed"
+		      " block size\n", xbks->blkno, header_size);
+		ASSERT(header_size <= blocksize);
+	}
+	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 (xbks->not_found)
+		need = ENTRY_SIZE + 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 = xbks->here;
+		if (ocfs2_xattr_is_local(xe))
+			old = OCFS2_XATTR_SIZE(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;
+
+	DEBUG("xbks->not_found = %d, in xattr bucket #%"PRIu64": free = %d,"
+	      " need = %d, max_free = %d, xh_free_start = %u,"
+	      " xh_name_value_len = %u\n", xbks->not_found,
+	      xbks->blkno, free, need, max_free, xh->xh_free_start,
+	      xh->xh_name_value_len);
+
+	if (free < need ||
+	    (xbks->not_found && count == ocfs2_xattr_max_xe_in_bucket(fs))) {
+		if (need <= max_free &&
+		    count < ocfs2_xattr_max_xe_in_bucket(fs)) {
+			/*
+			 * 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(ci, xbks->blkbuf,
+							xbks->blkno);
+			if (ret)
+				goto out;
+
+			xh_free_start = 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;
+
+			DEBUG("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.
+		 */
+		ASSERT(!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(ci, xbks->blkbuf,
+							 xbks->blkno,
+							 xi->name);
+		if (ret)
+			goto out;
+		ret = ocfs2_add_new_xattr_bucket(ci, &block, &bucket);
+		if (ret)
+			goto out;
+
+		/*
+		 * ocfs2_add_new_xattr_bucket() will have updated
+		 * xs->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.
+		 */
+		ret = ocfs2_xattr_index_block_find(ci, xi->name_index,
+						   xi->name, xsi);
+		if (ret)
+			goto out;
+		allocation = 1;
+		goto try_again;
+	}
+
+xattr_set:
+	ret = ocfs2_xattr_set_in_bucket(ci, xi, xsi->xi_bucket);
+out:
+	return ret;
+}
+
+
+/*
+ * ocfs2_xattr_block_set()
+ *
+ * Set, replace or remove an extended attribute into external block.
+ *
+ */
+static errcode_t ocfs2_xattr_block_set(ocfs2_cached_inode *ci,
+				       struct ocfs2_xattr_info *xi,
+				       struct ocfs2_xattr_search_info *xsi)
+{
+	char *buf = xsi->xi_block->blkbuf;
+	ocfs2_filesys *fs = ci->ci_fs;
+	struct ocfs2_xattr_block *xblk = NULL;
+	uint64_t blkno;
+	int ret;
+
+	if (!xsi->xi_block->blkno) {
+		/* Get and initialize ocfs2_xattr_block */
+		ret = ocfs2_new_xattr_block(fs, &blkno);
+		if (ret)
+			return ret;
+		/*
+		 * ocfs2_new_xattr_block already format
+		 * that block to xattr block.
+		 */
+		ret = ocfs2_read_xattr_block(fs, blkno, buf);
+		if (ret)
+			goto out;
+
+		xsi->xi_block->blkno = blkno;
+
+		xblk = (struct ocfs2_xattr_block *)buf;
+		xsi->xi_block->header = &xblk->xb_attrs.xb_header;
+		xsi->xi_block->base = (char *)xsi->xi_block->header;
+		xsi->xi_block->end = buf + fs->fs_blocksize;
+		xsi->xi_block->here = xsi->xi_block->header->xh_entries;
+
+		ci->ci_inode->i_xattr_loc = blkno;
+		ret = ocfs2_write_cached_inode(fs, ci);
+		if (ret)
+			goto out;
+		ret = ocfs2_write_xattr_block(fs, blkno, buf);
+		if (ret)
+			goto out;
+	} else
+		xblk = (struct ocfs2_xattr_block *)xsi->xi_block->blkbuf;
+
+	if (!(xblk->xb_flags & OCFS2_XATTR_INDEXED)) {
+		/* Set extended attribute into external block */
+		ret = ocfs2_xattr_set_entry(ci, xi, xsi->xi_block,
+					    OCFS2_HAS_XATTR_FL);
+		if (!ret)
+			ret = ocfs2_write_xattr_block(fs, xsi->xi_block->blkno,
+						      xsi->xi_block->blkbuf);
+		if (ret != OCFS2_ET_XATTR_NOSPC)
+			goto out;
+
+		ret = ocfs2_xattr_create_index_block(ci, xsi);
+		if (ret)
+			goto out;
+	}
+
+	ret = ocfs2_xattr_set_entry_index_block(ci, xi, xsi);
+	if (ret)
+		goto out;
+	ret = ocfs2_write_xattr_block(fs, xsi->xi_block->blkno,
+				      xsi->xi_block->blkbuf);
+	if (ret)
+		goto out;
+	ret = ocfs2_write_xattr_bucket(fs, xsi->xi_bucket->blkno,
+					xsi->xi_bucket->blkbuf);
+
+out:
+	return ret;
+}
+
+static errcode_t ocfs2_xattr_set_generic(ocfs2_cached_inode *ci,
+					 int name_index,
+					 const char *name,
+					 const char *value,
+					 size_t value_len)
+{
+	errcode_t ret = 0;
+	ocfs2_filesys *fs = ci->ci_fs;
+	int bpb = ocfs2_blocks_per_xattr_bucket(fs);
+	struct ocfs2_xattr_info xi = {
+		.name_index = name_index,
+		.name = name,
+		.value = value,
+		.value_len = value_len,
+	};
+	struct ocfs2_xattr_search xis = {
+		.blkbuf = (char *)ci->ci_inode,
+		.blkno = ci->ci_blkno,
+		.not_found = OCFS2_ET_XATTR_NODATA,
+	};
+	struct ocfs2_xattr_search xbs = {.not_found = OCFS2_ET_XATTR_NODATA,};
+	struct ocfs2_xattr_search xbks = {.not_found = OCFS2_ET_XATTR_NODATA,};
+	struct ocfs2_xattr_search_info xsi = {
+		.xi_inode = &xis,
+		.xi_block = &xbs,
+		.xi_bucket = &xbks,
+	};
+
+	/* alloc block buffer for xattr block */
+	ret = ocfs2_malloc_block(fs->fs_io, &xbs.blkbuf);
+	if (ret)
+		return ret;
+
+	/* alloc block buffer for xattr bucket */
+	ret = ocfs2_malloc_blocks(fs->fs_io, bpb, &xbks.blkbuf);
+	if (ret)
+		return ret;
+
+	/*
+	 * Scan inode and external block to find the same name
+	 * extended attribute and collect search infomation.
+	 */
+	ret = ocfs2_xattr_ibody_find(ci, name_index, name, &xis);
+	if (ret)
+		goto cleanup;
+	if (xis.not_found) {
+		ret = ocfs2_xattr_block_find(ci, name_index, name, &xsi);
+		if (ret)
+			goto cleanup;
+	}
+	if (!xi.value) {
+		/* Remove existing extended attribute */
+		if (!xis.not_found)
+			ret = ocfs2_xattr_ibody_set(ci, &xi, &xis);
+		else if (!xbs.not_found)
+			ret = ocfs2_xattr_block_set(ci, &xi, &xsi);
+	} else {
+		/* We always try to set extended attribute into inode first*/
+		ret = ocfs2_xattr_ibody_set(ci, &xi, &xis);
+		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;
+			ret = ocfs2_xattr_block_set(ci, &xi, &xsi);
+		} else if (ret == OCFS2_ET_XATTR_NOSPC) {
+			if (ci->ci_inode->i_xattr_loc && !xsi.xi_block->blkno) {
+				ret = ocfs2_xattr_block_find(ci, name_index,
+							     name, &xsi);
+				if (ret)
+					goto cleanup;
+			}
+			/*
+			 * If no space in inode, we will set extended attribute
+			 * into external block.
+			 */
+			ret = ocfs2_xattr_block_set(ci, &xi, &xsi);
+			if (ret)
+				goto cleanup;
+			if (!xis.not_found) {
+				/*
+				 * If succeed and that extended attribute
+				 * existing in inode, we will remove it.
+				 */
+				xi.value = NULL;
+				xi.value_len = 0;
+				ret = ocfs2_xattr_ibody_set(ci, &xi, &xis);
+			}
+		}
+	}
+cleanup:
+	if (xbs.blkbuf)
+		ocfs2_free(&xbs.blkbuf);
+	if (xbks.blkbuf)
+		ocfs2_free(&xbks.blkbuf);
+	return ret;
+}
+
+static const char *strcmp_prefix(const char *a, const char *a_prefix)
+{
+	while (*a_prefix && *a == *a_prefix) {
+		a++;
+		a_prefix++;
+	}
+	return *a_prefix ? NULL : a;
+}
+
+/*
+ * Find the xattr_handler with the matching prefix.
+ */
+static int ocfs2_xattr_resolve_name(const char **name)
+{
+	int i;
+
+	if (!*name)
+		return -1;
+
+	for (i = 1; i < OCFS2_XATTR_MAX; i++) {
+		const char *n = strcmp_prefix(*name, ocfs2_xattr_prefix[i]);
+		if (n) {
+			*name = n;
+			return i;
+		}
+	}
+	return -1;
+}
+
+/*
+ * Read the value of xattr 'name' from the inode 'ci'.  Fill 'buf' up
+ * to 'count' bytes.  If 'got' is not NULL, fill it with how many bytes
+ * were actually read.
+ */
+errcode_t ocfs2_xattr_get(ocfs2_cached_inode *ci, const char *name,
+			  char *buf, size_t count, size_t *got)
+{
+	int name_index;
+	struct ocfs2_super_block *sb = OCFS2_RAW_SB(ci->ci_fs->fs_super);
+	struct ocfs2_dinode *di = ci->ci_inode;
+
+	if (!(sb->s_feature_incompat & OCFS2_FEATURE_INCOMPAT_XATTR))
+		return OCFS2_ET_UNSUPP_FEATURE;
+	if (!(di->i_dyn_features & OCFS2_HAS_XATTR_FL))
+		return OCFS2_ET_XATTR_NODATA;
+
+	name_index = ocfs2_xattr_resolve_name(&name);
+	if (name_index < 0)
+		return OCFS2_ET_INVALID_ARGUMENT;
+	return ocfs2_xattr_get_generic(ci, name_index, name, buf, count, got);
+}
+
+/*
+ * Set the value of xattr 'name' on the inode 'ci'.  The value is 'count'
+ * bytes long in 'buf'.
+ */
+errcode_t ocfs2_xattr_set(ocfs2_cached_inode *ci,
+			  const char *name,
+			  const char *buf,
+			  size_t count)
+{
+	int name_index = 0;
+	struct ocfs2_super_block *sb = OCFS2_RAW_SB(ci->ci_fs->fs_super);
+
+	if (!(sb->s_feature_incompat & OCFS2_FEATURE_INCOMPAT_XATTR))
+		return OCFS2_ET_UNSUPP_FEATURE;
+
+	name_index = ocfs2_xattr_resolve_name(&name);
+	if (name_index < 0)
+		return OCFS2_ET_INVALID_ARGUMENT;
+	return ocfs2_xattr_set_generic(ci, name_index, name, buf, count);
+}
diff --git a/libocfs2/xattr.h b/libocfs2/xattr.h
index 475f0f2..a66b0c0 100644
--- a/libocfs2/xattr.h
+++ b/libocfs2/xattr.h
@@ -17,3 +17,18 @@
 
 #define OCFS2_MAX_XATTR_TREE_LEAF_SIZE	65536
 
+enum ocfs2_xattr_type {
+	OCFS2_XATTR_INDEX_USER = 1,
+	OCFS2_XATTR_INDEX_POSIX_ACL_ACCESS,
+	OCFS2_XATTR_INDEX_POSIX_ACL_DEFAULT,
+	OCFS2_XATTR_INDEX_TRUSTED,
+	OCFS2_XATTR_INDEX_SECURITY,
+	OCFS2_XATTR_MAX
+};
+
+struct ocfs2_xattr_value_buf {
+	char *vb_buf;
+	uint64_t vb_blkno;
+	struct ocfs2_xattr_value_root *vb_xv;
+};
+
-- 
1.5.4.1




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