ocfs2: Add extended attribute support

This patch implements storing extended attributes both in inode or a single
external block. We only store EA's in-inode when blocksize > 512 or that
inode block has free space for it. When an EA's value is larger than 80
bytes, we will store the value via b-tree outside inode or block.

Signed-off-by: Tiger Yang <tiger.yang@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>

1 files changed, 1620 insertions, 0 deletions

diff --git a/fs/ocfs2/xattr.c b/fs/ocfs2/xattr.c
index 9604a4cd02bb..67bebd9259e7 100644
--- a/fs/ocfs2/xattr.c
+++ b/fs/ocfs2/xattr.c
@@ -5,6 +5,9 @@
  *
  * Copyright (C) 2008 Oracle.  All rights reserved.
  *
+ * CREDITS:
+ * Lots of code in this file is taken from ext3.
+ *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public
  * License as published by the Free Software Foundation; either
@@ -21,6 +24,19 @@
  * Boston, MA 021110-1307, USA.
  */
 
+#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>
+
 #define MLOG_MASK_PREFIX ML_XATTR
 #include <cluster/masklog.h>
 
@@ -28,12 +44,119 @@
 #include "alloc.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 "xattr.h"
+
+
+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))
+#define OCFS2_XATTR_INLINE_SIZE	80
+
+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,
+	&ocfs2_xattr_trusted_handler,
+	NULL
+};
+
+static struct xattr_handler *ocfs2_xattr_handler_map[] = {
+	[OCFS2_XATTR_INDEX_USER]	= &ocfs2_xattr_user_handler,
+	[OCFS2_XATTR_INDEX_TRUSTED]	= &ocfs2_xattr_trusted_handler,
+};
+
+struct ocfs2_xattr_info {
+	int name_index;
+	const char *name;
+	const void *value;
+	size_t value_len;
+};
+
+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;
+	void *base;
+	void *end;
+	struct ocfs2_xattr_entry *here;
+	int not_found;
+};
+
+static inline struct xattr_handler *ocfs2_xattr_handler(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;
+}
+
+static inline u32 ocfs2_xattr_name_hash(struct inode *inode,
+					char *prefix,
+					int prefix_len,
+					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 prefix */
+	for (i = 0; i < prefix_len; i++) {
+		hash = (hash << OCFS2_HASH_SHIFT) ^
+		       (hash >> (8*sizeof(hash) - OCFS2_HASH_SHIFT)) ^
+		       *prefix++;
+	}
+	/* 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;
+	struct xattr_handler *handler =
+			ocfs2_xattr_handler(ocfs2_xattr_get_type(entry));
+	char *prefix = handler->prefix;
+	char *name = (char *)header + le16_to_cpu(entry->xe_name_offset);
+	int prefix_len = strlen(handler->prefix);
+
+	hash = ocfs2_xattr_name_hash(inode, prefix, prefix_len, name,
+				     entry->xe_name_len);
+	entry->xe_name_hash = cpu_to_le32(hash);
+
+	return;
+}
 
 static int ocfs2_xattr_extend_allocation(struct inode *inode,
 					 u32 clusters_to_add,
@@ -303,3 +426,1500 @@ static int ocfs2_xattr_value_truncate(struct inode *inode,
 
 	return ret;
 }
+
+static int ocfs2_xattr_list_entries(struct inode *inode,
+				    struct ocfs2_xattr_header *header,
+				    char *buffer, size_t buffer_size)
+{
+	size_t rest = buffer_size;
+	int i;
+
+	for (i = 0 ; i < le16_to_cpu(header->xh_count); i++) {
+		struct ocfs2_xattr_entry *entry = &header->xh_entries[i];
+		struct xattr_handler *handler =
+			ocfs2_xattr_handler(ocfs2_xattr_get_type(entry));
+
+		if (handler) {
+			size_t size = handler->list(inode, buffer, rest,
+					((char *)header +
+					le16_to_cpu(entry->xe_name_offset)),
+					entry->xe_name_len);
+			if (buffer) {
+				if (size > rest)
+					return -ERANGE;
+				buffer += size;
+			}
+			rest -= size;
+		}
+	}
+
+	return buffer_size - rest;
+}
+
+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_header *header = NULL;
+	int ret = 0;
+
+	if (!di->i_xattr_loc)
+		return ret;
+
+	ret = ocfs2_read_block(OCFS2_SB(inode->i_sb),
+			       le64_to_cpu(di->i_xattr_loc),
+			       &blk_bh, OCFS2_BH_CACHED, inode);
+	if (ret < 0) {
+		mlog_errno(ret);
+		return ret;
+	}
+	/*Verify the signature of xattr block*/
+	if (memcmp((void *)blk_bh->b_data, OCFS2_XATTR_BLOCK_SIGNATURE,
+		   strlen(OCFS2_XATTR_BLOCK_SIGNATURE))) {
+		ret = -EFAULT;
+		goto cleanup;
+	}
+
+	header = &((struct ocfs2_xattr_block *)blk_bh->b_data)->
+		 xb_attrs.xb_header;
+
+	ret = ocfs2_xattr_list_entries(inode, header, buffer, buffer_size);
+cleanup:
+	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 (!(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_search *xs,
+					 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_xattr_value_root *xv;
+	struct ocfs2_extent_list *el;
+
+	xv = (struct ocfs2_xattr_value_root *)
+		(xs->base + le16_to_cpu(xs->here->xe_name_offset) +
+		OCFS2_XATTR_SIZE(xs->here->xe_name_len));
+	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(OCFS2_SB(inode->i_sb), blkno,
+					       &bh, OCFS2_BH_CACHED, inode);
+			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;
+	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 {
+			ret = ocfs2_xattr_get_value_outside(inode, xs,
+							    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_dinode *di = (struct ocfs2_dinode *)xs->inode_bh->b_data;
+	struct buffer_head *blk_bh = NULL;
+	struct ocfs2_xattr_block *xb;
+	size_t size;
+	int ret = -ENODATA;
+
+	if (!di->i_xattr_loc)
+		return ret;
+
+	ret = ocfs2_read_block(OCFS2_SB(inode->i_sb),
+			       le64_to_cpu(di->i_xattr_loc),
+			       &blk_bh, OCFS2_BH_CACHED, inode);
+	if (ret < 0) {
+		mlog_errno(ret);
+		return ret;
+	}
+	/*Verify the signature of xattr block*/
+	if (memcmp((void *)blk_bh->b_data, OCFS2_XATTR_BLOCK_SIGNATURE,
+		   strlen(OCFS2_XATTR_BLOCK_SIGNATURE))) {
+		ret = -EFAULT;
+		goto cleanup;
+	}
+
+	xs->xattr_bh = blk_bh;
+	xb = (struct ocfs2_xattr_block *)blk_bh->b_data;
+	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);
+	if (ret)
+		goto cleanup;
+	size = le64_to_cpu(xs->here->xe_value_size);
+	if (buffer) {
+		ret = -ERANGE;
+		if (size > buffer_size)
+			goto cleanup;
+		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 {
+			ret = ocfs2_xattr_get_value_outside(inode, xs,
+							    buffer, size);
+			if (ret < 0) {
+				mlog_errno(ret);
+				goto cleanup;
+			}
+		}
+	}
+	ret = size;
+cleanup:
+	brelse(blk_bh);
+
+	return ret;
+}
+
+/* ocfs2_xattr_get()
+ *
+ * Copy an extended attribute into the buffer provided.
+ * Buffer is NULL to compute the size of buffer required.
+ */
+int ocfs2_xattr_get(struct inode *inode,
+		    int name_index,
+		    const char *name,
+		    void *buffer,
+		    size_t buffer_size)
+{
+	int ret;
+	struct ocfs2_dinode *di = NULL;
+	struct buffer_head *di_bh = 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 (!(oi->ip_dyn_features & OCFS2_HAS_XATTR_FL))
+		ret = -ENODATA;
+
+	ret = ocfs2_inode_lock(inode, &di_bh, 0);
+	if (ret < 0) {
+		mlog_errno(ret);
+		return ret;
+	}
+	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)
+		ret = ocfs2_xattr_block_get(inode, name_index, name, buffer,
+					    buffer_size, &xbs);
+	up_read(&oi->ip_xattr_sem);
+	ocfs2_inode_unlock(inode, 0);
+
+	brelse(di_bh);
+
+	return ret;
+}
+
+static int __ocfs2_xattr_set_value_outside(struct inode *inode,
+					   struct ocfs2_xattr_value_root *xv,
+					   const void *value,
+					   int value_len)
+{
+	int ret = 0, i, cp_len, credits;
+	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;
+	handle_t *handle;
+
+	BUG_ON(clusters > le32_to_cpu(xv->xr_clusters));
+
+	credits = clusters * bpc;
+	handle = ocfs2_start_trans(OCFS2_SB(inode->i_sb), credits);
+	if (IS_ERR(handle)) {
+		ret = PTR_ERR(handle);
+		mlog_errno(ret);
+		goto out;
+	}
+
+	while (cpos < clusters) {
+		ret = ocfs2_xattr_get_clusters(inode, cpos, &p_cluster,
+					       &num_clusters, &xv->xr_list);
+		if (ret) {
+			mlog_errno(ret);
+			goto out_commit;
+		}
+
+		blkno = ocfs2_clusters_to_blocks(inode->i_sb, p_cluster);
+
+		for (i = 0; i < num_clusters * bpc; i++, blkno++) {
+			ret = ocfs2_read_block(OCFS2_SB(inode->i_sb), blkno,
+					       &bh, OCFS2_BH_CACHED, inode);
+			if (ret) {
+				mlog_errno(ret);
+				goto out_commit;
+			}
+
+			ret = ocfs2_journal_access(handle,
+						   inode,
+						   bh,
+						   OCFS2_JOURNAL_ACCESS_WRITE);
+			if (ret < 0) {
+				mlog_errno(ret);
+				goto out_commit;
+			}
+
+			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_commit;
+			}
+			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_commit:
+	ocfs2_commit_trans(OCFS2_SB(inode->i_sb), handle);
+out:
+	brelse(bh);
+
+	return ret;
+}
+
+static int ocfs2_xattr_cleanup(struct inode *inode,
+			       struct ocfs2_xattr_info *xi,
+			       struct ocfs2_xattr_search *xs,
+			       size_t offs)
+{
+	handle_t *handle = NULL;
+	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;
+
+	handle = ocfs2_start_trans((OCFS2_SB(inode->i_sb)),
+				   OCFS2_XATTR_BLOCK_UPDATE_CREDITS);
+	if (IS_ERR(handle)) {
+		ret = PTR_ERR(handle);
+		mlog_errno(ret);
+		goto out;
+	}
+	ret = ocfs2_journal_access(handle, inode, xs->xattr_bh,
+				   OCFS2_JOURNAL_ACCESS_WRITE);
+	if (ret) {
+		mlog_errno(ret);
+		goto out_commit;
+	}
+	/* 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, xs->xattr_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_update_entry(struct inode *inode,
+				    struct ocfs2_xattr_info *xi,
+				    struct ocfs2_xattr_search *xs,
+				    size_t offs)
+{
+	handle_t *handle = NULL;
+	int ret = 0;
+
+	handle = ocfs2_start_trans((OCFS2_SB(inode->i_sb)),
+				   OCFS2_XATTR_BLOCK_UPDATE_CREDITS);
+	if (IS_ERR(handle)) {
+		ret = PTR_ERR(handle);
+		mlog_errno(ret);
+		goto out;
+	}
+	ret = ocfs2_journal_access(handle, inode, xs->xattr_bh,
+				   OCFS2_JOURNAL_ACCESS_WRITE);
+	if (ret) {
+		mlog_errno(ret);
+		goto out_commit;
+	}
+
+	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, xs->xattr_bh);
+	if (ret < 0)
+		mlog_errno(ret);
+out_commit:
+	ocfs2_commit_trans(OCFS2_SB(inode->i_sb), handle);
+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,
+					 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;
+
+	ret = ocfs2_xattr_value_truncate(inode, xs->xattr_bh, xv,
+					 xi->value_len);
+	if (ret < 0) {
+		mlog_errno(ret);
+		return ret;
+	}
+	ret = __ocfs2_xattr_set_value_outside(inode, xv, xi->value,
+					      xi->value_len);
+	if (ret < 0) {
+		mlog_errno(ret);
+		return ret;
+	}
+	ret = ocfs2_xattr_update_entry(inode, xi, xs, offs);
+	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,
+				 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 = NULL;
+	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,
+	};
+
+	/* 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) - sizeof(__u32);
+	if (free < 0)
+		return -EFAULT;
+
+	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,
+							    offs);
+			if (ret < 0)
+				mlog_errno(ret);
+			goto out;
+		} else if (!ocfs2_xattr_is_local(xs->here)) {
+			/* For existing xattr which has value outside */
+			struct ocfs2_xattr_value_root *xv = NULL;
+			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,
+								 xs->xattr_bh,
+								 xv,
+								 xi->value_len);
+				if (ret < 0) {
+					mlog_errno(ret);
+					goto out;
+				}
+
+				ret = __ocfs2_xattr_set_value_outside(inode,
+								xv,
+								xi->value,
+								xi->value_len);
+				if (ret < 0) {
+					mlog_errno(ret);
+					goto out;
+				}
+
+				ret = ocfs2_xattr_update_entry(inode,
+							       xi,
+							       xs,
+							       offs);
+				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,
+								 xs->xattr_bh,
+								 xv,
+								 0);
+				if (ret < 0)
+					mlog_errno(ret);
+			}
+		}
+	}
+
+	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(handle, inode, xs->inode_bh,
+				   OCFS2_JOURNAL_ACCESS_WRITE);
+	if (ret) {
+		mlog_errno(ret);
+		goto out_commit;
+	}
+
+	if (!(flag & OCFS2_INLINE_XATTR_FL)) {
+		/*set extended attribue in external blcok*/
+		ret = ocfs2_extend_trans(handle,
+					 OCFS2_XATTR_BLOCK_UPDATE_CREDITS);
+		if (ret) {
+			mlog_errno(ret);
+			goto out_commit;
+		}
+		ret = ocfs2_journal_access(handle, inode, xs->xattr_bh,
+					   OCFS2_JOURNAL_ACCESS_WRITE);
+		if (ret) {
+			mlog_errno(ret);
+			goto out_commit;
+		}
+	}
+
+	/*
+	 * 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_commit;
+		}
+	}
+
+	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);
+	/* Update inode ctime */
+	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);
+
+	ret = ocfs2_journal_dirty(handle, xs->inode_bh);
+	if (ret < 0)
+		mlog_errno(ret);
+
+out_commit:
+	ocfs2_commit_trans(OCFS2_SB(inode->i_sb), handle);
+
+	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, 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, xi, xs, offs);
+			if (ret2 < 0)
+				mlog_errno(ret2);
+		}
+	}
+out:
+	return ret;
+
+}
+
+static int ocfs2_xattr_free_block(handle_t *handle,
+				  struct ocfs2_super *osb,
+				  struct ocfs2_xattr_block *xb)
+{
+	struct inode *xb_alloc_inode;
+	struct buffer_head *xb_alloc_bh = NULL;
+	u64 blk = le64_to_cpu(xb->xb_blkno);
+	u16 bit = le16_to_cpu(xb->xb_suballoc_bit);
+	u64 bg_blkno = ocfs2_which_suballoc_group(blk, bit);
+	int ret = 0;
+
+	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;
+	}
+	ret = ocfs2_extend_trans(handle, OCFS2_SUBALLOC_FREE);
+	if (ret < 0) {
+		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);
+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:
+	return ret;
+}
+
+static int ocfs2_remove_value_outside(struct inode*inode,
+				      struct buffer_head *bh,
+				      struct ocfs2_xattr_header *header)
+{
+	int ret = 0, i;
+
+	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)) {
+			struct ocfs2_xattr_value_root *xv;
+			void *val;
+
+			val = (void *)header +
+				le16_to_cpu(entry->xe_name_offset);
+			xv = (struct ocfs2_xattr_value_root *)
+				(val + OCFS2_XATTR_SIZE(entry->xe_name_len));
+			ret = ocfs2_xattr_value_truncate(inode, bh, xv, 0);
+			if (ret < 0) {
+				mlog_errno(ret);
+				return ret;
+			}
+		}
+	}
+
+	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;
+
+	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, di_bh, header);
+
+	return ret;
+}
+
+static int ocfs2_xattr_block_remove(struct inode *inode,
+				    struct buffer_head *blk_bh)
+{
+	struct ocfs2_xattr_block *xb;
+	struct ocfs2_xattr_header *header;
+	int ret = 0;
+
+	xb = (struct ocfs2_xattr_block *)blk_bh->b_data;
+	header = &(xb->xb_attrs.xb_header);
+
+	ret = ocfs2_remove_value_outside(inode, blk_bh, header);
+
+	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_xattr_block *xb;
+	struct buffer_head *blk_bh = NULL;
+	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+	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 (!(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_read_block(OCFS2_SB(inode->i_sb),
+				       le64_to_cpu(di->i_xattr_loc),
+				       &blk_bh, OCFS2_BH_CACHED, inode);
+		if (ret < 0) {
+			mlog_errno(ret);
+			return ret;
+		}
+		/*Verify the signature of xattr block*/
+		if (memcmp((void *)blk_bh->b_data, OCFS2_XATTR_BLOCK_SIGNATURE,
+			   strlen(OCFS2_XATTR_BLOCK_SIGNATURE))) {
+			ret = -EFAULT;
+			goto out;
+		}
+
+		ret = ocfs2_xattr_block_remove(inode, blk_bh);
+		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(handle, inode, di_bh,
+				   OCFS2_JOURNAL_ACCESS_WRITE);
+	if (ret) {
+		mlog_errno(ret);
+		goto out_commit;
+	}
+
+	if (di->i_xattr_loc) {
+		xb = (struct ocfs2_xattr_block *)blk_bh->b_data;
+		ocfs2_xattr_free_block(handle, osb, xb);
+		di->i_xattr_loc = cpu_to_le64(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:
+	brelse(blk_bh);
+
+	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_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,
+				(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;
+	int ret = 0;
+
+	if (!di->i_xattr_loc)
+		return ret;
+
+	ret = ocfs2_read_block(OCFS2_SB(inode->i_sb),
+			       le64_to_cpu(di->i_xattr_loc),
+			       &blk_bh, OCFS2_BH_CACHED, inode);
+	if (ret < 0) {
+		mlog_errno(ret);
+		return ret;
+	}
+	/*Verify the signature of xattr block*/
+	if (memcmp((void *)blk_bh->b_data, OCFS2_XATTR_BLOCK_SIGNATURE,
+		   strlen(OCFS2_XATTR_BLOCK_SIGNATURE))) {
+			ret = -EFAULT;
+			goto cleanup;
+	}
+
+	xs->xattr_bh = blk_bh;
+	xs->header = &((struct ocfs2_xattr_block *)blk_bh->b_data)->
+			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);
+	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 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;
+	struct ocfs2_alloc_context *meta_ac = NULL;
+	handle_t *handle = NULL;
+	struct ocfs2_xattr_block *xblk = NULL;
+	u16 suballoc_bit_start;
+	u32 num_got;
+	u64 first_blkno;
+	int ret;
+
+	if (!xs->xattr_bh) {
+		/*
+		 * Alloc one external block for extended attribute
+		 * outside of inode.
+		 */
+		ret = ocfs2_reserve_new_metadata_blocks(osb, 1, &meta_ac);
+		if (ret < 0) {
+			mlog_errno(ret);
+			goto out;
+		}
+		handle = ocfs2_start_trans(osb,
+					   OCFS2_XATTR_BLOCK_CREATE_CREDITS);
+		if (IS_ERR(handle)) {
+			ret = PTR_ERR(handle);
+			mlog_errno(ret);
+			goto out;
+		}
+		ret = ocfs2_journal_access(handle, inode, xs->inode_bh,
+					   OCFS2_JOURNAL_ACCESS_CREATE);
+		if (ret < 0) {
+			mlog_errno(ret);
+			goto out_commit;
+		}
+
+		ret = ocfs2_claim_metadata(osb, handle, meta_ac, 1,
+					   &suballoc_bit_start, &num_got,
+					   &first_blkno);
+		if (ret < 0) {
+			mlog_errno(ret);
+			goto out_commit;
+		}
+
+		new_bh = sb_getblk(inode->i_sb, first_blkno);
+		ocfs2_set_new_buffer_uptodate(inode, new_bh);
+
+		ret = ocfs2_journal_access(handle, inode, new_bh,
+					   OCFS2_JOURNAL_ACCESS_CREATE);
+		if (ret < 0) {
+			mlog_errno(ret);
+			goto out_commit;
+		}
+
+		/* 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 out_commit;
+		}
+		di->i_xattr_loc = cpu_to_le64(first_blkno);
+		ret = ocfs2_journal_dirty(handle, xs->inode_bh);
+		if (ret < 0)
+			mlog_errno(ret);
+out_commit:
+		ocfs2_commit_trans(osb, handle);
+out:
+		if (meta_ac)
+			ocfs2_free_alloc_context(meta_ac);
+		if (ret < 0)
+			return ret;
+	}
+
+	/* Set extended attribute into external block */
+	ret = ocfs2_xattr_set_entry(inode, xi, xs, OCFS2_HAS_XATTR_FL);
+
+	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;
+
+	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,
+	};
+
+	ret = ocfs2_inode_lock(inode, &di_bh, 1);
+	if (ret < 0) {
+		mlog_errno(ret);
+		return ret;
+	}
+	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;
+	}
+
+	if (!value) {
+		/* Remove existing extended attribute */
+		if (!xis.not_found)
+			ret = ocfs2_xattr_ibody_set(inode, &xi, &xis);
+		else if (!xbs.not_found)
+			ret = ocfs2_xattr_block_set(inode, &xi, &xbs);
+	} else {
+		/* We always try to set extended attribute into inode first*/
+		ret = ocfs2_xattr_ibody_set(inode, &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(inode, &xi, &xbs);
+		} else if (ret == -ENOSPC) {
+			if (di->i_xattr_loc && !xbs.xattr_bh) {
+				ret = ocfs2_xattr_block_find(inode, name_index,
+							     name, &xbs);
+				if (ret)
+					goto cleanup;
+			}
+			/*
+			 * If no space in inode, we will set extended attribute
+			 * into external block.
+			 */
+			ret = ocfs2_xattr_block_set(inode, &xi, &xbs);
+			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(inode, &xi, &xis);
+			}
+		}
+	}
+cleanup:
+	up_write(&OCFS2_I(inode)->ip_xattr_sem);
+	ocfs2_inode_unlock(inode, 1);
+	brelse(di_bh);
+	brelse(xbs.xattr_bh);
+
+	return ret;
+}
+