Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 3165 insertions, 0 deletions

diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
new file mode 100644
index 000000000..eaed9fd2f
--- /dev/null
+++ b/fs/ext4/xattr.c
@@ -0,0 +1,3165 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/ext4/xattr.c
+ *
+ * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de>
+ *
+ * Fix by Harrison Xing <harrison@mountainviewdata.com>.
+ * Ext4 code with a lot of help from Eric Jarman <ejarman@acm.org>.
+ * Extended attributes for symlinks and special files added per
+ *  suggestion of Luka Renko <luka.renko@hermes.si>.
+ * xattr consolidation Copyright (c) 2004 James Morris <jmorris@redhat.com>,
+ *  Red Hat Inc.
+ * ea-in-inode support by Alex Tomas <alex@clusterfs.com> aka bzzz
+ *  and Andreas Gruenbacher <agruen@suse.de>.
+ */
+
+/*
+ * Extended attributes are stored directly in inodes (on file systems with
+ * inodes bigger than 128 bytes) and on additional disk blocks. The i_file_acl
+ * field contains the block number if an inode uses an additional block. All
+ * attributes must fit in the inode and one additional block. Blocks that
+ * contain the identical set of attributes may be shared among several inodes.
+ * Identical blocks are detected by keeping a cache of blocks that have
+ * recently been accessed.
+ *
+ * The attributes in inodes and on blocks have a different header; the entries
+ * are stored in the same format:
+ *
+ *   +------------------+
+ *   | header           |
+ *   | entry 1          | |
+ *   | entry 2          | | growing downwards
+ *   | entry 3          | v
+ *   | four null bytes  |
+ *   | . . .            |
+ *   | value 1          | ^
+ *   | value 3          | | growing upwards
+ *   | value 2          | |
+ *   +------------------+
+ *
+ * The header is followed by multiple entry descriptors. In disk blocks, the
+ * entry descriptors are kept sorted. In inodes, they are unsorted. The
+ * attribute values are aligned to the end of the block in no specific order.
+ *
+ * Locking strategy
+ * ----------------
+ * EXT4_I(inode)->i_file_acl is protected by EXT4_I(inode)->xattr_sem.
+ * EA blocks are only changed if they are exclusive to an inode, so
+ * holding xattr_sem also means that nothing but the EA block's reference
+ * count can change. Multiple writers to the same block are synchronized
+ * by the buffer lock.
+ */
+
+#include <linux/init.h>
+#include <linux/fs.h>
+#include <linux/slab.h>
+#include <linux/mbcache.h>
+#include <linux/quotaops.h>
+#include <linux/iversion.h>
+#include "ext4_jbd2.h"
+#include "ext4.h"
+#include "xattr.h"
+#include "acl.h"
+
+#ifdef EXT4_XATTR_DEBUG
+# define ea_idebug(inode, fmt, ...)					\
+	printk(KERN_DEBUG "inode %s:%lu: " fmt "\n",			\
+	       inode->i_sb->s_id, inode->i_ino, ##__VA_ARGS__)
+# define ea_bdebug(bh, fmt, ...)					\
+	printk(KERN_DEBUG "block %pg:%lu: " fmt "\n",			\
+	       bh->b_bdev, (unsigned long)bh->b_blocknr, ##__VA_ARGS__)
+#else
+# define ea_idebug(inode, fmt, ...)	no_printk(fmt, ##__VA_ARGS__)
+# define ea_bdebug(bh, fmt, ...)	no_printk(fmt, ##__VA_ARGS__)
+#endif
+
+static void ext4_xattr_block_cache_insert(struct mb_cache *,
+					  struct buffer_head *);
+static struct buffer_head *
+ext4_xattr_block_cache_find(struct inode *, struct ext4_xattr_header *,
+			    struct mb_cache_entry **);
+static __le32 ext4_xattr_hash_entry(char *name, size_t name_len, __le32 *value,
+				    size_t value_count);
+static void ext4_xattr_rehash(struct ext4_xattr_header *);
+
+static const struct xattr_handler * const ext4_xattr_handler_map[] = {
+	[EXT4_XATTR_INDEX_USER]		     = &ext4_xattr_user_handler,
+#ifdef CONFIG_EXT4_FS_POSIX_ACL
+	[EXT4_XATTR_INDEX_POSIX_ACL_ACCESS]  = &posix_acl_access_xattr_handler,
+	[EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT] = &posix_acl_default_xattr_handler,
+#endif
+	[EXT4_XATTR_INDEX_TRUSTED]	     = &ext4_xattr_trusted_handler,
+#ifdef CONFIG_EXT4_FS_SECURITY
+	[EXT4_XATTR_INDEX_SECURITY]	     = &ext4_xattr_security_handler,
+#endif
+	[EXT4_XATTR_INDEX_HURD]		     = &ext4_xattr_hurd_handler,
+};
+
+const struct xattr_handler *ext4_xattr_handlers[] = {
+	&ext4_xattr_user_handler,
+	&ext4_xattr_trusted_handler,
+#ifdef CONFIG_EXT4_FS_POSIX_ACL
+	&posix_acl_access_xattr_handler,
+	&posix_acl_default_xattr_handler,
+#endif
+#ifdef CONFIG_EXT4_FS_SECURITY
+	&ext4_xattr_security_handler,
+#endif
+	&ext4_xattr_hurd_handler,
+	NULL
+};
+
+#define EA_BLOCK_CACHE(inode)	(((struct ext4_sb_info *) \
+				inode->i_sb->s_fs_info)->s_ea_block_cache)
+
+#define EA_INODE_CACHE(inode)	(((struct ext4_sb_info *) \
+				inode->i_sb->s_fs_info)->s_ea_inode_cache)
+
+static int
+ext4_expand_inode_array(struct ext4_xattr_inode_array **ea_inode_array,
+			struct inode *inode);
+
+#ifdef CONFIG_LOCKDEP
+void ext4_xattr_inode_set_class(struct inode *ea_inode)
+{
+	struct ext4_inode_info *ei = EXT4_I(ea_inode);
+
+	lockdep_set_subclass(&ea_inode->i_rwsem, 1);
+	(void) ei;	/* shut up clang warning if !CONFIG_LOCKDEP */
+	lockdep_set_subclass(&ei->i_data_sem, I_DATA_SEM_EA);
+}
+#endif
+
+static __le32 ext4_xattr_block_csum(struct inode *inode,
+				    sector_t block_nr,
+				    struct ext4_xattr_header *hdr)
+{
+	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+	__u32 csum;
+	__le64 dsk_block_nr = cpu_to_le64(block_nr);
+	__u32 dummy_csum = 0;
+	int offset = offsetof(struct ext4_xattr_header, h_checksum);
+
+	csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&dsk_block_nr,
+			   sizeof(dsk_block_nr));
+	csum = ext4_chksum(sbi, csum, (__u8 *)hdr, offset);
+	csum = ext4_chksum(sbi, csum, (__u8 *)&dummy_csum, sizeof(dummy_csum));
+	offset += sizeof(dummy_csum);
+	csum = ext4_chksum(sbi, csum, (__u8 *)hdr + offset,
+			   EXT4_BLOCK_SIZE(inode->i_sb) - offset);
+
+	return cpu_to_le32(csum);
+}
+
+static int ext4_xattr_block_csum_verify(struct inode *inode,
+					struct buffer_head *bh)
+{
+	struct ext4_xattr_header *hdr = BHDR(bh);
+	int ret = 1;
+
+	if (ext4_has_metadata_csum(inode->i_sb)) {
+		lock_buffer(bh);
+		ret = (hdr->h_checksum == ext4_xattr_block_csum(inode,
+							bh->b_blocknr, hdr));
+		unlock_buffer(bh);
+	}
+	return ret;
+}
+
+static void ext4_xattr_block_csum_set(struct inode *inode,
+				      struct buffer_head *bh)
+{
+	if (ext4_has_metadata_csum(inode->i_sb))
+		BHDR(bh)->h_checksum = ext4_xattr_block_csum(inode,
+						bh->b_blocknr, BHDR(bh));
+}
+
+static inline const struct xattr_handler *
+ext4_xattr_handler(int name_index)
+{
+	const struct xattr_handler *handler = NULL;
+
+	if (name_index > 0 && name_index < ARRAY_SIZE(ext4_xattr_handler_map))
+		handler = ext4_xattr_handler_map[name_index];
+	return handler;
+}
+
+static int
+ext4_xattr_check_entries(struct ext4_xattr_entry *entry, void *end,
+			 void *value_start)
+{
+	struct ext4_xattr_entry *e = entry;
+
+	/* Find the end of the names list */
+	while (!IS_LAST_ENTRY(e)) {
+		struct ext4_xattr_entry *next = EXT4_XATTR_NEXT(e);
+		if ((void *)next >= end)
+			return -EFSCORRUPTED;
+		if (strnlen(e->e_name, e->e_name_len) != e->e_name_len)
+			return -EFSCORRUPTED;
+		e = next;
+	}
+
+	/* Check the values */
+	while (!IS_LAST_ENTRY(entry)) {
+		u32 size = le32_to_cpu(entry->e_value_size);
+
+		if (size > EXT4_XATTR_SIZE_MAX)
+			return -EFSCORRUPTED;
+
+		if (size != 0 && entry->e_value_inum == 0) {
+			u16 offs = le16_to_cpu(entry->e_value_offs);
+			void *value;
+
+			/*
+			 * The value cannot overlap the names, and the value
+			 * with padding cannot extend beyond 'end'.  Check both
+			 * the padded and unpadded sizes, since the size may
+			 * overflow to 0 when adding padding.
+			 */
+			if (offs > end - value_start)
+				return -EFSCORRUPTED;
+			value = value_start + offs;
+			if (value < (void *)e + sizeof(u32) ||
+			    size > end - value ||
+			    EXT4_XATTR_SIZE(size) > end - value)
+				return -EFSCORRUPTED;
+		}
+		entry = EXT4_XATTR_NEXT(entry);
+	}
+
+	return 0;
+}
+
+static inline int
+__ext4_xattr_check_block(struct inode *inode, struct buffer_head *bh,
+			 const char *function, unsigned int line)
+{
+	int error = -EFSCORRUPTED;
+
+	if (BHDR(bh)->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC) ||
+	    BHDR(bh)->h_blocks != cpu_to_le32(1))
+		goto errout;
+	if (buffer_verified(bh))
+		return 0;
+
+	error = -EFSBADCRC;
+	if (!ext4_xattr_block_csum_verify(inode, bh))
+		goto errout;
+	error = ext4_xattr_check_entries(BFIRST(bh), bh->b_data + bh->b_size,
+					 bh->b_data);
+errout:
+	if (error)
+		__ext4_error_inode(inode, function, line, 0, -error,
+				   "corrupted xattr block %llu",
+				   (unsigned long long) bh->b_blocknr);
+	else
+		set_buffer_verified(bh);
+	return error;
+}
+
+#define ext4_xattr_check_block(inode, bh) \
+	__ext4_xattr_check_block((inode), (bh),  __func__, __LINE__)
+
+
+static int
+__xattr_check_inode(struct inode *inode, struct ext4_xattr_ibody_header *header,
+			 void *end, const char *function, unsigned int line)
+{
+	int error = -EFSCORRUPTED;
+
+	if (end - (void *)header < sizeof(*header) + sizeof(u32) ||
+	    (header->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC)))
+		goto errout;
+	error = ext4_xattr_check_entries(IFIRST(header), end, IFIRST(header));
+errout:
+	if (error)
+		__ext4_error_inode(inode, function, line, 0, -error,
+				   "corrupted in-inode xattr");
+	return error;
+}
+
+#define xattr_check_inode(inode, header, end) \
+	__xattr_check_inode((inode), (header), (end), __func__, __LINE__)
+
+static int
+xattr_find_entry(struct inode *inode, struct ext4_xattr_entry **pentry,
+		 void *end, int name_index, const char *name, int sorted)
+{
+	struct ext4_xattr_entry *entry, *next;
+	size_t name_len;
+	int cmp = 1;
+
+	if (name == NULL)
+		return -EINVAL;
+	name_len = strlen(name);
+	for (entry = *pentry; !IS_LAST_ENTRY(entry); entry = next) {
+		next = EXT4_XATTR_NEXT(entry);
+		if ((void *) next >= end) {
+			EXT4_ERROR_INODE(inode, "corrupted xattr entries");
+			return -EFSCORRUPTED;
+		}
+		cmp = name_index - entry->e_name_index;
+		if (!cmp)
+			cmp = name_len - entry->e_name_len;
+		if (!cmp)
+			cmp = memcmp(name, entry->e_name, name_len);
+		if (cmp <= 0 && (sorted || cmp == 0))
+			break;
+	}
+	*pentry = entry;
+	return cmp ? -ENODATA : 0;
+}
+
+static u32
+ext4_xattr_inode_hash(struct ext4_sb_info *sbi, const void *buffer, size_t size)
+{
+	return ext4_chksum(sbi, sbi->s_csum_seed, buffer, size);
+}
+
+static u64 ext4_xattr_inode_get_ref(struct inode *ea_inode)
+{
+	return ((u64)ea_inode->i_ctime.tv_sec << 32) |
+		(u32) inode_peek_iversion_raw(ea_inode);
+}
+
+static void ext4_xattr_inode_set_ref(struct inode *ea_inode, u64 ref_count)
+{
+	ea_inode->i_ctime.tv_sec = (u32)(ref_count >> 32);
+	inode_set_iversion_raw(ea_inode, ref_count & 0xffffffff);
+}
+
+static u32 ext4_xattr_inode_get_hash(struct inode *ea_inode)
+{
+	return (u32)ea_inode->i_atime.tv_sec;
+}
+
+static void ext4_xattr_inode_set_hash(struct inode *ea_inode, u32 hash)
+{
+	ea_inode->i_atime.tv_sec = hash;
+}
+
+/*
+ * Read the EA value from an inode.
+ */
+static int ext4_xattr_inode_read(struct inode *ea_inode, void *buf, size_t size)
+{
+	int blocksize = 1 << ea_inode->i_blkbits;
+	int bh_count = (size + blocksize - 1) >> ea_inode->i_blkbits;
+	int tail_size = (size % blocksize) ?: blocksize;
+	struct buffer_head *bhs_inline[8];
+	struct buffer_head **bhs = bhs_inline;
+	int i, ret;
+
+	if (bh_count > ARRAY_SIZE(bhs_inline)) {
+		bhs = kmalloc_array(bh_count, sizeof(*bhs), GFP_NOFS);
+		if (!bhs)
+			return -ENOMEM;
+	}
+
+	ret = ext4_bread_batch(ea_inode, 0 /* block */, bh_count,
+			       true /* wait */, bhs);
+	if (ret)
+		goto free_bhs;
+
+	for (i = 0; i < bh_count; i++) {
+		/* There shouldn't be any holes in ea_inode. */
+		if (!bhs[i]) {
+			ret = -EFSCORRUPTED;
+			goto put_bhs;
+		}
+		memcpy((char *)buf + blocksize * i, bhs[i]->b_data,
+		       i < bh_count - 1 ? blocksize : tail_size);
+	}
+	ret = 0;
+put_bhs:
+	for (i = 0; i < bh_count; i++)
+		brelse(bhs[i]);
+free_bhs:
+	if (bhs != bhs_inline)
+		kfree(bhs);
+	return ret;
+}
+
+#define EXT4_XATTR_INODE_GET_PARENT(inode) ((__u32)(inode)->i_mtime.tv_sec)
+
+static int ext4_xattr_inode_iget(struct inode *parent, unsigned long ea_ino,
+				 u32 ea_inode_hash, struct inode **ea_inode)
+{
+	struct inode *inode;
+	int err;
+
+	/*
+	 * We have to check for this corruption early as otherwise
+	 * iget_locked() could wait indefinitely for the state of our
+	 * parent inode.
+	 */
+	if (parent->i_ino == ea_ino) {
+		ext4_error(parent->i_sb,
+			   "Parent and EA inode have the same ino %lu", ea_ino);
+		return -EFSCORRUPTED;
+	}
+
+	inode = ext4_iget(parent->i_sb, ea_ino, EXT4_IGET_EA_INODE);
+	if (IS_ERR(inode)) {
+		err = PTR_ERR(inode);
+		ext4_error(parent->i_sb,
+			   "error while reading EA inode %lu err=%d", ea_ino,
+			   err);
+		return err;
+	}
+	ext4_xattr_inode_set_class(inode);
+
+	/*
+	 * Check whether this is an old Lustre-style xattr inode. Lustre
+	 * implementation does not have hash validation, rather it has a
+	 * backpointer from ea_inode to the parent inode.
+	 */
+	if (ea_inode_hash != ext4_xattr_inode_get_hash(inode) &&
+	    EXT4_XATTR_INODE_GET_PARENT(inode) == parent->i_ino &&
+	    inode->i_generation == parent->i_generation) {
+		ext4_set_inode_state(inode, EXT4_STATE_LUSTRE_EA_INODE);
+		ext4_xattr_inode_set_ref(inode, 1);
+	} else {
+		inode_lock(inode);
+		inode->i_flags |= S_NOQUOTA;
+		inode_unlock(inode);
+	}
+
+	*ea_inode = inode;
+	return 0;
+}
+
+/* Remove entry from mbcache when EA inode is getting evicted */
+void ext4_evict_ea_inode(struct inode *inode)
+{
+	struct mb_cache_entry *oe;
+
+	if (!EA_INODE_CACHE(inode))
+		return;
+	/* Wait for entry to get unused so that we can remove it */
+	while ((oe = mb_cache_entry_delete_or_get(EA_INODE_CACHE(inode),
+			ext4_xattr_inode_get_hash(inode), inode->i_ino))) {
+		mb_cache_entry_wait_unused(oe);
+		mb_cache_entry_put(EA_INODE_CACHE(inode), oe);
+	}
+}
+
+static int
+ext4_xattr_inode_verify_hashes(struct inode *ea_inode,
+			       struct ext4_xattr_entry *entry, void *buffer,
+			       size_t size)
+{
+	u32 hash;
+
+	/* Verify stored hash matches calculated hash. */
+	hash = ext4_xattr_inode_hash(EXT4_SB(ea_inode->i_sb), buffer, size);
+	if (hash != ext4_xattr_inode_get_hash(ea_inode))
+		return -EFSCORRUPTED;
+
+	if (entry) {
+		__le32 e_hash, tmp_data;
+
+		/* Verify entry hash. */
+		tmp_data = cpu_to_le32(hash);
+		e_hash = ext4_xattr_hash_entry(entry->e_name, entry->e_name_len,
+					       &tmp_data, 1);
+		if (e_hash != entry->e_hash)
+			return -EFSCORRUPTED;
+	}
+	return 0;
+}
+
+/*
+ * Read xattr value from the EA inode.
+ */
+static int
+ext4_xattr_inode_get(struct inode *inode, struct ext4_xattr_entry *entry,
+		     void *buffer, size_t size)
+{
+	struct mb_cache *ea_inode_cache = EA_INODE_CACHE(inode);
+	struct inode *ea_inode;
+	int err;
+
+	err = ext4_xattr_inode_iget(inode, le32_to_cpu(entry->e_value_inum),
+				    le32_to_cpu(entry->e_hash), &ea_inode);
+	if (err) {
+		ea_inode = NULL;
+		goto out;
+	}
+
+	if (i_size_read(ea_inode) != size) {
+		ext4_warning_inode(ea_inode,
+				   "ea_inode file size=%llu entry size=%zu",
+				   i_size_read(ea_inode), size);
+		err = -EFSCORRUPTED;
+		goto out;
+	}
+
+	err = ext4_xattr_inode_read(ea_inode, buffer, size);
+	if (err)
+		goto out;
+
+	if (!ext4_test_inode_state(ea_inode, EXT4_STATE_LUSTRE_EA_INODE)) {
+		err = ext4_xattr_inode_verify_hashes(ea_inode, entry, buffer,
+						     size);
+		if (err) {
+			ext4_warning_inode(ea_inode,
+					   "EA inode hash validation failed");
+			goto out;
+		}
+
+		if (ea_inode_cache)
+			mb_cache_entry_create(ea_inode_cache, GFP_NOFS,
+					ext4_xattr_inode_get_hash(ea_inode),
+					ea_inode->i_ino, true /* reusable */);
+	}
+out:
+	iput(ea_inode);
+	return err;
+}
+
+static int
+ext4_xattr_block_get(struct inode *inode, int name_index, const char *name,
+		     void *buffer, size_t buffer_size)
+{
+	struct buffer_head *bh = NULL;
+	struct ext4_xattr_entry *entry;
+	size_t size;
+	void *end;
+	int error;
+	struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
+
+	ea_idebug(inode, "name=%d.%s, buffer=%p, buffer_size=%ld",
+		  name_index, name, buffer, (long)buffer_size);
+
+	if (!EXT4_I(inode)->i_file_acl)
+		return -ENODATA;
+	ea_idebug(inode, "reading block %llu",
+		  (unsigned long long)EXT4_I(inode)->i_file_acl);
+	bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
+	if (IS_ERR(bh))
+		return PTR_ERR(bh);
+	ea_bdebug(bh, "b_count=%d, refcount=%d",
+		atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount));
+	error = ext4_xattr_check_block(inode, bh);
+	if (error)
+		goto cleanup;
+	ext4_xattr_block_cache_insert(ea_block_cache, bh);
+	entry = BFIRST(bh);
+	end = bh->b_data + bh->b_size;
+	error = xattr_find_entry(inode, &entry, end, name_index, name, 1);
+	if (error)
+		goto cleanup;
+	size = le32_to_cpu(entry->e_value_size);
+	error = -ERANGE;
+	if (unlikely(size > EXT4_XATTR_SIZE_MAX))
+		goto cleanup;
+	if (buffer) {
+		if (size > buffer_size)
+			goto cleanup;
+		if (entry->e_value_inum) {
+			error = ext4_xattr_inode_get(inode, entry, buffer,
+						     size);
+			if (error)
+				goto cleanup;
+		} else {
+			u16 offset = le16_to_cpu(entry->e_value_offs);
+			void *p = bh->b_data + offset;
+
+			if (unlikely(p + size > end))
+				goto cleanup;
+			memcpy(buffer, p, size);
+		}
+	}
+	error = size;
+
+cleanup:
+	brelse(bh);
+	return error;
+}
+
+int
+ext4_xattr_ibody_get(struct inode *inode, int name_index, const char *name,
+		     void *buffer, size_t buffer_size)
+{
+	struct ext4_xattr_ibody_header *header;
+	struct ext4_xattr_entry *entry;
+	struct ext4_inode *raw_inode;
+	struct ext4_iloc iloc;
+	size_t size;
+	void *end;
+	int error;
+
+	if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR))
+		return -ENODATA;
+	error = ext4_get_inode_loc(inode, &iloc);
+	if (error)
+		return error;
+	raw_inode = ext4_raw_inode(&iloc);
+	header = IHDR(inode, raw_inode);
+	end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
+	error = xattr_check_inode(inode, header, end);
+	if (error)
+		goto cleanup;
+	entry = IFIRST(header);
+	error = xattr_find_entry(inode, &entry, end, name_index, name, 0);
+	if (error)
+		goto cleanup;
+	size = le32_to_cpu(entry->e_value_size);
+	error = -ERANGE;
+	if (unlikely(size > EXT4_XATTR_SIZE_MAX))
+		goto cleanup;
+	if (buffer) {
+		if (size > buffer_size)
+			goto cleanup;
+		if (entry->e_value_inum) {
+			error = ext4_xattr_inode_get(inode, entry, buffer,
+						     size);
+			if (error)
+				goto cleanup;
+		} else {
+			u16 offset = le16_to_cpu(entry->e_value_offs);
+			void *p = (void *)IFIRST(header) + offset;
+
+			if (unlikely(p + size > end))
+				goto cleanup;
+			memcpy(buffer, p, size);
+		}
+	}
+	error = size;
+
+cleanup:
+	brelse(iloc.bh);
+	return error;
+}
+
+/*
+ * ext4_xattr_get()
+ *
+ * Copy an extended attribute into the buffer
+ * provided, or compute the buffer size required.
+ * Buffer is NULL to compute the size of the buffer required.
+ *
+ * Returns a negative error number on failure, or the number of bytes
+ * used / required on success.
+ */
+int
+ext4_xattr_get(struct inode *inode, int name_index, const char *name,
+	       void *buffer, size_t buffer_size)
+{
+	int error;
+
+	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
+		return -EIO;
+
+	if (strlen(name) > 255)
+		return -ERANGE;
+
+	down_read(&EXT4_I(inode)->xattr_sem);
+	error = ext4_xattr_ibody_get(inode, name_index, name, buffer,
+				     buffer_size);
+	if (error == -ENODATA)
+		error = ext4_xattr_block_get(inode, name_index, name, buffer,
+					     buffer_size);
+	up_read(&EXT4_I(inode)->xattr_sem);
+	return error;
+}
+
+static int
+ext4_xattr_list_entries(struct dentry *dentry, struct ext4_xattr_entry *entry,
+			char *buffer, size_t buffer_size)
+{
+	size_t rest = buffer_size;
+
+	for (; !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry)) {
+		const struct xattr_handler *handler =
+			ext4_xattr_handler(entry->e_name_index);
+
+		if (handler && (!handler->list || handler->list(dentry))) {
+			const char *prefix = handler->prefix ?: handler->name;
+			size_t prefix_len = strlen(prefix);
+			size_t size = prefix_len + entry->e_name_len + 1;
+
+			if (buffer) {
+				if (size > rest)
+					return -ERANGE;
+				memcpy(buffer, prefix, prefix_len);
+				buffer += prefix_len;
+				memcpy(buffer, entry->e_name, entry->e_name_len);
+				buffer += entry->e_name_len;
+				*buffer++ = 0;
+			}
+			rest -= size;
+		}
+	}
+	return buffer_size - rest;  /* total size */
+}
+
+static int
+ext4_xattr_block_list(struct dentry *dentry, char *buffer, size_t buffer_size)
+{
+	struct inode *inode = d_inode(dentry);
+	struct buffer_head *bh = NULL;
+	int error;
+
+	ea_idebug(inode, "buffer=%p, buffer_size=%ld",
+		  buffer, (long)buffer_size);
+
+	if (!EXT4_I(inode)->i_file_acl)
+		return 0;
+	ea_idebug(inode, "reading block %llu",
+		  (unsigned long long)EXT4_I(inode)->i_file_acl);
+	bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
+	if (IS_ERR(bh))
+		return PTR_ERR(bh);
+	ea_bdebug(bh, "b_count=%d, refcount=%d",
+		atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount));
+	error = ext4_xattr_check_block(inode, bh);
+	if (error)
+		goto cleanup;
+	ext4_xattr_block_cache_insert(EA_BLOCK_CACHE(inode), bh);
+	error = ext4_xattr_list_entries(dentry, BFIRST(bh), buffer,
+					buffer_size);
+cleanup:
+	brelse(bh);
+	return error;
+}
+
+static int
+ext4_xattr_ibody_list(struct dentry *dentry, char *buffer, size_t buffer_size)
+{
+	struct inode *inode = d_inode(dentry);
+	struct ext4_xattr_ibody_header *header;
+	struct ext4_inode *raw_inode;
+	struct ext4_iloc iloc;
+	void *end;
+	int error;
+
+	if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR))
+		return 0;
+	error = ext4_get_inode_loc(inode, &iloc);
+	if (error)
+		return error;
+	raw_inode = ext4_raw_inode(&iloc);
+	header = IHDR(inode, raw_inode);
+	end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
+	error = xattr_check_inode(inode, header, end);
+	if (error)
+		goto cleanup;
+	error = ext4_xattr_list_entries(dentry, IFIRST(header),
+					buffer, buffer_size);
+
+cleanup:
+	brelse(iloc.bh);
+	return error;
+}
+
+/*
+ * Inode operation listxattr()
+ *
+ * d_inode(dentry)->i_rwsem: don't care
+ *
+ * Copy a list of attribute names into the buffer
+ * provided, or compute the buffer size required.
+ * Buffer is NULL to compute the size of the buffer required.
+ *
+ * Returns a negative error number on failure, or the number of bytes
+ * used / required on success.
+ */
+ssize_t
+ext4_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size)
+{
+	int ret, ret2;
+
+	down_read(&EXT4_I(d_inode(dentry))->xattr_sem);
+	ret = ret2 = ext4_xattr_ibody_list(dentry, buffer, buffer_size);
+	if (ret < 0)
+		goto errout;
+	if (buffer) {
+		buffer += ret;
+		buffer_size -= ret;
+	}
+	ret = ext4_xattr_block_list(dentry, buffer, buffer_size);
+	if (ret < 0)
+		goto errout;
+	ret += ret2;
+errout:
+	up_read(&EXT4_I(d_inode(dentry))->xattr_sem);
+	return ret;
+}
+
+/*
+ * If the EXT4_FEATURE_COMPAT_EXT_ATTR feature of this file system is
+ * not set, set it.
+ */
+static void ext4_xattr_update_super_block(handle_t *handle,
+					  struct super_block *sb)
+{
+	if (ext4_has_feature_xattr(sb))
+		return;
+
+	BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access");
+	if (ext4_journal_get_write_access(handle, sb, EXT4_SB(sb)->s_sbh,
+					  EXT4_JTR_NONE) == 0) {
+		lock_buffer(EXT4_SB(sb)->s_sbh);
+		ext4_set_feature_xattr(sb);
+		ext4_superblock_csum_set(sb);
+		unlock_buffer(EXT4_SB(sb)->s_sbh);
+		ext4_handle_dirty_metadata(handle, NULL, EXT4_SB(sb)->s_sbh);
+	}
+}
+
+int ext4_get_inode_usage(struct inode *inode, qsize_t *usage)
+{
+	struct ext4_iloc iloc = { .bh = NULL };
+	struct buffer_head *bh = NULL;
+	struct ext4_inode *raw_inode;
+	struct ext4_xattr_ibody_header *header;
+	struct ext4_xattr_entry *entry;
+	qsize_t ea_inode_refs = 0;
+	void *end;
+	int ret;
+
+	lockdep_assert_held_read(&EXT4_I(inode)->xattr_sem);
+
+	if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
+		ret = ext4_get_inode_loc(inode, &iloc);
+		if (ret)
+			goto out;
+		raw_inode = ext4_raw_inode(&iloc);
+		header = IHDR(inode, raw_inode);
+		end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
+		ret = xattr_check_inode(inode, header, end);
+		if (ret)
+			goto out;
+
+		for (entry = IFIRST(header); !IS_LAST_ENTRY(entry);
+		     entry = EXT4_XATTR_NEXT(entry))
+			if (entry->e_value_inum)
+				ea_inode_refs++;
+	}
+
+	if (EXT4_I(inode)->i_file_acl) {
+		bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
+		if (IS_ERR(bh)) {
+			ret = PTR_ERR(bh);
+			bh = NULL;
+			goto out;
+		}
+
+		ret = ext4_xattr_check_block(inode, bh);
+		if (ret)
+			goto out;
+
+		for (entry = BFIRST(bh); !IS_LAST_ENTRY(entry);
+		     entry = EXT4_XATTR_NEXT(entry))
+			if (entry->e_value_inum)
+				ea_inode_refs++;
+	}
+	*usage = ea_inode_refs + 1;
+	ret = 0;
+out:
+	brelse(iloc.bh);
+	brelse(bh);
+	return ret;
+}
+
+static inline size_t round_up_cluster(struct inode *inode, size_t length)
+{
+	struct super_block *sb = inode->i_sb;
+	size_t cluster_size = 1 << (EXT4_SB(sb)->s_cluster_bits +
+				    inode->i_blkbits);
+	size_t mask = ~(cluster_size - 1);
+
+	return (length + cluster_size - 1) & mask;
+}
+
+static int ext4_xattr_inode_alloc_quota(struct inode *inode, size_t len)
+{
+	int err;
+
+	err = dquot_alloc_inode(inode);
+	if (err)
+		return err;
+	err = dquot_alloc_space_nodirty(inode, round_up_cluster(inode, len));
+	if (err)
+		dquot_free_inode(inode);
+	return err;
+}
+
+static void ext4_xattr_inode_free_quota(struct inode *parent,
+					struct inode *ea_inode,
+					size_t len)
+{
+	if (ea_inode &&
+	    ext4_test_inode_state(ea_inode, EXT4_STATE_LUSTRE_EA_INODE))
+		return;
+	dquot_free_space_nodirty(parent, round_up_cluster(parent, len));
+	dquot_free_inode(parent);
+}
+
+int __ext4_xattr_set_credits(struct super_block *sb, struct inode *inode,
+			     struct buffer_head *block_bh, size_t value_len,
+			     bool is_create)
+{
+	int credits;
+	int blocks;
+
+	/*
+	 * 1) Owner inode update
+	 * 2) Ref count update on old xattr block
+	 * 3) new xattr block
+	 * 4) block bitmap update for new xattr block
+	 * 5) group descriptor for new xattr block
+	 * 6) block bitmap update for old xattr block
+	 * 7) group descriptor for old block
+	 *
+	 * 6 & 7 can happen if we have two racing threads T_a and T_b
+	 * which are each trying to set an xattr on inodes I_a and I_b
+	 * which were both initially sharing an xattr block.
+	 */
+	credits = 7;
+
+	/* Quota updates. */
+	credits += EXT4_MAXQUOTAS_TRANS_BLOCKS(sb);
+
+	/*
+	 * In case of inline data, we may push out the data to a block,
+	 * so we need to reserve credits for this eventuality
+	 */
+	if (inode && ext4_has_inline_data(inode))
+		credits += ext4_writepage_trans_blocks(inode) + 1;
+
+	/* We are done if ea_inode feature is not enabled. */
+	if (!ext4_has_feature_ea_inode(sb))
+		return credits;
+
+	/* New ea_inode, inode map, block bitmap, group descriptor. */
+	credits += 4;
+
+	/* Data blocks. */
+	blocks = (value_len + sb->s_blocksize - 1) >> sb->s_blocksize_bits;
+
+	/* Indirection block or one level of extent tree. */
+	blocks += 1;
+
+	/* Block bitmap and group descriptor updates for each block. */
+	credits += blocks * 2;
+
+	/* Blocks themselves. */
+	credits += blocks;
+
+	if (!is_create) {
+		/* Dereference ea_inode holding old xattr value.
+		 * Old ea_inode, inode map, block bitmap, group descriptor.
+		 */
+		credits += 4;
+
+		/* Data blocks for old ea_inode. */
+		blocks = XATTR_SIZE_MAX >> sb->s_blocksize_bits;
+
+		/* Indirection block or one level of extent tree for old
+		 * ea_inode.
+		 */
+		blocks += 1;
+
+		/* Block bitmap and group descriptor updates for each block. */
+		credits += blocks * 2;
+	}
+
+	/* We may need to clone the existing xattr block in which case we need
+	 * to increment ref counts for existing ea_inodes referenced by it.
+	 */
+	if (block_bh) {
+		struct ext4_xattr_entry *entry = BFIRST(block_bh);
+
+		for (; !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry))
+			if (entry->e_value_inum)
+				/* Ref count update on ea_inode. */
+				credits += 1;
+	}
+	return credits;
+}
+
+static int ext4_xattr_inode_update_ref(handle_t *handle, struct inode *ea_inode,
+				       int ref_change)
+{
+	struct ext4_iloc iloc;
+	s64 ref_count;
+	int ret;
+
+	inode_lock(ea_inode);
+
+	ret = ext4_reserve_inode_write(handle, ea_inode, &iloc);
+	if (ret)
+		goto out;
+
+	ref_count = ext4_xattr_inode_get_ref(ea_inode);
+	ref_count += ref_change;
+	ext4_xattr_inode_set_ref(ea_inode, ref_count);
+
+	if (ref_change > 0) {
+		WARN_ONCE(ref_count <= 0, "EA inode %lu ref_count=%lld",
+			  ea_inode->i_ino, ref_count);
+
+		if (ref_count == 1) {
+			WARN_ONCE(ea_inode->i_nlink, "EA inode %lu i_nlink=%u",
+				  ea_inode->i_ino, ea_inode->i_nlink);
+
+			set_nlink(ea_inode, 1);
+			ext4_orphan_del(handle, ea_inode);
+		}
+	} else {
+		WARN_ONCE(ref_count < 0, "EA inode %lu ref_count=%lld",
+			  ea_inode->i_ino, ref_count);
+
+		if (ref_count == 0) {
+			WARN_ONCE(ea_inode->i_nlink != 1,
+				  "EA inode %lu i_nlink=%u",
+				  ea_inode->i_ino, ea_inode->i_nlink);
+
+			clear_nlink(ea_inode);
+			ext4_orphan_add(handle, ea_inode);
+		}
+	}
+
+	ret = ext4_mark_iloc_dirty(handle, ea_inode, &iloc);
+	if (ret)
+		ext4_warning_inode(ea_inode,
+				   "ext4_mark_iloc_dirty() failed ret=%d", ret);
+out:
+	inode_unlock(ea_inode);
+	return ret;
+}
+
+static int ext4_xattr_inode_inc_ref(handle_t *handle, struct inode *ea_inode)
+{
+	return ext4_xattr_inode_update_ref(handle, ea_inode, 1);
+}
+
+static int ext4_xattr_inode_dec_ref(handle_t *handle, struct inode *ea_inode)
+{
+	return ext4_xattr_inode_update_ref(handle, ea_inode, -1);
+}
+
+static int ext4_xattr_inode_inc_ref_all(handle_t *handle, struct inode *parent,
+					struct ext4_xattr_entry *first)
+{
+	struct inode *ea_inode;
+	struct ext4_xattr_entry *entry;
+	struct ext4_xattr_entry *failed_entry;
+	unsigned int ea_ino;
+	int err, saved_err;
+
+	for (entry = first; !IS_LAST_ENTRY(entry);
+	     entry = EXT4_XATTR_NEXT(entry)) {
+		if (!entry->e_value_inum)
+			continue;
+		ea_ino = le32_to_cpu(entry->e_value_inum);
+		err = ext4_xattr_inode_iget(parent, ea_ino,
+					    le32_to_cpu(entry->e_hash),
+					    &ea_inode);
+		if (err)
+			goto cleanup;
+		err = ext4_xattr_inode_inc_ref(handle, ea_inode);
+		if (err) {
+			ext4_warning_inode(ea_inode, "inc ref error %d", err);
+			iput(ea_inode);
+			goto cleanup;
+		}
+		iput(ea_inode);
+	}
+	return 0;
+
+cleanup:
+	saved_err = err;
+	failed_entry = entry;
+
+	for (entry = first; entry != failed_entry;
+	     entry = EXT4_XATTR_NEXT(entry)) {
+		if (!entry->e_value_inum)
+			continue;
+		ea_ino = le32_to_cpu(entry->e_value_inum);
+		err = ext4_xattr_inode_iget(parent, ea_ino,
+					    le32_to_cpu(entry->e_hash),
+					    &ea_inode);
+		if (err) {
+			ext4_warning(parent->i_sb,
+				     "cleanup ea_ino %u iget error %d", ea_ino,
+				     err);
+			continue;
+		}
+		err = ext4_xattr_inode_dec_ref(handle, ea_inode);
+		if (err)
+			ext4_warning_inode(ea_inode, "cleanup dec ref error %d",
+					   err);
+		iput(ea_inode);
+	}
+	return saved_err;
+}
+
+static int ext4_xattr_restart_fn(handle_t *handle, struct inode *inode,
+			struct buffer_head *bh, bool block_csum, bool dirty)
+{
+	int error;
+
+	if (bh && dirty) {
+		if (block_csum)
+			ext4_xattr_block_csum_set(inode, bh);
+		error = ext4_handle_dirty_metadata(handle, NULL, bh);
+		if (error) {
+			ext4_warning(inode->i_sb, "Handle metadata (error %d)",
+				     error);
+			return error;
+		}
+	}
+	return 0;
+}
+
+static void
+ext4_xattr_inode_dec_ref_all(handle_t *handle, struct inode *parent,
+			     struct buffer_head *bh,
+			     struct ext4_xattr_entry *first, bool block_csum,
+			     struct ext4_xattr_inode_array **ea_inode_array,
+			     int extra_credits, bool skip_quota)
+{
+	struct inode *ea_inode;
+	struct ext4_xattr_entry *entry;
+	bool dirty = false;
+	unsigned int ea_ino;
+	int err;
+	int credits;
+
+	/* One credit for dec ref on ea_inode, one for orphan list addition, */
+	credits = 2 + extra_credits;
+
+	for (entry = first; !IS_LAST_ENTRY(entry);
+	     entry = EXT4_XATTR_NEXT(entry)) {
+		if (!entry->e_value_inum)
+			continue;
+		ea_ino = le32_to_cpu(entry->e_value_inum);
+		err = ext4_xattr_inode_iget(parent, ea_ino,
+					    le32_to_cpu(entry->e_hash),
+					    &ea_inode);
+		if (err)
+			continue;
+
+		err = ext4_expand_inode_array(ea_inode_array, ea_inode);
+		if (err) {
+			ext4_warning_inode(ea_inode,
+					   "Expand inode array err=%d", err);
+			iput(ea_inode);
+			continue;
+		}
+
+		err = ext4_journal_ensure_credits_fn(handle, credits, credits,
+			ext4_free_metadata_revoke_credits(parent->i_sb, 1),
+			ext4_xattr_restart_fn(handle, parent, bh, block_csum,
+					      dirty));
+		if (err < 0) {
+			ext4_warning_inode(ea_inode, "Ensure credits err=%d",
+					   err);
+			continue;
+		}
+		if (err > 0) {
+			err = ext4_journal_get_write_access(handle,
+					parent->i_sb, bh, EXT4_JTR_NONE);
+			if (err) {
+				ext4_warning_inode(ea_inode,
+						"Re-get write access err=%d",
+						err);
+				continue;
+			}
+		}
+
+		err = ext4_xattr_inode_dec_ref(handle, ea_inode);
+		if (err) {
+			ext4_warning_inode(ea_inode, "ea_inode dec ref err=%d",
+					   err);
+			continue;
+		}
+
+		if (!skip_quota)
+			ext4_xattr_inode_free_quota(parent, ea_inode,
+					      le32_to_cpu(entry->e_value_size));
+
+		/*
+		 * Forget about ea_inode within the same transaction that
+		 * decrements the ref count. This avoids duplicate decrements in
+		 * case the rest of the work spills over to subsequent
+		 * transactions.
+		 */
+		entry->e_value_inum = 0;
+		entry->e_value_size = 0;
+
+		dirty = true;
+	}
+
+	if (dirty) {
+		/*
+		 * Note that we are deliberately skipping csum calculation for
+		 * the final update because we do not expect any journal
+		 * restarts until xattr block is freed.
+		 */
+
+		err = ext4_handle_dirty_metadata(handle, NULL, bh);
+		if (err)
+			ext4_warning_inode(parent,
+					   "handle dirty metadata err=%d", err);
+	}
+}
+
+/*
+ * Release the xattr block BH: If the reference count is > 1, decrement it;
+ * otherwise free the block.
+ */
+static void
+ext4_xattr_release_block(handle_t *handle, struct inode *inode,
+			 struct buffer_head *bh,
+			 struct ext4_xattr_inode_array **ea_inode_array,
+			 int extra_credits)
+{
+	struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
+	u32 hash, ref;
+	int error = 0;
+
+	BUFFER_TRACE(bh, "get_write_access");
+	error = ext4_journal_get_write_access(handle, inode->i_sb, bh,
+					      EXT4_JTR_NONE);
+	if (error)
+		goto out;
+
+retry_ref:
+	lock_buffer(bh);
+	hash = le32_to_cpu(BHDR(bh)->h_hash);
+	ref = le32_to_cpu(BHDR(bh)->h_refcount);
+	if (ref == 1) {
+		ea_bdebug(bh, "refcount now=0; freeing");
+		/*
+		 * This must happen under buffer lock for
+		 * ext4_xattr_block_set() to reliably detect freed block
+		 */
+		if (ea_block_cache) {
+			struct mb_cache_entry *oe;
+
+			oe = mb_cache_entry_delete_or_get(ea_block_cache, hash,
+							  bh->b_blocknr);
+			if (oe) {
+				unlock_buffer(bh);
+				mb_cache_entry_wait_unused(oe);
+				mb_cache_entry_put(ea_block_cache, oe);
+				goto retry_ref;
+			}
+		}
+		get_bh(bh);
+		unlock_buffer(bh);
+
+		if (ext4_has_feature_ea_inode(inode->i_sb))
+			ext4_xattr_inode_dec_ref_all(handle, inode, bh,
+						     BFIRST(bh),
+						     true /* block_csum */,
+						     ea_inode_array,
+						     extra_credits,
+						     true /* skip_quota */);
+		ext4_free_blocks(handle, inode, bh, 0, 1,
+				 EXT4_FREE_BLOCKS_METADATA |
+				 EXT4_FREE_BLOCKS_FORGET);
+	} else {
+		ref--;
+		BHDR(bh)->h_refcount = cpu_to_le32(ref);
+		if (ref == EXT4_XATTR_REFCOUNT_MAX - 1) {
+			struct mb_cache_entry *ce;
+
+			if (ea_block_cache) {
+				ce = mb_cache_entry_get(ea_block_cache, hash,
+							bh->b_blocknr);
+				if (ce) {
+					set_bit(MBE_REUSABLE_B, &ce->e_flags);
+					mb_cache_entry_put(ea_block_cache, ce);
+				}
+			}
+		}
+
+		ext4_xattr_block_csum_set(inode, bh);
+		/*
+		 * Beware of this ugliness: Releasing of xattr block references
+		 * from different inodes can race and so we have to protect
+		 * from a race where someone else frees the block (and releases
+		 * its journal_head) before we are done dirtying the buffer. In
+		 * nojournal mode this race is harmless and we actually cannot
+		 * call ext4_handle_dirty_metadata() with locked buffer as
+		 * that function can call sync_dirty_buffer() so for that case
+		 * we handle the dirtying after unlocking the buffer.
+		 */
+		if (ext4_handle_valid(handle))
+			error = ext4_handle_dirty_metadata(handle, inode, bh);
+		unlock_buffer(bh);
+		if (!ext4_handle_valid(handle))
+			error = ext4_handle_dirty_metadata(handle, inode, bh);
+		if (IS_SYNC(inode))
+			ext4_handle_sync(handle);
+		dquot_free_block(inode, EXT4_C2B(EXT4_SB(inode->i_sb), 1));
+		ea_bdebug(bh, "refcount now=%d; releasing",
+			  le32_to_cpu(BHDR(bh)->h_refcount));
+	}
+out:
+	ext4_std_error(inode->i_sb, error);
+	return;
+}
+
+/*
+ * Find the available free space for EAs. This also returns the total number of
+ * bytes used by EA entries.
+ */
+static size_t ext4_xattr_free_space(struct ext4_xattr_entry *last,
+				    size_t *min_offs, void *base, int *total)
+{
+	for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
+		if (!last->e_value_inum && last->e_value_size) {
+			size_t offs = le16_to_cpu(last->e_value_offs);
+			if (offs < *min_offs)
+				*min_offs = offs;
+		}
+		if (total)
+			*total += EXT4_XATTR_LEN(last->e_name_len);
+	}
+	return (*min_offs - ((void *)last - base) - sizeof(__u32));
+}
+
+/*
+ * Write the value of the EA in an inode.
+ */
+static int ext4_xattr_inode_write(handle_t *handle, struct inode *ea_inode,
+				  const void *buf, int bufsize)
+{
+	struct buffer_head *bh = NULL;
+	unsigned long block = 0;
+	int blocksize = ea_inode->i_sb->s_blocksize;
+	int max_blocks = (bufsize + blocksize - 1) >> ea_inode->i_blkbits;
+	int csize, wsize = 0;
+	int ret = 0, ret2 = 0;
+	int retries = 0;
+
+retry:
+	while (ret >= 0 && ret < max_blocks) {
+		struct ext4_map_blocks map;
+		map.m_lblk = block += ret;
+		map.m_len = max_blocks -= ret;
+
+		ret = ext4_map_blocks(handle, ea_inode, &map,
+				      EXT4_GET_BLOCKS_CREATE);
+		if (ret <= 0) {
+			ext4_mark_inode_dirty(handle, ea_inode);
+			if (ret == -ENOSPC &&
+			    ext4_should_retry_alloc(ea_inode->i_sb, &retries)) {
+				ret = 0;
+				goto retry;
+			}
+			break;
+		}
+	}
+
+	if (ret < 0)
+		return ret;
+
+	block = 0;
+	while (wsize < bufsize) {
+		brelse(bh);
+		csize = (bufsize - wsize) > blocksize ? blocksize :
+								bufsize - wsize;
+		bh = ext4_getblk(handle, ea_inode, block, 0);
+		if (IS_ERR(bh))
+			return PTR_ERR(bh);
+		if (!bh) {
+			WARN_ON_ONCE(1);
+			EXT4_ERROR_INODE(ea_inode,
+					 "ext4_getblk() return bh = NULL");
+			return -EFSCORRUPTED;
+		}
+		ret = ext4_journal_get_write_access(handle, ea_inode->i_sb, bh,
+						   EXT4_JTR_NONE);
+		if (ret)
+			goto out;
+
+		memcpy(bh->b_data, buf, csize);
+		set_buffer_uptodate(bh);
+		ext4_handle_dirty_metadata(handle, ea_inode, bh);
+
+		buf += csize;
+		wsize += csize;
+		block += 1;
+	}
+
+	inode_lock(ea_inode);
+	i_size_write(ea_inode, wsize);
+	ext4_update_i_disksize(ea_inode, wsize);
+	inode_unlock(ea_inode);
+
+	ret2 = ext4_mark_inode_dirty(handle, ea_inode);
+	if (unlikely(ret2 && !ret))
+		ret = ret2;
+
+out:
+	brelse(bh);
+
+	return ret;
+}
+
+/*
+ * Create an inode to store the value of a large EA.
+ */
+static struct inode *ext4_xattr_inode_create(handle_t *handle,
+					     struct inode *inode, u32 hash)
+{
+	struct inode *ea_inode = NULL;
+	uid_t owner[2] = { i_uid_read(inode), i_gid_read(inode) };
+	int err;
+
+	if (inode->i_sb->s_root == NULL) {
+		ext4_warning(inode->i_sb,
+			     "refuse to create EA inode when umounting");
+		WARN_ON(1);
+		return ERR_PTR(-EINVAL);
+	}
+
+	/*
+	 * Let the next inode be the goal, so we try and allocate the EA inode
+	 * in the same group, or nearby one.
+	 */
+	ea_inode = ext4_new_inode(handle, inode->i_sb->s_root->d_inode,
+				  S_IFREG | 0600, NULL, inode->i_ino + 1, owner,
+				  EXT4_EA_INODE_FL);
+	if (!IS_ERR(ea_inode)) {
+		ea_inode->i_op = &ext4_file_inode_operations;
+		ea_inode->i_fop = &ext4_file_operations;
+		ext4_set_aops(ea_inode);
+		ext4_xattr_inode_set_class(ea_inode);
+		unlock_new_inode(ea_inode);
+		ext4_xattr_inode_set_ref(ea_inode, 1);
+		ext4_xattr_inode_set_hash(ea_inode, hash);
+		err = ext4_mark_inode_dirty(handle, ea_inode);
+		if (!err)
+			err = ext4_inode_attach_jinode(ea_inode);
+		if (err) {
+			if (ext4_xattr_inode_dec_ref(handle, ea_inode))
+				ext4_warning_inode(ea_inode,
+					"cleanup dec ref error %d", err);
+			iput(ea_inode);
+			return ERR_PTR(err);
+		}
+
+		/*
+		 * Xattr inodes are shared therefore quota charging is performed
+		 * at a higher level.
+		 */
+		dquot_free_inode(ea_inode);
+		dquot_drop(ea_inode);
+		inode_lock(ea_inode);
+		ea_inode->i_flags |= S_NOQUOTA;
+		inode_unlock(ea_inode);
+	}
+
+	return ea_inode;
+}
+
+static struct inode *
+ext4_xattr_inode_cache_find(struct inode *inode, const void *value,
+			    size_t value_len, u32 hash)
+{
+	struct inode *ea_inode;
+	struct mb_cache_entry *ce;
+	struct mb_cache *ea_inode_cache = EA_INODE_CACHE(inode);
+	void *ea_data;
+
+	if (!ea_inode_cache)
+		return NULL;
+
+	ce = mb_cache_entry_find_first(ea_inode_cache, hash);
+	if (!ce)
+		return NULL;
+
+	WARN_ON_ONCE(ext4_handle_valid(journal_current_handle()) &&
+		     !(current->flags & PF_MEMALLOC_NOFS));
+
+	ea_data = kvmalloc(value_len, GFP_KERNEL);
+	if (!ea_data) {
+		mb_cache_entry_put(ea_inode_cache, ce);
+		return NULL;
+	}
+
+	while (ce) {
+		ea_inode = ext4_iget(inode->i_sb, ce->e_value,
+				     EXT4_IGET_EA_INODE);
+		if (IS_ERR(ea_inode))
+			goto next_entry;
+		ext4_xattr_inode_set_class(ea_inode);
+		if (i_size_read(ea_inode) == value_len &&
+		    !ext4_xattr_inode_read(ea_inode, ea_data, value_len) &&
+		    !ext4_xattr_inode_verify_hashes(ea_inode, NULL, ea_data,
+						    value_len) &&
+		    !memcmp(value, ea_data, value_len)) {
+			mb_cache_entry_touch(ea_inode_cache, ce);
+			mb_cache_entry_put(ea_inode_cache, ce);
+			kvfree(ea_data);
+			return ea_inode;
+		}
+		iput(ea_inode);
+	next_entry:
+		ce = mb_cache_entry_find_next(ea_inode_cache, ce);
+	}
+	kvfree(ea_data);
+	return NULL;
+}
+
+/*
+ * Add value of the EA in an inode.
+ */
+static int ext4_xattr_inode_lookup_create(handle_t *handle, struct inode *inode,
+					  const void *value, size_t value_len,
+					  struct inode **ret_inode)
+{
+	struct inode *ea_inode;
+	u32 hash;
+	int err;
+
+	hash = ext4_xattr_inode_hash(EXT4_SB(inode->i_sb), value, value_len);
+	ea_inode = ext4_xattr_inode_cache_find(inode, value, value_len, hash);
+	if (ea_inode) {
+		err = ext4_xattr_inode_inc_ref(handle, ea_inode);
+		if (err) {
+			iput(ea_inode);
+			return err;
+		}
+
+		*ret_inode = ea_inode;
+		return 0;
+	}
+
+	/* Create an inode for the EA value */
+	ea_inode = ext4_xattr_inode_create(handle, inode, hash);
+	if (IS_ERR(ea_inode))
+		return PTR_ERR(ea_inode);
+
+	err = ext4_xattr_inode_write(handle, ea_inode, value, value_len);
+	if (err) {
+		ext4_xattr_inode_dec_ref(handle, ea_inode);
+		iput(ea_inode);
+		return err;
+	}
+
+	if (EA_INODE_CACHE(inode))
+		mb_cache_entry_create(EA_INODE_CACHE(inode), GFP_NOFS, hash,
+				      ea_inode->i_ino, true /* reusable */);
+
+	*ret_inode = ea_inode;
+	return 0;
+}
+
+/*
+ * Reserve min(block_size/8, 1024) bytes for xattr entries/names if ea_inode
+ * feature is enabled.
+ */
+#define EXT4_XATTR_BLOCK_RESERVE(inode)	min(i_blocksize(inode)/8, 1024U)
+
+static int ext4_xattr_set_entry(struct ext4_xattr_info *i,
+				struct ext4_xattr_search *s,
+				handle_t *handle, struct inode *inode,
+				bool is_block)
+{
+	struct ext4_xattr_entry *last, *next;
+	struct ext4_xattr_entry *here = s->here;
+	size_t min_offs = s->end - s->base, name_len = strlen(i->name);
+	int in_inode = i->in_inode;
+	struct inode *old_ea_inode = NULL;
+	struct inode *new_ea_inode = NULL;
+	size_t old_size, new_size;
+	int ret;
+
+	/* Space used by old and new values. */
+	old_size = (!s->not_found && !here->e_value_inum) ?
+			EXT4_XATTR_SIZE(le32_to_cpu(here->e_value_size)) : 0;
+	new_size = (i->value && !in_inode) ? EXT4_XATTR_SIZE(i->value_len) : 0;
+
+	/*
+	 * Optimization for the simple case when old and new values have the
+	 * same padded sizes. Not applicable if external inodes are involved.
+	 */
+	if (new_size && new_size == old_size) {
+		size_t offs = le16_to_cpu(here->e_value_offs);
+		void *val = s->base + offs;
+
+		here->e_value_size = cpu_to_le32(i->value_len);
+		if (i->value == EXT4_ZERO_XATTR_VALUE) {
+			memset(val, 0, new_size);
+		} else {
+			memcpy(val, i->value, i->value_len);
+			/* Clear padding bytes. */
+			memset(val + i->value_len, 0, new_size - i->value_len);
+		}
+		goto update_hash;
+	}
+
+	/* Compute min_offs and last. */
+	last = s->first;
+	for (; !IS_LAST_ENTRY(last); last = next) {
+		next = EXT4_XATTR_NEXT(last);
+		if ((void *)next >= s->end) {
+			EXT4_ERROR_INODE(inode, "corrupted xattr entries");
+			ret = -EFSCORRUPTED;
+			goto out;
+		}
+		if (!last->e_value_inum && last->e_value_size) {
+			size_t offs = le16_to_cpu(last->e_value_offs);
+			if (offs < min_offs)
+				min_offs = offs;
+		}
+	}
+
+	/* Check whether we have enough space. */
+	if (i->value) {
+		size_t free;
+
+		free = min_offs - ((void *)last - s->base) - sizeof(__u32);
+		if (!s->not_found)
+			free += EXT4_XATTR_LEN(name_len) + old_size;
+
+		if (free < EXT4_XATTR_LEN(name_len) + new_size) {
+			ret = -ENOSPC;
+			goto out;
+		}
+
+		/*
+		 * If storing the value in an external inode is an option,
+		 * reserve space for xattr entries/names in the external
+		 * attribute block so that a long value does not occupy the
+		 * whole space and prevent further entries being added.
+		 */
+		if (ext4_has_feature_ea_inode(inode->i_sb) &&
+		    new_size && is_block &&
+		    (min_offs + old_size - new_size) <
+					EXT4_XATTR_BLOCK_RESERVE(inode)) {
+			ret = -ENOSPC;
+			goto out;
+		}
+	}
+
+	/*
+	 * Getting access to old and new ea inodes is subject to failures.
+	 * Finish that work before doing any modifications to the xattr data.
+	 */
+	if (!s->not_found && here->e_value_inum) {
+		ret = ext4_xattr_inode_iget(inode,
+					    le32_to_cpu(here->e_value_inum),
+					    le32_to_cpu(here->e_hash),
+					    &old_ea_inode);
+		if (ret) {
+			old_ea_inode = NULL;
+			goto out;
+		}
+	}
+	if (i->value && in_inode) {
+		WARN_ON_ONCE(!i->value_len);
+
+		ret = ext4_xattr_inode_alloc_quota(inode, i->value_len);
+		if (ret)
+			goto out;
+
+		ret = ext4_xattr_inode_lookup_create(handle, inode, i->value,
+						     i->value_len,
+						     &new_ea_inode);
+		if (ret) {
+			new_ea_inode = NULL;
+			ext4_xattr_inode_free_quota(inode, NULL, i->value_len);
+			goto out;
+		}
+	}
+
+	if (old_ea_inode) {
+		/* We are ready to release ref count on the old_ea_inode. */
+		ret = ext4_xattr_inode_dec_ref(handle, old_ea_inode);
+		if (ret) {
+			/* Release newly required ref count on new_ea_inode. */
+			if (new_ea_inode) {
+				int err;
+
+				err = ext4_xattr_inode_dec_ref(handle,
+							       new_ea_inode);
+				if (err)
+					ext4_warning_inode(new_ea_inode,
+						  "dec ref new_ea_inode err=%d",
+						  err);
+				ext4_xattr_inode_free_quota(inode, new_ea_inode,
+							    i->value_len);
+			}
+			goto out;
+		}
+
+		ext4_xattr_inode_free_quota(inode, old_ea_inode,
+					    le32_to_cpu(here->e_value_size));
+	}
+
+	/* No failures allowed past this point. */
+
+	if (!s->not_found && here->e_value_size && !here->e_value_inum) {
+		/* Remove the old value. */
+		void *first_val = s->base + min_offs;
+		size_t offs = le16_to_cpu(here->e_value_offs);
+		void *val = s->base + offs;
+
+		memmove(first_val + old_size, first_val, val - first_val);
+		memset(first_val, 0, old_size);
+		min_offs += old_size;
+
+		/* Adjust all value offsets. */
+		last = s->first;
+		while (!IS_LAST_ENTRY(last)) {
+			size_t o = le16_to_cpu(last->e_value_offs);
+
+			if (!last->e_value_inum &&
+			    last->e_value_size && o < offs)
+				last->e_value_offs = cpu_to_le16(o + old_size);
+			last = EXT4_XATTR_NEXT(last);
+		}
+	}
+
+	if (!i->value) {
+		/* Remove old name. */
+		size_t size = EXT4_XATTR_LEN(name_len);
+
+		last = ENTRY((void *)last - size);
+		memmove(here, (void *)here + size,
+			(void *)last - (void *)here + sizeof(__u32));
+		memset(last, 0, size);
+
+		/*
+		 * Update i_inline_off - moved ibody region might contain
+		 * system.data attribute.  Handling a failure here won't
+		 * cause other complications for setting an xattr.
+		 */
+		if (!is_block && ext4_has_inline_data(inode)) {
+			ret = ext4_find_inline_data_nolock(inode);
+			if (ret) {
+				ext4_warning_inode(inode,
+					"unable to update i_inline_off");
+				goto out;
+			}
+		}
+	} else if (s->not_found) {
+		/* Insert new name. */
+		size_t size = EXT4_XATTR_LEN(name_len);
+		size_t rest = (void *)last - (void *)here + sizeof(__u32);
+
+		memmove((void *)here + size, here, rest);
+		memset(here, 0, size);
+		here->e_name_index = i->name_index;
+		here->e_name_len = name_len;
+		memcpy(here->e_name, i->name, name_len);
+	} else {
+		/* This is an update, reset value info. */
+		here->e_value_inum = 0;
+		here->e_value_offs = 0;
+		here->e_value_size = 0;
+	}
+
+	if (i->value) {
+		/* Insert new value. */
+		if (in_inode) {
+			here->e_value_inum = cpu_to_le32(new_ea_inode->i_ino);
+		} else if (i->value_len) {
+			void *val = s->base + min_offs - new_size;
+
+			here->e_value_offs = cpu_to_le16(min_offs - new_size);
+			if (i->value == EXT4_ZERO_XATTR_VALUE) {
+				memset(val, 0, new_size);
+			} else {
+				memcpy(val, i->value, i->value_len);
+				/* Clear padding bytes. */
+				memset(val + i->value_len, 0,
+				       new_size - i->value_len);
+			}
+		}
+		here->e_value_size = cpu_to_le32(i->value_len);
+	}
+
+update_hash:
+	if (i->value) {
+		__le32 hash = 0;
+
+		/* Entry hash calculation. */
+		if (in_inode) {
+			__le32 crc32c_hash;
+
+			/*
+			 * Feed crc32c hash instead of the raw value for entry
+			 * hash calculation. This is to avoid walking
+			 * potentially long value buffer again.
+			 */
+			crc32c_hash = cpu_to_le32(
+				       ext4_xattr_inode_get_hash(new_ea_inode));
+			hash = ext4_xattr_hash_entry(here->e_name,
+						     here->e_name_len,
+						     &crc32c_hash, 1);
+		} else if (is_block) {
+			__le32 *value = s->base + le16_to_cpu(
+							here->e_value_offs);
+
+			hash = ext4_xattr_hash_entry(here->e_name,
+						     here->e_name_len, value,
+						     new_size >> 2);
+		}
+		here->e_hash = hash;
+	}
+
+	if (is_block)
+		ext4_xattr_rehash((struct ext4_xattr_header *)s->base);
+
+	ret = 0;
+out:
+	iput(old_ea_inode);
+	iput(new_ea_inode);
+	return ret;
+}
+
+struct ext4_xattr_block_find {
+	struct ext4_xattr_search s;
+	struct buffer_head *bh;
+};
+
+static int
+ext4_xattr_block_find(struct inode *inode, struct ext4_xattr_info *i,
+		      struct ext4_xattr_block_find *bs)
+{
+	struct super_block *sb = inode->i_sb;
+	int error;
+
+	ea_idebug(inode, "name=%d.%s, value=%p, value_len=%ld",
+		  i->name_index, i->name, i->value, (long)i->value_len);
+
+	if (EXT4_I(inode)->i_file_acl) {
+		/* The inode already has an extended attribute block. */
+		bs->bh = ext4_sb_bread(sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
+		if (IS_ERR(bs->bh)) {
+			error = PTR_ERR(bs->bh);
+			bs->bh = NULL;
+			return error;
+		}
+		ea_bdebug(bs->bh, "b_count=%d, refcount=%d",
+			atomic_read(&(bs->bh->b_count)),
+			le32_to_cpu(BHDR(bs->bh)->h_refcount));
+		error = ext4_xattr_check_block(inode, bs->bh);
+		if (error)
+			return error;
+		/* Find the named attribute. */
+		bs->s.base = BHDR(bs->bh);
+		bs->s.first = BFIRST(bs->bh);
+		bs->s.end = bs->bh->b_data + bs->bh->b_size;
+		bs->s.here = bs->s.first;
+		error = xattr_find_entry(inode, &bs->s.here, bs->s.end,
+					 i->name_index, i->name, 1);
+		if (error && error != -ENODATA)
+			return error;
+		bs->s.not_found = error;
+	}
+	return 0;
+}
+
+static int
+ext4_xattr_block_set(handle_t *handle, struct inode *inode,
+		     struct ext4_xattr_info *i,
+		     struct ext4_xattr_block_find *bs)
+{
+	struct super_block *sb = inode->i_sb;
+	struct buffer_head *new_bh = NULL;
+	struct ext4_xattr_search s_copy = bs->s;
+	struct ext4_xattr_search *s = &s_copy;
+	struct mb_cache_entry *ce = NULL;
+	int error = 0;
+	struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
+	struct inode *ea_inode = NULL, *tmp_inode;
+	size_t old_ea_inode_quota = 0;
+	unsigned int ea_ino;
+
+
+#define header(x) ((struct ext4_xattr_header *)(x))
+
+	if (s->base) {
+		int offset = (char *)s->here - bs->bh->b_data;
+
+		BUFFER_TRACE(bs->bh, "get_write_access");
+		error = ext4_journal_get_write_access(handle, sb, bs->bh,
+						      EXT4_JTR_NONE);
+		if (error)
+			goto cleanup;
+		lock_buffer(bs->bh);
+
+		if (header(s->base)->h_refcount == cpu_to_le32(1)) {
+			__u32 hash = le32_to_cpu(BHDR(bs->bh)->h_hash);
+
+			/*
+			 * This must happen under buffer lock for
+			 * ext4_xattr_block_set() to reliably detect modified
+			 * block
+			 */
+			if (ea_block_cache) {
+				struct mb_cache_entry *oe;
+
+				oe = mb_cache_entry_delete_or_get(ea_block_cache,
+					hash, bs->bh->b_blocknr);
+				if (oe) {
+					/*
+					 * Xattr block is getting reused. Leave
+					 * it alone.
+					 */
+					mb_cache_entry_put(ea_block_cache, oe);
+					goto clone_block;
+				}
+			}
+			ea_bdebug(bs->bh, "modifying in-place");
+			error = ext4_xattr_set_entry(i, s, handle, inode,
+						     true /* is_block */);
+			ext4_xattr_block_csum_set(inode, bs->bh);
+			unlock_buffer(bs->bh);
+			if (error == -EFSCORRUPTED)
+				goto bad_block;
+			if (!error)
+				error = ext4_handle_dirty_metadata(handle,
+								   inode,
+								   bs->bh);
+			if (error)
+				goto cleanup;
+			goto inserted;
+		}
+clone_block:
+		unlock_buffer(bs->bh);
+		ea_bdebug(bs->bh, "cloning");
+		s->base = kmemdup(BHDR(bs->bh), bs->bh->b_size, GFP_NOFS);
+		error = -ENOMEM;
+		if (s->base == NULL)
+			goto cleanup;
+		s->first = ENTRY(header(s->base)+1);
+		header(s->base)->h_refcount = cpu_to_le32(1);
+		s->here = ENTRY(s->base + offset);
+		s->end = s->base + bs->bh->b_size;
+
+		/*
+		 * If existing entry points to an xattr inode, we need
+		 * to prevent ext4_xattr_set_entry() from decrementing
+		 * ref count on it because the reference belongs to the
+		 * original block. In this case, make the entry look
+		 * like it has an empty value.
+		 */
+		if (!s->not_found && s->here->e_value_inum) {
+			ea_ino = le32_to_cpu(s->here->e_value_inum);
+			error = ext4_xattr_inode_iget(inode, ea_ino,
+				      le32_to_cpu(s->here->e_hash),
+				      &tmp_inode);
+			if (error)
+				goto cleanup;
+
+			if (!ext4_test_inode_state(tmp_inode,
+					EXT4_STATE_LUSTRE_EA_INODE)) {
+				/*
+				 * Defer quota free call for previous
+				 * inode until success is guaranteed.
+				 */
+				old_ea_inode_quota = le32_to_cpu(
+						s->here->e_value_size);
+			}
+			iput(tmp_inode);
+
+			s->here->e_value_inum = 0;
+			s->here->e_value_size = 0;
+		}
+	} else {
+		/* Allocate a buffer where we construct the new block. */
+		s->base = kzalloc(sb->s_blocksize, GFP_NOFS);
+		error = -ENOMEM;
+		if (s->base == NULL)
+			goto cleanup;
+		header(s->base)->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC);
+		header(s->base)->h_blocks = cpu_to_le32(1);
+		header(s->base)->h_refcount = cpu_to_le32(1);
+		s->first = ENTRY(header(s->base)+1);
+		s->here = ENTRY(header(s->base)+1);
+		s->end = s->base + sb->s_blocksize;
+	}
+
+	error = ext4_xattr_set_entry(i, s, handle, inode, true /* is_block */);
+	if (error == -EFSCORRUPTED)
+		goto bad_block;
+	if (error)
+		goto cleanup;
+
+	if (i->value && s->here->e_value_inum) {
+		/*
+		 * A ref count on ea_inode has been taken as part of the call to
+		 * ext4_xattr_set_entry() above. We would like to drop this
+		 * extra ref but we have to wait until the xattr block is
+		 * initialized and has its own ref count on the ea_inode.
+		 */
+		ea_ino = le32_to_cpu(s->here->e_value_inum);
+		error = ext4_xattr_inode_iget(inode, ea_ino,
+					      le32_to_cpu(s->here->e_hash),
+					      &ea_inode);
+		if (error) {
+			ea_inode = NULL;
+			goto cleanup;
+		}
+	}
+
+inserted:
+	if (!IS_LAST_ENTRY(s->first)) {
+		new_bh = ext4_xattr_block_cache_find(inode, header(s->base),
+						     &ce);
+		if (new_bh) {
+			/* We found an identical block in the cache. */
+			if (new_bh == bs->bh)
+				ea_bdebug(new_bh, "keeping");
+			else {
+				u32 ref;
+
+#ifdef EXT4_XATTR_DEBUG
+				WARN_ON_ONCE(dquot_initialize_needed(inode));
+#endif
+				/* The old block is released after updating
+				   the inode. */
+				error = dquot_alloc_block(inode,
+						EXT4_C2B(EXT4_SB(sb), 1));
+				if (error)
+					goto cleanup;
+				BUFFER_TRACE(new_bh, "get_write_access");
+				error = ext4_journal_get_write_access(
+						handle, sb, new_bh,
+						EXT4_JTR_NONE);
+				if (error)
+					goto cleanup_dquot;
+				lock_buffer(new_bh);
+				/*
+				 * We have to be careful about races with
+				 * adding references to xattr block. Once we
+				 * hold buffer lock xattr block's state is
+				 * stable so we can check the additional
+				 * reference fits.
+				 */
+				ref = le32_to_cpu(BHDR(new_bh)->h_refcount) + 1;
+				if (ref > EXT4_XATTR_REFCOUNT_MAX) {
+					/*
+					 * Undo everything and check mbcache
+					 * again.
+					 */
+					unlock_buffer(new_bh);
+					dquot_free_block(inode,
+							 EXT4_C2B(EXT4_SB(sb),
+								  1));
+					brelse(new_bh);
+					mb_cache_entry_put(ea_block_cache, ce);
+					ce = NULL;
+					new_bh = NULL;
+					goto inserted;
+				}
+				BHDR(new_bh)->h_refcount = cpu_to_le32(ref);
+				if (ref == EXT4_XATTR_REFCOUNT_MAX)
+					clear_bit(MBE_REUSABLE_B, &ce->e_flags);
+				ea_bdebug(new_bh, "reusing; refcount now=%d",
+					  ref);
+				ext4_xattr_block_csum_set(inode, new_bh);
+				unlock_buffer(new_bh);
+				error = ext4_handle_dirty_metadata(handle,
+								   inode,
+								   new_bh);
+				if (error)
+					goto cleanup_dquot;
+			}
+			mb_cache_entry_touch(ea_block_cache, ce);
+			mb_cache_entry_put(ea_block_cache, ce);
+			ce = NULL;
+		} else if (bs->bh && s->base == bs->bh->b_data) {
+			/* We were modifying this block in-place. */
+			ea_bdebug(bs->bh, "keeping this block");
+			ext4_xattr_block_cache_insert(ea_block_cache, bs->bh);
+			new_bh = bs->bh;
+			get_bh(new_bh);
+		} else {
+			/* We need to allocate a new block */
+			ext4_fsblk_t goal, block;
+
+#ifdef EXT4_XATTR_DEBUG
+			WARN_ON_ONCE(dquot_initialize_needed(inode));
+#endif
+			goal = ext4_group_first_block_no(sb,
+						EXT4_I(inode)->i_block_group);
+			block = ext4_new_meta_blocks(handle, inode, goal, 0,
+						     NULL, &error);
+			if (error)
+				goto cleanup;
+
+			ea_idebug(inode, "creating block %llu",
+				  (unsigned long long)block);
+
+			new_bh = sb_getblk(sb, block);
+			if (unlikely(!new_bh)) {
+				error = -ENOMEM;
+getblk_failed:
+				ext4_free_blocks(handle, inode, NULL, block, 1,
+						 EXT4_FREE_BLOCKS_METADATA);
+				goto cleanup;
+			}
+			error = ext4_xattr_inode_inc_ref_all(handle, inode,
+						      ENTRY(header(s->base)+1));
+			if (error)
+				goto getblk_failed;
+			if (ea_inode) {
+				/* Drop the extra ref on ea_inode. */
+				error = ext4_xattr_inode_dec_ref(handle,
+								 ea_inode);
+				if (error)
+					ext4_warning_inode(ea_inode,
+							   "dec ref error=%d",
+							   error);
+				iput(ea_inode);
+				ea_inode = NULL;
+			}
+
+			lock_buffer(new_bh);
+			error = ext4_journal_get_create_access(handle, sb,
+							new_bh, EXT4_JTR_NONE);
+			if (error) {
+				unlock_buffer(new_bh);
+				error = -EIO;
+				goto getblk_failed;
+			}
+			memcpy(new_bh->b_data, s->base, new_bh->b_size);
+			ext4_xattr_block_csum_set(inode, new_bh);
+			set_buffer_uptodate(new_bh);
+			unlock_buffer(new_bh);
+			ext4_xattr_block_cache_insert(ea_block_cache, new_bh);
+			error = ext4_handle_dirty_metadata(handle, inode,
+							   new_bh);
+			if (error)
+				goto cleanup;
+		}
+	}
+
+	if (old_ea_inode_quota)
+		ext4_xattr_inode_free_quota(inode, NULL, old_ea_inode_quota);
+
+	/* Update the inode. */
+	EXT4_I(inode)->i_file_acl = new_bh ? new_bh->b_blocknr : 0;
+
+	/* Drop the previous xattr block. */
+	if (bs->bh && bs->bh != new_bh) {
+		struct ext4_xattr_inode_array *ea_inode_array = NULL;
+
+		ext4_xattr_release_block(handle, inode, bs->bh,
+					 &ea_inode_array,
+					 0 /* extra_credits */);
+		ext4_xattr_inode_array_free(ea_inode_array);
+	}
+	error = 0;
+
+cleanup:
+	if (ea_inode) {
+		int error2;
+
+		error2 = ext4_xattr_inode_dec_ref(handle, ea_inode);
+		if (error2)
+			ext4_warning_inode(ea_inode, "dec ref error=%d",
+					   error2);
+
+		/* If there was an error, revert the quota charge. */
+		if (error)
+			ext4_xattr_inode_free_quota(inode, ea_inode,
+						    i_size_read(ea_inode));
+		iput(ea_inode);
+	}
+	if (ce)
+		mb_cache_entry_put(ea_block_cache, ce);
+	brelse(new_bh);
+	if (!(bs->bh && s->base == bs->bh->b_data))
+		kfree(s->base);
+
+	return error;
+
+cleanup_dquot:
+	dquot_free_block(inode, EXT4_C2B(EXT4_SB(sb), 1));
+	goto cleanup;
+
+bad_block:
+	EXT4_ERROR_INODE(inode, "bad block %llu",
+			 EXT4_I(inode)->i_file_acl);
+	goto cleanup;
+
+#undef header
+}
+
+int ext4_xattr_ibody_find(struct inode *inode, struct ext4_xattr_info *i,
+			  struct ext4_xattr_ibody_find *is)
+{
+	struct ext4_xattr_ibody_header *header;
+	struct ext4_inode *raw_inode;
+	int error;
+
+	if (!EXT4_INODE_HAS_XATTR_SPACE(inode))
+		return 0;
+
+	raw_inode = ext4_raw_inode(&is->iloc);
+	header = IHDR(inode, raw_inode);
+	is->s.base = is->s.first = IFIRST(header);
+	is->s.here = is->s.first;
+	is->s.end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
+	if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
+		error = xattr_check_inode(inode, header, is->s.end);
+		if (error)
+			return error;
+		/* Find the named attribute. */
+		error = xattr_find_entry(inode, &is->s.here, is->s.end,
+					 i->name_index, i->name, 0);
+		if (error && error != -ENODATA)
+			return error;
+		is->s.not_found = error;
+	}
+	return 0;
+}
+
+int ext4_xattr_ibody_set(handle_t *handle, struct inode *inode,
+				struct ext4_xattr_info *i,
+				struct ext4_xattr_ibody_find *is)
+{
+	struct ext4_xattr_ibody_header *header;
+	struct ext4_xattr_search *s = &is->s;
+	int error;
+
+	if (!EXT4_INODE_HAS_XATTR_SPACE(inode))
+		return -ENOSPC;
+
+	error = ext4_xattr_set_entry(i, s, handle, inode, false /* is_block */);
+	if (error)
+		return error;
+	header = IHDR(inode, ext4_raw_inode(&is->iloc));
+	if (!IS_LAST_ENTRY(s->first)) {
+		header->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC);
+		ext4_set_inode_state(inode, EXT4_STATE_XATTR);
+	} else {
+		header->h_magic = cpu_to_le32(0);
+		ext4_clear_inode_state(inode, EXT4_STATE_XATTR);
+	}
+	return 0;
+}
+
+static int ext4_xattr_value_same(struct ext4_xattr_search *s,
+				 struct ext4_xattr_info *i)
+{
+	void *value;
+
+	/* When e_value_inum is set the value is stored externally. */
+	if (s->here->e_value_inum)
+		return 0;
+	if (le32_to_cpu(s->here->e_value_size) != i->value_len)
+		return 0;
+	value = ((void *)s->base) + le16_to_cpu(s->here->e_value_offs);
+	return !memcmp(value, i->value, i->value_len);
+}
+
+static struct buffer_head *ext4_xattr_get_block(struct inode *inode)
+{
+	struct buffer_head *bh;
+	int error;
+
+	if (!EXT4_I(inode)->i_file_acl)
+		return NULL;
+	bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
+	if (IS_ERR(bh))
+		return bh;
+	error = ext4_xattr_check_block(inode, bh);
+	if (error) {
+		brelse(bh);
+		return ERR_PTR(error);
+	}
+	return bh;
+}
+
+/*
+ * ext4_xattr_set_handle()
+ *
+ * Create, replace or remove an extended attribute for this inode.  Value
+ * is NULL to remove an existing extended attribute, and non-NULL to
+ * either replace an existing extended attribute, or create a new extended
+ * attribute. The flags XATTR_REPLACE and XATTR_CREATE
+ * specify that an extended attribute must exist and must not exist
+ * previous to the call, respectively.
+ *
+ * Returns 0, or a negative error number on failure.
+ */
+int
+ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
+		      const char *name, const void *value, size_t value_len,
+		      int flags)
+{
+	struct ext4_xattr_info i = {
+		.name_index = name_index,
+		.name = name,
+		.value = value,
+		.value_len = value_len,
+		.in_inode = 0,
+	};
+	struct ext4_xattr_ibody_find is = {
+		.s = { .not_found = -ENODATA, },
+	};
+	struct ext4_xattr_block_find bs = {
+		.s = { .not_found = -ENODATA, },
+	};
+	int no_expand;
+	int error;
+
+	if (!name)
+		return -EINVAL;
+	if (strlen(name) > 255)
+		return -ERANGE;
+
+	ext4_write_lock_xattr(inode, &no_expand);
+
+	/* Check journal credits under write lock. */
+	if (ext4_handle_valid(handle)) {
+		struct buffer_head *bh;
+		int credits;
+
+		bh = ext4_xattr_get_block(inode);
+		if (IS_ERR(bh)) {
+			error = PTR_ERR(bh);
+			goto cleanup;
+		}
+
+		credits = __ext4_xattr_set_credits(inode->i_sb, inode, bh,
+						   value_len,
+						   flags & XATTR_CREATE);
+		brelse(bh);
+
+		if (jbd2_handle_buffer_credits(handle) < credits) {
+			error = -ENOSPC;
+			goto cleanup;
+		}
+		WARN_ON_ONCE(!(current->flags & PF_MEMALLOC_NOFS));
+	}
+
+	error = ext4_reserve_inode_write(handle, inode, &is.iloc);
+	if (error)
+		goto cleanup;
+
+	if (ext4_test_inode_state(inode, EXT4_STATE_NEW)) {
+		struct ext4_inode *raw_inode = ext4_raw_inode(&is.iloc);
+		memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size);
+		ext4_clear_inode_state(inode, EXT4_STATE_NEW);
+	}
+
+	error = ext4_xattr_ibody_find(inode, &i, &is);
+	if (error)
+		goto cleanup;
+	if (is.s.not_found)
+		error = ext4_xattr_block_find(inode, &i, &bs);
+	if (error)
+		goto cleanup;
+	if (is.s.not_found && bs.s.not_found) {
+		error = -ENODATA;
+		if (flags & XATTR_REPLACE)
+			goto cleanup;
+		error = 0;
+		if (!value)
+			goto cleanup;
+	} else {
+		error = -EEXIST;
+		if (flags & XATTR_CREATE)
+			goto cleanup;
+	}
+
+	if (!value) {
+		if (!is.s.not_found)
+			error = ext4_xattr_ibody_set(handle, inode, &i, &is);
+		else if (!bs.s.not_found)
+			error = ext4_xattr_block_set(handle, inode, &i, &bs);
+	} else {
+		error = 0;
+		/* Xattr value did not change? Save us some work and bail out */
+		if (!is.s.not_found && ext4_xattr_value_same(&is.s, &i))
+			goto cleanup;
+		if (!bs.s.not_found && ext4_xattr_value_same(&bs.s, &i))
+			goto cleanup;
+
+		if (ext4_has_feature_ea_inode(inode->i_sb) &&
+		    (EXT4_XATTR_SIZE(i.value_len) >
+			EXT4_XATTR_MIN_LARGE_EA_SIZE(inode->i_sb->s_blocksize)))
+			i.in_inode = 1;
+retry_inode:
+		error = ext4_xattr_ibody_set(handle, inode, &i, &is);
+		if (!error && !bs.s.not_found) {
+			i.value = NULL;
+			error = ext4_xattr_block_set(handle, inode, &i, &bs);
+		} else if (error == -ENOSPC) {
+			if (EXT4_I(inode)->i_file_acl && !bs.s.base) {
+				brelse(bs.bh);
+				bs.bh = NULL;
+				error = ext4_xattr_block_find(inode, &i, &bs);
+				if (error)
+					goto cleanup;
+			}
+			error = ext4_xattr_block_set(handle, inode, &i, &bs);
+			if (!error && !is.s.not_found) {
+				i.value = NULL;
+				error = ext4_xattr_ibody_set(handle, inode, &i,
+							     &is);
+			} else if (error == -ENOSPC) {
+				/*
+				 * Xattr does not fit in the block, store at
+				 * external inode if possible.
+				 */
+				if (ext4_has_feature_ea_inode(inode->i_sb) &&
+				    i.value_len && !i.in_inode) {
+					i.in_inode = 1;
+					goto retry_inode;
+				}
+			}
+		}
+	}
+	if (!error) {
+		ext4_xattr_update_super_block(handle, inode->i_sb);
+		inode->i_ctime = current_time(inode);
+		inode_inc_iversion(inode);
+		if (!value)
+			no_expand = 0;
+		error = ext4_mark_iloc_dirty(handle, inode, &is.iloc);
+		/*
+		 * The bh is consumed by ext4_mark_iloc_dirty, even with
+		 * error != 0.
+		 */
+		is.iloc.bh = NULL;
+		if (IS_SYNC(inode))
+			ext4_handle_sync(handle);
+	}
+	ext4_fc_mark_ineligible(inode->i_sb, EXT4_FC_REASON_XATTR, handle);
+
+cleanup:
+	brelse(is.iloc.bh);
+	brelse(bs.bh);
+	ext4_write_unlock_xattr(inode, &no_expand);
+	return error;
+}
+
+int ext4_xattr_set_credits(struct inode *inode, size_t value_len,
+			   bool is_create, int *credits)
+{
+	struct buffer_head *bh;
+	int err;
+
+	*credits = 0;
+
+	if (!EXT4_SB(inode->i_sb)->s_journal)
+		return 0;
+
+	down_read(&EXT4_I(inode)->xattr_sem);
+
+	bh = ext4_xattr_get_block(inode);
+	if (IS_ERR(bh)) {
+		err = PTR_ERR(bh);
+	} else {
+		*credits = __ext4_xattr_set_credits(inode->i_sb, inode, bh,
+						    value_len, is_create);
+		brelse(bh);
+		err = 0;
+	}
+
+	up_read(&EXT4_I(inode)->xattr_sem);
+	return err;
+}
+
+/*
+ * ext4_xattr_set()
+ *
+ * Like ext4_xattr_set_handle, but start from an inode. This extended
+ * attribute modification is a filesystem transaction by itself.
+ *
+ * Returns 0, or a negative error number on failure.
+ */
+int
+ext4_xattr_set(struct inode *inode, int name_index, const char *name,
+	       const void *value, size_t value_len, int flags)
+{
+	handle_t *handle;
+	struct super_block *sb = inode->i_sb;
+	int error, retries = 0;
+	int credits;
+
+	error = dquot_initialize(inode);
+	if (error)
+		return error;
+
+retry:
+	error = ext4_xattr_set_credits(inode, value_len, flags & XATTR_CREATE,
+				       &credits);
+	if (error)
+		return error;
+
+	handle = ext4_journal_start(inode, EXT4_HT_XATTR, credits);
+	if (IS_ERR(handle)) {
+		error = PTR_ERR(handle);
+	} else {
+		int error2;
+
+		error = ext4_xattr_set_handle(handle, inode, name_index, name,
+					      value, value_len, flags);
+		error2 = ext4_journal_stop(handle);
+		if (error == -ENOSPC &&
+		    ext4_should_retry_alloc(sb, &retries))
+			goto retry;
+		if (error == 0)
+			error = error2;
+	}
+	ext4_fc_mark_ineligible(inode->i_sb, EXT4_FC_REASON_XATTR, NULL);
+
+	return error;
+}
+
+/*
+ * Shift the EA entries in the inode to create space for the increased
+ * i_extra_isize.
+ */
+static void ext4_xattr_shift_entries(struct ext4_xattr_entry *entry,
+				     int value_offs_shift, void *to,
+				     void *from, size_t n)
+{
+	struct ext4_xattr_entry *last = entry;
+	int new_offs;
+
+	/* We always shift xattr headers further thus offsets get lower */
+	BUG_ON(value_offs_shift > 0);
+
+	/* Adjust the value offsets of the entries */
+	for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
+		if (!last->e_value_inum && last->e_value_size) {
+			new_offs = le16_to_cpu(last->e_value_offs) +
+							value_offs_shift;
+			last->e_value_offs = cpu_to_le16(new_offs);
+		}
+	}
+	/* Shift the entries by n bytes */
+	memmove(to, from, n);
+}
+
+/*
+ * Move xattr pointed to by 'entry' from inode into external xattr block
+ */
+static int ext4_xattr_move_to_block(handle_t *handle, struct inode *inode,
+				    struct ext4_inode *raw_inode,
+				    struct ext4_xattr_entry *entry)
+{
+	struct ext4_xattr_ibody_find *is = NULL;
+	struct ext4_xattr_block_find *bs = NULL;
+	char *buffer = NULL, *b_entry_name = NULL;
+	size_t value_size = le32_to_cpu(entry->e_value_size);
+	struct ext4_xattr_info i = {
+		.value = NULL,
+		.value_len = 0,
+		.name_index = entry->e_name_index,
+		.in_inode = !!entry->e_value_inum,
+	};
+	struct ext4_xattr_ibody_header *header = IHDR(inode, raw_inode);
+	int needs_kvfree = 0;
+	int error;
+
+	is = kzalloc(sizeof(struct ext4_xattr_ibody_find), GFP_NOFS);
+	bs = kzalloc(sizeof(struct ext4_xattr_block_find), GFP_NOFS);
+	b_entry_name = kmalloc(entry->e_name_len + 1, GFP_NOFS);
+	if (!is || !bs || !b_entry_name) {
+		error = -ENOMEM;
+		goto out;
+	}
+
+	is->s.not_found = -ENODATA;
+	bs->s.not_found = -ENODATA;
+	is->iloc.bh = NULL;
+	bs->bh = NULL;
+
+	/* Save the entry name and the entry value */
+	if (entry->e_value_inum) {
+		buffer = kvmalloc(value_size, GFP_NOFS);
+		if (!buffer) {
+			error = -ENOMEM;
+			goto out;
+		}
+		needs_kvfree = 1;
+		error = ext4_xattr_inode_get(inode, entry, buffer, value_size);
+		if (error)
+			goto out;
+	} else {
+		size_t value_offs = le16_to_cpu(entry->e_value_offs);
+		buffer = (void *)IFIRST(header) + value_offs;
+	}
+
+	memcpy(b_entry_name, entry->e_name, entry->e_name_len);
+	b_entry_name[entry->e_name_len] = '\0';
+	i.name = b_entry_name;
+
+	error = ext4_get_inode_loc(inode, &is->iloc);
+	if (error)
+		goto out;
+
+	error = ext4_xattr_ibody_find(inode, &i, is);
+	if (error)
+		goto out;
+
+	i.value = buffer;
+	i.value_len = value_size;
+	error = ext4_xattr_block_find(inode, &i, bs);
+	if (error)
+		goto out;
+
+	/* Move ea entry from the inode into the block */
+	error = ext4_xattr_block_set(handle, inode, &i, bs);
+	if (error)
+		goto out;
+
+	/* Remove the chosen entry from the inode */
+	i.value = NULL;
+	i.value_len = 0;
+	error = ext4_xattr_ibody_set(handle, inode, &i, is);
+
+out:
+	kfree(b_entry_name);
+	if (needs_kvfree && buffer)
+		kvfree(buffer);
+	if (is)
+		brelse(is->iloc.bh);
+	if (bs)
+		brelse(bs->bh);
+	kfree(is);
+	kfree(bs);
+
+	return error;
+}
+
+static int ext4_xattr_make_inode_space(handle_t *handle, struct inode *inode,
+				       struct ext4_inode *raw_inode,
+				       int isize_diff, size_t ifree,
+				       size_t bfree, int *total_ino)
+{
+	struct ext4_xattr_ibody_header *header = IHDR(inode, raw_inode);
+	struct ext4_xattr_entry *small_entry;
+	struct ext4_xattr_entry *entry;
+	struct ext4_xattr_entry *last;
+	unsigned int entry_size;	/* EA entry size */
+	unsigned int total_size;	/* EA entry size + value size */
+	unsigned int min_total_size;
+	int error;
+
+	while (isize_diff > ifree) {
+		entry = NULL;
+		small_entry = NULL;
+		min_total_size = ~0U;
+		last = IFIRST(header);
+		/* Find the entry best suited to be pushed into EA block */
+		for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
+			/* never move system.data out of the inode */
+			if ((last->e_name_len == 4) &&
+			    (last->e_name_index == EXT4_XATTR_INDEX_SYSTEM) &&
+			    !memcmp(last->e_name, "data", 4))
+				continue;
+			total_size = EXT4_XATTR_LEN(last->e_name_len);
+			if (!last->e_value_inum)
+				total_size += EXT4_XATTR_SIZE(
+					       le32_to_cpu(last->e_value_size));
+			if (total_size <= bfree &&
+			    total_size < min_total_size) {
+				if (total_size + ifree < isize_diff) {
+					small_entry = last;
+				} else {
+					entry = last;
+					min_total_size = total_size;
+				}
+			}
+		}
+
+		if (entry == NULL) {
+			if (small_entry == NULL)
+				return -ENOSPC;
+			entry = small_entry;
+		}
+
+		entry_size = EXT4_XATTR_LEN(entry->e_name_len);
+		total_size = entry_size;
+		if (!entry->e_value_inum)
+			total_size += EXT4_XATTR_SIZE(
+					      le32_to_cpu(entry->e_value_size));
+		error = ext4_xattr_move_to_block(handle, inode, raw_inode,
+						 entry);
+		if (error)
+			return error;
+
+		*total_ino -= entry_size;
+		ifree += total_size;
+		bfree -= total_size;
+	}
+
+	return 0;
+}
+
+/*
+ * Expand an inode by new_extra_isize bytes when EAs are present.
+ * Returns 0 on success or negative error number on failure.
+ */
+int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
+			       struct ext4_inode *raw_inode, handle_t *handle)
+{
+	struct ext4_xattr_ibody_header *header;
+	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+	static unsigned int mnt_count;
+	size_t min_offs;
+	size_t ifree, bfree;
+	int total_ino;
+	void *base, *end;
+	int error = 0, tried_min_extra_isize = 0;
+	int s_min_extra_isize = le16_to_cpu(sbi->s_es->s_min_extra_isize);
+	int isize_diff;	/* How much do we need to grow i_extra_isize */
+
+retry:
+	isize_diff = new_extra_isize - EXT4_I(inode)->i_extra_isize;
+	if (EXT4_I(inode)->i_extra_isize >= new_extra_isize)
+		return 0;
+
+	header = IHDR(inode, raw_inode);
+
+	/*
+	 * Check if enough free space is available in the inode to shift the
+	 * entries ahead by new_extra_isize.
+	 */
+
+	base = IFIRST(header);
+	end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
+	min_offs = end - base;
+	total_ino = sizeof(struct ext4_xattr_ibody_header) + sizeof(u32);
+
+	error = xattr_check_inode(inode, header, end);
+	if (error)
+		goto cleanup;
+
+	ifree = ext4_xattr_free_space(base, &min_offs, base, &total_ino);
+	if (ifree >= isize_diff)
+		goto shift;
+
+	/*
+	 * Enough free space isn't available in the inode, check if
+	 * EA block can hold new_extra_isize bytes.
+	 */
+	if (EXT4_I(inode)->i_file_acl) {
+		struct buffer_head *bh;
+
+		bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
+		if (IS_ERR(bh)) {
+			error = PTR_ERR(bh);
+			goto cleanup;
+		}
+		error = ext4_xattr_check_block(inode, bh);
+		if (error) {
+			brelse(bh);
+			goto cleanup;
+		}
+		base = BHDR(bh);
+		end = bh->b_data + bh->b_size;
+		min_offs = end - base;
+		bfree = ext4_xattr_free_space(BFIRST(bh), &min_offs, base,
+					      NULL);
+		brelse(bh);
+		if (bfree + ifree < isize_diff) {
+			if (!tried_min_extra_isize && s_min_extra_isize) {
+				tried_min_extra_isize++;
+				new_extra_isize = s_min_extra_isize;
+				goto retry;
+			}
+			error = -ENOSPC;
+			goto cleanup;
+		}
+	} else {
+		bfree = inode->i_sb->s_blocksize;
+	}
+
+	error = ext4_xattr_make_inode_space(handle, inode, raw_inode,
+					    isize_diff, ifree, bfree,
+					    &total_ino);
+	if (error) {
+		if (error == -ENOSPC && !tried_min_extra_isize &&
+		    s_min_extra_isize) {
+			tried_min_extra_isize++;
+			new_extra_isize = s_min_extra_isize;
+			goto retry;
+		}
+		goto cleanup;
+	}
+shift:
+	/* Adjust the offsets and shift the remaining entries ahead */
+	ext4_xattr_shift_entries(IFIRST(header), EXT4_I(inode)->i_extra_isize
+			- new_extra_isize, (void *)raw_inode +
+			EXT4_GOOD_OLD_INODE_SIZE + new_extra_isize,
+			(void *)header, total_ino);
+	EXT4_I(inode)->i_extra_isize = new_extra_isize;
+
+	if (ext4_has_inline_data(inode))
+		error = ext4_find_inline_data_nolock(inode);
+
+cleanup:
+	if (error && (mnt_count != le16_to_cpu(sbi->s_es->s_mnt_count))) {
+		ext4_warning(inode->i_sb, "Unable to expand inode %lu. Delete some EAs or run e2fsck.",
+			     inode->i_ino);
+		mnt_count = le16_to_cpu(sbi->s_es->s_mnt_count);
+	}
+	return error;
+}
+
+#define EIA_INCR 16 /* must be 2^n */
+#define EIA_MASK (EIA_INCR - 1)
+
+/* Add the large xattr @inode into @ea_inode_array for deferred iput().
+ * If @ea_inode_array is new or full it will be grown and the old
+ * contents copied over.
+ */
+static int
+ext4_expand_inode_array(struct ext4_xattr_inode_array **ea_inode_array,
+			struct inode *inode)
+{
+	if (*ea_inode_array == NULL) {
+		/*
+		 * Start with 15 inodes, so it fits into a power-of-two size.
+		 * If *ea_inode_array is NULL, this is essentially offsetof()
+		 */
+		(*ea_inode_array) =
+			kmalloc(offsetof(struct ext4_xattr_inode_array,
+					 inodes[EIA_MASK]),
+				GFP_NOFS);
+		if (*ea_inode_array == NULL)
+			return -ENOMEM;
+		(*ea_inode_array)->count = 0;
+	} else if (((*ea_inode_array)->count & EIA_MASK) == EIA_MASK) {
+		/* expand the array once all 15 + n * 16 slots are full */
+		struct ext4_xattr_inode_array *new_array = NULL;
+		int count = (*ea_inode_array)->count;
+
+		/* if new_array is NULL, this is essentially offsetof() */
+		new_array = kmalloc(
+				offsetof(struct ext4_xattr_inode_array,
+					 inodes[count + EIA_INCR]),
+				GFP_NOFS);
+		if (new_array == NULL)
+			return -ENOMEM;
+		memcpy(new_array, *ea_inode_array,
+		       offsetof(struct ext4_xattr_inode_array, inodes[count]));
+		kfree(*ea_inode_array);
+		*ea_inode_array = new_array;
+	}
+	(*ea_inode_array)->inodes[(*ea_inode_array)->count++] = inode;
+	return 0;
+}
+
+/*
+ * ext4_xattr_delete_inode()
+ *
+ * Free extended attribute resources associated with this inode. Traverse
+ * all entries and decrement reference on any xattr inodes associated with this
+ * inode. This is called immediately before an inode is freed. We have exclusive
+ * access to the inode. If an orphan inode is deleted it will also release its
+ * references on xattr block and xattr inodes.
+ */
+int ext4_xattr_delete_inode(handle_t *handle, struct inode *inode,
+			    struct ext4_xattr_inode_array **ea_inode_array,
+			    int extra_credits)
+{
+	struct buffer_head *bh = NULL;
+	struct ext4_xattr_ibody_header *header;
+	struct ext4_iloc iloc = { .bh = NULL };
+	struct ext4_xattr_entry *entry;
+	struct inode *ea_inode;
+	int error;
+
+	error = ext4_journal_ensure_credits(handle, extra_credits,
+			ext4_free_metadata_revoke_credits(inode->i_sb, 1));
+	if (error < 0) {
+		EXT4_ERROR_INODE(inode, "ensure credits (error %d)", error);
+		goto cleanup;
+	}
+
+	if (ext4_has_feature_ea_inode(inode->i_sb) &&
+	    ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
+
+		error = ext4_get_inode_loc(inode, &iloc);
+		if (error) {
+			EXT4_ERROR_INODE(inode, "inode loc (error %d)", error);
+			goto cleanup;
+		}
+
+		error = ext4_journal_get_write_access(handle, inode->i_sb,
+						iloc.bh, EXT4_JTR_NONE);
+		if (error) {
+			EXT4_ERROR_INODE(inode, "write access (error %d)",
+					 error);
+			goto cleanup;
+		}
+
+		header = IHDR(inode, ext4_raw_inode(&iloc));
+		if (header->h_magic == cpu_to_le32(EXT4_XATTR_MAGIC))
+			ext4_xattr_inode_dec_ref_all(handle, inode, iloc.bh,
+						     IFIRST(header),
+						     false /* block_csum */,
+						     ea_inode_array,
+						     extra_credits,
+						     false /* skip_quota */);
+	}
+
+	if (EXT4_I(inode)->i_file_acl) {
+		bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
+		if (IS_ERR(bh)) {
+			error = PTR_ERR(bh);
+			if (error == -EIO) {
+				EXT4_ERROR_INODE_ERR(inode, EIO,
+						     "block %llu read error",
+						     EXT4_I(inode)->i_file_acl);
+			}
+			bh = NULL;
+			goto cleanup;
+		}
+		error = ext4_xattr_check_block(inode, bh);
+		if (error)
+			goto cleanup;
+
+		if (ext4_has_feature_ea_inode(inode->i_sb)) {
+			for (entry = BFIRST(bh); !IS_LAST_ENTRY(entry);
+			     entry = EXT4_XATTR_NEXT(entry)) {
+				if (!entry->e_value_inum)
+					continue;
+				error = ext4_xattr_inode_iget(inode,
+					      le32_to_cpu(entry->e_value_inum),
+					      le32_to_cpu(entry->e_hash),
+					      &ea_inode);
+				if (error)
+					continue;
+				ext4_xattr_inode_free_quota(inode, ea_inode,
+					      le32_to_cpu(entry->e_value_size));
+				iput(ea_inode);
+			}
+
+		}
+
+		ext4_xattr_release_block(handle, inode, bh, ea_inode_array,
+					 extra_credits);
+		/*
+		 * Update i_file_acl value in the same transaction that releases
+		 * block.
+		 */
+		EXT4_I(inode)->i_file_acl = 0;
+		error = ext4_mark_inode_dirty(handle, inode);
+		if (error) {
+			EXT4_ERROR_INODE(inode, "mark inode dirty (error %d)",
+					 error);
+			goto cleanup;
+		}
+		ext4_fc_mark_ineligible(inode->i_sb, EXT4_FC_REASON_XATTR, handle);
+	}
+	error = 0;
+cleanup:
+	brelse(iloc.bh);
+	brelse(bh);
+	return error;
+}
+
+void ext4_xattr_inode_array_free(struct ext4_xattr_inode_array *ea_inode_array)
+{
+	int idx;
+
+	if (ea_inode_array == NULL)
+		return;
+
+	for (idx = 0; idx < ea_inode_array->count; ++idx)
+		iput(ea_inode_array->inodes[idx]);
+	kfree(ea_inode_array);
+}
+
+/*
+ * ext4_xattr_block_cache_insert()
+ *
+ * Create a new entry in the extended attribute block cache, and insert
+ * it unless such an entry is already in the cache.
+ *
+ * Returns 0, or a negative error number on failure.
+ */
+static void
+ext4_xattr_block_cache_insert(struct mb_cache *ea_block_cache,
+			      struct buffer_head *bh)
+{
+	struct ext4_xattr_header *header = BHDR(bh);
+	__u32 hash = le32_to_cpu(header->h_hash);
+	int reusable = le32_to_cpu(header->h_refcount) <
+		       EXT4_XATTR_REFCOUNT_MAX;
+	int error;
+
+	if (!ea_block_cache)
+		return;
+	error = mb_cache_entry_create(ea_block_cache, GFP_NOFS, hash,
+				      bh->b_blocknr, reusable);
+	if (error) {
+		if (error == -EBUSY)
+			ea_bdebug(bh, "already in cache");
+	} else
+		ea_bdebug(bh, "inserting [%x]", (int)hash);
+}
+
+/*
+ * ext4_xattr_cmp()
+ *
+ * Compare two extended attribute blocks for equality.
+ *
+ * Returns 0 if the blocks are equal, 1 if they differ, and
+ * a negative error number on errors.
+ */
+static int
+ext4_xattr_cmp(struct ext4_xattr_header *header1,
+	       struct ext4_xattr_header *header2)
+{
+	struct ext4_xattr_entry *entry1, *entry2;
+
+	entry1 = ENTRY(header1+1);
+	entry2 = ENTRY(header2+1);
+	while (!IS_LAST_ENTRY(entry1)) {
+		if (IS_LAST_ENTRY(entry2))
+			return 1;
+		if (entry1->e_hash != entry2->e_hash ||
+		    entry1->e_name_index != entry2->e_name_index ||
+		    entry1->e_name_len != entry2->e_name_len ||
+		    entry1->e_value_size != entry2->e_value_size ||
+		    entry1->e_value_inum != entry2->e_value_inum ||
+		    memcmp(entry1->e_name, entry2->e_name, entry1->e_name_len))
+			return 1;
+		if (!entry1->e_value_inum &&
+		    memcmp((char *)header1 + le16_to_cpu(entry1->e_value_offs),
+			   (char *)header2 + le16_to_cpu(entry2->e_value_offs),
+			   le32_to_cpu(entry1->e_value_size)))
+			return 1;
+
+		entry1 = EXT4_XATTR_NEXT(entry1);
+		entry2 = EXT4_XATTR_NEXT(entry2);
+	}
+	if (!IS_LAST_ENTRY(entry2))
+		return 1;
+	return 0;
+}
+
+/*
+ * ext4_xattr_block_cache_find()
+ *
+ * Find an identical extended attribute block.
+ *
+ * Returns a pointer to the block found, or NULL if such a block was
+ * not found or an error occurred.
+ */
+static struct buffer_head *
+ext4_xattr_block_cache_find(struct inode *inode,
+			    struct ext4_xattr_header *header,
+			    struct mb_cache_entry **pce)
+{
+	__u32 hash = le32_to_cpu(header->h_hash);
+	struct mb_cache_entry *ce;
+	struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
+
+	if (!ea_block_cache)
+		return NULL;
+	if (!header->h_hash)
+		return NULL;  /* never share */
+	ea_idebug(inode, "looking for cached blocks [%x]", (int)hash);
+	ce = mb_cache_entry_find_first(ea_block_cache, hash);
+	while (ce) {
+		struct buffer_head *bh;
+
+		bh = ext4_sb_bread(inode->i_sb, ce->e_value, REQ_PRIO);
+		if (IS_ERR(bh)) {
+			if (PTR_ERR(bh) == -ENOMEM)
+				return NULL;
+			bh = NULL;
+			EXT4_ERROR_INODE(inode, "block %lu read error",
+					 (unsigned long)ce->e_value);
+		} else if (ext4_xattr_cmp(header, BHDR(bh)) == 0) {
+			*pce = ce;
+			return bh;
+		}
+		brelse(bh);
+		ce = mb_cache_entry_find_next(ea_block_cache, ce);
+	}
+	return NULL;
+}
+
+#define NAME_HASH_SHIFT 5
+#define VALUE_HASH_SHIFT 16
+
+/*
+ * ext4_xattr_hash_entry()
+ *
+ * Compute the hash of an extended attribute.
+ */
+static __le32 ext4_xattr_hash_entry(char *name, size_t name_len, __le32 *value,
+				    size_t value_count)
+{
+	__u32 hash = 0;
+
+	while (name_len--) {
+		hash = (hash << NAME_HASH_SHIFT) ^
+		       (hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^
+		       *name++;
+	}
+	while (value_count--) {
+		hash = (hash << VALUE_HASH_SHIFT) ^
+		       (hash >> (8*sizeof(hash) - VALUE_HASH_SHIFT)) ^
+		       le32_to_cpu(*value++);
+	}
+	return cpu_to_le32(hash);
+}
+
+#undef NAME_HASH_SHIFT
+#undef VALUE_HASH_SHIFT
+
+#define BLOCK_HASH_SHIFT 16
+
+/*
+ * ext4_xattr_rehash()
+ *
+ * Re-compute the extended attribute hash value after an entry has changed.
+ */
+static void ext4_xattr_rehash(struct ext4_xattr_header *header)
+{
+	struct ext4_xattr_entry *here;
+	__u32 hash = 0;
+
+	here = ENTRY(header+1);
+	while (!IS_LAST_ENTRY(here)) {
+		if (!here->e_hash) {
+			/* Block is not shared if an entry's hash value == 0 */
+			hash = 0;
+			break;
+		}
+		hash = (hash << BLOCK_HASH_SHIFT) ^
+		       (hash >> (8*sizeof(hash) - BLOCK_HASH_SHIFT)) ^
+		       le32_to_cpu(here->e_hash);
+		here = EXT4_XATTR_NEXT(here);
+	}
+	header->h_hash = cpu_to_le32(hash);
+}
+
+#undef BLOCK_HASH_SHIFT
+
+#define	HASH_BUCKET_BITS	10
+
+struct mb_cache *
+ext4_xattr_create_cache(void)
+{
+	return mb_cache_create(HASH_BUCKET_BITS);
+}
+
+void ext4_xattr_destroy_cache(struct mb_cache *cache)
+{
+	if (cache)
+		mb_cache_destroy(cache);
+}
+