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 // 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)
 {
     lockdep_set_subclass(&ea_inode->i_rwsem, 1);
 }
 #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;
 
     inode = ext4_iget(parent->i_sb, ea_ino, EXT4_IGET_NORMAL);
     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;
     }
 
     if (is_bad_inode(inode)) {
         ext4_error(parent->i_sb,
                "error while reading EA inode %lu is_bad_inode",
                ea_ino);
         err = -EIO;
         goto error;
     }
 
     if (!(EXT4_I(inode)->i_flags & EXT4_EA_INODE_FL)) {
         ext4_error(parent->i_sb,
                "EA inode %lu does not have EXT4_EA_INODE_FL flag",
                 ea_ino);
         err = -EINVAL;
         goto error;
     }
 
     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;
 error:
     iput(inode);
     return err;
 }
 
 /* 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) {
                     ce->e_reusable = 1;
                     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;
 
     /*
      * 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) {
             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_NORMAL);
         if (!IS_ERR(ea_inode) &&
             !is_bad_inode(ea_inode) &&
             (EXT4_I(ea_inode)->i_flags & EXT4_EA_INODE_FL) &&
             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;
         }
 
         if (!IS_ERR(ea_inode))
             iput(ea_inode);
         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);
     } 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;
 
                 WARN_ON_ONCE(dquot_initialize_needed(inode));
 
                 /* 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)
                     ce->e_reusable = 0;
                 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;
 
             WARN_ON_ONCE(dquot_initialize_needed(inode));
 
             goal = ext4_group_first_block_no(sb,
                         EXT4_I(inode)->i_block_group);
 
             /* non-extent files can't have physical blocks past 2^32 */
             if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
                 goal = goal & EXT4_MAX_BLOCK_FILE_PHYS;
 
             block = ext4_new_meta_blocks(handle, inode, goal, 0,
                              NULL, &error);
             if (error)
                 goto cleanup;
 
             if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
                 BUG_ON(block > EXT4_MAX_BLOCK_FILE_PHYS);
 
             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);
         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 error;
 
     is = kzalloc(sizeof(struct ext4_xattr_ibody_find), GFP_NOFS);
     bs = kzalloc(sizeof(struct ext4_xattr_block_find), GFP_NOFS);
     buffer = kmalloc(value_size, GFP_NOFS);
     b_entry_name = kmalloc(entry->e_name_len + 1, GFP_NOFS);
     if (!is || !bs || !buffer || !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) {
         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);
         memcpy(buffer, (void *)IFIRST(header) + value_offs, value_size);
     }
 
     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;
 
     /* Remove the chosen entry from the inode */
     error = ext4_xattr_ibody_set(handle, 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;
 
     /* Add entry which was removed from the inode into the block */
     error = ext4_xattr_block_set(handle, inode, &i, bs);
     if (error)
         goto out;
     error = 0;
 out:
     kfree(b_entry_name);
     kfree(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;
 
 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);
 }