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Diffstat (limited to 'fs/ext4/xattr.c')
-rw-r--r--fs/ext4/xattr.c61
1 files changed, 45 insertions, 16 deletions
diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
index 1423c48..a5d2f1b 100644
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -141,8 +141,7 @@ static int ext4_xattr_block_csum_verify(struct inode *inode,
sector_t block_nr,
struct ext4_xattr_header *hdr)
{
- if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
- EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
+ if (ext4_has_metadata_csum(inode->i_sb) &&
(hdr->h_checksum != ext4_xattr_block_csum(inode, block_nr, hdr)))
return 0;
return 1;
@@ -152,8 +151,7 @@ static void ext4_xattr_block_csum_set(struct inode *inode,
sector_t block_nr,
struct ext4_xattr_header *hdr)
{
- if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
- EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+ if (!ext4_has_metadata_csum(inode->i_sb))
return;
hdr->h_checksum = ext4_xattr_block_csum(inode, block_nr, hdr);
@@ -189,14 +187,28 @@ ext4_listxattr(struct dentry *dentry, char *buffer, size_t size)
}
static int
-ext4_xattr_check_names(struct ext4_xattr_entry *entry, void *end)
+ext4_xattr_check_names(struct ext4_xattr_entry *entry, void *end,
+ void *value_start)
{
- while (!IS_LAST_ENTRY(entry)) {
- struct ext4_xattr_entry *next = EXT4_XATTR_NEXT(entry);
+ struct ext4_xattr_entry *e = entry;
+
+ while (!IS_LAST_ENTRY(e)) {
+ struct ext4_xattr_entry *next = EXT4_XATTR_NEXT(e);
if ((void *)next >= end)
return -EIO;
- entry = next;
+ e = next;
+ }
+
+ while (!IS_LAST_ENTRY(entry)) {
+ if (entry->e_value_size != 0 &&
+ (value_start + le16_to_cpu(entry->e_value_offs) <
+ (void *)e + sizeof(__u32) ||
+ value_start + le16_to_cpu(entry->e_value_offs) +
+ le32_to_cpu(entry->e_value_size) > end))
+ return -EIO;
+ entry = EXT4_XATTR_NEXT(entry);
}
+
return 0;
}
@@ -213,7 +225,8 @@ ext4_xattr_check_block(struct inode *inode, struct buffer_head *bh)
return -EIO;
if (!ext4_xattr_block_csum_verify(inode, bh->b_blocknr, BHDR(bh)))
return -EIO;
- error = ext4_xattr_check_names(BFIRST(bh), bh->b_data + bh->b_size);
+ error = ext4_xattr_check_names(BFIRST(bh), bh->b_data + bh->b_size,
+ bh->b_data);
if (!error)
set_buffer_verified(bh);
return error;
@@ -329,7 +342,7 @@ ext4_xattr_ibody_get(struct inode *inode, int name_index, const char *name,
header = IHDR(inode, raw_inode);
entry = IFIRST(header);
end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
- error = ext4_xattr_check_names(entry, end);
+ error = ext4_xattr_check_names(entry, end, entry);
if (error)
goto cleanup;
error = ext4_xattr_find_entry(&entry, name_index, name,
@@ -457,7 +470,7 @@ ext4_xattr_ibody_list(struct dentry *dentry, char *buffer, size_t buffer_size)
raw_inode = ext4_raw_inode(&iloc);
header = IHDR(inode, raw_inode);
end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
- error = ext4_xattr_check_names(IFIRST(header), end);
+ error = ext4_xattr_check_names(IFIRST(header), end, IFIRST(header));
if (error)
goto cleanup;
error = ext4_xattr_list_entries(dentry, IFIRST(header),
@@ -517,8 +530,8 @@ static void ext4_xattr_update_super_block(handle_t *handle,
}
/*
- * Release the xattr block BH: If the reference count is > 1, decrement
- * it; otherwise free the block.
+ * 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,
@@ -538,16 +551,31 @@ ext4_xattr_release_block(handle_t *handle, struct inode *inode,
if (ce)
mb_cache_entry_free(ce);
get_bh(bh);
+ unlock_buffer(bh);
ext4_free_blocks(handle, inode, bh, 0, 1,
EXT4_FREE_BLOCKS_METADATA |
EXT4_FREE_BLOCKS_FORGET);
- unlock_buffer(bh);
} else {
le32_add_cpu(&BHDR(bh)->h_refcount, -1);
if (ce)
mb_cache_entry_release(ce);
+ /*
+ * 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_xattr_block() 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_xattr_block(handle, inode,
+ bh);
unlock_buffer(bh);
- error = ext4_handle_dirty_xattr_block(handle, inode, bh);
+ if (!ext4_handle_valid(handle))
+ error = ext4_handle_dirty_xattr_block(handle, inode,
+ bh);
if (IS_SYNC(inode))
ext4_handle_sync(handle);
dquot_free_block(inode, EXT4_C2B(EXT4_SB(inode->i_sb), 1));
@@ -957,7 +985,8 @@ int ext4_xattr_ibody_find(struct inode *inode, struct ext4_xattr_info *i,
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 = ext4_xattr_check_names(IFIRST(header), is->s.end);
+ error = ext4_xattr_check_names(IFIRST(header), is->s.end,
+ IFIRST(header));
if (error)
return error;
/* Find the named attribute. */