diff options
Diffstat (limited to 'fs/ext4')
| -rw-r--r-- | fs/ext4/xattr.c | 92 |
1 files changed, 77 insertions, 15 deletions
diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c index e88748e55c0f..e56c9ed7d6e3 100644 --- a/fs/ext4/xattr.c +++ b/fs/ext4/xattr.c @@ -122,6 +122,58 @@ const struct xattr_handler *ext4_xattr_handlers[] = { NULL }; +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); + struct ext4_inode_info *ei = EXT4_I(inode); + __u32 csum, old; + + old = hdr->h_checksum; + hdr->h_checksum = 0; + if (le32_to_cpu(hdr->h_refcount) != 1) { + block_nr = cpu_to_le64(block_nr); + csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&block_nr, + sizeof(block_nr)); + } else + csum = ei->i_csum_seed; + csum = ext4_chksum(sbi, csum, (__u8 *)hdr, + EXT4_BLOCK_SIZE(inode->i_sb)); + hdr->h_checksum = old; + return cpu_to_le32(csum); +} + +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) && + (hdr->h_checksum != ext4_xattr_block_csum(inode, block_nr, hdr))) + return 0; + return 1; +} + +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)) + return; + + hdr->h_checksum = ext4_xattr_block_csum(inode, block_nr, hdr); +} + +static inline int ext4_handle_dirty_xattr_block(handle_t *handle, + struct inode *inode, + struct buffer_head *bh) +{ + ext4_xattr_block_csum_set(inode, bh->b_blocknr, BHDR(bh)); + return ext4_handle_dirty_metadata(handle, inode, bh); +} + static inline const struct xattr_handler * ext4_xattr_handler(int name_index) { @@ -156,12 +208,22 @@ ext4_xattr_check_names(struct ext4_xattr_entry *entry, void *end) } static inline int -ext4_xattr_check_block(struct buffer_head *bh) +ext4_xattr_check_block(struct inode *inode, struct buffer_head *bh) { + int error; + + if (buffer_verified(bh)) + return 0; + if (BHDR(bh)->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC) || BHDR(bh)->h_blocks != cpu_to_le32(1)) return -EIO; - return ext4_xattr_check_names(BFIRST(bh), bh->b_data + bh->b_size); + 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); + if (!error) + set_buffer_verified(bh); + return error; } static inline int @@ -224,7 +286,7 @@ ext4_xattr_block_get(struct inode *inode, int name_index, const char *name, goto cleanup; ea_bdebug(bh, "b_count=%d, refcount=%d", atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount)); - if (ext4_xattr_check_block(bh)) { + if (ext4_xattr_check_block(inode, bh)) { bad_block: EXT4_ERROR_INODE(inode, "bad block %llu", EXT4_I(inode)->i_file_acl); @@ -369,7 +431,7 @@ ext4_xattr_block_list(struct dentry *dentry, char *buffer, size_t buffer_size) goto cleanup; ea_bdebug(bh, "b_count=%d, refcount=%d", atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount)); - if (ext4_xattr_check_block(bh)) { + if (ext4_xattr_check_block(inode, bh)) { EXT4_ERROR_INODE(inode, "bad block %llu", EXT4_I(inode)->i_file_acl); error = -EIO; @@ -492,7 +554,7 @@ ext4_xattr_release_block(handle_t *handle, struct inode *inode, if (ce) mb_cache_entry_release(ce); unlock_buffer(bh); - error = ext4_handle_dirty_metadata(handle, inode, bh); + error = ext4_handle_dirty_xattr_block(handle, inode, bh); if (IS_SYNC(inode)) ext4_handle_sync(handle); dquot_free_block(inode, 1); @@ -662,7 +724,7 @@ ext4_xattr_block_find(struct inode *inode, struct ext4_xattr_info *i, ea_bdebug(bs->bh, "b_count=%d, refcount=%d", atomic_read(&(bs->bh->b_count)), le32_to_cpu(BHDR(bs->bh)->h_refcount)); - if (ext4_xattr_check_block(bs->bh)) { + if (ext4_xattr_check_block(inode, bs->bh)) { EXT4_ERROR_INODE(inode, "bad block %llu", EXT4_I(inode)->i_file_acl); error = -EIO; @@ -725,9 +787,9 @@ ext4_xattr_block_set(handle_t *handle, struct inode *inode, if (error == -EIO) goto bad_block; if (!error) - error = ext4_handle_dirty_metadata(handle, - inode, - bs->bh); + error = ext4_handle_dirty_xattr_block(handle, + inode, + bs->bh); if (error) goto cleanup; goto inserted; @@ -796,9 +858,9 @@ inserted: ea_bdebug(new_bh, "reusing; refcount now=%d", le32_to_cpu(BHDR(new_bh)->h_refcount)); unlock_buffer(new_bh); - error = ext4_handle_dirty_metadata(handle, - inode, - new_bh); + error = ext4_handle_dirty_xattr_block(handle, + inode, + new_bh); if (error) goto cleanup_dquot; } @@ -855,8 +917,8 @@ getblk_failed: set_buffer_uptodate(new_bh); unlock_buffer(new_bh); ext4_xattr_cache_insert(new_bh); - error = ext4_handle_dirty_metadata(handle, - inode, new_bh); + error = ext4_handle_dirty_xattr_block(handle, + inode, new_bh); if (error) goto cleanup; } @@ -1193,7 +1255,7 @@ retry: error = -EIO; if (!bh) goto cleanup; - if (ext4_xattr_check_block(bh)) { + if (ext4_xattr_check_block(inode, bh)) { EXT4_ERROR_INODE(inode, "bad block %llu", EXT4_I(inode)->i_file_acl); error = -EIO; |