On Jun 3, 2020, at 03:44, Chengguang Xu <cgxu519@xxxxxxxxxxxx> wrote:
>
> Currently ext2 uses mdcache for deduplication of extended
(typo) this should be "mbcache"
> attribution blocks. However, there is lack of handling for
> corrupted blocks, so newly created EAs may still links to
> corrupted blocks. This patch tries to drop cached block
> when detecting corruption to mitigate the effect.
>
> Signed-off-by: Chengguang Xu <cgxu519@xxxxxxxxxxxx>
> ---
> fs/ext2/xattr.c | 25 ++++++++++++++++++++++---
> 1 file changed, 22 insertions(+), 3 deletions(-)
>
> diff --git a/fs/ext2/xattr.c b/fs/ext2/xattr.c
> index 943cc469f42f..969521e39753 100644
> --- a/fs/ext2/xattr.c
> +++ b/fs/ext2/xattr.c
> @@ -93,6 +93,8 @@ static int ext2_xattr_set2(struct inode *, struct buffer_head *,
> struct ext2_xattr_header *);
>
> static int ext2_xattr_cache_insert(struct mb_cache *, struct buffer_head *);
> +static void ext2_xattr_cache_remove(struct mb_cache *cache,
> + struct buffer_head *bh);
> static struct buffer_head *ext2_xattr_cache_find(struct inode *,
> struct ext2_xattr_header *);
> static void ext2_xattr_rehash(struct ext2_xattr_header *,
> @@ -237,8 +239,10 @@ ext2_xattr_get(struct inode *inode, int name_index, const char *name,
> entry = FIRST_ENTRY(bh);
> while (!IS_LAST_ENTRY(entry)) {
> if (!ext2_xattr_entry_valid(entry, end,
> - inode->i_sb->s_blocksize))
> + inode->i_sb->s_blocksize)) {
> + ext2_xattr_cache_remove(ea_block_cache, bh);
> goto bad_block;
> + }
>
> not_found = ext2_xattr_cmp_entry(name_index, name_len, name,
> entry);
> @@ -323,8 +327,10 @@ ext2_xattr_list(struct dentry *dentry, char *buffer, size_t buffer_size)
> entry = FIRST_ENTRY(bh);
> while (!IS_LAST_ENTRY(entry)) {
> if (!ext2_xattr_entry_valid(entry, end,
> - inode->i_sb->s_blocksize))
> + inode->i_sb->s_blocksize)) {
> + ext2_xattr_cache_remove(ea_block_cache, bh);
> goto bad_block;
> + }
> entry = EXT2_XATTR_NEXT(entry);
> }
> if (ext2_xattr_cache_insert(ea_block_cache, bh))
> @@ -407,6 +413,7 @@ int
> ext2_xattr_set(struct inode *inode, int name_index, const char *name,
> const void *value, size_t value_len, int flags)
> {
> + struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
> struct super_block *sb = inode->i_sb;
> struct buffer_head *bh = NULL;
> struct ext2_xattr_header *header = NULL;
> @@ -464,8 +471,11 @@ ext2_xattr_set(struct inode *inode, int name_index, const char *name,
> */
> last = FIRST_ENTRY(bh);
> while (!IS_LAST_ENTRY(last)) {
> - if (!ext2_xattr_entry_valid(last, end, sb->s_blocksize))
> + if (!ext2_xattr_entry_valid(last, end,
> + sb->s_blocksize)) {
> + ext2_xattr_cache_remove(ea_block_cache, bh);
> goto bad_block;
> + }
> if (last->e_value_size) {
> size_t offs = le16_to_cpu(last->e_value_offs);
> if (offs < min_offs)
> @@ -881,6 +891,15 @@ ext2_xattr_cache_insert(struct mb_cache *cache, struct buffer_head *bh)
> return error;
> }
>
> +static void
> +ext2_xattr_cache_remove(struct mb_cache *cache, struct buffer_head *bh)
> +{
> + lock_buffer(bh);
> + mb_cache_entry_delete(cache, le32_to_cpu(HDR(bh)->h_hash),
> + bh->b_blocknr);
> + unlock_buffer(bh);
> +}
> +
> /*
> * ext2_xattr_cmp()
> *
> --
> 2.20.1
>
>
