[PATCH 2/2] ext4: propagate errors from ext4_sb_bread() in ext4_xattr_block_cache_find()

From: libaokun
Date: Sat May 04 2024 - 04:05:55 EST


From: Baokun Li <libaokun1@xxxxxxxxxx>

In ext4_xattr_block_cache_find(), when ext4_sb_bread() returns an error,
we will either continue to find the next ea block or return NULL to try to
insert a new ea block. But whether ext4_sb_bread() returns -EIO or -ENOMEM,
the next operation is most likely to fail with the same error. So propagate
the error returned by ext4_sb_bread() to make ext4_xattr_block_set() fail
to reduce pointless operations.

Signed-off-by: Baokun Li <libaokun1@xxxxxxxxxx>
---
fs/ext4/xattr.c | 25 ++++++++++++++-----------
1 file changed, 14 insertions(+), 11 deletions(-)

diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
index 9fdd13422073..11742e1f16d7 100644
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -2059,8 +2059,13 @@ ext4_xattr_block_set(handle_t *handle, struct inode *inode,

inserted:
if (!IS_LAST_ENTRY(s->first)) {
- new_bh = ext4_xattr_block_cache_find(inode, header(s->base),
- &ce);
+ new_bh = ext4_xattr_block_cache_find(inode, header(s->base), &ce);
+ if (IS_ERR(new_bh)) {
+ error = PTR_ERR(new_bh);
+ new_bh = NULL;
+ goto cleanup;
+ }
+
if (new_bh) {
/* We found an identical block in the cache. */
if (new_bh == bs->bh)
@@ -3090,8 +3095,8 @@ ext4_xattr_cmp(struct ext4_xattr_header *header1,
*
* 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.
+ * Returns a pointer to the block found, or NULL if such a block was not
+ * found, or an error pointer if an error occurred while reading ea block.
*/
static struct buffer_head *
ext4_xattr_block_cache_find(struct inode *inode,
@@ -3113,13 +3118,11 @@ ext4_xattr_block_cache_find(struct inode *inode,

bh = ext4_sb_bread(inode->i_sb, ce->e_value, REQ_PRIO);
if (IS_ERR(bh)) {
- if (PTR_ERR(bh) == -ENOMEM) {
- mb_cache_entry_put(ea_block_cache, ce);
- return NULL;
- }
- bh = NULL;
- EXT4_ERROR_INODE(inode, "block %lu read error",
- (unsigned long)ce->e_value);
+ if (PTR_ERR(bh) != -ENOMEM)
+ EXT4_ERROR_INODE(inode, "block %lu read error",
+ (unsigned long)ce->e_value);
+ mb_cache_entry_put(ea_block_cache, ce);
+ return bh;
} else if (ext4_xattr_cmp(header, BHDR(bh)) == 0) {
*pce = ce;
return bh;
--
2.39.2