ext4: propagate errors up to ext4_find_entry()'s callers
commit 36de928641ee48b2078d3fe9514242aaa2f92013 upstream.
If we run into some kind of error, such as ENOMEM, while calling
ext4_getblk() or ext4_dx_find_entry(), we need to make sure this error
gets propagated up to ext4_find_entry() and then to its callers. This
way, transient errors such as ENOMEM can get propagated to the VFS.
This is important so that the system calls return the appropriate
error, and also so that in the case of ext4_lookup(), we return an
error instead of a NULL inode, since that will result in a negative
dentry cache entry that will stick around long past the OOM condition
which caused a transient ENOMEM error.
Google-Bug-Id: #17142205
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
[lizf: Backported to 3.4:
- adjust context
- s/old.bh/old_bh/g
- s/new.bh/new_bh/g
- drop the changes to ext4_find_delete_entry() and ext4_cross_rename()
- add return value check for one more exr4_find_entry() in ext4_rename()]
Signed-off-by: Zefan Li <lizefan@huawei.com>
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 2922486..521ba9d 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1674,7 +1674,7 @@
/*
* Special error return code only used by dx_probe() and its callers.
*/
-#define ERR_BAD_DX_DIR -75000
+#define ERR_BAD_DX_DIR (-(MAX_ERRNO - 1))
void ext4_get_group_no_and_offset(struct super_block *sb, ext4_fsblk_t blocknr,
ext4_group_t *blockgrpp, ext4_grpblk_t *offsetp);