| Message ID | 20170806200319.21077-1-tahsin@google.com |
|---|---|
| State | Accepted, archived |
| Headers | show |
On Sun, Aug 06, 2017 at 01:03:19PM -0700, Tahsin Erdogan wrote: > When updating an extended attribute, if the padded value sizes are the > same, a shortcut is taken to avoid the bulk of the work. This was fine > until the xattr hash update was moved inside ext4_xattr_set_entry(). > With that change, the hash update got missed in the shortcut case. > > Thanks to ZhangYi (yizhang089@gmail.com) for root causing the problem. > > Fixes: daf8328172df ("ext4: eliminate xattr entry e_hash recalculation for removes") > > Reported-by: Miklos Szeredi <miklos@szeredi.hu> > Signed-off-by: Tahsin Erdogan <tahsin@google.com> Thanks, applied. - Ted
diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c index 82a5af9f6668..3dd970168448 100644 --- a/fs/ext4/xattr.c +++ b/fs/ext4/xattr.c @@ -1543,7 +1543,7 @@ static int ext4_xattr_set_entry(struct ext4_xattr_info *i, /* Clear padding bytes. */ memset(val + i->value_len, 0, new_size - i->value_len); } - return 0; + goto update_hash; } /* Compute min_offs and last. */ @@ -1707,6 +1707,7 @@ static int ext4_xattr_set_entry(struct ext4_xattr_info *i, here->e_value_size = cpu_to_le32(i->value_len); } +update_hash: if (i->value) { __le32 hash = 0; @@ -1725,7 +1726,8 @@ static int ext4_xattr_set_entry(struct ext4_xattr_info *i, here->e_name_len, &crc32c_hash, 1); } else if (is_block) { - __le32 *value = s->base + min_offs - new_size; + __le32 *value = s->base + le16_to_cpu( + here->e_value_offs); hash = ext4_xattr_hash_entry(here->e_name, here->e_name_len, value,
When updating an extended attribute, if the padded value sizes are the same, a shortcut is taken to avoid the bulk of the work. This was fine until the xattr hash update was moved inside ext4_xattr_set_entry(). With that change, the hash update got missed in the shortcut case. Thanks to ZhangYi (yizhang089@gmail.com) for root causing the problem. Fixes: daf8328172df ("ext4: eliminate xattr entry e_hash recalculation for removes") Reported-by: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: Tahsin Erdogan <tahsin@google.com> --- fs/ext4/xattr.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)