On 13/11/2024 10:08, Johannes Thumshirn wrote:
Hi Johannes,
Could you kindly repost this patch? Sorry for not paying attention to it
further previously.
BTW, on a related topic, should we check for a negative error code in
btrfs_append_map_length() -> bio_split_rw_at() result?
Thanks,
John
On 13.11.24 10:51, John Garry wrote:
On 04/11/2024 12:13, Johannes Thumshirn wrote:
From: Johannes Thumshirn <johannes.thumshirn@xxxxxxx>
Now that bio_split() can return errors, add error handling for it in
btrfs_split_bio() and ultimately btrfs_submit_chunk().
I have a couple of comments, below; However, since I am not familiar
with the code, maybe they are invalid.
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@xxxxxxx>
---
This is based on top of John Garry's series "bio_split() error handling
rework" explicitly on the patch titled "block: Rework bio_split() return
value", which are as of now (Tue Oct 29 10:02:16 2024) not yet merged into
any tree.
Changes to v2:
- assign the split bbio to a new variable, so we can keep the old error
paths and end the original bbio
Changes to v1:
- convert ERR_PTR to blk_status_t
- correctly fail already split bbios
---
fs/btrfs/bio.c | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)
diff --git a/fs/btrfs/bio.c b/fs/btrfs/bio.c
index 1f216d07eff6..7a0998d0abe3 100644
--- a/fs/btrfs/bio.c
+++ b/fs/btrfs/bio.c
@@ -81,6 +81,9 @@ static struct btrfs_bio *btrfs_split_bio(struct btrfs_fs_info *fs_info,
bio = bio_split(&orig_bbio->bio, map_length >> SECTOR_SHIFT, GFP_NOFS,
&btrfs_clone_bioset);
+ if (IS_ERR(bio))
+ return ERR_CAST(bio);
+
bbio = btrfs_bio(bio);
btrfs_bio_init(bbio, fs_info, NULL, orig_bbio);
bbio->inode = orig_bbio->inode;
@@ -678,7 +681,7 @@ static bool btrfs_submit_chunk(struct btrfs_bio *bbio, int mirror_num)
&bioc, &smap, &mirror_num);
if (error) {
ret = errno_to_blk_status(error);
- goto fail;
+ goto end_bbio;
eh, I am not sure why this has changed (and we now skip the "fail" label
actions)
Because we want to skip the 'if (map_length < length) {' part below the
'fail' label and directly go to btrfs_bio_end_io().
}
map_length = min(map_length, length);
@@ -686,7 +689,14 @@ static bool btrfs_submit_chunk(struct btrfs_bio *bbio, int mirror_num)
map_length = btrfs_append_map_length(bbio, map_length);
if (map_length < length) {
- bbio = btrfs_split_bio(fs_info, bbio, map_length);
+ struct btrfs_bio *split;
+
+ split = btrfs_split_bio(fs_info, bbio, map_length);
+ if (IS_ERR(split)) {
+ ret = errno_to_blk_status(PTR_ERR(split));
+ goto end_bbio;
Do we need to undo the btrfs_bio_counter_inc() (not shown)?
Yes we do.
+ }
+ bbio = split;
bio = &bbio->bio;
}
@@ -760,6 +770,7 @@ static bool btrfs_submit_chunk(struct btrfs_bio *bbio, int mirror_num)
btrfs_bio_end_io(remaining, ret);
}
+end_bbio:
btrfs_bio_end_io(bbio, ret);
/* Do not submit another chunk */
return true;
