From: Gao Xiang <hsiang...@redhat.com>
Martin reported an issue that directory read could be hung on the
latest -rc kernel with some certain image. The root cause is that
commit baa2c7c97153 ("block: set .bi_max_vecs as actual allocated
vector number") changes .bi_max_vecs behavior. bio->bi_max_vecs
is set as actual allocated vector number rather than the requested
number now.
Let's avoid using .bi_max_vecs completely instead.
Reported-by: Martin DEVERA <de...@eaxlabs.cz>
Signed-off-by: Gao Xiang <hsiang...@redhat.com>
---
Hi Chao,
Could you take some time on reviewing this patchset in advance?
I'd like to upstream this regression fix asap since it has noticable
impact on 5.12-rc kernel.
Thanks,
Gao Xiang
fs/erofs/data.c | 13 ++-----------
1 file changed, 2 insertions(+), 11 deletions(-)
diff --git a/fs/erofs/data.c b/fs/erofs/data.c
index f88851c5c250..fa25d0eab5de 100644
--- a/fs/erofs/data.c
+++ b/fs/erofs/data.c
@@ -231,14 +231,6 @@ static inline struct bio *erofs_read_raw_page(struct bio
*bio,
goto submit_bio_retry;
*last_block = current_block;
-
- /* shift in advance in case of it followed by too many gaps */
- if (bio->bi_iter.bi_size >= bio->bi_max_vecs * PAGE_SIZE) {
- /* err should reassign to 0 after submitting */
- err = 0;
- goto submit_bio_out;
- }
-
return bio;
err_out:
@@ -252,7 +244,6 @@ static inline struct bio *erofs_read_raw_page(struct bio
*bio,
/* if updated manually, continuous pages has a gap */
if (bio)
-submit_bio_out:
submit_bio(bio);
return err ? ERR_PTR(err) : NULL;
}
@@ -274,7 +265,8 @@ static int erofs_raw_access_readpage(struct file *file,
struct page *page)
if (IS_ERR(bio))
return PTR_ERR(bio);
- DBG_BUGON(bio); /* since we have only one bio -- must be NULL */
+ if (bio)
+ submit_bio(bio);
return 0;
}
@@ -305,7 +297,6 @@ static void erofs_raw_access_readahead(struct
readahead_control *rac)
put_page(page);
}
- /* the rare case (end in gaps) */
if (bio)
submit_bio(bio);
}
--
2.20.1
