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author | Linus Torvalds <torvalds@linux-foundation.org> | 2021-03-13 12:26:22 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-03-13 12:26:22 -0800 |
commit | 420623430a7015ae9adab8a087de82c186bc9989 (patch) | |
tree | 24a16dec576c99d3dd79e02f5cd53d692279c2d1 | |
parent | e83bad7f77a4348277c3ebe9bea4a5b0cd6dfcb5 (diff) | |
parent | 9f377622a484de0818c49ee01e0ab4eedf6acd81 (diff) | |
download | lwn-420623430a7015ae9adab8a087de82c186bc9989.tar.gz lwn-420623430a7015ae9adab8a087de82c186bc9989.zip |
Merge tag 'erofs-for-5.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs
Pull erofs fix from Gao Xiang:
"Fix an urgent regression introduced by commit baa2c7c97153 ("block:
set .bi_max_vecs as actual allocated vector number"), which could
cause unexpected hung since linux 5.12-rc1.
Resolve it by avoiding using bio->bi_max_vecs completely"
* tag 'erofs-for-5.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs:
erofs: fix bio->bi_max_vecs behavior change
-rw-r--r-- | fs/erofs/data.c | 28 |
1 files changed, 11 insertions, 17 deletions
diff --git a/fs/erofs/data.c b/fs/erofs/data.c index f88851c5c250..1249e74b3bf0 100644 --- a/fs/erofs/data.c +++ b/fs/erofs/data.c @@ -129,6 +129,7 @@ static inline struct bio *erofs_read_raw_page(struct bio *bio, struct page *page, erofs_off_t *last_block, unsigned int nblocks, + unsigned int *eblks, bool ra) { struct inode *const inode = mapping->host; @@ -145,8 +146,7 @@ static inline struct bio *erofs_read_raw_page(struct bio *bio, /* note that for readpage case, bio also equals to NULL */ if (bio && - /* not continuous */ - *last_block + 1 != current_block) { + (*last_block + 1 != current_block || !*eblks)) { submit_bio_retry: submit_bio(bio); bio = NULL; @@ -216,7 +216,8 @@ submit_bio_retry: if (nblocks > DIV_ROUND_UP(map.m_plen, PAGE_SIZE)) nblocks = DIV_ROUND_UP(map.m_plen, PAGE_SIZE); - bio = bio_alloc(GFP_NOIO, bio_max_segs(nblocks)); + *eblks = bio_max_segs(nblocks); + bio = bio_alloc(GFP_NOIO, *eblks); bio->bi_end_io = erofs_readendio; bio_set_dev(bio, sb->s_bdev); @@ -229,16 +230,8 @@ submit_bio_retry: /* out of the extent or bio is full */ if (err < PAGE_SIZE) goto submit_bio_retry; - + --*eblks; *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 +245,6 @@ has_updated: /* if updated manually, continuous pages has a gap */ if (bio) -submit_bio_out: submit_bio(bio); return err ? ERR_PTR(err) : NULL; } @@ -264,23 +256,26 @@ submit_bio_out: static int erofs_raw_access_readpage(struct file *file, struct page *page) { erofs_off_t last_block; + unsigned int eblks; struct bio *bio; trace_erofs_readpage(page, true); bio = erofs_read_raw_page(NULL, page->mapping, - page, &last_block, 1, false); + page, &last_block, 1, &eblks, false); 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; } static void erofs_raw_access_readahead(struct readahead_control *rac) { erofs_off_t last_block; + unsigned int eblks; struct bio *bio = NULL; struct page *page; @@ -291,7 +286,7 @@ static void erofs_raw_access_readahead(struct readahead_control *rac) prefetchw(&page->flags); bio = erofs_read_raw_page(bio, rac->mapping, page, &last_block, - readahead_count(rac), true); + readahead_count(rac), &eblks, true); /* all the page errors are ignored when readahead */ if (IS_ERR(bio)) { @@ -305,7 +300,6 @@ static void erofs_raw_access_readahead(struct readahead_control *rac) put_page(page); } - /* the rare case (end in gaps) */ if (bio) submit_bio(bio); } |