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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2022-05-05 16:52:15 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2022-05-05 16:52:15 -0700 |
| commit | fe27d189e3f42e31d3c8223d5daed7285e334c5e (patch) | |
| tree | 766fa93ae394a9d1bc922d97e8e30fca6ef22312 /mm/readahead.c | |
| parent | f47c960e9395743a8aa3bd939d4d3a0f582f565e (diff) | |
| parent | b9ff43dd27434dbd850b908e2e0e1f6e794efd9b (diff) | |
| download | linux-fe27d189e3f42e31d3c8223d5daed7285e334c5e.tar.bz2 | |
Merge tag 'folio-5.18f' of git://git.infradead.org/users/willy/pagecache
Pull folio fixes from Matthew Wilcox:
"Two folio fixes for 5.18.
Darrick and Brian have done amazing work debugging the race I created
in the folio BIO iterator. The readahead problem was deterministic, so
easy to fix.
- Fix a race when we were calling folio_next() in the BIO folio iter
without holding a reference, meaning the folio could be split or
freed, and we'd jump to the next page instead of the intended next
folio.
- Fix readahead creating single-page folios instead of the intended
large folios when doing reads that are not a power of two in size"
* tag 'folio-5.18f' of git://git.infradead.org/users/willy/pagecache:
mm/readahead: Fix readahead with large folios
block: Do not call folio_next() on an unreferenced folio
Diffstat (limited to 'mm/readahead.c')
| -rw-r--r-- | mm/readahead.c | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/mm/readahead.c b/mm/readahead.c index 8e3775829513..4a60cdb64262 100644 --- a/mm/readahead.c +++ b/mm/readahead.c @@ -474,7 +474,8 @@ static inline int ra_alloc_folio(struct readahead_control *ractl, pgoff_t index, if (!folio) return -ENOMEM; - if (mark - index < (1UL << order)) + mark = round_up(mark, 1UL << order); + if (index == mark) folio_set_readahead(folio); err = filemap_add_folio(ractl->mapping, folio, index, gfp); if (err) @@ -555,8 +556,9 @@ static void ondemand_readahead(struct readahead_control *ractl, struct file_ra_state *ra = ractl->ra; unsigned long max_pages = ra->ra_pages; unsigned long add_pages; - unsigned long index = readahead_index(ractl); - pgoff_t prev_index; + pgoff_t index = readahead_index(ractl); + pgoff_t expected, prev_index; + unsigned int order = folio ? folio_order(folio) : 0; /* * If the request exceeds the readahead window, allow the read to @@ -575,8 +577,9 @@ static void ondemand_readahead(struct readahead_control *ractl, * It's the expected callback index, assume sequential access. * Ramp up sizes, and push forward the readahead window. */ - if ((index == (ra->start + ra->size - ra->async_size) || - index == (ra->start + ra->size))) { + expected = round_up(ra->start + ra->size - ra->async_size, + 1UL << order); + if (index == expected || index == (ra->start + ra->size)) { ra->start += ra->size; ra->size = get_next_ra_size(ra, max_pages); ra->async_size = ra->size; @@ -662,7 +665,7 @@ readit: } ractl->_index = ra->start; - page_cache_ra_order(ractl, ra, folio ? folio_order(folio) : 0); + page_cache_ra_order(ractl, ra, order); } void page_cache_sync_ra(struct readahead_control *ractl, |