diff options
| author | Matthew Wilcox (Oracle) <willy@infradead.org> | 2023-06-28 19:55:48 +0100 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2023-07-08 09:29:30 -0700 |
| commit | 8344a3d44be3d18671e18c4ba23bb03dd21e14ad (patch) | |
| tree | d7e0f804bcf56763da3324a659ccfde50bccc4b1 /mm | |
| parent | 6dca4ac6fc91fd41ea4d6c4511838d37f4e0eab2 (diff) | |
writeback: account the number of pages written back
nr_to_write is a count of pages, so we need to decrease it by the number
of pages in the folio we just wrote, not by 1. Most callers specify
either LONG_MAX or 1, so are unaffected, but writeback_sb_inodes() might
end up writing 512x as many pages as it asked for.
Dave added:
: XFS is the only filesystem this would affect, right? AFAIA, nothing
: else enables large folios and uses writeback through
: write_cache_pages() at this point...
:
: In which case, I'd be surprised if much difference, if any, gets
: noticed by anyone.
Link: https://lkml.kernel.org/r/20230628185548.981888-1-willy@infradead.org
Fixes: 793917d997df ("mm/readahead: Add large folio readahead")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Jan Kara <jack@suse.cz>
Cc: Dave Chinner <david@fromorbit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/page-writeback.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 1d17fb1ec863..d3f42009bb70 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -2434,6 +2434,7 @@ int write_cache_pages(struct address_space *mapping, for (i = 0; i < nr_folios; i++) { struct folio *folio = fbatch.folios[i]; + unsigned long nr; done_index = folio->index; @@ -2471,6 +2472,7 @@ continue_unlock: trace_wbc_writepage(wbc, inode_to_bdi(mapping->host)); error = writepage(folio, wbc, data); + nr = folio_nr_pages(folio); if (unlikely(error)) { /* * Handle errors according to the type of @@ -2489,8 +2491,7 @@ continue_unlock: error = 0; } else if (wbc->sync_mode != WB_SYNC_ALL) { ret = error; - done_index = folio->index + - folio_nr_pages(folio); + done_index = folio->index + nr; done = 1; break; } @@ -2504,7 +2505,8 @@ continue_unlock: * keep going until we have written all the pages * we tagged for writeback prior to entering this loop. */ - if (--wbc->nr_to_write <= 0 && + wbc->nr_to_write -= nr; + if (wbc->nr_to_write <= 0 && wbc->sync_mode == WB_SYNC_NONE) { done = 1; break; |