The quilt patch titled
Subject: writeback: account the number of pages written back
has been removed from the -mm tree. Its filename was
writeback-account-the-number-of-pages-written-back.patch
This patch was dropped because it was merged into the mm-hotfixes-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
------------------------------------------------------
From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>
Subject: writeback: account the number of pages written back
Date: Wed, 28 Jun 2023 19:55:48 +0100
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@xxxxxxxxxxxxx
Fixes: 793917d997df ("mm/readahead: Add large folio readahead")
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Cc: Jan Kara <jack@xxxxxxx>
Cc: Dave Chinner <david@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/page-writeback.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
--- a/mm/page-writeback.c~writeback-account-the-number-of-pages-written-back
+++ a/mm/page-writeback.c
@@ -2434,6 +2434,7 @@ int write_cache_pages(struct address_spa
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;
_
Patches currently in -mm which might be from willy@xxxxxxxxxxxxx are
rmap-pass-the-folio-to-__page_check_anon_rmap.patch
