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authorMatthew Wilcox (Oracle) <willy@infradead.org>2022-06-28 20:15:29 -0400
committerMatthew Wilcox (Oracle) <willy@infradead.org>2022-06-29 08:49:43 -0400
commitfb5c2029f8221e904e604938171c4a8ef169aadb (patch)
tree2fffeceec685ebba8d5fbd83d5d89b3b605e189b /mm/huge_memory.c
parent0840a7914caa14315a3191178a9f72c742477860 (diff)
downloadlwn-fb5c2029f8221e904e604938171c4a8ef169aadb.tar.gz
lwn-fb5c2029f8221e904e604938171c4a8ef169aadb.zip
mm: Account dirty folios properly during splits
If the last folio in a file is split as a result of truncation, we simply clear the dirty bits for the pages we're discarding. That causes NR_FILE_DIRTY (among other counters) to be thrown off and eventually Linux will hang in balance_dirty_pages_ratelimited() Reported-by: Dave Chinner <dchinner@redhat.com> Tested-by: Dave Chinner <dchinner@redhat.com> Tested-by: Darrick J. Wong <djwong@kernel.org> Fixes: d68eccad3706 ("mm/filemap: Allow large folios to be added to the page cache") Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Diffstat (limited to 'mm/huge_memory.c')
-rw-r--r--mm/huge_memory.c11
1 files changed, 8 insertions, 3 deletions
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 834f288b3769..15965084816d 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -18,6 +18,7 @@
#include <linux/shrinker.h>
#include <linux/mm_inline.h>
#include <linux/swapops.h>
+#include <linux/backing-dev.h>
#include <linux/dax.h>
#include <linux/khugepaged.h>
#include <linux/freezer.h>
@@ -2440,11 +2441,15 @@ static void __split_huge_page(struct page *page, struct list_head *list,
__split_huge_page_tail(head, i, lruvec, list);
/* Some pages can be beyond EOF: drop them from page cache */
if (head[i].index >= end) {
- ClearPageDirty(head + i);
- __delete_from_page_cache(head + i, NULL);
+ struct folio *tail = page_folio(head + i);
+
if (shmem_mapping(head->mapping))
shmem_uncharge(head->mapping->host, 1);
- put_page(head + i);
+ else if (folio_test_clear_dirty(tail))
+ folio_account_cleaned(tail,
+ inode_to_wb(folio->mapping->host));
+ __filemap_remove_folio(tail, NULL);
+ folio_put(tail);
} else if (!PageAnon(page)) {
__xa_store(&head->mapping->i_pages, head[i].index,
head + i, 0);