* [merged] mm-filemap-drop-check-for-truncated-page-after-i-o.patch removed from -mm tree
@ 2021-05-08 22:40 akpm
0 siblings, 0 replies; only message in thread
From: akpm @ 2021-05-08 22:40 UTC (permalink / raw)
To: mm-commits, william.kucharski, willy
The patch titled
Subject: mm/filemap: drop check for truncated page after I/O
has been removed from the -mm tree. Its filename was
mm-filemap-drop-check-for-truncated-page-after-i-o.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Subject: mm/filemap: drop check for truncated page after I/O
If the I/O completed successfully, the page will remain Uptodate, even if
it is subsequently truncated. If the I/O completed with an error, this
check would cause us to retry the I/O if the page were truncated before we
woke up. There is no need to retry the I/O; the I/O to fill the page
failed, so we can legitimately just return -EIO.
This code was originally added by commit 56f0d5fe6851 ("[PATCH]
readpage-vs-invalidate fix") in 2005 (this commit ID is from the
linux-fullhistory tree; it is also commit ba1f08f14b52 in tglx-history).
At the time, truncate_complete_page() called ClearPageUptodate(), and so
this was fixing a real bug. In 2008, commit 84209e02de48 ("mm: dont clear
PG_uptodate on truncate/invalidate") removed the call to
ClearPageUptodate, and this check has been unnecessary ever since.
It doesn't do any real harm, but there's no need to keep it.
Link: https://lkml.kernel.org/r/20210303222547.1056428-1-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: William Kucharski <william.kucharski@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
mm/filemap.c | 2 --
1 file changed, 2 deletions(-)
--- a/mm/filemap.c~mm-filemap-drop-check-for-truncated-page-after-i-o
+++ a/mm/filemap.c
@@ -2348,8 +2348,6 @@ static int filemap_read_page(struct file
return error;
if (PageUptodate(page))
return 0;
- if (!page->mapping) /* page truncated */
- return AOP_TRUNCATED_PAGE;
shrink_readahead_size_eio(&file->f_ra);
return -EIO;
}
_
Patches currently in -mm which might be from willy@infradead.org are
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2021-05-08 22:40 [merged] mm-filemap-drop-check-for-truncated-page-after-i-o.patch removed from -mm tree akpm
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