This is a note to let you know that I've just added the patch titled
xfs: don't zero partial page cache pages during
to the 3.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
xfs-don-t-zero-partial-page-cache-pages-during.patch
and it can be found in the queue-3.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 85e584da3212140ee80fd047f9058bbee0bc00d5 Mon Sep 17 00:00:00 2001
From: Chris Mason <clm@xxxxxx>
Date: Tue, 2 Sep 2014 12:12:52 +1000
Subject: xfs: don't zero partial page cache pages during
O_DIRECT writes
From: Chris Mason <clm@xxxxxx>
commit 85e584da3212140ee80fd047f9058bbee0bc00d5 upstream.
xfs is using truncate_pagecache_range to invalidate the page cache
during DIO reads. This is different from the other filesystems who
only invalidate pages during DIO writes.
truncate_pagecache_range is meant to be used when we are freeing the
underlying data structs from disk, so it will zero any partial
ranges in the page. This means a DIO read can zero out part of the
page cache page, and it is possible the page will stay in cache.
buffered reads will find an up to date page with zeros instead of
the data actually on disk.
This patch fixes things by using invalidate_inode_pages2_range
instead. It preserves the page cache invalidation, but won't zero
any pages.
[dchinner: catch error and warn if it fails. Comment.]
Signed-off-by: Chris Mason <clm@xxxxxx>
Reviewed-by: Dave Chinner <dchinner@xxxxxxxxxx>
Reviewed-by: Brian Foster <bfoster@xxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Dave Chinner <david@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/xfs/xfs_file.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -298,7 +298,16 @@ xfs_file_aio_read(
xfs_rw_iunlock(ip, XFS_IOLOCK_EXCL);
return ret;
}
- truncate_pagecache_range(VFS_I(ip), pos, -1);
+
+ /*
+ * Invalidate whole pages. This can return an error if
+ * we fail to invalidate a page, but this should never
+ * happen on XFS. Warn if it does fail.
+ */
+ ret = invalidate_inode_pages2_range(VFS_I(ip)->i_mapping,
+ pos >> PAGE_CACHE_SHIFT, -1);
+ WARN_ON_ONCE(ret);
+ ret = 0;
}
xfs_rw_ilock_demote(ip, XFS_IOLOCK_EXCL);
}
Patches currently in stable-queue which might be from clm@xxxxxx are
queue-3.10/xfs-don-t-zero-partial-page-cache-pages-during.patch
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