Re: [PATCH v6 1/5] block: Don't invalidate pagecache for invalid falloc modes
From: "Darrick J. Wong" <djwong@kernel.org>
Date: 2023-05-12 18:32:42
Also in:
dm-devel, linux-ext4, linux-fsdevel, lkml, stable
On Fri, May 05, 2023 at 11:29:05PM -0700, Sarthak Kukreti wrote:
Only call truncate_bdev_range() if the fallocate mode is
supported. This fixes a bug where data in the pagecache
could be invalidated if the fallocate() was called on the
block device with an invalid mode.
Fixes: 25f4c41415e5 ("block: implement (some of) fallocate for block devices")
Cc: stable@vger.kernel.org
Reported-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Sarthak Kukreti <redacted>Ideally you'd only take filemap_invalidate_lock for valid modes, but eh who cares about efficiency for the EOPNOTSUPP case, let's move on. :) Reviewed-by: Darrick J. Wong <djwong@kernel.org> --D
quoted hunk ↗ jump to hunk
--- block/fops.c | 21 ++++++++++++++++----- 1 file changed, 16 insertions(+), 5 deletions(-)diff --git a/block/fops.c b/block/fops.c index d2e6be4e3d1c..4c70fdc546e7 100644 --- a/block/fops.c +++ b/block/fops.c@@ -648,24 +648,35 @@ static long blkdev_fallocate(struct file *file, int mode, loff_t start, filemap_invalidate_lock(inode->i_mapping); - /* Invalidate the page cache, including dirty pages. */ - error = truncate_bdev_range(bdev, file->f_mode, start, end); - if (error) - goto fail; - + /* + * Invalidate the page cache, including dirty pages, for valid + * de-allocate mode calls to fallocate(). + */ switch (mode) { case FALLOC_FL_ZERO_RANGE: case FALLOC_FL_ZERO_RANGE | FALLOC_FL_KEEP_SIZE: + error = truncate_bdev_range(bdev, file->f_mode, start, end); + if (error) + goto fail; + error = blkdev_issue_zeroout(bdev, start >> SECTOR_SHIFT, len >> SECTOR_SHIFT, GFP_KERNEL, BLKDEV_ZERO_NOUNMAP); break; case FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE: + error = truncate_bdev_range(bdev, file->f_mode, start, end); + if (error) + goto fail; + error = blkdev_issue_zeroout(bdev, start >> SECTOR_SHIFT, len >> SECTOR_SHIFT, GFP_KERNEL, BLKDEV_ZERO_NOFALLBACK); break; case FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE | FALLOC_FL_NO_HIDE_STALE: + error = truncate_bdev_range(bdev, file->f_mode, start, end); + if (error) + goto fail; + error = blkdev_issue_discard(bdev, start >> SECTOR_SHIFT, len >> SECTOR_SHIFT, GFP_KERNEL); break;-- 2.40.1.521.gf1e218fcd8-goog