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 sarthakkukreti@chromium.org Reviewed-by: Christoph Hellwig hch@lst.de Reviewed-by: "Darrick J. Wong" djwong@kernel.org Signed-off-by: Mike Snitzer snitzer@kernel.org Link: https://lore.kernel.org/r/20231011201230.750105-1-sarthakkukreti@chromium.or... Signed-off-by: Jens Axboe axboe@kernel.dk (cherry picked from commit 1364a3c391aedfeb32aa025303ead3d7c91cdf9d) Signed-off-by: Sarthak Kukreti sarthakkukreti@chromium.org --- fs/block_dev.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/fs/block_dev.c b/fs/block_dev.c index b34f76af59c4..5c6ff1572405 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -2041,21 +2041,26 @@ static long blkdev_fallocate(struct file *file, int mode, loff_t start, if ((start | len) & (bdev_logical_block_size(bdev) - 1)) return -EINVAL;
- /* Invalidate the page cache, including dirty pages. */ + /* + * Invalidate the page cache, including dirty pages, for valid + * de-allocate mode calls to fallocate(). + */ mapping = bdev->bd_inode->i_mapping; - truncate_inode_pages_range(mapping, start, end);
switch (mode) { case FALLOC_FL_ZERO_RANGE: case FALLOC_FL_ZERO_RANGE | FALLOC_FL_KEEP_SIZE: + truncate_inode_pages_range(mapping, start, end); error = blkdev_issue_zeroout(bdev, start >> 9, len >> 9, GFP_KERNEL, BLKDEV_ZERO_NOUNMAP); break; case FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE: + truncate_inode_pages_range(mapping, start, end); error = blkdev_issue_zeroout(bdev, start >> 9, len >> 9, GFP_KERNEL, BLKDEV_ZERO_NOFALLBACK); break; case FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE | FALLOC_FL_NO_HIDE_STALE: + truncate_inode_pages_range(mapping, start, end); error = blkdev_issue_discard(bdev, start >> 9, len >> 9, GFP_KERNEL, 0); break;