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 | 21 ++++++++++++++++----- 1 file changed, 16 insertions(+), 5 deletions(-)
diff --git a/fs/block_dev.c b/fs/block_dev.c index 29f020c4b2d0..906f985c74e7 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -2031,22 +2031,33 @@ 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. */ - error = truncate_bdev_range(bdev, file->f_mode, start, end); - if (error) - return error; - + /* + * 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) + break; + error = blkdev_issue_zeroout(bdev, start >> 9, len >> 9, 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) + break; + 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: + error = truncate_bdev_range(bdev, file->f_mode, start, end); + if (error) + break; + error = blkdev_issue_discard(bdev, start >> 9, len >> 9, GFP_KERNEL, 0); break;