6.5-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sarthak Kukreti <sarthakkukreti@xxxxxxxxxxxx> commit 1364a3c391aedfeb32aa025303ead3d7c91cdf9d upstream. 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@xxxxxxxxxxxxxxx Reported-by: "Darrick J. Wong" <djwong@xxxxxxxxxx> Signed-off-by: Sarthak Kukreti <sarthakkukreti@xxxxxxxxxxxx> Reviewed-by: Christoph Hellwig <hch@xxxxxx> Reviewed-by: "Darrick J. Wong" <djwong@xxxxxxxxxx> Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx> Fixes: line? I've never seen those wrapped. Link: https://lore.kernel.org/r/20231011201230.750105-1-sarthakkukreti@xxxxxxxxxxxx Signed-off-by: Jens Axboe <axboe@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- block/fops.c | 21 ++++++++++++++++----- 1 file changed, 16 insertions(+), 5 deletions(-) --- a/block/fops.c +++ b/block/fops.c @@ -659,24 +659,35 @@ static long blkdev_fallocate(struct file filemap_invalidate_lock(inode->i_mapping); - /* Invalidate the page cache, including dirty pages. */ - error = truncate_bdev_range(bdev, file_to_blk_mode(file), 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_to_blk_mode(file), 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_to_blk_mode(file), 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_to_blk_mode(file), start, end); + if (error) + goto fail; + error = blkdev_issue_discard(bdev, start >> SECTOR_SHIFT, len >> SECTOR_SHIFT, GFP_KERNEL); break;