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>
Link: https://lore.kernel.org/r/20231011201230.750105-1-sarthakkukreti@xxxxxxxxxxxx
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
(cherry picked from commit 1364a3c391aedfeb32aa025303ead3d7c91cdf9d)
Signed-off-by: Sarthak Kukreti <sarthakkukreti@xxxxxxxxxxxx>
---
block/fops.c | 21 ++++++++++++++++-----
1 file changed, 16 insertions(+), 5 deletions(-)
diff --git a/block/fops.c b/block/fops.c
index 6197d1c41652..01cb6260fa24 100644
--- a/block/fops.c
+++ b/block/fops.c
@@ -655,24 +655,35 @@ 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;
--
2.43.0.472.g3155946c3a-goog
