[PATCH 5/5] block: don't allow fatal signals to interrupt (__)blkdev_issue_discard

[Christoph Hellwig]

File system won't to handle fatal signals themselves and are generally
not prepared for EINTR errors from (__)blkdev_issue_discard.  Remove
the logic from the generic helpers and instead open code the discard
bio submission in the ioctl handler that wants it.

Fixes: 8a08c5fd89b4 ("blk-lib: check for kill signal")
Signed-off-by: Christoph Hellwig <hch at lst.de>
---
 block/blk-lib.c | 12 +++---------
 block/ioctl.c   | 24 ++++++++++++++++++++++--
 2 files changed, 25 insertions(+), 11 deletions(-)

diff --git a/block/blk-lib.c b/block/blk-lib.c
index 8021bc3831d56a..90b75605299b9c 100644
--- a/block/blk-lib.c
+++ b/block/blk-lib.c
@@ -65,16 +65,10 @@ int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 {
 	struct bio *bio;
 
-	while (!fatal_signal_pending(current)) {
-		bio = blk_alloc_discard_bio(bdev, &sector, &nr_sects, gfp_mask);
-		if (!bio)
-			return 0;
+	while ((bio = blk_alloc_discard_bio(bdev, &sector, &nr_sects,
+			gfp_mask)))
 		*biop = bio_chain_and_submit(*biop, bio);
-	}
-
-	if (*biop)
-		bio_await_chain(*biop);
-	return -EINTR;
+	return 0;
 }
 EXPORT_SYMBOL(__blkdev_issue_discard);
 
diff --git a/block/ioctl.c b/block/ioctl.c
index 57c8171fda93c5..32bbdba77d6941 100644
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -96,10 +96,12 @@ static int blk_ioctl_discard(struct block_device *bdev, blk_mode_t mode,
 		unsigned long arg)
 {
 	sector_t bs_mask = (bdev_logical_block_size(bdev) >> SECTOR_SHIFT) - 1;
+	struct inode *inode = bdev->bd_inode;
 	sector_t sector, nr_sects;
+	struct bio *bio = NULL, *new;
+	struct blk_plug plug;
 	uint64_t range[2];
 	uint64_t start, len;
-	struct inode *inode = bdev->bd_inode;
 	int err;
 
 	if (!(mode & BLK_OPEN_WRITE))
@@ -129,7 +131,25 @@ static int blk_ioctl_discard(struct block_device *bdev, blk_mode_t mode,
 	err = truncate_bdev_range(bdev, mode, start, start + len - 1);
 	if (err)
 		goto fail;
-	err = blkdev_issue_discard(bdev, sector, nr_sects, GFP_KERNEL);
+	blk_start_plug(&plug);
+	while (!fatal_signal_pending(current)) {
+		new = blk_alloc_discard_bio(bdev, &sector, &nr_sects,
+				GFP_KERNEL);
+		if (!new)
+			break;
+		bio = bio_chain_and_submit(bio, new);
+	}
+	if (fatal_signal_pending(current)) {
+		if (bio)
+			bio_await_chain(bio);
+		err = -EINTR;
+	} else if (bio) {
+		err = submit_bio_wait(bio);
+		if (err == -EOPNOTSUPP)
+			err = 0;
+		bio_put(bio);
+	}
+	blk_finish_plug(&plug);
 fail:
 	filemap_invalidate_unlock(inode->i_mapping);
 	return err;
-- 
2.39.2