[PATCH 4/5] block: add a bio_submit_or_kill helper

[Christoph Hellwig <hch@lst.de>]

Factor the common logic for the ioctl helpers to either submit a bio or
end if the process is being killed.  As this is now the only user of
bio_await_chain, open code that.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
---
 block/bio.c     | 23 ++++++++++++++---------
 block/blk-lib.c | 16 ++--------------
 block/blk.h     |  2 +-
 block/ioctl.c   | 11 ++---------
 4 files changed, 19 insertions(+), 33 deletions(-)

diff --git a/block/bio.c b/block/bio.c
index 61d65c544bcc..641ef0928d73 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -1520,6 +1520,20 @@ static void bio_endio_cb(struct bio *bio, void *priv)
 	bio_endio(bio);
 }
 
+/*
+ * Submit @bio synchronously, or call bio_endio on it if the current process
+ * is being killed.
+ */
+int bio_submit_or_kill(struct bio *bio, unsigned int flags)
+{
+	if ((flags & BLKDEV_ZERO_KILLABLE) && fatal_signal_pending(current)) {
+		bio_await(bio, NULL, bio_endio_cb);
+		return -EINTR;
+	}
+
+	return submit_bio_wait(bio);
+}
+
 /**
  * bdev_rw_virt - synchronously read into / write from kernel mapping
  * @bdev:	block device to access
@@ -1550,15 +1564,6 @@ int bdev_rw_virt(struct block_device *bdev, sector_t sector, void *data,
 }
 EXPORT_SYMBOL_GPL(bdev_rw_virt);
 
-/*
- * bio_await_chain - ends @bio and waits for every chained bio to complete
- */
-void bio_await_chain(struct bio *bio)
-{
-	bio_await(bio, NULL, bio_endio_cb);
-	bio_put(bio);
-}
-
 void __bio_advance(struct bio *bio, unsigned bytes)
 {
 	if (bio_integrity(bio))
diff --git a/block/blk-lib.c b/block/blk-lib.c
index 3213afc7f0d5..688bc67cbf73 100644
--- a/block/blk-lib.c
+++ b/block/blk-lib.c
@@ -155,13 +155,7 @@ static int blkdev_issue_write_zeroes(struct block_device *bdev, sector_t sector,
 	__blkdev_issue_write_zeroes(bdev, sector, nr_sects, gfp, &bio,
 			flags, limit);
 	if (bio) {
-		if ((flags & BLKDEV_ZERO_KILLABLE) &&
-		    fatal_signal_pending(current)) {
-			bio_await_chain(bio);
-			blk_finish_plug(&plug);
-			return -EINTR;
-		}
-		ret = submit_bio_wait(bio);
+		ret = bio_submit_or_kill(bio, flags);
 		bio_put(bio);
 	}
 	blk_finish_plug(&plug);
@@ -236,13 +230,7 @@ static int blkdev_issue_zero_pages(struct block_device *bdev, sector_t sector,
 	blk_start_plug(&plug);
 	__blkdev_issue_zero_pages(bdev, sector, nr_sects, gfp, &bio, flags);
 	if (bio) {
-		if ((flags & BLKDEV_ZERO_KILLABLE) &&
-		    fatal_signal_pending(current)) {
-			bio_await_chain(bio);
-			blk_finish_plug(&plug);
-			return -EINTR;
-		}
-		ret = submit_bio_wait(bio);
+		ret = bio_submit_or_kill(bio, flags);
 		bio_put(bio);
 	}
 	blk_finish_plug(&plug);
diff --git a/block/blk.h b/block/blk.h
index 103cb1d0b9cb..ec4674cdf2ea 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -55,7 +55,7 @@ bool __blk_freeze_queue_start(struct request_queue *q,
 			      struct task_struct *owner);
 int __bio_queue_enter(struct request_queue *q, struct bio *bio);
 void submit_bio_noacct_nocheck(struct bio *bio, bool split);
-void bio_await_chain(struct bio *bio);
+int bio_submit_or_kill(struct bio *bio, unsigned int flags);
 
 static inline bool blk_try_enter_queue(struct request_queue *q, bool pm)
 {
diff --git a/block/ioctl.c b/block/ioctl.c
index 0b04661ac809..fc3be0549aa7 100644
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -153,13 +153,7 @@ static int blk_ioctl_discard(struct block_device *bdev, blk_mode_t mode,
 	nr_sects = len >> SECTOR_SHIFT;
 
 	blk_start_plug(&plug);
-	while (1) {
-		if (fatal_signal_pending(current)) {
-			if (prev)
-				bio_await_chain(prev);
-			err = -EINTR;
-			goto out_unplug;
-		}
+	while (!fatal_signal_pending(current)) {
 		bio = blk_alloc_discard_bio(bdev, &sector, &nr_sects,
 				GFP_KERNEL);
 		if (!bio)
@@ -167,12 +161,11 @@ static int blk_ioctl_discard(struct block_device *bdev, blk_mode_t mode,
 		prev = bio_chain_and_submit(prev, bio);
 	}
 	if (prev) {
-		err = submit_bio_wait(prev);
+		err = bio_submit_or_kill(prev, BLKDEV_ZERO_KILLABLE);
 		if (err == -EOPNOTSUPP)
 			err = 0;
 		bio_put(prev);
 	}
-out_unplug:
 	blk_finish_plug(&plug);
 fail:
 	filemap_invalidate_unlock(bdev->bd_mapping);
-- 
2.47.3