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authorLinus Torvalds <torvalds@linux-foundation.org>2016-03-18 16:43:11 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2016-03-18 16:43:11 -0700
commit35d88d97bee90fc09286d28209a64a991291a64a (patch)
treeb4ba0eaa1e87f64b0b5d251f12881d5282076d8d /block/bio.c
parent040e3abbb958f5a038c16c1af7258e396303c2e1 (diff)
parent4ee86babe09f0682a60b1c56be99819bbe4ba62c (diff)
Merge branch 'for-4.6/core' of git://git.kernel.dk/linux-block
Pull core block updates from Jens Axboe: "Here are the core block changes for this merge window. Not a lot of exciting stuff going on in this round, most of the changes have been on the driver side of things. That pull request is coming next. This pull request contains: - A set of fixes for chained bio handling from Christoph. - A tag bounds check for blk-mq from Hannes, ensuring that we don't do something stupid if a device reports an invalid tag value. - A set of fixes/updates for the CFQ IO scheduler from Jan Kara. - A set of blk-mq fixes from Keith, adding support for dynamic hardware queues, and fixing init of max_dev_sectors for stacking devices. - A fix for the dynamic hw context from Ming. - Enabling of cgroup writeback support on a block device, from Shaohua" * 'for-4.6/core' of git://git.kernel.dk/linux-block: blk-mq: add bounds check on tag-to-rq conversion block: bio_remaining_done() isn't unlikely block: cleanup bio_endio block: factor out chained bio completion block: don't unecessarily clobber bi_error for chained bios block-dev: enable writeback cgroup support blk-mq: Fix NULL pointer updating nr_requests blk-mq: mark request queue as mq asap block: Initialize max_dev_sectors to 0 blk-mq: dynamic h/w context count cfq-iosched: Allow parent cgroup to preempt its child cfq-iosched: Allow sync noidle workloads to preempt each other cfq-iosched: Reorder checks in cfq_should_preempt() cfq-iosched: Don't group_idle if cfqq has big thinktime
Diffstat (limited to 'block/bio.c')
-rw-r--r--block/bio.c50
1 files changed, 26 insertions, 24 deletions
diff --git a/block/bio.c b/block/bio.c
index cf7591551b17..f124a0a624fc 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -296,13 +296,19 @@ void bio_reset(struct bio *bio)
}
EXPORT_SYMBOL(bio_reset);
-static void bio_chain_endio(struct bio *bio)
+static struct bio *__bio_chain_endio(struct bio *bio)
{
struct bio *parent = bio->bi_private;
- parent->bi_error = bio->bi_error;
- bio_endio(parent);
+ if (!parent->bi_error)
+ parent->bi_error = bio->bi_error;
bio_put(bio);
+ return parent;
+}
+
+static void bio_chain_endio(struct bio *bio)
+{
+ bio_endio(__bio_chain_endio(bio));
}
/*
@@ -1742,29 +1748,25 @@ static inline bool bio_remaining_done(struct bio *bio)
**/
void bio_endio(struct bio *bio)
{
- while (bio) {
- if (unlikely(!bio_remaining_done(bio)))
- break;
+again:
+ if (!bio_remaining_done(bio))
+ return;
- /*
- * Need to have a real endio function for chained bios,
- * otherwise various corner cases will break (like stacking
- * block devices that save/restore bi_end_io) - however, we want
- * to avoid unbounded recursion and blowing the stack. Tail call
- * optimization would handle this, but compiling with frame
- * pointers also disables gcc's sibling call optimization.
- */
- if (bio->bi_end_io == bio_chain_endio) {
- struct bio *parent = bio->bi_private;
- parent->bi_error = bio->bi_error;
- bio_put(bio);
- bio = parent;
- } else {
- if (bio->bi_end_io)
- bio->bi_end_io(bio);
- bio = NULL;
- }
+ /*
+ * Need to have a real endio function for chained bios, otherwise
+ * various corner cases will break (like stacking block devices that
+ * save/restore bi_end_io) - however, we want to avoid unbounded
+ * recursion and blowing the stack. Tail call optimization would
+ * handle this, but compiling with frame pointers also disables
+ * gcc's sibling call optimization.
+ */
+ if (bio->bi_end_io == bio_chain_endio) {
+ bio = __bio_chain_endio(bio);
+ goto again;
}
+
+ if (bio->bi_end_io)
+ bio->bi_end_io(bio);
}
EXPORT_SYMBOL(bio_endio);