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authorLinus Torvalds <torvalds@linux-foundation.org>2014-12-13 14:14:23 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2014-12-13 14:14:23 -0800
commitcaf292ae5bb9d57198ce001d8b762f7abae3a94d (patch)
tree5fd5d6d971503818ab2824407134cf36a80c53d0 /block/bio.c
parent8f4385d590d4296ec38e228d17b1d002f6031dd2 (diff)
parentfcbf6a087a7e4d3f03d28333678a1010810a53c3 (diff)
downloadlinux-caf292ae5bb9d57198ce001d8b762f7abae3a94d.tar.gz
Merge branch 'for-3.19/core' of git://git.kernel.dk/linux-block
Pull block driver core update from Jens Axboe: "This is the pull request for the core block IO changes for 3.19. Not a huge round this time, mostly lots of little good fixes: - Fix a bug in sysfs blktrace interface causing a NULL pointer dereference, when enabled/disabled through that API. From Arianna Avanzini. - Various updates/fixes/improvements for blk-mq: - A set of updates from Bart, mostly fixing buts in the tag handling. - Cleanup/code consolidation from Christoph. - Extend queue_rq API to be able to handle batching issues of IO requests. NVMe will utilize this shortly. From me. - A few tag and request handling updates from me. - Cleanup of the preempt handling for running queues from Paolo. - Prevent running of unmapped hardware queues from Ming Lei. - Move the kdump memory limiting check to be in the correct location, from Shaohua. - Initialize all software queues at init time from Takashi. This prevents a kobject warning when CPUs are brought online that weren't online when a queue was registered. - Single writeback fix for I_DIRTY clearing from Tejun. Queued with the core IO changes, since it's just a single fix. - Version X of the __bio_add_page() segment addition retry from Maurizio. Hope the Xth time is the charm. - Documentation fixup for IO scheduler merging from Jan. - Introduce (and use) generic IO stat accounting helpers for non-rq drivers, from Gu Zheng. - Kill off artificial limiting of max sectors in a request from Christoph" * 'for-3.19/core' of git://git.kernel.dk/linux-block: (26 commits) bio: modify __bio_add_page() to accept pages that don't start a new segment blk-mq: Fix uninitialized kobject at CPU hotplugging blktrace: don't let the sysfs interface remove trace from running list blk-mq: Use all available hardware queues blk-mq: Micro-optimize bt_get() blk-mq: Fix a race between bt_clear_tag() and bt_get() blk-mq: Avoid that __bt_get_word() wraps multiple times blk-mq: Fix a use-after-free blk-mq: prevent unmapped hw queue from being scheduled blk-mq: re-check for available tags after running the hardware queue blk-mq: fix hang in bt_get() blk-mq: move the kdump check to blk_mq_alloc_tag_set blk-mq: cleanup tag free handling blk-mq: use 'nr_cpu_ids' as highest CPU ID count for hwq <-> cpu map blk: introduce generic io stat accounting help function blk-mq: handle the single queue case in blk_mq_hctx_next_cpu genhd: check for int overflow in disk_expand_part_tbl() blk-mq: add blk_mq_free_hctx_request() blk-mq: export blk_mq_free_request() blk-mq: use get_cpu/put_cpu instead of preempt_disable/preempt_enable ...
Diffstat (limited to 'block/bio.c')
-rw-r--r--block/bio.c82
1 files changed, 58 insertions, 24 deletions
diff --git a/block/bio.c b/block/bio.c
index 3e6e1986a5b2..471d7382c7d1 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -748,6 +748,7 @@ static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page
}
}
+ bio->bi_iter.bi_size += len;
goto done;
}
@@ -764,29 +765,32 @@ static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page
return 0;
/*
- * we might lose a segment or two here, but rather that than
- * make this too complex.
+ * setup the new entry, we might clear it again later if we
+ * cannot add the page
+ */
+ bvec = &bio->bi_io_vec[bio->bi_vcnt];
+ bvec->bv_page = page;
+ bvec->bv_len = len;
+ bvec->bv_offset = offset;
+ bio->bi_vcnt++;
+ bio->bi_phys_segments++;
+ bio->bi_iter.bi_size += len;
+
+ /*
+ * Perform a recount if the number of segments is greater
+ * than queue_max_segments(q).
*/
- while (bio->bi_phys_segments >= queue_max_segments(q)) {
+ while (bio->bi_phys_segments > queue_max_segments(q)) {
if (retried_segments)
- return 0;
+ goto failed;
retried_segments = 1;
blk_recount_segments(q, bio);
}
/*
- * setup the new entry, we might clear it again later if we
- * cannot add the page
- */
- bvec = &bio->bi_io_vec[bio->bi_vcnt];
- bvec->bv_page = page;
- bvec->bv_len = len;
- bvec->bv_offset = offset;
-
- /*
* if queue has other restrictions (eg varying max sector size
* depending on offset), it can specify a merge_bvec_fn in the
* queue to get further control
@@ -795,7 +799,7 @@ static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page
struct bvec_merge_data bvm = {
.bi_bdev = bio->bi_bdev,
.bi_sector = bio->bi_iter.bi_sector,
- .bi_size = bio->bi_iter.bi_size,
+ .bi_size = bio->bi_iter.bi_size - len,
.bi_rw = bio->bi_rw,
};
@@ -803,23 +807,25 @@ static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page
* merge_bvec_fn() returns number of bytes it can accept
* at this offset
*/
- if (q->merge_bvec_fn(q, &bvm, bvec) < bvec->bv_len) {
- bvec->bv_page = NULL;
- bvec->bv_len = 0;
- bvec->bv_offset = 0;
- return 0;
- }
+ if (q->merge_bvec_fn(q, &bvm, bvec) < bvec->bv_len)
+ goto failed;
}
/* If we may be able to merge these biovecs, force a recount */
- if (bio->bi_vcnt && (BIOVEC_PHYS_MERGEABLE(bvec-1, bvec)))
+ if (bio->bi_vcnt > 1 && (BIOVEC_PHYS_MERGEABLE(bvec-1, bvec)))
bio->bi_flags &= ~(1 << BIO_SEG_VALID);
- bio->bi_vcnt++;
- bio->bi_phys_segments++;
done:
- bio->bi_iter.bi_size += len;
return len;
+
+ failed:
+ bvec->bv_page = NULL;
+ bvec->bv_len = 0;
+ bvec->bv_offset = 0;
+ bio->bi_vcnt--;
+ bio->bi_iter.bi_size -= len;
+ blk_recount_segments(q, bio);
+ return 0;
}
/**
@@ -1739,6 +1745,34 @@ void bio_check_pages_dirty(struct bio *bio)
}
}
+void generic_start_io_acct(int rw, unsigned long sectors,
+ struct hd_struct *part)
+{
+ int cpu = part_stat_lock();
+
+ part_round_stats(cpu, part);
+ part_stat_inc(cpu, part, ios[rw]);
+ part_stat_add(cpu, part, sectors[rw], sectors);
+ part_inc_in_flight(part, rw);
+
+ part_stat_unlock();
+}
+EXPORT_SYMBOL(generic_start_io_acct);
+
+void generic_end_io_acct(int rw, struct hd_struct *part,
+ unsigned long start_time)
+{
+ unsigned long duration = jiffies - start_time;
+ int cpu = part_stat_lock();
+
+ part_stat_add(cpu, part, ticks[rw], duration);
+ part_round_stats(cpu, part);
+ part_dec_in_flight(part, rw);
+
+ part_stat_unlock();
+}
+EXPORT_SYMBOL(generic_end_io_acct);
+
#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
void bio_flush_dcache_pages(struct bio *bi)
{