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authorLinus Torvalds <torvalds@linux-foundation.org>2015-06-26 12:35:01 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2015-06-26 12:35:01 -0700
commit22165fa79814e71e7a5974b3c37a5028ed16c8f9 (patch)
tree2dd55b3e3d21017410a0f1b1c2c0281fe4bc8e6c /block
parenta2f54be94f4cbce269bca6188d3fb4310c346fd1 (diff)
parentb5451e456840af027b794afc2c7c84c2a17f569b (diff)
downloadlwn-22165fa79814e71e7a5974b3c37a5028ed16c8f9.tar.gz
lwn-22165fa79814e71e7a5974b3c37a5028ed16c8f9.zip
Merge tag 'dm-4.2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm
Pull device mapper fixes from Mike Snitzer: "Apologies for not pressing this request-based DM partial completion issue further, it was an oversight on my part. We'll have to get it fixed up properly and revisit for a future release. - Revert block and DM core changes the removed request-based DM's ability to handle partial request completions -- otherwise with the current SCSI LLDs these changes could lead to silent data corruption. - Fix two DM version bumps that were missing from the initial 4.2 DM pull request (enabled userspace lvm2 to know certain changes have been made)" * tag 'dm-4.2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: dm cache policy smq: fix "default" version to be 1.4.0 dm: bump the ioctl version to 4.32.0 Revert "block, dm: don't copy bios for request clones" Revert "dm: do not allocate any mempools for blk-mq request-based DM"
Diffstat (limited to 'block')
-rw-r--r--block/blk-core.c94
1 files changed, 83 insertions, 11 deletions
diff --git a/block/blk-core.c b/block/blk-core.c
index 688ae9482cb8..82819e68f58b 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -142,7 +142,7 @@ EXPORT_SYMBOL(blk_rq_init);
static void req_bio_endio(struct request *rq, struct bio *bio,
unsigned int nbytes, int error)
{
- if (error && !(rq->cmd_flags & REQ_CLONE))
+ if (error)
clear_bit(BIO_UPTODATE, &bio->bi_flags);
else if (!test_bit(BIO_UPTODATE, &bio->bi_flags))
error = -EIO;
@@ -153,8 +153,7 @@ static void req_bio_endio(struct request *rq, struct bio *bio,
bio_advance(bio, nbytes);
/* don't actually finish bio if it's part of flush sequence */
- if (bio->bi_iter.bi_size == 0 &&
- !(rq->cmd_flags & (REQ_FLUSH_SEQ|REQ_CLONE)))
+ if (bio->bi_iter.bi_size == 0 && !(rq->cmd_flags & REQ_FLUSH_SEQ))
bio_endio(bio, error);
}
@@ -2927,22 +2926,95 @@ int blk_lld_busy(struct request_queue *q)
}
EXPORT_SYMBOL_GPL(blk_lld_busy);
-void blk_rq_prep_clone(struct request *dst, struct request *src)
+/**
+ * blk_rq_unprep_clone - Helper function to free all bios in a cloned request
+ * @rq: the clone request to be cleaned up
+ *
+ * Description:
+ * Free all bios in @rq for a cloned request.
+ */
+void blk_rq_unprep_clone(struct request *rq)
+{
+ struct bio *bio;
+
+ while ((bio = rq->bio) != NULL) {
+ rq->bio = bio->bi_next;
+
+ bio_put(bio);
+ }
+}
+EXPORT_SYMBOL_GPL(blk_rq_unprep_clone);
+
+/*
+ * Copy attributes of the original request to the clone request.
+ * The actual data parts (e.g. ->cmd, ->sense) are not copied.
+ */
+static void __blk_rq_prep_clone(struct request *dst, struct request *src)
{
dst->cpu = src->cpu;
- dst->cmd_flags |= (src->cmd_flags & REQ_CLONE_MASK);
- dst->cmd_flags |= REQ_NOMERGE | REQ_CLONE;
+ dst->cmd_flags |= (src->cmd_flags & REQ_CLONE_MASK) | REQ_NOMERGE;
dst->cmd_type = src->cmd_type;
dst->__sector = blk_rq_pos(src);
dst->__data_len = blk_rq_bytes(src);
dst->nr_phys_segments = src->nr_phys_segments;
dst->ioprio = src->ioprio;
dst->extra_len = src->extra_len;
- dst->bio = src->bio;
- dst->biotail = src->biotail;
- dst->cmd = src->cmd;
- dst->cmd_len = src->cmd_len;
- dst->sense = src->sense;
+}
+
+/**
+ * blk_rq_prep_clone - Helper function to setup clone request
+ * @rq: the request to be setup
+ * @rq_src: original request to be cloned
+ * @bs: bio_set that bios for clone are allocated from
+ * @gfp_mask: memory allocation mask for bio
+ * @bio_ctr: setup function to be called for each clone bio.
+ * Returns %0 for success, non %0 for failure.
+ * @data: private data to be passed to @bio_ctr
+ *
+ * Description:
+ * Clones bios in @rq_src to @rq, and copies attributes of @rq_src to @rq.
+ * The actual data parts of @rq_src (e.g. ->cmd, ->sense)
+ * are not copied, and copying such parts is the caller's responsibility.
+ * Also, pages which the original bios are pointing to are not copied
+ * and the cloned bios just point same pages.
+ * So cloned bios must be completed before original bios, which means
+ * the caller must complete @rq before @rq_src.
+ */
+int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
+ struct bio_set *bs, gfp_t gfp_mask,
+ int (*bio_ctr)(struct bio *, struct bio *, void *),
+ void *data)
+{
+ struct bio *bio, *bio_src;
+
+ if (!bs)
+ bs = fs_bio_set;
+
+ __rq_for_each_bio(bio_src, rq_src) {
+ bio = bio_clone_fast(bio_src, gfp_mask, bs);
+ if (!bio)
+ goto free_and_out;
+
+ if (bio_ctr && bio_ctr(bio, bio_src, data))
+ goto free_and_out;
+
+ if (rq->bio) {
+ rq->biotail->bi_next = bio;
+ rq->biotail = bio;
+ } else
+ rq->bio = rq->biotail = bio;
+ }
+
+ __blk_rq_prep_clone(rq, rq_src);
+
+ return 0;
+
+free_and_out:
+ if (bio)
+ bio_put(bio);
+ blk_rq_unprep_clone(rq);
+
+ return -ENOMEM;
}
EXPORT_SYMBOL_GPL(blk_rq_prep_clone);