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authorIngo Molnar <mingo@elte.hu>2009-02-27 09:04:43 +0100
committerIngo Molnar <mingo@elte.hu>2009-02-27 09:04:43 +0100
commitf701d354075914296474d062f18fc8ee681a2318 (patch)
tree4c39db49f4bc9827a1a0dabc6a83fb30bd2c7ac4 /block
parent1b49061d400c9e51e3ac2aac026a099fe599b9bb (diff)
parent64e71303e44f3697e4568147caa966de74bdb4fb (diff)
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Merge branches 'tracing/ftrace' and 'linus' into tracing/core
Diffstat (limited to 'block')
-rw-r--r--block/blk-merge.c94
-rw-r--r--block/genhd.c16
2 files changed, 69 insertions, 41 deletions
diff --git a/block/blk-merge.c b/block/blk-merge.c
index b92f5b0866b..a104593e70c 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -38,72 +38,84 @@ void blk_recalc_rq_sectors(struct request *rq, int nsect)
}
}
-void blk_recalc_rq_segments(struct request *rq)
+static unsigned int __blk_recalc_rq_segments(struct request_queue *q,
+ struct bio *bio,
+ unsigned int *seg_size_ptr)
{
- int nr_phys_segs;
unsigned int phys_size;
struct bio_vec *bv, *bvprv = NULL;
- int seg_size;
- int cluster;
- struct req_iterator iter;
- int high, highprv = 1;
- struct request_queue *q = rq->q;
+ int cluster, i, high, highprv = 1;
+ unsigned int seg_size, nr_phys_segs;
+ struct bio *fbio;
- if (!rq->bio)
- return;
+ if (!bio)
+ return 0;
+ fbio = bio;
cluster = test_bit(QUEUE_FLAG_CLUSTER, &q->queue_flags);
seg_size = 0;
phys_size = nr_phys_segs = 0;
- rq_for_each_segment(bv, rq, iter) {
- /*
- * the trick here is making sure that a high page is never
- * considered part of another segment, since that might
- * change with the bounce page.
- */
- high = page_to_pfn(bv->bv_page) > q->bounce_pfn;
- if (high || highprv)
- goto new_segment;
- if (cluster) {
- if (seg_size + bv->bv_len > q->max_segment_size)
- goto new_segment;
- if (!BIOVEC_PHYS_MERGEABLE(bvprv, bv))
- goto new_segment;
- if (!BIOVEC_SEG_BOUNDARY(q, bvprv, bv))
+ for_each_bio(bio) {
+ bio_for_each_segment(bv, bio, i) {
+ /*
+ * the trick here is making sure that a high page is
+ * never considered part of another segment, since that
+ * might change with the bounce page.
+ */
+ high = page_to_pfn(bv->bv_page) > q->bounce_pfn;
+ if (high || highprv)
goto new_segment;
+ if (cluster) {
+ if (seg_size + bv->bv_len > q->max_segment_size)
+ goto new_segment;
+ if (!BIOVEC_PHYS_MERGEABLE(bvprv, bv))
+ goto new_segment;
+ if (!BIOVEC_SEG_BOUNDARY(q, bvprv, bv))
+ goto new_segment;
+
+ seg_size += bv->bv_len;
+ bvprv = bv;
+ continue;
+ }
+new_segment:
+ if (nr_phys_segs == 1 && seg_size >
+ fbio->bi_seg_front_size)
+ fbio->bi_seg_front_size = seg_size;
- seg_size += bv->bv_len;
+ nr_phys_segs++;
bvprv = bv;
- continue;
+ seg_size = bv->bv_len;
+ highprv = high;
}
-new_segment:
- if (nr_phys_segs == 1 && seg_size > rq->bio->bi_seg_front_size)
- rq->bio->bi_seg_front_size = seg_size;
-
- nr_phys_segs++;
- bvprv = bv;
- seg_size = bv->bv_len;
- highprv = high;
}
- if (nr_phys_segs == 1 && seg_size > rq->bio->bi_seg_front_size)
+ if (seg_size_ptr)
+ *seg_size_ptr = seg_size;
+
+ return nr_phys_segs;
+}
+
+void blk_recalc_rq_segments(struct request *rq)
+{
+ unsigned int seg_size = 0, phys_segs;
+
+ phys_segs = __blk_recalc_rq_segments(rq->q, rq->bio, &seg_size);
+
+ if (phys_segs == 1 && seg_size > rq->bio->bi_seg_front_size)
rq->bio->bi_seg_front_size = seg_size;
if (seg_size > rq->biotail->bi_seg_back_size)
rq->biotail->bi_seg_back_size = seg_size;
- rq->nr_phys_segments = nr_phys_segs;
+ rq->nr_phys_segments = phys_segs;
}
void blk_recount_segments(struct request_queue *q, struct bio *bio)
{
- struct request rq;
struct bio *nxt = bio->bi_next;
- rq.q = q;
- rq.bio = rq.biotail = bio;
+
bio->bi_next = NULL;
- blk_recalc_rq_segments(&rq);
+ bio->bi_phys_segments = __blk_recalc_rq_segments(q, bio, NULL);
bio->bi_next = nxt;
- bio->bi_phys_segments = rq.nr_phys_segments;
bio->bi_flags |= (1 << BIO_SEG_VALID);
}
EXPORT_SYMBOL(blk_recount_segments);
diff --git a/block/genhd.c b/block/genhd.c
index e1eadcc9546..a9ec910974c 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -256,6 +256,22 @@ void blkdev_show(struct seq_file *seqf, off_t offset)
}
#endif /* CONFIG_PROC_FS */
+/**
+ * register_blkdev - register a new block device
+ *
+ * @major: the requested major device number [1..255]. If @major=0, try to
+ * allocate any unused major number.
+ * @name: the name of the new block device as a zero terminated string
+ *
+ * The @name must be unique within the system.
+ *
+ * The return value depends on the @major input parameter.
+ * - if a major device number was requested in range [1..255] then the
+ * function returns zero on success, or a negative error code
+ * - if any unused major number was requested with @major=0 parameter
+ * then the return value is the allocated major number in range
+ * [1..255] or a negative error code otherwise
+ */
int register_blkdev(unsigned int major, const char *name)
{
struct blk_major_name **n, *p;