Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block
* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
xen/blkfront: use blk_rq_map_sg to generate ring entries
block: reduce stack footprint of blk_recount_segments()
cciss: shorten 30s timeout on controller reset
block: add documentation for register_blkdev()
block: fix bogus gcc warning for uninitialized var usage
diff --git a/block/blk-merge.c b/block/blk-merge.c
index b92f5b0..a104593 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -38,72 +38,84 @@
}
}
-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)
+ 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 (!BIOVEC_PHYS_MERGEABLE(bvprv, bv))
- goto new_segment;
- if (!BIOVEC_SEG_BOUNDARY(q, bvprv, bv))
- 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;
- }
+ seg_size += bv->bv_len;
+ bvprv = bv;
+ continue;
+ }
new_segment:
- if (nr_phys_segs == 1 && seg_size > rq->bio->bi_seg_front_size)
- rq->bio->bi_seg_front_size = seg_size;
+ if (nr_phys_segs == 1 && seg_size >
+ fbio->bi_seg_front_size)
+ fbio->bi_seg_front_size = seg_size;
- nr_phys_segs++;
- bvprv = bv;
- seg_size = bv->bv_len;
- highprv = high;
+ 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 e1eadcc..a9ec910 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -256,6 +256,22 @@
}
#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;
diff --git a/drivers/block/cciss.c b/drivers/block/cciss.c
index d2cb67b..b5a0611 100644
--- a/drivers/block/cciss.c
+++ b/drivers/block/cciss.c
@@ -3611,11 +3611,15 @@
schedule_timeout_uninterruptible(30*HZ);
/* Now try to get the controller to respond to a no-op */
- for (i=0; i<12; i++) {
+ for (i=0; i<30; i++) {
if (cciss_noop(pdev) == 0)
break;
- else
- printk("cciss: no-op failed%s\n", (i < 11 ? "; re-trying" : ""));
+
+ schedule_timeout_uninterruptible(HZ);
+ }
+ if (i == 30) {
+ printk(KERN_ERR "cciss: controller seems dead\n");
+ return -EBUSY;
}
}
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 918ef725..b6c8ce2 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -40,6 +40,7 @@
#include <linux/hdreg.h>
#include <linux/cdrom.h>
#include <linux/module.h>
+#include <linux/scatterlist.h>
#include <xen/xenbus.h>
#include <xen/grant_table.h>
@@ -82,6 +83,7 @@
enum blkif_state connected;
int ring_ref;
struct blkif_front_ring ring;
+ struct scatterlist sg[BLKIF_MAX_SEGMENTS_PER_REQUEST];
unsigned int evtchn, irq;
struct request_queue *rq;
struct work_struct work;
@@ -204,12 +206,11 @@
struct blkfront_info *info = req->rq_disk->private_data;
unsigned long buffer_mfn;
struct blkif_request *ring_req;
- struct req_iterator iter;
- struct bio_vec *bvec;
unsigned long id;
unsigned int fsect, lsect;
- int ref;
+ int i, ref;
grant_ref_t gref_head;
+ struct scatterlist *sg;
if (unlikely(info->connected != BLKIF_STATE_CONNECTED))
return 1;
@@ -238,12 +239,13 @@
if (blk_barrier_rq(req))
ring_req->operation = BLKIF_OP_WRITE_BARRIER;
- ring_req->nr_segments = 0;
- rq_for_each_segment(bvec, req, iter) {
- BUG_ON(ring_req->nr_segments == BLKIF_MAX_SEGMENTS_PER_REQUEST);
- buffer_mfn = pfn_to_mfn(page_to_pfn(bvec->bv_page));
- fsect = bvec->bv_offset >> 9;
- lsect = fsect + (bvec->bv_len >> 9) - 1;
+ ring_req->nr_segments = blk_rq_map_sg(req->q, req, info->sg);
+ BUG_ON(ring_req->nr_segments > BLKIF_MAX_SEGMENTS_PER_REQUEST);
+
+ for_each_sg(info->sg, sg, ring_req->nr_segments, i) {
+ buffer_mfn = pfn_to_mfn(page_to_pfn(sg_page(sg)));
+ fsect = sg->offset >> 9;
+ lsect = fsect + (sg->length >> 9) - 1;
/* install a grant reference. */
ref = gnttab_claim_grant_reference(&gref_head);
BUG_ON(ref == -ENOSPC);
@@ -254,16 +256,12 @@
buffer_mfn,
rq_data_dir(req) );
- info->shadow[id].frame[ring_req->nr_segments] =
- mfn_to_pfn(buffer_mfn);
-
- ring_req->seg[ring_req->nr_segments] =
+ info->shadow[id].frame[i] = mfn_to_pfn(buffer_mfn);
+ ring_req->seg[i] =
(struct blkif_request_segment) {
.gref = ref,
.first_sect = fsect,
.last_sect = lsect };
-
- ring_req->nr_segments++;
}
info->ring.req_prod_pvt++;
@@ -622,6 +620,8 @@
SHARED_RING_INIT(sring);
FRONT_RING_INIT(&info->ring, sring, PAGE_SIZE);
+ sg_init_table(info->sg, BLKIF_MAX_SEGMENTS_PER_REQUEST);
+
err = xenbus_grant_ring(dev, virt_to_mfn(info->ring.sring));
if (err < 0) {
free_page((unsigned long)sring);
diff --git a/fs/bio.c b/fs/bio.c
index 72ab251..124b95c 100644
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -302,7 +302,7 @@
struct bio *bio_alloc_bioset(gfp_t gfp_mask, int nr_iovecs, struct bio_set *bs)
{
struct bio *bio = NULL;
- void *p;
+ void *uninitialized_var(p);
if (bs) {
p = mempool_alloc(bs->bio_pool, gfp_mask);
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index dcaa0fd..465d6ba 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -708,6 +708,8 @@
};
/* This should not be used directly - use rq_for_each_segment */
+#define for_each_bio(_bio) \
+ for (; _bio; _bio = _bio->bi_next)
#define __rq_for_each_bio(_bio, rq) \
if ((rq->bio)) \
for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
