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
This commit is contained in:
Linus Torvalds 2009-02-26 10:36:35 -08:00
commit babb29b0a3
6 changed files with 94 additions and 60 deletions

View File

@ -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;
}
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);

View File

@ -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;

View File

@ -3611,11 +3611,15 @@ static int __devinit cciss_init_one(struct pci_dev *pdev,
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;
}
}

View File

@ -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 @@ struct blkfront_info
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 @@ static int blkif_queue_request(struct request *req)
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 @@ static int blkif_queue_request(struct request *req)
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 @@ static int blkif_queue_request(struct request *req)
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 @@ static int setup_blkring(struct xenbus_device *dev,
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);

View File

@ -302,7 +302,7 @@ void bio_init(struct bio *bio)
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);

View File

@ -708,6 +708,8 @@ struct req_iterator {
};
/* 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)