### Comments for ChangeSet
Sometimes raid0 and linear are required to take a single page bio that
spans two devices. We use bio_split to split such a bio into two.
The the same time, bio.h is included by linux/raid/md.h so
we don't included it elsewhere anymore.
We also modify the mergeable_bvec functions to allow a bvec
that doesn't fit if it is the first bvec to be added to
the bio, and be careful never to return a negative length from a
bvec_mergable funciton.
----------- Diffstat output ------------
./drivers/md/linear.c | 31 +++++++++++++++++++++++++++--
./drivers/md/md.c | 1
./drivers/md/multipath.c | 1
./drivers/md/raid0.c | 41 ++++++++++++++++++++++++++-------------
./drivers/md/raid1.c | 1
./drivers/md/raid5.c | 1
./include/linux/raid/md.h | 1
./include/linux/raid/multipath.h | 1
./include/linux/raid/raid5.h | 1
9 files changed, 58 insertions(+), 21 deletions(-)
diff ./drivers/md/linear.c~current~ ./drivers/md/linear.c
--- ./drivers/md/linear.c~current~ 2003-05-27 11:51:05.000000000 +1000
+++ ./drivers/md/linear.c 2003-05-27 11:58:20.000000000 +1000
@@ -20,7 +20,6 @@
#include <linux/raid/md.h>
#include <linux/slab.h>
-#include <linux/bio.h>
#include <linux/raid/linear.h>
#define MAJOR_NR MD_MAJOR
@@ -67,7 +66,18 @@ static int linear_mergeable_bvec(request
dev0 = which_dev(mddev, bio->bi_sector);
maxsectors = (dev0->size << 1) - (bio->bi_sector - (dev0->offset<<1));
- return (maxsectors - bio_sectors) << 9;
+ if (maxsectors < bio_sectors)
+ maxsectors = 0;
+ else
+ maxsectors -= bio_sectors;
+
+ if (maxsectors <= (PAGE_SIZE >> 9 ) && bio_sectors == 0)
+ return biovec->bv_len;
+ /* The bytes available at this offset could be really big,
+ * so we cap at 2^31 to avoid overflow */
+ if (maxsectors > (1 << (31-9)))
+ return 1<<31;
+ return maxsectors << 9;
}
static int linear_run (mddev_t *mddev)
@@ -209,6 +219,23 @@ static int linear_make_request (request_
bio_io_error(bio, bio->bi_size);
return 0;
}
+ if (unlikely(bio->bi_sector + (bio->bi_size >> 9) >
+ (tmp_dev->offset + tmp_dev->size)<<1)) {
+ /* This bio crosses a device boundary, so we have to
+ * split it.
+ */
+ struct bio_pair *bp;
+ bp = bio_split(bio, bio_split_pool,
+ (bio->bi_sector + (bio->bi_size >> 9) -
+ (tmp_dev->offset + tmp_dev->size))<<1);
+ if (linear_make_request(q, &bp->bio1))
+ generic_make_request(&bp->bio1);
+ if (linear_make_request(q, &bp->bio2))
+ generic_make_request(&bp->bio2);
+ bio_pair_release(bp);
+ return 0;
+ }
+
bio->bi_bdev = tmp_dev->rdev->bdev;
bio->bi_sector = bio->bi_sector - (tmp_dev->offset << 1) + tmp_dev->rdev->data_offset;
diff ./drivers/md/md.c~current~ ./drivers/md/md.c
--- ./drivers/md/md.c~current~ 2003-05-27 11:51:05.000000000 +1000
+++ ./drivers/md/md.c 2003-05-27 11:58:20.000000000 +1000
@@ -33,7 +33,6 @@
#include <linux/linkage.h>
#include <linux/raid/md.h>
#include <linux/sysctl.h>
-#include <linux/bio.h>
#include <linux/devfs_fs_kernel.h>
#include <linux/buffer_head.h> /* for invalidate_bdev */
#include <linux/suspend.h>
diff ./drivers/md/multipath.c~current~ ./drivers/md/multipath.c
--- ./drivers/md/multipath.c~current~ 2003-05-27 11:51:05.000000000 +1000
+++ ./drivers/md/multipath.c 2003-05-27 11:58:20.000000000 +1000
@@ -23,7 +23,6 @@
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/raid/multipath.h>
-#include <linux/bio.h>
#include <linux/buffer_head.h>
#include <asm/atomic.h>
diff ./drivers/md/raid0.c~current~ ./drivers/md/raid0.c
--- ./drivers/md/raid0.c~current~ 2003-05-27 11:51:05.000000000 +1000
+++ ./drivers/md/raid0.c 2003-05-27 11:58:20.000000000 +1000
@@ -20,7 +20,6 @@
#include <linux/module.h>
#include <linux/raid/raid0.h>
-#include <linux/bio.h>
#define MAJOR_NR MD_MAJOR
#define MD_DRIVER
@@ -179,15 +178,17 @@ static int create_strip_zones (mddev_t *
static int raid0_mergeable_bvec(request_queue_t *q, struct bio *bio, struct bio_vec *biovec)
{
mddev_t *mddev = q->queuedata;
- sector_t sector;
- unsigned int chunk_sectors;
- unsigned int bio_sectors;
-
- chunk_sectors = mddev->chunk_size >> 9;
- sector = bio->bi_sector;
- bio_sectors = bio->bi_size >> 9;
-
- return (chunk_sectors - ((sector & (chunk_sectors - 1)) + bio_sectors)) << 9;
+ sector_t sector = bio->bi_sector;
+ int max;
+ unsigned int chunk_sectors = mddev->chunk_size >> 9;
+ unsigned int bio_sectors = bio->bi_size >> 9;
+
+ max = (chunk_sectors - ((sector & (chunk_sectors - 1)) + bio_sectors)) << 9;
+ if (max < 0) max = 0; /* bio_add cannot handle a negative return */
+ if (max <= biovec->bv_len && bio_sectors == 0)
+ return biovec->bv_len;
+ else
+ return max;
}
static int raid0_run (mddev_t *mddev)
@@ -322,9 +323,23 @@ static int raid0_make_request (request_q
hash = conf->hash_table + x;
}
- /* Sanity check -- queue functions should prevent this happening */
- if (unlikely(chunk_size < (block & (chunk_size - 1)) + (bio->bi_size >> 10)))
- goto bad_map;
+ if (unlikely(chunk_size < (block & (chunk_size - 1)) + (bio->bi_size >> 10))) {
+ struct bio_pair *bp;
+ /* Sanity check -- queue functions should prevent this happening */
+ if (bio->bi_vcnt != 1 ||
+ bio->bi_idx != 0)
+ goto bad_map;
+ /* This is a one page bio that upper layers
+ * refuse to split for us, so we need to split it.
+ */
+ bp = bio_split(bio, bio_split_pool, (chunk_size - (block & (chunk_size - 1)))<<1 );
+ if (raid0_make_request(q, &bp->bio1))
+ generic_make_request(&bp->bio1);
+ if (raid0_make_request(q, &bp->bio2))
+ generic_make_request(&bp->bio2);
+ bio_pair_release(bp);
+ return 0;
+ }
if (!hash)
goto bad_hash;
diff ./drivers/md/raid1.c~current~ ./drivers/md/raid1.c
--- ./drivers/md/raid1.c~current~ 2003-05-27 11:51:05.000000000 +1000
+++ ./drivers/md/raid1.c 2003-05-27 11:58:20.000000000 +1000
@@ -23,7 +23,6 @@
*/
#include <linux/raid/raid1.h>
-#include <linux/bio.h>
#define MAJOR_NR MD_MAJOR
#define MD_DRIVER
diff ./drivers/md/raid5.c~current~ ./drivers/md/raid5.c
--- ./drivers/md/raid5.c~current~ 2003-05-27 11:51:05.000000000 +1000
+++ ./drivers/md/raid5.c 2003-05-27 11:58:20.000000000 +1000
@@ -20,7 +20,6 @@
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/raid/raid5.h>
-#include <linux/bio.h>
#include <linux/highmem.h>
#include <asm/bitops.h>
#include <asm/atomic.h>
diff ./include/linux/raid/md.h~current~ ./include/linux/raid/md.h
--- ./include/linux/raid/md.h~current~ 2003-05-27 11:51:05.000000000 +1000
+++ ./include/linux/raid/md.h 2003-05-27 11:58:20.000000000 +1000
@@ -40,6 +40,7 @@
#include <linux/reboot.h>
#include <linux/vmalloc.h>
#include <linux/blkpg.h>
+#include <linux/bio.h>
/*
* 'md_p.h' holds the 'physical' layout of RAID devices
diff ./include/linux/raid/multipath.h~current~ ./include/linux/raid/multipath.h
--- ./include/linux/raid/multipath.h~current~ 2003-05-27 11:51:05.000000000 +1000
+++ ./include/linux/raid/multipath.h 2003-05-27 11:58:20.000000000 +1000
@@ -2,7 +2,6 @@
#define _MULTIPATH_H
#include <linux/raid/md.h>
-#include <linux/bio.h>
struct multipath_info {
mdk_rdev_t *rdev;
diff ./include/linux/raid/raid5.h~current~ ./include/linux/raid/raid5.h
--- ./include/linux/raid/raid5.h~current~ 2003-05-27 11:51:05.000000000 +1000
+++ ./include/linux/raid/raid5.h 2003-05-27 11:58:20.000000000 +1000
@@ -3,7 +3,6 @@
#include <linux/raid/md.h>
#include <linux/raid/xor.h>
-#include <linux/bio.h>
/*
*
-
To unsubscribe from this list: send the line "unsubscribe linux-raid" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
