Commit e4c8b3ba authored by Neil Brown's avatar Neil Brown Committed by Linus Torvalds
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[PATCH] dm: mirror sector offset fix 



The device-mapper core does not perform any remapping of bios before passing
them to the targets.  If a particular mapping begins part-way into a device,
targets obtain the sector relative to the start of the mapping by subtracting
ti->begin.

The dm-raid1 target didn't do this everywhere: this patch fixes it, taking
care to subtract ti->begin exactly once for each bio.

[akpm: too late for 2.6.17 - suitable for 2.6.17.x after it has settled]

Signed-off-by: default avatarNeil Brown <neilb@suse.de>
Signed-off-by: default avatarAlasdair G Kergon <agk@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent f0b04115

drivers/md/dm-raid1.c

+32 −31
Original line number Diff line number Diff line
@@ -106,12 +106,42 @@ struct region { 
	struct bio_list delayed_bios;

};





/*-----------------------------------------------------------------

 * Mirror set structures.

 *---------------------------------------------------------------*/

struct mirror {

	atomic_t error_count;

	struct dm_dev *dev;

	sector_t offset;

};



struct mirror_set {

	struct dm_target *ti;

	struct list_head list;

	struct region_hash rh;

	struct kcopyd_client *kcopyd_client;



	spinlock_t lock;	/* protects the next two lists */

	struct bio_list reads;

	struct bio_list writes;



	/* recovery */

	region_t nr_regions;

	int in_sync;



	struct mirror *default_mirror;	/* Default mirror */



	unsigned int nr_mirrors;

	struct mirror mirror[0];

};



/*

 * Conversion fns

 */

static inline region_t bio_to_region(struct region_hash *rh, struct bio *bio)

{

	return bio->bi_sector >> rh->region_shift;

	return (bio->bi_sector - rh->ms->ti->begin) >> rh->region_shift;

}



static inline sector_t region_to_sector(struct region_hash *rh, region_t region)
@@ -539,35 +569,6 @@ static void rh_start_recovery(struct region_hash *rh) 
	wake();

}



/*-----------------------------------------------------------------

 * Mirror set structures.

 *---------------------------------------------------------------*/

struct mirror {

	atomic_t error_count;

	struct dm_dev *dev;

	sector_t offset;

};



struct mirror_set {

	struct dm_target *ti;

	struct list_head list;

	struct region_hash rh;

	struct kcopyd_client *kcopyd_client;



	spinlock_t lock;	/* protects the next two lists */

	struct bio_list reads;

	struct bio_list writes;



	/* recovery */

	region_t nr_regions;

	int in_sync;



	struct mirror *default_mirror;	/* Default mirror */



	unsigned int nr_mirrors;

	struct mirror mirror[0];

};



/*

 * Every mirror should look like this one.

 */
@@ -1113,7 +1114,7 @@ static int mirror_map(struct dm_target *ti, struct bio *bio, 
	struct mirror *m;

	struct mirror_set *ms = ti->private;



	map_context->ll = bio->bi_sector >> ms->rh.region_shift;

	map_context->ll = bio_to_region(&ms->rh, bio);



	if (rw == WRITE) {

		queue_bio(ms, bio, rw);

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