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Commit 69335ef3 authored by NeilBrown's avatar NeilBrown
Browse files

md/raid10: prepare data structures for handling replacement. 



Allow each slot in the RAID10 to have 2 devices, the want_replacement
and the replacement.

Also an r10bio to have 2 bios, and for resync/recovery allocate the
second bio if there are any replacement devices.

Signed-off-by: default avatarNeilBrown <neilb@suse.de>
parent 3a6de292

drivers/md/raid10.c

+41 −7
Original line number Diff line number Diff line
@@ -73,7 +73,8 @@ static void * r10bio_pool_alloc(gfp_t gfp_flags, void *data) 
	struct r10conf *conf = data;

	int size = offsetof(struct r10bio, devs[conf->copies]);



	/* allocate a r10bio with room for raid_disks entries in the bios array */

	/* allocate a r10bio with room for raid_disks entries in the

	 * bios array */

	return kzalloc(size, gfp_flags);

}
@@ -123,12 +124,19 @@ static void * r10buf_pool_alloc(gfp_t gfp_flags, void *data) 
		if (!bio)

			goto out_free_bio;

		r10_bio->devs[j].bio = bio;

		if (!conf->have_replacement)

			continue;

		bio = bio_kmalloc(gfp_flags, RESYNC_PAGES);

		if (!bio)

			goto out_free_bio;

		r10_bio->devs[j].repl_bio = bio;

	}

	/*

	 * Allocate RESYNC_PAGES data pages and attach them

	 * where needed.

	 */

	for (j = 0 ; j < nalloc; j++) {

		struct bio *rbio = r10_bio->devs[j].repl_bio;

		bio = r10_bio->devs[j].bio;

		for (i = 0; i < RESYNC_PAGES; i++) {

			if (j == 1 && !test_bit(MD_RECOVERY_SYNC,
@@ -143,6 +151,8 @@ static void * r10buf_pool_alloc(gfp_t gfp_flags, void *data) 
				goto out_free_pages;



			bio->bi_io_vec[i].bv_page = page;

			if (rbio)

				rbio->bi_io_vec[i].bv_page = page;

		}

	}
@@ -156,8 +166,11 @@ static void * r10buf_pool_alloc(gfp_t gfp_flags, void *data) 
			safe_put_page(r10_bio->devs[j].bio->bi_io_vec[i].bv_page);

	j = -1;

out_free_bio:

	while ( ++j < nalloc )

	while (++j < nalloc) {

		bio_put(r10_bio->devs[j].bio);

		if (r10_bio->devs[j].repl_bio)

			bio_put(r10_bio->devs[j].repl_bio);

	}

	r10bio_pool_free(r10_bio, conf);

	return NULL;

}
@@ -178,6 +191,9 @@ static void r10buf_pool_free(void *__r10_bio, void *data) 
			}

			bio_put(bio);

		}

		bio = r10bio->devs[j].repl_bio;

		if (bio)

			bio_put(bio);

	}

	r10bio_pool_free(r10bio, conf);

}
@@ -191,6 +207,10 @@ static void put_all_bios(struct r10conf *conf, struct r10bio *r10_bio) 
		if (!BIO_SPECIAL(*bio))

			bio_put(*bio);

		*bio = NULL;

		bio = &r10_bio->devs[i].repl_bio;

		if (r10_bio->read_slot < 0 && !BIO_SPECIAL(*bio))

			bio_put(*bio);

		*bio = NULL;

	}

}
@@ -275,19 +295,27 @@ static inline void update_head_pos(int slot, struct r10bio *r10_bio) 
 * Find the disk number which triggered given bio

 */

static int find_bio_disk(struct r10conf *conf, struct r10bio *r10_bio,

			 struct bio *bio, int *slotp)

			 struct bio *bio, int *slotp, int *replp)

{

	int slot;

	int repl = 0;



	for (slot = 0; slot < conf->copies; slot++)

	for (slot = 0; slot < conf->copies; slot++) {

		if (r10_bio->devs[slot].bio == bio)

			break;

		if (r10_bio->devs[slot].repl_bio == bio) {

			repl = 1;

			break;

		}

	}



	BUG_ON(slot == conf->copies);

	update_head_pos(slot, r10_bio);



	if (slotp)

		*slotp = slot;

	if (replp)

		*replp = repl;

	return r10_bio->devs[slot].devnum;

}
@@ -368,7 +396,7 @@ static void raid10_end_write_request(struct bio *bio, int error) 
	struct r10conf *conf = r10_bio->mddev->private;

	int slot;



	dev = find_bio_disk(conf, r10_bio, bio, &slot);

	dev = find_bio_disk(conf, r10_bio, bio, &slot, NULL);



	/*

	 * this branch is our 'one mirror IO has finished' event handler:
@@ -1025,6 +1053,7 @@ static void make_request(struct mddev *mddev, struct bio * bio) 
	 */

	plugged = mddev_check_plugged(mddev);



	r10_bio->read_slot = -1; /* make sure repl_bio gets freed */

	raid10_find_phys(conf, r10_bio);

retry_write:

	blocked_rdev = NULL;
@@ -1431,7 +1460,7 @@ static void end_sync_read(struct bio *bio, int error) 
	struct r10conf *conf = r10_bio->mddev->private;

	int d;



	d = find_bio_disk(conf, r10_bio, bio, NULL);

	d = find_bio_disk(conf, r10_bio, bio, NULL, NULL);



	if (test_bit(BIO_UPTODATE, &bio->bi_flags))

		set_bit(R10BIO_Uptodate, &r10_bio->state);
@@ -1493,7 +1522,7 @@ static void end_sync_write(struct bio *bio, int error) 
	int bad_sectors;

	int slot;



	d = find_bio_disk(conf, r10_bio, bio, &slot);

	d = find_bio_disk(conf, r10_bio, bio, &slot, NULL);



	if (!uptodate) {

		set_bit(WriteErrorSeen, &conf->mirrors[d].rdev->flags);
@@ -2271,9 +2300,14 @@ static void raid10d(struct mddev *mddev) 
static int init_resync(struct r10conf *conf)

{

	int buffs;

	int i;



	buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE;

	BUG_ON(conf->r10buf_pool);

	conf->have_replacement = 0;

	for (i = 0; i < conf->raid_disks; i++)

		if (conf->mirrors[i].replacement)

			conf->have_replacement = 1;

	conf->r10buf_pool = mempool_create(buffs, r10buf_pool_alloc, r10buf_pool_free, conf);

	if (!conf->r10buf_pool)

		return -ENOMEM;

drivers/md/raid10.h

+37 −24
Original line number Diff line number Diff line
@@ -2,7 +2,7 @@ 
#define _RAID10_H



struct mirror_info {

	struct md_rdev	*rdev;

	struct md_rdev	*rdev, *replacement;

	sector_t	head_position;

	int		recovery_disabled;	/* matches

						 * mddev->recovery_disabled
@@ -18,12 +18,13 @@ struct r10conf { 
	spinlock_t		device_lock;



	/* geometry */

	int			near_copies;  /* number of copies laid out raid0 style */

	int			near_copies;  /* number of copies laid out

					       * raid0 style */

	int 			far_copies;   /* number of copies laid out

					       * at large strides across drives

					       */

	int			far_offset;   /* far_copies are offset by 1 stripe

					       * instead of many

	int			far_offset;   /* far_copies are offset by 1

					       * stripe instead of many

					       */

	int			copies;	      /* near_copies * far_copies.

					       * must be <= raid_disks
@@ -34,7 +35,8 @@ struct r10conf { 
					       * 1 stripe.

					       */



	sector_t		dev_sectors;  /* temp copy of mddev->dev_sectors */

	sector_t		dev_sectors;  /* temp copy of

					       * mddev->dev_sectors */



	int			chunk_shift; /* shift from chunks to sectors */

	sector_t		chunk_mask;
@@ -54,7 +56,9 @@ struct r10conf { 
					    * (fresh device added).

					    * Cleared when a sync completes.

					    */



	int			have_replacement; /* There is at least one

						   * replacement device.

						   */

	wait_queue_head_t	wait_barrier;



	mempool_t		*r10bio_pool;
@@ -98,9 +102,16 @@ struct r10bio { 
	 * When resyncing we also use one for each copy.

	 * When reconstructing, we use 2 bios, one for read, one for write.

	 * We choose the number when they are allocated.

	 * We sometimes need an extra bio to write to the replacement.

	 */

	struct {

		struct bio	*bio;

		union {

			struct bio	*repl_bio; /* used for resync and

						    * writes */

			struct md_rdev	*rdev;	   /* used for reads

						    * (read_slot >= 0) */

		};

		sector_t	addr;

		int		devnum;

	} devs[0];
@@ -121,17 +132,19 @@ struct r10bio { 
#define BIO_SPECIAL(bio) ((unsigned long)bio <= 2)



/* bits for r10bio.state */

#define	R10BIO_Uptodate	0

#define	R10BIO_IsSync	1

#define	R10BIO_IsRecover 2

#define	R10BIO_Degraded 3

enum r10bio_state {

	R10BIO_Uptodate,

	R10BIO_IsSync,

	R10BIO_IsRecover,

	R10BIO_Degraded,

/* Set ReadError on bios that experience a read error

 * so that raid10d knows what to do with them.

 */

#define	R10BIO_ReadError 4

	R10BIO_ReadError,

/* If a write for this request means we can clear some

 * known-bad-block records, we set this flag.

 */

#define	R10BIO_MadeGood 5

#define	R10BIO_WriteError 6

	R10BIO_MadeGood,

	R10BIO_WriteError,

};

#endif