c93983bf51
The "industry standard" DDF format allows for a stripe/offset layout where data is duplicated on different stripes. e.g. A B C D D A B C E F G H H E F G (columns are drives, rows are stripes, LETTERS are chunks of data). This is similar to raid10's 'far' mode, but not quite the same. So enhance 'far' mode with a 'far/offset' option which follows the layout of DDFs stripe/offset. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
124 lines
3 KiB
C
124 lines
3 KiB
C
#ifndef _RAID10_H
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#define _RAID10_H
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#include <linux/raid/md.h>
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typedef struct mirror_info mirror_info_t;
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struct mirror_info {
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mdk_rdev_t *rdev;
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sector_t head_position;
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};
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typedef struct r10bio_s r10bio_t;
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struct r10_private_data_s {
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mddev_t *mddev;
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mirror_info_t *mirrors;
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int raid_disks;
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int working_disks;
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spinlock_t device_lock;
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/* geometry */
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int near_copies; /* number of copies layed out raid0 style */
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int far_copies; /* number of copies layed out
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* at large strides across drives
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*/
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int far_offset; /* far_copies are offset by 1 stripe
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* instead of many
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*/
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int copies; /* near_copies * far_copies.
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* must be <= raid_disks
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*/
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sector_t stride; /* distance between far copies.
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* This is size / far_copies unless
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* far_offset, in which case it is
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* 1 stripe.
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*/
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int chunk_shift; /* shift from chunks to sectors */
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sector_t chunk_mask;
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struct list_head retry_list;
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/* queue pending writes and submit them on unplug */
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struct bio_list pending_bio_list;
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spinlock_t resync_lock;
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int nr_pending;
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int nr_waiting;
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int nr_queued;
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int barrier;
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sector_t next_resync;
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int fullsync; /* set to 1 if a full sync is needed,
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* (fresh device added).
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* Cleared when a sync completes.
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*/
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wait_queue_head_t wait_barrier;
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mempool_t *r10bio_pool;
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mempool_t *r10buf_pool;
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struct page *tmppage;
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};
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typedef struct r10_private_data_s conf_t;
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/*
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* this is the only point in the RAID code where we violate
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* C type safety. mddev->private is an 'opaque' pointer.
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*/
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#define mddev_to_conf(mddev) ((conf_t *) mddev->private)
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/*
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* this is our 'private' RAID10 bio.
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*
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* it contains information about what kind of IO operations were started
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* for this RAID10 operation, and about their status:
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*/
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struct r10bio_s {
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atomic_t remaining; /* 'have we finished' count,
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* used from IRQ handlers
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*/
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sector_t sector; /* virtual sector number */
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int sectors;
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unsigned long state;
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mddev_t *mddev;
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/*
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* original bio going to /dev/mdx
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*/
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struct bio *master_bio;
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/*
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* if the IO is in READ direction, then this is where we read
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*/
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int read_slot;
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struct list_head retry_list;
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/*
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* if the IO is in WRITE direction, then multiple bios are used,
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* one for each copy.
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* When resyncing we also use one for each copy.
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* When reconstructing, we use 2 bios, one for read, one for write.
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* We choose the number when they are allocated.
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*/
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struct {
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struct bio *bio;
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sector_t addr;
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int devnum;
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} devs[0];
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};
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/* when we get a read error on a read-only array, we redirect to another
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* device without failing the first device, or trying to over-write to
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* correct the read error. To keep track of bad blocks on a per-bio
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* level, we store IO_BLOCKED in the appropriate 'bios' pointer
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*/
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#define IO_BLOCKED ((struct bio*)1)
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/* bits for r10bio.state */
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#define R10BIO_Uptodate 0
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#define R10BIO_IsSync 1
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#define R10BIO_IsRecover 2
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#define R10BIO_Degraded 3
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#endif
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