173 строки
4.9 KiB
C
173 строки
4.9 KiB
C
#ifndef _RAID1_H
|
|
#define _RAID1_H
|
|
|
|
struct mirror_info {
|
|
struct md_rdev *rdev;
|
|
sector_t head_position;
|
|
};
|
|
|
|
/*
|
|
* memory pools need a pointer to the mddev, so they can force an unplug
|
|
* when memory is tight, and a count of the number of drives that the
|
|
* pool was allocated for, so they know how much to allocate and free.
|
|
* mddev->raid_disks cannot be used, as it can change while a pool is active
|
|
* These two datums are stored in a kmalloced struct.
|
|
*/
|
|
|
|
struct pool_info {
|
|
struct mddev *mddev;
|
|
int raid_disks;
|
|
};
|
|
|
|
struct r1conf {
|
|
struct mddev *mddev;
|
|
struct mirror_info *mirrors;
|
|
int raid_disks;
|
|
|
|
/* When choose the best device for a read (read_balance())
|
|
* we try to keep sequential reads one the same device
|
|
* using 'last_used' and 'next_seq_sect'
|
|
*/
|
|
int last_used;
|
|
sector_t next_seq_sect;
|
|
/* During resync, read_balancing is only allowed on the part
|
|
* of the array that has been resynced. 'next_resync' tells us
|
|
* where that is.
|
|
*/
|
|
sector_t next_resync;
|
|
|
|
spinlock_t device_lock;
|
|
|
|
/* list of 'struct r1bio' that need to be processed by raid1d,
|
|
* whether to retry a read, writeout a resync or recovery
|
|
* block, or anything else.
|
|
*/
|
|
struct list_head retry_list;
|
|
|
|
/* queue pending writes to be submitted on unplug */
|
|
struct bio_list pending_bio_list;
|
|
int pending_count;
|
|
|
|
/* for use when syncing mirrors:
|
|
* We don't allow both normal IO and resync/recovery IO at
|
|
* the same time - resync/recovery can only happen when there
|
|
* is no other IO. So when either is active, the other has to wait.
|
|
* See more details description in raid1.c near raise_barrier().
|
|
*/
|
|
wait_queue_head_t wait_barrier;
|
|
spinlock_t resync_lock;
|
|
int nr_pending;
|
|
int nr_waiting;
|
|
int nr_queued;
|
|
int barrier;
|
|
|
|
/* Set to 1 if a full sync is needed, (fresh device added).
|
|
* Cleared when a sync completes.
|
|
*/
|
|
int fullsync;
|
|
|
|
/* When the same as mddev->recovery_disabled we don't allow
|
|
* recovery to be attempted as we expect a read error.
|
|
*/
|
|
int recovery_disabled;
|
|
|
|
|
|
/* poolinfo contains information about the content of the
|
|
* mempools - it changes when the array grows or shrinks
|
|
*/
|
|
struct pool_info *poolinfo;
|
|
mempool_t *r1bio_pool;
|
|
mempool_t *r1buf_pool;
|
|
|
|
/* temporary buffer to synchronous IO when attempting to repair
|
|
* a read error.
|
|
*/
|
|
struct page *tmppage;
|
|
|
|
|
|
/* When taking over an array from a different personality, we store
|
|
* the new thread here until we fully activate the array.
|
|
*/
|
|
struct md_thread *thread;
|
|
};
|
|
|
|
/*
|
|
* this is our 'private' RAID1 bio.
|
|
*
|
|
* it contains information about what kind of IO operations were started
|
|
* for this RAID1 operation, and about their status:
|
|
*/
|
|
|
|
struct r1bio {
|
|
atomic_t remaining; /* 'have we finished' count,
|
|
* used from IRQ handlers
|
|
*/
|
|
atomic_t behind_remaining; /* number of write-behind ios remaining
|
|
* in this BehindIO request
|
|
*/
|
|
sector_t sector;
|
|
int sectors;
|
|
unsigned long state;
|
|
struct mddev *mddev;
|
|
/*
|
|
* original bio going to /dev/mdx
|
|
*/
|
|
struct bio *master_bio;
|
|
/*
|
|
* if the IO is in READ direction, then this is where we read
|
|
*/
|
|
int read_disk;
|
|
|
|
struct list_head retry_list;
|
|
/* Next two are only valid when R1BIO_BehindIO is set */
|
|
struct bio_vec *behind_bvecs;
|
|
int behind_page_count;
|
|
/*
|
|
* if the IO is in WRITE direction, then multiple bios are used.
|
|
* We choose the number when they are allocated.
|
|
*/
|
|
struct bio *bios[0];
|
|
/* DO NOT PUT ANY NEW FIELDS HERE - bios array is contiguously alloced*/
|
|
};
|
|
|
|
/* when we get a read error on a read-only array, we redirect to another
|
|
* device without failing the first device, or trying to over-write to
|
|
* correct the read error. To keep track of bad blocks on a per-bio
|
|
* level, we store IO_BLOCKED in the appropriate 'bios' pointer
|
|
*/
|
|
#define IO_BLOCKED ((struct bio *)1)
|
|
/* When we successfully write to a known bad-block, we need to remove the
|
|
* bad-block marking which must be done from process context. So we record
|
|
* the success by setting bios[n] to IO_MADE_GOOD
|
|
*/
|
|
#define IO_MADE_GOOD ((struct bio *)2)
|
|
|
|
#define BIO_SPECIAL(bio) ((unsigned long)bio <= 2)
|
|
|
|
/* bits for r1bio.state */
|
|
#define R1BIO_Uptodate 0
|
|
#define R1BIO_IsSync 1
|
|
#define R1BIO_Degraded 2
|
|
#define R1BIO_BehindIO 3
|
|
/* Set ReadError on bios that experience a readerror so that
|
|
* raid1d knows what to do with them.
|
|
*/
|
|
#define R1BIO_ReadError 4
|
|
/* For write-behind requests, we call bi_end_io when
|
|
* the last non-write-behind device completes, providing
|
|
* any write was successful. Otherwise we call when
|
|
* any write-behind write succeeds, otherwise we call
|
|
* with failure when last write completes (and all failed).
|
|
* Record that bi_end_io was called with this flag...
|
|
*/
|
|
#define R1BIO_Returned 6
|
|
/* If a write for this request means we can clear some
|
|
* known-bad-block records, we set this flag
|
|
*/
|
|
#define R1BIO_MadeGood 7
|
|
#define R1BIO_WriteError 8
|
|
|
|
extern int md_raid1_congested(struct mddev *mddev, int bits);
|
|
|
|
#endif
|