Commit ce550c20 authored by NeilBrown's avatar NeilBrown

md/raid1: add documentation to r1_private_data_s data structure.

There wasn't much and it is inconsistent.
Also rearrange fields to keep related fields together.
Reported-by: default avatarAapo Laine <aapo.laine@shiftmail.org>
Signed-off-by: default avatarNeilBrown <neilb@suse.de>
parent 2dba6a91
......@@ -28,42 +28,67 @@ struct r1_private_data_s {
mddev_t *mddev;
mirror_info_t *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 'r1bio_t' 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 and submit them on unplug */
struct bio_list pending_bio_list;
/* for use when syncing mirrors: */
/* queue pending writes to be submitted on unplug */
struct bio_list pending_bio_list;
/* 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;
sector_t next_resync;
int fullsync; /* set to 1 if a full sync is needed,
* (fresh device added).
* Cleared when a sync completes.
*/
int recovery_disabled; /* when the same as
* mddev->recovery_disabled
* we don't allow recovery
* to be attempted as we
* expect a read error
*/
wait_queue_head_t wait_barrier;
/* Set to 1 if a full sync is needed, (fresh device added).
* Cleared when a sync completes.
*/
int fullsync;
struct pool_info *poolinfo;
/* When the same as mddev->recovery_disabled we don't allow
* recovery to be attempted as we expect a read error.
*/
int recovery_disabled;
struct page *tmppage;
/* 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.
*/
......
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