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![NeilBrown](/assets/img/avatar_default.png)
If a device is marked FailFast, and it is not the only device we can read from, we mark the bio as MD_FAILFAST. If this does fail-fast, we don't try read repair but just allow failure. If it was the last device, it doesn't get marked Faulty so the retry happens on the same device - this time without FAILFAST. A subsequent failure will not retry but will just pass up the error. During resync we may use FAILFAST requests, and on a failure we will simply use the other device(s). During recovery we will only use FAILFAST in the unusual case were there are multiple places to read from - i.e. if there are > 2 devices. If we get a failure we will fail the device and complete the resync/recovery with remaining devices. Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Shaohua Li <shli@fb.com>
162 lines
4.2 KiB
C
162 lines
4.2 KiB
C
#ifndef _RAID10_H
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#define _RAID10_H
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struct raid10_info {
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struct md_rdev *rdev, *replacement;
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sector_t head_position;
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int recovery_disabled; /* matches
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* mddev->recovery_disabled
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* when we shouldn't try
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* recovering this device.
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*/
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};
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struct r10conf {
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struct mddev *mddev;
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struct raid10_info *mirrors;
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struct raid10_info *mirrors_new, *mirrors_old;
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spinlock_t device_lock;
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/* geometry */
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struct geom {
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int raid_disks;
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int near_copies; /* number of copies laid out
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* raid0 style */
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int far_copies; /* number of copies laid 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
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* stripe instead of many
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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 far_set_size; /* The number of devices in a set,
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* where a 'set' are devices that
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* contain far/offset copies of
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* each other.
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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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} prev, geo;
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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 dev_sectors; /* temp copy of
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* mddev->dev_sectors */
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sector_t reshape_progress;
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sector_t reshape_safe;
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unsigned long reshape_checkpoint;
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sector_t offset_diff;
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struct list_head retry_list;
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/* A separate list of r1bio which just need raid_end_bio_io called.
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* This mustn't happen for writes which had any errors if the superblock
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* needs to be written.
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*/
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struct list_head bio_end_io_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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int pending_count;
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spinlock_t resync_lock;
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atomic_t 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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int array_freeze_pending;
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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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int have_replacement; /* There is at least one
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* replacement device.
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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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/* When taking over an array from a different personality, we store
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* the new thread here until we fully activate the array.
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*/
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struct md_thread *thread;
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};
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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 {
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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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struct mddev *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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* We sometimes need an extra bio to write to the replacement.
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*/
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struct r10dev {
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struct bio *bio;
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union {
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struct bio *repl_bio; /* used for resync and
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* writes */
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struct md_rdev *rdev; /* used for reads
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* (read_slot >= 0) */
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};
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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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/* bits for r10bio.state */
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enum r10bio_state {
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R10BIO_Uptodate,
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R10BIO_IsSync,
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R10BIO_IsRecover,
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R10BIO_IsReshape,
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R10BIO_Degraded,
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/* Set ReadError on bios that experience a read error
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* so that raid10d knows what to do with them.
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*/
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R10BIO_ReadError,
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/* If a write for this request means we can clear some
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* known-bad-block records, we set this flag.
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*/
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R10BIO_MadeGood,
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R10BIO_WriteError,
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/* During a reshape we might be performing IO on the
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* 'previous' part of the array, in which case this
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* flag is set
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*/
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R10BIO_Previous,
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/* failfast devices did receive failfast requests. */
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R10BIO_FailFast,
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};
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#endif
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