diff options
Diffstat (limited to 'drivers/md/raid1-10.c')
| -rw-r--r-- | drivers/md/raid1-10.c | 175 |
1 files changed, 175 insertions, 0 deletions
diff --git a/drivers/md/raid1-10.c b/drivers/md/raid1-10.c new file mode 100644 index 000000000..3f22edec7 --- /dev/null +++ b/drivers/md/raid1-10.c @@ -0,0 +1,175 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Maximum size of each resync request */ +#define RESYNC_BLOCK_SIZE (64*1024) +#define RESYNC_PAGES ((RESYNC_BLOCK_SIZE + PAGE_SIZE-1) / PAGE_SIZE) + +/* + * Number of guaranteed raid bios in case of extreme VM load: + */ +#define NR_RAID_BIOS 256 + +/* 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 devs[n].bio to IO_MADE_GOOD + */ +#define IO_MADE_GOOD ((struct bio *)2) + +#define BIO_SPECIAL(bio) ((unsigned long)bio <= 2) +#define MAX_PLUG_BIO 32 + +/* for managing resync I/O pages */ +struct resync_pages { + void *raid_bio; + struct page *pages[RESYNC_PAGES]; +}; + +struct raid1_plug_cb { + struct blk_plug_cb cb; + struct bio_list pending; + unsigned int count; +}; + +static void rbio_pool_free(void *rbio, void *data) +{ + kfree(rbio); +} + +static inline int resync_alloc_pages(struct resync_pages *rp, + gfp_t gfp_flags) +{ + int i; + + for (i = 0; i < RESYNC_PAGES; i++) { + rp->pages[i] = alloc_page(gfp_flags); + if (!rp->pages[i]) + goto out_free; + } + + return 0; + +out_free: + while (--i >= 0) + put_page(rp->pages[i]); + return -ENOMEM; +} + +static inline void resync_free_pages(struct resync_pages *rp) +{ + int i; + + for (i = 0; i < RESYNC_PAGES; i++) + put_page(rp->pages[i]); +} + +static inline void resync_get_all_pages(struct resync_pages *rp) +{ + int i; + + for (i = 0; i < RESYNC_PAGES; i++) + get_page(rp->pages[i]); +} + +static inline struct page *resync_fetch_page(struct resync_pages *rp, + unsigned idx) +{ + if (WARN_ON_ONCE(idx >= RESYNC_PAGES)) + return NULL; + return rp->pages[idx]; +} + +/* + * 'strct resync_pages' stores actual pages used for doing the resync + * IO, and it is per-bio, so make .bi_private points to it. + */ +static inline struct resync_pages *get_resync_pages(struct bio *bio) +{ + return bio->bi_private; +} + +/* generally called after bio_reset() for reseting bvec */ +static void md_bio_reset_resync_pages(struct bio *bio, struct resync_pages *rp, + int size) +{ + int idx = 0; + + /* initialize bvec table again */ + do { + struct page *page = resync_fetch_page(rp, idx); + int len = min_t(int, size, PAGE_SIZE); + + if (WARN_ON(!bio_add_page(bio, page, len, 0))) { + bio->bi_status = BLK_STS_RESOURCE; + bio_endio(bio); + return; + } + + size -= len; + } while (idx++ < RESYNC_PAGES && size > 0); +} + + +static inline void raid1_submit_write(struct bio *bio) +{ + struct md_rdev *rdev = (void *)bio->bi_bdev; + + bio->bi_next = NULL; + bio_set_dev(bio, rdev->bdev); + if (test_bit(Faulty, &rdev->flags)) + bio_io_error(bio); + else if (unlikely(bio_op(bio) == REQ_OP_DISCARD && + !bdev_max_discard_sectors(bio->bi_bdev))) + /* Just ignore it */ + bio_endio(bio); + else + submit_bio_noacct(bio); +} + +static inline bool raid1_add_bio_to_plug(struct mddev *mddev, struct bio *bio, + blk_plug_cb_fn unplug, int copies) +{ + struct raid1_plug_cb *plug = NULL; + struct blk_plug_cb *cb; + + /* + * If bitmap is not enabled, it's safe to submit the io directly, and + * this can get optimal performance. + */ + if (!md_bitmap_enabled(mddev->bitmap)) { + raid1_submit_write(bio); + return true; + } + + cb = blk_check_plugged(unplug, mddev, sizeof(*plug)); + if (!cb) + return false; + + plug = container_of(cb, struct raid1_plug_cb, cb); + bio_list_add(&plug->pending, bio); + if (++plug->count / MAX_PLUG_BIO >= copies) { + list_del(&cb->list); + cb->callback(cb, false); + } + + + return true; +} + +/* + * current->bio_list will be set under submit_bio() context, in this case bitmap + * io will be added to the list and wait for current io submission to finish, + * while current io submission must wait for bitmap io to be done. In order to + * avoid such deadlock, submit bitmap io asynchronously. + */ +static inline void raid1_prepare_flush_writes(struct bitmap *bitmap) +{ + if (current->bio_list) + md_bitmap_unplug_async(bitmap); + else + md_bitmap_unplug(bitmap); +} |