diff options
| -rw-r--r-- | drivers/md/bitmap.c | 26 | ||||
| -rw-r--r-- | drivers/md/raid1.c | 124 | ||||
| -rw-r--r-- | include/linux/raid/bitmap.h | 15 | ||||
| -rw-r--r-- | include/linux/raid/md_k.h | 3 | ||||
| -rw-r--r-- | include/linux/raid/raid1.h | 13 |
5 files changed, 165 insertions, 16 deletions
diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c index 2925219f088..2c84de2b4ad 100644 --- a/drivers/md/bitmap.c +++ b/drivers/md/bitmap.c @@ -437,6 +437,7 @@ void bitmap_print_sb(struct bitmap *bitmap) printk(KERN_DEBUG " daemon sleep: %ds\n", le32_to_cpu(sb->daemon_sleep)); printk(KERN_DEBUG " sync size: %llu KB\n", (unsigned long long)le64_to_cpu(sb->sync_size)/2); + printk(KERN_DEBUG "max write behind: %d\n", le32_to_cpu(sb->write_behind)); kunmap(bitmap->sb_page); } @@ -445,7 +446,7 @@ static int bitmap_read_sb(struct bitmap *bitmap) { char *reason = NULL; bitmap_super_t *sb; - unsigned long chunksize, daemon_sleep; + unsigned long chunksize, daemon_sleep, write_behind; unsigned long bytes_read; unsigned long long events; int err = -EINVAL; @@ -474,6 +475,7 @@ static int bitmap_read_sb(struct bitmap *bitmap) chunksize = le32_to_cpu(sb->chunksize); daemon_sleep = le32_to_cpu(sb->daemon_sleep); + write_behind = le32_to_cpu(sb->write_behind); /* verify that the bitmap-specific fields are valid */ if (sb->magic != cpu_to_le32(BITMAP_MAGIC)) @@ -485,7 +487,9 @@ static int bitmap_read_sb(struct bitmap *bitmap) else if ((1 << ffz(~chunksize)) != chunksize) reason = "bitmap chunksize not a power of 2"; else if (daemon_sleep < 1 || daemon_sleep > 15) - reason = "daemon sleep period out of range"; + reason = "daemon sleep period out of range (1-15s)"; + else if (write_behind > COUNTER_MAX) + reason = "write-behind limit out of range (0 - 16383)"; if (reason) { printk(KERN_INFO "%s: invalid bitmap file superblock: %s\n", bmname(bitmap), reason); @@ -518,6 +522,7 @@ success: /* assign fields using values from superblock */ bitmap->chunksize = chunksize; bitmap->daemon_sleep = daemon_sleep; + bitmap->max_write_behind = write_behind; bitmap->flags |= sb->state; bitmap->events_cleared = le64_to_cpu(sb->events_cleared); if (sb->state & BITMAP_STALE) @@ -1282,9 +1287,16 @@ static bitmap_counter_t *bitmap_get_counter(struct bitmap *bitmap, } } -int bitmap_startwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors) +int bitmap_startwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors, int behind) { if (!bitmap) return 0; + + if (behind) { + atomic_inc(&bitmap->behind_writes); + PRINTK(KERN_DEBUG "inc write-behind count %d/%d\n", + atomic_read(&bitmap->behind_writes), bitmap->max_write_behind); + } + while (sectors) { int blocks; bitmap_counter_t *bmc; @@ -1319,9 +1331,15 @@ int bitmap_startwrite(struct bitmap *bitmap, sector_t offset, unsigned long sect } void bitmap_endwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors, - int success) + int success, int behind) { if (!bitmap) return; + if (behind) { + atomic_dec(&bitmap->behind_writes); + PRINTK(KERN_DEBUG "dec write-behind count %d/%d\n", + atomic_read(&bitmap->behind_writes), bitmap->max_write_behind); + } + while (sectors) { int blocks; unsigned long flags; diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c index 28839a8193f..ba7f5f25616 100644 --- a/drivers/md/raid1.c +++ b/drivers/md/raid1.c @@ -222,8 +222,17 @@ static void raid_end_bio_io(r1bio_t *r1_bio) { struct bio *bio = r1_bio->master_bio; - bio_endio(bio, bio->bi_size, - test_bit(R1BIO_Uptodate, &r1_bio->state) ? 0 : -EIO); + /* if nobody has done the final endio yet, do it now */ + if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) { + PRINTK(KERN_DEBUG "raid1: sync end %s on sectors %llu-%llu\n", + (bio_data_dir(bio) == WRITE) ? "write" : "read", + (unsigned long long) bio->bi_sector, + (unsigned long long) bio->bi_sector + + (bio->bi_size >> 9) - 1); + + bio_endio(bio, bio->bi_size, + test_bit(R1BIO_Uptodate, &r1_bio->state) ? 0 : -EIO); + } free_r1bio(r1_bio); } @@ -292,7 +301,7 @@ static int raid1_end_write_request(struct bio *bio, unsigned int bytes_done, int { int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); r1bio_t * r1_bio = (r1bio_t *)(bio->bi_private); - int mirror; + int mirror, behind; conf_t *conf = mddev_to_conf(r1_bio->mddev); if (bio->bi_size) @@ -323,16 +332,46 @@ static int raid1_end_write_request(struct bio *bio, unsigned int bytes_done, int update_head_pos(mirror, r1_bio); + behind = test_bit(R1BIO_BehindIO, &r1_bio->state); + if (behind) { + if (test_bit(WriteMostly, &conf->mirrors[mirror].rdev->flags)) + atomic_dec(&r1_bio->behind_remaining); + + /* In behind mode, we ACK the master bio once the I/O has safely + * reached all non-writemostly disks. Setting the Returned bit + * ensures that this gets done only once -- we don't ever want to + * return -EIO here, instead we'll wait */ + + if (atomic_read(&r1_bio->behind_remaining) >= (atomic_read(&r1_bio->remaining)-1) && + test_bit(R1BIO_Uptodate, &r1_bio->state)) { + /* Maybe we can return now */ + if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) { + struct bio *mbio = r1_bio->master_bio; + PRINTK(KERN_DEBUG "raid1: behind end write sectors %llu-%llu\n", + (unsigned long long) mbio->bi_sector, + (unsigned long long) mbio->bi_sector + + (mbio->bi_size >> 9) - 1); + bio_endio(mbio, mbio->bi_size, 0); + } + } + } /* * * Let's see if all mirrored write operations have finished * already. */ if (atomic_dec_and_test(&r1_bio->remaining)) { + if (test_bit(R1BIO_BehindIO, &r1_bio->state)) { + /* free extra copy of the data pages */ + int i = bio->bi_vcnt; + while (i--) + __free_page(bio->bi_io_vec[i].bv_page); + } /* clear the bitmap if all writes complete successfully */ bitmap_endwrite(r1_bio->mddev->bitmap, r1_bio->sector, r1_bio->sectors, - !test_bit(R1BIO_Degraded, &r1_bio->state)); + !test_bit(R1BIO_Degraded, &r1_bio->state), + behind); md_write_end(r1_bio->mddev); raid_end_bio_io(r1_bio); } @@ -562,6 +601,39 @@ static void device_barrier(conf_t *conf, sector_t sect) spin_unlock_irq(&conf->resync_lock); } +/* duplicate the data pages for behind I/O */ +static struct page **alloc_behind_pages(struct bio *bio) +{ + int i; + struct bio_vec *bvec; + struct page **pages = kmalloc(bio->bi_vcnt * sizeof(struct page *), + GFP_NOIO); + if (unlikely(!pages)) + goto do_sync_io; + + memset(pages, 0, bio->bi_vcnt * sizeof(struct page *)); + + bio_for_each_segment(bvec, bio, i) { + pages[i] = alloc_page(GFP_NOIO); + if (unlikely(!pages[i])) + goto do_sync_io; + memcpy(kmap(pages[i]) + bvec->bv_offset, + kmap(bvec->bv_page) + bvec->bv_offset, bvec->bv_len); + kunmap(pages[i]); + kunmap(bvec->bv_page); + } + + return pages; + +do_sync_io: + if (pages) + for (i = 0; i < bio->bi_vcnt && pages[i]; i++) + __free_page(pages[i]); + kfree(pages); + PRINTK("%dB behind alloc failed, doing sync I/O\n", bio->bi_size); + return NULL; +} + static int make_request(request_queue_t *q, struct bio * bio) { mddev_t *mddev = q->queuedata; @@ -574,6 +646,7 @@ static int make_request(request_queue_t *q, struct bio * bio) struct bitmap *bitmap = mddev->bitmap; unsigned long flags; struct bio_list bl; + struct page **behind_pages = NULL; if (unlikely(bio_barrier(bio))) { bio_endio(bio, bio->bi_size, -EOPNOTSUPP); @@ -613,8 +686,6 @@ static int make_request(request_queue_t *q, struct bio * bio) r1_bio->mddev = mddev; r1_bio->sector = bio->bi_sector; - r1_bio->state = 0; - if (bio_data_dir(bio) == READ) { /* * read balancing logic: @@ -675,13 +746,22 @@ static int make_request(request_queue_t *q, struct bio * bio) } rcu_read_unlock(); + BUG_ON(targets == 0); /* we never fail the last device */ + if (targets < conf->raid_disks) { /* array is degraded, we will not clear the bitmap * on I/O completion (see raid1_end_write_request) */ set_bit(R1BIO_Degraded, &r1_bio->state); } + /* do behind I/O ? */ + if (bitmap && + atomic_read(&bitmap->behind_writes) < bitmap->max_write_behind && + (behind_pages = alloc_behind_pages(bio)) != NULL) + set_bit(R1BIO_BehindIO, &r1_bio->state); + atomic_set(&r1_bio->remaining, 0); + atomic_set(&r1_bio->behind_remaining, 0); bio_list_init(&bl); for (i = 0; i < disks; i++) { @@ -698,12 +778,31 @@ static int make_request(request_queue_t *q, struct bio * bio) mbio->bi_rw = WRITE; mbio->bi_private = r1_bio; + if (behind_pages) { + struct bio_vec *bvec; + int j; + + /* Yes, I really want the '__' version so that + * we clear any unused pointer in the io_vec, rather + * than leave them unchanged. This is important + * because when we come to free the pages, we won't + * know the originial bi_idx, so we just free + * them all + */ + __bio_for_each_segment(bvec, mbio, j, 0) + bvec->bv_page = behind_pages[j]; + if (test_bit(WriteMostly, &conf->mirrors[i].rdev->flags)) + atomic_inc(&r1_bio->behind_remaining); + } + atomic_inc(&r1_bio->remaining); bio_list_add(&bl, mbio); } + kfree(behind_pages); /* the behind pages are attached to the bios now */ - bitmap_startwrite(bitmap, bio->bi_sector, r1_bio->sectors); + bitmap_startwrite(bitmap, bio->bi_sector, r1_bio->sectors, + test_bit(R1BIO_BehindIO, &r1_bio->state)); spin_lock_irqsave(&conf->device_lock, flags); bio_list_merge(&conf->pending_bio_list, &bl); bio_list_init(&bl); @@ -1471,6 +1570,17 @@ out: static int stop(mddev_t *mddev) { conf_t *conf = mddev_to_conf(mddev); + struct bitmap *bitmap = mddev->bitmap; + int behind_wait = 0; + + /* wait for behind writes to complete */ + while (bitmap && atomic_read(&bitmap->behind_writes) > 0) { + behind_wait++; + printk(KERN_INFO "raid1: behind writes in progress on device %s, waiting to stop (%d)\n", mdname(mddev), behind_wait); + set_current_state(TASK_UNINTERRUPTIBLE); + schedule_timeout(HZ); /* wait a second */ + /* need to kick something here to make sure I/O goes? */ + } md_unregister_thread(mddev->thread); mddev->thread = NULL; diff --git a/include/linux/raid/bitmap.h b/include/linux/raid/bitmap.h index 4bf1659f8aa..9de99198caf 100644 --- a/include/linux/raid/bitmap.h +++ b/include/linux/raid/bitmap.h @@ -7,7 +7,7 @@ #define BITMAP_H 1 #define BITMAP_MAJOR 3 -#define BITMAP_MINOR 38 +#define BITMAP_MINOR 39 /* * in-memory bitmap: @@ -147,8 +147,9 @@ typedef struct bitmap_super_s { __u32 state; /* 48 bitmap state information */ __u32 chunksize; /* 52 the bitmap chunk size in bytes */ __u32 daemon_sleep; /* 56 seconds between disk flushes */ + __u32 write_behind; /* 60 number of outstanding write-behind writes */ - __u8 pad[256 - 60]; /* set to zero */ + __u8 pad[256 - 64]; /* set to zero */ } bitmap_super_t; /* notes: @@ -226,6 +227,9 @@ struct bitmap { unsigned long flags; + unsigned long max_write_behind; /* write-behind mode */ + atomic_t behind_writes; + /* * the bitmap daemon - periodically wakes up and sweeps the bitmap * file, cleaning up bits and flushing out pages to disk as necessary @@ -260,9 +264,10 @@ int bitmap_setallbits(struct bitmap *bitmap); void bitmap_write_all(struct bitmap *bitmap); /* these are exported */ -int bitmap_startwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors); -void bitmap_endwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors, - int success); +int bitmap_startwrite(struct bitmap *bitmap, sector_t offset, + unsigned long sectors, int behind); +void bitmap_endwrite(struct bitmap *bitmap, sector_t offset, + unsigned long sectors, int success, int behind); int bitmap_start_sync(struct bitmap *bitmap, sector_t offset, int *blocks, int degraded); void bitmap_end_sync(struct bitmap *bitmap, sector_t offset, int *blocks, int aborted); void bitmap_close_sync(struct bitmap *bitmap); diff --git a/include/linux/raid/md_k.h b/include/linux/raid/md_k.h index 7ef78e15ce0..2514e5fcda7 100644 --- a/include/linux/raid/md_k.h +++ b/include/linux/raid/md_k.h @@ -275,6 +275,9 @@ struct mddev_s atomic_t writes_pending; request_queue_t *queue; /* for plugging ... */ + atomic_t write_behind; /* outstanding async IO */ + unsigned int max_write_behind; /* 0 = sync */ + struct bitmap *bitmap; /* the bitmap for the device */ struct file *bitmap_file; /* the bitmap file */ long bitmap_offset; /* offset from superblock of diff --git a/include/linux/raid/raid1.h b/include/linux/raid/raid1.h index 9d93cf12e89..60e19b66754 100644 --- a/include/linux/raid/raid1.h +++ b/include/linux/raid/raid1.h @@ -80,6 +80,9 @@ struct r1bio_s { 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; @@ -107,4 +110,14 @@ struct r1bio_s { #define R1BIO_Uptodate 0 #define R1BIO_IsSync 1 #define R1BIO_Degraded 2 +#define R1BIO_BehindIO 3 +/* 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 4 + #endif |