--- /dev/null
+/*
+ * raid1.c : Multiple Devices driver for Linux
+ *
+ * Copyright (C) 1999, 2000, 2001 Ingo Molnar, Red Hat
+ *
+ * Copyright (C) 1996, 1997, 1998 Ingo Molnar, Miguel de Icaza, Gadi Oxman
+ *
+ * RAID-1 management functions.
+ *
+ * Better read-balancing code written by Mika Kuoppala <miku@iki.fi>, 2000
+ *
+ * Fixes to reconstruction by Jakob Østergaard" <jakob@ostenfeld.dk>
+ * Various fixes by Neil Brown <neilb@cse.unsw.edu.au>
+ *
+ * Changes by Peter T. Breuer <ptb@it.uc3m.es> 31/1/2003 to support
+ * bitmapped intelligence in resync:
+ *
+ * - bitmap marked during normal i/o
+ * - bitmap used to skip nondirty blocks during sync
+ *
+ * Additions to bitmap code, (C) 2003-2004 Paul Clements, SteelEye Technology:
+ * - persistent bitmap code
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * You should have received a copy of the GNU General Public License
+ * (for example /usr/src/linux/COPYING); if not, write to the Free
+ * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/blkdev.h>
+#include <linux/seq_file.h>
+#include "md.h"
+#include "raid1.h"
+#include "bitmap.h"
+
+#define DEBUG 0
+#if DEBUG
+#define PRINTK(x...) printk(x)
+#else
+#define PRINTK(x...)
+#endif
+
+/*
+ * Number of guaranteed r1bios in case of extreme VM load:
+ */
+#define NR_RAID1_BIOS 256
+
+
+static void allow_barrier(conf_t *conf);
+static void lower_barrier(conf_t *conf);
+
+static void * r1bio_pool_alloc(gfp_t gfp_flags, void *data)
+{
+ struct pool_info *pi = data;
+ int size = offsetof(r1bio_t, bios[pi->raid_disks]);
+
+ /* allocate a r1bio with room for raid_disks entries in the bios array */
+ return kzalloc(size, gfp_flags);
+}
+
+static void r1bio_pool_free(void *r1_bio, void *data)
+{
+ kfree(r1_bio);
+}
+
+#define RESYNC_BLOCK_SIZE (64*1024)
+//#define RESYNC_BLOCK_SIZE PAGE_SIZE
+#define RESYNC_SECTORS (RESYNC_BLOCK_SIZE >> 9)
+#define RESYNC_PAGES ((RESYNC_BLOCK_SIZE + PAGE_SIZE-1) / PAGE_SIZE)
+#define RESYNC_WINDOW (2048*1024)
+
+static void * r1buf_pool_alloc(gfp_t gfp_flags, void *data)
+{
+ struct pool_info *pi = data;
+ struct page *page;
+ r1bio_t *r1_bio;
+ struct bio *bio;
+ int i, j;
+
+ r1_bio = r1bio_pool_alloc(gfp_flags, pi);
+ if (!r1_bio)
+ return NULL;
+
+ /*
+ * Allocate bios : 1 for reading, n-1 for writing
+ */
+ for (j = pi->raid_disks ; j-- ; ) {
+ bio = bio_kmalloc(gfp_flags, RESYNC_PAGES);
+ if (!bio)
+ goto out_free_bio;
+ r1_bio->bios[j] = bio;
+ }
+ /*
+ * Allocate RESYNC_PAGES data pages and attach them to
+ * the first bio.
+ * If this is a user-requested check/repair, allocate
+ * RESYNC_PAGES for each bio.
+ */
+ if (test_bit(MD_RECOVERY_REQUESTED, &pi->mddev->recovery))
+ j = pi->raid_disks;
+ else
+ j = 1;
+ while(j--) {
+ bio = r1_bio->bios[j];
+ for (i = 0; i < RESYNC_PAGES; i++) {
+ page = alloc_page(gfp_flags);
+ if (unlikely(!page))
+ goto out_free_pages;
+
+ bio->bi_io_vec[i].bv_page = page;
+ bio->bi_vcnt = i+1;
+ }
+ }
+ /* If not user-requests, copy the page pointers to all bios */
+ if (!test_bit(MD_RECOVERY_REQUESTED, &pi->mddev->recovery)) {
+ for (i=0; i<RESYNC_PAGES ; i++)
+ for (j=1; j<pi->raid_disks; j++)
+ r1_bio->bios[j]->bi_io_vec[i].bv_page =
+ r1_bio->bios[0]->bi_io_vec[i].bv_page;
+ }
+
+ r1_bio->master_bio = NULL;
+
+ return r1_bio;
+
+out_free_pages:
+ for (j=0 ; j < pi->raid_disks; j++)
+ for (i=0; i < r1_bio->bios[j]->bi_vcnt ; i++)
+ put_page(r1_bio->bios[j]->bi_io_vec[i].bv_page);
+ j = -1;
+out_free_bio:
+ while ( ++j < pi->raid_disks )
+ bio_put(r1_bio->bios[j]);
+ r1bio_pool_free(r1_bio, data);
+ return NULL;
+}
+
+static void r1buf_pool_free(void *__r1_bio, void *data)
+{
+ struct pool_info *pi = data;
+ int i,j;
+ r1bio_t *r1bio = __r1_bio;
+
+ for (i = 0; i < RESYNC_PAGES; i++)
+ for (j = pi->raid_disks; j-- ;) {
+ if (j == 0 ||
+ r1bio->bios[j]->bi_io_vec[i].bv_page !=
+ r1bio->bios[0]->bi_io_vec[i].bv_page)
+ safe_put_page(r1bio->bios[j]->bi_io_vec[i].bv_page);
+ }
+ for (i=0 ; i < pi->raid_disks; i++)
+ bio_put(r1bio->bios[i]);
+
+ r1bio_pool_free(r1bio, data);
+}
+
+static void put_all_bios(conf_t *conf, r1bio_t *r1_bio)
+{
+ int i;
+
+ for (i = 0; i < conf->raid_disks; i++) {
+ struct bio **bio = r1_bio->bios + i;
+ if (*bio && *bio != IO_BLOCKED)
+ bio_put(*bio);
+ *bio = NULL;
+ }
+}
+
+static void free_r1bio(r1bio_t *r1_bio)
+{
+ conf_t *conf = r1_bio->mddev->private;
+
+ /*
+ * Wake up any possible resync thread that waits for the device
+ * to go idle.
+ */
+ allow_barrier(conf);
+
+ put_all_bios(conf, r1_bio);
+ mempool_free(r1_bio, conf->r1bio_pool);
+}
+
+static void put_buf(r1bio_t *r1_bio)
+{
+ conf_t *conf = r1_bio->mddev->private;
+ int i;
+
+ for (i=0; i<conf->raid_disks; i++) {
+ struct bio *bio = r1_bio->bios[i];
+ if (bio->bi_end_io)
+ rdev_dec_pending(conf->mirrors[i].rdev, r1_bio->mddev);
+ }
+
+ mempool_free(r1_bio, conf->r1buf_pool);
+
+ lower_barrier(conf);
+}
+
+static void reschedule_retry(r1bio_t *r1_bio)
+{
+ unsigned long flags;
+ mddev_t *mddev = r1_bio->mddev;
+ conf_t *conf = mddev->private;
+
+ spin_lock_irqsave(&conf->device_lock, flags);
+ list_add(&r1_bio->retry_list, &conf->retry_list);
+ conf->nr_queued ++;
+ spin_unlock_irqrestore(&conf->device_lock, flags);
+
+ wake_up(&conf->wait_barrier);
+ md_wakeup_thread(mddev->thread);
+}
+
+/*
+ * raid_end_bio_io() is called when we have finished servicing a mirrored
+ * operation and are ready to return a success/failure code to the buffer
+ * cache layer.
+ */
+static void raid_end_bio_io(r1bio_t *r1_bio)
+{
+ struct bio *bio = r1_bio->master_bio;
+
+ /* 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,
+ test_bit(R1BIO_Uptodate, &r1_bio->state) ? 0 : -EIO);
+ }
+ free_r1bio(r1_bio);
+}
+
+/*
+ * Update disk head position estimator based on IRQ completion info.
+ */
+static inline void update_head_pos(int disk, r1bio_t *r1_bio)
+{
+ conf_t *conf = r1_bio->mddev->private;
+
+ conf->mirrors[disk].head_position =
+ r1_bio->sector + (r1_bio->sectors);
+}
+
+static void raid1_end_read_request(struct bio *bio, int error)
+{
+ int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
+ r1bio_t *r1_bio = bio->bi_private;
+ int mirror;
+ conf_t *conf = r1_bio->mddev->private;
+
+ mirror = r1_bio->read_disk;
+ /*
+ * this branch is our 'one mirror IO has finished' event handler:
+ */
+ update_head_pos(mirror, r1_bio);
+
+ if (uptodate)
+ set_bit(R1BIO_Uptodate, &r1_bio->state);
+ else {
+ /* If all other devices have failed, we want to return
+ * the error upwards rather than fail the last device.
+ * Here we redefine "uptodate" to mean "Don't want to retry"
+ */
+ unsigned long flags;
+ spin_lock_irqsave(&conf->device_lock, flags);
+ if (r1_bio->mddev->degraded == conf->raid_disks ||
+ (r1_bio->mddev->degraded == conf->raid_disks-1 &&
+ !test_bit(Faulty, &conf->mirrors[mirror].rdev->flags)))
+ uptodate = 1;
+ spin_unlock_irqrestore(&conf->device_lock, flags);
+ }
+
+ if (uptodate)
+ raid_end_bio_io(r1_bio);
+ else {
+ /*
+ * oops, read error:
+ */
+ char b[BDEVNAME_SIZE];
+ if (printk_ratelimit())
+ printk(KERN_ERR "md/raid1:%s: %s: rescheduling sector %llu\n",
+ mdname(conf->mddev),
+ bdevname(conf->mirrors[mirror].rdev->bdev,b), (unsigned long long)r1_bio->sector);
+ reschedule_retry(r1_bio);
+ }
+
+ rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev);
+}
+
+static void r1_bio_write_done(r1bio_t *r1_bio)
+{
+ if (atomic_dec_and_test(&r1_bio->remaining))
+ {
+ /* it really is the end of this request */
+ if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
+ /* free extra copy of the data pages */
+ int i = r1_bio->behind_page_count;
+ while (i--)
+ safe_put_page(r1_bio->behind_pages[i]);
+ kfree(r1_bio->behind_pages);
+ r1_bio->behind_pages = NULL;
+ }
+ /* 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_BehindIO, &r1_bio->state));
+ md_write_end(r1_bio->mddev);
+ raid_end_bio_io(r1_bio);
+ }
+}
+
+static void raid1_end_write_request(struct bio *bio, int error)
+{
+ int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
+ r1bio_t *r1_bio = bio->bi_private;
+ int mirror, behind = test_bit(R1BIO_BehindIO, &r1_bio->state);
+ conf_t *conf = r1_bio->mddev->private;
+ struct bio *to_put = NULL;
+
+
+ for (mirror = 0; mirror < conf->raid_disks; mirror++)
+ if (r1_bio->bios[mirror] == bio)
+ break;
+
+ /*
+ * 'one mirror IO has finished' event handler:
+ */
+ r1_bio->bios[mirror] = NULL;
+ to_put = bio;
+ if (!uptodate) {
+ md_error(r1_bio->mddev, conf->mirrors[mirror].rdev);
+ /* an I/O failed, we can't clear the bitmap */
+ set_bit(R1BIO_Degraded, &r1_bio->state);
+ } else
+ /*
+ * Set R1BIO_Uptodate in our master bio, so that we
+ * will return a good error code for to the higher
+ * levels even if IO on some other mirrored buffer
+ * fails.
+ *
+ * The 'master' represents the composite IO operation
+ * to user-side. So if something waits for IO, then it
+ * will wait for the 'master' bio.
+ */
+ set_bit(R1BIO_Uptodate, &r1_bio->state);
+
+ update_head_pos(mirror, r1_bio);
+
+ 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, 0);
+ }
+ }
+ }
+ rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev);
+
+ /*
+ * Let's see if all mirrored write operations have finished
+ * already.
+ */
+ r1_bio_write_done(r1_bio);
+
+ if (to_put)
+ bio_put(to_put);
+}
+
+
+/*
+ * This routine returns the disk from which the requested read should
+ * be done. There is a per-array 'next expected sequential IO' sector
+ * number - if this matches on the next IO then we use the last disk.
+ * There is also a per-disk 'last know head position' sector that is
+ * maintained from IRQ contexts, both the normal and the resync IO
+ * completion handlers update this position correctly. If there is no
+ * perfect sequential match then we pick the disk whose head is closest.
+ *
+ * If there are 2 mirrors in the same 2 devices, performance degrades
+ * because position is mirror, not device based.
+ *
+ * The rdev for the device selected will have nr_pending incremented.
+ */
+static int read_balance(conf_t *conf, r1bio_t *r1_bio)
+{
+ const sector_t this_sector = r1_bio->sector;
+ const int sectors = r1_bio->sectors;
+ int start_disk;
+ int best_disk;
+ int i;
+ sector_t best_dist;
+ mdk_rdev_t *rdev;
+ int choose_first;
+
+ rcu_read_lock();
+ /*
+ * Check if we can balance. We can balance on the whole
+ * device if no resync is going on, or below the resync window.
+ * We take the first readable disk when above the resync window.
+ */
+ retry:
+ best_disk = -1;
+ best_dist = MaxSector;
+ if (conf->mddev->recovery_cp < MaxSector &&
+ (this_sector + sectors >= conf->next_resync)) {
+ choose_first = 1;
+ start_disk = 0;
+ } else {
+ choose_first = 0;
+ start_disk = conf->last_used;
+ }
+
+ for (i = 0 ; i < conf->raid_disks ; i++) {
+ sector_t dist;
+ int disk = start_disk + i;
+ if (disk >= conf->raid_disks)
+ disk -= conf->raid_disks;
+
+ rdev = rcu_dereference(conf->mirrors[disk].rdev);
+ if (r1_bio->bios[disk] == IO_BLOCKED
+ || rdev == NULL
+ || test_bit(Faulty, &rdev->flags))
+ continue;
+ if (!test_bit(In_sync, &rdev->flags) &&
+ rdev->recovery_offset < this_sector + sectors)
+ continue;
+ if (test_bit(WriteMostly, &rdev->flags)) {
+ /* Don't balance among write-mostly, just
+ * use the first as a last resort */
+ if (best_disk < 0)
+ best_disk = disk;
+ continue;
+ }
+ /* This is a reasonable device to use. It might
+ * even be best.
+ */
+ dist = abs(this_sector - conf->mirrors[disk].head_position);
+ if (choose_first
+ /* Don't change to another disk for sequential reads */
+ || conf->next_seq_sect == this_sector
+ || dist == 0
+ /* If device is idle, use it */
+ || atomic_read(&rdev->nr_pending) == 0) {
+ best_disk = disk;
+ break;
+ }
+ if (dist < best_dist) {
+ best_dist = dist;
+ best_disk = disk;
+ }
+ }
+
+ if (best_disk >= 0) {
+ rdev = rcu_dereference(conf->mirrors[best_disk].rdev);
+ if (!rdev)
+ goto retry;
+ atomic_inc(&rdev->nr_pending);
+ if (test_bit(Faulty, &rdev->flags)) {
+ /* cannot risk returning a device that failed
+ * before we inc'ed nr_pending
+ */
+ rdev_dec_pending(rdev, conf->mddev);
+ goto retry;
+ }
+ conf->next_seq_sect = this_sector + sectors;
+ conf->last_used = best_disk;
+ }
+ rcu_read_unlock();
+
+ return best_disk;
+}
+
+int md_raid1_congested(mddev_t *mddev, int bits)
+{
+ conf_t *conf = mddev->private;
+ int i, ret = 0;
+
+ rcu_read_lock();
+ for (i = 0; i < mddev->raid_disks; i++) {
+ mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
+ if (rdev && !test_bit(Faulty, &rdev->flags)) {
+ struct request_queue *q = bdev_get_queue(rdev->bdev);
+
+ BUG_ON(!q);
+
+ /* Note the '|| 1' - when read_balance prefers
+ * non-congested targets, it can be removed
+ */
+ if ((bits & (1<<BDI_async_congested)) || 1)
+ ret |= bdi_congested(&q->backing_dev_info, bits);
+ else
+ ret &= bdi_congested(&q->backing_dev_info, bits);
+ }
+ }
+ rcu_read_unlock();
+ return ret;
+}
+EXPORT_SYMBOL_GPL(md_raid1_congested);
+
+static int max_queued = INT_MAX;
+static int raid1_congested(void *data, int bits)
+{
+ mddev_t *mddev = data;
+
+ return mddev_congested(mddev, bits) ||
+ md_raid1_congested(mddev, bits);
+}
+
+static void flush_pending_writes(conf_t *conf)
+{
+ /* Any writes that have been queued but are awaiting
+ * bitmap updates get flushed here.
+ */
+ spin_lock_irq(&conf->device_lock);
+
+ if (conf->pending_bio_list.head) {
+ struct bio *bio;
+ bio = bio_list_get(&conf->pending_bio_list);
+ conf->pending_count = 0;
+ spin_unlock_irq(&conf->device_lock);
+ wake_up(&conf->wait_barrier);
+ /* flush any pending bitmap writes to
+ * disk before proceeding w/ I/O */
+ bitmap_unplug(conf->mddev->bitmap);
+
+ while (bio) { /* submit pending writes */
+ struct bio *next = bio->bi_next;
+ bio->bi_next = NULL;
+ generic_make_request(bio);
+ bio = next;
+ }
+ } else
+ spin_unlock_irq(&conf->device_lock);
+}
+
+/* Barriers....
+ * Sometimes we need to suspend IO while we do something else,
+ * either some resync/recovery, or reconfigure the array.
+ * To do this we raise a 'barrier'.
+ * The 'barrier' is a counter that can be raised multiple times
+ * to count how many activities are happening which preclude
+ * normal IO.
+ * We can only raise the barrier if there is no pending IO.
+ * i.e. if nr_pending == 0.
+ * We choose only to raise the barrier if no-one is waiting for the
+ * barrier to go down. This means that as soon as an IO request
+ * is ready, no other operations which require a barrier will start
+ * until the IO request has had a chance.
+ *
+ * So: regular IO calls 'wait_barrier'. When that returns there
+ * is no backgroup IO happening, It must arrange to call
+ * allow_barrier when it has finished its IO.
+ * backgroup IO calls must call raise_barrier. Once that returns
+ * there is no normal IO happeing. It must arrange to call
+ * lower_barrier when the particular background IO completes.
+ */
+#define RESYNC_DEPTH 32
+
+static void raise_barrier(conf_t *conf)
+{
+ spin_lock_irq(&conf->resync_lock);
+
+ /* Wait until no block IO is waiting */
+ wait_event_lock_irq(conf->wait_barrier, !conf->nr_waiting,
+ conf->resync_lock, );
+
+ /* block any new IO from starting */
+ conf->barrier++;
+
+ /* Now wait for all pending IO to complete */
+ wait_event_lock_irq(conf->wait_barrier,
+ !conf->nr_pending && conf->barrier < RESYNC_DEPTH,
+ conf->resync_lock, );
+
+ spin_unlock_irq(&conf->resync_lock);
+}
+
+static void lower_barrier(conf_t *conf)
+{
+ unsigned long flags;
+ BUG_ON(conf->barrier <= 0);
+ spin_lock_irqsave(&conf->resync_lock, flags);
+ conf->barrier--;
+ spin_unlock_irqrestore(&conf->resync_lock, flags);
+ wake_up(&conf->wait_barrier);
+}
+
+static void wait_barrier(conf_t *conf)
+{
+ spin_lock_irq(&conf->resync_lock);
+ if (conf->barrier) {
+ conf->nr_waiting++;
+ wait_event_lock_irq(conf->wait_barrier, !conf->barrier,
+ conf->resync_lock,
+ );
+ conf->nr_waiting--;
+ }
+ conf->nr_pending++;
+ spin_unlock_irq(&conf->resync_lock);
+}
+
+static void allow_barrier(conf_t *conf)
+{
+ unsigned long flags;
+ spin_lock_irqsave(&conf->resync_lock, flags);
+ conf->nr_pending--;
+ spin_unlock_irqrestore(&conf->resync_lock, flags);
+ wake_up(&conf->wait_barrier);
+}
+
+static void freeze_array(conf_t *conf)
+{
+ /* stop syncio and normal IO and wait for everything to
+ * go quite.
+ * We increment barrier and nr_waiting, and then
+ * wait until nr_pending match nr_queued+1
+ * This is called in the context of one normal IO request
+ * that has failed. Thus any sync request that might be pending
+ * will be blocked by nr_pending, and we need to wait for
+ * pending IO requests to complete or be queued for re-try.
+ * Thus the number queued (nr_queued) plus this request (1)
+ * must match the number of pending IOs (nr_pending) before
+ * we continue.
+ */
+ spin_lock_irq(&conf->resync_lock);
+ conf->barrier++;
+ conf->nr_waiting++;
+ wait_event_lock_irq(conf->wait_barrier,
+ conf->nr_pending == conf->nr_queued+1,
+ conf->resync_lock,
+ flush_pending_writes(conf));
+ spin_unlock_irq(&conf->resync_lock);
+}
+static void unfreeze_array(conf_t *conf)
+{
+ /* reverse the effect of the freeze */
+ spin_lock_irq(&conf->resync_lock);
+ conf->barrier--;
+ conf->nr_waiting--;
+ wake_up(&conf->wait_barrier);
+ spin_unlock_irq(&conf->resync_lock);
+}
+
+
+/* duplicate the data pages for behind I/O
+ */
+static void alloc_behind_pages(struct bio *bio, r1bio_t *r1_bio)
+{
+ int i;
+ struct bio_vec *bvec;
+ struct page **pages = kzalloc(bio->bi_vcnt * sizeof(struct page*),
+ GFP_NOIO);
+ if (unlikely(!pages))
+ return;
+
+ 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);
+ }
+ r1_bio->behind_pages = pages;
+ r1_bio->behind_page_count = bio->bi_vcnt;
+ set_bit(R1BIO_BehindIO, &r1_bio->state);
+ return;
+
+do_sync_io:
+ for (i = 0; i < bio->bi_vcnt; i++)
+ if (pages[i])
+ put_page(pages[i]);
+ kfree(pages);
+ PRINTK("%dB behind alloc failed, doing sync I/O\n", bio->bi_size);
+}
+
+static int make_request(mddev_t *mddev, struct bio * bio)
+{
+ conf_t *conf = mddev->private;
+ mirror_info_t *mirror;
+ r1bio_t *r1_bio;
+ struct bio *read_bio;
+ int i, targets = 0, disks;
+ struct bitmap *bitmap;
+<<<<<<<
+ unsigned long flags;
+|||||||
+ unsigned long flags;
+ struct bio_list bl;
+ struct page **behind_pages = NULL;
+=======
+ unsigned long flags;
+ struct bio_list bl;
+ int bl_count;
+ struct page **behind_pages = NULL;
+>>>>>>>
+ const int rw = bio_data_dir(bio);
+ const unsigned long do_sync = (bio->bi_rw & REQ_SYNC);
+ const unsigned long do_flush_fua = (bio->bi_rw & (REQ_FLUSH | REQ_FUA));
+ mdk_rdev_t *blocked_rdev;
+ int plugged;
+
+ /*
+ * Register the new request and wait if the reconstruction
+ * thread has put up a bar for new requests.
+ * Continue immediately if no resync is active currently.
+ */
+
+ md_write_start(mddev, bio); /* wait on superblock update early */
+
+ if (bio_data_dir(bio) == WRITE &&
+ bio->bi_sector + bio->bi_size/512 > mddev->suspend_lo &&
+ bio->bi_sector < mddev->suspend_hi) {
+ /* As the suspend_* range is controlled by
+ * userspace, we want an interruptible
+ * wait.
+ */
+ DEFINE_WAIT(w);
+ for (;;) {
+ flush_signals(current);
+ prepare_to_wait(&conf->wait_barrier,
+ &w, TASK_INTERRUPTIBLE);
+ if (bio->bi_sector + bio->bi_size/512 <= mddev->suspend_lo ||
+ bio->bi_sector >= mddev->suspend_hi)
+ break;
+ schedule();
+ }
+ finish_wait(&conf->wait_barrier, &w);
+ }
+
+ wait_barrier(conf);
+
+ bitmap = mddev->bitmap;
+
+ /*
+ * make_request() can abort the operation when READA is being
+ * used and no empty request is available.
+ *
+ */
+ r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
+
+ r1_bio->master_bio = bio;
+ r1_bio->sectors = bio->bi_size >> 9;
+ r1_bio->state = 0;
+ r1_bio->mddev = mddev;
+ r1_bio->sector = bio->bi_sector;
+
+ if (rw == READ) {
+ /*
+ * read balancing logic:
+ */
+ int rdisk = read_balance(conf, r1_bio);
+
+ if (rdisk < 0) {
+ /* couldn't find anywhere to read from */
+ raid_end_bio_io(r1_bio);
+ return 0;
+ }
+ mirror = conf->mirrors + rdisk;
+
+ if (test_bit(WriteMostly, &mirror->rdev->flags) &&
+ bitmap) {
+ /* Reading from a write-mostly device must
+ * take care not to over-take any writes
+ * that are 'behind'
+ */
+ wait_event(bitmap->behind_wait,
+ atomic_read(&bitmap->behind_writes) == 0);
+ }
+ r1_bio->read_disk = rdisk;
+
+ read_bio = bio_clone_mddev(bio, GFP_NOIO, mddev);
+
+ r1_bio->bios[rdisk] = read_bio;
+
+ read_bio->bi_sector = r1_bio->sector + mirror->rdev->data_offset;
+ read_bio->bi_bdev = mirror->rdev->bdev;
+ read_bio->bi_end_io = raid1_end_read_request;
+ read_bio->bi_rw = READ | do_sync;
+ read_bio->bi_private = r1_bio;
+
+ generic_make_request(read_bio);
+ return 0;
+ }
+
+ /*
+ * WRITE:
+ */
+ if (conf->pending_count >= max_queued) {
+ md_wakeup_thread(mddev->thread);
+ wait_event(conf->wait_barrier,
+ conf->pending_count < max_queued);
+ }
+ /* first select target devices under spinlock and
+ * inc refcount on their rdev. Record them by setting
+ * bios[x] to bio
+ */
+ plugged = mddev_check_plugged(mddev);
+
+ disks = conf->raid_disks;
+ retry_write:
+ blocked_rdev = NULL;
+ rcu_read_lock();
+ for (i = 0; i < disks; i++) {
+ mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
+ if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
+ atomic_inc(&rdev->nr_pending);
+ blocked_rdev = rdev;
+ break;
+ }
+ if (rdev && !test_bit(Faulty, &rdev->flags)) {
+ atomic_inc(&rdev->nr_pending);
+ if (test_bit(Faulty, &rdev->flags)) {
+ rdev_dec_pending(rdev, mddev);
+ r1_bio->bios[i] = NULL;
+ } else {
+ r1_bio->bios[i] = bio;
+ targets++;
+ }
+ } else
+ r1_bio->bios[i] = NULL;
+ }
+ rcu_read_unlock();
+
+ if (unlikely(blocked_rdev)) {
+ /* Wait for this device to become unblocked */
+ int j;
+
+ for (j = 0; j < i; j++)
+ if (r1_bio->bios[j])
+ rdev_dec_pending(conf->mirrors[j].rdev, mddev);
+
+ allow_barrier(conf);
+ md_wait_for_blocked_rdev(blocked_rdev, mddev);
+ wait_barrier(conf);
+ goto retry_write;
+ }
+
+ 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 ?
+ * Not if there are too many, or cannot allocate memory,
+ * or a reader on WriteMostly is waiting for behind writes
+ * to flush */
+ if (bitmap &&
+ (atomic_read(&bitmap->behind_writes)
+ < mddev->bitmap_info.max_write_behind) &&
+ !waitqueue_active(&bitmap->behind_wait))
+ alloc_behind_pages(bio, r1_bio);
+
+ atomic_set(&r1_bio->remaining, 1);
+ atomic_set(&r1_bio->behind_remaining, 0);
+
+ bitmap_startwrite(bitmap, bio->bi_sector, r1_bio->sectors,
+ test_bit(R1BIO_BehindIO, &r1_bio->state));
+ bl_count = 0;
+ for (i = 0; i < disks; i++) {
+ struct bio *mbio;
+ if (!r1_bio->bios[i])
+ continue;
+
+ mbio = bio_clone_mddev(bio, GFP_NOIO, mddev);
+ r1_bio->bios[i] = mbio;
+
+ mbio->bi_sector = r1_bio->sector + conf->mirrors[i].rdev->data_offset;
+ mbio->bi_bdev = conf->mirrors[i].rdev->bdev;
+ mbio->bi_end_io = raid1_end_write_request;
+ mbio->bi_rw = WRITE | do_flush_fua | do_sync;
+ mbio->bi_private = r1_bio;
+
+ if (r1_bio->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 original bi_idx, so we just free
+ * them all
+ */
+ __bio_for_each_segment(bvec, mbio, j, 0)
+ bvec->bv_page = r1_bio->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 */
+
+=======
+ bio_list_add(&bl, mbio);
+ bl_count++;
+ }
+ kfree(behind_pages); /* the behind pages are attached to the bios now */
+
+>>>>>>>
+<<<<<<<
+ spin_lock_irqsave(&conf->device_lock, flags);
+ bio_list_add(&conf->pending_bio_list, mbio);
+ spin_unlock_irqrestore(&conf->device_lock, flags);
+ }
+|||||||
+ 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);
+
+=======
+ test_bit(R1BIO_BehindIO, &r1_bio->state));
+ spin_lock_irqsave(&conf->device_lock, flags);
+ bio_list_merge(&conf->pending_bio_list, &bl);
+ conf->pending_count += bl_count;
+ bio_list_init(&bl);
+
+>>>>>>>
+ r1_bio_write_done(r1_bio);
+
+ /* In case raid1d snuck in to freeze_array */
+ wake_up(&conf->wait_barrier);
+
+ if (do_sync || !bitmap || !plugged)
+ md_wakeup_thread(mddev->thread);
+
+ return 0;
+}
+
+static void status(struct seq_file *seq, mddev_t *mddev)
+{
+ conf_t *conf = mddev->private;
+ int i;
+
+ seq_printf(seq, " [%d/%d] [", conf->raid_disks,
+ conf->raid_disks - mddev->degraded);
+ rcu_read_lock();
+ for (i = 0; i < conf->raid_disks; i++) {
+ mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
+ seq_printf(seq, "%s",
+ rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_");
+ }
+ rcu_read_unlock();
+ seq_printf(seq, "]");
+}
+
+
+static void error(mddev_t *mddev, mdk_rdev_t *rdev)
+{
+ char b[BDEVNAME_SIZE];
+ conf_t *conf = mddev->private;
+
+ /*
+ * If it is not operational, then we have already marked it as dead
+ * else if it is the last working disks, ignore the error, let the
+ * next level up know.
+ * else mark the drive as failed
+ */
+ if (test_bit(In_sync, &rdev->flags)
+ && (conf->raid_disks - mddev->degraded) == 1) {
+ /*
+ * Don't fail the drive, act as though we were just a
+ * normal single drive.
+ * However don't try a recovery from this drive as
+ * it is very likely to fail.
+ */
+ mddev->recovery_disabled = 1;
+ return;
+ }
+ if (test_and_clear_bit(In_sync, &rdev->flags)) {
+ unsigned long flags;
+ spin_lock_irqsave(&conf->device_lock, flags);
+ mddev->degraded++;
+ set_bit(Faulty, &rdev->flags);
+ spin_unlock_irqrestore(&conf->device_lock, flags);
+ /*
+ * if recovery is running, make sure it aborts.
+ */
+ set_bit(MD_RECOVERY_INTR, &mddev->recovery);
+ } else
+ set_bit(Faulty, &rdev->flags);
+ set_bit(MD_CHANGE_DEVS, &mddev->flags);
+ printk(KERN_ALERT
+ "md/raid1:%s: Disk failure on %s, disabling device.\n"
+ "md/raid1:%s: Operation continuing on %d devices.\n",
+ mdname(mddev), bdevname(rdev->bdev, b),
+ mdname(mddev), conf->raid_disks - mddev->degraded);
+}
+
+static void print_conf(conf_t *conf)
+{
+ int i;
+
+ printk(KERN_DEBUG "RAID1 conf printout:\n");
+ if (!conf) {
+ printk(KERN_DEBUG "(!conf)\n");
+ return;
+ }
+ printk(KERN_DEBUG " --- wd:%d rd:%d\n", conf->raid_disks - conf->mddev->degraded,
+ conf->raid_disks);
+
+ if ((bits & (1 << BDI_async_congested)) &&
+ conf->pending_count >= max_queued)
+ return 1;
+
+ rcu_read_lock();
+ for (i = 0; i < conf->raid_disks; i++) {
+ char b[BDEVNAME_SIZE];
+ mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
+ if (rdev)
+ printk(KERN_DEBUG " disk %d, wo:%d, o:%d, dev:%s\n",
+ i, !test_bit(In_sync, &rdev->flags),
+ !test_bit(Faulty, &rdev->flags),
+ bdevname(rdev->bdev,b));
+ }
+ rcu_read_unlock();
+}
+
+static void close_sync(conf_t *conf)
+{
+ wait_barrier(conf);
+ allow_barrier(conf);
+
+ mempool_destroy(conf->r1buf_pool);
+ conf->r1buf_pool = NULL;
+}
+
+static int raid1_spare_active(mddev_t *mddev)
+{
+ int i;
+ conf_t *conf = mddev->private;
+ int count = 0;
+ unsigned long flags;
+
+ /*
+ * Find all failed disks within the RAID1 configuration
+ * and mark them readable.
+ * Called under mddev lock, so rcu protection not needed.
+ */
+ for (i = 0; i < conf->raid_disks; i++) {
+ mdk_rdev_t *rdev = conf->mirrors[i].rdev;
+ if (rdev
+ && !test_bit(Faulty, &rdev->flags)
+ && !test_and_set_bit(In_sync, &rdev->flags)) {
+ count++;
+ sysfs_notify_dirent(rdev->sysfs_state);
+ }
+ }
+ spin_lock_irqsave(&conf->device_lock, flags);
+ mddev->degraded -= count;
+ spin_unlock_irqrestore(&conf->device_lock, flags);
+
+ print_conf(conf);
+ return count;
+}
+
+
+static int raid1_add_disk(mddev_t *mddev, mdk_rdev_t *rdev)
+{
+ conf_t *conf = mddev->private;
+ int err = -EEXIST;
+ int mirror = 0;
+ mirror_info_t *p;
+ int first = 0;
+ int last = mddev->raid_disks - 1;
+
+ if (rdev->raid_disk >= 0)
+ first = last = rdev->raid_disk;
+
+ for (mirror = first; mirror <= last; mirror++)
+ if ( !(p=conf->mirrors+mirror)->rdev) {
+
+ disk_stack_limits(mddev->gendisk, rdev->bdev,
+ rdev->data_offset << 9);
+ /* as we don't honour merge_bvec_fn, we must
+ * never risk violating it, so limit
+ * ->max_segments to one lying with a single
+ * page, as a one page request is never in
+ * violation.
+ */
+ if (rdev->bdev->bd_disk->queue->merge_bvec_fn) {
+ blk_queue_max_segments(mddev->queue, 1);
+ blk_queue_segment_boundary(mddev->queue,
+ PAGE_CACHE_SIZE - 1);
+ }
+
+ p->head_position = 0;
+ rdev->raid_disk = mirror;
+ err = 0;
+ /* As all devices are equivalent, we don't need a full recovery
+ * if this was recently any drive of the array
+ */
+ if (rdev->saved_raid_disk < 0)
+ conf->fullsync = 1;
+ rcu_assign_pointer(p->rdev, rdev);
+ break;
+ }
+ md_integrity_add_rdev(rdev, mddev);
+ print_conf(conf);
+ return err;
+}
+
+static int raid1_remove_disk(mddev_t *mddev, int number)
+{
+ conf_t *conf = mddev->private;
+ int err = 0;
+ mdk_rdev_t *rdev;
+ mirror_info_t *p = conf->mirrors+ number;
+
+ print_conf(conf);
+ rdev = p->rdev;
+ if (rdev) {
+ if (test_bit(In_sync, &rdev->flags) ||
+ atomic_read(&rdev->nr_pending)) {
+ err = -EBUSY;
+ goto abort;
+ }
+ /* Only remove non-faulty devices if recovery
+ * is not possible.
+ */
+ if (!test_bit(Faulty, &rdev->flags) &&
+ !mddev->recovery_disabled &&
+ mddev->degraded < conf->raid_disks) {
+ err = -EBUSY;
+ goto abort;
+ }
+ p->rdev = NULL;
+ synchronize_rcu();
+ if (atomic_read(&rdev->nr_pending)) {
+ /* lost the race, try later */
+ err = -EBUSY;
+ p->rdev = rdev;
+ goto abort;
+ }
+ err = md_integrity_register(mddev);
+ }
+abort:
+
+ print_conf(conf);
+ return err;
+}
+
+
+static void end_sync_read(struct bio *bio, int error)
+{
+ r1bio_t *r1_bio = bio->bi_private;
+ int i;
+
+ for (i=r1_bio->mddev->raid_disks; i--; )
+ if (r1_bio->bios[i] == bio)
+ break;
+ BUG_ON(i < 0);
+ update_head_pos(i, r1_bio);
+ /*
+ * we have read a block, now it needs to be re-written,
+ * or re-read if the read failed.
+ * We don't do much here, just schedule handling by raid1d
+ */
+ if (test_bit(BIO_UPTODATE, &bio->bi_flags))
+ set_bit(R1BIO_Uptodate, &r1_bio->state);
+
+ if (atomic_dec_and_test(&r1_bio->remaining))
+ reschedule_retry(r1_bio);
+}
+
+static void end_sync_write(struct bio *bio, int error)
+{
+ int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
+ r1bio_t *r1_bio = bio->bi_private;
+ mddev_t *mddev = r1_bio->mddev;
+ conf_t *conf = mddev->private;
+ int i;
+ int mirror=0;
+
+ for (i = 0; i < conf->raid_disks; i++)
+ if (r1_bio->bios[i] == bio) {
+ mirror = i;
+ break;
+ }
+ if (!uptodate) {
+ sector_t sync_blocks = 0;
+ sector_t s = r1_bio->sector;
+ long sectors_to_go = r1_bio->sectors;
+ /* make sure these bits doesn't get cleared. */
+ do {
+ bitmap_end_sync(mddev->bitmap, s,
+ &sync_blocks, 1);
+ s += sync_blocks;
+ sectors_to_go -= sync_blocks;
+ } while (sectors_to_go > 0);
+ md_error(mddev, conf->mirrors[mirror].rdev);
+ }
+
+ update_head_pos(mirror, r1_bio);
+
+ if (atomic_dec_and_test(&r1_bio->remaining)) {
+ sector_t s = r1_bio->sectors;
+ put_buf(r1_bio);
+ md_done_sync(mddev, s, uptodate);
+ }
+}
+
+static int fix_sync_read_error(r1bio_t *r1_bio)
+{
+ /* Try some synchronous reads of other devices to get
+ * good data, much like with normal read errors. Only
+ * read into the pages we already have so we don't
+ * need to re-issue the read request.
+ * We don't need to freeze the array, because being in an
+ * active sync request, there is no normal IO, and
+ * no overlapping syncs.
+ */
+ mddev_t *mddev = r1_bio->mddev;
+ conf_t *conf = mddev->private;
+ struct bio *bio = r1_bio->bios[r1_bio->read_disk];
+ sector_t sect = r1_bio->sector;
+ int sectors = r1_bio->sectors;
+ int idx = 0;
+
+ while(sectors) {
+ int s = sectors;
+ int d = r1_bio->read_disk;
+ int success = 0;
+ mdk_rdev_t *rdev;
+ int start;
+
+ if (s > (PAGE_SIZE>>9))
+ s = PAGE_SIZE >> 9;
+ do {
+ if (r1_bio->bios[d]->bi_end_io == end_sync_read) {
+ /* No rcu protection needed here devices
+ * can only be removed when no resync is
+ * active, and resync is currently active
+ */
+ rdev = conf->mirrors[d].rdev;
+ if (sync_page_io(rdev,
+ sect,
+ s<<9,
+ bio->bi_io_vec[idx].bv_page,
+ READ, false)) {
+ success = 1;
+ break;
+ }
+ }
+ d++;
+ if (d == conf->raid_disks)
+ d = 0;
+ } while (!success && d != r1_bio->read_disk);
+
+ if (!success) {
+ char b[BDEVNAME_SIZE];
+ /* Cannot read from anywhere, array is toast */
+ md_error(mddev, conf->mirrors[r1_bio->read_disk].rdev);
+ printk(KERN_ALERT "md/raid1:%s: %s: unrecoverable I/O read error"
+ " for block %llu\n",
+ mdname(mddev),
+ bdevname(bio->bi_bdev, b),
+ (unsigned long long)r1_bio->sector);
+ md_done_sync(mddev, r1_bio->sectors, 0);
+ put_buf(r1_bio);
+ return 0;
+ }
+
+ start = d;
+ /* write it back and re-read */
+ while (d != r1_bio->read_disk) {
+ if (d == 0)
+ d = conf->raid_disks;
+ d--;
+ if (r1_bio->bios[d]->bi_end_io != end_sync_read)
+ continue;
+ rdev = conf->mirrors[d].rdev;
+ if (sync_page_io(rdev,
+ sect,
+ s<<9,
+ bio->bi_io_vec[idx].bv_page,
+ WRITE, false) == 0) {
+ r1_bio->bios[d]->bi_end_io = NULL;
+ rdev_dec_pending(rdev, mddev);
+ md_error(mddev, rdev);
+ } else
+ atomic_add(s, &rdev->corrected_errors);
+ }
+ d = start;
+ while (d != r1_bio->read_disk) {
+ if (d == 0)
+ d = conf->raid_disks;
+ d--;
+ if (r1_bio->bios[d]->bi_end_io != end_sync_read)
+ continue;
+ rdev = conf->mirrors[d].rdev;
+ if (sync_page_io(rdev,
+ sect,
+ s<<9,
+ bio->bi_io_vec[idx].bv_page,
+ READ, false) == 0)
+ md_error(mddev, rdev);
+ }
+ sectors -= s;
+ sect += s;
+ idx ++;
+ }
+ set_bit(R1BIO_Uptodate, &r1_bio->state);
+ set_bit(BIO_UPTODATE, &bio->bi_flags);
+ return 1;
+}
+
+static int process_checks(r1bio_t *r1_bio)
+{
+ /* We have read all readable devices. If we haven't
+ * got the block, then there is no hope left.
+ * If we have, then we want to do a comparison
+ * and skip the write if everything is the same.
+ * If any blocks failed to read, then we need to
+ * attempt an over-write
+ */
+ mddev_t *mddev = r1_bio->mddev;
+ conf_t *conf = mddev->private;
+ int primary;
+ int i;
+
+ for (primary = 0; primary < conf->raid_disks; primary++)
+ if (r1_bio->bios[primary]->bi_end_io == end_sync_read &&
+ test_bit(BIO_UPTODATE, &r1_bio->bios[primary]->bi_flags)) {
+ r1_bio->bios[primary]->bi_end_io = NULL;
+ rdev_dec_pending(conf->mirrors[primary].rdev, mddev);
+ break;
+ }
+ r1_bio->read_disk = primary;
+ for (i = 0; i < conf->raid_disks; i++) {
+ int j;
+ int vcnt = r1_bio->sectors >> (PAGE_SHIFT- 9);
+ struct bio *pbio = r1_bio->bios[primary];
+ struct bio *sbio = r1_bio->bios[i];
+ int size;
+
+ if (r1_bio->bios[i]->bi_end_io != end_sync_read)
+ continue;
+
+ if (test_bit(BIO_UPTODATE, &sbio->bi_flags)) {
+ for (j = vcnt; j-- ; ) {
+ struct page *p, *s;
+ p = pbio->bi_io_vec[j].bv_page;
+ s = sbio->bi_io_vec[j].bv_page;
+ if (memcmp(page_address(p),
+ page_address(s),
+ PAGE_SIZE))
+ break;
+ }
+ } else
+ j = 0;
+ if (j >= 0)
+ mddev->resync_mismatches += r1_bio->sectors;
+ if (j < 0 || (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)
+ && test_bit(BIO_UPTODATE, &sbio->bi_flags))) {
+ /* No need to write to this device. */
+ sbio->bi_end_io = NULL;
+ rdev_dec_pending(conf->mirrors[i].rdev, mddev);
+ continue;
+ }
+ /* fixup the bio for reuse */
+ sbio->bi_vcnt = vcnt;
+ sbio->bi_size = r1_bio->sectors << 9;
+ sbio->bi_idx = 0;
+ sbio->bi_phys_segments = 0;
+ sbio->bi_flags &= ~(BIO_POOL_MASK - 1);
+ sbio->bi_flags |= 1 << BIO_UPTODATE;
+ sbio->bi_next = NULL;
+ sbio->bi_sector = r1_bio->sector +
+ conf->mirrors[i].rdev->data_offset;
+ sbio->bi_bdev = conf->mirrors[i].rdev->bdev;
+ size = sbio->bi_size;
+ for (j = 0; j < vcnt ; j++) {
+ struct bio_vec *bi;
+ bi = &sbio->bi_io_vec[j];
+ bi->bv_offset = 0;
+ if (size > PAGE_SIZE)
+ bi->bv_len = PAGE_SIZE;
+ else
+ bi->bv_len = size;
+ size -= PAGE_SIZE;
+ memcpy(page_address(bi->bv_page),
+ page_address(pbio->bi_io_vec[j].bv_page),
+ PAGE_SIZE);
+ }
+ }
+ return 0;
+}
+
+static void sync_request_write(mddev_t *mddev, r1bio_t *r1_bio)
+{
+ conf_t *conf = mddev->private;
+ int i;
+ int disks = conf->raid_disks;
+ struct bio *bio, *wbio;
+
+ bio = r1_bio->bios[r1_bio->read_disk];
+
+ if (!test_bit(R1BIO_Uptodate, &r1_bio->state))
+ /* ouch - failed to read all of that. */
+ if (!fix_sync_read_error(r1_bio))
+ return;
+
+ if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
+ if (process_checks(r1_bio) < 0)
+ return;
+ /*
+ * schedule writes
+ */
+ atomic_set(&r1_bio->remaining, 1);
+ for (i = 0; i < disks ; i++) {
+ wbio = r1_bio->bios[i];
+ if (wbio->bi_end_io == NULL ||
+ (wbio->bi_end_io == end_sync_read &&
+ (i == r1_bio->read_disk ||
+ !test_bit(MD_RECOVERY_SYNC, &mddev->recovery))))
+ continue;
+
+ wbio->bi_rw = WRITE;
+ wbio->bi_end_io = end_sync_write;
+ atomic_inc(&r1_bio->remaining);
+ md_sync_acct(conf->mirrors[i].rdev->bdev, wbio->bi_size >> 9);
+
+ generic_make_request(wbio);
+ }
+
+ if (atomic_dec_and_test(&r1_bio->remaining)) {
+ /* if we're here, all write(s) have completed, so clean up */
+ md_done_sync(mddev, r1_bio->sectors, 1);
+ put_buf(r1_bio);
+ }
+}
+
+/*
+ * This is a kernel thread which:
+ *
+ * 1. Retries failed read operations on working mirrors.
+ * 2. Updates the raid superblock when problems encounter.
+ * 3. Performs writes following reads for array syncronising.
+ */
+
+static void fix_read_error(conf_t *conf, int read_disk,
+ sector_t sect, int sectors)
+{
+ mddev_t *mddev = conf->mddev;
+ while(sectors) {
+ int s = sectors;
+ int d = read_disk;
+ int success = 0;
+ int start;
+ mdk_rdev_t *rdev;
+
+ if (s > (PAGE_SIZE>>9))
+ s = PAGE_SIZE >> 9;
+
+ do {
+ /* Note: no rcu protection needed here
+ * as this is synchronous in the raid1d thread
+ * which is the thread that might remove
+ * a device. If raid1d ever becomes multi-threaded....
+ */
+ rdev = conf->mirrors[d].rdev;
+ if (rdev &&
+ test_bit(In_sync, &rdev->flags) &&
+ sync_page_io(rdev, sect, s<<9,
+ conf->tmppage, READ, false))
+ success = 1;
+ else {
+ d++;
+ if (d == conf->raid_disks)
+ d = 0;
+ }
+ } while (!success && d != read_disk);
+
+ if (!success) {
+ /* Cannot read from anywhere -- bye bye array */
+ md_error(mddev, conf->mirrors[read_disk].rdev);
+ break;
+ }
+ /* write it back and re-read */
+ start = d;
+ while (d != read_disk) {
+ if (d==0)
+ d = conf->raid_disks;
+ d--;
+ rdev = conf->mirrors[d].rdev;
+ if (rdev &&
+ test_bit(In_sync, &rdev->flags)) {
+ if (sync_page_io(rdev, sect, s<<9,
+ conf->tmppage, WRITE, false)
+ == 0)
+ /* Well, this device is dead */
+ md_error(mddev, rdev);
+ }
+ }
+ d = start;
+ while (d != read_disk) {
+ char b[BDEVNAME_SIZE];
+ if (d==0)
+ d = conf->raid_disks;
+ d--;
+ rdev = conf->mirrors[d].rdev;
+ if (rdev &&
+ test_bit(In_sync, &rdev->flags)) {
+ if (sync_page_io(rdev, sect, s<<9,
+ conf->tmppage, READ, false)
+ == 0)
+ /* Well, this device is dead */
+ md_error(mddev, rdev);
+ else {
+ atomic_add(s, &rdev->corrected_errors);
+ printk(KERN_INFO
+ "md/raid1:%s: read error corrected "
+ "(%d sectors at %llu on %s)\n",
+ mdname(mddev), s,
+ (unsigned long long)(sect +
+ rdev->data_offset),
+ bdevname(rdev->bdev, b));
+ }
+ }
+ }
+ sectors -= s;
+ sect += s;
+ }
+}
+
+static void raid1d(mddev_t *mddev)
+{
+ r1bio_t *r1_bio;
+ struct bio *bio;
+ unsigned long flags;
+ conf_t *conf = mddev->private;
+ struct list_head *head = &conf->retry_list;
+ mdk_rdev_t *rdev;
+ struct blk_plug plug;
+
+ md_check_recovery(mddev);
+
+ blk_start_plug(&plug);
+ for (;;) {
+ char b[BDEVNAME_SIZE];
+
+ if (atomic_read(&mddev->plug_cnt) == 0)
+ flush_pending_writes(conf);
+
+ spin_lock_irqsave(&conf->device_lock, flags);
+ if (list_empty(head)) {
+ spin_unlock_irqrestore(&conf->device_lock, flags);
+ break;
+ }
+ r1_bio = list_entry(head->prev, r1bio_t, retry_list);
+ list_del(head->prev);
+ conf->nr_queued--;
+ spin_unlock_irqrestore(&conf->device_lock, flags);
+
+ mddev = r1_bio->mddev;
+ conf = mddev->private;
+ if (test_bit(R1BIO_IsSync, &r1_bio->state))
+ sync_request_write(mddev, r1_bio);
+ else {
+ int disk;
+
+ /* we got a read error. Maybe the drive is bad. Maybe just
+ * the block and we can fix it.
+ * We freeze all other IO, and try reading the block from
+ * other devices. When we find one, we re-write
+ * and check it that fixes the read error.
+ * This is all done synchronously while the array is
+ * frozen
+ */
+ if (mddev->ro == 0) {
+ freeze_array(conf);
+ fix_read_error(conf, r1_bio->read_disk,
+ r1_bio->sector,
+ r1_bio->sectors);
+ unfreeze_array(conf);
+ } else
+ md_error(mddev,
+ conf->mirrors[r1_bio->read_disk].rdev);
+
+ bio = r1_bio->bios[r1_bio->read_disk];
+ if ((disk=read_balance(conf, r1_bio)) == -1) {
+ printk(KERN_ALERT "md/raid1:%s: %s: unrecoverable I/O"
+ " read error for block %llu\n",
+ mdname(mddev),
+ bdevname(bio->bi_bdev,b),
+ (unsigned long long)r1_bio->sector);
+ raid_end_bio_io(r1_bio);
+ } else {
+ const unsigned long do_sync = r1_bio->master_bio->bi_rw & REQ_SYNC;
+ r1_bio->bios[r1_bio->read_disk] =
+ mddev->ro ? IO_BLOCKED : NULL;
+ r1_bio->read_disk = disk;
+ bio_put(bio);
+ bio = bio_clone_mddev(r1_bio->master_bio,
+ GFP_NOIO, mddev);
+ r1_bio->bios[r1_bio->read_disk] = bio;
+ rdev = conf->mirrors[disk].rdev;
+ if (printk_ratelimit())
+ printk(KERN_ERR "md/raid1:%s: redirecting sector %llu to"
+ " other mirror: %s\n",
+ mdname(mddev),
+ (unsigned long long)r1_bio->sector,
+ bdevname(rdev->bdev,b));
+ bio->bi_sector = r1_bio->sector + rdev->data_offset;
+ bio->bi_bdev = rdev->bdev;
+ bio->bi_end_io = raid1_end_read_request;
+ bio->bi_rw = READ | do_sync;
+ bio->bi_private = r1_bio;
+ generic_make_request(bio);
+ }
+ }
+ cond_resched();
+ }
+ blk_finish_plug(&plug);
+}
+
+
+static int init_resync(conf_t *conf)
+{
+ int buffs;
+
+ buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE;
+ BUG_ON(conf->r1buf_pool);
+ conf->r1buf_pool = mempool_create(buffs, r1buf_pool_alloc, r1buf_pool_free,
+ conf->poolinfo);
+ if (!conf->r1buf_pool)
+ return -ENOMEM;
+ conf->next_resync = 0;
+ return 0;
+}
+
+/*
+ * perform a "sync" on one "block"
+ *
+ * We need to make sure that no normal I/O request - particularly write
+ * requests - conflict with active sync requests.
+ *
+ * This is achieved by tracking pending requests and a 'barrier' concept
+ * that can be installed to exclude normal IO requests.
+ */
+
+static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster)
+{
+ conf_t *conf = mddev->private;
+ r1bio_t *r1_bio;
+ struct bio *bio;
+ sector_t max_sector, nr_sectors;
+ int disk = -1;
+ int i;
+ int wonly = -1;
+ int write_targets = 0, read_targets = 0;
+ sector_t sync_blocks;
+ int still_degraded = 0;
+
+ if (!conf->r1buf_pool)
+ if (init_resync(conf))
+ return 0;
+
+ max_sector = mddev->dev_sectors;
+ if (sector_nr >= max_sector) {
+ /* If we aborted, we need to abort the
+ * sync on the 'current' bitmap chunk (there will
+ * only be one in raid1 resync.
+ * We can find the current addess in mddev->curr_resync
+ */
+ if (mddev->curr_resync < max_sector) /* aborted */
+ bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
+ &sync_blocks, 1);
+ else /* completed sync */
+ conf->fullsync = 0;
+
+ bitmap_close_sync(mddev->bitmap);
+ close_sync(conf);
+ return 0;
+ }
+
+ if (mddev->bitmap == NULL &&
+ mddev->recovery_cp == MaxSector &&
+ !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
+ conf->fullsync == 0) {
+ *skipped = 1;
+ return max_sector - sector_nr;
+ }
+ /* before building a request, check if we can skip these blocks..
+ * This call the bitmap_start_sync doesn't actually record anything
+ */
+ if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
+ !conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
+ /* We can skip this block, and probably several more */
+ *skipped = 1;
+ return sync_blocks;
+ }
+ /*
+ * If there is non-resync activity waiting for a turn,
+ * and resync is going fast enough,
+ * then let it though before starting on this new sync request.
+ */
+ if (!go_faster && conf->nr_waiting)
+ msleep_interruptible(1000);
+
+ bitmap_cond_end_sync(mddev->bitmap, sector_nr);
+ r1_bio = mempool_alloc(conf->r1buf_pool, GFP_NOIO);
+ raise_barrier(conf);
+
+ conf->next_resync = sector_nr;
+
+ rcu_read_lock();
+ /*
+ * If we get a correctably read error during resync or recovery,
+ * we might want to read from a different device. So we
+ * flag all drives that could conceivably be read from for READ,
+ * and any others (which will be non-In_sync devices) for WRITE.
+ * If a read fails, we try reading from something else for which READ
+ * is OK.
+ */
+
+ r1_bio->mddev = mddev;
+ r1_bio->sector = sector_nr;
+ r1_bio->state = 0;
+ set_bit(R1BIO_IsSync, &r1_bio->state);
+
+ for (i=0; i < conf->raid_disks; i++) {
+ mdk_rdev_t *rdev;
+ bio = r1_bio->bios[i];
+
+ /* take from bio_init */
+ bio->bi_next = NULL;
+ bio->bi_flags &= ~(BIO_POOL_MASK-1);
+ bio->bi_flags |= 1 << BIO_UPTODATE;
+ bio->bi_comp_cpu = -1;
+ bio->bi_rw = READ;
+ bio->bi_vcnt = 0;
+ bio->bi_idx = 0;
+ bio->bi_phys_segments = 0;
+ bio->bi_size = 0;
+ bio->bi_end_io = NULL;
+ bio->bi_private = NULL;
+
+ rdev = rcu_dereference(conf->mirrors[i].rdev);
+ if (rdev == NULL ||
+ test_bit(Faulty, &rdev->flags)) {
+ still_degraded = 1;
+ continue;
+ } else if (!test_bit(In_sync, &rdev->flags)) {
+ bio->bi_rw = WRITE;
+ bio->bi_end_io = end_sync_write;
+ write_targets ++;
+ } else {
+ /* may need to read from here */
+ bio->bi_rw = READ;
+ bio->bi_end_io = end_sync_read;
+ if (test_bit(WriteMostly, &rdev->flags)) {
+ if (wonly < 0)
+ wonly = i;
+ } else {
+ if (disk < 0)
+ disk = i;
+ }
+ read_targets++;
+ }
+ atomic_inc(&rdev->nr_pending);
+ bio->bi_sector = sector_nr + rdev->data_offset;
+ bio->bi_bdev = rdev->bdev;
+ bio->bi_private = r1_bio;
+ }
+ rcu_read_unlock();
+ if (disk < 0)
+ disk = wonly;
+ r1_bio->read_disk = disk;
+
+ if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) && read_targets > 0)
+ /* extra read targets are also write targets */
+ write_targets += read_targets-1;
+
+ if (write_targets == 0 || read_targets == 0) {
+ /* There is nowhere to write, so all non-sync
+ * drives must be failed - so we are finished
+ */
+ sector_t rv = max_sector - sector_nr;
+ *skipped = 1;
+ put_buf(r1_bio);
+ return rv;
+ }
+
+ if (max_sector > mddev->resync_max)
+ max_sector = mddev->resync_max; /* Don't do IO beyond here */
+ nr_sectors = 0;
+ sync_blocks = 0;
+ do {
+ struct page *page;
+ int len = PAGE_SIZE;
+ if (sector_nr + (len>>9) > max_sector)
+ len = (max_sector - sector_nr) << 9;
+ if (len == 0)
+ break;
+ if (sync_blocks == 0) {
+ if (!bitmap_start_sync(mddev->bitmap, sector_nr,
+ &sync_blocks, still_degraded) &&
+ !conf->fullsync &&
+ !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
+ break;
+ BUG_ON(sync_blocks < (PAGE_SIZE>>9));
+ if ((len >> 9) > sync_blocks)
+ len = sync_blocks<<9;
+ }
+
+ for (i=0 ; i < conf->raid_disks; i++) {
+ bio = r1_bio->bios[i];
+ if (bio->bi_end_io) {
+ page = bio->bi_io_vec[bio->bi_vcnt].bv_page;
+ if (bio_add_page(bio, page, len, 0) == 0) {
+ /* stop here */
+ bio->bi_io_vec[bio->bi_vcnt].bv_page = page;
+ while (i > 0) {
+ i--;
+ bio = r1_bio->bios[i];
+ if (bio->bi_end_io==NULL)
+ continue;
+ /* remove last page from this bio */
+ bio->bi_vcnt--;
+ bio->bi_size -= len;
+ bio->bi_flags &= ~(1<< BIO_SEG_VALID);
+ }
+ goto bio_full;
+ }
+ }
+ }
+ nr_sectors += len>>9;
+ sector_nr += len>>9;
+ sync_blocks -= (len>>9);
+ } while (r1_bio->bios[disk]->bi_vcnt < RESYNC_PAGES);
+ bio_full:
+ r1_bio->sectors = nr_sectors;
+
+ /* For a user-requested sync, we read all readable devices and do a
+ * compare
+ */
+ if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
+ atomic_set(&r1_bio->remaining, read_targets);
+ for (i=0; i<conf->raid_disks; i++) {
+ bio = r1_bio->bios[i];
+ if (bio->bi_end_io == end_sync_read) {
+ md_sync_acct(bio->bi_bdev, nr_sectors);
+ generic_make_request(bio);
+ }
+ }
+ } else {
+ atomic_set(&r1_bio->remaining, 1);
+ bio = r1_bio->bios[r1_bio->read_disk];
+ md_sync_acct(bio->bi_bdev, nr_sectors);
+ generic_make_request(bio);
+
+ }
+ return nr_sectors;
+}
+
+static sector_t raid1_size(mddev_t *mddev, sector_t sectors, int raid_disks)
+{
+ if (sectors)
+ return sectors;
+
+ return mddev->dev_sectors;
+}
+
+static conf_t *setup_conf(mddev_t *mddev)
+{
+ conf_t *conf;
+ int i;
+ mirror_info_t *disk;
+ mdk_rdev_t *rdev;
+ int err = -ENOMEM;
+
+ conf = kzalloc(sizeof(conf_t), GFP_KERNEL);
+ if (!conf)
+ goto abort;
+
+ conf->mirrors = kzalloc(sizeof(struct mirror_info)*mddev->raid_disks,
+ GFP_KERNEL);
+ if (!conf->mirrors)
+ goto abort;
+
+ conf->tmppage = alloc_page(GFP_KERNEL);
+ if (!conf->tmppage)
+ goto abort;
+
+ conf->poolinfo = kzalloc(sizeof(*conf->poolinfo), GFP_KERNEL);
+ if (!conf->poolinfo)
+ goto abort;
+ conf->poolinfo->raid_disks = mddev->raid_disks;
+ conf->r1bio_pool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
+ r1bio_pool_free,
+ conf->poolinfo);
+ if (!conf->r1bio_pool)
+ goto abort;
+
+ conf->poolinfo->mddev = mddev;
+
+ spin_lock_init(&conf->device_lock);
+ list_for_each_entry(rdev, &mddev->disks, same_set) {
+ int disk_idx = rdev->raid_disk;
+ if (disk_idx >= mddev->raid_disks
+ || disk_idx < 0)
+ continue;
+ disk = conf->mirrors + disk_idx;
+
+ disk->rdev = rdev;
+
+ disk->head_position = 0;
+ }
+ conf->raid_disks = mddev->raid_disks;
+ conf->mddev = mddev;
+ INIT_LIST_HEAD(&conf->retry_list);
+
+ spin_lock_init(&conf->resync_lock);
+ init_waitqueue_head(&conf->wait_barrier);
+
+<<<<<<<
+ bio_list_init(&conf->pending_bio_list);
+
+ conf->last_used = -1;
+ for (i = 0; i < conf->raid_disks; i++) {
+
+ disk = conf->mirrors + i;
+
+ if (!disk->rdev ||
+ !test_bit(In_sync, &disk->rdev->flags)) {
+ disk->head_position = 0;
+ if (disk->rdev)
+ conf->fullsync = 1;
+ } else if (conf->last_used < 0)
+ /*
+ * The first working device is used as a
+ * starting point to read balancing.
+ */
+ conf->last_used = i;
+ }
+
+ err = -EIO;
+ if (conf->last_used < 0) {
+ printk(KERN_ERR "md/raid1:%s: no operational mirrors\n",
+ mdname(mddev));
+ goto abort;
+ }
+ err = -ENOMEM;
+ conf->thread = md_register_thread(raid1d, mddev, NULL);
+ if (!conf->thread) {
+ printk(KERN_ERR
+ "md/raid1:%s: couldn't allocate thread\n",
+ mdname(mddev));
+ goto abort;
+ }
+
+ return conf;
+
+ abort:
+ if (conf) {
+ if (conf->r1bio_pool)
+ mempool_destroy(conf->r1bio_pool);
+ kfree(conf->mirrors);
+ safe_put_page(conf->tmppage);
+ kfree(conf->poolinfo);
+ kfree(conf);
+ }
+ return ERR_PTR(err);
+}
+
+static int run(mddev_t *mddev)
+{
+ conf_t *conf;
+ int i;
+ mdk_rdev_t *rdev;
+
+ if (mddev->level != 1) {
+ printk(KERN_ERR "md/raid1:%s: raid level not set to mirroring (%d)\n",
+ mdname(mddev), mddev->level);
+ return -EIO;
+ }
+ if (mddev->reshape_position != MaxSector) {
+ printk(KERN_ERR "md/raid1:%s: reshape_position set but not supported\n",
+ mdname(mddev));
+ return -EIO;
+ }
+ /*
+ * copy the already verified devices into our private RAID1
+ * bookkeeping area. [whatever we allocate in run(),
+ * should be freed in stop()]
+ */
+ if (mddev->private == NULL)
+ conf = setup_conf(mddev);
+ else
+ conf = mddev->private;
+
+ if (IS_ERR(conf))
+ return PTR_ERR(conf);
+
+ list_for_each_entry(rdev, &mddev->disks, same_set) {
+ if (!mddev->gendisk)
+ continue;
+ disk_stack_limits(mddev->gendisk, rdev->bdev,
+ rdev->data_offset << 9);
+ /* as we don't honour merge_bvec_fn, we must never risk
+ * violating it, so limit ->max_segments to 1 lying within
+ * a single page, as a one page request is never in violation.
+ */
+ if (rdev->bdev->bd_disk->queue->merge_bvec_fn) {
+ blk_queue_max_segments(mddev->queue, 1);
+ blk_queue_segment_boundary(mddev->queue,
+ PAGE_CACHE_SIZE - 1);
+ }
+ }
+
+ mddev->degraded = 0;
+ for (i=0; i < conf->raid_disks; i++)
+ if (conf->mirrors[i].rdev == NULL ||
+ !test_bit(In_sync, &conf->mirrors[i].rdev->flags) ||
+ test_bit(Faulty, &conf->mirrors[i].rdev->flags))
+ mddev->degraded++;
+
+ if (conf->raid_disks - mddev->degraded == 1)
+ mddev->recovery_cp = MaxSector;
+
+ if (mddev->recovery_cp != MaxSector)
+ printk(KERN_NOTICE "md/raid1:%s: not clean"
+ " -- starting background reconstruction\n",
+ mdname(mddev));
+ printk(KERN_INFO
+ "md/raid1:%s: active with %d out of %d mirrors\n",
+ mdname(mddev), mddev->raid_disks - mddev->degraded,
+ mddev->raid_disks);
+
+ /*
+ * Ok, everything is just fine now
+ */
+ mddev->thread = conf->thread;
+ conf->thread = NULL;
+ mddev->private = conf;
+
+ md_set_array_sectors(mddev, raid1_size(mddev, 0, 0));
+
+ if (mddev->queue) {
+ mddev->queue->backing_dev_info.congested_fn = raid1_congested;
+ mddev->queue->backing_dev_info.congested_data = mddev;
+ }
+ return md_integrity_register(mddev);
+}
+
+static int stop(mddev_t *mddev)
+{
+ conf_t *conf = mddev->private;
+ struct bitmap *bitmap = mddev->bitmap;
+
+ /* wait for behind writes to complete */
+ if (bitmap && atomic_read(&bitmap->behind_writes) > 0) {
+ printk(KERN_INFO "md/raid1:%s: behind writes in progress - waiting to stop.\n",
+ mdname(mddev));
+ /* need to kick something here to make sure I/O goes? */
+ wait_event(bitmap->behind_wait,
+ atomic_read(&bitmap->behind_writes) == 0);
+ }
+
+ raise_barrier(conf);
+ lower_barrier(conf);
+
+ md_unregister_thread(mddev->thread);
+ mddev->thread = NULL;
+ if (conf->r1bio_pool)
+ mempool_destroy(conf->r1bio_pool);
+ kfree(conf->mirrors);
+ kfree(conf->poolinfo);
+ kfree(conf);
+ mddev->private = NULL;
+ return 0;
+}
+
+static int raid1_resize(mddev_t *mddev, sector_t sectors)
+{
+ /* no resync is happening, and there is enough space
+ * on all devices, so we can resize.
+ * We need to make sure resync covers any new space.
+ * If the array is shrinking we should possibly wait until
+ * any io in the removed space completes, but it hardly seems
+ * worth it.
+ */
+ md_set_array_sectors(mddev, raid1_size(mddev, sectors, 0));
+ if (mddev->array_sectors > raid1_size(mddev, sectors, 0))
+ return -EINVAL;
+ set_capacity(mddev->gendisk, mddev->array_sectors);
+ revalidate_disk(mddev->gendisk);
+ if (sectors > mddev->dev_sectors &&
+ mddev->recovery_cp > mddev->dev_sectors) {
+ mddev->recovery_cp = mddev->dev_sectors;
+ set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
+ }
+ mddev->dev_sectors = sectors;
+ mddev->resync_max_sectors = sectors;
+ return 0;
+}
+
+static int raid1_reshape(mddev_t *mddev)
+{
+ /* We need to:
+ * 1/ resize the r1bio_pool
+ * 2/ resize conf->mirrors
+ *
+ * We allocate a new r1bio_pool if we can.
+ * Then raise a device barrier and wait until all IO stops.
+ * Then resize conf->mirrors and swap in the new r1bio pool.
+ *
+ * At the same time, we "pack" the devices so that all the missing
+ * devices have the higher raid_disk numbers.
+ */
+ mempool_t *newpool, *oldpool;
+ struct pool_info *newpoolinfo;
+ mirror_info_t *newmirrors;
+ conf_t *conf = mddev->private;
+ int cnt, raid_disks;
+ unsigned long flags;
+ int d, d2, err;
+
+ /* Cannot change chunk_size, layout, or level */
+ if (mddev->chunk_sectors != mddev->new_chunk_sectors ||
+ mddev->layout != mddev->new_layout ||
+ mddev->level != mddev->new_level) {
+ mddev->new_chunk_sectors = mddev->chunk_sectors;
+ mddev->new_layout = mddev->layout;
+ mddev->new_level = mddev->level;
+ return -EINVAL;
+ }
+
+ err = md_allow_write(mddev);
+ if (err)
+ return err;
+
+ raid_disks = mddev->raid_disks + mddev->delta_disks;
+
+ if (raid_disks < conf->raid_disks) {
+ cnt=0;
+ for (d= 0; d < conf->raid_disks; d++)
+ if (conf->mirrors[d].rdev)
+ cnt++;
+ if (cnt > raid_disks)
+ return -EBUSY;
+ }
+
+ newpoolinfo = kmalloc(sizeof(*newpoolinfo), GFP_KERNEL);
+ if (!newpoolinfo)
+ return -ENOMEM;
+ newpoolinfo->mddev = mddev;
+ newpoolinfo->raid_disks = raid_disks;
+
+ newpool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
+ r1bio_pool_free, newpoolinfo);
+ if (!newpool) {
+ kfree(newpoolinfo);
+ return -ENOMEM;
+ }
+ newmirrors = kzalloc(sizeof(struct mirror_info) * raid_disks, GFP_KERNEL);
+ if (!newmirrors) {
+ kfree(newpoolinfo);
+ mempool_destroy(newpool);
+ return -ENOMEM;
+ }
+
+ raise_barrier(conf);
+
+ /* ok, everything is stopped */
+ oldpool = conf->r1bio_pool;
+ conf->r1bio_pool = newpool;
+
+ for (d = d2 = 0; d < conf->raid_disks; d++) {
+ mdk_rdev_t *rdev = conf->mirrors[d].rdev;
+ if (rdev && rdev->raid_disk != d2) {
+ char nm[20];
+ sprintf(nm, "rd%d", rdev->raid_disk);
+ sysfs_remove_link(&mddev->kobj, nm);
+ rdev->raid_disk = d2;
+ sprintf(nm, "rd%d", rdev->raid_disk);
+ sysfs_remove_link(&mddev->kobj, nm);
+ if (sysfs_create_link(&mddev->kobj,
+ &rdev->kobj, nm))
+ printk(KERN_WARNING
+ "md/raid1:%s: cannot register "
+ "%s\n",
+ mdname(mddev), nm);
+ }
+ if (rdev)
+ newmirrors[d2++].rdev = rdev;
+ }
+ kfree(conf->mirrors);
+ conf->mirrors = newmirrors;
+ kfree(conf->poolinfo);
+ conf->poolinfo = newpoolinfo;
+
+ spin_lock_irqsave(&conf->device_lock, flags);
+ mddev->degraded += (raid_disks - conf->raid_disks);
+ spin_unlock_irqrestore(&conf->device_lock, flags);
+ conf->raid_disks = mddev->raid_disks = raid_disks;
+ mddev->delta_disks = 0;
+
+ conf->last_used = 0; /* just make sure it is in-range */
+ lower_barrier(conf);
+
+ set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
+ md_wakeup_thread(mddev->thread);
+
+ mempool_destroy(oldpool);
+ return 0;
+}
+
+static void raid1_quiesce(mddev_t *mddev, int state)
+{
+ conf_t *conf = mddev->private;
+
+ switch(state) {
+ case 2: /* wake for suspend */
+ wake_up(&conf->wait_barrier);
+ break;
+ case 1:
+ raise_barrier(conf);
+ break;
+ case 0:
+ lower_barrier(conf);
+ break;
+ }
+}
+
+static void *raid1_takeover(mddev_t *mddev)
+{
+ /* raid1 can take over:
+ * raid5 with 2 devices, any layout or chunk size
+ */
+ if (mddev->level == 5 && mddev->raid_disks == 2) {
+ conf_t *conf;
+ mddev->new_level = 1;
+ mddev->new_layout = 0;
+ mddev->new_chunk_sectors = 0;
+ conf = setup_conf(mddev);
+ if (!IS_ERR(conf))
+ conf->barrier = 1;
+ return conf;
+ }
+ return ERR_PTR(-EINVAL);
+}
+
+static struct mdk_personality raid1_personality =
+{
+ .name = "raid1",
+ .level = 1,
+ .owner = THIS_MODULE,
+ .make_request = make_request,
+ .run = run,
+ .stop = stop,
+ .status = status,
+ .error_handler = error,
+ .hot_add_disk = raid1_add_disk,
+ .hot_remove_disk= raid1_remove_disk,
+ .spare_active = raid1_spare_active,
+ .sync_request = sync_request,
+ .resize = raid1_resize,
+ .size = raid1_size,
+ .check_reshape = raid1_reshape,
+ .quiesce = raid1_quiesce,
+ .takeover = raid1_takeover,
+};
+
+static int __init raid_init(void)
+{
+ return register_md_personality(&raid1_personality);
+}
+
+static void raid_exit(void)
+{
+ unregister_md_personality(&raid1_personality);
+}
+
+module_init(raid_init);
+module_exit(raid_exit);
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("RAID1 (mirroring) personality for MD");
+MODULE_ALIAS("md-personality-3"); /* RAID1 */
+MODULE_ALIAS("md-raid1");
+MODULE_ALIAS("md-level-1");
+
+module_param(max_queued, int, S_IRUGO|S_IWUSR);
+|||||||
+ bio_list_init(&conf->pending_bio_list);
+ bio_list_init(&conf->flushing_bio_list);
+
+
+=======
+ bio_list_init(&conf->pending_bio_list);
+ conf->pending_count = 0;
+ bio_list_init(&conf->flushing_bio_list);
+
+
+>>>>>>>
--- /dev/null
+/*
+ * raid1.c : Multiple Devices driver for Linux
+ *
+ * Copyright (C) 1999, 2000, 2001 Ingo Molnar, Red Hat
+ *
+ * Copyright (C) 1996, 1997, 1998 Ingo Molnar, Miguel de Icaza, Gadi Oxman
+ *
+ * RAID-1 management functions.
+ *
+ * Better read-balancing code written by Mika Kuoppala <miku@iki.fi>, 2000
+ *
+ * Fixes to reconstruction by Jakob Østergaard" <jakob@ostenfeld.dk>
+ * Various fixes by Neil Brown <neilb@cse.unsw.edu.au>
+ *
+ * Changes by Peter T. Breuer <ptb@it.uc3m.es> 31/1/2003 to support
+ * bitmapped intelligence in resync:
+ *
+ * - bitmap marked during normal i/o
+ * - bitmap used to skip nondirty blocks during sync
+ *
+ * Additions to bitmap code, (C) 2003-2004 Paul Clements, SteelEye Technology:
+ * - persistent bitmap code
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * You should have received a copy of the GNU General Public License
+ * (for example /usr/src/linux/COPYING); if not, write to the Free
+ * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/blkdev.h>
+#include <linux/seq_file.h>
+#include "md.h"
+#include "raid1.h"
+#include "bitmap.h"
+
+#define DEBUG 0
+#if DEBUG
+#define PRINTK(x...) printk(x)
+#else
+#define PRINTK(x...)
+#endif
+
+/*
+ * Number of guaranteed r1bios in case of extreme VM load:
+ */
+#define NR_RAID1_BIOS 256
+
+
+static void allow_barrier(conf_t *conf);
+static void lower_barrier(conf_t *conf);
+
+static void * r1bio_pool_alloc(gfp_t gfp_flags, void *data)
+{
+ struct pool_info *pi = data;
+ int size = offsetof(r1bio_t, bios[pi->raid_disks]);
+
+ /* allocate a r1bio with room for raid_disks entries in the bios array */
+ return kzalloc(size, gfp_flags);
+}
+
+static void r1bio_pool_free(void *r1_bio, void *data)
+{
+ kfree(r1_bio);
+}
+
+#define RESYNC_BLOCK_SIZE (64*1024)
+//#define RESYNC_BLOCK_SIZE PAGE_SIZE
+#define RESYNC_SECTORS (RESYNC_BLOCK_SIZE >> 9)
+#define RESYNC_PAGES ((RESYNC_BLOCK_SIZE + PAGE_SIZE-1) / PAGE_SIZE)
+#define RESYNC_WINDOW (2048*1024)
+
+static void * r1buf_pool_alloc(gfp_t gfp_flags, void *data)
+{
+ struct pool_info *pi = data;
+ struct page *page;
+ r1bio_t *r1_bio;
+ struct bio *bio;
+ int i, j;
+
+ r1_bio = r1bio_pool_alloc(gfp_flags, pi);
+ if (!r1_bio)
+ return NULL;
+
+ /*
+ * Allocate bios : 1 for reading, n-1 for writing
+ */
+ for (j = pi->raid_disks ; j-- ; ) {
+ bio = bio_kmalloc(gfp_flags, RESYNC_PAGES);
+ if (!bio)
+ goto out_free_bio;
+ r1_bio->bios[j] = bio;
+ }
+ /*
+ * Allocate RESYNC_PAGES data pages and attach them to
+ * the first bio.
+ * If this is a user-requested check/repair, allocate
+ * RESYNC_PAGES for each bio.
+ */
+ if (test_bit(MD_RECOVERY_REQUESTED, &pi->mddev->recovery))
+ j = pi->raid_disks;
+ else
+ j = 1;
+ while(j--) {
+ bio = r1_bio->bios[j];
+ for (i = 0; i < RESYNC_PAGES; i++) {
+ page = alloc_page(gfp_flags);
+ if (unlikely(!page))
+ goto out_free_pages;
+
+ bio->bi_io_vec[i].bv_page = page;
+ bio->bi_vcnt = i+1;
+ }
+ }
+ /* If not user-requests, copy the page pointers to all bios */
+ if (!test_bit(MD_RECOVERY_REQUESTED, &pi->mddev->recovery)) {
+ for (i=0; i<RESYNC_PAGES ; i++)
+ for (j=1; j<pi->raid_disks; j++)
+ r1_bio->bios[j]->bi_io_vec[i].bv_page =
+ r1_bio->bios[0]->bi_io_vec[i].bv_page;
+ }
+
+ r1_bio->master_bio = NULL;
+
+ return r1_bio;
+
+out_free_pages:
+ for (j=0 ; j < pi->raid_disks; j++)
+ for (i=0; i < r1_bio->bios[j]->bi_vcnt ; i++)
+ put_page(r1_bio->bios[j]->bi_io_vec[i].bv_page);
+ j = -1;
+out_free_bio:
+ while ( ++j < pi->raid_disks )
+ bio_put(r1_bio->bios[j]);
+ r1bio_pool_free(r1_bio, data);
+ return NULL;
+}
+
+static void r1buf_pool_free(void *__r1_bio, void *data)
+{
+ struct pool_info *pi = data;
+ int i,j;
+ r1bio_t *r1bio = __r1_bio;
+
+ for (i = 0; i < RESYNC_PAGES; i++)
+ for (j = pi->raid_disks; j-- ;) {
+ if (j == 0 ||
+ r1bio->bios[j]->bi_io_vec[i].bv_page !=
+ r1bio->bios[0]->bi_io_vec[i].bv_page)
+ safe_put_page(r1bio->bios[j]->bi_io_vec[i].bv_page);
+ }
+ for (i=0 ; i < pi->raid_disks; i++)
+ bio_put(r1bio->bios[i]);
+
+ r1bio_pool_free(r1bio, data);
+}
+
+static void put_all_bios(conf_t *conf, r1bio_t *r1_bio)
+{
+ int i;
+
+ for (i = 0; i < conf->raid_disks; i++) {
+ struct bio **bio = r1_bio->bios + i;
+ if (*bio && *bio != IO_BLOCKED)
+ bio_put(*bio);
+ *bio = NULL;
+ }
+}
+
+static void free_r1bio(r1bio_t *r1_bio)
+{
+ conf_t *conf = r1_bio->mddev->private;
+
+ /*
+ * Wake up any possible resync thread that waits for the device
+ * to go idle.
+ */
+ allow_barrier(conf);
+
+ put_all_bios(conf, r1_bio);
+ mempool_free(r1_bio, conf->r1bio_pool);
+}
+
+static void put_buf(r1bio_t *r1_bio)
+{
+ conf_t *conf = r1_bio->mddev->private;
+ int i;
+
+ for (i=0; i<conf->raid_disks; i++) {
+ struct bio *bio = r1_bio->bios[i];
+ if (bio->bi_end_io)
+ rdev_dec_pending(conf->mirrors[i].rdev, r1_bio->mddev);
+ }
+
+ mempool_free(r1_bio, conf->r1buf_pool);
+
+ lower_barrier(conf);
+}
+
+static void reschedule_retry(r1bio_t *r1_bio)
+{
+ unsigned long flags;
+ mddev_t *mddev = r1_bio->mddev;
+ conf_t *conf = mddev->private;
+
+ spin_lock_irqsave(&conf->device_lock, flags);
+ list_add(&r1_bio->retry_list, &conf->retry_list);
+ conf->nr_queued ++;
+ spin_unlock_irqrestore(&conf->device_lock, flags);
+
+ wake_up(&conf->wait_barrier);
+ md_wakeup_thread(mddev->thread);
+}
+
+/*
+ * raid_end_bio_io() is called when we have finished servicing a mirrored
+ * operation and are ready to return a success/failure code to the buffer
+ * cache layer.
+ */
+static void raid_end_bio_io(r1bio_t *r1_bio)
+{
+ struct bio *bio = r1_bio->master_bio;
+
+ /* 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,
+ test_bit(R1BIO_Uptodate, &r1_bio->state) ? 0 : -EIO);
+ }
+ free_r1bio(r1_bio);
+}
+
+/*
+ * Update disk head position estimator based on IRQ completion info.
+ */
+static inline void update_head_pos(int disk, r1bio_t *r1_bio)
+{
+ conf_t *conf = r1_bio->mddev->private;
+
+ conf->mirrors[disk].head_position =
+ r1_bio->sector + (r1_bio->sectors);
+}
+
+static void raid1_end_read_request(struct bio *bio, int error)
+{
+ int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
+ r1bio_t *r1_bio = bio->bi_private;
+ int mirror;
+ conf_t *conf = r1_bio->mddev->private;
+
+ mirror = r1_bio->read_disk;
+ /*
+ * this branch is our 'one mirror IO has finished' event handler:
+ */
+ update_head_pos(mirror, r1_bio);
+
+ if (uptodate)
+ set_bit(R1BIO_Uptodate, &r1_bio->state);
+ else {
+ /* If all other devices have failed, we want to return
+ * the error upwards rather than fail the last device.
+ * Here we redefine "uptodate" to mean "Don't want to retry"
+ */
+ unsigned long flags;
+ spin_lock_irqsave(&conf->device_lock, flags);
+ if (r1_bio->mddev->degraded == conf->raid_disks ||
+ (r1_bio->mddev->degraded == conf->raid_disks-1 &&
+ !test_bit(Faulty, &conf->mirrors[mirror].rdev->flags)))
+ uptodate = 1;
+ spin_unlock_irqrestore(&conf->device_lock, flags);
+ }
+
+ if (uptodate)
+ raid_end_bio_io(r1_bio);
+ else {
+ /*
+ * oops, read error:
+ */
+ char b[BDEVNAME_SIZE];
+ if (printk_ratelimit())
+ printk(KERN_ERR "md/raid1:%s: %s: rescheduling sector %llu\n",
+ mdname(conf->mddev),
+ bdevname(conf->mirrors[mirror].rdev->bdev,b), (unsigned long long)r1_bio->sector);
+ reschedule_retry(r1_bio);
+ }
+
+ rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev);
+}
+
+static void r1_bio_write_done(r1bio_t *r1_bio)
+{
+ if (atomic_dec_and_test(&r1_bio->remaining))
+ {
+ /* it really is the end of this request */
+ if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
+ /* free extra copy of the data pages */
+ int i = r1_bio->behind_page_count;
+ while (i--)
+ safe_put_page(r1_bio->behind_pages[i]);
+ kfree(r1_bio->behind_pages);
+ r1_bio->behind_pages = NULL;
+ }
+ /* 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_BehindIO, &r1_bio->state));
+ md_write_end(r1_bio->mddev);
+ raid_end_bio_io(r1_bio);
+ }
+}
+
+static void raid1_end_write_request(struct bio *bio, int error)
+{
+ int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
+ r1bio_t *r1_bio = bio->bi_private;
+ int mirror, behind = test_bit(R1BIO_BehindIO, &r1_bio->state);
+ conf_t *conf = r1_bio->mddev->private;
+ struct bio *to_put = NULL;
+
+
+ for (mirror = 0; mirror < conf->raid_disks; mirror++)
+ if (r1_bio->bios[mirror] == bio)
+ break;
+
+ /*
+ * 'one mirror IO has finished' event handler:
+ */
+ r1_bio->bios[mirror] = NULL;
+ to_put = bio;
+ if (!uptodate) {
+ md_error(r1_bio->mddev, conf->mirrors[mirror].rdev);
+ /* an I/O failed, we can't clear the bitmap */
+ set_bit(R1BIO_Degraded, &r1_bio->state);
+ } else
+ /*
+ * Set R1BIO_Uptodate in our master bio, so that we
+ * will return a good error code for to the higher
+ * levels even if IO on some other mirrored buffer
+ * fails.
+ *
+ * The 'master' represents the composite IO operation
+ * to user-side. So if something waits for IO, then it
+ * will wait for the 'master' bio.
+ */
+ set_bit(R1BIO_Uptodate, &r1_bio->state);
+
+ update_head_pos(mirror, r1_bio);
+
+ 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, 0);
+ }
+ }
+ }
+ rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev);
+
+ /*
+ * Let's see if all mirrored write operations have finished
+ * already.
+ */
+ r1_bio_write_done(r1_bio);
+
+ if (to_put)
+ bio_put(to_put);
+}
+
+
+/*
+ * This routine returns the disk from which the requested read should
+ * be done. There is a per-array 'next expected sequential IO' sector
+ * number - if this matches on the next IO then we use the last disk.
+ * There is also a per-disk 'last know head position' sector that is
+ * maintained from IRQ contexts, both the normal and the resync IO
+ * completion handlers update this position correctly. If there is no
+ * perfect sequential match then we pick the disk whose head is closest.
+ *
+ * If there are 2 mirrors in the same 2 devices, performance degrades
+ * because position is mirror, not device based.
+ *
+ * The rdev for the device selected will have nr_pending incremented.
+ */
+static int read_balance(conf_t *conf, r1bio_t *r1_bio)
+{
+ const sector_t this_sector = r1_bio->sector;
+ const int sectors = r1_bio->sectors;
+ int start_disk;
+ int best_disk;
+ int i;
+ sector_t best_dist;
+ mdk_rdev_t *rdev;
+ int choose_first;
+
+ rcu_read_lock();
+ /*
+ * Check if we can balance. We can balance on the whole
+ * device if no resync is going on, or below the resync window.
+ * We take the first readable disk when above the resync window.
+ */
+ retry:
+ best_disk = -1;
+ best_dist = MaxSector;
+ if (conf->mddev->recovery_cp < MaxSector &&
+ (this_sector + sectors >= conf->next_resync)) {
+ choose_first = 1;
+ start_disk = 0;
+ } else {
+ choose_first = 0;
+ start_disk = conf->last_used;
+ }
+
+ for (i = 0 ; i < conf->raid_disks ; i++) {
+ sector_t dist;
+ int disk = start_disk + i;
+ if (disk >= conf->raid_disks)
+ disk -= conf->raid_disks;
+
+ rdev = rcu_dereference(conf->mirrors[disk].rdev);
+ if (r1_bio->bios[disk] == IO_BLOCKED
+ || rdev == NULL
+ || test_bit(Faulty, &rdev->flags))
+ continue;
+ if (!test_bit(In_sync, &rdev->flags) &&
+ rdev->recovery_offset < this_sector + sectors)
+ continue;
+ if (test_bit(WriteMostly, &rdev->flags)) {
+ /* Don't balance among write-mostly, just
+ * use the first as a last resort */
+ if (best_disk < 0)
+ best_disk = disk;
+ continue;
+ }
+ /* This is a reasonable device to use. It might
+ * even be best.
+ */
+ dist = abs(this_sector - conf->mirrors[disk].head_position);
+ if (choose_first
+ /* Don't change to another disk for sequential reads */
+ || conf->next_seq_sect == this_sector
+ || dist == 0
+ /* If device is idle, use it */
+ || atomic_read(&rdev->nr_pending) == 0) {
+ best_disk = disk;
+ break;
+ }
+ if (dist < best_dist) {
+ best_dist = dist;
+ best_disk = disk;
+ }
+ }
+
+ if (best_disk >= 0) {
+ rdev = rcu_dereference(conf->mirrors[best_disk].rdev);
+ if (!rdev)
+ goto retry;
+ atomic_inc(&rdev->nr_pending);
+ if (test_bit(Faulty, &rdev->flags)) {
+ /* cannot risk returning a device that failed
+ * before we inc'ed nr_pending
+ */
+ rdev_dec_pending(rdev, conf->mddev);
+ goto retry;
+ }
+ conf->next_seq_sect = this_sector + sectors;
+ conf->last_used = best_disk;
+ }
+ rcu_read_unlock();
+
+ return best_disk;
+}
+
+int md_raid1_congested(mddev_t *mddev, int bits)
+{
+ conf_t *conf = mddev->private;
+ int i, ret = 0;
+
+ rcu_read_lock();
+ for (i = 0; i < mddev->raid_disks; i++) {
+ mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
+ if (rdev && !test_bit(Faulty, &rdev->flags)) {
+ struct request_queue *q = bdev_get_queue(rdev->bdev);
+
+ BUG_ON(!q);
+
+ /* Note the '|| 1' - when read_balance prefers
+ * non-congested targets, it can be removed
+ */
+ if ((bits & (1<<BDI_async_congested)) || 1)
+ ret |= bdi_congested(&q->backing_dev_info, bits);
+ else
+ ret &= bdi_congested(&q->backing_dev_info, bits);
+ }
+ }
+ rcu_read_unlock();
+ return ret;
+}
+EXPORT_SYMBOL_GPL(md_raid1_congested);
+
+static int max_queued = INT_MAX;
+static int raid1_congested(void *data, int bits)
+{
+ mddev_t *mddev = data;
+
+ return mddev_congested(mddev, bits) ||
+ md_raid1_congested(mddev, bits);
+}
+
+static void flush_pending_writes(conf_t *conf)
+{
+ /* Any writes that have been queued but are awaiting
+ * bitmap updates get flushed here.
+ */
+ spin_lock_irq(&conf->device_lock);
+
+ if (conf->pending_bio_list.head) {
+ struct bio *bio;
+ bio = bio_list_get(&conf->pending_bio_list);
+ spin_unlock_irq(&conf->device_lock);
+ /* flush any pending bitmap writes to
+ * disk before proceeding w/ I/O */
+ bitmap_unplug(conf->mddev->bitmap);
+
+ while (bio) { /* submit pending writes */
+ struct bio *next = bio->bi_next;
+ bio->bi_next = NULL;
+ generic_make_request(bio);
+ bio = next;
+ }
+ } else
+ spin_unlock_irq(&conf->device_lock);
+}
+
+/* Barriers....
+ * Sometimes we need to suspend IO while we do something else,
+ * either some resync/recovery, or reconfigure the array.
+ * To do this we raise a 'barrier'.
+ * The 'barrier' is a counter that can be raised multiple times
+ * to count how many activities are happening which preclude
+ * normal IO.
+ * We can only raise the barrier if there is no pending IO.
+ * i.e. if nr_pending == 0.
+ * We choose only to raise the barrier if no-one is waiting for the
+ * barrier to go down. This means that as soon as an IO request
+ * is ready, no other operations which require a barrier will start
+ * until the IO request has had a chance.
+ *
+ * So: regular IO calls 'wait_barrier'. When that returns there
+ * is no backgroup IO happening, It must arrange to call
+ * allow_barrier when it has finished its IO.
+ * backgroup IO calls must call raise_barrier. Once that returns
+ * there is no normal IO happeing. It must arrange to call
+ * lower_barrier when the particular background IO completes.
+ */
+#define RESYNC_DEPTH 32
+
+static void raise_barrier(conf_t *conf)
+{
+ spin_lock_irq(&conf->resync_lock);
+
+ /* Wait until no block IO is waiting */
+ wait_event_lock_irq(conf->wait_barrier, !conf->nr_waiting,
+ conf->resync_lock, );
+
+ /* block any new IO from starting */
+ conf->barrier++;
+
+ /* Now wait for all pending IO to complete */
+ wait_event_lock_irq(conf->wait_barrier,
+ !conf->nr_pending && conf->barrier < RESYNC_DEPTH,
+ conf->resync_lock, );
+
+ spin_unlock_irq(&conf->resync_lock);
+}
+
+static void lower_barrier(conf_t *conf)
+{
+ unsigned long flags;
+ BUG_ON(conf->barrier <= 0);
+ spin_lock_irqsave(&conf->resync_lock, flags);
+ conf->barrier--;
+ spin_unlock_irqrestore(&conf->resync_lock, flags);
+ wake_up(&conf->wait_barrier);
+}
+
+static void wait_barrier(conf_t *conf)
+{
+ spin_lock_irq(&conf->resync_lock);
+ if (conf->barrier) {
+ conf->nr_waiting++;
+ wait_event_lock_irq(conf->wait_barrier, !conf->barrier,
+ conf->resync_lock,
+ );
+ conf->nr_waiting--;
+ }
+ conf->nr_pending++;
+ spin_unlock_irq(&conf->resync_lock);
+}
+
+static void allow_barrier(conf_t *conf)
+{
+ unsigned long flags;
+ spin_lock_irqsave(&conf->resync_lock, flags);
+ conf->nr_pending--;
+ spin_unlock_irqrestore(&conf->resync_lock, flags);
+ wake_up(&conf->wait_barrier);
+}
+
+static void freeze_array(conf_t *conf)
+{
+ /* stop syncio and normal IO and wait for everything to
+ * go quite.
+ * We increment barrier and nr_waiting, and then
+ * wait until nr_pending match nr_queued+1
+ * This is called in the context of one normal IO request
+ * that has failed. Thus any sync request that might be pending
+ * will be blocked by nr_pending, and we need to wait for
+ * pending IO requests to complete or be queued for re-try.
+ * Thus the number queued (nr_queued) plus this request (1)
+ * must match the number of pending IOs (nr_pending) before
+ * we continue.
+ */
+ spin_lock_irq(&conf->resync_lock);
+ conf->barrier++;
+ conf->nr_waiting++;
+ wait_event_lock_irq(conf->wait_barrier,
+ conf->nr_pending == conf->nr_queued+1,
+ conf->resync_lock,
+ flush_pending_writes(conf));
+ spin_unlock_irq(&conf->resync_lock);
+}
+static void unfreeze_array(conf_t *conf)
+{
+ /* reverse the effect of the freeze */
+ spin_lock_irq(&conf->resync_lock);
+ conf->barrier--;
+ conf->nr_waiting--;
+ wake_up(&conf->wait_barrier);
+ spin_unlock_irq(&conf->resync_lock);
+}
+
+
+/* duplicate the data pages for behind I/O
+ */
+static void alloc_behind_pages(struct bio *bio, r1bio_t *r1_bio)
+{
+ int i;
+ struct bio_vec *bvec;
+ struct page **pages = kzalloc(bio->bi_vcnt * sizeof(struct page*),
+ GFP_NOIO);
+ if (unlikely(!pages))
+ return;
+
+ 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);
+ }
+ r1_bio->behind_pages = pages;
+ r1_bio->behind_page_count = bio->bi_vcnt;
+ set_bit(R1BIO_BehindIO, &r1_bio->state);
+ return;
+
+do_sync_io:
+ for (i = 0; i < bio->bi_vcnt; i++)
+ if (pages[i])
+ put_page(pages[i]);
+ kfree(pages);
+ PRINTK("%dB behind alloc failed, doing sync I/O\n", bio->bi_size);
+}
+
+static int make_request(mddev_t *mddev, struct bio * bio)
+{
+ conf_t *conf = mddev->private;
+ mirror_info_t *mirror;
+ r1bio_t *r1_bio;
+ struct bio *read_bio;
+ int i, targets = 0, disks;
+ struct bitmap *bitmap;
+ unsigned long flags;
+ const int rw = bio_data_dir(bio);
+ const unsigned long do_sync = (bio->bi_rw & REQ_SYNC);
+ const unsigned long do_flush_fua = (bio->bi_rw & (REQ_FLUSH | REQ_FUA));
+ mdk_rdev_t *blocked_rdev;
+ int plugged;
+
+ /*
+ * Register the new request and wait if the reconstruction
+ * thread has put up a bar for new requests.
+ * Continue immediately if no resync is active currently.
+ */
+
+ md_write_start(mddev, bio); /* wait on superblock update early */
+
+ if (bio_data_dir(bio) == WRITE &&
+ bio->bi_sector + bio->bi_size/512 > mddev->suspend_lo &&
+ bio->bi_sector < mddev->suspend_hi) {
+ /* As the suspend_* range is controlled by
+ * userspace, we want an interruptible
+ * wait.
+ */
+ DEFINE_WAIT(w);
+ for (;;) {
+ flush_signals(current);
+ prepare_to_wait(&conf->wait_barrier,
+ &w, TASK_INTERRUPTIBLE);
+ if (bio->bi_sector + bio->bi_size/512 <= mddev->suspend_lo ||
+ bio->bi_sector >= mddev->suspend_hi)
+ break;
+ schedule();
+ }
+ finish_wait(&conf->wait_barrier, &w);
+ }
+
+ wait_barrier(conf);
+
+ bitmap = mddev->bitmap;
+
+ /*
+ * make_request() can abort the operation when READA is being
+ * used and no empty request is available.
+ *
+ */
+ r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
+
+ r1_bio->master_bio = bio;
+ r1_bio->sectors = bio->bi_size >> 9;
+ r1_bio->state = 0;
+ r1_bio->mddev = mddev;
+ r1_bio->sector = bio->bi_sector;
+
+ if (rw == READ) {
+ /*
+ * read balancing logic:
+ */
+ int rdisk = read_balance(conf, r1_bio);
+
+ if (rdisk < 0) {
+ /* couldn't find anywhere to read from */
+ raid_end_bio_io(r1_bio);
+ return 0;
+ }
+ mirror = conf->mirrors + rdisk;
+
+ if (test_bit(WriteMostly, &mirror->rdev->flags) &&
+ bitmap) {
+ /* Reading from a write-mostly device must
+ * take care not to over-take any writes
+ * that are 'behind'
+ */
+ wait_event(bitmap->behind_wait,
+ atomic_read(&bitmap->behind_writes) == 0);
+ }
+ r1_bio->read_disk = rdisk;
+
+ read_bio = bio_clone_mddev(bio, GFP_NOIO, mddev);
+
+ r1_bio->bios[rdisk] = read_bio;
+
+ read_bio->bi_sector = r1_bio->sector + mirror->rdev->data_offset;
+ read_bio->bi_bdev = mirror->rdev->bdev;
+ read_bio->bi_end_io = raid1_end_read_request;
+ read_bio->bi_rw = READ | do_sync;
+ read_bio->bi_private = r1_bio;
+
+ generic_make_request(read_bio);
+ return 0;
+ }
+
+ /*
+ * WRITE:
+ */
+ /* first select target devices under spinlock and
+ * inc refcount on their rdev. Record them by setting
+ * bios[x] to bio
+ */
+ plugged = mddev_check_plugged(mddev);
+
+ disks = conf->raid_disks;
+ retry_write:
+ blocked_rdev = NULL;
+ rcu_read_lock();
+ for (i = 0; i < disks; i++) {
+ mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
+ if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
+ atomic_inc(&rdev->nr_pending);
+ blocked_rdev = rdev;
+ break;
+ }
+ if (rdev && !test_bit(Faulty, &rdev->flags)) {
+ atomic_inc(&rdev->nr_pending);
+ if (test_bit(Faulty, &rdev->flags)) {
+ rdev_dec_pending(rdev, mddev);
+ r1_bio->bios[i] = NULL;
+ } else {
+ r1_bio->bios[i] = bio;
+ targets++;
+ }
+ } else
+ r1_bio->bios[i] = NULL;
+ }
+ rcu_read_unlock();
+
+ if (unlikely(blocked_rdev)) {
+ /* Wait for this device to become unblocked */
+ int j;
+
+ for (j = 0; j < i; j++)
+ if (r1_bio->bios[j])
+ rdev_dec_pending(conf->mirrors[j].rdev, mddev);
+
+ allow_barrier(conf);
+ md_wait_for_blocked_rdev(blocked_rdev, mddev);
+ wait_barrier(conf);
+ goto retry_write;
+ }
+
+ 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 ?
+ * Not if there are too many, or cannot allocate memory,
+ * or a reader on WriteMostly is waiting for behind writes
+ * to flush */
+ if (bitmap &&
+ (atomic_read(&bitmap->behind_writes)
+ < mddev->bitmap_info.max_write_behind) &&
+ !waitqueue_active(&bitmap->behind_wait))
+ alloc_behind_pages(bio, r1_bio);
+
+ atomic_set(&r1_bio->remaining, 1);
+ atomic_set(&r1_bio->behind_remaining, 0);
+
+ bitmap_startwrite(bitmap, bio->bi_sector, r1_bio->sectors,
+ test_bit(R1BIO_BehindIO, &r1_bio->state));
+ for (i = 0; i < disks; i++) {
+ struct bio *mbio;
+ if (!r1_bio->bios[i])
+ continue;
+
+ mbio = bio_clone_mddev(bio, GFP_NOIO, mddev);
+ r1_bio->bios[i] = mbio;
+
+ mbio->bi_sector = r1_bio->sector + conf->mirrors[i].rdev->data_offset;
+ mbio->bi_bdev = conf->mirrors[i].rdev->bdev;
+ mbio->bi_end_io = raid1_end_write_request;
+ mbio->bi_rw = WRITE | do_flush_fua | do_sync;
+ mbio->bi_private = r1_bio;
+
+ if (r1_bio->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 original bi_idx, so we just free
+ * them all
+ */
+ __bio_for_each_segment(bvec, mbio, j, 0)
+ bvec->bv_page = r1_bio->behind_pages[j];
+ if (test_bit(WriteMostly, &conf->mirrors[i].rdev->flags))
+ atomic_inc(&r1_bio->behind_remaining);
+ }
+
+ atomic_inc(&r1_bio->remaining);
+ spin_lock_irqsave(&conf->device_lock, flags);
+ bio_list_add(&conf->pending_bio_list, mbio);
+ spin_unlock_irqrestore(&conf->device_lock, flags);
+ }
+ r1_bio_write_done(r1_bio);
+
+ /* In case raid1d snuck in to freeze_array */
+ wake_up(&conf->wait_barrier);
+
+ if (do_sync || !bitmap || !plugged)
+ md_wakeup_thread(mddev->thread);
+
+ return 0;
+}
+
+static void status(struct seq_file *seq, mddev_t *mddev)
+{
+ conf_t *conf = mddev->private;
+ int i;
+
+ seq_printf(seq, " [%d/%d] [", conf->raid_disks,
+ conf->raid_disks - mddev->degraded);
+ rcu_read_lock();
+ for (i = 0; i < conf->raid_disks; i++) {
+ mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
+ seq_printf(seq, "%s",
+ rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_");
+ }
+ rcu_read_unlock();
+ seq_printf(seq, "]");
+}
+
+
+static void error(mddev_t *mddev, mdk_rdev_t *rdev)
+{
+ char b[BDEVNAME_SIZE];
+ conf_t *conf = mddev->private;
+
+ /*
+ * If it is not operational, then we have already marked it as dead
+ * else if it is the last working disks, ignore the error, let the
+ * next level up know.
+ * else mark the drive as failed
+ */
+ if (test_bit(In_sync, &rdev->flags)
+ && (conf->raid_disks - mddev->degraded) == 1) {
+ /*
+ * Don't fail the drive, act as though we were just a
+ * normal single drive.
+ * However don't try a recovery from this drive as
+ * it is very likely to fail.
+ */
+ mddev->recovery_disabled = 1;
+ return;
+ }
+ if (test_and_clear_bit(In_sync, &rdev->flags)) {
+ unsigned long flags;
+ spin_lock_irqsave(&conf->device_lock, flags);
+ mddev->degraded++;
+ set_bit(Faulty, &rdev->flags);
+ spin_unlock_irqrestore(&conf->device_lock, flags);
+ /*
+ * if recovery is running, make sure it aborts.
+ */
+ set_bit(MD_RECOVERY_INTR, &mddev->recovery);
+ } else
+ set_bit(Faulty, &rdev->flags);
+ set_bit(MD_CHANGE_DEVS, &mddev->flags);
+ printk(KERN_ALERT
+ "md/raid1:%s: Disk failure on %s, disabling device.\n"
+ "md/raid1:%s: Operation continuing on %d devices.\n",
+ mdname(mddev), bdevname(rdev->bdev, b),
+ mdname(mddev), conf->raid_disks - mddev->degraded);
+}
+
+static void print_conf(conf_t *conf)
+{
+ int i;
+
+ printk(KERN_DEBUG "RAID1 conf printout:\n");
+ if (!conf) {
+ printk(KERN_DEBUG "(!conf)\n");
+ return;
+ }
+ printk(KERN_DEBUG " --- wd:%d rd:%d\n", conf->raid_disks - conf->mddev->degraded,
+ conf->raid_disks);
+
+ if ((bits & (1 << BDI_async_congested)) &&
+ conf->pending_count >= max_queued)
+ return 1;
+
+ rcu_read_lock();
+ for (i = 0; i < conf->raid_disks; i++) {
+ char b[BDEVNAME_SIZE];
+ mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
+ if (rdev)
+ printk(KERN_DEBUG " disk %d, wo:%d, o:%d, dev:%s\n",
+ i, !test_bit(In_sync, &rdev->flags),
+ !test_bit(Faulty, &rdev->flags),
+ bdevname(rdev->bdev,b));
+ }
+ rcu_read_unlock();
+}
+
+static void close_sync(conf_t *conf)
+{
+ wait_barrier(conf);
+ allow_barrier(conf);
+
+ mempool_destroy(conf->r1buf_pool);
+ conf->r1buf_pool = NULL;
+}
+
+static int raid1_spare_active(mddev_t *mddev)
+{
+ int i;
+ conf_t *conf = mddev->private;
+ int count = 0;
+ unsigned long flags;
+
+ /*
+ * Find all failed disks within the RAID1 configuration
+ * and mark them readable.
+ * Called under mddev lock, so rcu protection not needed.
+ */
+ for (i = 0; i < conf->raid_disks; i++) {
+ mdk_rdev_t *rdev = conf->mirrors[i].rdev;
+ if (rdev
+ && !test_bit(Faulty, &rdev->flags)
+ && !test_and_set_bit(In_sync, &rdev->flags)) {
+ count++;
+ sysfs_notify_dirent(rdev->sysfs_state);
+ }
+ }
+ spin_lock_irqsave(&conf->device_lock, flags);
+ mddev->degraded -= count;
+ spin_unlock_irqrestore(&conf->device_lock, flags);
+
+ print_conf(conf);
+ return count;
+}
+
+
+static int raid1_add_disk(mddev_t *mddev, mdk_rdev_t *rdev)
+{
+ conf_t *conf = mddev->private;
+ int err = -EEXIST;
+ int mirror = 0;
+ mirror_info_t *p;
+ int first = 0;
+ int last = mddev->raid_disks - 1;
+
+ if (rdev->raid_disk >= 0)
+ first = last = rdev->raid_disk;
+
+ for (mirror = first; mirror <= last; mirror++)
+ if ( !(p=conf->mirrors+mirror)->rdev) {
+
+ disk_stack_limits(mddev->gendisk, rdev->bdev,
+ rdev->data_offset << 9);
+ /* as we don't honour merge_bvec_fn, we must
+ * never risk violating it, so limit
+ * ->max_segments to one lying with a single
+ * page, as a one page request is never in
+ * violation.
+ */
+ if (rdev->bdev->bd_disk->queue->merge_bvec_fn) {
+ blk_queue_max_segments(mddev->queue, 1);
+ blk_queue_segment_boundary(mddev->queue,
+ PAGE_CACHE_SIZE - 1);
+ }
+
+ p->head_position = 0;
+ rdev->raid_disk = mirror;
+ err = 0;
+ /* As all devices are equivalent, we don't need a full recovery
+ * if this was recently any drive of the array
+ */
+ if (rdev->saved_raid_disk < 0)
+ conf->fullsync = 1;
+ rcu_assign_pointer(p->rdev, rdev);
+ break;
+ }
+ md_integrity_add_rdev(rdev, mddev);
+ print_conf(conf);
+ return err;
+}
+
+static int raid1_remove_disk(mddev_t *mddev, int number)
+{
+ conf_t *conf = mddev->private;
+ int err = 0;
+ mdk_rdev_t *rdev;
+ mirror_info_t *p = conf->mirrors+ number;
+
+ print_conf(conf);
+ rdev = p->rdev;
+ if (rdev) {
+ if (test_bit(In_sync, &rdev->flags) ||
+ atomic_read(&rdev->nr_pending)) {
+ err = -EBUSY;
+ goto abort;
+ }
+ /* Only remove non-faulty devices if recovery
+ * is not possible.
+ */
+ if (!test_bit(Faulty, &rdev->flags) &&
+ !mddev->recovery_disabled &&
+ mddev->degraded < conf->raid_disks) {
+ err = -EBUSY;
+ goto abort;
+ }
+ p->rdev = NULL;
+ synchronize_rcu();
+ if (atomic_read(&rdev->nr_pending)) {
+ /* lost the race, try later */
+ err = -EBUSY;
+ p->rdev = rdev;
+ goto abort;
+ }
+ err = md_integrity_register(mddev);
+ }
+abort:
+
+ print_conf(conf);
+ return err;
+}
+
+
+static void end_sync_read(struct bio *bio, int error)
+{
+ r1bio_t *r1_bio = bio->bi_private;
+ int i;
+
+ for (i=r1_bio->mddev->raid_disks; i--; )
+ if (r1_bio->bios[i] == bio)
+ break;
+ BUG_ON(i < 0);
+ update_head_pos(i, r1_bio);
+ /*
+ * we have read a block, now it needs to be re-written,
+ * or re-read if the read failed.
+ * We don't do much here, just schedule handling by raid1d
+ */
+ if (test_bit(BIO_UPTODATE, &bio->bi_flags))
+ set_bit(R1BIO_Uptodate, &r1_bio->state);
+
+ if (atomic_dec_and_test(&r1_bio->remaining))
+ reschedule_retry(r1_bio);
+}
+
+static void end_sync_write(struct bio *bio, int error)
+{
+ int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
+ r1bio_t *r1_bio = bio->bi_private;
+ mddev_t *mddev = r1_bio->mddev;
+ conf_t *conf = mddev->private;
+ int i;
+ int mirror=0;
+
+ for (i = 0; i < conf->raid_disks; i++)
+ if (r1_bio->bios[i] == bio) {
+ mirror = i;
+ break;
+ }
+ if (!uptodate) {
+ sector_t sync_blocks = 0;
+ sector_t s = r1_bio->sector;
+ long sectors_to_go = r1_bio->sectors;
+ /* make sure these bits doesn't get cleared. */
+ do {
+ bitmap_end_sync(mddev->bitmap, s,
+ &sync_blocks, 1);
+ s += sync_blocks;
+ sectors_to_go -= sync_blocks;
+ } while (sectors_to_go > 0);
+ md_error(mddev, conf->mirrors[mirror].rdev);
+ }
+
+ update_head_pos(mirror, r1_bio);
+
+ if (atomic_dec_and_test(&r1_bio->remaining)) {
+ sector_t s = r1_bio->sectors;
+ put_buf(r1_bio);
+ md_done_sync(mddev, s, uptodate);
+ }
+}
+
+static int fix_sync_read_error(r1bio_t *r1_bio)
+{
+ /* Try some synchronous reads of other devices to get
+ * good data, much like with normal read errors. Only
+ * read into the pages we already have so we don't
+ * need to re-issue the read request.
+ * We don't need to freeze the array, because being in an
+ * active sync request, there is no normal IO, and
+ * no overlapping syncs.
+ */
+ mddev_t *mddev = r1_bio->mddev;
+ conf_t *conf = mddev->private;
+ struct bio *bio = r1_bio->bios[r1_bio->read_disk];
+ sector_t sect = r1_bio->sector;
+ int sectors = r1_bio->sectors;
+ int idx = 0;
+
+ while(sectors) {
+ int s = sectors;
+ int d = r1_bio->read_disk;
+ int success = 0;
+ mdk_rdev_t *rdev;
+ int start;
+
+ if (s > (PAGE_SIZE>>9))
+ s = PAGE_SIZE >> 9;
+ do {
+ if (r1_bio->bios[d]->bi_end_io == end_sync_read) {
+ /* No rcu protection needed here devices
+ * can only be removed when no resync is
+ * active, and resync is currently active
+ */
+ rdev = conf->mirrors[d].rdev;
+ if (sync_page_io(rdev,
+ sect,
+ s<<9,
+ bio->bi_io_vec[idx].bv_page,
+ READ, false)) {
+ success = 1;
+ break;
+ }
+ }
+ d++;
+ if (d == conf->raid_disks)
+ d = 0;
+ } while (!success && d != r1_bio->read_disk);
+
+ if (!success) {
+ char b[BDEVNAME_SIZE];
+ /* Cannot read from anywhere, array is toast */
+ md_error(mddev, conf->mirrors[r1_bio->read_disk].rdev);
+ printk(KERN_ALERT "md/raid1:%s: %s: unrecoverable I/O read error"
+ " for block %llu\n",
+ mdname(mddev),
+ bdevname(bio->bi_bdev, b),
+ (unsigned long long)r1_bio->sector);
+ md_done_sync(mddev, r1_bio->sectors, 0);
+ put_buf(r1_bio);
+ return 0;
+ }
+
+ start = d;
+ /* write it back and re-read */
+ while (d != r1_bio->read_disk) {
+ if (d == 0)
+ d = conf->raid_disks;
+ d--;
+ if (r1_bio->bios[d]->bi_end_io != end_sync_read)
+ continue;
+ rdev = conf->mirrors[d].rdev;
+ if (sync_page_io(rdev,
+ sect,
+ s<<9,
+ bio->bi_io_vec[idx].bv_page,
+ WRITE, false) == 0) {
+ r1_bio->bios[d]->bi_end_io = NULL;
+ rdev_dec_pending(rdev, mddev);
+ md_error(mddev, rdev);
+ } else
+ atomic_add(s, &rdev->corrected_errors);
+ }
+ d = start;
+ while (d != r1_bio->read_disk) {
+ if (d == 0)
+ d = conf->raid_disks;
+ d--;
+ if (r1_bio->bios[d]->bi_end_io != end_sync_read)
+ continue;
+ rdev = conf->mirrors[d].rdev;
+ if (sync_page_io(rdev,
+ sect,
+ s<<9,
+ bio->bi_io_vec[idx].bv_page,
+ READ, false) == 0)
+ md_error(mddev, rdev);
+ }
+ sectors -= s;
+ sect += s;
+ idx ++;
+ }
+ set_bit(R1BIO_Uptodate, &r1_bio->state);
+ set_bit(BIO_UPTODATE, &bio->bi_flags);
+ return 1;
+}
+
+static int process_checks(r1bio_t *r1_bio)
+{
+ /* We have read all readable devices. If we haven't
+ * got the block, then there is no hope left.
+ * If we have, then we want to do a comparison
+ * and skip the write if everything is the same.
+ * If any blocks failed to read, then we need to
+ * attempt an over-write
+ */
+ mddev_t *mddev = r1_bio->mddev;
+ conf_t *conf = mddev->private;
+ int primary;
+ int i;
+
+ for (primary = 0; primary < conf->raid_disks; primary++)
+ if (r1_bio->bios[primary]->bi_end_io == end_sync_read &&
+ test_bit(BIO_UPTODATE, &r1_bio->bios[primary]->bi_flags)) {
+ r1_bio->bios[primary]->bi_end_io = NULL;
+ rdev_dec_pending(conf->mirrors[primary].rdev, mddev);
+ break;
+ }
+ r1_bio->read_disk = primary;
+ for (i = 0; i < conf->raid_disks; i++) {
+ int j;
+ int vcnt = r1_bio->sectors >> (PAGE_SHIFT- 9);
+ struct bio *pbio = r1_bio->bios[primary];
+ struct bio *sbio = r1_bio->bios[i];
+ int size;
+
+ if (r1_bio->bios[i]->bi_end_io != end_sync_read)
+ continue;
+
+ if (test_bit(BIO_UPTODATE, &sbio->bi_flags)) {
+ for (j = vcnt; j-- ; ) {
+ struct page *p, *s;
+ p = pbio->bi_io_vec[j].bv_page;
+ s = sbio->bi_io_vec[j].bv_page;
+ if (memcmp(page_address(p),
+ page_address(s),
+ PAGE_SIZE))
+ break;
+ }
+ } else
+ j = 0;
+ if (j >= 0)
+ mddev->resync_mismatches += r1_bio->sectors;
+ if (j < 0 || (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)
+ && test_bit(BIO_UPTODATE, &sbio->bi_flags))) {
+ /* No need to write to this device. */
+ sbio->bi_end_io = NULL;
+ rdev_dec_pending(conf->mirrors[i].rdev, mddev);
+ continue;
+ }
+ /* fixup the bio for reuse */
+ sbio->bi_vcnt = vcnt;
+ sbio->bi_size = r1_bio->sectors << 9;
+ sbio->bi_idx = 0;
+ sbio->bi_phys_segments = 0;
+ sbio->bi_flags &= ~(BIO_POOL_MASK - 1);
+ sbio->bi_flags |= 1 << BIO_UPTODATE;
+ sbio->bi_next = NULL;
+ sbio->bi_sector = r1_bio->sector +
+ conf->mirrors[i].rdev->data_offset;
+ sbio->bi_bdev = conf->mirrors[i].rdev->bdev;
+ size = sbio->bi_size;
+ for (j = 0; j < vcnt ; j++) {
+ struct bio_vec *bi;
+ bi = &sbio->bi_io_vec[j];
+ bi->bv_offset = 0;
+ if (size > PAGE_SIZE)
+ bi->bv_len = PAGE_SIZE;
+ else
+ bi->bv_len = size;
+ size -= PAGE_SIZE;
+ memcpy(page_address(bi->bv_page),
+ page_address(pbio->bi_io_vec[j].bv_page),
+ PAGE_SIZE);
+ }
+ }
+ return 0;
+}
+
+static void sync_request_write(mddev_t *mddev, r1bio_t *r1_bio)
+{
+ conf_t *conf = mddev->private;
+ int i;
+ int disks = conf->raid_disks;
+ struct bio *bio, *wbio;
+
+ bio = r1_bio->bios[r1_bio->read_disk];
+
+ if (!test_bit(R1BIO_Uptodate, &r1_bio->state))
+ /* ouch - failed to read all of that. */
+ if (!fix_sync_read_error(r1_bio))
+ return;
+
+ if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
+ if (process_checks(r1_bio) < 0)
+ return;
+ /*
+ * schedule writes
+ */
+ atomic_set(&r1_bio->remaining, 1);
+ for (i = 0; i < disks ; i++) {
+ wbio = r1_bio->bios[i];
+ if (wbio->bi_end_io == NULL ||
+ (wbio->bi_end_io == end_sync_read &&
+ (i == r1_bio->read_disk ||
+ !test_bit(MD_RECOVERY_SYNC, &mddev->recovery))))
+ continue;
+
+ wbio->bi_rw = WRITE;
+ wbio->bi_end_io = end_sync_write;
+ atomic_inc(&r1_bio->remaining);
+ md_sync_acct(conf->mirrors[i].rdev->bdev, wbio->bi_size >> 9);
+
+ generic_make_request(wbio);
+ }
+
+ if (atomic_dec_and_test(&r1_bio->remaining)) {
+ /* if we're here, all write(s) have completed, so clean up */
+ md_done_sync(mddev, r1_bio->sectors, 1);
+ put_buf(r1_bio);
+ }
+}
+
+/*
+ * This is a kernel thread which:
+ *
+ * 1. Retries failed read operations on working mirrors.
+ * 2. Updates the raid superblock when problems encounter.
+ * 3. Performs writes following reads for array syncronising.
+ */
+
+static void fix_read_error(conf_t *conf, int read_disk,
+ sector_t sect, int sectors)
+{
+ mddev_t *mddev = conf->mddev;
+ while(sectors) {
+ int s = sectors;
+ int d = read_disk;
+ int success = 0;
+ int start;
+ mdk_rdev_t *rdev;
+
+ if (s > (PAGE_SIZE>>9))
+ s = PAGE_SIZE >> 9;
+
+ do {
+ /* Note: no rcu protection needed here
+ * as this is synchronous in the raid1d thread
+ * which is the thread that might remove
+ * a device. If raid1d ever becomes multi-threaded....
+ */
+ rdev = conf->mirrors[d].rdev;
+ if (rdev &&
+ test_bit(In_sync, &rdev->flags) &&
+ sync_page_io(rdev, sect, s<<9,
+ conf->tmppage, READ, false))
+ success = 1;
+ else {
+ d++;
+ if (d == conf->raid_disks)
+ d = 0;
+ }
+ } while (!success && d != read_disk);
+
+ if (!success) {
+ /* Cannot read from anywhere -- bye bye array */
+ md_error(mddev, conf->mirrors[read_disk].rdev);
+ break;
+ }
+ /* write it back and re-read */
+ start = d;
+ while (d != read_disk) {
+ if (d==0)
+ d = conf->raid_disks;
+ d--;
+ rdev = conf->mirrors[d].rdev;
+ if (rdev &&
+ test_bit(In_sync, &rdev->flags)) {
+ if (sync_page_io(rdev, sect, s<<9,
+ conf->tmppage, WRITE, false)
+ == 0)
+ /* Well, this device is dead */
+ md_error(mddev, rdev);
+ }
+ }
+ d = start;
+ while (d != read_disk) {
+ char b[BDEVNAME_SIZE];
+ if (d==0)
+ d = conf->raid_disks;
+ d--;
+ rdev = conf->mirrors[d].rdev;
+ if (rdev &&
+ test_bit(In_sync, &rdev->flags)) {
+ if (sync_page_io(rdev, sect, s<<9,
+ conf->tmppage, READ, false)
+ == 0)
+ /* Well, this device is dead */
+ md_error(mddev, rdev);
+ else {
+ atomic_add(s, &rdev->corrected_errors);
+ printk(KERN_INFO
+ "md/raid1:%s: read error corrected "
+ "(%d sectors at %llu on %s)\n",
+ mdname(mddev), s,
+ (unsigned long long)(sect +
+ rdev->data_offset),
+ bdevname(rdev->bdev, b));
+ }
+ }
+ }
+ sectors -= s;
+ sect += s;
+ }
+}
+
+static void raid1d(mddev_t *mddev)
+{
+ r1bio_t *r1_bio;
+ struct bio *bio;
+ unsigned long flags;
+ conf_t *conf = mddev->private;
+ struct list_head *head = &conf->retry_list;
+ mdk_rdev_t *rdev;
+ struct blk_plug plug;
+
+ md_check_recovery(mddev);
+
+ blk_start_plug(&plug);
+ for (;;) {
+ char b[BDEVNAME_SIZE];
+
+ if (atomic_read(&mddev->plug_cnt) == 0)
+ flush_pending_writes(conf);
+
+ spin_lock_irqsave(&conf->device_lock, flags);
+ if (list_empty(head)) {
+ spin_unlock_irqrestore(&conf->device_lock, flags);
+ break;
+ }
+ r1_bio = list_entry(head->prev, r1bio_t, retry_list);
+ list_del(head->prev);
+ conf->nr_queued--;
+ spin_unlock_irqrestore(&conf->device_lock, flags);
+
+ mddev = r1_bio->mddev;
+ conf = mddev->private;
+ if (test_bit(R1BIO_IsSync, &r1_bio->state))
+ sync_request_write(mddev, r1_bio);
+ else {
+ int disk;
+
+ /* we got a read error. Maybe the drive is bad. Maybe just
+ * the block and we can fix it.
+ * We freeze all other IO, and try reading the block from
+ * other devices. When we find one, we re-write
+ * and check it that fixes the read error.
+ * This is all done synchronously while the array is
+ * frozen
+ */
+ if (mddev->ro == 0) {
+ freeze_array(conf);
+ fix_read_error(conf, r1_bio->read_disk,
+ r1_bio->sector,
+ r1_bio->sectors);
+ unfreeze_array(conf);
+ } else
+ md_error(mddev,
+ conf->mirrors[r1_bio->read_disk].rdev);
+
+ bio = r1_bio->bios[r1_bio->read_disk];
+ if ((disk=read_balance(conf, r1_bio)) == -1) {
+ printk(KERN_ALERT "md/raid1:%s: %s: unrecoverable I/O"
+ " read error for block %llu\n",
+ mdname(mddev),
+ bdevname(bio->bi_bdev,b),
+ (unsigned long long)r1_bio->sector);
+ raid_end_bio_io(r1_bio);
+ } else {
+ const unsigned long do_sync = r1_bio->master_bio->bi_rw & REQ_SYNC;
+ r1_bio->bios[r1_bio->read_disk] =
+ mddev->ro ? IO_BLOCKED : NULL;
+ r1_bio->read_disk = disk;
+ bio_put(bio);
+ bio = bio_clone_mddev(r1_bio->master_bio,
+ GFP_NOIO, mddev);
+ r1_bio->bios[r1_bio->read_disk] = bio;
+ rdev = conf->mirrors[disk].rdev;
+ if (printk_ratelimit())
+ printk(KERN_ERR "md/raid1:%s: redirecting sector %llu to"
+ " other mirror: %s\n",
+ mdname(mddev),
+ (unsigned long long)r1_bio->sector,
+ bdevname(rdev->bdev,b));
+ bio->bi_sector = r1_bio->sector + rdev->data_offset;
+ bio->bi_bdev = rdev->bdev;
+ bio->bi_end_io = raid1_end_read_request;
+ bio->bi_rw = READ | do_sync;
+ bio->bi_private = r1_bio;
+ generic_make_request(bio);
+ }
+ }
+ cond_resched();
+ }
+ blk_finish_plug(&plug);
+}
+
+
+static int init_resync(conf_t *conf)
+{
+ int buffs;
+
+ buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE;
+ BUG_ON(conf->r1buf_pool);
+ conf->r1buf_pool = mempool_create(buffs, r1buf_pool_alloc, r1buf_pool_free,
+ conf->poolinfo);
+ if (!conf->r1buf_pool)
+ return -ENOMEM;
+ conf->next_resync = 0;
+ return 0;
+}
+
+/*
+ * perform a "sync" on one "block"
+ *
+ * We need to make sure that no normal I/O request - particularly write
+ * requests - conflict with active sync requests.
+ *
+ * This is achieved by tracking pending requests and a 'barrier' concept
+ * that can be installed to exclude normal IO requests.
+ */
+
+static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster)
+{
+ conf_t *conf = mddev->private;
+ r1bio_t *r1_bio;
+ struct bio *bio;
+ sector_t max_sector, nr_sectors;
+ int disk = -1;
+ int i;
+ int wonly = -1;
+ int write_targets = 0, read_targets = 0;
+ sector_t sync_blocks;
+ int still_degraded = 0;
+
+ if (!conf->r1buf_pool)
+ if (init_resync(conf))
+ return 0;
+
+ max_sector = mddev->dev_sectors;
+ if (sector_nr >= max_sector) {
+ /* If we aborted, we need to abort the
+ * sync on the 'current' bitmap chunk (there will
+ * only be one in raid1 resync.
+ * We can find the current addess in mddev->curr_resync
+ */
+ if (mddev->curr_resync < max_sector) /* aborted */
+ bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
+ &sync_blocks, 1);
+ else /* completed sync */
+ conf->fullsync = 0;
+
+ bitmap_close_sync(mddev->bitmap);
+ close_sync(conf);
+ return 0;
+ }
+
+ if (mddev->bitmap == NULL &&
+ mddev->recovery_cp == MaxSector &&
+ !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
+ conf->fullsync == 0) {
+ *skipped = 1;
+ return max_sector - sector_nr;
+ }
+ /* before building a request, check if we can skip these blocks..
+ * This call the bitmap_start_sync doesn't actually record anything
+ */
+ if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
+ !conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
+ /* We can skip this block, and probably several more */
+ *skipped = 1;
+ return sync_blocks;
+ }
+ /*
+ * If there is non-resync activity waiting for a turn,
+ * and resync is going fast enough,
+ * then let it though before starting on this new sync request.
+ */
+ if (!go_faster && conf->nr_waiting)
+ msleep_interruptible(1000);
+
+ bitmap_cond_end_sync(mddev->bitmap, sector_nr);
+ r1_bio = mempool_alloc(conf->r1buf_pool, GFP_NOIO);
+ raise_barrier(conf);
+
+ conf->next_resync = sector_nr;
+
+ rcu_read_lock();
+ /*
+ * If we get a correctably read error during resync or recovery,
+ * we might want to read from a different device. So we
+ * flag all drives that could conceivably be read from for READ,
+ * and any others (which will be non-In_sync devices) for WRITE.
+ * If a read fails, we try reading from something else for which READ
+ * is OK.
+ */
+
+ r1_bio->mddev = mddev;
+ r1_bio->sector = sector_nr;
+ r1_bio->state = 0;
+ set_bit(R1BIO_IsSync, &r1_bio->state);
+
+ for (i=0; i < conf->raid_disks; i++) {
+ mdk_rdev_t *rdev;
+ bio = r1_bio->bios[i];
+
+ /* take from bio_init */
+ bio->bi_next = NULL;
+ bio->bi_flags &= ~(BIO_POOL_MASK-1);
+ bio->bi_flags |= 1 << BIO_UPTODATE;
+ bio->bi_comp_cpu = -1;
+ bio->bi_rw = READ;
+ bio->bi_vcnt = 0;
+ bio->bi_idx = 0;
+ bio->bi_phys_segments = 0;
+ bio->bi_size = 0;
+ bio->bi_end_io = NULL;
+ bio->bi_private = NULL;
+
+ rdev = rcu_dereference(conf->mirrors[i].rdev);
+ if (rdev == NULL ||
+ test_bit(Faulty, &rdev->flags)) {
+ still_degraded = 1;
+ continue;
+ } else if (!test_bit(In_sync, &rdev->flags)) {
+ bio->bi_rw = WRITE;
+ bio->bi_end_io = end_sync_write;
+ write_targets ++;
+ } else {
+ /* may need to read from here */
+ bio->bi_rw = READ;
+ bio->bi_end_io = end_sync_read;
+ if (test_bit(WriteMostly, &rdev->flags)) {
+ if (wonly < 0)
+ wonly = i;
+ } else {
+ if (disk < 0)
+ disk = i;
+ }
+ read_targets++;
+ }
+ atomic_inc(&rdev->nr_pending);
+ bio->bi_sector = sector_nr + rdev->data_offset;
+ bio->bi_bdev = rdev->bdev;
+ bio->bi_private = r1_bio;
+ }
+ rcu_read_unlock();
+ if (disk < 0)
+ disk = wonly;
+ r1_bio->read_disk = disk;
+
+ if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) && read_targets > 0)
+ /* extra read targets are also write targets */
+ write_targets += read_targets-1;
+
+ if (write_targets == 0 || read_targets == 0) {
+ /* There is nowhere to write, so all non-sync
+ * drives must be failed - so we are finished
+ */
+ sector_t rv = max_sector - sector_nr;
+ *skipped = 1;
+ put_buf(r1_bio);
+ return rv;
+ }
+
+ if (max_sector > mddev->resync_max)
+ max_sector = mddev->resync_max; /* Don't do IO beyond here */
+ nr_sectors = 0;
+ sync_blocks = 0;
+ do {
+ struct page *page;
+ int len = PAGE_SIZE;
+ if (sector_nr + (len>>9) > max_sector)
+ len = (max_sector - sector_nr) << 9;
+ if (len == 0)
+ break;
+ if (sync_blocks == 0) {
+ if (!bitmap_start_sync(mddev->bitmap, sector_nr,
+ &sync_blocks, still_degraded) &&
+ !conf->fullsync &&
+ !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
+ break;
+ BUG_ON(sync_blocks < (PAGE_SIZE>>9));
+ if ((len >> 9) > sync_blocks)
+ len = sync_blocks<<9;
+ }
+
+ for (i=0 ; i < conf->raid_disks; i++) {
+ bio = r1_bio->bios[i];
+ if (bio->bi_end_io) {
+ page = bio->bi_io_vec[bio->bi_vcnt].bv_page;
+ if (bio_add_page(bio, page, len, 0) == 0) {
+ /* stop here */
+ bio->bi_io_vec[bio->bi_vcnt].bv_page = page;
+ while (i > 0) {
+ i--;
+ bio = r1_bio->bios[i];
+ if (bio->bi_end_io==NULL)
+ continue;
+ /* remove last page from this bio */
+ bio->bi_vcnt--;
+ bio->bi_size -= len;
+ bio->bi_flags &= ~(1<< BIO_SEG_VALID);
+ }
+ goto bio_full;
+ }
+ }
+ }
+ nr_sectors += len>>9;
+ sector_nr += len>>9;
+ sync_blocks -= (len>>9);
+ } while (r1_bio->bios[disk]->bi_vcnt < RESYNC_PAGES);
+ bio_full:
+ r1_bio->sectors = nr_sectors;
+
+ /* For a user-requested sync, we read all readable devices and do a
+ * compare
+ */
+ if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
+ atomic_set(&r1_bio->remaining, read_targets);
+ for (i=0; i<conf->raid_disks; i++) {
+ bio = r1_bio->bios[i];
+ if (bio->bi_end_io == end_sync_read) {
+ md_sync_acct(bio->bi_bdev, nr_sectors);
+ generic_make_request(bio);
+ }
+ }
+ } else {
+ atomic_set(&r1_bio->remaining, 1);
+ bio = r1_bio->bios[r1_bio->read_disk];
+ md_sync_acct(bio->bi_bdev, nr_sectors);
+ generic_make_request(bio);
+
+ }
+ return nr_sectors;
+}
+
+static sector_t raid1_size(mddev_t *mddev, sector_t sectors, int raid_disks)
+{
+ if (sectors)
+ return sectors;
+
+ return mddev->dev_sectors;
+}
+
+static conf_t *setup_conf(mddev_t *mddev)
+{
+ conf_t *conf;
+ int i;
+ mirror_info_t *disk;
+ mdk_rdev_t *rdev;
+ int err = -ENOMEM;
+
+ conf = kzalloc(sizeof(conf_t), GFP_KERNEL);
+ if (!conf)
+ goto abort;
+
+ conf->mirrors = kzalloc(sizeof(struct mirror_info)*mddev->raid_disks,
+ GFP_KERNEL);
+ if (!conf->mirrors)
+ goto abort;
+
+ conf->tmppage = alloc_page(GFP_KERNEL);
+ if (!conf->tmppage)
+ goto abort;
+
+ conf->poolinfo = kzalloc(sizeof(*conf->poolinfo), GFP_KERNEL);
+ if (!conf->poolinfo)
+ goto abort;
+ conf->poolinfo->raid_disks = mddev->raid_disks;
+ conf->r1bio_pool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
+ r1bio_pool_free,
+ conf->poolinfo);
+ if (!conf->r1bio_pool)
+ goto abort;
+
+ conf->poolinfo->mddev = mddev;
+
+ spin_lock_init(&conf->device_lock);
+ list_for_each_entry(rdev, &mddev->disks, same_set) {
+ int disk_idx = rdev->raid_disk;
+ if (disk_idx >= mddev->raid_disks
+ || disk_idx < 0)
+ continue;
+ disk = conf->mirrors + disk_idx;
+
+ disk->rdev = rdev;
+
+ disk->head_position = 0;
+ }
+ conf->raid_disks = mddev->raid_disks;
+ conf->mddev = mddev;
+ INIT_LIST_HEAD(&conf->retry_list);
+
+ spin_lock_init(&conf->resync_lock);
+ init_waitqueue_head(&conf->wait_barrier);
+
+ bio_list_init(&conf->pending_bio_list);
+
+ conf->last_used = -1;
+ for (i = 0; i < conf->raid_disks; i++) {
+
+ disk = conf->mirrors + i;
+
+ if (!disk->rdev ||
+ !test_bit(In_sync, &disk->rdev->flags)) {
+ disk->head_position = 0;
+ if (disk->rdev)
+ conf->fullsync = 1;
+ } else if (conf->last_used < 0)
+ /*
+ * The first working device is used as a
+ * starting point to read balancing.
+ */
+ conf->last_used = i;
+ }
+
+ err = -EIO;
+ if (conf->last_used < 0) {
+ printk(KERN_ERR "md/raid1:%s: no operational mirrors\n",
+ mdname(mddev));
+ goto abort;
+ }
+ err = -ENOMEM;
+ conf->thread = md_register_thread(raid1d, mddev, NULL);
+ if (!conf->thread) {
+ printk(KERN_ERR
+ "md/raid1:%s: couldn't allocate thread\n",
+ mdname(mddev));
+ goto abort;
+ }
+
+ return conf;
+
+ abort:
+ if (conf) {
+ if (conf->r1bio_pool)
+ mempool_destroy(conf->r1bio_pool);
+ kfree(conf->mirrors);
+ safe_put_page(conf->tmppage);
+ kfree(conf->poolinfo);
+ kfree(conf);
+ }
+ return ERR_PTR(err);
+}
+
+static int run(mddev_t *mddev)
+{
+ conf_t *conf;
+ int i;
+ mdk_rdev_t *rdev;
+
+ if (mddev->level != 1) {
+ printk(KERN_ERR "md/raid1:%s: raid level not set to mirroring (%d)\n",
+ mdname(mddev), mddev->level);
+ return -EIO;
+ }
+ if (mddev->reshape_position != MaxSector) {
+ printk(KERN_ERR "md/raid1:%s: reshape_position set but not supported\n",
+ mdname(mddev));
+ return -EIO;
+ }
+ /*
+ * copy the already verified devices into our private RAID1
+ * bookkeeping area. [whatever we allocate in run(),
+ * should be freed in stop()]
+ */
+ if (mddev->private == NULL)
+ conf = setup_conf(mddev);
+ else
+ conf = mddev->private;
+
+ if (IS_ERR(conf))
+ return PTR_ERR(conf);
+
+ list_for_each_entry(rdev, &mddev->disks, same_set) {
+ if (!mddev->gendisk)
+ continue;
+ disk_stack_limits(mddev->gendisk, rdev->bdev,
+ rdev->data_offset << 9);
+ /* as we don't honour merge_bvec_fn, we must never risk
+ * violating it, so limit ->max_segments to 1 lying within
+ * a single page, as a one page request is never in violation.
+ */
+ if (rdev->bdev->bd_disk->queue->merge_bvec_fn) {
+ blk_queue_max_segments(mddev->queue, 1);
+ blk_queue_segment_boundary(mddev->queue,
+ PAGE_CACHE_SIZE - 1);
+ }
+ }
+
+ mddev->degraded = 0;
+ for (i=0; i < conf->raid_disks; i++)
+ if (conf->mirrors[i].rdev == NULL ||
+ !test_bit(In_sync, &conf->mirrors[i].rdev->flags) ||
+ test_bit(Faulty, &conf->mirrors[i].rdev->flags))
+ mddev->degraded++;
+
+ if (conf->raid_disks - mddev->degraded == 1)
+ mddev->recovery_cp = MaxSector;
+
+ if (mddev->recovery_cp != MaxSector)
+ printk(KERN_NOTICE "md/raid1:%s: not clean"
+ " -- starting background reconstruction\n",
+ mdname(mddev));
+ printk(KERN_INFO
+ "md/raid1:%s: active with %d out of %d mirrors\n",
+ mdname(mddev), mddev->raid_disks - mddev->degraded,
+ mddev->raid_disks);
+
+ /*
+ * Ok, everything is just fine now
+ */
+ mddev->thread = conf->thread;
+ conf->thread = NULL;
+ mddev->private = conf;
+
+ md_set_array_sectors(mddev, raid1_size(mddev, 0, 0));
+
+ if (mddev->queue) {
+ mddev->queue->backing_dev_info.congested_fn = raid1_congested;
+ mddev->queue->backing_dev_info.congested_data = mddev;
+ }
+ return md_integrity_register(mddev);
+}
+
+static int stop(mddev_t *mddev)
+{
+ conf_t *conf = mddev->private;
+ struct bitmap *bitmap = mddev->bitmap;
+
+ /* wait for behind writes to complete */
+ if (bitmap && atomic_read(&bitmap->behind_writes) > 0) {
+ printk(KERN_INFO "md/raid1:%s: behind writes in progress - waiting to stop.\n",
+ mdname(mddev));
+ /* need to kick something here to make sure I/O goes? */
+ wait_event(bitmap->behind_wait,
+ atomic_read(&bitmap->behind_writes) == 0);
+ }
+
+ raise_barrier(conf);
+ lower_barrier(conf);
+
+ md_unregister_thread(mddev->thread);
+ mddev->thread = NULL;
+ if (conf->r1bio_pool)
+ mempool_destroy(conf->r1bio_pool);
+ kfree(conf->mirrors);
+ kfree(conf->poolinfo);
+ kfree(conf);
+ mddev->private = NULL;
+ return 0;
+}
+
+static int raid1_resize(mddev_t *mddev, sector_t sectors)
+{
+ /* no resync is happening, and there is enough space
+ * on all devices, so we can resize.
+ * We need to make sure resync covers any new space.
+ * If the array is shrinking we should possibly wait until
+ * any io in the removed space completes, but it hardly seems
+ * worth it.
+ */
+ md_set_array_sectors(mddev, raid1_size(mddev, sectors, 0));
+ if (mddev->array_sectors > raid1_size(mddev, sectors, 0))
+ return -EINVAL;
+ set_capacity(mddev->gendisk, mddev->array_sectors);
+ revalidate_disk(mddev->gendisk);
+ if (sectors > mddev->dev_sectors &&
+ mddev->recovery_cp > mddev->dev_sectors) {
+ mddev->recovery_cp = mddev->dev_sectors;
+ set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
+ }
+ mddev->dev_sectors = sectors;
+ mddev->resync_max_sectors = sectors;
+ return 0;
+}
+
+static int raid1_reshape(mddev_t *mddev)
+{
+ /* We need to:
+ * 1/ resize the r1bio_pool
+ * 2/ resize conf->mirrors
+ *
+ * We allocate a new r1bio_pool if we can.
+ * Then raise a device barrier and wait until all IO stops.
+ * Then resize conf->mirrors and swap in the new r1bio pool.
+ *
+ * At the same time, we "pack" the devices so that all the missing
+ * devices have the higher raid_disk numbers.
+ */
+ mempool_t *newpool, *oldpool;
+ struct pool_info *newpoolinfo;
+ mirror_info_t *newmirrors;
+ conf_t *conf = mddev->private;
+ int cnt, raid_disks;
+ unsigned long flags;
+ int d, d2, err;
+
+ /* Cannot change chunk_size, layout, or level */
+ if (mddev->chunk_sectors != mddev->new_chunk_sectors ||
+ mddev->layout != mddev->new_layout ||
+ mddev->level != mddev->new_level) {
+ mddev->new_chunk_sectors = mddev->chunk_sectors;
+ mddev->new_layout = mddev->layout;
+ mddev->new_level = mddev->level;
+ return -EINVAL;
+ }
+
+ err = md_allow_write(mddev);
+ if (err)
+ return err;
+
+ raid_disks = mddev->raid_disks + mddev->delta_disks;
+
+ if (raid_disks < conf->raid_disks) {
+ cnt=0;
+ for (d= 0; d < conf->raid_disks; d++)
+ if (conf->mirrors[d].rdev)
+ cnt++;
+ if (cnt > raid_disks)
+ return -EBUSY;
+ }
+
+ newpoolinfo = kmalloc(sizeof(*newpoolinfo), GFP_KERNEL);
+ if (!newpoolinfo)
+ return -ENOMEM;
+ newpoolinfo->mddev = mddev;
+ newpoolinfo->raid_disks = raid_disks;
+
+ newpool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
+ r1bio_pool_free, newpoolinfo);
+ if (!newpool) {
+ kfree(newpoolinfo);
+ return -ENOMEM;
+ }
+ newmirrors = kzalloc(sizeof(struct mirror_info) * raid_disks, GFP_KERNEL);
+ if (!newmirrors) {
+ kfree(newpoolinfo);
+ mempool_destroy(newpool);
+ return -ENOMEM;
+ }
+
+ raise_barrier(conf);
+
+ /* ok, everything is stopped */
+ oldpool = conf->r1bio_pool;
+ conf->r1bio_pool = newpool;
+
+ for (d = d2 = 0; d < conf->raid_disks; d++) {
+ mdk_rdev_t *rdev = conf->mirrors[d].rdev;
+ if (rdev && rdev->raid_disk != d2) {
+ char nm[20];
+ sprintf(nm, "rd%d", rdev->raid_disk);
+ sysfs_remove_link(&mddev->kobj, nm);
+ rdev->raid_disk = d2;
+ sprintf(nm, "rd%d", rdev->raid_disk);
+ sysfs_remove_link(&mddev->kobj, nm);
+ if (sysfs_create_link(&mddev->kobj,
+ &rdev->kobj, nm))
+ printk(KERN_WARNING
+ "md/raid1:%s: cannot register "
+ "%s\n",
+ mdname(mddev), nm);
+ }
+ if (rdev)
+ newmirrors[d2++].rdev = rdev;
+ }
+ kfree(conf->mirrors);
+ conf->mirrors = newmirrors;
+ kfree(conf->poolinfo);
+ conf->poolinfo = newpoolinfo;
+
+ spin_lock_irqsave(&conf->device_lock, flags);
+ mddev->degraded += (raid_disks - conf->raid_disks);
+ spin_unlock_irqrestore(&conf->device_lock, flags);
+ conf->raid_disks = mddev->raid_disks = raid_disks;
+ mddev->delta_disks = 0;
+
+ conf->last_used = 0; /* just make sure it is in-range */
+ lower_barrier(conf);
+
+ set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
+ md_wakeup_thread(mddev->thread);
+
+ mempool_destroy(oldpool);
+ return 0;
+}
+
+static void raid1_quiesce(mddev_t *mddev, int state)
+{
+ conf_t *conf = mddev->private;
+
+ switch(state) {
+ case 2: /* wake for suspend */
+ wake_up(&conf->wait_barrier);
+ break;
+ case 1:
+ raise_barrier(conf);
+ break;
+ case 0:
+ lower_barrier(conf);
+ break;
+ }
+}
+
+static void *raid1_takeover(mddev_t *mddev)
+{
+ /* raid1 can take over:
+ * raid5 with 2 devices, any layout or chunk size
+ */
+ if (mddev->level == 5 && mddev->raid_disks == 2) {
+ conf_t *conf;
+ mddev->new_level = 1;
+ mddev->new_layout = 0;
+ mddev->new_chunk_sectors = 0;
+ conf = setup_conf(mddev);
+ if (!IS_ERR(conf))
+ conf->barrier = 1;
+ return conf;
+ }
+ return ERR_PTR(-EINVAL);
+}
+
+static struct mdk_personality raid1_personality =
+{
+ .name = "raid1",
+ .level = 1,
+ .owner = THIS_MODULE,
+ .make_request = make_request,
+ .run = run,
+ .stop = stop,
+ .status = status,
+ .error_handler = error,
+ .hot_add_disk = raid1_add_disk,
+ .hot_remove_disk= raid1_remove_disk,
+ .spare_active = raid1_spare_active,
+ .sync_request = sync_request,
+ .resize = raid1_resize,
+ .size = raid1_size,
+ .check_reshape = raid1_reshape,
+ .quiesce = raid1_quiesce,
+ .takeover = raid1_takeover,
+};
+
+static int __init raid_init(void)
+{
+ return register_md_personality(&raid1_personality);
+}
+
+static void raid_exit(void)
+{
+ unregister_md_personality(&raid1_personality);
+}
+
+module_init(raid_init);
+module_exit(raid_exit);
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("RAID1 (mirroring) personality for MD");
+MODULE_ALIAS("md-personality-3"); /* RAID1 */
+MODULE_ALIAS("md-raid1");
+MODULE_ALIAS("md-level-1");
+
+module_param(max_queued, int, S_IRUGO|S_IWUSR);
--- /dev/null
+--- drivers/md/raid1.c
++++ drivers/md/raid1.c
+@@ -618,7 +623,9 @@
+ struct bio *bio;
+ bio = bio_list_get(&conf->pending_bio_list);
+ blk_remove_plug(conf->mddev->queue);
++ conf->pending_count = 0;
+ spin_unlock_irq(&conf->device_lock);
++ wake_up(&conf->wait_barrier);
+ /* flush any pending bitmap writes to
+ * disk before proceeding w/ I/O */
+ bitmap_unplug(conf->mddev->bitmap);
+@@ -788,6 +795,7 @@
+ struct bitmap *bitmap;
+ unsigned long flags;
+ struct bio_list bl;
++ int bl_count;
+ struct page **behind_pages = NULL;
+ const int rw = bio_data_dir(bio);
+ const bool do_sync = bio_rw_flagged(bio, BIO_RW_SYNCIO);
+@@ -878,6 +886,11 @@
+ /*
+ * WRITE:
+ */
++ if (conf->pending_count >= max_queued) {
++ md_wakeup_thread(mddev->thread);
++ wait_event(conf->wait_barrier,
++ conf->pending_count < max_queued);
++ }
+ /* first select target devices under spinlock and
+ * inc refcount on their rdev. Record them by setting
+ * bios[x] to bio
+@@ -954,6 +967,7 @@
+ set_bit(R1BIO_Barrier, &r1_bio->state);
+
+ bio_list_init(&bl);
++ bl_count = 0;
+ for (i = 0; i < disks; i++) {
+ struct bio *mbio;
+ if (!r1_bio->bios[i])
+@@ -989,6 +1003,7 @@
+ atomic_inc(&r1_bio->remaining);
+
+ bio_list_add(&bl, mbio);
++ bl_count++;
+ }
+ kfree(behind_pages); /* the behind pages are attached to the bios now */
+
+@@ -996,6 +1011,7 @@
+ test_bit(R1BIO_BehindIO, &r1_bio->state));
+ spin_lock_irqsave(&conf->device_lock, flags);
+ bio_list_merge(&conf->pending_bio_list, &bl);
++ conf->pending_count += bl_count;
+ bio_list_init(&bl);
+
+ blk_plug_device(mddev->queue);
+@@ -2040,6 +2056,7 @@
+ init_waitqueue_head(&conf->wait_barrier);
+
+ bio_list_init(&conf->pending_bio_list);
++ conf->pending_count = 0;
+ bio_list_init(&conf->flushing_bio_list);
+
+
projects / wiggle.git / commitdiff