[PATCH] md: Fix issues with referencing rdev in md/raid1
We need to be careful when referencing mirrors[i].rdev. It can disappear under us at various times. So: fix a couple of problem places. comment a couple of non-problem places move an 'atomic_add' which deferences rdev down a little way to some where where it is sure to not be NULL. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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1 changed files with 35 additions and 22 deletions
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@ -930,10 +930,13 @@ static void status(struct seq_file *seq, mddev_t *mddev)
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seq_printf(seq, " [%d/%d] [", conf->raid_disks,
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seq_printf(seq, " [%d/%d] [", conf->raid_disks,
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conf->working_disks);
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conf->working_disks);
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for (i = 0; i < conf->raid_disks; i++)
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rcu_read_lock();
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for (i = 0; i < conf->raid_disks; i++) {
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mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
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seq_printf(seq, "%s",
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seq_printf(seq, "%s",
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conf->mirrors[i].rdev &&
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rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_");
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test_bit(In_sync, &conf->mirrors[i].rdev->flags) ? "U" : "_");
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}
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rcu_read_unlock();
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seq_printf(seq, "]");
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seq_printf(seq, "]");
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}
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}
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@ -975,7 +978,6 @@ static void error(mddev_t *mddev, mdk_rdev_t *rdev)
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static void print_conf(conf_t *conf)
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static void print_conf(conf_t *conf)
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{
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{
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int i;
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int i;
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mirror_info_t *tmp;
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printk("RAID1 conf printout:\n");
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printk("RAID1 conf printout:\n");
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if (!conf) {
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if (!conf) {
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@ -985,14 +987,17 @@ static void print_conf(conf_t *conf)
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printk(" --- wd:%d rd:%d\n", conf->working_disks,
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printk(" --- wd:%d rd:%d\n", conf->working_disks,
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conf->raid_disks);
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conf->raid_disks);
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rcu_read_lock();
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for (i = 0; i < conf->raid_disks; i++) {
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for (i = 0; i < conf->raid_disks; i++) {
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char b[BDEVNAME_SIZE];
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char b[BDEVNAME_SIZE];
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tmp = conf->mirrors + i;
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mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
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if (tmp->rdev)
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if (rdev)
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printk(" disk %d, wo:%d, o:%d, dev:%s\n",
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printk(" disk %d, wo:%d, o:%d, dev:%s\n",
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i, !test_bit(In_sync, &tmp->rdev->flags), !test_bit(Faulty, &tmp->rdev->flags),
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i, !test_bit(In_sync, &rdev->flags),
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bdevname(tmp->rdev->bdev,b));
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!test_bit(Faulty, &rdev->flags),
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bdevname(rdev->bdev,b));
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}
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}
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rcu_read_unlock();
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}
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}
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static void close_sync(conf_t *conf)
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static void close_sync(conf_t *conf)
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@ -1008,20 +1013,20 @@ static int raid1_spare_active(mddev_t *mddev)
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{
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{
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int i;
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int i;
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conf_t *conf = mddev->private;
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conf_t *conf = mddev->private;
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mirror_info_t *tmp;
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/*
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/*
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* Find all failed disks within the RAID1 configuration
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* Find all failed disks within the RAID1 configuration
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* and mark them readable
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* and mark them readable.
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* Called under mddev lock, so rcu protection not needed.
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*/
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*/
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for (i = 0; i < conf->raid_disks; i++) {
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for (i = 0; i < conf->raid_disks; i++) {
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tmp = conf->mirrors + i;
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mdk_rdev_t *rdev = conf->mirrors[i].rdev;
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if (tmp->rdev
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if (rdev
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&& !test_bit(Faulty, &tmp->rdev->flags)
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&& !test_bit(Faulty, &rdev->flags)
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&& !test_bit(In_sync, &tmp->rdev->flags)) {
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&& !test_bit(In_sync, &rdev->flags)) {
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conf->working_disks++;
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conf->working_disks++;
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mddev->degraded--;
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mddev->degraded--;
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set_bit(In_sync, &tmp->rdev->flags);
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set_bit(In_sync, &rdev->flags);
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}
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}
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}
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}
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@ -1237,7 +1242,7 @@ static void sync_request_write(mddev_t *mddev, r1bio_t *r1_bio)
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/* ouch - failed to read all of that.
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/* ouch - failed to read all of that.
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* Try some synchronous reads of other devices to get
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* Try some synchronous reads of other devices to get
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* good data, much like with normal read errors. Only
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* good data, much like with normal read errors. Only
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* read into the pages we already have so they we don't
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* read into the pages we already have so we don't
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* need to re-issue the read request.
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* need to re-issue the read request.
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* We don't need to freeze the array, because being in an
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* We don't need to freeze the array, because being in an
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* active sync request, there is no normal IO, and
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* active sync request, there is no normal IO, and
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@ -1257,6 +1262,10 @@ static void sync_request_write(mddev_t *mddev, r1bio_t *r1_bio)
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s = PAGE_SIZE >> 9;
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s = PAGE_SIZE >> 9;
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do {
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do {
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if (r1_bio->bios[d]->bi_end_io == end_sync_read) {
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if (r1_bio->bios[d]->bi_end_io == end_sync_read) {
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/* No rcu protection needed here devices
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* can only be removed when no resync is
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* active, and resync is currently active
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*/
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rdev = conf->mirrors[d].rdev;
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rdev = conf->mirrors[d].rdev;
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if (sync_page_io(rdev->bdev,
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if (sync_page_io(rdev->bdev,
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sect + rdev->data_offset,
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sect + rdev->data_offset,
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@ -1463,6 +1472,11 @@ static void raid1d(mddev_t *mddev)
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s = PAGE_SIZE >> 9;
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s = PAGE_SIZE >> 9;
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do {
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do {
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/* Note: no rcu protection needed here
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* as this is synchronous in the raid1d thread
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* which is the thread that might remove
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* a device. If raid1d ever becomes multi-threaded....
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*/
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rdev = conf->mirrors[d].rdev;
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rdev = conf->mirrors[d].rdev;
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if (rdev &&
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if (rdev &&
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test_bit(In_sync, &rdev->flags) &&
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test_bit(In_sync, &rdev->flags) &&
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@ -1486,7 +1500,6 @@ static void raid1d(mddev_t *mddev)
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d = conf->raid_disks;
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d = conf->raid_disks;
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d--;
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d--;
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rdev = conf->mirrors[d].rdev;
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rdev = conf->mirrors[d].rdev;
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atomic_add(s, &rdev->corrected_errors);
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if (rdev &&
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if (rdev &&
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test_bit(In_sync, &rdev->flags)) {
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test_bit(In_sync, &rdev->flags)) {
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if (sync_page_io(rdev->bdev,
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if (sync_page_io(rdev->bdev,
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@ -1509,9 +1522,11 @@ static void raid1d(mddev_t *mddev)
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s<<9, conf->tmppage, READ) == 0)
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s<<9, conf->tmppage, READ) == 0)
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/* Well, this device is dead */
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/* Well, this device is dead */
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md_error(mddev, rdev);
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md_error(mddev, rdev);
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else
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else {
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atomic_add(s, &rdev->corrected_errors);
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printk(KERN_INFO "raid1:%s: read error corrected (%d sectors at %llu on %s)\n",
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printk(KERN_INFO "raid1:%s: read error corrected (%d sectors at %llu on %s)\n",
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mdname(mddev), s, (unsigned long long)(sect + rdev->data_offset), bdevname(rdev->bdev, b));
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mdname(mddev), s, (unsigned long long)(sect + rdev->data_offset), bdevname(rdev->bdev, b));
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}
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}
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}
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}
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}
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} else {
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} else {
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@ -1787,19 +1802,17 @@ static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, i
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for (i=0; i<conf->raid_disks; i++) {
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for (i=0; i<conf->raid_disks; i++) {
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bio = r1_bio->bios[i];
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bio = r1_bio->bios[i];
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if (bio->bi_end_io == end_sync_read) {
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if (bio->bi_end_io == end_sync_read) {
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md_sync_acct(conf->mirrors[i].rdev->bdev, nr_sectors);
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md_sync_acct(bio->bi_bdev, nr_sectors);
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generic_make_request(bio);
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generic_make_request(bio);
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}
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}
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}
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}
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} else {
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} else {
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atomic_set(&r1_bio->remaining, 1);
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atomic_set(&r1_bio->remaining, 1);
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bio = r1_bio->bios[r1_bio->read_disk];
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bio = r1_bio->bios[r1_bio->read_disk];
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md_sync_acct(conf->mirrors[r1_bio->read_disk].rdev->bdev,
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md_sync_acct(bio->bi_bdev, nr_sectors);
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nr_sectors);
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generic_make_request(bio);
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generic_make_request(bio);
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}
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}
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return nr_sectors;
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return nr_sectors;
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}
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}
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