1 files changed, 92 insertions, 42 deletions

diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index fb6b866c28f5..1cbf51fbd43f 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -301,7 +301,7 @@ static int raid1_end_write_request(struct bio *bio, unsigned int bytes_done, int
 {
         int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
         r1bio_t * r1_bio = (r1bio_t *)(bio->bi_private);
-        int mirror, behind;
+        int mirror, behind = test_bit(R1BIO_BehindIO, &r1_bio->state);
         conf_t *conf = mddev_to_conf(r1_bio->mddev);
 
         if (bio->bi_size)
@@ -311,47 +311,54 @@ static int raid1_end_write_request(struct bio *bio, unsigned int bytes_done, int
                 if (r1_bio->bios[mirror] == bio)
                         break;
 
-        /*
-         * this branch is our 'one mirror IO has finished' event handler:
-         */
-        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
+        if (error == -ENOTSUPP && test_bit(R1BIO_Barrier, &r1_bio->state)) {
+                set_bit(BarriersNotsupp, &conf->mirrors[mirror].rdev->flags);
+                set_bit(R1BIO_BarrierRetry, &r1_bio->state);
+                r1_bio->mddev->barriers_work = 0;
+        } 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.
+                 * this branch is our 'one mirror IO has finished' event handler:
                  */
-                set_bit(R1BIO_Uptodate, &r1_bio->state);
-
-        update_head_pos(mirror, r1_bio);
-
-        behind = test_bit(R1BIO_BehindIO, &r1_bio->state);
-        if (behind) {
-                if (test_bit(WriteMostly, &conf->mirrors[mirror].rdev->flags))
-                        atomic_dec(&r1_bio->behind_remaining);
-
-                /* In behind mode, we ACK the master bio once the I/O has safely
-                 * reached all non-writemostly disks. Setting the Returned bit
-                 * ensures that this gets done only once -- we don't ever want to
-                 * return -EIO here, instead we'll wait */
-
-                if (atomic_read(&r1_bio->behind_remaining) >= (atomic_read(&r1_bio->remaining)-1) &&
-                    test_bit(R1BIO_Uptodate, &r1_bio->state)) {
-                        /* Maybe we can return now */
-                        if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
-                                struct bio *mbio = r1_bio->master_bio;
-                                PRINTK(KERN_DEBUG "raid1: behind end write sectors %llu-%llu\n",
-                                       (unsigned long long) mbio->bi_sector,
-                                       (unsigned long long) mbio->bi_sector +
-                                       (mbio->bi_size >> 9) - 1);
-                                bio_endio(mbio, mbio->bi_size, 0);
+                r1_bio->bios[mirror] = NULL;
+                bio_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, mbio->bi_size, 0);
+                                }
                         }
                 }
         }
@@ -361,8 +368,16 @@ static int raid1_end_write_request(struct bio *bio, unsigned int bytes_done, int
          * already.
          */
         if (atomic_dec_and_test(&r1_bio->remaining)) {
+                if (test_bit(R1BIO_BarrierRetry, &r1_bio->state)) {
+                        reschedule_retry(r1_bio);
+                        /* Don't dec_pending yet, we want to hold
+                         * the reference over the retry
+                         */
+                        return 0;
+                }
                 if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
                         /* free extra copy of the data pages */
+/* FIXME bio has been freed!!! */
                         int i = bio->bi_vcnt;
                         while (i--)
                                 __free_page(bio->bi_io_vec[i].bv_page);
@@ -648,8 +663,9 @@ static int make_request(request_queue_t *q, struct bio * bio)
         struct bio_list bl;
         struct page **behind_pages = NULL;
         const int rw = bio_data_dir(bio);
+        int do_barriers;
 
-        if (unlikely(bio_barrier(bio))) {
+        if (unlikely(!mddev->barriers_work && bio_barrier(bio))) {
                 bio_endio(bio, bio->bi_size, -EOPNOTSUPP);
                 return 0;
         }
@@ -759,6 +775,10 @@ static int make_request(request_queue_t *q, struct bio * bio)
         atomic_set(&r1_bio->remaining, 0);
         atomic_set(&r1_bio->behind_remaining, 0);
 
+        do_barriers = bio->bi_rw & BIO_RW_BARRIER;
+        if (do_barriers)
+                set_bit(R1BIO_Barrier, &r1_bio->state);
+
         bio_list_init(&bl);
         for (i = 0; i < disks; i++) {
                 struct bio *mbio;
@@ -771,7 +791,7 @@ static int make_request(request_queue_t *q, struct bio * bio)
                 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;
+                mbio->bi_rw = WRITE | do_barriers;
                 mbio->bi_private = r1_bio;
 
                 if (behind_pages) {
@@ -1153,6 +1173,36 @@ static void raid1d(mddev_t *mddev)
                 if (test_bit(R1BIO_IsSync, &r1_bio->state)) {
                         sync_request_write(mddev, r1_bio);
                         unplug = 1;
+                } else if (test_bit(R1BIO_BarrierRetry, &r1_bio->state)) {
+                        /* some requests in the r1bio were BIO_RW_BARRIER
+                         * requests which failed with -ENOTSUPP.  Hohumm..
+                         * Better resubmit without the barrier.
+                         * We know which devices to resubmit for, because
+                         * all others have had their bios[] entry cleared.
+                         */
+                        int i;
+                        clear_bit(R1BIO_BarrierRetry, &r1_bio->state);
+                        clear_bit(R1BIO_Barrier, &r1_bio->state);
+                        for (i=0; i < conf->raid_disks; i++)
+                                if (r1_bio->bios[i]) {
+                                        struct bio_vec *bvec;
+                                        int j;
+
+                                        bio = bio_clone(r1_bio->master_bio, GFP_NOIO);
+                                        /* copy pages from the failed bio, as
+                                         * this might be a write-behind device */
+                                        __bio_for_each_segment(bvec, bio, j, 0)
+                                                bvec->bv_page = bio_iovec_idx(r1_bio->bios[i], j)->bv_page;
+                                        bio_put(r1_bio->bios[i]);
+                                        bio->bi_sector = r1_bio->sector +
+                                                conf->mirrors[i].rdev->data_offset;
+                                        bio->bi_bdev = conf->mirrors[i].rdev->bdev;
+                                        bio->bi_end_io = raid1_end_write_request;
+                                        bio->bi_rw = WRITE;
+                                        bio->bi_private = r1_bio;
+                                        r1_bio->bios[i] = bio;
+                                        generic_make_request(bio);
+                                }
                 } else {
                         int disk;
                         bio = r1_bio->bios[r1_bio->read_disk];