1 files changed, 128 insertions, 28 deletions

diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index a8bc93d6ff63..7fbb60883280 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -106,15 +106,30 @@ static void * r1buf_pool_alloc(gfp_t gfp_flags, void *data)
         }
         /*
          * Allocate RESYNC_PAGES data pages and attach them to
-         * the first bio;
+         * the first bio.
+         * If this is a user-requested check/repair, allocate
+         * RESYNC_PAGES for each bio.
          */
-        bio = r1_bio->bios[0];
-        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;
+        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;
+                }
+        }
+        /* 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;
@@ -122,8 +137,10 @@ static void * r1buf_pool_alloc(gfp_t gfp_flags, void *data)
         return r1_bio;
 
 out_free_pages:
-        for ( ; i > 0 ; i--)
-                __free_page(bio->bi_io_vec[i-1].bv_page);
+        for (i=0; i < RESYNC_PAGES ; i++)
+                for (j=0 ; j < pi->raid_disks; j++)
+                        __free_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]);
@@ -134,14 +151,16 @@ out_free_bio:
 static void r1buf_pool_free(void *__r1_bio, void *data)
 {
         struct pool_info *pi = data;
-        int i;
+        int i,j;
         r1bio_t *r1bio = __r1_bio;
-        struct bio *bio = r1bio->bios[0];
 
-        for (i = 0; i < RESYNC_PAGES; i++) {
-                __free_page(bio->bi_io_vec[i].bv_page);
-                bio->bi_io_vec[i].bv_page = NULL;
-        }
+        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)
+                                __free_page(r1bio->bios[j]->bi_io_vec[i].bv_page);
+                }
         for (i=0 ; i < pi->raid_disks; i++)
                 bio_put(r1bio->bios[i]);
 
@@ -1077,13 +1096,16 @@ abort:
 static int end_sync_read(struct bio *bio, unsigned int bytes_done, int error)
 {
         r1bio_t * r1_bio = (r1bio_t *)(bio->bi_private);
+        int i;
 
         if (bio->bi_size)
                 return 1;
 
-        if (r1_bio->bios[r1_bio->read_disk] != bio)
-                BUG();
-        update_head_pos(r1_bio->read_disk, r1_bio);
+        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.
@@ -1091,7 +1113,9 @@ static int end_sync_read(struct bio *bio, unsigned int bytes_done, int error)
          */
         if (test_bit(BIO_UPTODATE, &bio->bi_flags))
                 set_bit(R1BIO_Uptodate, &r1_bio->state);
-        reschedule_retry(r1_bio);
+
+        if (atomic_dec_and_test(&r1_bio->remaining))
+                reschedule_retry(r1_bio);
         return 0;
 }
 
@@ -1134,9 +1158,65 @@ static void sync_request_write(mddev_t *mddev, r1bio_t *r1_bio)
         bio = r1_bio->bios[r1_bio->read_disk];
 
 
-        /*
-         * schedule writes
-         */
+        if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
+                /* 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
+                 */
+                int primary;
+                if (!test_bit(R1BIO_Uptodate, &r1_bio->state)) {
+                        for (i=0; i<mddev->raid_disks; i++)
+                                if (r1_bio->bios[i]->bi_end_io == end_sync_read)
+                                        md_error(mddev, conf->mirrors[i].rdev);
+
+                        md_done_sync(mddev, r1_bio->sectors, 1);
+                        put_buf(r1_bio);
+                        return;
+                }
+                for (primary=0; primary<mddev->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;
+                                break;
+                        }
+                r1_bio->read_disk = primary;
+                for (i=0; i<mddev->raid_disks; i++)
+                        if (r1_bio->bios[i]->bi_end_io == end_sync_read &&
+                            test_bit(BIO_UPTODATE, &r1_bio->bios[i]->bi_flags)) {
+                                int j;
+                                int vcnt = r1_bio->sectors >> (PAGE_SHIFT- 9);
+                                struct bio *pbio = r1_bio->bios[primary];
+                                struct bio *sbio = r1_bio->bios[i];
+                                for (j = vcnt; j-- ; )
+                                        if (memcmp(page_address(pbio->bi_io_vec[j].bv_page),
+                                                   page_address(sbio->bi_io_vec[j].bv_page),
+                                                   PAGE_SIZE))
+                                                break;
+                                if (j >= 0)
+                                        mddev->resync_mismatches += r1_bio->sectors;
+                                if (j < 0 || test_bit(MD_RECOVERY_CHECK, &mddev->recovery))
+                                        sbio->bi_end_io = NULL;
+                                else {
+                                        /* 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_hw_segments = 0;
+                                        sbio->bi_hw_front_size = 0;
+                                        sbio->bi_hw_back_size = 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;
+                                }
+                        }
+        }
         if (!test_bit(R1BIO_Uptodate, &r1_bio->state)) {
                 /* ouch - failed to read all of that.
                  * Try some synchronous reads of other devices to get
@@ -1216,6 +1296,10 @@ static void sync_request_write(mddev_t *mddev, r1bio_t *r1_bio)
                         idx ++;
                 }
         }
+
+        /*
+         * schedule writes
+         */
         atomic_set(&r1_bio->remaining, 1);
         for (i = 0; i < disks ; i++) {
                 wbio = r1_bio->bios[i];
@@ -1618,10 +1702,10 @@ static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, i
                 for (i=0 ; i < conf->raid_disks; i++) {
                         bio = r1_bio->bios[i];
                         if (bio->bi_end_io) {
-                                page = r1_bio->bios[0]->bi_io_vec[bio->bi_vcnt].bv_page;
+                                page = bio->bi_io_vec[bio->bi_vcnt].bv_page;
                                 if (bio_add_page(bio, page, len, 0) == 0) {
                                         /* stop here */
-                                        r1_bio->bios[0]->bi_io_vec[bio->bi_vcnt].bv_page = page;
+                                        bio->bi_io_vec[bio->bi_vcnt].bv_page = page;
                                         while (i > 0) {
                                                 i--;
                                                 bio = r1_bio->bios[i];
@@ -1641,12 +1725,28 @@ static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, i
                 sync_blocks -= (len>>9);
         } while (r1_bio->bios[disk]->bi_vcnt < RESYNC_PAGES);
  bio_full:
-        bio = r1_bio->bios[r1_bio->read_disk];
         r1_bio->sectors = nr_sectors;
 
-        md_sync_acct(conf->mirrors[r1_bio->read_disk].rdev->bdev, 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(conf->mirrors[i].rdev->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(conf->mirrors[r1_bio->read_disk].rdev->bdev,
+                             nr_sectors);
+                generic_make_request(bio);
 
-        generic_make_request(bio);
+        }
 
         return nr_sectors;
 }