Merge tag 'dm-3.3-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm

Pull device-mapper fixes for 3.3 from Alasdair Kergon

Eight small device-mapper bug fixes.

* tag 'dm-3.3-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm:
  dm raid: fix flush support
  dm raid: set MD_CHANGE_DEVS when rebuilding
  dm thin metadata: decrement counter after removing mapped block
  dm thin metadata: unlock superblock in init_pmd error path
  dm thin metadata: remove incorrect close_device on creation error paths
  dm flakey: fix crash on read when corrupt_bio_byte not set
  dm io: fix discard support
  dm ioctl: do not leak argv if target message only contains whitespace

5 files changed, 49 insertions, 20 deletions

diff --git a/drivers/md/dm-flakey.c b/drivers/md/dm-flakey.c
index 9fb18c147825..b280c433e4a0 100644
--- a/drivers/md/dm-flakey.c
+++ b/drivers/md/dm-flakey.c
@@ -323,7 +323,7 @@ static int flakey_end_io(struct dm_target *ti, struct bio *bio,
          * Corrupt successful READs while in down state.
          * If flags were specified, only corrupt those that match.
          */
-        if (!error && bio_submitted_while_down &&
+        if (fc->corrupt_bio_byte && !error && bio_submitted_while_down &&
             (bio_data_dir(bio) == READ) && (fc->corrupt_bio_rw == READ) &&
             all_corrupt_bio_flags_match(bio, fc))
                 corrupt_bio_data(bio, fc);
diff --git a/drivers/md/dm-io.c b/drivers/md/dm-io.c
index ad2eba40e319..ea5dd289fe2a 100644
--- a/drivers/md/dm-io.c
+++ b/drivers/md/dm-io.c
@@ -296,6 +296,8 @@ static void do_region(int rw, unsigned region, struct dm_io_region *where,
         unsigned offset;
         unsigned num_bvecs;
         sector_t remaining = where->count;
+        struct request_queue *q = bdev_get_queue(where->bdev);
+        sector_t discard_sectors;
 
         /*
          * where->count may be zero if rw holds a flush and we need to
@@ -305,9 +307,12 @@ static void do_region(int rw, unsigned region, struct dm_io_region *where,
                 /*
                  * Allocate a suitably sized-bio.
                  */
-                num_bvecs = dm_sector_div_up(remaining,
-                                             (PAGE_SIZE >> SECTOR_SHIFT));
-                num_bvecs = min_t(int, bio_get_nr_vecs(where->bdev), num_bvecs);
+                if (rw & REQ_DISCARD)
+                        num_bvecs = 1;
+                else
+                        num_bvecs = min_t(int, bio_get_nr_vecs(where->bdev),
+                                          dm_sector_div_up(remaining, (PAGE_SIZE >> SECTOR_SHIFT)));
+
                 bio = bio_alloc_bioset(GFP_NOIO, num_bvecs, io->client->bios);
                 bio->bi_sector = where->sector + (where->count - remaining);
                 bio->bi_bdev = where->bdev;
@@ -315,10 +320,14 @@ static void do_region(int rw, unsigned region, struct dm_io_region *where,
                 bio->bi_destructor = dm_bio_destructor;
                 store_io_and_region_in_bio(bio, io, region);
 
-                /*
-                 * Try and add as many pages as possible.
-                 */
-                while (remaining) {
+                if (rw & REQ_DISCARD) {
+                        discard_sectors = min_t(sector_t, q->limits.max_discard_sectors, remaining);
+                        bio->bi_size = discard_sectors << SECTOR_SHIFT;
+                        remaining -= discard_sectors;
+                } else while (remaining) {
+                        /*
+                         * Try and add as many pages as possible.
+                         */
                         dp->get_page(dp, &page, &len, &offset);
                         len = min(len, to_bytes(remaining));
                         if (!bio_add_page(bio, page, len, offset))
diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c
index 31c2dc25886d..1ce84ed0b765 100644
--- a/drivers/md/dm-ioctl.c
+++ b/drivers/md/dm-ioctl.c
@@ -1437,7 +1437,7 @@ static int target_message(struct dm_ioctl *param, size_t param_size)
 
         if (!argc) {
                 DMWARN("Empty message received.");
-                goto out;
+                goto out_argv;
         }
 
         table = dm_get_live_table(md);
diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c
index 86cb7e5d83d5..787022c18187 100644
--- a/drivers/md/dm-raid.c
+++ b/drivers/md/dm-raid.c
@@ -668,7 +668,14 @@ static int super_load(struct md_rdev *rdev, struct md_rdev *refdev)
                 return ret;
 
         sb = page_address(rdev->sb_page);
-        if (sb->magic != cpu_to_le32(DM_RAID_MAGIC)) {
+
+        /*
+         * Two cases that we want to write new superblocks and rebuild:
+         * 1) New device (no matching magic number)
+         * 2) Device specified for rebuild (!In_sync w/ offset == 0)
+         */
+        if ((sb->magic != cpu_to_le32(DM_RAID_MAGIC)) ||
+            (!test_bit(In_sync, &rdev->flags) && !rdev->recovery_offset)) {
                 super_sync(rdev->mddev, rdev);
 
                 set_bit(FirstUse, &rdev->flags);
@@ -745,11 +752,8 @@ static int super_init_validation(struct mddev *mddev, struct md_rdev *rdev)
          */
         rdev_for_each(r, t, mddev) {
                 if (!test_bit(In_sync, &r->flags)) {
-                        if (!test_bit(FirstUse, &r->flags))
-                                DMERR("Superblock area of "
-                                      "rebuild device %d should have been "
-                                      "cleared.", r->raid_disk);
-                        set_bit(FirstUse, &r->flags);
+                        DMINFO("Device %d specified for rebuild: "
+                               "Clearing superblock", r->raid_disk);
                         rebuilds++;
                 } else if (test_bit(FirstUse, &r->flags))
                         new_devs++;
@@ -971,6 +975,7 @@ static int raid_ctr(struct dm_target *ti, unsigned argc, char **argv)
 
         INIT_WORK(&rs->md.event_work, do_table_event);
         ti->private = rs;
+        ti->num_flush_requests = 1;
 
         mutex_lock(&rs->md.reconfig_mutex);
         ret = md_run(&rs->md);
diff --git a/drivers/md/dm-thin-metadata.c b/drivers/md/dm-thin-metadata.c
index 59c4f0446ffa..237571af77fd 100644
--- a/drivers/md/dm-thin-metadata.c
+++ b/drivers/md/dm-thin-metadata.c
@@ -385,6 +385,7 @@ static int init_pmd(struct dm_pool_metadata *pmd,
                 data_sm = dm_sm_disk_create(tm, nr_blocks);
                 if (IS_ERR(data_sm)) {
                         DMERR("sm_disk_create failed");
+                        dm_tm_unlock(tm, sblock);
                         r = PTR_ERR(data_sm);
                         goto bad;
                 }
@@ -789,6 +790,11 @@ int dm_pool_metadata_close(struct dm_pool_metadata *pmd)
         return 0;
 }
 
+/*
+ * __open_device: Returns @td corresponding to device with id @dev,
+ * creating it if @create is set and incrementing @td->open_count.
+ * On failure, @td is undefined.
+ */
 static int __open_device(struct dm_pool_metadata *pmd,
                          dm_thin_id dev, int create,
                          struct dm_thin_device **td)
@@ -799,10 +805,16 @@ static int __open_device(struct dm_pool_metadata *pmd,
         struct disk_device_details details_le;
 
         /*
-         * Check the device isn't already open.
+         * If the device is already open, return it.
          */
         list_for_each_entry(td2, &pmd->thin_devices, list)
                 if (td2->id == dev) {
+                        /*
+                         * May not create an already-open device.
+                         */
+                        if (create)
+                                return -EEXIST;
+
                         td2->open_count++;
                         *td = td2;
                         return 0;
@@ -817,6 +829,9 @@ static int __open_device(struct dm_pool_metadata *pmd,
                 if (r != -ENODATA || !create)
                         return r;
 
+                /*
+                 * Create new device.
+                 */