Merge git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dm

* git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dm:
  dm snapshot: fix on disk chunk size validation
  dm exception store: split set_chunk_size
  dm snapshot: fix header corruption race on invalidation
  dm snapshot: refactor zero_disk_area to use chunk_io
  dm log: userspace add luid to distinguish between concurrent log instances
  dm raid1: do not allow log_failure variable to unset after being set
  dm log: remove incorrect field from userspace table output
  dm log: fix userspace status output
  dm stripe: expose correct io hints
  dm table: add more context to terse warning messages
  dm table: fix queue_limit checking device iterator
  dm snapshot: implement iterate devices
  dm multipath: fix oops when request based io fails when no paths

13 files changed, 198 insertions, 81 deletions

diff --git a/drivers/md/dm-exception-store.c b/drivers/md/dm-exception-store.c
index 3710ff88fc10..556acff3952f 100644
--- a/drivers/md/dm-exception-store.c
+++ b/drivers/md/dm-exception-store.c
@@ -171,6 +171,14 @@ static int set_chunk_size(struct dm_exception_store *store,
          */
         chunk_size_ulong = round_up(chunk_size_ulong, PAGE_SIZE >> 9);
 
+        return dm_exception_store_set_chunk_size(store, chunk_size_ulong,
+                                                 error);
+}
+
+int dm_exception_store_set_chunk_size(struct dm_exception_store *store,
+                                      unsigned long chunk_size_ulong,
+                                      char **error)
+{
         /* Check chunk_size is a power of 2 */
         if (!is_power_of_2(chunk_size_ulong)) {
                 *error = "Chunk size is not a power of 2";
@@ -183,6 +191,11 @@ static int set_chunk_size(struct dm_exception_store *store,
                 return -EINVAL;
         }
 
+        if (chunk_size_ulong > INT_MAX >> SECTOR_SHIFT) {
+                *error = "Chunk size is too high";
+                return -EINVAL;
+        }
+
         store->chunk_size = chunk_size_ulong;
         store->chunk_mask = chunk_size_ulong - 1;
         store->chunk_shift = ffs(chunk_size_ulong) - 1;
diff --git a/drivers/md/dm-exception-store.h b/drivers/md/dm-exception-store.h
index 2442c8c07898..812c71872ba0 100644
--- a/drivers/md/dm-exception-store.h
+++ b/drivers/md/dm-exception-store.h
@@ -168,6 +168,10 @@ static inline chunk_t sector_to_chunk(struct dm_exception_store *store,
 int dm_exception_store_type_register(struct dm_exception_store_type *type);
 int dm_exception_store_type_unregister(struct dm_exception_store_type *type);
 
+int dm_exception_store_set_chunk_size(struct dm_exception_store *store,
+                                      unsigned long chunk_size_ulong,
+                                      char **error);
+
 int dm_exception_store_create(struct dm_target *ti, int argc, char **argv,
                               unsigned *args_used,
                               struct dm_exception_store **store);
diff --git a/drivers/md/dm-log-userspace-base.c b/drivers/md/dm-log-userspace-base.c
index e69b96560997..6e186b1a062d 100644
--- a/drivers/md/dm-log-userspace-base.c
+++ b/drivers/md/dm-log-userspace-base.c
@@ -21,6 +21,7 @@ struct log_c {
         struct dm_target *ti;
         uint32_t region_size;
         region_t region_count;
+        uint64_t luid;
         char uuid[DM_UUID_LEN];
 
         char *usr_argv_str;
@@ -63,7 +64,7 @@ static int userspace_do_request(struct log_c *lc, const char *uuid,
          * restored.
          */
 retry:
-        r = dm_consult_userspace(uuid, request_type, data,
+        r = dm_consult_userspace(uuid, lc->luid, request_type, data,
                                  data_size, rdata, rdata_size);
 
         if (r != -ESRCH)
@@ -74,14 +75,15 @@ retry:
                 set_current_state(TASK_INTERRUPTIBLE);
                 schedule_timeout(2*HZ);
                 DMWARN("Attempting to contact userspace log server...");
-                r = dm_consult_userspace(uuid, DM_ULOG_CTR, lc->usr_argv_str,
+                r = dm_consult_userspace(uuid, lc->luid, DM_ULOG_CTR,
+                                         lc->usr_argv_str,
                                          strlen(lc->usr_argv_str) + 1,
                                          NULL, NULL);
                 if (!r)
                         break;
         }
         DMINFO("Reconnected to userspace log server... DM_ULOG_CTR complete");
-        r = dm_consult_userspace(uuid, DM_ULOG_RESUME, NULL,
+        r = dm_consult_userspace(uuid, lc->luid, DM_ULOG_RESUME, NULL,
                                  0, NULL, NULL);
         if (!r)
                 goto retry;
@@ -111,10 +113,9 @@ static int build_constructor_string(struct dm_target *ti,
                 return -ENOMEM;
         }
 
-        for (i = 0, str_size = 0; i < argc; i++)
-                str_size += sprintf(str + str_size, "%s ", argv[i]);
-        str_size += sprintf(str + str_size, "%llu",
-                            (unsigned long long)ti->len);
+        str_size = sprintf(str, "%llu", (unsigned long long)ti->len);
+        for (i = 0; i < argc; i++)
+                str_size += sprintf(str + str_size, " %s", argv[i]);
 
         *ctr_str = str;
         return str_size;
@@ -154,6 +155,9 @@ static int userspace_ctr(struct dm_dirty_log *log, struct dm_target *ti,
                 return -ENOMEM;
         }
 
+        /* The ptr value is sufficient for local unique id */
+        lc->luid = (uint64_t)lc;
+
         lc->ti = ti;
 
         if (strlen(argv[0]) > (DM_UUID_LEN - 1)) {
@@ -173,7 +177,7 @@ static int userspace_ctr(struct dm_dirty_log *log, struct dm_target *ti,
         }
 
         /* Send table string */
-        r = dm_consult_userspace(lc->uuid, DM_ULOG_CTR,
+        r = dm_consult_userspace(lc->uuid, lc->luid, DM_ULOG_CTR,
                                  ctr_str, str_size, NULL, NULL);
 
         if (r == -ESRCH) {
@@ -183,7 +187,7 @@ static int userspace_ctr(struct dm_dirty_log *log, struct dm_target *ti,
 
         /* Since the region size does not change, get it now */
         rdata_size = sizeof(rdata);
-        r = dm_consult_userspace(lc->uuid, DM_ULOG_GET_REGION_SIZE,
+        r = dm_consult_userspace(lc->uuid, lc->luid, DM_ULOG_GET_REGION_SIZE,
                                  NULL, 0, (char *)&rdata, &rdata_size);
 
         if (r) {
@@ -212,7 +216,7 @@ static void userspace_dtr(struct dm_dirty_log *log)
         int r;
         struct log_c *lc = log->context;
 
-        r = dm_consult_userspace(lc->uuid, DM_ULOG_DTR,
+        r = dm_consult_userspace(lc->uuid, lc->luid, DM_ULOG_DTR,
                                  NULL, 0,
                                  NULL, NULL);
 
@@ -227,7 +231,7 @@ static int userspace_presuspend(struct dm_dirty_log *log)
         int r;
         struct log_c *lc = log->context;
 
-        r = dm_consult_userspace(lc->uuid, DM_ULOG_PRESUSPEND,
+        r = dm_consult_userspace(lc->uuid, lc->luid, DM_ULOG_PRESUSPEND,
                                  NULL, 0,
                                  NULL, NULL);
 
@@ -239,7 +243,7 @@ static int userspace_postsuspend(struct dm_dirty_log *log)
         int r;
         struct log_c *lc = log->context;
 
-        r = dm_consult_userspace(lc->uuid, DM_ULOG_POSTSUSPEND,
+        r = dm_consult_userspace(lc->uuid, lc->luid, DM_ULOG_POSTSUSPEND,
                                  NULL, 0,
                                  NULL, NULL);
 
@@ -252,7 +256,7 @@ static int userspace_resume(struct dm_dirty_log *log)
         struct log_c *lc = log->context;
 
         lc->in_sync_hint = 0;
-        r = dm_consult_userspace(lc->uuid, DM_ULOG_RESUME,
+        r = dm_consult_userspace(lc->uuid, lc->luid, DM_ULOG_RESUME,
                                  NULL, 0,
                                  NULL, NULL);
 
@@ -561,6 +565,7 @@ static int userspace_status(struct dm_dirty_log *log, status_type_t status_type,
                             char *result, unsigned maxlen)
 {
         int r = 0;
+        char *table_args;
         size_t sz = (size_t)maxlen;
         struct log_c *lc = log->context;
 
@@ -577,8 +582,12 @@ static int userspace_status(struct dm_dirty_log *log, status_type_t status_type,
                 break;
         case STATUSTYPE_TABLE:
                 sz = 0;
-                DMEMIT("%s %u %s %s", log->type->name, lc->usr_argc + 1,
-                       lc->uuid, lc->usr_argv_str);
+                table_args = strstr(lc->usr_argv_str, " ");
+                BUG_ON(!table_args); /* There will always be a ' ' */
+                table_args++;
+
+                DMEMIT("%s %u %s %s ", log->type->name, lc->usr_argc,
+                       lc->uuid, table_args);
                 break;
         }
         return (r) ? 0 : (int)sz;
diff --git a/drivers/md/dm-log-userspace-transfer.c b/drivers/md/dm-log-userspace-transfer.c
index 8ce74d95ae4d..ba0edad2d048 100644
--- a/drivers/md/dm-log-userspace-transfer.c
+++ b/drivers/md/dm-log-userspace-transfer.c
@@ -147,7 +147,8 @@ static void cn_ulog_callback(void *data)
 
 /**
  * dm_consult_userspace
- * @uuid: log's uuid (must be DM_UUID_LEN in size)
+ * @uuid: log's universal unique identifier (must be DM_UUID_LEN in size)
+ * @luid: log's local unique identifier
  * @request_type:  found in include/linux/dm-log-userspace.h
  * @data: data to tx to the server
  * @data_size: size of data in bytes
@@ -163,7 +164,7 @@ static void cn_ulog_callback(void *data)
  *
  * Returns: 0 on success, -EXXX on failure
  **/
-int dm_consult_userspace(const char *uuid, int request_type,
+int dm_consult_userspace(const char *uuid, uint64_t luid, int request_type,
                          char *data, size_t data_size,
                          char *rdata, size_t *rdata_size)
 {
@@ -190,6 +191,7 @@ resend:
 
         memset(tfr, 0, DM_ULOG_PREALLOCED_SIZE - overhead_size);
         memcpy(tfr->uuid, uuid, DM_UUID_LEN);
+        tfr->luid = luid;
         tfr->seq = dm_ulog_seq++;
 
         /*
diff --git a/drivers/md/dm-log-userspace-transfer.h b/drivers/md/dm-log-userspace-transfer.h
index c26d8e4e2710..04ee874f9153 100644
--- a/drivers/md/dm-log-userspace-transfer.h
+++ b/drivers/md/dm-log-userspace-transfer.h
@@ -11,7 +11,7 @@
 
 int dm_ulog_tfr_init(void);
 void dm_ulog_tfr_exit(void);
-int dm_consult_userspace(const char *uuid, int request_type,
+int dm_consult_userspace(const char *uuid, uint64_t luid, int request_type,
                          char *data, size_t data_size,
                          char *rdata, size_t *rdata_size);
 
diff --git a/drivers/md/dm-raid1.c b/drivers/md/dm-raid1.c
index 9726577cde49..33f179e66bf5 100644
--- a/drivers/md/dm-raid1.c
+++ b/drivers/md/dm-raid1.c
@@ -648,7 +648,13 @@ static void do_writes(struct mirror_set *ms, struct bio_list *writes)
          */
         dm_rh_inc_pending(ms->rh, &sync);
         dm_rh_inc_pending(ms->rh, &nosync);
-        ms->log_failure = dm_rh_flush(ms->rh) ? 1 : 0;
+
+        /*
+         * If the flush fails on a previous call and succeeds here,
+         * we must not reset the log_failure variable.  We need
+         * userspace interaction to do that.
+         */
+        ms->log_failure = dm_rh_flush(ms->rh) ? 1 : ms->log_failure;
 
         /*
          * Dispatch io.
diff --git a/drivers/md/dm-snap-persistent.c b/drivers/md/dm-snap-persistent.c
index 6e3fe4f14934..d5b2e08750d5 100644
--- a/drivers/md/dm-snap-persistent.c
+++ b/drivers/md/dm-snap-persistent.c
@@ -106,6 +106,13 @@ struct pstore {
         void *zero_area;
 
         /*
+         * An area used for header. The header can be written
+         * concurrently with metadata (when invalidating the snapshot),
+         * so it needs a separate buffer.
+         */
+        void *header_area;
+
+        /*
          * Used to keep track of which metadata area the data in
          * 'chunk' refers to.
          */
@@ -148,16 +155,27 @@ static int alloc_area(struct pstore *ps)
          */
         ps->area = vmalloc(len);
         if (!ps->area)
-                return r;
+                goto err_area;
 
         ps->zero_area = vmalloc(len);
-        if (!ps->zero_area) {
-                vfree(ps->area);
-                return r;
-        }
+        if (!ps->zero_area)
+                goto err_zero_area;
         memset(ps->zero_area, 0, len);
 
+        ps->header_area = vmalloc(len);
+        if (!ps->header_area)
+                goto err_header_area;
+
         return 0;
+
+err_header_area:
+        vfree(ps->zero_area);
+
+err_zero_area:
+        vfree(ps->area);
+
+err_area:
+        return r;
 }
 
 static void free_area(struct pstore *ps)
@@ -169,6 +187,10 @@ static void free_area(struct pstore *ps)
         if (ps->zero_area)
                 vfree(ps->zero_area);
         ps->zero_area = NULL;
+
+        if (ps->header_area)
+                vfree(ps->header_area);
+        ps->header_area = NULL;
 }
 
 struct mdata_req {
@@ -188,7 +210,8 @@ static void do_metadata(struct work_struct *work)
 /*
  * Read or write a chunk aligned and sized block of data from a device.
  */
-static int chunk_io(struct pstore *ps, chunk_t chunk, int rw, int metadata)
+static int chunk_io(struct pstore *ps, void *area, chunk_t chunk, int rw,
+                    int metadata)
 {
         struct dm_io_region where = {
                 .bdev = ps->store->cow->bdev,
@@ -198,7 +221,7 @@ static int chunk_io(struct pstore *ps, chunk_t chunk, int rw, int metadata)
         struct dm_io_request io_req = {
                 .bi_rw = rw,
                 .mem.type = DM_IO_VMA,
-                .mem.ptr.vma = ps->area,
+                .mem.ptr.vma = area,
                 .client = ps->io_client,
                 .notify.fn = NULL,
         };
@@ -240,7 +263,7 @@ static int area_io(struct pstore *ps, int rw)
 
         chunk = area_location(ps, ps->current_area);
 
-        r = chunk_io(ps, chunk, rw, 0);
+        r = chunk_io(ps, ps->area, chunk, rw, 0);
         if (r)
                 return r;
 
@@ -254,20 +277,7 @@ static void zero_memory_area(struct pstore *ps)
 
 static int zero_disk_area(struct pstore *ps, chunk_t area)
 {
-        struct dm_io_region where = {
-                .bdev = ps->store->cow->bdev,
-                .sector = ps->store->chunk_size * area_location(ps, area),
-                .count = ps->store->chunk_size,
-        };
-        struct dm_io_request io_req = {
-                .bi_rw = WRITE,
-                .mem.type = DM_IO_VMA,
-                .mem.ptr.vma = ps->zero_area,
-                .client = ps->io_client,
-                .notify.fn = NULL,
-        };
-
-        return dm_io(&io_req, 1, &where, NULL);
+        return chunk_io(ps, ps->zero_area, area_location(ps, area), WRITE, 0);
 }
 
 static int read_header(struct pstore *ps, int *new_snapshot)
@@ -276,6 +286,7 @@ static int read_header(struct pstore *ps, int *new_snapshot)
         struct disk_header *dh;
         chunk_t chunk_size;
         int chunk_size_supplied = 1;
+        char *chunk_err;
 
         /*
          * Use default chunk size (or hardsect_size, if larger) if none supplied
@@ -297,11 +308,11 @@ static int read_header(struct pstore *ps, int *new_snapshot)
         if (r)
                 return r;
 
-        r = chunk_io(ps, 0, READ, 1);
+        r = chunk_io(ps, ps->header_area, 0, READ, 1);
         if (r)
                 goto bad;
 
-        dh = (struct disk_header *) ps->area;
+        dh = ps->header_area;
 
         if (le32_to_cpu(dh->magic) == 0) {
                 *new_snapshot = 1;
@@ -319,20 +330,25 @@ static int read_header(struct pstore *ps, int *new_snapshot)
         ps->version = le32_to_cpu(dh->version);
         chunk_size = le32_to_cpu(dh->chunk_size);
 
-        if (!chunk_size_supplied || ps->store->chunk_size == chunk_size)
+        if (ps->store->chunk_size == chunk_size)
                 return 0;
 
-        DMWARN("chunk size %llu in device metadata overrides "
-               "table chunk size of %llu.",
-               (unsigned long long)chunk_size,
-               (unsigned long long)ps->store->chunk_size);
+        if (chunk_size_supplied)
+                DMWARN("chunk size %llu in device metadata overrides "
+                       "table chunk size of %llu.",
+                       (unsigned long long)chunk_size,
+                       (unsigned long long)ps->store->chunk_size);
 
         /* We had a bogus chunk_size. Fix stuff up. */
         free_area(ps);
 
-        ps->store->chunk_size = chunk_size;
-        ps->store->chunk_mask = chunk_size - 1;
-        ps->store->chunk_shift = ffs(chunk_size) - 1;
+        r = dm_exception_store_set_chunk_size(ps->store, chunk_size,
+                                              &chunk_err);
+        if (r) {
+                DMERR("invalid on-disk chunk size %llu: %s.",
+                      (unsigned long long)chunk_size, chunk_err);
+                return r;
+        }
 
         r = dm_io_client_resize(sectors_to_pages(ps->store->chunk_size),
                                 ps->io_client);
@@ -351,15 +367,15 @@ static int write_header(struct pstore *ps)
 {
         struct disk_header *dh;
 
-        memset(ps->area, 0, ps->store->chunk_size << SECTOR_SHIFT);
+        memset(ps->header_area, 0, ps->store->chunk_size << SECTOR_SHIFT);
 
-        dh = (struct disk_header *) ps->area;
+        dh = ps->header_area;
         dh->magic = cpu_to_le32(SNAP_MAGIC);
         dh->valid = cpu_to_le32(ps->valid);
         dh->version = cpu_to_le32(ps->version);
         dh->chunk_size = cpu_to_le32(ps->store->chunk_size);
 
-        return chunk_io(ps, 0, WRITE, 1);
+        return chunk_io(ps, ps->header_area, 0, WRITE, 1);
 }
 
 /*
@@ -679,6 +695,8 @@ static int persistent_ctr(struct dm_exception_store *store,
         ps->valid = 1;
         ps->version = SNAPSHOT_DISK_VERSION;
         ps->area = NULL;
+        ps->zero_area = NULL;
+        ps->header_area = NULL;
         ps->next_free = 2;      /* skipping the header and first area */
         ps->current_committed = 0;
 
diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c
index d573165cd2b7..57f1bf7f3b7a 100644
--- a/drivers/md/dm-snap.c
+++ b/drivers/md/dm-snap.c
@@ -1176,6 +1176,15 @@ static int snapshot_status(struct dm_target *ti, status_type_t type,
         return 0;
 }
 
+static int snapshot_iterate_devices(struct dm_target *ti,
+                                    iterate_devices_callout_fn fn, void *data)
+{
+        struct dm_snapshot *snap = ti->private;
+
+        return fn(ti, snap->origin, 0, ti->len, data);
+}
+
+
 /*-----------------------------------------------------------------
  * Origin methods
  *---------------------------------------------------------------*/
@@ -1410,20 +1419,29 @@ static int origin_status(struct dm_target *ti, status_type_t type, char *result,
         return 0;
 }
 
+static int origin_iterate_devices(struct dm_target *ti,
+                                  iterate_devices_callout_fn fn, void *data)
+{
+        struct dm_dev *dev = ti->private;
+
+        return fn(ti, dev, 0, ti->len, data);
+}
+
 static struct target_type origin_target = {
         .name    = "snapshot-origin",
-        .version = {1, 6, 0},
+        .version = {1, 7, 0},
         .module  = THIS_MODULE,
         .ctr     = origin_ctr,
         .dtr     = origin_dtr,
         .map     = origin_map,
         .resume  = origin_resume,
         .status  = origin_status,
+        .iterate_devices = origin_iterate_devices,
 };
 
 static struct target_type snapshot_target = {
         .name    = "snapshot",
-        .version = {1, 6, 0},
+        .version = {1, 7, 0},
         .module  = THIS_MODULE,
         .ctr     = snapshot_ctr,
         .dtr     = snapshot_dtr,
@@ -1431,6 +1449,7 @@ static struct target_type snapshot_target = {
         .end_io  = snapshot_end_io,
         .resume  = snapshot_resume,
         .status  = snapshot_status,
+        .iterate_devices = snapshot_iterate_devices,
 };
 
 static int __init dm_snapshot_init(void)
diff --git a/drivers/md/dm-stripe.c b/drivers/md/dm-stripe.c
index 4e0e5937e42a..3e563d251733 100644
--- a/drivers/md/dm-stripe.c
+++ b/drivers/md/dm-stripe.c
@@ -329,9 +329,19 @@ static int stripe_iterate_devices(struct dm_target *ti,
         return ret;
 }
 
+static void stripe_io_hints(struct dm_target *ti,
+                            struct queue_limits *limits)
+{
+        struct stripe_c *sc = ti->private;
+        unsigned chunk_size = (sc->chunk_mask + 1) << 9;
+
+        blk_limits_io_min(limits, chunk_size);
+        limits->io_opt = chunk_size * sc->stripes;
+}
+
 static struct target_type stripe_target = {
         .name   = "striped",
-        .version = {1, 2, 0},
+        .version = {1, 3, 0},
         .module = THIS_MODULE,
         .ctr    = stripe_ctr,
         .dtr    = stripe_dtr,
@@ -339,6 +349,7 @@ static struct target_type stripe_target = {
         .end_io = stripe_end_io,
         .status = stripe_status,
         .iterate_devices = stripe_iterate_devices,
+        .io_hints = stripe_io_hints,
 };
 
 int __init dm_stripe_init(void)
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index d952b3441913..1a6cb3c7822e 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -343,10 +343,10 @@ static void close_dev(struct dm_dev_internal *d, struct mapped_device *md)
 }
 
 /*
- * If possible, this checks an area of a destination device is valid.
+ * If possible, this checks an area of a destination device is invalid.
  */
-static int device_area_is_valid(struct dm_target *ti, struct dm_dev *dev,
-                                sector_t start, sector_t len, void *data)
+static int device_area_is_invalid(struct dm_target *ti, struct dm_dev *dev,
+                                  sector_t start, sector_t len, void *data)
 {
         struct queue_limits *limits = data;
         struct block_device *bdev = dev->bdev;
@@ -357,36 +357,40 @@ static int device_area_is_valid(struct dm_target *ti, struct dm_dev *dev,
         char b[BDEVNAME_SIZE];
 
         if (!dev_size)
-                return 1;
+                return 0;
 
         if ((start >= dev_size) || (start + len > dev_size)) {
-                DMWARN("%s: %s too small for target",
-                       dm_device_name(ti->table->md), bdevname(bdev, b));
-                return 0;
+                DMWARN("%s: %s too small for target: "
+                       "start=%llu, len=%llu, dev_size=%llu",
+                       dm_device_name(ti->table->md), bdevname(bdev, b),
+                       (unsigned long long)start,
+                       (unsigned long long)len,
+                       (unsigned long long)dev_size);
+                return 1;
         }
 
         if (logical_block_size_sectors <= 1)
-                return 1;
+                return 0;
 
         if (start & (logical_block_size_sectors - 1)) {
                 DMWARN("%s: start=%llu not aligned to h/w "
-                       "logical block size %hu of %s",
+                       "logical block size %u of %s",
                        dm_device_name(ti->table->md),
                        (unsigned long long)start,
                        limits->logical_block_size, bdevname(bdev, b));
-                return 0;
+                return 1;
         }
 
         if (len & (logical_block_size_sectors - 1)) {
                 DMWARN("%s: len=%llu not aligned to h/w "
-                       "logical block size %hu of %s",
+                       "logical block size %u of %s",
                        dm_device_name(ti->table->md),
                        (unsigned long long)len,
                        limits->logical_block_size, bdevname(bdev, b));
-                return 0;
+                return 1;
         }
 
-        return 1;
+        return 0;
 }
 
 /*
@@ -496,8 +500,15 @@ int dm_set_device_limits(struct dm_target *ti, struct dm_dev *dev,
         }
 
         if (blk_stack_limits(limits, &q->limits, start << 9) < 0)
-                DMWARN("%s: target device %s is misaligned",
-                       dm_device_name(ti->table->md), bdevname(bdev, b));
+                DMWARN("%s: target device %s is misaligned: "
+                       "physical_block_size=%u, logical_block_size=%u, "
+                       "alignment_offset=%u, start=%llu",
+                       dm_device_name(ti->table->md), bdevname(bdev, b),
+                       q->limits.physical_block_size,
+                       q->limits.logical_block_size,
+                       q->limits.alignment_offset,
+                       (unsigned long long) start << 9);
+
 
         /*
          * Check if merge fn is supported.
@@ -698,7 +709,7 @@ static int validate_hardware_logical_block_alignment(struct dm_table *table,
 
         if (remaining) {
                 DMWARN("%s: table line %u (start sect %llu len %llu) "
-                       "not aligned to h/w logical block size %hu",
+                       "not aligned to h/w logical block size %u",
                        dm_device_name(table->md), i,
                        (unsigned long long) ti->begin,
                        (unsigned long long) ti->len,
@@ -996,12 +1007,16 @@ int dm_calculate_queue_limits(struct dm_table *table,
                 ti->type->iterate_devices(ti, dm_set_device_limits,
                                           &ti_limits);
 
+                /* Set I/O hints portion of queue limits */
+                if (ti->type->io_hints)
+                        ti->type->io_hints(ti, &ti_limits);
+
                 /*
                  * Check each device area is consistent with the target's
                  * overall queue limits.
                  */
-                if (!ti->type->iterate_devices(ti, device_area_is_valid,
-                                               &ti_limits))
+                if (ti->type->iterate_devices(ti, device_area_is_invalid,
+                                              &ti_limits))
                         return -EINVAL;
 
 combine_limits:
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 8a311ea0d441..b4845b14740d 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -738,16 +738,22 @@ static void rq_completed(struct mapped_device *md, int run_queue)
         dm_put(md);
 }
 
+static void free_rq_clone(struct request *clone)
+{
+        struct dm_rq_target_io *tio = clone->end_io_data;
+
+        blk_rq_unprep_clone(clone);
+        free_rq_tio(tio);
+}
+
 static void dm_unprep_request(struct request *rq)
 {
         struct request *clone = rq->special;
-        struct dm_rq_target_io *tio = clone->end_io_data;
 
         rq->special = NULL;
         rq->cmd_flags &= ~REQ_DONTPREP;
 
-        blk_rq_unprep_clone(clone);
-        free_rq_tio(tio);
+        free_rq_clone(clone);
 }
 
 /*
@@ -825,8 +831,7 @@ static void dm_end_request(struct request *clone, int error)
                         rq->sense_len = clone->sense_len;
         }
 
-        BUG_ON(clone->bio);
-        free_rq_tio(tio);
+        free_rq_clone(clone);
 
         blk_end_request_all(rq, error);
 
diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h
index 655e7721580a..df7607e6dce8 100644
--- a/include/linux/device-mapper.h
+++ b/include/linux/device-mapper.h
@@ -91,6 +91,9 @@ typedef int (*dm_iterate_devices_fn) (struct dm_target *ti,
                                       iterate_devices_callout_fn fn,
                                       void *data);
 
+typedef void (*dm_io_hints_fn) (struct dm_target *ti,
+                                struct queue_limits *limits);
+
 /*
  * Returns:
  *    0: The target can handle the next I/O immediately.
@@ -151,6 +154,7 @@ struct target_type {
         dm_merge_fn merge;
         dm_busy_fn busy;
         dm_iterate_devices_fn iterate_devices;
+        dm_io_hints_fn io_hints;
 
         /* For internal device-mapper use. */
         struct list_head list;
diff --git a/include/linux/dm-log-userspace.h b/include/linux/dm-log-userspace.h
index 642e3017b51f..8a1f972c0fe9 100644
--- a/include/linux/dm-log-userspace.h
+++ b/include/linux/dm-log-userspace.h
@@ -371,7 +371,18 @@
         (DM_ULOG_REQUEST_MASK & (request_type))
 
 struct dm_ulog_request {
-        char uuid[DM_UUID_LEN]; /* Ties a request to a specific mirror log */
+        /*
+         * The local unique identifier (luid) and the universally unique
+         * identifier (uuid) are used to tie a request to a specific
+         * mirror log.  A single machine log could probably make due with
+         * just the 'luid', but a cluster-aware log must use the 'uuid' and
+         * the 'luid'.  The uuid is what is required for node to node
+         * communication concerning a particular log, but the 'luid' helps
+         * differentiate between logs that are being swapped and have the
+         * same 'uuid'.  (Think "live" and "inactive" device-mapper tables.)
+         */
+        uint64_t luid;
+        char uuid[DM_UUID_LEN];
         char padding[7];        /* Padding because DM_UUID_LEN = 129 */
 
         int32_t error;          /* Used to report back processing errors */