[PATCH] dm: improve error message consistency

Tidy device-mapper error messages to include context information
automatically.

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

17 files changed, 142 insertions, 112 deletions

diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index 61a590bb6241..6022ed12a795 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -20,7 +20,7 @@
 
 #include "dm.h"
 
-#define PFX     "crypt: "
+#define DM_MSG_PREFIX "crypt"
 
 /*
  * per bio private data
@@ -125,19 +125,19 @@ static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti,
         u8 *salt;
 
         if (opts == NULL) {
-                ti->error = PFX "Digest algorithm missing for ESSIV mode";
+                ti->error = "Digest algorithm missing for ESSIV mode";
                 return -EINVAL;
         }
 
         /* Hash the cipher key with the given hash algorithm */
         hash_tfm = crypto_alloc_tfm(opts, CRYPTO_TFM_REQ_MAY_SLEEP);
         if (hash_tfm == NULL) {
-                ti->error = PFX "Error initializing ESSIV hash";
+                ti->error = "Error initializing ESSIV hash";
                 return -EINVAL;
         }
 
         if (crypto_tfm_alg_type(hash_tfm) != CRYPTO_ALG_TYPE_DIGEST) {
-                ti->error = PFX "Expected digest algorithm for ESSIV hash";
+                ti->error = "Expected digest algorithm for ESSIV hash";
                 crypto_free_tfm(hash_tfm);
                 return -EINVAL;
         }
@@ -145,7 +145,7 @@ static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti,
         saltsize = crypto_tfm_alg_digestsize(hash_tfm);
         salt = kmalloc(saltsize, GFP_KERNEL);
         if (salt == NULL) {
-                ti->error = PFX "Error kmallocing salt storage in ESSIV";
+                ti->error = "Error kmallocing salt storage in ESSIV";
                 crypto_free_tfm(hash_tfm);
                 return -ENOMEM;
         }
@@ -159,20 +159,20 @@ static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti,
                                      CRYPTO_TFM_MODE_ECB |
                                      CRYPTO_TFM_REQ_MAY_SLEEP);
         if (essiv_tfm == NULL) {
-                ti->error = PFX "Error allocating crypto tfm for ESSIV";
+                ti->error = "Error allocating crypto tfm for ESSIV";
                 kfree(salt);
                 return -EINVAL;
         }
         if (crypto_tfm_alg_blocksize(essiv_tfm)
             != crypto_tfm_alg_ivsize(cc->tfm)) {
-                ti->error = PFX "Block size of ESSIV cipher does "
+                ti->error = "Block size of ESSIV cipher does "
                                 "not match IV size of block cipher";
                 crypto_free_tfm(essiv_tfm);
                 kfree(salt);
                 return -EINVAL;
         }
         if (crypto_cipher_setkey(essiv_tfm, salt, saltsize) < 0) {
-                ti->error = PFX "Failed to set key for ESSIV cipher";
+                ti->error = "Failed to set key for ESSIV cipher";
                 crypto_free_tfm(essiv_tfm);
                 kfree(salt);
                 return -EINVAL;
@@ -521,7 +521,7 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
         unsigned long long tmpll;
 
         if (argc != 5) {
-                ti->error = PFX "Not enough arguments";
+                ti->error = "Not enough arguments";
                 return -EINVAL;
         }
 
@@ -532,21 +532,21 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
         ivmode = strsep(&ivopts, ":");
 
         if (tmp)
-                DMWARN(PFX "Unexpected additional cipher options");
+                DMWARN("Unexpected additional cipher options");
 
         key_size = strlen(argv[1]) >> 1;
 
         cc = kmalloc(sizeof(*cc) + key_size * sizeof(u8), GFP_KERNEL);
         if (cc == NULL) {
                 ti->error =
-                        PFX "Cannot allocate transparent encryption context";
+                        "Cannot allocate transparent encryption context";
                 return -ENOMEM;
         }
 
         cc->key_size = key_size;
         if ((!key_size && strcmp(argv[1], "-") != 0) ||
             (key_size && crypt_decode_key(cc->key, argv[1], key_size) < 0)) {
-                ti->error = PFX "Error decoding key";
+                ti->error = "Error decoding key";
                 goto bad1;
         }
 
@@ -562,22 +562,22 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
         else if (strcmp(chainmode, "ecb") == 0)
                 crypto_flags = CRYPTO_TFM_MODE_ECB;
         else {
-                ti->error = PFX "Unknown chaining mode";
+                ti->error = "Unknown chaining mode";
                 goto bad1;
         }
 
         if (crypto_flags != CRYPTO_TFM_MODE_ECB && !ivmode) {
-                ti->error = PFX "This chaining mode requires an IV mechanism";
+                ti->error = "This chaining mode requires an IV mechanism";
                 goto bad1;
         }
 
         tfm = crypto_alloc_tfm(cipher, crypto_flags | CRYPTO_TFM_REQ_MAY_SLEEP);
         if (!tfm) {
-                ti->error = PFX "Error allocating crypto tfm";
+                ti->error = "Error allocating crypto tfm";
                 goto bad1;
         }
         if (crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER) {
-                ti->error = PFX "Expected cipher algorithm";
+                ti->error = "Expected cipher algorithm";
                 goto bad2;
         }
 
@@ -595,7 +595,7 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
         else if (strcmp(ivmode, "essiv") == 0)
                 cc->iv_gen_ops = &crypt_iv_essiv_ops;
         else {
-                ti->error = PFX "Invalid IV mode";
+                ti->error = "Invalid IV mode";
                 goto bad2;
         }
 
@@ -610,7 +610,7 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
         else {
                 cc->iv_size = 0;
                 if (cc->iv_gen_ops) {
-                        DMWARN(PFX "Selected cipher does not support IVs");
+                        DMWARN("Selected cipher does not support IVs");
                         if (cc->iv_gen_ops->dtr)
                                 cc->iv_gen_ops->dtr(cc);
                         cc->iv_gen_ops = NULL;
@@ -619,36 +619,36 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 
         cc->io_pool = mempool_create_slab_pool(MIN_IOS, _crypt_io_pool);
         if (!cc->io_pool) {
-                ti->error = PFX "Cannot allocate crypt io mempool";
+                ti->error = "Cannot allocate crypt io mempool";
                 goto bad3;
         }
 
         cc->page_pool = mempool_create_page_pool(MIN_POOL_PAGES, 0);
         if (!cc->page_pool) {
-                ti->error = PFX "Cannot allocate page mempool";
+                ti->error = "Cannot allocate page mempool";
                 goto bad4;
         }
 
         if (tfm->crt_cipher.cit_setkey(tfm, cc->key, key_size) < 0) {
-                ti->error = PFX "Error setting key";
+                ti->error = "Error setting key";
                 goto bad5;
         }
 
         if (sscanf(argv[2], "%llu", &tmpll) != 1) {
-                ti->error = PFX "Invalid iv_offset sector";
+                ti->error = "Invalid iv_offset sector";
                 goto bad5;
         }
         cc->iv_offset = tmpll;
 
         if (sscanf(argv[4], "%llu", &tmpll) != 1) {
-                ti->error = PFX "Invalid device sector";
+                ti->error = "Invalid device sector";
                 goto bad5;
         }
         cc->start = tmpll;
 
         if (dm_get_device(ti, argv[3], cc->start, ti->len,
                           dm_table_get_mode(ti->table), &cc->dev)) {
-                ti->error = PFX "Device lookup failed";
+                ti->error = "Device lookup failed";
                 goto bad5;
         }
 
@@ -657,7 +657,7 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
                         *(ivopts - 1) = ':';
                 cc->iv_mode = kmalloc(strlen(ivmode) + 1, GFP_KERNEL);
                 if (!cc->iv_mode) {
-                        ti->error = PFX "Error kmallocing iv_mode string";
+                        ti->error = "Error kmallocing iv_mode string";
                         goto bad5;
                 }
                 strcpy(cc->iv_mode, ivmode);
@@ -918,13 +918,13 @@ static int __init dm_crypt_init(void)
         _kcryptd_workqueue = create_workqueue("kcryptd");
         if (!_kcryptd_workqueue) {
                 r = -ENOMEM;
-                DMERR(PFX "couldn't create kcryptd");
+                DMERR("couldn't create kcryptd");
                 goto bad1;
         }
 
         r = dm_register_target(&crypt_target);
         if (r < 0) {
-                DMERR(PFX "register failed %d", r);
+                DMERR("register failed %d", r);
                 goto bad2;
         }
 
@@ -942,7 +942,7 @@ static void __exit dm_crypt_exit(void)
         int r = dm_unregister_target(&crypt_target);
 
         if (r < 0)
-                DMERR(PFX "unregister failed %d", r);
+                DMERR("unregister failed %d", r);
 
         destroy_workqueue(_kcryptd_workqueue);
         kmem_cache_destroy(_crypt_io_pool);
diff --git a/drivers/md/dm-emc.c b/drivers/md/dm-emc.c
index c7067674dcb7..2a374ccb30dd 100644
--- a/drivers/md/dm-emc.c
+++ b/drivers/md/dm-emc.c
@@ -12,6 +12,8 @@
 #include <scsi/scsi.h>
 #include <scsi/scsi_cmnd.h>
 
+#define DM_MSG_PREFIX "multipath emc"
+
 struct emc_handler {
         spinlock_t lock;
 
@@ -66,7 +68,7 @@ static struct bio *get_failover_bio(struct path *path, unsigned data_size)
 
         bio = bio_alloc(GFP_ATOMIC, 1);
         if (!bio) {
-                DMERR("dm-emc: get_failover_bio: bio_alloc() failed.");
+                DMERR("get_failover_bio: bio_alloc() failed.");
                 return NULL;
         }
 
@@ -78,13 +80,13 @@ static struct bio *get_failover_bio(struct path *path, unsigned data_size)
 
         page = alloc_page(GFP_ATOMIC);
         if (!page) {
-                DMERR("dm-emc: get_failover_bio: alloc_page() failed.");
+                DMERR("get_failover_bio: alloc_page() failed.");
                 bio_put(bio);
                 return NULL;
         }
 
         if (bio_add_page(bio, page, data_size, 0) != data_size) {
-                DMERR("dm-emc: get_failover_bio: alloc_page() failed.");
+                DMERR("get_failover_bio: alloc_page() failed.");
                 __free_page(page);
                 bio_put(bio);
                 return NULL;
@@ -103,7 +105,7 @@ static struct request *get_failover_req(struct emc_handler *h,
         /* FIXME: Figure out why it fails with GFP_ATOMIC. */
         rq = blk_get_request(q, WRITE, __GFP_WAIT);
         if (!rq) {
-                DMERR("dm-emc: get_failover_req: blk_get_request failed");
+                DMERR("get_failover_req: blk_get_request failed");
                 return NULL;
         }
 
@@ -160,7 +162,7 @@ static struct request *emc_trespass_get(struct emc_handler *h,
 
         bio = get_failover_bio(path, data_size);
         if (!bio) {
-                DMERR("dm-emc: emc_trespass_get: no bio");
+                DMERR("emc_trespass_get: no bio");
                 return NULL;
         }
 
@@ -173,7 +175,7 @@ static struct request *emc_trespass_get(struct emc_handler *h,
         /* get request for block layer packet command */
         rq = get_failover_req(h, bio, path);
         if (!rq) {
-                DMERR("dm-emc: emc_trespass_get: no rq");
+                DMERR("emc_trespass_get: no rq");
                 free_bio(bio);
                 return NULL;
         }
@@ -200,18 +202,18 @@ static void emc_pg_init(struct hw_handler *hwh, unsigned bypassed,
          * initial state passed into us and then get an update here.
          */
         if (!q) {
-                DMINFO("dm-emc: emc_pg_init: no queue");
+                DMINFO("emc_pg_init: no queue");
                 goto fail_path;
         }
 
         /* FIXME: The request should be pre-allocated. */
         rq = emc_trespass_get(hwh->context, path);
         if (!rq) {
-                DMERR("dm-emc: emc_pg_init: no rq");
+                DMERR("emc_pg_init: no rq");
                 goto fail_path;
         }
 
-        DMINFO("dm-emc: emc_pg_init: sending switch-over command");
+        DMINFO("emc_pg_init: sending switch-over command");
         elv_add_request(q, rq, ELEVATOR_INSERT_FRONT, 1);
         return;
 
@@ -241,18 +243,18 @@ static int emc_create(struct hw_handler *hwh, unsigned argc, char **argv)
                 hr = 0;
                 short_trespass = 0;
         } else if (argc != 2) {
-                DMWARN("dm-emc hwhandler: incorrect number of arguments");
+                DMWARN("incorrect number of arguments");
                 return -EINVAL;
         } else {
                 if ((sscanf(argv[0], "%u", &short_trespass) != 1)
                         || (short_trespass > 1)) {
-                        DMWARN("dm-emc: invalid trespass mode selected");
+                        DMWARN("invalid trespass mode selected");
                         return -EINVAL;
                 }
 
                 if ((sscanf(argv[1], "%u", &hr) != 1)
                         || (hr > 1)) {
-                        DMWARN("dm-emc: invalid honor reservation flag selected");
+                        DMWARN("invalid honor reservation flag selected");
                         return -EINVAL;
                 }
         }
@@ -264,14 +266,14 @@ static int emc_create(struct hw_handler *hwh, unsigned argc, char **argv)
         hwh->context = h;
 
         if ((h->short_trespass = short_trespass))
-                DMWARN("dm-emc: short trespass command will be send");
+                DMWARN("short trespass command will be send");
         else
-                DMWARN("dm-emc: long trespass command will be send");
+                DMWARN("long trespass command will be send");
 
         if ((h->hr = hr))
-                DMWARN("dm-emc: honor reservation bit will be set");
+                DMWARN("honor reservation bit will be set");
         else
-                DMWARN("dm-emc: honor reservation bit will not be set (default)");
+                DMWARN("honor reservation bit will not be set (default)");
 
         return 0;
 }
@@ -336,9 +338,9 @@ static int __init dm_emc_init(void)
         int r = dm_register_hw_handler(&emc_hwh);
 
         if (r < 0)
-                DMERR("emc: register failed %d", r);
+                DMERR("register failed %d", r);
 
-        DMINFO("dm-emc version 0.0.3 loaded");
+        DMINFO("version 0.0.3 loaded");
 
         return r;
 }
@@ -348,7 +350,7 @@ static void __exit dm_emc_exit(void)
         int r = dm_unregister_hw_handler(&emc_hwh);
 
         if (r < 0)
-                DMERR("emc: unregister failed %d", r);
+                DMERR("unregister failed %d", r);
 }
 
 module_init(dm_emc_init);
diff --git a/drivers/md/dm-exception-store.c b/drivers/md/dm-exception-store.c
index 34a75939a0ca..d12379b5cdb5 100644
--- a/drivers/md/dm-exception-store.c
+++ b/drivers/md/dm-exception-store.c
@@ -16,6 +16,8 @@
 #include <linux/vmalloc.h>
 #include <linux/slab.h>
 
+#define DM_MSG_PREFIX "snapshots"
+
 /*-----------------------------------------------------------------
  * Persistent snapshots, by persistent we mean that the snapshot
  * will survive a reboot.
diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c
index c6ce13b18747..3edb3477f987 100644
--- a/drivers/md/dm-ioctl.c
+++ b/drivers/md/dm-ioctl.c
@@ -19,6 +19,7 @@
 
 #include <asm/uaccess.h>
 
+#define DM_MSG_PREFIX "ioctl"
 #define DM_DRIVER_EMAIL "dm-devel@redhat.com"
 
 /*-----------------------------------------------------------------
diff --git a/drivers/md/dm-linear.c b/drivers/md/dm-linear.c
index daf586c0898d..47b3c62bbdb8 100644
--- a/drivers/md/dm-linear.c
+++ b/drivers/md/dm-linear.c
@@ -12,6 +12,8 @@
 #include <linux/bio.h>
 #include <linux/slab.h>
 
+#define DM_MSG_PREFIX "linear"
+
 /*
  * Linear: maps a linear range of a device.
  */
@@ -29,7 +31,7 @@ static int linear_ctr(struct dm_target *ti, unsigned int argc, char **argv)
         unsigned long long tmp;
 
         if (argc != 2) {
-                ti->error = "dm-linear: Invalid argument count";
+                ti->error = "Invalid argument count";
                 return -EINVAL;
         }
 
@@ -111,7 +113,7 @@ int __init dm_linear_init(void)
         int r = dm_register_target(&linear_target);
 
         if (r < 0)
-                DMERR("linear: register failed %d", r);
+                DMERR("register failed %d", r);
 
         return r;
 }
@@ -121,5 +123,5 @@ void dm_linear_exit(void)
         int r = dm_unregister_target(&linear_target);
 
         if (r < 0)
-                DMERR("linear: unregister failed %d", r);
+                DMERR("unregister failed %d", r);
 }
diff --git a/drivers/md/dm-log.c b/drivers/md/dm-log.c
index ba98bf57c7c0..64b764bd02cc 100644
--- a/drivers/md/dm-log.c
+++ b/drivers/md/dm-log.c
@@ -12,6 +12,8 @@
 #include "dm-log.h"
 #include "dm-io.h"
 
+#define DM_MSG_PREFIX "mirror log"
+
 static LIST_HEAD(_log_types);
 static DEFINE_SPINLOCK(_lock);
 
diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index 1816f30678ed..217615b33223 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -21,6 +21,7 @@
 #include <linux/workqueue.h>
 #include <asm/atomic.h>
 
+#define DM_MSG_PREFIX "multipath"
 #define MESG_STR(x) x, sizeof(x)
 
 /* Path properties */
@@ -446,8 +447,6 @@ struct param {
         char *error;
 };
 
-#define ESTR(s) ("dm-multipath: " s)
-
 static int read_param(struct param *param, char *str, unsigned *v, char **error)
 {
         if (!str ||
@@ -495,12 +494,12 @@ static int parse_path_selector(struct arg_set *as, struct priority_group *pg,
         unsigned ps_argc;
 
         static struct param _params[] = {
-                {0, 1024, ESTR("invalid number of path selector args")},
+                {0, 1024, "invalid number of path selector args"},
         };
 
         pst = dm_get_path_selector(shift(as));
         if (!pst) {
-                ti->error = ESTR("unknown path selector type");
+                ti->error = "unknown path selector type";
                 return -EINVAL;
         }
 
@@ -511,7 +510,7 @@ static int parse_path_selector(struct arg_set *as, struct priority_group *pg,
         r = pst->create(&pg->ps, ps_argc, as->argv);
         if (r) {
                 dm_put_path_selector(pst);
-                ti->error = ESTR("path selector constructor failed");
+                ti->error = "path selector constructor failed";
                 return r;
         }
 
@@ -529,7 +528,7 @@ static struct pgpath *parse_path(struct arg_set *as, struct path_selector *ps,
 
         /* we need at least a path arg */
         if (as->argc < 1) {
-                ti->error = ESTR("no device given");
+                ti->error = "no device given";
                 return NULL;
         }
 
@@ -540,7 +539,7 @@ static struct pgpath *parse_path(struct arg_set *as, struct path_selector *ps,
         r = dm_get_device(ti, shift(as), ti->begin, ti->len,
                           dm_table_get_mode(ti->table), &p->path.dev);
         if (r) {
-                ti->error = ESTR("error getting device");
+                ti->error = "error getting device";
                 goto bad;
         }
 
@@ -562,8 +561,8 @@ static struct priority_group *parse_priority_group(struct arg_set *as,
                                                    struct dm_target *ti)
 {
         static struct param _params[] = {
-                {1, 1024, ESTR("invalid number of paths")},
-                {0, 1024, ESTR("invalid number of selector args")}
+                {1, 1024, "invalid number of paths"},
+                {0, 1024, "invalid number of selector args"}
         };
 
         int r;
@@ -572,13 +571,13 @@ static struct priority_group *parse_priority_group(struct arg_set *as,
 
         if (as->argc < 2) {
                 as->argc = 0;
-                ti->error = ESTR("not enough priority group aruments");
+                ti->error = "not enough priority group aruments";
                 return NULL;
         }
 
         pg = alloc_priority_group();
         if (!pg) {
-                ti->error = ESTR("couldn't allocate priority group");
+                ti->error = "couldn't allocate priority group";
                 return NULL;
         }
         pg->m = m;
@@ -633,7 +632,7 @@ static int parse_hw_handler(struct arg_set *as, struct multipath *m,
         unsigned hw_argc;
 
         static struct param _params[] = {
-                {0, 1024, ESTR("invalid number of hardware handler args")},
+                {0, 1024, "invalid number of hardware handler args"},
         };
 
         r = read_param(_params, shift(as), &hw_argc, &ti->error);
@@ -645,14 +644,14 @@ static int parse_hw_handler(struct arg_set *as, struct multipath *m,
 
         hwht = dm_get_hw_handler(shift(as));
         if (!hwht) {
-                ti->error = ESTR("unknown hardware handler type");
+                ti->error = "unknown hardware handler type";
                 return -EINVAL;
         }
 
         r = hwht->create(&m->hw_handler, hw_argc - 1, as->argv);
         if (r) {
                 dm_put_hw_handler(hwht);
-                ti->error = ESTR("hardware handler constructor failed");
+                ti->error = "hardware handler constructor failed";
                 return r;
         }
 
@@ -669,7 +668,7 @@ static int parse_features(struct arg_set *as, struct multipath *m,
         unsigned argc;
 
         static struct param _params[] = {
-                {0, 1, ESTR("invalid number of feature args")},
+                {0, 1, "invalid number of feature args"},
         };
 
         r = read_param(_params, shift(as), &argc, &ti->error);
@@ -692,8 +691,8 @@ static int multipath_ctr(struct dm_target *ti, unsigned int argc,
 {
         /* target parameters */
         static struct param _params[] = {
-                {1, 1024, ESTR("invalid number of priority groups")},
-                {1, 1024, ESTR("invalid initial priority group number")},
+                {1, 1024, "invalid number of priority groups"},
+                {1, 1024, "invalid initial priority group number"},
         };
 
         int r;
@@ -707,7 +706,7 @@ static int multipath_ctr(struct dm_target *ti, unsigned int argc,
 
         m = alloc_multipath();
         if (!m) {
-                ti->error = ESTR("can't allocate multipath");
+                ti->error = "can't allocate multipath";
                 return -EINVAL;
         }
 
@@ -746,7 +745,7 @@ static int multipath_ctr(struct dm_target *ti, unsigned int argc,
         }
 
         if (pg_count != m->nr_priority_groups) {
-                ti->error = ESTR("priority group count mismatch");
+                ti->error = "priority group count mismatch";
                 r = -EINVAL;
                 goto bad;
         }
@@ -807,7 +806,7 @@ static int fail_path(struct pgpath *pgpath)
         if (!pgpath->path.is_active)
                 goto out;
 
-        DMWARN("dm-multipath: Failing path %s.", pgpath->path.dev->name);
+        DMWARN("Failing path %s.", pgpath->path.dev->name);
 
         pgpath->pg->ps.type->fail_path(&pgpath->pg->ps, &pgpath->path);
         pgpath->path.is_active = 0;
@@ -1250,7 +1249,7 @@ static int multipath_message(struct dm_target *ti, unsigned argc, char **argv)
         r = dm_get_device(ti, argv[1], ti->begin, ti->len,
                           dm_table_get_mode(ti->table), &dev);
         if (r) {
-                DMWARN("dm-multipath message: error getting device %s",
+                DMWARN("message: error getting device %s",
                        argv[1]);
                 return -EINVAL;
         }
@@ -1309,7 +1308,7 @@ static int __init dm_multipath_init(void)
                 return -ENOMEM;
         }
 
-        DMINFO("dm-multipath version %u.%u.%u loaded",
+        DMINFO("version %u.%u.%u loaded",
                multipath_target.version[0], multipath_target.version[1],
                multipath_target.version[2]);
 
diff --git a/drivers/md/dm-raid1.c b/drivers/md/dm-raid1.c
index 6ae42f1d76ae..be48cedf986b 100644
--- a/drivers/md/dm-raid1.c
+++ b/drivers/md/dm-raid1.c
@@ -20,6 +20,8 @@
 #include <linux/vmalloc.h>
 #include <linux/workqueue.h>
 
+#define DM_MSG_PREFIX "raid1"
+
 static struct workqueue_struct *_kmirrord_wq;
 static struct work_struct _kmirrord_work;
 
@@ -892,7 +894,7 @@ static struct mirror_set *alloc_context(unsigned int nr_mirrors,
 
         ms = kmalloc(len, GFP_KERNEL);
         if (!ms) {
-                ti->error = "dm-mirror: Cannot allocate mirror context";
+                ti->error = "Cannot allocate mirror context";
                 return NULL;
         }
 
@@ -906,7 +908,7 @@ static struct mirror_set *alloc_context(unsigned int nr_mirrors,
         ms->default_mirror = &ms->mirror[DEFAULT_MIRROR];
 
         if (rh_init(&ms->rh, ms, dl, region_size, ms->nr_regions)) {
-                ti->error = "dm-mirror: Error creating dirty region hash";
+                ti->error = "Error creating dirty region hash";
                 kfree(ms);
                 return NULL;
         }
@@ -936,14 +938,14 @@ static int get_mirror(struct mirror_set *ms, struct dm_target *ti,
         unsigned long long offset;
 
         if (sscanf(argv[1], "%llu", &offset) != 1) {
-                ti->error = "dm-mirror: Invalid offset";
+                ti->error = "Invalid offset";
                 return -EINVAL;
         }
 
         if (dm_get_device(ti, argv[0], offset, ti->len,
                           dm_table_get_mode(ti->table),
                           &ms->mirror[mirror].dev)) {
-                ti->error = "dm-mirror: Device lookup failure";
+                ti->error = "Device lookup failure";
                 return -ENXIO;
         }
 
@@ -980,30 +982,30 @@ static struct dirty_log *create_dirty_log(struct dm_target *ti,
         struct dirty_log *dl;
 
         if (argc < 2) {
-                ti->error = "dm-mirror: Insufficient mirror log arguments";
+                ti->error = "Insufficient mirror log arguments";
                 return NULL;
         }
 
         if (sscanf(argv[1], "%u", &param_count) != 1) {
-                ti->error = "dm-mirror: Invalid mirror log argument count";
+                ti->error = "Invalid mirror log argument count";
                 return NULL;
         }
 
         *args_used = 2 + param_count;
 
         if (argc < *args_used) {
-                ti->error = "dm-mirror: Insufficient mirror log arguments";
+                ti->error = "Insufficient mirror log arguments";
                 return NULL;
         }
 
         dl = dm_create_dirty_log(argv[0], ti, param_count, argv + 2);
         if (!dl) {
-                ti->error = "dm-mirror: Error creating mirror dirty log";
+                ti->error = "Error creating mirror dirty log";
                 return NULL;
         }
 
         if (!_check_region_size(ti, dl->type->get_region_size(dl))) {
-                ti->error = "dm-mirror: Invalid region size";
+                ti->error = "Invalid region size";
                 dm_destroy_dirty_log(dl);
                 return NULL;
         }
@@ -1037,7 +1039,7 @@ static int mirror_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 
         if (!argc || sscanf(argv[0], "%u", &nr_mirrors) != 1 ||
             nr_mirrors < 2 || nr_mirrors > KCOPYD_MAX_REGIONS + 1) {
-                ti->error = "dm-mirror: Invalid number of mirrors";
+                ti->error = "Invalid number of mirrors";
                 dm_destroy_dirty_log(dl);
                 return -EINVAL;
         }
@@ -1045,7 +1047,7 @@ static int mirror_ctr(struct dm_target *ti, unsigned int argc, char **argv)
         argv++, argc--;
 
         if (argc != nr_mirrors * 2) {
-                ti->error = "dm-mirror: Wrong number of mirror arguments";
+                ti->error = "Wrong number of mirror arguments";
                 dm_destroy_dirty_log(dl);
                 return -EINVAL;
         }
diff --git a/drivers/md/dm-round-robin.c b/drivers/md/dm-round-robin.c
index d0024865a789..c5a16c550122 100644
--- a/drivers/md/dm-round-robin.c
+++ b/drivers/md/dm-round-robin.c
@@ -14,6 +14,8 @@
 
 #include <linux/slab.h>
 
+#define DM_MSG_PREFIX "multipath round-robin"
+
 /*-----------------------------------------------------------------
  * Path-handling code, paths are held in lists
  *---------------------------------------------------------------*/
@@ -191,9 +193,9 @@ static int __init dm_rr_init(void)
         int r = dm_register_path_selector(&rr_ps);
 
         if (r < 0)
-                DMERR("round-robin: register failed %d", r);
+                DMERR("register failed %d", r);
 
-        DMINFO("dm-round-robin version 1.0.0 loaded");
+        DMINFO("version 1.0.0 loaded");
 
         return r;
 }
diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c
index b84bc1aae353..8eea0ddbf5ec 100644
--- a/drivers/md/dm-snap.c
+++ b/drivers/md/dm-snap.c
@@ -23,6 +23,8 @@
 #include "dm-bio-list.h"
 #include "kcopyd.h"
 
+#define DM_MSG_PREFIX "snapshots"
+
 /*
  * The percentage increment we will wake up users at
  */
@@ -117,7 +119,7 @@ static int init_origin_hash(void)
         _origins = kmalloc(ORIGIN_HASH_SIZE * sizeof(struct list_head),
                            GFP_KERNEL);
         if (!_origins) {
-                DMERR("Device mapper: Snapshot: unable to allocate memory");
+                DMERR("unable to allocate memory");
                 return -ENOMEM;
         }
 
@@ -412,7 +414,7 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv)
         int blocksize;
 
         if (argc < 4) {
-                ti->error = "dm-snapshot: requires exactly 4 arguments";
+                ti->error = "requires exactly 4 arguments";
                 r = -EINVAL;
                 goto bad1;
         }
@@ -1127,7 +1129,7 @@ static int origin_ctr(struct dm_target *ti, unsigned int argc, char **argv)
         struct dm_dev *dev;
 
         if (argc != 1) {
-                ti->error = "dm-origin: incorrect number of arguments";
+                ti->error = "origin: incorrect number of arguments";
                 return -EINVAL;
         }
 
@@ -1236,7 +1238,7 @@ static int __init dm_snapshot_init(void)
 
         r = dm_register_target(&origin_target);
         if (r < 0) {
-                DMERR("Device mapper: Origin: register failed %d\n", r);
+                DMERR("Origin target register failed %d", r);
                 goto bad1;
         }
 
diff --git a/drivers/md/dm-stripe.c b/drivers/md/dm-stripe.c
index 08328a8f5a3c..6c29fcecd892 100644
--- a/drivers/md/dm-stripe.c
+++ b/drivers/md/dm-stripe.c
@@ -12,6 +12,8 @@
 #include <linux/bio.h>
 #include <linux/slab.h>
 
+#define DM_MSG_PREFIX "striped"
+
 struct stripe {
         struct dm_dev *dev;
         sector_t physical_start;
@@ -78,19 +80,19 @@ static int stripe_ctr(struct dm_target *ti, unsigned int argc, char **argv)
         unsigned int i;
 
         if (argc < 2) {
-                ti->error = "dm-stripe: Not enough arguments";
+                ti->error = "Not enough arguments";
                 return -EINVAL;
         }
 
         stripes = simple_strtoul(argv[0], &end, 10);
         if (*end) {
-                ti->error = "dm-stripe: Invalid stripe count";
+                ti->error = "Invalid stripe count";
                 return -EINVAL;
         }
 
         chunk_size = simple_strtoul(argv[1], &end, 10);
         if (*end) {
-                ti->error = "dm-stripe: Invalid chunk_size";
+                ti->error = "Invalid chunk_size";
                 return -EINVAL;
         }
 
@@ -99,19 +101,19 @@ static int stripe_ctr(struct dm_target *ti, unsigned int argc, char **argv)
          */
         if (!chunk_size || (chunk_size & (chunk_size - 1)) ||
             (chunk_size < (PAGE_SIZE >> SECTOR_SHIFT))) {
-                ti->error = "dm-stripe: Invalid chunk size";
+                ti->error = "Invalid chunk size";
                 return -EINVAL;
         }
 
         if (ti->len & (chunk_size - 1)) {
-                ti->error = "dm-stripe: Target length not divisible by "
+                ti->error = "Target length not divisible by "
                     "chunk size";
                 return -EINVAL;
         }
 
         width = ti->len;
         if (sector_div(width, stripes)) {
-                ti->error = "dm-stripe: Target length not divisible by "
+                ti->error = "Target length not divisible by "
                     "number of stripes";
                 return -EINVAL;
         }
@@ -120,14 +122,14 @@ static int stripe_ctr(struct dm_target *ti, unsigned int argc, char **argv)
          * Do we have enough arguments for that many stripes ?
          */
         if (argc != (2 + 2 * stripes)) {
-                ti->error = "dm-stripe: Not enough destinations "
+                ti->error = "Not enough destinations "
                         "specified";
                 return -EINVAL;
         }
 
         sc = alloc_context(stripes);
         if (!sc) {
-                ti->error = "dm-stripe: Memory allocation for striped context "
+                ti->error = "Memory allocation for striped context "
                     "failed";
                 return -ENOMEM;
         }
@@ -149,8 +151,7 @@ static int stripe_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 
                 r = get_stripe(ti, sc, i, argv);
                 if (r < 0) {
-                        ti->error = "dm-stripe: Couldn't parse stripe "
-                                "destination";
+                        ti->error = "Couldn't parse stripe destination";
                         while (i--)
                                 dm_put_device(ti, sc->stripe[i].dev);
                         kfree(sc);
@@ -227,7 +228,7 @@ int __init dm_stripe_init(void)
 
         r = dm_register_target(&stripe_target);
         if (r < 0)
-                DMWARN("striped target registration failed");
+                DMWARN("target registration failed");
 
         return r;
 }
@@ -235,7 +236,7 @@ int __init dm_stripe_init(void)
 void dm_stripe_exit(void)
 {
         if (dm_unregister_target(&stripe_target))
-                DMWARN("striped target unregistration failed");
+                DMWARN("target unregistration failed");
 
         return;
 }
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index 827b648fac50..75fe9493e6af 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -17,6 +17,8 @@
 #include <linux/mutex.h>
 #include <asm/atomic.h>
 
+#define DM_MSG_PREFIX "table"
+
 #define MAX_DEPTH 16
 #define NODE_SIZE L1_CACHE_BYTES
 #define KEYS_PER_NODE (NODE_SIZE / sizeof(sector_t))
@@ -715,15 +717,14 @@ int dm_table_add_target(struct dm_table *t, const char *type,
         memset(tgt, 0, sizeof(*tgt));
 
         if (!len) {
-                tgt->error = "zero-length target";
-                DMERR("%s", tgt->error);
+                DMERR("%s: zero-length target", dm_device_name(t->md));
                 return -EINVAL;
         }
 
         tgt->type = dm_get_target_type(type);
         if (!tgt->type) {
-                tgt->error = "unknown target type";
-                DMERR("%s", tgt->error);
+                DMERR("%s: %s: unknown target type", dm_device_name(t->md),
+                      type);
                 return -EINVAL;
         }
 
@@ -760,7 +761,7 @@ int dm_table_add_target(struct dm_table *t, const char *type,
         return 0;
 
  bad:
-        DMERR("%s", tgt->error);
+        DMERR("%s: %s: %s", dm_device_name(t->md), type, tgt->error);
         dm_put_target_type(tgt->type);
         return r;
 }
diff --git a/drivers/md/dm-target.c b/drivers/md/dm-target.c
index 64fd8e79ea4c..477a041a41cf 100644
--- a/drivers/md/dm-target.c
+++ b/drivers/md/dm-target.c
@@ -12,6 +12,8 @@
 #include <linux/bio.h>
 #include <linux/slab.h>
 
+#define DM_MSG_PREFIX "target"
+
 struct tt_internal {
         struct target_type tt;
 
diff --git a/drivers/md/dm-zero.c b/drivers/md/dm-zero.c
index 51c0639b2487..ea569f7348d2 100644
--- a/drivers/md/dm-zero.c
+++ b/drivers/md/dm-zero.c
@@ -10,13 +10,15 @@
 #include <linux/init.h>
 #include <linux/bio.h>
 
+#define DM_MSG_PREFIX "zero"
+
 /*
  * Construct a dummy mapping that only returns zeros
  */
 static int zero_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 {
         if (argc != 0) {
-                ti->error = "dm-zero: No arguments required";
+                ti->error = "No arguments required";
                 return -EINVAL;
         }
 
@@ -60,7 +62,7 @@ static int __init dm_zero_init(void)
         int r = dm_register_target(&zero_target);
 
         if (r < 0)
-                DMERR("zero: register failed %d", r);
+                DMERR("register failed %d", r);
 
         return r;
 }
@@ -70,7 +72,7 @@ static void __exit dm_zero_exit(void)
         int r = dm_unregister_target(&zero_target);
 
         if (r < 0)
-                DMERR("zero: unregister failed %d", r);
+                DMERR("unregister failed %d", r);
 }
 
 module_init(dm_zero_init)
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 6982f86db6dc..3ed2e53b9eb6 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -21,6 +21,8 @@
 #include <linux/hdreg.h>
 #include <linux/blktrace_api.h>
 
+#define DM_MSG_PREFIX "core"
+
 static const char *_name = DM_NAME;
 
 static unsigned int major = 0;
@@ -1108,6 +1110,12 @@ void dm_get(struct mapped_device *md)
         atomic_inc(&md->holders);
 }
 
+const char *dm_device_name(struct mapped_device *md)
+{
+        return md->name;
+}
+EXPORT_SYMBOL_GPL(dm_device_name);
+
 void dm_put(struct mapped_device *md)
 {
         struct dm_table *map;
diff --git a/drivers/md/dm.h b/drivers/md/dm.h
index 9ebb24b037bc..3c03c0ecab7e 100644
--- a/drivers/md/dm.h
+++ b/drivers/md/dm.h
@@ -17,9 +17,10 @@
 #include <linux/hdreg.h>
 
 #define DM_NAME "device-mapper"
-#define DMWARN(f, x...) printk(KERN_WARNING DM_NAME ": " f "\n" , ## x)
-#define DMERR(f, x...) printk(KERN_ERR DM_NAME ": " f "\n" , ## x)
-#define DMINFO(f, x...) printk(KERN_INFO DM_NAME ": " f "\n" , ## x)
+
+#define DMERR(f, arg...) printk(KERN_ERR DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg)
+#define DMWARN(f, arg...) printk(KERN_WARNING DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg)
+#define DMINFO(f, arg...) printk(KERN_INFO DM_NAME ": " DM_MSG_PREFIX ": " f "\n", ## arg)
 
 #define DMEMIT(x...) sz += ((sz >= maxlen) ? \
                           0 : scnprintf(result + sz, maxlen - sz, x))
diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h
index 61103d2bc244..e3d1c33d1558 100644
--- a/include/linux/device-mapper.h
+++ b/include/linux/device-mapper.h
@@ -171,6 +171,7 @@ int dm_wait_event(struct mapped_device *md, int event_nr);
 /*
  * Info functions.
  */
+const char *dm_device_name(struct mapped_device *md);
 struct gendisk *dm_disk(struct mapped_device *md);
 int dm_suspended(struct mapped_device *md);