dm: do not override error code returned from dm_get_device()

Some of the device mapper targets override the error code returned by
dm_get_device() and return either -EINVAL or -ENXIO.  There is nothing
gained by this override.  It is better to propagate the returned error
code unchanged to caller.

This work was motivated by hitting an issue where the underlying device
was busy but -EINVAL was being returned.  After this change we get
-EBUSY instead and it is easier to figure out the problem.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

7 files changed, 41 insertions, 19 deletions

diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index 0f48fed44a17..9a75d462b3fb 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -1811,11 +1811,13 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
         }
         cc->iv_offset = tmpll;
 
-        if (dm_get_device(ti, argv[3], dm_table_get_mode(ti->table), &cc->dev)) {
+        ret = dm_get_device(ti, argv[3], dm_table_get_mode(ti->table), &cc->dev);
+        if (ret) {
                 ti->error = "Device lookup failed";
                 goto bad;
         }
 
+        ret = -EINVAL;
         if (sscanf(argv[4], "%llu%c", &tmpll, &dummy) != 1) {
                 ti->error = "Invalid device sector";
                 goto bad;
diff --git a/drivers/md/dm-delay.c b/drivers/md/dm-delay.c
index 57b6a1901c91..b34f6e27293d 100644
--- a/drivers/md/dm-delay.c
+++ b/drivers/md/dm-delay.c
@@ -129,6 +129,7 @@ static int delay_ctr(struct dm_target *ti, unsigned int argc, char **argv)
         struct delay_c *dc;
         unsigned long long tmpll;
         char dummy;
+        int ret;
 
         if (argc != 3 && argc != 6) {
                 ti->error = "requires exactly 3 or 6 arguments";
@@ -143,6 +144,7 @@ static int delay_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 
         dc->reads = dc->writes = 0;
 
+        ret = -EINVAL;
         if (sscanf(argv[1], "%llu%c", &tmpll, &dummy) != 1) {
                 ti->error = "Invalid device sector";
                 goto bad;
@@ -154,12 +156,14 @@ static int delay_ctr(struct dm_target *ti, unsigned int argc, char **argv)
                 goto bad;
         }
 
-        if (dm_get_device(ti, argv[0], dm_table_get_mode(ti->table),
-                          &dc->dev_read)) {
+        ret = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table),
+                            &dc->dev_read);
+        if (ret) {
                 ti->error = "Device lookup failed";
                 goto bad;
         }
 
+        ret = -EINVAL;
         dc->dev_write = NULL;
         if (argc == 3)
                 goto out;
@@ -175,13 +179,15 @@ static int delay_ctr(struct dm_target *ti, unsigned int argc, char **argv)
                 goto bad_dev_read;
         }
 
-        if (dm_get_device(ti, argv[3], dm_table_get_mode(ti->table),
-                          &dc->dev_write)) {
+        ret = dm_get_device(ti, argv[3], dm_table_get_mode(ti->table),
+                            &dc->dev_write);
+        if (ret) {
                 ti->error = "Write device lookup failed";
                 goto bad_dev_read;
         }
 
 out:
+        ret = -EINVAL;
         dc->kdelayd_wq = alloc_workqueue("kdelayd", WQ_MEM_RECLAIM, 0);
         if (!dc->kdelayd_wq) {
                 DMERR("Couldn't start kdelayd");
@@ -208,7 +214,7 @@ bad_dev_read:
         dm_put_device(ti, dc->dev_read);
 bad:
         kfree(dc);
-        return -EINVAL;
+        return ret;
 }
 
 static void delay_dtr(struct dm_target *ti)
diff --git a/drivers/md/dm-flakey.c b/drivers/md/dm-flakey.c
index b257e46876d3..ffb994527bcf 100644
--- a/drivers/md/dm-flakey.c
+++ b/drivers/md/dm-flakey.c
@@ -183,6 +183,7 @@ static int flakey_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 
         devname = dm_shift_arg(&as);
 
+        r = -EINVAL;
         if (sscanf(dm_shift_arg(&as), "%llu%c", &tmpll, &dummy) != 1) {
                 ti->error = "Invalid device sector";
                 goto bad;
@@ -211,7 +212,8 @@ static int flakey_ctr(struct dm_target *ti, unsigned int argc, char **argv)
         if (r)
                 goto bad;
 
-        if (dm_get_device(ti, devname, dm_table_get_mode(ti->table), &fc->dev)) {
+        r = dm_get_device(ti, devname, dm_table_get_mode(ti->table), &fc->dev);
+        if (r) {
                 ti->error = "Device lookup failed";
                 goto bad;
         }
@@ -224,7 +226,7 @@ static int flakey_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 
 bad:
         kfree(fc);
-        return -EINVAL;
+        return r;
 }
 
 static void flakey_dtr(struct dm_target *ti)
diff --git a/drivers/md/dm-linear.c b/drivers/md/dm-linear.c
index 53e848c10939..62c26e4ad6ac 100644
--- a/drivers/md/dm-linear.c
+++ b/drivers/md/dm-linear.c
@@ -30,6 +30,7 @@ static int linear_ctr(struct dm_target *ti, unsigned int argc, char **argv)
         struct linear_c *lc;
         unsigned long long tmp;
         char dummy;
+        int ret;
 
         if (argc != 2) {
                 ti->error = "Invalid argument count";
@@ -42,13 +43,15 @@ static int linear_ctr(struct dm_target *ti, unsigned int argc, char **argv)
                 return -ENOMEM;
         }
 
+        ret = -EINVAL;
         if (sscanf(argv[1], "%llu%c", &tmp, &dummy) != 1) {
                 ti->error = "dm-linear: Invalid device sector";
                 goto bad;
         }
         lc->start = tmp;
 
-        if (dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &lc->dev)) {
+        ret = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &lc->dev);
+        if (ret) {
                 ti->error = "dm-linear: Device lookup failed";
                 goto bad;
         }
@@ -61,7 +64,7 @@ static int linear_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 
       bad:
         kfree(lc);
-        return -EINVAL;
+        return ret;
 }
 
 static void linear_dtr(struct dm_target *ti)
diff --git a/drivers/md/dm-log-writes.c b/drivers/md/dm-log-writes.c
index ad1b049ae2ab..51d29b67eb01 100644
--- a/drivers/md/dm-log-writes.c
+++ b/drivers/md/dm-log-writes.c
@@ -420,6 +420,7 @@ static int log_writes_ctr(struct dm_target *ti, unsigned int argc, char **argv)
         struct log_writes_c *lc;
         struct dm_arg_set as;
         const char *devname, *logdevname;
+        int ret;
 
         as.argc = argc;
         as.argv = argv;
@@ -443,18 +444,22 @@ static int log_writes_ctr(struct dm_target *ti, unsigned int argc, char **argv)
         atomic_set(&lc->pending_blocks, 0);
 
         devname = dm_shift_arg(&as);
-        if (dm_get_device(ti, devname, dm_table_get_mode(ti->table), &lc->dev)) {
+        ret = dm_get_device(ti, devname, dm_table_get_mode(ti->table), &lc->dev);
+        if (ret) {
                 ti->error = "Device lookup failed";
                 goto bad;
         }
 
         logdevname = dm_shift_arg(&as);
-        if (dm_get_device(ti, logdevname, dm_table_get_mode(ti->table), &lc->logdev)) {
+        ret = dm_get_device(ti, logdevname, dm_table_get_mode(ti->table),
+                            &lc->logdev);
+        if (ret) {
                 ti->error = "Log device lookup failed";
                 dm_put_device(ti, lc->dev);
                 goto bad;
         }
 
+        ret = -EINVAL;
         lc->log_kthread = kthread_run(log_writes_kthread, lc, "log-write");
         if (!lc->log_kthread) {
                 ti->error = "Couldn't alloc kthread";
@@ -479,7 +484,7 @@ static int log_writes_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 
 bad:
         kfree(lc);
-        return -EINVAL;
+        return ret;
 }
 
 static int log_mark(struct log_writes_c *lc, char *data)
diff --git a/drivers/md/dm-raid1.c b/drivers/md/dm-raid1.c
index d83696bf403b..933a1fd99b77 100644
--- a/drivers/md/dm-raid1.c
+++ b/drivers/md/dm-raid1.c
@@ -943,16 +943,18 @@ static int get_mirror(struct mirror_set *ms, struct dm_target *ti,
 {
         unsigned long long offset;
         char dummy;
+        int ret;
 
         if (sscanf(argv[1], "%llu%c", &offset, &dummy) != 1) {
                 ti->error = "Invalid offset";
                 return -EINVAL;
         }
 
-        if (dm_get_device(ti, argv[0], dm_table_get_mode(ti->table),
-                          &ms->mirror[mirror].dev)) {
+        ret = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table),
+                            &ms->mirror[mirror].dev);
+        if (ret) {
                 ti->error = "Device lookup failure";
-                return -ENXIO;
+                return ret;
         }
 
         ms->mirror[mirror].ms = ms;
diff --git a/drivers/md/dm-stripe.c b/drivers/md/dm-stripe.c
index a672a1502c14..9a814a5eb89f 100644
--- a/drivers/md/dm-stripe.c
+++ b/drivers/md/dm-stripe.c
@@ -75,13 +75,15 @@ static int get_stripe(struct dm_target *ti, struct stripe_c *sc,
 {
         unsigned long long start;
         char dummy;
+        int ret;
 
         if (sscanf(argv[1], "%llu%c", &start, &dummy) != 1)
                 return -EINVAL;
 
-        if (dm_get_device(ti, argv[0], dm_table_get_mode(ti->table),
-                          &sc->stripe[stripe].dev))
-                return -ENXIO;
+        ret = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table),
+                            &sc->stripe[stripe].dev);
+        if (ret)
+                return ret;
 
         sc->stripe[stripe].physical_start = start;