dm-flakey: Clean up parsing messages

There were a number of cases where the error message for an invalid
table line did not match the actual problem. Fix these. Additionally,
error out when duplicate corrupt_bio_byte, random_read_corrupt, or
random_write_corrupt features are present. Also, error_reads is
incompatible with random_read_corrupt and corrupt_bio_byte with the READ
flag set, so disallow that.

Reported-by: Kent Overstreet <kent.overstreet@linux.dev>
Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>

diff --git a/drivers/md/dm-flakey.c b/drivers/md/dm-flakey.c
index b690905ab89ffb1e97482ae792679990270ce26b..f5f8d25d1b2daf2d0c4f585cde7eafb6ac637bb9 100644 (file)
--- a/drivers/md/dm-flakey.c
+++ b/drivers/md/dm-flakey.c
@@ -128,8 +128,11 @@ static int parse_features(struct dm_arg_set *as, struct flakey_c *fc,
                 * corrupt_bio_byte <Nth_byte> <direction> <value> <bio_flags>
                 */
                if (!strcasecmp(arg_name, "corrupt_bio_byte")) {
-                       if (!argc) {
-                               ti->error = "Feature corrupt_bio_byte requires parameters";
+                       if (fc->corrupt_bio_byte) {
+                               ti->error = "Feature corrupt_bio_byte duplicated";
+                               return -EINVAL;
+                       } else if (argc < 4) {
+                               ti->error = "Feature corrupt_bio_byte requires 4 parameters";
                                return -EINVAL;
                        }
 
@@ -176,7 +179,10 @@ static int parse_features(struct dm_arg_set *as, struct flakey_c *fc,
                }
 
                if (!strcasecmp(arg_name, "random_read_corrupt")) {
-                       if (!argc) {
+                       if (fc->random_read_corrupt) {
+                               ti->error = "Feature random_read_corrupt duplicated";
+                               return -EINVAL;
+                       } else if (!argc) {
                                ti->error = "Feature random_read_corrupt requires a parameter";
                                return -EINVAL;
                        }
@@ -189,7 +195,10 @@ static int parse_features(struct dm_arg_set *as, struct flakey_c *fc,
                }
 
                if (!strcasecmp(arg_name, "random_write_corrupt")) {
-                       if (!argc) {
+                       if (fc->random_write_corrupt) {
+                               ti->error = "Feature random_write_corrupt duplicated";
+                               return -EINVAL;
+                       } else if (!argc) {
                                ti->error = "Feature random_write_corrupt requires a parameter";
                                return -EINVAL;
                        }
@@ -205,12 +214,18 @@ static int parse_features(struct dm_arg_set *as, struct flakey_c *fc,
                return -EINVAL;
        }
 
-       if (test_bit(DROP_WRITES, &fc->flags) && (fc->corrupt_bio_rw == WRITE)) {
-               ti->error = "drop_writes is incompatible with corrupt_bio_byte with the WRITE flag set";
+       if (test_bit(DROP_WRITES, &fc->flags) &&
+           (fc->corrupt_bio_rw == WRITE || fc->random_write_corrupt)) {
+               ti->error = "drop_writes is incompatible with random_write_corrupt or corrupt_bio_byte with the WRITE flag set";
                return -EINVAL;
 
-       } else if (test_bit(ERROR_WRITES, &fc->flags) && (fc->corrupt_bio_rw == WRITE)) {
-               ti->error = "error_writes is incompatible with corrupt_bio_byte with the WRITE flag set";
+       } else if (test_bit(ERROR_WRITES, &fc->flags) &&
+                  (fc->corrupt_bio_rw == WRITE || fc->random_write_corrupt)) {
+               ti->error = "error_writes is incompatible with random_write_corrupt or corrupt_bio_byte with the WRITE flag set";
+               return -EINVAL;
+       } else if (test_bit(ERROR_READS, &fc->flags) &&
+                  (fc->corrupt_bio_rw == READ || fc->random_read_corrupt)) {
+               ti->error = "error_reads is incompatible with random_read_corrupt or corrupt_bio_byte with the READ flag set";
                return -EINVAL;
        }
 
@@ -278,7 +293,7 @@ static int flakey_ctr(struct dm_target *ti, unsigned int argc, char **argv)
        if (r)
                goto bad;
 
-       r = dm_read_arg(_args, &as, &fc->down_interval, &ti->error);
+       r = dm_read_arg(_args + 1, &as, &fc->down_interval, &ti->error);
        if (r)
                goto bad;