dm raid: cleanup / provide infrastructure
authorHeinz Mauelshagen <heinzm@redhat.com>
Thu, 19 May 2016 16:49:26 +0000 (18:49 +0200)
committerMike Snitzer <snitzer@redhat.com>
Mon, 13 Jun 2016 18:40:24 +0000 (14:40 -0400)
Provide necessary infrastructure to handle ctr flags and their names
and cleanup setting ti->error:

 - comment constructor flags

 - introduce constructor flag manipulation

 - introduce ti_error_*() functions to simplify
   setting the error message (use in other targets?)

 - introduce array to hold ctr flag <-> flag name mapping

 - introduce argument name by flag functions for that array

 - use those functions throughout the ctr call path

Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
drivers/md/dm-raid.c

index 01aa511..ab7aa7d 100644 (file)
@@ -1,6 +1,6 @@
 /*
  * Copyright (C) 2010-2011 Neil Brown
- * Copyright (C) 2010-2015 Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2010-2016 Red Hat, Inc. All rights reserved.
  *
  * This file is released under the GPL.
  */
@@ -47,18 +47,22 @@ struct raid_dev {
 
 /*
  * Flags for rs->ctr_flags field.
+ *
+ * 1 = no flag value
+ * 2 = flag with value
  */
-#define CTR_FLAG_SYNC              0x1
-#define CTR_FLAG_NOSYNC            0x2
-#define CTR_FLAG_REBUILD           0x4
-#define CTR_FLAG_DAEMON_SLEEP      0x8
-#define CTR_FLAG_MIN_RECOVERY_RATE 0x10
-#define CTR_FLAG_MAX_RECOVERY_RATE 0x20
-#define CTR_FLAG_MAX_WRITE_BEHIND  0x40
-#define CTR_FLAG_STRIPE_CACHE      0x80
-#define CTR_FLAG_REGION_SIZE       0x100
-#define CTR_FLAG_RAID10_COPIES     0x200
-#define CTR_FLAG_RAID10_FORMAT     0x400
+#define CTR_FLAG_SYNC              0x1   /* 1 */ /* Not with raid0! */
+#define CTR_FLAG_NOSYNC            0x2   /* 1 */ /* Not with raid0! */
+#define CTR_FLAG_REBUILD           0x4   /* 2 */ /* Not with raid0! */
+#define CTR_FLAG_DAEMON_SLEEP      0x8   /* 2 */ /* Not with raid0! */
+#define CTR_FLAG_MIN_RECOVERY_RATE 0x10  /* 2 */ /* Not with raid0! */
+#define CTR_FLAG_MAX_RECOVERY_RATE 0x20  /* 2 */ /* Not with raid0! */
+#define CTR_FLAG_MAX_WRITE_BEHIND  0x40  /* 2 */ /* Only with raid1! */
+#define CTR_FLAG_WRITE_MOSTLY      0x80  /* 2 */ /* Only with raid1! */
+#define CTR_FLAG_STRIPE_CACHE      0x100 /* 2 */ /* Only with raid4/5/6! */
+#define CTR_FLAG_REGION_SIZE       0x200 /* 2 */ /* Not with raid0! */
+#define CTR_FLAG_RAID10_COPIES     0x400 /* 2 */ /* Only with raid10 */
+#define CTR_FLAG_RAID10_FORMAT     0x800 /* 2 */ /* Only with raid10 */
 
 struct raid_set {
        struct dm_target *ti;
@@ -101,6 +105,83 @@ static bool _in_range(long v, long min, long max)
        return v >= min && v <= max;
 }
 
+/* ctr flag bit manipulation... */
+/* Set single @flag in @flags */
+static void _set_flag(uint32_t flag, uint32_t *flags)
+{
+       WARN_ON_ONCE(hweight32(flag) != 1);
+       *flags |= flag;
+}
+
+/* Test single @flag in @flags */
+static bool _test_flag(uint32_t flag, uint32_t flags)
+{
+       WARN_ON_ONCE(hweight32(flag) != 1);
+       return (flag & flags) ? true : false;
+}
+
+/* Return true if single @flag is set in @*flags, else set it and return false */
+static bool _test_and_set_flag(uint32_t flag, uint32_t *flags)
+{
+       if (_test_flag(flag, *flags))
+               return true;
+
+       _set_flag(flag, flags);
+       return false;
+}
+/* ...ctr and runtime flag bit manipulation */
+
+/* All table line arguments are defined here */
+static struct arg_name_flag {
+       const uint32_t flag;
+       const char *name;
+} _arg_name_flags[] = {
+       { CTR_FLAG_SYNC, "sync"},
+       { CTR_FLAG_NOSYNC, "nosync"},
+       { CTR_FLAG_REBUILD, "rebuild"},
+       { CTR_FLAG_DAEMON_SLEEP, "daemon_sleep"},
+       { CTR_FLAG_MIN_RECOVERY_RATE, "min_recovery_rate"},
+       { CTR_FLAG_MAX_RECOVERY_RATE, "max_recovery_rate"},
+       { CTR_FLAG_MAX_WRITE_BEHIND, "max_write_behind"},
+       { CTR_FLAG_WRITE_MOSTLY, "writemostly"},
+       { CTR_FLAG_STRIPE_CACHE, "stripe_cache"},
+       { CTR_FLAG_REGION_SIZE, "region_size"},
+       { CTR_FLAG_RAID10_COPIES, "raid10_copies"},
+       { CTR_FLAG_RAID10_FORMAT, "raid10_format"},
+};
+
+/* Return argument name string for given @flag */
+static const char *_argname_by_flag(const uint32_t flag)
+{
+       if (hweight32(flag) == 1) {
+               struct arg_name_flag *anf = _arg_name_flags + ARRAY_SIZE(_arg_name_flags);
+
+               while (anf-- > _arg_name_flags)
+                       if (_test_flag(flag, anf->flag))
+                               return anf->name;
+
+       } else
+               DMERR("%s called with more than one flag!", __func__);
+
+       return NULL;
+}
+
+/*
+ * Convenience functions to set ti->error to @errmsg and
+ * return @r in order to shorten code in a lot of places
+ */
+static int ti_error_ret(struct dm_target *ti, const char *errmsg, int r)
+{
+       ti->error = (char *) errmsg;
+       return r;
+}
+
+static int ti_error_einval(struct dm_target *ti, const char *errmsg)
+{
+       return ti_error_ret(ti, errmsg, -EINVAL);
+}
+/* END: convenience functions to set ti->error to @errmsg... */
+
 static char *raid10_md_layout_to_format(int layout)
 {
        /*
@@ -157,16 +238,12 @@ static struct raid_set *context_alloc(struct dm_target *ti, struct raid_type *ra
        unsigned i;
        struct raid_set *rs;
 
-       if (raid_devs <= raid_type->parity_devs) {
-               ti->error = "Insufficient number of devices";
-               return ERR_PTR(-EINVAL);
-       }
+       if (raid_devs <= raid_type->parity_devs)
+               return ERR_PTR(ti_error_einval(ti, "Insufficient number of devices"));
 
        rs = kzalloc(sizeof(*rs) + raid_devs * sizeof(rs->dev[0]), GFP_KERNEL);
-       if (!rs) {
-               ti->error = "Cannot allocate raid context";
-               return ERR_PTR(-ENOMEM);
-       }
+       if (!rs)
+               return ERR_PTR(ti_error_ret(ti, "Cannot allocate raid context", -ENOMEM));
 
        mddev_init(&rs->md);
 
@@ -226,7 +303,7 @@ static void context_free(struct raid_set *rs)
  * This code parses those words.  If there is a failure,
  * the caller must use context_free to unwind the operations.
  */
-static int parse_dev_parms(struct raid_set *rs, struct dm_arg_set *as)
+static int parse_dev_params(struct raid_set *rs, struct dm_arg_set *as)
 {
        int i;
        int rebuild = 0;
@@ -260,13 +337,12 @@ static int parse_dev_parms(struct raid_set *rs, struct dm_arg_set *as)
                        r = dm_get_device(rs->ti, arg,
                                            dm_table_get_mode(rs->ti->table),
                                            &rs->dev[i].meta_dev);
-                       rs->ti->error = "RAID metadata device lookup failure";
                        if (r)
-                               return r;
+                               return ti_error_ret(rs->ti, "RAID metadata device lookup failure", r);
 
                        rs->dev[i].rdev.sb_page = alloc_page(GFP_KERNEL);
                        if (!rs->dev[i].rdev.sb_page)
-                               return -ENOMEM;
+                               return ti_error_ret(rs->ti, "Failed to allocate superblock page", -ENOMEM);
                }
 
                arg = dm_shift_arg(as);
@@ -275,14 +351,11 @@ static int parse_dev_parms(struct raid_set *rs, struct dm_arg_set *as)
 
                if (!strcmp(arg, "-")) {
                        if (!test_bit(In_sync, &rs->dev[i].rdev.flags) &&
-                           (!rs->dev[i].rdev.recovery_offset)) {
-                               rs->ti->error = "Drive designated for rebuild not specified";
-                               return -EINVAL;
-                       }
+                           (!rs->dev[i].rdev.recovery_offset))
+                               return ti_error_einval(rs->ti, "Drive designated for rebuild not specified");
 
-                       rs->ti->error = "No data device supplied with metadata device";
                        if (rs->dev[i].meta_dev)
-                               return -EINVAL;
+                               return ti_error_einval(rs->ti, "No data device supplied with metadata device");
 
                        continue;
                }
@@ -290,10 +363,8 @@ static int parse_dev_parms(struct raid_set *rs, struct dm_arg_set *as)
                r = dm_get_device(rs->ti, arg,
                                    dm_table_get_mode(rs->ti->table),
                                    &rs->dev[i].data_dev);
-               if (r) {
-                       rs->ti->error = "RAID device lookup failure";
-                       return r;
-               }
+               if (r)
+                       return ti_error_ret(rs->ti, "RAID device lookup failure", r);
 
                if (rs->dev[i].meta_dev) {
                        metadata_available = 1;
@@ -322,8 +393,7 @@ static int parse_dev_parms(struct raid_set *rs, struct dm_arg_set *as)
                 * User could specify 'nosync' option if desperate.
                 */
                DMERR("Unable to rebuild drive while array is not in-sync");
-               rs->ti->error = "RAID device lookup failure";
-               return -EINVAL;
+               return ti_error_einval(rs->ti, "Unable to rebuild drive while array is not in-sync");
        }
 
        return 0;
@@ -360,27 +430,20 @@ static int validate_region_size(struct raid_set *rs, unsigned long region_size)
                /*
                 * Validate user-supplied value.
                 */
-               if (region_size > rs->ti->len) {
-                       rs->ti->error = "Supplied region size is too large";
-                       return -EINVAL;
-               }
+               if (region_size > rs->ti->len)
+                       return ti_error_einval(rs->ti, "Supplied region size is too large");
 
                if (region_size < min_region_size) {
                        DMERR("Supplied region_size (%lu sectors) below minimum (%lu)",
                              region_size, min_region_size);
-                       rs->ti->error = "Supplied region size is too small";
-                       return -EINVAL;
+                       return ti_error_einval(rs->ti, "Supplied region size is too small");
                }
 
-               if (!is_power_of_2(region_size)) {
-                       rs->ti->error = "Region size is not a power of 2";
-                       return -EINVAL;
-               }
+               if (!is_power_of_2(region_size))
+                       return ti_error_einval(rs->ti, "Region size is not a power of 2");
 
-               if (region_size < rs->md.chunk_sectors) {
-                       rs->ti->error = "Region size is smaller than the chunk size";
-                       return -EINVAL;
-               }
+               if (region_size < rs->md.chunk_sectors)
+                       return ti_error_einval(rs->ti, "Region size is smaller than the chunk size");
        }
 
        /*
@@ -522,14 +585,13 @@ static int parse_raid_params(struct raid_set *rs, struct dm_arg_set *as,
        sector_t sectors_per_dev = rs->ti->len;
        sector_t max_io_len;
        const char *arg, *key;
+       struct raid_dev *rd;
 
        arg = dm_shift_arg(as);
        num_raid_params--; /* Account for chunk_size argument */
 
-       if (kstrtouint(arg, 10, &value) < 0) {
-               rs->ti->error = "Bad numerical argument given for chunk_size";
-               return -EINVAL;
-       }
+       if (kstrtouint(arg, 10, &value) < 0)
+               return ti_error_einval(rs->ti, "Bad numerical argument given for chunk_size");
 
        /*
         * First, parse the in-order required arguments
@@ -539,13 +601,10 @@ static int parse_raid_params(struct raid_set *rs, struct dm_arg_set *as,
                if (value)
                        DMERR("Ignoring chunk size parameter for RAID 1");
                value = 0;
-       } else if (!is_power_of_2(value)) {
-               rs->ti->error = "Chunk size must be a power of 2";
-               return -EINVAL;
-       } else if (value < 8) {
-               rs->ti->error = "Chunk size value is too small";
-               return -EINVAL;
-       }
+       } else if (!is_power_of_2(value))
+               return ti_error_einval(rs->ti, "Chunk size must be a power of 2");
+       else if (value < 8)
+               return ti_error_einval(rs->ti, "Chunk size value is too small");
 
        rs->md.new_chunk_sectors = rs->md.chunk_sectors = value;
 
@@ -576,144 +635,134 @@ static int parse_raid_params(struct raid_set *rs, struct dm_arg_set *as,
         */
        for (i = 0; i < num_raid_params; i++) {
                arg = dm_shift_arg(as);
-               if (!arg) {
-                       rs->ti->error = "Not enough raid parameters given";
-                       return -EINVAL;
-               }
+               if (!arg)
+                       return ti_error_einval(rs->ti, "Not enough raid parameters given");
 
                if (!strcasecmp(arg, "nosync")) {
                        rs->md.recovery_cp = MaxSector;
-                       rs->ctr_flags |= CTR_FLAG_NOSYNC;
+                       _set_flag(CTR_FLAG_NOSYNC, &rs->ctr_flags);
                        continue;
                }
                if (!strcasecmp(arg, "sync")) {
                        rs->md.recovery_cp = 0;
-                       rs->ctr_flags |= CTR_FLAG_SYNC;
+                       _set_flag(CTR_FLAG_SYNC, &rs->ctr_flags);
                        continue;
                }
 
-               /* The rest of the optional arguments come in key/value pairs */
-               if ((i + 1) >= num_raid_params) {
-                       rs->ti->error = "Wrong number of raid parameters given";
-                       return -EINVAL;
-               }
-
                key = arg;
                arg = dm_shift_arg(as);
                i++; /* Account for the argument pairs */
+               if (!arg)
+                       return ti_error_einval(rs->ti, "Wrong number of raid parameters given");
 
-               /* Parameters that take a string value are checked here. */
-               if (!strcasecmp(key, "raid10_format")) {
-                       if (rs->raid_type->level != 10) {
-                               rs->ti->error = "'raid10_format' is an invalid parameter for this RAID type";
-                               return -EINVAL;
-                       }
+               /*
+                * Parameters that take a string value are checked here.
+                */
+
+               if (!strcasecmp(key, _argname_by_flag(CTR_FLAG_RAID10_FORMAT))) {
+                       if (_test_and_set_flag(CTR_FLAG_RAID10_FORMAT, &rs->ctr_flags))
+                               return ti_error_einval(rs->ti, "Only one raid10_format argument pair allowed");
+                       if (rs->raid_type->level != 10)
+                               return ti_error_einval(rs->ti, "'raid10_format' is an invalid parameter for this RAID type");
                        if (strcmp("near", arg) &&
                            strcmp("far", arg) &&
-                           strcmp("offset", arg)) {
-                               rs->ti->error = "Invalid 'raid10_format' value given";
-                               return -EINVAL;
-                       }
+                           strcmp("offset", arg))
+                               return ti_error_einval(rs->ti, "Invalid 'raid10_format' value given");
+
                        raid10_format = (char *) arg;
-                       rs->ctr_flags |= CTR_FLAG_RAID10_FORMAT;
                        continue;
                }
 
-               if (kstrtouint(arg, 10, &value) < 0) {
-                       rs->ti->error = "Bad numerical argument given in raid params";
-                       return -EINVAL;
-               }
+               if (kstrtouint(arg, 10, &value) < 0)
+                       return ti_error_einval(rs->ti, "Bad numerical argument given in raid params");
+
+               if (!strcasecmp(key, _argname_by_flag(CTR_FLAG_REBUILD))) {
+                       /*
+                        * "rebuild" is being passed in by userspace to provide
+                        * indexes of replaced devices and to set up additional
+                        * devices on raid level takeover.
+                        */
+                       if (!_in_range(value, 0, rs->md.raid_disks - 1))
+                               return ti_error_einval(rs->ti, "Invalid rebuild index given");
+
+                       rd = rs->dev + value;
+                       clear_bit(In_sync, &rd->rdev.flags);
+                       clear_bit(Faulty, &rd->rdev.flags);
+                       rd->rdev.recovery_offset = 0;
+                       _set_flag(CTR_FLAG_REBUILD, &rs->ctr_flags);
+               } else if (!strcasecmp(key, _argname_by_flag(CTR_FLAG_WRITE_MOSTLY))) {
+                       if (rs->raid_type->level != 1)
+                               return ti_error_einval(rs->ti, "write_mostly option is only valid for RAID1");
+
+                       if (!_in_range(value, 0, rs->md.raid_disks - 1))
+                               return ti_error_einval(rs->ti, "Invalid write_mostly index given");
 
-               /* Parameters that take a numeric value are checked here */
-               if (!strcasecmp(key, "rebuild")) {
-                       if (value >= rs->md.raid_disks) {
-                               rs->ti->error = "Invalid rebuild index given";
-                               return -EINVAL;
-                       }
-                       clear_bit(In_sync, &rs->dev[value].rdev.flags);
-                       rs->dev[value].rdev.recovery_offset = 0;
-                       rs->ctr_flags |= CTR_FLAG_REBUILD;
-               } else if (!strcasecmp(key, "write_mostly")) {
-                       if (rs->raid_type->level != 1) {
-                               rs->ti->error = "write_mostly option is only valid for RAID1";
-                               return -EINVAL;
-                       }
-                       if (value >= rs->md.raid_disks) {
-                               rs->ti->error = "Invalid write_mostly drive index given";
-                               return -EINVAL;
-                       }
                        set_bit(WriteMostly, &rs->dev[value].rdev.flags);
-               } else if (!strcasecmp(key, "max_write_behind")) {
-                       if (rs->raid_type->level != 1) {
-                               rs->ti->error = "max_write_behind option is only valid for RAID1";
-                               return -EINVAL;
-                       }
-                       rs->ctr_flags |= CTR_FLAG_MAX_WRITE_BEHIND;
+                       _set_flag(CTR_FLAG_WRITE_MOSTLY, &rs->ctr_flags);
+               } else if (!strcasecmp(key, _argname_by_flag(CTR_FLAG_MAX_WRITE_BEHIND))) {
+                       if (rs->raid_type->level != 1)
+                               return ti_error_einval(rs->ti, "max_write_behind option is only valid for RAID1");
+
+                       if (_test_and_set_flag(CTR_FLAG_MAX_WRITE_BEHIND, &rs->ctr_flags))
+                               return ti_error_einval(rs->ti, "Only one max_write_behind argument pair allowed");
 
                        /*
                         * In device-mapper, we specify things in sectors, but
                         * MD records this value in kB
                         */
                        value /= 2;
-                       if (value > COUNTER_MAX) {
-                               rs->ti->error = "Max write-behind limit out of range";
-                               return -EINVAL;
-                       }
+                       if (value > COUNTER_MAX)
+                               return ti_error_einval(rs->ti, "Max write-behind limit out of range");
+
                        rs->md.bitmap_info.max_write_behind = value;
-               } else if (!strcasecmp(key, "daemon_sleep")) {
-                       rs->ctr_flags |= CTR_FLAG_DAEMON_SLEEP;
-                       if (!value || (value > MAX_SCHEDULE_TIMEOUT)) {
-                               rs->ti->error = "daemon sleep period out of range";
-                               return -EINVAL;
-                       }
+               } else if (!strcasecmp(key, _argname_by_flag(CTR_FLAG_DAEMON_SLEEP))) {
+                       if (_test_and_set_flag(CTR_FLAG_DAEMON_SLEEP, &rs->ctr_flags))
+                               return ti_error_einval(rs->ti, "Only one daemon_sleep argument pair allowed");
+                       if (!value || (value > MAX_SCHEDULE_TIMEOUT))
+                               return ti_error_einval(rs->ti, "daemon sleep period out of range");
                        rs->md.bitmap_info.daemon_sleep = value;
-               } else if (!strcasecmp(key, "stripe_cache")) {
-                       rs->ctr_flags |= CTR_FLAG_STRIPE_CACHE;
-
+               } else if (!strcasecmp(key, _argname_by_flag(CTR_FLAG_STRIPE_CACHE))) {
+                       if (_test_and_set_flag(CTR_FLAG_STRIPE_CACHE, &rs->ctr_flags))
+                               return ti_error_einval(rs->ti, "Only one stripe_cache argument pair allowed");
                        /*
                         * In device-mapper, we specify things in sectors, but
                         * MD records this value in kB
                         */
                        value /= 2;
 
-                       if ((rs->raid_type->level != 5) &&
-                           (rs->raid_type->level != 6)) {
-                               rs->ti->error = "Inappropriate argument: stripe_cache";
-                               return -EINVAL;
-                       }
-                       if (raid5_set_cache_size(&rs->md, (int)value)) {
-                               rs->ti->error = "Bad stripe_cache size";
-                               return -EINVAL;
-                       }
-               } else if (!strcasecmp(key, "min_recovery_rate")) {
-                       rs->ctr_flags |= CTR_FLAG_MIN_RECOVERY_RATE;
-                       if (value > INT_MAX) {
-                               rs->ti->error = "min_recovery_rate out of range";
-                               return -EINVAL;
-                       }
+                       if (!_in_range(rs->raid_type->level, 4, 6))
+                               return ti_error_einval(rs->ti, "Inappropriate argument: stripe_cache");
+                       if (raid5_set_cache_size(&rs->md, (int)value))
+                               return ti_error_einval(rs->ti, "Bad stripe_cache size");
+
+               } else if (!strcasecmp(key, _argname_by_flag(CTR_FLAG_MIN_RECOVERY_RATE))) {
+                       if (_test_and_set_flag(CTR_FLAG_MIN_RECOVERY_RATE, &rs->ctr_flags))
+                               return ti_error_einval(rs->ti, "Only one min_recovery_rate argument pair allowed");
+                       if (value > INT_MAX)
+                               return ti_error_einval(rs->ti, "min_recovery_rate out of range");
                        rs->md.sync_speed_min = (int)value;
-               } else if (!strcasecmp(key, "max_recovery_rate")) {
-                       rs->ctr_flags |= CTR_FLAG_MAX_RECOVERY_RATE;
-                       if (value > INT_MAX) {
-                               rs->ti->error = "max_recovery_rate out of range";
-                               return -EINVAL;
-                       }
+               } else if (!strcasecmp(key, _argname_by_flag(CTR_FLAG_MAX_RECOVERY_RATE))) {
+                       if (_test_and_set_flag(CTR_FLAG_MIN_RECOVERY_RATE, &rs->ctr_flags))
+                               return ti_error_einval(rs->ti, "Only one max_recovery_rate argument pair allowed");
+                       if (value > INT_MAX)
+                               return ti_error_einval(rs->ti, "max_recovery_rate out of range");
                        rs->md.sync_speed_max = (int)value;
-               } else if (!strcasecmp(key, "region_size")) {
-                       rs->ctr_flags |= CTR_FLAG_REGION_SIZE;
+               } else if (!strcasecmp(key, _argname_by_flag(CTR_FLAG_REGION_SIZE))) {
+                       if (_test_and_set_flag(CTR_FLAG_REGION_SIZE, &rs->ctr_flags))
+                               return ti_error_einval(rs->ti, "Only one region_size argument pair allowed");
+
                        region_size = value;
-               } else if (!strcasecmp(key, "raid10_copies") &&
-                          (rs->raid_type->level == 10)) {
-                       if ((value < 2) || (value > 0xFF)) {
-                               rs->ti->error = "Bad value for 'raid10_copies'";
-                               return -EINVAL;
-                       }
-                       rs->ctr_flags |= CTR_FLAG_RAID10_COPIES;
+               } else if (!strcasecmp(key, _argname_by_flag(CTR_FLAG_RAID10_COPIES))) {
+                       if (_test_and_set_flag(CTR_FLAG_RAID10_COPIES, &rs->ctr_flags))
+                               return ti_error_einval(rs->ti, "Only one raid10_copies argument pair allowed");
+
+                       if (!_in_range(value, 2, rs->md.raid_disks))
+                               return ti_error_einval(rs->ti, "Bad value for 'raid10_copies'");
+
                        raid10_copies = value;
                } else {
                        DMERR("Unable to parse RAID parameter: %s", key);
-                       rs->ti->error = "Unable to parse RAID parameters";
-                       return -EINVAL;
+                       return ti_error_einval(rs->ti, "Unable to parse RAID parameters");
                }
        }
 
@@ -729,19 +778,15 @@ static int parse_raid_params(struct raid_set *rs, struct dm_arg_set *as,
                return -EINVAL;
 
        if (rs->raid_type->level == 10) {
-               if (raid10_copies > rs->md.raid_disks) {
-                       rs->ti->error = "Not enough devices to satisfy specification";
-                       return -EINVAL;
-               }
+               if (raid10_copies > rs->md.raid_disks)
+                       return ti_error_einval(rs->ti, "Not enough devices to satisfy specification");
 
                /*
                 * If the format is not "near", we only support
                 * two copies at the moment.
                 */
-               if (strcmp("near", raid10_format) && (raid10_copies > 2)) {
-                       rs->ti->error = "Too many copies for given RAID10 format.";
-                       return -EINVAL;
-               }
+               if (strcmp("near", raid10_format) && (raid10_copies > 2))
+                       return ti_error_einval(rs->ti, "Too many copies for given RAID10 format.");
 
                /* (Len * #mirrors) / #devices */
                sectors_per_dev = rs->ti->len * raid10_copies;
@@ -752,10 +797,9 @@ static int parse_raid_params(struct raid_set *rs, struct dm_arg_set *as,
                rs->md.new_layout = rs->md.layout;
        } else if ((!rs->raid_type->level || rs->raid_type->level > 1) &&
                   sector_div(sectors_per_dev,
-                             (rs->md.raid_disks - rs->raid_type->parity_devs))) {
-               rs->ti->error = "Target length not divisible by number of data devices";
-               return -EINVAL;
-       }
+                             (rs->md.raid_disks - rs->raid_type->parity_devs)))
+               return ti_error_einval(rs->ti, "Target length not divisible by number of data devices");
+
        rs->md.dev_sectors = sectors_per_dev;
 
        /* Assume there are no metadata devices until the drives are parsed */
@@ -1035,11 +1079,9 @@ static int super_init_validation(struct mddev *mddev, struct md_rdev *rdev)
                if (!test_bit(FirstUse, &r->flags) && (r->raid_disk >= 0)) {
                        role = le32_to_cpu(sb2->array_position);
                        if (role != r->raid_disk) {
-                               if (rs->raid_type->level != 1) {
-                                       rs->ti->error = "Cannot change device "
-                                               "positions in RAID array";
-                                       return -EINVAL;
-                               }
+                               if (rs->raid_type->level != 1)
+                                       return ti_error_einval(rs->ti, "Cannot change device "
+                                                                      "positions in RAID array");
                                DMINFO("RAID1 device #%d now at position #%d",
                                       role, r->raid_disk);
                        }
@@ -1170,18 +1212,15 @@ static int analyse_superblocks(struct dm_target *ti, struct raid_set *rs)
        if (!freshest)
                return 0;
 
-       if (validate_raid_redundancy(rs)) {
-               rs->ti->error = "Insufficient redundancy to activate array";
-               return -EINVAL;
-       }
+       if (validate_raid_redundancy(rs))
+               return ti_error_einval(rs->ti, "Insufficient redundancy to activate array");
 
        /*
         * Validation of the freshest device provides the source of
         * validation for the remaining devices.
         */
-       ti->error = "Unable to assemble array: Invalid superblocks";
        if (super_validate(rs, freshest))
-               return -EINVAL;
+               return ti_error_einval(rs->ti, "Unable to assemble array: Invalid superblocks");
 
        rdev_for_each(rdev, mddev)
                if ((rdev != freshest) && super_validate(rs, rdev))
@@ -1265,16 +1304,12 @@ static int raid_ctr(struct dm_target *ti, unsigned argc, char **argv)
 
        /* Must have <raid_type> */
        arg = dm_shift_arg(&as);
-       if (!arg) {
-               ti->error = "No arguments";
-               return -EINVAL;
-       }
+       if (!arg)
+               return ti_error_einval(rs->ti, "No arguments");
 
        rt = get_raid_type(arg);
-       if (!rt) {
-               ti->error = "Unrecognised raid_type";
-               return -EINVAL;
-       }
+       if (!rt)
+               return ti_error_einval(rs->ti, "Unrecognised raid_type");
 
        /* Must have <#raid_params> */
        if (dm_read_arg_group(_args, &as, &num_raid_params, &ti->error))
@@ -1287,10 +1322,8 @@ static int raid_ctr(struct dm_target *ti, unsigned argc, char **argv)
        if (dm_read_arg(_args + 1, &as_nrd, &num_raid_devs, &ti->error))
                 return -EINVAL;
 
-       if (!_in_range(num_raid_devs, 1, MAX_RAID_DEVICES)) {
-               ti->error = "Invalid number of supplied raid devices";
-                return -EINVAL;
-       }
+       if (!_in_range(num_raid_devs, 1, MAX_RAID_DEVICES))
+               return ti_error_einval(rs->ti, "Invalid number of supplied raid devices");
 
        rs = context_alloc(ti, rt, num_raid_devs);
        if (IS_ERR(rs))
@@ -1300,7 +1333,7 @@ static int raid_ctr(struct dm_target *ti, unsigned argc, char **argv)
        if (r)
                goto bad;
 
-       r = parse_dev_parms(rs, &as);
+       r = parse_dev_params(rs, &as);
        if (r)
                goto bad;
 
@@ -1330,8 +1363,7 @@ static int raid_ctr(struct dm_target *ti, unsigned argc, char **argv)
        }
 
        if (ti->len != rs->md.array_sectors) {
-               ti->error = "Array size does not match requested target length";
-               r = -EINVAL;
+               r = ti_error_einval(ti, "Array size does not match requested target length");
                goto size_mismatch;
        }
        rs->callbacks.congested_fn = raid_is_congested;
@@ -1751,7 +1783,7 @@ static void raid_resume(struct dm_target *ti)
 
 static struct target_type raid_target = {
        .name = "raid",
-       .version = {1, 8, 0},
+       .version = {1, 8, 1},
        .module = THIS_MODULE,
        .ctr = raid_ctr,
        .dtr = raid_dtr,