bcache: Replace bch_read_string_list() by __sysfs_match_string()

BugLink: https://bugs.launchpad.net/bugs/1784665
Kernel library has a common function to match user input from sysfs
against an array of strings. Thus, replace bch_read_string_list() by
__sysfs_match_string().

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
(cherry picked from commit ce4c3e19e5201424357a0c82176633b32a98d2ec)
Signed-off-by: Andrea Righi <andrea.righi@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Acked-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

diff --git a/drivers/md/bcache/sysfs.c b/drivers/md/bcache/sysfs.c
index 5507b21fadbd13f4f967e1dc07550e6c06ef6d79..cac8a2e16b14fa977bdf89cc5858dd245c1ae9f6 100644 (file)
--- a/drivers/md/bcache/sysfs.c
+++ b/drivers/md/bcache/sysfs.c
@@ -18,7 +18,6 @@
 
 /* Default is -1; we skip past it for struct cached_dev's cache mode */
 static const char * const bch_cache_modes[] = {
-       "default",
        "writethrough",
        "writeback",
        "writearound",
@@ -28,7 +27,6 @@ static const char * const bch_cache_modes[] = {
 
 /* Default is -1; we skip past it for stop_when_cache_set_failed */
 static const char * const bch_stop_on_failure_modes[] = {
-       "default",
        "auto",
        "always",
        NULL
@@ -146,27 +144,6 @@ static ssize_t bch_snprint_string_list(char *buf, size_t size, const char * cons
        return out - buf;
 }
 
-static ssize_t bch_read_string_list(const char *buf, const char * const list[])
-{
-       size_t i;
-       char *s, *d = kstrndup(buf, PAGE_SIZE - 1, GFP_KERNEL);
-       if (!d)
-               return -ENOMEM;
-
-       s = strim(d);
-
-       for (i = 0; list[i]; i++)
-               if (!strcmp(list[i], s))
-                       break;
-
-       kfree(d);
-
-       if (!list[i])
-               return -EINVAL;
-
-       return i;
-}
-
 SHOW(__bch_cached_dev)
 {
        struct cached_dev *dc = container_of(kobj, struct cached_dev,
@@ -177,12 +154,12 @@ SHOW(__bch_cached_dev)
 
        if (attr == &sysfs_cache_mode)
                return bch_snprint_string_list(buf, PAGE_SIZE,
-                                              bch_cache_modes + 1,
+                                              bch_cache_modes,
                                               BDEV_CACHE_MODE(&dc->sb));
 
        if (attr == &sysfs_stop_when_cache_set_failed)
                return bch_snprint_string_list(buf, PAGE_SIZE,
-                                              bch_stop_on_failure_modes + 1,
+                                              bch_stop_on_failure_modes,
                                               dc->stop_when_cache_set_failed);
 
 
@@ -313,8 +290,7 @@ STORE(__cached_dev)
                bch_cached_dev_run(dc);
 
        if (attr == &sysfs_cache_mode) {
-               v = bch_read_string_list(buf, bch_cache_modes + 1);
-
+               v = __sysfs_match_string(bch_cache_modes, -1, buf);
                if (v < 0)
                        return v;
 
@@ -325,8 +301,7 @@ STORE(__cached_dev)
        }
 
        if (attr == &sysfs_stop_when_cache_set_failed) {
-               v = bch_read_string_list(buf, bch_stop_on_failure_modes + 1);
-
+               v = __sysfs_match_string(bch_stop_on_failure_modes, -1, buf);
                if (v < 0)
                        return v;
 
@@ -701,6 +676,7 @@ SHOW_LOCKED(bch_cache_set)
 STORE(__bch_cache_set)
 {
        struct cache_set *c = container_of(kobj, struct cache_set, kobj);
+       ssize_t v;
 
        if (attr == &sysfs_unregister)
                bch_cache_set_unregister(c);
@@ -764,8 +740,7 @@ STORE(__bch_cache_set)
                      c->congested_write_threshold_us);
 
        if (attr == &sysfs_errors) {
-               ssize_t v = bch_read_string_list(buf, error_actions);
-
+               v = __sysfs_match_string(error_actions, -1, buf);
                if (v < 0)
                        return v;
 
@@ -789,8 +764,7 @@ STORE(__bch_cache_set)
        }
 
        if (attr == &sysfs_io_disable) {
-               int v = strtoul_or_return(buf);
-
+               v = strtoul_or_return(buf);
                if (v) {
                        if (test_and_set_bit(CACHE_SET_IO_DISABLE,
                                             &c->flags))
@@ -1004,6 +978,7 @@ SHOW_LOCKED(bch_cache)
 STORE(__bch_cache)
 {
        struct cache *ca = container_of(kobj, struct cache, kobj);
+       ssize_t v;
 
        if (attr == &sysfs_discard) {
                bool v = strtoul_or_return(buf);
@@ -1018,8 +993,7 @@ STORE(__bch_cache)
        }
 
        if (attr == &sysfs_cache_replacement_policy) {
-               ssize_t v = bch_read_string_list(buf, cache_replacement_policies);
-
+               v = __sysfs_match_string(cache_replacement_policies, -1, buf);
                if (v < 0)
                        return v;