On Thu, 10 Sep 2015 20:48:37 +0900 Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx> wrote:
> From: Sergey SENOZHATSKY <sergey.senozhatsky@xxxxxxxxx>
>
> Constify `struct zpool' ->type.
>
I think I prefer Dan's patch, which deletes stuff:
From: Dan Streetman <ddstreet@xxxxxxxx>
Subject: zpool: remove redundant zpool->type string, const-ify zpool_get_type
Make the return type of zpool_get_type const; the string belongs to the
zpool driver and should not be modified. Remove the redundant type field
in the struct zpool; it is private to zpool.c and isn't needed since
->driver->type can be used directly. Add comments indicating strings must
be null-terminated.
Signed-off-by: Dan Streetman <ddstreet@xxxxxxxx>
Cc: Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx>
Cc: Seth Jennings <sjennings@xxxxxxxxxxxxxx>
Cc: Minchan Kim <minchan@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/zpool.h | 2 +-
mm/zpool.c | 14 ++++++++------
2 files changed, 9 insertions(+), 7 deletions(-)
diff -puN include/linux/zpool.h~zpool-remove-redundant-zpool-type-string-const-ify-zpool_get_type include/linux/zpool.h
--- a/include/linux/zpool.h~zpool-remove-redundant-zpool-type-string-const-ify-zpool_get_type
+++ a/include/linux/zpool.h
@@ -41,7 +41,7 @@ bool zpool_has_pool(char *type);
struct zpool *zpool_create_pool(char *type, char *name,
gfp_t gfp, const struct zpool_ops *ops);
-char *zpool_get_type(struct zpool *pool);
+const char *zpool_get_type(struct zpool *pool);
void zpool_destroy_pool(struct zpool *pool);
diff -puN mm/zpool.c~zpool-remove-redundant-zpool-type-string-const-ify-zpool_get_type mm/zpool.c
--- a/mm/zpool.c~zpool-remove-redundant-zpool-type-string-const-ify-zpool_get_type
+++ a/mm/zpool.c
@@ -18,8 +18,6 @@
#include <linux/zpool.h>
struct zpool {
- char *type;
-
struct zpool_driver *driver;
void *pool;
const struct zpool_ops *ops;
@@ -73,6 +71,7 @@ int zpool_unregister_driver(struct zpool
}
EXPORT_SYMBOL(zpool_unregister_driver);
+/* this assumes @type is null-terminated. */
static struct zpool_driver *zpool_get_driver(char *type)
{
struct zpool_driver *driver;
@@ -113,6 +112,8 @@ static void zpool_put_driver(struct zpoo
* not be loaded, and calling @zpool_create_pool() with the pool type will
* fail.
*
+ * The @type string must be null-terminated.
+ *
* Returns: true if @type pool is available, false if not
*/
bool zpool_has_pool(char *type)
@@ -145,6 +146,8 @@ EXPORT_SYMBOL(zpool_has_pool);
*
* Implementations must guarantee this to be thread-safe.
*
+ * The @type and @name strings must be null-terminated.
+ *
* Returns: New zpool on success, NULL on failure.
*/
struct zpool *zpool_create_pool(char *type, char *name, gfp_t gfp,
@@ -174,7 +177,6 @@ struct zpool *zpool_create_pool(char *ty
return NULL;
}
- zpool->type = driver->type;
zpool->driver = driver;
zpool->pool = driver->create(name, gfp, ops, zpool);
zpool->ops = ops;
@@ -208,7 +210,7 @@ struct zpool *zpool_create_pool(char *ty
*/
void zpool_destroy_pool(struct zpool *zpool)
{
- pr_debug("destroying pool type %s\n", zpool->type);
+ pr_debug("destroying pool type %s\n", zpool->driver->type);
spin_lock(&pools_lock);
list_del(&zpool->list);
@@ -228,9 +230,9 @@ void zpool_destroy_pool(struct zpool *zp
*
* Returns: The type of zpool.
*/
-char *zpool_get_type(struct zpool *zpool)
+const char *zpool_get_type(struct zpool *zpool)
{
- return zpool->type;
+ return zpool->driver->type;
}
/**
_
--
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