On Sat, Aug 27, 2022 at 12:12 PM Liu Shixin <liushixin2@xxxxxxxxxx> wrote:
>
> zswap_init_started indicates that the initialization is started. And
> zswap_init_failed indicates that the initialization is failed. As we will
> support to init zswap after system startup, it's necessary to add a state
> to indicate the initialization is complete and succeed to avoid
> concurrency issues. Since we don't care about the difference between
> init started with init completion. We only need three states:
> uninitialized, initial failed, initial succeed.
>
> Signed-off-by: Liu Shixin <liushixin2@xxxxxxxxxx>
Reviewed-by: Vitaly Wool <vitaly.wool@xxxxxxxxxxx>
> ---
> mm/zswap.c | 22 +++++++++++-----------
> 1 file changed, 11 insertions(+), 11 deletions(-)
>
> diff --git a/mm/zswap.c b/mm/zswap.c
> index 2d48fd59cc7a..84e38300f571 100644
> --- a/mm/zswap.c
> +++ b/mm/zswap.c
> @@ -214,11 +214,12 @@ static DEFINE_SPINLOCK(zswap_pools_lock);
> /* pool counter to provide unique names to zpool */
> static atomic_t zswap_pools_count = ATOMIC_INIT(0);
>
> -/* used by param callback function */
> -static bool zswap_init_started;
> +#define ZSWAP_UNINIT 0
> +#define ZSWAP_INIT_SUCCEED 1
> +#define ZSWAP_INIT_FAILED 2
>
> -/* fatal error during init */
> -static bool zswap_init_failed;
> +/* init state */
> +static int zswap_init_state;
>
> /* init completed, but couldn't create the initial pool */
> static bool zswap_has_pool;
> @@ -772,7 +773,7 @@ static int __zswap_param_set(const char *val, const struct kernel_param *kp,
> char *s = strstrip((char *)val);
> int ret;
>
> - if (zswap_init_failed) {
> + if (zswap_init_state == ZSWAP_INIT_FAILED) {
> pr_err("can't set param, initialization failed\n");
> return -ENODEV;
> }
> @@ -784,7 +785,7 @@ static int __zswap_param_set(const char *val, const struct kernel_param *kp,
> /* if this is load-time (pre-init) param setting,
> * don't create a pool; that's done during init.
> */
> - if (!zswap_init_started)
> + if (zswap_init_state == ZSWAP_UNINIT)
> return param_set_charp(s, kp);
>
> if (!type) {
> @@ -875,11 +876,11 @@ static int zswap_zpool_param_set(const char *val,
> static int zswap_enabled_param_set(const char *val,
> const struct kernel_param *kp)
> {
> - if (zswap_init_failed) {
> + if (zswap_init_state == ZSWAP_INIT_FAILED) {
> pr_err("can't enable, initialization failed\n");
> return -ENODEV;
> }
> - if (!zswap_has_pool && zswap_init_started) {
> + if (!zswap_has_pool && zswap_init_state == ZSWAP_INIT_SUCCEED) {
> pr_err("can't enable, no pool configured\n");
> return -ENODEV;
> }
> @@ -1476,8 +1477,6 @@ static int __init init_zswap(void)
> struct zswap_pool *pool;
> int ret;
>
> - zswap_init_started = true;
> -
> if (zswap_entry_cache_create()) {
> pr_err("entry cache creation failed\n");
> goto cache_fail;
> @@ -1517,6 +1516,7 @@ static int __init init_zswap(void)
> goto destroy_wq;
> if (zswap_debugfs_init())
> pr_warn("debugfs initialization failed\n");
> + zswap_init_state = ZSWAP_INIT_SUCCEED;
> return 0;
>
> destroy_wq:
> @@ -1530,7 +1530,7 @@ static int __init init_zswap(void)
> zswap_entry_cache_destroy();
> cache_fail:
> /* if built-in, we aren't unloaded on failure; don't allow use */
> - zswap_init_failed = true;
> + zswap_init_state = ZSWAP_INIT_FAILED;
> zswap_enabled = false;
> return -ENOMEM;
> }
> --
> 2.25.1
>
