zram: propagate error to user

When we initialized zcomp with single, we couldn't change
max_comp_streams without zram reset but current interface doesn't show
any error to user and even it changes max_comp_streams's value without
any effect so it would make user very confusing.

This patch prevents max_comp_streams's change when zcomp was initialized
as single zcomp and emit the error to user(ex, echo).

[[email protected]: don't return with the lock held, per Sergey]
[[email protected]: fix coccinelle warnings]
Signed-off-by: Minchan Kim <[email protected]>
Cc: Nitin Gupta <[email protected]>
Cc: Jerome Marchand <[email protected]>
Acked-by: Sergey Senozhatsky <[email protected]>
Signed-off-by: Fengguang Wu <[email protected]>
Cc: Stephen Rothwell <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
This commit is contained in:
Minchan Kim 2014-04-07 15:38:21 -07:00 • committed by Linus Torvalds
commit 60a726e333
4 changed files with 25 additions and 15 deletions

View file

@ -153,7 +153,7 @@ static void zcomp_strm_multi_release(struct zcomp *comp, struct zcomp_strm *zstr
}
/* change max_strm limit */
static int zcomp_strm_multi_set_max_streams(struct zcomp *comp, int num_strm)
static bool zcomp_strm_multi_set_max_streams(struct zcomp *comp, int num_strm)
{
struct zcomp_strm_multi *zs = comp->stream;
struct zcomp_strm *zstrm;
@ -172,7 +172,7 @@ static int zcomp_strm_multi_set_max_streams(struct zcomp *comp, int num_strm)
zs->avail_strm--;
}
spin_unlock(&zs->strm_lock);
return 0;
return true;
}
static void zcomp_strm_multi_destroy(struct zcomp *comp)
@ -232,10 +232,10 @@ static void zcomp_strm_single_release(struct zcomp *comp,
mutex_unlock(&zs->strm_lock);
}
static int zcomp_strm_single_set_max_streams(struct zcomp *comp, int num_strm)
static bool zcomp_strm_single_set_max_streams(struct zcomp *comp, int num_strm)
{
/* zcomp_strm_single support only max_comp_streams == 1 */
return -ENOTSUPP;
return false;
}
static void zcomp_strm_single_destroy(struct zcomp *comp)
@ -284,7 +284,7 @@ ssize_t zcomp_available_show(const char *comp, char *buf)
return sz;
}
int zcomp_set_max_streams(struct zcomp *comp, int num_strm)
bool zcomp_set_max_streams(struct zcomp *comp, int num_strm)
{
return comp->set_max_streams(comp, num_strm);
}

View file

@ -46,7 +46,7 @@ struct zcomp {
struct zcomp_strm *(*strm_find)(struct zcomp *comp);
void (*strm_release)(struct zcomp *comp, struct zcomp_strm *zstrm);
int (*set_max_streams)(struct zcomp *comp, int num_strm);
bool (*set_max_streams)(struct zcomp *comp, int num_strm);
void (*destroy)(struct zcomp *comp);
};
@ -64,5 +64,5 @@ int zcomp_compress(struct zcomp *comp, struct zcomp_strm *zstrm,
int zcomp_decompress(struct zcomp *comp, const unsigned char *src,
size_t src_len, unsigned char *dst);
int zcomp_set_max_streams(struct zcomp *comp, int num_strm);
bool zcomp_set_max_streams(struct zcomp *comp, int num_strm);
#endif /* _ZCOMP_H_ */

View file

@ -127,19 +127,28 @@ static ssize_t max_comp_streams_store(struct device *dev,
{
int num;
struct zram *zram = dev_to_zram(dev);
int ret;
if (kstrtoint(buf, 0, &num))
return -EINVAL;
ret = kstrtoint(buf, 0, &num);
if (ret < 0)
return ret;
if (num < 1)
return -EINVAL;
down_write(&zram->init_lock);
if (init_done(zram)) {
if (zcomp_set_max_streams(zram->comp, num))
if (!zcomp_set_max_streams(zram->comp, num)) {
pr_info("Cannot change max compression streams\n");
ret = -EINVAL;
goto out;
}
}
zram->max_comp_streams = num;
ret = len;
out:
up_write(&zram->init_lock);
return len;
return ret;
}
static ssize_t comp_algorithm_show(struct device *dev,