aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorSergey Senozhatsky2015-06-25 15:00:32 -0700
committerLinus Torvalds2015-06-25 17:00:37 -0700
commitd93435c3fba4a47b773693b0c8992470d38510d5 (patch)
tree0eee23d9451b404c4f2aa9ad7e6a6fe970806cae
parent4bbacd51a683e45c13f7d6df6f85cb7391590311 (diff)
zram: check comp algorithm availability earlier
Improvement idea by Marcin Jabrzyk. comp_algorithm_store() silently accepts any supplied algorithm name, because zram performs algorithm availability check later, during the device configuration phase in disksize_store() and emits the following error: "zram: Cannot initialise %s compressing backend" this error line is somewhat generic and, besides, can indicate a failed attempt to allocate compression backend's working buffers. add algorithm availability check to comp_algorithm_store(): echo lzz > /sys/block/zram0/comp_algorithm -bash: echo: write error: Invalid argument Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reported-by: Marcin Jabrzyk <m.jabrzyk@samsung.com> Acked-by: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--drivers/block/zram/zcomp.c5
-rw-r--r--drivers/block/zram/zcomp.h1
-rw-r--r--drivers/block/zram/zram_drv.c3
3 files changed, 9 insertions, 0 deletions
diff --git a/drivers/block/zram/zcomp.c b/drivers/block/zram/zcomp.c
index a1a8b8ee9fda..965d1afb0eaa 100644
--- a/drivers/block/zram/zcomp.c
+++ b/drivers/block/zram/zcomp.c
@@ -286,6 +286,11 @@ ssize_t zcomp_available_show(const char *comp, char *buf)
return sz;
}
+bool zcomp_available_algorithm(const char *comp)
+{
+ return find_backend(comp) != NULL;
+}
+
bool zcomp_set_max_streams(struct zcomp *comp, int num_strm)
{
return comp->set_max_streams(comp, num_strm);
diff --git a/drivers/block/zram/zcomp.h b/drivers/block/zram/zcomp.h
index c59d1fca72c0..46e2b9f8f1f0 100644
--- a/drivers/block/zram/zcomp.h
+++ b/drivers/block/zram/zcomp.h
@@ -51,6 +51,7 @@ struct zcomp {
};
ssize_t zcomp_available_show(const char *comp, char *buf);
+bool zcomp_available_algorithm(const char *comp);
struct zcomp *zcomp_create(const char *comp, int max_strm);
void zcomp_destroy(struct zcomp *comp);
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index d94696b28a85..fb655e8d1e3b 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -378,6 +378,9 @@ static ssize_t comp_algorithm_store(struct device *dev,
if (sz > 0 && zram->compressor[sz - 1] == '\n')
zram->compressor[sz - 1] = 0x00;
+ if (!zcomp_available_algorithm(zram->compressor))
+ len = -EINVAL;
+
up_write(&zram->init_lock);
return len;
}