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| author | Sergey Senozhatsky <sergey.senozhatsky@gmail.com> | 2015-06-25 15:00:32 -0700 |
|---|---|---|
| committer | Mister Oyster <oysterized@gmail.com> | 2017-09-25 20:40:44 +0200 |
| commit | 777d82fc14ed8782f93f9ee908f25b07eaa98dd6 (patch) | |
| tree | 2a06e4c6ccb156c31e7097ad30ef4d90a636d11f /drivers/block/zram | |
| parent | 857b3f24a051a0e49ce03b5b9b0b41b6d0f88964 (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>
Diffstat (limited to 'drivers/block/zram')
| -rw-r--r-- | drivers/block/zram/zcomp.c | 5 | ||||
| -rw-r--r-- | drivers/block/zram/zram_drv.c | 3 |
2 files changed, 8 insertions, 0 deletions
diff --git a/drivers/block/zram/zcomp.c b/drivers/block/zram/zcomp.c index 9d200f89e..c4c48e879 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/zram_drv.c b/drivers/block/zram/zram_drv.c index 836925e91..c3c5e7039 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -379,6 +379,9 @@ 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; } |