zram: propagate error to user
authorMinchan Kim <minchan@kernel.org>
Mon, 7 Apr 2014 22:38:21 +0000 (15:38 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Mon, 7 Apr 2014 23:36:02 +0000 (16:36 -0700)
commit60a726e33375a1096e85399cfa1327081b4c38be
tree3316be45cfc8844bdec5e742cac59f1ebc0dab2f
parentfcfa8d95cacf5cbbe6dee6b8d229fe86142266e0
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).

[akpm@linux-foundation.org: don't return with the lock held, per Sergey]
[fengguang.wu@intel.com: fix coccinelle warnings]
Signed-off-by: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Jerome Marchand <jmarchan@redhat.com>
Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Documentation/blockdev/zram.txt
drivers/block/zram/zcomp.c
drivers/block/zram/zcomp.h
drivers/block/zram/zram_drv.c