block: avoid using uninitialized value in from queue_var_store

Date	Wed, 3 Apr 2013 15:30:52 +0000

As found by gcc-4.8, the QUEUE_SYSFS_BIT_FNS macro creates functions
that use a value generated by queue_var_store independent of whether
that value was set or not.

block/blk-sysfs.c: In function 'queue_store_nonrot':
block/blk-sysfs.c:244:385: warning: 'val' may be used uninitialized in this function [-Wmaybe-uninitialized]

Unlike most other such warnings, this one is not a false positive,
writing any non-number string into the sysfs files indeed has
an undefined result, rather than returning an error.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Jens Axboe <jaxboe@fusionio.com>
block: blk-core: add printk_ratelimit

On failure of requests the console is flooded with prints,
which result in a watchdog bark.
This patch limits the number of prints to console thus, avoiding
the bark.

CRs-Fixed: 458071
Change-Id: I614002cc1305ab7b5c6a64d278139291c1baa3c4
Signed-off-by: Asutosh Das <asutoshd@codeaurora.org>