block: avoid using uninitialized value in from queue_var_store
authorArnd Bergmann <arnd@arndb.de>
Wed, 3 Apr 2013 19:53:57 +0000 (21:53 +0200)
committerBen Hutchings <ben@decadent.org.uk>
Thu, 25 Apr 2013 19:25:47 +0000 (20:25 +0100)
commit4316936730689af432346fa1d71c3f69f22ec3ac
tree505051afe4ac78c015aa7da91f46c6fbe11b3c91
parentb11b9b2c5e21f294be556c8ab9fe6cee48fca567
block: avoid using uninitialized value in from queue_var_store

commit c678ef5286ddb5cf70384ad5af286b0afc9b73e1 upstream.

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>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
block/blk-sysfs.c