From: Mike Snitzer Date: Wed, 6 Jul 2011 19:30:50 +0000 (+0200) Subject: block: eliminate potential for infinite loop in blkdev_issue_discard X-Git-Tag: v3.1-rc1~252^2~12 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0f79960391a5a1e3679956024e18aeeb0369ac44;p=pandora-kernel.git block: eliminate potential for infinite loop in blkdev_issue_discard Due to the recently identified overflow in read_capacity_16() it was possible for max_discard_sectors to be zero but still have discards enabled on the associated device's queue. Eliminate the possibility for blkdev_issue_discard to infinitely loop. Interestingly this issue wasn't identified until a device, whose discard_granularity was 0 due to read_capacity_16 overflow, was consumed by blk_stack_limits() to construct limits for a higher-level DM multipath device. The multipath device's resulting limits never had the discard limits stacked because blk_stack_limits() will only do so if the bottom device's discard_granularity != 0. This resulted in the multipath device's limits.max_discard_sectors being 0. Signed-off-by: Mike Snitzer Signed-off-by: Jens Axboe --- Reading git-diff-tree failed