kernel/linux.git/block/blk-stat.c, branch v5.15.208

block: prevent division by zero in blk_rq_stat_sum()

2024-04-13T11:01:45+00:00

[ Upstream commit 93f52fbeaf4b676b21acfe42a5152620e6770d02 ] The expression dst->nr_samples + src->nr_samples may have zero value on overflow. It is necessary to add a check to avoid division by zero. Found by Linux Verification Center (linuxtesting.org) with Svace. Signed-off-by: Roman Smirnov Reviewed-by: Sergey Shtylyov Link: https://lore.kernel.org/r/20240305134509.23108-1-r.smirnov@omp.ru Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

blk-stat: make q->stats->lock irqsafe

2020-09-01T22:48:46+00:00

blk-iocost calls blk_stat_enable_accounting() while holding an irqsafe lock which triggers a lockdep splat because q->stats->lock isn't irqsafe. Let's make it irqsafe. Signed-off-by: Tejun Heo Fixes: cd006509b0a9 ("blk-iocost: account for IO size when testing latencies") Cc: stable@vger.kernel.org # v5.8+ Signed-off-by: Jens Axboe

blk-stat: Optimise blk_stat_add()

2019-10-08T03:19:10+00:00

blk_stat_add() calls {get,put}_cpu_ptr() in a loop, which entails overhead of disabling/enabling preemption. The loop is under RCU (i.e.short) anyway, so do get_cpu() in advance. Signed-off-by: Pavel Begunkov Signed-off-by: Jens Axboe

block: add SPDX tags to block layer files missing licensing information

2019-04-30T22:12:03+00:00

Various block layer files do not have any licensing information at all. Add SPDX tags for the default kernel GPLv2 license to those. Reviewed-by: Chaitanya Kulkarni Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe

block: remove a few unused exports

2018-11-15T19:13:25+00:00

Reviewed-by: Hannes Reinecke Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe

block: export blk_stat_enable_accounting()

2018-09-27T23:34:54+00:00

Kyber will need this in a future change if it is built as a module. Signed-off-by: Omar Sandoval Signed-off-by: Jens Axboe

blk-stat: export helpers for modifying blk_rq_stat

2018-07-09T15:07:54+00:00

We need to use blk_rq_stat in the blkcg qos stuff, so export some of these helpers so they can be used by other things. Signed-off-by: Josef Bacik Acked-by: Tejun Heo Signed-off-by: Jens Axboe

block: consolidate struct request timestamp fields

2018-05-09T14:33:09+00:00

Currently, struct request has four timestamp fields: - A start time, set at get_request time, in jiffies, used for iostats - An I/O start time, set at start_request time, in ktime nanoseconds, used for blk-stats (i.e., wbt, kyber, hybrid polling) - Another start time and another I/O start time, used for cfq and bfq These can all be consolidated into one start time and one I/O start time, both in ktime nanoseconds, shaving off up to 16 bytes from struct request depending on the kernel config. Signed-off-by: Omar Sandoval Signed-off-by: Jens Axboe

block: get rid of struct blk_issue_stat

2018-05-09T14:33:05+00:00

struct blk_issue_stat squashes three things into one u64: - The time the driver started working on a request - The original size of the request (for the io.low controller) - Flags for writeback throttling It turns out that on x86_64, we have a 4 byte hole in struct request which we can fill with the non-timestamp fields from blk_issue_stat, simplifying things quite a bit. Signed-off-by: Omar Sandoval Signed-off-by: Jens Axboe

block: Protect queue flag changes with the queue lock

2018-03-08T21:13:48+00:00

Since the queue flags may be changed concurrently from multiple contexts after a queue becomes visible in sysfs, make these changes safe by protecting these with the queue lock. Cc: Christoph Hellwig Cc: Hannes Reinecke Cc: Ming Lei Reviewed-by: Martin K. Petersen Reviewed-by: Johannes Thumshirn Signed-off-by: Bart Van Assche Signed-off-by: Jens Axboe