linux/block, branch v5.7

Revert "block: end bio with BLK_STS_AGAIN in case of non-mq devs and REQ_NOWAIT"

2020-05-28T19:20:39Z

This reverts commit c58c1f83436b501d45d4050fd1296d71a9760bcb. io_uring does do the right thing for this case, and we're still returning -EAGAIN to userspace for the cases we don't support. Revert this change to avoid doing endless spins of resubmits. Cc: stable@vger.kernel.org # v5.6 Reported-by: Bijan Mottahedeh Signed-off-by: Jens Axboe

bdi: use bdi_dev_name() to get device name

2020-05-09T22:07:39Z

Use the common interface bdi_dev_name() to get device name. Signed-off-by: Yufen Yu Signed-off-by: Christoph Hellwig Reviewed-by: Greg Kroah-Hartman Reviewed-by: Jan Kara Reviewed-by: Bart Van Assche Add missing include BFQ Signed-off-by: Jens Axboe

iocost: protect iocg->abs_vdebt with iocg->waitq.lock

2020-05-05T15:23:18Z

abs_vdebt is an atomic_64 which tracks how much over budget a given cgroup is and controls the activation of use_delay mechanism. Once a cgroup goes over budget from forced IOs, it has to pay it back with its future budget. The progress guarantee on debt paying comes from the iocg being active - active iocgs are processed by the periodic timer, which ensures that as time passes the debts dissipate and the iocg returns to normal operation. However, both iocg activation and vdebt handling are asynchronous and a sequence like the following may happen. 1. The iocg is in the process of being deactivated by the periodic timer. 2. A bio enters ioc_rqos_throttle(), calls iocg_activate() which returns without anything because it still sees that the iocg is already active. 3. The iocg is deactivated. 4. The bio from #2 is over budget but needs to be forced. It increases abs_vdebt and goes over the threshold and enables use_delay. 5. IO control is enabled for the iocg's subtree and now IOs are attributed to the descendant cgroups and the iocg itself no longer issues IOs. This leaves the iocg with stuck abs_vdebt - it has debt but inactive and no further IOs which can activate it. This can end up unduly punishing all the descendants cgroups. The usual throttling path has the same issue - the iocg must be active while throttled to ensure that future event will wake it up - and solves the problem by synchronizing the throttling path with a spinlock. abs_vdebt handling is another form of overage handling and shares a lot of characteristics including the fact that it isn't in the hottest path. This patch fixes the above and other possible races by strictly synchronizing abs_vdebt and use_delay handling with iocg->waitq.lock. Signed-off-by: Tejun Heo Reported-by: Vlad Dmitriev Cc: stable@vger.kernel.org # v5.4+ Fixes: e1518f63f246 ("blk-iocost: Don't let merges push vtime into the future") Signed-off-by: Jens Axboe

block: remove the bd_openers checks in blk_drop_partitions

2020-04-30T16:25:43Z

When replacing the bd_super check with a bd_openers I followed a logical conclusion, which turns out to be utterly wrong. When a block device has bd_super sets it has a mount file system on it (although not every mounted file system sets bd_super), but that also implies it doesn't even have partitions to start with. So instead of trying to come up with a logical check for all openers, just remove the check entirely. Fixes: d3ef5536274f ("block: fix busy device checking in blk_drop_partitions") Fixes: cb6b771b05c3 ("block: fix busy device checking in blk_drop_partitions again") Reported-by: Michal Koutný Reported-by: Yang Xu Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe

blk-iocost: Fix error on iocost_ioc_vrate_adj

2020-04-21T15:49:36Z

Systemtap 4.2 is unable to correctly interpret the "u32 (*missed_ppm)[2]" argument of the iocost_ioc_vrate_adj trace entry defined in include/trace/events/iocost.h leading to the following error: /tmp/stapAcz0G0/stap_c89c58b83cea1724e26395efa9ed4939_6321_aux_6.c:78:8: error: expected ‘;’, ‘,’ or ‘)’ before ‘*’ token , u32[]* __tracepoint_arg_missed_ppm That argument type is indeed rather complex and hard to read. Looking at block/blk-iocost.c. It is just a 2-entry u32 array. By simplifying the argument to a simple "u32 *missed_ppm" and adjusting the trace entry accordingly, the compilation error was gone. Fixes: 7caa47151ab2 ("blkcg: implement blk-iocost") Acked-by: Steven Rostedt (VMware) Acked-by: Tejun Heo Signed-off-by: Waiman Long Signed-off-by: Jens Axboe

blk-wbt: Use tracepoint_string() for wbt_step tracepoint string literals

2020-04-17T14:21:44Z

Use tracepoint_string() for string literals that are used in the wbt_step tracepoint, so that userspace tools can display the string content. Signed-off-by: Tommi Rantala Signed-off-by: Jens Axboe

blk-mq: Put driver tag in blk_mq_dispatch_rq_list() when no budget

2020-04-16T15:27:03Z

If in blk_mq_dispatch_rq_list() we find no budget, then we break of the dispatch loop, but the request may keep the driver tag, evaulated in 'nxt' in the previous loop iteration. Fix by putting the driver tag for that request. Reviewed-by: Ming Lei Signed-off-by: John Garry Signed-off-by: Jens Axboe

Merge tag 'block-5.7-2020-04-10' of git://git.kernel.dk/linux-block

2020-04-10T17:06:54Z

Pull block fixes from Jens Axboe: "Here's a set of fixes that should go into this merge window. This contains: - NVMe pull request from Christoph with various fixes - Better discard support for loop (Evan) - Only call ->commit_rqs() if we have queued IO (Keith) - blkcg offlining fixes (Tejun) - fix (and fix the fix) for busy partitions" * tag 'block-5.7-2020-04-10' of git://git.kernel.dk/linux-block: block: fix busy device checking in blk_drop_partitions again block: fix busy device checking in blk_drop_partitions nvmet-rdma: fix double free of rdma queue blk-mq: don't commit_rqs() if none were queued nvme-fc: Revert "add module to ops template to allow module references" nvme: fix deadlock caused by ANA update wrong locking nvmet-rdma: fix bonding failover possible NULL deref loop: Better discard support for block devices loop: Report EOPNOTSUPP properly nvmet: fix NULL dereference when removing a referral nvme: inherit stable pages constraint in the mpath stack device blkcg: don't offline parent blkcg first blkcg: rename blkcg->cgwb_refcnt to ->online_pin and always use it nvme-tcp: fix possible crash in recv error flow nvme-tcp: don't poll a non-live queue nvme-tcp: fix possible crash in write_zeroes processing nvmet-fc: fix typo in comment nvme-rdma: Replace comma with a semicolon nvme-fcloop: fix deallocation of working context nvme: fix compat address handling in several ioctls

block: fix busy device checking in blk_drop_partitions again

2020-04-10T14:34:11Z

The previous fix had an off by one in the bd_openers checking, counting the callers blkdev_get. Fixes: d3ef5536274f ("block: fix busy device checking in blk_drop_partitions") Reported-by: Qian Cai Signed-off-by: Christoph Hellwig Tested-by: Qian Cai Signed-off-by: Jens Axboe

block: fix busy device checking in blk_drop_partitions

2020-04-07T20:42:59Z

bd_super is only set by get_tree_bdev and mount_bdev, and thus not by other openers like btrfs or the XFS realtime and log devices, as well as block devices directly opened from user space. Check bd_openers instead. Fixes: 77032ca66f86 ("Return EBUSY from BLKRRPART for mounted whole-dev fs") Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe