linux/drivers/block/loop.c, branch v4.1

block: destroy bdi before blockdev is unregistered.

2015-04-27T16:27:20Z

Because of the peculiar way that md devices are created (automatically when the device node is opened), a new device can be created and registered immediately after the blk_unregister_region(disk_devt(disk), disk->minors); call in del_gendisk(). Therefore it is important that all visible artifacts of the previous device are removed before this call. In particular, the 'bdi'. Since: commit c4db59d31e39ea067c32163ac961e9c80198fd37 Author: Christoph Hellwig fs: don't reassign dirty inodes to default_backing_dev_info moved the device_unregister(bdi->dev); call from bdi_unregister() to bdi_destroy() it has been quite easy to lose a race and have a new (e.g.) "md127" be created after the blk_unregister_region() call and before bdi_destroy() is ultimately called by the final 'put_disk', which must come after del_gendisk(). The new device finds that the bdi name is already registered in sysfs and complains > [ 9627.630029] WARNING: CPU: 18 PID: 3330 at fs/sysfs/dir.c:31 sysfs_warn_dup+0x5a/0x70() > [ 9627.630032] sysfs: cannot create duplicate filename '/devices/virtual/bdi/9:127' We can fix this by moving the bdi_destroy() call out of blk_release_queue() (which can happen very late when a refcount reaches zero) and into blk_cleanup_queue() - which happens exactly when the md device driver calls it. Then it is only necessary for md to call blk_cleanup_queue() before del_gendisk(). As loop.c devices are also created on demand by opening the device node, we make the same change there. Fixes: c4db59d31e39ea067c32163ac961e9c80198fd37 Reported-by: Azat Khuzhin Cc: Christoph Hellwig Cc: stable@vger.kernel.org (v4.0) Signed-off-by: NeilBrown Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe

block: loop: switch to VFS ITER_BVEC

2015-04-15T19:06:33Z

Signed-off-by: Christoph Hellwig Signed-off-by: Al Viro

switch /dev/loop to vfs_iter_write()

2015-04-12T02:29:39Z

all writable files that might be used as backing store for /dev/loop already support ->write_iter() Signed-off-by: Al Viro

loop: add blk-mq.h include

2015-01-02T22:20:25Z

Looks like we pull it in through other ways on x86, but we fail on sparc: In file included from drivers/block/cryptoloop.c:30:0: drivers/block/loop.h:63:24: error: field 'tag_set' has incomplete type struct blk_mq_tag_set tag_set; Add the include to loop.h, kill it from loop.c. Signed-off-by: Jens Axboe

block: loop: don't handle REQ_FUA explicitly

2015-01-02T22:07:49Z

block core handles REQ_FUA by its flush state machine, so won't do it in loop explicitly. Signed-off-by: Ming Lei Signed-off-by: Jens Axboe

block: loop: introduce lo_discard() and lo_req_flush()

2015-01-02T22:07:49Z

No behaviour change, just move the handling for REQ_DISCARD and REQ_FLUSH in these two functions. Signed-off-by: Ming Lei Signed-off-by: Jens Axboe

block: loop: say goodby to bio

2015-01-02T22:07:49Z

Switch to block request completely. Signed-off-by: Ming Lei Signed-off-by: Jens Axboe

block: loop: improve performance via blk-mq

2015-01-02T22:07:49Z

The conversion is a bit straightforward, and use work queue to dispatch requests of loop block, and one big change is that requests is submitted to backend file/device concurrently with work queue, so throughput may get improved much. Given write requests over same file are often run exclusively, so don't handle them concurrently for avoiding extra context switch cost, possible lock contention and work schedule cost. Also with blk-mq, there is opportunity to get loop I/O merged before submitting to backend file/device. In the following test: - base: v3.19-rc2-2041231 - loop over file in ext4 file system on SSD disk - bs: 4k, libaio, io depth: 64, O_DIRECT, num of jobs: 1 - throughput: IOPS ------------------------------------------------------ | | base | base with loop-mq | delta | ------------------------------------------------------ | randread | 1740 | 25318 | +1355%| ------------------------------------------------------ | read | 42196 | 51771 | +22.6%| ----------------------------------------------------- | randwrite | 35709 | 34624 | -3% | ----------------------------------------------------- | write | 39137 | 40326 | +3% | ----------------------------------------------------- So loop-mq can improve throughput for both read and randread, meantime, performance of write and randwrite isn't hurted basically. Another benefit is that loop driver code gets simplified much after blk-mq conversion, and the patch can be thought as cleanup too. Signed-off-by: Ming Lei Signed-off-by: Jens Axboe

Merge branch 'sched/urgent' into sched/core, to avoid conflicts

2014-05-07T11:15:46Z

Signed-off-by: Ingo Molnar

sched, treewide: Replace hardcoded nice values with MIN_NICE/MAX_NICE

2014-04-18T10:07:24Z

Replace various -20/+19 hardcoded nice values with MIN_NICE/MAX_NICE. Signed-off-by: Dongsheng Yang Acked-by: Tejun Heo Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/ff13819fd09b7a5dba5ab5ae797f2e7019bdfa17.1394532288.git.yangds.fnst@cn.fujitsu.com Cc: devel@driverdev.osuosl.org Cc: devicetree@vger.kernel.org Cc: fcoe-devel@open-fcoe.org Cc: linux390@de.ibm.com Cc: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org Cc: linux-s390@vger.kernel.org Cc: linux-scsi@vger.kernel.org Cc: nbd-general@lists.sourceforge.net Cc: ocfs2-devel@oss.oracle.com Cc: openipmi-developer@lists.sourceforge.net Cc: qla2xxx-upstream@qlogic.com Cc: linux-arch@vger.kernel.org [ Consolidated the patches, twiddled the changelog. ] Signed-off-by: Ingo Molnar