linux/drivers/block/loop.c, branch v4.3

blk-mq: fix racy updates of rq->errors

2015-10-01T08:10:55Z

blk_mq_complete_request may be a no-op if the request has already been completed by others means (e.g. a timeout or cancellation), but currently drivers have to set rq->errors before calling blk_mq_complete_request, which might leave us with the wrong error value. Add an error parameter to blk_mq_complete_request so that we can defer setting rq->errors until we known we won the race to complete the request. Signed-off-by: Christoph Hellwig Reviewed-by: Sagi Grimberg Signed-off-by: Jens Axboe

block: have drivers use blk_queue_max_discard_sectors()

2015-07-17T14:41:53Z

Some drivers use it now, others just set the limits field manually. But in preparation for splitting this into a hard and soft limit, ensure that they all call the proper function for setting the hw limit for discards. Reviewed-by: Jeff Moyer Signed-off-by: Jens Axboe

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2015-07-05T02:36:06Z

Pull more vfs updates from Al Viro: "Assorted VFS fixes and related cleanups (IMO the most interesting in that part are f_path-related things and Eric's descriptor-related stuff). UFS regression fixes (it got broken last cycle). 9P fixes. fs-cache series, DAX patches, Jan's file_remove_suid() work" [ I'd say this is much more than "fixes and related cleanups". The file_table locking rule change by Eric Dumazet is a rather big and fundamental update even if the patch isn't huge. - Linus ] * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (49 commits) 9p: cope with bogus responses from server in p9_client_{read,write} p9_client_write(): avoid double p9_free_req() 9p: forgetting to cancel request on interrupted zero-copy RPC dax: bdev_direct_access() may sleep block: Add support for DAX reads/writes to block devices dax: Use copy_from_iter_nocache dax: Add block size note to documentation fs/file.c: __fget() and dup2() atomicity rules fs/file.c: don't acquire files->file_lock in fd_install() fs:super:get_anon_bdev: fix race condition could cause dev exceed its upper limitation vfs: avoid creation of inode number 0 in get_next_ino namei: make set_root_rcu() return void make simple_positive() public ufs: use dir_pages instead of ufs_dir_pages() pagemap.h: move dir_pages() over there remove the pointless include of lglock.h fs: cleanup slight list_entry abuse xfs: Correctly lock inode when removing suid and file capabilities fs: Call security_ops->inode_killpriv on truncate fs: Provide function telling whether file_remove_privs() will do anything ...

Merge branch 'for-4.2/drivers' of git://git.kernel.dk/linux-block

2015-06-25T22:12:50Z

Pull block driver updates from Jens Axboe: "This contains: - a few race fixes for null_blk, from Akinobu Mita. - a series of fixes for mtip32xx, from Asai Thambi and Selvan Mani at Micron. - NVMe: * Fix for missing error return on allocation failure, from Axel Lin. * Code consolidation and cleanups from Christoph. * Memory barrier addition, syncing queue count and queue pointers. From Jon Derrick. * Various fixes from Keith, an addition to support user issue reset from sysfs or ioctl, and automatic namespace rescan. * Fix from Matias, avoiding losing some request flags when marking the request failfast. - small cleanups and sparse fixups for ps3vram. From Geert Uytterhoeven and Geoff Lavand. - s390/dasd dead code removal, from Jarod Wilson. - a set of fixes and optimizations for loop, from Ming Lei. - conversion to blkdev_reread_part() of loop, dasd, ndb. From Ming Lei. - updates to cciss. From Tomas Henzl" * 'for-4.2/drivers' of git://git.kernel.dk/linux-block: (44 commits) mtip32xx: Fix accessing freed memory block: nvme-scsi: Catch kcalloc failure NVMe: Fix IO for extended metadata formats nvme: don't overwrite req->cmd_flags on sync cmd mtip32xx: increase wait time for hba reset mtip32xx: fix minor number mtip32xx: remove unnecessary sleep in mtip_ftl_rebuild_poll() mtip32xx: fix crash on surprise removal of the drive mtip32xx: Abort I/O during secure erase operation mtip32xx: fix incorrectly setting MTIP_DDF_SEC_LOCK_BIT mtip32xx: remove unused variable 'port->allocated' mtip32xx: fix rmmod issue MAINTAINERS: Update ps3vram block driver block/ps3vram: Remove obsolete reference to MTD block/ps3vram: Fix sparse warnings NVMe: Automatic namespace rescan NVMe: Memory barrier before queue_count is incremented NVMe: add sysfs and ioctl controller reset null_blk: restart request processing on completion handler null_blk: prevent timer handler running on a different CPU where started ...

vfs: add file_path() helper

2015-06-23T22:00:05Z

Turn d_path(&file->f_path, ...); into file_path(file, ...); Signed-off-by: Miklos Szeredi Signed-off-by: Al Viro

loop: remove (now) unused 'out' label

2015-05-20T15:54:35Z

gcc, righfully, complains: drivers/block/loop.c:1369:1: warning: label 'out' defined but not used [-Wunused-label] Kill it. Signed-off-by: Jens Axboe

block: loop: fix another reread part failure

2015-05-20T15:06:11Z

loop_clr_fd() can be run piggyback with lo_release(), and under this situation, reread partition may always fail because bd_mutex has been held already. This patch detects the situation by the reference count, and call __blkdev_reread_part() to avoid acquiring the lock again. In the meantime, this patch switches to new kernel APIs of blkdev_reread_part() and __blkdev_reread_part(). Reviewed-by: Christoph Hellwig Tested-by: Jarod Wilson Acked-by: Jarod Wilson Signed-off-by: Jarod Wilson Signed-off-by: Ming Lei Signed-off-by: Jens Axboe

block: loop: don't hold lo_ctl_mutex in lo_open

2015-05-20T15:06:09Z

The lo_ctl_mutex is held for running all ioctl handlers, and in some ioctl handlers, ioctl_by_bdev(BLKRRPART) is called for rereading partitions, which requires bd_mutex. So it is easy to cause failure because trylock(bd_mutex) may fail inside blkdev_reread_part(), and follows the lock context: blkid or other application: ->open() ->mutex_lock(bd_mutex) ->lo_open() ->mutex_lock(lo_ctl_mutex) losetup(set fd ioctl): ->mutex_lock(lo_ctl_mutex) ->ioctl_by_bdev(BLKRRPART) ->trylock(bd_mutex) This patch trys to eliminate the ABBA lock dependency by removing lo_ctl_mutext in lo_open() with the following approach: 1) make lo_refcnt as atomic_t and avoid acquiring lo_ctl_mutex in lo_open(): - for open vs. add/del loop, no any problem because of loop_index_mutex - freeze request queue during clr_fd, so I/O can't come until clearing fd is completed, like the effect of holding lo_ctl_mutex in lo_open - both open() and release() have been serialized by bd_mutex already 2) don't hold lo_ctl_mutex for decreasing/checking lo_refcnt in lo_release(), then lo_ctl_mutex is only required for the last release. Reviewed-by: Christoph Hellwig Tested-by: Jarod Wilson Acked-by: Jarod Wilson Signed-off-by: Ming Lei Signed-off-by: Jens Axboe

block: loop: avoiding too many pending per work I/O

2015-05-05T19:46:55Z

If there are too many pending per work I/O, too many high priority work thread can be generated so that system performance can be effected. This patch limits the max_active parameter of workqueue as 16. This patch fixes Fedora 22 live booting performance regression when it is booted from squashfs over dm based on loop, and looks the following reasons are related with the problem: - not like other filesyststems(such as ext4), squashfs is a bit special, and I observed that increasing I/O jobs to access file in squashfs only improve I/O performance a little, but it can make big difference for ext4 - nested loop: both squashfs.img and ext3fs.img are mounted as loop block, and ext3fs.img is inside the squashfs - during booting, lots of tasks may run concurrently Fixes: b5dd2f6047ca108001328aac0e8588edd15f1778 Cc: stable@vger.kernel.org (v4.0) Cc: Justin M. Forbes Signed-off-by: Ming Lei Acked-by: Tejun Heo Signed-off-by: Jens Axboe

block: loop: convert to per-device workqueue

2015-05-05T19:46:53Z

Documentation/workqueue.txt: If there is dependency among multiple work items used during memory reclaim, they should be queued to separate wq each with WQ_MEM_RECLAIM. Loop devices can be stacked, so we have to convert to per-device workqueue. One example is Fedora live CD. Fixes: b5dd2f6047ca108001328aac0e8588edd15f1778 Cc: stable@vger.kernel.org (v4.0) Cc: Justin M. Forbes Signed-off-by: Ming Lei Acked-by: Tejun Heo Signed-off-by: Jens Axboe