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path: root/drivers/block/loop.c
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2018-05-07loop: remember whether sysfs_create_group() was doneTetsuo Handa
syzbot is hitting WARN() triggered by memory allocation fault injection [1] because loop module is calling sysfs_remove_group() when sysfs_create_group() failed. Fix this by remembering whether sysfs_create_group() succeeded. [1] https://syzkaller.appspot.com/bug?id=3f86c0edf75c86d2633aeb9dd69eccc70bc7e90b Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Reported-by: syzbot <syzbot+9f03168400f56df89dbc6f1751f4458fe739ff29@syzkaller.appspotmail.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Renamed sysfs_ready -> sysfs_inited. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-04-14loop: handle short DIO readsJens Axboe
We ran into an issue with loop and btrfs, where btrfs would complain about checksum errors. It turns out that is because we don't handle short reads at all, we just zero fill the remainder. Worse than that, we don't handle the filling properly, which results in loop trying to advance a single bio by much more than its size, since it doesn't take chaining into account. Handle short reads appropriately, by simply retrying at the new correct offset. End the remainder of the request with EIO, if we get a 0 read. Fixes: bc07c10a3603 ("block: loop: support DIO & AIO") Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-04-14loop: remove cmd->rq memberJens Axboe
We can always get at the request from the payload, no need to store a pointer to it. Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-04-10loop: fix LOOP_GET_STATUS lock imbalanceOmar Sandoval
Commit 2d1d4c1e591f made loop_get_status() drop lo_ctx_mutex before returning, but the loop_get_status_old(), loop_get_status64(), and loop_get_status_compat() wrappers don't call loop_get_status() if the passed argument is NULL. The callers expect that the lock is dropped, so make sure we drop it in that case, too. Reported-by: syzbot+31e8daa8b3fc129e75f2@syzkaller.appspotmail.com Fixes: 2d1d4c1e591f ("loop: don't call into filesystem while holding lo_ctl_mutex") Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-04-10block/loop: fix deadlock after loop_set_statusTetsuo Handa
syzbot is reporting deadlocks at __blkdev_get() [1]. ---------------------------------------- [ 92.493919] systemd-udevd D12696 525 1 0x00000000 [ 92.495891] Call Trace: [ 92.501560] schedule+0x23/0x80 [ 92.502923] schedule_preempt_disabled+0x5/0x10 [ 92.504645] __mutex_lock+0x416/0x9e0 [ 92.510760] __blkdev_get+0x73/0x4f0 [ 92.512220] blkdev_get+0x12e/0x390 [ 92.518151] do_dentry_open+0x1c3/0x2f0 [ 92.519815] path_openat+0x5d9/0xdc0 [ 92.521437] do_filp_open+0x7d/0xf0 [ 92.527365] do_sys_open+0x1b8/0x250 [ 92.528831] do_syscall_64+0x6e/0x270 [ 92.530341] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 92.931922] 1 lock held by systemd-udevd/525: [ 92.933642] #0: 00000000a2849e25 (&bdev->bd_mutex){+.+.}, at: __blkdev_get+0x73/0x4f0 ---------------------------------------- The reason of deadlock turned out that wait_event_interruptible() in blk_queue_enter() got stuck with bdev->bd_mutex held at __blkdev_put() due to q->mq_freeze_depth == 1. ---------------------------------------- [ 92.787172] a.out S12584 634 633 0x80000002 [ 92.789120] Call Trace: [ 92.796693] schedule+0x23/0x80 [ 92.797994] blk_queue_enter+0x3cb/0x540 [ 92.803272] generic_make_request+0xf0/0x3d0 [ 92.807970] submit_bio+0x67/0x130 [ 92.810928] submit_bh_wbc+0x15e/0x190 [ 92.812461] __block_write_full_page+0x218/0x460 [ 92.815792] __writepage+0x11/0x50 [ 92.817209] write_cache_pages+0x1ae/0x3d0 [ 92.825585] generic_writepages+0x5a/0x90 [ 92.831865] do_writepages+0x43/0xd0 [ 92.836972] __filemap_fdatawrite_range+0xc1/0x100 [ 92.838788] filemap_write_and_wait+0x24/0x70 [ 92.840491] __blkdev_put+0x69/0x1e0 [ 92.841949] blkdev_close+0x16/0x20 [ 92.843418] __fput+0xda/0x1f0 [ 92.844740] task_work_run+0x87/0xb0 [ 92.846215] do_exit+0x2f5/0xba0 [ 92.850528] do_group_exit+0x34/0xb0 [ 92.852018] SyS_exit_group+0xb/0x10 [ 92.853449] do_syscall_64+0x6e/0x270 [ 92.854944] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 92.943530] 1 lock held by a.out/634: [ 92.945105] #0: 00000000a2849e25 (&bdev->bd_mutex){+.+.}, at: __blkdev_put+0x3c/0x1e0 ---------------------------------------- The reason of q->mq_freeze_depth == 1 turned out that loop_set_status() forgot to call blk_mq_unfreeze_queue() at error paths for info->lo_encrypt_type != NULL case. ---------------------------------------- [ 37.509497] CPU: 2 PID: 634 Comm: a.out Tainted: G W 4.16.0+ #457 [ 37.513608] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 05/19/2017 [ 37.518832] RIP: 0010:blk_freeze_queue_start+0x17/0x40 [ 37.521778] RSP: 0018:ffffb0c2013e7c60 EFLAGS: 00010246 [ 37.524078] RAX: 0000000000000000 RBX: ffff8b07b1519798 RCX: 0000000000000000 [ 37.527015] RDX: 0000000000000002 RSI: ffffb0c2013e7cc0 RDI: ffff8b07b1519798 [ 37.529934] RBP: ffffb0c2013e7cc0 R08: 0000000000000008 R09: 47a189966239b898 [ 37.532684] R10: dad78b99b278552f R11: 9332dca72259d5ef R12: ffff8b07acd73678 [ 37.535452] R13: 0000000000004c04 R14: 0000000000000000 R15: ffff8b07b841e940 [ 37.538186] FS: 00007fede33b9740(0000) GS:ffff8b07b8e80000(0000) knlGS:0000000000000000 [ 37.541168] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 37.543590] CR2: 00000000206fdf18 CR3: 0000000130b30006 CR4: 00000000000606e0 [ 37.546410] Call Trace: [ 37.547902] blk_freeze_queue+0x9/0x30 [ 37.549968] loop_set_status+0x67/0x3c0 [loop] [ 37.549975] loop_set_status64+0x3b/0x70 [loop] [ 37.549986] lo_ioctl+0x223/0x810 [loop] [ 37.549995] blkdev_ioctl+0x572/0x980 [ 37.550003] block_ioctl+0x34/0x40 [ 37.550006] do_vfs_ioctl+0xa7/0x6d0 [ 37.550017] ksys_ioctl+0x6b/0x80 [ 37.573076] SyS_ioctl+0x5/0x10 [ 37.574831] do_syscall_64+0x6e/0x270 [ 37.576769] entry_SYSCALL_64_after_hwframe+0x42/0xb7 ---------------------------------------- [1] https://syzkaller.appspot.com/bug?id=cd662bc3f6022c0979d01a262c318fab2ee9b56f Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Reported-by: syzbot <bot+48594378e9851eab70bcd6f99327c7db58c5a28a@syzkaller.appspotmail.com> Fixes: ecdd09597a572513 ("block/loop: fix race between I/O and set_status") Cc: Ming Lei <tom.leiming@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: stable <stable@vger.kernel.org> Cc: Jens Axboe <axboe@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-04-05Merge tag 'for-4.17/block-20180402' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block layer updates from Jens Axboe: "It's a pretty quiet round this time, which is nice. This contains: - series from Bart, cleaning up the way we set/test/clear atomic queue flags. - series from Bart, fixing races between gendisk and queue registration and removal. - set of bcache fixes and improvements from various folks, by way of Michael Lyle. - set of lightnvm updates from Matias, most of it being the 1.2 to 2.0 transition. - removal of unused DIO flags from Nikolay. - blk-mq/sbitmap memory ordering fixes from Omar. - divide-by-zero fix for BFQ from Paolo. - minor documentation patches from Randy. - timeout fix from Tejun. - Alpha "can't write a char atomically" fix from Mikulas. - set of NVMe fixes by way of Keith. - bsg and bsg-lib improvements from Christoph. - a few sed-opal fixes from Jonas. - cdrom check-disk-change deadlock fix from Maurizio. - various little fixes, comment fixes, etc from various folks" * tag 'for-4.17/block-20180402' of git://git.kernel.dk/linux-block: (139 commits) blk-mq: Directly schedule q->timeout_work when aborting a request blktrace: fix comment in blktrace_api.h lightnvm: remove function name in strings lightnvm: pblk: remove some unnecessary NULL checks lightnvm: pblk: don't recover unwritten lines lightnvm: pblk: implement 2.0 support lightnvm: pblk: implement get log report chunk lightnvm: pblk: rename ppaf* to addrf* lightnvm: pblk: check for supported version lightnvm: implement get log report chunk helpers lightnvm: make address conversions depend on generic device lightnvm: add support for 2.0 address format lightnvm: normalize geometry nomenclature lightnvm: complete geo structure with maxoc* lightnvm: add shorten OCSSD version in geo lightnvm: add minor version to generic geometry lightnvm: simplify geometry structure lightnvm: pblk: refactor init/exit sequences lightnvm: Avoid validation of default op value lightnvm: centralize permission check for lightnvm ioctl ...
2018-03-27loop: use killable lock in ioctlsOmar Sandoval
Even after the previous patch to drop lo_ctl_mutex while calling vfs_getattr(), there are other cases where we can end up sleeping for a long time while holding lo_ctl_mutex. Let's avoid the uninterruptible sleep from the ioctls. Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-03-27loop: don't call into filesystem while holding lo_ctl_mutexOmar Sandoval
We hit an issue where a loop device on NFS was stuck in loop_get_status() doing vfs_getattr() after the NFS server died, which caused a pile-up of uninterruptible processes waiting on lo_ctl_mutex. There's no reason to hold this lock while we wait on the filesystem; let's drop it so that other processes can do their thing. We need to grab a reference on lo_backing_file while we use it, and we can get rid of the check on lo_device, which has been unnecessary since commit a34c0ae9ebd6 ("[PATCH] loop: remove the bio remapping capability") in the linux-history tree. Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-03-09loop: Fix lost writes caused by missing flagRoss Zwisler
The following commit: commit aa4d86163e4e ("block: loop: switch to VFS ITER_BVEC") replaced __do_lo_send_write(), which used ITER_KVEC iterators, with lo_write_bvec() which uses ITER_BVEC iterators. In this change, though, the WRITE flag was lost: - iov_iter_kvec(&from, ITER_KVEC | WRITE, &kvec, 1, len); + iov_iter_bvec(&i, ITER_BVEC, bvec, 1, bvec->bv_len); This flag is necessary for the DAX case because we make decisions based on whether or not the iterator is a READ or a WRITE in dax_iomap_actor() and in dax_iomap_rw(). We end up going through this path in configurations where we combine a PMEM device with 4k sectors, a loopback device and DAX. The consequence of this missed flag is that what we intend as a write actually turns into a read in the DAX code, so no data is ever written. The very simplest test case is to create a loopback device and try and write a small string to it, then hexdump a few bytes of the device to see if the write took. Without this patch you read back all zeros, with this you read back the string you wrote. For XFS this causes us to fail or panic during the following xfstests: xfs/074 xfs/078 xfs/216 xfs/217 xfs/250 For ext4 we have a similar issue where writes never happen, but we don't currently have any xfstests that use loopback and show this issue. Fix this by restoring the WRITE flag argument to iov_iter_bvec(). This causes the xfstests to all pass. Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: stable@vger.kernel.org Fixes: commit aa4d86163e4e ("block: loop: switch to VFS ITER_BVEC") Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-03-08block: Use blk_queue_flag_*() in drivers instead of queue_flag_*()Bart Van Assche
This patch has been generated as follows: for verb in set_unlocked clear_unlocked set clear; do replace-in-files queue_flag_${verb} blk_queue_flag_${verb%_unlocked} \ $(git grep -lw queue_flag_${verb} drivers block/bsg*) done Except for protecting all queue flag changes with the queue lock this patch does not change any functionality. Cc: Mike Snitzer <snitzer@redhat.com> Cc: Shaohua Li <shli@fb.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.de> Cc: Ming Lei <ming.lei@redhat.com> Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Acked-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-02-28block/loop: Delete gendisk before cleaning up the request queueBart Van Assche
Remove the disk, partition and bdi sysfs attributes before cleaning up the request queue associated with the disk. Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Cc: Josef Bacik <jbacik@fb.com> Cc: Shaohua Li <shli@fb.com> Cc: Omar Sandoval <osandov@fb.com> Cc: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-02-26genhd: Rename get_disk() to get_disk_and_module()Jan Kara
Rename get_disk() to get_disk_and_module() to make sure what the function does. It's not a great name but at least it is now clear that put_disk() is not it's counterpart. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-01-06loop: fix concurrent lo_open/lo_releaseLinus Torvalds
范龙飞 reports that KASAN can report a use-after-free in __lock_acquire. The reason is due to insufficient serialization in lo_release(), which will continue to use the loop device even after it has decremented the lo_refcnt to zero. In the meantime, another process can come in, open the loop device again as it is being shut down. Confusion ensues. Reported-by: 范龙飞 <long7573@126.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-09-26block: fix a build errorShaohua Li
The code is only for blkcg not for all cgroups Fixes: d4478e92d618 ("block/loop: make loop cgroup aware") Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-09-26block/loop: make loop cgroup awareShaohua Li
loop block device handles IO in a separate thread. The actual IO dispatched isn't cloned from the IO loop device received, so the dispatched IO loses the cgroup context. I'm ignoring buffer IO case now, which is quite complicated. Making the loop thread aware cgroup context doesn't really help. The loop device only writes to a single file. In current writeback cgroup implementation, the file can only belong to one cgroup. For direct IO case, we could workaround the issue in theory. For example, say we assign cgroup1 5M/s BW for loop device and cgroup2 10M/s. We can create a special cgroup for loop thread and assign at least 15M/s for the underlayer disk. In this way, we correctly throttle the two cgroups. But this is tricky to setup. This patch tries to address the issue. We record bio's css in loop command. When loop thread is handling the command, we then use the API provided in patch 1 to set the css for current task. The bio layer will use the css for new IO (from patch 3). Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-09-06loop: set physical block size to logical block sizeOmar Sandoval
Commit 6c6b6f28b333 ("loop: set physical block size to PAGE_SIZE") caused mkfs.xfs to barf on ppc64 [1]. Always using PAGE_SIZE as the physical block size still makes the most sense semantically, but let's just lie and always set it to the same value as the logical block size (same goes for io_min). In the future we might want to at least bump up io_min to PAGE_SIZE but I'm sick of these stupid changes so let's play it safe. 1: https://marc.info/?l=linux-xfs&m=150459024723753&w=2 Tested-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-09-01block/loop: fix use after freeShaohua Li
lo_rw_aio->call_read_iter-> 1 aops->direct_IO 2 iov_iter_revert lo_rw_aio_complete could happen between 1 and 2, the bio and bvec could be freed before 2, which accesses bvec. Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-09-01block/loop: allow request merge for directio modeShaohua Li
Currently loop disables merge. While it makes sense for buffer IO mode, directio mode can benefit from request merge. Without merge, loop could send small size IO to underlayer disk and harm performance. Reviewed-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-09-01block/loop: set hw_sectorsShaohua Li
Loop can handle any size of request. Limiting it to 255 sectors just burns the CPU for bio split and request merge for underlayer disk and also cause bad fs block allocation in directio mode. Reviewed-by: Omar Sandoval <osandov@fb.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-31loop: fold loop_switch() into callersOmar Sandoval
The comments here are really outdated, and blk-mq made flushing much simpler, so just fold the two cases into the callers. Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-31loop: add ioctl for changing logical block sizeOmar Sandoval
This is a different approach from the first attempt in f2c6df7dbf9a ("loop: support 4k physical blocksize"). Rather than extending LOOP_{GET,SET}_STATUS, add a separate ioctl just for setting the block size. Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-31loop: set physical block size to PAGE_SIZEOmar Sandoval
The physical block size is "the lowest possible sector size that the hardware can operate on without reverting to read-modify-write operations" (from the comment on blk_queue_physical_block_size()). Since loop does buffered I/O on the backing file by default, the RMW unit is a page. This isn't the case for direct I/O mode, but let's keep it simple. Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-31loop: get rid of lo_blocksizeOmar Sandoval
This is only used for setting the soft block size on the struct block_device once and then never used again. Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-28Merge tag 'v4.13-rc7' into for-4.14/block-postmergeJens Axboe
Linux 4.13-rc7 Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-23Revert "loop: support 4k physical blocksize"Omar Sandoval
There's some stuff still up in the air, let's not get stuck with a subpar ABI. I'll follow up with something better for 4.14. Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-15loop: fix to a race condition due to the early registration of deviceAnton Volkov
The early device registration made possible a race leading to allocations of disks with wrong minors. This patch moves the device registration further down the loop_init function to make the race infeasible. Found by Linux Driver Verification project (linuxtesting.org). Signed-off-by: Anton Volkov <avolkov@ispras.ru> Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-07-05Merge branch 'work.read_write' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull read/write updates from Al Viro: "Christoph's fs/read_write.c series - consolidation and cleanups" * 'work.read_write' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: nfsd: remove nfsd_vfs_read nfsd: use vfs_iter_read/write fs: implement vfs_iter_write using do_iter_write fs: implement vfs_iter_read using do_iter_read fs: move more code into do_iter_read/do_iter_write fs: remove __do_readv_writev fs: remove do_compat_readv_writev fs: remove do_readv_writev
2017-06-29fs: implement vfs_iter_write using do_iter_writeChristoph Hellwig
De-dupliate some code and allow for passing the flags argument to vfs_iter_write. Additionally it now properly updates timestamps. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-06-29fs: implement vfs_iter_read using do_iter_readChristoph Hellwig
De-dupliate some code and allow for passing the flags argument to vfs_iter_read. Additional it properly updates atime now. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-06-18loop: Add PF_LESS_THROTTLE to block/loop device thread.NeilBrown
When a filesystem is mounted from a loop device, writes are throttled by balance_dirty_pages() twice: once when writing to the filesystem and once when the loop_handle_cmd() writes to the backing file. This double-throttling can trigger positive feedback loops that create significant delays. The throttling at the lower level is seen by the upper level as a slow device, so it throttles extra hard. The PF_LESS_THROTTLE flag was created to handle exactly this circumstance, though with an NFS filesystem mounted from a local NFS server. It reduces the throttling on the lower layer so that it can proceed largely unthrottled. To demonstrate this, create a filesystem on a loop device and write (e.g. with dd) several large files which combine to consume significantly more than the limit set by /proc/sys/vm/dirty_ratio or dirty_bytes. Measure the total time taken. When I do this directly on a device (no loop device) the total time for several runs (mkfs, mount, write 200 files, umount) is fairly stable: 28-35 seconds. When I do this over a loop device the times are much worse and less stable. 52-460 seconds. Half below 100seconds, half above. When I apply this patch, the times become stable again, though not as fast as the no-loop-back case: 53-72 seconds. There may be room for further improvement as the total overhead still seems too high, but this is a big improvement. Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ming Lei <tom.leiming@gmail.com> Suggested-by: Michal Hocko <mhocko@suse.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2017-06-12Merge tag 'v4.12-rc5' into for-4.13/blockJens Axboe
We've already got a few conflicts and upcoming work depends on some of the changes that have gone into mainline as regression fixes for this series. Pull in 4.12-rc5 to resolve these conflicts and make it easier on down stream trees to continue working on 4.13 changes. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-06-09blk-mq: switch ->queue_rq return value to blk_status_tChristoph Hellwig
Use the same values for use for request completion errors as the return value from ->queue_rq. BLK_STS_RESOURCE is special cased to cause a requeue, and all the others are completed as-is. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2017-06-09block: introduce new block status code typeChristoph Hellwig
Currently we use nornal Linux errno values in the block layer, and while we accept any error a few have overloaded magic meanings. This patch instead introduces a new blk_status_t value that holds block layer specific status codes and explicitly explains their meaning. Helpers to convert from and to the previous special meanings are provided for now, but I suspect we want to get rid of them in the long run - those drivers that have a errno input (e.g. networking) usually get errnos that don't know about the special block layer overloads, and similarly returning them to userspace will usually return somethings that strictly speaking isn't correct for file system operations, but that's left as an exercise for later. For now the set of errors is a very limited set that closely corresponds to the previous overloaded errno values, but there is some low hanging fruite to improve it. blk_status_t (ab)uses the sparse __bitwise annotations to allow for sparse typechecking, so that we can easily catch places passing the wrong values. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2017-06-09loop: fix error handling regressionArnd Bergmann
gcc points out an unusual indentation: drivers/block/loop.c: In function 'loop_set_status': drivers/block/loop.c:1149:3: error: this 'if' clause does not guard... [-Werror=misleading-indentation] if (figure_loop_size(lo, info->lo_offset, info->lo_sizelimit, ^~ drivers/block/loop.c:1152:4: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if' goto exit; This was introduced by a new feature that accidentally moved the opening braces from one condition to another. Adding a second pair of braces makes it work correctly again and also more readable. Fixes: f2c6df7dbf9a ("loop: support 4k physical blocksize") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2017-06-08loop: support 4k physical blocksizeHannes Reinecke
When generating bootable VM images certain systems (most notably s390x) require devices with 4k blocksize. This patch implements a new flag 'LO_FLAGS_BLOCKSIZE' which will set the physical blocksize to that of the underlying device, and allow to change the logical blocksize for up to the physical blocksize. Signed-off-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2017-06-08loop: Remove unused 'bdev' argument from loop_set_capacityHannes Reinecke
Signed-off-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2017-06-08Fix loop device flush before configure v3James Wang
While installing SLES-12 (based on v4.4), I found that the installer will stall for 60+ seconds during LVM disk scan. The root cause was determined to be the removal of a bound device check in loop_flush() by commit b5dd2f6047ca ("block: loop: improve performance via blk-mq"). Restoring this check, examining ->lo_state as set by loop_set_fd() eliminates the bad behavior. Test method: modprobe loop max_loop=64 dd if=/dev/zero of=disk bs=512 count=200K for((i=0;i<4;i++))do losetup -f disk; done mkfs.ext4 -F /dev/loop0 for((i=0;i<4;i++))do mkdir t$i; mount /dev/loop$i t$i;done for f in `ls /dev/loop[0-9]*|sort`; do \ echo $f; dd if=$f of=/dev/null bs=512 count=1; \ done Test output: stock patched /dev/loop0 18.1217e-05 8.3842e-05 /dev/loop1 6.1114e-05 0.000147979 /dev/loop10 0.414701 0.000116564 /dev/loop11 0.7474 6.7942e-05 /dev/loop12 0.747986 8.9082e-05 /dev/loop13 0.746532 7.4799e-05 /dev/loop14 0.480041 9.3926e-05 /dev/loop15 1.26453 7.2522e-05 Note that from loop10 onward, the device is not mounted, yet the stock kernel consumes several orders of magnitude more wall time than it does for a mounted device. (Thanks for Mike Galbraith <efault@gmx.de>, give a changelog review.) Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: James Wang <jnwang@suse.com> Fixes: b5dd2f6047ca ("block: loop: improve performance via blk-mq") Signed-off-by: Jens Axboe <axboe@fb.com>
2017-05-02blk-mq: update ->init_request and ->exit_request prototypesChristoph Hellwig
Remove the request_idx parameter, which can't be used safely now that we support I/O schedulers with blk-mq. Except for a superflous check in mtip32xx it was unused anyway. Also pass the tag_set instead of just the driver data - this allows drivers to avoid some code duplication in a follow on cleanup. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2017-04-20blk-mq: remove the error argument to blk_mq_complete_requestChristoph Hellwig
Now that all drivers that call blk_mq_complete_requests have a ->complete callback we can remove the direct call to blk_mq_end_request, as well as the error argument to blk_mq_complete_request. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2017-04-20loop: zero-fill bio on the submitting cpuChristoph Hellwig
In thruth I've just audited which blk-mq drivers don't currently have a complete callback, but I think this change is at least borderline useful. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2017-04-08block: remove the discard_zeroes_data flagChristoph Hellwig
Now that we use the proper REQ_OP_WRITE_ZEROES operation everywhere we can kill this hack. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2017-04-08loop: implement REQ_OP_WRITE_ZEROESChristoph Hellwig
It's identical to discard as hole punches will always leave us with zeroes on reads. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2017-03-31blk-mq: constify struct blk_mq_opsEric Biggers
Constify all instances of blk_mq_ops, as they are never modified. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2017-03-03Merge branch 'rebased-statx' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs 'statx()' update from Al Viro. This adds the new extended stat() interface that internally subsumes our previous stat interfaces, and allows user mode to specify in more detail what kind of information it wants. It also allows for some explicit synchronization information to be passed to the filesystem, which can be relevant for network filesystems: is the cached value ok, or do you need open/close consistency, or what? From David Howells. Andreas Dilger points out that the first version of the extended statx interface was posted June 29, 2010: https://www.spinics.net/lists/linux-fsdevel/msg33831.html * 'rebased-statx' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: statx: Add a system call to make enhanced file info available
2017-03-03Merge branch 'for-linus' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block layer fixes from Jens Axboe: "A collection of fixes for this merge window, either fixes for existing issues, or parts that were waiting for acks to come in. This pull request contains: - Allocation of nvme queues on the right node from Shaohua. This was ready long before the merge window, but waiting on an ack from Bjorn on the PCI bit. Now that we have that, the three patches can go in. - Two fixes for blk-mq-sched with nvmeof, which uses hctx specific request allocations. This caused an oops. One part from Sagi, one part from Omar. - A loop partition scan deadlock fix from Omar, fixing a regression in this merge window. - A three-patch series from Keith, closing up a hole on clearing out requests on shutdown/resume. - A stable fix for nbd from Josef, fixing a leak of sockets. - Two fixes for a regression in this window from Jan, fixing a problem with one of his earlier patches dealing with queue vs bdi life times. - A fix for a regression with virtio-blk, causing an IO stall if scheduling is used. From me. - A fix for an io context lock ordering problem. From me" * 'for-linus' of git://git.kernel.dk/linux-block: block: Move bdi_unregister() to del_gendisk() blk-mq: ensure that bd->last is always set correctly block: don't call ioc_exit_icq() with the queue lock held for blk-mq block: Initialize bd_bdi on inode initialization loop: fix LO_FLAGS_PARTSCAN hang nvme: Complete all stuck requests blk-mq: Provide freeze queue timeout blk-mq: Export blk_mq_freeze_queue_wait nbd: stop leaking sockets blk-mq: move update of tags->rqs to __blk_mq_alloc_request() blk-mq: kill blk_mq_set_alloc_data() blk-mq: make blk_mq_alloc_request_hctx() allocate a scheduler request blk-mq-sched: Allocate sched reserved tags as specified in the original queue tagset nvme: allocate nvme_queue in correct node PCI: add an API to get node from vector blk-mq: allocate blk_mq_tags and requests in correct node
2017-03-02statx: Add a system call to make enhanced file info availableDavid Howells
Add a system call to make extended file information available, including file creation and some attribute flags where available through the underlying filesystem. The getattr inode operation is altered to take two additional arguments: a u32 request_mask and an unsigned int flags that indicate the synchronisation mode. This change is propagated to the vfs_getattr*() function. Functions like vfs_stat() are now inline wrappers around new functions vfs_statx() and vfs_statx_fd() to reduce stack usage. ======== OVERVIEW ======== The idea was initially proposed as a set of xattrs that could be retrieved with getxattr(), but the general preference proved to be for a new syscall with an extended stat structure. A number of requests were gathered for features to be included. The following have been included: (1) Make the fields a consistent size on all arches and make them large. (2) Spare space, request flags and information flags are provided for future expansion. (3) Better support for the y2038 problem [Arnd Bergmann] (tv_sec is an __s64). (4) Creation time: The SMB protocol carries the creation time, which could be exported by Samba, which will in turn help CIFS make use of FS-Cache as that can be used for coherency data (stx_btime). This is also specified in NFSv4 as a recommended attribute and could be exported by NFSD [Steve French]. (5) Lightweight stat: Ask for just those details of interest, and allow a netfs (such as NFS) to approximate anything not of interest, possibly without going to the server [Trond Myklebust, Ulrich Drepper, Andreas Dilger] (AT_STATX_DONT_SYNC). (6) Heavyweight stat: Force a netfs to go to the server, even if it thinks its cached attributes are up to date [Trond Myklebust] (AT_STATX_FORCE_SYNC). And the following have been left out for future extension: (7) Data version number: Could be used by userspace NFS servers [Aneesh Kumar]. Can also be used to modify fill_post_wcc() in NFSD which retrieves i_version directly, but has just called vfs_getattr(). It could get it from the kstat struct if it used vfs_xgetattr() instead. (There's disagreement on the exact semantics of a single field, since not all filesystems do this the same way). (8) BSD stat compatibility: Including more fields from the BSD stat such as creation time (st_btime) and inode generation number (st_gen) [Jeremy Allison, Bernd Schubert]. (9) Inode generation number: Useful for FUSE and userspace NFS servers [Bernd Schubert]. (This was asked for but later deemed unnecessary with the open-by-handle capability available and caused disagreement as to whether it's a security hole or not). (10) Extra coherency data may be useful in making backups [Andreas Dilger]. (No particular data were offered, but things like last backup timestamp, the data version number and the DOS archive bit would come into this category). (11) Allow the filesystem to indicate what it can/cannot provide: A filesystem can now say it doesn't support a standard stat feature if that isn't available, so if, for instance, inode numbers or UIDs don't exist or are fabricated locally... (This requires a separate system call - I have an fsinfo() call idea for this). (12) Store a 16-byte volume ID in the superblock that can be returned in struct xstat [Steve French]. (Deferred to fsinfo). (13) Include granularity fields in the time data to indicate the granularity of each of the times (NFSv4 time_delta) [Steve French]. (Deferred to fsinfo). (14) FS_IOC_GETFLAGS value. These could be translated to BSD's st_flags. Note that the Linux IOC flags are a mess and filesystems such as Ext4 define flags that aren't in linux/fs.h, so translation in the kernel may be a necessity (or, possibly, we provide the filesystem type too). (Some attributes are made available in stx_attributes, but the general feeling was that the IOC flags were to ext[234]-specific and shouldn't be exposed through statx this way). (15) Mask of features available on file (eg: ACLs, seclabel) [Brad Boyer, Michael Kerrisk]. (Deferred, probably to fsinfo. Finding out if there's an ACL or seclabal might require extra filesystem operations). (16) Femtosecond-resolution timestamps [Dave Chinner]. (A __reserved field has been left in the statx_timestamp struct for this - if there proves to be a need). (17) A set multiple attributes syscall to go with this. =============== NEW SYSTEM CALL =============== The new system call is: int ret = statx(int dfd, const char *filename, unsigned int flags, unsigned int mask, struct statx *buffer); The dfd, filename and flags parameters indicate the file to query, in a similar way to fstatat(). There is no equivalent of lstat() as that can be emulated with statx() by passing AT_SYMLINK_NOFOLLOW in flags. There is also no equivalent of fstat() as that can be emulated by passing a NULL filename to statx() with the fd of interest in dfd. Whether or not statx() synchronises the attributes with the backing store can be controlled by OR'ing a value into the flags argument (this typically only affects network filesystems): (1) AT_STATX_SYNC_AS_STAT tells statx() to behave as stat() does in this respect. (2) AT_STATX_FORCE_SYNC will require a network filesystem to synchronise its attributes with the server - which might require data writeback to occur to get the timestamps correct. (3) AT_STATX_DONT_SYNC will suppress synchronisation with the server in a network filesystem. The resulting values should be considered approximate. mask is a bitmask indicating the fields in struct statx that are of interest to the caller. The user should set this to STATX_BASIC_STATS to get the basic set returned by stat(). It should be noted that asking for more information may entail extra I/O operations. buffer points to the destination for the data. This must be 256 bytes in size. ====================== MAIN ATTRIBUTES RECORD ====================== The following structures are defined in which to return the main attribute set: struct statx_timestamp { __s64 tv_sec; __s32 tv_nsec; __s32 __reserved; }; struct statx { __u32 stx_mask; __u32 stx_blksize; __u64 stx_attributes; __u32 stx_nlink; __u32 stx_uid; __u32 stx_gid; __u16 stx_mode; __u16 __spare0[1]; __u64 stx_ino; __u64 stx_size; __u64 stx_blocks; __u64 __spare1[1]; struct statx_timestamp stx_atime; struct statx_timestamp stx_btime; struct statx_timestamp stx_ctime; struct statx_timestamp stx_mtime; __u32 stx_rdev_major; __u32 stx_rdev_minor; __u32 stx_dev_major; __u32 stx_dev_minor; __u64 __spare2[14]; }; The defined bits in request_mask and stx_mask are: STATX_TYPE Want/got stx_mode & S_IFMT STATX_MODE Want/got stx_mode & ~S_IFMT STATX_NLINK Want/got stx_nlink STATX_UID Want/got stx_uid STATX_GID Want/got stx_gid STATX_ATIME Want/got stx_atime{,_ns} STATX_MTIME Want/got stx_mtime{,_ns} STATX_CTIME Want/got stx_ctime{,_ns} STATX_INO Want/got stx_ino STATX_SIZE Want/got stx_size STATX_BLOCKS Want/got stx_blocks STATX_BASIC_STATS [The stuff in the normal stat struct] STATX_BTIME Want/got stx_btime{,_ns} STATX_ALL [All currently available stuff] stx_btime is the file creation time, stx_mask is a bitmask indicating the data provided and __spares*[] are where as-yet undefined fields can be placed. Time fields are structures with separate seconds and nanoseconds fields plus a reserved field in case we want to add even finer resolution. Note that times will be negative if before 1970; in such a case, the nanosecond fields will also be negative if not zero. The bits defined in the stx_attributes field convey information about a file, how it is accessed, where it is and what it does. The following attributes map to FS_*_FL flags and are the same numerical value: STATX_ATTR_COMPRESSED File is compressed by the fs STATX_ATTR_IMMUTABLE File is marked immutable STATX_ATTR_APPEND File is append-only STATX_ATTR_NODUMP File is not to be dumped STATX_ATTR_ENCRYPTED File requires key to decrypt in fs Within the kernel, the supported flags are listed by: KSTAT_ATTR_FS_IOC_FLAGS [Are any other IOC flags of sufficient general interest to be exposed through this interface?] New flags include: STATX_ATTR_AUTOMOUNT Object is an automount trigger These are for the use of GUI tools that might want to mark files specially, depending on what they are. Fields in struct statx come in a number of classes: (0) stx_dev_*, stx_blksize. These are local system information and are always available. (1) stx_mode, stx_nlinks, stx_uid, stx_gid, stx_[amc]time, stx_ino, stx_size, stx_blocks. These will be returned whether the caller asks for them or not. The corresponding bits in stx_mask will be set to indicate whether they actually have valid values. If the caller didn't ask for them, then they may be approximated. For example, NFS won't waste any time updating them from the server, unless as a byproduct of updating something requested. If the values don't actually exist for the underlying object (such as UID or GID on a DOS file), then the bit won't be set in the stx_mask, even if the caller asked for the value. In such a case, the returned value will be a fabrication. Note that there are instances where the type might not be valid, for instance Windows reparse points. (2) stx_rdev_*. This will be set only if stx_mode indicates we're looking at a blockdev or a chardev, otherwise will be 0. (3) stx_btime. Similar to (1), except this will be set to 0 if it doesn't exist. ======= TESTING ======= The following test program can be used to test the statx system call: samples/statx/test-statx.c Just compile and run, passing it paths to the files you want to examine. The file is built automatically if CONFIG_SAMPLES is enabled. Here's some example output. Firstly, an NFS directory that crosses to another FSID. Note that the AUTOMOUNT attribute is set because transiting this directory will cause d_automount to be invoked by the VFS. [root@andromeda ~]# /tmp/test-statx -A /warthog/data statx(/warthog/data) = 0 results=7ff Size: 4096 Blocks: 8 IO Block: 1048576 directory Device: 00:26 Inode: 1703937 Links: 125 Access: (3777/drwxrwxrwx) Uid: 0 Gid: 4041 Access: 2016-11-24 09:02:12.219699527+0000 Modify: 2016-11-17 10:44:36.225653653+0000 Change: 2016-11-17 10:44:36.225653653+0000 Attributes: 0000000000001000 (-------- -------- -------- -------- -------- -------- ---m---- --------) Secondly, the result of automounting on that directory. [root@andromeda ~]# /tmp/test-statx /warthog/data statx(/warthog/data) = 0 results=7ff Size: 4096 Blocks: 8 IO Block: 1048576 directory Device: 00:27 Inode: 2 Links: 125 Access: (3777/drwxrwxrwx) Uid: 0 Gid: 4041 Access: 2016-11-24 09:02:12.219699527+0000 Modify: 2016-11-17 10:44:36.225653653+0000 Change: 2016-11-17 10:44:36.225653653+0000 Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-03-02Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs pile two from Al Viro: - orangefs fix - series of fs/namei.c cleanups from me - VFS stuff coming from overlayfs tree * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: orangefs: Use RCU for destroy_inode vfs: use helper for calling f_op->fsync() mm: use helper for calling f_op->mmap() vfs: use helpers for calling f_op->{read,write}_iter() vfs: pass type instead of fn to do_{loop,iter}_readv_writev() vfs: extract common parts of {compat_,}do_readv_writev() vfs: wrap write f_ops with file_{start,end}_write() vfs: deny copy_file_range() for non regular files vfs: deny fallocate() on directory vfs: create vfs helper vfs_tmpfile() namei.c: split unlazy_walk() namei.c: fold the check for DCACHE_OP_REVALIDATE into d_revalidate() lookup_fast(): clean up the logics around the fallback to non-rcu mode namei: fold unlazy_link() into its sole caller
2017-03-02loop: fix LO_FLAGS_PARTSCAN hangOmar Sandoval
loop_reread_partitions() needs to do I/O, but we just froze the queue, so we end up waiting forever. This can easily be reproduced with losetup -P. Fix it by moving the reread to after we unfreeze the queue. Fixes: ecdd09597a57 ("block/loop: fix race between I/O and set_status") Reported-by: Tejun Heo <tj@kernel.org> Cc: stable@vger.kernel.org Signed-off-by: Omar Sandoval <osandov@fb.com> Reviewed-by: Ming Lei <tom.leiming@gmail.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2017-03-02Merge remote-tracking branch 'ovl/for-viro' into for-linusAl Viro
Overlayfs-related series from Miklos and Amir
2017-02-27scripts/spelling.txt: add "algined" pattern and fix typo instancesMasahiro Yamada
Fix typos and add the following to the scripts/spelling.txt: algined||aligned While we are here, fix the "appplication" in the touched line in drivers/block/loop.c. Also, fix the "may not naturally ..." to "may not be naturally ..." in the touched line in mm/page_alloc. Link: http://lkml.kernel.org/r/1481573103-11329-9-git-send-email-yamada.masahiro@socionext.com Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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