user/sven/linux.git/drivers/block, branch v4.14.156

nbd: handle racing with error'ed out commands

2019-11-10T10:25:20Z

[ Upstream commit 7ce23e8e0a9cd38338fc8316ac5772666b565ca9 ] We hit the following warning in production print_req_error: I/O error, dev nbd0, sector 7213934408 flags 80700 ------------[ cut here ]------------ refcount_t: underflow; use-after-free. WARNING: CPU: 25 PID: 32407 at lib/refcount.c:190 refcount_sub_and_test_checked+0x53/0x60 Workqueue: knbd-recv recv_work [nbd] RIP: 0010:refcount_sub_and_test_checked+0x53/0x60 Call Trace: blk_mq_free_request+0xb7/0xf0 blk_mq_complete_request+0x62/0xf0 recv_work+0x29/0xa1 [nbd] process_one_work+0x1f5/0x3f0 worker_thread+0x2d/0x3d0 ? rescuer_thread+0x340/0x340 kthread+0x111/0x130 ? kthread_create_on_node+0x60/0x60 ret_from_fork+0x1f/0x30 ---[ end trace b079c3c67f98bb7c ]--- This was preceded by us timing out everything and shutting down the sockets for the device. The problem is we had a request in the queue at the same time, so we completed the request twice. This can actually happen in a lot of cases, we fail to get a ref on our config, we only have one connection and just error out the command, etc. Fix this by checking cmd->status in nbd_read_stat. We only change this under the cmd->lock, so we are safe to check this here and see if we've already error'ed this command out, which would indicate that we've completed it as well. Reviewed-by: Mike Christie Signed-off-by: Josef Bacik Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

nbd: verify socket is supported during setup

2019-11-06T11:43:21Z

[ Upstream commit cf1b2326b734896734c6e167e41766f9cee7686a ] nbd requires socket families to support the shutdown method so the nbd recv workqueue can be woken up from its sock_recvmsg call. If the socket does not support the callout we will leave recv works running or get hangs later when the device or module is removed. This adds a check during socket connection/reconnection to make sure the socket being passed in supports the needed callout. Reported-by: syzbot+24c12fa8d218ed26011a@syzkaller.appspotmail.com Fixes: e9e006f5fcf2 ("nbd: fix max number of supported devs") Tested-by: Richard W.M. Jones Signed-off-by: Mike Christie Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

nbd: fix possible sysfs duplicate warning

2019-11-06T11:43:18Z

[ Upstream commit 862488105b84ca744b3d8ff131e0fcfe10644be1 ] 1. nbd_put takes the mutex and drops nbd->ref to 0. It then does idr_remove and drops the mutex. 2. nbd_genl_connect takes the mutex. idr_find/idr_for_each fails to find an existing device, so it does nbd_dev_add. 3. just before the nbd_put could call nbd_dev_remove or not finished totally, but if nbd_dev_add try to add_disk, we can hit: debugfs: Directory 'nbd1' with parent 'block' already present! This patch will make sure all the disk add/remove stuff are done by holding the nbd_index_mutex lock. Reported-by: Mike Christie Reviewed-by: Josef Bacik Signed-off-by: Xiubo Li Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

zram: fix race between backing_dev_show and backing_dev_store

2019-11-06T11:42:50Z

[ Upstream commit f7daefe4231e57381d92c2e2ad905a899c28e402 ] CPU0: CPU1: backing_dev_show backing_dev_store ...... ...... file = zram->backing_dev; down_read(&zram->init_lock); down_read(&zram->init_init_lock) file_path(file, ...); zram->backing_dev = backing_dev; up_read(&zram->init_lock); up_read(&zram->init_lock); gets the value of zram->backing_dev too early in backing_dev_show, which resultin the value being NULL at the beginning, and not NULL later. backtrace: d_path+0xcc/0x174 file_path+0x10/0x18 backing_dev_show+0x40/0xb4 dev_attr_show+0x20/0x54 sysfs_kf_seq_show+0x9c/0x10c kernfs_seq_show+0x28/0x30 seq_read+0x184/0x488 kernfs_fop_read+0x5c/0x1a4 __vfs_read+0x44/0x128 vfs_read+0xa0/0x138 SyS_read+0x54/0xb4 Link: http://lkml.kernel.org/r/1571046839-16814-1-git-send-email-chenwandun@huawei.com Signed-off-by: Chenwandun Acked-by: Minchan Kim Cc: Sergey Senozhatsky Cc: Jens Axboe Cc: [4.14+] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin

loop: Add LOOP_SET_DIRECT_IO to compat ioctl

2019-10-29T08:17:04Z

[ Upstream commit fdbe4eeeb1aac219b14f10c0ed31ae5d1123e9b8 ] Enabling Direct I/O with loop devices helps reducing memory usage by avoiding double caching. 32 bit applications running on 64 bits systems are currently not able to request direct I/O because is missing from the lo_compat_ioctl. This patch fixes the compatibility issue mentioned above by exporting LOOP_SET_DIRECT_IO as additional lo_compat_ioctl() entry. The input argument for this ioctl is a single long converted to a 1-bit boolean, so compatibility is preserved. Cc: Jens Axboe Signed-off-by: Alessio Balsini Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

nbd: fix max number of supported devs

2019-10-11T16:18:44Z

[ Upstream commit e9e006f5fcf2bab59149cb38a48a4817c1b538b4 ] This fixes a bug added in 4.10 with commit: commit 9561a7ade0c205bc2ee035a2ac880478dcc1a024 Author: Josef Bacik Date: Tue Nov 22 14:04:40 2016 -0500 nbd: add multi-connection support that limited the number of devices to 256. Before the patch we could create 1000s of devices, but the patch switched us from using our own thread to using a work queue which has a default limit of 256 active works. The problem is that our recv_work function sits in a loop until disconnection but only handles IO for one connection. The work is started when the connection is started/restarted, but if we end up creating 257 or more connections, the queue_work call just queues connection257+'s recv_work and that waits for connection 1 - 256's recv_work to be disconnected and that work instance completing. Instead of reverting back to kthreads, this has us allocate a workqueue_struct per device, so we can block in the work. Cc: stable@vger.kernel.org Reviewed-by: Josef Bacik Signed-off-by: Mike Christie Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

block/ndb: add WQ_UNBOUND to the knbd-recv workqueue

2019-10-11T16:18:44Z

[ Upstream commit 2189c97cdbed630d5971ab22f05dc998774e354e ] Add WQ_UNBOUND to the knbd-recv workqueue so we're not bound to a single CPU that is selected at device creation time. Signed-off-by: Dan Melnic Reviewed-by: Josef Bacik Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

nbd: fix crash when the blksize is zero

2019-10-11T16:18:43Z

[ Upstream commit 553768d1169a48c0cd87c4eb4ab57534ee663415 ] This will allow the blksize to be set zero and then use 1024 as default. Reviewed-by: Josef Bacik Signed-off-by: Xiubo Li [fix to use goto out instead of return in genl_connect] Signed-off-by: Mike Christie Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

pktcdvd: remove warning on attempting to register non-passthrough dev

2019-10-07T16:55:13Z

[ Upstream commit eb09b3cc464d2c3bbde9a6648603c8d599ea8582 ] Anatoly reports that he gets the below warning when booting -git on a sparc64 box on debian unstable: ... [ 13.352975] aes_sparc64: Using sparc64 aes opcodes optimized AES implementation [ 13.428002] ------------[ cut here ]------------ [ 13.428081] WARNING: CPU: 21 PID: 586 at drivers/block/pktcdvd.c:2597 pkt_setup_dev+0x2e4/0x5a0 [pktcdvd] [ 13.428147] Attempt to register a non-SCSI queue [ 13.428184] Modules linked in: pktcdvd libdes cdrom aes_sparc64 n2_rng md5_sparc64 sha512_sparc64 rng_core sha256_sparc64 flash sha1_sparc64 ip_tables x_tables ipv6 crc_ccitt nf_defrag_ipv6 autofs4 ext4 crc16 mbcache jbd2 raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor xor async_tx raid6_pq raid1 raid0 multipath linear md_mod crc32c_sparc64 [ 13.428452] CPU: 21 PID: 586 Comm: pktsetup Not tainted 5.3.0-10169-g574cc4539762 #1234 [ 13.428507] Call Trace: [ 13.428542] [00000000004635c0] __warn+0xc0/0x100 [ 13.428582] [0000000000463634] warn_slowpath_fmt+0x34/0x60 [ 13.428626] [000000001045b244] pkt_setup_dev+0x2e4/0x5a0 [pktcdvd] [ 13.428674] [000000001045ccf4] pkt_ctl_ioctl+0x94/0x220 [pktcdvd] [ 13.428724] [00000000006b95c8] do_vfs_ioctl+0x628/0x6e0 [ 13.428764] [00000000006b96c8] ksys_ioctl+0x48/0x80 [ 13.428803] [00000000006b9714] sys_ioctl+0x14/0x40 [ 13.428847] [0000000000406294] linux_sparc_syscall+0x34/0x44 [ 13.428890] irq event stamp: 4181 [ 13.428924] hardirqs last enabled at (4189): [<00000000004e0a74>] console_unlock+0x634/0x6c0 [ 13.428984] hardirqs last disabled at (4196): [<00000000004e0540>] console_unlock+0x100/0x6c0 [ 13.429048] softirqs last enabled at (3978): [<0000000000b2e2d8>] __do_softirq+0x498/0x520 [ 13.429110] softirqs last disabled at (3967): [<000000000042cfb4>] do_softirq_own_stack+0x34/0x60 [ 13.429172] ---[ end trace 2220ca468f32967d ]--- [ 13.430018] pktcdvd: setup of pktcdvd device failed [ 13.455589] des_sparc64: Using sparc64 des opcodes optimized DES implementation [ 13.515334] camellia_sparc64: Using sparc64 camellia opcodes optimized CAMELLIA implementation [ 13.522856] pktcdvd: setup of pktcdvd device failed [ 13.529327] pktcdvd: setup of pktcdvd device failed [ 13.532932] pktcdvd: setup of pktcdvd device failed [ 13.536165] pktcdvd: setup of pktcdvd device failed [ 13.539372] pktcdvd: setup of pktcdvd device failed [ 13.542834] pktcdvd: setup of pktcdvd device failed [ 13.546536] pktcdvd: setup of pktcdvd device failed [ 15.431071] XFS (dm-0): Mounting V5 Filesystem ... Apparently debian auto-attaches any cdrom like device to pktcdvd, which can lead to the above warning. There's really no reason to warn for this situation, kill it. Reported-by: Anatoly Pugachev Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

nbd: add missing config put

2019-10-05T10:47:53Z

[ Upstream commit 887e975c4172d0d5670c39ead2f18ba1e4ec8133 ] Fix bug added with the patch: commit 8f3ea35929a0806ad1397db99a89ffee0140822a Author: Josef Bacik Date: Mon Jul 16 12:11:35 2018 -0400 nbd: handle unexpected replies better where if the timeout handler runs when the completion path is and we fail to grab the mutex in the timeout handler we will leave a config reference and cannot free the config later. Reviewed-by: Josef Bacik Signed-off-by: Mike Christie Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin