- 04 Dec, 2023 2 commits
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Keith Busch authored
A different CPU may be setting the ctrl->state value, so ensure proper barriers to prevent optimizing to a stale state. Normally it isn't a problem to observe the wrong state as it is merely advisory to take a quicker path during initialization and error recovery, but seeing an old state can report unexpected ENETRESET errors when a reset request was in fact successful. Reported-by:
Minh Hoang <mh2022@meta.com> Reviewed-by:
Sagi Grimberg <sagi@grimberg.me> Signed-off-by:
Keith Busch <kbusch@kernel.org> Signed-off-by:
Hannes Reinecke <hare@suse.de>
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Keith Busch authored
The controller state is typically written by another CPU, so reading it should ensure no optimizations are taken. This is a repeated pattern in the driver, so start with adding a convenience function that returns the controller state with READ_ONCE(). Reviewed-by:
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- 02 Dec, 2023 1 commit
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Jens Axboe authored
Merge tag 'md-fixes-20231201-1' of https://git.kernel.org/pub/scm/linux/kernel/git/song/md into block-6.7 Pull MD fix from Song: "This change fixes issue with raid456 reshape." * tag 'md-fixes-20231201-1' of https://git.kernel.org/pub/scm/linux/kernel/git/song/md: md/raid6: use valid sector values to determine if an I/O should wait on the reshape
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- 01 Dec, 2023 4 commits
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David Jeffery authored
During a reshape or a RAID6 array such as expanding by adding an additional disk, I/Os to the region of the array which have not yet been reshaped can stall indefinitely. This is from errors in the stripe_ahead_of_reshape function causing md to think the I/O is to a region in the actively undergoing the reshape. stripe_ahead_of_reshape fails to account for the q disk having a sector value of 0. By not excluding the q disk from the for loop, raid6 will always generate a min_sector value of 0, causing a return value which stalls. The function's max_sector calculation also uses min() when it should use max(), causing the max_sector value to always be 0. During a backwards rebuild this can cause the opposite problem where it allows I/O to advance when it should wait. Fixing these errors will allow safe I/O to advance in a timely manner and delay only I/O which is unsafe due to stripes in the middle of undergoing the reshape. Fixes: 486f6055 ("md/raid5: Check all disks in a stripe_head for reshape progress") Cc: stable@vger.kernel.org # v6.0+ Signed-off-by:
David Jeffery <djeffery@redhat.com> Tested-by:
Laurence Oberman <loberman@redhat.com> Signed-off-by:
Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20231128181233.6187-1-djeffery@redhat.com
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git://git.infradead.org/nvmeJens Axboe authored
Pull NVMe fixes from Keith: "nvme fixes for Linux 6.7 - Invalid namespace identification error handling (Marizio Ewan, Keith) - Fabrics keep-alive tuning (Mark)" * tag 'nvme-6.7-2023-12-01' of git://git.infradead.org/nvme: nvme-core: check for too small lba shift nvme: check for valid nvme_identify_ns() before using it nvme-core: fix a memory leak in nvme_ns_info_from_identify() nvme: fine-tune sending of first keep-alive
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Keith Busch authored
The block layer doesn't support logical block sizes smaller than 512 bytes. The nvme spec doesn't support that small either, but the driver isn't checking to make sure the device responded with usable data. Failing to catch this will result in a kernel bug, either from a division by zero when stacking, or a zero length bio. Reviewed-by:
Jens Axboe <axboe@kernel.dk> Signed-off-by:
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Ming Lei authored
Request queue quiesce may interrupt flush sequence, and the original request may have been marked as COMPLETE, but can't get finished because of queue quiesce. This way is fine from driver viewpoint, because flush sequence is block layer concept, and it isn't related with driver. However, driver(such as dm-rq) can call blk_mq_queue_inflight() to count & drain inflight requests, then the wait & drain never gets done because the completed & not-finished flush request is counted as inflight. Fix this issue by not counting completed flush data request as inflight in case of quiesce. Cc: Mike Snitzer <snitzer@kernel.org> Cc: David Jeffery <djeffery@redhat.com> Cc: John Pittman <jpittman@redhat.com> Signed-off-by:
Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20231201085605.577730-1-ming.lei@redhat.comSigned-off-by:
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- 29 Nov, 2023 1 commit
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Bart Van Assche authored
It is nontrivial to derive the role of the two attribute groups in source file block/blk-sysfs.c. Hence add a comment that explains their roles. See also commit 6d85ebf9 ("blk-sysfs: add a new attr_group for blk_mq"). Cc: Christoph Hellwig <hch@lst.de> Cc: Yu Kuai <yukuai3@huawei.com> Signed-off-by:
Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20231128194019.72762-1-bvanassche@acm.orgSigned-off-by:
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- 28 Nov, 2023 2 commits
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Yu Kuai authored
Commit 1b0a151c ("blk-core: use pr_warn_ratelimited() in bio_check_ro()") fix message storm by limit the rate, however, there will still be lots of message in the long term. Fix it better by warn once for each partition. Signed-off-by:
Yu Kuai <yukuai3@huawei.com> Signed-off-by:
Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20231128123027.971610-3-yukuai1@huaweicloud.comSigned-off-by:
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Ming Lei authored
The .bd_inode field of block_device is used in IO fast path of blkdev_write_iter() and blkdev_llseek(), so it is more efficient to keep it into the 1st cacheline. .bd_openers is only touched in open()/close(), and .bd_size_lock is only for updating bdev capacity, which is in slow path too. So swap .bd_inode layout with .bd_openers & .bd_size_lock to move .bd_inode into the 1st cache line. Cc: Yu Kuai <yukuai3@huawei.com> Signed-off-by:
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- 27 Nov, 2023 3 commits
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Ewan D. Milne authored
When scanning namespaces, it is possible to get valid data from the first call to nvme_identify_ns() in nvme_alloc_ns(), but not from the second call in nvme_update_ns_info_block(). In particular, if the NSID becomes inactive between the two commands, a storage device may return a buffer filled with zero as per 4.1.5.1. In this case, we can get a kernel crash due to a divide-by-zero in blk_stack_limits() because ns->lba_shift will be set to zero. PID: 326 TASK: ffff95fec3cd8000 CPU: 29 COMMAND: "kworker/u98:10" #0 [ffffad8f8702f9e0] machine_kexec at ffffffff91c76ec7 #1 [ffffad8f8702fa38] __crash_kexec at ffffffff91dea4fa #2 [ffffad8f8702faf8] crash_kexec at ffffffff91deb788 #3 [ffffad8f8702fb00] oops_end at ffffffff91c2e4bb #4 [ffffad8f8702fb20] do_trap at ffffffff91c2a4ce #5 [ffffad8f8702fb70] do_error_trap at ffffffff91c2a595 #6 [ffffad8f8702fbb0] exc_divide_error at ffffffff928506e6 #7 [ffffad8f8702fbd0] asm_exc_divide_error at ffffffff92a00926 [exception RIP: blk_stack_limits+434] RIP: ffffffff92191872 RSP: ffffad8f8702fc80 RFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff95efa0c91800 RCX: 0000000000000001 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001 RBP: 00000000ffffffff R8: ffff95fec7df35a8 R9: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: ffff95fed33c09a8 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 #8 [ffffad8f8702fce0] nvme_update_ns_info_block at ffffffffc06d3533 [nvme_core] #9 [ffffad8f8702fd18] nvme_scan_ns at ffffffffc06d6fa7 [nvme_core] This happened when the check for valid data was moved out of nvme_identify_ns() into one of the callers. Fix this by checking in both callers. Link: https://bugzilla.kernel.org/show_bug.cgi?id=218186 Fixes: 0dd6fff2 ("nvme: bring back auto-removal of deleted namespaces during sequential scan") Cc: stable@vger.kernel.org Signed-off-by:Ewan D. Milne <emilne@redhat.com> Signed-off-by:
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Maurizio Lombardi authored
In case of error, free the nvme_id_ns structure that was allocated by nvme_identify_ns(). Signed-off-by:
Maurizio Lombardi <mlombard@redhat.com> Reviewed-by:
Kanchan Joshi <joshi.k@samsung.com> Signed-off-by:
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Mark O'Donovan authored
Keep-alive commands are sent half-way through the kato period. This normally works well but fails when the keep-alive system is started when we are more than half way through the kato. This can happen on larger setups or due to host delays. With this change we now time the initial keep-alive command from the controller initialisation time, rather than the keep-alive mechanism activation time. Signed-off-by:
Mark O'Donovan <shiftee@posteo.net> Reviewed-by:
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- 24 Nov, 2023 1 commit
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Markus Weippert authored
Commit 028ddcac ("bcache: Remove unnecessary NULL point check in node allocations") replaced IS_ERR_OR_NULL by IS_ERR. This leads to a NULL pointer dereference. BUG: kernel NULL pointer dereference, address: 0000000000000080 Call Trace: ? __die_body.cold+0x1a/0x1f ? page_fault_oops+0xd2/0x2b0 ? exc_page_fault+0x70/0x170 ? asm_exc_page_fault+0x22/0x30 ? btree_node_free+0xf/0x160 [bcache] ? up_write+0x32/0x60 btree_gc_coalesce+0x2aa/0x890 [bcache] ? bch_extent_bad+0x70/0x170 [bcache] btree_gc_recurse+0x130/0x390 [bcache] ? btree_gc_mark_node+0x72/0x230 [bcache] bch_btree_gc+0x5da/0x600 [bcache] ? cpuusage_read+0x10/0x10 ? bch_btree_gc+0x600/0x600 [bcache] bch_gc_thread+0x135/0x180 [bcache] The relevant code starts with: new_nodes[0] = NULL; for (i = 0; i < nodes; i++) { if (__bch_keylist_realloc(&keylist, bkey_u64s(&r[i].b->key))) goto out_nocoalesce; // ... out_nocoalesce: // ... for (i = 0; i < nodes; i++) if (!IS_ERR(new_nodes[i])) { // IS_ERR_OR_NULL before 028ddcac btree_node_free(new_nodes[i]); // new_nodes[0] is NULL rw_unlock(true, new_nodes[i]); } This patch replaces IS_ERR() by IS_ERR_OR_NULL() to fix this. Fixes: 028ddcac ("bcache: Remove unnecessary NULL point check in node allocations") Link: https://lore.kernel.org/all/3DF4A87A-2AC1-4893-AE5F-E921478419A9@suse.de/ Cc: stable@vger.kernel.org Cc: Zheng Wang <zyytlz.wz@163.com> Cc: Coly Li <colyli@suse.de> Signed-off-by:
Markus Weippert <markus@gekmihesg.de> Signed-off-by:
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- 23 Nov, 2023 3 commits
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Arnd Bergmann authored
When CONFIG_NVME_KEYRING is enabled as a loadable module, but the TCP host code is built-in, it fails to link: arm-linux-gnueabi-ld: drivers/nvme/host/tcp.o: in function `nvme_tcp_setup_ctrl': tcp.c:(.text+0x1940): undefined reference to `nvme_tls_psk_default' The problem is that the compile-time conditionals are inconsistent here, using a mix of #ifdef CONFIG_NVME_TCP_TLS, IS_ENABLED(CONFIG_NVME_TCP_TLS) and IS_ENABLED(CONFIG_NVME_KEYRING) checks, with CONFIG_NVME_KEYRING controlling whether the implementation is actually built. Change it to use IS_ENABLED(CONFIG_NVME_KEYRING) checks consistently, which should help readability and make it less error-prone. Combining it with the check for the ctrl->opts->tls flag lets the compiler drop all the TLS code in configurations without this feature, which also helps runtime behavior in addition to avoiding the link failure. To make it possible for the compiler to build the dead code, both the tls_handshake_timeout variable and the TLS specific members of nvme_tcp_queue need to be moved out of the #ifdef block as well, but at least the former of these gets optimized out again. Signed-off-by:
Arnd Bergmann <arnd@arndb.de> Link: https://lore.kernel.org/r/20231122224719.4042108-4-arnd@kernel.orgSigned-off-by:
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Arnd Bergmann authored
When the NVME target code is built-in but its TCP frontend is a loadable module, enabling keyring support causes a link failure: x86_64-linux-ld: vmlinux.o: in function `nvmet_ports_make': configfs.c:(.text+0x100a2110): undefined reference to `nvme_keyring_id' The problem is that CONFIG_NVME_TARGET_TCP_TLS is a 'bool' symbol that depends on the tristate CONFIG_NVME_TARGET_TCP, so any 'select' from it inherits the state of the tristate symbol rather than the intended CONFIG_NVME_TARGET one that contains the actual call. The same thing is true for CONFIG_KEYS, which itself is required for NVME_KEYRING. Signed-off-by:
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Arnd Bergmann authored
In configurations without CONFIG_NVME_TARGET_TCP_TLS, the keyring code might not be available, or using it will result in a runtime failure: x86_64-linux-ld: vmlinux.o: in function `nvmet_ports_make': configfs.c:(.text+0x100a2110): undefined reference to `nvme_keyring_id' Add a check to ensure we only check the keyring if there is a chance of it being used, which avoids both the runtime and link-time problems. Signed-off-by:
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- 22 Nov, 2023 2 commits
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git://git.infradead.org/nvmeJens Axboe authored
Pull NVMe fixes from Keith: "nvme fixes for Linux 6.7 - TCP TLS fixes (Hannes) - Authentifaction fixes (Mark, Hannes) - Properly terminate target names (Christoph)" * tag 'nvme-6.7-2023-11-22' of git://git.infradead.org/nvme: nvme: move nvme_stop_keep_alive() back to original position nvmet-tcp: always initialize tls_handshake_tmo_work nvmet: nul-terminate the NQNs passed in the connect command nvme: blank out authentication fabrics options if not configured nvme: catch errors from nvme_configure_metadata() nvme-tcp: only evaluate 'tls' option if TLS is selected nvme-auth: set explanation code for failure2 msgs nvme-auth: unlock mutex in one place only
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Hannes Reinecke authored
Stopping keep-alive not only stops the keep-alive workqueue, but also needs to be synchronized with I/O termination as we must not send a keep-alive command after all I/O had been terminated. So to avoid any regressions move the call to stop_keep_alive() back to its original position and ensure that keep-alive is correctly stopped failing to setup the admin queue. Fixes: 4733b65d ("nvme: start keep-alive after admin queue setup") Suggested-by:
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- 21 Nov, 2023 1 commit
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Li Nan authored
If a socket is processing ioctl 'NBD_SET_SOCK', config->socks might be krealloc in nbd_add_socket(), and a garbage request is received now, a UAF may occurs. T1 nbd_ioctl __nbd_ioctl nbd_add_socket blk_mq_freeze_queue T2 recv_work nbd_read_reply sock_xmit krealloc config->socks def config->socks Pass nbd_sock to nbd_read_reply(). And introduce a new function sock_xmit_recv(), which differs from sock_xmit only in the way it get socket. ================================================================== BUG: KASAN: use-after-free in sock_xmit+0x525/0x550 Read of size 8 at addr ffff8880188ec428 by task kworker/u12:1/18779 Workqueue: knbd4-recv recv_work Call Trace: __dump_stack dump_stack+0xbe/0xfd print_address_description.constprop.0+0x19/0x170 __kasan_report.cold+0x6c/0x84 kasan_report+0x3a/0x50 sock_xmit+0x525/0x550 nbd_read_reply+0xfe/0x2c0 recv_work+0x1c2/0x750 process_one_work+0x6b6/0xf10 worker_thread+0xdd/0xd80 kthread+0x30a/0x410 ret_from_fork+0x22/0x30 Allocated by task 18784: kasan_save_stack+0x1b/0x40 kasan_set_track set_alloc_info __kasan_kmalloc __kasan_kmalloc.constprop.0+0xf0/0x130 slab_post_alloc_hook slab_alloc_node slab_alloc __kmalloc_track_caller+0x157/0x550 __do_krealloc krealloc+0x37/0xb0 nbd_add_socket +0x2d3/0x880 __nbd_ioctl nbd_ioctl+0x584/0x8e0 __blkdev_driver_ioctl blkdev_ioctl+0x2a0/0x6e0 block_ioctl+0xee/0x130 vfs_ioctl __do_sys_ioctl __se_sys_ioctl+0x138/0x190 do_syscall_64+0x33/0x40 entry_SYSCALL_64_after_hwframe+0x61/0xc6 Freed by task 18784: kasan_save_stack+0x1b/0x40 kasan_set_track+0x1c/0x30 kasan_set_free_info+0x20/0x40 __kasan_slab_free.part.0+0x13f/0x1b0 slab_free_hook slab_free_freelist_hook slab_free kfree+0xcb/0x6c0 krealloc+0x56/0xb0 nbd_add_socket+0x2d3/0x880 __nbd_ioctl nbd_ioctl+0x584/0x8e0 __blkdev_driver_ioctl blkdev_ioctl+0x2a0/0x6e0 block_ioctl+0xee/0x130 vfs_ioctl __do_sys_ioctl __se_sys_ioctl+0x138/0x190 do_syscall_64+0x33/0x40 entry_SYSCALL_64_after_hwframe+0x61/0xc6 Signed-off-by:Li Nan <linan122@huawei.com> Reviewed-by:
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- 20 Nov, 2023 20 commits
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Jan Höppner authored
In dasd_profile_start() the amount of requests on the device queue are counted. The access to the device queue is unprotected against concurrent access. With a lot of parallel I/O, especially with alias devices enabled, the device queue can change while dasd_profile_start() is accessing the queue. In the worst case this leads to a kernel panic due to incorrect pointer accesses. Fix this by taking the device lock before accessing the queue and counting the requests. Additionally the check for a valid profile data pointer can be done earlier to avoid unnecessary locking in a hot path. Cc: <stable@vger.kernel.org> Fixes: 4fa52aa7 ("[S390] dasd: add enhanced DASD statistics interface") Reviewed-by:
Stefan Haberland <sth@linux.ibm.com> Signed-off-by:
Jan Höppner <hoeppner@linux.ibm.com> Signed-off-by:
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Muhammad Muzammil authored
resolve typing mistake from pimary to primary Signed-off-by:
Muhammad Muzammil <m.muzzammilashraf@gmail.com> Link: https://lore.kernel.org/r/20231010043140.28416-1-m.muzzammilashraf@gmail.comSigned-off-by:
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Chengming Zhou authored
When CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION is enabled, null_queue_rq() would return BLK_STS_RESOURCE or BLK_STS_DEV_RESOURCE for the request, which has been marked as MQ_RQ_IN_FLIGHT by blk_mq_start_request(). Then null_queue_rqs() put these requests in the rqlist, return back to the block layer core, which would try to queue them individually again, so the warning in blk_mq_start_request() triggered. Fix it by splitting the null_queue_rq() into two parts: the first is the preparation of request, the second is the handling of request. We put the blk_mq_start_request() after the preparation part, which may fail and return back to the block layer core. The throttling also belongs to the preparation part, so move it before blk_mq_start_request(). And change the return type of null_handle_cmd() to void, since it always return BLK_STS_OK now. Reported-by:
<syzbot+fcc47ba2476570cbbeb0@syzkaller.appspotmail.com> Closes: https://lore.kernel.org/all/0000000000000e6aac06098aee0c@google.com/ Fixes: d78bfa13 ("block/null_blk: add queue_rqs() support") Suggested-by:
Chengming Zhou <zhouchengming@bytedance.com> Link: https://lore.kernel.org/r/20231120032521.1012037-1-chengming.zhou@linux.devSigned-off-by:
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Hannes Reinecke authored
The TLS handshake timeout work item should always be initialized to avoid a crash when cancelling the workqueue. Fixes: 675b453e ("nvmet-tcp: enable TLS handshake upcall") Suggested-by:
Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com> Tested-by:
Yi Zhang <yi.zhang@redhat.com> Reviewed-by:
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Christoph Hellwig authored
The host and subsystem NQNs are passed in the connect command payload and interpreted as nul-terminated strings. Ensure they actually are nul-terminated before using them. Fixes: a07b4970 "nvmet: add a generic NVMe target") Reported-by:
Alon Zahavi <zahavi.alon@gmail.com> Reviewed-by:
Chaitanya Kulkarni <kch@nvidia.com> Signed-off-by:
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Hannes Reinecke authored
If the config option NVME_HOST_AUTH is not selected we should not accept the corresponding fabrics options. This allows userspace to detect if NVMe authentication has been enabled for the kernel. Cc: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com> Fixes: f50fff73 ("nvme: implement In-Band authentication") Signed-off-by:
Daniel Wagner <dwagner@suse.de> Reviewed-by:
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Hannes Reinecke authored
nvme_configure_metadata() is issuing I/O, so we might incur an I/O error which will cause the connection to be reset. But in that case any further probing will race with reset and cause UAF errors. So return a status from nvme_configure_metadata() and abort probing if there was an I/O error. Signed-off-by:
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Hannes Reinecke authored
We only need to evaluate the 'tls' connect option if TLS is enabled; otherwise we might be getting a link error. Fixes: 706add13 ("nvme: keyring: fix conditional compilation") Reported-by:
kernel test robot <yujie.liu@intel.com> Closes: https://lore.kernel.org/r/202311140426.0eHrTXBr-lkp@intel.com/Signed-off-by:
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Mark O'Donovan authored
Some error cases were not setting an auth-failure-reason-code-explanation. This means an AUTH_Failure2 message will be sent with an explanation value of 0 which is a reserved value. Signed-off-by:
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Mark O'Donovan authored
Signed-off-by:
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Damien Le Moal authored
The function blk_set_runtime_active() is called only from blk_post_runtime_resume(), so there is no need for that function to be exported. Open-code this function directly in blk_post_runtime_resume() and remove it. Signed-off-by:
Damien Le Moal <dlemoal@kernel.org> Reviewed-by:
Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20231120070611.33951-1-dlemoal@kernel.orgSigned-off-by:
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Li Nan authored
Memory reordering may occur in nbd_genl_connect(), causing config_refs to be set to 1 while nbd->config is still empty. Opening nbd at this time will cause null-ptr-dereference. T1 T2 nbd_open nbd_get_config_unlocked nbd_genl_connect nbd_alloc_and_init_config //memory reordered refcount_set(&nbd->config_refs, 1) // 2 nbd->config ->null point nbd->config = config // 1 Fix it by adding smp barrier to guarantee the execution sequence. Signed-off-by:Josef Bacik <josef@toxicpanda.com> Link: https://lore.kernel.org/r/20231116162316.1740402-4-linan666@huaweicloud.comSigned-off-by:
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Li Nan authored
There are no functional changes, just to make code cleaner and prepare to fix null-ptr-dereference while accessing 'nbd->config'. Signed-off-by:
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Li Nan authored
There are no functional changes, make the code cleaner and prepare to fix null-ptr-dereference while accessing 'nbd->config'. Signed-off-by:
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Jens Axboe authored
Merge tag 'md-fixes-20231120' of https://git.kernel.org/pub/scm/linux/kernel/git/song/md into block-6.7 Pull MD fix from Song. * tag 'md-fixes-20231120' of https://git.kernel.org/pub/scm/linux/kernel/git/song/md: md: fix bi_status reporting in md_end_clone_io
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Coly Li authored
In run_cache_set() after c->root returned from bch_btree_node_get(), it is checked by IS_ERR_OR_NULL(). Indeed it is unncessary to check NULL because bch_btree_node_get() will not return NULL pointer to caller. This patch replaces IS_ERR_OR_NULL() by IS_ERR() for the above reason. Signed-off-by:
Coly Li <colyli@suse.de> Link: https://lore.kernel.org/r/20231120052503.6122-11-colyli@suse.deSigned-off-by:
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Coly Li authored
This patch adds code comments to bch_btree_node_get() and __bch_btree_node_alloc() that NULL pointer will not be returned and it is unnecessary to check NULL pointer by the callers of these routines. Signed-off-by:
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Coly Li authored
Commit 028ddcac ("bcache: Remove unnecessary NULL point check in node allocations") do the following change inside btree_gc_coalesce(), 31 @@ -1340,7 +1340,7 @@ static int btree_gc_coalesce( 32 memset(new_nodes, 0, sizeof(new_nodes)); 33 closure_init_stack(&cl); 34 35 - while (nodes < GC_MERGE_NODES && !IS_ERR_OR_NULL(r[nodes].b)) 36 + while (nodes < GC_MERGE_NODES && !IS_ERR(r[nodes].b)) 37 keys += r[nodes++].keys; 38 39 blocks = btree_default_blocks(b->c) * 2 / 3; At line 35 the original r[nodes].b is not always allocatored from __bch_btree_node_alloc(), and possibly initialized as NULL pointer by caller of btree_gc_coalesce(). Therefore the change at line 36 is not correct. This patch replaces the mistaken IS_ERR() by IS_ERR_OR_NULL() to avoid potential issue. Fixes: 028ddcac ("bcache: Remove unnecessary NULL point check in node allocations") Cc: <stable@vger.kernel.org> # 6.5+ Cc: Zheng Wang <zyytlz.wz@163.com> Signed-off-by:
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Mingzhe Zou authored
We get a kernel crash about "unable to handle kernel paging request": ```dmesg [368033.032005] BUG: unable to handle kernel paging request at ffffffffad9ae4b5 [368033.032007] PGD fc3a0d067 P4D fc3a0d067 PUD fc3a0e063 PMD 8000000fc38000e1 [368033.032012] Oops: 0003 [#1] SMP PTI [368033.032015] CPU: 23 PID: 55090 Comm: bch_dirtcnt[0] Kdump: loaded Tainted: G OE --------- - - 4.18.0-147.5.1.es8_24.x86_64 #1 [368033.032017] Hardware name: Tsinghua Tongfang THTF Chaoqiang Server/072T6D, BIOS 2.4.3 01/17/2017 [368033.032027] RIP: 0010:native_queued_spin_lock_slowpath+0x183/0x1d0 [368033.032029] Code: 8b 02 48 85 c0 74 f6 48 89 c1 eb d0 c1 e9 12 83 e0 03 83 e9 01 48 c1 e0 05 48 63 c9 48 05 c0 3d 02 00 48 03 04 cd 60 68 93 ad <48> 89 10 8b 42 08 85 c0 75 09 f3 90 8b 42 08 85 c0 74 f7 48 8b 02 [368033.032031] RSP: 0018:ffffbb48852abe00 EFLAGS: 00010082 [368033.032032] RAX: ffffffffad9ae4b5 RBX: 0000000000000246 RCX: 0000000000003bf3 [368033.032033] RDX: ffff97b0ff8e3dc0 RSI: 0000000000600000 RDI: ffffbb4884743c68 [368033.032034] RBP: 0000000000000001 R08: 0000000000000000 R09: 000007ffffffffff [368033.032035] R10: ffffbb486bb01000 R11: 0000000000000001 R12: ffffffffc068da70 [368033.032036] R13: 0000000000000003 R14: 0000000000000000 R15: 0000000000000000 [368033.032038] FS: 0000000000000000(0000) GS:ffff97b0ff8c0000(0000) knlGS:0000000000000000 [368033.032039] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [368033.032040] CR2: ffffffffad9ae4b5 CR3: 0000000fc3a0a002 CR4: 00000000003626e0 [368033.032042] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [368033.032043] bcache: bch_cached_dev_attach() Caching rbd479 as bcache462 on set 8cff3c36-4a76-4242-afaa-7630206bc70b [368033.032045] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [368033.032046] Call Trace: [368033.032054] _raw_spin_lock_irqsave+0x32/0x40 [368033.032061] __wake_up_common_lock+0x63/0xc0 [368033.032073] ? bch_ptr_invalid+0x10/0x10 [bcache] [368033.033502] bch_dirty_init_thread+0x14c/0x160 [bcache] [368033.033511] ? read_dirty_submit+0x60/0x60 [bcache] [368033.033516] kthread+0x112/0x130 [368033.033520] ? kthread_flush_work_fn+0x10/0x10 [368033.034505] ret_from_fork+0x35/0x40 ``` The crash occurred when call wake_up(&state->wait), and then we want to look at the value in the state. However, bch_sectors_dirty_init() is not found in the stack of any task. Since state is allocated on the stack, we guess that bch_sectors_dirty_init() has exited, causing bch_dirty_init_thread() to be unable to handle kernel paging request. In order to verify this idea, we added some printing information during wake_up(&state->wait). We find that "wake up" is printed twice, however we only expect the last thread to wake up once. ```dmesg [ 994.641004] alcache: bch_dirty_init_thread() wake up [ 994.641018] alcache: bch_dirty_init_thread() wake up [ 994.641523] alcache: bch_sectors_dirty_init() init exit ``` There is a race. If bch_sectors_dirty_init() exits after the first wake up, the second wake up will trigger this bug("unable to handle kernel paging request"). Proceed as follows: bch_sectors_dirty_init kthread_run ==============> bch_dirty_init_thread(bch_dirtcnt[0]) ... ... atomic_inc(&state.started) ... ... ... atomic_read(&state.enough) ... ... atomic_set(&state->enough, 1) kthread_run ======================================================> bch_dirty_init_thread(bch_dirtcnt[1]) ... atomic_dec_and_test(&state->started) ... atomic_inc(&state.started) ... ... ... wake_up(&state->wait) ... atomic_read(&state.enough) atomic_dec_and_test(&state->started) ... ... wait_event(state.wait, atomic_read(&state.started) == 0) ... return ... wake_up(&state->wait) We believe it is very common to wake up twice if there is no dirty, but crash is an extremely low probability event. It's hard for us to reproduce this issue. We attached and detached continuously for a week, with a total of more than one million attaches and only one crash. Putting atomic_inc(&state.started) before kthread_run() can avoid waking up twice. Fixes: b144e45f ("bcache: make bch_sectors_dirty_init() to be multithreaded") Signed-off-by:Mingzhe Zou <mingzhe.zou@easystack.cn> Cc: <stable@vger.kernel.org> Signed-off-by:
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Mingzhe Zou authored
We had a problem with io hung because it was waiting for c->root to release the lock. crash> cache_set.root -l cache_set.list ffffa03fde4c0050 root = 0xffff802ef454c800 crash> btree -o 0xffff802ef454c800 | grep rw_semaphore [ffff802ef454c858] struct rw_semaphore lock; crash> struct rw_semaphore ffff802ef454c858 struct rw_semaphore { count = { counter = -4294967297 }, wait_list = { next = 0xffff00006786fc28, prev = 0xffff00005d0efac8 }, wait_lock = { raw_lock = { { val = { counter = 0 }, { locked = 0 '\000', pending = 0 '\000' }, { locked_pending = 0, tail = 0 } } } }, osq = { tail = { counter = 0 } }, owner = 0xffffa03fdc586603 } The "counter = -4294967297" means that lock count is -1 and a write lock is being attempted. Then, we found that there is a btree with a counter of 1 in btree_cache_freeable. crash> cache_set -l cache_set.list ffffa03fde4c0050 -o|grep btree_cache [ffffa03fde4c1140] struct list_head btree_cache; [ffffa03fde4c1150] struct list_head btree_cache_freeable; [ffffa03fde4c1160] struct list_head btree_cache_freed; [ffffa03fde4c1170] unsigned int btree_cache_used; [ffffa03fde4c1178] wait_queue_head_t btree_cache_wait; [ffffa03fde4c1190] struct task_struct *btree_cache_alloc_lock; crash> list -H ffffa03fde4c1140|wc -l 973 crash> list -H ffffa03fde4c1150|wc -l 1123 crash> cache_set.btree_cache_used -l cache_set.list ffffa03fde4c0050 btree_cache_used = 2097 crash> list -s btree -l btree.list -H ffffa03fde4c1140|grep -E -A2 "^ lock = {" > btree_cache.txt crash> list -s btree -l btree.list -H ffffa03fde4c1150|grep -E -A2 "^ lock = {" > btree_cache_freeable.txt [root@node-3 127.0.0.1-2023-08-04-16:40:28]# pwd /var/crash/127.0.0.1-2023-08-04-16:40:28 [root@node-3 127.0.0.1-2023-08-04-16:40:28]# cat btree_cache.txt|grep counter|grep -v "counter = 0" [root@node-3 127.0.0.1-2023-08-04-16:40:28]# cat btree_cache_freeable.txt|grep counter|grep -v "counter = 0" counter = 1 We found that this is a bug in bch_sectors_dirty_init() when locking c->root: (1). Thread X has locked c->root(A) write. (2). Thread Y failed to lock c->root(A), waiting for the lock(c->root A). (3). Thread X bch_btree_set_root() changes c->root from A to B. (4). Thread X releases the lock(c->root A). (5). Thread Y successfully locks c->root(A). (6). Thread Y releases the lock(c->root B). down_write locked ---(1)----------------------┐ | | | down_read waiting ---(2)----┐ | | | ┌-------------┐ ┌-------------┐ bch_btree_set_root ===(3)========>> | c->root A | | c->root B | | | └-------------┘ └-------------┘ up_write ---(4)---------------------┘ | | | | | down_read locked ---(5)-----------┘ | | | up_read ---(6)-----------------------------┘ Since c->root may change, the correct steps to lock c->root should be the same as bch_root_usage(), compare after locking. static unsigned int bch_root_usage(struct cache_set *c) { unsigned int bytes = 0; struct bkey *k; struct btree *b; struct btree_iter iter; goto lock_root; do { rw_unlock(false, b); lock_root: b = c->root; rw_lock(false, b, b->level); } while (b != c->root); for_each_key_filter(&b->keys, k, &iter, bch_ptr_bad) bytes += bkey_bytes(k); rw_unlock(false, b); return (bytes * 100) / btree_bytes(c); } Fixes: b144e45f ("bcache: make bch_sectors_dirty_init() to be multithreaded") Signed-off-by:
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