Cheng Lin 353b19562a nfs_common: need lock during iterate through the list ... [ Upstream commit 4a9d81caf8 ] If the elem is deleted during be iterated on it, the iteration process will fall into an endless loop. kernel: NMI watchdog: BUG: soft lockup - CPU#4 stuck for 22s! [nfsd:17137] PID: 17137  TASK: ffff8818d93c0000  CPU: 4   COMMAND: "nfsd"     [exception RIP: __state_in_grace+76]     RIP: ffffffffc00e817c  RSP: ffff8818d3aefc98  RFLAGS: 00000246     RAX: ffff881dc0c38298  RBX: ffffffff81b03580  RCX: ffff881dc02c9f50     RDX: ffff881e3fce8500  RSI: 0000000000000001  RDI: ffffffff81b03580     RBP: ffff8818d3aefca0   R8: 0000000000000020   R9: ffff8818d3aefd40     R10: ffff88017fc03800  R11: ffff8818e83933c0  R12: ffff8818d3aefd40     R13: 0000000000000000  R14: ffff8818e8391068  R15: ffff8818fa6e4000     CS: 0010  SS: 0018  #0 [ffff8818d3aefc98] opens_in_grace at ffffffffc00e81e3 [grace]  #1 [ffff8818d3aefca8] nfs4_preprocess_stateid_op at ffffffffc02a3e6c [nfsd]  #2 [ffff8818d3aefd18] nfsd4_write at ffffffffc028ed5b [nfsd]  #3 [ffff8818d3aefd80] nfsd4_proc_compound at ffffffffc0290a0d [nfsd]  #4 [ffff8818d3aefdd0] nfsd_dispatch at ffffffffc027b800 [nfsd]  #5 [ffff8818d3aefe08] svc_process_common at ffffffffc02017f3 [sunrpc]  #6 [ffff8818d3aefe70] svc_process at ffffffffc0201ce3 [sunrpc]  #7 [ffff8818d3aefe98] nfsd at ffffffffc027b117 [nfsd]  #8 [ffff8818d3aefec8] kthread at ffffffff810b88c1  #9 [ffff8818d3aeff50] ret_from_fork at ffffffff816d1607 The troublemake elem: crash> lock_manager ffff881dc0c38298 struct lock_manager {   list = {     next = 0xffff881dc0c38298,     prev = 0xffff881dc0c38298   },   block_opens = false } Fixes: c87fb4a378 ("lockd: NLM grace period shouldn't block NFSv4 opens") Signed-off-by: Cheng Lin <cheng.lin130@zte.com.cn> Signed-off-by: Yi Wang <wang.yi59@zte.com.cn> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>		2020-12-30 11:51:22 +01:00
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grace.c	nfs_common: need lock during iterate through the list	2020-12-30 11:51:22 +01:00
Makefile
nfsacl.c