svn commit: r363069 - head/sys/kern

Mateusz Guzik mjguzik at gmail.com
Fri Jul 10 09:04:37 UTC 2020


On 7/10/20, Peter Holm <pho at freebsd.org> wrote:
> On Fri, Jul 10, 2020 at 06:47:58AM +0000, Mateusz Guzik wrote:
>> Author: mjg
>> Date: Fri Jul 10 06:47:58 2020
>> New Revision: 363069
>> URL: https://svnweb.freebsd.org/changeset/base/363069
>>
>> Log:
>>   vfs: depessimize getfsstat when only the count is requested
>>
>>   This avoids relocking mountlist_mtx for each entry.
>>
>> Modified:
>>   head/sys/kern/vfs_syscalls.c
>>
>> Modified: head/sys/kern/vfs_syscalls.c
>> ==============================================================================
>> --- head/sys/kern/vfs_syscalls.c	Fri Jul 10 06:46:42 2020	(r363068)
>
> Could this one be yours?
>
> 20200710 09:46:31 all (267/723): procfs.sh
> panic: lock (sleep mutex) mountlist not locked @ kern/vfs_syscalls.c:561
> cpuid = 4
> time = 1594367192
> KDB: stack backtrace:
> db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame
> 0xfffffe00377a6910
> vpanic() at vpanic+0x182/frame 0xfffffe00377a6960
> panic() at panic+0x43/frame 0xfffffe00377a69c0
> witness_unlock() at witness_unlock+0x147/frame 0xfffffe00377a6a00
> __mtx_unlock_flags() at __mtx_unlock_flags+0x4d/frame 0xfffffe00377a6a30
> kern_getfsstat() at kern_getfsstat+0x40b/frame 0xfffffe00377a6ab0
> sys_getfsstat() at sys_getfsstat+0x22/frame 0xfffffe00377a6ad0
> amd64_syscall() at amd64_syscall+0x159/frame 0xfffffe00377a6bf0
> fast_syscall_common() at fast_syscall_common+0x101/frame 0xfffffe00377a6bf0
> --- syscall (557, FreeBSD ELF64, sys_getfsstat), rip = 0x80032db1a, rsp =
> 0x7fffffffd738, rbp = 0x7fffffffd790 ---
> KDB: enter: panic
>
> https://people.freebsd.org/~pho/stress/log/mjguzik030.txt
>

Does this fix it for you?

diff --git a/sys/kern/vfs_syscalls.c b/sys/kern/vfs_syscalls.c
index f37a54809e24..2caf09f3412c 100644
--- a/sys/kern/vfs_syscalls.c
+++ b/sys/kern/vfs_syscalls.c
@@ -551,7 +551,7 @@ kern_getfsstat(struct thread *td, struct statfs
**buf, size_t bufsize,

                if (count == maxcount) {
                        vfs_unbusy(mp);
-                       break;
+                       goto out;
                }

                mtx_lock(&mountlist_mtx);

-- 
Mateusz Guzik <mjguzik gmail.com>


More information about the svn-src-head mailing list