getdirtybuf()'s kdb_backtrace fired

[Steve Watt]

A number of times yesterday.  That's a first on this system, though
I've seen the lock order reversal problem with ffs suspend vs fsync().

Anyhoo, the traces:

Aug  9 15:08:26 wattres kernel: KDB: stack backtrace:
> kdb_backtrace(c0931dd8,2,c5afb0cc,0,22) at kdb_backtrace+0x2f
> getdirtybuf(d0287bac,0,1,c5afb0cc,1) at getdirtybuf+0x28
> flush_deplist(c253c94c,1,d0287bd4,d0287bd8,0) at flush_deplist+0x4a
> flush_inodedep_deps(c15ee800,33c24,8,c08b2c61,c27d4c60) at flush_inodedep_deps+0x98
> softdep_sync_metadata(d0287c98,0,c08b2c61,137,0) at softdep_sync_metadata+0x95
> ffs_fsync(d0287c98,0,c08a5b1c,bd5,0) at ffs_fsync+0x3c0
> fsync(c1dbb780,d0287d04,c08bb2dd,3e7,1) at fsync+0x15a
> syscall(2f,2f,2f,bfbfabb0,bfbfaba8) at syscall+0x291
> Xint0x80_syscall() at Xint0x80_syscall+0x1f
> --- syscall (95, FreeBSD ELF32, fsync), eip = 0x282cb56b, esp = 0xbfbfab7c, ebp = 0xbfbfb468 ---

Aug  9 15:08:27 wattres kernel: KDB: stack backtrace:
> kdb_backtrace(c0931dd8,2,c5b27030,0,22) at kdb_backtrace+0x2f
> getdirtybuf(d05e3bac,0,1,c5b27030,1) at getdirtybuf+0x28
> flush_deplist(c29e42cc,1,d05e3bd4,d05e3bd8,0) at flush_deplist+0x4a
> flush_inodedep_deps(c15ee800,33c26,8,c08b2c61,c21f3000) at flush_inodedep_deps+0x98
> softdep_sync_metadata(d05e3c98,0,c08b2c61,137,0) at softdep_sync_metadata+0x95
> ffs_fsync(d05e3c98,0,c08a5b1c,bd5,0) at ffs_fsync+0x3c0
> fsync(c2adfc00,d05e3d04,c08bb2dd,3e7,1) at fsync+0x15a
> syscall(2f,2f,2f,bfbfabb0,bfbfaba8) at syscall+0x291
> Xint0x80_syscall() at Xint0x80_syscall+0x1f
> --- syscall (95, FreeBSD ELF32, fsync), eip = 0x282cb56b, esp = 0xbfbfab7c, ebp = 0xbfbfb468 ---

Aug  9 15:08:27 wattres kernel: KDB: stack backtrace:
> kdb_backtrace(c0931dd8,2,c5b5f6d8,0,22) at kdb_backtrace+0x2f
> getdirtybuf(cf873bac,0,1,c5b5f6d8,1) at getdirtybuf+0x28
> flush_deplist(c2a71ecc,1,cf873bd4,cf873bd8,0) at flush_deplist+0x4a
> flush_inodedep_deps(c15ee800,33c28,8,c08b2c61,c234b420) at flush_inodedep_deps+0x98
> softdep_sync_metadata(cf873c98,0,c08b2c61,137,0) at softdep_sync_metadata+0x95
> ffs_fsync(cf873c98,0,c08a5b1c,bd5,0) at ffs_fsync+0x3c0
> fsync(c1670000,cf873d04,c08bb2dd,3e7,1) at fsync+0x15a
> syscall(2f,2f,2f,bfbfabb0,bfbfaba8) at syscall+0x291
> Xint0x80_syscall() at Xint0x80_syscall+0x1f
> --- syscall (95, FreeBSD ELF32, fsync), eip = 0x282cb56b, esp = 0xbfbfab7c, ebp = 0xbfbfb468 ---

Aug  9 15:10:16 wattres kernel: KDB: stack backtrace:
> kdb_backtrace(c0931dd8,2,c5b50f38,0,22) at kdb_backtrace+0x2f
> getdirtybuf(d02d6bac,0,1,c5b50f38,1) at getdirtybuf+0x28
> flush_deplist(c24860cc,1,d02d6bd4,d02d6bd8,0) at flush_deplist+0x4a
> flush_inodedep_deps(c15ee800,33cff,8,c08b2c61,c177a840) at flush_inodedep_deps+0x98
> softdep_sync_metadata(d02d6c98,0,c08b2c61,137,0) at softdep_sync_metadata+0x95
> ffs_fsync(d02d6c98,0,c08a5b1c,bd5,0) at ffs_fsync+0x3c0
> fsync(c179c780,d02d6d04,c08bb2dd,3e7,1) at fsync+0x15a
> syscall(2f,2f,2f,bfbfc630,bfbfc628) at syscall+0x291
> Xint0x80_syscall() at Xint0x80_syscall+0x1f
> --- syscall (95, FreeBSD ELF32, fsync), eip = 0x282cb56b, esp = 0xbfbfc5fc, ebp = 0xbfbfcee8 ---

Aug  9 15:10:52 wattres kernel: KDB: stack backtrace:
> kdb_backtrace(c0931dd8,2,c5b46d6c,0,22) at kdb_backtrace+0x2f
> getdirtybuf(d018cbac,0,1,c5b46d6c,1) at getdirtybuf+0x28
> flush_deplist(c229394c,1,d018cbd4,d018cbd8,0) at flush_deplist+0x4a
> flush_inodedep_deps(c15ee800,33cc1,8,c08b2c61,c1f69b58) at flush_inodedep_deps+0x98
> softdep_sync_metadata(d018cc98,0,c08b2c61,137,0) at softdep_sync_metadata+0x95
> ffs_fsync(d018cc98,0,c08a5b1c,bd5,0) at ffs_fsync+0x3c0
> fsync(c1b21300,d018cd04,c08bb2dd,3e7,1) at fsync+0x15a
> syscall(2f,2f,2f,810f560,0) at syscall+0x291
> Xint0x80_syscall() at Xint0x80_syscall+0x1f
> --- syscall (95, FreeBSD ELF32, fsync), eip = 0x282cb56b, esp = 0xbfbf94fc, ebp = 0xbfbfaed8 ---

Aug  9 15:11:10 wattres kernel: KDB: stack backtrace:
> kdb_backtrace(c0931dd8,2,c5b3a10c,0,22) at kdb_backtrace+0x2f
> getdirtybuf(d0327bac,0,1,c5b3a10c,1) at getdirtybuf+0x28
> flush_deplist(c2a7184c,1,d0327bd4,d0327bd8,0) at flush_deplist+0x4a
> flush_inodedep_deps(c15ee800,33d0f,8,c08b2c61,c1f20e70) at flush_inodedep_deps+0x98
> softdep_sync_metadata(d0327c98,0,c08b2c61,137,0) at softdep_sync_metadata+0x95
> ffs_fsync(d0327c98,0,c08a5b1c,bd5,0) at ffs_fsync+0x3c0
> fsync(c2166480,d0327d04,c08bb2dd,3e7,1) at fsync+0x15a
> syscall(2f,2f,2f,bfbfc630,bfbfc628) at syscall+0x291
> Xint0x80_syscall() at Xint0x80_syscall+0x1f
> --- syscall (95, FreeBSD ELF32, fsync), eip = 0x282cb56b, esp = 0xbfbfc5fc, ebp = 0xbfbfcee8 ---

The system in question is 5-STABLE updated around 17Z on 2 May.
It's running inn, sendmail, and a bevy of milterish things, but is
otherwise pretty quiet, a few thousand email per day, no jails, no
weird (i.e. all are ufs or devfs) filesystems in use.

-- 
Steve Watt KD6GGD  PP-ASEL-IA          ICBM: 121W 56' 57.8" / 37N 20' 14.9"
 Internet: steve @ Watt.COM                         Whois: SW32
   Free time?  There's no such thing.  It just comes in varying prices...