Here's what the test is doing. It does multiple parallel instances of this, each one doing thousands of the following in a loop. Console output with mutex and lock debug is in http://www.citi.umich.edu/projects/nfsv4/pnfs/block/download/console.txt getpid() = 2431 open("t_mtab~2431", O_WRONLY|O_CREAT, 0) = 3 close(3) = 0 link("t_mtab~2431", "t_mtab~") = 0 unlink("t_mtab~2431") = 0 open("t_mtab~", O_WRONLY) = 3 fcntl(3, F_SETLK, {type=F_WRLCK, whence=SEEK_SET, start=0, len=0}) = 0 close(3) = 0 brk(0) = 0x19ab000 brk(0x19cc000) = 0x19cc000 brk(0) = 0x19cc000 open("t_mtab", O_RDONLY) = 3 open("t_mtab.tmp", O_WRONLY|O_CREAT|O_TRUNC, 0666) = 4 read(3, "/proc on /proc type proc (rw,rel"..., 4096) = 2598 write(4, "/proc on /proc type proc (rw,rel"..., 2598) = 2598 read(3, "", 4096) = 0 close(3) = 0 fchmod(4, 0644) = 0 close(4) = 0 stat("t_mtab", {st_mode=S_IFREG|0644, st_size=2598, ...}) = 0 chown("t_mtab.tmp", 99, 0) = -1 EINVAL (Invalid argument) rename("t_mtab.tmp", "t_mtab") = 0 unlink("t_mtab~") = 0 fstat(1, {st_mode=S_IFCHR|0620, st_rdev=makedev(136, 0), ...}) = 0 mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fd95cd76000 write(1, "completed 1 iterations\n", 23) = 23 exit_group(0) = ? -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html