NFSv4 : open blocked

[Vincent ROQUETA]

Hello all,

Here is a simple test that blocks NFSv4 on kernel 2.6.21-rc3+CITI, using 16K 
pages.


1/ Run fsstress during few time (3 minutes) with this parameters
fsstress -l 0 -d /mnt/nfsv4/ -n 1000 -p 50 -r
2/ cat an existing file on NFS
For example :
---------------------------------------------------------------------------------------------------------
strace cat fichierTest.fsxlog
execve("/bin/cat", ["cat", "fichierTest.fsxlog"], [/* 34 vars */]) = 0
uname({sys="Linux", node="sar4", ...})  = 0
brk(0)                                  = 0x600000000000c000
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or 
directory)
open("/etc/ld.so.cache", O_RDONLY)      = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=52804, ...}) = 0
mmap(NULL, 52804, PROT_READ, MAP_PRIVATE, 3, 0) = 0x2000000000044000
close(3)                                = 0
open("/lib/tls/libc.so.6.1", O_RDONLY)  = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0002\0\1\0\0\0\240\226"..., 832) = 
832
fstat(3, {st_mode=S_IFREG|0755, st_size=2790936, ...}) = 0
mmap(NULL, 2527936, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 
0x2000000000054000
mprotect(0x20000000002a8000, 86720, PROT_NONE) = 0
mmap(0x20000000002b4000, 32768, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|
MAP_DENYWRITE, 3, 0x250000) = 0x20000000002b4000
mmap(0x20000000002bc000, 4800, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|
MAP_ANONYMOUS, -1, 0) = 0x20000000002bc000
close(3)                                = 0
mmap(NULL, 16384, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 
0x20000000002c0000
mmap(NULL, 32768, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 
0x20000000002c4000
munmap(0x2000000000044000, 52804)       = 0
brk(0)                                  = 0x600000000000c000
brk(0x6000000000030000)                 = 0x6000000000030000
open("/usr/lib/locale/locale-archive", O_RDONLY) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=55337968, ...}) = 0
mmap(NULL, 55337968, PROT_READ, MAP_PRIVATE, 3, 0) = 0x20000000002cc000
close(3)                                = 0
fstat(1, {st_mode=S_IFCHR|0620, st_rdev=makedev(136, 1), ...}) = 0
open("fichierTest.fsxlog", O_RDONLY <unfinished ...>
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Open remains blocked, until I kill the "cat" process. In similar conditions I 
have caused a kernel bug (umount process). Anyone have more ideas to 
investigate those bugs ?

Vincent