kernel_optimize_test/fs
Eric W. Biederman 077130c0cf [NET]: Fix race when opening a proc file while a network namespace is exiting.
The problem:  proc_net files remember which network namespace the are
against but do not remember hold a reference count (as that would pin
the network namespace).   So we currently have a small window where
the reference count on a network namespace may be incremented when opening
a /proc file when it has already gone to zero.

To fix this introduce maybe_get_net and get_proc_net.

maybe_get_net increments the network namespace reference count only if it is
greater then zero, ensuring we don't increment a reference count after it
has gone to zero.

get_proc_net handles all of the magic to go from a proc inode to the network
namespace instance and call maybe_get_net on it.

PROC_NET the old accessor is removed so that we don't get confused and use
the wrong helper function.

Then I fix up the callers to use get_proc_net and handle the case case
where get_proc_net returns NULL.  In that case I return -ENXIO because
effectively the network namespace has already gone away so the files
we are trying to access don't exist anymore.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Paul E. McKenney <paulmck@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:49:22 -07:00
..
9p
adfs
affs
afs
autofs
autofs4
befs
bfs
cifs
coda
configfs
cramfs
debugfs
devpts
dlm
ecryptfs
efs
exportfs
ext2
ext3
ext4
fat
freevxfs
fuse
gfs2
hfs
hfsplus
hostfs
hpfs
hppfs
hugetlbfs
isofs
jbd
jbd2
jffs2
jfs
lockd
minix
msdos
ncpfs
nfs
nfs_common
nfsd
nls
ntfs
ocfs2
openpromfs
partitions
proc
qnx4
ramfs
reiserfs
romfs
smbfs
sysfs
sysv
udf
ufs
vfat
xfs
aio.c
anon_inodes.c
attr.c
bad_inode.c
binfmt_aout.c
binfmt_elf_fdpic.c
binfmt_elf.c
binfmt_em86.c
binfmt_flat.c
binfmt_misc.c
binfmt_script.c
binfmt_som.c
bio.c
block_dev.c
buffer.c
char_dev.c
compat_ioctl.c
compat.c
dcache.c
dcookies.c
direct-io.c
dnotify.c
dquot.c
drop_caches.c
eventfd.c
eventpoll.c
exec.c
fcntl.c
fifo.c
file_table.c
file.c
filesystems.c
fs-writeback.c
generic_acl.c
inode.c
inotify_user.c
inotify.c
internal.h
ioctl.c
ioprio.c
Kconfig
Kconfig.binfmt
libfs.c
locks.c
Makefile
mbcache.c
mpage.c
namei.c
namespace.c
nfsctl.c
no-block.c
open.c
pipe.c
pnode.c
pnode.h
posix_acl.c
quota_v1.c
quota_v2.c
quota.c
read_write.c
read_write.h
readdir.c
select.c
seq_file.c
signalfd.c
splice.c
stack.c
stat.c
super.c
sync.c
timerfd.c
utimes.c
xattr_acl.c
xattr.c