kevin/linux
1
Fork 0
Code
5f57cbcc02
linux/fs
History
Nick Piggin 5f57cbcc02 fs: dcache remove d_mounted 
Rather than keep a d_mounted count in the dentry, set a dentry flag instead.
The flag can be cleared by checking the hash table to see if there are any
mounts left, which is not time critical because it is performed at detach time.

The mounted state of a dentry is only used to speculatively take a look in the
mount hash table if it is set -- before following the mount, vfsmount lock is
taken and mount re-checked without races.

This saves 4 bytes on 32-bit, nothing on 64-bit but it does provide a hole I
might use later (and some configs have larger than 32-bit spinlocks which might
make use of the hole).

Autofs4 conversion and changelog by Ian Kent <raven@themaw.net>:
In autofs4, when expring direct (or offset) mounts we need to ensure that we
block user path walks into the autofs mount, which is covered by another mount.
To do this we clear the mounted status so that follows stop before walking into
the mount and are essentially blocked until the expire is completed. The
automount daemon still finds the correct dentry for the umount due to the
follow mount logic in fs/autofs4/root.c:autofs4_follow_link(), which is set as
an inode operation for direct and offset mounts only and is called following
the lookup that stopped at the covered mount.

At the end of the expire the covering mount probably has gone away so the
mounted status need not be restored. But we need to check this and only restore
the mounted status if the expire failed.

XXX: autofs may not work right if we have other mounts go over the top of it?

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:28 +11:00
..
9p fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
adfs fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
affs fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
afs fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
autofs4 fs: dcache remove d_mounted 2011-01-07 17:50:28 +11:00
befs fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
bfs fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
btrfs fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
cachefiles
ceph fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
cifs fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
coda fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
configfs fs: dcache rationalise dget variants 2011-01-07 17:50:24 +11:00
cramfs new helper: mount_bdev() 2010-10-29 04:16:13 -04:00
debugfs convert get_sb_single() users 2010-10-29 04:16:28 -04:00
devpts convert get_sb_single() users 2010-10-29 04:16:28 -04:00
dlm Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/teigland/dlm 2010-10-22 17:33:16 -07:00
ecryptfs fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
efs fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
exofs fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
exportfs fs: dcache rationalise dget variants 2011-01-07 17:50:24 +11:00
ext2 fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
ext3 fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
ext4 fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
fat fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
freevxfs fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
fscache
fuse fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
gfs2 fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
hfs fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
hfsplus fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
hostfs fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
hpfs fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
hppfs fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
hugetlbfs fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
isofs fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
jbd Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs-2.6 2010-10-27 20:13:18 -07:00
jbd2 jbd2: fix /proc/fs/jbd2/<dev> when using an external journal 2010-11-17 21:46:26 -05:00
jffs2 fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
jfs fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
lockd BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
logfs fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
minix fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
ncpfs fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
nfs fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
nfs_common
nfsd fs: dcache scale dentry refcount 2011-01-07 17:50:21 +11:00
nilfs2 fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
nls
notify fs: dcache remove dcache_lock 2011-01-07 17:50:23 +11:00
ntfs fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
ocfs2 fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
omfs new helper: mount_bdev() 2010-10-29 04:16:13 -04:00
openpromfs fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
partitions Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block 2010-10-25 07:45:10 -07:00
proc fs: rcu-walk for path lookup 2011-01-07 17:50:27 +11:00
qnx4 fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
quota quota: Fix possible oops in __dquot_initialize() 2010-10-28 01:30:06 +02:00
ramfs convert get_sb_nodev() users 2010-10-29 04:16:31 -04:00
reiserfs fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
romfs fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
squashfs fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
sysfs fs: change d_delete semantics 2011-01-07 17:50:18 +11:00
sysv fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
ubifs fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
udf fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
ufs fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
xfs fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
aio.c new helper: ihold() 2010-10-25 21:26:11 -04:00
anon_inodes.c convert get_sb_pseudo() users 2010-10-29 04:16:33 -04:00
attr.c
bad_inode.c
binfmt_aout.c
binfmt_elf_fdpic.c
binfmt_elf.c
binfmt_em86.c
binfmt_flat.c
binfmt_misc.c convert get_sb_single() users 2010-10-29 04:16:28 -04:00
binfmt_script.c
binfmt_som.c
bio-integrity.c
bio.c bio: take care not overflow page count when mapping/copying user data 2010-11-10 14:40:43 +01:00
block_dev.c fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
buffer.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2010-10-26 17:58:44 -07:00
char_dev.c
compat_binfmt_elf.c
compat_ioctl.c BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
compat.c exec: copy-and-paste the fixes into compat_do_execve() paths 2010-11-30 17:56:38 -08:00
dcache.c fs: dcache remove d_mounted 2011-01-07 17:50:28 +11:00
dcookies.c
direct-io.c fs/direct-io.c: fix truncation error in dio_complete() return 2010-10-26 16:52:13 -07:00
drop_caches.c
eventfd.c
eventpoll.c epoll: make epoll_wait() use the hrtimer range feature 2010-10-27 18:03:18 -07:00
exec.c install_special_mapping skips security_file_mmap check. 2010-12-15 12:30:36 -08:00
fcntl.c fasync: Fix placement of FASYNC flag comment 2010-10-27 18:17:02 -07:00
fifo.c
file_table.c fs: allow for more than 2^31 files 2010-10-26 16:52:15 -07:00
file.c
filesystems.c fs: rcu-walk for path lookup 2011-01-07 17:50:27 +11:00
fs_struct.c fs: fs_struct use seqlock 2011-01-07 17:50:27 +11:00
fs-writeback.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable 2010-10-30 09:05:48 -07:00
generic_acl.c
inode.c fs: avoid inode RCU freeing for pseudo fs 2011-01-07 17:50:26 +11:00
internal.h braino in internal.h 2010-10-29 05:49:13 -04:00
ioctl.c Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 2010-11-19 19:46:45 -08:00
ioprio.c ioprio: grab rcu_read_lock in sys_ioprio_{set,get}() 2010-11-15 10:23:31 +01:00
Kconfig Merge 'staging-next' to Linus's tree 2010-10-28 09:44:56 -07:00
Kconfig.binfmt coredump: default CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS=y 2010-10-27 18:03:12 -07:00
libfs.c fs: dcache remove dcache_lock 2011-01-07 17:50:23 +11:00
locks.c fs: dcache scale dentry refcount 2011-01-07 17:50:21 +11:00
Makefile Merge 'staging-next' to Linus's tree 2010-10-28 09:44:56 -07:00
mbcache.c
mpage.c
namei.c fs: fs_struct use seqlock 2011-01-07 17:50:27 +11:00
namespace.c fs: dcache remove d_mounted 2011-01-07 17:50:28 +11:00
nfsctl.c
no-block.c
open.c fix open/umount race 2010-10-29 04:14:56 -04:00
pipe.c fs: avoid inode RCU freeing for pseudo fs 2011-01-07 17:50:26 +11:00
pnode.c
pnode.h
posix_acl.c
read_write.c BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
read_write.h
readdir.c
select.c epoll: make epoll_wait() use the hrtimer range feature 2010-10-27 18:03:18 -07:00
seq_file.c fs: take dcache_lock inside __d_path 2010-10-25 21:26:12 -04:00
signalfd.c Merge branch 'hwpoison' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6 2010-10-26 10:13:10 -07:00
splice.c Export 'get_pipe_info()' to other users 2010-11-28 14:09:57 -08:00
stack.c
stat.c
statfs.c
super.c switch get_sb_ns() users 2010-10-29 04:17:03 -04:00
sync.c
timerfd.c
utimes.c
xattr_acl.c
xattr.c