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| author | Jan Blunck <jblunck@infradead.org> | 2010-08-15 22:51:10 +0200 |
|---|---|---|
| committer | Arnd Bergmann <arnd@arndb.de> | 2010-10-04 21:10:10 +0200 |
| commit | db71922217a214e5c9268448e537b54fc1f301ea (patch) | |
| tree | 9c9afbf29411547891f6968e5ade29ce59d66c07 /kernel/cgroup.c | |
| parent | 899611ee7d373e5eeda08e9a8632684e1ebbbf00 (diff) | |
| download | linux-db71922217a214e5c9268448e537b54fc1f301ea.tar.gz linux-db71922217a214e5c9268448e537b54fc1f301ea.tar.bz2 linux-db71922217a214e5c9268448e537b54fc1f301ea.zip | |
BKL: Explicitly add BKL around get_sb/fill_super
This patch is a preparation necessary to remove the BKL from do_new_mount().
It explicitly adds calls to lock_kernel()/unlock_kernel() around
get_sb/fill_super operations for filesystems that still uses the BKL.
I've read through all the code formerly covered by the BKL inside
do_kern_mount() and have satisfied myself that it doesn't need the BKL
any more.
do_kern_mount() is already called without the BKL when mounting the rootfs
and in nfsctl. do_kern_mount() calls vfs_kern_mount(), which is called
from various places without BKL: simple_pin_fs(), nfs_do_clone_mount()
through nfs_follow_mountpoint(), afs_mntpt_do_automount() through
afs_mntpt_follow_link(). Both later functions are actually the filesystems
follow_link inode operation. vfs_kern_mount() is calling the specified
get_sb function and lets the filesystem do its job by calling the given
fill_super function.
Therefore I think it is safe to push down the BKL from the VFS to the
low-level filesystems get_sb/fill_super operation.
[arnd: do not add the BKL to those file systems that already
don't use it elsewhere]
Signed-off-by: Jan Blunck <jblunck@infradead.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Christoph Hellwig <hch@infradead.org>
Diffstat (limited to 'kernel/cgroup.c')
| -rw-r--r-- | kernel/cgroup.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c index c9483d8f6140..a7ba3bccadc5 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -1430,6 +1430,8 @@ static int cgroup_get_sb(struct file_system_type *fs_type, struct super_block *sb; struct cgroupfs_root *new_root; + lock_kernel(); + /* First find the desired set of subsystems */ mutex_lock(&cgroup_mutex); ret = parse_cgroupfs_options(data, &opts); @@ -1559,6 +1561,7 @@ static int cgroup_get_sb(struct file_system_type *fs_type, simple_set_mnt(mnt, sb); kfree(opts.release_agent); kfree(opts.name); + unlock_kernel(); return 0; drop_new_super: @@ -1568,6 +1571,7 @@ static int cgroup_get_sb(struct file_system_type *fs_type, out_err: kfree(opts.release_agent); kfree(opts.name); + unlock_kernel(); return ret; } |