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>
diff --git a/fs/jffs2/super.c b/fs/jffs2/super.c
index 662bba0..58dd9cf 100644
--- a/fs/jffs2/super.c
+++ b/fs/jffs2/super.c
@@ -146,14 +146,19 @@
static int jffs2_fill_super(struct super_block *sb, void *data, int silent)
{
struct jffs2_sb_info *c;
+ int ret;
+
+ lock_kernel();
D1(printk(KERN_DEBUG "jffs2_get_sb_mtd():"
" New superblock for device %d (\"%s\")\n",
sb->s_mtd->index, sb->s_mtd->name));
c = kzalloc(sizeof(*c), GFP_KERNEL);
- if (!c)
+ if (!c) {
+ unlock_kernel();
return -ENOMEM;
+ }
c->mtd = sb->s_mtd;
c->os_priv = sb;
@@ -175,7 +180,9 @@
#ifdef CONFIG_JFFS2_FS_POSIX_ACL
sb->s_flags |= MS_POSIXACL;
#endif
- return jffs2_do_fill_super(sb, data, silent);
+ ret = jffs2_do_fill_super(sb, data, silent);
+ unlock_kernel();
+ return ret;
}
static int jffs2_get_sb(struct file_system_type *fs_type,