From db71922217a214e5c9268448e537b54fc1f301ea Mon Sep 17 00:00:00 2001 From: Jan Blunck Date: Sun, 15 Aug 2010 22:51:10 +0200 Subject: 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 Signed-off-by: Arnd Bergmann Cc: Matthew Wilcox Cc: Christoph Hellwig --- fs/jffs2/super.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) (limited to 'fs/jffs2/super.c') diff --git a/fs/jffs2/super.c b/fs/jffs2/super.c index 662bba099501..58dd9cf06206 100644 --- a/fs/jffs2/super.c +++ b/fs/jffs2/super.c @@ -146,14 +146,19 @@ static const struct super_operations jffs2_super_operations = 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 @@ static int jffs2_fill_super(struct super_block *sb, void *data, int silent) #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, -- cgit v1.2.3-59-g8ed1b