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/afs/super.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'fs/afs') diff --git a/fs/afs/super.c b/fs/afs/super.c index 77e1e5a..6c2fef4 100644 --- a/fs/afs/super.c +++ b/fs/afs/super.c @@ -302,12 +302,15 @@ static int afs_fill_super(struct super_block *sb, void *data) struct inode *inode = NULL; int ret; + lock_kernel(); + _enter(""); /* allocate a superblock info record */ as = kzalloc(sizeof(struct afs_super_info), GFP_KERNEL); if (!as) { _leave(" = -ENOMEM"); + unlock_kernel(); return -ENOMEM; } @@ -341,6 +344,7 @@ static int afs_fill_super(struct super_block *sb, void *data) sb->s_root = root; _leave(" = 0"); + unlock_kernel(); return 0; error_inode: @@ -354,6 +358,7 @@ error: sb->s_fs_info = NULL; _leave(" = %d", ret); + unlock_kernel(); return ret; } -- cgit v1.1