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/bfs/inode.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) (limited to 'fs/bfs') diff --git a/fs/bfs/inode.c b/fs/bfs/inode.c index c4daf0f5fc0..d2e09363dd9 100644 --- a/fs/bfs/inode.c +++ b/fs/bfs/inode.c @@ -322,9 +322,13 @@ static int bfs_fill_super(struct super_block *s, void *data, int silent) int ret = -EINVAL; unsigned long i_sblock, i_eblock, i_eoff, s_size; + lock_kernel(); + info = kzalloc(sizeof(*info), GFP_KERNEL); - if (!info) + if (!info) { + unlock_kernel(); return -ENOMEM; + } mutex_init(&info->bfs_lock); s->s_fs_info = info; @@ -439,6 +443,7 @@ static int bfs_fill_super(struct super_block *s, void *data, int silent) brelse(bh); brelse(sbh); dump_imap("read_super", s); + unlock_kernel(); return 0; out3: @@ -452,6 +457,7 @@ out: mutex_destroy(&info->bfs_lock); kfree(info); s->s_fs_info = NULL; + unlock_kernel(); return ret; } -- cgit v1.2.3-18-g5258