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/qnx4/inode.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) (limited to 'fs/qnx4/inode.c') diff --git a/fs/qnx4/inode.c b/fs/qnx4/inode.c index 16829722be93..86a7be1399a8 100644 --- a/fs/qnx4/inode.c +++ b/fs/qnx4/inode.c @@ -234,9 +234,13 @@ static int qnx4_fill_super(struct super_block *s, void *data, int silent) struct qnx4_sb_info *qs; int ret = -EINVAL; + lock_kernel(); + qs = kzalloc(sizeof(struct qnx4_sb_info), GFP_KERNEL); - if (!qs) + if (!qs) { + unlock_kernel(); return -ENOMEM; + } s->s_fs_info = qs; sb_set_blocksize(s, QNX4_BLOCK_SIZE); @@ -284,6 +288,7 @@ static int qnx4_fill_super(struct super_block *s, void *data, int silent) brelse(bh); + unlock_kernel(); return 0; outi: @@ -293,6 +298,7 @@ static int qnx4_fill_super(struct super_block *s, void *data, int silent) outnobh: kfree(qs); s->s_fs_info = NULL; + unlock_kernel(); return ret; } -- cgit v1.2.3