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/hfs/super.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) (limited to 'fs/hfs') diff --git a/fs/hfs/super.c b/fs/hfs/super.c index 34235d4bf08b..3069416fa8ef 100644 --- a/fs/hfs/super.c +++ b/fs/hfs/super.c @@ -382,9 +382,13 @@ static int hfs_fill_super(struct super_block *sb, void *data, int silent) struct inode *root_inode; int res; + lock_kernel(); + sbi = kzalloc(sizeof(struct hfs_sb_info), GFP_KERNEL); - if (!sbi) + if (!sbi) { + unlock_kernel(); return -ENOMEM; + } sb->s_fs_info = sbi; INIT_HLIST_HEAD(&sbi->rsrc_inodes); @@ -435,6 +439,7 @@ static int hfs_fill_super(struct super_block *sb, void *data, int silent) sb->s_root->d_op = &hfs_dentry_operations; /* everything's okay */ + unlock_kernel(); return 0; bail_iput: @@ -443,6 +448,7 @@ bail_no_root: printk(KERN_ERR "hfs: get root inode failed.\n"); bail: hfs_mdb_put(sb); + unlock_kernel(); return res; } -- cgit v1.2.3-59-g8ed1b