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/hpfs/super.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) (limited to 'fs/hpfs') diff --git a/fs/hpfs/super.c b/fs/hpfs/super.c index 2607010be2fe..c969a1aa163a 100644 --- a/fs/hpfs/super.c +++ b/fs/hpfs/super.c @@ -477,11 +477,15 @@ static int hpfs_fill_super(struct super_block *s, void *options, int silent) int o; + lock_kernel(); + save_mount_options(s, options); sbi = kzalloc(sizeof(*sbi), GFP_KERNEL); - if (!sbi) + if (!sbi) { + unlock_kernel(); return -ENOMEM; + } s->s_fs_info = sbi; sbi->sb_bmp_dir = NULL; @@ -666,6 +670,7 @@ static int hpfs_fill_super(struct super_block *s, void *options, int silent) root->i_blocks = 5; hpfs_brelse4(&qbh); } + unlock_kernel(); return 0; bail4: brelse(bh2); @@ -677,6 +682,7 @@ bail0: kfree(sbi->sb_cp_table); s->s_fs_info = NULL; kfree(sbi); + unlock_kernel(); return -EINVAL; } -- cgit v1.2.2