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/ntfs/super.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'fs/ntfs') diff --git a/fs/ntfs/super.c b/fs/ntfs/super.c index 512806171bf..1f31e77fc41 100644 --- a/fs/ntfs/super.c +++ b/fs/ntfs/super.c @@ -2732,6 +2732,8 @@ static int ntfs_fill_super(struct super_block *sb, void *opt, const int silent) struct inode *tmp_ino; int blocksize, result; + lock_kernel(); + /* * We do a pretty difficult piece of bootstrap by reading the * MFT (and other metadata) from disk into memory. We'll only @@ -2755,6 +2757,7 @@ static int ntfs_fill_super(struct super_block *sb, void *opt, const int silent) ntfs_error(sb, "Allocation of NTFS volume structure " "failed. Aborting mount..."); lockdep_on(); + unlock_kernel(); return -ENOMEM; } /* Initialize ntfs_volume structure. */ @@ -2942,6 +2945,7 @@ static int ntfs_fill_super(struct super_block *sb, void *opt, const int silent) sb->s_export_op = &ntfs_export_ops; lock_kernel(); lockdep_on(); + unlock_kernel(); return 0; } ntfs_error(sb, "Failed to allocate root directory."); @@ -3062,6 +3066,7 @@ err_out_now: kfree(vol); ntfs_debug("Failed, returning -EINVAL."); lockdep_on(); + unlock_kernel(); return -EINVAL; } -- cgit v1.2.3-18-g5258