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/jfs/super.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) (limited to 'fs/jfs/super.c') diff --git a/fs/jfs/super.c b/fs/jfs/super.c index ec8c3e4baca3..eb31f677347d 100644 --- a/fs/jfs/super.c +++ b/fs/jfs/super.c @@ -438,14 +438,20 @@ static int jfs_fill_super(struct super_block *sb, void *data, int silent) s64 newLVSize = 0; int flag, ret = -EINVAL; + lock_kernel(); + jfs_info("In jfs_read_super: s_flags=0x%lx", sb->s_flags); - if (!new_valid_dev(sb->s_bdev->bd_dev)) + if (!new_valid_dev(sb->s_bdev->bd_dev)) { + unlock_kernel(); return -EOVERFLOW; + } sbi = kzalloc(sizeof (struct jfs_sb_info), GFP_KERNEL); - if (!sbi) + if (!sbi) { + unlock_kernel(); return -ENOMEM; + } sb->s_fs_info = sbi; sbi->sb = sb; sbi->uid = sbi->gid = sbi->umask = -1; @@ -542,6 +548,7 @@ static int jfs_fill_super(struct super_block *sb, void *data, int silent) sb->s_maxbytes = min(((u64) PAGE_CACHE_SIZE << 32) - 1, (u64)sb->s_maxbytes); #endif sb->s_time_gran = 1; + unlock_kernel(); return 0; out_no_root: @@ -564,6 +571,7 @@ out_unload: unload_nls(sbi->nls_tab); out_kfree: kfree(sbi); + unlock_kernel(); return ret; } -- cgit v1.2.1