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/ext4/super.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'fs/ext4') diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 26147746c27..0f0021f4990 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -2568,6 +2568,8 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) int err; unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO; + lock_kernel(); + sbi = kzalloc(sizeof(*sbi), GFP_KERNEL); if (!sbi) goto out_free_orig; @@ -3166,7 +3168,6 @@ no_journal: if (es->s_error_count) mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */ - lock_kernel(); kfree(orig_data); return 0; @@ -3213,8 +3214,11 @@ out_fail: sb->s_fs_info = NULL; kfree(sbi->s_blockgroup_lock); kfree(sbi); - lock_kernel(); + kfree(orig_data); + return ret; + out_free_orig: + unlock_kernel(); kfree(orig_data); return ret; } -- cgit v1.2.3-70-g09d2