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/coda/inode.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) (limited to 'fs/coda') diff --git a/fs/coda/inode.c b/fs/coda/inode.c index 6526e6f..bfe8179 100644 --- a/fs/coda/inode.c +++ b/fs/coda/inode.c @@ -148,6 +148,8 @@ static int coda_fill_super(struct super_block *sb, void *data, int silent) int error; int idx; + lock_kernel(); + idx = get_device_index((struct coda_mount_data *) data); /* Ignore errors in data, for backward compatibility */ @@ -159,11 +161,13 @@ static int coda_fill_super(struct super_block *sb, void *data, int silent) vc = &coda_comms[idx]; if (!vc->vc_inuse) { printk("coda_read_super: No pseudo device\n"); + unlock_kernel(); return -EINVAL; } if ( vc->vc_sb ) { printk("coda_read_super: Device already mounted\n"); + unlock_kernel(); return -EBUSY; } @@ -202,7 +206,8 @@ static int coda_fill_super(struct super_block *sb, void *data, int silent) sb->s_root = d_alloc_root(root); if (!sb->s_root) goto error; - return 0; + unlock_kernel(); + return 0; error: bdi_destroy(&vc->bdi); @@ -212,6 +217,7 @@ static int coda_fill_super(struct super_block *sb, void *data, int silent) if (vc) vc->vc_sb = NULL; + unlock_kernel(); return -EINVAL; } -- cgit v1.1