Re: [PATCH 03/20] BKL: Explicitly add BKL around get_sb/fill_super

[Anders Larsen <al@alarsen.net>]

On 2009-11-18 10:24:36, Jan Blunck wrote:
> 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.
> 
> Signed-off-by: Jan Blunck <jblunck@suse.de>
> Cc: Matthew Wilcox <matthew@wil.cx>
> Cc: Christoph Hellwig <hch@infradead.org>
> Cc: Arnd Bergmann <arnd@arndb.de>

Wrt fs/qnx4:
Acked-by: Anders Larsen <al@alarsen.net>