[PATCH] block: add unlocked_ioctl support for block devices

This patch allows block device drivers to convert their ioctl functions to
unlocked_ioctl() like character devices and other subsystems.  All
functions that were called with the BKL held before are still used that
way, but I would not be surprised if it could be removed from the ioctl
functions in drivers/block/ioctl.c themselves.

As a side note, I found that compat_blkdev_ioctl() acquires the BKL as
well, which looks like a bug.  I have checked that every user of
disk->fops->compat_ioctl() in the current git tree gets the BKL itself, so
it could easily be removed from compat_blkdev_ioctl().

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 2 insertions, 3 deletions

diff --git a/fs/block_dev.c b/fs/block_dev.c
index c0cbd1bc1a02..e0df94c37b7e 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -777,8 +777,7 @@ static ssize_t blkdev_file_aio_write(struct kiocb *iocb, const char __user *buf,
         return generic_file_aio_write_nolock(iocb, &local_iov, 1, &iocb->ki_pos);
 }
 
-static int block_ioctl(struct inode *inode, struct file *file, unsigned cmd,
-                        unsigned long arg)
+static long block_ioctl(struct file *file, unsigned cmd, unsigned long arg)
 {
         return blkdev_ioctl(file->f_mapping->host, file, cmd, arg);
 }
@@ -803,7 +802,7 @@ struct file_operations def_blk_fops = {
         .aio_write      = blkdev_file_aio_write, 
         .mmap           = generic_file_mmap,
         .fsync          = block_fsync,
-        .ioctl          = block_ioctl,
+        .unlocked_ioctl = block_ioctl,
 #ifdef CONFIG_COMPAT
         .compat_ioctl   = compat_blkdev_ioctl,
 #endif