On Mon, Sep 08, 2008 at 08:52:45PM +0900, Takashi Sato wrote: > diff -uprN -X linux-2.6.27-rc5.org/Documentation/dontdiff linux-2.6.27-rc5.org/fs/block_dev.c linux-2.6.27-rc5-freeze/fs > /block_dev.c > --- linux-2.6.27-rc5.org/fs/block_dev.c 2008-08-29 07:52:02.000000000 +0900 > +++ linux-2.6.27-rc5-freeze/fs/block_dev.c 2008-09-05 20:00:29.000000000 +0900 > @@ -285,6 +285,8 @@ static void init_once(void *foo) > INIT_LIST_HEAD(&bdev->bd_holder_list); > #endif > inode_init_once(&ei->vfs_inode); > + /* Initialize mutex for freeze. */ > + mutex_init(&bdev->bd_fsfreeze_mutex); Why not just freeze_mutex? > struct super_block *freeze_bdev(struct block_device *bdev) > { > struct super_block *sb; > > + mutex_lock(&bdev->bd_fsfreeze_mutex); > + if (bdev->bd_fsfreeze_count > 0) { > + bdev->bd_fsfreeze_count++; > + sb = get_super(bdev); > + mutex_unlock(&bdev->bd_fsfreeze_mutex); > + return sb; > + } > + bdev->bd_fsfreeze_count++; > + > down(&bdev->bd_mount_sem); Note that we still have duplication with the bd_mount_sem. I think you should look into getting rid of it and instead do a check of the freeze_count under proper freeze_mutex protection. > +int thaw_bdev(struct block_device *bdev, struct super_block *sb) > { > + mutex_lock(&bdev->bd_fsfreeze_mutex); > + if (!bdev->bd_fsfreeze_count) { > + mutex_unlock(&bdev->bd_fsfreeze_mutex); > + return 0; > + } > + > + bdev->bd_fsfreeze_count--; > + if (bdev->bd_fsfreeze_count > 0) { > + if (sb) > + drop_super(sb); > + mutex_unlock(&bdev->bd_fsfreeze_mutex); > + return 0; > + } > + > if (sb) { > BUG_ON(sb->s_bdev != bdev); > > @@ -244,6 +274,8 @@ void thaw_bdev(struct block_device *bdev > } > > up(&bdev->bd_mount_sem); > + mutex_unlock(&bdev->bd_fsfreeze_mutex); > + return 0; Why do you add a return value here if we always return 0 anyway? -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html