[PATCH 12/13] vfs: Mobs creation and mgmt API

[Pavel Emelyanov <xemul@parallels.com>]

These are ioctl-s, sorry. I've spent many time thinking which API for 
that would be better, but didn't find any perfect solutions, so this
is to be discussed.

The cgroups as they are implemented now are not suitable as they work
for controllers, that controll the per-task-groups resources. The dcache
is obviously not such.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>

---
 fs/ioctl.c         |    9 +++++++++
 include/linux/fs.h |    3 +++
 2 files changed, 12 insertions(+), 0 deletions(-)

diff --git a/fs/ioctl.c b/fs/ioctl.c
index 1eebeb7..e0c1e77 100644
--- a/fs/ioctl.c
+++ b/fs/ioctl.c
@@ -15,6 +15,7 @@
 #include <linux/writeback.h>
 #include <linux/buffer_head.h>
 #include <linux/falloc.h>
+#include <linux/dcache.h>
 
 #include <asm/ioctls.h>
 
@@ -596,6 +597,14 @@ int do_vfs_ioctl(struct file *filp, unsigned int fd, unsigned int cmd,
 		return put_user(inode->i_sb->s_blocksize, p);
 	}
 
+	case FIMOBROOT:
+		return dcache_new_mob(filp->f_path.dentry);
+	case FIMOBSIZE:
+		return dcache_set_mob_size(filp->f_path.dentry, arg);
+	case FIMOBSTAT:
+		return dcache_get_mob_stat(filp->f_path.dentry,
+				(struct dentry_mob_stat __user *)arg);
+
 	default:
 		if (S_ISREG(filp->f_path.dentry->d_inode->i_mode))
 			error = file_ioctl(filp, cmd, arg);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index a236ea3..4bf54bb 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -327,6 +327,9 @@ struct inodes_stat_t {
 #define FIFREEZE	_IOWR('X', 119, int)	/* Freeze */
 #define FITHAW		_IOWR('X', 120, int)	/* Thaw */
 #define FITRIM		_IOWR('X', 121, struct fstrim_range)	/* Trim */
+#define FIMOBROOT	_IO('X', 122)
+#define FIMOBSIZE	_IOW('X', 123, unsigned long)
+#define FIMOBSTAT	_IOR('X', 124, struct dentry_mob_stat)
 
 #define	FS_IOC_GETFLAGS			_IOR('f', 1, long)
 #define	FS_IOC_SETFLAGS			_IOW('f', 2, long)
-- 
1.5.5.6