fs: Add new pre-allocation ioctls to vfs for compatibility with legacy xfs ioctls

This patch adds ioctls to vfs for compatibility with legacy XFS
pre-allocation ioctls (XFS_IOC_*RESVP*). The implementation
effectively invokes sys_fallocate for the new ioctls.
Also handles the compat_ioctl case.
Note: These legacy ioctls are also implemented by OCFS2.

[AV: folded fixes from hch]

Signed-off-by: Ankit Jain <me@ankitjain.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

2 files changed, 27 insertions, 0 deletions

diff --git a/include/linux/falloc.h b/include/linux/falloc.h
index 8e912ab6a072..3c155107d61f 100644
--- a/include/linux/falloc.h
+++ b/include/linux/falloc.h
@@ -3,4 +3,25 @@
 
 #define FALLOC_FL_KEEP_SIZE     0x01 /* default is extend size */
 
+#ifdef __KERNEL__
+
+/*
+ * Space reservation ioctls and argument structure
+ * are designed to be compatible with the legacy XFS ioctls.
+ */
+struct space_resv {
+        __s16           l_type;
+        __s16           l_whence;
+        __s64           l_start;
+        __s64           l_len;          /* len == 0 means until end of file */
+        __s32           l_sysid;
+        __u32           l_pid;
+        __s32           l_pad[4];       /* reserved area */
+};
+
+#define FS_IOC_RESVSP           _IOW('X', 40, struct space_resv)
+#define FS_IOC_RESVSP64         _IOW('X', 42, struct space_resv)
+
+#endif /* __KERNEL__ */
+
 #endif /* _FALLOC_H_ */
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 1ff5e4e01952..79e302ddde0f 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1906,6 +1906,8 @@ static inline int break_lease(struct inode *inode, unsigned int mode)
 
 extern int do_truncate(struct dentry *, loff_t start, unsigned int time_attrs,
                        struct file *filp);
+extern int do_fallocate(struct file *file, int mode, loff_t offset,
+                        loff_t len);
 extern long do_sys_open(int dfd, const char __user *filename, int flags,
                         int mode);
 extern struct file *filp_open(const char *, int, int);
@@ -1914,6 +1916,10 @@ extern struct file * dentry_open(struct dentry *, struct vfsmount *, int,
 extern int filp_close(struct file *, fl_owner_t id);
 extern char * getname(const char __user *);
 
+/* fs/ioctl.c */
+
+extern int ioctl_preallocate(struct file *filp, void __user *argp);
+
 /* fs/dcache.c */
 extern void __init vfs_caches_init_early(void);
 extern void __init vfs_caches_init(unsigned long);