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>

1 files changed, 48 insertions, 0 deletions

diff --git a/fs/compat_ioctl.c b/fs/compat_ioctl.c
index c135202c38b3..626c7483b4de 100644
--- a/fs/compat_ioctl.c
+++ b/fs/compat_ioctl.c
@@ -31,6 +31,7 @@
 #include <linux/skbuff.h>
 #include <linux/netlink.h>
 #include <linux/vt.h>
+#include <linux/falloc.h>
 #include <linux/fs.h>
 #include <linux/file.h>
 #include <linux/ppp_defs.h>
@@ -1779,6 +1780,41 @@ lp_timeout_trans(unsigned int fd, unsigned int cmd, unsigned long arg)
         return sys_ioctl(fd, cmd, (unsigned long)tn);
 }
 
+/* on ia32 l_start is on a 32-bit boundary */
+#if defined(CONFIG_IA64) || defined(CONFIG_X86_64)
+struct space_resv_32 {
+        __s16           l_type;
+        __s16           l_whence;
+        __s64           l_start __attribute__((packed));
+                        /* len == 0 means until end of file */
+        __s64           l_len __attribute__((packed));
+        __s32           l_sysid;
+        __u32           l_pid;
+        __s32           l_pad[4];       /* reserve area */
+};
+
+#define FS_IOC_RESVSP_32                _IOW ('X', 40, struct space_resv_32)
+#define FS_IOC_RESVSP64_32      _IOW ('X', 42, struct space_resv_32)
+
+/* just account for different alignment */
+static int compat_ioctl_preallocate(struct file *file, unsigned long arg)
+{
+        struct space_resv_32    __user *p32 = (void __user *)arg;
+        struct space_resv       __user *p = compat_alloc_user_space(sizeof(*p));
+
+        if (copy_in_user(&p->l_type,    &p32->l_type,   sizeof(s16)) ||
+            copy_in_user(&p->l_whence,  &p32->l_whence, sizeof(s16)) ||
+            copy_in_user(&p->l_start,   &p32->l_start,  sizeof(s64)) ||
+            copy_in_user(&p->l_len,     &p32->l_len,    sizeof(s64)) ||
+            copy_in_user(&p->l_sysid,   &p32->l_sysid,  sizeof(s32)) ||
+            copy_in_user(&p->l_pid,     &p32->l_pid,    sizeof(u32)) ||
+            copy_in_user(&p->l_pad,     &p32->l_pad,    4*sizeof(u32)))
+                return -EFAULT;
+
+        return ioctl_preallocate(file, p);
+}
+#endif
+
 
 typedef int (*ioctl_trans_handler_t)(unsigned int, unsigned int,
                                         unsigned long, struct file *);
@@ -2756,6 +2792,18 @@ asmlinkage long compat_sys_ioctl(unsigned int fd, unsigned int cmd,
         case FIOQSIZE:
                 break;
 
+#if defined(CONFIG_IA64) || defined(CONFIG_X86_64)
+        case FS_IOC_RESVSP_32:
+        case FS_IOC_RESVSP64_32:
+                error = compat_ioctl_preallocate(filp, arg);
+                goto out_fput;
+#else
+        case FS_IOC_RESVSP:
+        case FS_IOC_RESVSP64:
+                error = ioctl_preallocate(filp, (void __user *)arg);
+                goto out_fput;
+#endif
+
         case FIBMAP:
         case FIGETBSZ:
         case FIONREAD: