nilfs2: add compat ioctl

The current FS_IOC_GETFLAGS/SETFLAGS/GETVERSION will fail if
application is 32 bit and kernel is 64 bit.

This issue is avoidable by adding compat_ioctl method.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

4 files changed, 24 insertions, 2 deletions

diff --git a/fs/nilfs2/dir.c b/fs/nilfs2/dir.c
index b72833a2cc1c..3a1923943b14 100644
--- a/fs/nilfs2/dir.c
+++ b/fs/nilfs2/dir.c
@@ -681,7 +681,7 @@ const struct file_operations nilfs_dir_operations = {
         .readdir        = nilfs_readdir,
         .unlocked_ioctl = nilfs_ioctl,
 #ifdef CONFIG_COMPAT
-        .compat_ioctl   = nilfs_ioctl,
+        .compat_ioctl   = nilfs_compat_ioctl,
 #endif  /* CONFIG_COMPAT */
         .fsync          = nilfs_sync_file,
 
diff --git a/fs/nilfs2/file.c b/fs/nilfs2/file.c
index 2f560c9fb808..7a5e4ab15c6e 100644
--- a/fs/nilfs2/file.c
+++ b/fs/nilfs2/file.c
@@ -142,7 +142,7 @@ const struct file_operations nilfs_file_operations = {
         .aio_write      = generic_file_aio_write,
         .unlocked_ioctl = nilfs_ioctl,
 #ifdef CONFIG_COMPAT
-        .compat_ioctl   = nilfs_ioctl,
+        .compat_ioctl   = nilfs_compat_ioctl,
 #endif  /* CONFIG_COMPAT */
         .mmap           = nilfs_file_mmap,
         .open           = generic_file_open,
diff --git a/fs/nilfs2/ioctl.c b/fs/nilfs2/ioctl.c
index 3aad6413aba4..d89173edd7fe 100644
--- a/fs/nilfs2/ioctl.c
+++ b/fs/nilfs2/ioctl.c
@@ -26,6 +26,7 @@
 #include <linux/capability.h>   /* capable() */
 #include <linux/uaccess.h>      /* copy_from_user(), copy_to_user() */
 #include <linux/vmalloc.h>
+#include <linux/compat.h>       /* compat_ptr() */
 #include <linux/mount.h>        /* mnt_want_write(), mnt_drop_write() */
 #include <linux/nilfs2_fs.h>
 #include "nilfs.h"
@@ -766,3 +767,23 @@ long nilfs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
                 return -ENOTTY;
         }
 }
+
+#ifdef CONFIG_COMPAT
+long nilfs_compat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
+{
+        switch (cmd) {
+        case FS_IOC32_GETFLAGS:
+                cmd = FS_IOC_GETFLAGS;
+                break;
+        case FS_IOC32_SETFLAGS:
+                cmd = FS_IOC_SETFLAGS;
+                break;
+        case FS_IOC32_GETVERSION:
+                cmd = FS_IOC_GETVERSION;
+                break;
+        default:
+                return -ENOIOCTLCMD;
+        }
+        return nilfs_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
+}
+#endif
diff --git a/fs/nilfs2/nilfs.h b/fs/nilfs2/nilfs.h
index 3e3acb1fdd2f..45b1fd1d0245 100644
--- a/fs/nilfs2/nilfs.h
+++ b/fs/nilfs2/nilfs.h
@@ -246,6 +246,7 @@ extern int nilfs_sync_file(struct file *, int);
 
 /* ioctl.c */
 long nilfs_ioctl(struct file *, unsigned int, unsigned long);
+long nilfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
 int nilfs_ioctl_prepare_clean_segments(struct the_nilfs *, struct nilfs_argv *,
                                        void **);