gfs2: add compat_ioctl support

commit 8d0980704842e8a68df2c3164c1c165e5c7ebc08 upstream.

Out of the four ioctl commands supported on gfs2, only FITRIM
works in compat mode.

Add a proper handler based on the ext4 implementation.

Fixes: 6ddc5c3ddf25 ("gfs2: getlabel support")
Reviewed-by: Bob Peterson <rpeterso@redhat.com>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c
index c53e3b892210f785d8ca6d2d4b01741b2e906207..01ff37b76652cdaeb5cd5fc01f6a1a1ca6f5b189 100644 (file)
--- a/fs/gfs2/file.c
+++ b/fs/gfs2/file.c
@@ -6,6 +6,7 @@
 
 #include <linux/slab.h>
 #include <linux/spinlock.h>
+#include <linux/compat.h>
 #include <linux/completion.h>
 #include <linux/buffer_head.h>
 #include <linux/pagemap.h>
@@ -354,6 +355,31 @@ static long gfs2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
        return -ENOTTY;
 }
 
+#ifdef CONFIG_COMPAT
+static long gfs2_compat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
+{
+       switch(cmd) {
+       /* These are just misnamed, they actually get/put from/to user an int */
+       case FS_IOC32_GETFLAGS:
+               cmd = FS_IOC_GETFLAGS;
+               break;
+       case FS_IOC32_SETFLAGS:
+               cmd = FS_IOC_SETFLAGS;
+               break;
+       /* Keep this list in sync with gfs2_ioctl */
+       case FITRIM:
+       case FS_IOC_GETFSLABEL:
+               break;
+       default:
+               return -ENOIOCTLCMD;
+       }
+
+       return gfs2_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
+}
+#else
+#define gfs2_compat_ioctl NULL
+#endif
+
 /**
  * gfs2_size_hint - Give a hint to the size of a write request
  * @filep: The struct file
@@ -1294,6 +1320,7 @@ const struct file_operations gfs2_file_fops = {
        .write_iter     = gfs2_file_write_iter,
        .iopoll         = iomap_dio_iopoll,
        .unlocked_ioctl = gfs2_ioctl,
+       .compat_ioctl   = gfs2_compat_ioctl,
        .mmap           = gfs2_mmap,
        .open           = gfs2_open,
        .release        = gfs2_release,
@@ -1309,6 +1336,7 @@ const struct file_operations gfs2_file_fops = {
 const struct file_operations gfs2_dir_fops = {
        .iterate_shared = gfs2_readdir,
        .unlocked_ioctl = gfs2_ioctl,
+       .compat_ioctl   = gfs2_compat_ioctl,
        .open           = gfs2_open,
        .release        = gfs2_release,
        .fsync          = gfs2_fsync,
@@ -1325,6 +1353,7 @@ const struct file_operations gfs2_file_fops_nolock = {
        .write_iter     = gfs2_file_write_iter,
        .iopoll         = iomap_dio_iopoll,
        .unlocked_ioctl = gfs2_ioctl,
+       .compat_ioctl   = gfs2_compat_ioctl,
        .mmap           = gfs2_mmap,
        .open           = gfs2_open,
        .release        = gfs2_release,
@@ -1338,6 +1367,7 @@ const struct file_operations gfs2_file_fops_nolock = {
 const struct file_operations gfs2_dir_fops_nolock = {
        .iterate_shared = gfs2_readdir,
        .unlocked_ioctl = gfs2_ioctl,
+       .compat_ioctl   = gfs2_compat_ioctl,
        .open           = gfs2_open,
        .release        = gfs2_release,
        .fsync          = gfs2_fsync,