[PATCH 5.4 129/203] gfs2: add compat_ioctl support

Greg Kroah-Hartman
2020-01-16T23:44:16Z

From: Arnd Bergmann <arnd@arndb.de>

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>

---
fs/gfs2/file.c | 30 ++++++++++++++++++++++++++++++
1 file changed, 30 insertions(+)

--- 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
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_f
.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_f
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_f
.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_f
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,