[PATCH 4.9 75/78] xfs: dont set v3 xflags for v2 inodes

From: Greg Kroah-Hartman
Date: Mon Sep 18 2017 - 05:17:51 EST


4.9-stable review patch. If anyone has any objections, please let me know.

------------------

From: Christoph Hellwig <hch@xxxxxx>

commit dd60687ee541ca3f6df8758f38e6f22f57c42a37 upstream.

Reject attempts to set XFLAGS that correspond to di_flags2 inode flags
if the inode isn't a v3 inode, because di_flags2 only exists on v3.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/xfs/xfs_ioctl.c | 38 +++++++++++++++++++++++++-------------
1 file changed, 25 insertions(+), 13 deletions(-)

--- a/fs/xfs/xfs_ioctl.c
+++ b/fs/xfs/xfs_ioctl.c
@@ -928,16 +928,15 @@ xfs_ioc_fsgetxattr(
return 0;
}

-STATIC void
-xfs_set_diflags(
+STATIC uint16_t
+xfs_flags2diflags(
struct xfs_inode *ip,
unsigned int xflags)
{
- unsigned int di_flags;
- uint64_t di_flags2;
-
/* can't set PREALLOC this way, just preserve it */
- di_flags = (ip->i_d.di_flags & XFS_DIFLAG_PREALLOC);
+ uint16_t di_flags =
+ (ip->i_d.di_flags & XFS_DIFLAG_PREALLOC);
+
if (xflags & FS_XFLAG_IMMUTABLE)
di_flags |= XFS_DIFLAG_IMMUTABLE;
if (xflags & FS_XFLAG_APPEND)
@@ -967,19 +966,24 @@ xfs_set_diflags(
if (xflags & FS_XFLAG_EXTSIZE)
di_flags |= XFS_DIFLAG_EXTSIZE;
}
- ip->i_d.di_flags = di_flags;

- /* diflags2 only valid for v3 inodes. */
- if (ip->i_d.di_version < 3)
- return;
+ return di_flags;
+}
+
+STATIC uint64_t
+xfs_flags2diflags2(
+ struct xfs_inode *ip,
+ unsigned int xflags)
+{
+ uint64_t di_flags2 =
+ (ip->i_d.di_flags2 & XFS_DIFLAG2_REFLINK);

- di_flags2 = (ip->i_d.di_flags2 & XFS_DIFLAG2_REFLINK);
if (xflags & FS_XFLAG_DAX)
di_flags2 |= XFS_DIFLAG2_DAX;
if (xflags & FS_XFLAG_COWEXTSIZE)
di_flags2 |= XFS_DIFLAG2_COWEXTSIZE;

- ip->i_d.di_flags2 = di_flags2;
+ return di_flags2;
}

STATIC void
@@ -1020,6 +1024,7 @@ xfs_ioctl_setattr_xflags(
struct fsxattr *fa)
{
struct xfs_mount *mp = ip->i_mount;
+ uint64_t di_flags2;

/* Can't change realtime flag if any extents are allocated. */
if ((ip->i_d.di_nextents || ip->i_delayed_blks) &&
@@ -1050,7 +1055,14 @@ xfs_ioctl_setattr_xflags(
!capable(CAP_LINUX_IMMUTABLE))
return -EPERM;

- xfs_set_diflags(ip, fa->fsx_xflags);
+ /* diflags2 only valid for v3 inodes. */
+ di_flags2 = xfs_flags2diflags2(ip, fa->fsx_xflags);
+ if (di_flags2 && ip->i_d.di_version < 3)
+ return -EINVAL;
+
+ ip->i_d.di_flags = xfs_flags2diflags(ip, fa->fsx_xflags);
+ ip->i_d.di_flags2 = di_flags2;
+
xfs_diflags_to_linux(ip);
xfs_trans_ichgtime(tp, ip, XFS_ICHGTIME_CHG);
xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);