Merge tag 'xfs-reflink-for-linus-4.9-rc1' of git://git.kernel.org/pub/scm/linux/kerne...

[cascardo/linux.git] / fs / xfs / xfs_ioctl.c

diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
index 0d9021f..c245bed 100644 (file)
--- a/fs/xfs/xfs_ioctl.c
+++ b/fs/xfs/xfs_ioctl.c
@@ -903,6 +903,8 @@ xfs_ioc_fsgetxattr(
        xfs_ilock(ip, XFS_ILOCK_SHARED);
        fa.fsx_xflags = xfs_ip2xflags(ip);
        fa.fsx_extsize = ip->i_d.di_extsize << ip->i_mount->m_sb.sb_blocklog;
+       fa.fsx_cowextsize = ip->i_d.di_cowextsize <<
+                       ip->i_mount->m_sb.sb_blocklog;
        fa.fsx_projid = xfs_get_projid(ip);
 
        if (attr) {
@@ -973,12 +975,13 @@ xfs_set_diflags(
        if (ip->i_d.di_version < 3)
                return;
 
-       di_flags2 = 0;
+       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;
-
 }
 
 STATIC void
@@ -1031,6 +1034,14 @@ xfs_ioctl_setattr_xflags(
                        return -EINVAL;
        }
 
+       /* Clear reflink if we are actually able to set the rt flag. */
+       if ((fa->fsx_xflags & FS_XFLAG_REALTIME) && xfs_is_reflink_inode(ip))
+               ip->i_d.di_flags2 &= ~XFS_DIFLAG2_REFLINK;
+
+       /* Don't allow us to set DAX mode for a reflinked file for now. */
+       if ((fa->fsx_xflags & FS_XFLAG_DAX) && xfs_is_reflink_inode(ip))
+               return -EINVAL;
+
        /*
         * Can't modify an immutable/append-only file unless
         * we have appropriate permission.
@@ -1219,6 +1230,56 @@ xfs_ioctl_setattr_check_extsize(
        return 0;
 }
 
+/*
+ * CoW extent size hint validation rules are:
+ *
+ * 1. CoW extent size hint can only be set if reflink is enabled on the fs.
+ *    The inode does not have to have any shared blocks, but it must be a v3.
+ * 2. FS_XFLAG_COWEXTSIZE is only valid for directories and regular files;
+ *    for a directory, the hint is propagated to new files.
+ * 3. Can be changed on files & directories at any time.
+ * 4. CoW extsize hint of 0 turns off hints, clears inode flags.
+ * 5. Extent size must be a multiple of the appropriate block size.
+ * 6. The extent size hint must be limited to half the AG size to avoid
+ *    alignment extending the extent beyond the limits of the AG.
+ */
+static int
+xfs_ioctl_setattr_check_cowextsize(
+       struct xfs_inode        *ip,
+       struct fsxattr          *fa)
+{
+       struct xfs_mount        *mp = ip->i_mount;
+
+       if (!(fa->fsx_xflags & FS_XFLAG_COWEXTSIZE))
+               return 0;
+
+       if (!xfs_sb_version_hasreflink(&ip->i_mount->m_sb) ||
+           ip->i_d.di_version != 3)
+               return -EINVAL;
+
+       if (!S_ISREG(VFS_I(ip)->i_mode) && !S_ISDIR(VFS_I(ip)->i_mode))
+               return -EINVAL;
+
+       if (fa->fsx_cowextsize != 0) {
+               xfs_extlen_t    size;
+               xfs_fsblock_t   cowextsize_fsb;
+
+               cowextsize_fsb = XFS_B_TO_FSB(mp, fa->fsx_cowextsize);
+               if (cowextsize_fsb > MAXEXTLEN)
+                       return -EINVAL;
+
+               size = mp->m_sb.sb_blocksize;
+               if (cowextsize_fsb > mp->m_sb.sb_agblocks / 2)
+                       return -EINVAL;
+
+               if (fa->fsx_cowextsize % size)
+                       return -EINVAL;
+       } else
+               fa->fsx_xflags &= ~FS_XFLAG_COWEXTSIZE;
+
+       return 0;
+}
+
 static int
 xfs_ioctl_setattr_check_projid(
        struct xfs_inode        *ip,
@@ -1311,6 +1372,10 @@ xfs_ioctl_setattr(
        if (code)
                goto error_trans_cancel;
 
+       code = xfs_ioctl_setattr_check_cowextsize(ip, fa);
+       if (code)
+               goto error_trans_cancel;
+
        code = xfs_ioctl_setattr_xflags(tp, ip, fa);
        if (code)
                goto error_trans_cancel;
@@ -1346,6 +1411,12 @@ xfs_ioctl_setattr(
                ip->i_d.di_extsize = fa->fsx_extsize >> mp->m_sb.sb_blocklog;
        else
                ip->i_d.di_extsize = 0;
+       if (ip->i_d.di_version == 3 &&
+           (ip->i_d.di_flags2 & XFS_DIFLAG2_COWEXTSIZE))
+               ip->i_d.di_cowextsize = fa->fsx_cowextsize >>
+                               mp->m_sb.sb_blocklog;
+       else
+               ip->i_d.di_cowextsize = 0;
 
        code = xfs_trans_commit(tp);