[1/5] xfs: Propagate dentry down to inode_change_ok()
diff mbox

Message ID 1464279600-13009-2-git-send-email-jack@suse.cz
State New
Headers show

Commit Message

Jan Kara May 26, 2016, 4:19 p.m. UTC
To avoid clearing of capabilities or security related extended
attributes too early, inode_change_ok() will need to take dentry instead
of inode. Propagate dentry down to functions calling inode_change_ok().
This is rather straightforward except for xfs_set_mode() function which
does not have dentry easily available. Luckily that function does not
call inode_change_ok() anyway so we just have to do a little dance with
function prototypes.

Signed-off-by: Jan Kara <jack@suse.cz>
---
 fs/xfs/xfs_file.c  |  2 +-
 fs/xfs/xfs_inode.c |  2 +-
 fs/xfs/xfs_ioctl.c |  2 +-
 fs/xfs/xfs_iops.c  | 60 ++++++++++++++++++++++++++++++++++--------------------
 fs/xfs/xfs_iops.h  |  2 +-
 5 files changed, 42 insertions(+), 26 deletions(-)

Comments

Dave Chinner May 26, 2016, 9:53 p.m. UTC | #1
On Thu, May 26, 2016 at 06:19:56PM +0200, Jan Kara wrote:
> To avoid clearing of capabilities or security related extended
> attributes too early, inode_change_ok() will need to take dentry instead
> of inode. Propagate dentry down to functions calling inode_change_ok().
> This is rather straightforward except for xfs_set_mode() function which
> does not have dentry easily available. Luckily that function does not
> call inode_change_ok() anyway so we just have to do a little dance with
> function prototypes.

The idea behind the change is good, but I think the little dance
could be improved as it makes the layering of the code seem weirdly
unbalanced to me. e.g.

xfs_vn_setattr()
  xfs_vn_setattr_size()		<<<< inode_change_ok() here

xfs_vn_setattr()
  xfs_vn_setattr_nonsize()	<<<< inode_change_ok() here
    xfs_setattr_nonsize()

xfs_vn_setattr()
  xfs_vn_setattr_size()
    xfs_vn_setattr_nonsize()	<<<< inode_change_ok() here
      xfs_setattr_nonsize()

And to be more confusing, the externally callable functions for the
rest of the XFS code are now xfs_vn_setattr_size() and
xfs_setattr_nonsize() which now have different calling context
limitations.

I think adding a little symmetric make sense. i.e:

xfs_vn_change_ok(dentry, iattr)
{
+	if (mp->m_flags & XFS_MOUNT_RDONLY)
+		return -EROFS;
+
+	if (XFS_FORCED_SHUTDOWN(mp))
+		return -EIO;
+
+	error = inode_change_ok(inode, iattr);
+	if (error)
+		return error;
+
}

xfs_vn_setattr_size(d, i)
{
	xfs_vn_change_ok(d, i)
	xfs_setattr_size(ip, i)
}

xfs_vn_setattr_nonsize(d, i)
{
	xfs_vn_change_ok(d, i)
	xfs_setattr_nonsize(ip, i)
}

xfs_vn_setattr(d, i)
{
	xfs_vn_change_ok(d, i)
	<rest of xfs_vn_setattr unchanged>
}

And remove the inode_change_ok() code from xfs_setattr_size and
xfs_setattr_nonsize() completely.  You've already done this with
xfs_vn_setattr_nonsize() - it just needs to be made symmetric to
keep a clean layering between VFS interfaces and internal XFS
interfaces...

Cheers,

Dave.

Patch
diff mbox

diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 85ce3032f815..b562cc5faae1 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -1024,7 +1024,7 @@  xfs_file_fallocate(
 
 		iattr.ia_valid = ATTR_SIZE;
 		iattr.ia_size = new_size;
-		error = xfs_setattr_size(ip, &iattr);
+		error = xfs_vn_setattr_size(file_dentry(file), &iattr);
 		if (error)
 			goto out_unlock;
 	}
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index 96f606deee31..6adfc757d8c6 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -1724,7 +1724,7 @@  xfs_inactive_truncate(
 	/*
 	 * Log the inode size first to prevent stale data exposure in the event
 	 * of a system crash before the truncate completes. See the related
-	 * comment in xfs_setattr_size() for details.
+	 * comment in xfs_vn_setattr_size() for details.
 	 */
 	ip->i_d.di_size = 0;
 	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
index bcb6c19ce3ea..1d441bfacf59 100644
--- a/fs/xfs/xfs_ioctl.c
+++ b/fs/xfs/xfs_ioctl.c
@@ -731,7 +731,7 @@  xfs_ioc_space(
 		iattr.ia_valid = ATTR_SIZE;
 		iattr.ia_size = bf->l_start;
 
-		error = xfs_setattr_size(ip, &iattr);
+		error = xfs_vn_setattr_size(file_dentry(filp), &iattr);
 		break;
 	default:
 		ASSERT(0);
diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
index fb7dc61f4a29..ef050f69589b 100644
--- a/fs/xfs/xfs_iops.c
+++ b/fs/xfs/xfs_iops.c
@@ -527,6 +527,12 @@  xfs_setattr_time(
 		inode->i_mtime = iattr->ia_mtime;
 }
 
+/*
+ * Set non-size attributes of an inode.
+ *
+ * Caution: The caller of this function is responsible for calling
+ * inode_change_ok() or otherwise verifying the change is fine.
+ */
 int
 xfs_setattr_nonsize(
 	struct xfs_inode	*ip,
@@ -543,21 +549,6 @@  xfs_setattr_nonsize(
 	struct xfs_dquot	*udqp = NULL, *gdqp = NULL;
 	struct xfs_dquot	*olddquot1 = NULL, *olddquot2 = NULL;
 
-	trace_xfs_setattr(ip);
-
-	/* If acls are being inherited, we already have this checked */
-	if (!(flags & XFS_ATTR_NOACL)) {
-		if (mp->m_flags & XFS_MOUNT_RDONLY)
-			return -EROFS;
-
-		if (XFS_FORCED_SHUTDOWN(mp))
-			return -EIO;
-
-		error = inode_change_ok(inode, iattr);
-		if (error)
-			return error;
-	}
-
 	ASSERT((mask & ATTR_SIZE) == 0);
 
 	/*
@@ -731,14 +722,39 @@  out_trans_cancel:
 	return error;
 }
 
+static int
+xfs_vn_setattr_nonsize(
+	struct dentry		*dentry,
+	struct iattr		*iattr)
+{
+	struct inode		*inode = d_inode(dentry);
+	struct xfs_inode	*ip = XFS_I(inode);
+	struct xfs_mount	*mp = ip->i_mount;
+	int error;
+
+	trace_xfs_setattr(ip);
+
+	if (mp->m_flags & XFS_MOUNT_RDONLY)
+		return -EROFS;
+
+	if (XFS_FORCED_SHUTDOWN(mp))
+		return -EIO;
+
+	error = inode_change_ok(inode, iattr);
+	if (error)
+		return error;
+	return xfs_setattr_nonsize(ip, iattr, 0);
+}
+
 /*
  * Truncate file.  Must have write permission and not be a directory.
  */
 int
-xfs_setattr_size(
-	struct xfs_inode	*ip,
+xfs_vn_setattr_size(
+	struct dentry		*dentry,
 	struct iattr		*iattr)
 {
+	struct xfs_inode	*ip = XFS_I(d_inode(dentry));
 	struct xfs_mount	*mp = ip->i_mount;
 	struct inode		*inode = VFS_I(ip);
 	xfs_off_t		oldsize, newsize;
@@ -779,7 +795,7 @@  xfs_setattr_size(
 		 * Use the regular setattr path to update the timestamps.
 		 */
 		iattr->ia_valid &= ~ATTR_SIZE;
-		return xfs_setattr_nonsize(ip, iattr, 0);
+		return xfs_vn_setattr_nonsize(dentry, iattr);
 	}
 
 	/*
@@ -936,11 +952,11 @@  xfs_vn_setattr(
 	struct dentry		*dentry,
 	struct iattr		*iattr)
 {
-	struct xfs_inode	*ip = XFS_I(d_inode(dentry));
 	int			error;
 
 	if (iattr->ia_valid & ATTR_SIZE) {
-		uint		iolock = XFS_IOLOCK_EXCL;
+		struct xfs_inode	*ip = XFS_I(d_inode(dentry));
+		uint			iolock = XFS_IOLOCK_EXCL;
 
 		xfs_ilock(ip, iolock);
 		error = xfs_break_layouts(d_inode(dentry), &iolock, true);
@@ -948,11 +964,11 @@  xfs_vn_setattr(
 			xfs_ilock(ip, XFS_MMAPLOCK_EXCL);
 			iolock |= XFS_MMAPLOCK_EXCL;
 
-			error = xfs_setattr_size(ip, iattr);
+			error = xfs_vn_setattr_size(dentry, iattr);
 		}
 		xfs_iunlock(ip, iolock);
 	} else {
-		error = xfs_setattr_nonsize(ip, iattr, 0);
+		error = xfs_vn_setattr_nonsize(dentry, iattr);
 	}
 
 	return error;
diff --git a/fs/xfs/xfs_iops.h b/fs/xfs/xfs_iops.h
index a0f84abb0d09..8648037a1c1b 100644
--- a/fs/xfs/xfs_iops.h
+++ b/fs/xfs/xfs_iops.h
@@ -33,6 +33,6 @@  extern ssize_t xfs_vn_listxattr(struct dentry *, char *data, size_t size);
 extern void xfs_setattr_time(struct xfs_inode *ip, struct iattr *iattr);
 extern int xfs_setattr_nonsize(struct xfs_inode *ip, struct iattr *vap,
 			       int flags);
-extern int xfs_setattr_size(struct xfs_inode *ip, struct iattr *vap);
+extern int xfs_vn_setattr_size(struct dentry *dentry, struct iattr *vap);
 
 #endif /* __XFS_IOPS_H__ */