Subject: [PATCH 4/8] xfs: refactor setflags to use setattr code directly
From:   "Darrick J. Wong" <darrick.wong@oracle.com>
To:     darrick.wong@oracle.com
Cc:     linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org,
        linux-ext4@vger.kernel.org, linux-btrfs@vger.kernel.org,
        linux-mm@kvack.org
Date:   Wed, 17 Apr 2019 12:04:54 -0700
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From: Darrick J. Wong <darrick.wong@oracle.com>

Refactor the SETFLAGS implementation to use the SETXATTR code directly
instead of partially constructing a struct fsxattr and calling bits and
pieces of the setxattr code.  This reduces code size and becomes
necessary in the next patch to maintain the behavior of allowing
userspace to set immutable on an immutable file so long as nothing
/else/ about the attributes change.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
 fs/xfs/xfs_ioctl.c |   76 ++++++++++++++++++++--------------------------------
 1 file changed, 29 insertions(+), 47 deletions(-)


diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
index de35cf4469f6..fdabf47532ed 100644
--- a/fs/xfs/xfs_ioctl.c
+++ b/fs/xfs/xfs_ioctl.c
@@ -882,38 +882,46 @@ xfs_di2lxflags(
 	return flags;
 }
 
-STATIC int
-xfs_ioc_fsgetxattr(
-	xfs_inode_t		*ip,
-	int			attr,
-	void			__user *arg)
+static inline void
+xfs_inode_getfsxattr(
+	struct xfs_inode	*ip,
+	bool			attr,
+	struct fsxattr		*fa)
 {
-	struct fsxattr		fa;
-
-	memset(&fa, 0, sizeof(struct fsxattr));
+	memset(fa, 0, sizeof(struct fsxattr));
 
 	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);
+	fa->fsx_xflags = xfs_ip2xflags(ip);
+	fa->fsx_extsize = XFS_FSB_TO_B(ip->i_mount, ip->i_d.di_extsize);
+	fa->fsx_cowextsize = XFS_FSB_TO_B(ip->i_mount, ip->i_d.di_cowextsize);
+	fa->fsx_projid = xfs_get_projid(ip);
 
 	if (attr) {
 		if (ip->i_afp) {
 			if (ip->i_afp->if_flags & XFS_IFEXTENTS)
-				fa.fsx_nextents = xfs_iext_count(ip->i_afp);
+				fa->fsx_nextents = xfs_iext_count(ip->i_afp);
 			else
-				fa.fsx_nextents = ip->i_d.di_anextents;
+				fa->fsx_nextents = ip->i_d.di_anextents;
 		} else
-			fa.fsx_nextents = 0;
+			fa->fsx_nextents = 0;
 	} else {
 		if (ip->i_df.if_flags & XFS_IFEXTENTS)
-			fa.fsx_nextents = xfs_iext_count(&ip->i_df);
+			fa->fsx_nextents = xfs_iext_count(&ip->i_df);
 		else
-			fa.fsx_nextents = ip->i_d.di_nextents;
+			fa->fsx_nextents = ip->i_d.di_nextents;
 	}
 	xfs_iunlock(ip, XFS_ILOCK_SHARED);
+}
+
+STATIC int
+xfs_ioc_fsgetxattr(
+	xfs_inode_t		*ip,
+	int			attr,
+	void			__user *arg)
+{
+	struct fsxattr		fa;
+
+	xfs_inode_getfsxattr(ip, attr, &fa);
 
 	if (copy_to_user(arg, &fa, sizeof(fa)))
 		return -EFAULT;
@@ -1528,10 +1536,8 @@ xfs_ioc_setxflags(
 	struct file		*filp,
 	void			__user *arg)
 {
-	struct xfs_trans	*tp;
 	struct fsxattr		fa;
 	unsigned int		flags;
-	int			join_flags = 0;
 	int			error;
 
 	if (copy_from_user(&flags, arg, sizeof(flags)))
@@ -1542,37 +1548,13 @@ xfs_ioc_setxflags(
 		      FS_SYNC_FL))
 		return -EOPNOTSUPP;
 
-	fa.fsx_xflags = xfs_merge_ioc_xflags(flags, xfs_ip2xflags(ip));
+	xfs_inode_getfsxattr(ip, false, &fa);
+	fa.fsx_xflags = xfs_merge_ioc_xflags(flags, fa.fsx_xflags);
 
 	error = mnt_want_write_file(filp);
 	if (error)
 		return error;
-
-	/*
-	 * Changing DAX config may require inode locking for mapping
-	 * invalidation. These need to be held all the way to transaction commit
-	 * or cancel time, so need to be passed through to
-	 * xfs_ioctl_setattr_get_trans() so it can apply them to the join call
-	 * appropriately.
-	 */
-	error = xfs_ioctl_setattr_dax_invalidate(ip, &fa, &join_flags);
-	if (error)
-		goto out_drop_write;
-
-	tp = xfs_ioctl_setattr_get_trans(ip, join_flags);
-	if (IS_ERR(tp)) {
-		error = PTR_ERR(tp);
-		goto out_drop_write;
-	}
-
-	error = xfs_ioctl_setattr_xflags(tp, ip, &fa);
-	if (error) {
-		xfs_trans_cancel(tp);
-		goto out_drop_write;
-	}
-
-	error = xfs_trans_commit(tp);
-out_drop_write:
+	error = xfs_ioctl_setattr(ip, &fa);
 	mnt_drop_write_file(filp);
 	return error;
 }