xfs: pack icreate initialization parameters into a separate structure

Callers that want to create an inode currently pass all possible file
attribute values for the new inode into xfs_init_new_inode as ten
separate parameters.  This causes two code maintenance issues: first, we
have large multi-line call sites which programmers must read carefully
to make sure they did not accidentally invert a value.  Second, all
three file id parameters must be passed separately to the quota
functions; any discrepancy results in quota count errors.

Clean this up by creating a new icreate_args structure to hold all this
information, some helpers to initialize them properly, and make the
callers pass this structure through to the creation function, whose name
we shorten to xfs_icreate.  This eliminates the issues, enables us to
keep the inode init code in sync with userspace via libxfs, and is
needed for future metadata directory tree management.

(A subsequent cleanup will also fix the quota alloc calls.)

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

1 files changed, 58 insertions, 33 deletions

diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index afc798ffa164..4f13ad0fa14e 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -662,18 +662,13 @@ xfs_inode_inherit_flags2(
  * Caller is responsible for unlocking the inode manually upon return
  */
 int
-xfs_init_new_inode(
-	struct mnt_idmap	*idmap,
+xfs_icreate(
 	struct xfs_trans	*tp,
-	struct xfs_inode	*pip,
 	xfs_ino_t		ino,
-	umode_t			mode,
-	xfs_nlink_t		nlink,
-	dev_t			rdev,
-	prid_t			prid,
-	bool			init_xattrs,
+	const struct xfs_icreate_args *args,
 	struct xfs_inode	**ipp)
 {
+	struct xfs_inode	*pip = args->pip;
 	struct inode		*dir = pip ? VFS_I(pip) : NULL;
 	struct xfs_mount	*mp = tp->t_mountp;
 	struct xfs_inode	*ip;
@@ -706,26 +701,43 @@ xfs_init_new_inode(
 
 	ASSERT(ip != NULL);
 	inode = VFS_I(ip);
-	set_nlink(inode, nlink);
-	inode->i_rdev = rdev;
-	ip->i_projid = prid;
-
-	if (dir && !(dir->i_mode & S_ISGID) && xfs_has_grpid(mp)) {
-		inode_fsuid_set(inode, idmap);
-		inode->i_gid = dir->i_gid;
-		inode->i_mode = mode;
+
+	if (args->flags & XFS_ICREATE_TMPFILE)
+		set_nlink(inode, 0);
+	else if (S_ISDIR(args->mode))
+		set_nlink(inode, 2);
+	else
+		set_nlink(inode, 1);
+	inode->i_rdev = args->rdev;
+
+	if (!args->idmap || pip == NULL) {
+		/* creating a tree root, sb rooted, or detached file */
+		inode->i_uid = GLOBAL_ROOT_UID;
+		inode->i_gid = GLOBAL_ROOT_GID;
+		ip->i_projid = 0;
+		inode->i_mode = args->mode;
 	} else {
-		inode_init_owner(idmap, inode, dir, mode);
-	}
+		/* creating a child in the directory tree */
+		if (dir && !(dir->i_mode & S_ISGID) && xfs_has_grpid(mp)) {
+			inode_fsuid_set(inode, args->idmap);
+			inode->i_gid = dir->i_gid;
+			inode->i_mode = args->mode;
+		} else {
+			inode_init_owner(args->idmap, inode, dir, args->mode);
+		}
 
-	/*
-	 * If the group ID of the new file does not match the effective group
-	 * ID or one of the supplementary group IDs, the S_ISGID bit is cleared
-	 * (and only if the irix_sgid_inherit compatibility variable is set).
-	 */
-	if (irix_sgid_inherit && (inode->i_mode & S_ISGID) &&
-	    !vfsgid_in_group_p(i_gid_into_vfsgid(idmap, inode)))
-		inode->i_mode &= ~S_ISGID;
+		/*
+		 * If the group ID of the new file does not match the effective
+		 * group ID or one of the supplementary group IDs, the S_ISGID
+		 * bit is cleared (and only if the irix_sgid_inherit
+		 * compatibility variable is set).
+		 */
+		if (irix_sgid_inherit && (inode->i_mode & S_ISGID) &&
+		    !vfsgid_in_group_p(i_gid_into_vfsgid(args->idmap, inode)))
+			inode->i_mode &= ~S_ISGID;
+
+		ip->i_projid = pip ? xfs_get_initial_prid(pip) : 0;
+	}
 
 	ip->i_disk_size = 0;
 	ip->i_df.if_nextents = 0;
@@ -745,7 +757,7 @@ xfs_init_new_inode(
 	}
 
 	flags = XFS_ILOG_CORE;
-	switch (mode & S_IFMT) {
+	switch (args->mode & S_IFMT) {
 	case S_IFIFO:
 	case S_IFCHR:
 	case S_IFBLK:
@@ -778,7 +790,7 @@ xfs_init_new_inode(
 	 * this saves us from needing to run a separate transaction to set the
 	 * fork offset in the immediate future.
 	 */
-	if (init_xattrs) {
+	if (args->flags & XFS_ICREATE_INIT_XATTRS) {
 		ip->i_forkoff = xfs_default_attroffset(ip) >> 3;
 		xfs_ifork_init_attr(ip, XFS_DINODE_FMT_EXTENTS, 0);
 
@@ -941,6 +953,13 @@ xfs_create(
 	bool			init_xattrs,
 	xfs_inode_t		**ipp)
 {
+	struct xfs_icreate_args	args = {
+		.idmap		= idmap,
+		.pip		= dp,
+		.rdev		= rdev,
+		.mode		= mode,
+		.flags		= init_xattrs ? XFS_ICREATE_INIT_XATTRS : 0,
+	};
 	int			is_dir = S_ISDIR(mode);
 	struct xfs_mount	*mp = dp->i_mount;
 	struct xfs_inode	*ip = NULL;
@@ -1016,8 +1035,7 @@ xfs_create(
 	 */
 	error = xfs_dialloc(&tp, dp->i_ino, mode, &ino);
 	if (!error)
-		error = xfs_init_new_inode(idmap, tp, dp, ino, mode,
-				is_dir ? 2 : 1, rdev, prid, init_xattrs, &ip);
+		error = xfs_icreate(tp, ino, &args, &ip);
 	if (error)
 		goto out_trans_cancel;
 
@@ -1125,11 +1143,17 @@ xfs_create_tmpfile(
 	bool			init_xattrs,
 	struct xfs_inode	**ipp)
 {
+	struct xfs_icreate_args	args = {
+		.idmap		= idmap,
+		.pip		= dp,
+		.mode		= mode,
+		.flags		= XFS_ICREATE_TMPFILE,
+	};
 	struct xfs_mount	*mp = dp->i_mount;
 	struct xfs_inode	*ip = NULL;
 	struct xfs_trans	*tp = NULL;
 	int			error;
-	prid_t                  prid;
+	prid_t			prid;
 	struct xfs_dquot	*udqp = NULL;
 	struct xfs_dquot	*gdqp = NULL;
 	struct xfs_dquot	*pdqp = NULL;
@@ -1141,6 +1165,8 @@ xfs_create_tmpfile(
 		return -EIO;
 
 	prid = xfs_get_initial_prid(dp);
+	if (init_xattrs)
+		args.flags |= XFS_ICREATE_INIT_XATTRS;
 
 	/*
 	 * Make sure that we have allocated dquot(s) on disk.  The uid/gid
@@ -1164,8 +1190,7 @@ xfs_create_tmpfile(
 
 	error = xfs_dialloc(&tp, dp->i_ino, mode, &ino);
 	if (!error)
-		error = xfs_init_new_inode(idmap, tp, dp, ino, mode,
-				0, 0, prid, init_xattrs, &ip);
+		error = xfs_icreate(tp, ino, &args, &ip);
 	if (error)
 		goto out_trans_cancel;