[28/36] xfs: iget for metadata inodes

Commit Message

Darrick J. Wong Dec. 6, 2024, 11:37 p.m. UTC

From: Darrick J. Wong <[e-mail]>

Source kernel commit df2e495bb92c84a401b6b90c835a9d1be84a3a0f

Create a xfs_trans_metafile_iget function for metadata inodes to ensure
that when we try to iget a metadata file, the inode is allocated and its
file mode matches the metadata file type the caller expects.

Signed-off-by: "Darrick J. Wong" <[e-mail]>
Reviewed-by: Christoph Hellwig <[e-mail]>
---
 include/libxfs.h         |    1 +
 include/xfs_inode.h      |    5 ++++
 libxfs/Makefile          |    1 +
 libxfs/inode.c           |   55 ++++++++++++++++++++++++++++++++++++++++++++++
 libxfs/libxfs_api_defs.h |    5 ++++
 libxfs/xfs_metafile.h    |   16 +++++++++++++
 6 files changed, 83 insertions(+)
 create mode 100644 libxfs/xfs_metafile.h

Patch

diff --git a/include/libxfs.h b/include/libxfs.h
index fe8e6584f1caca..0356bc57b956a9 100644
--- a/include/libxfs.h
+++ b/include/libxfs.h
@@ -95,6 +95,7 @@  struct iomap;
 #include "xfs_btree_mem.h"
 #include "xfs_parent.h"
 #include "xfs_ag_resv.h"
+#include "xfs_metafile.h"
 
 #ifndef ARRAY_SIZE
 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
diff --git a/include/xfs_inode.h b/include/xfs_inode.h
index e03521bc9aaaa2..6f2d23987d5f8a 100644
--- a/include/xfs_inode.h
+++ b/include/xfs_inode.h
@@ -210,6 +210,11 @@  static inline struct timespec64 inode_set_ctime_current(struct inode *inode)
 	return now;
 }
 
+static inline bool inode_wrong_type(const struct inode *inode, umode_t mode)
+{
+	return (inode->i_mode ^ mode) & S_IFMT;
+}
+
 typedef struct xfs_inode {
 	struct cache_node	i_node;
 	struct xfs_mount	*i_mount;	/* fs mount struct ptr */
diff --git a/libxfs/Makefile b/libxfs/Makefile
index 470583006de69a..765c84a16408f8 100644
--- a/libxfs/Makefile
+++ b/libxfs/Makefile
@@ -55,6 +55,7 @@  HFILES = \
 	xfs_inode_buf.h \
 	xfs_inode_fork.h \
 	xfs_inode_util.h \
+	xfs_metafile.h \
 	xfs_parent.h \
 	xfs_quota_defs.h \
 	xfs_refcount.h \
diff --git a/libxfs/inode.c b/libxfs/inode.c
index 9230ad24a5cb6c..1eb0bccae48906 100644
--- a/libxfs/inode.c
+++ b/libxfs/inode.c
@@ -205,6 +205,61 @@  libxfs_iget(
 	return error;
 }
 
+/*
+ * Get a metadata inode.
+ *
+ * The metafile type must match the file mode exactly.
+ */
+int
+libxfs_trans_metafile_iget(
+	struct xfs_trans	*tp,
+	xfs_ino_t		ino,
+	enum xfs_metafile_type	metafile_type,
+	struct xfs_inode	**ipp)
+{
+	struct xfs_mount	*mp = tp->t_mountp;
+	struct xfs_inode	*ip;
+	umode_t			mode;
+	int			error;
+
+	error = libxfs_iget(mp, tp, ino, 0, &ip);
+	if (error)
+		return error;
+
+	if (metafile_type == XFS_METAFILE_DIR)
+		mode = S_IFDIR;
+	else
+		mode = S_IFREG;
+	if (inode_wrong_type(VFS_I(ip), mode))
+		goto bad_rele;
+
+	*ipp = ip;
+	return 0;
+bad_rele:
+	libxfs_irele(ip);
+	return -EFSCORRUPTED;
+}
+
+/* Grab a metadata file if the caller doesn't already have a transaction. */
+int
+libxfs_metafile_iget(
+	struct xfs_mount	*mp,
+	xfs_ino_t		ino,
+	enum xfs_metafile_type	metafile_type,
+	struct xfs_inode	**ipp)
+{
+	struct xfs_trans	*tp;
+	int			error;
+
+	error = libxfs_trans_alloc_empty(mp, &tp);
+	if (error)
+		return error;
+
+	error = libxfs_trans_metafile_iget(tp, ino, metafile_type, ipp);
+	libxfs_trans_cancel(tp);
+	return error;
+}
+
 static void
 libxfs_idestroy(
 	struct xfs_inode	*ip)
diff --git a/libxfs/libxfs_api_defs.h b/libxfs/libxfs_api_defs.h
index 92e26eebabfed8..fefae9256555a0 100644
--- a/libxfs/libxfs_api_defs.h
+++ b/libxfs/libxfs_api_defs.h
@@ -184,6 +184,7 @@ 
 #define xfs_iext_next			libxfs_iext_next
 #define xfs_ifork_zap_attr		libxfs_ifork_zap_attr
 #define xfs_imap_to_bp			libxfs_imap_to_bp
+
 #define xfs_initialize_perag		libxfs_initialize_perag
 #define xfs_initialize_perag_data	libxfs_initialize_perag_data
 #define xfs_init_local_fork		libxfs_init_local_fork
@@ -208,8 +209,12 @@ 
 #define xfs_log_calc_minimum_size	libxfs_log_calc_minimum_size
 #define xfs_log_get_max_trans_res	libxfs_log_get_max_trans_res
 #define xfs_log_sb			libxfs_log_sb
+
+#define xfs_metafile_iget		libxfs_metafile_iget
+#define xfs_trans_metafile_iget		libxfs_trans_metafile_iget
 #define xfs_mode_to_ftype		libxfs_mode_to_ftype
 #define xfs_mkdir_space_res		libxfs_mkdir_space_res
+
 #define xfs_parent_addname		libxfs_parent_addname
 #define xfs_parent_finish		libxfs_parent_finish
 #define xfs_parent_hashval		libxfs_parent_hashval
diff --git a/libxfs/xfs_metafile.h b/libxfs/xfs_metafile.h
new file mode 100644
index 00000000000000..60fe1890611277
--- /dev/null
+++ b/libxfs/xfs_metafile.h
@@ -0,0 +1,16 @@ 
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (c) 2018-2024 Oracle.  All Rights Reserved.
+ * Author: Darrick J. Wong <[e-mail]>
+ */
+#ifndef __XFS_METAFILE_H__
+#define __XFS_METAFILE_H__
+
+/* Code specific to kernel/userspace; must be provided externally. */
+
+int xfs_trans_metafile_iget(struct xfs_trans *tp, xfs_ino_t ino,
+		enum xfs_metafile_type metafile_type, struct xfs_inode **ipp);
+int xfs_metafile_iget(struct xfs_mount *mp, xfs_ino_t ino,
+		enum xfs_metafile_type metafile_type, struct xfs_inode **ipp);
+
+#endif /* __XFS_METAFILE_H__ */