1 files changed, 142 insertions, 0 deletions
diff --git a/fs/jfs/jfs_metapage.h b/fs/jfs/jfs_metapage.h
new file mode 100644
index 000000000..4179f9df4
--- /dev/null
+++ b/fs/jfs/jfs_metapage.h
@@ -0,0 +1,142 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ *   Copyright (C) International Business Machines Corp., 2000-2002
+ *   Portions Copyright (C) Christoph Hellwig, 2001-2002
+ */
+#ifndef	_H_JFS_METAPAGE
+#define _H_JFS_METAPAGE
+
+#include <linux/pagemap.h>
+
+struct metapage {
+	/* Common logsyncblk prefix (see jfs_logmgr.h) */
+	u16 xflag;
+	u16 unused;
+	lid_t lid;
+	int lsn;
+	struct list_head synclist;
+	/* End of logsyncblk prefix */
+
+	unsigned long flag;	/* See Below */
+	unsigned long count;	/* Reference count */
+	void *data;		/* Data pointer */
+	sector_t index;		/* block address of page */
+	wait_queue_head_t wait;
+
+	/* implementation */
+	struct page *page;
+	struct super_block *sb;
+	unsigned int logical_size;
+
+	/* Journal management */
+	int clsn;
+	int nohomeok;
+	struct jfs_log *log;
+};
+
+/* metapage flag */
+#define META_locked	0
+#define META_dirty	2
+#define META_sync	3
+#define META_discard	4
+#define META_forcewrite	5
+#define META_io		6
+
+#define mark_metapage_dirty(mp) set_bit(META_dirty, &(mp)->flag)
+
+/* function prototypes */
+extern int metapage_init(void);
+extern void metapage_exit(void);
+extern struct metapage *__get_metapage(struct inode *inode,
+				  unsigned long lblock, unsigned int size,
+				  int absolute, unsigned long new);
+
+#define read_metapage(inode, lblock, size, absolute)\
+	 __get_metapage(inode, lblock, size, absolute, false)
+
+#define get_metapage(inode, lblock, size, absolute)\
+	 __get_metapage(inode, lblock, size, absolute, true)
+
+extern void release_metapage(struct metapage *);
+extern void grab_metapage(struct metapage *);
+extern void force_metapage(struct metapage *);
+
+/*
+ * hold_metapage and put_metapage are used in conjunction.  The page lock
+ * is not dropped between the two, so no other threads can get or release
+ * the metapage
+ */
+extern void hold_metapage(struct metapage *);
+extern void put_metapage(struct metapage *);
+
+static inline void write_metapage(struct metapage *mp)
+{
+	set_bit(META_dirty, &mp->flag);
+	release_metapage(mp);
+}
+
+static inline void flush_metapage(struct metapage *mp)
+{
+	set_bit(META_sync, &mp->flag);
+	write_metapage(mp);
+}
+
+static inline void discard_metapage(struct metapage *mp)
+{
+	clear_bit(META_dirty, &mp->flag);
+	set_bit(META_discard, &mp->flag);
+	release_metapage(mp);
+}
+
+static inline void metapage_nohomeok(struct metapage *mp)
+{
+	struct page *page = mp->page;
+	lock_page(page);
+	if (!mp->nohomeok++) {
+		mark_metapage_dirty(mp);
+		get_page(page);
+		wait_on_page_writeback(page);
+	}
+	unlock_page(page);
+}
+
+/*
+ * This serializes access to mp->lsn when metapages are added to logsynclist
+ * without setting nohomeok.  i.e. updating imap & dmap
+ */
+static inline void metapage_wait_for_io(struct metapage *mp)
+{
+	if (test_bit(META_io, &mp->flag))
+		wait_on_page_writeback(mp->page);
+}
+
+/*
+ * This is called when already holding the metapage
+ */
+static inline void _metapage_homeok(struct metapage *mp)
+{
+	if (!--mp->nohomeok)
+		put_page(mp->page);
+}
+
+static inline void metapage_homeok(struct metapage *mp)
+{
+	hold_metapage(mp);
+	_metapage_homeok(mp);
+	put_metapage(mp);
+}
+
+extern const struct address_space_operations jfs_metapage_aops;
+
+/*
+ * This routines invalidate all pages for an extent.
+ */
+extern void __invalidate_metapages(struct inode *, s64, int);
+#define invalidate_pxd_metapages(ip, pxd) \
+	__invalidate_metapages((ip), addressPXD(&(pxd)), lengthPXD(&(pxd)))
+#define invalidate_dxd_metapages(ip, dxd) \
+	__invalidate_metapages((ip), addressDXD(&(dxd)), lengthDXD(&(dxd)))
+#define invalidate_xad_metapages(ip, xad) \
+	__invalidate_metapages((ip), addressXAD(&(xad)), lengthXAD(&(xad)))
+
+#endif				/* _H_JFS_METAPAGE */