File-copy from v4.4.100
This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Please refer to that tree for all history prior to this point.
Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/fs/jfs/jfs_metapage.h b/fs/jfs/jfs_metapage.h
new file mode 100644
index 0000000..337e9e5
--- /dev/null
+++ b/fs/jfs/jfs_metapage.h
@@ -0,0 +1,154 @@
+/*
+ * Copyright (C) International Business Machines Corp., 2000-2002
+ * Portions Copyright (C) Christoph Hellwig, 2001-2002
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
+ * the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+#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;
+ 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);
+ page_cache_get(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)
+ page_cache_release(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 */