[PATCH] JFS: Support page sizes greater than 4K

jfs has never worked on architecutures where the page size was not 4K.

Signed-off-by: Dave Kleikamp <shaggy@austin.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 59 insertions, 21 deletions

diff --git a/fs/jfs/jfs_metapage.h b/fs/jfs/jfs_metapage.h
index 0e58aba58c37..991e9fb84c75 100644
--- a/fs/jfs/jfs_metapage.h
+++ b/fs/jfs/jfs_metapage.h
@@ -33,38 +33,27 @@ struct metapage {
         unsigned long flag;     /* See Below */
         unsigned long count;    /* Reference count */
         void *data;             /* Data pointer */
-
-        /* list management stuff */
-        struct metapage *hash_prev;
-        struct metapage *hash_next;     /* Also used for free list */
-
-        /*
-         * mapping & index become redundant, but we need these here to
-         * add the metapage to the hash before we have the real page
-         */
-        struct address_space *mapping;
-        unsigned long index;
+        sector_t index;         /* block address of page */
         wait_queue_head_t wait;
 
         /* implementation */
         struct page *page;
-        unsigned long logical_size;
+        unsigned int logical_size;
 
         /* Journal management */
         int clsn;
-        atomic_t nohomeok;
+        int nohomeok;
         struct jfs_log *log;
 };
 
 /* metapage flag */
 #define META_locked     0
-#define META_absolute   1
-#define META_free       2
-#define META_dirty      3
-#define META_sync       4
-#define META_discard    5
-#define META_forced     6
-#define META_stale      7
+#define META_free       1
+#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)
 
@@ -80,7 +69,16 @@ extern struct metapage *__get_metapage(struct inode *inode,
          __get_metapage(inode, lblock, size, absolute, TRUE)
 
 extern void release_metapage(struct metapage *);
-extern void hold_metapage(struct metapage *, int);
+extern void grab_metapage(struct metapage *);
+extern void force_metapage(struct metapage *);
+
+/*
+ * hold_metapage and put_metapage are used in conjuction.  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)
 {
@@ -101,6 +99,46 @@ static inline void discard_metapage(struct metapage *mp)
         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 struct address_space_operations jfs_metapage_aops;
+
 /*
  * This routines invalidate all pages for an extent.
  */