vserver 2.0 rc7
[linux-2.6.git] / fs / jfs / jfs_metapage.c
index 1cd9bdf..41bf078 100644 (file)
@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) International Business Machines Corp., 2000-2003
+ *   Copyright (C) International Business Machines Corp., 2000-2005
  *   Portions Copyright (C) Christoph Hellwig, 2001-2002
  *
  *   This program is free software;  you can redistribute it and/or modify
@@ -18,6 +18,8 @@
  */
 
 #include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/bio.h>
 #include <linux/init.h>
 #include <linux/buffer_head.h>
 #include <linux/mempool.h>
@@ -28,8 +30,6 @@
 #include "jfs_txnmgr.h"
 #include "jfs_debug.h"
 
-static DEFINE_SPINLOCK(meta_lock);
-
 #ifdef CONFIG_JFS_STATISTICS
 static struct {
        uint    pagealloc;      /* # of page allocations */
@@ -38,22 +38,8 @@ static struct {
 } mpStat;
 #endif
 
-
-#define HASH_BITS 10           /* This makes hash_table 1 4K page */
-#define HASH_SIZE (1 << HASH_BITS)
-static struct metapage **hash_table = NULL;
-static unsigned long hash_order;
-
-
-static inline int metapage_locked(struct metapage *mp)
-{
-       return test_bit(META_locked, &mp->flag);
-}
-
-static inline int trylock_metapage(struct metapage *mp)
-{
-       return test_and_set_bit(META_locked, &mp->flag);
-}
+#define metapage_locked(mp) test_bit(META_locked, &(mp)->flag)
+#define trylock_metapage(mp) test_and_set_bit(META_locked, &(mp)->flag)
 
 static inline void unlock_metapage(struct metapage *mp)
 {
@@ -61,26 +47,26 @@ static inline void unlock_metapage(struct metapage *mp)
        wake_up(&mp->wait);
 }
 
-static void __lock_metapage(struct metapage *mp)
+static inline void __lock_metapage(struct metapage *mp)
 {
        DECLARE_WAITQUEUE(wait, current);
-
        INCREMENT(mpStat.lockwait);
-
        add_wait_queue_exclusive(&mp->wait, &wait);
        do {
                set_current_state(TASK_UNINTERRUPTIBLE);
                if (metapage_locked(mp)) {
-                       spin_unlock(&meta_lock);
+                       unlock_page(mp->page);
                        schedule();
-                       spin_lock(&meta_lock);
+                       lock_page(mp->page);
                }
        } while (trylock_metapage(mp));
        __set_current_state(TASK_RUNNING);
        remove_wait_queue(&mp->wait, &wait);
 }
 
-/* needs meta_lock */
+/*
+ * Must have mp->page locked
+ */
 static inline void lock_metapage(struct metapage *mp)
 {
        if (trylock_metapage(mp))
@@ -91,6 +77,110 @@ static inline void lock_metapage(struct metapage *mp)
 static kmem_cache_t *metapage_cache;
 static mempool_t *metapage_mempool;
 
+#define MPS_PER_PAGE (PAGE_CACHE_SIZE >> L2PSIZE)
+
+#if MPS_PER_PAGE > 1
+
+struct meta_anchor {
+       int mp_count;
+       atomic_t io_count;
+       struct metapage *mp[MPS_PER_PAGE];
+};
+#define mp_anchor(page) ((struct meta_anchor *)page->private)
+
+static inline struct metapage *page_to_mp(struct page *page, uint offset)
+{
+       if (!PagePrivate(page))
+               return NULL;
+       return mp_anchor(page)->mp[offset >> L2PSIZE];
+}
+
+static inline int insert_metapage(struct page *page, struct metapage *mp)
+{
+       struct meta_anchor *a;
+       int index;
+       int l2mp_blocks;        /* log2 blocks per metapage */
+
+       if (PagePrivate(page))
+               a = mp_anchor(page);
+       else {
+               a = kmalloc(sizeof(struct meta_anchor), GFP_NOFS);
+               if (!a)
+                       return -ENOMEM;
+               memset(a, 0, sizeof(struct meta_anchor));
+               page->private = (unsigned long)a;
+               SetPagePrivate(page);
+               kmap(page);
+       }
+
+       if (mp) {
+               l2mp_blocks = L2PSIZE - page->mapping->host->i_blkbits;
+               index = (mp->index >> l2mp_blocks) & (MPS_PER_PAGE - 1);
+               a->mp_count++;
+               a->mp[index] = mp;
+       }
+
+       return 0;
+}
+
+static inline void remove_metapage(struct page *page, struct metapage *mp)
+{
+       struct meta_anchor *a = mp_anchor(page);
+       int l2mp_blocks = L2PSIZE - page->mapping->host->i_blkbits;
+       int index;
+
+       index = (mp->index >> l2mp_blocks) & (MPS_PER_PAGE - 1);
+
+       BUG_ON(a->mp[index] != mp);
+
+       a->mp[index] = NULL;
+       if (--a->mp_count == 0) {
+               kfree(a);
+               page->private = 0;
+               ClearPagePrivate(page);
+               kunmap(page);
+       }
+}
+
+static inline void inc_io(struct page *page)
+{
+       atomic_inc(&mp_anchor(page)->io_count);
+}
+
+static inline void dec_io(struct page *page, void (*handler) (struct page *))
+{
+       if (atomic_dec_and_test(&mp_anchor(page)->io_count))
+               handler(page);
+}
+
+#else
+static inline struct metapage *page_to_mp(struct page *page, uint offset)
+{
+       return PagePrivate(page) ? (struct metapage *)page->private : NULL;
+}
+
+static inline int insert_metapage(struct page *page, struct metapage *mp)
+{
+       if (mp) {
+               page->private = (unsigned long)mp;
+               SetPagePrivate(page);
+               kmap(page);
+       }
+       return 0;
+}
+
+static inline void remove_metapage(struct page *page, struct metapage *mp)
+{
+       page->private = 0;
+       ClearPagePrivate(page);
+       kunmap(page);
+}
+
+#define inc_io(page) do {} while(0)
+#define dec_io(page, handler) handler(page)
+
+#endif
+
 static void init_once(void *foo, kmem_cache_t *cachep, unsigned long flags)
 {
        struct metapage *mp = (struct metapage *)foo;
@@ -138,16 +228,6 @@ int __init metapage_init(void)
                kmem_cache_destroy(metapage_cache);
                return -ENOMEM;
        }
-       /*
-        * Now the hash list
-        */
-       for (hash_order = 0;
-            ((PAGE_SIZE << hash_order) / sizeof(void *)) < HASH_SIZE;
-            hash_order++);
-       hash_table =
-           (struct metapage **) __get_free_pages(GFP_KERNEL, hash_order);
-       assert(hash_table);
-       memset(hash_table, 0, PAGE_SIZE << hash_order);
 
        return 0;
 }
@@ -158,73 +238,388 @@ void metapage_exit(void)
        kmem_cache_destroy(metapage_cache);
 }
 
+static inline void drop_metapage(struct page *page, struct metapage *mp)
+{
+       if (mp->count || mp->nohomeok || test_bit(META_dirty, &mp->flag) ||
+           test_bit(META_io, &mp->flag))
+               return;
+       remove_metapage(page, mp);
+       INCREMENT(mpStat.pagefree);
+       free_metapage(mp);
+}
+
 /*
- * Basically same hash as in pagemap.h, but using our hash table
+ * Metapage address space operations
  */
-static struct metapage **meta_hash(struct address_space *mapping,
-                                  unsigned long index)
+
+static sector_t metapage_get_blocks(struct inode *inode, sector_t lblock,
+                                   unsigned int *len)
 {
-#define i (((unsigned long)mapping)/ \
-          (sizeof(struct inode) & ~(sizeof(struct inode) -1 )))
-#define s(x) ((x) + ((x) >> HASH_BITS))
-       return hash_table + (s(i + index) & (HASH_SIZE - 1));
-#undef i
-#undef s
+       int rc = 0;
+       int xflag;
+       s64 xaddr;
+       sector_t file_blocks = (inode->i_size + inode->i_blksize - 1) >>
+                              inode->i_blkbits;
+
+       if (lblock >= file_blocks)
+               return 0;
+       if (lblock + *len > file_blocks)
+               *len = file_blocks - lblock;
+
+       if (inode->i_ino) {
+               rc = xtLookup(inode, (s64)lblock, *len, &xflag, &xaddr, len, 0);
+               if ((rc == 0) && *len)
+                       lblock = (sector_t)xaddr;
+               else
+                       lblock = 0;
+       } /* else no mapping */
+
+       return lblock;
 }
 
-static struct metapage *search_hash(struct metapage ** hash_ptr,
-                                   struct address_space *mapping,
-                              unsigned long index)
+static void last_read_complete(struct page *page)
 {
-       struct metapage *ptr;
+       if (!PageError(page))
+               SetPageUptodate(page);
+       unlock_page(page);
+}
 
-       for (ptr = *hash_ptr; ptr; ptr = ptr->hash_next) {
-               if ((ptr->mapping == mapping) && (ptr->index == index))
-                       return ptr;
+static int metapage_read_end_io(struct bio *bio, unsigned int bytes_done,
+                               int err)
+{
+       struct page *page = bio->bi_private;
+
+       if (bio->bi_size)
+               return 1;
+
+       if (!test_bit(BIO_UPTODATE, &bio->bi_flags)) {
+               printk(KERN_ERR "metapage_read_end_io: I/O error\n");
+               SetPageError(page);
        }
 
-       return NULL;
+       dec_io(page, last_read_complete);
+       bio_put(bio);
+
+       return 0;
 }
 
-static void add_to_hash(struct metapage * mp, struct metapage ** hash_ptr)
+static void remove_from_logsync(struct metapage *mp)
 {
-       if (*hash_ptr)
-               (*hash_ptr)->hash_prev = mp;
+       struct jfs_log *log = mp->log;
+       unsigned long flags;
+/*
+ * This can race.  Recheck that log hasn't been set to null, and after
+ * acquiring logsync lock, recheck lsn
+ */
+       if (!log)
+               return;
 
-       mp->hash_prev = NULL;
-       mp->hash_next = *hash_ptr;
-       *hash_ptr = mp;
+       LOGSYNC_LOCK(log, flags);
+       if (mp->lsn) {
+               mp->log = NULL;
+               mp->lsn = 0;
+               mp->clsn = 0;
+               log->count--;
+               list_del(&mp->synclist);
+       }
+       LOGSYNC_UNLOCK(log, flags);
 }
 
-static void remove_from_hash(struct metapage * mp, struct metapage ** hash_ptr)
+static void last_write_complete(struct page *page)
 {
-       if (mp->hash_prev)
-               mp->hash_prev->hash_next = mp->hash_next;
-       else {
-               assert(*hash_ptr == mp);
-               *hash_ptr = mp->hash_next;
+       struct metapage *mp;
+       unsigned int offset;
+
+       for (offset = 0; offset < PAGE_CACHE_SIZE; offset += PSIZE) {
+               mp = page_to_mp(page, offset);
+               if (mp && test_bit(META_io, &mp->flag)) {
+                       if (mp->lsn)
+                               remove_from_logsync(mp);
+                       clear_bit(META_io, &mp->flag);
+               }
+               /*
+                * I'd like to call drop_metapage here, but I don't think it's
+                * safe unless I have the page locked
+                */
        }
+       end_page_writeback(page);
+}
+
+static int metapage_write_end_io(struct bio *bio, unsigned int bytes_done,
+                                int err)
+{
+       struct page *page = bio->bi_private;
+
+       BUG_ON(!PagePrivate(page));
 
-       if (mp->hash_next)
-               mp->hash_next->hash_prev = mp->hash_prev;
+       if (bio->bi_size)
+               return 1;
+
+       if (! test_bit(BIO_UPTODATE, &bio->bi_flags)) {
+               printk(KERN_ERR "metapage_write_end_io: I/O error\n");
+               SetPageError(page);
+       }
+       dec_io(page, last_write_complete);
+       bio_put(bio);
+       return 0;
 }
 
+static int metapage_writepage(struct page *page, struct writeback_control *wbc)
+{
+       struct bio *bio = NULL;
+       unsigned int block_offset;      /* block offset of mp within page */
+       struct inode *inode = page->mapping->host;
+       unsigned int blocks_per_mp = JFS_SBI(inode->i_sb)->nbperpage;
+       unsigned int len;
+       unsigned int xlen;
+       struct metapage *mp;
+       int redirty = 0;
+       sector_t lblock;
+       sector_t pblock;
+       sector_t next_block = 0;
+       sector_t page_start;
+       unsigned long bio_bytes = 0;
+       unsigned long bio_offset = 0;
+       unsigned int offset;
+
+       page_start = (sector_t)page->index <<
+                    (PAGE_CACHE_SHIFT - inode->i_blkbits);
+       BUG_ON(!PageLocked(page));
+       BUG_ON(PageWriteback(page));
+
+       for (offset = 0; offset < PAGE_CACHE_SIZE; offset += PSIZE) {
+               mp = page_to_mp(page, offset);
+
+               if (!mp || !test_bit(META_dirty, &mp->flag))
+                       continue;
+
+               if (mp->nohomeok && !test_bit(META_forcewrite, &mp->flag)) {
+                       redirty = 1;
+                       continue;
+               }
+
+               clear_bit(META_dirty, &mp->flag);
+               block_offset = offset >> inode->i_blkbits;
+               lblock = page_start + block_offset;
+               if (bio) {
+                       if (xlen && lblock == next_block) {
+                               /* Contiguous, in memory & on disk */
+                               len = min(xlen, blocks_per_mp);
+                               xlen -= len;
+                               bio_bytes += len << inode->i_blkbits;
+                               set_bit(META_io, &mp->flag);
+                               continue;
+                       }
+                       /* Not contiguous */
+                       if (bio_add_page(bio, page, bio_bytes, bio_offset) <
+                           bio_bytes)
+                               goto add_failed;
+                       /*
+                        * Increment counter before submitting i/o to keep
+                        * count from hitting zero before we're through
+                        */
+                       inc_io(page);
+                       if (!bio->bi_size)
+                               goto dump_bio;
+                       submit_bio(WRITE, bio);
+                       bio = NULL;
+               } else {
+                       set_page_writeback(page);
+                       inc_io(page);
+               }
+               xlen = (PAGE_CACHE_SIZE - offset) >> inode->i_blkbits;
+               pblock = metapage_get_blocks(inode, lblock, &xlen);
+               if (!pblock) {
+                       /* Need better error handling */
+                       printk(KERN_ERR "JFS: metapage_get_blocks failed\n");
+                       dec_io(page, last_write_complete);
+                       continue;
+               }
+               set_bit(META_io, &mp->flag);
+               len = min(xlen, (uint) JFS_SBI(inode->i_sb)->nbperpage);
+
+               bio = bio_alloc(GFP_NOFS, 1);
+               bio->bi_bdev = inode->i_sb->s_bdev;
+               bio->bi_sector = pblock << (inode->i_blkbits - 9);
+               bio->bi_end_io = metapage_write_end_io;
+               bio->bi_private = page;
+
+               /* Don't call bio_add_page yet, we may add to this vec */
+               bio_offset = offset;
+               bio_bytes = len << inode->i_blkbits;
+
+               xlen -= len;
+               next_block = lblock + len;
+       }
+       if (bio) {
+               if (bio_add_page(bio, page, bio_bytes, bio_offset) < bio_bytes)
+                               goto add_failed;
+               if (!bio->bi_size)
+                       goto dump_bio;
+               
+               submit_bio(WRITE, bio);
+       }
+       if (redirty)
+               redirty_page_for_writepage(wbc, page);
+
+       unlock_page(page);
+
+       return 0;
+add_failed:
+       /* We should never reach here, since we're only adding one vec */
+       printk(KERN_ERR "JFS: bio_add_page failed unexpectedly\n");
+       goto skip;
+dump_bio:
+       dump_mem("bio", bio, sizeof(*bio));
+skip:
+       bio_put(bio);
+       unlock_page(page);
+       dec_io(page, last_write_complete);
+
+       return -EIO;
+}
+
+static int metapage_readpage(struct file *fp, struct page *page)
+{
+       struct inode *inode = page->mapping->host;
+       struct bio *bio = NULL;
+       unsigned int block_offset;
+       unsigned int blocks_per_page = PAGE_CACHE_SIZE >> inode->i_blkbits;
+       sector_t page_start;    /* address of page in fs blocks */
+       sector_t pblock;
+       unsigned int xlen;
+       unsigned int len;
+       unsigned int offset;
+
+       BUG_ON(!PageLocked(page));
+       page_start = (sector_t)page->index <<
+                    (PAGE_CACHE_SHIFT - inode->i_blkbits);
+
+       block_offset = 0;
+       while (block_offset < blocks_per_page) {
+               xlen = blocks_per_page - block_offset;
+               pblock = metapage_get_blocks(inode, page_start + block_offset,
+                                            &xlen);
+               if (pblock) {
+                       if (!PagePrivate(page))
+                               insert_metapage(page, NULL);
+                       inc_io(page);
+                       if (bio)
+                               submit_bio(READ, bio);
+
+                       bio = bio_alloc(GFP_NOFS, 1);
+                       bio->bi_bdev = inode->i_sb->s_bdev;
+                       bio->bi_sector = pblock << (inode->i_blkbits - 9);
+                       bio->bi_end_io = metapage_read_end_io;
+                       bio->bi_private = page;
+                       len = xlen << inode->i_blkbits;
+                       offset = block_offset << inode->i_blkbits;
+                       if (bio_add_page(bio, page, len, offset) < len)
+                               goto add_failed;
+                       block_offset += xlen;
+               } else
+                       block_offset++;
+       }
+       if (bio)
+               submit_bio(READ, bio);
+       else
+               unlock_page(page);
+
+       return 0;
+
+add_failed:
+       printk(KERN_ERR "JFS: bio_add_page failed unexpectedly\n");
+       bio_put(bio);
+       dec_io(page, last_read_complete);
+       return -EIO;
+}
+
+static int metapage_releasepage(struct page *page, int gfp_mask)
+{
+       struct metapage *mp;
+       int busy = 0;
+       unsigned int offset;
+
+       for (offset = 0; offset < PAGE_CACHE_SIZE; offset += PSIZE) {
+               mp = page_to_mp(page, offset);
+
+               if (!mp)
+                       continue;
+
+               jfs_info("metapage_releasepage: mp = 0x%p", mp);
+               if (mp->count || mp->nohomeok) {
+                       jfs_info("count = %ld, nohomeok = %d", mp->count,
+                                mp->nohomeok);
+                       busy = 1;
+                       continue;
+               }
+               wait_on_page_writeback(page);
+               //WARN_ON(test_bit(META_dirty, &mp->flag));
+               if (test_bit(META_dirty, &mp->flag)) {
+                       dump_mem("dirty mp in metapage_releasepage", mp,
+                                sizeof(struct metapage));
+                       dump_mem("page", page, sizeof(struct page));
+                       dump_stack();
+               }
+               WARN_ON(mp->lsn);
+               if (mp->lsn)
+                       remove_from_logsync(mp);
+               remove_metapage(page, mp);
+               INCREMENT(mpStat.pagefree);
+               free_metapage(mp);
+       }
+       if (busy)
+               return -1;
+
+       return 0;
+}
+
+static int metapage_invalidatepage(struct page *page, unsigned long offset)
+{
+       BUG_ON(offset);
+
+       if (PageWriteback(page))
+               return 0;
+
+       return metapage_releasepage(page, 0);
+}
+
+struct address_space_operations jfs_metapage_aops = {
+       .readpage       = metapage_readpage,
+       .writepage      = metapage_writepage,
+       .sync_page      = block_sync_page,
+       .releasepage    = metapage_releasepage,
+       .invalidatepage = metapage_invalidatepage,
+       .set_page_dirty = __set_page_dirty_nobuffers,
+};
+
 struct metapage *__get_metapage(struct inode *inode, unsigned long lblock,
                                unsigned int size, int absolute,
                                unsigned long new)
 {
-       struct metapage **hash_ptr;
        int l2BlocksPerPage;
        int l2bsize;
        struct address_space *mapping;
-       struct metapage *mp;
+       struct metapage *mp = NULL;
+       struct page *page;
        unsigned long page_index;
        unsigned long page_offset;
 
-       jfs_info("__get_metapage: inode = 0x%p, lblock = 0x%lx", inode, lblock);
-
+       jfs_info("__get_metapage: ino = %ld, lblock = 0x%lx, abs=%d",
+                inode->i_ino, lblock, absolute);
+
+       l2bsize = inode->i_blkbits;
+       l2BlocksPerPage = PAGE_CACHE_SHIFT - l2bsize;
+       page_index = lblock >> l2BlocksPerPage;
+       page_offset = (lblock - (page_index << l2BlocksPerPage)) << l2bsize;
+       if ((page_offset + size) > PAGE_CACHE_SIZE) {
+               jfs_err("MetaData crosses page boundary!!");
+               jfs_err("lblock = %lx, size  = %d", lblock, size);
+               dump_stack();
+               return NULL;
+       }
        if (absolute)
-               mapping = inode->i_sb->s_bdev->bd_inode->i_mapping;
+               mapping = JFS_SBI(inode->i_sb)->direct_inode->i_mapping;
        else {
                /*
                 * If an nfs client tries to read an inode that is larger
@@ -236,323 +631,212 @@ struct metapage *__get_metapage(struct inode *inode, unsigned long lblock,
                mapping = inode->i_mapping;
        }
 
-       hash_ptr = meta_hash(mapping, lblock);
-again:
-       spin_lock(&meta_lock);
-       mp = search_hash(hash_ptr, mapping, lblock);
+       if (new && (PSIZE == PAGE_CACHE_SIZE)) {
+               page = grab_cache_page(mapping, page_index);
+               if (!page) {
+                       jfs_err("grab_cache_page failed!");
+                       return NULL;
+               }
+               SetPageUptodate(page);
+       } else {
+               page = read_cache_page(mapping, page_index,
+                           (filler_t *)mapping->a_ops->readpage, NULL);
+               if (IS_ERR(page)) {
+                       jfs_err("read_cache_page failed!");
+                       return NULL;
+               }
+               lock_page(page);
+       }
+
+       mp = page_to_mp(page, page_offset);
        if (mp) {
-             page_found:
+               if (mp->logical_size != size) {
+                       jfs_error(inode->i_sb,
+                                 "__get_metapage: mp->logical_size != size");
+                       jfs_err("logical_size = %d, size = %d",
+                               mp->logical_size, size);
+                       dump_stack();
+                       goto unlock; 
+               }
                mp->count++;
                lock_metapage(mp);
-               spin_unlock(&meta_lock);
-               if (test_bit(META_stale, &mp->flag)) {
-                       release_metapage(mp);
-                       yield();        /* Let other waiters release it, too */
-                       goto again;
-               }
                if (test_bit(META_discard, &mp->flag)) {
                        if (!new) {
                                jfs_error(inode->i_sb,
                                          "__get_metapage: using a "
                                          "discarded metapage");
-                               release_metapage(mp);
-                               return NULL;
+                               discard_metapage(mp);
+                               goto unlock; 
                        }
                        clear_bit(META_discard, &mp->flag);
                }
-               jfs_info("__get_metapage: found 0x%p, in hash", mp);
-               if (mp->logical_size != size) {
-                       jfs_error(inode->i_sb,
-                                 "__get_metapage: mp->logical_size != size");
-                       release_metapage(mp);
-                       return NULL;
-               }
        } else {
-               l2bsize = inode->i_blkbits;
-               l2BlocksPerPage = PAGE_CACHE_SHIFT - l2bsize;
-               page_index = lblock >> l2BlocksPerPage;
-               page_offset = (lblock - (page_index << l2BlocksPerPage)) <<
-                   l2bsize;
-               if ((page_offset + size) > PAGE_CACHE_SIZE) {
-                       spin_unlock(&meta_lock);
-                       jfs_err("MetaData crosses page boundary!!");
-                       return NULL;
-               }
-               
-               /*
-                * Locks held on aggregate inode pages are usually
-                * not held long, and they are taken in critical code
-                * paths (committing dirty inodes, txCommit thread) 
-                * 
-                * Attempt to get metapage without blocking, tapping into
-                * reserves if necessary.
-                */
-               mp = NULL;
-               if (JFS_IP(inode)->fileset == AGGREGATE_I) {
-                       mp = alloc_metapage(GFP_ATOMIC);
-                       if (!mp) {
-                               /*
-                                * mempool is supposed to protect us from
-                                * failing here.  We will try a blocking
-                                * call, but a deadlock is possible here
-                                */
-                               printk(KERN_WARNING
-                                      "__get_metapage: atomic call to mempool_alloc failed.\n");
-                               printk(KERN_WARNING
-                                      "Will attempt blocking call\n");
-                       }
-               }
-               if (!mp) {
-                       struct metapage *mp2;
-
-                       spin_unlock(&meta_lock);
-                       mp = alloc_metapage(GFP_NOFS);
-                       spin_lock(&meta_lock);
-
-                       /* we dropped the meta_lock, we need to search the
-                        * hash again.
-                        */
-                       mp2 = search_hash(hash_ptr, mapping, lblock);
-                       if (mp2) {
-                               free_metapage(mp);
-                               mp = mp2;
-                               goto page_found;
-                       }
-               }
+               INCREMENT(mpStat.pagealloc);
+               mp = alloc_metapage(GFP_NOFS);
+               mp->page = page;
                mp->flag = 0;
-               lock_metapage(mp);
-               if (absolute)
-                       set_bit(META_absolute, &mp->flag);
                mp->xflag = COMMIT_PAGE;
                mp->count = 1;
-               atomic_set(&mp->nohomeok,0);
-               mp->mapping = mapping;
-               mp->index = lblock;
-               mp->page = NULL;
+               mp->nohomeok = 0;
                mp->logical_size = size;
-               add_to_hash(mp, hash_ptr);
-               spin_unlock(&meta_lock);
-
-               if (new) {
-                       jfs_info("__get_metapage: Calling grab_cache_page");
-                       mp->page = grab_cache_page(mapping, page_index);
-                       if (!mp->page) {
-                               jfs_err("grab_cache_page failed!");
-                               goto freeit;
-                       } else {
-                               INCREMENT(mpStat.pagealloc);
-                               unlock_page(mp->page);
-                       }
-               } else {
-                       jfs_info("__get_metapage: Calling read_cache_page");
-                       mp->page = read_cache_page(mapping, lblock,
-                                   (filler_t *)mapping->a_ops->readpage, NULL);
-                       if (IS_ERR(mp->page)) {
-                               jfs_err("read_cache_page failed!");
-                               goto freeit;
-                       } else
-                               INCREMENT(mpStat.pagealloc);
+               mp->data = page_address(page) + page_offset;
+               mp->index = lblock;
+               if (unlikely(insert_metapage(page, mp))) {
+                       free_metapage(mp);
+                       goto unlock;
                }
-               mp->data = kmap(mp->page) + page_offset;
+               lock_metapage(mp);
        }
 
-       if (new)
+       if (new) {
+               jfs_info("zeroing mp = 0x%p", mp);
                memset(mp->data, 0, PSIZE);
+       }
 
-       jfs_info("__get_metapage: returning = 0x%p", mp);
+       unlock_page(page);
+       jfs_info("__get_metapage: returning = 0x%p data = 0x%p", mp, mp->data);
        return mp;
 
-freeit:
-       spin_lock(&meta_lock);
-       remove_from_hash(mp, hash_ptr);
-       free_metapage(mp);
-       spin_unlock(&meta_lock);
+unlock:
+       unlock_page(page);
        return NULL;
 }
 
-void hold_metapage(struct metapage * mp, int force)
+void grab_metapage(struct metapage * mp)
 {
-       spin_lock(&meta_lock);
-
+       jfs_info("grab_metapage: mp = 0x%p", mp);
+       page_cache_get(mp->page);
+       lock_page(mp->page);
        mp->count++;
-
-       if (force) {
-               ASSERT (!(test_bit(META_forced, &mp->flag)));
-               if (trylock_metapage(mp))
-                       set_bit(META_forced, &mp->flag);
-       } else
-               lock_metapage(mp);
-
-       spin_unlock(&meta_lock);
+       lock_metapage(mp);
+       unlock_page(mp->page);
 }
 
-static void __write_metapage(struct metapage * mp)
+void force_metapage(struct metapage *mp)
 {
-       int l2bsize = mp->mapping->host->i_blkbits;
-       int l2BlocksPerPage = PAGE_CACHE_SHIFT - l2bsize;
-       unsigned long page_index;
-       unsigned long page_offset;
-       int rc;
-
-       jfs_info("__write_metapage: mp = 0x%p", mp);
-
-       page_index = mp->page->index;
-       page_offset =
-           (mp->index - (page_index << l2BlocksPerPage)) << l2bsize;
+       struct page *page = mp->page;
+       jfs_info("force_metapage: mp = 0x%p", mp);
+       set_bit(META_forcewrite, &mp->flag);
+       clear_bit(META_sync, &mp->flag);
+       page_cache_get(page);
+       lock_page(page);
+       set_page_dirty(page);
+       write_one_page(page, 1);
+       clear_bit(META_forcewrite, &mp->flag);
+       page_cache_release(page);
+}
 
+extern void hold_metapage(struct metapage *mp)
+{
        lock_page(mp->page);
-       rc = mp->mapping->a_ops->prepare_write(NULL, mp->page, page_offset,
-                                              page_offset +
-                                              mp->logical_size);
-       if (rc) {
-               jfs_err("prepare_write return %d!", rc);
-               ClearPageUptodate(mp->page);
+}
+
+extern void put_metapage(struct metapage *mp)
+{
+       if (mp->count || mp->nohomeok) {
+               /* Someone else will release this */
                unlock_page(mp->page);
-               clear_bit(META_dirty, &mp->flag);
                return;
        }
-       rc = mp->mapping->a_ops->commit_write(NULL, mp->page, page_offset,
-                                             page_offset +
-                                             mp->logical_size);
-       if (rc) {
-               jfs_err("commit_write returned %d", rc);
-       }
-
+       page_cache_get(mp->page);
+       mp->count++;
+       lock_metapage(mp);
        unlock_page(mp->page);
-       clear_bit(META_dirty, &mp->flag);
-
-       jfs_info("__write_metapage done");
-}
-
-static inline void sync_metapage(struct metapage *mp)
-{
-       struct page *page = mp->page;
-
-       page_cache_get(page);
-       lock_page(page);
-
-       /* we're done with this page - no need to check for errors */
-       if (page_has_buffers(page))
-               write_one_page(page, 1);
-       else
-               unlock_page(page);
-       page_cache_release(page);
+       release_metapage(mp);
 }
 
 void release_metapage(struct metapage * mp)
 {
-       struct jfs_log *log;
-
+       struct page *page = mp->page;
        jfs_info("release_metapage: mp = 0x%p, flag = 0x%lx", mp, mp->flag);
 
-       spin_lock(&meta_lock);
-       if (test_bit(META_forced, &mp->flag)) {
-               clear_bit(META_forced, &mp->flag);
-               mp->count--;
-               spin_unlock(&meta_lock);
-               return;
-       }
+       BUG_ON(!page);
+
+       lock_page(page);
+       unlock_metapage(mp);
 
        assert(mp->count);
-       if (--mp->count || atomic_read(&mp->nohomeok)) {
-               unlock_metapage(mp);
-               spin_unlock(&meta_lock);
+       if (--mp->count || mp->nohomeok) {
+               unlock_page(page);
+               page_cache_release(page);
                return;
        }
 
-       if (mp->page) {
-               /* Releasing spinlock, we have to check mp->count later */
-               set_bit(META_stale, &mp->flag);
-               spin_unlock(&meta_lock);
-               kunmap(mp->page);
-               mp->data = NULL;
-               if (test_bit(META_dirty, &mp->flag))
-                       __write_metapage(mp);
+       if (test_bit(META_dirty, &mp->flag)) {
+               set_page_dirty(page);
                if (test_bit(META_sync, &mp->flag)) {
-                       sync_metapage(mp);
                        clear_bit(META_sync, &mp->flag);
+                       write_one_page(page, 1);
+                       lock_page(page); /* write_one_page unlocks the page */
                }
+       } else if (mp->lsn)     /* discard_metapage doesn't remove it */
+               remove_from_logsync(mp);
 
-               if (test_bit(META_discard, &mp->flag)) {
-                       lock_page(mp->page);
-                       block_invalidatepage(mp->page, 0);
-                       unlock_page(mp->page);
-               }
-
-               page_cache_release(mp->page);
-               mp->page = NULL;
-               INCREMENT(mpStat.pagefree);
-               spin_lock(&meta_lock);
-       }
+#if MPS_PER_PAGE == 1
+       /*
+        * If we know this is the only thing in the page, we can throw
+        * the page out of the page cache.  If pages are larger, we
+        * don't want to do this.
+        */
 
-       if (mp->lsn) {
-               /*
-                * Remove metapage from logsynclist.
-                */
-               log = mp->log;
-               LOGSYNC_LOCK(log);
-               mp->log = NULL;
-               mp->lsn = 0;
-               mp->clsn = 0;
-               log->count--;
-               list_del(&mp->synclist);
-               LOGSYNC_UNLOCK(log);
-       }
-       if (mp->count) {
-               /* Someone else is trying to get this metpage */
-               unlock_metapage(mp);
-               spin_unlock(&meta_lock);
-               return;
+       /* Retest mp->count since we may have released page lock */
+       if (test_bit(META_discard, &mp->flag) && !mp->count) {
+               clear_page_dirty(page);
+               ClearPageUptodate(page);
+#ifdef _NOT_YET
+               if (page->mapping) {
+               /* Remove from page cache and page cache reference */
+                       remove_from_page_cache(page);
+                       page_cache_release(page);
+                       metapage_releasepage(page, 0);
+               }
+#endif
        }
-       remove_from_hash(mp, meta_hash(mp->mapping, mp->index));
-       spin_unlock(&meta_lock);
-
-       free_metapage(mp);
+#else
+       /* Try to keep metapages from using up too much memory */
+       drop_metapage(page, mp);
+#endif
+       unlock_page(page);
+       page_cache_release(page);
 }
 
 void __invalidate_metapages(struct inode *ip, s64 addr, int len)
 {
-       struct metapage **hash_ptr;
-       unsigned long lblock;
+       sector_t lblock;
        int l2BlocksPerPage = PAGE_CACHE_SHIFT - ip->i_blkbits;
+       int BlocksPerPage = 1 << l2BlocksPerPage;
        /* All callers are interested in block device's mapping */
-       struct address_space *mapping = ip->i_sb->s_bdev->bd_inode->i_mapping;
+       struct address_space *mapping =
+               JFS_SBI(ip->i_sb)->direct_inode->i_mapping;
        struct metapage *mp;
        struct page *page;
+       unsigned int offset;
 
        /*
-        * First, mark metapages to discard.  They will eventually be
+        * Mark metapages to discard.  They will eventually be
         * released, but should not be written.
         */
-       for (lblock = addr; lblock < addr + len;
-            lblock += 1 << l2BlocksPerPage) {
-               hash_ptr = meta_hash(mapping, lblock);
-again:
-               spin_lock(&meta_lock);
-               mp = search_hash(hash_ptr, mapping, lblock);
-               if (mp) {
-                       if (test_bit(META_stale, &mp->flag)) {
-                               /* Racing with release_metapage */
-                               mp->count++;
-                               lock_metapage(mp);
-                               spin_unlock(&meta_lock);
-                               /* racing release_metapage should be done now */
-                               release_metapage(mp);
-                               goto again;
-                       }
+       for (lblock = addr & ~(BlocksPerPage - 1); lblock < addr + len;
+            lblock += BlocksPerPage) {
+               page = find_lock_page(mapping, lblock >> l2BlocksPerPage);
+               if (!page)
+                       continue;
+               for (offset = 0; offset < PAGE_CACHE_SIZE; offset += PSIZE) {
+                       mp = page_to_mp(page, offset);
+                       if (!mp)
+                               continue;
+                       if (mp->index < addr)
+                               continue;
+                       if (mp->index >= addr + len)
+                               break;
 
                        clear_bit(META_dirty, &mp->flag);
                        set_bit(META_discard, &mp->flag);
-                       spin_unlock(&meta_lock);
-               } else {
-                       spin_unlock(&meta_lock);
-                       page = find_lock_page(mapping, lblock>>l2BlocksPerPage);
-                       if (page) {
-                               block_invalidatepage(page, 0);
-                               unlock_page(page);
-                               page_cache_release(page);
-                       }
+                       if (mp->lsn)
+                               remove_from_logsync(mp);
                }
+               unlock_page(page);
+               page_cache_release(page);
        }
 }