[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, 601 insertions, 307 deletions

diff --git a/fs/jfs/jfs_metapage.c b/fs/jfs/jfs_metapage.c
index 4c0a3ac75c08..41bf078dce05 100644
--- a/fs/jfs/jfs_metapage.c
+++ b/fs/jfs/jfs_metapage.c
@@ -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
@@ -18,10 +18,11 @@
  */
 
 #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>
-#include <linux/delay.h>
 #include "jfs_incore.h"
 #include "jfs_superblock.h"
 #include "jfs_filsys.h"
@@ -29,8 +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 */
@@ -39,22 +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)
 {
@@ -62,26 +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))
@@ -92,6 +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;
@@ -139,16 +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;
 }
@@ -159,73 +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);
+}
+
+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;
 
-        for (ptr = *hash_ptr; ptr; ptr = ptr->hash_next) {
-                if ((ptr->mapping == mapping) && (ptr->index == index))
-                        return ptr;
+        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;
+
+        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);
+}
 
-        mp->hash_prev = NULL;
-        mp->hash_next = *hash_ptr;
-        *hash_ptr = mp;
+static void last_write_complete(struct page *page)
+{
+        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 void remove_from_hash(struct metapage * mp, struct metapage ** hash_ptr)
+static int metapage_write_end_io(struct bio *bio, unsigned int bytes_done,
+                                 int err)
 {
-        if (mp->hash_prev)
-                mp->hash_prev->hash_next = mp->hash_next;
-        else {
-                assert(*hash_ptr == mp);
-                *hash_ptr = mp->hash_next;
+        struct page *page = bio->bi_private;
+
+        BUG_ON(!PagePrivate(page));
+
+        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;
 
-        if (mp->hash_next)
-                mp->hash_next->hash_prev = mp->hash_prev;
+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
@@ -237,312 +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 (test_bit(META_stale, &mp->flag)) {
-                        spin_unlock(&meta_lock);
-                        msleep(1);
-                        goto again;
+                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_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) {
-                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);
+        /* 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)) {
-                                spin_unlock(&meta_lock);
-                                msleep(1);
-                                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);
         }
 }