JFS: use block device inode/mapping instead of direct_inode/direct_mapping

Change __get_metapage to use the block device mapping to back metapages
that are addresses by filesystem relative blocks.  Remove all code to
implement the JFS-private per-filesystem mapping and fake inode.

fs/jfs/jfs_imap.c

@@ -1179,7 +1179,7 @@ int diFree(struct inode *ip)
 	 * invalidate any page of the inode extent freed from buffer cache;
 	 */
 	freepxd = iagp->inoext[extno];
-	invalidate_pxd_metapages(JFS_SBI(ip->i_sb)->direct_inode, freepxd);
+	invalidate_pxd_metapages(ip->i_sb->s_bdev->bd_inode, freepxd);
 
 	/*
 	 *      update iag list(s) (careful update step 2)

fs/jfs/jfs_incore.h

@@ -152,8 +152,6 @@ struct jfs_sb_info {
         /* Formerly in ipbmap */
 	struct bmap	*bmap;		/* 4: incore bmap descriptor	*/
 	struct nls_table *nls_tab;	/* 4: current codepage		*/
-	struct inode	*direct_inode;	/* 4: inode for physical I/O	*/
-	struct address_space *direct_mapping; /* 4: mapping for physical I/O */
 	uint		state;		/* 4: mount/recovery state	*/
 };
 

fs/jfs/jfs_logmgr.c

@@ -960,20 +960,22 @@ int lmLogSync(log_t * log, int nosyncwait)
 	 * reset syncpt = sync
 	 */
 	if (log->sync != log->syncpt) {
-		struct jfs_sb_info	*sbi = JFS_SBI(log->sb);
+		struct super_block *sb = log->sb;
+		struct jfs_sb_info *sbi = JFS_SBI(sb);
+
 		/*
 		 * We need to make sure all of the "written" metapages
 		 * actually make it to disk
 		 */
 		filemap_fdatawait(sbi->ipbmap->i_mapping);
 		filemap_fdatawait(sbi->ipimap->i_mapping);
-		filemap_fdatawait(sbi->direct_inode->i_mapping);
+		filemap_fdatawait(sb->s_bdev->bd_inode->i_mapping);
 		filemap_fdatawrite(sbi->ipbmap->i_mapping);
 		filemap_fdatawrite(sbi->ipimap->i_mapping);
-		filemap_fdatawrite(sbi->direct_inode->i_mapping);
+		filemap_fdatawrite(sb->s_bdev->bd_inode->i_mapping);
 		filemap_fdatawait(sbi->ipbmap->i_mapping);
 		filemap_fdatawait(sbi->ipimap->i_mapping);
-		filemap_fdatawait(sbi->direct_inode->i_mapping);
+		filemap_fdatawait(sb->s_bdev->bd_inode->i_mapping);
 
 		lrd.logtid = 0;
 		lrd.backchain = 0;

fs/jfs/jfs_metapage.c

@@ -217,51 +217,6 @@ static void remove_from_hash(metapage_t * mp, metapage_t ** hash_ptr)
 		mp->hash_next->hash_prev = mp->hash_prev;
 }
 
-/*
- * Direct address space operations
- */
-
-static int direct_get_block(struct inode *ip, sector_t lblock,
-			    struct buffer_head *bh_result, int create)
-{
-	if (create)
-		set_buffer_new(bh_result);
-
-	map_bh(bh_result, ip->i_sb, lblock);
-
-	return 0;
-}
-
-static int direct_writepage(struct page *page)
-{
-	return block_write_full_page(page, direct_get_block);
-}
-
-static int direct_readpage(struct file *fp, struct page *page)
-{
-	return block_read_full_page(page, direct_get_block);
-}
-
-static int direct_prepare_write(struct file *file, struct page *page,
-				unsigned from, unsigned to)
-{
-	return block_prepare_write(page, from, to, direct_get_block);
-}
-
-static int direct_bmap(struct address_space *mapping, long block)
-{
-	return generic_block_bmap(mapping, block, direct_get_block);
-}
-
-struct address_space_operations direct_aops = {
-	.readpage	= direct_readpage,
-	.writepage	= direct_writepage,
-	.sync_page	= block_sync_page,
-	.prepare_write	= direct_prepare_write,
-	.commit_write	= generic_commit_write,
-	.bmap		= direct_bmap,
-};
-
 metapage_t *__get_metapage(struct inode *inode,
 			   unsigned long lblock, unsigned int size,
 			   int absolute, unsigned long new)
@@ -278,14 +233,12 @@ metapage_t *__get_metapage(struct inode *inode,
 		 inode, lblock));
 
 	if (absolute)
-		mapping = JFS_SBI(inode->i_sb)->direct_mapping;
+		mapping = inode->i_sb->s_bdev->bd_inode->i_mapping;
 	else
 		mapping = inode->i_mapping;
 
 	spin_lock(&meta_lock);
-
 	hash_ptr = meta_hash(mapping, lblock);
-
 	mp = search_hash(hash_ptr, mapping, lblock);
 	if (mp) {
 	      page_found:
@@ -301,7 +254,7 @@ metapage_t *__get_metapage(struct inode *inode,
 		lock_metapage(mp);
 		spin_unlock(&meta_lock);
 	} else {
-		l2bsize = inode->i_sb->s_blocksize_bits;
+		l2bsize = inode->i_blkbits;
 		l2BlocksPerPage = PAGE_CACHE_SHIFT - l2bsize;
 		page_index = lblock >> l2BlocksPerPage;
 		page_offset = (lblock - (page_index << l2BlocksPerPage)) <<
@@ -423,12 +376,11 @@ void hold_metapage(metapage_t * mp, int force)
 
 static void __write_metapage(metapage_t * mp)
 {
-	struct inode *ip = (struct inode *) mp->mapping->host;
+	int l2bsize = mp->mapping->host->i_blkbits;
+	int l2BlocksPerPage = PAGE_CACHE_SHIFT - l2bsize;
 	unsigned long page_index;
 	unsigned long page_offset;
 	int rc;
-	int l2bsize = ip->i_sb->s_blocksize_bits;
-	int l2BlocksPerPage = PAGE_CACHE_SHIFT - l2bsize;
 
 	jFYI(1, ("__write_metapage: mp = 0x%p\n", mp));
 
@@ -553,7 +505,7 @@ void __invalidate_metapages(struct inode *ip, s64 addr, int len)
 {
 	metapage_t **hash_ptr;
 	unsigned long lblock;
-	int l2BlocksPerPage = PAGE_CACHE_SHIFT - ip->i_sb->s_blocksize_bits;
+	int l2BlocksPerPage = PAGE_CACHE_SHIFT - ip->i_blkbits;
 	struct address_space *mapping = ip->i_mapping;
 	metapage_t *mp;
 	struct page *page;

fs/jfs/jfs_metapage.h

@@ -57,11 +57,6 @@ typedef struct metapage {
 	struct jfs_log *log;
 } metapage_t;
 
-/*
- * Direct-access address space operations
- */
-extern struct address_space_operations direct_aops;
-
 /* metapage flag */
 #define META_locked	0
 #define META_absolute	1

fs/jfs/jfs_umount.c

@@ -108,14 +108,6 @@ int jfs_umount(struct super_block *sb)
 	diFreeSpecial(ipbmap);
 	sbi->ipimap = NULL;
 
-	/*
-	 * Make sure all metadata makes it to disk before we mark
-	 * the superblock as clean
-	 */
-	filemap_fdatawait(sbi->direct_inode->i_mapping);
-	filemap_fdatawrite(sbi->direct_inode->i_mapping);
-	filemap_fdatawait(sbi->direct_inode->i_mapping);
-
 	/*
 	 * ensure all file system file pages are propagated to their
 	 * home blocks on disk (and their in-memory buffer pages are 
@@ -159,9 +151,6 @@ int jfs_umount_rw(struct super_block *sb)
 	 */
 	dbSync(sbi->ipbmap);
 	diSync(sbi->ipimap);
-	filemap_fdatawait(sbi->direct_inode->i_mapping);
-	filemap_fdatawrite(sbi->direct_inode->i_mapping);
-	filemap_fdatawait(sbi->direct_inode->i_mapping);
 
 	updateSuper(sb, FM_CLEAN);
 	sbi->log = NULL;

fs/jfs/super.c

@@ -142,18 +142,6 @@ static void jfs_put_super(struct super_block *sb)
 	unload_nls(sbi->nls_tab);
 	sbi->nls_tab = NULL;
 
-	/*
-	 * We need to clean out the direct_inode pages since this inode
-	 * is not in the inode hash.
-	 */
-	filemap_fdatawait(sbi->direct_inode->i_mapping);
-	filemap_fdatawrite(sbi->direct_inode->i_mapping);
-	filemap_fdatawait(sbi->direct_inode->i_mapping);
-	truncate_inode_pages(sbi->direct_mapping, 0);
-	iput(sbi->direct_inode);
-	sbi->direct_inode = NULL;
-	sbi->direct_mapping = NULL;
-
 	kfree(sbi);
 }
 
@@ -222,7 +210,6 @@ static int parse_options(char *options, struct super_block *sb, s64 *newLVSize)
 
 int jfs_remount(struct super_block *sb, int *flags, char *data)
 {
-	struct jfs_sb_info *sbi = JFS_SBI(sb);
 	s64 newLVSize = 0;
 	int rc = 0;
 
@@ -240,15 +227,9 @@ int jfs_remount(struct super_block *sb, int *flags, char *data)
 			return rc;
 	}
 
-	if ((sb->s_flags & MS_RDONLY) && !(*flags & MS_RDONLY)) {
-		/*
-		 * Invalidate any previously read metadata.  fsck may
-		 * have changed the on-disk data since we mounted r/o
-		 */
-		truncate_inode_pages(sbi->direct_mapping, 0);
-
+	if ((sb->s_flags & MS_RDONLY) && !(*flags & MS_RDONLY))
 		return jfs_mount_rw(sb, 1);
-	} else if ((!(sb->s_flags & MS_RDONLY)) && (*flags & MS_RDONLY))
+	else if ((!(sb->s_flags & MS_RDONLY)) && (*flags & MS_RDONLY))
 		return jfs_umount_rw(sb);
 
 	return 0;
@@ -290,28 +271,13 @@ static int jfs_fill_super(struct super_block *sb, void *data, int silent)
 	sb->s_op = &jfs_super_operations;
 	sb->s_export_op = &jfs_export_operations;
 
-	/*
-	 * Initialize direct-mapping inode/address-space
-	 */
-	inode = new_inode(sb);
-	if (inode == NULL)
-		goto out_kfree;
-	inode->i_ino = 0;
-	inode->i_nlink = 1;
-	inode->i_size = 0x0000010000000000LL;
-	inode->i_mapping->a_ops = &direct_aops;
-	inode->i_mapping->gfp_mask = GFP_NOFS;
-
-	sbi->direct_inode = inode;
-	sbi->direct_mapping = inode->i_mapping;
-
 	rc = jfs_mount(sb);
 	if (rc) {
 		if (!silent) {
 			jERROR(1,
 			       ("jfs_mount failed w/return code = %d\n", rc));
 		}
-		goto out_mount_failed;
+		goto out_kfree;
 	}
 	if (sb->s_flags & MS_RDONLY)
 		sbi->log = 0;
@@ -361,15 +327,6 @@ static int jfs_fill_super(struct super_block *sb, void *data, int silent)
 	if (rc) {
 		jERROR(1, ("jfs_umount failed with return code %d\n", rc));
 	}
-out_mount_failed:
-	filemap_fdatawait(sbi->direct_inode->i_mapping);
-	filemap_fdatawrite(sbi->direct_inode->i_mapping);
-	filemap_fdatawait(sbi->direct_inode->i_mapping);
-	truncate_inode_pages(sbi->direct_mapping, 0);
-	make_bad_inode(sbi->direct_inode);
-	iput(sbi->direct_inode);
-	sbi->direct_inode = NULL;
-	sbi->direct_mapping = NULL;
 out_kfree:
 	if (sbi->nls_tab)
 		unload_nls(sbi->nls_tab);