From: Josef Bacik <josef@redhat.com>
Date: Tue, 1 Dec 2009 21:34:22 -0500
Subject: [fs] ext2: convert to new aops
Message-id: <20091201213421.GA22526@localhost.localdomain>
Patchwork-id: 21623
O-Subject: [PATCH] [RHEL 5.5 PATCH] ext2: convert to new aops
Bugzilla: 513136
RH-Acked-by: Eric Sandeen <sandeen@redhat.com>

This patch is in reference to bz 513136.  When I backported the new address
space operations to 5.4 I left out ext2 in case something when horribly wrong.
Well nothing went horribly wrong and customers noticed that ext2 was slower than
it was in 5.3.  This patch converts ext2 to the new aops, and is a direct
backport of

f34fb6eccc962e4137b77c4bbe1e9a31d27a30e6

With fixes to deal with the ABI weirdness.  This has been tested with iozone and
fsx and appears to be safe.  Thanks,

Josef


diff --git a/fs/ext2/dir.c b/fs/ext2/dir.c
index 4d41aad..7ee2319 100644
--- a/fs/ext2/dir.c
+++ b/fs/ext2/dir.c
@@ -22,7 +22,9 @@
  */
 
 #include "ext2.h"
+#include <linux/buffer_head.h>
 #include <linux/pagemap.h>
+#include <linux/swap.h>
 #include <linux/smp_lock.h>
 
 typedef struct ext2_dir_entry_2 ext2_dirent;
@@ -62,16 +64,25 @@ ext2_last_byte(struct inode *inode, unsigned long page_nr)
 	return last_byte;
 }
 
-static int ext2_commit_chunk(struct page *page, unsigned from, unsigned to)
+static int ext2_commit_chunk(struct page *page, loff_t pos, unsigned len)
 {
-	struct inode *dir = page->mapping->host;
+	struct address_space *mapping = page->mapping;
+	struct inode *dir = mapping->host;
 	int err = 0;
+
 	dir->i_version++;
-	page->mapping->a_ops->commit_write(NULL, page, from, to);
+	block_write_end(NULL, mapping, pos, len, len, page, NULL);
+
+	if (pos+len > dir->i_size) {
+		i_size_write(dir, pos+len);
+		mark_inode_dirty(dir);
+	}
+
 	if (IS_DIRSYNC(dir))
 		err = write_one_page(page, 1);
 	else
 		unlock_page(page);
+
 	return err;
 }
 
@@ -423,16 +434,18 @@ ino_t ext2_inode_by_name(struct inode * dir, struct dentry *dentry)
 void ext2_set_link(struct inode *dir, struct ext2_dir_entry_2 *de,
 			struct page *page, struct inode *inode)
 {
-	unsigned from = (char *) de - (char *) page_address(page);
-	unsigned to = from + le16_to_cpu(de->rec_len);
+	loff_t pos = page_offset(page) +
+			(char *) de - (char *) page_address(page);
+	unsigned len = le16_to_cpu(de->rec_len);
 	int err;
 
 	lock_page(page);
-	err = page->mapping->a_ops->prepare_write(NULL, page, from, to);
+	err = __ext2_write_begin(NULL, page->mapping, pos, len,
+				AOP_FLAG_UNINTERRUPTIBLE, &page, NULL);
 	BUG_ON(err);
 	de->inode = cpu_to_le32(inode->i_ino);
-	ext2_set_de_type (de, inode);
-	err = ext2_commit_chunk(page, from, to);
+	ext2_set_de_type(de, inode);
+	err = ext2_commit_chunk(page, pos, len);
 	ext2_put_page(page);
 	dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
 	EXT2_I(dir)->i_flags &= ~EXT2_BTREE_FL;
@@ -455,7 +468,7 @@ int ext2_add_link (struct dentry *dentry, struct inode *inode)
 	unsigned long npages = dir_pages(dir);
 	unsigned long n;
 	char *kaddr;
-	unsigned from, to;
+	loff_t pos;
 	int err;
 
 	/*
@@ -508,9 +521,10 @@ int ext2_add_link (struct dentry *dentry, struct inode *inode)
 	return -EINVAL;
 
 got_it:
-	from = (char*)de - (char*)page_address(page);
-	to = from + rec_len;
-	err = page->mapping->a_ops->prepare_write(NULL, page, from, to);
+	pos = page_offset(page) +
+		(char*)de - (char*)page_address(page);
+	err = __ext2_write_begin(NULL, page->mapping, pos, rec_len, 0,
+							&page, NULL);
 	if (err)
 		goto out_unlock;
 	if (de->inode) {
@@ -520,10 +534,10 @@ got_it:
 		de = de1;
 	}
 	de->name_len = namelen;
-	memcpy (de->name, name, namelen);
+	memcpy(de->name, name, namelen);
 	de->inode = cpu_to_le32(inode->i_ino);
 	ext2_set_de_type (de, inode);
-	err = ext2_commit_chunk(page, from, to);
+	err = ext2_commit_chunk(page, pos, rec_len);
 	dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
 	EXT2_I(dir)->i_flags &= ~EXT2_BTREE_FL;
 	mark_inode_dirty(dir);
@@ -548,6 +562,7 @@ int ext2_delete_entry (struct ext2_dir_entry_2 * dir, struct page * page )
 	char *kaddr = page_address(page);
 	unsigned from = ((char*)dir - kaddr) & ~(ext2_chunk_size(inode)-1);
 	unsigned to = ((char*)dir - kaddr) + le16_to_cpu(dir->rec_len);
+	loff_t pos;
 	ext2_dirent * pde = NULL;
 	ext2_dirent * de = (ext2_dirent *) (kaddr + from);
 	int err;
@@ -564,13 +579,15 @@ int ext2_delete_entry (struct ext2_dir_entry_2 * dir, struct page * page )
 	}
 	if (pde)
 		from = (char*)pde - (char*)page_address(page);
+	pos = page_offset(page) + from;
 	lock_page(page);
-	err = mapping->a_ops->prepare_write(NULL, page, from, to);
+	err = __ext2_write_begin(NULL, page->mapping, pos, to - from, 0,
+							&page, NULL);
 	BUG_ON(err);
 	if (pde)
-		pde->rec_len = cpu_to_le16(to-from);
+		pde->rec_len = cpu_to_le16(to - from);
 	dir->inode = 0;
-	err = ext2_commit_chunk(page, from, to);
+	err = ext2_commit_chunk(page, pos, to - from);
 	inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC;
 	EXT2_I(inode)->i_flags &= ~EXT2_BTREE_FL;
 	mark_inode_dirty(inode);
@@ -593,7 +610,9 @@ int ext2_make_empty(struct inode *inode, struct inode *parent)
 
 	if (!page)
 		return -ENOMEM;
-	err = mapping->a_ops->prepare_write(NULL, page, 0, chunk_size);
+
+	err = __ext2_write_begin(NULL, page->mapping, 0, chunk_size, 0,
+							&page, NULL);
 	if (err) {
 		unlock_page(page);
 		goto fail;
diff --git a/fs/ext2/ext2.h b/fs/ext2/ext2.h
index b94117e..d6ddadf 100644
--- a/fs/ext2/ext2.h
+++ b/fs/ext2/ext2.h
@@ -135,6 +135,10 @@ extern int ext2_setattr (struct dentry *, struct iattr *);
 extern void ext2_set_inode_flags(struct inode *inode);
 extern int ext2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 		       u64 start, u64 len);
+int __ext2_write_begin(struct file *file, struct address_space *mapping,
+		loff_t pos, unsigned len, unsigned flags,
+		struct page **pagep, void **fsdata);
+
 
 /* ioctl.c */
 extern int ext2_ioctl (struct inode *, struct file *, unsigned int,
@@ -164,7 +168,7 @@ extern const struct file_operations ext2_file_operations;
 extern const struct file_operations ext2_xip_file_operations;
 
 /* inode.c */
-extern const struct address_space_operations ext2_aops;
+extern const struct address_space_operations_ext ext2_aops;
 extern const struct address_space_operations ext2_aops_xip;
 extern const struct address_space_operations ext2_nobh_aops;
 
diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c
index 62297a2..0d66e40 100644
--- a/fs/ext2/inode.c
+++ b/fs/ext2/inode.c
@@ -650,18 +650,21 @@ ext2_readpages(struct file *file, struct address_space *mapping,
 	return mpage_readpages(mapping, pages, nr_pages, ext2_get_block);
 }
 
-static int
-ext2_prepare_write(struct file *file, struct page *page,
-			unsigned from, unsigned to)
+int __ext2_write_begin(struct file *file, struct address_space *mapping,
+		loff_t pos, unsigned len, unsigned flags,
+		struct page **pagep, void **fsdata)
 {
-	return block_prepare_write(page,from,to,ext2_get_block);
+	return block_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
+							ext2_get_block);
 }
 
 static int
-ext2_nobh_prepare_write(struct file *file, struct page *page,
-			unsigned from, unsigned to)
+ext2_write_begin(struct file *file, struct address_space *mapping,
+		loff_t pos, unsigned len, unsigned flags,
+		struct page **pagep, void **fsdata)
 {
-	return nobh_prepare_write(page,from,to,ext2_get_block);
+	*pagep = NULL;
+	return __ext2_write_begin(file, mapping, pos, len, flags, pagep,fsdata);
 }
 
 static int ext2_nobh_writepage(struct page *page,
@@ -692,17 +695,17 @@ ext2_writepages(struct address_space *mapping, struct writeback_control *wbc)
 	return mpage_writepages(mapping, wbc, ext2_get_block);
 }
 
-const struct address_space_operations ext2_aops = {
-	.readpage		= ext2_readpage,
-	.readpages		= ext2_readpages,
-	.writepage		= ext2_writepage,
-	.sync_page		= block_sync_page,
-	.prepare_write		= ext2_prepare_write,
-	.commit_write		= generic_commit_write,
-	.bmap			= ext2_bmap,
-	.direct_IO		= ext2_direct_IO,
-	.writepages		= ext2_writepages,
-	.migratepage		= buffer_migrate_page,
+const struct address_space_operations_ext ext2_aops = {
+	.orig_aops.readpage		= ext2_readpage,
+	.orig_aops.readpages		= ext2_readpages,
+	.orig_aops.writepage		= ext2_writepage,
+	.orig_aops.sync_page		= block_sync_page,
+	.write_begin			= ext2_write_begin,
+	.write_end			= generic_write_end,
+	.orig_aops.bmap			= ext2_bmap,
+	.orig_aops.direct_IO		= ext2_direct_IO,
+	.orig_aops.writepages		= ext2_writepages,
+	.orig_aops.migratepage		= buffer_migrate_page,
 };
 
 const struct address_space_operations ext2_aops_xip = {
@@ -715,8 +718,7 @@ const struct address_space_operations ext2_nobh_aops = {
 	.readpages		= ext2_readpages,
 	.writepage		= ext2_nobh_writepage,
 	.sync_page		= block_sync_page,
-	.prepare_write		= ext2_nobh_prepare_write,
-	.commit_write		= nobh_commit_write,
+	/* XXX: todo */
 	.bmap			= ext2_bmap,
 	.direct_IO		= ext2_direct_IO,
 	.writepages		= ext2_writepages,
@@ -1138,7 +1140,8 @@ void ext2_read_inode (struct inode * inode)
 			inode->i_mapping->a_ops = &ext2_nobh_aops;
 			inode->i_fop = &ext2_file_operations;
 		} else {
-			inode->i_mapping->a_ops = &ext2_aops;
+			inode->i_mapping->a_ops =
+				(struct address_space_operations *)&ext2_aops;
 			inode->i_fop = &ext2_file_operations;
 		}
 	} else if (S_ISDIR(inode->i_mode)) {
@@ -1147,7 +1150,8 @@ void ext2_read_inode (struct inode * inode)
 		if (test_opt(inode->i_sb, NOBH))
 			inode->i_mapping->a_ops = &ext2_nobh_aops;
 		else
-			inode->i_mapping->a_ops = &ext2_aops;
+			inode->i_mapping->a_ops =
+				(struct address_space_operations *)&ext2_aops;
 	} else if (S_ISLNK(inode->i_mode)) {
 		if (ext2_inode_is_fast_symlink(inode))
 			inode->i_op = &ext2_fast_symlink_inode_operations;
@@ -1156,7 +1160,9 @@ void ext2_read_inode (struct inode * inode)
 			if (test_opt(inode->i_sb, NOBH))
 				inode->i_mapping->a_ops = &ext2_nobh_aops;
 			else
-				inode->i_mapping->a_ops = &ext2_aops;
+				inode->i_mapping->a_ops =
+					(struct address_space_operations *)
+					&ext2_aops;
 		}
 	} else {
 		inode->i_op = &ext2_special_inode_operations;
diff --git a/fs/ext2/namei.c b/fs/ext2/namei.c
index 4ca8249..3f774b9 100644
--- a/fs/ext2/namei.c
+++ b/fs/ext2/namei.c
@@ -116,7 +116,8 @@ static int ext2_create (struct inode * dir, struct dentry * dentry, int mode, st
 			inode->i_mapping->a_ops = &ext2_nobh_aops;
 			inode->i_fop = &ext2_file_operations;
 		} else {
-			inode->i_mapping->a_ops = &ext2_aops;
+			inode->i_mapping->a_ops =
+				(struct address_space_operations *)&ext2_aops;
 			inode->i_fop = &ext2_file_operations;
 		}
 		mark_inode_dirty(inode);
@@ -168,7 +169,8 @@ static int ext2_symlink (struct inode * dir, struct dentry * dentry,
 		if (test_opt(inode->i_sb, NOBH))
 			inode->i_mapping->a_ops = &ext2_nobh_aops;
 		else
-			inode->i_mapping->a_ops = &ext2_aops;
+			inode->i_mapping->a_ops =
+				(struct address_space_operations *)&ext2_aops;
 		err = page_symlink(inode, symname, l);
 		if (err)
 			goto out_fail;
@@ -225,7 +227,8 @@ static int ext2_mkdir(struct inode * dir, struct dentry * dentry, int mode)
 	if (test_opt(inode->i_sb, NOBH))
 		inode->i_mapping->a_ops = &ext2_nobh_aops;
 	else
-		inode->i_mapping->a_ops = &ext2_aops;
+		inode->i_mapping->a_ops =
+			(struct address_space_operations *)&ext2_aops;
 
 	inode_inc_link_count(inode);
 
diff --git a/fs/ext2/super.c b/fs/ext2/super.c
index b83f4ed..321d478 100644
--- a/fs/ext2/super.c
+++ b/fs/ext2/super.c
@@ -720,6 +720,7 @@ static int ext2_fill_super(struct super_block *sb, void *data, int silent)
 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
 		((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
 		 MS_POSIXACL : 0);
+	sb->s_flags |= MS_HAS_NEW_AOPS;
 
 	ext2_xip_verify_sb(sb); /* see if bdev supports xip, unset
 				    EXT2_MOUNT_XIP if not */
@@ -1028,6 +1029,7 @@ static int ext2_remount (struct super_block * sb, int * flags, char * data)
 
 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
 		((sbi->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
+	sb->s_flags |= MS_HAS_NEW_AOPS;
 
 	es = sbi->s_es;
 	if (((sbi->s_mount_opt & EXT2_MOUNT_XIP) !=