Convert simple filesystems: ramfs, configfs, sysfs to new truncate

sequence.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jan Kara <jack@suse.cz>
Cc: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Steven French <sfrench@us.ibm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

fs/configfs/inode.c

@@ -57,6 +57,7 @@ static struct backing_dev_info configfs_backing_dev_info = {
 };
 
 static const struct inode_operations configfs_inode_operations ={
+	.new_truncate	= 1,
 	.setattr	= configfs_setattr,
 };
 
@@ -77,9 +78,13 @@ int configfs_setattr(struct dentry * dentry, struct iattr * iattr)
 	if (error)
 		return error;
 
-	error = inode_setattr(inode, iattr);
-	if (error)
-		return error;
+	if (iattr->ia_valid & ATTR_SIZE) {
+		error = simple_setsize(inode, iattr->ia_size);
+		if (error)
+			return error;
+	}
+
+	generic_setattr(inode, iattr);
 
 	if (!sd_iattr) {
 		/* setting attributes for the first time, allocate now */

fs/ramfs/file-mmu.c

@@ -50,5 +50,7 @@ const struct file_operations ramfs_file_operations = {
 };
 
 const struct inode_operations ramfs_file_inode_operations = {
+	.new_truncate	= 1,
+	.setattr	= simple_setattr,
 	.getattr	= simple_getattr,
 };

fs/ramfs/file-nommu.c

@@ -48,6 +48,7 @@ const struct file_operations ramfs_file_operations = {
 };
 
 const struct inode_operations ramfs_file_inode_operations = {
+	.new_truncate		= 1,
 	.setattr		= ramfs_nommu_setattr,
 	.getattr		= simple_getattr,
 };
@@ -169,7 +170,7 @@ static int ramfs_nommu_resize(struct inode *inode, loff_t newsize, loff_t size)
 			return ret;
 	}
 
-	ret = vmtruncate(inode, newsize);
+	ret = simple_setsize(inode, newsize);
 
 	return ret;
 }
@@ -192,7 +193,8 @@ static int ramfs_nommu_setattr(struct dentry *dentry, struct iattr *ia)
 
 	/* pick out size-changing events */
 	if (ia->ia_valid & ATTR_SIZE) {
-		loff_t size = i_size_read(inode);
+		loff_t size = inode->i_size;
+
 		if (ia->ia_size != size) {
 			ret = ramfs_nommu_resize(inode, ia->ia_size, size);
 			if (ret < 0 || ia->ia_valid == ATTR_SIZE)
@@ -205,7 +207,7 @@ static int ramfs_nommu_setattr(struct dentry *dentry, struct iattr *ia)
 		}
 	}
 
-	ret = inode_setattr(inode, ia);
+	generic_setattr(inode, ia);
  out:
 	ia->ia_valid = old_ia_valid;
 	return ret;

fs/sysfs/inode.c

@@ -35,6 +35,7 @@ static struct backing_dev_info sysfs_backing_dev_info = {
 };
 
 static const struct inode_operations sysfs_inode_operations ={
+	.new_truncate	= 1,
 	.setattr	= sysfs_setattr,
 };
 
@@ -60,11 +61,7 @@ int sysfs_setattr(struct dentry * dentry, struct iattr * iattr)
 	if (error)
 		return error;
 
-	iattr->ia_valid &= ~ATTR_SIZE; /* ignore size changes */
-
-	error = inode_setattr(inode, iattr);
-	if (error)
-		return error;
+	generic_setattr(inode, iattr);
 
 	if (!sd_iattr) {
 		/* setting attributes for the first time, allocate now */