[PATCH 14/n] sysv: new truncate sequence

[Christoph Hellwig <hch@infradead.org>]

Signed-off-by: Christoph Hellwig <hch@lst.de>

Index: vfs-2.6.git/fs/sysv/file.c
===================================================================
--- vfs-2.6.git.orig/fs/sysv/file.c	2009-09-22 15:23:55.049764156 -0300
+++ vfs-2.6.git/fs/sysv/file.c	2009-09-22 15:35:52.993764871 -0300
@@ -31,6 +31,7 @@ const struct file_operations sysv_file_o
 };
 
 const struct inode_operations sysv_file_inode_operations = {
-	.truncate	= sysv_truncate,
+	.truncate_kludge_to_be_killed = 1,
+	.setattr	= sysv_setattr,
 	.getattr	= sysv_getattr,
 };
Index: vfs-2.6.git/fs/sysv/inode.c
===================================================================
--- vfs-2.6.git.orig/fs/sysv/inode.c	2009-09-22 15:23:55.077764435 -0300
+++ vfs-2.6.git/fs/sysv/inode.c	2009-09-22 15:31:45.210264810 -0300
@@ -305,7 +305,8 @@ static void sysv_delete_inode(struct ino
 {
 	truncate_inode_pages(&inode->i_data, 0);
 	inode->i_size = 0;
-	sysv_truncate(inode);
+	if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
+		sysv_truncate_blocks(inode, 0);
 	sysv_free_inode(inode);
 }
 
Index: vfs-2.6.git/fs/sysv/itree.c
===================================================================
--- vfs-2.6.git.orig/fs/sysv/itree.c	2009-09-22 15:23:55.121765981 -0300
+++ vfs-2.6.git/fs/sysv/itree.c	2009-09-22 15:39:17.898295684 -0300
@@ -360,7 +360,7 @@ static void free_branches(struct inode *
 		free_data(inode, p, q);
 }
 
-void sysv_truncate (struct inode * inode)
+void sysv_truncate_blocks(struct inode *inode, loff_t offset)
 {
 	sysv_zone_t *i_data = SYSV_I(inode)->i_data;
 	int offsets[DEPTH];
@@ -371,15 +371,8 @@ void sysv_truncate (struct inode * inode
 	long iblock;
 	unsigned blocksize;
 
-	if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
-	    S_ISLNK(inode->i_mode)))
-		return;
-
 	blocksize = inode->i_sb->s_blocksize;
-	iblock = (inode->i_size + blocksize-1)
-					>> inode->i_sb->s_blocksize_bits;
-
-	block_truncate_page(inode->i_mapping, inode->i_size, get_block);
+	iblock = (offset + blocksize - 1) >> inode->i_sb->s_blocksize_bits;
 
 	n = block_to_path(inode, iblock, offsets);
 	if (n == 0)
@@ -449,6 +442,47 @@ int sysv_getattr(struct vfsmount *mnt, s
 	return 0;
 }
 
+static int sysv_setsize(struct inode *inode, loff_t newsize)
+{
+	loff_t oldsize;
+	int error;
+
+	error = inode_newsize_ok(inode, newsize);
+	if (error)
+		return error;
+
+	oldsize = inode->i_size;
+	i_size_write(inode, newsize);
+	truncate_pagecache(inode, oldsize, newsize);
+
+	error = block_truncate_page(inode->i_mapping, newsize, get_block);
+	if (error)
+		return error;
+
+	sysv_truncate_blocks(inode, newsize);
+	return 0;
+}
+
+int sysv_setattr(struct dentry *dentry, struct iattr *iattr)
+{
+	struct inode *inode = dentry->d_inode;
+	int error;
+
+	error = inode_change_ok(inode, iattr);
+	if (error)
+		return error;
+
+	if (iattr->ia_valid & ATTR_SIZE) {
+		error = sysv_setsize(inode, iattr->ia_size);
+		if (error)
+			return error;
+	}
+
+	generic_setattr(inode, iattr);
+	mark_inode_dirty(inode);
+	return 0;
+}
+
 static int sysv_writepage(struct page *page, struct writeback_control *wbc)
 {
 	return block_write_full_page(page,get_block,wbc);
@@ -471,8 +505,33 @@ static int sysv_write_begin(struct file 
 			loff_t pos, unsigned len, unsigned flags,
 			struct page **pagep, void **fsdata)
 {
+	int ret;
+
 	*pagep = NULL;
-	return __sysv_write_begin(file, mapping, pos, len, flags, pagep, fsdata);
+	ret = __sysv_write_begin(file, mapping, pos, len, flags, pagep, fsdata);
+	if (ret < 0) {
+		struct inode *inode = mapping->host;
+		loff_t isize = inode->i_size;
+		if (pos + len > isize)
+			sysv_truncate_blocks(inode, isize);
+	}
+	return ret;
+}
+
+static int sysv_write_end(struct file *file, struct address_space *mapping,
+		loff_t pos, unsigned len, unsigned copied,
+		struct page *page, void *fsdata)
+{
+	int ret;
+
+	ret = generic_write_end(file, mapping, pos, len, copied, page, fsdata);
+	if (ret < len) {
+		struct inode *inode = mapping->host;
+		loff_t isize = inode->i_size;
+		if (pos + len > isize)
+			sysv_truncate_blocks(inode, isize);
+	}
+	return ret;
 }
 
 static sector_t sysv_bmap(struct address_space *mapping, sector_t block)
@@ -485,6 +544,6 @@ const struct address_space_operations sy
 	.writepage = sysv_writepage,
 	.sync_page = block_sync_page,
 	.write_begin = sysv_write_begin,
-	.write_end = generic_write_end,
+	.write_end = sysv_write_end,
 	.bmap = sysv_bmap
 };
Index: vfs-2.6.git/fs/sysv/sysv.h
===================================================================
--- vfs-2.6.git.orig/fs/sysv/sysv.h	2009-09-22 15:23:55.097764604 -0300
+++ vfs-2.6.git/fs/sysv/sysv.h	2009-09-22 15:32:51.722266473 -0300
@@ -135,7 +135,7 @@ extern void sysv_free_block(struct super
 extern unsigned long sysv_count_free_blocks(struct super_block *);
 
 /* itree.c */
-extern void sysv_truncate(struct inode *);
+extern void sysv_truncate_blocks(struct inode *, loff_t);
 extern int __sysv_write_begin(struct file *file, struct address_space *mapping,
 			loff_t pos, unsigned len, unsigned flags,
 			struct page **pagep, void **fsdata);
@@ -146,6 +146,7 @@ extern int sysv_write_inode(struct inode
 extern int sysv_sync_inode(struct inode *);
 extern void sysv_set_inode(struct inode *, dev_t);
 extern int sysv_getattr(struct vfsmount *, struct dentry *, struct kstat *);
+extern int sysv_setattr(struct dentry *dentry, struct iattr *iattr);
 extern int sysv_init_icache(void);
 extern void sysv_destroy_icache(void);