ufs: free excessive blocks upon ->write_begin() failure/short copy

Broken in "[PATCH] ufs: truncate should allocate block for last byte";
all way back in 2006.  ufs_setattr() hadn't been the only user of
vmtruncate() and eliminating ->truncate() method required corrections
in a bunch of places.  Eventually those places had migrated into
->write_begin() failure exit and ->write_end() after short copy...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/ufs/inode.c b/fs/ufs/inode.c
index 282b0ce..a4fc3ad 100644 (file)
--- a/fs/ufs/inode.c
+++ b/fs/ufs/inode.c
@@ -530,8 +530,10 @@ static void ufs_write_failed(struct address_space *mapping, loff_t to)
 {
        struct inode *inode = mapping->host;
 
-       if (to > inode->i_size)
+       if (to > inode->i_size) {
                truncate_pagecache(inode, inode->i_size);
+               ufs_truncate_blocks(inode);
+       }
 }
 
 static int ufs_write_begin(struct file *file, struct address_space *mapping,
@@ -548,6 +550,18 @@ static int ufs_write_begin(struct file *file, struct address_space *mapping,
        return ret;
 }
 
+static int ufs_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)
+               ufs_write_failed(mapping, pos + len);
+       return ret;
+}
+
 static sector_t ufs_bmap(struct address_space *mapping, sector_t block)
 {
        return generic_block_bmap(mapping,block,ufs_getfrag_block);
@@ -557,7 +571,7 @@ const struct address_space_operations ufs_aops = {
        .readpage = ufs_readpage,
        .writepage = ufs_writepage,
        .write_begin = ufs_write_begin,
-       .write_end = generic_write_end,
+       .write_end = ufs_write_end,
        .bmap = ufs_bmap
 };