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authorChristoph Hellwig <hch@lst.de>2010-06-04 11:30:04 +0200
committerAl Viro <viro@zeniv.linux.org.uk>2010-08-09 16:47:39 -0400
commit2c27c65ed0696f0b5df2dad2cf6462d72164d547 (patch)
tree7d9036e3dea98938f7fd7074366ee73929e9b2e5 /mm/truncate.c
parentdb78b877f7744bec4a9d9f9e7d10da3931d7cd39 (diff)
check ATTR_SIZE contraints in inode_change_ok
Make sure we check the truncate constraints early on in ->setattr by adding those checks to inode_change_ok. Also clean up and document inode_change_ok to make this obvious. As a fallout we don't have to call inode_newsize_ok from simple_setsize and simplify it down to a truncate_setsize which doesn't return an error. This simplifies a lot of setattr implementations and means we use truncate_setsize almost everywhere. Get rid of fat_setsize now that it's trivial and mark ext2_setsize static to make the calling convention obvious. Keep the inode_newsize_ok in vmtruncate for now as all callers need an audit for its removal anyway. Note: setattr code in ecryptfs doesn't call inode_change_ok at all and needs a deeper audit, but that is left for later. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'mm/truncate.c')
-rw-r--r--mm/truncate.c38
1 files changed, 29 insertions, 9 deletions
diff --git a/mm/truncate.c b/mm/truncate.c
index 937571b8b233..ba887bff48c5 100644
--- a/mm/truncate.c
+++ b/mm/truncate.c
@@ -541,28 +541,48 @@ void truncate_pagecache(struct inode *inode, loff_t old, loff_t new)
EXPORT_SYMBOL(truncate_pagecache);
/**
+ * truncate_setsize - update inode and pagecache for a new file size
+ * @inode: inode
+ * @newsize: new file size
+ *
+ * truncate_setsize updastes i_size update and performs pagecache
+ * truncation (if necessary) for a file size updates. It will be
+ * typically be called from the filesystem's setattr function when
+ * ATTR_SIZE is passed in.
+ *
+ * Must be called with inode_mutex held and after all filesystem
+ * specific block truncation has been performed.
+ */
+void truncate_setsize(struct inode *inode, loff_t newsize)
+{
+ loff_t oldsize;
+
+ oldsize = inode->i_size;
+ i_size_write(inode, newsize);
+
+ truncate_pagecache(inode, oldsize, newsize);
+}
+EXPORT_SYMBOL(truncate_setsize);
+
+/**
* vmtruncate - unmap mappings "freed" by truncate() syscall
* @inode: inode of the file used
* @offset: file offset to start truncating
*
- * NOTE! We have to be ready to update the memory sharing
- * between the file and the memory map for a potential last
- * incomplete page. Ugly, but necessary.
- *
- * This function is deprecated and simple_setsize or truncate_pagecache
- * should be used instead.
+ * This function is deprecated and truncate_setsize or truncate_pagecache
+ * should be used instead, together with filesystem specific block truncation.
*/
int vmtruncate(struct inode *inode, loff_t offset)
{
int error;
- error = simple_setsize(inode, offset);
+ error = inode_newsize_ok(inode, offset);
if (error)
return error;
+ truncate_setsize(inode, offset);
if (inode->i_op->truncate)
inode->i_op->truncate(inode);
-
- return error;
+ return 0;
}
EXPORT_SYMBOL(vmtruncate);

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