Commit efd124b9 authored Dec 27, 2009 by Boaz Harrosh

exofs: simple_write_end does not mark_inode_dirty



exofs uses simple_write_end() for it's .write_end handler. But
it is not enough because simple_write_end() does not call
mark_inode_dirty() when it extends i_size. So even if we do
call mark_inode_dirty at beginning of write out, with a very
long IO and a saturated system we might get the .write_inode()
called while still extend-writing to file and miss out on the last
i_size updates.

So override .write_end, call simple_write_end(), and afterwords if
i_size was changed call mark_inode_dirty().

It stands to logic that since simple_write_end() was the one extending
i_size it should also call mark_inode_dirty(). But it looks like all
users of simple_write_end() are memory-bound pseudo filesystems, who
could careless about mark_inode_dirty(). I might submit a
warning-comment patch to simple_write_end() in future.

CC: Stable <stable@kernel.org>
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>

parent 89be5030

fs/exofs/inode.c

+16 −1

Original line number	Diff line number	Diff line
		@@ -738,13 +738,28 @@ static int exofs_write_begin_export(struct file *file,
		fsdata);
		}

		static int exofs_write_end(struct file file, struct address_space mapping,
		loff_t pos, unsigned len, unsigned copied,
		struct page page, void fsdata)
		{
		struct inode *inode = mapping->host;
		/* According to comment in simple_write_end i_mutex is held */
		loff_t i_size = inode->i_size;
		int ret;

		ret = simple_write_end(file, mapping,pos, len, copied, page, fsdata);
		if (i_size != inode->i_size)
		mark_inode_dirty(inode);
		return ret;
		}

		const struct address_space_operations exofs_aops = {
		.readpage = exofs_readpage,
		.readpages = exofs_readpages,
		.writepage = exofs_writepage,
		.writepages = exofs_writepages,
		.write_begin = exofs_write_begin_export,
		.write_end = simple_write_end,
		.write_end = exofs_write_end,
		};

		/******************************************************************************