exofs: simple_write_end does not mark_inode_dirty (efd124b9) · Commits · 戴 / test

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>

fs/exofs/inode.c

+16 −1

Original line number	Original line	Diff line number	Diff line
	@@ -738,13 +738,28 @@ static int exofs_write_begin_export(struct file *file,
	fsdata);		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 = {		const struct address_space_operations exofs_aops = {
	.readpage = exofs_readpage,		.readpage = exofs_readpage,
	.readpages = exofs_readpages,		.readpages = exofs_readpages,
	.writepage = exofs_writepage,		.writepage = exofs_writepage,
	.writepages = exofs_writepages,		.writepages = exofs_writepages,
	.write_begin = exofs_write_begin_export,		.write_begin = exofs_write_begin_export,
	.write_end = simple_write_end,		.write_end = exofs_write_end,
	};		};

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

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