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Commit 77469c3f authored by Al Viro's avatar Al Viro
Browse files

9p: saner ->write_end() on failing copy into non-uptodate page 



If we had a short copy into an uptodate page, there's no reason
whatsoever to zero anything; OTOH, if that page had _not_ been
uptodate, we must have been trying to overwrite it completely
and got a short copy.  In that case, overwriting the end with
zeroes, marking uptodate and sending to server is just plain
wrong.  Just unlock, keep it non-uptodate and return 0.

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 43388b21

fs/9p/vfs_addr.c

+4 −11
Original line number Diff line number Diff line
@@ -309,18 +309,10 @@ static int v9fs_write_end(struct file *filp, struct address_space *mapping, 


	p9_debug(P9_DEBUG_VFS, "filp %p, mapping %p\n", filp, mapping);



	if (unlikely(copied < len)) {

		/*

		 * zero out the rest of the area

		 */

		unsigned from = pos & (PAGE_SIZE - 1);



		zero_user(page, from + copied, len - copied);

		flush_dcache_page(page);

	if (unlikely(copied < len && !PageUptodate(page))) {

		copied = 0;

		goto out;

	}



	if (!PageUptodate(page))

		SetPageUptodate(page);

	/*

	 * No need to use i_size_read() here, the i_size

	 * cannot change under us because we hold the i_mutex.
@@ -330,6 +322,7 @@ static int v9fs_write_end(struct file *filp, struct address_space *mapping, 
		i_size_write(inode, last_pos);

	}

	set_page_dirty(page);

out:

	unlock_page(page);

	put_page(page);