Commit 94e18007 authored Mar 04, 2013 by Jeff Layton Committed by Steve French Mar 06, 2013

cifs: don't try to unlock pagecache page after releasing it



We had a recent fix to fix the release of pagecache pages when
cifs_writev_requeue writes fail. Unfortunately, it releases the page
before trying to unlock it. At that point, the page might be gone by the
time the unlock comes in.

Unlock the page first before checking the value of "rc", and only then
end writeback and release the pages. The page lock isn't required for
any of those operations so this should be safe.

Reported-by: Anton Altaparmakov <aia21@cam.ac.uk>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

parent 25189643

fs/cifs/cifssmb.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -1909,12 +1909,12 @@ cifs_writev_requeue(struct cifs_writedata *wdata)
		} while (rc == -EAGAIN);

		for (i = 0; i < wdata->nr_pages; i++) {
		unlock_page(wdata->pages[i]);
		if (rc != 0) {
		SetPageError(wdata->pages[i]);
		end_page_writeback(wdata->pages[i]);
		page_cache_release(wdata->pages[i]);
		}
		unlock_page(wdata->pages[i]);
		}

		mapping_set_error(inode->i_mapping, rc);

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