[ 202/221] libceph: avoid using freed osd in __kick_osd_requests()

Greg Kroah-Hartman
2013-01-15T22:36:06Z

From: Alex Elder <elder@inktank.com>

(cherry picked from commit 685a7555ca69030739ddb57a47f0ea8ea80196a4)

If an osd has no requests and no linger requests, __reset_osd()
will just remove it with a call to __remove_osd(). That drops
a reference to the osd, and therefore the osd may have been free
by the time __reset_osd() returns. That function offers no
indication this may have occurred, and as a result the osd will
continue to be used even when it's no longer valid.

Change__reset_osd() so it returns an error (ENODEV) when it
deletes the osd being reset. And change __kick_osd_requests() so it
returns immediately (before referencing osd again) if __reset_osd()
returns *any* error.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/ceph/osd_client.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/net/ceph/osd_client.c
+++ b/net/ceph/osd_client.c
@@ -581,7 +581,7 @@ static void __kick_osd_requests(struct c

dout("__kick_osd_requests osd%d\n", osd->o_osd);
err = __reset_osd(osdc, osd);
- if (err == -EAGAIN)
+ if (err)
return;

list_for_each_entry(req, &osd->o_requests, r_osd_item) {
@@ -752,6 +752,7 @@ static int __reset_osd(struct ceph_osd_c
if (list_empty(&osd->o_requests) &&
list_empty(&osd->o_linger_requests)) {
__remove_osd(osdc, osd);
+ ret = -ENODEV;
} else if (memcmp(&osdc->osdmap->osd_addr[osd->o_osd],
&osd->o_con.peer_addr,
sizeof(osd->o_con.peer_addr)) == 0 &&