[PATCH 4.2 080/134] NFSv4.1/pNFS: Fix borken function _same_data_server_addrs_locked()

Greg Kroah-Hartman
2015-09-26T21:00:05Z

From: Trond Myklebust <trond.myklebust@primarydata.com>

commit 6f536936b79bd4b5cea8fb0e5b8b0bce8cd1ea4a upstream.

- Switch back to using list_for_each_entry(). Fixes an incorrect test
for list NULL termination.
- Do not assume that lists are sorted.
- Finally, consider an existing entry to match if it consists of a subset
of the addresses in the new entry.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
fs/nfs/pnfs_nfs.c | 31 ++++++++++++++++++-------------
1 file changed, 18 insertions(+), 13 deletions(-)

--- a/fs/nfs/pnfs_nfs.c
+++ b/fs/nfs/pnfs_nfs.c
@@ -359,26 +359,31 @@ same_sockaddr(struct sockaddr *addr1, st
return false;
}

+/*
+ * Checks if 'dsaddrs1' contains a subset of 'dsaddrs2'. If it does,
+ * declare a match.
+ */
static bool
_same_data_server_addrs_locked(const struct list_head *dsaddrs1,
const struct list_head *dsaddrs2)
{
struct nfs4_pnfs_ds_addr *da1, *da2;
+ struct sockaddr *sa1, *sa2;
+ bool match = false;

- /* step through both lists, comparing as we go */
- for (da1 = list_first_entry(dsaddrs1, typeof(*da1), da_node),
- da2 = list_first_entry(dsaddrs2, typeof(*da2), da_node);
- da1 != NULL && da2 != NULL;
- da1 = list_entry(da1->da_node.next, typeof(*da1), da_node),
- da2 = list_entry(da2->da_node.next, typeof(*da2), da_node)) {
- if (!same_sockaddr((struct sockaddr *)&da1->da_addr,
- (struct sockaddr *)&da2->da_addr))
- return false;
+ list_for_each_entry(da1, dsaddrs1, da_node) {
+ sa1 = (struct sockaddr *)&da1->da_addr;
+ match = false;
+ list_for_each_entry(da2, dsaddrs2, da_node) {
+ sa2 = (struct sockaddr *)&da2->da_addr;
+ match = same_sockaddr(sa1, sa2);
+ if (match)
+ break;
+ }
+ if (!match)
+ break;
}
- if (da1 == NULL && da2 == NULL)
- return true;
-
- return false;
+ return match;
}

/*