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authorDavid Howells <dhowells@redhat.com>2018-02-06 14:12:32 +0000
committerDavid Howells <dhowells@redhat.com>2018-02-06 14:36:54 +0000
commit45df8462730d2149834980d3db16e2d2b9daaf60 (patch)
treeb884a2ea9e5c704a5ec90caf905a3a1902f7ce74 /fs/afs/vlclient.c
parent8305e579c653b127b292fcdce551e930f9560260 (diff)
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afs: Fix server list handling
Fix server list handling in the following ways: (1) In afs_alloc_volume(), remove duplicate server list build code. This was already done by afs_alloc_server_list() which afs_alloc_volume() previously called. This just results in twice as many VL RPCs. (2) In afs_deliver_vl_get_entry_by_name_u(), use the number of server records indicated by ->nServers in the UVLDB record returned by the VL.GetEntryByNameU RPC call rather than scanning all NMAXNSERVERS slots. Unused slots may contain garbage. (3) In afs_alloc_server_list(), don't stop converting a UVLDB record into a server list just because we can't look up one of the servers. Just skip that server and go on to the next. If we can't look up any of the servers then we'll fail at the end. Without this patch, an attempt to view the umich.edu root cell using something like "ls /afs/umich.edu" on a dynamic root (future patch) mount or an autocell mount will result in ENOMEDIUM. The failure is due to kafs not stopping after nServers'worth of records have been read, but then trying to access a server with a garbage UUID and getting an error, which aborts the server list build. Fixes: d2ddc776a458 ("afs: Overhaul volume and server record caching and fileserver rotation") Reported-by: Jonathan Billings <jsbillings@jsbillings.org> Signed-off-by: David Howells <dhowells@redhat.com> cc: stable@vger.kernel.org
Diffstat (limited to 'fs/afs/vlclient.c')
-rw-r--r--fs/afs/vlclient.c10
1 files changed, 7 insertions, 3 deletions
diff --git a/fs/afs/vlclient.c b/fs/afs/vlclient.c
index e372f89fd36a..5d8562f1ad4a 100644
--- a/fs/afs/vlclient.c
+++ b/fs/afs/vlclient.c
@@ -23,7 +23,7 @@ static int afs_deliver_vl_get_entry_by_name_u(struct afs_call *call)
struct afs_uvldbentry__xdr *uvldb;
struct afs_vldb_entry *entry;
bool new_only = false;
- u32 tmp;
+ u32 tmp, nr_servers;
int i, ret;
_enter("");
@@ -36,6 +36,10 @@ static int afs_deliver_vl_get_entry_by_name_u(struct afs_call *call)
uvldb = call->buffer;
entry = call->reply[0];
+ nr_servers = ntohl(uvldb->nServers);
+ if (nr_servers > AFS_NMAXNSERVERS)
+ nr_servers = AFS_NMAXNSERVERS;
+
for (i = 0; i < ARRAY_SIZE(uvldb->name) - 1; i++)
entry->name[i] = (u8)ntohl(uvldb->name[i]);
entry->name[i] = 0;
@@ -44,14 +48,14 @@ static int afs_deliver_vl_get_entry_by_name_u(struct afs_call *call)
/* If there is a new replication site that we can use, ignore all the
* sites that aren't marked as new.
*/
- for (i = 0; i < AFS_NMAXNSERVERS; i++) {
+ for (i = 0; i < nr_servers; i++) {
tmp = ntohl(uvldb->serverFlags[i]);
if (!(tmp & AFS_VLSF_DONTUSE) &&
(tmp & AFS_VLSF_NEWREPSITE))
new_only = true;
}
- for (i = 0; i < AFS_NMAXNSERVERS; i++) {
+ for (i = 0; i < nr_servers; i++) {
struct afs_uuid__xdr *xdr;
struct afs_uuid *uuid;
int j;