afs: Fix missing net error handling

kAFS can be given certain network errors (EADDRNOTAVAIL, EHOSTDOWN and
ERFKILL) that it doesn't handle in its server/address rotation algorithms.
They cause the probing and rotation to abort immediately rather than
rotating.

Fix this by:

 (1) Abstracting out the error prioritisation from the VL and FS rotation
     algorithms into a common function and expand usage into the server
     probing code.

     When multiple errors are available, this code selects the one we'd
     prefer to return.

 (2) Add handling for EADDRNOTAVAIL, EHOSTDOWN and ERFKILL.

Fixes: 0fafdc9f888b ("afs: Fix file locking")
Fixes: 0338747d8454 ("afs: Probe multiple fileservers simultaneously")
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 10 insertions, 40 deletions

diff --git a/fs/afs/vl_rotate.c b/fs/afs/vl_rotate.c
index b64a284b99d2..7adde83a0648 100644
--- a/fs/afs/vl_rotate.c
+++ b/fs/afs/vl_rotate.c
@@ -71,8 +71,9 @@ bool afs_select_vlserver(struct afs_vl_cursor *vc)
 {
 	struct afs_addr_list *alist;
 	struct afs_vlserver *vlserver;
+	struct afs_error e;
 	u32 rtt;
-	int error = vc->ac.error, abort_code, i;
+	int error = vc->ac.error, i;
 
 	_enter("%lx[%d],%lx[%d],%d,%d",
 	       vc->untried, vc->index,
@@ -119,8 +120,11 @@ bool afs_select_vlserver(struct afs_vl_cursor *vc)
 			goto failed;
 		}
 
+	case -ERFKILL:
+	case -EADDRNOTAVAIL:
 	case -ENETUNREACH:
 	case -EHOSTUNREACH:
+	case -EHOSTDOWN:
 	case -ECONNREFUSED:
 	case -ETIMEDOUT:
 	case -ETIME:
@@ -235,50 +239,15 @@ no_more_servers:
 	if (vc->flags & AFS_VL_CURSOR_RETRY)
 		goto restart_from_beginning;
 
-	abort_code = 0;
-	error = -EDESTADDRREQ;
+	e.error = -EDESTADDRREQ;
+	e.responded = false;
 	for (i = 0; i < vc->server_list->nr_servers; i++) {
 		struct afs_vlserver *s = vc->server_list->servers[i].server;
-		int probe_error = READ_ONCE(s->probe.error);
 
-		switch (probe_error) {
-		case 0:
-			continue;
-		default:
-			if (error == -ETIMEDOUT ||
-			    error == -ETIME)
-				continue;
-		case -ETIMEDOUT:
-		case -ETIME:
-			if (error == -ENOMEM ||
-			    error == -ENONET)
-				continue;
-		case -ENOMEM:
-		case -ENONET:
-			if (error == -ENETUNREACH)
-				continue;
-		case -ENETUNREACH:
-			if (error == -EHOSTUNREACH)
-				continue;
-		case -EHOSTUNREACH:
-			if (error == -ECONNREFUSED)
-				continue;
-		case -ECONNREFUSED:
-			if (error == -ECONNRESET)
-				continue;
-		case -ECONNRESET: /* Responded, but call expired. */
-			if (error == -ECONNABORTED)
-				continue;
-		case -ECONNABORTED:
-			abort_code = s->probe.abort_code;
-			error = probe_error;
-			continue;
-		}
+		afs_prioritise_error(&e, READ_ONCE(s->probe.error),
+				     s->probe.abort_code);
 	}
 
-	if (error == -ECONNABORTED)
-		error = afs_abort_to_error(abort_code);
-
 failed_set_error:
 	vc->error = error;
 failed:
@@ -341,6 +310,7 @@ int afs_end_vlserver_operation(struct afs_vl_cursor *vc)
 	struct afs_net *net = vc->cell->net;
 
 	if (vc->error == -EDESTADDRREQ ||
+	    vc->error == -EADDRNOTAVAIL ||
 	    vc->error == -ENETUNREACH ||
 	    vc->error == -EHOSTUNREACH)
 		afs_vl_dump_edestaddrreq(vc);