[PATCH 6.8 602/715] afs: Don't cache preferred address

Sasha Levin
2024-03-24T22:44:55Z

From: David Howells <dhowells@redhat.com>

[ Upstream commit 83505bde45e347f1451d007b3ddd7f06cee4c269 ]

In the AFS fileserver rotation algorithm, don't cache the preferred address
for the server as that will override the explicit preference if a
non-preferred address responds first.

Fixes: 495f2ae9e355 ("afs: Fix fileserver rotation")
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20240313081505.3060173-2-dhowells@redhat.com
Reviewed-by: Marc Dionne <marc.dionne@auristor.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/afs/rotate.c | 21 ++++-----------------
1 file changed, 4 insertions(+), 17 deletions(-)

diff --git a/fs/afs/rotate.c b/fs/afs/rotate.c
index 700a27bc8c257..ed04bd1eeae89 100644
--- a/fs/afs/rotate.c
+++ b/fs/afs/rotate.c
@@ -602,6 +602,8 @@ bool afs_select_fileserver(struct afs_operation *op)
goto wait_for_more_probe_results;

alist = op->estate->addresses;
+ best_prio = -1;
+ addr_index = 0;
for (i = 0; i < alist->nr_addrs; i++) {
if (alist->addrs[i].prio > best_prio) {
addr_index = i;
@@ -609,9 +611,7 @@ bool afs_select_fileserver(struct afs_operation *op)
}
}

- addr_index = READ_ONCE(alist->preferred);
- if (!test_bit(addr_index, &set))
- addr_index = __ffs(set);
+ alist->preferred = addr_index;

op->addr_index = addr_index;
set_bit(addr_index, &op->addr_tried);
@@ -656,12 +656,6 @@ bool afs_select_fileserver(struct afs_operation *op)
next_server:
trace_afs_rotate(op, afs_rotate_trace_next_server, 0);
_debug("next");
- ASSERT(op->estate);
- alist = op->estate->addresses;
- if (op->call_responded &&
- op->addr_index != READ_ONCE(alist->preferred) &&
- test_bit(alist->preferred, &op->addr_tried))
- WRITE_ONCE(alist->preferred, op->addr_index);
op->estate = NULL;
goto pick_server;

@@ -690,14 +684,7 @@ bool afs_select_fileserver(struct afs_operation *op)
failed:
trace_afs_rotate(op, afs_rotate_trace_failed, 0);
op->flags |= AFS_OPERATION_STOP;
- if (op->estate) {
- alist = op->estate->addresses;
- if (op->call_responded &&
- op->addr_index != READ_ONCE(alist->preferred) &&
- test_bit(alist->preferred, &op->addr_tried))
- WRITE_ONCE(alist->preferred, op->addr_index);
- op->estate = NULL;
- }
+ op->estate = NULL;
_leave(" = f [failed %d]", afs_op_error(op));
return false;
}
--
2.43.0