diff options
| author | David Howells <dhowells@redhat.com> | 2025-02-18 19:22:47 +0000 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2025-02-21 15:06:29 -0800 |
| commit | add117e48df4788a86a21bd0515833c0a6db1ad1 (patch) | |
| tree | d9ceec6fe1bd80813f2276f6cd3e8ad0ee83489c /fs | |
| parent | 71f5409176f4ffd460689eb5423a20332d00e342 (diff) | |
afs: Fix the server_list to unuse a displaced server rather than putting it
When allocating and building an afs_server_list struct object from a VLDB
record, we look up each server address to get the server record for it -
but a server may have more than one entry in the record and we discard the
duplicate pointers. Currently, however, when we discard, we only put a
server record, not unuse it - but the lookup got as an active-user count.
The active-user count on an afs_server_list object determines its lifetime
whereas the refcount keeps the memory backing it around. Failing to reduce
the active-user counter prevents the record from being cleaned up and can
lead to multiple copied being seen - and pointing to deleted afs_cell
objects and other such things.
Fix this by switching the incorrect 'put' to an 'unuse' instead.
Without this, occasionally, a dead server record can be seen in
/proc/net/afs/servers and list corruption may be observed:
list_del corruption. prev->next should be ffff888102423e40, but was 0000000000000000. (prev=ffff88810140cd38)
Fixes: 977e5f8ed0ab ("afs: Split the usage count on struct afs_server")
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: Simon Horman <horms@kernel.org>
cc: linux-afs@lists.infradead.org
Link: https://patch.msgid.link/20250218192250.296870-5-dhowells@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/afs/server_list.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/fs/afs/server_list.c b/fs/afs/server_list.c index 7e7e567a7f8a..d20cd902ef94 100644 --- a/fs/afs/server_list.c +++ b/fs/afs/server_list.c @@ -97,8 +97,8 @@ struct afs_server_list *afs_alloc_server_list(struct afs_volume *volume, break; if (j < slist->nr_servers) { if (slist->servers[j].server == server) { - afs_put_server(volume->cell->net, server, - afs_server_trace_put_slist_isort); + afs_unuse_server(volume->cell->net, server, + afs_server_trace_put_slist_isort); continue; } |