From fe342cf77bc3c3ba89e8bb1e4eddbe614df4efa4 Mon Sep 17 00:00:00 2001 From: David Howells Date: Mon, 9 Apr 2018 21:12:31 +0100 Subject: afs: Fix checker warnings Fix warnings raised by checker, including: (*) Warnings raised by unequal comparison for the purposes of sorting, where the endianness doesn't matter: fs/afs/addr_list.c:246:21: warning: restricted __be16 degrades to integer fs/afs/addr_list.c:246:30: warning: restricted __be16 degrades to integer fs/afs/addr_list.c:248:21: warning: restricted __be32 degrades to integer fs/afs/addr_list.c:248:49: warning: restricted __be32 degrades to integer fs/afs/addr_list.c:283:21: warning: restricted __be16 degrades to integer fs/afs/addr_list.c:283:30: warning: restricted __be16 degrades to integer (*) afs_set_cb_interest() is not actually used and can be removed. (*) afs_cell_gc_delay() should be provided with a sysctl. (*) afs_cell_destroy() needs to use rcu_access_pointer() to read cell->vl_addrs. (*) afs_init_fs_cursor() should be static. (*) struct afs_vnode::permit_cache needs to be marked __rcu. (*) afs_server_rcu() needs to use rcu_access_pointer(). (*) afs_destroy_server() should use rcu_access_pointer() on server->addresses as the server object is no longer accessible. (*) afs_find_server() casts __be16/__be32 values to int in order to directly compare them for the purpose of finding a match in a list, but is should also annotate the cast with __force to avoid checker warnings. (*) afs_check_permit() accesses vnode->permit_cache outside of the RCU readlock, though it doesn't then access the value; the extraneous access is deleted. False positives: (*) Conditional locking around the code in xdr_decode_AFSFetchStatus. This can be dealt with in a separate patch. fs/afs/fsclient.c:148:9: warning: context imbalance in 'xdr_decode_AFSFetchStatus' - different lock contexts for basic block (*) Incorrect handling of seq-retry lock context balance: fs/afs/inode.c:455:38: warning: context imbalance in 'afs_getattr' - different lock contexts for basic block fs/afs/server.c:52:17: warning: context imbalance in 'afs_find_server' - different lock contexts for basic block fs/afs/server.c:128:17: warning: context imbalance in 'afs_find_server_by_uuid' - different lock contexts for basic block Errors: (*) afs_lookup_cell_rcu() needs to break out of the seq-retry loop, not go round again if it successfully found the workstation cell. (*) Fix UUID decode in afs_deliver_cb_probe_uuid(). (*) afs_cache_permit() has a missing rcu_read_unlock() before one of the jumps to the someone_else_changed_it label. Move the unlock to after the label. (*) afs_vl_get_addrs_u() is using ntohl() rather than htonl() when encoding to XDR. (*) afs_deliver_yfsvl_get_endpoints() is using htonl() rather than ntohl() when decoding from XDR. Signed-off-by: David Howells --- fs/afs/security.c | 11 +++-------- 1 file changed, 3 insertions(+), 8 deletions(-) (limited to 'fs/afs/security.c') diff --git a/fs/afs/security.c b/fs/afs/security.c index b88b7d45fdaa..bd82c5bf4a6a 100644 --- a/fs/afs/security.c +++ b/fs/afs/security.c @@ -178,18 +178,14 @@ void afs_cache_permit(struct afs_vnode *vnode, struct key *key, } } - if (cb_break != (vnode->cb_break + vnode->cb_interest->server->cb_s_break)) { - rcu_read_unlock(); + if (cb_break != (vnode->cb_break + vnode->cb_interest->server->cb_s_break)) goto someone_else_changed_it; - } /* We need a ref on any permits list we want to copy as we'll have to * drop the lock to do memory allocation. */ - if (permits && !refcount_inc_not_zero(&permits->usage)) { - rcu_read_unlock(); + if (permits && !refcount_inc_not_zero(&permits->usage)) goto someone_else_changed_it; - } rcu_read_unlock(); @@ -278,6 +274,7 @@ someone_else_changed_it: /* Someone else changed the cache under us - don't recheck at this * time. */ + rcu_read_unlock(); return; } @@ -296,8 +293,6 @@ int afs_check_permit(struct afs_vnode *vnode, struct key *key, _enter("{%x:%u},%x", vnode->fid.vid, vnode->fid.vnode, key_serial(key)); - permits = vnode->permit_cache; - /* check the permits to see if we've got one yet */ if (key == vnode->volume->cell->anonymous_key) { _debug("anon"); -- cgit v1.2.3