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| author | David Howells <dhowells@redhat.com> | 2019-05-20 08:48:46 +0100 |
|---|---|---|
| committer | David Howells <dhowells@redhat.com> | 2019-09-02 11:43:54 +0100 |
| commit | 8b6a666a97544bf307190a05947742b8357aa962 (patch) | |
| tree | 16c344dabab751936bd81e720cc58620013976be /fs/afs | |
| parent | 23a289137ab82daeea826eeb9556c6f89b1fcd67 (diff) | |
| download | linux-stable-8b6a666a97544bf307190a05947742b8357aa962.tar.gz linux-stable-8b6a666a97544bf307190a05947742b8357aa962.tar.bz2 linux-stable-8b6a666a97544bf307190a05947742b8357aa962.zip | |
afs: Provide an RCU-capable key lookup
Provide an RCU-capable key lookup function. We don't want to call
afs_request_key() in RCU-mode pathwalk as request_key() might sleep, even if
we don't ask it to construct anything as it might find a key that is currently
undergoing construction.
Signed-off-by: David Howells <dhowells@redhat.com>
Diffstat (limited to 'fs/afs')
| -rw-r--r-- | fs/afs/internal.h | 1 | ||||
| -rw-r--r-- | fs/afs/security.c | 33 |
2 files changed, 32 insertions, 2 deletions
diff --git a/fs/afs/internal.h b/fs/afs/internal.h index f66a3be12fd6..9cdfabaeaa0b 100644 --- a/fs/afs/internal.h +++ b/fs/afs/internal.h @@ -1217,6 +1217,7 @@ extern void afs_cache_permit(struct afs_vnode *, struct key *, unsigned int, struct afs_status_cb *); extern void afs_zap_permits(struct rcu_head *); extern struct key *afs_request_key(struct afs_cell *); +extern struct key *afs_request_key_rcu(struct afs_cell *); extern int afs_check_permit(struct afs_vnode *, struct key *, afs_access_t *); extern int afs_permission(struct inode *, int); extern void __exit afs_clean_up_permit_cache(void); diff --git a/fs/afs/security.c b/fs/afs/security.c index 71e71c07568f..ef2fd34ba282 100644 --- a/fs/afs/security.c +++ b/fs/afs/security.c @@ -27,8 +27,37 @@ struct key *afs_request_key(struct afs_cell *cell) _enter("{%x}", key_serial(cell->anonymous_key)); _debug("key %s", cell->anonymous_key->description); - key = request_key(&key_type_rxrpc, cell->anonymous_key->description, - NULL); + key = request_key_net(&key_type_rxrpc, cell->anonymous_key->description, + cell->net->net, NULL); + if (IS_ERR(key)) { + if (PTR_ERR(key) != -ENOKEY) { + _leave(" = %ld", PTR_ERR(key)); + return key; + } + + /* act as anonymous user */ + _leave(" = {%x} [anon]", key_serial(cell->anonymous_key)); + return key_get(cell->anonymous_key); + } else { + /* act as authorised user */ + _leave(" = {%x} [auth]", key_serial(key)); + return key; + } +} + +/* + * Get a key when pathwalk is in rcuwalk mode. + */ +struct key *afs_request_key_rcu(struct afs_cell *cell) +{ + struct key *key; + + _enter("{%x}", key_serial(cell->anonymous_key)); + + _debug("key %s", cell->anonymous_key->description); + key = request_key_net_rcu(&key_type_rxrpc, + cell->anonymous_key->description, + cell->net->net); if (IS_ERR(key)) { if (PTR_ERR(key) != -ENOKEY) { _leave(" = %ld", PTR_ERR(key)); |