From fea013e020e6ecc7be75bea0d61697b7e916b44d Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Lu=C3=ADs=20Henriques?= Date: Tue, 24 May 2022 17:06:27 +0100 Subject: [PATCH] ceph: use correct index when encoding client supported features MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Feature bits have to be encoded into the correct locations. This hasn't been an issue so far because the only hole in the feature bits was in bit 10 (CEPHFS_FEATURE_RECLAIM_CLIENT), which is located in the 2nd byte. When adding more bits that go beyond the this 2nd byte, the bug will show up. [xiubli: remove incorrect comment for CEPHFS_FEATURES_CLIENT_SUPPORTED] Fixes: 9ba1e224538a ("ceph: allocate the correct amount of extra bytes for the session features") Signed-off-by: Luís Henriques Reviewed-by: Jeff Layton Signed-off-by: Xiubo Li Signed-off-by: Ilya Dryomov --- fs/ceph/mds_client.c | 7 +++++-- fs/ceph/mds_client.h | 6 ------ 2 files changed, 5 insertions(+), 8 deletions(-) diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c index 33f517d549ce..0aded10375fd 100644 --- a/fs/ceph/mds_client.c +++ b/fs/ceph/mds_client.c @@ -1220,14 +1220,17 @@ static int encode_supported_features(void **p, void *end) if (count > 0) { size_t i; size_t size = FEATURE_BYTES(count); + unsigned long bit; if (WARN_ON_ONCE(*p + 4 + size > end)) return -ERANGE; ceph_encode_32(p, size); memset(*p, 0, size); - for (i = 0; i < count; i++) - ((unsigned char*)(*p))[i / 8] |= BIT(feature_bits[i] % 8); + for (i = 0; i < count; i++) { + bit = feature_bits[i]; + ((unsigned char *)(*p))[bit / 8] |= BIT(bit % 8); + } *p += size; } else { if (WARN_ON_ONCE(*p + 4 > end)) diff --git a/fs/ceph/mds_client.h b/fs/ceph/mds_client.h index 1140aecd82ce..2a49e331987b 100644 --- a/fs/ceph/mds_client.h +++ b/fs/ceph/mds_client.h @@ -33,10 +33,6 @@ enum ceph_feature_type { CEPHFS_FEATURE_MAX = CEPHFS_FEATURE_METRIC_COLLECT, }; -/* - * This will always have the highest feature bit value - * as the last element of the array. - */ #define CEPHFS_FEATURES_CLIENT_SUPPORTED { \ 0, 1, 2, 3, 4, 5, 6, 7, \ CEPHFS_FEATURE_MIMIC, \ @@ -45,8 +41,6 @@ enum ceph_feature_type { CEPHFS_FEATURE_MULTI_RECONNECT, \ CEPHFS_FEATURE_DELEG_INO, \ CEPHFS_FEATURE_METRIC_COLLECT, \ - \ - CEPHFS_FEATURE_MAX, \ } #define CEPHFS_FEATURES_CLIENT_REQUIRED {}