From a6fffc8db39689a5c06a86aa27899e5fd87a5ec0 Mon Sep 17 00:00:00 2001 From: =?utf8?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=utf8 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 the 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 --- 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 dea564c5a6998..8efb8927ffb98 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 1140aecd82ce4..2a49e331987be 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 {} -- 2.39.5