From: Luís Henriques lhenriques@suse.de
stable inclusion from stable-v5.10.138 commit 97cea2cb7c861f9c2f7870c6068c1131f59311ae category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I60QFD
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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commit fea013e020e6ecc7be75bea0d61697b7e916b44d upstream.
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 lhenriques@suse.de Reviewed-by: Jeff Layton jlayton@kernel.org Signed-off-by: Xiubo Li xiubli@redhat.com Signed-off-by: Ilya Dryomov idryomov@gmail.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com Reviewed-by: Wei Li liwei391@huawei.com --- 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 981a91590631..6859967df2b1 100644 --- a/fs/ceph/mds_client.c +++ b/fs/ceph/mds_client.c @@ -1184,14 +1184,17 @@ 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 f5adbebcb38e..acf33d7192bb 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 {}