fuse: fetch arbitrary number of groups from /proc/[pid]/status

Glusterfs so far constrained itself with an arbitrary limit (32)
for the number of groups read from /proc/[pid]/status (this was
the number of groups shown there prior to Linux commit
v3.7-9553-g8d238027b87e (v3.8-rc1~74^2~59); since this commit, all
groups are shown).

With this change we'll read groups up to the number Glusterfs
supports in general (64k).

Note: the actual number of groups that are made use of in a
regular Glusterfs setup shall still be capped at ~93 due to limitations
of the RPC transport. To be able to handle more groups than that,
brick side gid resolution (server.manage-gids option) can be used along
with NIS, LDAP or other such networked directory service (see
https://github.com/gluster/glusterdocs/blob/5ba15a2/docs/Administrator%20Guide/Handling-of-users-with-many-groups.md#limit-in-the-glusterfs-protocol
).

Also adding some diagnostic messages to frame_fill_groups().

Change-Id: I271f3dc3e6d3c44d6d989c7a2073ea5f16c26ee0
fixes: #1075
Signed-off-by: Csaba Henk <csaba@redhat.com>

1 files changed, 11 insertions, 2 deletions

diff --git a/tests/bugs/fuse/many-groups-for-acl.t b/tests/bugs/fuse/many-groups-for-acl.t
index d959f750ee0..a51b1bc7267 100755
--- a/tests/bugs/fuse/many-groups-for-acl.t
+++ b/tests/bugs/fuse/many-groups-for-acl.t
@@ -38,6 +38,13 @@ do
 done
 TEST useradd -o -M -u ${NEW_UID} -g ${NEW_GID} -G ${NEW_USER}-${NEW_GIDS} ${NEW_USER}
 
+# Linux < 3.8 exports only first 32 gids of pid to userspace
+kernel_exports_few_gids=0
+if [ "$OSTYPE" = Linux ] && \
+   su -m ${NEW_USER} -c "grep ^Groups: /proc/self/status | wc -w | xargs -I@ expr @ - 1 '<' $LAST_GID - $NEW_GID + 1" > /dev/null; then
+       kernel_exports_few_gids=1
+fi
+
 # preparation done, start the tests
 
 TEST glusterd
@@ -48,6 +55,8 @@ TEST $CLI volume set $V0 nfs.disable off
 TEST $CLI volume set ${V0} server.manage-gids off
 TEST $CLI volume start ${V0}
 
+# This is just a synchronization hack to make sure the bricks are
+# up before going on.
 EXPECT_WITHIN ${NFS_EXPORT_TIMEOUT} "1" is_nfs_export_available
 
 # mount the volume with POSIX ACL support, without --resolve-gids
@@ -69,8 +78,8 @@ TEST [ $? -eq 0 ]
 su -m ${NEW_USER} -c "touch ${M0}/first-32-gids-2/success > /dev/null"
 TEST [ $? -eq 0 ]
 
-su -m ${NEW_USER} -c "touch ${M0}/gid-64/failure > /dev/null"
-TEST [ $? -ne 0 ]
+su -m ${NEW_USER} -c "touch ${M0}/gid-64/success--if-all-gids-exported > /dev/null"
+TEST [ $? -eq $kernel_exports_few_gids ]
 
 su -m ${NEW_USER} -c "touch ${M0}/gid-120/failure > /dev/null"
 TEST [ $? -ne 0 ]