Description of problem: On a fuse mount, I created 40 files each one with a different group. Also, I create a user and add all the 40 groups as secondary groups to that user. The groups have been give rw access by setting an ACL entry. When I login as user and try to read/write into the files, it only works for the first 31 files. On further examination, the proc status showed only 32 groups.

The read and writes were successful for all the 40 files when tried on the backend directly.


How reproducible:

MOUNT=/mnt/gluster
useradd testing_random

mkdir -p $MOUNT/testing
chmod -R 777 $MOUNT/testing


for i in `seq 1 40`; do 
   groupadd test_grps_$i; 
   newgrp test_grps_$i <<EOF
       touch $MOUNT/testing/file_$i
   EOF
done

for i in `seq 1 40`; do 
   usermod -a -G test_grps_$i testing_random; 
done

for i in `seq 1 40`; do 
    setfacl -m o::---,g::rw $MOUNT/testing/file_$i; 
done

for i in `seq 1 40`; do su testing_random -c "echo '234343' > /mnt/gluster/testing/file_$i"; done


getfacl testing/file_1
# file: testing/file_1
# owner: root
# group: test_grps_1
user::rw-
group::rw-
other::---





Additional info:

# id testing_random
uid=1010(testing_random) gid=1010(testing_random) groups=1010(testing_random),1022(test_grps_1),1023(test_grps_2),1024(test_grps_3),1025(test_grps_4),1026(test_grps_5),1027(test_grps_6),1028(test_grps_7),1029(test_grps_8),1030(test_grps_9),1031(test_grps_10),1032(test_grps_11),1033(test_grps_12),1034(test_grps_13),1035(test_grps_14),1036(test_grps_15),1037(test_grps_16),1038(test_grps_17),1039(test_grps_18),1040(test_grps_19),1041(test_grps_20),1042(test_grps_21),1043(test_grps_22),1044(test_grps_23),1045(test_grps_24),1046(test_grps_25),1047(test_grps_26),1048(test_grps_27),1049(test_grps_28),1050(test_grps_29),1051(test_grps_30),1052(test_grps_31),1053(test_grps_32),1054(test_grps_33),1055(test_grps_34),1056(test_grps_35),1057(test_grps_36),1058(test_grps_37),1059(test_grps_38),1060(test_grps_39),1061(test_grps_40)



cat /proc/17747/status | grep Group
Groups:	1011 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 


(gdb) b io_stats_open
Breakpoint 1 at 0x7fcc6620ec3c: file io-stats.c, line 2027.
(gdb) c
Continuing.
[Switching to Thread 0x7fcc65065700 (LWP 3362)]

Breakpoint 1, io_stats_open (frame=0x7fcc69f5b0d8, this=0x2607110, loc=0x7fcc60012f50, flags=32769, fd=0x7fcc6506f384, wbflags=0)
    at io-stats.c:2027
2027	        frame->local = gf_strdup (loc->path);
(gdb) p *frame->local
Attempt to dereference a generic pointer.
(gdb) p *frame->root
$1 = {{all_frames = {next = 0x7fcc68f12850, prev = 0x25fc5a0}, {next_call = 0x7fcc68f12850, prev_call = 0x25fc5a0}}, pool = 0x25fc5a0, 
  stack_lock = 1, trans = 0x0, unique = 4858, state = 0x7fcc60012f30, uid = 1011, gid = 1011, pid = 17747, ngrps = 32, groups = {1011, 
    1022, 1023, 1024, 1025, 1026, 1027, 1028, 1029, 1030, 1031, 1032, 1033, 1034, 1035, 1036, 1037, 1038, 1039, 1040, 1041, 1042, 1043, 
    1044, 1045, 1046, 1047, 1048, 1049, 1050, 1051, 1052, 0 <repeats 168 times>}, lk_owner = {len = 8, data = '\000' <repeats 1023 times>}, 
  frames = {root = 0x7fcc68f1202c, parent = 0x0, next = 0x7fcc69f5b0d8, prev = 0x0, local = 0x0, this = 0x25fceb0, ret = 0, ref_count = 1, 
    lock = 1, cookie = 0x0, complete = _gf_false, op = GF_FOP_OPEN, begin = {tv_sec = 0, tv_usec = 0}, end = {tv_sec = 0, tv_usec = 0}, 
    wind_from = 0x0, wind_to = 0x0, unwind_from = 0x0, unwind_to = 0x0}, op = 11, type = 1 '\001'}