8:32 a.m.
I think maybe there must be an extra deref somewhere. I don't think it
can be in this path. dirent->entry is protected by the content_lock,
and it's refcount is protected by content_lock under write, so read
cases should be safe to access/use that field if it's set.
Daniel
On 6/3/19 6:54 AM, Madhu P Punjabi wrote:
(gdb) bt
#0 0x00003fffb2829684 in .raise () from /lib64/libpthread.so.0
#1 0x0000000010056c78 in crash_handler (signo=11, info=0x3fff6488bf38,
ctx=0x3fff6488b1c0)
at
/usr/src/debug/nfs-ganesha-2.7.3-ibm050.09lookupfix/MainNFSD/nfs_init.c:244
#2 <signal handler called>
#3 0x00000000101b29f8 in _mdcache_lru_ref (entry=0xc0000000007b24a1,
flags=0, func=0x10235e18 <__func__.23505> "mdcache_get", line=175)
at
/usr/src/debug/nfs-ganesha-2.7.3-ibm050.09lookupfix/FSAL/Stackable_FSALs/FSAL_MDCACHE/mdcache_lru.c:1889
#4 0x00000000101c4864 in mdcache_get (entry=0xc0000000007b24a1)
at
/usr/src/debug/nfs-ganesha-2.7.3-ibm050.09lookupfix/FSAL/Stackable_FSALs/FSAL_MDCACHE/mdcache_lru.h:175
#5 0x00000000101d26d8 in mdcache_readdir_chunked
(directory=0x3fff4c0dde70, whence=0, dir_state=0x3fff6488c6d8,
cb=@0x1025b708: 0x10041390 <populate_dirent>,
attrmask=122830, eod_met=0x3fff6488c820) at
/usr/src/debug/nfs-ganesha-2.7.3-ibm050.09lookupfix/FSAL/Stackable_FSALs/FSAL_MDCACHE/mdcache_helpers.c:3000
#6 0x00000000101bad28 in mdcache_readdir (dir_hdl=0x3fff4c0ddea8,
whence=0x3fff6488c790, dir_state=0x3fff6488c6d8, cb=@0x1025b708:
0x10041390 <populate_dirent>,
attrmask=122830, eod_met=0x3fff6488c820) at
/usr/src/debug/nfs-ganesha-2.7.3-ibm050.09lookupfix/FSAL/Stackable_FSALs/FSAL_MDCACHE/mdcache_handle.c:559
#7 0x0000000010041f9c in fsal_readdir (directory=0x3fff4c0ddea8,
cookie=0, nbfound=0x3fff6488c830, eod_met=0x3fff6488c820, attrmask=122830,
cb=@0x1025f6e8: 0x100a69ec <nfs4_readdir_callback>,
opaque=0x3fff6488c838) at
/usr/src/debug/nfs-ganesha-2.7.3-ibm050.09lookupfix/FSAL/fsal_helper.c:1160
#8 0x00000000100a8528 in nfs4_op_readdir (op=0x3ffd5021a300,
data=0x3fff6488caf8, resp=0x3ffd5021a7a0)
at
/usr/src/debug/nfs-ganesha-2.7.3-ibm050.09lookupfix/Protocols/NFS/nfs4_op_readdir.c:664
#9 0x0000000010082a94 in nfs4_Compound (arg=0x3ffd50203e78,
req=0x3ffd50203770, res=0x3ffd5019cc40)
at
/usr/src/debug/nfs-ganesha-2.7.3-ibm050.09lookupfix/Protocols/NFS/nfs4_Compound.c:942
#10 0x000000001007e630 in nfs_rpc_process_request
(reqdata=0x3ffd50203770) at
/usr/src/debug/nfs-ganesha-2.7.3-ibm050.09lookupfix/MainNFSD/nfs_worker_thread.c:1328
#11 0x000000001007f004 in nfs_rpc_valid_NFS (req=0x3ffd50203770) at
/usr/src/debug/nfs-ganesha-2.7.3-ibm050.09lookupfix/MainNFSD/nfs_worker_thread.c:1538
#12 0x00003fffb2d1b420 in svc_vc_decode (req=0x3ffd50203770) at
/usr/src/debug/nfs-ganesha-2.7.3-ibm050.09lookupfix/libntirpc/src/svc_vc.c:829
#13 0x000000001006a520 in nfs_rpc_decode_request (xprt=0x3ffc68272f80,
xdrs=0x3ffd501edd40)
at
/usr/src/debug/nfs-ganesha-2.7.3-ibm050.09lookupfix/MainNFSD/nfs_rpc_dispatcher_thread.c:1345
#14 0x00003fffb2d1b290 in svc_vc_recv (xprt=0x3ffc68272f80) at
/usr/src/debug/nfs-ganesha-2.7.3-ibm050.09lookupfix/libntirpc/src/svc_vc.c:802
#15 0x00003fffb2d15b58 in svc_rqst_xprt_task (wpe=0x3ffc68273198) at
/usr/src/debug/nfs-ganesha-2.7.3-ibm050.09lookupfix/libntirpc/src/svc_rqst.c:769
#16 0x00003fffb2d161cc in svc_rqst_epoll_events (sr_rec=0x10008c87e20,
n_events=1)
at
/usr/src/debug/nfs-ganesha-2.7.3-ibm050.09lookupfix/libntirpc/src/svc_rqst.c:941
#17 0x00003fffb2d16568 in svc_rqst_epoll_loop (sr_rec=0x10008c87e20) at
/usr/src/debug/nfs-ganesha-2.7.3-ibm050.09lookupfix/libntirpc/src/svc_rqst.c:1014
#18 0x00003fffb2d1669c in svc_rqst_run_task (wpe=0x10008c87e20) at
/usr/src/debug/nfs-ganesha-2.7.3-ibm050.09lookupfix/libntirpc/src/svc_rqst.c:1050
#19 0x00003fffb2d24124 in work_pool_thread (arg=0x3ffc9c005a90) at
/usr/src/debug/nfs-ganesha-2.7.3-ibm050.09lookupfix/libntirpc/src/work_pool.c:181
#20 0x00003fffb281c93c in .start_thread () from /lib64/libpthread.so.0
#21 0x00003fffb26c7a3c in .__clone () from /lib64/libc.so.6
(gdb) f 3
#3 0x00000000101b29f8 in _mdcache_lru_ref (entry=0xc0000000007b24a1,
flags=0, func=0x10235e18 <__func__.23505> "mdcache_get", line=175)
at
/usr/src/debug/nfs-ganesha-2.7.3-ibm050.09lookupfix/FSAL/Stackable_FSALs/FSAL_MDCACHE/mdcache_lru.c:1889
1889 struct lru_q_lane *qlane = &LRU[lru->lane];
(gdb) p *lru
Cannot access memory at address 0xc0000000007b26c9
(gdb) p *entry
Cannot access memory at address 0xc0000000007b24a1
(gdb) f 5
#5 0x00000000101d26d8 in mdcache_readdir_chunked
(directory=0x3fff4c0dde70, whence=0, dir_state=0x3fff6488c6d8,
cb=@0x1025b708: 0x10041390 <populate_dirent>,
attrmask=122830, eod_met=0x3fff6488c820) at
/usr/src/debug/nfs-ganesha-2.7.3-ibm050.09lookupfix/FSAL/Stackable_FSALs/FSAL_MDCACHE/mdcache_helpers.c:3000
3000 mdcache_get(entry);
(gdb) l
2995 status.major = ERR_FSAL_NO_ERROR;
2996 /* We have the content_lock for at least read. */
2997 if (dirent->entry) {
2998 /* Take a ref for our use */
2999 entry = dirent->entry;
3000 mdcache_get(entry);
3001 } else {
3002 /* Not cached, get actual entry using
the dirent ckey */
3003 status =
mdcache_find_keyed_reason(&dirent->ckey,
3004 &entry,
(gdb)