Description of problem:

glusterfs client crashed due to abort while running posix_compliance tests in mdc_symlink_cbk. Did stat-prefetch (which is now md-cache) off while tests are running.

This is the backtrace of the core.

Core was generated by `/usr/local/sbin/glusterfs --volfile-id=mirror --volfile-server=hyperspace /mnt/'.
Program terminated with signal 6, Aborted.
#0  0x00007f895d5c0d05 in raise (sig=6) at ../nptl/sysdeps/unix/sysv/linux/raise.c:64
64	../nptl/sysdeps/unix/sysv/linux/raise.c: Transport endpoint is not connected.
	in ../nptl/sysdeps/unix/sysv/linux/raise.c
(gdb) bt
#0  0x00007f895d5c0d05 in raise (sig=6) at ../nptl/sysdeps/unix/sysv/linux/raise.c:64
#1  0x00007f895d5c4ab6 in abort () at abort.c:92
#2  0x00007f895d5b97c5 in __assert_fail (assertion=0x7f895e1f47bd "0", file=<value optimized out>, line=273, function=<value optimized out>)
    at assert.c:81
#3  0x00007f895e1c6c35 in __gf_free (free_ptr=0xa3b940) at ../../../libglusterfs/src/mem-pool.c:273
#4  0x00007f89577ab793 in mdc_local_wipe (this=0xa49070, local=0xa5b3b0) at ../../../../../xlators/performance/md-cache/src/md-cache.c:232
#5  0x00007f89577af75d in mdc_symlink_cbk (frame=0x7f895c77b9b4, cookie=0x7f895c77b704, this=0xa49070, op_ret=0, op_errno=0, 
    inode=0x7f89560c8208, buf=0xa59f78, preparent=0xa59ff0, postparent=0xa5a060)
    at ../../../../../xlators/performance/md-cache/src/md-cache.c:1043
#6  0x00007f895e1976b0 in default_symlink_cbk (frame=0x7f895c77b704, cookie=0x7f895c77b250, this=0xa47d80, op_ret=0, op_errno=0, 
    inode=0x7f89560c8208, buf=0xa59f78, preparent=0xa59ff0, postparent=0xa5a060) at ../../../libglusterfs/src/defaults.c:147
#7  0x00007f895e1976b0 in default_symlink_cbk (frame=0x7f895c77b250, cookie=0x7f895c77b85c, this=0xa46b60, op_ret=0, op_errno=0, 
    inode=0x7f89560c8208, buf=0xa59f78, preparent=0xa59ff0, postparent=0xa5a060) at ../../../libglusterfs/src/defaults.c:147
#8  0x00007f895e1976b0 in default_symlink_cbk (frame=0x7f895c77b85c, cookie=0x7f895c77b04c, this=0xa458d0, op_ret=0, op_errno=0, 
    inode=0x7f89560c8208, buf=0xa59f78, preparent=0xa59ff0, postparent=0xa5a060) at ../../../libglusterfs/src/defaults.c:147
#9  0x00007f895e1976b0 in default_symlink_cbk (frame=0x7f895c77b04c, cookie=0x7f895c77b0f8, this=0xa44620, op_ret=0, op_errno=0, 
    inode=0x7f89560c8208, buf=0xa59f78, preparent=0xa59ff0, postparent=0xa5a060) at ../../../libglusterfs/src/defaults.c:147
#10 0x00007f895821fb91 in afr_symlink_unwind (frame=0x7f895b73484c, this=0xa43390)
    at ../../../../../xlators/cluster/afr/src/afr-dir-write.c:1026
#11 0x00007f895821ffd1 in afr_symlink_wind_cbk (frame=0x7f895b73484c, cookie=0x0, this=0xa43390, op_ret=0, op_errno=0, inode=0x7f89560c8208, 
    buf=0x7fff1a4087d0, preparent=0x7fff1a408760, postparent=0x7fff1a4086f0) at ../../../../../xlators/cluster/afr/src/afr-dir-write.c:1089
#12 0x00007f89584a5d0d in client3_1_symlink_cbk (req=0x7f89563971c4, iov=0x7f8956397204, count=1, myframe=0x7f895c77b7b0)
    at ../../../../../xlators/protocol/client/src/client3_1-fops.c:180
#13 0x00007f895df6fb4f in rpc_clnt_handle_reply (clnt=0xa54db0, pollin=0x7f8950000990) at ../../../../rpc/rpc-lib/src/rpc-clnt.c:796
#14 0x00007f895df6fec7 in rpc_clnt_notify (trans=0xa55090, mydata=0xa54de0, event=RPC_TRANSPORT_MSG_RECEIVED, data=0x7f8950000990)
    at ../../../../rpc/rpc-lib/src/rpc-clnt.c:915
#15 0x00007f895df6bef1 in rpc_transport_notify (this=0xa55090, event=RPC_TRANSPORT_MSG_RECEIVED, data=0x7f8950000990)
    at ../../../../rpc/rpc-lib/src/rpc-transport.c:498
#16 0x00007f895910a3a5 in socket_event_poll_in (this=0xa55090) at ../../../../../rpc/rpc-transport/socket/src/socket.c:1686
#17 0x00007f895910a919 in socket_event_handler (fd=7, idx=1, data=0xa55090, poll_in=1, poll_out=0, poll_err=0)
    at ../../../../../rpc/rpc-transport/socket/src/socket.c:1801
#18 0x00007f895e1c5c05 in event_dispatch_epoll_handler (event_pool=0xa31370, events=0xa3ace0, i=1) at ../../../libglusterfs/src/event.c:794
#19 0x00007f895e1c5e1f in event_dispatch_epoll (event_pool=0xa31370) at ../../../libglusterfs/src/event.c:856
#20 0x00007f895e1c6191 in event_dispatch (event_pool=0xa31370) at ../../../libglusterfs/src/event.c:956
#21 0x0000000000407f33 in main (argc=4, argv=0x7fff1a408d38) at ../../../glusterfsd/src/glusterfsd.c:1601
(gdb) f 3
#3  0x00007f895e1c6c35 in __gf_free (free_ptr=0xa3b940) at ../../../libglusterfs/src/mem-pool.c:273
273	                GF_ASSERT (0);
(gdb) l
268	
269	        ptr = (char *)free_ptr - 8 - 4;
270	
271	        if (GF_MEM_HEADER_MAGIC != *(uint32_t *)ptr) {
272	                //Possible corruption, assert here
273	                GF_ASSERT (0);
274	        }
275	
276	        *(uint32_t *)ptr = 0;
277	
(gdb) p ptr
$1 = 0xa3b934 ""
(gdb) p /x GF_MEM_HEADER_MAGIC
$2 = 0xcafebabe
(gdb)  f 5
#5  0x00007f89577af75d in mdc_symlink_cbk (frame=0x7f895c77b9b4, cookie=0x7f895c77b704, this=0xa49070, op_ret=0, op_errno=0, 
    inode=0x7f89560c8208, buf=0xa59f78, preparent=0xa59ff0, postparent=0xa5a060)
    at ../../../../../xlators/performance/md-cache/src/md-cache.c:1043
warning: Source file is more recent than executable.
1043	        MDC_STACK_UNWIND (symlink, frame, op_ret, op_errno, inode, buf,
(gdb) f 4
#4  0x00007f89577ab793 in mdc_local_wipe (this=0xa49070, local=0xa5b3b0) at ../../../../../xlators/performance/md-cache/src/md-cache.c:232
232	                GF_FREE (local->linkname);
(gdb) l
227	
228	        if (local->fd)
229	                fd_unref (local->fd);
230	
231	        if (local->linkname)
232	                GF_FREE (local->linkname);
233	
234	        if (local->xattr)
235	                dict_unref (local->xattr);
236	
(gdb) p local->linkname
$3 = 0xa3b940 "fstest_d686a1b113c2aa209baeb1ef10180a3a"
(gdb) l mdc_symlink
1047	
1048	
1049	int
1050	mdc_symlink (call_frame_t *frame, xlator_t *this, const char *linkname,
1051	             loc_t *loc, dict_t *params)
1052	{
1053	        mdc_local_t  *local = NULL;
1054	
1055	        local = mdc_local_get (frame);
1056	
(gdb) 
1057	        loc_copy (&local->loc, loc);
1058	
1059	        local->linkname = gf_strdup (linkname);
1060	
1061	        STACK_WIND (frame, mdc_symlink_cbk,
1062	                    FIRST_CHILD(this), FIRST_CHILD(this)->fops->symlink,
1063	                    linkname, loc, params);
1064	        return 0;
1065	}
1066	
(gdb) 

In mdc_symlink we are allocating the memory for linkname using strdup, while for freeing it we are using GF_FREE. We should use gf_strdup for allocating in marker _symlink.




Version-Release number of selected component (if applicable):


How reproducible:

Steps to Reproduce:
1.Run posix compliance test 
2.turn stat-prefetch off while tests are running
3.
  
Actual results:

glusterfs client crashed.
Expected results:

glusterfs client should not crash.

Additional info:

[2012-02-21 15:29:18.036852] I [client-handshake.c:1544:select_server_supported_programs] 0-mirror-client-1: Using Program GlusterFS 3git, Num
 (1298437), Version (330)
[2012-02-21 15:29:18.037119] I [client-handshake.c:1324:client_setvolume_cbk] 0-mirror-client-0: clnt-lk-version = 1, server-lk-version = 0
[2012-02-21 15:29:18.037191] I [client-handshake.c:1350:client_setvolume_cbk] 0-mirror-client-0: Connected to 127.0.0.1:24009, attached to rem
ote volume '/mnt/sda7/export3'.
[2012-02-21 15:29:18.037431] I [afr-common.c:3461:afr_notify] 0-mirror-replicate-0: Subvolume 'mirror-client-0' came back up; going online.
[2012-02-21 15:29:18.037575] I [client-handshake.c:1324:client_setvolume_cbk] 0-mirror-client-1: clnt-lk-version = 1, server-lk-version = 0
[2012-02-21 15:29:18.037617] I [client-handshake.c:1350:client_setvolume_cbk] 0-mirror-client-1: Connected to 127.0.0.1:24010, attached to rem
ote volume '/mnt/sda8/export3'.
[2012-02-21 15:29:18.053132] I [fuse-bridge.c:4089:fuse_graph_setup] 0-fuse: switched to graph 0
[2012-02-21 15:29:18.054488] I [fuse-bridge.c:3336:fuse_init] 0-glusterfs-fuse: FUSE inited with protocol versions: glusterfs 7.13 kernel 7.16
[2012-02-21 15:29:18.055507] I [afr-common.c:1827:afr_set_root_inode_on_first_lookup] 0-mirror-replicate-0: added root inode
pending frames:
frame : type(1) op(SYMLINK)
frame : type(1) op(SYMLINK)

patchset: git://git.gluster.com/glusterfs.git
signal received: 6
time of crash: 2012-02-21 15:29:29
configuration details:
argp 1
backtrace 1
dlfcn 1
fdatasync 1
libpthread 1
llistxattr 1
setfsid 1
spinlock 1
epoll.h 1
xattr.h 1
st_atim.tv_nsec 1
package-string: glusterfs 3git
/lib/x86_64-linux-gnu/libc.so.6(+0x33d80)[0x7f895d5c0d80]
/lib/x86_64-linux-gnu/libc.so.6(gsignal+0x35)[0x7f895d5c0d05]
/lib/x86_64-linux-gnu/libc.so.6(abort+0x186)[0x7f895d5c4ab6]
/lib/x86_64-linux-gnu/libc.so.6(__assert_fail+0xf5)[0x7f895d5b97c5]
/usr/local/lib/libglusterfs.so.0(__gf_free+0xa3)[0x7f895e1c6c35]
/usr/local/lib/glusterfs/3git/xlator/performance/md-cache.so(mdc_local_wipe+0x7d)[0x7f89577ab793]
/usr/local/lib/glusterfs/3git/xlator/performance/md-cache.so(mdc_symlink_cbk+0x23f)[0x7f89577af75d]
/usr/local/lib/libglusterfs.so.0(default_symlink_cbk+0x169)[0x7f895e1976b0]