nvmft: Export more info for a ctl port for use by ctladm

[jhb]

Summary

In particular, export a "port" entry as well as an array of "host"
entries for each active connection.

[jhb]

Exporting the "port" attribute adds a new column in the output of ctladm portlist:

# ctladm portlist
Port Online Frontend Name     pp vp
0    NO     camsim   camsim   0  0  naa.50000001dc007b01
1    YES    ioctl    ioctl    0  0  
2    YES    tpc      tpc      0  0  
3    YES    iscsi    iscsi    257 1  iqn.2001-03.com.chelsio:frodo0,t,0x0101
4    YES    nvmf     nvmf     1  0  nqn.2001-03.com.chelsio:frodo0,p,1

Note though that this does uncover an issue in ctl I need to fix which is a LOR:

lock order reversal: (sleepable after non-sleepable)
 1st 0xfffff8013ff93000 CTL mutex (CTL mutex, sleep mutex) @ /mnt/jhb/work/git/freebsd/sys/cam/ctl/ctl.c:3346
 2nd 0xfffffe08ce3dc3e0 nvmft port (nvmft port, sx) @ /mnt/jhb/work/git/freebsd/sys/dev/nvmf/controller/ctl_frontend_nvmf.c:105
lock order CTL mutex -> nvmft port attempted at:
#0 0xffffffff80af22eb at witness_checkorder+0x8cb
#1 0xffffffff80a90efa at _sx_slock_int+0x6a
#2 0xffffffff80a91779 at _sx_slock+0x9
#3 0xffffffff831c93f1 at nvmft_info+0x31
#4 0xffffffff83186c8f at ctl_ioctl+0x9ff
#5 0xffffffff80926f55 at devfs_ioctl+0xd5
#6 0xffffffff81017a0e at VOP_IOCTL_APV+0x2e
#7 0xffffffff80b86ea4 at VOP_IOCTL+0x34
#8 0xffffffff80b818c4 at vn_ioctl+0xf4
#9 0xffffffff8092744e at devfs_ioctl_f+0x1e
#10 0xffffffff80af7ceb at fo_ioctl+0xb
#11 0xffffffff80af7c13 at kern_ioctl+0x243
#12 0xffffffff80af796f at sys_ioctl+0x12f
#13 0xffffffff80f63625 at syscallenter+0x115
#14 0xffffffff80f6332d at amd64_syscall+0x2d
#15 0xffffffff80f39dbb at fast_syscall_common+0xf8

I will need to probably fix this by converting the relevant lock in ctl to an sx lock (which I believe will fix some other races in ctl(4)).