| Message ID | 20190308153757.25794-1-kwolf@redhat.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | file-posix: Make auto-read-only dynamic | expand |
On Fri, Mar 08, 2019 at 16:37:49 +0100, Kevin Wolf wrote: > We introduced the auto-read-only option to fix the problem that block > jobs that reopen a backing file read-write don't work any more when all > nodes are created individually with -blockdev. The reason is that > bs->file of these backing files doesn't inherit the read-only option > from the format layer node any more if it's created separately. > > The way auto-read-only was designed to fix this is that it just always > opens the file node read-write if it can, so reopening the format layer > node is enough to make the backing file writable when necessary. > > This works in principle, but not when libvirt uses sVirt: Then QEMU > doesn't even have the permissions to open the image file read-write > until libvirt performs an operation where write access is needed. > > This series changes auto-read-only so that it works dynamically and > automatically reopens the file read-only or read-write depending on the > permissions that users attached to the node requested. While testing this series by attempting a non-active layer block-commit I've got an assertion failure: qemu-system-x86_64: block/file-posix.c:2715: raw_check_perm: Assertion `!s->perm_change_fd' failed. Thread 1 "qemu-system-x86" received signal SIGABRT, Aborted. 0x00007f69fe08753f in raise () from target:/lib64/libc.so.6 Thread 1 (Thread 0x7f69f3b08680 (LWP 2694)): #0 0x00007f69fe08753f in raise () from target:/lib64/libc.so.6 #1 0x00007f69fe071895 in abort () from target:/lib64/libc.so.6 #2 0x00007f69fe071769 in __assert_fail_base.cold.0 () from target:/lib64/libc.so.6 #3 0x00007f69fe07f9f6 in __assert_fail () from target:/lib64/libc.so.6 #4 0x00005563cfeea7e9 in raw_check_perm (bs=0x5563d1f90100, perm=11, shared=21, errp=0x7fffc280c0f0) at block/file-posix.c:2715 #5 0x00005563cfe9aab4 in bdrv_check_perm (bs=bs@entry=0x5563d1f90100, q=0x5563d2bd0170, q@entry=0xbed88f135e2a5600, cumulative_perms=11, cumulative_shared_perms=21, ignore_children=ignore_children@entry=0x7f69a47f9710, errp=errp@entry=0x7fffc280c0f0) at block.c:1790 #6 0x00005563cfe9a875 in bdrv_check_update_perm (bs=0x5563d1f90100, q=0xbed88f135e2a5600, q@entry=0x5563d2bd0170, new_used_perm=new_used_perm@entry=11, new_shared_perm=new_shared_perm@entry=21, ignore_children=ignore_children@entry=0x7f69a47f9710, errp=errp@entry=0x7fffc280c0f0) at block.c:1976 #7 0x00005563cfe9a9ba in bdrv_child_check_perm (c=c@entry=0x5563d1eb9dd0, q=q@entry=0x5563d2bd0170, perm=11, shared=21, ignore_children=0x7f69a47f9710, ignore_children@entry=0x5563d1a57810, errp=errp@entry=0x7fffc280c0f0) at block.c:1989 #8 0x00005563cfe9ab44 in bdrv_check_perm (bs=0x5563d1f943a0, bs@entry=0xb, q=0x5563d2bd0170, q@entry=0xbed88f135e2a5600, cumulative_perms=0, cumulative_shared_perms=31, ignore_children=ignore_children@entry=0x5563d1a57810, errp=0x7fffc280c0f0, errp@entry=0x15) at block.c:1806 #9 0x00005563cfe9a875 in bdrv_check_update_perm (bs=0xb, q=0xbed88f135e2a5600, q@entry=0x5563d2bd0170, new_used_perm=new_used_perm@entry=0, new_shared_perm=new_shared_perm@entry=31, ignore_children=ignore_children@entry=0x5563d1a57810, errp=0x15, errp@entry=0x7fffc280c0f0) at block.c:1976 #10 0x00005563cfe9a9ba in bdrv_child_check_perm (c=c@entry=0x5563d1eb9910, q=q@entry=0x5563d2bd0170, perm=0, shared=31, ignore_children=0x5563d1a57810, ignore_children@entry=0x5563d32dfd40, errp=errp@entry=0x7fffc280c0f0) at block.c:1989 #11 0x00005563cfe9ab44 in bdrv_check_perm (bs=0x5563d2011320, bs@entry=0x0, q=0x5563d2bd0170, q@entry=0xbed88f135e2a5600, cumulative_perms=0, cumulative_shared_perms=6, ignore_children=ignore_children@entry=0x5563d32dfd40, errp=0x7fffc280c0f0, errp@entry=0x1f) at block.c:1806 #12 0x00005563cfe9a875 in bdrv_check_update_perm (bs=0x0, q=0xbed88f135e2a5600, q@entry=0x5563d2bd0170, new_used_perm=new_used_perm@entry=0, new_shared_perm=new_shared_perm@entry=31, ignore_children=ignore_children@entry=0x5563d32dfd40, errp=0x1f, errp@entry=0x7fffc280c0f0) at block.c:1976 #13 0x00005563cfe9a9ba in bdrv_child_check_perm (c=c@entry=0x5563d1d96690, q=q@entry=0x5563d2bd0170, perm=0, shared=31, ignore_children=0x5563d32dfd40, ignore_children@entry=0x5563d32dfe00, errp=errp@entry=0x7fffc280c0f0) at block.c:1989 #14 0x00005563cfe9ab44 in bdrv_check_perm (bs=0x5563d2092340, bs@entry=0x0, q=0x5563d2bd0170, q@entry=0xbed88f135e2a5600, cumulative_perms=0, cumulative_shared_perms=6, ignore_children=ignore_children@entry=0x5563d32dfe00, errp=0x7fffc280c0f0, errp@entry=0x1f) at block.c:1806 #15 0x00005563cfe9a875 in bdrv_check_update_perm (bs=0x0, q=0xbed88f135e2a5600, q@entry=0x5563d2bd0170, new_used_perm=new_used_perm@entry=0, new_shared_perm=new_shared_perm@entry=31, ignore_children=ignore_children@entry=0x5563d32dfe00, errp=0x1f, errp@entry=0x7fffc280c0f0) at block.c:1976 #16 0x00005563cfe9a9ba in bdrv_child_check_perm (c=c@entry=0x5563d37424d0, q=q@entry=0x5563d2bd0170, perm=0, shared=31, ignore_children=0x5563d32dfe00, ignore_children@entry=0x5563d32dfb40, errp=errp@entry=0x7fffc280c0f0) at block.c:1989 #17 0x00005563cfe9ab44 in bdrv_check_perm (bs=0x5563d2fea010, bs@entry=0x0, q=0x5563d2bd0170, q@entry=0xbed88f135e2a5600, cumulative_perms=1, cumulative_shared_perms=21, ignore_children=ignore_children@entry=0x5563d32dfb40, errp=0x7fffc280c0f0, errp@entry=0x1f) at block.c:1806 #18 0x00005563cfe9a875 in bdrv_check_update_perm (bs=0x0, q=0xbed88f135e2a5600, q@entry=0x5563d2bd0170, new_used_perm=new_used_perm@entry=1, new_shared_perm=new_shared_perm@entry=21, ignore_children=ignore_children@entry=0x5563d32dfb40, errp=0x1f, errp@entry=0x7fffc280c0f0) at block.c:1976 #19 0x00005563cfe9a9ba in bdrv_child_check_perm (c=c@entry=0x5563d1e17a50, q=q@entry=0x5563d2bd0170, perm=1, shared=21, ignore_children=0x5563d32dfb40, ignore_children@entry=0x0, errp=errp@entry=0x7fffc280c0f0) at block.c:1989 #20 0x00005563cfe9ab44 in bdrv_check_perm (bs=0x5563d2113340, q=q@entry=0x5563d2bd0170, cumulative_perms=1, cumulative_shared_perms=21, ignore_children=ignore_children@entry=0x0, errp=errp@entry=0x7fffc280c0f0) at block.c:1806 #21 0x00005563cfe9f317 in bdrv_reopen_multiple (ctx=<optimized out>, bs_queue=0x5563d2bd0170, errp=errp@entry=0x7fffc280c0f0) at block.c:3167 #22 0x00005563cfe9f451 in bdrv_reopen_set_read_only (bs=bs@entry=0x5563d2113340, read_only=read_only@entry=false, errp=errp@entry=0x7fffc280c0f0) at block.c:5293 #23 0x00005563cfe9f4fd in bdrv_backing_update_filename (c=<optimized out>, base=0x5563d1f943a0, filename=0x5563d1f943d1 "/tmp/commit0.qcow2", errp=0x7fffc280c0f0) at block.c:1119 #24 0x00005563cfe9f66f in bdrv_drop_intermediate (top=0x5563d2fea010, base=0x5563d1f943a0, backing_file_str=0x5563d1f943d1 "/tmp/commit0.qcow2") at block.c:4018 #25 0x00005563cfea4689 in job_prepare (job=0x5563d2539880) at job.c:771 #26 job_txn_apply (txn=<optimized out>, fn=<optimized out>) at job.c:146 #27 job_do_finalize (job=0x5563d2539880) at job.c:788 #28 0x00005563cfea4941 in job_completed_txn_success (job=0x5563d2539880) at job.c:842 #29 job_completed (job=0x5563d2539880) at job.c:855 #30 job_completed (job=0x5563d2539880) at job.c:846 #31 0x00005563cfea49a0 in job_exit (opaque=0x5563d2539880) at job.c:874 #32 0x00005563cff991de in aio_bh_call (bh=0x7f69a0004800) at util/async.c:118 #33 aio_bh_poll (ctx=ctx@entry=0x5563d1beb7a0) at util/async.c:118 #34 0x00005563cff9c790 in aio_dispatch (ctx=0x5563d1beb7a0) at util/aio-posix.c:460 #35 0x00005563cff990be in aio_ctx_dispatch (source=<optimized out>, callback=<optimized out>, user_data=<optimized out>) at util/async.c:261 #36 0x00007f6a0013506d in g_main_context_dispatch () from target:/lib64/libglib-2.0.so.0 #37 0x00005563cff9b9a8 in glib_pollfds_poll () at util/main-loop.c:215 #38 os_host_main_loop_wait (timeout=<optimized out>) at util/main-loop.c:238 #39 main_loop_wait (nonblocking=<optimized out>) at util/main-loop.c:514 #40 0x00005563cfcac499 in main_loop () at vl.c:1923 #41 0x00005563cfb4c943 in main (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>) at vl.c:4579 This is the log of QEMU monitor interactions by libvirtd: [trimmed boring startup of qemu] 2019-03-11 12:57:10.485+0000: 3228: info : qemuMonitorIOWrite:553 : QEMU_MONITOR_IO_WRITE: mon=0x7fcff4027880 buf={"execute":"cont","id":"libvirt-18"}^M 2019-03-11 12:57:10.485+0000: 3228: info : qemuMonitorJSONIOProcessLine:219 : QEMU_MONITOR_RECV_EVENT: mon=0x7fcff4027880 event={"timestamp": {"seconds": 1552309030, "microseconds": 485648}, "event": "RESUME"} 2019-03-11 12:57:10.486+0000: 3228: info : qemuMonitorJSONIOProcessLine:224 : QEMU_MONITOR_RECV_REPLY: mon=0x7fcff4027880 reply={"return": {}, "id": "libvirt-18"} 2019-03-11 12:57:20.398+0000: 3243: info : qemuMonitorSend:1085 : QEMU_MONITOR_SEND_MSG: mon=0x7fcff4027880 msg={"execute":"block-commit","arguments":{"device":"libvirt-2-format","job-id":"commit-vdb-libvirt-10-format","top-node":"libvirt-10-format","base-node":"libvirt-12-format","auto-finalize":true,"auto-dismiss":false},"id":"libvirt-19"}^M 2019-03-11 12:57:20.398+0000: 3228: info : qemuMonitorIOWrite:553 : QEMU_MONITOR_IO_WRITE: mon=0x7fcff4027880 buf={"execute":"block-commit","arguments":{"device":"libvirt-2-format","job-id":"commit-vdb-libvirt-10-format","top-node":"libvirt-10-format","base-node":"libvirt-12-format","auto-finalize":true,"auto-dismiss":false},"id":"libvirt-19"}^M 2019-03-11 12:57:20.400+0000: 3228: info : qemuMonitorJSONIOProcessLine:219 : QEMU_MONITOR_RECV_EVENT: mon=0x7fcff4027880 event={"timestamp": {"seconds": 1552309040, "microseconds": 400150}, "event": "JOB_STATUS_CHANGE", "data": {"status": "created", "id": "commit-vdb-libvirt-10-format"}} 2019-03-11 12:57:20.400+0000: 3228: info : qemuMonitorJSONIOProcessLine:219 : QEMU_MONITOR_RECV_EVENT: mon=0x7fcff4027880 event={"timestamp": {"seconds": 1552309040, "microseconds": 400643}, "event": "JOB_STATUS_CHANGE", "data": {"status": "running", "id": "commit-vdb-libvirt-10-format"}} 2019-03-11 12:57:20.400+0000: 3228: info : qemuMonitorJSONIOProcessLine:224 : QEMU_MONITOR_RECV_REPLY: mon=0x7fcff4027880 reply={"return": {}, "id": "libvirt-19"} 2019-03-11 12:57:20.400+0000: 3228: info : qemuMonitorJSONIOProcessLine:219 : QEMU_MONITOR_RECV_EVENT: mon=0x7fcff4027880 event={"timestamp": {"seconds": 1552309040, "microseconds": 400800}, "event": "JOB_STATUS_CHANGE", "data": {"status": "waiting", "id": "commit-vdb-libvirt-10-format"}} 2019-03-11 12:57:20.401+0000: 3228: info : qemuMonitorJSONIOProcessLine:219 : QEMU_MONITOR_RECV_EVENT: mon=0x7fcff4027880 event={"timestamp": {"seconds": 1552309040, "microseconds": 400825}, "event": "JOB_STATUS_CHANGE", "data": {"status": "pending", "id": "commit-vdb-libvirt-10-format"}} 2019-03-11 12:57:20.737+0000: 3386: info : qemuMonitorClose:1007 : QEMU_MONITOR_CLOSE: mon=0x7fcff4027880 refs=1 The following command line was used: LC_ALL=C \ PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin \ QEMU_AUDIO_DRV=spice \ /home/pipo/git/qemu.git/x86_64-softmmu/qemu-system-x86_64 \ -name guest=upstream-bj,debug-threads=on \ -S \ -object secret,id=masterKey0,format=raw,file=/var/lib/libvirt/qemu/domain-23-upstream-bj/master-key.aes \ -machine pc-i440fx-2.9,accel=kvm,usb=off,vmport=off,dump-guest-core=off \ -m 1000 \ -realtime mlock=off \ -smp 2,maxcpus=8,sockets=8,cores=1,threads=1 \ -object memory-backend-file,id=ram-node0,mem-path=/var/lib/libvirt/qemu/ram/libvirt/qemu/23-upstream-bj/ram-node0,share=yes,size=524288000,host-nodes=0,policy=bind \ -numa node,nodeid=0,cpus=0,cpus=2,cpus=4,cpus=6,memdev=ram-node0 \ -object memory-backend-file,id=ram-node1,mem-path=/var/lib/libvirt/qemu/ram/libvirt/qemu/23-upstream-bj/ram-node1,share=yes,size=524288000,host-nodes=0,policy=bind \ -numa node,nodeid=1,cpus=1,cpus=3,cpus=5,cpus=7,memdev=ram-node1 \ -uuid 841752b8-9452-4078-a62b-8fd9a9af011c \ -no-user-config \ -nodefaults \ -chardev socket,id=charmonitor,fd=29,server,nowait \ -mon chardev=charmonitor,id=monitor,mode=control \ -rtc base=utc,driftfix=slew \ -global kvm-pit.lost_tick_policy=delay \ -no-hpet \ -no-shutdown \ -global PIIX4_PM.disable_s3=1 \ -global PIIX4_PM.disable_s4=1 \ -boot menu=on,strict=on \ -device ich9-usb-ehci1,id=usb,bus=pci.0,addr=0x6.0x7 \ -device ich9-usb-uhci1,masterbus=usb.0,firstport=0,bus=pci.0,multifunction=on,addr=0x6 \ -device ich9-usb-uhci2,masterbus=usb.0,firstport=2,bus=pci.0,addr=0x6.0x1 \ -device ich9-usb-uhci3,masterbus=usb.0,firstport=4,bus=pci.0,addr=0x6.0x2 \ -device lsi,id=scsi0,bus=pci.0,addr=0x9 \ -device ahci,id=sata0,bus=pci.0,addr=0xb \ -device virtio-serial-pci,id=virtio-serial0,bus=pci.0,addr=0x5 \ -blockdev '{"driver":"file","filename":"/var/lib/libvirt/images/systemrescuecd-x86-4.9.5.iso","node-name":"libvirt-4-storage","auto-read-only":true,"discard":"unmap"}' \ -blockdev '{"node-name":"libvirt-4-format","read-only":true,"driver":"raw","file":"libvirt-4-storage"}' \ -device ide-cd,bus=ide.0,unit=0,drive=libvirt-4-format,id=ide0-0-0,bootindex=1 \ -blockdev '{"driver":"file","filename":"/tmp/pull0.qcow2","node-name":"libvirt-16-storage","auto-read-only":true,"discard":"unmap"}' \ -blockdev '{"node-name":"libvirt-16-format","read-only":true,"driver":"qcow2","file":"libvirt-16-storage","backing":null}' \ -blockdev '{"driver":"file","filename":"/tmp/pull1.qcow2","node-name":"libvirt-15-storage","auto-read-only":true,"discard":"unmap"}' \ -blockdev '{"node-name":"libvirt-15-format","read-only":true,"driver":"qcow2","file":"libvirt-15-storage","backing":"libvirt-16-format"}' \ -blockdev '{"driver":"file","filename":"/tmp/pull2.qcow2","node-name":"libvirt-14-storage","auto-read-only":true,"discard":"unmap"}' \ -blockdev '{"node-name":"libvirt-14-format","read-only":true,"driver":"qcow2","file":"libvirt-14-storage","backing":"libvirt-15-format"}' \ -blockdev '{"driver":"file","filename":"/tmp/pull3.qcow2","node-name":"libvirt-13-storage","auto-read-only":true,"discard":"unmap"}' \ -blockdev '{"node-name":"libvirt-13-format","read-only":true,"driver":"qcow2","file":"libvirt-13-storage","backing":"libvirt-14-format"}' \ -blockdev '{"driver":"file","filename":"/tmp/pull4.qcow2","node-name":"libvirt-3-storage","auto-read-only":true,"discard":"unmap"}' \ -blockdev '{"node-name":"libvirt-3-format","read-only":false,"driver":"qcow2","file":"libvirt-3-storage","backing":"libvirt-13-format"}' \ -device virtio-blk-pci,scsi=off,bus=pci.0,addr=0xa,drive=libvirt-3-format,id=virtio-disk0 \ -blockdev '{"driver":"file","filename":"/tmp/commit0.qcow2","node-name":"libvirt-12-storage","auto-read-only":true,"discard":"unmap"}' \ -blockdev '{"node-name":"libvirt-12-format","read-only":true,"driver":"qcow2","file":"libvirt-12-storage","backing":null}' \ -blockdev '{"driver":"file","filename":"/tmp/commit1.qcow2","node-name":"libvirt-11-storage","auto-read-only":true,"discard":"unmap"}' \ -blockdev '{"node-name":"libvirt-11-format","read-only":true,"driver":"qcow2","file":"libvirt-11-storage","backing":"libvirt-12-format"}' \ -blockdev '{"driver":"file","filename":"/tmp/commit2.qcow2","node-name":"libvirt-10-storage","auto-read-only":true,"discard":"unmap"}' \ -blockdev '{"node-name":"libvirt-10-format","read-only":true,"driver":"qcow2","file":"libvirt-10-storage","backing":"libvirt-11-format"}' \ -blockdev '{"driver":"file","filename":"/tmp/commit3.qcow2","node-name":"libvirt-9-storage","auto-read-only":true,"discard":"unmap"}' \ -blockdev '{"node-name":"libvirt-9-format","read-only":true,"driver":"qcow2","file":"libvirt-9-storage","backing":"libvirt-10-format"}' \ -blockdev '{"driver":"file","filename":"/tmp/commit4.qcow2","node-name":"libvirt-2-storage","auto-read-only":true,"discard":"unmap"}' \ -blockdev '{"node-name":"libvirt-2-format","read-only":false,"driver":"qcow2","file":"libvirt-2-storage","backing":"libvirt-9-format"}' \ -device virtio-blk-pci,scsi=off,bus=pci.0,addr=0xc,drive=libvirt-2-format,id=virtio-disk1 \ -blockdev '{"driver":"file","filename":"/tmp/copy0.qcow2","node-name":"libvirt-8-storage","auto-read-only":true,"discard":"unmap"}' \ -blockdev '{"node-name":"libvirt-8-format","read-only":true,"driver":"qcow2","file":"libvirt-8-storage","backing":null}' \ -blockdev '{"driver":"file","filename":"/tmp/copy1.qcow2","node-name":"libvirt-7-storage","auto-read-only":true,"discard":"unmap"}' \ -blockdev '{"node-name":"libvirt-7-format","read-only":true,"driver":"qcow2","file":"libvirt-7-storage","backing":"libvirt-8-format"}' \ -blockdev '{"driver":"file","filename":"/tmp/copy2.qcow2","node-name":"libvirt-6-storage","auto-read-only":true,"discard":"unmap"}' \ -blockdev '{"node-name":"libvirt-6-format","read-only":true,"driver":"qcow2","file":"libvirt-6-storage","backing":"libvirt-7-format"}' \ -blockdev '{"driver":"file","filename":"/tmp/copy3.qcow2","node-name":"libvirt-5-storage","auto-read-only":true,"discard":"unmap"}' \ -blockdev '{"node-name":"libvirt-5-format","read-only":true,"driver":"qcow2","file":"libvirt-5-storage","backing":"libvirt-6-format"}' \ -blockdev '{"driver":"file","filename":"/tmp/copy4.qcow2","node-name":"libvirt-1-storage","auto-read-only":true,"discard":"unmap"}' \ -blockdev '{"node-name":"libvirt-1-format","read-only":false,"driver":"qcow2","file":"libvirt-1-storage","backing":"libvirt-5-format"}' \ -device virtio-blk-pci,scsi=off,bus=pci.0,addr=0xd,drive=libvirt-1-format,id=virtio-disk2 \ -netdev tap,fd=31,id=hostnet0,vhost=on,vhostfd=32 \ -device virtio-net-pci,netdev=hostnet0,id=net0,mac=52:54:00:36:bd:3b,bus=pci.0,addr=0x3 \ -netdev tap,fd=33,id=hostnet1 \ -device rtl8139,netdev=hostnet1,id=net1,mac=52:54:00:2e:f1:27,bus=pci.0,addr=0x8 \ -chardev pty,id=charserial0 \ -device isa-serial,chardev=charserial0,id=serial0 \ -chardev socket,id=charchannel0,fd=34,server,nowait \ -device virtserialport,bus=virtio-serial0.0,nr=1,chardev=charchannel0,id=channel0,name=org.qemu.guest_agent.0 \ -chardev spicevmc,id=charchannel1,name=vdagent \ -device virtserialport,bus=virtio-serial0.0,nr=2,chardev=charchannel1,id=channel1,name=com.redhat.spice.0 \ -device usb-tablet,id=input0,bus=usb.0,port=1 \ -spice port=5900,addr=127.0.0.1,disable-ticketing,image-compression=off,seamless-migration=on \ -device qxl-vga,id=video0,ram_size=67108864,vram_size=67108864,vram64_size_mb=0,vgamem_mb=16,max_outputs=1,bus=pci.0,addr=0x2 \ -device intel-hda,id=sound0,bus=pci.0,addr=0x4 \ -device hda-duplex,id=sound0-codec0,bus=sound0.0,cad=0 \ -chardev spicevmc,id=charredir0,name=usbredir \ -device usb-redir,chardev=charredir0,id=redir0,bus=usb.0,port=2 \ -chardev spicevmc,id=charredir1,name=usbredir \ -device usb-redir,chardev=charredir1,id=redir1,bus=usb.0,port=3 \ -object rng-random,id=objrng0,filename=/dev/random \ -device virtio-rng-pci,rng=objrng0,id=rng0,bus=pci.0,addr=0x7 \ -sandbox on,obsolete=deny,elevateprivileges=deny,spawn=deny,resourcecontrol=deny \ -msg timestamp=on