From cbc20bfb8fc293333abbef6aacf052f5f8d72f98 Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Tue, 29 Sep 2020 13:55:15 +0100 Subject: [PATCH] block: move block exports to libblockdev Block exports are used by softmmu, qemu-storage-daemon, and qemu-nbd. They are not used by other programs and are not otherwise needed in libblock. Undo the recent move of blockdev-nbd.c from blockdev_ss into block_ss. Since bdrv_close_all() (libblock) calls blk_exp_close_all() (libblockdev) a stub function is required.. Make qemu-nbd.c use signal handling utility functions instead of duplicating the code. This helps because os-posix.c is in libblockdev and it depends on a qemu_system_killed() symbol that qemu-nbd.c lacks. Once we use the signal handling utility functions we also end up providing the necessary symbol. Signed-off-by: Stefan Hajnoczi Reviewed-by: Paolo Bonzini Reviewed-by: Eric Blake Message-id: 20200929125516.186715-4-stefanha@redhat.com [Fixed s/ndb/nbd/ typo in commit description as suggested by Eric Blake --Stefan] Signed-off-by: Stefan Hajnoczi --- block/export/meson.build | 4 ++-- meson.build | 4 ++-- nbd/meson.build | 2 ++ qemu-nbd.c | 21 ++++++++------------- stubs/blk-exp-close-all.c | 7 +++++++ stubs/meson.build | 1 + 6 files changed, 22 insertions(+), 17 deletions(-) create mode 100644 stubs/blk-exp-close-all.c diff --git a/block/export/meson.build b/block/export/meson.build index fffe6b09e8..9fb4fbf81d 100644 --- a/block/export/meson.build +++ b/block/export/meson.build @@ -1,2 +1,2 @@ -block_ss.add(files('export.c')) -block_ss.add(when: ['CONFIG_LINUX', 'CONFIG_VHOST_USER'], if_true: files('vhost-user-blk-server.c')) +blockdev_ss.add(files('export.c')) +blockdev_ss.add(when: ['CONFIG_LINUX', 'CONFIG_VHOST_USER'], if_true: files('vhost-user-blk-server.c')) diff --git a/meson.build b/meson.build index 880683407f..b349c9bda8 100644 --- a/meson.build +++ b/meson.build @@ -1443,7 +1443,6 @@ subdir('dump') block_ss.add(files( 'block.c', - 'blockdev-nbd.c', 'blockjob.c', 'job.c', 'qemu-io-cmds.c', @@ -1456,6 +1455,7 @@ subdir('block') blockdev_ss.add(files( 'blockdev.c', + 'blockdev-nbd.c', 'iothread.c', 'job-qmp.c', )) @@ -1832,7 +1832,7 @@ if have_tools qemu_io = executable('qemu-io', files('qemu-io.c'), dependencies: [block, qemuutil], install: true) qemu_nbd = executable('qemu-nbd', files('qemu-nbd.c'), - dependencies: [block, qemuutil], install: true) + dependencies: [blockdev, qemuutil], install: true) subdir('storage-daemon') subdir('contrib/rdmacm-mux') diff --git a/nbd/meson.build b/nbd/meson.build index 0c00a776d3..2baaa36948 100644 --- a/nbd/meson.build +++ b/nbd/meson.build @@ -1,5 +1,7 @@ block_ss.add(files( 'client.c', 'common.c', +)) +blockdev_ss.add(files( 'server.c', )) diff --git a/qemu-nbd.c b/qemu-nbd.c index bc644a0670..a0701cdf36 100644 --- a/qemu-nbd.c +++ b/qemu-nbd.c @@ -25,6 +25,7 @@ #include "qapi/error.h" #include "qemu/cutils.h" #include "sysemu/block-backend.h" +#include "sysemu/runstate.h" /* for qemu_system_killed() prototype */ #include "block/block_int.h" #include "block/nbd.h" #include "qemu/main-loop.h" @@ -155,7 +156,11 @@ QEMU_COPYRIGHT "\n" } #ifdef CONFIG_POSIX -static void termsig_handler(int signum) +/* + * The client thread uses SIGTERM to interrupt the server. A signal + * handler ensures that "qemu-nbd -v -c" exits with a nice status code. + */ +void qemu_system_killed(int signum, pid_t pid) { qatomic_cmpxchg(&state, RUNNING, TERMINATE); qemu_notify_event(); @@ -582,18 +587,8 @@ int main(int argc, char **argv) BlockExportOptions *export_opts; #ifdef CONFIG_POSIX - /* - * Exit gracefully on various signals, which includes SIGTERM used - * by 'qemu-nbd -v -c'. - */ - struct sigaction sa_sigterm; - memset(&sa_sigterm, 0, sizeof(sa_sigterm)); - sa_sigterm.sa_handler = termsig_handler; - sigaction(SIGTERM, &sa_sigterm, NULL); - sigaction(SIGINT, &sa_sigterm, NULL); - sigaction(SIGHUP, &sa_sigterm, NULL); - - signal(SIGPIPE, SIG_IGN); + os_setup_early_signal_handling(); + os_setup_signal_handling(); #endif socket_init(); diff --git a/stubs/blk-exp-close-all.c b/stubs/blk-exp-close-all.c new file mode 100644 index 0000000000..1c71316763 --- /dev/null +++ b/stubs/blk-exp-close-all.c @@ -0,0 +1,7 @@ +#include "qemu/osdep.h" +#include "block/export.h" + +/* Only used in programs that support block exports (libblockdev.fa) */ +void blk_exp_close_all(void) +{ +} diff --git a/stubs/meson.build b/stubs/meson.build index 67f2a8c069..7b733fadb7 100644 --- a/stubs/meson.build +++ b/stubs/meson.build @@ -1,6 +1,7 @@ stub_ss.add(files('arch_type.c')) stub_ss.add(files('bdrv-next-monitor-owned.c')) stub_ss.add(files('blk-commit-all.c')) +stub_ss.add(files('blk-exp-close-all.c')) stub_ss.add(files('blockdev-close-all-bdrv-states.c')) stub_ss.add(files('change-state-handler.c')) stub_ss.add(files('cmos.c'))