97 lines
3.2 KiB
Diff
97 lines
3.2 KiB
Diff
|
From 9d0247153a70ab1909d0690ec9b7f4d20e8cb602 Mon Sep 17 00:00:00 2001
|
||
|
|
Message-Id: <9d0247153a70ab1909d0690ec9b7f4d20e8cb602@dist-git>
|
||
|
|
From: Vasiliy Ulyanov <vulyanov@suse.de>
|
||
|
|
Date: Wed, 2 Feb 2022 17:28:15 +0100
|
||
|
|
Subject: [PATCH] virpidfile: Add virPidFileReadPathIfLocked func
|
||
|
|
|
||
|
|
The function will attempt to read a pid from @path, and store it in
|
||
|
|
@pid. The @pid will only be set, however, if @path is locked by
|
||
|
|
virFileLock() at byte 0 and the pid in @path is running.
|
||
|
|
|
||
|
|
Signed-off-by: Vasiliy Ulyanov <vulyanov@suse.de>
|
||
|
|
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
|
||
|
|
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
|
||
|
|
(cherry picked from commit 013ab22f79d1345daf6b2778ca498acb16939011)
|
||
|
|
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=2152188
|
||
|
|
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
|
||
|
|
---
|
||
|
|
src/libvirt_private.syms | 1 +
|
||
|
|
src/util/virpidfile.c | 35 +++++++++++++++++++++++++++++++++++
|
||
|
|
src/util/virpidfile.h | 2 ++
|
||
|
|
3 files changed, 38 insertions(+)
|
||
|
|
|
||
|
|
diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
|
||
|
|
index fa734dfd33..568b0f34a1 100644
|
||
|
|
--- a/src/libvirt_private.syms
|
||
|
|
+++ b/src/libvirt_private.syms
|
||
|
|
@@ -3061,6 +3061,7 @@ virPidFileRead;
|
||
|
|
virPidFileReadIfAlive;
|
||
|
|
virPidFileReadPath;
|
||
|
|
virPidFileReadPathIfAlive;
|
||
|
|
+virPidFileReadPathIfLocked;
|
||
|
|
virPidFileRelease;
|
||
|
|
virPidFileReleasePath;
|
||
|
|
virPidFileWrite;
|
||
|
|
diff --git a/src/util/virpidfile.c b/src/util/virpidfile.c
|
||
|
|
index 7069f8343d..9d194f7336 100644
|
||
|
|
--- a/src/util/virpidfile.c
|
||
|
|
+++ b/src/util/virpidfile.c
|
||
|
|
@@ -302,6 +302,41 @@ int virPidFileReadIfAlive(const char *dir,
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
+/**
|
||
|
|
+ * virPidFileReadPathIfLocked:
|
||
|
|
+ * @path: path to pidfile
|
||
|
|
+ * @pid: variable to return pid in
|
||
|
|
+ *
|
||
|
|
+ * This will attempt to read a pid from @path, and store it in
|
||
|
|
+ * @pid. The @pid will only be set, however, if the pid in @path
|
||
|
|
+ * is running, and @path is locked by virFileLock() at byte 0
|
||
|
|
+ * (which is exactly what virCommandSetPidFile() results in).
|
||
|
|
+ * This adds protection against returning a stale pid.
|
||
|
|
+ *
|
||
|
|
+ * Returns -1 upon error, or zero on successful
|
||
|
|
+ * reading of the pidfile. If @path is not locked
|
||
|
|
+ * or if the PID was not still alive, zero will
|
||
|
|
+ * be returned, but @pid will be set to -1.
|
||
|
|
+ */
|
||
|
|
+int virPidFileReadPathIfLocked(const char *path, pid_t *pid)
|
||
|
|
+{
|
||
|
|
+ VIR_AUTOCLOSE fd = -1;
|
||
|
|
+
|
||
|
|
+ if ((fd = open(path, O_RDWR)) < 0)
|
||
|
|
+ return -1;
|
||
|
|
+
|
||
|
|
+ if (virFileLock(fd, false, 0, 1, false) >= 0) {
|
||
|
|
+ /* The file isn't locked. PID is stale. */
|
||
|
|
+ *pid = -1;
|
||
|
|
+ return 0;
|
||
|
|
+ }
|
||
|
|
+
|
||
|
|
+ if (virPidFileReadPathIfAlive(path, pid, NULL) < 0)
|
||
|
|
+ return -1;
|
||
|
|
+
|
||
|
|
+ return 0;
|
||
|
|
+}
|
||
|
|
+
|
||
|
|
|
||
|
|
int virPidFileDeletePath(const char *pidfile)
|
||
|
|
{
|
||
|
|
diff --git a/src/util/virpidfile.h b/src/util/virpidfile.h
|
||
|
|
index fd8013c41e..e84542f298 100644
|
||
|
|
--- a/src/util/virpidfile.h
|
||
|
|
+++ b/src/util/virpidfile.h
|
||
|
|
@@ -48,6 +48,8 @@ int virPidFileReadIfAlive(const char *dir,
|
||
|
|
const char *name,
|
||
|
|
pid_t *pid,
|
||
|
|
const char *binpath) G_GNUC_WARN_UNUSED_RESULT;
|
||
|
|
+int virPidFileReadPathIfLocked(const char *path,
|
||
|
|
+ pid_t *pid) G_GNUC_WARN_UNUSED_RESULT;
|
||
|
|
|
||
|
|
int virPidFileDeletePath(const char *path);
|
||
|
|
int virPidFileDelete(const char *dir,
|
||
|
|
--
|
||
|
|
2.39.0
|
||
|
|
|