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update submodule and patches to 7.1.0
[pve-qemu.git] / debian / patches / pve / 0058-PVE-Backup-ensure-jobs-in-di_list-are-referenced.patch
diff --git a/debian/patches/pve/0058-PVE-Backup-ensure-jobs-in-di_list-are-referenced.patch b/debian/patches/pve/0058-PVE-Backup-ensure-jobs-in-di_list-are-referenced.patch
new file mode 100644 (file)
index 0000000..f3bfb15
--- /dev/null
@@ -0,0 +1,76 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Fabian Ebner <f.ebner@proxmox.com>
+Date: Wed, 25 May 2022 13:59:38 +0200
+Subject: [PATCH] PVE-Backup: ensure jobs in di_list are referenced
+
+Ensures that qmp_backup_cancel doesn't pick a job that's already been
+freed. With unlucky timings it seems possible that:
+1. job_exit -> job_completed -> job_finalize_single starts
+2. pvebackup_co_complete_stream gets spawned in completion callback
+3. job finalize_single finishes -> job's refcount hits zero -> job is
+   freed
+4. qmp_backup_cancel comes in and locks backup_state.backup_mutex
+   before pvebackup_co_complete_stream can remove the job from the
+   di_list
+5. qmp_backup_cancel will pick a job that's already been freed
+
+Signed-off-by: Fabian Ebner <f.ebner@proxmox.com>
+Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>
+---
+ pve-backup.c | 25 ++++++++++++++++++++-----
+ 1 file changed, 20 insertions(+), 5 deletions(-)
+
+diff --git a/pve-backup.c b/pve-backup.c
+index 5bed6f4014..0c34428713 100644
+--- a/pve-backup.c
++++ b/pve-backup.c
+@@ -316,6 +316,14 @@ static void coroutine_fn pvebackup_co_complete_stream(void *opaque)
+         }
+     }
++    if (di->job) {
++        AioContext *ctx = di->job->job.aio_context;
++        aio_context_acquire(ctx);
++        job_unref(&di->job->job);
++        di->job = NULL;
++        aio_context_release(ctx);
++    }
++
+     // remove self from job list
+     backup_state.di_list = g_list_remove(backup_state.di_list, di);
+@@ -491,9 +499,12 @@ static void create_backup_jobs_bh(void *opaque) {
+             bitmap_mode, false, NULL, &perf, BLOCKDEV_ON_ERROR_REPORT, BLOCKDEV_ON_ERROR_REPORT,
+             JOB_DEFAULT, pvebackup_complete_cb, di, backup_state.txn, &local_err);
+-        aio_context_release(aio_context);
+-
+         di->job = job;
++        if (job) {
++            job_ref(&job->job);
++        }
++
++        aio_context_release(aio_context);
+         if (!job || local_err) {
+             error_setg(errp, "backup_job_create failed: %s",
+@@ -521,12 +532,16 @@ static void create_backup_jobs_bh(void *opaque) {
+                 di->target = NULL;
+             }
+-            if (!canceled && di->job) {
++            if (di->job) {
+                 AioContext *ctx = di->job->job.aio_context;
+                 aio_context_acquire(ctx);
+-                job_cancel_sync(&di->job->job, true);
++                if (!canceled) {
++                    job_cancel_sync(&di->job->job, true);
++                    canceled = true;
++                }
++                job_unref(&di->job->job);
++                di->job = NULL;
+                 aio_context_release(ctx);
+-                canceled = true;
+             }
+         }
+     }