[RFC v5 081/126] qga: introduce ERRP_AUTO_PROPAGATE

[Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>]

If we want to add some info to errp (by error_prepend() or
error_append_hint()), we must use the ERRP_AUTO_PROPAGATE macro.
Otherwise, this info will not be added when errp == &fatal_err
(the program will exit prior to the error_append_hint() or
error_prepend() call).  Fix such cases.

If we want to check error after errp-function call, we need to
introduce local_err and than propagate it to errp. Instead, use
ERRP_AUTO_PROPAGATE macro, benefits are:
1. No need of explicit error_propagate call
2. No need of explicit local_err variable: use errp directly
3. ERRP_AUTO_PROPAGATE leaves errp as is if it's not NULL or
   &error_fatel, this means that we don't break error_abort
   (we'll abort on error_set, not on error_propagate)

This commit (together with its neighbors) was generated by

for f in $(git grep -l errp \*.[ch]); do \
    spatch --sp-file scripts/coccinelle/auto-propagated-errp.cocci \
    --macro-file scripts/cocci-macro-file.h --in-place --no-show-diff $f; \
done;

then fix a bit of compilation problems: coccinelle for some reason
leaves several
f() {
    ...
    goto out;
    ...
    out:
}
patterns, with "out:" at function end.

then
./python/commit-per-subsystem.py MAINTAINERS "$(< auto-msg)"

(auto-msg was a file with this commit message)

Still, for backporting it may be more comfortable to use only the first
command and then do one huge commit.

Reported-by: Kevin Wolf <kwolf@redhat.com>
Reported-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 qga/commands-posix.c | 220 +++++++++++++++++++------------------------
 1 file changed, 97 insertions(+), 123 deletions(-)

diff --git a/qga/commands-posix.c b/qga/commands-posix.c
index 6dcd2d5db6..257eaaf0da 100644
--- a/qga/commands-posix.c
+++ b/qga/commands-posix.c
@@ -82,8 +82,8 @@ static void ga_wait_child(pid_t pid, int *status, Error **errp)
 
 void qmp_guest_shutdown(bool has_mode, const char *mode, Error **errp)
 {
+    ERRP_AUTO_PROPAGATE();
     const char *shutdown_flag;
-    Error *local_err = NULL;
     pid_t pid;
     int status;
 
@@ -116,9 +116,8 @@ void qmp_guest_shutdown(bool has_mode, const char *mode, Error **errp)
         return;
     }
 
-    ga_wait_child(pid, &status, &local_err);
-    if (local_err) {
-        error_propagate(errp, local_err);
+    ga_wait_child(pid, &status, errp);
+    if (*errp) {
         return;
     }
 
@@ -151,10 +150,10 @@ int64_t qmp_guest_get_time(Error **errp)
 
 void qmp_guest_set_time(bool has_time, int64_t time_ns, Error **errp)
 {
+    ERRP_AUTO_PROPAGATE();
     int ret;
     int status;
     pid_t pid;
-    Error *local_err = NULL;
     struct timeval tv;
 
     /* If user has passed a time, validate and set it. */
@@ -203,9 +202,8 @@ void qmp_guest_set_time(bool has_time, int64_t time_ns, Error **errp)
         return;
     }
 
-    ga_wait_child(pid, &status, &local_err);
-    if (local_err) {
-        error_propagate(errp, local_err);
+    ga_wait_child(pid, &status, errp);
+    if (*errp) {
         return;
     }
 
@@ -328,11 +326,11 @@ find_open_flag(const char *mode_str, Error **errp)
 static FILE *
 safe_open_or_create(const char *path, const char *mode, Error **errp)
 {
-    Error *local_err = NULL;
+    ERRP_AUTO_PROPAGATE();
     int oflag;
 
-    oflag = find_open_flag(mode, &local_err);
-    if (local_err == NULL) {
+    oflag = find_open_flag(mode, errp);
+    if (*errp == NULL) {
         int fd;
 
         /* If the caller wants / allows creation of a new file, we implement it
@@ -364,13 +362,13 @@ safe_open_or_create(const char *path, const char *mode, Error **errp)
         }
 
         if (fd == -1) {
-            error_setg_errno(&local_err, errno, "failed to open file '%s' "
+            error_setg_errno(errp, errno, "failed to open file '%s' "
                              "(mode: '%s')", path, mode);
         } else {
             qemu_set_cloexec(fd);
 
             if ((oflag & O_CREAT) && fchmod(fd, DEFAULT_NEW_FILE_MODE) == -1) {
-                error_setg_errno(&local_err, errno, "failed to set permission "
+                error_setg_errno(errp, errno, "failed to set permission "
                                  "0%03o on new file '%s' (mode: '%s')",
                                  (unsigned)DEFAULT_NEW_FILE_MODE, path, mode);
             } else {
@@ -378,7 +376,7 @@ safe_open_or_create(const char *path, const char *mode, Error **errp)
 
                 f = fdopen(fd, mode);
                 if (f == NULL) {
-                    error_setg_errno(&local_err, errno, "failed to associate "
+                    error_setg_errno(errp, errno, "failed to associate "
                                      "stdio stream with file descriptor %d, "
                                      "file '%s' (mode: '%s')", fd, path, mode);
                 } else {
@@ -393,24 +391,22 @@ safe_open_or_create(const char *path, const char *mode, Error **errp)
         }
     }
 
-    error_propagate(errp, local_err);
     return NULL;
 }
 
 int64_t qmp_guest_file_open(const char *path, bool has_mode, const char *mode,
                             Error **errp)
 {
+    ERRP_AUTO_PROPAGATE();
     FILE *fh;
-    Error *local_err = NULL;
     int64_t handle;
 
     if (!has_mode) {
         mode = "r";
     }
     slog("guest-file-open called, filepath: %s, mode: %s", path, mode);
-    fh = safe_open_or_create(path, mode, &local_err);
-    if (local_err != NULL) {
-        error_propagate(errp, local_err);
+    fh = safe_open_or_create(path, mode, errp);
+    if (*errp) {
         return -1;
     }
 
@@ -563,21 +559,20 @@ struct GuestFileSeek *qmp_guest_file_seek(int64_t handle, int64_t offset,
                                           GuestFileWhence *whence_code,
                                           Error **errp)
 {
+    ERRP_AUTO_PROPAGATE();
     GuestFileHandle *gfh = guest_file_handle_find(handle, errp);
     GuestFileSeek *seek_data = NULL;
     FILE *fh;
     int ret;
     int whence;
-    Error *err = NULL;
 
     if (!gfh) {
         return NULL;
     }
 
     /* We stupidly exposed 'whence':'int' in our qapi */
-    whence = ga_parse_whence(whence_code, &err);
-    if (err) {
-        error_propagate(errp, err);
+    whence = ga_parse_whence(whence_code, errp);
+    if (*errp) {
         return NULL;
     }
 
@@ -1150,15 +1145,14 @@ static GuestFilesystemInfo *build_guest_fsinfo(struct FsMount *mount,
 
 GuestFilesystemInfoList *qmp_guest_get_fsinfo(Error **errp)
 {
+    ERRP_AUTO_PROPAGATE();
     FsMountList mounts;
     struct FsMount *mount;
     GuestFilesystemInfoList *new, *ret = NULL;
-    Error *local_err = NULL;
 
     QTAILQ_INIT(&mounts);
-    build_fs_mount_list(&mounts, &local_err);
-    if (local_err) {
-        error_propagate(errp, local_err);
+    build_fs_mount_list(&mounts, errp);
+    if (*errp) {
         return NULL;
     }
 
@@ -1166,11 +1160,10 @@ GuestFilesystemInfoList *qmp_guest_get_fsinfo(Error **errp)
         g_debug("Building guest fsinfo for '%s'", mount->dirname);
 
         new = g_malloc0(sizeof(*ret));
-        new->value = build_guest_fsinfo(mount, &local_err);
+        new->value = build_guest_fsinfo(mount, errp);
         new->next = ret;
         ret = new;
-        if (local_err) {
-            error_propagate(errp, local_err);
+        if (*errp) {
             qapi_free_GuestFilesystemInfoList(ret);
             ret = NULL;
             break;
@@ -1194,11 +1187,11 @@ static const char *fsfreeze_hook_arg_string[] = {
 
 static void execute_fsfreeze_hook(FsfreezeHookArg arg, Error **errp)
 {
+    ERRP_AUTO_PROPAGATE();
     int status;
     pid_t pid;
     const char *hook;
     const char *arg_str = fsfreeze_hook_arg_string[arg];
-    Error *local_err = NULL;
 
     hook = ga_fsfreeze_hook(ga_state);
     if (!hook) {
@@ -1224,9 +1217,8 @@ static void execute_fsfreeze_hook(FsfreezeHookArg arg, Error **errp)
         return;
     }
 
-    ga_wait_child(pid, &status, &local_err);
-    if (local_err) {
-        error_propagate(errp, local_err);
+    ga_wait_child(pid, &status, errp);
+    if (*errp) {
         return;
     }
 
@@ -1267,25 +1259,23 @@ int64_t qmp_guest_fsfreeze_freeze_list(bool has_mountpoints,
                                        strList *mountpoints,
                                        Error **errp)
 {
+    ERRP_AUTO_PROPAGATE();
     int ret = 0, i = 0;
     strList *list;
     FsMountList mounts;
     struct FsMount *mount;
-    Error *local_err = NULL;
     int fd;
 
     slog("guest-fsfreeze called");
 
-    execute_fsfreeze_hook(FSFREEZE_HOOK_FREEZE, &local_err);
-    if (local_err) {
-        error_propagate(errp, local_err);
+    execute_fsfreeze_hook(FSFREEZE_HOOK_FREEZE, errp);
+    if (*errp) {
         return -1;
     }
 
     QTAILQ_INIT(&mounts);
-    build_fs_mount_list(&mounts, &local_err);
-    if (local_err) {
-        error_propagate(errp, local_err);
+    build_fs_mount_list(&mounts, errp);
+    if (*errp) {
         return -1;
     }
 
@@ -1358,16 +1348,15 @@ error:
  */
 int64_t qmp_guest_fsfreeze_thaw(Error **errp)
 {
+    ERRP_AUTO_PROPAGATE();
     int ret;
     FsMountList mounts;
     FsMount *mount;
     int fd, i = 0, logged;
-    Error *local_err = NULL;
 
     QTAILQ_INIT(&mounts);
-    build_fs_mount_list(&mounts, &local_err);
-    if (local_err) {
-        error_propagate(errp, local_err);
+    build_fs_mount_list(&mounts, errp);
+    if (*errp) {
         return 0;
     }
 
@@ -1433,6 +1422,7 @@ static void guest_fsfreeze_cleanup(void)
 GuestFilesystemTrimResponse *
 qmp_guest_fstrim(bool has_minimum, int64_t minimum, Error **errp)
 {
+    ERRP_AUTO_PROPAGATE();
     GuestFilesystemTrimResponse *response;
     GuestFilesystemTrimResultList *list;
     GuestFilesystemTrimResult *result;
@@ -1440,15 +1430,13 @@ qmp_guest_fstrim(bool has_minimum, int64_t minimum, Error **errp)
     FsMountList mounts;
     struct FsMount *mount;
     int fd;
-    Error *local_err = NULL;
     struct fstrim_range r;
 
     slog("guest-fstrim called");
 
     QTAILQ_INIT(&mounts);
-    build_fs_mount_list(&mounts, &local_err);
-    if (local_err) {
-        error_propagate(errp, local_err);
+    build_fs_mount_list(&mounts, errp);
+    if (*errp) {
         return NULL;
     }
 
@@ -1554,13 +1542,13 @@ static int run_process_child(const char *command[], Error **errp)
 
 static bool systemd_supports_mode(SuspendMode mode, Error **errp)
 {
-    Error *local_err = NULL;
+    ERRP_AUTO_PROPAGATE();
     const char *systemctl_args[3] = {"systemd-hibernate", "systemd-suspend",
                                      "systemd-hybrid-sleep"};
     const char *cmd[4] = {"systemctl", "status", systemctl_args[mode], NULL};
     int status;
 
-    status = run_process_child(cmd, &local_err);
+    status = run_process_child(cmd, errp);
 
     /*
      * systemctl status uses LSB return codes so we can expect
@@ -1574,31 +1562,29 @@ static bool systemd_supports_mode(SuspendMode mode, Error **errp)
         return true;
     }
 
-    error_propagate(errp, local_err);
     return false;
 }
 
 static void systemd_suspend(SuspendMode mode, Error **errp)
 {
-    Error *local_err = NULL;
+    ERRP_AUTO_PROPAGATE();
     const char *systemctl_args[3] = {"hibernate", "suspend", "hybrid-sleep"};
     const char *cmd[3] = {"systemctl", systemctl_args[mode], NULL};
     int status;
 
-    status = run_process_child(cmd, &local_err);
+    status = run_process_child(cmd, errp);
 
     if (status == 0) {
         return;
     }
 
-    if ((status == -1) && !local_err) {
+    if ((status == -1) && !*errp) {
         error_setg(errp, "the helper program 'systemctl %s' was not found",
                    systemctl_args[mode]);
         return;
     }
 
-    if (local_err) {
-        error_propagate(errp, local_err);
+    if (*errp) {
     } else {
         error_setg(errp, "the helper program 'systemctl %s' returned an "
                    "unexpected exit status code (%d)",
@@ -1608,24 +1594,23 @@ static void systemd_suspend(SuspendMode mode, Error **errp)
 
 static bool pmutils_supports_mode(SuspendMode mode, Error **errp)
 {
-    Error *local_err = NULL;
+    ERRP_AUTO_PROPAGATE();
     const char *pmutils_args[3] = {"--hibernate", "--suspend",
                                    "--suspend-hybrid"};
     const char *cmd[3] = {"pm-is-supported", pmutils_args[mode], NULL};
     int status;
 
-    status = run_process_child(cmd, &local_err);
+    status = run_process_child(cmd, errp);
 
     if (status == SUSPEND_SUPPORTED) {
         return true;
     }
 
-    if ((status == -1) && !local_err) {
+    if ((status == -1) && !*errp) {
         return false;
     }
 
-    if (local_err) {
-        error_propagate(errp, local_err);
+    if (*errp) {
     } else {
         error_setg(errp,
                    "the helper program '%s' returned an unexpected exit"
@@ -1637,26 +1622,25 @@ static bool pmutils_supports_mode(SuspendMode mode, Error **errp)
 
 static void pmutils_suspend(SuspendMode mode, Error **errp)
 {
-    Error *local_err = NULL;
+    ERRP_AUTO_PROPAGATE();
     const char *pmutils_binaries[3] = {"pm-hibernate", "pm-suspend",
                                        "pm-suspend-hybrid"};
     const char *cmd[2] = {pmutils_binaries[mode], NULL};
     int status;
 
-    status = run_process_child(cmd, &local_err);
+    status = run_process_child(cmd, errp);
 
     if (status == 0) {
         return;
     }
 
-    if ((status == -1) && !local_err) {
+    if ((status == -1) && !*errp) {
         error_setg(errp, "the helper program '%s' was not found",
                    pmutils_binaries[mode]);
         return;
     }
 
-    if (local_err) {
-        error_propagate(errp, local_err);
+    if (*errp) {
     } else {
         error_setg(errp,
                    "the helper program '%s' returned an unexpected exit"
@@ -1697,7 +1681,7 @@ static bool linux_sys_state_supports_mode(SuspendMode mode, Error **errp)
 
 static void linux_sys_state_suspend(SuspendMode mode, Error **errp)
 {
-    Error *local_err = NULL;
+    ERRP_AUTO_PROPAGATE();
     const char *sysfile_strs[3] = {"disk", "mem", NULL};
     const char *sysfile_str = sysfile_strs[mode];
     pid_t pid;
@@ -1733,9 +1717,8 @@ static void linux_sys_state_suspend(SuspendMode mode, Error **errp)
         return;
     }
 
-    ga_wait_child(pid, &status, &local_err);
-    if (local_err) {
-        error_propagate(errp, local_err);
+    ga_wait_child(pid, &status, errp);
+    if (*errp) {
         return;
     }
 
@@ -1747,41 +1730,40 @@ static void linux_sys_state_suspend(SuspendMode mode, Error **errp)
 
 static void guest_suspend(SuspendMode mode, Error **errp)
 {
-    Error *local_err = NULL;
+    ERRP_AUTO_PROPAGATE();
     bool mode_supported = false;
 
-    if (systemd_supports_mode(mode, &local_err)) {
+    if (systemd_supports_mode(mode, errp)) {
         mode_supported = true;
-        systemd_suspend(mode, &local_err);
+        systemd_suspend(mode, errp);
     }
 
-    if (!local_err) {
+    if (!*errp) {
         return;
     }
 
-    error_free(local_err);
+    error_free_errp(errp);
 
-    if (pmutils_supports_mode(mode, &local_err)) {
+    if (pmutils_supports_mode(mode, errp)) {
         mode_supported = true;
-        pmutils_suspend(mode, &local_err);
+        pmutils_suspend(mode, errp);
     }
 
-    if (!local_err) {
+    if (!*errp) {
         return;
     }
 
-    error_free(local_err);
+    error_free_errp(errp);
 
-    if (linux_sys_state_supports_mode(mode, &local_err)) {
+    if (linux_sys_state_supports_mode(mode, errp)) {
         mode_supported = true;
-        linux_sys_state_suspend(mode, &local_err);
+        linux_sys_state_suspend(mode, errp);
     }
 
     if (!mode_supported) {
         error_setg(errp,
                    "the requested suspend mode is not supported by the guest");
     } else {
-        error_propagate(errp, local_err);
     }
 }
 
@@ -2120,17 +2102,17 @@ static void transfer_vcpu(GuestLogicalProcessor *vcpu, bool sys2vcpu,
 
 GuestLogicalProcessorList *qmp_guest_get_vcpus(Error **errp)
 {
+    ERRP_AUTO_PROPAGATE();
     int64_t current;
     GuestLogicalProcessorList *head, **link;
     long sc_max;
-    Error *local_err = NULL;
 
     current = 0;
     head = NULL;
     link = &head;
-    sc_max = SYSCONF_EXACT(_SC_NPROCESSORS_CONF, &local_err);
+    sc_max = SYSCONF_EXACT(_SC_NPROCESSORS_CONF, errp);
 
-    while (local_err == NULL && current < sc_max) {
+    while (*errp == NULL && current < sc_max) {
         GuestLogicalProcessor *vcpu;
         GuestLogicalProcessorList *entry;
         int64_t id = current++;
@@ -2141,7 +2123,7 @@ GuestLogicalProcessorList *qmp_guest_get_vcpus(Error **errp)
             vcpu = g_malloc0(sizeof *vcpu);
             vcpu->logical_id = id;
             vcpu->has_can_offline = true; /* lolspeak ftw */
-            transfer_vcpu(vcpu, true, path, &local_err);
+            transfer_vcpu(vcpu, true, path, errp);
             entry = g_malloc0(sizeof *entry);
             entry->value = vcpu;
             *link = entry;
@@ -2150,41 +2132,39 @@ GuestLogicalProcessorList *qmp_guest_get_vcpus(Error **errp)
         g_free(path);
     }
 
-    if (local_err == NULL) {
+    if (*errp == NULL) {
         /* there's no guest with zero VCPUs */
         g_assert(head != NULL);
         return head;
     }
 
     qapi_free_GuestLogicalProcessorList(head);
-    error_propagate(errp, local_err);
     return NULL;
 }
 
 int64_t qmp_guest_set_vcpus(GuestLogicalProcessorList *vcpus, Error **errp)
 {
+    ERRP_AUTO_PROPAGATE();
     int64_t processed;
-    Error *local_err = NULL;
 
     processed = 0;
     while (vcpus != NULL) {
         char *path = g_strdup_printf("/sys/devices/system/cpu/cpu%" PRId64 "/",
                                      vcpus->value->logical_id);
 
-        transfer_vcpu(vcpus->value, false, path, &local_err);
+        transfer_vcpu(vcpus->value, false, path, errp);
         g_free(path);
-        if (local_err != NULL) {
+        if (*errp) {
             break;
         }
         ++processed;
         vcpus = vcpus->next;
     }
 
-    if (local_err != NULL) {
+    if (*errp) {
         if (processed == 0) {
-            error_propagate(errp, local_err);
         } else {
-            error_free(local_err);
+            error_free_errp(errp);
         }
     }
 
@@ -2196,7 +2176,7 @@ void qmp_guest_set_user_password(const char *username,
                                  bool crypted,
                                  Error **errp)
 {
-    Error *local_err = NULL;
+    ERRP_AUTO_PROPAGATE();
     char *passwd_path = NULL;
     pid_t pid;
     int status;
@@ -2268,9 +2248,8 @@ void qmp_guest_set_user_password(const char *username,
     close(datafd[1]);
     datafd[1] = -1;
 
-    ga_wait_child(pid, &status, &local_err);
-    if (local_err) {
-        error_propagate(errp, local_err);
+    ga_wait_child(pid, &status, errp);
+    if (*errp) {
         goto out;
     }
 
@@ -2356,10 +2335,10 @@ static void transfer_memory_block(GuestMemoryBlock *mem_blk, bool sys2memblk,
                                   GuestMemoryBlockResponse *result,
                                   Error **errp)
 {
+    ERRP_AUTO_PROPAGATE();
     char *dirpath;
     int dirfd;
     char *status;
-    Error *local_err = NULL;
 
     if (!sys2memblk) {
         DIR *dp;
@@ -2404,11 +2383,11 @@ static void transfer_memory_block(GuestMemoryBlock *mem_blk, bool sys2memblk,
     g_free(dirpath);
 
     status = g_malloc0(10);
-    ga_read_sysfs_file(dirfd, "state", status, 10, &local_err);
-    if (local_err) {
+    ga_read_sysfs_file(dirfd, "state", status, 10, errp);
+    if (*errp) {
         /* treat with sysfs file that not exist in old kernel */
         if (errno == ENOENT) {
-            error_free(local_err);
+            error_free_errp(errp);
             if (sys2memblk) {
                 mem_blk->online = true;
                 mem_blk->can_offline = false;
@@ -2418,7 +2397,6 @@ static void transfer_memory_block(GuestMemoryBlock *mem_blk, bool sys2memblk,
             }
         } else {
             if (sys2memblk) {
-                error_propagate(errp, local_err);
             } else {
                 result->response =
                     GUEST_MEMORY_BLOCK_RESPONSE_TYPE_OPERATION_FAILED;
@@ -2432,14 +2410,13 @@ static void transfer_memory_block(GuestMemoryBlock *mem_blk, bool sys2memblk,
 
         mem_blk->online = (strncmp(status, "online", 6) == 0);
 
-        ga_read_sysfs_file(dirfd, "removable", &removable, 1, &local_err);
-        if (local_err) {
+        ga_read_sysfs_file(dirfd, "removable", &removable, 1, errp);
+        if (*errp) {
             /* if no 'removable' file, it doesn't support offline mem blk */
             if (errno == ENOENT) {
-                error_free(local_err);
+                error_free_errp(errp);
                 mem_blk->can_offline = false;
             } else {
-                error_propagate(errp, local_err);
             }
         } else {
             mem_blk->can_offline = (removable != '0');
@@ -2449,9 +2426,9 @@ static void transfer_memory_block(GuestMemoryBlock *mem_blk, bool sys2memblk,
             const char *new_state = mem_blk->online ? "online" : "offline";
 
             ga_write_sysfs_file(dirfd, "state", new_state, strlen(new_state),
-                                &local_err);
-            if (local_err) {
-                error_free(local_err);
+                                errp);
+            if (*errp) {
+                error_free_errp(errp);
                 result->response =
                     GUEST_MEMORY_BLOCK_RESPONSE_TYPE_OPERATION_FAILED;
                 goto out2;
@@ -2477,8 +2454,8 @@ out1:
 
 GuestMemoryBlockList *qmp_guest_get_memory_blocks(Error **errp)
 {
+    ERRP_AUTO_PROPAGATE();
     GuestMemoryBlockList *head, **link;
-    Error *local_err = NULL;
     struct dirent *de;
     DIR *dp;
 
@@ -2516,7 +2493,7 @@ GuestMemoryBlockList *qmp_guest_get_memory_blocks(Error **errp)
         /* The d_name is "memoryXXX",  phys_index is block id, same as XXX */
         mem_blk->phys_index = strtoul(&de->d_name[6], NULL, 10);
         mem_blk->has_can_offline = true; /* lolspeak ftw */
-        transfer_memory_block(mem_blk, true, NULL, &local_err);
+        transfer_memory_block(mem_blk, true, NULL, errp);
 
         entry = g_malloc0(sizeof *entry);
         entry->value = mem_blk;
@@ -2526,7 +2503,7 @@ GuestMemoryBlockList *qmp_guest_get_memory_blocks(Error **errp)
     }
 
     closedir(dp);
-    if (local_err == NULL) {
+    if (*errp == NULL) {
         /* there's no guest with zero memory blocks */
         if (head == NULL) {
             error_setg(errp, "guest reported zero memory blocks!");
@@ -2535,15 +2512,14 @@ GuestMemoryBlockList *qmp_guest_get_memory_blocks(Error **errp)
     }
 
     qapi_free_GuestMemoryBlockList(head);
-    error_propagate(errp, local_err);
     return NULL;
 }
 
 GuestMemoryBlockResponseList *
 qmp_guest_set_memory_blocks(GuestMemoryBlockList *mem_blks, Error **errp)
 {
+    ERRP_AUTO_PROPAGATE();
     GuestMemoryBlockResponseList *head, **link;
-    Error *local_err = NULL;
 
     head = NULL;
     link = &head;
@@ -2555,8 +2531,8 @@ qmp_guest_set_memory_blocks(GuestMemoryBlockList *mem_blks, Error **errp)
 
         result = g_malloc0(sizeof(*result));
         result->phys_index = current_mem_blk->phys_index;
-        transfer_memory_block(current_mem_blk, false, result, &local_err);
-        if (local_err) { /* should never happen */
+        transfer_memory_block(current_mem_blk, false, result, errp);
+        if (*errp) { /* should never happen */
             goto err;
         }
         entry = g_malloc0(sizeof *entry);
@@ -2570,13 +2546,12 @@ qmp_guest_set_memory_blocks(GuestMemoryBlockList *mem_blks, Error **errp)
     return head;
 err:
     qapi_free_GuestMemoryBlockResponseList(head);
-    error_propagate(errp, local_err);
     return NULL;
 }
 
 GuestMemoryBlockInfo *qmp_guest_get_memory_block_info(Error **errp)
 {
-    Error *local_err = NULL;
+    ERRP_AUTO_PROPAGATE();
     char *dirpath;
     int dirfd;
     char *buf;
@@ -2592,11 +2567,10 @@ GuestMemoryBlockInfo *qmp_guest_get_memory_block_info(Error **errp)
     g_free(dirpath);
 
     buf = g_malloc0(20);
-    ga_read_sysfs_file(dirfd, "block_size_bytes", buf, 20, &local_err);
+    ga_read_sysfs_file(dirfd, "block_size_bytes", buf, 20, errp);
     close(dirfd);
-    if (local_err) {
+    if (*errp) {
         g_free(buf);
-        error_propagate(errp, local_err);
         return NULL;
     }
 
-- 
2.21.0