| Message ID | 20210226170816.231173-1-pbonzini@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] qemu-config: add error propagation to qemu_config_parse | expand |
On 2/26/21 6:08 PM, Paolo Bonzini wrote: > This enables some simplification of vl.c via error_fatal, and improves > error messages. Before: > > Before: > $ ./qemu-system-x86_64 -readconfig . > qemu-system-x86_64: error reading file > qemu-system-x86_64: -readconfig .: read config .: Invalid argument > $ /usr/libexec/qemu-kvm -readconfig foo > qemu-kvm: -readconfig foo: read config foo: No such file or directory > > After: > > $ ./qemu-system-x86_64 -readconfig . > qemu-system-x86_64: -readconfig .: error reading file: Is a directory > $ ./qemu-system-x86_64 -readconfig foo > qemu-system-x86_64: -readconfig foo: Cannot read config file foo: No such file or directory > > Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> > --- > block/blkdebug.c | 3 +-- > include/qemu/config-file.h | 5 +++-- > softmmu/vl.c | 29 +++++++++++------------------ > util/qemu-config.c | 23 ++++++++++++----------- > 4 files changed, 27 insertions(+), 33 deletions(-) Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Paolo Bonzini <pbonzini@redhat.com> writes: > This enables some simplification of vl.c via error_fatal, and improves > error messages. Before: > > Before: > $ ./qemu-system-x86_64 -readconfig . > qemu-system-x86_64: error reading file > qemu-system-x86_64: -readconfig .: read config .: Invalid argument > $ /usr/libexec/qemu-kvm -readconfig foo > qemu-kvm: -readconfig foo: read config foo: No such file or directory > > After: > > $ ./qemu-system-x86_64 -readconfig . > qemu-system-x86_64: -readconfig .: error reading file: Is a directory > $ ./qemu-system-x86_64 -readconfig foo > qemu-system-x86_64: -readconfig foo: Cannot read config file foo: No such file or directory > > Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Lovely :) > --- > block/blkdebug.c | 3 +-- > include/qemu/config-file.h | 5 +++-- > softmmu/vl.c | 29 +++++++++++------------------ > util/qemu-config.c | 23 ++++++++++++----------- > 4 files changed, 27 insertions(+), 33 deletions(-) > > diff --git a/block/blkdebug.c b/block/blkdebug.c > index 5fe6172da9..7eaa8a28bf 100644 > --- a/block/blkdebug.c > +++ b/block/blkdebug.c > @@ -279,9 +279,8 @@ static int read_config(BDRVBlkdebugState *s, const char *filename, > return -errno; > } > > - ret = qemu_config_parse(f, config_groups, filename); > + ret = qemu_config_parse(f, config_groups, filename, errp); > if (ret < 0) { > - error_setg(errp, "Could not parse blkdebug config file"); > goto fail; > } > } > diff --git a/include/qemu/config-file.h b/include/qemu/config-file.h > index 29226107bd..8d3e53ae4d 100644 > --- a/include/qemu/config-file.h > +++ b/include/qemu/config-file.h > @@ -11,9 +11,10 @@ void qemu_add_drive_opts(QemuOptsList *list); > int qemu_global_option(const char *str); > > void qemu_config_write(FILE *fp); > -int qemu_config_parse(FILE *fp, QemuOptsList **lists, const char *fname); > +int qemu_config_parse(FILE *fp, QemuOptsList **lists, const char *fname, > + Error **errp); > > -int qemu_read_config_file(const char *filename); > +int qemu_read_config_file(const char *filename, Error **errp); > > /* Parse QDict options as a replacement for a config file (allowing multiple > enumerated (0..(n-1)) configuration "sections") */ > diff --git a/softmmu/vl.c b/softmmu/vl.c > index e67f91dd37..e80859c40d 100644 > --- a/softmmu/vl.c > +++ b/softmmu/vl.c > @@ -2062,17 +2062,19 @@ static int global_init_func(void *opaque, QemuOpts *opts, Error **errp) > return 0; > } > > -static int qemu_read_default_config_file(void) > +static void qemu_read_default_config_file(Error **errp) > { > + ERRP_GUARD(); > int ret; > g_autofree char *file = get_relocated_path(CONFIG_QEMU_CONFDIR "/qemu.conf"); > > - ret = qemu_read_config_file(file); > - if (ret < 0 && ret != -ENOENT) { > - return ret; > + ret = qemu_read_config_file(file, errp); > + if (ret < 0) { > + if (ret == -ENOENT) { > + error_free(*errp); > + *errp = NULL; > + } > } > - > - return 0; > } This change to return void goes against advice in error.h: * - Whenever practical, also return a value that indicates success / * failure. This can make the error checking more concise, and can * avoid useless error object creation and destruction. Note that * we still have many functions returning void. We recommend * • bool-valued functions return true on success / false on failure, * • pointer-valued functions return non-null / null pointer, and * • integer-valued functions return non-negative / negative. Tolerable. The only caller wouldn't profit from a return value (it passes &error_fatal), and more callers seem quite unlikely. > > static int qemu_set_option(const char *str) > @@ -2640,9 +2642,7 @@ void qemu_init(int argc, char **argv, char **envp) > } > > if (userconfig) { > - if (qemu_read_default_config_file() < 0) { > - exit(1); > - } > + qemu_read_default_config_file(&error_fatal); > } > > /* second pass of option parsing */ > @@ -3330,15 +3330,8 @@ void qemu_init(int argc, char **argv, char **envp) > qemu_plugin_opt_parse(optarg, &plugin_list); > break; > case QEMU_OPTION_readconfig: > - { > - int ret = qemu_read_config_file(optarg); > - if (ret < 0) { > - error_report("read config %s: %s", optarg, > - strerror(-ret)); > - exit(1); > - } > - break; > - } > + qemu_read_config_file(optarg, &error_fatal); > + break; > case QEMU_OPTION_spice: > olist = qemu_find_opts_err("spice", NULL); > if (!olist) { > diff --git a/util/qemu-config.c b/util/qemu-config.c > index e2a700b284..af89df109d 100644 > --- a/util/qemu-config.c > +++ b/util/qemu-config.c > @@ -350,7 +350,7 @@ void qemu_config_write(FILE *fp) > } > > /* Returns number of config groups on success, -errno on error */ > -int qemu_config_parse(FILE *fp, QemuOptsList **lists, const char *fname) > +int qemu_config_parse(FILE *fp, QemuOptsList **lists, const char *fname, Error **errp) > { > char line[1024], group[64], id[64], arg[64], value[1024]; > Location loc; > @@ -375,7 +375,7 @@ int qemu_config_parse(FILE *fp, QemuOptsList **lists, const char *fname) > /* group with id */ > list = find_list(lists, group, &local_err); > if (local_err) { > - error_report_err(local_err); > + error_propagate(errp, local_err); > goto out; > } Please avoid error_propagate() where possible: list = find_list(lists, group, errp); if (!list) { goto out; } > opts = qemu_opts_create(list, id, 1, NULL); > @@ -386,7 +386,7 @@ int qemu_config_parse(FILE *fp, QemuOptsList **lists, const char *fname) > /* group without id */ > list = find_list(lists, group, &local_err); > if (local_err) { > - error_report_err(local_err); > + error_propagate(errp, local_err); > goto out; > } Likewise. > opts = qemu_opts_create(list, NULL, 0, &error_abort); > @@ -398,21 +398,21 @@ int qemu_config_parse(FILE *fp, QemuOptsList **lists, const char *fname) > sscanf(line, " %63s = \"\"", arg) == 1) { > /* arg = value */ > if (opts == NULL) { > - error_report("no group defined"); > + error_setg(errp, "no group defined"); > goto out; > } > - if (!qemu_opt_set(opts, arg, value, &local_err)) { > - error_report_err(local_err); > + if (!qemu_opt_set(opts, arg, value, errp)) { > goto out; > } > continue; > } > - error_report("parse error"); > + error_setg(errp, "parse error"); > goto out; > } > if (ferror(fp)) { > - error_report("error reading file"); > - goto out; > + loc_pop(&loc); > + error_setg_errno(errp, errno, "error reading file"); > + return res; > } > res = count; > out: > @@ -420,16 +420,17 @@ out: > return res; > } > > -int qemu_read_config_file(const char *filename) > +int qemu_read_config_file(const char *filename, Error **errp) > { > FILE *f = fopen(filename, "r"); > int ret; > > if (f == NULL) { > + error_setg_errno(errp, errno, "Cannot read config file %s", filename); > return -errno; > } > > - ret = qemu_config_parse(f, vm_config_groups, filename); > + ret = qemu_config_parse(f, vm_config_groups, filename, errp); > fclose(f); > return ret; > } Not avoiding error_propagate() isn't wrong, so Reviewed-by: Markus Armbruster <armbru@redhat.com> But please consider avoiding it anyway.
On 03/03/21 14:48, Markus Armbruster wrote: > Reviewed-by: Markus Armbruster<armbru@redhat.com> > > But please consider avoiding it anyway. It does make for a smaller patch, so I'll use that as an excuse instead of me being old school. I'll clean it up in a separate patch. Paolo
diff --git a/block/blkdebug.c b/block/blkdebug.c index 5fe6172da9..7eaa8a28bf 100644 --- a/block/blkdebug.c +++ b/block/blkdebug.c @@ -279,9 +279,8 @@ static int read_config(BDRVBlkdebugState *s, const char *filename, return -errno; } - ret = qemu_config_parse(f, config_groups, filename); + ret = qemu_config_parse(f, config_groups, filename, errp); if (ret < 0) { - error_setg(errp, "Could not parse blkdebug config file"); goto fail; } } diff --git a/include/qemu/config-file.h b/include/qemu/config-file.h index 29226107bd..8d3e53ae4d 100644 --- a/include/qemu/config-file.h +++ b/include/qemu/config-file.h @@ -11,9 +11,10 @@ void qemu_add_drive_opts(QemuOptsList *list); int qemu_global_option(const char *str); void qemu_config_write(FILE *fp); -int qemu_config_parse(FILE *fp, QemuOptsList **lists, const char *fname); +int qemu_config_parse(FILE *fp, QemuOptsList **lists, const char *fname, + Error **errp); -int qemu_read_config_file(const char *filename); +int qemu_read_config_file(const char *filename, Error **errp); /* Parse QDict options as a replacement for a config file (allowing multiple enumerated (0..(n-1)) configuration "sections") */ diff --git a/softmmu/vl.c b/softmmu/vl.c index e67f91dd37..e80859c40d 100644 --- a/softmmu/vl.c +++ b/softmmu/vl.c @@ -2062,17 +2062,19 @@ static int global_init_func(void *opaque, QemuOpts *opts, Error **errp) return 0; } -static int qemu_read_default_config_file(void) +static void qemu_read_default_config_file(Error **errp) { + ERRP_GUARD(); int ret; g_autofree char *file = get_relocated_path(CONFIG_QEMU_CONFDIR "/qemu.conf"); - ret = qemu_read_config_file(file); - if (ret < 0 && ret != -ENOENT) { - return ret; + ret = qemu_read_config_file(file, errp); + if (ret < 0) { + if (ret == -ENOENT) { + error_free(*errp); + *errp = NULL; + } } - - return 0; } static int qemu_set_option(const char *str) @@ -2640,9 +2642,7 @@ void qemu_init(int argc, char **argv, char **envp) } if (userconfig) { - if (qemu_read_default_config_file() < 0) { - exit(1); - } + qemu_read_default_config_file(&error_fatal); } /* second pass of option parsing */ @@ -3330,15 +3330,8 @@ void qemu_init(int argc, char **argv, char **envp) qemu_plugin_opt_parse(optarg, &plugin_list); break; case QEMU_OPTION_readconfig: - { - int ret = qemu_read_config_file(optarg); - if (ret < 0) { - error_report("read config %s: %s", optarg, - strerror(-ret)); - exit(1); - } - break; - } + qemu_read_config_file(optarg, &error_fatal); + break; case QEMU_OPTION_spice: olist = qemu_find_opts_err("spice", NULL); if (!olist) { diff --git a/util/qemu-config.c b/util/qemu-config.c index e2a700b284..af89df109d 100644 --- a/util/qemu-config.c +++ b/util/qemu-config.c @@ -350,7 +350,7 @@ void qemu_config_write(FILE *fp) } /* Returns number of config groups on success, -errno on error */ -int qemu_config_parse(FILE *fp, QemuOptsList **lists, const char *fname) +int qemu_config_parse(FILE *fp, QemuOptsList **lists, const char *fname, Error **errp) { char line[1024], group[64], id[64], arg[64], value[1024]; Location loc; @@ -375,7 +375,7 @@ int qemu_config_parse(FILE *fp, QemuOptsList **lists, const char *fname) /* group with id */ list = find_list(lists, group, &local_err); if (local_err) { - error_report_err(local_err); + error_propagate(errp, local_err); goto out; } opts = qemu_opts_create(list, id, 1, NULL); @@ -386,7 +386,7 @@ int qemu_config_parse(FILE *fp, QemuOptsList **lists, const char *fname) /* group without id */ list = find_list(lists, group, &local_err); if (local_err) { - error_report_err(local_err); + error_propagate(errp, local_err); goto out; } opts = qemu_opts_create(list, NULL, 0, &error_abort); @@ -398,21 +398,21 @@ int qemu_config_parse(FILE *fp, QemuOptsList **lists, const char *fname) sscanf(line, " %63s = \"\"", arg) == 1) { /* arg = value */ if (opts == NULL) { - error_report("no group defined"); + error_setg(errp, "no group defined"); goto out; } - if (!qemu_opt_set(opts, arg, value, &local_err)) { - error_report_err(local_err); + if (!qemu_opt_set(opts, arg, value, errp)) { goto out; } continue; } - error_report("parse error"); + error_setg(errp, "parse error"); goto out; } if (ferror(fp)) { - error_report("error reading file"); - goto out; + loc_pop(&loc); + error_setg_errno(errp, errno, "error reading file"); + return res; } res = count; out: @@ -420,16 +420,17 @@ out: return res; } -int qemu_read_config_file(const char *filename) +int qemu_read_config_file(const char *filename, Error **errp) { FILE *f = fopen(filename, "r"); int ret; if (f == NULL) { + error_setg_errno(errp, errno, "Cannot read config file %s", filename); return -errno; } - ret = qemu_config_parse(f, vm_config_groups, filename); + ret = qemu_config_parse(f, vm_config_groups, filename, errp); fclose(f); return ret; }
This enables some simplification of vl.c via error_fatal, and improves error messages. Before: Before: $ ./qemu-system-x86_64 -readconfig . qemu-system-x86_64: error reading file qemu-system-x86_64: -readconfig .: read config .: Invalid argument $ /usr/libexec/qemu-kvm -readconfig foo qemu-kvm: -readconfig foo: read config foo: No such file or directory After: $ ./qemu-system-x86_64 -readconfig . qemu-system-x86_64: -readconfig .: error reading file: Is a directory $ ./qemu-system-x86_64 -readconfig foo qemu-system-x86_64: -readconfig foo: Cannot read config file foo: No such file or directory Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> --- block/blkdebug.c | 3 +-- include/qemu/config-file.h | 5 +++-- softmmu/vl.c | 29 +++++++++++------------------ util/qemu-config.c | 23 ++++++++++++----------- 4 files changed, 27 insertions(+), 33 deletions(-)