[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Xen-devel] [PATCH 2 of 2] xl: Make clear distinction between "filename" and "data source"



On Tue, 2012-05-15 at 15:51 +0100, George Dunlap wrote:
> Many places in xl there's a variable or element named "filename" which
> does not contain a filename, but the source of the data for reporting
> purposes.  Worse, there are variables which are sometimes actually
> used or interpreted as a filename depending on what other variables
> are set.  This makes it difficult to tell when a string is purely
> cosmetic, and when another bit of code may actually attempt to call
> "open" with the string.
> 
> This patch makes a consistent distinction between "filename" (which
> always refers to the name of an actual file, and may be interpreted as
> such at some point) and "source" (which may be a filename, or may be
> another data source such as a migration stream or saved data).
> 
> This does add some variables and reshuffle where assignments happen;
> most notably, the "restore_filename" element of struct domain_create
> is now only set when restoring from a file.
> 
> But at a high level, there should be no funcitonal changes.
> 
> Signed-off-by: George Dunlap <george.dunlap@xxxxxxxxxxxxx>

I've committed this (and the preceding patch), there were a few
conflicts with Goncalo's vncviewer patch (a new param to
parse_config_data). Please do check I've done the right thing.

> 
> diff -r 750b4dbab4b5 -r d555dd6614af tools/libxl/libxl_utils.c
> --- a/tools/libxl/libxl_utils.c Tue May 15 15:45:55 2012 +0100
> +++ b/tools/libxl/libxl_utils.c Tue May 15 15:51:25 2012 +0100
> @@ -334,7 +334,7 @@ int libxl_read_file_contents(libxl_ctx *
>                                                                            \
>    int libxl_##rw##_exactly(libxl_ctx *ctx, int fd,                 \
>                             constdata void *data, ssize_t sz,              \
> -                           const char *filename, const char *what) {      \
> +                           const char *source, const char *what) {      \
>        ssize_t got;                                                        \
>                                                                            \
>        while (sz > 0) {                                                    \
> @@ -343,7 +343,7 @@ int libxl_read_file_contents(libxl_ctx *
>                if (errno == EINTR) continue;                               \
>                if (!ctx) return errno;                                     \
>                LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR, "failed to " #rw " 
> %s%s%s", \
> -                           what?what:"", what?" from ":"", filename);     \
> +                           what?what:"", what?" from ":"", source);       \
>                return errno;                                               \
>            }                                                               \
>            if (got == 0) {                                                 \
> @@ -352,7 +352,7 @@ int libxl_read_file_contents(libxl_ctx *
>                       zero_is_eof                                          \
>                       ? "file/stream truncated reading %s%s%s"             \
>                       : "file/stream write returned 0! writing %s%s%s",    \
> -                     what?what:"", what?" from ":"", filename);           \
> +                     what?what:"", what?" from ":"", source);             \
>                return EPROTO;                                              \
>            }                                                               \
>            sz -= got;                                                      \
> diff -r 750b4dbab4b5 -r d555dd6614af tools/libxl/xl_cmdimpl.c
> --- a/tools/libxl/xl_cmdimpl.c  Tue May 15 15:45:55 2012 +0100
> +++ b/tools/libxl/xl_cmdimpl.c  Tue May 15 15:51:25 2012 +0100
> @@ -520,9 +520,9 @@ vcpp_out:
>      return rc;
>  }
> 
> -static void parse_config_data(const char *configfile_filename_report,
> -                              const char *configfile_data,
> -                              int configfile_len,
> +static void parse_config_data(const char *config_source,
> +                              const char *config_data,
> +                              int config_len,
>                                libxl_domain_config *d_config)
>  {
>      const char *buf;
> @@ -537,15 +537,15 @@ static void parse_config_data(const char
>      libxl_domain_create_info *c_info = &d_config->c_info;
>      libxl_domain_build_info *b_info = &d_config->b_info;
> 
> -    config= xlu_cfg_init(stderr, configfile_filename_report);
> +    config= xlu_cfg_init(stderr, config_source);
>      if (!config) {
>          fprintf(stderr, "Failed to allocate for configuration\n");
>          exit(1);
>      }
> 
> -    e= xlu_cfg_readdata(config, configfile_data, configfile_len);
> +    e= xlu_cfg_readdata(config, config_data, config_len);
>      if (e) {
> -        fprintf(stderr, "Failed to parse config file: %s\n", strerror(e));
> +        fprintf(stderr, "Failed to parse config: %s\n", strerror(e));
>          exit(1);
>      }
> 
> @@ -1524,6 +1524,8 @@ static int create_domain(struct domain_c
>      const char *config_file = dom_info->config_file;
>      const char *extra_config = dom_info->extra_config;
>      const char *restore_file = dom_info->restore_file;
> +    const char *config_source = NULL;
> +    const char *restore_source = NULL;
>      int migrate_fd = dom_info->migrate_fd;
> 
>      int i;
> @@ -1539,24 +1541,28 @@ static int create_domain(struct domain_c
>      pid_t child_console_pid = -1;
>      struct save_file_header hdr;
> 
> +    int restoring = (restore_file || (migrate_fd >= 0));
> +
>      libxl_domain_config_init(&d_config);
> 
> -    if (restore_file) {
> +    if (restoring) {
>          uint8_t *optdata_begin = 0;
>          const uint8_t *optdata_here = 0;
>          union { uint32_t u32; char b[4]; } u32buf;
>          uint32_t badflags;
> 
>          if (migrate_fd >= 0) {
> +            restore_source = "<incoming migration stream>";
>              restore_fd = migrate_fd;
>          } else {
> +            restore_source = restore_file;
>              restore_fd = open(restore_file, O_RDONLY);
>              rc = libxl_fd_set_cloexec(ctx, restore_fd, 1);
>              if (rc) return rc;
>          }
> 
>          CHK_ERRNO( libxl_read_exactly(ctx, restore_fd, &hdr,
> -                   sizeof(hdr), restore_file, "header") );
> +                   sizeof(hdr), restore_source, "header") );
>          if (memcmp(hdr.magic, savefileheader_magic, sizeof(hdr.magic))) {
>              fprintf(stderr, "File has wrong magic number -"
>                      " corrupt or for a different tool?\n");
> @@ -1569,7 +1575,7 @@ static int create_domain(struct domain_c
>          fprintf(stderr, "Loading new save file %s"
>                  " (new xl fmt info"
>                  " 0x%"PRIx32"/0x%"PRIx32"/%"PRIu32")\n",
> -                restore_file, hdr.mandatory_flags, hdr.optional_flags,
> +                restore_source, hdr.mandatory_flags, hdr.optional_flags,
>                  hdr.optional_data_len);
> 
>          badflags = hdr.mandatory_flags & ~( 0 /* none understood yet */ );
> @@ -1582,7 +1588,7 @@ static int create_domain(struct domain_c
>          if (hdr.optional_data_len) {
>              optdata_begin = xmalloc(hdr.optional_data_len);
>              CHK_ERRNO( libxl_read_exactly(ctx, restore_fd, optdata_begin,
> -                   hdr.optional_data_len, restore_file, "optdata") );
> +                   hdr.optional_data_len, restore_source, "optdata") );
>          }
> 
>  #define OPTDATA_LEFT  (hdr.optional_data_len - (optdata_here - 
> optdata_begin))
> @@ -1617,7 +1623,7 @@ static int create_domain(struct domain_c
>                                         &config_data, &config_len);
>          if (ret) { fprintf(stderr, "Failed to read config file: %s: %s\n",
>                             config_file, strerror(errno)); return ERROR_FAIL; 
> }
> -        if (!restore_file && extra_config && strlen(extra_config)) {
> +        if (!restoring && extra_config && strlen(extra_config)) {
>              if (config_len > INT_MAX - (strlen(extra_config) + 2 + 1)) {
>                  fprintf(stderr, "Failed to attach extra configration\n");
>                  return ERROR_FAIL;
> @@ -1632,19 +1638,20 @@ static int create_domain(struct domain_c
>              config_len += sprintf(config_data + config_len, "\n%s\n",
>                  extra_config);
>          }
> +        config_source=config_file;
>      } else {
>          if (!config_data) {
>              fprintf(stderr, "Config file not specified and"
>                      " none in save file\n");
>              return ERROR_INVAL;
>          }
> -        config_file = "<saved>";
> +        config_source = "<saved>";
>      }
> 
>      if (!dom_info->quiet)
> -        printf("Parsing config file %s\n", config_file);
> -
> -    parse_config_data(config_file, config_data, config_len, &d_config);
> +        printf("Parsing config from %s\n", config_source);
> +
> +    parse_config_data(config_source, config_data, config_len, &d_config);
> 
>      if (migrate_fd >= 0) {
>          if (d_config.c_info.name) {
> @@ -1698,7 +1705,7 @@ start:
>          autoconnect_console_how = 0;
>      }
> 
> -    if ( restore_file ) {
> +    if ( restoring ) {
>          ret = libxl_domain_create_restore(ctx, &d_config,
>                                            &domid, restore_fd,
>                                            0, autoconnect_console_how);
> @@ -2559,7 +2566,7 @@ static void list_domains_details(const l
>  {
>      libxl_domain_config d_config;
> 
> -    char *config_file;
> +    char *config_source;
>      uint8_t *data;
>      int i, len, rc;
> 
> @@ -2570,13 +2577,13 @@ static void list_domains_details(const l
>          rc = libxl_userdata_retrieve(ctx, info[i].domid, "xl", &data, &len);
>          if (rc)
>              continue;
> -        CHK_ERRNO(asprintf(&config_file, "<domid %d data>", info[i].domid));
> +        CHK_ERRNO(asprintf(&config_source, "<domid %d data>", 
> info[i].domid));
>          libxl_domain_config_init(&d_config);
> -        parse_config_data(config_file, (char *)data, len, &d_config);
> +        parse_config_data(config_source, (char *)data, len, &d_config);
>          printf_info(default_output_format, info[i].domid, &d_config);
>          libxl_domain_config_dispose(&d_config);
>          free(data);
> -        free(config_file);
> +        free(config_source);
>      }
>  }
> 
> @@ -2679,7 +2686,7 @@ static void save_domain_core_begin(const
>      }
>  }
> 
> -static void save_domain_core_writeconfig(int fd, const char *filename,
> +static void save_domain_core_writeconfig(int fd, const char *source,
>                                    const uint8_t *config_data, int config_len)
>  {
>      struct save_file_header hdr;
> @@ -2708,13 +2715,13 @@ static void save_domain_core_writeconfig
>      /* that's the optional data */
> 
>      CHK_ERRNO( libxl_write_exactly(ctx, fd,
> -        &hdr, sizeof(hdr), filename, "header") );
> +        &hdr, sizeof(hdr), source, "header") );
>      CHK_ERRNO( libxl_write_exactly(ctx, fd,
> -        optdata_begin, hdr.optional_data_len, filename, "header") );
> +        optdata_begin, hdr.optional_data_len, source, "header") );
> 
>      fprintf(stderr, "Saving to %s new xl format (info"
>              " 0x%"PRIx32"/0x%"PRIx32"/%"PRIu32")\n",
> -            filename, hdr.mandatory_flags, hdr.optional_flags,
> +            source, hdr.mandatory_flags, hdr.optional_flags,
>              hdr.optional_data_len);
>  }
> 
> @@ -3039,7 +3046,6 @@ static void migrate_receive(int debug, i
>      dom_info.daemonize = daemonize;
>      dom_info.monitor = monitor;
>      dom_info.paused = 1;
> -    dom_info.restore_file = "incoming migration stream";
>      dom_info.migrate_fd = 0; /* stdin */
>      dom_info.migration_domname_r = &migration_domname;
>      dom_info.incr_generationid = 0;
> 
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@xxxxxxxxxxxxx
> http://lists.xen.org/xen-devel



_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel


 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.