Add --no-hard-links option to localedef (Bug 23923)
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Message ID 751dddf5-84fa-190f-19ff-073c267822a9@redhat.com
State New
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  • Add --no-hard-links option to localedef (Bug 23923)
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Commit Message

Carlos O'Donell Nov. 26, 2018, 3:21 p.m. UTC
[PATCH] Add --no-hard-links option to localedef (bug 23923)

Downstream distributions need consistent sets of hardlinks in
order for rpm to operate effectively. This means that even if
locales are built with a high level of parallelism that the
resulting files need to have consistent hardlink counts. The only
way to achieve this is with a post-install hardlink pass using a
program like 'hardklink' (shipped in Fedora).

If the downstream distro wants to post-process the hardlinks then
the time spent in localedef looking up sibling directories and
processing hardlinks is wasted effort.

To optimize the build and install pass we add a --no-hard-links
option to localedef to avoid doing the hardlink optimziation for
size.

Tested on x86_64 with 'make localedata/install-locale-files'
before and after. Without the patch we have files with 70+
hardlink counts. After the patch and running with --no-hard-links
all link counts are 1.

Signed-off-by: Carlos O'Donell <carlos@redhat.com>
---
 ChangeLog                   | 10 ++++++++++
 locale/programs/localedef.c | 10 ++++++++++
 locale/programs/localedef.h |  1 +
 locale/programs/locfile.c   | 16 +++++++++++++---
 4 files changed, 34 insertions(+), 3 deletions(-)

Comments

Florian Weimer Nov. 26, 2018, 4:05 p.m. UTC | #1
* Carlos O'Donell:

> +	[BZ #23923]
> +	* locale/programs/localedef.c: Declare boolean hard_links default true.
> +	(options): Add --no-hard-links option.
> +	(parse_opt): Add OPT_NO_HARD_LINKS case and set hard_links to false.
> +	* locale/programs/localedef.h: Declare prototype for hard_links.
> +	* locale/programs/locfile.c (write_locale_data): Don't use hard
> +	links if hard_links is false.

Looks reasonable to me.

This will need a makefile update, so that we can use this from “make
install-locales”.

Thanks,
Florian
Joseph Myers Nov. 26, 2018, 4:58 p.m. UTC | #2
On Mon, 26 Nov 2018, Carlos O'Donell wrote:

> If the downstream distro wants to post-process the hardlinks then
> the time spent in localedef looking up sibling directories and
> processing hardlinks is wasted effort.

Do you have figures for the time involved?

> +     other locales, and see if we can reuse it, to save disk space.
> +     If the user specified --no-hard-link to localedef then hard_links is
> +     false, other_paths remains NULL and we skip the optimization below.
> +     The use of --no-hard-link is distribution specific since some distros
> +     have post-processing hard-link steps and so doing this here is a waste
> +     of time.  */

This should refer to --no-hard-links, not --no-hard-link (twice).

This is not a review of other aspects of the patch (but I approve of 
improving determinism of the locale build, and also have such a hard-link 
post-processing step at Mentor).

Patch
diff mbox series

diff --git a/ChangeLog b/ChangeLog
index 03887874a2..b9bce8bc8e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@ 
+2018-11-26  Carlos O'Donell  <carlos@redhat.com>
+
+	[BZ #23923]
+	* locale/programs/localedef.c: Declare boolean hard_links default true.
+	(options): Add --no-hard-links option.
+	(parse_opt): Add OPT_NO_HARD_LINKS case and set hard_links to false.
+	* locale/programs/localedef.h: Declare prototype for hard_links.
+	* locale/programs/locfile.c (write_locale_data): Don't use hard
+	links if hard_links is false.
+
 2018-11-26  Carlos O'Donell  <carlos@redhat.com>
 
 	* scripts/abilist.awk: Handle .tdata. Error for unknown combinations.
diff --git a/locale/programs/localedef.c b/locale/programs/localedef.c
index d718d2e9f4..6c4936be6b 100644
--- a/locale/programs/localedef.c
+++ b/locale/programs/localedef.c
@@ -85,6 +85,9 @@  static bool replace_archive;
 /* If true list archive content.  */
 static bool list_archive;
 
+/* If true create hard links to other locales (default).  */
+bool hard_links = true;
+
 /* Maximum number of retries when opening the locale archive.  */
 int max_locarchive_open_retry = 10;
 
@@ -105,6 +108,7 @@  void (*argp_program_version_hook) (FILE *, struct argp_state *) = print_version;
 #define OPT_BIG_ENDIAN 401
 #define OPT_NO_WARN 402
 #define OPT_WARN 403
+#define OPT_NO_HARD_LINKS 404
 
 /* Definitions of arguments for argp functions.  */
 static const struct argp_option options[] =
@@ -120,6 +124,8 @@  static const struct argp_option options[] =
   { NULL, 0, NULL, 0, N_("Output control:") },
   { "force", 'c', NULL, 0,
     N_("Create output even if warning messages were issued") },
+  { "no-hard-links", OPT_NO_HARD_LINKS, NULL, 0,
+    N_("Do not create hard links between installed locales") },
   { "prefix", OPT_PREFIX, N_("PATH"), 0, N_("Optional output file prefix") },
   { "posix", OPT_POSIX, NULL, 0, N_("Strictly conform to POSIX") },
   { "quiet", OPT_QUIET, NULL, 0,
@@ -389,6 +395,10 @@  parse_opt (int key, char *arg, struct argp_state *state)
       /* Enable the warnings.  */
       set_warnings (arg, true);
       break;
+    case OPT_NO_HARD_LINKS:
+      /* Do not hard link to other locales.  */
+      hard_links = false;
+      break;
     case 'c':
       force_output = 1;
       break;
diff --git a/locale/programs/localedef.h b/locale/programs/localedef.h
index 0083faceab..e2b39e78f3 100644
--- a/locale/programs/localedef.h
+++ b/locale/programs/localedef.h
@@ -118,6 +118,7 @@  extern const char *repertoire_global;
 extern int max_locarchive_open_retry;
 extern bool no_archive;
 extern const char *alias_file;
+extern bool hard_links;
 
 
 /* Prototypes for a few program-wide used functions.  */
diff --git a/locale/programs/locfile.c b/locale/programs/locfile.c
index 32e5f761f2..14c743373d 100644
--- a/locale/programs/locfile.c
+++ b/locale/programs/locfile.c
@@ -702,7 +702,7 @@  write_locale_data (const char *output_path, int catidx, const char *category,
   size_t cnt, step, maxiov;
   int fd;
   char *fname;
-  const char **other_paths;
+  const char **other_paths = NULL;
   uint32_t header[2];
   size_t n_elem;
   struct iovec vec[3];
@@ -828,8 +828,18 @@  failure while writing data for category `%s'"), category);
   close (fd);
 
   /* Compare the file with the locale data files for the same category in
-     other locales, and see if we can reuse it, to save disk space.  */
-  other_paths = siblings (output_path);
+     other locales, and see if we can reuse it, to save disk space.
+     If the user specified --no-hard-link to localedef then hard_links is
+     false, other_paths remains NULL and we skip the optimization below.
+     The use of --no-hard-link is distribution specific since some distros
+     have post-processing hard-link steps and so doing this here is a waste
+     of time.  */
+  if (hard_links)
+    other_paths = siblings (output_path);
+
+  /* If there are other paths, then walk the sibling paths looking for
+     files with the same content so we can hard link and reduce disk
+     space usage.  */
   if (other_paths != NULL)
     {
       struct stat64 fname_stat;