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[PATCH 6/3] Export thread-safe version of 'has_symlink_leading_path()'

From
Linus Torvalds <torvalds@linux-foundation.org>
Date
Jul 9, 2009, 20:48 UTC
Message-ID
<alpine.LFD.2.01.0907091347080.3352@localhost.localdomain>
In-Reply-To
<alpine.LFD.2.01.0907091344530.3352@localhost.localdomain>
From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Thu, 9 Jul 2009 13:35:31 -0700
Subject: [PATCH 6/3] Export thread-safe version of 'has_symlink_leading_path()'

The threaded index preloading will want it, so that it can avoid locking by simply using a per-thread symlink/directory cache.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
This just exposes a thread-safe version of the symlink checking by 
allowing a caller to pass in its own local 'struct cache_def' to the 
function.
No users of this yet, but the next step is trivial and obvious..
 cache.h    |   10 ++++++++++
 symlinks.c |   21 ++++++++++-----------
 2 files changed, 20 insertions(+), 11 deletions(-)
diff --git a/cache.h b/cache.h
index 871c984..f1e5ede 100644
--- a/cache.h
+++ b/cache.h
@@ -744,7 +744,17 @@ struct checkout {
 };
 
 extern int checkout_entry(struct cache_entry *ce, const struct checkout *state, char *topath);
+
+struct cache_def {
+	char path[PATH_MAX + 1];
+	int len;
+	int flags;
+	int track_flags;
+	int prefix_len_stat_func;
+};
+
 extern int has_symlink_leading_path(const char *name, int len);
+extern int threaded_has_symlink_leading_path(struct cache_def *, const char *, int);
 extern int has_symlink_or_noent_leading_path(const char *name, int len);
 extern int has_dirs_only_path(const char *name, int len, int prefix_len);
 extern void invalidate_lstat_cache(const char *name, int len);
diff --git a/symlinks.c b/symlinks.c
index 08ad353..4bdded3 100644
--- a/symlinks.c
+++ b/symlinks.c
@@ -32,13 +32,7 @@ static int longest_path_match(const char *name_a, int len_a,
 	return match_len;
 }
 
-static struct cache_def {
-	char path[PATH_MAX + 1];
-	int len;
-	int flags;
-	int track_flags;
-	int prefix_len_stat_func;
-} default_cache;
+static struct cache_def default_cache;
 
 static inline void reset_lstat_cache(struct cache_def *cache)
 {
@@ -217,12 +211,17 @@ void clear_lstat_cache(void)
 /*
  * Return non-zero if path 'name' has a leading symlink component
  */
+int threaded_has_symlink_leading_path(struct cache_def *cache, const char *name, int len)
+{
+	return lstat_cache(cache, name, len, FL_SYMLINK|FL_DIR, USE_ONLY_LSTAT) & FL_SYMLINK;
+}
+
+/*
+ * Return non-zero if path 'name' has a leading symlink component
+ */
 int has_symlink_leading_path(const char *name, int len)
 {
-	struct cache_def *cache = &default_cache;	/* FIXME */
-	return lstat_cache(cache, name, len,
-			   FL_SYMLINK|FL_DIR, USE_ONLY_LSTAT) &
-		FL_SYMLINK;
+	return threaded_has_symlink_leading_path(&default_cache, name, len);
 }
 
 /*
-- 
1.6.3.3.415.ga8877
Previous: Linus TorvaldsNext: Linus Torvalds
Message 19 of 39 in “Too many 'stat' calls by git-status on Windows”
  1. Dmitry PotapovJul 7, 2009
  2. Ramsay JonesJul 8, 2009
  3. Linus TorvaldsJul 9, 2009
  4. Linus TorvaldsJul 9, 2009
  5. 1/3 Add 'fill_directory()' helper function for directory traversalLinus Torvalds, Jul 9, 2009
  6. 2/3 Simplify read_directory[_recursive]() argumentsLinus Torvalds, Jul 9, 2009
  7. 3/3 Avoid doing extra 'lstat()'s for d_type if we have an up-to-date cache entryLinus Torvalds, Jul 9, 2009
  8. Junio C HamanoJul 9, 2009
  9. Linus TorvaldsJul 9, 2009
  10. Junio C HamanoJul 9, 2009
  11. Linus TorvaldsJul 9, 2009
  12. Junio C HamanoJul 9, 2009
  13. Linus TorvaldsJul 9, 2009
  14. Linus TorvaldsJul 9, 2009
  15. Junio C HamanoJul 9, 2009
  16. Linus TorvaldsJul 9, 2009
  17. 4/3 Avoid using 'lstat()' to figure out directoriesLinus Torvalds, Jul 9, 2009
  18. 5/3 Prepare symlink caching for thread-safetyLinus Torvalds, Jul 9, 2009
  19. 6/3 Export thread-safe version of 'has_symlink_leading_path()'Linus Torvalds, Jul 9, 2009
  20. 7/3 Make index preloading check the whole path to the fileLinus Torvalds, Jul 9, 2009
  21. Linus TorvaldsJul 9, 2009
  22. Junio C HamanoJul 10, 2009
  23. Linus TorvaldsJul 10, 2009
  24. Linus TorvaldsJul 10, 2009
  25. Junio C HamanoJul 11, 2009
  26. Linus TorvaldsJul 11, 2009
  27. Kjetil BarvikJul 12, 2009
  28. Junio C HamanoJul 12, 2009
  29. Paolo BonziniJul 9, 2009
  30. Linus TorvaldsJul 9, 2009
  31. Linus TorvaldsJul 9, 2009
  32. Linus TorvaldsJul 10, 2009
  33. Junio C HamanoJul 9, 2009
  34. Dmitry PotapovJul 9, 2009
  35. Eric BlakeJul 9, 2009
  36. Dmitry PotapovJul 9, 2009
  37. Dmitry PotapovJul 10, 2009
  38. Dmitry PotapovJul 9, 2009
  39. Dmitry PotapovJul 9, 2009

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