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[PATCH v3 03/17] safe_create_leading_directories(): add explicit "slash" pointer

From
Michael Haggerty <mhagger@alum.mit.edu>
Date
Jan 18, 2014, 22:48 UTC
Message-ID
<1390085341-2553-4-git-send-email-mhagger@alum.mit.edu>
In-Reply-To
<1390085341-2553-1-git-send-email-mhagger@alum.mit.edu>

Keep track of the position of the slash character independently of "pos", thereby making the purpose of each variable clearer and working towards other upcoming changes.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
---
 sha1_file.c | 20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)
diff --git a/sha1_file.c b/sha1_file.c
index d8647c7..88b8d8c 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -111,19 +111,21 @@ int safe_create_leading_directories(char *path)
 
 	while (pos) {
 		struct stat st;
+		char *slash = strchr(pos, '/');
 
-		pos = strchr(pos, '/');
-		if (!pos)
+		if (!slash)
 			break;
-		while (*++pos == '/')
-			;
+		while (*(slash + 1) == '/')
+			slash++;
+		pos = slash + 1;
 		if (!*pos)
 			break;
-		*--pos = '\0';
+
+		*slash = '\0';
 		if (!stat(path, &st)) {
 			/* path exists */
 			if (!S_ISDIR(st.st_mode)) {
-				*pos = '/';
+				*slash = '/';
 				return -3;
 			}
 		} else if (mkdir(path, 0777)) {
@@ -131,14 +133,14 @@ int safe_create_leading_directories(char *path)
 			    !stat(path, &st) && S_ISDIR(st.st_mode)) {
 				; /* somebody created it since we checked */
 			} else {
-				*pos = '/';
+				*slash = '/';
 				return -1;
 			}
 		} else if (adjust_shared_perm(path)) {
-			*pos = '/';
+			*slash = '/';
 			return -2;
 		}
-		*pos++ = '/';
+		*slash = '/';
 	}
 	return 0;
 }
-- 
1.8.5.2
Previous: Michael HaggertyNext: Michael Haggerty
Message 4 of 18 in “Fix some mkdir/rmdir races”
  1. 00/17 Fix some mkdir/rmdir racesMichael Haggerty, Jan 18, 2014
  2. 01/17 safe_create_leading_directories(): fix format of "if" chainingMichael Haggerty, Jan 18, 2014
  3. 02/17 safe_create_leading_directories(): reduce scope of local variableMichael Haggerty, Jan 18, 2014
  4. 03/17 safe_create_leading_directories(): add explicit "slash" pointerMichael Haggerty, Jan 18, 2014
  5. 04/17 safe_create_leading_directories(): rename local variableMichael Haggerty, Jan 18, 2014
  6. 05/17 safe_create_leading_directories(): split on first of multiple slashesMichael Haggerty, Jan 18, 2014
  7. 06/17 safe_create_leading_directories(): always restore slash at end of loopMichael Haggerty, Jan 18, 2014
  8. 07/17 safe_create_leading_directories(): introduce enum for return valuesMichael Haggerty, Jan 18, 2014
  9. 08/17 cmd_init_db(): when creating directories, handle errors conservativelyMichael Haggerty, Jan 18, 2014
  10. 09/17 safe_create_leading_directories(): add new error value SCLD_VANISHEDMichael Haggerty, Jan 18, 2014
  11. 10/17 lock_ref_sha1_basic(): on SCLD_VANISHED, retryMichael Haggerty, Jan 18, 2014
  12. 11/17 lock_ref_sha1_basic(): if locking fails with ENOENT, retryMichael Haggerty, Jan 18, 2014
  13. 12/17 remove_dir_recurse(): tighten condition for removing unreadable dirMichael Haggerty, Jan 18, 2014
  14. 13/17 remove_dir_recurse(): handle disappearing files and directoriesMichael Haggerty, Jan 18, 2014
  15. 14/17 rename_ref(): extract function rename_tmp_log()Michael Haggerty, Jan 18, 2014
  16. 15/17 rename_tmp_log(): handle a possible mkdir/rmdir raceMichael Haggerty, Jan 18, 2014
  17. 16/17 rename_tmp_log(): limit the number of remote_empty_directories() attemptsMichael Haggerty, Jan 18, 2014
  18. 17/17 rename_tmp_log(): on SCLD_VANISHED, retryMichael Haggerty, Jan 18, 2014

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