Attachment 117691 Details for Bug 91000 – walk bottom up instead of top down

[patch] walk bottom up instead of top down

0001-mkdir_p-support-non-readable-parent-directories-FDO-.patch (text/plain), 2.71 KB, created by Patrick Ohly on 2015-08-14 16:47:24 UTC

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Creator: Patrick Ohly

Created: 2015-08-14 16:47:24 UTC

Size: 2.71 KB

patch

obsolete

>From bbfe468290a81b2235e5cf669a5afb8605b609ed Mon Sep 17 00:00:00 2001
>From: Patrick Ohly <patrick.ohly@intel.com>
>Date: Fri, 14 Aug 2015 18:42:47 +0200
>Subject: [PATCH] mkdir_p: support non-readable parent directories (FDO #91000)
>
>The previous mkdir_p() walked down top to bottom and checked each path
>entry as it went along. That approach failed unnecessarily when some
>existing parent directory could not be read (non-readable /home, for
>example).
>
>The new version tries to create the lowest directories first
>(brute-force) and only walks up when that is necessary to avoid an
>ENOENT.
>---
> src/syncevo/util.cpp | 45 ++++++++++++++++++++++++++-------------------
> 1 file changed, 26 insertions(+), 19 deletions(-)
>
>diff --git a/src/syncevo/util.cpp b/src/syncevo/util.cpp
>index fe4471b..a5ee2fe 100644
>--- a/src/syncevo/util.cpp
>+++ b/src/syncevo/util.cpp
>@@ -140,28 +140,35 @@ bool relToAbs(string &path)
> 
> void mkdir_p(const string &path)
> {
>-    boost::scoped_array<char> dirs(new char[path.size() + 1]);
>-    char *curr = dirs.get();
>-    strcpy(curr, path.c_str());
>-    do {
>-        char *nextdir = strchr(curr, '/');
>-        if (nextdir) {
>-            *nextdir = 0;
>-            nextdir++;
>-        }
>-        if (*curr) {
>-            if (access(dirs.get(),
>-                       nextdir ? (R_OK|X_OK) : (R_OK|X_OK|W_OK)) &&
>-                (errno != ENOENT ||
>-                 mkdir(dirs.get(), 0700))) {
>-                Exception::throwError(SE_HERE, string(dirs.get()), errno);
>+    // Try creating the requested directory. If that fails with ENOENT,
>+    // try creating the parent first, then retry. The advantage over
>+    // walking from top to bottom is that the we do not need read access
>+    // to the parent directories (for example, /home is only a+x and
>+    // not a+rx - FDO #91000).
>+    int res = mkdir(path.c_str(), 0700);
>+    if (res) {
>+        switch (errno) {
>+        case EEXIST:
>+            // Assume that it is a directory. If not, using it as a directory
>+            // will fail elsewhere.
>+            break;
>+        case ENOENT: {
>+            // Need to create parent first.
>+            std::string::size_type pos = path.rfind('/');
>+            if (pos != std::string::npos) {
>+                mkdir_p(path.substr(0, pos));
>+            }
>+            res = mkdir(path.c_str(), 0700);
>+            if (res) {
>+                Exception::throwError(SE_HERE, path, errno);
>             }
>+            break;
>         }
>-        if (nextdir) {
>-            nextdir[-1] = '/';
>+        default:
>+            Exception::throwError(SE_HERE, path, errno);
>+            break;
>         }
>-        curr = nextdir;
>-    } while (curr);
>+    }
> }
> 
> void rm_r(const string &path, boost::function<bool (const string &,
>-- 
>2.1.4
>

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