zsh-workers
 help / color / mirror / code / Atom feed
From: Roman Perepelitsa <roman.perepelitsa@gmail.com>
To: Bart Schaefer <schaefer@brasslantern.com>
Cc: Zsh hackers list <zsh-workers@zsh.org>
Subject: Re: [patch] Avoid race in zf_mkdir
Date: Thu, 22 Oct 2020 15:30:59 +0200	[thread overview]
Message-ID: <CAN=4vMr+57w69nEmmmFi+gbXxfTDwws-T0AQpDdnOS0fuKmqaA@mail.gmail.com> (raw)
In-Reply-To: <CAN=4vMqxasXspkeObObB0tgwnEidSkL8oJPeU_uMaS2kwUdKig@mail.gmail.com>

[-- Attachment #1: Type: text/plain, Size: 402 bytes --]

On Thu, Oct 15, 2020 at 5:36 PM Roman Perepelitsa
<roman.perepelitsa@gmail.com> wrote:
>
> On Thu, Oct 15, 2020 at 5:29 PM Bart Schaefer <schaefer@brasslantern.com> wrote:
> >
> > - I'm paranoid about tests like "while (n--)", I prefer "while (n-- > 0)".
>
> Changed. (Not publishing the new patch yet. Will do so once this
> discussion concludes.)

Here's the fixed version. Will commit soon.

Roman.

[-- Attachment #2: mkdir-patch-v3.txt --]
[-- Type: text/plain, Size: 932 bytes --]

diff --git a/Src/Modules/files.c b/Src/Modules/files.c
index 6d20e38a8..7ebacba6c 100644
--- a/Src/Modules/files.c
+++ b/Src/Modules/files.c
@@ -122,19 +122,29 @@ domkdir(char *nam, char *path, mode_t mode, int p)
 {
     int err;
     mode_t oumask;
+    struct stat st;
+    int n = 8;
     char const *rpath = unmeta(path);
 
-    if(p) {
-	struct stat st;
-
-	if(!stat(rpath, &st) && S_ISDIR(st.st_mode))
+    while(n-- > 0) {
+	oumask = umask(0);
+	err = mkdir(rpath, mode) ? errno : 0;
+	umask(oumask);
+	if (!err)
+	    return 0;
+	if(!p || err != EEXIST)
+	    break;
+	if(stat(rpath, &st)) {
+	    if(errno == ENOENT)
+		continue;
+	    err = errno;
+	    break;
+	}
+	if(S_ISDIR(st.st_mode))
 	    return 0;
+	break;
     }
-    oumask = umask(0);
-    err = mkdir(rpath, mode) ? errno : 0;
-    umask(oumask);
-    if(!err)
-	return 0;
+
     zwarnnam(nam, "cannot make directory `%s': %e", path, err);
     return 1;
 }

  parent reply	other threads:[~2020-10-22 13:31 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-09 20:07 Matthew Martin
2020-10-09 20:24 ` Bart Schaefer
2020-10-09 20:35   ` Roman Perepelitsa
2020-10-09 20:47     ` Bart Schaefer
2020-10-09 20:53       ` Matthew Martin
2020-10-09 21:22         ` Roman Perepelitsa
2020-10-09 21:27           ` Bart Schaefer
2020-10-10 11:50             ` Roman Perepelitsa
2020-10-15 10:01               ` Roman Perepelitsa
2020-10-15 15:29                 ` Bart Schaefer
2020-10-15 15:36                   ` Roman Perepelitsa
2020-10-15 16:47                     ` Bart Schaefer
2020-10-22 13:30                     ` Roman Perepelitsa [this message]
2020-10-09 21:40           ` Matthew Martin

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to='CAN=4vMr+57w69nEmmmFi+gbXxfTDwws-T0AQpDdnOS0fuKmqaA@mail.gmail.com' \
    --to=roman.perepelitsa@gmail.com \
    --cc=schaefer@brasslantern.com \
    --cc=zsh-workers@zsh.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
Code repositories for project(s) associated with this public inbox

	https://git.vuxu.org/mirror/zsh/

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).