From ead29c2a366eb2c5006d7da64963ce5f60deb684 Mon Sep 17 00:00:00 2001 From: Roman Perepelitsa Date: Fri, 23 Oct 2020 11:42:30 +0200 Subject: Fix a race condition in zf_mkdir -p If ~/foo does not exist and `zf_mkdir -p zf_mkdir -p` is executed concurrently in multiple shells, it was possible prior to this patch for the command to fail with EEXIST. --- ChangeLog | 5 +++++ Src/Modules/files.c | 28 +++++++++++++++++++--------- 2 files changed, 24 insertions(+), 9 deletions(-) diff --git a/ChangeLog b/ChangeLog index c6569edb7..5650bdd68 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,8 @@ +2020-10-18 Roman Perepelitsa + + * 47476: Src/Modules/files.c: Fix a race condition in zf_mkdir -p + (based on the patch by Matthew Martin in workers/47436) + 2020-10-18 Axel Beckert * 47468: Doc/Zsh/contrib.yo: Fix typo 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; } -- cgit 1.4.1