[PATCH v3 1/2] worktree: fix worktree add race.
- From
Michal Suchanek <msuchanek@suse.de>
- Date
- Feb 20, 2019, 16:16 UTC
- Message-ID
- <e134801d570d0a0c85424eb80b41893f4d8383ca.1550679076.git.msuchanek@suse.de>
- In-Reply-To
- <cover.1550508544.git.msuchanek@suse.de>
Git runs a stat loop to find a worktree name that's available and then does mkdir on the found name. Turn it to mkdir loop to avoid another invocation of worktree add finding the same free name and creating the directory first.
Signed-off-by: Michal Suchanek <msuchanek@suse.de> --- v2: - simplify loop exit condition - exit early if the mkdir fails for reason other than already present worktree - make counter unsigned --- builtin/worktree.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-)
diff --git a/builtin/worktree.c b/builtin/worktree.c index 3f9907fcc994..85a604cfe98c 100644 --- a/builtin/worktree.c +++ b/builtin/worktree.c @@ -268,10 +268,10 @@ static int add_worktree(const char *path, const char *refname, struct strbuf sb_git = STRBUF_INIT, sb_repo = STRBUF_INIT; struct strbuf sb = STRBUF_INIT; const char *name; - struct stat st; struct child_process cp = CHILD_PROCESS_INIT; struct argv_array child_env = ARGV_ARRAY_INIT; - int counter = 0, len, ret; + unsigned int counter = 0; + int len, ret; struct strbuf symref = STRBUF_INIT; struct commit *commit = NULL; int is_branch = 0; @@ -295,8 +295,12 @@ static int add_worktree(const char *path, const char *refname, if (safe_create_leading_directories_const(sb_repo.buf)) die_errno(_("could not create leading directories of '%s'"), sb_repo.buf); - while (!stat(sb_repo.buf, &st)) { + + while (mkdir(sb_repo.buf, 0777)) { counter++; + if ((errno != EEXIST) || !counter /* overflow */) + die_errno(_("could not create directory of '%s'"), + sb_repo.buf); strbuf_setlen(&sb_repo, len); strbuf_addf(&sb_repo, "%d", counter); } @@ -306,8 +310,6 @@ static int add_worktree(const char *path, const char *refname, atexit(remove_junk); sigchain_push_common(remove_junk_on_signal); - if (mkdir(sb_repo.buf, 0777)) - die_errno(_("could not create directory of '%s'"), sb_repo.buf); junk_git_dir = xstrdup(sb_repo.buf); is_junk = 1;
-- 2.20.1