diff options
| -rw-r--r-- | builtin/init-db.c | 9 | ||||
| -rw-r--r-- | cache.h | 25 | ||||
| -rw-r--r-- | dir.c | 27 | ||||
| -rw-r--r-- | merge-recursive.c | 2 | ||||
| -rw-r--r-- | refs.c | 92 | ||||
| -rw-r--r-- | sha1_file.c | 67 |
6 files changed, 155 insertions, 67 deletions
diff --git a/builtin/init-db.c b/builtin/init-db.c index b3f03cf0d..c7c76bbf2 100644 --- a/builtin/init-db.c +++ b/builtin/init-db.c @@ -515,13 +515,14 @@ int cmd_init_db(int argc, const char **argv, const char *prefix) saved = shared_repository; shared_repository = 0; switch (safe_create_leading_directories_const(argv[0])) { - case -3: + case SCLD_OK: + case SCLD_PERMS: + break; + case SCLD_EXISTS: errno = EEXIST; /* fallthru */ - case -1: - die_errno(_("cannot mkdir %s"), argv[0]); - break; default: + die_errno(_("cannot mkdir %s"), argv[0]); break; } shared_repository = saved; @@ -737,8 +737,29 @@ enum sharedrepo { }; int git_config_perm(const char *var, const char *value); int adjust_shared_perm(const char *path); -int safe_create_leading_directories(char *path); -int safe_create_leading_directories_const(const char *path); + +/* + * Create the directory containing the named path, using care to be + * somewhat safe against races. Return one of the scld_error values + * to indicate success/failure. + * + * SCLD_VANISHED indicates that one of the ancestor directories of the + * path existed at one point during the function call and then + * suddenly vanished, probably because another process pruned the + * directory while we were working. To be robust against this kind of + * race, callers might want to try invoking the function again when it + * returns SCLD_VANISHED. + */ +enum scld_error { + SCLD_OK = 0, + SCLD_FAILED = -1, + SCLD_PERMS = -2, + SCLD_EXISTS = -3, + SCLD_VANISHED = -4 +}; +enum scld_error safe_create_leading_directories(char *path); +enum scld_error safe_create_leading_directories_const(const char *path); + int mkdir_in_gitdir(const char *path); extern void home_config_paths(char **global, char **xdg, char *file); extern char *expand_user_path(const char *path); @@ -1511,8 +1511,13 @@ static int remove_dir_recurse(struct strbuf *path, int flag, int *kept_up) flag &= ~REMOVE_DIR_KEEP_TOPLEVEL; dir = opendir(path->buf); if (!dir) { - /* an empty dir could be removed even if it is unreadble */ - if (!keep_toplevel) + if (errno == ENOENT) + return keep_toplevel ? -1 : 0; + else if (errno == EACCES && !keep_toplevel) + /* + * An empty dir could be removable even if it + * is unreadable: + */ return rmdir(path->buf); else return -1; @@ -1528,13 +1533,21 @@ static int remove_dir_recurse(struct strbuf *path, int flag, int *kept_up) strbuf_setlen(path, len); strbuf_addstr(path, e->d_name); - if (lstat(path->buf, &st)) - ; /* fall thru */ - else if (S_ISDIR(st.st_mode)) { + if (lstat(path->buf, &st)) { + if (errno == ENOENT) + /* + * file disappeared, which is what we + * wanted anyway + */ + continue; + /* fall thru */ + } else if (S_ISDIR(st.st_mode)) { if (!remove_dir_recurse(path, flag, &kept_down)) continue; /* happy */ - } else if (!only_empty && !unlink(path->buf)) + } else if (!only_empty && + (!unlink(path->buf) || errno == ENOENT)) { continue; /* happy, too */ + } /* path too long, stat fails, or non-directory still exists */ ret = -1; @@ -1544,7 +1557,7 @@ static int remove_dir_recurse(struct strbuf *path, int flag, int *kept_up) strbuf_setlen(path, original_len); if (!ret && !keep_toplevel && !kept_down) - ret = rmdir(path->buf); + ret = (!rmdir(path->buf) || errno == ENOENT) ? 0 : -1; else if (kept_up) /* * report the uplevel that it is not an error that we diff --git a/merge-recursive.c b/merge-recursive.c index a18bd15dd..8400a8e93 100644 --- a/merge-recursive.c +++ b/merge-recursive.c @@ -693,7 +693,7 @@ static int make_room_for_path(struct merge_options *o, const char *path) /* Make sure leading directories are created */ status = safe_create_leading_directories_const(path); if (status) { - if (status == -3) { + if (status == SCLD_EXISTS) { /* something else exists */ error(msg, path, _(": perhaps a D/F conflict?")); return -1; @@ -2039,6 +2039,7 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname, int type, lflags; int mustexist = (old_sha1 && !is_null_sha1(old_sha1)); int missing = 0; + int attempts_remaining = 3; lock = xcalloc(1, sizeof(struct ref_lock)); lock->lock_fd = -1; @@ -2080,7 +2081,7 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname, lock->lk = xcalloc(1, sizeof(struct lock_file)); - lflags = LOCK_DIE_ON_ERROR; + lflags = 0; if (flags & REF_NODEREF) { refname = orig_refname; lflags |= LOCK_NODEREF; @@ -2093,13 +2094,32 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname, if ((flags & REF_NODEREF) && (type & REF_ISSYMREF)) lock->force_write = 1; - if (safe_create_leading_directories(ref_file)) { + retry: + switch (safe_create_leading_directories(ref_file)) { + case SCLD_OK: + break; /* success */ + case SCLD_VANISHED: + if (--attempts_remaining > 0) + goto retry; + /* fall through */ + default: last_errno = errno; error("unable to create directory for %s", ref_file); goto error_return; } lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, lflags); + if (lock->lock_fd < 0) { + if (errno == ENOENT && --attempts_remaining > 0) + /* + * Maybe somebody just deleted one of the + * directories leading to ref_file. Try + * again: + */ + goto retry; + else + unable_to_lock_index_die(ref_file, errno); + } return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock; error_return: @@ -2508,6 +2528,51 @@ int delete_ref(const char *refname, const unsigned char *sha1, int delopt) */ #define TMP_RENAMED_LOG "logs/refs/.tmp-renamed-log" +static int rename_tmp_log(const char *newrefname) +{ + int attempts_remaining = 4; + + retry: + switch (safe_create_leading_directories(git_path("logs/%s", newrefname))) { + case SCLD_OK: + break; /* success */ + case SCLD_VANISHED: + if (--attempts_remaining > 0) + goto retry; + /* fall through */ + default: + error("unable to create directory for %s", newrefname); + return -1; + } + + if (rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", newrefname))) { + if ((errno==EISDIR || errno==ENOTDIR) && --attempts_remaining > 0) { + /* + * rename(a, b) when b is an existing + * directory ought to result in ISDIR, but + * Solaris 5.8 gives ENOTDIR. Sheesh. + */ + if (remove_empty_directories(git_path("logs/%s", newrefname))) { + error("Directory not empty: logs/%s", newrefname); + return -1; + } + goto retry; + } else if (errno == ENOENT && --attempts_remaining > 0) { + /* + * Maybe another process just deleted one of + * the directories in the path to newrefname. + * Try again from the beginning. + */ + goto retry; + } else { + error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s", + newrefname, strerror(errno)); + return -1; + } + } + return 0; +} + int rename_ref(const char *oldrefname, const char *newrefname, const char *logmsg) { unsigned char sha1[20], orig_sha1[20]; @@ -2555,30 +2620,9 @@ int rename_ref(const char *oldrefname, const char *newrefname, const char *logms } } - if (log && safe_create_leading_directories(git_path("logs/%s", newrefname))) { - error("unable to create directory for %s", newrefname); + if (log && rename_tmp_log(newrefname)) goto rollback; - } - retry: - if (log && rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", newrefname))) { - if (errno==EISDIR || errno==ENOTDIR) { - /* - * rename(a, b) when b is an existing - * directory ought to result in ISDIR, but - * Solaris 5.8 gives ENOTDIR. Sheesh. - */ - if (remove_empty_directories(git_path("logs/%s", newrefname))) { - error("Directory not empty: logs/%s", newrefname); - goto rollback; - } - goto retry; - } else { - error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s", - newrefname, strerror(errno)); - goto rollback; - } - } logmoved = log; lock = lock_ref_sha1_basic(newrefname, NULL, 0, NULL); diff --git a/sha1_file.c b/sha1_file.c index e13bd2c3e..8b0849f93 100644 --- a/sha1_file.c +++ b/sha1_file.c @@ -105,50 +105,59 @@ int mkdir_in_gitdir(const char *path) return adjust_shared_perm(path); } -int safe_create_leading_directories(char *path) +enum scld_error safe_create_leading_directories(char *path) { - char *pos = path + offset_1st_component(path); - struct stat st; + char *next_component = path + offset_1st_component(path); + enum scld_error ret = SCLD_OK; + + while (ret == SCLD_OK && next_component) { + struct stat st; + char *slash = strchr(next_component, '/'); - while (pos) { - pos = strchr(pos, '/'); - if (!pos) + if (!slash) break; - while (*++pos == '/') - ; - if (!*pos) + + next_component = slash + 1; + while (*next_component == '/') + next_component++; + if (!*next_component) break; - *--pos = '\0'; + + *slash = '\0'; if (!stat(path, &st)) { /* path exists */ - if (!S_ISDIR(st.st_mode)) { - *pos = '/'; - return -3; - } - } - else if (mkdir(path, 0777)) { + if (!S_ISDIR(st.st_mode)) + ret = SCLD_EXISTS; + } else if (mkdir(path, 0777)) { if (errno == EEXIST && - !stat(path, &st) && S_ISDIR(st.st_mode)) { + !stat(path, &st) && S_ISDIR(st.st_mode)) ; /* somebody created it since we checked */ - } else { - *pos = '/'; - return -1; - } - } - else if (adjust_shared_perm(path)) { - *pos = '/'; - return -2; + else if (errno == ENOENT) + /* + * Either mkdir() failed because + * somebody just pruned the containing + * directory, or stat() failed because + * the file that was in our way was + * just removed. Either way, inform + * the caller that it might be worth + * trying again: + */ + ret = SCLD_VANISHED; + else + ret = SCLD_FAILED; + } else if (adjust_shared_perm(path)) { + ret = SCLD_PERMS; } - *pos++ = '/'; + *slash = '/'; } - return 0; + return ret; } -int safe_create_leading_directories_const(const char *path) +enum scld_error safe_create_leading_directories_const(const char *path) { /* path points to cache entries, so xstrdup before messing with it */ char *buf = xstrdup(path); - int result = safe_create_leading_directories(buf); + enum scld_error result = safe_create_leading_directories(buf); free(buf); return result; } |