[PATCH v4 17/32] commit_lock_file(): die() if called for unlocked lockfile object
From: Michael Haggerty <hidden>
Date: 2016-06-15 23:02:27
Subsystem:
documentation, the rest · Maintainers:
Jonathan Corbet, Linus Torvalds
It was previously a bug to call commit_lock_file() with a lock_file object that was not active (an illegal access would happen within the function). It was presumably never done, but this would be an easy programming error to overlook. So before continuing, do a consistency check that the lock_file object really is locked. Helped-by: Johannes Sixt [off-list ref] Signed-off-by: Michael Haggerty <redacted> --- Documentation/technical/api-lockfile.txt | 4 +++- lockfile.c | 3 +++ 2 files changed, 6 insertions(+), 1 deletion(-)
diff --git a/Documentation/technical/api-lockfile.txt b/Documentation/technical/api-lockfile.txt
index b53e300..9a94ead 100644
--- a/Documentation/technical/api-lockfile.txt
+++ b/Documentation/technical/api-lockfile.txt@@ -68,7 +68,9 @@ commit_lock_file:: with an earlier call to `hold_lock_file_for_update()`, close the file descriptor and rename the lockfile to its final destination. Returns 0 upon success, a negative - value on failure to close(2) or rename(2). + value on failure to close(2) or rename(2). It is a bug to + call `commit_lock_file()` for a `lock_file` object that is not + currently locked. rollback_lock_file::
diff --git a/lockfile.c b/lockfile.c
index d64cf6b..716b674 100644
--- a/lockfile.c
+++ b/lockfile.c@@ -307,6 +307,9 @@ int commit_lock_file(struct lock_file *lk) { char result_file[PATH_MAX]; + if (!lk->filename[0]) + die("BUG: attempt to commit unlocked object"); + if (lk->fd >= 0 && close_lock_file(lk)) return -1;
--
2.1.0