[PATCH] git_open_noatime: return with errno=0 on success
- From
Clemens Buchacher <clemens.buchacher@intel.com>
- Date
- Aug 4, 2015, 08:24 UTC
- Message-ID
- <20150804082429.GA22271@musxeris015.imu.intel.com>
- In-Reply-To
- <CAPig+cSacM_JwZzagOVZpMJF=oE7m3rMnq1eKr=aNsGY0vvmfQ@mail.gmail.com>
In read_sha1_file_extended we die if read_object fails with a fatal error. We detect a fatal error if errno is non-zero and is not ENOENT. If the object could not be read because it does not exist, this is not considered a fatal error and we want to return NULL.
Somewhere down the line, read_object calls git_open_noatime to open a pack index file, for example. We first try open with O_NOATIME. If O_NOATIME fails with EPERM, we retry without O_NOATIME. When the second open succeeds, errno is however still set to EPERM from the first attempt. When we finally determine that the object does not exist, read_object returns NULL and read_sha1_file_extended dies with a fatal error:
fatal: failed to read object <sha1>: Operation not permitted
Fix this by resetting errno to zero before we call open again.
Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Clemens Buchacher <clemens.buchacher@intel.com> ---
This is a re-submission without changes except for a typo fix in the comments (thanks Eric). The original submission received no other comments, but I think it is a clear improvement and I hope it was just missed the first time.
Best regards, Clemens
sha1_file.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/sha1_file.c b/sha1_file.c index 77cd81d..62b7ad6 100644 --- a/sha1_file.c +++ b/sha1_file.c @@ -1453,6 +1453,7 @@ int git_open_noatime(const char *name) static int sha1_file_open_flag = O_NOATIME; for (;;) { + errno = 0; int fd = open(name, O_RDONLY | sha1_file_open_flag); if (fd >= 0) return fd;
-- 1.9.4