On 12/3/18 2:16 PM, Dave Chinner wrote:
> On Mon, Dec 03, 2018 at 08:20:30AM -0800, Darrick J. Wong wrote:
>> On Mon, Dec 03, 2018 at 07:53:42AM +1100, Dave Chinner wrote:
>>> From: Dave Chinner <dchinner@xxxxxxxxxx>
>>>
>>> So that O_RDONLY open commands (such as from copy_range) do not
>>> block forever waiting on a non-existent writer.
>>>
>>> Signed-off-by: Dave Chinner <dchinner@xxxxxxxxxx>
>>> ---
>>> io/open.c | 13 +++++++++++++
>>> 1 file changed, 13 insertions(+)
>>>
>>> diff --git a/io/open.c b/io/open.c
>>> index 6ea3e9a2019f..b1d9a0fa317c 100644
>>> --- a/io/open.c
>>> +++ b/io/open.c
>>> @@ -56,6 +56,7 @@ openfile(
>>> struct fs_path *fs_path)
>>> {
>>> struct fs_path *fsp;
>>> + struct stat st;
>>> int fd;
>>> int oflags;
>>>
>>> @@ -79,6 +80,18 @@ openfile(
>>> if (flags & IO_NOFOLLOW)
>>> oflags |= O_NOFOLLOW;
>>>
>>> + /*
>>> + * if we've been passed a pipe to open, don't block waiting for a
>>> + * reader or writer to appear. We want to either succeed or error out
>>> + * immediately.
>>> + */
>>> + if (stat(path, &st) < 0 && errno != ENOENT) {
>>> + perror("stat");
>>> + return -1;
>>> + }
>>> + if (S_ISFIFO(st.st_mode))
>>
>> Hmm... does stat() set st.st_mode even if it returns ENOENT? Or are we
>> possibly branching on an uninitialized st here?
>>
>> struct stat st = { 0 }; ?
>
> Yeah, I'll fix that.
I'll just do that on commit.
-Eric
