Re: pread() over NFS (again) [1.5.5.4]
On Thu, Jun 26, 2008 at 04:36:27PM -0700, logank@sent.com wrote:
Show 12 quoted lines
> On Jun 26, 2008, at 1:56 PM, Junio C Hamano wrote:
>
>>> "The file shouldn't be short unless someone truncated it, or there
>>> is a bug in index-pack. Neither is very likely, but I don't think
>>> we would want to retry pread'ing the same block forever.
>>
>> I don't think we would want to retry even once. Return value of 0
>> from
>> pread is defined to be an EOF, isn't it?
>
> No, it seems to be a simple error-out in this case. We have 2.4.20
> systems
That version's for the client or the server?
--b.
Show 40 quoted lines
> with nfs-utils 0.3.3 and used to frequently get the same error
> while pushing. I made a similar change back in February and haven't had a
> problem since:
>
> diff --git a/index-pack.c b/index-pack.c
> index 5ac91ba..85c8bdb 100644
> --- a/index-pack.c
> +++ b/index-pack.c
> @@ -313,7 +313,14 @@ static void *get_data_from_pack(struct object_entry
> *obj)
> src = xmalloc(len);
> data = src;
> do {
> + // It appears that if multiple threads read across NFS, the
> + // second read will fail. I know this is awful, but we wait for
> + // a little bit and try again.
> ssize_t n = pread(pack_fd, data + rdy, len - rdy, from + rdy);
> + if (n <= 0) {
> + sleep(1);
> + n = pread(pack_fd, data + rdy, len - rdy, from + rdy);
> + }
> if (n <= 0)
> die("cannot pread pack file: %s", strerror(errno));
> rdy += n;
>
> I use a sleep request since it seems less likely that the other thread
> will have an outstanding request after a second of waiting.
>
> --
> Logan Kennelly
> ,,,
> (. .)
> --ooO-(_)-Ooo--
>
>
>
> --
> To unsubscribe from this list: send the line "unsubscribe git" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html