Subject: Re: Error "fatal: cannot pread pack file: Success"

From: "Shawn O. Pearce" <[email-masked]>
Date: Tue, 27 Feb 2007 23:47:19 -0500

"Shawn O. Pearce" <[email-masked]> wrote:
> Bill Lear <[email-masked]> wrote:
> > Using 1.5.0.1.  Can't see what is wrong with this clone...
> ...
> > Indexing 4589 objects.
> > remote: Total 4589 (delta 2209), reused 4589 (delta 2209)
> >  100% (4589/4589) done
> > Resolving 2209 deltas.
> > fatal: cannot pread pack file: Success
> > fatal: index-pack died with error code 128
> > fetch-pack from '/home/rael/devel/project/.git' failed.
> 
> I think the pread() in get_data_from_pack of index-pack is wrong,
> it really should be looping until we fill the buffer in case the
> OS doesn't fully satisfy our read request the first time.

Does this fix your problem?

-->8--
[PATCH] index-pack: Loop over pread until data loading is complete.

A filesystem might not be able to completely supply our pread
request in one system call, such as if we are reading data from a
network file system and the requested length is just simply huge.

Signed-off-by: Shawn O. Pearce <[email-masked]>
---
 index-pack.c |   10 ++++++++--
 1 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/index-pack.c b/index-pack.c
index 859ec01..cf81a99 100644
--- a/index-pack.c
+++ b/index-pack.c
@@ -277,13 +277,19 @@ static void *get_data_from_pack(struct object_entry *obj)
 {
 	unsigned long from = obj[0].offset + obj[0].hdr_size;
 	unsigned long len = obj[1].offset - from;
+	unsigned long rdy = 0;
 	unsigned char *src, *data;
 	z_stream stream;
 	int st;
 
 	src = xmalloc(len);
-	if (pread(pack_fd, src, len, from) != len)
-		die("cannot pread pack file: %s", strerror(errno));
+	data = src;
+	do {
+		ssize_t n = pread(pack_fd, data + rdy, len - rdy, from + rdy);
+		if (n <= 0)
+			die("cannot pread pack file: %s", strerror(errno));
+		rdy += n;
+	} while (rdy < len);
 	data = xmalloc(obj->size);
 	memset(&stream, 0, sizeof(stream));
 	stream.next_out = data;
-- 
1.5.0.2.775.g1a500

-- 
Shawn.