From 4f4d71b941e568b158da73978e25105b94afd7fd Mon Sep 17 00:00:00 2001
From: cinap_lenrek <cinap_lenrek@felloff.net>
Date: Mon, 29 Sep 2014 21:01:51 +0200
Subject: [PATCH] hgfs: make data files with meta headers having the right size
 after open

to get the right data size of a file, the revlog needs to have been
opened and the metaheader parsed. as an optimization, we used to
open revlog only on the first read resulting revlogs with metaheaders
having the wrong size returned by fstat() until the first read().

tar relies on fstat() giving the correct file size, so just open
the revlog on open. reading directories can still yield the wrong
size but it is not that critical.
---
 sys/src/cmd/hgfs/fs.c | 29 +++++++++++++++--------------
 1 file changed, 15 insertions(+), 14 deletions(-)

diff --git a/sys/src/cmd/hgfs/fs.c b/sys/src/cmd/hgfs/fs.c
index ab820f656..09644b8a5 100644
--- a/sys/src/cmd/hgfs/fs.c
+++ b/sys/src/cmd/hgfs/fs.c
@@ -606,6 +606,19 @@ fsopen(Req *r)
 		if(rf->node == nil || rf->node->mode != 'x')
 			break;
 	case OREAD:
+		if(rf->level == Qlog){
+			if((rf->fd = revlogopentemp(&changelog, hashrev(&changelog, rf->info->chash))) < 0){
+				responderror(r);
+				return;
+			}
+			rf->doff = rf->info->logoff;
+		} else if(rf->level == Qtree && rf->node->down == nil){
+			if((rf->fd = revlogopentemp(rf->rlog, hashrev(rf->rlog, rf->node->hash))) < 0){
+				responderror(r);
+				return;
+			}
+			rf->doff = fmetaheader(rf->fd);
+		}
 		respond(r, nil);
 		return;
 	}
@@ -697,13 +710,6 @@ fsread(Req *r)
 			len = 0;
 		else if((off + len) >= rf->info->loglen)
 			len = rf->info->loglen - off;
-		if(rf->fd >= 0)
-			goto Fdgen;
-		if((rf->fd = revlogopentemp(&changelog, hashrev(&changelog, rf->info->chash))) < 0){
-			responderror(r);
-			return;
-		}
-		rf->doff = rf->info->logoff;
 		goto Fdgen;
 	case Qwho:
 		s = rf->info->who;
@@ -724,14 +730,9 @@ fsread(Req *r)
 			respond(r, nil);
 			return;
 		}
-		if(rf->fd >= 0)
-			goto Fdgen;
-		if((rf->fd = revlogopentemp(rf->rlog, hashrev(rf->rlog, rf->node->hash))) < 0){
-			responderror(r);
-			return;
-		}
-		rf->doff = fmetaheader(rf->fd);
 	Fdgen:
+		if(rf->fd < 0)
+			break;
 		if((n = pread(rf->fd, r->ofcall.data, len, off + rf->doff)) < 0){
 			responderror(r);
 			return;