From 0ca9ca0c55922f72dbf324c4ac1aecf8069d1dbe Mon Sep 17 00:00:00 2001
From: rsc <rsc>
Date: Sun, 31 May 2009 00:23:00 +0000
Subject: [PATCH] slight rearrangement; sleep on b not buf.
---
bio.c | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)
diff --git a/bio.c b/bio.c
index b761c3b..aea7835 100644
--- a/bio.c
+++ b/bio.c
@@ -69,22 +69,22 @@ bget(uint dev, uint sector)
for(b = bufhead.next; b != &bufhead; b = b->next){
if((b->flags & (B_BUSY|B_VALID)) &&
b->dev == dev && b->sector == sector){
- if(b->flags & B_BUSY){
- sleep(buf, &buf_table_lock);
- goto loop;
+ if(!(b->flags & B_BUSY)){
+ b->flags |= B_BUSY;
+ release(&buf_table_lock);
+ return b;
}
- b->flags |= B_BUSY;
- release(&buf_table_lock);
- return b;
+ sleep(b, &buf_table_lock);
+ goto loop;
}
}
// Allocate fresh block.
for(b = bufhead.prev; b != &bufhead; b = b->prev){
if((b->flags & B_BUSY) == 0){
- b->flags = B_BUSY;
b->dev = dev;
b->sector = sector;
+ b->flags = B_BUSY;
release(&buf_table_lock);
return b;
}
@@ -131,7 +131,7 @@ brelse(struct buf *b)
bufhead.next = b;
b->flags &= ~B_BUSY;
- wakeup(buf);
+ wakeup(b);
release(&buf_table_lock);
}
--
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