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Date: Thu, 7 Aug 1997 03:07:13 +1000
From: Bruce Evans <bde@zeta.org.au>
Message-Id: <199708061707.DAA08697@godzilla.zeta.org.au>
To: current@freebsd.org
Subject: ext2fs currupts numdirtybuffers
Cc: dyson@freebsd.org
Sender: owner-freebsd-current@freebsd.org
X-Loop: FreeBSD.org
Precedence: bulk

ext2fs doesn't maintain the numdirtybuffers count properly.  This makes
all file systems very slow (throughput is reduced 10 times here).

Bruce

diff -c2 ext2_linux_ialloc.c~ ext2_linux_ialloc.c
*** ext2_linux_ialloc.c~	Tue Aug  5 02:14:14 1997
--- ext2_linux_ialloc.c	Thu Aug  7 02:42:00 1997
***************
*** 54,59 ****
  void mark_buffer_dirty(struct buf *bh)
  {
! 	numdirtybuffers++;
! 	bh->b_flags |= B_DELWRI;
  	bh->b_flags &= ~(B_READ | B_ERROR);
  } 
--- 54,61 ----
  void mark_buffer_dirty(struct buf *bh)
  {
! 	if (!(bh->b_flags & B_DELWRI)) {
! 		numdirtybuffers++;
! 		bh->b_flags |= B_DELWRI;
! 	}
  	bh->b_flags &= ~(B_READ | B_ERROR);
  }