Re: svn commit: r329078 - in head/sys: kern sys

[Conrad Meyer]

On Fri, Feb 9, 2018 at 11:50 AM, Kirk McKusick  wrote:
> Author: mckusick
> Date: Fri Feb  9 19:50:47 2018
> New Revision: 329078
> URL: https://svnweb.freebsd.org/changeset/base/329078
>
> Log:
>   Merge biodone_finish() back into biodone(). The primary purpose is
>   to make the order of operations clearer to avoid the race condition
>   that was fixed in r328914. In particular, this commit corrects a
>   similar race that existed in the soft updates callback.

Thanks!
___
svn-src-head@freebsd.org mailing list
https://lists.freebsd.org/mailman/listinfo/svn-src-head
To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"

svn commit: r329078 - in head/sys: kern sys

[Kirk McKusick]

Author: mckusick
Date: Fri Feb  9 19:50:47 2018
New Revision: 329078
URL: https://svnweb.freebsd.org/changeset/base/329078

Log:
  Merge biodone_finish() back into biodone(). The primary purpose is
  to make the order of operations clearer to avoid the race condition
  that was fixed in r328914. In particular, this commit corrects a
  similar race that existed in the soft updates callback.
  
  Doing some sleuthing through the SVN repository, it appears that
  bufdone_finish() was added to support XFS:
  
  
  r153192 | rodrigc | 2005-12-06 19:39:08 -0800 (Tue, 06 Dec 2005) | 13 lines
  
  Changes imported from XFS for FreeBSD project:
  - add fields to struct buf (needed by XFS)
  - 3 private fields: b_fsprivate1, b_fsprivate2, b_fsprivate3
  - b_pin_count, count of pinned buffer
  
  - add new B_MANAGED flag
  - add breada() function to initiate asynchronous I/O on read-ahead blocks.
  - add bufdone_finish(), bpin(), bunpin_wait() functions
  
  Patches provided by:kan
  Reviewed by:phk
  Silence on: arch@
  
  
  
  It does not appear to ever have been used for anything else.  XFS was
  disconnected in r241607:
  
  
  r241607 | attilio | 2012-10-16 03:04:00 -0700 (Tue, 16 Oct 2012) | 5 lines
  
  Disconnect non-MPSAFE XFS from the build in preparation for dropping
  GIANT from VFS.
  
  This is not targeted for MFC.
  
  
  
  and removed entirely in r247631:
  
  
  r247631 | attilio | 2013-03-02 07:33:54 -0800 (Sat, 02 Mar 2013) | 5 lines
  
  Garbage collect XFS bits which are now already completely disconnected
  from the tree since few months.
  
  This is not targeted for MFC.
  
  
  
  Since XFS support is gone, there is no reason to retain biodone_finish().
  
  Suggested by: Warner Losh (imp)
  Discussed with: cem, kib
  Tested by: Peter Holm (pho)

Modified:
  head/sys/kern/vfs_bio.c
  head/sys/sys/buf.h

Modified: head/sys/kern/vfs_bio.c
==
--- head/sys/kern/vfs_bio.c Fri Feb  9 19:46:51 2018(r329077)
+++ head/sys/kern/vfs_bio.c Fri Feb  9 19:50:47 2018(r329078)
@@ -4086,21 +4086,6 @@ bufdone(struct buf *bp)
bufobj_wdrop(dropobj);
return;
}
-
-   bufdone_finish(bp);
-
-   if (dropobj)
-   bufobj_wdrop(dropobj);
-}
-
-void
-bufdone_finish(struct buf *bp)
-{
-   BUF_ASSERT_HELD(bp);
-
-   if (!LIST_EMPTY(>b_dep))
-   buf_complete(bp);
-
if (bp->b_flags & B_VMIO) {
/*
 * Set B_CACHE if the op was a normal read and no error
@@ -4113,14 +4098,14 @@ bufdone_finish(struct buf *bp)
bp->b_flags |= B_CACHE;
vfs_vmio_iodone(bp);
}
+   if (!LIST_EMPTY(>b_dep))
+   buf_complete(bp);
if ((bp->b_flags & B_CKHASH) != 0) {
KASSERT(bp->b_iocmd == BIO_READ,
-   ("bufdone_finish: b_iocmd %d not BIO_READ", bp->b_iocmd));
-   KASSERT(buf_mapped(bp),
-   ("bufdone_finish: bp %p not mapped", bp));
+   ("bufdone: b_iocmd %d not BIO_READ", bp->b_iocmd));
+   KASSERT(buf_mapped(bp), ("bufdone: bp %p not mapped", bp));
(*bp->b_ckhashcalc)(bp);
}
-
/*
 * For asynchronous completions, release the buffer now. The brelse
 * will do a wakeup there if necessary - so no need to do a wakeup
@@ -4134,6 +4119,8 @@ bufdone_finish(struct buf *bp)
bqrelse(bp);
} else
bdone(bp);
+   if (dropobj)
+   bufobj_wdrop(dropobj);
 }
 
 /*

Modified: head/sys/sys/buf.h
==
--- head/sys/sys/buf.h  Fri Feb  9 19:46:51 2018(r329077)
+++ head/sys/sys/buf.h  Fri Feb  9 19:50:47 2018(r329078)
@@ -542,7 +542,6 @@ struct buf *geteblk(int, int);
 intbufwait(struct buf *);
 intbufwrite(struct buf *);
 void   bufdone(struct buf *);
-void   bufdone_finish(struct buf *);
 void   bd_speedup(void);
 
 intcluster_read(struct vnode *, u_quad_t, daddr_t, long,
___
svn-src-head@freebsd.org mailing list
https://lists.freebsd.org/mailman/listinfo/svn-src-head
To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"