[src/trunk]: src/sys/ufs/ffs ffs_copyonwrite(): If the write is to the in-fil...

[hannken <hannken%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/58b62bb4c650
branches:  trunk
changeset: 766760:58b62bb4c650
user:      hannken <hannken%NetBSD.org@localhost>
date:      Fri Jul 01 14:28:21 2011 +0000

description:
ffs_copyonwrite(): If the write is to the in-file-system journal
    there is no need to lock and check the snapshots.

diffstat:

 sys/ufs/ffs/ffs_snapshot.c |  24 +++++++++++++++++++-----
 1 files changed, 19 insertions(+), 5 deletions(-)

diffs (52 lines):

diff -r 1960c32cf6ed -r 58b62bb4c650 sys/ufs/ffs/ffs_snapshot.c
--- a/sys/ufs/ffs/ffs_snapshot.c        Fri Jul 01 13:30:18 2011 +0000
+++ b/sys/ufs/ffs/ffs_snapshot.c        Fri Jul 01 14:28:21 2011 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: ffs_snapshot.c,v 1.116 2011/06/12 03:36:00 rmind Exp $ */
+/*     $NetBSD: ffs_snapshot.c,v 1.117 2011/07/01 14:28:21 hannken Exp $       */
 
 /*
  * Copyright 2000 Marshall Kirk McKusick. All Rights Reserved.
@@ -38,7 +38,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: ffs_snapshot.c,v 1.116 2011/06/12 03:36:00 rmind Exp $");
+__KERNEL_RCSID(0, "$NetBSD: ffs_snapshot.c,v 1.117 2011/07/01 14:28:21 hannken Exp $");
 
 #if defined(_KERNEL_OPT)
 #include "opt_ffs.h"
@@ -1896,9 +1896,9 @@
                return 0;
        }
        /*
-        * First check to see if it is after the file system or
-        * in the preallocated list.
-        * By doing this check we avoid several potential deadlocks.
+        * First check to see if it is after the file system,
+        * in the journal or in the preallocated list.
+        * By doing these checks we avoid several potential deadlocks.
         */
        fs = ip->i_fs;
        lbn = fragstoblks(fs, dbtofsb(fs, bp->b_blkno));
@@ -1906,6 +1906,20 @@
                mutex_exit(&si->si_lock);
                return 0;
        }
+       if ((fs->fs_flags & FS_DOWAPBL) &&
+           fs->fs_journal_location == UFS_WAPBL_JOURNALLOC_IN_FILESYSTEM) {
+               off_t blk_off, log_start, log_end;
+
+               log_start = (off_t)fs->fs_journallocs[UFS_WAPBL_INFS_ADDR] *
+                   fs->fs_journallocs[UFS_WAPBL_INFS_BLKSZ];
+               log_end = log_start + fs->fs_journallocs[UFS_WAPBL_INFS_COUNT] *
+                   fs->fs_journallocs[UFS_WAPBL_INFS_BLKSZ];
+               blk_off = dbtob(bp->b_blkno);
+               if (blk_off >= log_start && blk_off < log_end) {
+                       mutex_exit(&si->si_lock);
+                       return 0;
+               }
+       }
        snapblklist = si->si_snapblklist;
        upper = (snapblklist != NULL ? snapblklist[0] - 1 : 0);
        lower = 1;