BSD 4.4 Lite Kernel Sources

1 files changed, 184 insertions, 0 deletions

diff --git a/sys/ufs/lfs/lfs_subr.c b/sys/ufs/lfs/lfs_subr.c
new file mode 100644
index 0000000..afcd8c2
--- /dev/null
+++ b/sys/ufs/lfs/lfs_subr.c
@@ -0,0 +1,184 @@
+/*
+ * Copyright (c) 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)lfs_subr.c	8.2 (Berkeley) 9/21/93
+ */
+
+#include <sys/param.h>
+#include <sys/namei.h>
+#include <sys/vnode.h>
+#include <sys/buf.h>
+#include <sys/mount.h>
+#include <sys/malloc.h>
+#include <sys/proc.h>
+
+#include <ufs/ufs/quota.h>
+#include <ufs/ufs/inode.h>
+#include <ufs/lfs/lfs.h>
+#include <ufs/lfs/lfs_extern.h>
+
+/*
+ * Return buffer with the contents of block "offset" from the beginning of
+ * directory "ip".  If "res" is non-zero, fill it in with a pointer to the
+ * remaining space in the directory.
+ */
+int
+lfs_blkatoff(ap)
+	struct vop_blkatoff_args /* {
+		struct vnode *a_vp;
+		off_t a_offset;
+		char **a_res;
+		struct buf **a_bpp;
+	} */ *ap;
+{
+	register struct lfs *fs;
+	struct inode *ip;
+	struct buf *bp;
+	daddr_t lbn;
+	int bsize, error;
+
+	ip = VTOI(ap->a_vp);
+	fs = ip->i_lfs;
+	lbn = lblkno(fs, ap->a_offset);
+	bsize = blksize(fs);
+
+	*ap->a_bpp = NULL;
+	if (error = bread(ap->a_vp, lbn, bsize, NOCRED, &bp)) {
+		brelse(bp);
+		return (error);
+	}
+	if (ap->a_res)
+		*ap->a_res = (char *)bp->b_data + blkoff(fs, ap->a_offset);
+	*ap->a_bpp = bp;
+	return (0);
+}
+
+
+/*
+ * lfs_seglock --
+ *	Single thread the segment writer.
+ */
+void
+lfs_seglock(fs, flags)
+	struct lfs *fs;
+	unsigned long flags;
+{
+	struct segment *sp;
+	int s;
+
+	if (fs->lfs_seglock)
+		if (fs->lfs_lockpid == curproc->p_pid) {
+			++fs->lfs_seglock;
+			fs->lfs_sp->seg_flags |= flags;
+			return;			
+		} else while (fs->lfs_seglock)
+			(void)tsleep(&fs->lfs_seglock, PRIBIO + 1,
+			    "lfs seglock", 0);
+
+	fs->lfs_seglock = 1;
+	fs->lfs_lockpid = curproc->p_pid;
+
+	sp = fs->lfs_sp = malloc(sizeof(struct segment), M_SEGMENT, M_WAITOK);
+	sp->bpp = malloc(((LFS_SUMMARY_SIZE - sizeof(SEGSUM)) /
+	    sizeof(daddr_t) + 1) * sizeof(struct buf *), M_SEGMENT, M_WAITOK);
+	sp->seg_flags = flags;
+	sp->vp = NULL;
+	(void) lfs_initseg(fs);
+
+	/*
+	 * Keep a cumulative count of the outstanding I/O operations.  If the
+	 * disk drive catches up with us it could go to zero before we finish,
+	 * so we artificially increment it by one until we've scheduled all of
+	 * the writes we intend to do.
+	 */
+	s = splbio();
+	++fs->lfs_iocount;
+	splx(s);
+}
+/*
+ * lfs_segunlock --
+ *	Single thread the segment writer.
+ */
+void
+lfs_segunlock(fs)
+	struct lfs *fs;
+{
+	struct segment *sp;
+	unsigned long sync, ckp;
+	int s;
+
+	if (fs->lfs_seglock == 1) {
+
+		sp = fs->lfs_sp;
+		sync = sp->seg_flags & SEGM_SYNC;
+		ckp = sp->seg_flags & SEGM_CKP;
+		if (sp->bpp != sp->cbpp) {
+			/* Free allocated segment summary */
+			fs->lfs_offset -= LFS_SUMMARY_SIZE / DEV_BSIZE;
+			brelvp(*sp->bpp);
+			free((*sp->bpp)->b_data, M_SEGMENT);
+			free(*sp->bpp, M_SEGMENT);
+		} else
+			printf ("unlock to 0 with no summary");
+		free(sp->bpp, M_SEGMENT);
+		free(sp, M_SEGMENT);
+
+		/*
+		 * If the I/O count is non-zero, sleep until it reaches zero.
+		 * At the moment, the user's process hangs around so we can
+		 * sleep.
+		 */
+		s = splbio();
+		--fs->lfs_iocount;
+		/*
+		 * We let checkpoints happen asynchronously.  That means
+		 * that during recovery, we have to roll forward between
+		 * the two segments described by the first and second
+		 * superblocks to make sure that the checkpoint described
+		 * by a superblock completed.
+		 */
+		if (sync && fs->lfs_iocount)
+		    (void)tsleep(&fs->lfs_iocount, PRIBIO + 1, "lfs vflush", 0);
+		splx(s);
+		if (ckp) {
+			fs->lfs_nactive = 0;
+			lfs_writesuper(fs);
+		}
+		--fs->lfs_seglock;
+		fs->lfs_lockpid = 0;
+		wakeup(&fs->lfs_seglock);
+	} else if (fs->lfs_seglock == 0) {
+		panic ("Seglock not held");
+	} else {
+		--fs->lfs_seglock;
+	}
+}