svn commit: r248628 - stable/9/sbin/fsck_ffs

[Kirk McKusick]

Author: mckusick
Date: Fri Mar 22 22:50:48 2013
New Revision: 248628
URL: http://svnweb.freebsd.org/changeset/base/248628

Log:
  MFS of 246812:
  
  Update fsck_ffs buffer cache manager to use TAILQ macros.
  No functional changes.

Modified:
  stable/9/sbin/fsck_ffs/fsck.h
  stable/9/sbin/fsck_ffs/fsutil.c
Directory Properties:
  stable/9/sbin/fsck_ffs/   (props changed)

Modified: stable/9/sbin/fsck_ffs/fsck.h
==============================================================================
--- stable/9/sbin/fsck_ffs/fsck.h	Fri Mar 22 22:46:19 2013	(r248627)
+++ stable/9/sbin/fsck_ffs/fsck.h	Fri Mar 22 22:50:48 2013	(r248628)
@@ -67,10 +67,13 @@
 #include <stdlib.h>
 #include <stdio.h>
 
+#include <sys/queue.h>
+
 #define	MAXDUP		10	/* limit on dup blks (per inode) */
 #define	MAXBAD		10	/* limit on bad blks (per inode) */
-#define	MAXBUFSPACE	40*1024	/* maximum space to allocate to buffers */
-#define	INOBUFSIZE	56*1024	/* size of buffer to read inodes in pass1 */
+#define	MINBUFS		10	/* minimum number of buffers required */
+#define	MAXBUFS		40	/* maximum space to allocate to buffers */
+#define	INOBUFSIZE	64*1024	/* size of buffer to read inodes in pass1 */
 
 union dinode {
 	struct ufs1_dinode dp1;
@@ -130,8 +133,7 @@ struct inostatlist {
  * buffer cache structure.
  */
 struct bufarea {
-	struct bufarea *b_next;		/* free list queue */
-	struct bufarea *b_prev;		/* free list queue */
+	TAILQ_ENTRY(bufarea) b_list;		/* buffer list */
 	ufs2_daddr_t b_bno;
 	int b_size;
 	int b_errs;
@@ -159,10 +161,11 @@ struct bufarea {
 		(bp)->b_un.b_indir2[i] = (val); \
 	} while (0)
 
-#define	B_INUSE 1
+/*
+ * Buffer flags
+ */
+#define	B_INUSE 	0x00000001	/* Buffer is in use */
 
-#define	MINBUFS		5	/* minimum number of buffers required */
-struct bufarea bufhead;		/* head of list of other blks in filesys */
 struct bufarea sblk;		/* file system superblock */
 struct bufarea cgblk;		/* cylinder group blocks */
 struct bufarea *pdirbp;		/* current directory contents */

Modified: stable/9/sbin/fsck_ffs/fsutil.c
==============================================================================
--- stable/9/sbin/fsck_ffs/fsutil.c	Fri Mar 22 22:46:19 2013	(r248627)
+++ stable/9/sbin/fsck_ffs/fsutil.c	Fri Mar 22 22:50:48 2013	(r248628)
@@ -67,6 +67,8 @@ long	diskreads, totalreads;	/* Disk cach
 struct timeval slowio_starttime;
 int slowio_delay_usec = 10000;	/* Initial IO delay for background fsck */
 int slowio_pollcnt;
+static TAILQ_HEAD(buflist, bufarea) bufhead;	/* head of buffer cache list */
+static int numbufs;				/* size of buffer cache */
 
 int
 ftypeok(union dinode *dp)
@@ -161,8 +163,8 @@ bufinit(void)
 		errx(EEXIT, "cannot allocate buffer pool");
 	cgblk.b_un.b_buf = bufp;
 	initbarea(&cgblk);
-	bufhead.b_next = bufhead.b_prev = &bufhead;
-	bufcnt = MAXBUFSPACE / sblock.fs_bsize;
+	TAILQ_INIT(&bufhead);
+	bufcnt = MAXBUFS;
 	if (bufcnt < MINBUFS)
 		bufcnt = MINBUFS;
 	for (i = 0; i < bufcnt; i++) {
@@ -174,13 +176,10 @@ bufinit(void)
 			errx(EEXIT, "cannot allocate buffer pool");
 		}
 		bp->b_un.b_buf = bufp;
-		bp->b_prev = &bufhead;
-		bp->b_next = bufhead.b_next;
-		bufhead.b_next->b_prev = bp;
-		bufhead.b_next = bp;
+		TAILQ_INSERT_HEAD(&bufhead, bp, b_list);
 		initbarea(bp);
 	}
-	bufhead.b_size = i;	/* save number of buffers */
+	numbufs = i;	/* save number of buffers */
 }
 
 /*
@@ -191,23 +190,19 @@ getdatablk(ufs2_daddr_t blkno, long size
 {
 	struct bufarea *bp;
 
-	for (bp = bufhead.b_next; bp != &bufhead; bp = bp->b_next)
+	TAILQ_FOREACH(bp, &bufhead, b_list)
 		if (bp->b_bno == fsbtodb(&sblock, blkno))
 			goto foundit;
-	for (bp = bufhead.b_prev; bp != &bufhead; bp = bp->b_prev)
+	TAILQ_FOREACH_REVERSE(bp, &bufhead, buflist, b_list)
 		if ((bp->b_flags & B_INUSE) == 0)
 			break;
-	if (bp == &bufhead)
+	if (bp == NULL)
 		errx(EEXIT, "deadlocked buffer pool");
 	getblk(bp, blkno, size);
 	/* fall through */
 foundit:
-	bp->b_prev->b_next = bp->b_next;
-	bp->b_next->b_prev = bp->b_prev;
-	bp->b_prev = &bufhead;
-	bp->b_next = bufhead.b_next;
-	bufhead.b_next->b_prev = bp;
-	bufhead.b_next = bp;
+	TAILQ_REMOVE(&bufhead, bp, b_list);
+	TAILQ_INSERT_HEAD(&bufhead, bp, b_list);
 	bp->b_flags |= B_INUSE;
 	return (bp);
 }
@@ -273,7 +268,7 @@ void
 ckfini(int markclean)
 {
 	struct bufarea *bp, *nbp;
-	int ofsmodified, cnt = 0;
+	int ofsmodified, cnt;
 
 	if (bkgrdflag) {
 		unlink(snapname);
@@ -294,6 +289,10 @@ ckfini(int markclean)
 			rerun = 1;
 		}
 	}
+	if (debug && totalreads > 0)
+		printf("cache with %d buffers missed %ld of %ld (%d%%)\n",
+		    numbufs, diskreads, totalreads,
+		    (int)(diskreads * 100 / totalreads));
 	if (fswritefd < 0) {
 		(void)close(fsreadfd);
 		return;
@@ -308,15 +307,16 @@ ckfini(int markclean)
 	}
 	flush(fswritefd, &cgblk);
 	free(cgblk.b_un.b_buf);
-	for (bp = bufhead.b_prev; bp && bp != &bufhead; bp = nbp) {
+	cnt = 0;
+	TAILQ_FOREACH_REVERSE_SAFE(bp, &bufhead, buflist, b_list, nbp) {
+		TAILQ_REMOVE(&bufhead, bp, b_list);
 		cnt++;
 		flush(fswritefd, bp);
-		nbp = bp->b_prev;
 		free(bp->b_un.b_buf);
 		free((char *)bp);
 	}
-	if (bufhead.b_size != cnt)
-		errx(EEXIT, "panic: lost %d buffers", bufhead.b_size - cnt);
+	if (numbufs != cnt)
+		errx(EEXIT, "panic: lost %d buffers", numbufs - cnt);
 	pbp = pdirbp = (struct bufarea *)0;
 	if (cursnapshot == 0 && sblock.fs_clean != markclean) {
 		if ((sblock.fs_clean = markclean) != 0) {
@@ -342,9 +342,6 @@ ckfini(int markclean)
 			rerun = 1;
 		}
 	}
-	if (debug && totalreads > 0)
-		printf("cache missed %ld of %ld (%d%%)\n", diskreads,
-		    totalreads, (int)(diskreads * 100 / totalreads));
 	(void)close(fsreadfd);
 	(void)close(fswritefd);
 }