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lfs_bio.c revision 1.9.2.1
      1  1.9.2.1  perseant /*	$NetBSD: lfs_bio.c,v 1.9.2.1 1999/04/13 21:33:55 perseant Exp $	*/
      2      1.2       cgd 
      3      1.7  perseant /*-
      4      1.7  perseant  * Copyright (c) 1999 The NetBSD Foundation, Inc.
      5      1.7  perseant  * All rights reserved.
      6      1.7  perseant  *
      7      1.7  perseant  * This code is derived from software contributed to The NetBSD Foundation
      8      1.7  perseant  * by Konrad E. Schroder <perseant (at) hhhh.org>.
      9      1.7  perseant  *
     10      1.7  perseant  * Redistribution and use in source and binary forms, with or without
     11      1.7  perseant  * modification, are permitted provided that the following conditions
     12      1.7  perseant  * are met:
     13      1.7  perseant  * 1. Redistributions of source code must retain the above copyright
     14      1.7  perseant  *    notice, this list of conditions and the following disclaimer.
     15      1.7  perseant  * 2. Redistributions in binary form must reproduce the above copyright
     16      1.7  perseant  *    notice, this list of conditions and the following disclaimer in the
     17      1.7  perseant  *    documentation and/or other materials provided with the distribution.
     18      1.7  perseant  * 3. All advertising materials mentioning features or use of this software
     19      1.7  perseant  *    must display the following acknowledgement:
     20      1.7  perseant  *      This product includes software developed by the NetBSD
     21      1.7  perseant  *      Foundation, Inc. and its contributors.
     22      1.7  perseant  * 4. Neither the name of The NetBSD Foundation nor the names of its
     23      1.7  perseant  *    contributors may be used to endorse or promote products derived
     24      1.7  perseant  *    from this software without specific prior written permission.
     25      1.7  perseant  *
     26      1.7  perseant  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     27      1.7  perseant  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     28      1.7  perseant  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     29      1.7  perseant  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     30      1.7  perseant  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     31      1.7  perseant  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     32      1.7  perseant  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     33      1.7  perseant  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     34      1.7  perseant  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     35      1.7  perseant  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     36      1.7  perseant  * POSSIBILITY OF SUCH DAMAGE.
     37      1.7  perseant  */
     38      1.1   mycroft /*
     39      1.1   mycroft  * Copyright (c) 1991, 1993
     40      1.1   mycroft  *	The Regents of the University of California.  All rights reserved.
     41      1.1   mycroft  *
     42      1.1   mycroft  * Redistribution and use in source and binary forms, with or without
     43      1.1   mycroft  * modification, are permitted provided that the following conditions
     44      1.1   mycroft  * are met:
     45      1.1   mycroft  * 1. Redistributions of source code must retain the above copyright
     46      1.1   mycroft  *    notice, this list of conditions and the following disclaimer.
     47      1.1   mycroft  * 2. Redistributions in binary form must reproduce the above copyright
     48      1.1   mycroft  *    notice, this list of conditions and the following disclaimer in the
     49      1.1   mycroft  *    documentation and/or other materials provided with the distribution.
     50      1.1   mycroft  * 3. All advertising materials mentioning features or use of this software
     51      1.1   mycroft  *    must display the following acknowledgement:
     52      1.1   mycroft  *	This product includes software developed by the University of
     53      1.1   mycroft  *	California, Berkeley and its contributors.
     54      1.1   mycroft  * 4. Neither the name of the University nor the names of its contributors
     55      1.1   mycroft  *    may be used to endorse or promote products derived from this software
     56      1.1   mycroft  *    without specific prior written permission.
     57      1.1   mycroft  *
     58      1.1   mycroft  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     59      1.1   mycroft  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     60      1.1   mycroft  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     61      1.1   mycroft  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     62      1.1   mycroft  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     63      1.1   mycroft  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     64      1.1   mycroft  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     65      1.1   mycroft  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     66      1.1   mycroft  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     67      1.1   mycroft  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     68      1.1   mycroft  * SUCH DAMAGE.
     69      1.1   mycroft  *
     70      1.6      fvdl  *	@(#)lfs_bio.c	8.10 (Berkeley) 6/10/95
     71      1.1   mycroft  */
     72      1.1   mycroft 
     73      1.1   mycroft #include <sys/param.h>
     74      1.5  christos #include <sys/systm.h>
     75      1.1   mycroft #include <sys/proc.h>
     76      1.1   mycroft #include <sys/buf.h>
     77      1.1   mycroft #include <sys/vnode.h>
     78      1.1   mycroft #include <sys/resourcevar.h>
     79      1.1   mycroft #include <sys/mount.h>
     80      1.1   mycroft #include <sys/kernel.h>
     81      1.1   mycroft 
     82      1.1   mycroft #include <ufs/ufs/quota.h>
     83      1.1   mycroft #include <ufs/ufs/inode.h>
     84      1.1   mycroft #include <ufs/ufs/ufsmount.h>
     85      1.5  christos #include <ufs/ufs/ufs_extern.h>
     86      1.1   mycroft 
     87      1.7  perseant #include <sys/malloc.h>
     88      1.1   mycroft #include <ufs/lfs/lfs.h>
     89      1.1   mycroft #include <ufs/lfs/lfs_extern.h>
     90      1.1   mycroft 
     91      1.7  perseant /* Macros to clear/set/test flags. */
     92      1.7  perseant # define	SET(t, f)	(t) |= (f)
     93      1.7  perseant # define	CLR(t, f)	(t) &= ~(f)
     94      1.7  perseant # define	ISSET(t, f)	((t) & (f))
     95      1.7  perseant 
     96      1.1   mycroft /*
     97      1.1   mycroft  * LFS block write function.
     98      1.1   mycroft  *
     99      1.1   mycroft  * XXX
    100      1.1   mycroft  * No write cost accounting is done.
    101      1.1   mycroft  * This is almost certainly wrong for synchronous operations and NFS.
    102      1.1   mycroft  */
    103      1.1   mycroft int	lfs_allclean_wakeup;		/* Cleaner wakeup address. */
    104      1.7  perseant int	locked_queue_count   = 0;	/* XXX Count of locked-down buffers. */
    105      1.7  perseant long	locked_queue_bytes   = 0L;	/* XXX Total size of locked buffers. */
    106      1.7  perseant int	lfs_writing          = 0;	/* Set if already kicked off a writer
    107      1.1   mycroft 					   because of buffer space */
    108      1.7  perseant extern int lfs_dostats;
    109      1.7  perseant 
    110      1.7  perseant 
    111      1.1   mycroft /*
    112      1.7  perseant  * #define WRITE_THRESHHOLD    ((nbuf >> 1) - 10)
    113      1.7  perseant  * #define WAIT_THRESHHOLD     (nbuf - (nbuf >> 2) - 10)
    114      1.7  perseant  */
    115      1.7  perseant #define LFS_MAX_BUFS        ((nbuf >> 2) - 10)
    116      1.7  perseant #define LFS_WAIT_BUFS       ((nbuf >> 1) - (nbuf >> 3) - 10)
    117      1.7  perseant /* These are new ... is LFS taking up too much memory in its buffers? */
    118      1.7  perseant #define LFS_MAX_BYTES       (((bufpages >> 2) - 10) * CLBYTES)
    119      1.7  perseant #define LFS_WAIT_BYTES      (((bufpages >> 1) - (bufpages >> 3) - 10) * CLBYTES)
    120      1.7  perseant #define LFS_BUFWAIT         2
    121      1.7  perseant /*
    122      1.7  perseant  *
    123      1.7  perseant  * XXX we don't let meta-data writes run out of space because they can
    124      1.7  perseant  * come from the segment writer.  We need to make sure that there is
    125      1.7  perseant  * enough space reserved so that there's room to write meta-data
    126      1.7  perseant  * blocks.
    127      1.7  perseant  *
    128      1.7  perseant  * Also, we don't let blocks that have come to us from the cleaner
    129      1.7  perseant  * run out of space.
    130      1.7  perseant  */
    131      1.7  perseant #define CANT_WAIT(BP,F) (IS_IFILE((BP)) || (BP)->b_lblkno<0 || ((F) & BW_CLEAN))
    132      1.1   mycroft 
    133      1.1   mycroft int
    134      1.5  christos lfs_bwrite(v)
    135      1.5  christos 	void *v;
    136      1.5  christos {
    137      1.1   mycroft 	struct vop_bwrite_args /* {
    138      1.1   mycroft 		struct buf *a_bp;
    139      1.5  christos 	} */ *ap = v;
    140      1.1   mycroft 	register struct buf *bp = ap->a_bp;
    141      1.7  perseant 
    142      1.7  perseant #ifdef DIAGNOSTIC
    143      1.7  perseant 	if(bp->b_flags & B_ASYNC)
    144      1.7  perseant 		panic("bawrite LFS buffer");
    145      1.7  perseant #endif /* DIAGNOSTIC */
    146      1.7  perseant 	return lfs_bwrite_ext(bp,0);
    147      1.7  perseant }
    148      1.7  perseant 
    149      1.7  perseant /*
    150      1.7  perseant  * Determine if there is enough room currently available to write db
    151      1.7  perseant  * disk blocks.  We need enough blocks for the new blocks, the current
    152      1.7  perseant  * inode blocks, a summary block, plus potentially the ifile inode and
    153      1.7  perseant  * the segment usage table, plus an ifile page.
    154      1.7  perseant  */
    155      1.7  perseant inline static int lfs_fits(struct lfs *fs, int db)
    156      1.7  perseant {
    157      1.7  perseant 	if(((db + (fs->lfs_uinodes + INOPB((fs))) /
    158      1.7  perseant 	     INOPB(fs) + fsbtodb(fs, 1) + LFS_SUMMARY_SIZE / DEV_BSIZE +
    159      1.7  perseant 	     fs->lfs_segtabsz)) >= fs->lfs_avail)
    160      1.7  perseant 	{
    161      1.7  perseant 		return 0;
    162      1.7  perseant 	}
    163      1.7  perseant 
    164      1.7  perseant 	/*
    165      1.7  perseant 	 * Also check the number of segments available for writing.
    166      1.7  perseant 	 * If you don't do this here, it is possible for the *cleaner* to
    167      1.7  perseant 	 * cause us to become starved of segments, by flushing the pending
    168      1.7  perseant 	 * block list.
    169      1.7  perseant 	 *
    170      1.7  perseant 	 * XXX the old lfs_markv did not have this problem.
    171      1.7  perseant 	 */
    172      1.7  perseant 	if (fs->lfs_nclean <= MIN_FREE_SEGS)
    173      1.7  perseant 		return 0;
    174      1.7  perseant 
    175      1.7  perseant 	return 1;
    176      1.7  perseant }
    177      1.7  perseant 
    178      1.7  perseant int
    179      1.7  perseant lfs_bwrite_ext(bp, flags)
    180      1.7  perseant 	struct buf *bp;
    181      1.7  perseant 	int flags;
    182      1.7  perseant {
    183      1.1   mycroft 	struct lfs *fs;
    184      1.1   mycroft 	struct inode *ip;
    185      1.6      fvdl 	int db, error, s;
    186      1.7  perseant 
    187      1.1   mycroft 	/*
    188      1.1   mycroft 	 * Set the delayed write flag and use reassignbuf to move the buffer
    189      1.1   mycroft 	 * from the clean list to the dirty one.
    190      1.1   mycroft 	 *
    191      1.1   mycroft 	 * Set the B_LOCKED flag and unlock the buffer, causing brelse to move
    192      1.1   mycroft 	 * the buffer onto the LOCKED free list.  This is necessary, otherwise
    193      1.1   mycroft 	 * getnewbuf() would try to reclaim the buffers using bawrite, which
    194      1.1   mycroft 	 * isn't going to work.
    195      1.1   mycroft 	 *
    196      1.1   mycroft 	 * XXX we don't let meta-data writes run out of space because they can
    197      1.1   mycroft 	 * come from the segment writer.  We need to make sure that there is
    198      1.1   mycroft 	 * enough space reserved so that there's room to write meta-data
    199      1.1   mycroft 	 * blocks.
    200      1.1   mycroft 	 */
    201      1.1   mycroft 	if (!(bp->b_flags & B_LOCKED)) {
    202      1.1   mycroft 		fs = VFSTOUFS(bp->b_vp->v_mount)->um_lfs;
    203      1.6      fvdl 		db = fragstodb(fs, numfrags(fs, bp->b_bcount));
    204      1.7  perseant #ifdef DEBUG_LFS
    205      1.7  perseant 		if(CANT_WAIT(bp,flags)) {
    206      1.7  perseant 			if(((db + (fs->lfs_uinodes + INOPB((fs))) / INOPB(fs)
    207      1.7  perseant 			     + fsbtodb(fs, 1)
    208      1.7  perseant 			     + LFS_SUMMARY_SIZE / DEV_BSIZE
    209      1.7  perseant 			     + fs->lfs_segtabsz)) >= fs->lfs_avail)
    210      1.7  perseant 			{
    211      1.7  perseant 				printf("A");
    212      1.7  perseant 			}
    213      1.7  perseant 			if (fs->lfs_nclean <= MIN_FREE_SEGS-1)
    214      1.7  perseant 				printf("M");
    215      1.7  perseant 		}
    216      1.7  perseant #endif
    217      1.7  perseant 		while (!lfs_fits(fs, db) && !CANT_WAIT(bp,flags)) {
    218      1.1   mycroft 			/* Out of space, need cleaner to run */
    219      1.7  perseant 
    220      1.1   mycroft 			wakeup(&lfs_allclean_wakeup);
    221      1.6      fvdl 			wakeup(&fs->lfs_nextseg);
    222      1.7  perseant 			error = tsleep(&fs->lfs_avail, PCATCH | PUSER, "cleaner", NULL);
    223      1.5  christos 			if (error) {
    224      1.7  perseant 				/* printf("lfs_bwrite: error in tsleep"); */
    225      1.1   mycroft 				brelse(bp);
    226      1.1   mycroft 				return (error);
    227      1.1   mycroft 			}
    228      1.1   mycroft 		}
    229      1.7  perseant 
    230      1.7  perseant 		ip = VTOI(bp->b_vp);
    231      1.9  perseant 		if (bp->b_flags & B_CALL)
    232      1.7  perseant 		{
    233      1.7  perseant 			if(!(ip->i_flag & IN_CLEANING))
    234      1.7  perseant 				++fs->lfs_uinodes;
    235      1.7  perseant 			ip->i_flag |= IN_CLEANING;
    236      1.7  perseant 		} else {
    237      1.7  perseant 			if(!(ip->i_flag & IN_MODIFIED))
    238      1.7  perseant 				++fs->lfs_uinodes;
    239      1.7  perseant 			ip->i_flag |= IN_CHANGE | IN_MODIFIED | IN_UPDATE;
    240      1.7  perseant 		}
    241      1.6      fvdl 		fs->lfs_avail -= db;
    242      1.1   mycroft 		++locked_queue_count;
    243      1.7  perseant 		locked_queue_bytes += bp->b_bufsize;
    244      1.7  perseant #ifdef LFS_HONOR_RDONLY
    245      1.7  perseant 		/*
    246      1.7  perseant 		 * XXX KS - Don't write blocks if we're mounted ro.
    247      1.7  perseant 		 * Placement here means that the cleaner can't write
    248      1.7  perseant 		 * blocks either.
    249      1.7  perseant 		 */
    250      1.7  perseant 	        if(VTOI(bp->b_vp)->i_lfs->lfs_ronly)
    251      1.7  perseant 			bp->b_flags &= ~(B_DELWRI|B_LOCKED);
    252      1.7  perseant 		else
    253      1.7  perseant #endif
    254      1.7  perseant 			bp->b_flags |= B_DELWRI | B_LOCKED;
    255      1.1   mycroft 		bp->b_flags &= ~(B_READ | B_ERROR);
    256      1.1   mycroft 		s = splbio();
    257      1.1   mycroft 		reassignbuf(bp, bp->b_vp);
    258      1.1   mycroft 		splx(s);
    259      1.9  perseant 
    260      1.1   mycroft 	}
    261      1.7  perseant 
    262      1.9  perseant 	if(bp->b_flags & B_CALL)
    263      1.7  perseant 		bp->b_flags &= ~B_BUSY;
    264      1.7  perseant 	else
    265      1.7  perseant 		brelse(bp);
    266      1.7  perseant 
    267      1.1   mycroft 	return (0);
    268      1.1   mycroft }
    269      1.1   mycroft 
    270      1.1   mycroft /*
    271      1.1   mycroft  * XXX
    272      1.1   mycroft  * This routine flushes buffers out of the B_LOCKED queue when LFS has too
    273      1.1   mycroft  * many locked down.  Eventually the pageout daemon will simply call LFS
    274      1.1   mycroft  * when pages need to be reclaimed.  Note, we have one static count of locked
    275      1.1   mycroft  * buffers, so we can't have more than a single file system.  To make this
    276      1.1   mycroft  * work for multiple file systems, put the count into the mount structure.
    277      1.1   mycroft  */
    278      1.1   mycroft void
    279      1.7  perseant lfs_flush(fs, flags)
    280      1.7  perseant 	struct lfs *fs;
    281      1.7  perseant 	int flags;
    282      1.1   mycroft {
    283      1.6      fvdl 	register struct mount *mp, *nmp;
    284      1.7  perseant 	struct lfs *lfsp;
    285      1.7  perseant 
    286      1.7  perseant 	if(lfs_dostats)
    287      1.7  perseant 		++lfs_stats.write_exceeded;
    288      1.7  perseant 	if (lfs_writing && flags==0) /* XXX flags */
    289      1.1   mycroft 		return;
    290      1.1   mycroft 	lfs_writing = 1;
    291      1.7  perseant 
    292      1.6      fvdl 	simple_lock(&mountlist_slock);
    293      1.6      fvdl 	for (mp = mountlist.cqh_first; mp != (void *)&mountlist; mp = nmp) {
    294      1.6      fvdl 		if (vfs_busy(mp, LK_NOWAIT, &mountlist_slock)) {
    295      1.6      fvdl 			nmp = mp->mnt_list.cqe_next;
    296      1.6      fvdl 			continue;
    297      1.6      fvdl 		}
    298      1.7  perseant 		if (strncmp(&mp->mnt_stat.f_fstypename[0], MOUNT_LFS, MFSNAMELEN)==0)
    299      1.7  perseant 		{
    300      1.7  perseant 			lfsp = ((struct ufsmount *)mp->mnt_data)->ufsmount_u.lfs;
    301      1.7  perseant 			if((mp->mnt_flag & MNT_RDONLY) == 0 &&
    302      1.7  perseant 			   lfsp->lfs_dirops==0)
    303      1.7  perseant 			{
    304      1.7  perseant 				/* disallow dirops during flush */
    305      1.7  perseant 				lfsp->lfs_writer++;
    306      1.7  perseant 
    307      1.7  perseant 				/*
    308      1.7  perseant 				 * We set the queue to 0 here because we
    309      1.7  perseant 				 * are about to write all the dirty
    310      1.7  perseant 				 * buffers we have.  If more come in
    311      1.7  perseant 				 * while we're writing the segment, they
    312      1.7  perseant 				 * may not get written, so we want the
    313      1.7  perseant 				 * count to reflect these new writes
    314      1.7  perseant 				 * after the segwrite completes.
    315      1.7  perseant 				 */
    316      1.7  perseant 				if(lfs_dostats)
    317      1.7  perseant 					++lfs_stats.flush_invoked;
    318      1.7  perseant 				lfs_segwrite(mp, flags);
    319      1.7  perseant 
    320      1.7  perseant 				/* XXX KS - allow dirops again */
    321      1.7  perseant 				if(--lfsp->lfs_writer==0)
    322      1.7  perseant 					wakeup(&lfsp->lfs_dirops);
    323      1.7  perseant 			}
    324      1.1   mycroft 		}
    325      1.6      fvdl 		simple_lock(&mountlist_slock);
    326      1.6      fvdl 		nmp = mp->mnt_list.cqe_next;
    327      1.6      fvdl 		vfs_unbusy(mp);
    328      1.1   mycroft 	}
    329      1.6      fvdl 	simple_unlock(&mountlist_slock);
    330      1.7  perseant 
    331      1.7  perseant 	lfs_countlocked(&locked_queue_count,&locked_queue_bytes);
    332      1.7  perseant 	wakeup(&locked_queue_count);
    333      1.7  perseant 
    334      1.1   mycroft 	lfs_writing = 0;
    335      1.1   mycroft }
    336      1.1   mycroft 
    337      1.1   mycroft int
    338      1.7  perseant lfs_check(vp, blkno, flags)
    339      1.1   mycroft 	struct vnode *vp;
    340      1.6      fvdl 	ufs_daddr_t blkno;
    341      1.7  perseant 	int flags;
    342      1.1   mycroft {
    343      1.1   mycroft 	int error;
    344  1.9.2.1  perseant 	struct lfs *fs;
    345  1.9.2.1  perseant 
    346      1.1   mycroft 	error = 0;
    347      1.1   mycroft 	if (incore(vp, blkno))
    348      1.1   mycroft 		return (0);
    349      1.7  perseant 
    350      1.7  perseant 	/* If out of buffers, wait on writer */
    351      1.7  perseant 	/* XXX KS - if it's the Ifile, we're probably the cleaner! */
    352      1.7  perseant 	if (VTOI(vp)->i_number == LFS_IFILE_INUM)
    353      1.7  perseant 		return 0;
    354      1.7  perseant 
    355  1.9.2.1  perseant 	/* If dirops are active, can't flush.  Wait for SET_ENDOP */
    356  1.9.2.1  perseant 	fs = VTOI(vp)->i_lfs;
    357  1.9.2.1  perseant 	if (fs->lfs_dirops)
    358  1.9.2.1  perseant 		return 0;
    359  1.9.2.1  perseant 
    360      1.7  perseant 	if (locked_queue_count > LFS_MAX_BUFS
    361  1.9.2.1  perseant 	    || locked_queue_bytes > LFS_MAX_BYTES
    362  1.9.2.1  perseant 	    || fs->lfs_dirvcount > LFS_MAXDIROP)
    363      1.7  perseant 	{
    364  1.9.2.1  perseant 		++fs->lfs_writer;
    365  1.9.2.1  perseant 		lfs_flush(fs, flags);
    366  1.9.2.1  perseant 		if(--fs->lfs_writer==0)
    367  1.9.2.1  perseant 			wakeup(&fs->lfs_dirops);
    368      1.7  perseant 	}
    369      1.7  perseant 	while  (locked_queue_count > LFS_WAIT_BUFS
    370      1.7  perseant 		|| locked_queue_bytes > LFS_WAIT_BYTES)
    371      1.7  perseant 	{
    372      1.7  perseant 		if(lfs_dostats)
    373      1.7  perseant 			++lfs_stats.wait_exceeded;
    374      1.7  perseant 		error = tsleep(&locked_queue_count, PCATCH | PUSER,
    375      1.7  perseant 			       "buffers", hz * LFS_BUFWAIT);
    376      1.7  perseant 	}
    377      1.7  perseant 	return (error);
    378      1.7  perseant }
    379      1.1   mycroft 
    380      1.7  perseant /*
    381      1.7  perseant  * Allocate a new buffer header.
    382      1.7  perseant  */
    383      1.7  perseant struct buf *
    384      1.7  perseant lfs_newbuf(vp, daddr, size)
    385      1.7  perseant 	struct vnode *vp;
    386      1.7  perseant 	ufs_daddr_t daddr;
    387      1.7  perseant 	size_t size;
    388      1.7  perseant {
    389      1.7  perseant 	struct buf *bp;
    390      1.7  perseant 	size_t nbytes;
    391      1.7  perseant 	int s;
    392      1.7  perseant 
    393      1.7  perseant 	nbytes = roundup(size, DEV_BSIZE);
    394      1.7  perseant 
    395      1.7  perseant 	bp = malloc(sizeof(struct buf), M_SEGMENT, M_WAITOK);
    396      1.7  perseant 	bzero(bp, sizeof(struct buf));
    397      1.7  perseant 	if (nbytes)
    398      1.7  perseant 		bp->b_data = malloc(nbytes, M_SEGMENT, M_WAITOK);
    399      1.7  perseant 	if(nbytes) {
    400      1.7  perseant 		bzero(bp->b_data, nbytes);
    401      1.7  perseant 	}
    402      1.7  perseant #ifdef DIAGNOSTIC
    403      1.7  perseant 	if(vp==NULL)
    404      1.7  perseant 		panic("vp is NULL in lfs_newbuf");
    405      1.7  perseant 	if(bp==NULL)
    406      1.7  perseant 		panic("bp is NULL after malloc in lfs_newbuf");
    407      1.1   mycroft #endif
    408      1.7  perseant 	s = splbio();
    409      1.7  perseant 	bgetvp(vp, bp);
    410      1.7  perseant 	splx(s);
    411      1.7  perseant 
    412      1.7  perseant 	bp->b_bufsize = size;
    413      1.7  perseant 	bp->b_bcount = size;
    414      1.7  perseant 	bp->b_lblkno = daddr;
    415      1.7  perseant 	bp->b_blkno = daddr;
    416      1.7  perseant 	bp->b_error = 0;
    417      1.7  perseant 	bp->b_resid = 0;
    418      1.7  perseant 	bp->b_iodone = lfs_callback;
    419      1.7  perseant 	bp->b_flags |= B_BUSY | B_CALL | B_NOCACHE;
    420      1.7  perseant 
    421      1.7  perseant 	return (bp);
    422      1.7  perseant }
    423      1.7  perseant 
    424      1.7  perseant void
    425      1.7  perseant lfs_freebuf(bp)
    426      1.7  perseant 	struct buf *bp;
    427      1.7  perseant {
    428      1.7  perseant 	int s;
    429      1.7  perseant 
    430      1.7  perseant 	s = splbio();
    431      1.7  perseant 	if(bp->b_vp)
    432      1.7  perseant 		brelvp(bp);
    433      1.7  perseant 	splx(s);
    434      1.7  perseant 	if (!(bp->b_flags & B_INVAL)) { /* B_INVAL indicates a "fake" buffer */
    435      1.7  perseant 		free(bp->b_data, M_SEGMENT);
    436      1.7  perseant 		bp->b_data = NULL;
    437      1.1   mycroft 	}
    438      1.7  perseant 	free(bp, M_SEGMENT);
    439      1.7  perseant }
    440      1.1   mycroft 
    441      1.7  perseant /*
    442      1.7  perseant  * Definitions for the buffer free lists.
    443      1.7  perseant  */
    444      1.7  perseant #define BQUEUES		4		/* number of free buffer queues */
    445      1.7  perseant 
    446      1.7  perseant #define BQ_LOCKED	0		/* super-blocks &c */
    447      1.7  perseant #define BQ_LRU		1		/* lru, useful buffers */
    448      1.7  perseant #define BQ_AGE		2		/* rubbish */
    449      1.7  perseant #define BQ_EMPTY	3		/* buffer headers with no memory */
    450      1.7  perseant 
    451      1.7  perseant extern TAILQ_HEAD(bqueues, buf) bufqueues[BQUEUES];
    452      1.7  perseant 
    453      1.7  perseant /*
    454      1.7  perseant  * Return a count of buffers on the "locked" queue.
    455      1.7  perseant  */
    456      1.7  perseant void
    457      1.7  perseant lfs_countlocked(count, bytes)
    458      1.7  perseant 	int *count;
    459      1.7  perseant 	long *bytes;
    460      1.7  perseant {
    461      1.7  perseant 	register struct buf *bp;
    462      1.7  perseant 	register int n = 0;
    463      1.7  perseant 	register long int size = 0L;
    464      1.7  perseant 
    465      1.7  perseant 	for (bp = bufqueues[BQ_LOCKED].tqh_first; bp;
    466      1.7  perseant 	    bp = bp->b_freelist.tqe_next) {
    467      1.7  perseant 		n++;
    468      1.7  perseant 		size += bp->b_bufsize;
    469      1.7  perseant 	}
    470      1.7  perseant 	*count = n;
    471      1.7  perseant 	*bytes = size;
    472      1.7  perseant 	return;
    473      1.1   mycroft }
    474