/* $OpenBSD: lfs_bio.c,v 1.12 2005/11/15 21:09:46 miod Exp $ */ /* $NetBSD: lfs_bio.c,v 1.5 1996/02/09 22:28:49 christos Exp $ */ /* * 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. 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_bio.c 8.10 (Berkeley) 6/10/95 */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * LFS block write function. * * XXX * No write cost accounting is done. * This is almost certainly wrong for synchronous operations and NFS. */ int lfs_allclean_wakeup; /* Cleaner wakeup address. */ int locked_queue_count; /* XXX Count of locked-down buffers. */ int lfs_writing; /* Set if already kicked off a writer because of buffer space */ /* #define WRITE_THRESHOLD ((nbuf >> 2) - 10) #define WAIT_THRESHOLD ((nbuf >> 1) - 10) */ #define WAIT_THRESHOLD (nbuf - (nbuf >> 2) - 10) #define WRITE_THRESHOLD ((nbuf >> 1) - 10) #define LFS_BUFWAIT 2 struct timeout wakeup_timeout; int lfs_bwrite(v) void *v; { struct vop_bwrite_args /* { struct buf *a_bp; } */ *ap = v; register struct buf *bp = ap->a_bp; struct lfs *fs; struct inode *ip; int db, error, s; /* * Set the delayed write flag and use reassignbuf to move the buffer * from the clean list to the dirty one. * * Set the B_LOCKED flag and unlock the buffer, causing brelse to move * the buffer onto the LOCKED free list. This is necessary, otherwise * getnewbuf() would try to reclaim the buffers using bawrite, which * isn't going to work. * * XXX we don't let meta-data writes run out of space because they can * come from the segment writer. We need to make sure that there is * enough space reserved so that there's room to write meta-data * blocks. */ if (!(bp->b_flags & B_LOCKED)) { fs = VFSTOUFS(bp->b_vp->v_mount)->um_lfs; db = fragstodb(fs, numfrags(fs, bp->b_bcount)); while (!LFS_FITS(fs, db) && !IS_IFILE(bp) && bp->b_lblkno > 0) { /* Out of space, need cleaner to run */ wakeup(&lfs_allclean_wakeup); wakeup(&fs->lfs_nextseg); error = tsleep(&fs->lfs_avail, PCATCH | PUSER, "cleaner", NULL); if (error) { brelse(bp); return (error); } } ip = VTOI((bp)->b_vp); if (!(ip->i_flag & IN_MODIFIED)) ++fs->lfs_uinodes; ip->i_flag |= IN_CHANGE | IN_MODIFIED | IN_UPDATE; fs->lfs_avail -= db; ++locked_queue_count; bp->b_flags |= B_LOCKED; TAILQ_INSERT_TAIL(&bdirties, bp, b_synclist); bp->b_synctime = time_second + 30; s = splbio(); if (TAILQ_FIRST(&bdirties) == bp) { if (timeout_triggered(&wakeup_timeout)) timeout_del(&wakeup_timeout); if (!timeout_initialized(&wakeup_timeout)) timeout_set(&wakeup_timeout, wakeup, &bdirties); timeout_add(&wakeup_timeout, 30 * hz); } bp->b_flags &= ~(B_READ | B_ERROR); buf_dirty(bp); splx(s); } brelse(bp); return (0); } /* * XXX * This routine flushes buffers out of the B_LOCKED queue when LFS has too * many locked down. Eventually the pageout daemon will simply call LFS * when pages need to be reclaimed. Note, we have one static count of locked * buffers, so we can't have more than a single file system. To make this * work for multiple file systems, put the count into the mount structure. */ void lfs_flush() { register struct mount *mp; #ifdef DOSTATS ++lfs_stats.write_exceeded; #endif if (lfs_writing) return; lfs_writing = 1; CIRCLEQ_FOREACH(mp, &mountlist, mnt_list) { /* The lock check below is to avoid races with unmount. */ if (!strncmp(&mp->mnt_stat.f_fstypename[0], MOUNT_LFS, MFSNAMELEN) && (mp->mnt_flag & (MNT_RDONLY)) == 0 && !((((struct ufsmount *)mp->mnt_data))->ufsmount_u.lfs)->lfs_dirops ) { /* * We set the queue to 0 here because we are about to * write all the dirty buffers we have. If more come * in while we're writing the segment, they may not * get written, so we want the count to reflect these * new writes after the segwrite completes. */ #ifdef DOSTATS ++lfs_stats.flush_invoked; #endif lfs_segwrite(mp, 0); } } lfs_writing = 0; } int lfs_check(vp, blkno) struct vnode *vp; ufs_daddr_t blkno; { int error; error = 0; if (incore(vp, blkno)) return (0); if (locked_queue_count > WRITE_THRESHOLD) lfs_flush(); /* If out of buffers, wait on writer */ while (locked_queue_count > WAIT_THRESHOLD) { #ifdef DOSTATS ++lfs_stats.wait_exceeded; #endif error = tsleep(&locked_queue_count, PCATCH | PUSER, "buffers", hz * LFS_BUFWAIT); } return (error); }