1 /* $NetBSD: lfs_bio.c,v 1.5 1996/02/09 22:28:49 christos Exp $ */ 2 3 /* 4 * Copyright (c) 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * @(#)lfs_bio.c 8.4 (Berkeley) 12/30/93 36 */ 37 38 #include <sys/param.h> 39 #include <sys/systm.h> 40 #include <sys/proc.h> 41 #include <sys/buf.h> 42 #include <sys/vnode.h> 43 #include <sys/resourcevar.h> 44 #include <sys/mount.h> 45 #include <sys/kernel.h> 46 47 #include <ufs/ufs/quota.h> 48 #include <ufs/ufs/inode.h> 49 #include <ufs/ufs/ufsmount.h> 50 #include <ufs/ufs/ufs_extern.h> 51 52 #include <ufs/lfs/lfs.h> 53 #include <ufs/lfs/lfs_extern.h> 54 55 /* 56 * LFS block write function. 57 * 58 * XXX 59 * No write cost accounting is done. 60 * This is almost certainly wrong for synchronous operations and NFS. 61 */ 62 int lfs_allclean_wakeup; /* Cleaner wakeup address. */ 63 int locked_queue_count; /* XXX Count of locked-down buffers. */ 64 int lfs_writing; /* Set if already kicked off a writer 65 because of buffer space */ 66 /* 67 #define WRITE_THRESHHOLD ((nbuf >> 2) - 10) 68 #define WAIT_THRESHHOLD ((nbuf >> 1) - 10) 69 */ 70 #define WAIT_THRESHHOLD (nbuf - (nbuf >> 2) - 10) 71 #define WRITE_THRESHHOLD ((nbuf >> 1) - 10) 72 #define LFS_BUFWAIT 2 73 74 int 75 lfs_bwrite(v) 76 void *v; 77 { 78 struct vop_bwrite_args /* { 79 struct buf *a_bp; 80 } */ *ap = v; 81 register struct buf *bp = ap->a_bp; 82 struct lfs *fs; 83 struct inode *ip; 84 int error, s; 85 86 /* 87 * Set the delayed write flag and use reassignbuf to move the buffer 88 * from the clean list to the dirty one. 89 * 90 * Set the B_LOCKED flag and unlock the buffer, causing brelse to move 91 * the buffer onto the LOCKED free list. This is necessary, otherwise 92 * getnewbuf() would try to reclaim the buffers using bawrite, which 93 * isn't going to work. 94 * 95 * XXX we don't let meta-data writes run out of space because they can 96 * come from the segment writer. We need to make sure that there is 97 * enough space reserved so that there's room to write meta-data 98 * blocks. 99 */ 100 if (!(bp->b_flags & B_LOCKED)) { 101 fs = VFSTOUFS(bp->b_vp->v_mount)->um_lfs; 102 while (!LFS_FITS(fs, fsbtodb(fs, 1)) && !IS_IFILE(bp) && 103 bp->b_lblkno > 0) { 104 /* Out of space, need cleaner to run */ 105 wakeup(&lfs_allclean_wakeup); 106 error = tsleep(&fs->lfs_avail, PCATCH | PUSER, 107 "cleaner", NULL); 108 if (error) { 109 brelse(bp); 110 return (error); 111 } 112 } 113 ip = VTOI((bp)->b_vp); 114 if (!(ip->i_flag & IN_MODIFIED)) 115 ++fs->lfs_uinodes; 116 ip->i_flag |= IN_CHANGE | IN_MODIFIED | IN_UPDATE; 117 fs->lfs_avail -= fsbtodb(fs, 1); 118 ++locked_queue_count; 119 bp->b_flags |= B_DELWRI | B_LOCKED; 120 bp->b_flags &= ~(B_READ | B_ERROR); 121 s = splbio(); 122 reassignbuf(bp, bp->b_vp); 123 splx(s); 124 } 125 brelse(bp); 126 return (0); 127 } 128 129 /* 130 * XXX 131 * This routine flushes buffers out of the B_LOCKED queue when LFS has too 132 * many locked down. Eventually the pageout daemon will simply call LFS 133 * when pages need to be reclaimed. Note, we have one static count of locked 134 * buffers, so we can't have more than a single file system. To make this 135 * work for multiple file systems, put the count into the mount structure. 136 */ 137 void 138 lfs_flush() 139 { 140 register struct mount *mp; 141 142 #ifdef DOSTATS 143 ++lfs_stats.write_exceeded; 144 #endif 145 if (lfs_writing) 146 return; 147 lfs_writing = 1; 148 for (mp = mountlist.cqh_first; mp != (void *)&mountlist; 149 mp = mp->mnt_list.cqe_next) { 150 /* The lock check below is to avoid races with unmount. */ 151 if (!strncmp(&mp->mnt_stat.f_fstypename[0], MOUNT_LFS, MFSNAMELEN) && 152 (mp->mnt_flag & (MNT_MLOCK|MNT_RDONLY|MNT_UNMOUNT)) == 0 && 153 !((((struct ufsmount *)mp->mnt_data))->ufsmount_u.lfs)->lfs_dirops ) { 154 /* 155 * We set the queue to 0 here because we are about to 156 * write all the dirty buffers we have. If more come 157 * in while we're writing the segment, they may not 158 * get written, so we want the count to reflect these 159 * new writes after the segwrite completes. 160 */ 161 #ifdef DOSTATS 162 ++lfs_stats.flush_invoked; 163 #endif 164 lfs_segwrite(mp, 0); 165 } 166 } 167 lfs_writing = 0; 168 } 169 170 int 171 lfs_check(vp, blkno) 172 struct vnode *vp; 173 daddr_t blkno; 174 { 175 int error; 176 177 error = 0; 178 if (incore(vp, blkno)) 179 return (0); 180 if (locked_queue_count > WRITE_THRESHHOLD) 181 lfs_flush(); 182 183 /* If out of buffers, wait on writer */ 184 while (locked_queue_count > WAIT_THRESHHOLD) { 185 #ifdef DOSTATS 186 ++lfs_stats.wait_exceeded; 187 #endif 188 error = tsleep(&locked_queue_count, PCATCH | PUSER, "buffers", 189 hz * LFS_BUFWAIT); 190 } 191 192 return (error); 193 } 194