convert VOP_UNLOCK and vrele into vput's; add proc parameter to union_dircache

[unix-history] / usr / src / sys / kern / vfs_cluster.c

diff --git a/usr/src/sys/kern/vfs_cluster.c b/usr/src/sys/kern/vfs_cluster.c
index a27c42e..e6b6b9a 100644 (file)
--- a/usr/src/sys/kern/vfs_cluster.c
+++ b/usr/src/sys/kern/vfs_cluster.c
@@ -1,643 +1,742 @@
 /*-
 /*-

- * Copyright (c) 1982, 1986, 1989 The Regents of the University of California.
- * All rights reserved.
+ * Copyright (c) 1993
+ *     The Regents of the University of California.  All rights reserved.

  *
  *

- * This module is believed to contain source code proprietary to AT&T.
- * Use and redistribution is subject to the Berkeley Software License
- * Agreement and your Software Agreement with AT&T (Western Electric).
+ * %sccs.include.redist.c%

  *
  *

- *     @(#)vfs_cluster.c       7.49 (Berkeley) %G%
+ *     @(#)vfs_cluster.c       8.10 (Berkeley) %G%

  */
 
 #include <sys/param.h>
 #include <sys/proc.h>
 #include <sys/buf.h>
 #include <sys/vnode.h>
  */
 
 #include <sys/param.h>
 #include <sys/proc.h>
 #include <sys/buf.h>
 #include <sys/vnode.h>

-#include <sys/specdev.h>

 #include <sys/mount.h>
 #include <sys/trace.h>
 #include <sys/mount.h>
 #include <sys/trace.h>

+#include <sys/malloc.h>

 #include <sys/resourcevar.h>
 #include <sys/resourcevar.h>

+#include <libkern/libkern.h>
+#include <ufs/ufs/quota.h>
+#include <ufs/ufs/inode.h>

 
 /*
 
 /*

- * Initialize buffers and hash links for buffers.
+ * Local declarations

  */
  */

-void
-bufinit()
-{
-       register int i;
-       register struct buf *bp, *dp;
-       register struct bufhd *hp;
-       int base, residual;
-
-       for (hp = bufhash, i = 0; i < BUFHSZ; i++, hp++)
-               hp->b_forw = hp->b_back = (struct buf *)hp;
-
-       for (dp = bfreelist; dp < &bfreelist[BQUEUES]; dp++) {
-               dp->b_forw = dp->b_back = dp->av_forw = dp->av_back = dp;
-               dp->b_flags = B_HEAD;
-       }
-       base = bufpages / nbuf;
-       residual = bufpages % nbuf;
-       for (i = 0; i < nbuf; i++) {
-               bp = &buf[i];
-               bp->b_dev = NODEV;
-               bp->b_bcount = 0;
-               bp->b_rcred = NOCRED;
-               bp->b_wcred = NOCRED;
-               bp->b_dirtyoff = 0;
-               bp->b_dirtyend = 0;
-               bp->b_validoff = 0;
-               bp->b_validend = 0;
-               bp->b_un.b_addr = buffers + i * MAXBSIZE;
-               if (i < residual)
-                       bp->b_bufsize = (base + 1) * CLBYTES;
-               else
-                       bp->b_bufsize = base * CLBYTES;
-               binshash(bp, &bfreelist[BQ_AGE]);
-               bp->b_flags = B_INVAL;
-               dp = bp->b_bufsize ? &bfreelist[BQ_AGE] : &bfreelist[BQ_EMPTY];
-               binsheadfree(bp, dp);
-       }
-}
-
+struct buf *cluster_newbuf __P((struct vnode *, struct buf *, long, daddr_t,
+           daddr_t, long, int));
+struct buf *cluster_rbuild __P((struct vnode *, u_quad_t, struct buf *,
+           daddr_t, daddr_t, long, int, long));
+void       cluster_wbuild __P((struct vnode *, struct buf *, long,
+           daddr_t, int, daddr_t));
+struct cluster_save *cluster_collectbufs __P((struct vnode *, struct buf *));
+
+#ifdef DIAGNOSTIC

 /*
 /*

- * Find the block in the buffer pool.
- * If the buffer is not present, allocate a new buffer and load
- * its contents according to the filesystem fill routine.
+ * Set to 1 if reads of block zero should cause readahead to be done.
+ * Set to 0 treats a read of block zero as a non-sequential read.
+ *
+ * Setting to one assumes that most reads of block zero of files are due to
+ * sequential passes over the files (e.g. cat, sum) where additional blocks
+ * will soon be needed.  Setting to zero assumes that the majority are
+ * surgical strikes to get particular info (e.g. size, file) where readahead
+ * blocks will not be used and, in fact, push out other potentially useful
+ * blocks from the cache.  The former seems intuitive, but some quick tests
+ * showed that the latter performed better from a system-wide point of view.

  */
  */

-bread(vp, blkno, size, cred, bpp)
-       struct vnode *vp;
-       daddr_t blkno;
-       int size;
-       struct ucred *cred;
-       struct buf **bpp;
-#ifdef SECSIZE
-       long secsize;
-#endif SECSIZE
-{
-       USES_VOP_STRATEGY;
-       struct proc *p = curproc;               /* XXX */
-       register struct buf *bp;
-
-       if (size == 0)
-               panic("bread: size 0");
-#ifdef SECSIZE
-       bp = getblk(dev, blkno, size, secsize);
-#else SECSIZE
-       *bpp = bp = getblk(vp, blkno, size);
-#endif SECSIZE
-       if (bp->b_flags & (B_DONE | B_DELWRI)) {
-               trace(TR_BREADHIT, pack(vp, size), blkno);
-               return (0);
-       }
-       bp->b_flags |= B_READ;
-       if (bp->b_bcount > bp->b_bufsize)
-               panic("bread");
-       if (bp->b_rcred == NOCRED && cred != NOCRED) {
-               crhold(cred);
-               bp->b_rcred = cred;
-       }
-       VOP_STRATEGY(bp);
-       trace(TR_BREADMISS, pack(vp, size), blkno);
-       p->p_stats->p_ru.ru_inblock++;          /* pay for read */
-       return (biowait(bp));
-}
+int    doclusterraz = 0;
+#define ISSEQREAD(vp, blk) \
+       (((blk) != 0 || doclusterraz) && \
+        ((blk) == (vp)->v_lastr + 1 || (blk) == (vp)->v_lastr))
+#else
+#define ISSEQREAD(vp, blk) \
+       ((blk) != 0 && ((blk) == (vp)->v_lastr + 1 || (blk) == (vp)->v_lastr))
+#endif

 
 /*
 
 /*

- * Operates like bread, but also starts I/O on the N specified
- * read-ahead blocks.
+ * This replaces bread.  If this is a bread at the beginning of a file and
+ * lastr is 0, we assume this is the first read and we'll read up to two
+ * blocks if they are sequential.  After that, we'll do regular read ahead
+ * in clustered chunks.
+ *
+ * There are 4 or 5 cases depending on how you count:
+ *     Desired block is in the cache:
+ *         1 Not sequential access (0 I/Os).
+ *         2 Access is sequential, do read-ahead (1 ASYNC).
+ *     Desired block is not in cache:
+ *         3 Not sequential access (1 SYNC).
+ *         4 Sequential access, next block is contiguous (1 SYNC).
+ *         5 Sequential access, next block is not contiguous (1 SYNC, 1 ASYNC)
+ *
+ * There are potentially two buffers that require I/O.
+ *     bp is the block requested.
+ *     rbp is the read-ahead block.
+ *     If either is NULL, then you don't have to do the I/O.

  */
  */

-breadn(vp, blkno, size, rablkno, rabsize, num, cred, bpp)
+cluster_read(vp, filesize, lblkno, size, cred, bpp)

        struct vnode *vp;
        struct vnode *vp;

-       daddr_t blkno; int size;
-#ifdef SECSIZE
-       long secsize;
-#endif SECSIZE
-       daddr_t rablkno[]; int rabsize[];
-       int num;
+       u_quad_t filesize;
+       daddr_t lblkno;
+       long size;

        struct ucred *cred;
        struct buf **bpp;
 {
        struct ucred *cred;
        struct buf **bpp;
 {

-       USES_VOP_STRATEGY;
-       struct proc *p = curproc;               /* XXX */
-       register struct buf *bp, *rabp;
-       register int i;
+       struct buf *bp, *rbp;
+       daddr_t blkno, ioblkno;
+       long flags;
+       int error, num_ra, alreadyincore;
+
+#ifdef DIAGNOSTIC
+       if (size == 0)
+               panic("cluster_read: size = 0");
+#endif

 
 

-       bp = NULL;
+       error = 0;
+       flags = B_READ;
+       *bpp = bp = getblk(vp, lblkno, size, 0, 0);
+       if (bp->b_flags & B_CACHE) {
+               /*
+                * Desired block is in cache; do any readahead ASYNC.
+                * Case 1, 2.
+                */
+               trace(TR_BREADHIT, pack(vp, size), lblkno);
+               flags |= B_ASYNC;
+               ioblkno = lblkno + (vp->v_ralen ? vp->v_ralen : 1);
+               alreadyincore = incore(vp, ioblkno) != NULL;
+               bp = NULL;
+       } else {
+               /* Block wasn't in cache, case 3, 4, 5. */
+               trace(TR_BREADMISS, pack(vp, size), lblkno);
+               bp->b_flags |= B_READ;
+               ioblkno = lblkno;
+               alreadyincore = 0;
+               curproc->p_stats->p_ru.ru_inblock++;            /* XXX */
+       }

        /*
        /*

-        * If the block is not memory resident,
-        * allocate a buffer and start I/O.
+        * XXX
+        * Replace 1 with a window size based on some permutation of
+        * maxcontig and rot_delay.  This will let you figure out how
+        * many blocks you should read-ahead (case 2, 4, 5).
+        *
+        * If the access isn't sequential, reset the window to 1.
+        * Note that a read to the same block is considered sequential.
+        * This catches the case where the file is being read sequentially,
+        * but at smaller than the filesystem block size.

         */
         */

-       if (!incore(vp, blkno)) {
-               *bpp = bp = getblk(vp, blkno, size);
-#endif SECSIZE
-               if ((bp->b_flags & (B_DONE | B_DELWRI)) == 0) {
-                       bp->b_flags |= B_READ;
-                       if (bp->b_bcount > bp->b_bufsize)
-                               panic("breadn");
-                       if (bp->b_rcred == NOCRED && cred != NOCRED) {
-                               crhold(cred);
-                               bp->b_rcred = cred;
+       rbp = NULL;
+       if (!ISSEQREAD(vp, lblkno)) {
+               vp->v_ralen = 0;
+               vp->v_maxra = lblkno;
+       } else if ((ioblkno + 1) * size <= filesize && !alreadyincore &&
+           !(error = VOP_BMAP(vp, ioblkno, NULL, &blkno, &num_ra)) &&
+           blkno != -1) {
+               /*
+                * Reading sequentially, and the next block is not in the
+                * cache.  We are going to try reading ahead.
+                */
+               if (num_ra) {
+                       /*
+                        * If our desired readahead block had been read
+                        * in a previous readahead but is no longer in
+                        * core, then we may be reading ahead too far
+                        * or are not using our readahead very rapidly.
+                        * In this case we scale back the window.
+                        */
+                       if (!alreadyincore && ioblkno <= vp->v_maxra)
+                               vp->v_ralen = max(vp->v_ralen >> 1, 1);
+                       /*
+                        * There are more sequential blocks than our current
+                        * window allows, scale up.  Ideally we want to get
+                        * in sync with the filesystem maxcontig value.
+                        */
+                       else if (num_ra > vp->v_ralen && lblkno != vp->v_lastr)
+                               vp->v_ralen = vp->v_ralen ?
+                                       min(num_ra, vp->v_ralen << 1) : 1;
+
+                       if (num_ra > vp->v_ralen)
+                               num_ra = vp->v_ralen;
+               }
+
+               if (num_ra)                             /* case 2, 4 */
+                       rbp = cluster_rbuild(vp, filesize,
+                           bp, ioblkno, blkno, size, num_ra, flags);
+               else if (ioblkno == lblkno) {
+                       bp->b_blkno = blkno;
+                       /* Case 5: check how many blocks to read ahead */
+                       ++ioblkno;
+                       if ((ioblkno + 1) * size > filesize ||
+                           incore(vp, ioblkno) || (error = VOP_BMAP(vp,
+                            ioblkno, NULL, &blkno, &num_ra)) || blkno == -1)
+                               goto skip_readahead;
+                       /*
+                        * Adjust readahead as above.
+                        * Don't check alreadyincore, we know it is 0 from
+                        * the previous conditional.
+                        */
+                       if (num_ra) {
+                               if (ioblkno <= vp->v_maxra)
+                                       vp->v_ralen = max(vp->v_ralen >> 1, 1);
+                               else if (num_ra > vp->v_ralen &&
+                                        lblkno != vp->v_lastr)
+                                       vp->v_ralen = vp->v_ralen ?
+                                               min(num_ra,vp->v_ralen<<1) : 1;
+                               if (num_ra > vp->v_ralen)
+                                       num_ra = vp->v_ralen;
+                       }
+                       flags |= B_ASYNC;
+                       if (num_ra)
+                               rbp = cluster_rbuild(vp, filesize,
+                                   NULL, ioblkno, blkno, size, num_ra, flags);
+                       else {
+                               rbp = getblk(vp, ioblkno, size, 0, 0);
+                               rbp->b_flags |= flags;
+                               rbp->b_blkno = blkno;

                        }
                        }

-                       VOP_STRATEGY(bp);
-                       trace(TR_BREADMISS, pack(vp, size), blkno);
-                       p->p_stats->p_ru.ru_inblock++;  /* pay for read */

                } else {
                } else {

-                       trace(TR_BREADHIT, pack(vp, size), blkno);
+                       /* case 2; read ahead single block */
+                       rbp = getblk(vp, ioblkno, size, 0, 0);
+                       rbp->b_flags |= flags;
+                       rbp->b_blkno = blkno;

                }
                }

-       }

 
 

-       /*
-        * If there's read-ahead block(s), start I/O
-        * on them also (as above).
-        */
-       for (i = 0; i < num; i++) {
-               if (incore(vp, rablkno[i]))
-                       continue;
-               rabp = getblk(vp, rablkno[i], rabsize[i]);
-#endif SECSIZE
-               if (rabp->b_flags & (B_DONE | B_DELWRI)) {
-                       brelse(rabp);
-                       trace(TR_BREADHITRA, pack(vp, rabsize[i]), rablkno[i]);
-               } else {
-                       rabp->b_flags |= B_ASYNC | B_READ;
-                       if (rabp->b_bcount > rabp->b_bufsize)
-                               panic("breadrabp");
-                       if (rabp->b_rcred == NOCRED && cred != NOCRED) {
-                               crhold(cred);
-                               rabp->b_rcred = cred;
-                       }
-                       VOP_STRATEGY(rabp);
-                       trace(TR_BREADMISSRA, pack(vp, rabsize[i]), rablkno[i]);
-                       p->p_stats->p_ru.ru_inblock++;  /* pay in advance */
+               if (rbp == bp)                  /* case 4 */
+                       rbp = NULL;
+               else if (rbp) {                 /* case 2, 5 */
+                       trace(TR_BREADMISSRA,
+                           pack(vp, (num_ra + 1) * size), ioblkno);
+                       curproc->p_stats->p_ru.ru_inblock++;    /* XXX */

                }
        }
 
                }
        }
 

+       /* XXX Kirk, do we need to make sure the bp has creds? */
+skip_readahead:
+       if (bp)
+               if (bp->b_flags & (B_DONE | B_DELWRI))
+                       panic("cluster_read: DONE bp");
+               else 
+                       error = VOP_STRATEGY(bp);
+
+       if (rbp)
+               if (error || rbp->b_flags & (B_DONE | B_DELWRI)) {
+                       rbp->b_flags &= ~(B_ASYNC | B_READ);
+                       brelse(rbp);
+               } else
+                       (void) VOP_STRATEGY(rbp);
+

        /*
        /*

-        * If block was memory resident, let bread get it.
-        * If block was not memory resident, the read was
-        * started above, so just wait for the read to complete.
+        * Recalculate our maximum readahead

         */
         */

-       if (bp == NULL)
-#ifdef SECSIZE
-               return (bread(dev, blkno, size, secsize));
-#else SECSIZE
-               return (bread(vp, blkno, size, cred, bpp));
-       return (biowait(bp));
+       if (rbp == NULL)
+               rbp = bp;
+       if (rbp)
+               vp->v_maxra = rbp->b_lblkno + (rbp->b_bufsize / size) - 1;
+
+       if (bp)
+               return(biowait(bp));
+       return(error);

 }
 
 /*
 }
 
 /*

- * Synchronous write.
- * Release buffer on completion.
+ * If blocks are contiguous on disk, use this to provide clustered
+ * read ahead.  We will read as many blocks as possible sequentially
+ * and then parcel them up into logical blocks in the buffer hash table.

  */
  */

-bwrite(bp)
-       register struct buf *bp;
+struct buf *
+cluster_rbuild(vp, filesize, bp, lbn, blkno, size, run, flags)
+       struct vnode *vp;
+       u_quad_t filesize;
+       struct buf *bp;
+       daddr_t lbn;
+       daddr_t blkno;
+       long size;
+       int run;
+       long flags;

 {
 {

-       USES_VOP_STRATEGY;
-       struct proc *p = curproc;               /* XXX */
-       register int flag;
-       int s, error = 0;
-
-       flag = bp->b_flags;
-       bp->b_flags &= ~(B_READ | B_DONE | B_ERROR | B_DELWRI);
-       if (flag & B_ASYNC) {
-               if ((flag & B_DELWRI) == 0)
-                       p->p_stats->p_ru.ru_oublock++;  /* no one paid yet */
-               else
-                       reassignbuf(bp, bp->b_vp);
+       struct cluster_save *b_save;
+       struct buf *tbp;
+       daddr_t bn;
+       int i, inc;
+
+#ifdef DIAGNOSTIC
+       if (size != vp->v_mount->mnt_stat.f_iosize)
+               panic("cluster_rbuild: size %d != filesize %d\n",
+                       size, vp->v_mount->mnt_stat.f_iosize);
+#endif
+       if (size * (lbn + run + 1) > filesize)
+               --run;
+       if (run == 0) {
+               if (!bp) {
+                       bp = getblk(vp, lbn, size, 0, 0);
+                       bp->b_blkno = blkno;
+                       bp->b_flags |= flags;
+               }
+               return(bp);

        }
        }

-       trace(TR_BWRITE, pack(bp->b_vp, bp->b_bcount), bp->b_lblkno);
-       if (bp->b_bcount > bp->b_bufsize)
-               panic("bwrite");
-       s = splbio();
-       bp->b_vp->v_numoutput++;
-       splx(s);
-       VOP_STRATEGY(bp);

 
 

+       bp = cluster_newbuf(vp, bp, flags, blkno, lbn, size, run + 1);
+       if (bp->b_flags & (B_DONE | B_DELWRI))
+               return (bp);
+
+       b_save = malloc(sizeof(struct buf *) * run + sizeof(struct cluster_save),
+           M_SEGMENT, M_WAITOK);
+       b_save->bs_bufsize = b_save->bs_bcount = size;
+       b_save->bs_nchildren = 0;
+       b_save->bs_children = (struct buf **)(b_save + 1);
+       b_save->bs_saveaddr = bp->b_saveaddr;
+       bp->b_saveaddr = (caddr_t) b_save;
+
+       inc = btodb(size);
+       for (bn = blkno + inc, i = 1; i <= run; ++i, bn += inc) {
+               /*
+                * A component of the cluster is already in core,
+                * terminate the cluster early.
+                */
+               if (incore(vp, lbn + i))
+                       break;
+               tbp = getblk(vp, lbn + i, 0, 0, 0);
+               /*
+                * getblk may return some memory in the buffer if there were
+                * no empty buffers to shed it to.  If there is currently
+                * memory in the buffer, we move it down size bytes to make
+                * room for the valid pages that cluster_callback will insert.
+                * We do this now so we don't have to do it at interrupt time
+                * in the callback routine.
+                */
+               if (tbp->b_bufsize != 0) {
+                       caddr_t bdata = (char *)tbp->b_data;
+
+                       /*
+                        * No room in the buffer to add another page,
+                        * terminate the cluster early.
+                        */
+                       if (tbp->b_bufsize + size > MAXBSIZE) {
+#ifdef DIAGNOSTIC
+                               if (tbp->b_bufsize != MAXBSIZE)
+                                       panic("cluster_rbuild: too much memory");
+#endif
+                               brelse(tbp);
+                               break;
+                       }
+                       if (tbp->b_bufsize > size) {
+                               /*
+                                * XXX if the source and destination regions
+                                * overlap we have to copy backward to avoid
+                                * clobbering any valid pages (i.e. pagemove
+                                * implementations typically can't handle
+                                * overlap).
+                                */
+                               bdata += tbp->b_bufsize;
+                               while (bdata > (char *)tbp->b_data) {
+                                       bdata -= CLBYTES;
+                                       pagemove(bdata, bdata + size, CLBYTES);
+                               }
+                       } else 
+                               pagemove(bdata, bdata + size, tbp->b_bufsize);
+               }
+               tbp->b_blkno = bn;
+               {
+                       daddr_t temp;
+                       VOP_BMAP(tbp->b_vp, tbp->b_lblkno, NULL, &temp, NULL);
+                       if (temp != bn) {
+                               printf("Block: %d Assigned address: %x Bmap address: %x\n",
+                                           tbp->b_lblkno, tbp->b_blkno, temp);
+                               panic("cluster_rbuild: wrong disk address");
+                       }
+               }
+               tbp->b_flags |= flags | B_READ | B_ASYNC;
+               ++b_save->bs_nchildren;
+               b_save->bs_children[i - 1] = tbp;
+       }

        /*
        /*

-        * If the write was synchronous, then await I/O completion.
-        * If the write was "delayed", then we put the buffer on
-        * the queue of blocks awaiting I/O completion status.
+        * The cluster may have been terminated early, adjust the cluster
+        * buffer size accordingly.  If no cluster could be formed,
+        * deallocate the cluster save info.

         */
         */

-       if ((flag & B_ASYNC) == 0) {
-               error = biowait(bp);
-               if ((flag&B_DELWRI) == 0)
-                       p->p_stats->p_ru.ru_oublock++;  /* no one paid yet */
-               else
-                       reassignbuf(bp, bp->b_vp);
-               brelse(bp);
-       } else if (flag & B_DELWRI) {
-               s = splbio();
-               bp->b_flags |= B_AGE;
-               splx(s);
+       if (i <= run) {
+               if (i == 1) {
+                       bp->b_saveaddr = b_save->bs_saveaddr;
+                       bp->b_flags &= ~B_CALL;
+                       bp->b_iodone = NULL;
+                       free(b_save, M_SEGMENT);
+               }
+               allocbuf(bp, size * i);

        }
        }

-       return (error);
+       return(bp);

 }
 
 }
 

-int
-vn_bwrite(ap)
-       struct vop_bwrite_args *ap;
-{
-       return bwrite (ap->a_bp);
-}
-
-

 /*
 /*

- * Delayed write.
- *
- * The buffer is marked dirty, but is not queued for I/O.
- * This routine should be used when the buffer is expected
- * to be modified again soon, typically a small write that
- * partially fills a buffer.
- *
- * NB: magnetic tapes cannot be delayed; they must be
- * written in the order that the writes are requested.
+ * Either get a new buffer or grow the existing one.

  */
  */

-bdwrite(bp)
-       register struct buf *bp;
+struct buf *
+cluster_newbuf(vp, bp, flags, blkno, lblkno, size, run)
+       struct vnode *vp;
+       struct buf *bp;
+       long flags;
+       daddr_t blkno;
+       daddr_t lblkno;
+       long size;
+       int run;

 {
 {

-       USES_VOP_IOCTL;
-       struct proc *p = curproc;               /* XXX */
-
-       if ((bp->b_flags & B_DELWRI) == 0) {
-               bp->b_flags |= B_DELWRI;
-               reassignbuf(bp, bp->b_vp);
-               p->p_stats->p_ru.ru_oublock++;          /* no one paid yet */
-       }
-       /*
-        * If this is a tape drive, the write must be initiated.
-        */
-       if (bdevsw[major(bp->b_dev)].d_flags & B_TAPE)
-               bawrite(bp);
-       } else {
-               bp->b_flags |= (B_DONE | B_DELWRI);
-               brelse(bp);
+       if (!bp) {
+               bp = getblk(vp, lblkno, size, 0, 0);
+               if (bp->b_flags & (B_DONE | B_DELWRI)) {
+                       bp->b_blkno = blkno;
+                       return(bp);
+               }

        }
        }

+       allocbuf(bp, run * size);
+       bp->b_blkno = blkno;
+       bp->b_iodone = cluster_callback;
+       bp->b_flags |= flags | B_CALL;
+       return(bp);

 }
 
 /*
 }
 
 /*

- * Asynchronous write.
- * Start I/O on a buffer, but do not wait for it to complete.
- * The buffer is released when the I/O completes.
+ * Cleanup after a clustered read or write.
+ * This is complicated by the fact that any of the buffers might have
+ * extra memory (if there were no empty buffer headers at allocbuf time)
+ * that we will need to shift around.

  */
  */

-bawrite(bp)
-       register struct buf *bp;
+void
+cluster_callback(bp)
+       struct buf *bp;

 {
 {

+       struct cluster_save *b_save;
+       struct buf **bpp, *tbp;
+       long bsize;
+       caddr_t cp;
+       int error = 0;

 
        /*
 
        /*

-        * Setting the ASYNC flag causes bwrite to return
-        * after starting the I/O.
+        * Must propogate errors to all the components.

         */
         */

-       bp->b_flags |= B_ASYNC;
-       (void) bwrite(bp);
-}
+       if (bp->b_flags & B_ERROR)
+               error = bp->b_error;

 
 

-/*
- * Release a buffer.
- * Even if the buffer is dirty, no I/O is started.
- */
-brelse(bp)
-       register struct buf *bp;
-{
-       register struct buf *flist;
-       int s;
+       daddr_t daddr;
+       b_save = (struct cluster_save *)(bp->b_saveaddr);
+       bp->b_saveaddr = b_save->bs_saveaddr;

 
 

-       trace(TR_BRELSE, pack(bp->b_vp, bp->b_bufsize), bp->b_lblkno);
+       bsize = b_save->bs_bufsize;
+       cp = (char *)bp->b_data + bsize;

        /*
        /*

-        * If a process is waiting for the buffer, or
-        * is waiting for a free buffer, awaken it.
+        * Move memory from the large cluster buffer into the component
+        * buffers and mark IO as done on these.

         */
         */

-       if (bp->b_flags & B_WANTED)
-               wakeup((caddr_t)bp);
-       if (bfreelist[0].b_flags & B_WANTED) {
-               bfreelist[0].b_flags &= ~B_WANTED;
-               wakeup((caddr_t)bfreelist);
+       for (bpp = b_save->bs_children; b_save->bs_nchildren--; ++bpp) {
+               tbp = *bpp;
+               pagemove(cp, tbp->b_data, bsize);
+               tbp->b_bufsize += bsize;
+               tbp->b_bcount = bsize;
+               if (error) {
+                       tbp->b_flags |= B_ERROR;
+                       tbp->b_error = error;
+               }
+               biodone(tbp);
+               bp->b_bufsize -= bsize;
+               cp += bsize;

        }
        /*
        }
        /*

-        * Retry I/O for locked buffers rather than invalidating them.
+        * If there was excess memory in the cluster buffer,
+        * slide it up adjacent to the remaining valid data.

         */
         */

-       s = splbio();
-       if ((bp->b_flags & B_ERROR) && (bp->b_flags & B_LOCKED))
-               bp->b_flags &= ~B_ERROR;
-       /*
-        * Disassociate buffers that are no longer valid.
-        */
-       if (bp->b_flags & (B_NOCACHE | B_ERROR))
-               bp->b_flags |= B_INVAL;
-       if ((bp->b_bufsize <= 0) || (bp->b_flags & (B_ERROR | B_INVAL))) {
-               if (bp->b_vp)
-                       brelvp(bp);
-               bp->b_flags &= ~B_DELWRI;
+       if (bp->b_bufsize != bsize) {
+               if (bp->b_bufsize < bsize)
+                       panic("cluster_callback: too little memory");
+               pagemove(cp, (char *)bp->b_data + bsize, bp->b_bufsize - bsize);

        }
        }

-       /*
-        * Stick the buffer back on a free list.
-        */
-       if (bp->b_bufsize <= 0) {
-               /* block has no buffer ... put at front of unused buffer list */
-               flist = &bfreelist[BQ_EMPTY];
-               binsheadfree(bp, flist);
-       } else if (bp->b_flags & (B_ERROR | B_INVAL)) {
-               /* block has no info ... put at front of most free list */
-               flist = &bfreelist[BQ_AGE];
-               binsheadfree(bp, flist);
-       } else {
-               if (bp->b_flags & B_LOCKED)
-                       flist = &bfreelist[BQ_LOCKED];
-               else if (bp->b_flags & B_AGE)
-                       flist = &bfreelist[BQ_AGE];
-               else
-                       flist = &bfreelist[BQ_LRU];
-               binstailfree(bp, flist);
+       bp->b_bcount = bsize;
+       bp->b_iodone = NULL;
+       free(b_save, M_SEGMENT);
+       if (bp->b_flags & B_ASYNC)
+               brelse(bp);
+       else {
+               bp->b_flags &= ~B_WANTED;
+               wakeup((caddr_t)bp);

        }
        }

-       bp->b_flags &= ~(B_WANTED | B_BUSY | B_ASYNC | B_AGE | B_NOCACHE);
-       splx(s);

 }
 
 /*
 }
 
 /*

- * Check to see if a block is currently memory resident.
+ * Do clustered write for FFS.
+ *
+ * Three cases:
+ *     1. Write is not sequential (write asynchronously)
+ *     Write is sequential:
+ *     2.      beginning of cluster - begin cluster
+ *     3.      middle of a cluster - add to cluster
+ *     4.      end of a cluster - asynchronously write cluster

  */
  */

-incore(vp, blkno)
-       struct vnode *vp;
-       daddr_t blkno;
+void
+cluster_write(bp, filesize)
+        struct buf *bp;
+       u_quad_t filesize;

 {
 {

-       register struct buf *bp;
-       register struct buf *dp;
-
-       dp = BUFHASH(vp, blkno);
-       for (bp = dp->b_forw; bp != dp; bp = bp->b_forw)
-               if (bp->b_lblkno == blkno && bp->b_vp == vp &&
-                   (bp->b_flags & B_INVAL) == 0)
-                       return (1);
-       return (0);
+        struct vnode *vp;
+        daddr_t lbn;
+        int maxclen, cursize;
+
+        vp = bp->b_vp;
+        lbn = bp->b_lblkno;
+
+       /* Initialize vnode to beginning of file. */
+       if (lbn == 0)
+               vp->v_lasta = vp->v_clen = vp->v_cstart = vp->v_lastw = 0;
+
+        if (vp->v_clen == 0 || lbn != vp->v_lastw + 1 ||
+           (bp->b_blkno != vp->v_lasta + btodb(bp->b_bcount))) {
+               maxclen = MAXBSIZE / vp->v_mount->mnt_stat.f_iosize - 1;
+               if (vp->v_clen != 0) {
+                       /*
+                        * Next block is not sequential.
+                        *
+                        * If we are not writing at end of file, the process
+                        * seeked to another point in the file since its
+                        * last write, or we have reached our maximum
+                        * cluster size, then push the previous cluster.
+                        * Otherwise try reallocating to make it sequential.
+                        */
+                       cursize = vp->v_lastw - vp->v_cstart + 1;
+                       if ((lbn + 1) * bp->b_bcount != filesize ||
+                           lbn != vp->v_lastw + 1 || vp->v_clen <= cursize) {
+                               cluster_wbuild(vp, NULL, bp->b_bcount,
+                                   vp->v_cstart, cursize, lbn);
+                       } else {
+                               struct buf **bpp, **endbp;
+                               struct cluster_save *buflist;
+
+                               buflist = cluster_collectbufs(vp, bp);
+                               endbp = &buflist->bs_children
+                                   [buflist->bs_nchildren - 1];
+                               if (VOP_REALLOCBLKS(vp, buflist)) {
+                                       /*
+                                        * Failed, push the previous cluster.
+                                        */
+                                       for (bpp = buflist->bs_children;
+                                            bpp < endbp; bpp++)
+                                               brelse(*bpp);
+                                       free(buflist, M_SEGMENT);
+                                       cluster_wbuild(vp, NULL, bp->b_bcount,
+                                           vp->v_cstart, cursize, lbn);
+                               } else {
+                                       /*
+                                        * Succeeded, keep building cluster.
+                                        */
+                                       for (bpp = buflist->bs_children;
+                                            bpp <= endbp; bpp++)
+                                               bdwrite(*bpp);
+                                       free(buflist, M_SEGMENT);
+                                       vp->v_lastw = lbn;
+                                       vp->v_lasta = bp->b_blkno;
+                                       return;
+                               }
+                       }
+               }
+               /*
+                * Consider beginning a cluster.
+                * If at end of file, make cluster as large as possible,
+                * otherwise find size of existing cluster.
+                */
+               if ((lbn + 1) * bp->b_bcount != filesize &&
+                   (VOP_BMAP(vp, lbn, NULL, &bp->b_blkno, &maxclen) ||
+                    bp->b_blkno == -1)) {
+                       bawrite(bp);
+                       vp->v_clen = 0;
+                       vp->v_lasta = bp->b_blkno;
+                       vp->v_cstart = lbn + 1;
+                       vp->v_lastw = lbn;
+                       return;
+               }
+                vp->v_clen = maxclen;
+                if (maxclen == 0) {            /* I/O not contiguous */
+                       vp->v_cstart = lbn + 1;
+                        bawrite(bp);
+                } else {                       /* Wait for rest of cluster */
+                       vp->v_cstart = lbn;
+                        bdwrite(bp);
+               }
+       } else if (lbn == vp->v_cstart + vp->v_clen) {
+               /*
+                * At end of cluster, write it out.
+                */
+               cluster_wbuild(vp, bp, bp->b_bcount, vp->v_cstart,
+                   vp->v_clen + 1, lbn);
+               vp->v_clen = 0;
+               vp->v_cstart = lbn + 1;
+       } else
+               /*
+                * In the middle of a cluster, so just delay the
+                * I/O for now.
+                */
+               bdwrite(bp);
+       vp->v_lastw = lbn;
+       vp->v_lasta = bp->b_blkno;

 }
 
 }
 

+

 /*
 /*

- * Check to see if a block is currently memory resident.
- * If it is resident, return it. If it is not resident,
- * allocate a new buffer and assign it to the block.
+ * This is an awful lot like cluster_rbuild...wish they could be combined.
+ * The last lbn argument is the current block on which I/O is being
+ * performed.  Check to see that it doesn't fall in the middle of
+ * the current block (if last_bp == NULL).

  */
  */

-struct buf *
-#ifdef SECSIZE
-getblk(dev, blkno, size, secsize)
-#else SECSIZE
-getblk(vp, blkno, size)
-       register struct vnode *vp;
-       daddr_t blkno;
-       int size;
-#ifdef SECSIZE
-       long secsize;
-#endif SECSIZE
+void
+cluster_wbuild(vp, last_bp, size, start_lbn, len, lbn)
+       struct vnode *vp;
+       struct buf *last_bp;
+       long size;
+       daddr_t start_lbn;
+       int len;
+       daddr_t lbn;

 {
 {

-       register struct buf *bp, *dp;
-       int s;
+       struct cluster_save *b_save;
+       struct buf *bp, *tbp;
+       caddr_t cp;
+       int i, s;
+
+#ifdef DIAGNOSTIC
+       if (size != vp->v_mount->mnt_stat.f_iosize)
+               panic("cluster_wbuild: size %d != filesize %d\n",
+                       size, vp->v_mount->mnt_stat.f_iosize);
+#endif
+redo:
+       while ((!incore(vp, start_lbn) || start_lbn == lbn) && len) {
+               ++start_lbn;
+               --len;
+       }

 
 

-       if (size > MAXBSIZE)
-               panic("getblk: size too big");
-       /*
-        * Search the cache for the block. If the buffer is found,
-        * but it is currently locked, the we must wait for it to
-        * become available.
-        */
-       dp = BUFHASH(vp, blkno);
-loop:
-       for (bp = dp->b_forw; bp != dp; bp = bp->b_forw) {
-               if (bp->b_lblkno != blkno || bp->b_vp != vp ||
-                   (bp->b_flags & B_INVAL))
-                       continue;
-               s = splbio();
-               if (bp->b_flags & B_BUSY) {
-                       bp->b_flags |= B_WANTED;
-                       sleep((caddr_t)bp, PRIBIO + 1);
-                       splx(s);
-                       goto loop;
-               }
-               bremfree(bp);
-               bp->b_flags |= B_BUSY;
-               splx(s);
-               if (bp->b_bcount != size) {
-                       printf("getblk: stray size");
-                       bp->b_flags |= B_INVAL;
-                       bwrite(bp);
-                       goto loop;
+       /* Get more memory for current buffer */
+       if (len <= 1) {
+               if (last_bp) {
+                       bawrite(last_bp);
+               } else if (len) {
+                       bp = getblk(vp, start_lbn, size, 0, 0);
+                       bawrite(bp);

                }
                }

-               bp->b_flags |= B_CACHE;
-               return (bp);
+               return;

        }
        }

-       bp = getnewbuf();
-       bremhash(bp);
-       bgetvp(vp, bp);
-       bp->b_bcount = 0;
-       bp->b_lblkno = blkno;
-#ifdef SECSIZE
-       bp->b_blksize = secsize;
-#endif SECSIZE
-       bp->b_blkno = blkno;
-       bp->b_error = 0;
-       bp->b_resid = 0;
-       binshash(bp, dp);
-       allocbuf(bp, size);
-       return (bp);
-}

 
 

-/*
- * Allocate a buffer.
- * The caller will assign it to a block.
- */
-struct buf *
-geteblk(size)
-       int size;
-{
-       register struct buf *bp, *flist;
-
-       if (size > MAXBSIZE)
-               panic("geteblk: size too big");
-       bp = getnewbuf();
-       bp->b_flags |= B_INVAL;
-       bremhash(bp);
-       flist = &bfreelist[BQ_AGE];
-       bp->b_bcount = 0;
-#ifdef SECSIZE
-       bp->b_blksize = DEV_BSIZE;
-#endif SECSIZE
-       bp->b_error = 0;
-       bp->b_resid = 0;
-       binshash(bp, flist);
-       allocbuf(bp, size);
-       return (bp);
-}
-
-/*
- * Expand or contract the actual memory allocated to a buffer.
- * If no memory is available, release buffer and take error exit.
- */
-allocbuf(tp, size)
-       register struct buf *tp;
-       int size;
-{
-       register struct buf *bp, *ep;
-       int sizealloc, take, s;
+       bp = getblk(vp, start_lbn, size, 0, 0);
+       if (!(bp->b_flags & B_DELWRI)) {
+               ++start_lbn;
+               --len;
+               brelse(bp);
+               goto redo;
+       }

 
 

-       sizealloc = roundup(size, CLBYTES);
-       /*
-        * Buffer size does not change
-        */
-       if (sizealloc == tp->b_bufsize)
-               goto out;

        /*
        /*

-        * Buffer size is shrinking.
-        * Place excess space in a buffer header taken from the
-        * BQ_EMPTY buffer list and placed on the "most free" list.
-        * If no extra buffer headers are available, leave the
-        * extra space in the present buffer.
+        * Extra memory in the buffer, punt on this buffer.
+        * XXX we could handle this in most cases, but we would have to
+        * push the extra memory down to after our max possible cluster
+        * size and then potentially pull it back up if the cluster was
+        * terminated prematurely--too much hassle.

         */
         */

-       if (sizealloc < tp->b_bufsize) {
-               ep = bfreelist[BQ_EMPTY].av_forw;
-               if (ep == &bfreelist[BQ_EMPTY])
-                       goto out;
-               s = splbio();
-               bremfree(ep);
-               ep->b_flags |= B_BUSY;
-               splx(s);
-               pagemove(tp->b_un.b_addr + sizealloc, ep->b_un.b_addr,
-                   (int)tp->b_bufsize - sizealloc);
-               ep->b_bufsize = tp->b_bufsize - sizealloc;
-               tp->b_bufsize = sizealloc;
-               ep->b_flags |= B_INVAL;
-               ep->b_bcount = 0;
-               brelse(ep);
-               goto out;
+       if (bp->b_bcount != bp->b_bufsize) {
+               ++start_lbn;
+               --len;
+               bawrite(bp);
+               goto redo;

        }
        }

-       /*
-        * More buffer space is needed. Get it out of buffers on
-        * the "most free" list, placing the empty headers on the
-        * BQ_EMPTY buffer header list.
-        */
-       while (tp->b_bufsize < sizealloc) {
-               take = sizealloc - tp->b_bufsize;
-               bp = getnewbuf();
-               if (take >= bp->b_bufsize)
-                       take = bp->b_bufsize;
-               pagemove(&bp->b_un.b_addr[bp->b_bufsize - take],
-                   &tp->b_un.b_addr[tp->b_bufsize], take);
-               tp->b_bufsize += take;
-               bp->b_bufsize = bp->b_bufsize - take;
-               if (bp->b_bcount > bp->b_bufsize)
-                       bp->b_bcount = bp->b_bufsize;
-               if (bp->b_bufsize <= 0) {
-                       bremhash(bp);
-                       binshash(bp, &bfreelist[BQ_EMPTY]);
-                       bp->b_dev = NODEV;
-                       bp->b_error = 0;
-                       bp->b_flags |= B_INVAL;
+
+       --len;
+       b_save = malloc(sizeof(struct buf *) * len + sizeof(struct cluster_save),
+           M_SEGMENT, M_WAITOK);
+       b_save->bs_bcount = bp->b_bcount;
+       b_save->bs_bufsize = bp->b_bufsize;
+       b_save->bs_nchildren = 0;
+       b_save->bs_children = (struct buf **)(b_save + 1);
+       b_save->bs_saveaddr = bp->b_saveaddr;
+       bp->b_saveaddr = (caddr_t) b_save;
+
+       bp->b_flags |= B_CALL;
+       bp->b_iodone = cluster_callback;
+       cp = (char *)bp->b_data + size;
+       for (++start_lbn, i = 0; i < len; ++i, ++start_lbn) {
+               /*
+                * Block is not in core or the non-sequential block
+                * ending our cluster was part of the cluster (in which
+                * case we don't want to write it twice).
+                */
+               if (!incore(vp, start_lbn) ||
+                   last_bp == NULL && start_lbn == lbn)
+                       break;
+
+               /*
+                * Get the desired block buffer (unless it is the final
+                * sequential block whose buffer was passed in explictly
+                * as last_bp).
+                */
+               if (last_bp == NULL || start_lbn != lbn) {
+                       tbp = getblk(vp, start_lbn, size, 0, 0);
+                       if (!(tbp->b_flags & B_DELWRI)) {
+                               brelse(tbp);
+                               break;
+                       }
+               } else
+                       tbp = last_bp;
+
+               ++b_save->bs_nchildren;
+
+               /* Move memory from children to parent */
+               if (tbp->b_blkno != (bp->b_blkno + btodb(bp->b_bufsize))) {
+                       printf("Clustered Block: %d addr %x bufsize: %d\n",
+                           bp->b_lblkno, bp->b_blkno, bp->b_bufsize);
+                       printf("Child Block: %d addr: %x\n", tbp->b_lblkno,
+                           tbp->b_blkno);
+                       panic("Clustered write to wrong blocks");

                }
                }

-               brelse(bp);
-       }
-out:
-       tp->b_bcount = size;
-       return (1);
-}

 
 

-/*
- * Find a buffer which is available for use.
- * Select something from a free list.
- * Preference is to AGE list, then LRU list.
- */
-struct buf *
-getnewbuf()
-{
-       register struct buf *bp, *dp;
-       register struct ucred *cred;
-       int s;
+               pagemove(tbp->b_data, cp, size);
+               bp->b_bcount += size;
+               bp->b_bufsize += size;

 
 

-#ifdef LFS
-       lfs_flush();
-#endif
-loop:
-       s = splbio();
-       for (dp = &bfreelist[BQ_AGE]; dp > bfreelist; dp--)
-               if (dp->av_forw != dp)
-                       break;
-       if (dp == bfreelist) {          /* no free blocks */
-               dp->b_flags |= B_WANTED;
-               sleep((caddr_t)dp, PRIBIO + 1);
+               tbp->b_bufsize -= size;
+               tbp->b_flags &= ~(B_READ | B_DONE | B_ERROR | B_DELWRI);
+               tbp->b_flags |= (B_ASYNC | B_AGE);
+               s = splbio();
+               reassignbuf(tbp, tbp->b_vp);            /* put on clean list */
+               ++tbp->b_vp->v_numoutput;

                splx(s);
                splx(s);

-               goto loop;
-       }
-       bp = dp->av_forw;
-       bremfree(bp);
-       bp->b_flags |= B_BUSY;
-       splx(s);
-       if (bp->b_flags & B_DELWRI) {
-               (void) bawrite(bp);
-               goto loop;
+               b_save->bs_children[i] = tbp;
+
+               cp += size;

        }
        }

-       trace(TR_BRELSE, pack(bp->b_vp, bp->b_bufsize), bp->b_lblkno);
-       if (bp->b_vp)
-               brelvp(bp);
-       if (bp->b_rcred != NOCRED) {
-               cred = bp->b_rcred;
-               bp->b_rcred = NOCRED;
-               crfree(cred);
+
+       if (i == 0) {
+               /* None to cluster */
+               bp->b_saveaddr = b_save->bs_saveaddr;
+               bp->b_flags &= ~B_CALL;
+               bp->b_iodone = NULL;
+               free(b_save, M_SEGMENT);

        }
        }

-       if (bp->b_wcred != NOCRED) {
-               cred = bp->b_wcred;
-               bp->b_wcred = NOCRED;
-               crfree(cred);
+       bawrite(bp);
+       if (i < len) {
+               len -= i + 1;
+               start_lbn += 1;
+               goto redo;

        }
        }

-       bp->b_flags = B_BUSY;
-       bp->b_dirtyoff = bp->b_dirtyend = 0;
-       bp->b_validoff = bp->b_validend = 0;
-       return (bp);

 }
 
 /*
 }
 
 /*

- * Wait for I/O to complete.
- *
- * Extract and return any errors associated with the I/O.
- * If the error flag is set, but no specific error is
- * given, return EIO.
+ * Collect together all the buffers in a cluster.
+ * Plus add one additional buffer.

  */
  */

-biowait(bp)
-       register struct buf *bp;
-{
-       int s;
-
-       s = splbio();
-       while ((bp->b_flags & B_DONE) == 0)
-               sleep((caddr_t)bp, PRIBIO);
-       splx(s);
-       if ((bp->b_flags & B_ERROR) == 0)
-               return (0);
-       if (bp->b_error)
-               return (bp->b_error);
-       return (EIO);
-}
-
-/*
- * Mark I/O complete on a buffer.
- *
- * If a callback has been requested, e.g. the pageout
- * daemon, do so. Otherwise, awaken waiting processes.
- */
-void
-biodone(bp)
-       register struct buf *bp;
+struct cluster_save *
+cluster_collectbufs(vp, last_bp)
+       struct vnode *vp;
+       struct buf *last_bp;

 {
 {

-
-       if (bp->b_flags & B_DONE)
-               panic("dup biodone");
-       bp->b_flags |= B_DONE;
-       if ((bp->b_flags & B_READ) == 0)
-               vwakeup(bp);
-       if (bp->b_flags & B_CALL) {
-               bp->b_flags &= ~B_CALL;
-               (*bp->b_iodone)(bp);
-               return;
-       }
-       if (bp->b_flags & B_ASYNC)
-               brelse(bp);
-       else {
-               bp->b_flags &= ~B_WANTED;
-               wakeup((caddr_t)bp);
-       }
+       struct cluster_save *buflist;
+       daddr_t lbn;
+       int i, len;
+
+       len = vp->v_lastw - vp->v_cstart + 1;
+       buflist = malloc(sizeof(struct buf *) * (len + 1) + sizeof(*buflist),
+           M_SEGMENT, M_WAITOK);
+       buflist->bs_nchildren = 0;
+       buflist->bs_children = (struct buf **)(buflist + 1);
+       for (lbn = vp->v_cstart, i = 0; i < len; lbn++, i++)
+                   (void)bread(vp, lbn, last_bp->b_bcount, NOCRED,
+                       &buflist->bs_children[i]);
+       buflist->bs_children[i] = last_bp;
+       buflist->bs_nchildren = i + 1;
+       return (buflist);

 }
 }