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have to save v_mountf before vput'ing the vnode
[unix-history] / usr / src / sys / kern / vfs_bio.c
diff --git a/usr/src/sys/kern/vfs_bio.c b/usr/src/sys/kern/vfs_bio.c
index 8adaf7d..a702845 100644 (file)
--- a/usr/src/sys/kern/vfs_bio.c
+++ b/usr/src/sys/kern/vfs_bio.c
@@ -1,55 +1,82 @@
-/*     vfs_bio.c       4.47    83/06/14        */
-
-#include "../machine/pte.h"
+/*
+ * Copyright (c) 1982, 1986, 1989 Regents of the University of California.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms are permitted
+ * provided that the above copyright notice and this paragraph are
+ * duplicated in all such forms and that any documentation,
+ * advertising materials, and other materials related to such
+ * distribution and use acknowledge that the software was developed
+ * by the University of California, Berkeley.  The name of the
+ * University may not be used to endorse or promote products derived
+ * from this software without specific prior written permission.
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ *     @(#)vfs_bio.c   7.17 (Berkeley) %G%
+ */
 
 
-#include "../h/param.h"
-#include "../h/systm.h"
-#include "../h/dir.h"
-#include "../h/user.h"
-#include "../h/buf.h"
-#include "../h/conf.h"
-#include "../h/proc.h"
-#include "../h/seg.h"
-#include "../h/vm.h"
-#include "../h/trace.h"
+#include "param.h"
+#include "user.h"
+#include "buf.h"
+#include "vnode.h"
+#include "mount.h"
+#include "trace.h"
+#include "ucred.h"
 
 /*
  * Read in (if necessary) the block and return a buffer pointer.
  */
 
 /*
  * Read in (if necessary) the block and return a buffer pointer.
  */
-struct buf *
-bread(dev, blkno, size)
-       dev_t dev;
+bread(vp, blkno, size, cred, bpp)
+       struct vnode *vp;
        daddr_t blkno;
        int size;
        daddr_t blkno;
        int size;
+       struct ucred *cred;
+       struct buf **bpp;
+#ifdef SECSIZE
+       long secsize;
+#endif SECSIZE
 {
        register struct buf *bp;
 
        if (size == 0)
                panic("bread: size 0");
 {
        register struct buf *bp;
 
        if (size == 0)
                panic("bread: size 0");
-       bp = getblk(dev, blkno, size);
-       if (bp->b_flags&B_DONE) {
-               trace(TR_BREADHIT, dev, blkno);
-               return(bp);
+#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->v_mount->m_fsid[0], size), blkno);
+               return (0);
        }
        bp->b_flags |= B_READ;
        if (bp->b_bcount > bp->b_bufsize)
                panic("bread");
        }
        bp->b_flags |= B_READ;
        if (bp->b_bcount > bp->b_bufsize)
                panic("bread");
-       (*bdevsw[major(dev)].d_strategy)(bp);
-       trace(TR_BREADMISS, dev, blkno);
+       if (bp->b_rcred == NOCRED && cred != NOCRED) {
+               crhold(cred);
+               bp->b_rcred = cred;
+       }
+       VOP_STRATEGY(bp);
+       trace(TR_BREADMISS, pack(vp->v_mount->m_fsid[0], size), blkno);
        u.u_ru.ru_inblock++;            /* pay for read */
        u.u_ru.ru_inblock++;            /* pay for read */
-       biowait(bp);
-       return(bp);
+       return (biowait(bp));
 }
 
 /*
  * Read in the block, like bread, but also start I/O on the
  * read-ahead block (which is not allocated to the caller)
  */
 }
 
 /*
  * Read in the block, like bread, but also start I/O on the
  * read-ahead block (which is not allocated to the caller)
  */
-struct buf *
-breada(dev, blkno, size, rablkno, rabsize)
-       dev_t dev;
+breada(vp, blkno, size, rablkno, rabsize, cred, bpp)
+       struct vnode *vp;
        daddr_t blkno; int size;
        daddr_t blkno; int size;
+#ifdef SECSIZE
+       long secsize;
+#endif SECSIZE
        daddr_t rablkno; int rabsize;
        daddr_t rablkno; int rabsize;
+       struct ucred *cred;
+       struct buf **bpp;
 {
        register struct buf *bp, *rabp;
 
 {
        register struct buf *bp, *rabp;
 
@@ -59,34 +86,48 @@ breada(dev, blkno, size, rablkno, rabsize)
         * a buffer and initiate i/o (getblk checks
         * for a cache hit).
         */
         * a buffer and initiate i/o (getblk checks
         * for a cache hit).
         */
-       if (!incore(dev, blkno)) {
-               bp = getblk(dev, blkno, size);
-               if ((bp->b_flags&B_DONE) == 0) {
+       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("breada");
                        bp->b_flags |= B_READ;
                        if (bp->b_bcount > bp->b_bufsize)
                                panic("breada");
-                       (*bdevsw[major(dev)].d_strategy)(bp);
-                       trace(TR_BREADMISS, dev, blkno);
+                       if (bp->b_rcred == NOCRED && cred != NOCRED) {
+                               crhold(cred);
+                               bp->b_rcred = cred;
+                       }
+                       VOP_STRATEGY(bp);
+                       trace(TR_BREADMISS, pack(vp->v_mount->m_fsid[0], size),
+                           blkno);
                        u.u_ru.ru_inblock++;            /* pay for read */
                } else
                        u.u_ru.ru_inblock++;            /* pay for read */
                } else
-                       trace(TR_BREADHIT, dev, blkno);
+                       trace(TR_BREADHIT, pack(vp->v_mount->m_fsid[0], size),
+                           blkno);
        }
 
        /*
         * If there's a read-ahead block, start i/o
         * on it also (as above).
         */
        }
 
        /*
         * If there's a read-ahead block, start i/o
         * on it also (as above).
         */
-       if (rablkno && !incore(dev, rablkno)) {
-               rabp = getblk(dev, rablkno, rabsize);
-               if (rabp->b_flags & B_DONE) {
+       if (rablkno && !incore(vp, rablkno)) {
+               rabp = getblk(vp, rablkno, rabsize);
+#endif SECSIZE
+               if (rabp->b_flags & (B_DONE|B_DELWRI)) {
                        brelse(rabp);
                        brelse(rabp);
-                       trace(TR_BREADHITRA, dev, blkno);
+                       trace(TR_BREADHITRA,
+                           pack(vp->v_mount->m_fsid[0], rabsize), rablkno);
                } else {
                        rabp->b_flags |= B_READ|B_ASYNC;
                        if (rabp->b_bcount > rabp->b_bufsize)
                                panic("breadrabp");
                } else {
                        rabp->b_flags |= B_READ|B_ASYNC;
                        if (rabp->b_bcount > rabp->b_bufsize)
                                panic("breadrabp");
-                       (*bdevsw[major(dev)].d_strategy)(rabp);
-                       trace(TR_BREADMISSRA, dev, rablock);
+                       if (rabp->b_rcred == NOCRED && cred != NOCRED) {
+                               crhold(cred);
+                               rabp->b_rcred = cred;
+                       }
+                       VOP_STRATEGY(rabp);
+                       trace(TR_BREADMISSRA,
+                           pack(vp->v_mount->m_fsid[0], rabsize), rablkno);
                        u.u_ru.ru_inblock++;            /* pay in advance */
                }
        }
                        u.u_ru.ru_inblock++;            /* pay in advance */
                }
        }
@@ -97,9 +138,11 @@ breada(dev, blkno, size, rablkno, rabsize)
         * above, and just wait for it.
         */
        if (bp == NULL)
         * above, and just wait for it.
         */
        if (bp == NULL)
-               return (bread(dev, blkno, size));
-       biowait(bp);
-       return (bp);
+#ifdef SECSIZE
+               return (bread(dev, blkno, size, secsize));
+#else SECSIZE
+               return (bread(vp, blkno, size, cred, bpp));
+       return (biowait(bp));
 }
 
 /*
 }
 
 /*
@@ -109,16 +152,18 @@ breada(dev, blkno, size, rablkno, rabsize)
 bwrite(bp)
        register struct buf *bp;
 {
 bwrite(bp)
        register struct buf *bp;
 {
-       register flag;
+       register int flag;
+       int error;
 
        flag = bp->b_flags;
        bp->b_flags &= ~(B_READ | B_DONE | B_ERROR | B_DELWRI);
        if ((flag&B_DELWRI) == 0)
                u.u_ru.ru_oublock++;            /* noone paid yet */
 
        flag = bp->b_flags;
        bp->b_flags &= ~(B_READ | B_DONE | B_ERROR | B_DELWRI);
        if ((flag&B_DELWRI) == 0)
                u.u_ru.ru_oublock++;            /* noone paid yet */
-       trace(TR_BWRITE, bp->b_dev, bp->b_blkno);
+       trace(TR_BWRITE,
+           pack(bp->b_vp->v_mount->m_fsid[0], bp->b_bcount), bp->b_lblkno);
        if (bp->b_bcount > bp->b_bufsize)
                panic("bwrite");
        if (bp->b_bcount > bp->b_bufsize)
                panic("bwrite");
-       (*bdevsw[major(bp->b_dev)].d_strategy)(bp);
+       VOP_STRATEGY(bp);
 
        /*
         * If the write was synchronous, then await i/o completion.
 
        /*
         * If the write was synchronous, then await i/o completion.
@@ -126,10 +171,13 @@ bwrite(bp)
         * the q of blocks awaiting i/o completion status.
         */
        if ((flag&B_ASYNC) == 0) {
         * the q of blocks awaiting i/o completion status.
         */
        if ((flag&B_ASYNC) == 0) {
-               biowait(bp);
+               error = biowait(bp);
                brelse(bp);
                brelse(bp);
-       } else if (flag & B_DELWRI)
+       } else if (flag & B_DELWRI) {
                bp->b_flags |= B_AGE;
                bp->b_flags |= B_AGE;
+               error = 0;
+       }
+       return (error);
 }
 
 /*
 }
 
 /*
@@ -143,14 +191,15 @@ bwrite(bp)
 bdwrite(bp)
        register struct buf *bp;
 {
 bdwrite(bp)
        register struct buf *bp;
 {
-       register int flags;
 
        if ((bp->b_flags&B_DELWRI) == 0)
                u.u_ru.ru_oublock++;            /* noone paid yet */
 
        if ((bp->b_flags&B_DELWRI) == 0)
                u.u_ru.ru_oublock++;            /* noone paid yet */
-       flags = bdevsw[major(bp->b_dev)].d_flags;
-       if(flags & B_TAPE)
+       /*
+        * If this is a tape drive, the write must be initiated.
+        */
+       if (bdevsw[major(bp->b_dev)].d_flags & B_TAPE)
                bawrite(bp);
                bawrite(bp);
-       else {
+       } else {
                bp->b_flags |= B_DELWRI | B_DONE;
                brelse(bp);
        }
                bp->b_flags |= B_DELWRI | B_DONE;
                brelse(bp);
        }
@@ -164,7 +213,7 @@ bawrite(bp)
 {
 
        bp->b_flags |= B_ASYNC;
 {
 
        bp->b_flags |= B_ASYNC;
-       bwrite(bp);
+       (void) bwrite(bp);
 }
 
 /*
 }
 
 /*
@@ -176,9 +225,11 @@ brelse(bp)
        register struct buf *flist;
        register s;
 
        register struct buf *flist;
        register s;
 
+       trace(TR_BRELSE,
+           pack(bp->b_vp->v_mount->m_fsid[0], bp->b_bufsize), bp->b_lblkno);
        /*
        /*
-        * If someone's waiting for the buffer, or
-        * is waiting for a buffer wake 'em up.
+        * If a process is waiting for the buffer, or
+        * is waiting for a free buffer, awaken it.
         */
        if (bp->b_flags&B_WANTED)
                wakeup((caddr_t)bp);
         */
        if (bp->b_flags&B_WANTED)
                wakeup((caddr_t)bp);
@@ -186,16 +237,26 @@ brelse(bp)
                bfreelist[0].b_flags &= ~B_WANTED;
                wakeup((caddr_t)bfreelist);
        }
                bfreelist[0].b_flags &= ~B_WANTED;
                wakeup((caddr_t)bfreelist);
        }
-       if (bp->b_flags&B_ERROR)
-               if (bp->b_flags & B_LOCKED)
-                       bp->b_flags &= ~B_ERROR;        /* try again later */
-               else
-                       bp->b_dev = NODEV;              /* no assoc */
+       /*
+        * Retry I/O for locked buffers rather than invalidating them.
+        */
+       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;
+       }
        /*
         * Stick the buffer back on a free list.
         */
        /*
         * Stick the buffer back on a free list.
         */
-       s = spl6();
+       s = splbio();
        if (bp->b_bufsize <= 0) {
                /* block has no buffer ... put at front of unused buffer list */
                flist = &bfreelist[BQ_EMPTY];
        if (bp->b_bufsize <= 0) {
                /* block has no buffer ... put at front of unused buffer list */
                flist = &bfreelist[BQ_EMPTY];
@@ -213,7 +274,7 @@ brelse(bp)
                        flist = &bfreelist[BQ_LRU];
                binstailfree(bp, flist);
        }
                        flist = &bfreelist[BQ_LRU];
                binstailfree(bp, flist);
        }
-       bp->b_flags &= ~(B_WANTED|B_BUSY|B_ASYNC|B_AGE);
+       bp->b_flags &= ~(B_WANTED|B_BUSY|B_ASYNC|B_AGE|B_NOCACHE);
        splx(s);
 }
 
        splx(s);
 }
 
@@ -221,30 +282,39 @@ brelse(bp)
  * See if the block is associated with some buffer
  * (mainly to avoid getting hung up on a wait in breada)
  */
  * See if the block is associated with some buffer
  * (mainly to avoid getting hung up on a wait in breada)
  */
-incore(dev, blkno)
-       dev_t dev;
+incore(vp, blkno)
+       struct vnode *vp;
        daddr_t blkno;
 {
        register struct buf *bp;
        register struct buf *dp;
 
        daddr_t blkno;
 {
        register struct buf *bp;
        register struct buf *dp;
 
-       dp = BUFHASH(dev, blkno);
+       dp = BUFHASH(vp, blkno);
        for (bp = dp->b_forw; bp != dp; bp = bp->b_forw)
        for (bp = dp->b_forw; bp != dp; bp = bp->b_forw)
-               if (bp->b_blkno == blkno && bp->b_dev == dev &&
+               if (bp->b_lblkno == blkno && bp->b_vp == vp &&
                    (bp->b_flags & B_INVAL) == 0)
                        return (1);
        return (0);
 }
 
                    (bp->b_flags & B_INVAL) == 0)
                        return (1);
        return (0);
 }
 
-struct buf *
-baddr(dev, blkno, size)
-       dev_t dev;
+/*
+ * Return a block if it is in memory.
+ */
+baddr(vp, blkno, size, cred, bpp)
+       struct vnode *vp;
        daddr_t blkno;
        int size;
        daddr_t blkno;
        int size;
+       struct ucred *cred;
+       struct buf **bpp;
+#ifdef SECSIZE
+       long secsize;
+#endif SECSIZE
 {
 
 {
 
-       if (incore(dev, blkno))
-               return (bread(dev, blkno, size));
+       if (incore(vp, blkno))
+               return (bread(vp, blkno, size, cred, bpp));
+       *bpp = 0;
+#endif SECSIZE
        return (0);
 }
 
        return (0);
 }
 
@@ -258,28 +328,48 @@ baddr(dev, blkno, size)
  * want to lower the ipl back to 0.
  */
 struct buf *
  * want to lower the ipl back to 0.
  */
 struct buf *
-getblk(dev, blkno, size)
-       dev_t dev;
+#ifdef SECSIZE
+getblk(dev, blkno, size, secsize)
+#else SECSIZE
+getblk(vp, blkno, size)
+       register struct vnode *vp;
        daddr_t blkno;
        int size;
        daddr_t blkno;
        int size;
+#ifdef SECSIZE
+       long secsize;
+#endif SECSIZE
 {
        register struct buf *bp, *dp;
        int s;
 
 {
        register struct buf *bp, *dp;
        int s;
 
-       if ((unsigned)blkno >= 1 << (sizeof(int)*NBBY-PGSHIFT)) /* XXX */
-               blkno = 1 << ((sizeof(int)*NBBY-PGSHIFT) + 1);
+       if (size > MAXBSIZE)
+               panic("getblk: size too big");
+       /*
+        * To prevent overflow of 32-bit ints when converting block
+        * numbers to byte offsets, blknos > 2^32 / DEV_BSIZE are set
+        * to the maximum number that can be converted to a byte offset
+        * without overflow. This is historic code; what bug it fixed,
+        * or whether it is still a reasonable thing to do is open to
+        * dispute. mkm 9/85
+        *
+        * Make it a panic to see if it ever really happens. mkm 11/89
+        */
+       if ((unsigned)blkno >= 1 << (sizeof(int)*NBBY-DEV_BSHIFT)) {
+               panic("getblk: blkno too big");
+               blkno = 1 << ((sizeof(int)*NBBY-DEV_BSHIFT) + 1);
+       }
        /*
         * Search the cache for the block.  If we hit, but
         * the buffer is in use for i/o, then we wait until
         * the i/o has completed.
         */
        /*
         * Search the cache for the block.  If we hit, but
         * the buffer is in use for i/o, then we wait until
         * the i/o has completed.
         */
-       dp = BUFHASH(dev, blkno);
+       dp = BUFHASH(vp, blkno);
 loop:
        for (bp = dp->b_forw; bp != dp; bp = bp->b_forw) {
 loop:
        for (bp = dp->b_forw; bp != dp; bp = bp->b_forw) {
-               if (bp->b_blkno != blkno || bp->b_dev != dev ||
+               if (bp->b_lblkno != blkno || bp->b_vp != vp ||
                    bp->b_flags&B_INVAL)
                        continue;
                    bp->b_flags&B_INVAL)
                        continue;
-               s = spl6();
+               s = splbio();
                if (bp->b_flags&B_BUSY) {
                        bp->b_flags |= B_WANTED;
                        sleep((caddr_t)bp, PRIBIO+1);
                if (bp->b_flags&B_BUSY) {
                        bp->b_flags |= B_WANTED;
                        sleep((caddr_t)bp, PRIBIO+1);
@@ -288,23 +378,29 @@ loop:
                }
                splx(s);
                notavail(bp);
                }
                splx(s);
                notavail(bp);
-               if (brealloc(bp, size) == 0)
+               if (bp->b_bcount != size) {
+                       printf("getblk: stray size");
+                       bp->b_flags |= B_INVAL;
+                       bwrite(bp);
                        goto loop;
                        goto loop;
+               }
                bp->b_flags |= B_CACHE;
                bp->b_flags |= B_CACHE;
-               return(bp);
+               return (bp);
        }
        }
-       if (major(dev) >= nblkdev)
-               panic("blkdev");
        bp = getnewbuf();
        bfree(bp);
        bremhash(bp);
        bp = getnewbuf();
        bfree(bp);
        bremhash(bp);
-       binshash(bp, dp);
-       bp->b_dev = dev;
+       bgetvp(vp, bp);
+       bp->b_lblkno = blkno;
+#ifdef SECSIZE
+       bp->b_blksize = secsize;
+#endif SECSIZE
        bp->b_blkno = blkno;
        bp->b_error = 0;
        bp->b_blkno = blkno;
        bp->b_error = 0;
-       if (brealloc(bp, size) == 0)
-               goto loop;
-       return(bp);
+       bp->b_resid = 0;
+       binshash(bp, dp);
+       brealloc(bp, size);
+       return (bp);
 }
 
 /*
 }
 
 /*
@@ -317,23 +413,25 @@ geteblk(size)
 {
        register struct buf *bp, *flist;
 
 {
        register struct buf *bp, *flist;
 
-loop:
+       if (size > MAXBSIZE)
+               panic("geteblk: size too big");
        bp = getnewbuf();
        bp->b_flags |= B_INVAL;
        bfree(bp);
        bremhash(bp);
        flist = &bfreelist[BQ_AGE];
        bp = getnewbuf();
        bp->b_flags |= B_INVAL;
        bfree(bp);
        bremhash(bp);
        flist = &bfreelist[BQ_AGE];
-       binshash(bp, flist);
-       bp->b_dev = (dev_t)NODEV;
+#ifdef SECSIZE
+       bp->b_blksize = DEV_BSIZE;
+#endif SECSIZE
        bp->b_error = 0;
        bp->b_error = 0;
-       if (brealloc(bp, size) == 0)
-               goto loop;
-       return(bp);
+       bp->b_resid = 0;
+       binshash(bp, flist);
+       brealloc(bp, size);
+       return (bp);
 }
 
 /*
  * Allocate space associated with a buffer.
 }
 
 /*
  * Allocate space associated with a buffer.
- * If can't get space, buffer is released
  */
 brealloc(bp, size)
        register struct buf *bp;
  */
 brealloc(bp, size)
        register struct buf *bp;
@@ -344,61 +442,9 @@ brealloc(bp, size)
        struct buf *dp;
        int s;
 
        struct buf *dp;
        int s;
 
-       /*
-        * First need to make sure that all overlaping previous I/O
-        * is dispatched with.
-        */
        if (size == bp->b_bcount)
        if (size == bp->b_bcount)
-               return (1);
-       if (size < bp->b_bcount) { 
-               if (bp->b_flags & B_DELWRI) {
-                       bwrite(bp);
-                       return (0);
-               }
-               if (bp->b_flags & B_LOCKED)
-                       panic("brealloc");
-               return (allocbuf(bp, size));
-       }
-       bp->b_flags &= ~B_DONE;
-       if (bp->b_dev == NODEV)
-               return (allocbuf(bp, size));
-
-       /*
-        * Search cache for any buffers that overlap the one that we
-        * are trying to allocate. Overlapping buffers must be marked
-        * invalid, after being written out if they are dirty. (indicated
-        * by B_DELWRI) A disk block must be mapped by at most one buffer
-        * at any point in time. Care must be taken to avoid deadlocking
-        * when two buffer are trying to get the same set of disk blocks.
-        */
-       start = bp->b_blkno;
-       last = start + btodb(size) - 1;
-       dp = BUFHASH(bp->b_dev, bp->b_blkno);
-loop:
-       for (ep = dp->b_forw; ep != dp; ep = ep->b_forw) {
-               if (ep == bp || ep->b_dev != bp->b_dev || (ep->b_flags&B_INVAL))
-                       continue;
-               /* look for overlap */
-               if (ep->b_bcount == 0 || ep->b_blkno > last ||
-                   ep->b_blkno + btodb(ep->b_bcount) <= start)
-                       continue;
-               s = spl6();
-               if (ep->b_flags&B_BUSY) {
-                       ep->b_flags |= B_WANTED;
-                       sleep((caddr_t)ep, PRIBIO+1);
-                       splx(s);
-                       goto loop;
-               }
-               splx(s);
-               notavail(ep);
-               if (ep->b_flags & B_DELWRI) {
-                       bwrite(ep);
-                       goto loop;
-               }
-               ep->b_flags |= B_INVAL;
-               brelse(ep);
-       }
-       return (allocbuf(bp, size));
+               return;
+       allocbuf(bp, size);
 }
 
 /*
 }
 
 /*
@@ -410,15 +456,12 @@ struct buf *
 getnewbuf()
 {
        register struct buf *bp, *dp;
 getnewbuf()
 {
        register struct buf *bp, *dp;
+       register struct ucred *cred;
        int s;
 
 loop:
        int s;
 
 loop:
-       s = spl6();
-#ifndef sun
+       s = splbio();
        for (dp = &bfreelist[BQ_AGE]; dp > bfreelist; dp--)
        for (dp = &bfreelist[BQ_AGE]; dp > bfreelist; dp--)
-#else
-       for (dp = &bfreelist[BQ_EMPTY]; dp > bfreelist; dp--)
-#endif
                if (dp->av_forw != dp)
                        break;
        if (dp == bfreelist) {          /* no free blocks */
                if (dp->av_forw != dp)
                        break;
        if (dp == bfreelist) {          /* no free blocks */
@@ -431,11 +474,23 @@ loop:
        bp = dp->av_forw;
        notavail(bp);
        if (bp->b_flags & B_DELWRI) {
        bp = dp->av_forw;
        notavail(bp);
        if (bp->b_flags & B_DELWRI) {
-               bp->b_flags |= B_ASYNC;
-               bwrite(bp);
+               (void) bawrite(bp);
                goto loop;
        }
                goto loop;
        }
-       trace(TR_BRELSE, bp->b_dev, bp->b_blkno);
+       trace(TR_BRELSE,
+           pack(bp->b_vp->v_mount->m_fsid[0], 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 (bp->b_wcred != NOCRED) {
+               cred = bp->b_wcred;
+               bp->b_wcred = NOCRED;
+               crfree(cred);
+       }
        bp->b_flags = B_BUSY;
        return (bp);
 }
        bp->b_flags = B_BUSY;
        return (bp);
 }
@@ -449,12 +504,19 @@ biowait(bp)
 {
        int s;
 
 {
        int s;
 
-       s = spl6();
-       while ((bp->b_flags&B_DONE)==0)
+       s = splbio();
+       while ((bp->b_flags & B_DONE) == 0)
                sleep((caddr_t)bp, PRIBIO);
        splx(s);
                sleep((caddr_t)bp, PRIBIO);
        splx(s);
-       if (u.u_error == 0)                     /* XXX */
-               u.u_error = geterror(bp);
+       /*
+        * Pick up the device's error number and pass it to the user;
+        * if there is an error but the number is 0 set a generalized code.
+        */
+       if ((bp->b_flags & B_ERROR) == 0)
+               return (0);
+       if (bp->b_error)
+               return (bp->b_error);
+       return (EIO);
 }
 
 /*
 }
 
 /*
@@ -470,6 +532,8 @@ biodone(bp)
        if (bp->b_flags & B_DONE)
                panic("dup biodone");
        bp->b_flags |= B_DONE;
        if (bp->b_flags & B_DONE)
                panic("dup biodone");
        bp->b_flags |= B_DONE;
+       if ((bp->b_flags & B_READ) == 0)
+               bp->b_dirtyoff = bp->b_dirtyend = 0;
        if (bp->b_flags & B_CALL) {
                bp->b_flags &= ~B_CALL;
                (*bp->b_iodone)(bp);
        if (bp->b_flags & B_CALL) {
                bp->b_flags &= ~B_CALL;
                (*bp->b_iodone)(bp);
@@ -484,113 +548,287 @@ biodone(bp)
 }
 
 /*
 }
 
 /*
- * Insure that no part of a specified block is in an incore buffer.
+ * Ensure that no part of a specified block is in an incore buffer.
+#ifdef SECSIZE
+ * "size" is given in device blocks (the units of b_lblkno).
+#endif SECSIZE
+#ifdef SECSIZE
+ * "size" is given in device blocks (the units of b_blkno).
+#endif SECSIZE
  */
  */
-blkflush(dev, blkno, size)
-       dev_t dev;
+blkflush(vp, blkno, size)
+       struct vnode *vp;
        daddr_t blkno;
        daddr_t blkno;
+#ifdef SECSIZE
+       int size;
+#else SECSIZE
        long size;
        long size;
+#endif SECSIZE
 {
        register struct buf *ep;
        struct buf *dp;
 {
        register struct buf *ep;
        struct buf *dp;
-       daddr_t start, last;
+       daddr_t curblk, nextblk, ecurblk, lastblk;
+       int s, error, allerrors = 0;
+
+       /*
+        * Iterate through each possible hash chain.
+        */
+       lastblk = blkno + btodb(size) - 1;
+       for (curblk = blkno; curblk <= lastblk; curblk = nextblk) {
+#if RND & (RND-1)
+               nextblk = ((curblk / RND) + 1) * RND;
+#else
+               nextblk = ((curblk & ~(RND-1)) + RND);
+#endif
+               ecurblk = nextblk > lastblk ? lastblk : nextblk - 1;
+               dp = BUFHASH(vp, curblk);
+loop:
+               for (ep = dp->b_forw; ep != dp; ep = ep->b_forw) {
+                       if (ep->b_vp != vp || (ep->b_flags & B_INVAL))
+                               continue;
+                       /* look for overlap */
+                       if (ep->b_bcount == 0 || ep->b_lblkno > ecurblk ||
+                           ep->b_lblkno + btodb(ep->b_bcount) <= curblk)
+                               continue;
+                       s = splbio();
+                       if (ep->b_flags&B_BUSY) {
+                               ep->b_flags |= B_WANTED;
+                               sleep((caddr_t)ep, PRIBIO+1);
+                               splx(s);
+                               goto loop;
+                       }
+                       if (ep->b_flags & B_DELWRI) {
+                               splx(s);
+                               notavail(ep);
+                               if (error = bwrite(ep))
+                                       allerrors = error;
+                               goto loop;
+                       }
+                       splx(s);
+               }
+       }
+       return (allerrors);
+}
+
+/*
+ * Make sure all write-behind blocks associated
+ * with mount point are flushed out (from sync).
+ */
+mntflushbuf(mountp, flags)
+       struct mount *mountp;
+       int flags;
+{
+       register struct vnode *vp;
+       struct vnode *nvp;
+
+loop:
+       for (vp = mountp->m_mounth; vp; vp = nvp) {
+               nvp = vp->v_mountf;
+               if (vget(vp))
+                       goto loop;
+               vflushbuf(vp, flags);
+               vput(vp);
+       }
+}
+
+/*
+ * Flush all dirty buffers associated with a vnode.
+ */
+vflushbuf(vp, flags)
+       register struct vnode *vp;
+       int flags;
+{
+       register struct buf *bp;
+       struct buf *nbp;
        int s;
 
        int s;
 
-       start = blkno;
-       last = start + btodb(size) - 1;
-       dp = BUFHASH(dev, blkno);
 loop:
 loop:
-       for (ep = dp->b_forw; ep != dp; ep = ep->b_forw) {
-               if (ep->b_dev != dev || (ep->b_flags&B_INVAL))
+       s = splbio();
+       for (bp = vp->v_blockh; bp; bp = nbp) {
+               nbp = bp->b_blockf;
+               if ((bp->b_flags & B_BUSY))
                        continue;
                        continue;
-               /* look for overlap */
-               if (ep->b_bcount == 0 || ep->b_blkno > last ||
-                   ep->b_blkno + btodb(ep->b_bcount) <= start)
+               if ((bp->b_flags & B_DELWRI) == 0)
                        continue;
                        continue;
-               s = spl6();
-               if (ep->b_flags&B_BUSY) {
-                       ep->b_flags |= B_WANTED;
-                       sleep((caddr_t)ep, PRIBIO+1);
+               splx(s);
+               notavail(bp);
+               (void) bawrite(bp);
+               goto loop;
+       }
+       splx(s);
+       if ((flags & B_SYNC) == 0)
+               return;
+wloop:
+       s = splbio();
+       for (bp = vp->v_blockh; bp; bp = nbp) {
+               nbp = bp->b_blockf;
+               if (bp->b_flags & B_BUSY) {
+                       bp->b_flags |= B_WANTED;
+                       sleep((caddr_t)bp, PRIBIO+1);
                        splx(s);
                        splx(s);
-                       goto loop;
+                       goto wloop;
                }
                }
-               if (ep->b_flags & B_DELWRI) {
+               if ((bp->b_flags & B_DELWRI)) {
                        splx(s);
                        splx(s);
-                       notavail(ep);
-                       bwrite(ep);
                        goto loop;
                }
                        goto loop;
                }
-               splx(s);
        }
        }
+       splx(s);
 }
 
 /*
 }
 
 /*
- * Make sure all write-behind blocks
- * on dev (or NODEV for all)
- * are flushed out.
- * (from umount and update)
+ * Invalidate in core blocks belonging to closed or umounted filesystem
+ *
+ * Go through the list of vnodes associated with the file system;
+ * for each vnode invalidate any buffers that it holds. Normally
+ * this routine is preceeded by a bflush call, so that on a quiescent
+ * filesystem there will be no dirty buffers when we are done. Binval
+ * returns the count of dirty buffers when it is finished.
  */
  */
-bflush(dev)
-       dev_t dev;
+mntinvalbuf(mountp)
+       struct mount *mountp;
+{
+       register struct vnode *vp;
+       struct vnode *nvp;
+       int dirty = 0;
+
+loop:
+       for (vp = mountp->m_mounth; vp; vp = nvp) {
+               nvp = vp->v_mountf;
+               if (vget(vp))
+                       goto loop;
+               dirty += vinvalbuf(vp, 1);
+               vput(vp);
+       }
+       return (dirty);
+}
+
+/*
+ * Flush out and invalidate all buffers associated with a vnode.
+ * Called with the underlying object locked.
+ */
+vinvalbuf(vp, save)
+       register struct vnode *vp;
+       int save;
 {
        register struct buf *bp;
 {
        register struct buf *bp;
-       register struct buf *flist;
-       int s;
+       struct buf *nbp;
+       int s, dirty = 0;
 
 loop:
 
 loop:
-       s = spl6();
-       for (flist = bfreelist; flist < &bfreelist[BQ_EMPTY]; flist++)
-       for (bp = flist->av_forw; bp != flist; bp = bp->av_forw) {
-               if ((bp->b_flags & B_DELWRI) == 0)
-                       continue;
-               if (dev == NODEV || dev == bp->b_dev) {
-                       bp->b_flags |= B_ASYNC;
-                       notavail(bp);
-                       bwrite(bp);
+       for (bp = vp->v_blockh; bp; bp = nbp) {
+               nbp = bp->b_blockf;
+               s = splbio();
+               if (bp->b_flags & B_BUSY) {
+                       bp->b_flags |= B_WANTED;
+                       sleep((caddr_t)bp, PRIBIO+1);
                        splx(s);
                        goto loop;
                }
                        splx(s);
                        goto loop;
                }
+               splx(s);
+               notavail(bp);
+               if (save) {
+                       if (bp->b_flags & B_DELWRI) {
+                               dirty++;
+                               (void) bwrite(bp);
+                               goto loop;
+                       }
+               }
+               bp->b_flags |= B_INVAL;
+               brelse(bp);
        }
        }
-       splx(s);
+       if (vp->v_blockh != 0)
+               panic("vinvalbuf: flush failed");
+       return (dirty);
 }
 
 /*
 }
 
 /*
- * Pick up the device's error number and pass it to the user;
- * if there is an error but the number is 0 set a generalized
- * code.  Actually the latter is always true because devices
- * don't yet return specific errors.
+ * Associate a buffer with a vnode.
  */
  */
-geterror(bp)
+bgetvp(vp, bp)
+       register struct vnode *vp;
        register struct buf *bp;
 {
        register struct buf *bp;
 {
-       int error = 0;
 
 
-       if (bp->b_flags&B_ERROR)
-               if ((error = bp->b_error)==0)
-                       return (EIO);
-       return (error);
+       if (bp->b_vp)
+               panic("bgetvp: not free");
+       VREF(vp);
+       bp->b_vp = vp;
+       if (vp->v_type == VBLK || vp->v_type == VCHR)
+               bp->b_dev = vp->v_rdev;
+       else
+               bp->b_dev = NODEV;
+       /*
+        * Insert onto list for new vnode.
+        */
+       if (vp->v_blockh) {
+               bp->b_blockf = vp->v_blockh;
+               bp->b_blockb = &vp->v_blockh;
+               vp->v_blockh->b_blockb = &bp->b_blockf;
+               vp->v_blockh = bp;
+       } else {
+               vp->v_blockh = bp;
+               bp->b_blockb = &vp->v_blockh;
+               bp->b_blockf = NULL;
+       }
 }
 
 /*
 }
 
 /*
- * Invalidate in core blocks belonging to closed or umounted filesystem
- *
- * This is not nicely done at all - the buffer ought to be removed from the
- * hash chains & have its dev/blkno fields clobbered, but unfortunately we
- * can't do that here, as it is quite possible that the block is still
- * being used for i/o. Eventually, all disc drivers should be forced to
- * have a close routine, which ought ensure that the queue is empty, then
- * properly flush the queues. Until that happy day, this suffices for
- * correctness.                                                ... kre
+ * Disassociate a buffer from a vnode.
  */
  */
-binval(dev)
-       dev_t dev;
+brelvp(bp)
+       register struct buf *bp;
 {
 {
+       struct buf *bq;
+       struct vnode *vp;
+
+       if (bp->b_vp == (struct vnode *) 0)
+               panic("brelvp: NULL");
+       /*
+        * Delete from old vnode list, if on one.
+        */
+       if (bp->b_blockb) {
+               if (bq = bp->b_blockf)
+                       bq->b_blockb = bp->b_blockb;
+               *bp->b_blockb = bq;
+               bp->b_blockf = NULL;
+               bp->b_blockb = NULL;
+       }
+       vp = bp->b_vp;
+       bp->b_vp = (struct vnode *) 0;
+       vrele(vp);
+}
+
+/*
+ * Reassign a buffer from one vnode to another.
+ * Used to assign file specific control information
+ * (indirect blocks) to the vnode to which they belong.
+ */
+reassignbuf(bp, newvp)
        register struct buf *bp;
        register struct buf *bp;
-       register struct bufhd *hp;
-#define dp ((struct buf *)hp)
+       register struct vnode *newvp;
+{
+       register struct buf *bq;
 
 
-       for (hp = bufhash; hp < &bufhash[BUFHSZ]; hp++)
-               for (bp = dp->b_forw; bp != dp; bp = bp->b_forw)
-                       if (bp->b_dev == dev)
-                               bp->b_flags |= B_INVAL;
+       /*
+        * Delete from old vnode list, if on one.
+        */
+       if (bp->b_blockb) {
+               if (bq = bp->b_blockf)
+                       bq->b_blockb = bp->b_blockb;
+               *bp->b_blockb = bq;
+       }
+       /*
+        * Insert onto list for new vnode.
+        */
+       if (newvp->v_blockh) {
+               bp->b_blockf = newvp->v_blockh;
+               bp->b_blockb = &newvp->v_blockh;
+               newvp->v_blockh->b_blockb = &bp->b_blockf;
+               newvp->v_blockh = bp;
+       } else {
+               newvp->v_blockh = bp;
+               bp->b_blockb = &newvp->v_blockh;
+               bp->b_blockf = NULL;
+       }
 }
 }
Continuous source code history from original PDP-7 UNIX to FreeBSD 2, the first fully unencumbered FreeBSD release.