replace 2 lines accidentally dropped in 4.13

[unix-history] / usr / src / sys / ufs / ffs / ufs_inode.c

diff --git a/usr/src/sys/ufs/ffs/ufs_inode.c b/usr/src/sys/ufs/ffs/ufs_inode.c
index c0d39c2..bcfb3ef 100644 (file)
--- a/usr/src/sys/ufs/ffs/ufs_inode.c
+++ b/usr/src/sys/ufs/ffs/ufs_inode.c
@@ -1,6 +1,4 @@
-/*     ufs_inode.c     4.10    82/04/19        */
-
-/* merged into kernel: @(#)iget.c 2.2 4/8/82 */
+/*     ufs_inode.c     4.16    82/07/01        */

 
 #include "../h/param.h"
 #include "../h/systm.h"
 
 #include "../h/param.h"
 #include "../h/systm.h"


@@ -14,9 +12,18 @@
 #include "../h/inline.h"
 
 #define        INOHSZ  63
 #include "../h/inline.h"
 
 #define        INOHSZ  63

+#if    ((INOHSZ&(INOHSZ-1)) == 0)
+#define        INOHASH(dev,ino)        (((dev)+(ino))&(INOHSZ-1))
+#else

 #define        INOHASH(dev,ino)        (((dev)+(ino))%INOHSZ)
 #define        INOHASH(dev,ino)        (((dev)+(ino))%INOHSZ)

-short  inohash[INOHSZ];
-short  ifreel;
+#endif
+
+union ihead {                          /* inode LRU cache, Chris Maltby */
+       union  ihead *ih_head[2];
+       struct inode *ih_chain[2];
+} ihead[INOHSZ];
+
+struct inode *ifreeh, **ifreet;

 
 /*
  * Initialize hash links for inodes
 
 /*
  * Initialize hash links for inodes


@@ -26,14 +33,49 @@ ihinit()
 {
        register int i;
        register struct inode *ip = inode;
 {
        register int i;
        register struct inode *ip = inode;

+       register union  ihead *ih = ihead;
+
+       for (i = INOHSZ; --i >= 0; ih++) {
+               ih->ih_head[0] = ih;
+               ih->ih_head[1] = ih;
+       }
+       ifreeh = ip;
+       ifreet = &ip->i_freef;
+       ip->i_freeb = &ifreeh;
+       ip->i_forw = ip;
+       ip->i_back = ip;
+       for (i = ninode; --i > 0; ) {
+               ++ip;
+               ip->i_forw = ip;
+               ip->i_back = ip;
+               *ifreet = ip;
+               ip->i_freeb = ifreet;
+               ifreet = &ip->i_freef;
+       }
+       ip->i_freef = NULL;
+}
+
+#ifdef notdef
+/*
+ * Find an inode if it is incore.
+ * This is the equivalent, for inodes,
+ * of ``incore'' in bio.c or ``pfind'' in subr.c.
+ */
+struct inode *
+ifind(dev, ino)
+       dev_t dev;
+       ino_t ino;
+{
+       register struct inode *ip;
+       register union  ihead *ih;

 
 

-       ifreel = 0;
-       for (i = 0; i < ninode-1; i++, ip++)
-               ip->i_hlink = i+1;
-       ip->i_hlink = -1;
-       for (i = 0; i < INOHSZ; i++)
-               inohash[i] = -1;
+       ih = &ihead[INOHASH(dev, ino)];
+       for (ip = ih->ih_chain[0]; ip != (struct inode *)ih; ip = ip->i_forw)
+               if (ino==ip->i_number && dev==ip->i_dev)
+                       return (ip);
+       return ((struct inode *)0);

 }
 }

+#endif notdef

 
 /*
  * Look up an inode by device,inumber.
 
 /*
  * Look up an inode by device,inumber.


@@ -57,17 +99,17 @@ iget(dev, fs, ino)
        ino_t ino;
 {
        register struct inode *ip;
        ino_t ino;
 {
        register struct inode *ip;

+       register union  ihead *ih;

        register struct mount *mp;
        register struct buf *bp;
        register struct dinode *dp;
        register struct mount *mp;
        register struct buf *bp;
        register struct dinode *dp;

-       register int slot;
+       register struct inode *iq;

 
 loop:
        if (getfs(dev) != fs)
                panic("iget: bad fs");
 
 loop:
        if (getfs(dev) != fs)
                panic("iget: bad fs");

-       slot = INOHASH(dev, ino);
-       ip = &inode[inohash[slot]];
-       while (ip != &inode[-1]) {
+       ih = &ihead[INOHASH(dev, ino)];
+       for (ip = ih->ih_chain[0]; ip != (struct inode *)ih; ip = ip->i_forw)

                if (ino == ip->i_number && dev == ip->i_dev) {
                        if ((ip->i_flag&ILOCK) != 0) {
                                ip->i_flag |= IWANT;
                if (ino == ip->i_number && dev == ip->i_dev) {
                        if ((ip->i_flag&ILOCK) != 0) {
                                ip->i_flag |= IWANT;


@@ -76,29 +118,47 @@ loop:
                        }
                        if ((ip->i_flag&IMOUNT) != 0) {
                                for (mp = &mount[0]; mp < &mount[NMOUNT]; mp++)
                        }
                        if ((ip->i_flag&IMOUNT) != 0) {
                                for (mp = &mount[0]; mp < &mount[NMOUNT]; mp++)

-                               if (mp->m_inodp == ip) {
-                                       dev = mp->m_dev;
-                                       fs = mp->m_bufp->b_un.b_fs;
-                                       ino = ROOTINO;
-                                       goto loop;
-                               }
+                                       if(mp->m_inodp == ip) {
+                                               dev = mp->m_dev;
+                                               fs = mp->m_bufp->b_un.b_fs;
+                                               ino = ROOTINO;
+                                               goto loop;
+                                       }

                                panic("no imt");
                        }
                                panic("no imt");
                        }

+                       if (ip->i_count == 0) {         /* ino on free list */
+                               if (iq = ip->i_freef)
+                                       iq->i_freeb = ip->i_freeb;
+                               else
+                                       ifreet = ip->i_freeb;
+                               *ip->i_freeb = iq;
+                               ip->i_freef = NULL;
+                               ip->i_freeb = NULL;
+                       }

                        ip->i_count++;
                        ip->i_flag |= ILOCK;
                        return(ip);
                }
                        ip->i_count++;
                        ip->i_flag |= ILOCK;
                        return(ip);
                }

-               ip = &inode[ip->i_hlink];
-       }
-       if (ifreel < 0) {
+
+       if ((ip = ifreeh) == NULL) {

                tablefull("inode");
                u.u_error = ENFILE;
                return(NULL);
        }
                tablefull("inode");
                u.u_error = ENFILE;
                return(NULL);
        }

-       ip = &inode[ifreel];
-       ifreel = ip->i_hlink;
-       ip->i_hlink = inohash[slot];
-       inohash[slot] = ip - inode;
+       if (iq = ip->i_freef)
+               iq->i_freeb = &ifreeh;
+       ifreeh = iq;
+       ip->i_freef = NULL;
+       ip->i_freeb = NULL;
+       /*
+        * Now to take inode off the hash chain it was on
+        * (initially, or after an iflush, it is on a "hash chain"
+        * consisting entirely of itself, and pointed to by no-one,
+        * but that doesn't matter), and put it on the chain for
+        * its new (ino, dev) pair
+        */
+       remque(ip);
+       insque(ip, ih);

        ip->i_dev = dev;
        ip->i_fs = fs;
        ip->i_number = ino;
        ip->i_dev = dev;
        ip->i_fs = fs;
        ip->i_number = ino;


@@ -111,6 +171,21 @@ loop:
         */
        if ((bp->b_flags&B_ERROR) != 0) {
                brelse(bp);
         */
        if ((bp->b_flags&B_ERROR) != 0) {
                brelse(bp);

+               /*
+                * the inode doesn't contain anything useful, so it would
+                * be misleading to leave it on its hash chain.
+                * 'iput' will take care of putting it back on the free list.
+                */
+               remque(ip);
+               ip->i_forw = ip;
+               ip->i_back = ip;
+               /*
+                * we also loose its inumber, just in case (as iput
+                * doesn't do that any more) - but as it isn't on its
+                * hash chain, I doubt if this is really necessary .. kre
+                * (probably the two methods are interchangable)
+                */
+               ip->i_number = 0;

                iput(ip);
                return(NULL);
        }
                iput(ip);
                return(NULL);
        }


@@ -131,6 +206,16 @@ loop:
 iput(ip)
        register struct inode *ip;
 {
 iput(ip)
        register struct inode *ip;
 {

+
+       if ((ip->i_flag & ILOCK) == 0)
+               panic("iput");
+       iunlock(ip);
+       irele(ip);
+}
+
+irele(ip)
+       register struct inode *ip;
+{

        register int i, x;
        register struct inode *jp;
        int mode;
        register int i, x;
        register struct inode *jp;
        int mode;


@@ -145,27 +230,28 @@ iput(ip)
                        ifree(ip, ip->i_number, mode);
                }
                IUPDAT(ip, &time, &time, 0);
                        ifree(ip, ip->i_number, mode);
                }
                IUPDAT(ip, &time, &time, 0);

-               irele(ip);
-               i = INOHASH(ip->i_dev, ip->i_number);
-               x = ip - inode;
-               if (inohash[i] == x) {
-                       inohash[i] = ip->i_hlink;
+               iunlock(ip);
+               ip->i_flag = 0;
+               /*
+                * Put the inode on the end of the free list.
+                * Possibly in some cases it would be better to
+                * put the inode at the head of the free list,
+                * (eg: where i_mode == 0 || i_number == 0)
+                * but I will think about that later .. kre
+                * (i_number is rarely 0 - only after an i/o error in iget,
+                * where i_mode == 0, the inode will probably be wanted
+                * again soon for an ialloc, so possibly we should keep it)
+                */
+               if (ifreeh) {
+                       *ifreet = ip;
+                       ip->i_freeb = ifreet;

                } else {
                } else {

-                       for (jp = &inode[inohash[i]]; jp != &inode[-1];
-                           jp = &inode[jp->i_hlink])
-                               if (jp->i_hlink == x) {
-                                       jp->i_hlink = ip->i_hlink;
-                                       goto done;
-                               }
-                       panic("iput");
+                       ifreeh = ip;
+                       ip->i_freeb = &ifreeh;

                }
                }

-done:
-               ip->i_hlink = ifreel;
-               ifreel = x;
-               ip->i_flag = 0;
-               ip->i_number = 0;
-       } else
-               irele(ip);
+               ip->i_freef = NULL;
+               ifreet = &ip->i_freef;
+       }

        ip->i_count--;
 }
 
        ip->i_count--;
 }
 


@@ -230,9 +316,6 @@ itrunc(ip)
        struct inode itmp;
        register struct fs *fs;
 
        struct inode itmp;
        register struct fs *fs;
 

-       i = ip->i_mode & IFMT;
-       if (i != IFREG && i != IFDIR && i != IFLNK)
-               return;

        /*
         * Clean inode on disk before freeing blocks
         * to insure no duplicates if system crashes.
        /*
         * Clean inode on disk before freeing blocks
         * to insure no duplicates if system crashes.


@@ -247,6 +330,13 @@ itrunc(ip)
        iupdat(&itmp, &time, &time, 1);
        ip->i_flag &= ~(IUPD|IACC|ICHG);
 
        iupdat(&itmp, &time, &time, 1);
        ip->i_flag &= ~(IUPD|IACC|ICHG);
 

+       /*
+        * Only plain files, directories and symbolic
+        * links contain blocks.
+        */
+       i = ip->i_mode & IFMT;
+       if (i != IFREG && i != IFDIR && i != IFLNK)
+               return;

        /*
         * Now return blocks to free list... if machine
         * crashes, they will be harmless MISSING blocks.
        /*
         * Now return blocks to free list... if machine
         * crashes, they will be harmless MISSING blocks.


@@ -455,11 +545,55 @@ wdir(ip)
        iput(u.u_pdir);
 }
 
        iput(u.u_pdir);
 }
 

+/*
+ * remove any inodes in the inode cache belonging to dev
+ *
+ * There should not be any active ones, return error if any are found
+ * (nb: this is a user error, not a system err)
+ *
+ * Also, count the references to dev by block devices - this really
+ * has nothing to do with the object of the procedure, but as we have
+ * to scan the inode table here anyway, we might as well get the
+ * extra benefit.
+ *
+ * this is called from sumount()/sys3.c when dev is being unmounted
+ */
+iflush(dev)
+       dev_t dev;
+{
+       register struct inode *ip;
+       register open = 0;
+
+       for (ip = inode; ip < inodeNINODE; ip++) {
+               if (ip->i_dev == dev)
+                       if (ip->i_count)
+                               return(-1);
+                       else {
+                               remque(ip);
+                               ip->i_forw = ip;
+                               ip->i_back = ip;
+                               /*
+                                * as i_count == 0, the inode was on the free
+                                * list already, just leave it there, it will
+                                * fall off the bottom eventually. We could
+                                * perhaps move it to the head of the free
+                                * list, but as umounts are done so
+                                * infrequently, we would gain very little,
+                                * while making the code bigger.
+                                */
+                       }
+               else if (ip->i_count && (ip->i_mode&IFMT)==IFBLK &&
+                   ip->i_rdev == dev)
+                       open++;
+       }
+       return (open);
+}
+

 #ifdef ilock
 #undef ilock
 #endif
 #ifdef ilock
 #undef ilock
 #endif

-#ifdef irele
-#undef irele
+#ifdef iunlock
+#undef iunlock

 #endif
 /*
  * Lock an inode. If its already locked, set the WANT bit and sleep.
 #endif
 /*
  * Lock an inode. If its already locked, set the WANT bit and sleep.


@@ -478,7 +612,7 @@ ilock(ip)
 /*
  * Unlock an inode.  If WANT bit is on, wakeup.
  */
 /*
  * Unlock an inode.  If WANT bit is on, wakeup.
  */

-irele(ip)
+iunlock(ip)

        register struct inode *ip;
 {
 
        register struct inode *ip;
 {