have to check that vnode is still associated with mount point before using it

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

diff --git a/usr/src/sys/kern/vfs_subr.c b/usr/src/sys/kern/vfs_subr.c
index 09e1f4d..782ff43 100644 (file)
--- a/usr/src/sys/kern/vfs_subr.c
+++ b/usr/src/sys/kern/vfs_subr.c
@@ -14,7 +14,7 @@
  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  *
  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  *

- *     @(#)vfs_subr.c  7.43 (Berkeley) %G%
+ *     @(#)vfs_subr.c  7.44 (Berkeley) %G%

  */
 
 /*
  */
 
 /*


@@ -532,7 +532,10 @@ vflush(mp, skipvp, flags)
 
        if ((mp->mnt_flag & MNT_MPBUSY) == 0)
                panic("vflush: not busy");
 
        if ((mp->mnt_flag & MNT_MPBUSY) == 0)
                panic("vflush: not busy");

+loop:

        for (vp = mp->mnt_mounth; vp; vp = nvp) {
        for (vp = mp->mnt_mounth; vp; vp = nvp) {

+               if (vp->v_mount != mp)
+                       goto loop;

                nvp = vp->v_mountf;
                /*
                 * Skip over a selected vnode.
                nvp = vp->v_mountf;
                /*
                 * Skip over a selected vnode.


@@ -873,7 +876,6 @@ kinfo_vnode(op, where, acopysize, arg, aneeded)
        int *acopysize, *aneeded;
 {
        register struct mount *mp = rootfs;
        int *acopysize, *aneeded;
 {
        register struct mount *mp = rootfs;

-       register struct vnode *nextvp;

        struct mount *omp;
        struct vnode *vp;
        register needed = 0;
        struct mount *omp;
        struct vnode *vp;
        register needed = 0;


@@ -888,7 +890,6 @@ kinfo_vnode(op, where, acopysize, arg, aneeded)
                return (0);
        }
                
                return (0);
        }
                

-#define RETRY  bp = savebp ; goto again

        do {
                if (vfs_busy(mp)) {
                        mp = mp->mnt_next;
        do {
                if (vfs_busy(mp)) {
                        mp = mp->mnt_next;


@@ -898,25 +899,25 @@ kinfo_vnode(op, where, acopysize, arg, aneeded)
                 * A vget can fail if the vnode is being
                 * recycled.  In this (rare) case, we have to start
                 * over with this filesystem.  Also, have to
                 * A vget can fail if the vnode is being
                 * recycled.  In this (rare) case, we have to start
                 * over with this filesystem.  Also, have to

-                * check that nextvp is still associated
+                * check that the next vp is still associated

                 * with this filesystem.  RACE: could have been
                 * with this filesystem.  RACE: could have been

-                * recycled onto same filesystem.
+                * recycled onto the same filesystem.

                 */
                savebp = bp;
 again:
                 */
                savebp = bp;
 again:

-               nextvp = mp->mnt_mounth;
-               while (vp = nextvp) {
+               for (vp = mp->mnt_mounth; vp; vp = vp->v_mountf) {
+                       if (vp->v_mount != mp) {
+                               if (kinfo_vdebug)
+                                       printf("kinfo: vp changed\n");
+                               bp = savebp;
+                               goto again;
+                       }

                        if (vget(vp)) {
                                if (kinfo_vdebug)
                                        printf("kinfo: vget failed\n");
                                kinfo_vgetfailed++;
                        if (vget(vp)) {
                                if (kinfo_vdebug)
                                        printf("kinfo: vget failed\n");
                                kinfo_vgetfailed++;

-                               RETRY;
-                       }
-                       if (vp->v_mount != mp) {
-                               if (kinfo_vdebug)
-                                       printf("kinfo: vp changed\n");
-                               vput(vp);
-                               RETRY;
+                               bp = savebp;
+                               goto again;

                        }
                        if ((bp + VPTRSZ + VNODESZ <= ewhere) && 
                            ((error = copyout((caddr_t)&vp, bp, VPTRSZ)) ||
                        }
                        if ((bp + VPTRSZ + VNODESZ <= ewhere) && 
                            ((error = copyout((caddr_t)&vp, bp, VPTRSZ)) ||


@@ -926,7 +927,6 @@ again:
                                return (error);
                        }
                        bp += VPTRSZ + VNODESZ;
                                return (error);
                        }
                        bp += VPTRSZ + VNODESZ;

-                       nextvp = vp->v_mountf;

                        vput(vp);
                }
                omp = mp;
                        vput(vp);
                }
                omp = mp;