cleanup & lint

SCCS-vsn: sys/miscfs/union/union.h 2.2
SCCS-vsn: sys/miscfs/union/union_subr.c 2.2
SCCS-vsn: sys/miscfs/union/union_vnops.c 2.2
SCCS-vsn: sys/miscfs/union/union_vfsops.c 2.2

diff --git a/usr/src/sys/miscfs/union/union.h b/usr/src/sys/miscfs/union/union.h
index 8041fb7..8ac2158 100644 (file)
--- a/usr/src/sys/miscfs/union/union.h
+++ b/usr/src/sys/miscfs/union/union.h
@@ -8,7 +8,7 @@
  *
  * %sccs.include.redist.c%
  *
  *
  * %sccs.include.redist.c%
  *

- *     @(#)union.h     2.1 (Berkeley) %G%
+ *     @(#)union.h     2.2 (Berkeley) %G%

  */
 
 struct union_args {
  */
 
 struct union_args {


@@ -42,7 +42,7 @@ struct union_mount {
  * A cache of vnode references
  */
 struct union_node {
  * A cache of vnode references
  */
 struct union_node {

-       struct union_node       *un_next;       /* Hash chain */
+       LIST_ENTRY(union_node)  un_cache;       /* Hash chain */

        struct vnode            *un_vnode;      /* Back pointer */
        struct vnode            *un_uppervp;    /* overlaying object */
        struct vnode            *un_lowervp;    /* underlying object */
        struct vnode            *un_vnode;      /* Back pointer */
        struct vnode            *un_uppervp;    /* overlaying object */
        struct vnode            *un_lowervp;    /* underlying object */


@@ -61,13 +61,6 @@ struct union_node {
 #define UN_ULOCK       0x04            /* Upper node is locked */
 #define UN_KLOCK       0x08            /* Keep upper node locked on vput */
 
 #define UN_ULOCK       0x04            /* Upper node is locked */
 #define UN_KLOCK       0x08            /* Keep upper node locked on vput */
 

-#define LOCKUVP(un) \
-               (((un)->un_flags & UN_ULOCK) ? \
-                 (0) : \
-                 (((un)->un_flags |= UN_ULOCK), VOP_LOCK((un)->un_uppervp)))
-#define UNLOCKUVP(un) \
-               ((un)->un_flags &= ~UN_ULOCK)
-

 extern int union_allocvp __P((struct vnode **, struct mount *,
                                struct vnode *, struct vnode *,
                                struct componentname *, struct vnode *,
 extern int union_allocvp __P((struct vnode **, struct mount *,
                                struct vnode *, struct vnode *,
                                struct componentname *, struct vnode *,


@@ -82,6 +75,8 @@ extern int union_cn_close __P((struct vnode *, int, struct ucred *,
                                struct proc *));
 extern void union_removed_upper __P((struct union_node *un));
 extern struct vnode *union_lowervp __P((struct vnode *));
                                struct proc *));
 extern void union_removed_upper __P((struct union_node *un));
 extern struct vnode *union_lowervp __P((struct vnode *));

+extern void union_newlower __P((struct union_node *, struct vnode *));
+extern void union_newupper __P((struct union_node *, struct vnode *));

 
 #define        MOUNTTOUNIONMOUNT(mp) ((struct union_mount *)((mp)->mnt_data))
 #define        VTOUNION(vp) ((struct union_node *)(vp)->v_data)
 
 #define        MOUNTTOUNIONMOUNT(mp) ((struct union_mount *)((mp)->mnt_data))
 #define        VTOUNION(vp) ((struct union_node *)(vp)->v_data)

diff --git a/usr/src/sys/miscfs/union/union_subr.c b/usr/src/sys/miscfs/union/union_subr.c
index 3319a34..161d586 100644 (file)
--- a/usr/src/sys/miscfs/union/union_subr.c
+++ b/usr/src/sys/miscfs/union/union_subr.c
@@ -8,7 +8,7 @@
  *
  * %sccs.include.redist.c%
  *
  *
  * %sccs.include.redist.c%
  *

- *     @(#)union_subr.c        2.1 (Berkeley) %G%
+ *     @(#)union_subr.c        2.2 (Berkeley) %G%

  */
 
 #include <sys/param.h>
  */
 
 #include <sys/param.h>


@@ -20,35 +20,139 @@
 #include <sys/malloc.h>
 #include <sys/file.h>
 #include <sys/filedesc.h>
 #include <sys/malloc.h>
 #include <sys/file.h>
 #include <sys/filedesc.h>

+#include <sys/queue.h>

 #include "union.h" /*<miscfs/union/union.h>*/
 
 #ifdef DIAGNOSTIC
 #include <sys/proc.h>
 #endif
 
 #include "union.h" /*<miscfs/union/union.h>*/
 
 #ifdef DIAGNOSTIC
 #include <sys/proc.h>
 #endif
 

-static struct union_node *unhead;
-static int unvplock;
+/* must be power of two, otherwise change UNION_HASH() */
+#define NHASH 32
+
+/* unsigned int ... */
+#define UNION_HASH(u, l) \
+       (((((unsigned long) (u)) + ((unsigned long) l)) >> 8) & (NHASH-1))
+
+static LIST_HEAD(unhead, union_node) unhead[NHASH];
+static int unvplock[NHASH];

 
 int
 union_init()
 {
 
 int
 union_init()
 {

+       int i;
+
+       for (i = 0; i < NHASH; i++)
+               LIST_INIT(&unhead[i]);
+       bzero((caddr_t) unvplock, sizeof(unvplock));
+}
+
+static int
+union_list_lock(ix)
+       int ix;
+{
+
+       if (unvplock[ix] & UN_LOCKED) {
+               unvplock[ix] |= UN_WANT;
+               sleep((caddr_t) &unvplock[ix], PINOD);
+               return (1);
+       }

 
 

-       unhead = 0;
-       unvplock = 0;
+       unvplock[ix] |= UN_LOCKED;
+
+       return (0);

 }
 
 static void
 }
 
 static void

-union_remlist(un)
+union_list_unlock(ix)
+       int ix;
+{
+
+       unvplock[ix] &= ~UN_LOCKED;
+
+       if (unvplock[ix] & UN_WANT) {
+               unvplock[ix] &= ~UN_WANT;
+               wakeup((caddr_t) &unvplock[ix]);
+       }
+}
+
+void
+union_updatevp(un, uppervp, lowervp)

        struct union_node *un;
        struct union_node *un;

+       struct vnode *uppervp;
+       struct vnode *lowervp;

 {
 {

-       struct union_node **unpp;
+       int ohash = UNION_HASH(un->un_uppervp, un->un_lowervp);
+       int nhash = UNION_HASH(uppervp, lowervp);

 
 

-       for (unpp = &unhead; *unpp != 0; unpp = &(*unpp)->un_next) {
-               if (*unpp == un) {
-                       *unpp = un->un_next;
-                       break;
+       if (ohash != nhash) {
+               /*
+                * Ensure locking is ordered from lower to higher
+                * to avoid deadlocks.
+                */
+               if (nhash < ohash) {
+                       int t = ohash;
+                       ohash = nhash;
+                       nhash = t;
+               }
+
+               while (union_list_lock(ohash))
+                       continue;
+
+               while (union_list_lock(nhash))
+                       continue;
+
+               LIST_REMOVE(un, un_cache);
+               union_list_unlock(ohash);
+       } else {        
+               while (union_list_lock(nhash))
+                       continue;
+       }
+
+       if (un->un_lowervp != lowervp) {
+               if (un->un_lowervp) {
+                       vrele(un->un_lowervp);
+                       if (un->un_path) {
+                               free(un->un_path, M_TEMP);
+                               un->un_path = 0;
+                       }
+                       if (un->un_dirvp) {
+                               vrele(un->un_dirvp);
+                               un->un_dirvp = NULLVP;
+                       }

                }
                }

+               un->un_lowervp = lowervp;
+       }
+
+       if (un->un_uppervp != uppervp) {
+               if (un->un_uppervp)
+                       vrele(un->un_uppervp);
+
+               un->un_uppervp = uppervp;

        }
        }

+
+       if (ohash != nhash)
+               LIST_INSERT_HEAD(&unhead[nhash], un, un_cache);
+
+       union_list_unlock(nhash);
+}
+
+void
+union_newlower(un, lowervp)
+       struct union_node *un;
+       struct vnode *lowervp;
+{
+
+       union_updatevp(un, un->un_uppervp, lowervp);
+}
+
+void
+union_newupper(un, uppervp)
+       struct union_node *un;
+       struct vnode *uppervp;
+{
+
+       union_updatevp(un, uppervp, un->un_lowervp);

 }
 
 /*
 }
 
 /*


@@ -95,27 +199,62 @@ union_allocvp(vpp, mp, undvp, dvp, cnp, uppervp, lowervp)
        int error;
        struct union_node *un;
        struct union_node **pp;
        int error;
        struct union_node *un;
        struct union_node **pp;

-       struct vnode *xlowervp = 0;
+       struct vnode *xlowervp = NULLVP;
+       int hash;
+       int try;

 
 

-       if (uppervp == 0 && lowervp == 0)
+       if (uppervp == NULLVP && lowervp == NULLVP)

                panic("union: unidentifiable allocation");
 
        if (uppervp && lowervp && (uppervp->v_type != lowervp->v_type)) {
                xlowervp = lowervp;
                panic("union: unidentifiable allocation");
 
        if (uppervp && lowervp && (uppervp->v_type != lowervp->v_type)) {
                xlowervp = lowervp;

-               lowervp = 0;
+               lowervp = NULLVP;

        }
 
 loop:
        }
 
 loop:

-       for (un = unhead; un != 0; un = un->un_next) {
-               if ((un->un_lowervp == lowervp ||
-                    un->un_lowervp == 0) &&
-                   (un->un_uppervp == uppervp ||
-                    un->un_uppervp == 0) &&
-                   (UNIONTOV(un)->v_mount == mp)) {
-                       if (vget(UNIONTOV(un), 0))
-                               goto loop;
+       for (try = 0; try < 3; try++) {
+               switch (try) {
+               case 0:
+                       if (lowervp == NULLVP)
+                               continue;
+                       hash = UNION_HASH(uppervp, lowervp);

                        break;
                        break;

+
+               case 1:
+                       if (uppervp == NULLVP)
+                               continue;
+                       hash = UNION_HASH(uppervp, NULLVP);
+                       break;
+
+               case 2:
+                       if (lowervp == NULLVP)
+                               continue;
+                       hash = UNION_HASH(NULLVP, lowervp);
+                       break;
+               }
+
+               while (union_list_lock(hash))
+                       continue;
+
+               for (un = unhead[hash].lh_first; un != 0;
+                                       un = un->un_cache.le_next) {
+                       if ((un->un_lowervp == lowervp ||
+                            un->un_lowervp == NULLVP) &&
+                           (un->un_uppervp == uppervp ||
+                            un->un_uppervp == NULLVP) &&
+                           (UNIONTOV(un)->v_mount == mp)) {
+                               if (vget(UNIONTOV(un), 0)) {
+                                       union_list_unlock(hash);
+                                       goto loop;
+                               }
+                               break;
+                       }

                }
                }

+
+               union_list_unlock(hash);
+
+               if (un)
+                       break;

        }
 
        if (un) {
        }
 
        if (un) {


@@ -169,9 +308,7 @@ loop:
                 * Save information about the upper layer.
                 */
                if (uppervp != un->un_uppervp) {
                 * Save information about the upper layer.
                 */
                if (uppervp != un->un_uppervp) {

-                       if (un->un_uppervp)
-                               vrele(un->un_uppervp);
-                       un->un_uppervp = uppervp;
+                       union_newupper(un, uppervp);

                } else if (uppervp) {
                        vrele(uppervp);
                }
                } else if (uppervp) {
                        vrele(uppervp);
                }


@@ -188,12 +325,7 @@ loop:
                 * might need.
                 */
                if (lowervp != un->un_lowervp) {
                 * might need.
                 */
                if (lowervp != un->un_lowervp) {

-                       if (un->un_lowervp) {
-                               vrele(un->un_lowervp);
-                               free(un->un_path, M_TEMP);
-                               vrele(un->un_dirvp);
-                       }
-                       un->un_lowervp = lowervp;
+                       union_newlower(un, lowervp);

                        if (cnp && (lowervp != NULLVP) &&
                            (lowervp->v_type == VREG)) {
                                un->un_hash = cnp->cn_hash;
                        if (cnp && (lowervp != NULLVP) &&
                            (lowervp->v_type == VREG)) {
                                un->un_hash = cnp->cn_hash;


@@ -216,12 +348,10 @@ loop:
         * otherwise lock the vp list while we call getnewvnode
         * since that can block.
         */ 
         * otherwise lock the vp list while we call getnewvnode
         * since that can block.
         */ 

-       if (unvplock & UN_LOCKED) {
-               unvplock |= UN_WANT;
-               sleep((caddr_t) &unvplock, PINOD);
+       hash = UNION_HASH(uppervp, lowervp);
+
+       if (union_list_lock(hash))

                goto loop;
                goto loop;

-       }
-       unvplock |= UN_LOCKED;

 
        error = getnewvnode(VT_UNION, mp, union_vnodeop_p, vpp);
        if (error) {
 
        error = getnewvnode(VT_UNION, mp, union_vnodeop_p, vpp);
        if (error) {


@@ -246,7 +376,6 @@ loop:
                (*vpp)->v_type = lowervp->v_type;
        un = VTOUNION(*vpp);
        un->un_vnode = *vpp;
                (*vpp)->v_type = lowervp->v_type;
        un = VTOUNION(*vpp);
        un->un_vnode = *vpp;

-       un->un_next = 0;

        un->un_uppervp = uppervp;
        un->un_lowervp = lowervp;
        un->un_openl = 0;
        un->un_uppervp = uppervp;
        un->un_lowervp = lowervp;
        un->un_openl = 0;


@@ -272,21 +401,13 @@ loop:
                un->un_dirvp = 0;
        }
 
                un->un_dirvp = 0;
        }
 

-       /* add to union vnode list */
-       for (pp = &unhead; *pp; pp = &(*pp)->un_next)
-               continue;
-       *pp = un;
+       LIST_INSERT_HEAD(&unhead[hash], un, un_cache);

 
        if (xlowervp)
                vrele(xlowervp);
 
 out:
 
        if (xlowervp)
                vrele(xlowervp);
 
 out:

-       unvplock &= ~UN_LOCKED;
-
-       if (unvplock & UN_WANT) {
-               unvplock &= ~UN_WANT;
-               wakeup((caddr_t) &unvplock);
-       }
+       union_list_unlock(hash);

 
        return (error);
 }
 
        return (error);
 }


@@ -297,10 +418,20 @@ union_freevp(vp)
 {
        struct union_node *un = VTOUNION(vp);
 
 {
        struct union_node *un = VTOUNION(vp);
 

-       union_remlist(un);
+       LIST_REMOVE(un, un_cache);
+
+       if (un->un_uppervp)
+               vrele(un->un_uppervp);
+       if (un->un_lowervp)
+               vrele(un->un_lowervp);
+       if (un->un_dirvp)
+               vrele(un->un_dirvp);
+       if (un->un_path)
+               free(un->un_path, M_TEMP);

 
        FREE(vp->v_data, M_TEMP);
        vp->v_data = 0;
 
        FREE(vp->v_data, M_TEMP);
        vp->v_data = 0;

+

        return (0);
 }
 
        return (0);
 }
 


@@ -579,11 +710,10 @@ union_removed_upper(un)
 {
        if (un->un_flags & UN_ULOCK) {
                un->un_flags &= ~UN_ULOCK;
 {
        if (un->un_flags & UN_ULOCK) {
                un->un_flags &= ~UN_ULOCK;

-               vput(un->un_uppervp);
-       } else {
-               vrele(un->un_uppervp);
+               VOP_UNLOCK(un->un_uppervp);

        }
        }

-       un->un_uppervp = NULLVP;
+
+       union_newupper(un, NULLVP);

 }
 
 struct vnode *
 }
 
 struct vnode *

diff --git a/usr/src/sys/miscfs/union/union_vfsops.c b/usr/src/sys/miscfs/union/union_vfsops.c
index 0df9f55..3a49fd8 100644 (file)
--- a/usr/src/sys/miscfs/union/union_vfsops.c
+++ b/usr/src/sys/miscfs/union/union_vfsops.c
@@ -8,7 +8,7 @@
  *
  * %sccs.include.redist.c%
  *
  *
  * %sccs.include.redist.c%
  *

- *     @(#)union_vfsops.c      2.1 (Berkeley) %G%
+ *     @(#)union_vfsops.c      2.2 (Berkeley) %G%

  */
 
 /*
  */
 
 /*


@@ -25,6 +25,7 @@
 #include <sys/namei.h>
 #include <sys/malloc.h>
 #include <sys/filedesc.h>
 #include <sys/namei.h>
 #include <sys/malloc.h>
 #include <sys/filedesc.h>

+#include <sys/queue.h>

 #include "union.h"
 
 /*
 #include "union.h"
 
 /*

diff --git a/usr/src/sys/miscfs/union/union_vnops.c b/usr/src/sys/miscfs/union/union_vnops.c
index 9a2e248..8bf9a55 100644 (file)
--- a/usr/src/sys/miscfs/union/union_vnops.c
+++ b/usr/src/sys/miscfs/union/union_vnops.c
@@ -8,7 +8,7 @@
  *
  * %sccs.include.redist.c%
  *
  *
  * %sccs.include.redist.c%
  *

- *     @(#)union_vnops.c       2.1 (Berkeley) %G%
+ *     @(#)union_vnops.c       2.2 (Berkeley) %G%

  */
 
 #include <sys/param.h>
  */
 
 #include <sys/param.h>


@@ -22,6 +22,7 @@
 #include <sys/namei.h>
 #include <sys/malloc.h>
 #include <sys/buf.h>
 #include <sys/namei.h>
 #include <sys/malloc.h>
 #include <sys/buf.h>

+#include <sys/queue.h>

 #include "union.h"
 
 static int
 #include "union.h"
 
 static int


@@ -394,7 +395,7 @@ union_open(ap)
                                return (error);
 
                        /* at this point, uppervp is locked */
                                return (error);
 
                        /* at this point, uppervp is locked */

-                       un->un_uppervp = vp;    /* XXX */
+                       union_newupper(un, vp);

                        un->un_flags |= UN_ULOCK;
 
                        /*
                        un->un_flags |= UN_ULOCK;
 
                        /*


@@ -1085,31 +1086,9 @@ union_reclaim(ap)
                struct vnode *a_vp;
        } */ *ap;
 {
                struct vnode *a_vp;
        } */ *ap;
 {

-       struct vnode *vp = ap->a_vp;
-       struct union_node *un = VTOUNION(vp);
-       struct vnode *uppervp = un->un_uppervp;
-       struct vnode *lowervp = un->un_lowervp;
-       struct vnode *dirvp = un->un_dirvp;
-       char *path = un->un_path;

 
 

-       /*
-        * Note: in vop_reclaim, vp->v_op == dead_vnodeop_p,
-        * so we can't call VOPs on ourself.
-        */
-       /* After this assignment, this node will not be re-used. */
-       un->un_uppervp = NULLVP;
-       un->un_lowervp = NULLVP;
-       un->un_dirvp = NULLVP;
-       un->un_path = NULL;
-       union_freevp(vp);
-       if (uppervp)
-               vrele(uppervp);
-       if (lowervp)
-               vrele(lowervp);
-       if (dirvp)
-               vrele(dirvp);
-       if (path)
-               free(path, M_TEMP);
+       union_freevp(ap->a_vp);
+

        return (0);
 }
 
        return (0);
 }