Rollback the allproclk and fileheadlk addition. When grabbing an

rwlock, the thread will release biglock if it sleeps, means that
atomicity from before the rw_enter() to after it is not guaranteed.
The change didn't address those, so pulling it until it does.

"go for it" tedu@

diff --git a/sys/kern/kern_descrip.c b/sys/kern/kern_descrip.c
index 8efcc92..12c44f0 100644 (file)
--- a/sys/kern/kern_descrip.c
+++ b/sys/kern/kern_descrip.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: kern_descrip.c,v 1.83 2010/03/24 23:18:17 tedu Exp $  */
+/*     $OpenBSD: kern_descrip.c,v 1.84 2010/07/19 23:00:15 guenther Exp $      */
 /*     $NetBSD: kern_descrip.c,v 1.42 1996/03/30 22:24:38 christos Exp $       */
 
 /*
@@ -68,7 +68,6 @@
  * Descriptor management.
  */
 struct filelist filehead;      /* head of list of open files */
-struct rwlock fileheadlk;
 int nfiles;                    /* actual number of open files */
 
 static __inline void fd_used(struct filedesc *, int);
@@ -88,7 +87,6 @@ filedesc_init(void)
        pool_init(&fdesc_pool, sizeof(struct filedesc0), 0, 0, 0, "fdescpl",
                &pool_allocator_nointr);
        LIST_INIT(&filehead);
-       rw_init(&fileheadlk, "filehead");
 }
 
 static __inline int
@@ -827,13 +825,11 @@ restart:
        nfiles++;
        fp = pool_get(&file_pool, PR_WAITOK|PR_ZERO);
        fp->f_iflags = FIF_LARVAL;
-       rw_enter_write(&fileheadlk);
        if ((fq = p->p_fd->fd_ofiles[0]) != NULL) {
                LIST_INSERT_AFTER(fq, fp, f_list);
        } else {
                LIST_INSERT_HEAD(&filehead, fp, f_list);
        }
-       rw_exit_write(&fileheadlk);
        p->p_fd->fd_ofiles[i] = fp;
        fp->f_count = 1;
        fp->f_cred = p->p_ucred;
@@ -1092,9 +1088,7 @@ closef(struct file *fp, struct proc *p)
                error = 0;
 
        /* Free fp */
-       rw_enter_write(&fileheadlk);
        LIST_REMOVE(fp, f_list);
-       rw_exit_write(&fileheadlk);
        crfree(fp->f_cred);
 #ifdef DIAGNOSTIC
        if (fp->f_count != 0 || fp->f_usecount != 1)

diff --git a/sys/kern/kern_exit.c b/sys/kern/kern_exit.c
index d8fc8a2..bf36116 100644 (file)
--- a/sys/kern/kern_exit.c
+++ b/sys/kern/kern_exit.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: kern_exit.c,v 1.94 2010/06/29 20:25:57 guenther Exp $ */
+/*     $OpenBSD: kern_exit.c,v 1.95 2010/07/19 23:00:15 guenther Exp $ */
 /*     $NetBSD: kern_exit.c,v 1.39 1996/04/22 01:38:25 christos Exp $  */
 
 /*
@@ -242,7 +242,6 @@ exit1(struct proc *p, int rv, int flags)
          * deadproc list later (using the p_hash member), and
          * wake up the reaper when we do.
          */
-       rw_enter_write(&allproclk);
        /*
         * NOTE: WE ARE NO LONGER ALLOWED TO SLEEP!
         */
@@ -251,7 +250,6 @@ exit1(struct proc *p, int rv, int flags)
        LIST_REMOVE(p, p_hash);
        LIST_REMOVE(p, p_list);
        LIST_INSERT_HEAD(&zombproc, p, p_list);
-       rw_exit_write(&allproclk);
 
        /*
         * Give orphaned children to init(8).
@@ -568,9 +566,7 @@ proc_zap(struct proc *p)
         * Unlink it from its process group and free it.
         */
        leavepgrp(p);
-       rw_enter_write(&allproclk);
        LIST_REMOVE(p, p_list); /* off zombproc */
-       rw_exit_write(&allproclk);
        LIST_REMOVE(p, p_sibling);
 
        /*

diff --git a/sys/kern/kern_fork.c b/sys/kern/kern_fork.c
index 8e4674c..8d30efd 100644 (file)
--- a/sys/kern/kern_fork.c
+++ b/sys/kern/kern_fork.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: kern_fork.c,v 1.119 2010/07/02 01:25:05 art Exp $     */
+/*     $OpenBSD: kern_fork.c,v 1.120 2010/07/19 23:00:15 guenther Exp $        */
 /*     $NetBSD: kern_fork.c,v 1.29 1996/02/09 18:59:34 christos Exp $  */
 
 /*
@@ -388,7 +388,6 @@ fork1(struct proc *p1, int exitsig, int flags, void *stack, size_t stacksize,
 #endif
 
        /* Find an unused pid satisfying 1 <= lastpid <= PID_MAX */
-       rw_enter_write(&allproclk);
        do {
                lastpid = 1 + (randompid ? arc4random() : lastpid) % PID_MAX;
        } while (pidtaken(lastpid));
@@ -396,7 +395,6 @@ fork1(struct proc *p1, int exitsig, int flags, void *stack, size_t stacksize,
 
        LIST_INSERT_HEAD(&allproc, p2, p_list);
        LIST_INSERT_HEAD(PIDHASH(p2->p_pid), p2, p_hash);
-       rw_exit_write(&allproclk);
        LIST_INSERT_HEAD(&p1->p_children, p2, p_sibling);
        LIST_INSERT_AFTER(p1, p2, p_pglist);
        if (p2->p_flag & P_TRACED) {

diff --git a/sys/kern/kern_proc.c b/sys/kern/kern_proc.c
index 2088492..96276b5 100644 (file)
--- a/sys/kern/kern_proc.c
+++ b/sys/kern/kern_proc.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: kern_proc.c,v 1.43 2010/07/10 21:29:37 guenther Exp $ */
+/*     $OpenBSD: kern_proc.c,v 1.44 2010/07/19 23:00:15 guenther Exp $ */
 /*     $NetBSD: kern_proc.c,v 1.14 1996/02/09 18:59:41 christos Exp $  */
 
 /*
@@ -40,7 +40,6 @@
 #include <sys/acct.h>
 #include <sys/wait.h>
 #include <sys/file.h>
-#include <sys/rwlock.h>
 #include <ufs/ufs/quota.h>
 #include <sys/uio.h>
 #include <sys/malloc.h>
@@ -62,7 +61,6 @@ u_long pidhash;
 struct pgrphashhead *pgrphashtbl;
 u_long pgrphash;
 struct proclist allproc;
-struct rwlock allproclk;
 struct proclist zombproc;
 
 struct pool proc_pool;
@@ -85,7 +83,6 @@ void
 procinit(void)
 {
        LIST_INIT(&allproc);
-       rw_init(&allproclk, "allproc");
        LIST_INIT(&zombproc);
 
 

diff --git a/sys/kern/kern_sysctl.c b/sys/kern/kern_sysctl.c
index 9fc2b8e..2e78801 100644 (file)
--- a/sys/kern/kern_sysctl.c
+++ b/sys/kern/kern_sysctl.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: kern_sysctl.c,v 1.189 2010/07/10 21:29:37 guenther Exp $      */
+/*     $OpenBSD: kern_sysctl.c,v 1.190 2010/07/19 23:00:15 guenther Exp $      */
 /*     $NetBSD: kern_sysctl.c,v 1.17 1996/05/20 17:49:05 mrg Exp $     */
 
 /*-
@@ -163,13 +163,8 @@ sys___sysctl(struct proc *p, void *v, register_t *retval)
        switch (name[0]) {
        case CTL_KERN:
                fn = kern_sysctl;
-               switch (name[1]) {      /* XXX */
-               case KERN_VNODE:
-               case KERN_FILE:
-               case KERN_FILE2:
+               if (name[1] == KERN_VNODE)      /* XXX */
                        dolock = 0;
-                       break;
-               }
                break;
        case CTL_HW:
                fn = hw_sysctl;
@@ -1004,12 +999,10 @@ sysctl_file(char *where, size_t *sizep, struct proc *p)
        /*
         * followed by an array of file structures
         */
-       rw_enter_read(&fileheadlk);
        LIST_FOREACH(fp, &filehead, f_list) {
                if (buflen < sizeof(struct file)) {
                        *sizep = where - start;
-                       error = ENOMEM;
-                       goto out;
+                       return (ENOMEM);
                }
 
                /* Only let the superuser or the owner see some information */
@@ -1023,14 +1016,12 @@ sysctl_file(char *where, size_t *sizep, struct proc *p)
                }
                error = copyout(&cfile, where, sizeof (struct file));
                if (error)
-                       goto out;
+                       return (error);
                buflen -= sizeof(struct file);
                where += sizeof(struct file);
        }
        *sizep = where - start;
-out:
-       rw_exit_read(&fileheadlk);
-       return (error);
+       return (0);
 }
 
 #ifndef SMALL_KERNEL
@@ -1234,13 +1225,11 @@ sysctl_file2(int *name, u_int namelen, char *where, size_t *sizep,
                        error = EINVAL;
                        break;
                }
-               rw_enter_read(&fileheadlk);
                LIST_FOREACH(fp, &filehead, f_list) {
                        if (fp->f_count == 0)
                                continue;
                        FILLIT(fp, NULL, 0, NULL, NULL);
                }
-               rw_exit_read(&fileheadlk);
                break;
        case KERN_FILE_BYPID:
                /* A arg of -1 indicates all processes */
@@ -1248,7 +1237,6 @@ sysctl_file2(int *name, u_int namelen, char *where, size_t *sizep,
                        error = EINVAL;
                        break;
                }
-               rw_enter_read(&allproclk);
                LIST_FOREACH(pp, &allproc, p_list) {
                        /* skip system, exiting, embryonic and undead processes */
                        if ((pp->p_flag & P_SYSTEM) || (pp->p_flag & P_WEXIT)
@@ -1259,7 +1247,6 @@ sysctl_file2(int *name, u_int namelen, char *where, size_t *sizep,
                                continue;
                        }
                        fdp = pp->p_fd;
-                       fdplock(fdp);
                        if (pp->p_textvp)
                                FILLIT(NULL, NULL, KERN_FILE_TEXT, pp->p_textvp, pp);
                        if (fdp->fd_cdir)
@@ -1275,12 +1262,9 @@ sysctl_file2(int *name, u_int namelen, char *where, size_t *sizep,
                                        continue;
                                FILLIT(fp, fdp, i, NULL, pp);
                        }
-                       fdpunlock(fdp);
                }
-               rw_exit_read(&allproclk);
                break;
        case KERN_FILE_BYUID:
-               rw_enter_read(&allproclk);
                LIST_FOREACH(pp, &allproc, p_list) {
                        /* skip system, exiting, embryonic and undead processes */
                        if ((pp->p_flag & P_SYSTEM) || (pp->p_flag & P_WEXIT)
@@ -1291,7 +1275,6 @@ sysctl_file2(int *name, u_int namelen, char *where, size_t *sizep,
                                continue;
                        }
                        fdp = pp->p_fd;
-                       fdplock(fdp);
                        if (fdp->fd_cdir)
                                FILLIT(NULL, NULL, KERN_FILE_CDIR, fdp->fd_cdir, pp);
                        if (fdp->fd_rdir)
@@ -1305,9 +1288,7 @@ sysctl_file2(int *name, u_int namelen, char *where, size_t *sizep,
                                        continue;
                                FILLIT(fp, fdp, i, NULL, pp);
                        }
-                       fdpunlock(fdp);
                }
-               rw_exit_read(&allproclk);
                break;
        default:
                error = EINVAL;
@@ -1362,7 +1343,6 @@ sysctl_doproc(int *name, u_int namelen, char *where, size_t *sizep)
                elem_count = name[4];
                kproc2 = malloc(sizeof(struct kinfo_proc2), M_TEMP, M_WAITOK);
        }
-       rw_enter_read(&allproclk);
        p = LIST_FIRST(&allproc);
        doingzomb = 0;
 again:
@@ -1479,7 +1459,6 @@ again:
                *sizep = needed;
        }
 err:
-       rw_exit_read(&allproclk);
        if (eproc)
                free(eproc, M_TEMP);
        if (kproc2)

diff --git a/sys/sys/file.h b/sys/sys/file.h
index 28474ac..8b7f00e 100644 (file)
--- a/sys/sys/file.h
+++ b/sys/sys/file.h
@@ -1,4 +1,4 @@
-/*     $OpenBSD: file.h,v 1.26 2010/03/24 23:18:17 tedu Exp $  */
+/*     $OpenBSD: file.h,v 1.27 2010/07/19 23:00:15 guenther Exp $      */
 /*     $NetBSD: file.h,v 1.11 1995/03/26 20:24:13 jtc Exp $    */
 
 /*
@@ -106,7 +106,6 @@ struct file {
 
 LIST_HEAD(filelist, file);
 extern struct filelist filehead;       /* head of list of open files */
-extern struct rwlock fileheadlk;
 extern int maxfiles;                   /* kernel limit on number of open files */
 extern int nfiles;                     /* actual number of open files */
 extern struct fileops vnops;           /* vnode operations for files */

diff --git a/sys/sys/proc.h b/sys/sys/proc.h
index 2cb299f..3e857da 100644 (file)
--- a/sys/sys/proc.h
+++ b/sys/sys/proc.h
@@ -1,4 +1,4 @@
-/*     $OpenBSD: proc.h,v 1.130 2010/07/03 04:44:51 guenther Exp $     */
+/*     $OpenBSD: proc.h,v 1.131 2010/07/19 23:00:15 guenther Exp $     */
 /*     $NetBSD: proc.h,v 1.44 1996/04/22 01:23:21 christos Exp $       */
 
 /*-
@@ -405,7 +405,6 @@ extern int randompid;                       /* fork() should create random pid's */
 
 LIST_HEAD(proclist, proc);
 extern struct proclist allproc;                /* List of all processes. */
-extern struct rwlock allproclk;                /* also used for zombie list */
 extern struct proclist zombproc;       /* List of zombie processes. */
 
 extern struct proc *initproc;          /* Process slots for init, pager. */