src/afs/NBSD/osi_vm.c

   1 /*
   2  * Copyright 2000, International Business Machines Corporation and others.
   3  * All Rights Reserved.
   4  *
   5  * This software has been released under the terms of the IBM Public
   6  * License.  For details, see the LICENSE file in the top-level source
   7  * directory or online at http://www.openafs.org/dl/license10.html
   8  */
   9
  10
  11 /* osi_vm.c implements:
  12  *
  13  * osi_VM_FlushVCache(avc)
  14  * osi_ubc_flush_dirty_and_wait(vp, flags)
  15  * osi_VM_StoreAllSegments(avc)
  16  * osi_VM_TryToSmush(avc, acred, sync)
  17  * osi_VM_FlushPages(avc, credp)
  18  * osi_VM_Truncate(avc, alen, acred)
  19  */
  20
  21 #include <afsconfig.h>
  22 #include "afs/param.h"
  23
  24 #include "afs/sysincludes.h"    /* Standard vendor system headers */
  25 #include "afs/afsincludes.h"    /* Afs-based standard headers */
  26 #include "afs/afs_stats.h"      /* statistics */
  27
  28 /* Try to discard pages, in order to recycle a vcache entry.
  29  *
  30  * We also make some sanity checks:  ref count, open count, held locks.
  31  *
  32  * We also do some non-VM-related chores, such as releasing the cred pointer
  33  * (for AIX and Solaris) and releasing the gnode (for AIX).
  34  *
  35  * Locking:  afs_xvcache lock is held. It must not be dropped.
  36  *
  37  * OSF/1 Locking:  VN_LOCK has been called.
  38  */
  39 int
  40 osi_VM_FlushVCache(struct vcache *avc)
  41 {
  42     struct vnode *vp = AFSTOV(avc);
  43
  44     if ((afs_debug & AFSDEB_VNLAYER) != 0) {
  45         printf("%s enter\n", __func__);
  46     }
  47
  48     if (vp == NULL) {
  49         printf("%s NULL vp\n", __func__);
  50         return 0;
  51     }
  52
  53     AFS_GUNLOCK();
  54     cache_purge(vp);
  55     vflushbuf(vp, 1);
  56     AFS_GLOCK();
  57
  58     if ((afs_debug & AFSDEB_VNLAYER) != 0) {
  59         printf("%s exit\n", __func__);
  60     }
  61
  62     return 0;
  63 }
  64
  65 /* Try to store pages to cache, in order to store a file back to the server.
  66  *
  67  * Locking:  the vcache entry's lock is held.  It will usually be dropped and
  68  * re-obtained.
  69  */
  70 void
  71 osi_VM_StoreAllSegments(struct vcache *avc)
  72 {
  73     struct vnode *vp;
  74
  75     if ((afs_debug & AFSDEB_VNLAYER) != 0) {
  76         printf("%s enter\n", __func__);
  77     }
  78
  79     ReleaseWriteLock(&avc->lock);
  80     AFS_GUNLOCK();
  81     vp = AFSTOV(avc);
  82     mutex_enter(&vp->v_interlock);
  83     VOP_PUTPAGES(vp, 0, 0, PGO_ALLPAGES|PGO_CLEANIT|PGO_SYNCIO);
  84     AFS_GLOCK();
  85     ObtainWriteLock(&avc->lock, 94);
  86     if ((afs_debug & AFSDEB_VNLAYER) != 0) {
  87         printf("%s exit\n", __func__);
  88     }
  89 }
  90
  91 /* Try to invalidate pages, for "fs flush" or "fs flushv"; or
  92  * try to free pages, when deleting a file.
  93  *
  94  * Locking:  the vcache entry's lock is held.  It may be dropped and
  95  * re-obtained.
  96  *
  97  * Since we drop and re-obtain the lock, we can't guarantee that there won't
  98  * be some pages around when we return, newly created by concurrent activity.
  99  */
 100 void
 101 osi_VM_TryToSmush(struct vcache *avc, afs_ucred_t *acred, int sync)
 102 {
 103     if ((afs_debug & AFSDEB_VNLAYER) != 0) {
 104         printf("%s enter\n", __func__);
 105     }
 106
 107     ReleaseWriteLock(&avc->lock);
 108     osi_VM_FlushVCache(avc);
 109     ObtainWriteLock(&avc->lock, 59);
 110
 111     if ((afs_debug & AFSDEB_VNLAYER) != 0) {
 112         printf("%s exit\n", __func__);
 113     }
 114 }
 115
 116 /* Purge VM for a file when its callback is revoked.
 117  *
 118  * Locking:  No lock is held, not even the global lock.
 119  */
 120 void
 121 osi_VM_FlushPages(struct vcache *avc, afs_ucred_t *credp)
 122 {
 123     struct vnode *vp = AFSTOV(avc);
 124
 125     if ((afs_debug & AFSDEB_VNLAYER) != 0) {
 126         printf("%s enter\n", __func__);
 127     }
 128
 129     if (!vp) {
 130         printf("%s NULL vp\n", __func__);
 131         return;
 132     }
 133
 134     cache_purge(vp);
 135     vinvalbuf(vp, 0, credp, curlwp, false, 1);
 136
 137     if ((afs_debug & AFSDEB_VNLAYER) != 0) {
 138         printf("%s exit\n", __func__);
 139     }
 140 }
 141
 142 /* Purge pages beyond end-of-file, when truncating a file.
 143  *
 144  * Locking:  no lock is held, not even the global lock.
 145  * activeV is raised.  This is supposed to block pageins, but at present
 146  * it only works on Solaris.
 147  */
 148 void
 149 osi_VM_Truncate(struct vcache *avc, voff_t alen, afs_ucred_t *acred)
 150 {
 151     struct vnode *vp = AFSTOV(avc);
 152
 153     if ((afs_debug & AFSDEB_VNLAYER) != 0) {
 154         printf("%s enter\n", __func__);
 155     }
 156
 157     vtruncbuf(vp, alen, false, 0);
 158
 159     if ((afs_debug & AFSDEB_VNLAYER) != 0) {
 160         printf("%s exit\n", __func__);
 161     }
 162 }