src/afs/DARWIN/osi_vcache.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 #include <afsconfig.h>
  11 #include "afs/param.h"
  12
  13 #include "afs/sysincludes.h"    /*Standard vendor system headers */
  14 #include "afsincludes.h"        /*AFS-based standard headers */
  15
  16 struct vcache *
  17 osi_NewVnode(void) {
  18     struct vcache *tvc;
  19
  20     tvc = afs_osi_Alloc(sizeof(struct vcache));
  21     osi_Assert(tvc != NULL);
  22     tvc->v = NULL; /* important to clean this, or use memset 0 */
  23
  24     return tvc;
  25 }
  26
  27
  28 #if defined(AFS_DARWIN80_ENV)
  29 int
  30 osi_TryEvictVCache(struct vcache *avc, int *slept, int defersleep) {
  31     *slept = 0;
  32
  33     /* we ignore defersleep, as we *always* need to sleep */
  34     if (!VREFCOUNT_GT(avc, 0) && avc->opens == 0 &&
  35         (avc->f.states & CUnlinkedDel) == 0) {
  36
  37         vnode_t tvp = AFSTOV(avc);
  38         /* VREFCOUNT_GT only sees usecounts, not iocounts */
  39         /* so this may fail to actually recycle the vnode now */
  40         /* must call vnode_get to avoid races. */
  41         if (vnode_get(tvp) == 0) {
  42             *slept=1;
  43             /* must release lock, since vnode_put will immediately
  44                reclaim if there are no other users */
  45             ReleaseWriteLock(&afs_xvcache);
  46             AFS_GUNLOCK();
  47             vnode_recycle(tvp);
  48             vnode_put(tvp);
  49             AFS_GLOCK();
  50             ObtainWriteLock(&afs_xvcache, 336);
  51         }
  52         /* we can't use the vnode_recycle return value to figure
  53          * this out, since the iocount we have to hold makes it
  54          * always "fail" */
  55         if (AFSTOV(avc) == tvp) {
  56             /* Caller will move this vcache to the head of the VLRU. */
  57             return 0;
  58         } else
  59             return 1;
  60     }
  61     return 0;
  62 }
  63 #else
  64 int
  65 osi_TryEvictVCache(struct vcache *avc, int *slept, int defersleep) {
  66     if (!VREFCOUNT_GT(avc,0)
  67         || ((VREFCOUNT(avc) == 1) && (UBCINFOEXISTS(AFSTOV(avc))))
  68         && avc->opens == 0 && (avc->f.states & CUnlinkedDel) == 0)
  69     {
  70         /*
  71          * vgone() reclaims the vnode, which calls afs_FlushVCache(),
  72          * then it puts the vnode on the free list.
  73          * If we don't do this we end up with a cleaned vnode that's
  74          * not on the free list.
  75          */
  76         AFS_GUNLOCK();
  77         vgone(AFSTOV(avc));
  78         AFS_GLOCK();
  79         return 1;
  80     }
  81     return 0;
  82 }
  83 #endif /* AFS_DARWIN80_ENV */
  84
  85 void
  86 osi_PrePopulateVCache(struct vcache *avc) {
  87     memset(avc, 0, sizeof(struct vcache));
  88 }
  89
  90 void
  91 osi_AttachVnode(struct vcache *avc, int seq) {
  92     ReleaseWriteLock(&afs_xvcache);
  93     AFS_GUNLOCK();
  94     afs_darwin_getnewvnode(avc);  /* includes one refcount */
  95     AFS_GLOCK();
  96     ObtainWriteLock(&afs_xvcache,338);
  97 #ifdef AFS_DARWIN80_ENV
  98     LOCKINIT(avc->rwlock);
  99 #else
 100     lockinit(&avc->rwlock, PINOD, "vcache", 0, 0);
 101 #endif
 102 }
 103
 104 void
 105 osi_PostPopulateVCache(struct vcache *avc) {
 106 #if !defined(AFS_DARWIN80_ENV)
 107    avc->v->v_mount = afs_globalVFS;
 108    vSetType(avc, VREG);
 109 #else
 110    vSetType(avc, VNON);
 111 #endif
 112 }