FBSD: Use UMA allocations instead of getpbuf()

FreeBSD commit 756a5412798b7de1709bb1de2db5ba2a5908cba3 (Allocate
pager bufs from UMA instead of 80-ish mutex protected linked list.)
removed getpbuf() and related functions; callers are supposed to use UMA
allocator functions instead. Use a private zone allocated by
pbuf_zsecond_create() like other filesystems do, and make our callers go
through new abstractions afs_getpbuf() and afs_relpbuf() to use the
right functions.

Change-Id: I303e9f848485481adb94ef5c7db5885f22288003
Reviewed-on: https://gerrit.openafs.org/15165
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Michael Meffie <mmeffie@sinenomine.net>
Reviewed-by: Andrew Deason <adeason@sinenomine.net>

src/afs/FBSD/osi_machdep.h

@@ -143,4 +143,10 @@ osi_GetTime(osi_timeval32_t *atv)
     atv->tv_usec = now.tv_usec;
 }
 
+#ifdef FBSD_UMA_GETPBUF
+extern uma_zone_t afs_pbuf_zone;
+#else
+extern int afs_pbuf_freecnt;
+#endif
+
 #endif /* _OSI_MACHDEP_H_ */

src/afs/FBSD/osi_vfsops.c

@@ -15,7 +15,12 @@
 
 struct vcache *afs_globalVp = NULL;
 struct mount *afs_globalVFS = NULL;
+
+#ifdef FBSD_UMA_GETPBUF
+uma_zone_t afs_pbuf_zone;
+#else
 int afs_pbuf_freecnt = -1;
+#endif
 
 extern int Afs_xsetgroups();
 
@@ -52,7 +57,11 @@ afs_init(struct vfsconf *vfc)
 	return code;
     }
     osi_Init();
+#ifdef FBSD_UMA_GETPBUF
+    afs_pbuf_zone = pbuf_zsecond_create("afspbuf", nswbuf / 2);
+#else
     afs_pbuf_freecnt = nswbuf / 2 + 1;
+#endif
     return 0;
 }
 
@@ -62,6 +71,10 @@ afs_uninit(struct vfsconf *vfc)
     if (afs_globalVFS)
 	return EBUSY;
 
+#ifdef FBSD_UMA_GETPBUF
+    uma_zdestroy(afs_pbuf_zone);
+#endif
+
     return syscall_helper_unregister(afs_syscalls);
 }
 

src/afs/FBSD/osi_vnodeops.c

@@ -62,7 +62,6 @@
 #include <vm/vm_pager.h>
 #include <vm/vnode_pager.h>
 #include <sys/vmmeter.h>
-extern int afs_pbuf_freecnt;
 
 #define GETNAME()       \
     struct componentname *cnp = ap->a_cnp; \
@@ -104,6 +103,29 @@ static __inline void ma_vm_page_unlock(vm_page_t m) { vm_page_unlock(m); };
 # define AFS_VM_CNT_INC(var)    PCPU_INC(cnt.var)
 #endif
 
+static __inline struct buf *
+afs_getpbuf(void)
+{
+#ifdef FBSD_UMA_GETPBUF
+    return uma_zalloc(afs_pbuf_zone, M_WAITOK);
+#else
+    return getpbuf(&afs_pbuf_freecnt);
+#endif
+}
+
+static __inline void
+afs_relpbuf(struct buf **a_bp)
+{
+    if (*a_bp == NULL)
+	return;
+#ifdef FBSD_UMA_GETPBUF
+    uma_zfree(afs_pbuf_zone, *a_bp);
+#else
+    relpbuf(*a_bp, &afs_pbuf_freecnt);
+#endif
+    *a_bp = NULL;
+}
+
 /*
  * Mosty copied from sys/ufs/ufs/ufs_vnops.c:ufs_pathconf().
  * We should know the correct answers to these questions with
@@ -546,7 +568,7 @@ afs_vop_getpages(struct vop_getpages_args *ap)
 	ma_vm_page_unlock_queues();
 	AFS_VM_OBJECT_WUNLOCK(object);
     }
-    bp = getpbuf(&afs_pbuf_freecnt);
+    bp = afs_getpbuf();
 
     kva = (vm_offset_t) bp->b_data;
     pmap_qenter(kva, pages, npages);
@@ -574,7 +596,7 @@ afs_vop_getpages(struct vop_getpages_args *ap)
     AFS_GUNLOCK();
     pmap_qremove(kva, npages);
 
-    relpbuf(bp, &afs_pbuf_freecnt);
+    afs_relpbuf(&bp);
 
     if (code && (uio.uio_resid == count)) {
 #ifndef FBSD_VOP_GETPAGES_BUSIED
@@ -730,7 +752,7 @@ afs_vop_putpages(struct vop_putpages_args *ap)
     npages = btoc(ap->a_count);
     for (i = 0; i < npages; i++)
 	ap->a_rtvals[i] = VM_PAGER_AGAIN;
-    bp = getpbuf(&afs_pbuf_freecnt);
+    bp = afs_getpbuf();
 
     kva = (vm_offset_t) bp->b_data;
     pmap_qenter(kva, ap->a_m, npages);
@@ -772,7 +794,7 @@ afs_vop_putpages(struct vop_putpages_args *ap)
     AFS_GUNLOCK();
 
     pmap_qremove(kva, npages);
-    relpbuf(bp, &afs_pbuf_freecnt);
+    afs_relpbuf(&bp);
 
     if (!code) {
 	AFS_VM_OBJECT_WLOCK(vp->v_object);

src/config/param.generic_fbsd.h

@@ -128,6 +128,11 @@ enum vcexcl { NONEXCL, EXCL };
 # define AFS_FBSD_NET_FOREACH TAILQ_FOREACH
 #endif
 
+/* r343030 removed getpbuf() et al, use UMA alloc instead */
+#if __FreeBSD_version >= 1300008
+# define FBSD_UMA_GETPBUF
+#endif
+
 /* r355537 removed VI_DOOMED, use VN_IS_DOOMED instead */
 #if __FreeBSD_version >= 1300064
 # define AFS_IS_DOOMED(vp) VN_IS_DOOMED(vp)