[src/trunk]: src/sys/rump/librump/rumpvfs Implement rumpblk_deregister, for u...

[pooka <pooka%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/ae34a320a480
branches:  trunk
changeset: 755677:ae34a320a480
user:      pooka <pooka%NetBSD.org@localhost>
date:      Tue Jun 15 18:53:48 2010 +0000

description:
Implement rumpblk_deregister, for unregistering fake block devices
(from etfs_deregister).  Prompted by use case from njoly.

diffstat:

 sys/rump/librump/rumpvfs/rump_vfs_private.h |   3 +-
 sys/rump/librump/rumpvfs/rumpblk.c          |  38 +++++++++++++++++++-
 sys/rump/librump/rumpvfs/rumpfs.c           |  53 ++++++++++++++++++++++------
 3 files changed, 79 insertions(+), 15 deletions(-)

diffs (205 lines):

diff -r 60ccee01e564 -r ae34a320a480 sys/rump/librump/rumpvfs/rump_vfs_private.h
--- a/sys/rump/librump/rumpvfs/rump_vfs_private.h       Tue Jun 15 17:23:31 2010 +0000
+++ b/sys/rump/librump/rumpvfs/rump_vfs_private.h       Tue Jun 15 18:53:48 2010 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: rump_vfs_private.h,v 1.12 2010/04/30 21:02:36 pooka Exp $      */
+/*     $NetBSD: rump_vfs_private.h,v 1.13 2010/06/15 18:53:48 pooka Exp $      */
 
 /*
  * Copyright (c) 2008 Antti Kantee.  All Rights Reserved.
@@ -41,6 +41,7 @@
 #define RUMPBLK_DEVMAJOR 197 /* from conf/majors, XXX: not via config yet */
 #define RUMPBLK_SIZENOTSET ((uint64_t)-1)
 int    rumpblk_register(const char *, devminor_t *, uint64_t, uint64_t);
+int    rumpblk_deregister(const char *);
 int    rumpblk_init(void);
 
 void   rump_biodone(void *, size_t, int);
diff -r 60ccee01e564 -r ae34a320a480 sys/rump/librump/rumpvfs/rumpblk.c
--- a/sys/rump/librump/rumpvfs/rumpblk.c        Tue Jun 15 17:23:31 2010 +0000
+++ b/sys/rump/librump/rumpvfs/rumpblk.c        Tue Jun 15 18:53:48 2010 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: rumpblk.c,v 1.39 2010/05/01 14:37:53 pooka Exp $       */
+/*     $NetBSD: rumpblk.c,v 1.40 2010/06/15 18:53:48 pooka Exp $       */
 
 /*
  * Copyright (c) 2009 Antti Kantee.  All Rights Reserved.
@@ -52,7 +52,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: rumpblk.c,v 1.39 2010/05/01 14:37:53 pooka Exp $");
+__KERNEL_RCSID(0, "$NetBSD: rumpblk.c,v 1.40 2010/06/15 18:53:48 pooka Exp $");
 
 #include <sys/param.h>
 #include <sys/buf.h>
@@ -384,7 +384,6 @@
        }
 }
 
-/* XXX: no deregister */
 int
 rumpblk_register(const char *path, devminor_t *dmin,
        uint64_t offset, uint64_t size)
@@ -442,6 +441,39 @@
        return 0;
 }
 
+/*
+ * Unregister rumpblk.  It's the callers responsibility to make
+ * sure it's no longer in use.
+ */
+int
+rumpblk_deregister(const char *path)
+{
+       struct rblkdev *rblk;
+       int i;
+
+       mutex_enter(&rumpblk_lock);
+       for (i = 0; i < RUMPBLK_SIZE; i++) {
+               if (minors[i].rblk_path&&strcmp(minors[i].rblk_path, path)==0) {
+                       break;
+               }
+       }
+       mutex_exit(&rumpblk_lock);
+
+       if (i == RUMPBLK_SIZE)
+               return ENOENT;
+
+       rblk = &minors[i];
+       KASSERT(rblk->rblk_fd == -1);
+       KASSERT(rblk->rblk_opencnt == 0);
+
+       wincleanup(rblk);
+       free(rblk->rblk_path, M_TEMP);
+       rblk->rblk_path = NULL;
+       memset(&rblk->rblk_label, 0, sizeof(rblk->rblk_label));
+
+       return 0;
+}
+
 int
 rumpblk_open(dev_t dev, int flag, int fmt, struct lwp *l)
 {
diff -r 60ccee01e564 -r ae34a320a480 sys/rump/librump/rumpvfs/rumpfs.c
--- a/sys/rump/librump/rumpvfs/rumpfs.c Tue Jun 15 17:23:31 2010 +0000
+++ b/sys/rump/librump/rumpvfs/rumpfs.c Tue Jun 15 18:53:48 2010 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: rumpfs.c,v 1.52 2010/06/15 17:23:31 njoly Exp $        */
+/*     $NetBSD: rumpfs.c,v 1.53 2010/06/15 18:53:48 pooka Exp $        */
 
 /*
  * Copyright (c) 2009  Antti Kantee.  All Rights Reserved.
@@ -26,7 +26,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: rumpfs.c,v 1.52 2010/06/15 17:23:31 njoly Exp $");
+__KERNEL_RCSID(0, "$NetBSD: rumpfs.c,v 1.53 2010/06/15 18:53:48 pooka Exp $");
 
 #include <sys/param.h>
 #include <sys/atomic.h>
@@ -172,6 +172,8 @@
        char et_key[MAXPATHLEN];
        size_t et_keylen;
        bool et_prefixkey;
+       bool et_removing;
+       devminor_t et_blkmin;
 
        LIST_ENTRY(etfs) et_entries;
 
@@ -267,7 +269,7 @@
        struct rumpfs_node *rn;
        uint64_t fsize;
        dev_t rdev = NODEV;
-       devminor_t dmin;
+       devminor_t dmin = -1;
        int hft, error;
 
        if (rumpuser_getfileinfo(hostpath, &fsize, &hft, &error))
@@ -303,8 +305,10 @@
        strcpy(et->et_key, key);
        et->et_keylen = strlen(et->et_key);
        et->et_rn = rn = makeprivate(ettype_to_vtype(ftype), rdev, size);
+       et->et_removing = false;
+       et->et_blkmin = dmin;
 
-       if (ftype == RUMP_ETFS_REG || REGDIR(ftype)) {
+       if (ftype == RUMP_ETFS_REG || REGDIR(ftype) || et->et_blkmin != -1) {
                size_t len = strlen(hostpath)+1;
 
                rn->rn_hostpath = malloc(len, M_TEMP, M_WAITOK | M_ZERO);
@@ -325,11 +329,12 @@
        mutex_enter(&etfs_lock);
        if (etfs_find(key, NULL, REGDIR(ftype))) {
                mutex_exit(&etfs_lock);
+               if (et->et_blkmin != -1)
+                       rumpblk_deregister(hostpath);
                if (et->et_rn->rn_hostpath != NULL)
                        free(et->et_rn->rn_hostpath, M_TEMP);
                kmem_free(et->et_rn, sizeof(*et->et_rn));
                kmem_free(et, sizeof(*et));
-               /* XXX: rumpblk_deregister(hostpath); */
                return EEXIST;
        }
        LIST_INSERT_HEAD(&etfs_list, et, et_entries);
@@ -366,27 +371,53 @@
        return doregister(key, hostpath, ftype, begin, size);
 }
 
+/* remove etfs mapping.  caller's responsibility to make sure it's not in use */
 int
 rump_etfs_remove(const char *key)
 {
        struct etfs *et;
        size_t keylen = strlen(key);
+       int rv;
 
        mutex_enter(&etfs_lock);
        LIST_FOREACH(et, &etfs_list, et_entries) {
                if (keylen == et->et_keylen && strcmp(et->et_key, key) == 0) {
-                       LIST_REMOVE(et, et_entries);
-                       if (et->et_rn->rn_hostpath != NULL)
-                               free(et->et_rn->rn_hostpath, M_TEMP);
-                       kmem_free(et->et_rn, sizeof(*et->et_rn));
-                       kmem_free(et, sizeof(*et));
+                       if (et->et_removing)
+                               et = NULL;
+                       else
+                               et->et_removing = true;
                        break;
                }
        }
        mutex_exit(&etfs_lock);
-
        if (!et)
                return ENOENT;
+
+       /*
+        * ok, we know what we want to remove and have signalled there
+        * actually are men at work.  first, unregister from rumpblk
+        */
+       if (et->et_blkmin != -1) {
+               rv = rumpblk_deregister(et->et_rn->rn_hostpath);
+       } else {
+               rv = 0;
+       }
+       KASSERT(rv == 0);
+
+       /* then do the actual removal */
+       mutex_enter(&etfs_lock);
+       LIST_REMOVE(et, et_entries);
+       mutex_exit(&etfs_lock);
+
+       /* node is unreachable, safe to nuke all device copies */
+       if (et->et_blkmin != -1)
+               vdevgone(RUMPBLK_DEVMAJOR, et->et_blkmin, et->et_blkmin, VBLK);
+
+       if (et->et_rn->rn_hostpath != NULL)
+               free(et->et_rn->rn_hostpath, M_TEMP);
+       kmem_free(et->et_rn, sizeof(*et->et_rn));
+       kmem_free(et, sizeof(*et));
+
        return 0;
 }