OpenZFS 7614, 9064 - zfs device evacuation/removal

[mirror_zfs.git] / module / zfs / spa_config.c

diff --git a/module/zfs/spa_config.c b/module/zfs/spa_config.c
index 8459e736281337e21d4b2d21fefdc12f362b0f22..4e9fd6c575ff5f50aabbbda088874f478568ac5c 100644 (file)
--- a/module/zfs/spa_config.c
+++ b/module/zfs/spa_config.c
@@ -55,7 +55,7 @@
  * configuration information.  When the module loads, we read this information
  * from /etc/zfs/zpool.cache and populate the SPA namespace.  This namespace is
  * maintained independently in spa.c.  Whenever the namespace is modified, or
- * the configuration of a pool is changed, we call spa_config_sync(), which
+ * the configuration of a pool is changed, we call spa_write_cachefile(), which
  * walks through all the active pools and writes the configuration to disk.
  */
 
@@ -147,6 +147,26 @@ out:
        kobj_close_file(file);
 }
 
+static int
+spa_config_remove(spa_config_dirent_t *dp)
+{
+#if defined(__linux__) && defined(_KERNEL)
+       int error, flags = FWRITE | FTRUNC;
+       uio_seg_t seg = UIO_SYSSPACE;
+       vnode_t *vp;
+
+       error = vn_open(dp->scd_path, seg, flags, 0644, &vp, 0, 0);
+       if (error == 0) {
+               (void) VOP_FSYNC(vp, FSYNC, kcred, NULL);
+               (void) VOP_CLOSE(vp, 0, 1, 0, kcred, NULL);
+       }
+
+       return (error);
+#else
+       return (vn_remove(dp->scd_path, UIO_SYSSPACE, RMFILE));
+#endif
+}
+
 static int
 spa_config_write(spa_config_dirent_t *dp, nvlist_t *nvl)
 {
@@ -161,12 +181,10 @@ spa_config_write(spa_config_dirent_t *dp, nvlist_t *nvl)
         * If the nvlist is empty (NULL), then remove the old cachefile.
         */
        if (nvl == NULL) {
-               err = vn_remove(dp->scd_path, UIO_SYSSPACE, RMFILE);
-               /*
-                * Don't report an error when the cache file is already removed
-                */
+               err = spa_config_remove(dp);
                if (err == ENOENT)
                        err = 0;
+
                return (err);
        }
 
@@ -179,9 +197,9 @@ spa_config_write(spa_config_dirent_t *dp, nvlist_t *nvl)
 #if defined(__linux__) && defined(_KERNEL)
        /*
         * Write the configuration to disk.  Due to the complexity involved
-        * in performing a rename from within the kernel the file is truncated
-        * and overwritten in place.  In the event of an error the file is
-        * unlinked to make sure we always have a consistent view of the data.
+        * in performing a rename and remove from within the kernel the file
+        * is instead truncated and overwritten in place.  This way we always
+        * have a consistent view of the data or a zero length file.
         */
        err = vn_open(dp->scd_path, UIO_SYSSPACE, oflags, 0644, &vp, 0, 0);
        if (err == 0) {
@@ -191,9 +209,8 @@ spa_config_write(spa_config_dirent_t *dp, nvlist_t *nvl)
                        err = VOP_FSYNC(vp, FSYNC, kcred, NULL);
 
                (void) VOP_CLOSE(vp, oflags, 1, 0, kcred, NULL);
-
                if (err)
-                       (void) vn_remove(dp->scd_path, UIO_SYSSPACE, RMFILE);
+                       (void) spa_config_remove(dp);
        }
 #else
        /*
@@ -232,7 +249,7 @@ spa_config_write(spa_config_dirent_t *dp, nvlist_t *nvl)
  * would be required.
  */
 void
-spa_config_sync(spa_t *target, boolean_t removing, boolean_t postsysevent)
+spa_write_cachefile(spa_t *target, boolean_t removing, boolean_t postsysevent)
 {
        spa_config_dirent_t *dp, *tdp;
        nvlist_t *nvl;
@@ -396,7 +413,6 @@ spa_config_generate(spa_t *spa, vdev_t *vd, uint64_t txg, int getstats)
        boolean_t locked = B_FALSE;
        uint64_t split_guid;
        char *pool_name;
-       int config_gen_flags = 0;
 
        if (vd == NULL) {
                vd = rvd;
@@ -446,6 +462,7 @@ spa_config_generate(spa_t *spa, vdev_t *vd, uint64_t txg, int getstats)
                fnvlist_add_uint64(config, ZPOOL_CONFIG_HOSTID, hostid);
        fnvlist_add_string(config, ZPOOL_CONFIG_HOSTNAME, utsname()->nodename);
 
+       int config_gen_flags = 0;
        if (vd != rvd) {
                fnvlist_add_uint64(config, ZPOOL_CONFIG_TOP_GUID,
                    vd->vdev_top->vdev_guid);
@@ -573,15 +590,16 @@ spa_config_update(spa_t *spa, int what)
        /*
         * Update the global config cache to reflect the new mosconfig.
         */
-       if (!spa->spa_is_root)
-               spa_config_sync(spa, B_FALSE, what != SPA_CONFIG_UPDATE_POOL);
+       if (!spa->spa_is_root) {
+               spa_write_cachefile(spa, B_FALSE,
+                   what != SPA_CONFIG_UPDATE_POOL);
+       }
 
        if (what == SPA_CONFIG_UPDATE_POOL)
                spa_config_update(spa, SPA_CONFIG_UPDATE_VDEVS);
 }
 
 #if defined(_KERNEL) && defined(HAVE_SPL)
-EXPORT_SYMBOL(spa_config_sync);
 EXPORT_SYMBOL(spa_config_load);
 EXPORT_SYMBOL(spa_all_configs);
 EXPORT_SYMBOL(spa_config_set);