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|
/*
*
* Copyright (c) International Business Machines Corp., 2001
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
* the GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* Module: shrink.c
*
*/
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <fullengine.h>
#include "shrink.h"
#include "engine.h"
#include "handlemgr.h"
#include "common.h"
#include "commit.h"
#include "discover.h"
#include "object.h"
#include "memman.h"
#include "internalAPI.h"
#include "message.h"
static inline int get_object_shrink_points(storage_object_t * obj, u_int64_t * max_delta_size, dlist_t shrink_points) {
int rc = 0;
LOG_PROC_ENTRY();
rc = obj->plugin->functions.plugin->can_shrink(obj, max_delta_size, shrink_points);
LOG_PROC_EXIT_INT(rc);
return rc;
}
static inline int get_volume_shrink_points(logical_volume_t * volume, dlist_t shrink_points) {
int rc = 0;
u_int64_t max_delta_size = -1;
LOG_PROC_ENTRY();
/*
* If the volume has an FSIM, gets its maximum delta shrink size. We reget
* the current size and limits because the file system could be mounted and
* be active.
*/
if (volume->file_system_manager != NULL) {
rc = volume->file_system_manager->functions.fsim->get_fs_size(volume, &volume->fs_size);
if (rc == 0) {
rc = volume->file_system_manager->functions.fsim->get_fs_limits(volume,
&volume->min_fs_size,
&volume->max_fs_size,
&volume->max_vol_size);
if (rc == 0) {
max_delta_size = volume->fs_size - volume->min_fs_size;
}
}
}
if (rc == 0) {
if (!(volume->flags & VOLFLAG_MKFS)) {
rc = get_object_shrink_points(volume->object, &max_delta_size, shrink_points);
} else {
LOG_ERROR("Volume \"%s\" cannot be shrunk because it is scheduled to have a file system installed on it.\n", volume->name);
rc = EINVAL;
}
}
if (rc == 0) {
/*
* If the volume has an FSIM and there are shrink points, check if the
* FSIM can handle the shrink.
*/
if (volume->file_system_manager != NULL) {
if (!ListEmpty(shrink_points)) {
rc = volume->file_system_manager->functions.fsim->can_shrink_by(volume, &max_delta_size);
/*
* The FSIM cannot handle the shrink. Delete all the shrink
* points from the list.
*/
if (rc != 0) {
DeleteAllItems(shrink_points, TRUE);
}
}
}
}
LOG_PROC_EXIT_INT(rc);
return rc;
}
/*
* Find out if an object can be shrunk. The "thing" must be either a volume
* or a top level object. What we'll do is call the internal
* get_shrink_points() and see if any shrink candidates show up. If we get
* shrink points then return 0 to say that the object can be shrunk. Else,
* return an error.
*/
int evms_can_shrink(object_handle_t thing) {
int rc = 0;
void * object;
object_type_t type;
LOG_PROC_ENTRY();
rc = check_engine_read_access();
if (rc == 0) {
rc = translate_handle(thing,
&object,
&type);
if (rc == HANDLE_MANAGER_NO_ERROR) {
dlist_t shrink_point_list = CreateList();
if (shrink_point_list != NULL) {
switch (type) {
case DISK:
case SEGMENT:
case REGION:
case EVMS_OBJECT:
{
storage_object_t * obj = object;
/*
* Shrinks can only be done on top level objects.
*/
if (is_top_object(obj)) {
dlist_t shrink_points = CreateList();
if (shrink_points != NULL) {
u_int64_t max_delta_size = obj->size;
rc = get_object_shrink_points(obj, &max_delta_size, shrink_points);
if (rc == 0) {
uint count = 0;
GetListSize(shrink_points, &count);
if (count == 0) {
rc = ENOENT;
}
}
DestroyList(&shrink_points, FALSE);
} else {
LOG_CRITICAL("Error allocating memory for a shrink point list.\n");
rc = ENOMEM;
}
} else {
LOG_ERROR("Object %s is not a top level object. Shrinks can only be done on volumes or top level objects.\n", obj->name);
rc = EINVAL;
}
}
break;
case VOLUME:
{
logical_volume_t * volume = (logical_volume_t *) object;
dlist_t shrink_points = CreateList();
if (shrink_points != NULL) {
rc = get_volume_shrink_points(volume, shrink_points);
if (rc == 0) {
uint count = 0;
GetListSize(shrink_points, &count);
if (count == 0) {
rc = ENOENT;
}
}
DestroyList(&shrink_points, FALSE);
} else {
LOG_CRITICAL("Error allocating memory for a shrink point list.\n");
rc = ENOMEM;
}
}
break;
default:
rc = EINVAL;
break;
}
DestroyList(&shrink_point_list, FALSE );
} else {
rc = ENOMEM;
}
}
}
LOG_PROC_EXIT_INT(rc);
return rc;
}
/*
* Given a shrink_info_t, add the app_handle for the object and the size to an
* shrink_handle_array_t.
* The parameters of this function are structured so that it can be called by
* ForEachItem().
*/
static int make_shrink_handle_entry(ADDRESS object,
TAG object_tag,
uint object_size,
ADDRESS object_handle,
ADDRESS parameters) {
int rc = 0;
shrink_object_info_t * object_info = (shrink_object_info_t *) object;
shrink_handle_array_t * sha = (shrink_handle_array_t *) parameters;
LOG_PROC_ENTRY();
LOG_DEBUG("Current number of entries in handle array: %d.\n", sha->count);
if (object_tag == SHRINK_OBJECT_TAG) {
LOG_DEBUG("Add entry for storage object %s.\n", object_info->object->name);
rc = ensure_app_handle(object_info->object,
object_info->object->object_type,
&(object_info->object->app_handle));
if (rc == 0) {
sha->shrink_point[sha->count].object = object_info->object->app_handle;
sha->shrink_point[sha->count].max_shrink_size = object_info->max_shrink_size;
sha->count++;
}
} else {
LOG_WARNING("Cannot make a shrink handle entry from an object with tag %ld.\n", object_tag);
}
LOG_PROC_EXIT_INT(rc);
return rc;
}
/*
* Make an array of shrink handles (shrink_handle_array_t) for the objects in
* a dlist_t.
*/
static int make_shrink_handle_array(dlist_t list, shrink_handle_array_t * * sha) {
int rc = 0;
uint count;
uint size;
LOG_PROC_ENTRY();
rc = GetListSize(list, &count);
if (rc == 0) {
LOG_DEBUG("Number of objects in the list: %d\n", count);
if (count > 1) {
size = sizeof(shrink_handle_array_t) + ((count -1) * sizeof(shrink_handle_t));
} else {
size = sizeof(shrink_handle_array_t);
}
*sha = alloc_app_struct(size, NULL);
if (*sha != NULL) {
rc = ForEachItem(list,
make_shrink_handle_entry,
*sha,
TRUE);
} else {
rc = ENOMEM;
}
}
LOG_PROC_EXIT_INT(rc);
return rc;
}
/*
* Find out which objects in the stack can shrink. evms_get_shrink_points()
* must be targeted at either a volume or a top level object. Any plug-in
* that can shrink will add a shrink_object_info_t to the shrink_points
* dlist. The dlist is then converted into a shrink_handle_array_t for return
* to the user.
*/
int evms_get_shrink_points(object_handle_t thing, shrink_handle_array_t * * shrink_points) {
int rc = 0;
void * object;
object_type_t type;
LOG_PROC_ENTRY();
rc = check_engine_read_access();
if (rc == 0) {
rc = translate_handle(thing,
&object,
&type);
if (rc == HANDLE_MANAGER_NO_ERROR) {
if (shrink_points != NULL) {
dlist_t shrink_point_list = CreateList();
if (shrink_point_list != NULL) {
switch (type) {
case VOLUME:
{
logical_volume_t * volume = (logical_volume_t *) object;
rc = get_volume_shrink_points(volume, shrink_point_list);
}
break;
case EVMS_OBJECT:
case REGION:
case SEGMENT:
case DISK:
{
storage_object_t * obj = (storage_object_t *) object;
/*
* Shrinks can only be done on top level objects.
*/
if (is_top_object(obj)) {
u_int64_t max_delta_size = obj->size;
rc = get_object_shrink_points(obj, &max_delta_size, shrink_point_list);
} else {
LOG_ERROR("Object %s is not a top level object. Shrinks can only be done on volumes or top level objects.\n", obj->name);
rc = EINVAL;
}
}
break;
default:
LOG_ERROR("An object of type %d cannot be shrunk.\n", type);
rc = EINVAL;
break;
}
if (rc == 0) {
rc = make_shrink_handle_array(shrink_point_list, shrink_points);
}
DestroyList(&shrink_point_list, FALSE);
}
} else {
LOG_ERROR("The pointer to the shrink points list cannot be NULL.\n");
rc = EINVAL;
}
} else {
LOG_CRITICAL("Error when allocating memory for a shrink point list.\n");
rc = ENOMEM;
}
}
LOG_PROC_EXIT_INT(rc);
return rc;
}
/*
* Determine if the given object is a storage object. Return 0 if it is, else
* an error code.
* The parameters of this function are structured so that it can be called by
* the ForEachItem() dlist processor.
*/
static int is_storage_object(ADDRESS object,
TAG object_tag,
uint object_size,
ADDRESS object_handle,
ADDRESS parameters) {
int rc = 0;
LOG_PROC_ENTRY();
if ((object_tag != EVMS_OBJECT_TAG) &&
(object_tag != REGION_TAG) &&
(object_tag != SEGMENT_TAG) &&
(object_tag != DISK_TAG)) {
switch (object_tag) {
case PLUGIN_TAG:
LOG_ERROR("Object is a plug-in.\n");
break;
case CONTAINER_TAG:
LOG_ERROR("Object is a container.\n");
break;
case VOLUME_TAG:
LOG_ERROR("Object is a volume.\n");
break;
default:
LOG_ERROR("Object is of unknown type %d.\n", object_tag);
break;
}
rc = EINVAL;
}
LOG_PROC_EXIT_INT(rc);
return rc;
}
/*
* If the object is part of a volume and the volume has no FSIM, warn the
* user that there is no FSIM to handle the shrink. The user has the
* choice of continuing or aborting.
* Returns 0 if the user wants to continue, EINTR if the user wants to abort.
*/
static int warn_if_no_fsim(storage_object_t * obj) {
int rc = 0;
LOG_PROC_ENTRY();
if (obj->volume != NULL) {
if (obj->volume->file_system_manager == NULL) {
char * choices[] = {"Continue", "Abort", NULL};
int answer = 0; /* Initialize to "Continue" */
engine_user_message(&answer,
choices,
"WARNING: Volume \"%s\" does not have an associated File System Interface Module which could coordinate the shrinking of the file system on the volume. "
"The file system will not be shrunk. "
"You may need to run a separate utility to shrink the file system before this operation starts. "
"Shrinking the volume may make the file system unusable. "
"Do you want to continue with the shrink or abort?\n",
obj->volume->name);
if (answer != 0) {
rc = EINTR;
}
}
}
LOG_PROC_EXIT_INT(rc);
return rc;
}
/*
* Shrink the size of an object. The shrink gets targeted at the top object of
* the feature stack. The plug-ins pass it on down until it hits the object
* that is to do the real shrink.
*/
int evms_shrink(object_handle_t thing, handle_array_t * input_objects, option_array_t * options) {
int rc = 0;
void * object;
object_type_t type;
LOG_PROC_ENTRY();
rc = check_engine_write_access();
if (rc == 0) {
rc = translate_handle(thing,
&object,
&type);
if (rc == HANDLE_MANAGER_NO_ERROR) {
if ((type == EVMS_OBJECT) ||
(type == REGION) ||
(type == SEGMENT) ||
(type == DISK)) {
storage_object_t * obj = (storage_object_t *) object;
if (obj->volume != NULL) {
if (obj->volume->flags & VOLFLAG_MKFS) {
LOG_ERROR("Volume \"%s\" cannot be shrunk because it is scheduled to have a file system installed on it.\n", obj->volume->name);
rc = EINVAL;
}
}
if (rc == 0) {
dlist_t input_object_list = CreateList();
if (input_object_list != NULL) {
rc = make_dlist(input_objects, input_object_list);
if (rc == 0) {
/*
* Make sure all of the input objects are storage
* objects. (The caller could have supplied handles
* for bogus items such as plug-ins or volumes.)
*/
rc = ForEachItem(input_object_list,
is_storage_object,
NULL,
TRUE);
if (rc == DLIST_SUCCESS) {
/*
* Find the top object in the feature stack.
*/
storage_object_t * top_object = obj;
uint parent_count = 0;
rc = GetListSize(top_object->parent_objects, &parent_count);
while ((rc == DLIST_SUCCESS) && (parent_count > 0)) {
rc = GetObject(top_object->parent_objects,
sizeof(storage_object_t),
EVMS_OBJECT_TAG,
NULL,
FALSE,
(ADDRESS *) &top_object);
if (rc == DLIST_SUCCESS) {
rc = GetListSize(top_object->parent_objects, &parent_count);
}
}
/* Clean up error codes that are OK. */
if ((rc == DLIST_EMPTY) || (rc == DLIST_END_OF_LIST)) {
rc = DLIST_SUCCESS;
}
if (rc == DLIST_SUCCESS) {
/*
* Warn the user if there is no FSIM to
* handle the shrink.
*/
rc = warn_if_no_fsim(obj);
if (rc == 0) {
/*
* Start the shrink at the top level
* object.
*/
rc = top_object->plugin->functions.plugin->shrink(top_object, obj, input_object_list, options);
if (rc == 0) {
/*
* Check if the input object(s)
* is/are different from the object
* that was shrunk.
*/
if ((input_objects->count > 1) ||
((input_objects->count == 1) &&
(input_objects->handle[0] != obj->app_handle))) {
/*
* Make sure the child objects
* are marked as not being part
* of a volume.
*/
ForEachItem(input_object_list,
set_volume_in_object,
NULL,
TRUE);
}
if (obj->object_type == EVMS_OBJECT) {
/*
* Mark all the child feature
* headers dirty to ensure that
* they get the correct depth
* and get written in the right
* place.
*/
ForEachItem(obj->child_objects,
mark_feature_headers_dirty,
NULL,
TRUE);
}
/*
* If the object is part of a
* volume...
*/
if (obj->volume != NULL) {
/* Mark it for rediscovery. */
engine_rediscover_volume(obj->volume, FALSE);
/*
* Mark it dirty so that the
* feature headers get written
* to their new locations.
*/
obj->volume->flags |= VOLFLAG_DIRTY;
/*
* Update the volume size. It
* may not be the resulting
* volume size after the FSIM
* does its shrink, but that
* will be updated after the
* commit.
*/
obj->volume->vol_size = top_object->size;
if (top_object->feature_header != NULL) {
/*
* Object has EVMS volume
* feature headers.
* Subtract them from the
* size.
*/
obj->volume->vol_size -= FEATURE_HEADER_SECTORS * 2;
}
}
}
}
} else {
LOG_WARNING("Error code %d encountered when trying to find the top level object.\n", rc);
}
} else {
LOG_ERROR("One or more items in the input object list is not a storage object.\n");
rc = EINVAL;
}
} else {
LOG_ERROR("Error code %d when making a dlist from the input_objects handle array.\n", rc);
}
DestroyList(&input_object_list, FALSE);
} else {
LOG_CRITICAL("Error allocating memory to create the input object list.\n");
rc = ENOMEM;
}
}
} else {
LOG_ERROR("Object of type %d cannot be shrunk.\n", type);
rc = EINVAL;
}
}
if (rc == 0) {
changes_pending = TRUE;
}
}
LOG_PROC_EXIT_INT(rc);
return rc;
}
/*
* engine_can_shrink_by() is a service that the Engine provides for the
* plug-ins. A plug-in calls engine_can_shrink_by() to find out if all of its
* parent objects, including the volume, would approve of a shrink by the
* specified amount. The Engine walks up the object tree calling each
* plug-in's can_shrink_by() function to see if it would approve of the
* shrink. Each plug-in can update the "size" if the resulting size of its
* object would have a different delta size than the delta size of its child
* object. If the top of the object stack is reached and the object is part of
* a volume, the Engine then checks the resulting delta size against any limits
* that an FSIM may have imposed on the volume.
*/
int engine_can_shrink_by(storage_object_t * object, sector_count_t * delta_size) {
int rc = 0;
storage_object_t * curr_object = object;
uint parent_count = 0;
sector_count_t original_delta_size = *delta_size;
LOG_PROC_ENTRY();
rc = GetListSize(object->parent_objects, &parent_count);
while ((rc == DLIST_SUCCESS) && (parent_count > 0)) {
rc = GetObject(curr_object->parent_objects,
sizeof(storage_object_t),
EVMS_OBJECT_TAG,
NULL,
FALSE,
(ADDRESS *) &curr_object);
if (rc == DLIST_SUCCESS) {
rc = curr_object->plugin->functions.plugin->can_shrink_by(curr_object, delta_size);
if (rc == 0) {
rc = GetListSize(curr_object->parent_objects, &parent_count);
}
}
}
/* Clean up error codes that are OK. */
if ((rc == DLIST_EMPTY) || (rc == DLIST_END_OF_LIST)) {
rc = DLIST_SUCCESS;
}
if (rc == 0) {
/*
* If this object is part of a volume and the volume has an FSIM, check
* to make sure the final size does not go below the FSIM's minimum size
* for the file system.
*/
if (object->volume != NULL) {
if (object->volume->file_system_manager != NULL) {
rc = object->volume->file_system_manager->functions.fsim->can_shrink_by(object->volume, delta_size);
}
}
}
if (rc == 0) {
if (*delta_size != original_delta_size) {
rc = EAGAIN;
}
}
LOG_PROC_EXIT_INT(rc);
return rc;
}
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