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![Tushar Sugandhi](/assets/img/avatar_default.png)
For device mapper targets to take advantage of IMA's measurement capabilities, the status functions for the individual targets need to be updated to handle the status_type_t case for value STATUSTYPE_IMA. Update status functions for the following target types, to log their respective attributes to be measured using IMA. 01. cache 02. crypt 03. integrity 04. linear 05. mirror 06. multipath 07. raid 08. snapshot 09. striped 10. verity For rest of the targets, handle the STATUSTYPE_IMA case by setting the measurement buffer to NULL. For IMA to measure the data on a given system, the IMA policy on the system needs to be updated to have the following line, and the system needs to be restarted for the measurements to take effect. /etc/ima/ima-policy measure func=CRITICAL_DATA label=device-mapper template=ima-buf The measurements will be reflected in the IMA logs, which are located at: /sys/kernel/security/integrity/ima/ascii_runtime_measurements /sys/kernel/security/integrity/ima/binary_runtime_measurements These IMA logs can later be consumed by various attestation clients running on the system, and send them to external services for attesting the system. The DM target data measured by IMA subsystem can alternatively be queried from userspace by setting DM_IMA_MEASUREMENT_FLAG with DM_TABLE_STATUS_CMD. Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
240 lines
5.1 KiB
C
240 lines
5.1 KiB
C
/*
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* Copyright (C) 2003 Sistina Software.
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* Copyright (C) 2004-2005 Red Hat, Inc. All rights reserved.
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*
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* Module Author: Heinz Mauelshagen
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*
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* This file is released under the GPL.
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*
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* Round-robin path selector.
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*/
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#include <linux/device-mapper.h>
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#include "dm-path-selector.h"
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#include <linux/slab.h>
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#include <linux/module.h>
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#define DM_MSG_PREFIX "multipath round-robin"
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#define RR_MIN_IO 1
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#define RR_VERSION "1.2.0"
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/*-----------------------------------------------------------------
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* Path-handling code, paths are held in lists
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*---------------------------------------------------------------*/
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struct path_info {
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struct list_head list;
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struct dm_path *path;
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unsigned repeat_count;
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};
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static void free_paths(struct list_head *paths)
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{
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struct path_info *pi, *next;
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list_for_each_entry_safe(pi, next, paths, list) {
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list_del(&pi->list);
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kfree(pi);
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}
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}
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/*-----------------------------------------------------------------
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* Round-robin selector
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*---------------------------------------------------------------*/
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struct selector {
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struct list_head valid_paths;
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struct list_head invalid_paths;
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spinlock_t lock;
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};
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static struct selector *alloc_selector(void)
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{
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struct selector *s = kmalloc(sizeof(*s), GFP_KERNEL);
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if (s) {
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INIT_LIST_HEAD(&s->valid_paths);
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INIT_LIST_HEAD(&s->invalid_paths);
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spin_lock_init(&s->lock);
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}
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return s;
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}
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static int rr_create(struct path_selector *ps, unsigned argc, char **argv)
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{
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struct selector *s;
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s = alloc_selector();
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if (!s)
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return -ENOMEM;
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ps->context = s;
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return 0;
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}
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static void rr_destroy(struct path_selector *ps)
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{
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struct selector *s = ps->context;
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free_paths(&s->valid_paths);
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free_paths(&s->invalid_paths);
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kfree(s);
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ps->context = NULL;
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}
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static int rr_status(struct path_selector *ps, struct dm_path *path,
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status_type_t type, char *result, unsigned int maxlen)
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{
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struct path_info *pi;
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int sz = 0;
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if (!path)
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DMEMIT("0 ");
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else {
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switch(type) {
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case STATUSTYPE_INFO:
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break;
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case STATUSTYPE_TABLE:
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pi = path->pscontext;
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DMEMIT("%u ", pi->repeat_count);
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break;
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case STATUSTYPE_IMA:
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*result = '\0';
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break;
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}
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}
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return sz;
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}
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/*
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* Called during initialisation to register each path with an
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* optional repeat_count.
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*/
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static int rr_add_path(struct path_selector *ps, struct dm_path *path,
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int argc, char **argv, char **error)
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{
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struct selector *s = ps->context;
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struct path_info *pi;
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unsigned repeat_count = RR_MIN_IO;
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char dummy;
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unsigned long flags;
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if (argc > 1) {
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*error = "round-robin ps: incorrect number of arguments";
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return -EINVAL;
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}
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/* First path argument is number of I/Os before switching path */
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if ((argc == 1) && (sscanf(argv[0], "%u%c", &repeat_count, &dummy) != 1)) {
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*error = "round-robin ps: invalid repeat count";
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return -EINVAL;
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}
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if (repeat_count > 1) {
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DMWARN_LIMIT("repeat_count > 1 is deprecated, using 1 instead");
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repeat_count = 1;
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}
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/* allocate the path */
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pi = kmalloc(sizeof(*pi), GFP_KERNEL);
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if (!pi) {
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*error = "round-robin ps: Error allocating path context";
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return -ENOMEM;
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}
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pi->path = path;
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pi->repeat_count = repeat_count;
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path->pscontext = pi;
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spin_lock_irqsave(&s->lock, flags);
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list_add_tail(&pi->list, &s->valid_paths);
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spin_unlock_irqrestore(&s->lock, flags);
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return 0;
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}
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static void rr_fail_path(struct path_selector *ps, struct dm_path *p)
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{
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unsigned long flags;
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struct selector *s = ps->context;
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struct path_info *pi = p->pscontext;
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spin_lock_irqsave(&s->lock, flags);
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list_move(&pi->list, &s->invalid_paths);
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spin_unlock_irqrestore(&s->lock, flags);
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}
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static int rr_reinstate_path(struct path_selector *ps, struct dm_path *p)
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{
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unsigned long flags;
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struct selector *s = ps->context;
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struct path_info *pi = p->pscontext;
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spin_lock_irqsave(&s->lock, flags);
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list_move(&pi->list, &s->valid_paths);
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spin_unlock_irqrestore(&s->lock, flags);
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return 0;
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}
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static struct dm_path *rr_select_path(struct path_selector *ps, size_t nr_bytes)
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{
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unsigned long flags;
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struct selector *s = ps->context;
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struct path_info *pi = NULL;
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spin_lock_irqsave(&s->lock, flags);
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if (!list_empty(&s->valid_paths)) {
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pi = list_entry(s->valid_paths.next, struct path_info, list);
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list_move_tail(&pi->list, &s->valid_paths);
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}
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spin_unlock_irqrestore(&s->lock, flags);
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return pi ? pi->path : NULL;
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}
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static struct path_selector_type rr_ps = {
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.name = "round-robin",
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.module = THIS_MODULE,
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.table_args = 1,
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.info_args = 0,
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.create = rr_create,
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.destroy = rr_destroy,
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.status = rr_status,
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.add_path = rr_add_path,
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.fail_path = rr_fail_path,
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.reinstate_path = rr_reinstate_path,
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.select_path = rr_select_path,
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};
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static int __init dm_rr_init(void)
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{
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int r = dm_register_path_selector(&rr_ps);
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if (r < 0)
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DMERR("register failed %d", r);
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DMINFO("version " RR_VERSION " loaded");
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return r;
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}
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static void __exit dm_rr_exit(void)
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{
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int r = dm_unregister_path_selector(&rr_ps);
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if (r < 0)
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DMERR("unregister failed %d", r);
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}
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module_init(dm_rr_init);
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module_exit(dm_rr_exit);
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MODULE_DESCRIPTION(DM_NAME " round-robin multipath path selector");
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MODULE_AUTHOR("Sistina Software <dm-devel@redhat.com>");
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MODULE_LICENSE("GPL");
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