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/*
* These functions implement tree of block devices. The devtree struct contains
* two basic lists:
*
* 1) devtree->devices -- This is simple list without any hierarchy. We use
* reference counting here.
*
* 2) devtree->roots -- The root nodes of the trees. The code does not use
* reference counting here due to complexity and it's unnecessary.
*
* Note that the same device maybe have more parents and more children. The
* device is allocated only once and shared within the tree. The dependence
* (devdep struct) contains reference to child as well as to parent and the
* dependence is reference by ls_childs from parent device and by ls_parents
* from child. (Yes, "childs" is used for children ;-)
*
* Copyright (C) 2018 Karel Zak <kzak@redhat.com>
*/
#include "lsblk.h"
#include "sysfs.h"
#include "pathnames.h"
void lsblk_reset_iter(struct lsblk_iter *itr, int direction)
{
if (direction == -1)
direction = itr->direction;
memset(itr, 0, sizeof(*itr));
itr->direction = direction;
}
struct lsblk_device *lsblk_new_device()
{
struct lsblk_device *dev;
dev = calloc(1, sizeof(*dev));
if (!dev)
return NULL;
dev->refcount = 1;
dev->removable = -1;
dev->discard_granularity = (uint64_t) -1;
INIT_LIST_HEAD(&dev->childs);
INIT_LIST_HEAD(&dev->parents);
INIT_LIST_HEAD(&dev->ls_roots);
INIT_LIST_HEAD(&dev->ls_devices);
DBG(DEV, ul_debugobj(dev, "alloc"));
return dev;
}
void lsblk_ref_device(struct lsblk_device *dev)
{
if (dev)
dev->refcount++;
}
/* removes dependence from child as well as from parent */
static int remove_dependence(struct lsblk_devdep *dep)
{
if (!dep)
return -EINVAL;
DBG(DEP, ul_debugobj(dep, " dealloc"));
list_del_init(&dep->ls_childs);
list_del_init(&dep->ls_parents);
free(dep);
return 0;
}
static int device_remove_dependences(struct lsblk_device *dev)
{
if (!dev)
return -EINVAL;
if (!list_empty(&dev->childs))
DBG(DEV, ul_debugobj(dev, " %s: remove all children deps", dev->name));
while (!list_empty(&dev->childs)) {
struct lsblk_devdep *dp = list_entry(dev->childs.next,
struct lsblk_devdep, ls_childs);
remove_dependence(dp);
}
if (!list_empty(&dev->parents))
DBG(DEV, ul_debugobj(dev, " %s: remove all parents deps", dev->name));
while (!list_empty(&dev->parents)) {
struct lsblk_devdep *dp = list_entry(dev->parents.next,
struct lsblk_devdep, ls_parents);
remove_dependence(dp);
}
return 0;
}
void lsblk_unref_device(struct lsblk_device *dev)
{
if (!dev)
return;
if (--dev->refcount <= 0) {
DBG(DEV, ul_debugobj(dev, " freeing [%s] <<", dev->name));
device_remove_dependences(dev);
lsblk_device_free_properties(dev->properties);
lsblk_device_free_filesystems(dev);
lsblk_unref_device(dev->wholedisk);
free(dev->dm_name);
free(dev->filename);
free(dev->dedupkey);
ul_unref_path(dev->sysfs);
DBG(DEV, ul_debugobj(dev, " >> dealloc [%s]", dev->name));
free(dev->name);
free(dev);
}
}
int lsblk_device_has_child(struct lsblk_device *dev, struct lsblk_device *child)
{
struct lsblk_device *x = NULL;
struct lsblk_iter itr;
lsblk_reset_iter(&itr, LSBLK_ITER_FORWARD);
while (lsblk_device_next_child(dev, &itr, &x) == 0) {
if (x == child)
return 1;
}
return 0;
}
int lsblk_device_new_dependence(struct lsblk_device *parent, struct lsblk_device *child)
{
struct lsblk_devdep *dp;
if (!parent || !child)
return -EINVAL;
if (lsblk_device_has_child(parent, child))
return 1;
dp = calloc(1, sizeof(*dp));
if (!dp)
return -ENOMEM;
INIT_LIST_HEAD(&dp->ls_childs);
INIT_LIST_HEAD(&dp->ls_parents);
dp->child = child;
list_add_tail(&dp->ls_childs, &parent->childs);
dp->parent = parent;
list_add_tail(&dp->ls_parents, &child->parents);
DBG(DEV, ul_debugobj(parent, "add dependence 0x%p [%s->%s]", dp, parent->name, child->name));
return 0;
}
static int device_next_child(struct lsblk_device *dev,
struct lsblk_iter *itr,
struct lsblk_devdep **dp)
{
int rc = 1;
if (!dev || !itr || !dp)
return -EINVAL;
*dp = NULL;
if (!itr->head)
LSBLK_ITER_INIT(itr, &dev->childs);
if (itr->p != itr->head) {
LSBLK_ITER_ITERATE(itr, *dp, struct lsblk_devdep, ls_childs);
rc = 0;
}
return rc;
}
int lsblk_device_next_child(struct lsblk_device *dev,
struct lsblk_iter *itr,
struct lsblk_device **child)
{
struct lsblk_devdep *dp = NULL;
int rc = device_next_child(dev, itr, &dp);
if (!child)
return -EINVAL;
*child = rc == 0 ? dp->child : NULL;
return rc;
}
int lsblk_device_is_last_parent(struct lsblk_device *dev, struct lsblk_device *parent)
{
struct lsblk_devdep *dp = list_last_entry(
&dev->parents,
struct lsblk_devdep, ls_parents);
if (!dp)
return 0;
return dp->parent == parent;
}
int lsblk_device_next_parent(
struct lsblk_device *dev,
struct lsblk_iter *itr,
struct lsblk_device **parent)
{
int rc = 1;
if (!dev || !itr || !parent)
return -EINVAL;
*parent = NULL;
if (!itr->head)
LSBLK_ITER_INIT(itr, &dev->parents);
if (itr->p != itr->head) {
struct lsblk_devdep *dp = NULL;
LSBLK_ITER_ITERATE(itr, dp, struct lsblk_devdep, ls_parents);
if (dp)
*parent = dp->parent;
rc = 0;
}
return rc;
}
struct lsblk_devtree *lsblk_new_devtree()
{
struct lsblk_devtree *tr;
tr = calloc(1, sizeof(*tr));
if (!tr)
return NULL;
tr->refcount = 1;
INIT_LIST_HEAD(&tr->roots);
INIT_LIST_HEAD(&tr->devices);
INIT_LIST_HEAD(&tr->pktcdvd_map);
DBG(TREE, ul_debugobj(tr, "alloc"));
return tr;
}
void lsblk_ref_devtree(struct lsblk_devtree *tr)
{
if (tr)
tr->refcount++;
}
void lsblk_unref_devtree(struct lsblk_devtree *tr)
{
if (!tr)
return;
if (--tr->refcount <= 0) {
DBG(TREE, ul_debugobj(tr, "dealloc"));
while (!list_empty(&tr->devices)) {
struct lsblk_device *dev = list_entry(tr->devices.next,
struct lsblk_device, ls_devices);
lsblk_devtree_remove_device(tr, dev);
}
while (!list_empty(&tr->pktcdvd_map)) {
struct lsblk_devnomap *map = list_entry(tr->pktcdvd_map.next,
struct lsblk_devnomap, ls_devnomap);
list_del(&map->ls_devnomap);
free(map);
}
free(tr);
}
}
int lsblk_devtree_add_root(struct lsblk_devtree *tr, struct lsblk_device *dev)
{
if (!lsblk_devtree_has_device(tr, dev))
lsblk_devtree_add_device(tr, dev);
/* We don't increment reference counter for tr->roots list. The primary
* reference is tr->devices */
DBG(TREE, ul_debugobj(tr, "add root device 0x%p [%s]", dev, dev->name));
list_add_tail(&dev->ls_roots, &tr->roots);
return 0;
}
int lsblk_devtree_remove_root(struct lsblk_devtree *tr __attribute__((unused)),
struct lsblk_device *dev)
{
DBG(TREE, ul_debugobj(tr, "remove root device 0x%p [%s]", dev, dev->name));
list_del_init(&dev->ls_roots);
return 0;
}
int lsblk_devtree_next_root(struct lsblk_devtree *tr,
struct lsblk_iter *itr,
struct lsblk_device **dev)
{
int rc = 1;
if (!tr || !itr || !dev)
return -EINVAL;
*dev = NULL;
if (!itr->head)
LSBLK_ITER_INIT(itr, &tr->roots);
if (itr->p != itr->head) {
LSBLK_ITER_ITERATE(itr, *dev, struct lsblk_device, ls_roots);
rc = 0;
}
return rc;
}
int lsblk_devtree_add_device(struct lsblk_devtree *tr, struct lsblk_device *dev)
{
lsblk_ref_device(dev);
DBG(TREE, ul_debugobj(tr, "add device 0x%p [%s]", dev, dev->name));
list_add_tail(&dev->ls_devices, &tr->devices);
return 0;
}
int lsblk_devtree_next_device(struct lsblk_devtree *tr,
struct lsblk_iter *itr,
struct lsblk_device **dev)
{
int rc = 1;
if (!tr || !itr || !dev)
return -EINVAL;
*dev = NULL;
if (!itr->head)
LSBLK_ITER_INIT(itr, &tr->devices);
if (itr->p != itr->head) {
LSBLK_ITER_ITERATE(itr, *dev, struct lsblk_device, ls_devices);
rc = 0;
}
return rc;
}
int lsblk_devtree_has_device(struct lsblk_devtree *tr, struct lsblk_device *dev)
{
struct lsblk_device *x = NULL;
struct lsblk_iter itr;
lsblk_reset_iter(&itr, LSBLK_ITER_FORWARD);
while (lsblk_devtree_next_device(tr, &itr, &x) == 0) {
if (x == dev)
return 1;
}
return 0;
}
struct lsblk_device *lsblk_devtree_get_device(struct lsblk_devtree *tr, const char *name)
{
struct lsblk_device *dev = NULL;
struct lsblk_iter itr;
lsblk_reset_iter(&itr, LSBLK_ITER_FORWARD);
while (lsblk_devtree_next_device(tr, &itr, &dev) == 0) {
if (strcmp(name, dev->name) == 0)
return dev;
}
return NULL;
}
int lsblk_devtree_remove_device(struct lsblk_devtree *tr, struct lsblk_device *dev)
{
DBG(TREE, ul_debugobj(tr, "remove device 0x%p [%s]", dev, dev->name));
if (!lsblk_devtree_has_device(tr, dev))
return 1;
list_del_init(&dev->ls_roots);
list_del_init(&dev->ls_devices);
lsblk_unref_device(dev);
return 0;
}
static void read_pktcdvd_map(struct lsblk_devtree *tr)
{
char buf[PATH_MAX];
FILE *f;
assert(tr->pktcdvd_read == 0);
f = ul_path_fopen(NULL, "r", _PATH_SYS_CLASS "/pktcdvd/device_map");
if (!f)
goto done;
while (fgets(buf, sizeof(buf), f)) {
struct lsblk_devnomap *map;
int pkt_maj, pkt_min, blk_maj, blk_min;
if (sscanf(buf, "%*s %d:%d %d:%d\n",
&pkt_maj, &pkt_min,
&blk_maj, &blk_min) != 4)
continue;
map = malloc(sizeof(*map));
if (!map)
break;
map->holder = makedev(pkt_maj, pkt_min);
map->slave = makedev(blk_maj, blk_min);
INIT_LIST_HEAD(&map->ls_devnomap);
list_add_tail(&map->ls_devnomap, &tr->pktcdvd_map);
}
fclose(f);
done:
tr->pktcdvd_read = 1;
}
/* returns opposite device of @devno for blk->pkt relation -- e.g. if devno
* is_slave (blk) then returns holder (pkt) and vice-versa */
dev_t lsblk_devtree_pktcdvd_get_mate(struct lsblk_devtree *tr, dev_t devno, int is_slave)
{
struct list_head *p;
if (!tr->pktcdvd_read)
read_pktcdvd_map(tr);
if (list_empty(&tr->pktcdvd_map))
return 0;
list_for_each(p, &tr->pktcdvd_map) {
struct lsblk_devnomap *x = list_entry(p, struct lsblk_devnomap, ls_devnomap);
if (is_slave && devno == x->slave)
return x->holder;
if (!is_slave && devno == x->holder)
return x->slave;
}
return 0;
}
static int device_dedupkey_is_equal(
struct lsblk_device *dev,
struct lsblk_device *pattern)
{
assert(pattern->dedupkey);
if (!dev->dedupkey || dev == pattern)
return 0;
if (strcmp(dev->dedupkey, pattern->dedupkey) == 0) {
if (!device_is_partition(dev) ||
!dev->wholedisk->dedupkey ||
strcmp(dev->dedupkey, dev->wholedisk->dedupkey) != 0) {
DBG(DEV, ul_debugobj(dev, "%s: match deduplication pattern", dev->name));
return 1;
}
}
return 0;
}
static void device_dedup_dependencies(
struct lsblk_device *dev,
struct lsblk_device *pattern)
{
struct lsblk_iter itr;
struct lsblk_devdep *dp;
lsblk_reset_iter(&itr, LSBLK_ITER_FORWARD);
while (device_next_child(dev, &itr, &dp) == 0) {
struct lsblk_device *child = dp->child;
if (device_dedupkey_is_equal(child, pattern)) {
DBG(DEV, ul_debugobj(dev, "remove duplicate dependence: 0x%p [%s]",
dp->child, dp->child->name));
remove_dependence(dp);
} else
device_dedup_dependencies(child, pattern);
}
}
static void devtree_dedup(struct lsblk_devtree *tr, struct lsblk_device *pattern)
{
struct lsblk_iter itr;
struct lsblk_device *dev = NULL;
lsblk_reset_iter(&itr, LSBLK_ITER_FORWARD);
DBG(TREE, ul_debugobj(tr, "de-duplicate by key: %s", pattern->dedupkey));
while (lsblk_devtree_next_root(tr, &itr, &dev) == 0) {
if (device_dedupkey_is_equal(dev, pattern)) {
DBG(TREE, ul_debugobj(tr, "remove duplicate device: 0x%p [%s]",
dev, dev->name));
/* Note that root list does not use ref-counting; the
* primary reference is ls_devices */
list_del_init(&dev->ls_roots);
} else
device_dedup_dependencies(dev, pattern);
}
}
static int cmp_devices_devno(struct list_head *a, struct list_head *b,
__attribute__((__unused__)) void *data)
{
struct lsblk_device *ax = list_entry(a, struct lsblk_device, ls_devices),
*bx = list_entry(b, struct lsblk_device, ls_devices);
return cmp_numbers(makedev(ax->maj, ax->min),
makedev(bx->maj, bx->min));
}
/* Note that dev->dedupkey has to be already set */
int lsblk_devtree_deduplicate_devices(struct lsblk_devtree *tr)
{
struct lsblk_device *pattern = NULL;
struct lsblk_iter itr;
char *last = NULL;
list_sort(&tr->devices, cmp_devices_devno, NULL);
lsblk_reset_iter(&itr, LSBLK_ITER_FORWARD);
while (lsblk_devtree_next_device(tr, &itr, &pattern) == 0) {
if (!pattern->dedupkey)
continue;
if (device_is_partition(pattern) &&
pattern->wholedisk->dedupkey &&
strcmp(pattern->dedupkey, pattern->wholedisk->dedupkey) == 0)
continue;
if (last && strcmp(pattern->dedupkey, last) == 0)
continue;
devtree_dedup(tr, pattern);
last = pattern->dedupkey;
}
return 0;
}