Signed-off-by: Matthew Wilcox <willy@xxxxxxxxxxxxx>
---
drivers/block/nbd.c | 145 ++++++++++++++++++--------------------------
1 file changed, 59 insertions(+), 86 deletions(-)
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index 90ba9f4c03f3..6e64884973dd 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -44,8 +44,8 @@
#include <linux/nbd-netlink.h>
#include <net/genetlink.h>
-static DEFINE_IDR(nbd_index_idr);
-static DEFINE_MUTEX(nbd_index_mutex);
+static DEFINE_XARRAY_ALLOC(nbd_devs);
+static DEFINE_MUTEX(nbd_global_mutex);
static int nbd_total_devices = 0;
struct nbd_sock {
@@ -223,10 +223,9 @@ static void nbd_dev_remove(struct nbd_device *nbd)
static void nbd_put(struct nbd_device *nbd)
{
- if (refcount_dec_and_mutex_lock(&nbd->refs,
- &nbd_index_mutex)) {
- idr_remove(&nbd_index_idr, nbd->index);
- mutex_unlock(&nbd_index_mutex);
+ if (refcount_dec_and_mutex_lock(&nbd->refs, &nbd_global_mutex)) {
+ xa_erase(&nbd_devs, nbd->index);
+ mutex_unlock(&nbd_global_mutex);
nbd_dev_remove(nbd);
}
}
@@ -1331,7 +1330,7 @@ static int nbd_open(struct block_device *bdev, fmode_t mode)
struct nbd_device *nbd;
int ret = 0;
- mutex_lock(&nbd_index_mutex);
+ mutex_lock(&nbd_global_mutex);
nbd = bdev->bd_disk->private_data;
if (!nbd) {
ret = -ENXIO;
@@ -1363,7 +1362,7 @@ static int nbd_open(struct block_device *bdev, fmode_t mode)
bdev->bd_invalidated = 1;
}
out:
- mutex_unlock(&nbd_index_mutex);
+ mutex_unlock(&nbd_global_mutex);
return ret;
}
@@ -1551,15 +1550,13 @@ static int nbd_dev_add(int index)
goto out_free_nbd;
if (index >= 0) {
- err = idr_alloc(&nbd_index_idr, nbd, index, index + 1,
- GFP_KERNEL);
- if (err == -ENOSPC)
- err = -EEXIST;
+ err = xa_insert(&nbd_devs, index, nbd, GFP_KERNEL);
} else {
- err = idr_alloc(&nbd_index_idr, nbd, 0, 0, GFP_KERNEL);
- if (err >= 0)
- index = err;
+ err = xa_alloc(&nbd_devs, &index, nbd, xa_limit_32b,
+ GFP_KERNEL);
}
+ if (err == -EBUSY)
+ err = -EEXIST;
if (err < 0)
goto out_free_disk;
@@ -1576,7 +1573,7 @@ static int nbd_dev_add(int index)
err = blk_mq_alloc_tag_set(&nbd->tag_set);
if (err)
- goto out_free_idr;
+ goto out_free_dev;
q = blk_mq_init_queue(&nbd->tag_set);
if (IS_ERR(q)) {
@@ -1613,8 +1610,8 @@ static int nbd_dev_add(int index)
out_free_tags:
blk_mq_free_tag_set(&nbd->tag_set);
-out_free_idr:
- idr_remove(&nbd_index_idr, index);
+out_free_dev:
+ xa_erase(&nbd_devs, index);
out_free_disk:
put_disk(disk);
out_free_nbd:
@@ -1623,18 +1620,6 @@ static int nbd_dev_add(int index)
return err;
}
-static int find_free_cb(int id, void *ptr, void *data)
-{
- struct nbd_device *nbd = ptr;
- struct nbd_device **found = data;
-
- if (!refcount_read(&nbd->config_refs)) {
- *found = nbd;
- return 1;
- }
- return 0;
-}
-
/* Netlink interface. */
static const struct nla_policy nbd_attr_policy[NBD_ATTR_MAX + 1] = {
[NBD_ATTR_INDEX] = { .type = NLA_U32 },
@@ -1683,46 +1668,51 @@ static int nbd_genl_connect(struct sk_buff *skb, struct genl_info *info)
return -EINVAL;
}
again:
- mutex_lock(&nbd_index_mutex);
+ mutex_lock(&nbd_global_mutex);
if (index == -1) {
- ret = idr_for_each(&nbd_index_idr, &find_free_cb, &nbd);
- if (ret == 0) {
+ unsigned long i;
+ xa_for_each(&nbd_devs, i, nbd) {
+ if (!refcount_read(&nbd->config_refs))
+ break;
+ }
+
+ if (!nbd) {
int new_index;
new_index = nbd_dev_add(-1);
if (new_index < 0) {
- mutex_unlock(&nbd_index_mutex);
+ mutex_unlock(&nbd_global_mutex);
printk(KERN_ERR "nbd: failed to add new device\n");
return new_index;
}
- nbd = idr_find(&nbd_index_idr, new_index);
+ nbd = xa_load(&nbd_devs, new_index);
}
} else {
- nbd = idr_find(&nbd_index_idr, index);
+ nbd = xa_load(&nbd_devs, index);
if (!nbd) {
ret = nbd_dev_add(index);
if (ret < 0) {
- mutex_unlock(&nbd_index_mutex);
+ mutex_unlock(&nbd_global_mutex);
printk(KERN_ERR "nbd: failed to add new device\n");
return ret;
}
- nbd = idr_find(&nbd_index_idr, index);
+ nbd = xa_load(&nbd_devs, index);
}
}
if (!nbd) {
+ mutex_unlock(&nbd_global_mutex);
printk(KERN_ERR "nbd: couldn't find device at index %d\n",
index);
- mutex_unlock(&nbd_index_mutex);
return -EINVAL;
}
if (!refcount_inc_not_zero(&nbd->refs)) {
- mutex_unlock(&nbd_index_mutex);
+ mutex_unlock(&nbd_global_mutex);
if (index == -1)
goto again;
printk(KERN_ERR "nbd: device at index %d is going down\n",
index);
return -EINVAL;
}
- mutex_unlock(&nbd_index_mutex);
+ mutex_unlock(&nbd_global_mutex);
mutex_lock(&nbd->config_lock);
if (refcount_read(&nbd->config_refs)) {
@@ -1850,21 +1840,21 @@ static int nbd_genl_disconnect(struct sk_buff *skb, struct genl_info *info)
return -EINVAL;
}
index = nla_get_u32(info->attrs[NBD_ATTR_INDEX]);
- mutex_lock(&nbd_index_mutex);
- nbd = idr_find(&nbd_index_idr, index);
+ mutex_lock(&nbd_global_mutex);
+ nbd = xa_load(&nbd_devs, index);
if (!nbd) {
- mutex_unlock(&nbd_index_mutex);
+ mutex_unlock(&nbd_global_mutex);
printk(KERN_ERR "nbd: couldn't find device at index %d\n",
index);
return -EINVAL;
}
if (!refcount_inc_not_zero(&nbd->refs)) {
- mutex_unlock(&nbd_index_mutex);
+ mutex_unlock(&nbd_global_mutex);
printk(KERN_ERR "nbd: device at index %d is going down\n",
index);
return -EINVAL;
}
- mutex_unlock(&nbd_index_mutex);
+ mutex_unlock(&nbd_global_mutex);
if (!refcount_inc_not_zero(&nbd->config_refs)) {
nbd_put(nbd);
return 0;
@@ -1891,21 +1881,21 @@ static int nbd_genl_reconfigure(struct sk_buff *skb, struct genl_info *info)
return -EINVAL;
}
index = nla_get_u32(info->attrs[NBD_ATTR_INDEX]);
- mutex_lock(&nbd_index_mutex);
- nbd = idr_find(&nbd_index_idr, index);
+ mutex_lock(&nbd_global_mutex);
+ nbd = xa_load(&nbd_devs, index);
if (!nbd) {
- mutex_unlock(&nbd_index_mutex);
+ mutex_unlock(&nbd_global_mutex);
printk(KERN_ERR "nbd: couldn't find a device at index %d\n",
index);
return -EINVAL;
}
if (!refcount_inc_not_zero(&nbd->refs)) {
- mutex_unlock(&nbd_index_mutex);
+ mutex_unlock(&nbd_global_mutex);
printk(KERN_ERR "nbd: device at index %d is going down\n",
index);
return -EINVAL;
}
- mutex_unlock(&nbd_index_mutex);
+ mutex_unlock(&nbd_global_mutex);
if (!refcount_inc_not_zero(&nbd->config_refs)) {
dev_err(nbd_to_dev(nbd),
@@ -2044,7 +2034,7 @@ static int populate_nbd_status(struct nbd_device *nbd, struct sk_buff *reply)
/* This is a little racey, but for status it's ok. The
* reason we don't take a ref here is because we can't
* take a ref in the index == -1 case as we would need
- * to put under the nbd_index_mutex, which could
+ * to put under the nbd_global_mutex, which could
* deadlock if we are configured to remove ourselves
* once we're disconnected.
*/
@@ -2064,16 +2054,11 @@ static int populate_nbd_status(struct nbd_device *nbd, struct sk_buff *reply)
return 0;
}
-static int status_cb(int id, void *ptr, void *data)
-{
- struct nbd_device *nbd = ptr;
- return populate_nbd_status(nbd, (struct sk_buff *)data);
-}
-
static int nbd_genl_status(struct sk_buff *skb, struct genl_info *info)
{
struct nlattr *dev_list;
struct sk_buff *reply;
+ struct nbd_device *nbd;
void *reply_head;
size_t msg_size;
int index = -1;
@@ -2082,7 +2067,7 @@ static int nbd_genl_status(struct sk_buff *skb, struct genl_info *info)
if (info->attrs[NBD_ATTR_INDEX])
index = nla_get_u32(info->attrs[NBD_ATTR_INDEX]);
- mutex_lock(&nbd_index_mutex);
+ mutex_lock(&nbd_global_mutex);
msg_size = nla_total_size(nla_attr_size(sizeof(u32)) +
nla_attr_size(sizeof(u8)));
@@ -2100,14 +2085,17 @@ static int nbd_genl_status(struct sk_buff *skb, struct genl_info *info)
dev_list = nla_nest_start(reply, NBD_ATTR_DEVICE_LIST);
if (index == -1) {
- ret = idr_for_each(&nbd_index_idr, &status_cb, reply);
- if (ret) {
- nlmsg_free(reply);
- goto out;
+ unsigned long i;
+
+ xa_for_each(&nbd_devs, i, nbd) {
+ ret = populate_nbd_status(nbd, reply);
+ if (ret) {
+ nlmsg_free(reply);
+ goto out;
+ }
}
} else {
- struct nbd_device *nbd;
- nbd = idr_find(&nbd_index_idr, index);
+ nbd = xa_load(&nbd_devs, index);
if (nbd) {
ret = populate_nbd_status(nbd, reply);
if (ret) {
@@ -2120,7 +2108,7 @@ static int nbd_genl_status(struct sk_buff *skb, struct genl_info *info)
genlmsg_end(reply, reply_head);
ret = genlmsg_reply(reply, info);
out:
- mutex_unlock(&nbd_index_mutex);
+ mutex_unlock(&nbd_global_mutex);
return ret;
}
@@ -2229,42 +2217,27 @@ static int __init nbd_init(void)
}
nbd_dbg_init();
- mutex_lock(&nbd_index_mutex);
+ mutex_lock(&nbd_global_mutex);
for (i = 0; i < nbds_max; i++)
nbd_dev_add(i);
- mutex_unlock(&nbd_index_mutex);
- return 0;
-}
-
-static int nbd_exit_cb(int id, void *ptr, void *data)
-{
- struct list_head *list = (struct list_head *)data;
- struct nbd_device *nbd = ptr;
-
- list_add_tail(&nbd->list, list);
+ mutex_unlock(&nbd_global_mutex);
return 0;
}
static void __exit nbd_cleanup(void)
{
struct nbd_device *nbd;
- LIST_HEAD(del_list);
+ unsigned long index;
nbd_dbg_close();
- mutex_lock(&nbd_index_mutex);
- idr_for_each(&nbd_index_idr, &nbd_exit_cb, &del_list);
- mutex_unlock(&nbd_index_mutex);
-
- while (!list_empty(&del_list)) {
- nbd = list_first_entry(&del_list, struct nbd_device, list);
- list_del_init(&nbd->list);
+ xa_for_each(&nbd_devs, index, nbd) {
if (refcount_read(&nbd->refs) != 1)
printk(KERN_ERR "nbd: possibly leaking a device\n");
nbd_put(nbd);
}
- idr_destroy(&nbd_index_idr);
+ xa_destroy(&nbd_devs);
genl_unregister_family(&nbd_genl_family);
destroy_workqueue(recv_workqueue);
unregister_blkdev(NBD_MAJOR, "nbd");
--
2.20.1
