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linux/drivers/target/target_core_user.c

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/*
* Copyright (C) 2013 Shaohua Li <shli@kernel.org>
* Copyright (C) 2014 Red Hat, Inc.
* Copyright (C) 2015 Arrikto, Inc.
* Copyright (C) 2017 Chinamobile, Inc.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope 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.,
* 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <linux/spinlock.h>
#include <linux/module.h>
#include <linux/idr.h>
#include <linux/kernel.h>
#include <linux/timer.h>
#include <linux/parser.h>
#include <linux/vmalloc.h>
#include <linux/uio_driver.h>
#include <linux/radix-tree.h>
#include <linux/stringify.h>
#include <linux/bitops.h>
#include <linux/highmem.h>
#include <linux/configfs.h>
#include <linux/mutex.h>
#include <linux/workqueue.h>
#include <net/genetlink.h>
#include <scsi/scsi_common.h>
#include <scsi/scsi_proto.h>
#include <target/target_core_base.h>
#include <target/target_core_fabric.h>
#include <target/target_core_backend.h>
#include <linux/target_core_user.h>
/**
* DOC: Userspace I/O
* Userspace I/O
* -------------
*
* Define a shared-memory interface for LIO to pass SCSI commands and
* data to userspace for processing. This is to allow backends that
* are too complex for in-kernel support to be possible.
*
* It uses the UIO framework to do a lot of the device-creation and
* introspection work for us.
*
* See the .h file for how the ring is laid out. Note that while the
* command ring is defined, the particulars of the data area are
* not. Offset values in the command entry point to other locations
* internal to the mmap-ed area. There is separate space outside the
* command ring for data buffers. This leaves maximum flexibility for
* moving buffer allocations, or even page flipping or other
* allocation techniques, without altering the command ring layout.
*
* SECURITY:
* The user process must be assumed to be malicious. There's no way to
* prevent it breaking the command ring protocol if it wants, but in
* order to prevent other issues we must only ever read *data* from
* the shared memory area, not offsets or sizes. This applies to
* command ring entries as well as the mailbox. Extra code needed for
* this may have a 'UAM' comment.
*/
#define TCMU_TIME_OUT (30 * MSEC_PER_SEC)
/* For cmd area, the size is fixed 8MB */
#define CMDR_SIZE (8 * 1024 * 1024)
/*
* For data area, the block size is PAGE_SIZE and
* the total size is 256K * PAGE_SIZE.
*/
#define DATA_BLOCK_SIZE PAGE_SIZE
#define DATA_BLOCK_SHIFT PAGE_SHIFT
#define DATA_BLOCK_BITS_DEF (256 * 1024)
#define TCMU_MBS_TO_BLOCKS(_mbs) (_mbs << (20 - DATA_BLOCK_SHIFT))
#define TCMU_BLOCKS_TO_MBS(_blocks) (_blocks >> (20 - DATA_BLOCK_SHIFT))
/*
* Default number of global data blocks(512K * PAGE_SIZE)
* when the unmap thread will be started.
*/
#define TCMU_GLOBAL_MAX_BLOCKS_DEF (512 * 1024)
static u8 tcmu_kern_cmd_reply_supported;
static u8 tcmu_netlink_blocked;
static struct device *tcmu_root_device;
struct tcmu_hba {
u32 host_id;
};
#define TCMU_CONFIG_LEN 256
static DEFINE_MUTEX(tcmu_nl_cmd_mutex);
static LIST_HEAD(tcmu_nl_cmd_list);
struct tcmu_dev;
struct tcmu_nl_cmd {
/* wake up thread waiting for reply */
struct completion complete;
struct list_head nl_list;
struct tcmu_dev *udev;
int cmd;
int status;
};
struct tcmu_dev {
struct list_head node;
struct kref kref;
struct se_device se_dev;
char *name;
struct se_hba *hba;
#define TCMU_DEV_BIT_OPEN 0
#define TCMU_DEV_BIT_BROKEN 1
#define TCMU_DEV_BIT_BLOCKED 2
unsigned long flags;
struct uio_info uio_info;
struct inode *inode;
struct tcmu_mailbox *mb_addr;
uint64_t dev_size;
u32 cmdr_size;
u32 cmdr_last_cleaned;
/* Offset of data area from start of mb */
/* Must add data_off and mb_addr to get the address */
size_t data_off;
size_t data_size;
uint32_t max_blocks;
size_t ring_size;
struct mutex cmdr_lock;
struct list_head qfull_queue;
uint32_t dbi_max;
uint32_t dbi_thresh;
unsigned long *data_bitmap;
struct radix_tree_root data_blocks;
struct idr commands;
struct timer_list cmd_timer;
unsigned int cmd_time_out;
struct list_head inflight_queue;
struct timer_list qfull_timer;
int qfull_time_out;
struct list_head timedout_entry;
struct tcmu_nl_cmd curr_nl_cmd;
char dev_config[TCMU_CONFIG_LEN];
int nl_reply_supported;
};
#define TCMU_DEV(_se_dev) container_of(_se_dev, struct tcmu_dev, se_dev)
#define CMDR_OFF sizeof(struct tcmu_mailbox)
struct tcmu_cmd {
struct se_cmd *se_cmd;
struct tcmu_dev *tcmu_dev;
struct list_head queue_entry;
uint16_t cmd_id;
/* Can't use se_cmd when cleaning up expired cmds, because if
cmd has been completed then accessing se_cmd is off limits */
uint32_t dbi_cnt;
uint32_t dbi_cur;
uint32_t *dbi;
unsigned long deadline;
#define TCMU_CMD_BIT_EXPIRED 0
#define TCMU_CMD_BIT_INFLIGHT 1
unsigned long flags;
};
/*
* To avoid dead lock the mutex lock order should always be:
*
* mutex_lock(&root_udev_mutex);
* ...
* mutex_lock(&tcmu_dev->cmdr_lock);
* mutex_unlock(&tcmu_dev->cmdr_lock);
* ...
* mutex_unlock(&root_udev_mutex);
*/
static DEFINE_MUTEX(root_udev_mutex);
static LIST_HEAD(root_udev);
static DEFINE_SPINLOCK(timed_out_udevs_lock);
static LIST_HEAD(timed_out_udevs);
static struct kmem_cache *tcmu_cmd_cache;
static atomic_t global_db_count = ATOMIC_INIT(0);
static struct delayed_work tcmu_unmap_work;
static int tcmu_global_max_blocks = TCMU_GLOBAL_MAX_BLOCKS_DEF;
static int tcmu_set_global_max_data_area(const char *str,
const struct kernel_param *kp)
{
int ret, max_area_mb;
ret = kstrtoint(str, 10, &max_area_mb);
if (ret)
return -EINVAL;
if (max_area_mb <= 0) {
pr_err("global_max_data_area must be larger than 0.\n");
return -EINVAL;
}
tcmu_global_max_blocks = TCMU_MBS_TO_BLOCKS(max_area_mb);
if (atomic_read(&global_db_count) > tcmu_global_max_blocks)
schedule_delayed_work(&tcmu_unmap_work, 0);
else
cancel_delayed_work_sync(&tcmu_unmap_work);
return 0;
}
static int tcmu_get_global_max_data_area(char *buffer,
const struct kernel_param *kp)
{
return sprintf(buffer, "%d", TCMU_BLOCKS_TO_MBS(tcmu_global_max_blocks));
}
static const struct kernel_param_ops tcmu_global_max_data_area_op = {
.set = tcmu_set_global_max_data_area,
.get = tcmu_get_global_max_data_area,
};
module_param_cb(global_max_data_area_mb, &tcmu_global_max_data_area_op, NULL,
S_IWUSR | S_IRUGO);
MODULE_PARM_DESC(global_max_data_area_mb,
"Max MBs allowed to be allocated to all the tcmu device's "
"data areas.");
static int tcmu_get_block_netlink(char *buffer,
const struct kernel_param *kp)
{
return sprintf(buffer, "%s\n", tcmu_netlink_blocked ?
"blocked" : "unblocked");
}
static int tcmu_set_block_netlink(const char *str,
const struct kernel_param *kp)
{
int ret;
u8 val;
ret = kstrtou8(str, 0, &val);
if (ret < 0)
return ret;
if (val > 1) {
pr_err("Invalid block netlink value %u\n", val);
return -EINVAL;
}
tcmu_netlink_blocked = val;
return 0;
}
static const struct kernel_param_ops tcmu_block_netlink_op = {
.set = tcmu_set_block_netlink,
.get = tcmu_get_block_netlink,
};
module_param_cb(block_netlink, &tcmu_block_netlink_op, NULL, S_IWUSR | S_IRUGO);
MODULE_PARM_DESC(block_netlink, "Block new netlink commands.");
static int tcmu_fail_netlink_cmd(struct tcmu_nl_cmd *nl_cmd)
{
struct tcmu_dev *udev = nl_cmd->udev;
if (!tcmu_netlink_blocked) {
pr_err("Could not reset device's netlink interface. Netlink is not blocked.\n");
return -EBUSY;
}
if (nl_cmd->cmd != TCMU_CMD_UNSPEC) {
pr_debug("Aborting nl cmd %d on %s\n", nl_cmd->cmd, udev->name);
nl_cmd->status = -EINTR;
list_del(&nl_cmd->nl_list);
complete(&nl_cmd->complete);
}
return 0;
}
static int tcmu_set_reset_netlink(const char *str,
const struct kernel_param *kp)
{
struct tcmu_nl_cmd *nl_cmd, *tmp_cmd;
int ret;
u8 val;
ret = kstrtou8(str, 0, &val);
if (ret < 0)
return ret;
if (val != 1) {
pr_err("Invalid reset netlink value %u\n", val);
return -EINVAL;
}
mutex_lock(&tcmu_nl_cmd_mutex);
list_for_each_entry_safe(nl_cmd, tmp_cmd, &tcmu_nl_cmd_list, nl_list) {
ret = tcmu_fail_netlink_cmd(nl_cmd);
if (ret)
break;
}
mutex_unlock(&tcmu_nl_cmd_mutex);
return ret;
}
static const struct kernel_param_ops tcmu_reset_netlink_op = {
.set = tcmu_set_reset_netlink,
};
module_param_cb(reset_netlink, &tcmu_reset_netlink_op, NULL, S_IWUSR);
MODULE_PARM_DESC(reset_netlink, "Reset netlink commands.");
/* multicast group */
enum tcmu_multicast_groups {
TCMU_MCGRP_CONFIG,
};
static const struct genl_multicast_group tcmu_mcgrps[] = {
[TCMU_MCGRP_CONFIG] = { .name = "config", },
};
static struct nla_policy tcmu_attr_policy[TCMU_ATTR_MAX+1] = {
[TCMU_ATTR_DEVICE] = { .type = NLA_STRING },
[TCMU_ATTR_MINOR] = { .type = NLA_U32 },
[TCMU_ATTR_CMD_STATUS] = { .type = NLA_S32 },
[TCMU_ATTR_DEVICE_ID] = { .type = NLA_U32 },
[TCMU_ATTR_SUPP_KERN_CMD_REPLY] = { .type = NLA_U8 },
};
static int tcmu_genl_cmd_done(struct genl_info *info, int completed_cmd)
{
struct tcmu_dev *udev = NULL;
struct tcmu_nl_cmd *nl_cmd;
int dev_id, rc, ret = 0;
if (!info->attrs[TCMU_ATTR_CMD_STATUS] ||
!info->attrs[TCMU_ATTR_DEVICE_ID]) {
printk(KERN_ERR "TCMU_ATTR_CMD_STATUS or TCMU_ATTR_DEVICE_ID not set, doing nothing\n");
return -EINVAL;
}
dev_id = nla_get_u32(info->attrs[TCMU_ATTR_DEVICE_ID]);
rc = nla_get_s32(info->attrs[TCMU_ATTR_CMD_STATUS]);
mutex_lock(&tcmu_nl_cmd_mutex);
list_for_each_entry(nl_cmd, &tcmu_nl_cmd_list, nl_list) {
if (nl_cmd->udev->se_dev.dev_index == dev_id) {
udev = nl_cmd->udev;
break;
}
}
if (!udev) {
pr_err("tcmu nl cmd %u/%d completion could not find device with dev id %u.\n",
completed_cmd, rc, dev_id);
ret = -ENODEV;
goto unlock;
}
list_del(&nl_cmd->nl_list);
pr_debug("%s genl cmd done got id %d curr %d done %d rc %d stat %d\n",
udev->name, dev_id, nl_cmd->cmd, completed_cmd, rc,
nl_cmd->status);
if (nl_cmd->cmd != completed_cmd) {
pr_err("Mismatched commands on %s (Expecting reply for %d. Current %d).\n",
udev->name, completed_cmd, nl_cmd->cmd);
ret = -EINVAL;
goto unlock;
}
nl_cmd->status = rc;
complete(&nl_cmd->complete);
unlock:
mutex_unlock(&tcmu_nl_cmd_mutex);
return ret;
}
static int tcmu_genl_rm_dev_done(struct sk_buff *skb, struct genl_info *info)
{
return tcmu_genl_cmd_done(info, TCMU_CMD_REMOVED_DEVICE);
}
static int tcmu_genl_add_dev_done(struct sk_buff *skb, struct genl_info *info)
{
return tcmu_genl_cmd_done(info, TCMU_CMD_ADDED_DEVICE);
}
static int tcmu_genl_reconfig_dev_done(struct sk_buff *skb,
struct genl_info *info)
{
return tcmu_genl_cmd_done(info, TCMU_CMD_RECONFIG_DEVICE);
}
static int tcmu_genl_set_features(struct sk_buff *skb, struct genl_info *info)
{
if (info->attrs[TCMU_ATTR_SUPP_KERN_CMD_REPLY]) {
tcmu_kern_cmd_reply_supported =
nla_get_u8(info->attrs[TCMU_ATTR_SUPP_KERN_CMD_REPLY]);
printk(KERN_INFO "tcmu daemon: command reply support %u.\n",
tcmu_kern_cmd_reply_supported);
}
return 0;
}
static const struct genl_ops tcmu_genl_ops[] = {
{
.cmd = TCMU_CMD_SET_FEATURES,
.flags = GENL_ADMIN_PERM,
.policy = tcmu_attr_policy,
.doit = tcmu_genl_set_features,
},
{
.cmd = TCMU_CMD_ADDED_DEVICE_DONE,
.flags = GENL_ADMIN_PERM,
.policy = tcmu_attr_policy,
.doit = tcmu_genl_add_dev_done,
},
{
.cmd = TCMU_CMD_REMOVED_DEVICE_DONE,
.flags = GENL_ADMIN_PERM,
.policy = tcmu_attr_policy,
.doit = tcmu_genl_rm_dev_done,
},
{
.cmd = TCMU_CMD_RECONFIG_DEVICE_DONE,
.flags = GENL_ADMIN_PERM,
.policy = tcmu_attr_policy,
.doit = tcmu_genl_reconfig_dev_done,
},
};
/* Our generic netlink family */
static struct genl_family tcmu_genl_family __ro_after_init = {
.module = THIS_MODULE,
.hdrsize = 0,
.name = "TCM-USER",
.version = 2,
.maxattr = TCMU_ATTR_MAX,
.mcgrps = tcmu_mcgrps,
.n_mcgrps = ARRAY_SIZE(tcmu_mcgrps),
.netnsok = true,
.ops = tcmu_genl_ops,
.n_ops = ARRAY_SIZE(tcmu_genl_ops),
};
#define tcmu_cmd_set_dbi_cur(cmd, index) ((cmd)->dbi_cur = (index))
#define tcmu_cmd_reset_dbi_cur(cmd) tcmu_cmd_set_dbi_cur(cmd, 0)
#define tcmu_cmd_set_dbi(cmd, index) ((cmd)->dbi[(cmd)->dbi_cur++] = (index))
#define tcmu_cmd_get_dbi(cmd) ((cmd)->dbi[(cmd)->dbi_cur++])
static void tcmu_cmd_free_data(struct tcmu_cmd *tcmu_cmd, uint32_t len)
{
struct tcmu_dev *udev = tcmu_cmd->tcmu_dev;
uint32_t i;
for (i = 0; i < len; i++)
clear_bit(tcmu_cmd->dbi[i], udev->data_bitmap);
}
static inline bool tcmu_get_empty_block(struct tcmu_dev *udev,
struct tcmu_cmd *tcmu_cmd)
{
struct page *page;
int ret, dbi;
dbi = find_first_zero_bit(udev->data_bitmap, udev->dbi_thresh);
if (dbi == udev->dbi_thresh)
return false;
page = radix_tree_lookup(&udev->data_blocks, dbi);
if (!page) {
if (atomic_add_return(1, &global_db_count) >
tcmu_global_max_blocks)
schedule_delayed_work(&tcmu_unmap_work, 0);
/* try to get new page from the mm */
page = alloc_page(GFP_KERNEL);
if (!page)
goto err_alloc;
ret = radix_tree_insert(&udev->data_blocks, dbi, page);
if (ret)
goto err_insert;
}
if (dbi > udev->dbi_max)
udev->dbi_max = dbi;
set_bit(dbi, udev->data_bitmap);
tcmu_cmd_set_dbi(tcmu_cmd, dbi);
return true;
err_insert:
__free_page(page);
err_alloc:
atomic_dec(&global_db_count);
return false;
}
static bool tcmu_get_empty_blocks(struct tcmu_dev *udev,
struct tcmu_cmd *tcmu_cmd)
{
int i;
for (i = tcmu_cmd->dbi_cur; i < tcmu_cmd->dbi_cnt; i++) {
if (!tcmu_get_empty_block(udev, tcmu_cmd))
return false;
}
return true;
}
static inline struct page *
tcmu_get_block_page(struct tcmu_dev *udev, uint32_t dbi)
{
return radix_tree_lookup(&udev->data_blocks, dbi);
}
static inline void tcmu_free_cmd(struct tcmu_cmd *tcmu_cmd)
{
kfree(tcmu_cmd->dbi);
kmem_cache_free(tcmu_cmd_cache, tcmu_cmd);
}
static inline size_t tcmu_cmd_get_data_length(struct tcmu_cmd *tcmu_cmd)
{
struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
size_t data_length = round_up(se_cmd->data_length, DATA_BLOCK_SIZE);
if (se_cmd->se_cmd_flags & SCF_BIDI) {
BUG_ON(!(se_cmd->t_bidi_data_sg && se_cmd->t_bidi_data_nents));
data_length += round_up(se_cmd->t_bidi_data_sg->length,
DATA_BLOCK_SIZE);
}
return data_length;
}
static inline uint32_t tcmu_cmd_get_block_cnt(struct tcmu_cmd *tcmu_cmd)
{
size_t data_length = tcmu_cmd_get_data_length(tcmu_cmd);
return data_length / DATA_BLOCK_SIZE;
}
static struct tcmu_cmd *tcmu_alloc_cmd(struct se_cmd *se_cmd)
{
struct se_device *se_dev = se_cmd->se_dev;
struct tcmu_dev *udev = TCMU_DEV(se_dev);
struct tcmu_cmd *tcmu_cmd;
tcmu_cmd = kmem_cache_zalloc(tcmu_cmd_cache, GFP_KERNEL);
if (!tcmu_cmd)
return NULL;
INIT_LIST_HEAD(&tcmu_cmd->queue_entry);
tcmu_cmd->se_cmd = se_cmd;
tcmu_cmd->tcmu_dev = udev;
tcmu_cmd_reset_dbi_cur(tcmu_cmd);
tcmu_cmd->dbi_cnt = tcmu_cmd_get_block_cnt(tcmu_cmd);
tcmu_cmd->dbi = kcalloc(tcmu_cmd->dbi_cnt, sizeof(uint32_t),
GFP_KERNEL);
if (!tcmu_cmd->dbi) {
kmem_cache_free(tcmu_cmd_cache, tcmu_cmd);
return NULL;
}
return tcmu_cmd;
}
static inline void tcmu_flush_dcache_range(void *vaddr, size_t size)
{
unsigned long offset = offset_in_page(vaddr);
void *start = vaddr - offset;
size = round_up(size+offset, PAGE_SIZE);
while (size) {
flush_dcache_page(virt_to_page(start));
start += PAGE_SIZE;
size -= PAGE_SIZE;
}
}
/*
* Some ring helper functions. We don't assume size is a power of 2 so
* we can't use circ_buf.h.
*/
static inline size_t spc_used(size_t head, size_t tail, size_t size)
{
int diff = head - tail;
if (diff >= 0)
return diff;
else
return size + diff;
}
static inline size_t spc_free(size_t head, size_t tail, size_t size)
{
/* Keep 1 byte unused or we can't tell full from empty */
return (size - spc_used(head, tail, size) - 1);
}
static inline size_t head_to_end(size_t head, size_t size)
{
return size - head;
}
static inline void new_iov(struct iovec **iov, int *iov_cnt)
{
struct iovec *iovec;
if (*iov_cnt != 0)
(*iov)++;
(*iov_cnt)++;
iovec = *iov;
memset(iovec, 0, sizeof(struct iovec));
}
#define UPDATE_HEAD(head, used, size) smp_store_release(&head, ((head % size) + used) % size)
/* offset is relative to mb_addr */
static inline size_t get_block_offset_user(struct tcmu_dev *dev,
int dbi, int remaining)
{
return dev->data_off + dbi * DATA_BLOCK_SIZE +
DATA_BLOCK_SIZE - remaining;
}
static inline size_t iov_tail(struct iovec *iov)
{
return (size_t)iov->iov_base + iov->iov_len;
}
static void scatter_data_area(struct tcmu_dev *udev,
struct tcmu_cmd *tcmu_cmd, struct scatterlist *data_sg,
unsigned int data_nents, struct iovec **iov,
int *iov_cnt, bool copy_data)
{
int i, dbi;
int block_remaining = 0;
void *from, *to = NULL;
size_t copy_bytes, to_offset, offset;
struct scatterlist *sg;
struct page *page;
for_each_sg(data_sg, sg, data_nents, i) {
int sg_remaining = sg->length;
from = kmap_atomic(sg_page(sg)) + sg->offset;
while (sg_remaining > 0) {
if (block_remaining == 0) {
if (to)
kunmap_atomic(to);
block_remaining = DATA_BLOCK_SIZE;
dbi = tcmu_cmd_get_dbi(tcmu_cmd);
page = tcmu_get_block_page(udev, dbi);
to = kmap_atomic(page);
}
/*
* Covert to virtual offset of the ring data area.
*/
to_offset = get_block_offset_user(udev, dbi,
block_remaining);
/*
* The following code will gather and map the blocks
* to the same iovec when the blocks are all next to
* each other.
*/
copy_bytes = min_t(size_t, sg_remaining,
block_remaining);
if (*iov_cnt != 0 &&
to_offset == iov_tail(*iov)) {
/*
* Will append to the current iovec, because
* the current block page is next to the
* previous one.
*/
(*iov)->iov_len += copy_bytes;
} else {
/*
* Will allocate a new iovec because we are
* first time here or the current block page
* is not next to the previous one.
*/
new_iov(iov, iov_cnt);
(*iov)->iov_base = (void __user *)to_offset;
(*iov)->iov_len = copy_bytes;
}
if (copy_data) {
offset = DATA_BLOCK_SIZE - block_remaining;
memcpy(to + offset,
from + sg->length - sg_remaining,
copy_bytes);
tcmu_flush_dcache_range(to, copy_bytes);
}
sg_remaining -= copy_bytes;
block_remaining -= copy_bytes;
}
kunmap_atomic(from - sg->offset);
}
if (to)
kunmap_atomic(to);
}
static void gather_data_area(struct tcmu_dev *udev, struct tcmu_cmd *cmd,
bool bidi, uint32_t read_len)
{
struct se_cmd *se_cmd = cmd->se_cmd;
int i, dbi;
int block_remaining = 0;
void *from = NULL, *to;
size_t copy_bytes, offset;
struct scatterlist *sg, *data_sg;
struct page *page;
unsigned int data_nents;
uint32_t count = 0;
if (!bidi) {
data_sg = se_cmd->t_data_sg;
data_nents = se_cmd->t_data_nents;
} else {
/*
* For bidi case, the first count blocks are for Data-Out
* buffer blocks, and before gathering the Data-In buffer
* the Data-Out buffer blocks should be discarded.
*/
count = DIV_ROUND_UP(se_cmd->data_length, DATA_BLOCK_SIZE);
data_sg = se_cmd->t_bidi_data_sg;
data_nents = se_cmd->t_bidi_data_nents;
}
tcmu_cmd_set_dbi_cur(cmd, count);
for_each_sg(data_sg, sg, data_nents, i) {
int sg_remaining = sg->length;
to = kmap_atomic(sg_page(sg)) + sg->offset;
while (sg_remaining > 0 && read_len > 0) {
if (block_remaining == 0) {
if (from)
kunmap_atomic(from);
block_remaining = DATA_BLOCK_SIZE;
dbi = tcmu_cmd_get_dbi(cmd);
page = tcmu_get_block_page(udev, dbi);
from = kmap_atomic(page);
}
copy_bytes = min_t(size_t, sg_remaining,
block_remaining);
if (read_len < copy_bytes)
copy_bytes = read_len;
offset = DATA_BLOCK_SIZE - block_remaining;
tcmu_flush_dcache_range(from, copy_bytes);
memcpy(to + sg->length - sg_remaining, from + offset,
copy_bytes);
sg_remaining -= copy_bytes;
block_remaining -= copy_bytes;
read_len -= copy_bytes;
}
kunmap_atomic(to - sg->offset);
if (read_len == 0)
break;
}
if (from)
kunmap_atomic(from);
}
static inline size_t spc_bitmap_free(unsigned long *bitmap, uint32_t thresh)
{
return thresh - bitmap_weight(bitmap, thresh);
}
/*
* We can't queue a command until we have space available on the cmd ring *and*
* space available on the data area.
*
* Called with ring lock held.
*/
static bool is_ring_space_avail(struct tcmu_dev *udev, struct tcmu_cmd *cmd,
size_t cmd_size, size_t data_needed)
{
struct tcmu_mailbox *mb = udev->mb_addr;
uint32_t blocks_needed = (data_needed + DATA_BLOCK_SIZE - 1)
/ DATA_BLOCK_SIZE;
size_t space, cmd_needed;
u32 cmd_head;
tcmu_flush_dcache_range(mb, sizeof(*mb));
cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
/*
* If cmd end-of-ring space is too small then we need space for a NOP plus
* original cmd - cmds are internally contiguous.
*/
if (head_to_end(cmd_head, udev->cmdr_size) >= cmd_size)
cmd_needed = cmd_size;
else
cmd_needed = cmd_size + head_to_end(cmd_head, udev->cmdr_size);
space = spc_free(cmd_head, udev->cmdr_last_cleaned, udev->cmdr_size);
if (space < cmd_needed) {
pr_debug("no cmd space: %u %u %u\n", cmd_head,
udev->cmdr_last_cleaned, udev->cmdr_size);
return false;
}
/* try to check and get the data blocks as needed */
space = spc_bitmap_free(udev->data_bitmap, udev->dbi_thresh);
if ((space * DATA_BLOCK_SIZE) < data_needed) {
unsigned long blocks_left =
(udev->max_blocks - udev->dbi_thresh) + space;
if (blocks_left < blocks_needed) {
pr_debug("no data space: only %lu available, but ask for %zu\n",
blocks_left * DATA_BLOCK_SIZE,
data_needed);
return false;
}
udev->dbi_thresh += blocks_needed;
if (udev->dbi_thresh > udev->max_blocks)
udev->dbi_thresh = udev->max_blocks;
}
return tcmu_get_empty_blocks(udev, cmd);
}
static inline size_t tcmu_cmd_get_base_cmd_size(size_t iov_cnt)
{
return max(offsetof(struct tcmu_cmd_entry, req.iov[iov_cnt]),
sizeof(struct tcmu_cmd_entry));
}
static inline size_t tcmu_cmd_get_cmd_size(struct tcmu_cmd *tcmu_cmd,
size_t base_command_size)
{
struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
size_t command_size;
command_size = base_command_size +
round_up(scsi_command_size(se_cmd->t_task_cdb),
TCMU_OP_ALIGN_SIZE);
WARN_ON(command_size & (TCMU_OP_ALIGN_SIZE-1));
return command_size;
}
static int tcmu_setup_cmd_timer(struct tcmu_cmd *tcmu_cmd, unsigned int tmo,
struct timer_list *timer)
{
struct tcmu_dev *udev = tcmu_cmd->tcmu_dev;
int cmd_id;
if (tcmu_cmd->cmd_id)
goto setup_timer;
cmd_id = idr_alloc(&udev->commands, tcmu_cmd, 1, USHRT_MAX, GFP_NOWAIT);
if (cmd_id < 0) {
pr_err("tcmu: Could not allocate cmd id.\n");
return cmd_id;
}
tcmu_cmd->cmd_id = cmd_id;
pr_debug("allocated cmd %u for dev %s tmo %lu\n", tcmu_cmd->cmd_id,
udev->name, tmo / MSEC_PER_SEC);
setup_timer:
if (!tmo)
return 0;
tcmu_cmd->deadline = round_jiffies_up(jiffies + msecs_to_jiffies(tmo));
if (!timer_pending(timer))
mod_timer(timer, tcmu_cmd->deadline);
return 0;
}
static int add_to_qfull_queue(struct tcmu_cmd *tcmu_cmd)
{
struct tcmu_dev *udev = tcmu_cmd->tcmu_dev;
unsigned int tmo;
int ret;
/*
* For backwards compat if qfull_time_out is not set use
* cmd_time_out and if that's not set use the default time out.
*/
if (!udev->qfull_time_out)
return -ETIMEDOUT;
else if (udev->qfull_time_out > 0)
tmo = udev->qfull_time_out;
else if (udev->cmd_time_out)
tmo = udev->cmd_time_out;
else
tmo = TCMU_TIME_OUT;
ret = tcmu_setup_cmd_timer(tcmu_cmd, tmo, &udev->qfull_timer);
if (ret)
return ret;
list_add_tail(&tcmu_cmd->queue_entry, &udev->qfull_queue);
pr_debug("adding cmd %u on dev %s to ring space wait queue\n",
tcmu_cmd->cmd_id, udev->name);
return 0;
}
/**
* queue_cmd_ring - queue cmd to ring or internally
* @tcmu_cmd: cmd to queue
* @scsi_err: TCM error code if failure (-1) returned.
*
* Returns:
* -1 we cannot queue internally or to the ring.
* 0 success
* 1 internally queued to wait for ring memory to free.
*/
static int queue_cmd_ring(struct tcmu_cmd *tcmu_cmd, sense_reason_t *scsi_err)
{
struct tcmu_dev *udev = tcmu_cmd->tcmu_dev;
struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
size_t base_command_size, command_size;
struct tcmu_mailbox *mb;
struct tcmu_cmd_entry *entry;
struct iovec *iov;
int iov_cnt, ret;
uint32_t cmd_head;
uint64_t cdb_off;
bool copy_to_data_area;
size_t data_length = tcmu_cmd_get_data_length(tcmu_cmd);
*scsi_err = TCM_NO_SENSE;
if (test_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags)) {
*scsi_err = TCM_LUN_BUSY;
return -1;
}
if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags)) {
*scsi_err = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
return -1;
}
/*
* Must be a certain minimum size for response sense info, but
* also may be larger if the iov array is large.
*
* We prepare as many iovs as possbile for potential uses here,
* because it's expensive to tell how many regions are freed in
* the bitmap & global data pool, as the size calculated here
* will only be used to do the checks.
*
* The size will be recalculated later as actually needed to save
* cmd area memories.
*/
base_command_size = tcmu_cmd_get_base_cmd_size(tcmu_cmd->dbi_cnt);
command_size = tcmu_cmd_get_cmd_size(tcmu_cmd, base_command_size);
if (!list_empty(&udev->qfull_queue))
goto queue;
mb = udev->mb_addr;
cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
if ((command_size > (udev->cmdr_size / 2)) ||
data_length > udev->data_size) {
pr_warn("TCMU: Request of size %zu/%zu is too big for %u/%zu "
"cmd ring/data area\n", command_size, data_length,
udev->cmdr_size, udev->data_size);
*scsi_err = TCM_INVALID_CDB_FIELD;
return -1;
}
if (!is_ring_space_avail(udev, tcmu_cmd, command_size, data_length)) {
/*
* Don't leave commands partially setup because the unmap
* thread might need the blocks to make forward progress.
*/
tcmu_cmd_free_data(tcmu_cmd, tcmu_cmd->dbi_cur);
tcmu_cmd_reset_dbi_cur(tcmu_cmd);
goto queue;
}
/* Insert a PAD if end-of-ring space is too small */
if (head_to_end(cmd_head, udev->cmdr_size) < command_size) {
size_t pad_size = head_to_end(cmd_head, udev->cmdr_size);
entry = (void *) mb + CMDR_OFF + cmd_head;
tcmu_hdr_set_op(&entry->hdr.len_op, TCMU_OP_PAD);
tcmu_hdr_set_len(&entry->hdr.len_op, pad_size);
entry->hdr.cmd_id = 0; /* not used for PAD */
entry->hdr.kflags = 0;
entry->hdr.uflags = 0;
tcmu_flush_dcache_range(entry, sizeof(*entry));
UPDATE_HEAD(mb->cmd_head, pad_size, udev->cmdr_size);
tcmu_flush_dcache_range(mb, sizeof(*mb));
cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
WARN_ON(cmd_head != 0);
}
entry = (void *) mb + CMDR_OFF + cmd_head;
memset(entry, 0, command_size);
tcmu_hdr_set_op(&entry->hdr.len_op, TCMU_OP_CMD);
/* Handle allocating space from the data area */
tcmu_cmd_reset_dbi_cur(tcmu_cmd);
iov = &entry->req.iov[0];
iov_cnt = 0;
copy_to_data_area = (se_cmd->data_direction == DMA_TO_DEVICE
|| se_cmd->se_cmd_flags & SCF_BIDI);
scatter_data_area(udev, tcmu_cmd, se_cmd->t_data_sg,
se_cmd->t_data_nents, &iov, &iov_cnt,
copy_to_data_area);
entry->req.iov_cnt = iov_cnt;
/* Handle BIDI commands */
iov_cnt = 0;
if (se_cmd->se_cmd_flags & SCF_BIDI) {
iov++;
scatter_data_area(udev, tcmu_cmd, se_cmd->t_bidi_data_sg,
se_cmd->t_bidi_data_nents, &iov, &iov_cnt,
false);
}
entry->req.iov_bidi_cnt = iov_cnt;
ret = tcmu_setup_cmd_timer(tcmu_cmd, udev->cmd_time_out,
&udev->cmd_timer);
if (ret) {
tcmu_cmd_free_data(tcmu_cmd, tcmu_cmd->dbi_cnt);
*scsi_err = TCM_OUT_OF_RESOURCES;
return -1;
}
entry->hdr.cmd_id = tcmu_cmd->cmd_id;
/*
* Recalaulate the command's base size and size according
* to the actual needs
*/
base_command_size = tcmu_cmd_get_base_cmd_size(entry->req.iov_cnt +
entry->req.iov_bidi_cnt);
command_size = tcmu_cmd_get_cmd_size(tcmu_cmd, base_command_size);
tcmu_hdr_set_len(&entry->hdr.len_op, command_size);
/* All offsets relative to mb_addr, not start of entry! */
cdb_off = CMDR_OFF + cmd_head + base_command_size;
memcpy((void *) mb + cdb_off, se_cmd->t_task_cdb, scsi_command_size(se_cmd->t_task_cdb));
entry->req.cdb_off = cdb_off;
tcmu_flush_dcache_range(entry, sizeof(*entry));
UPDATE_HEAD(mb->cmd_head, command_size, udev->cmdr_size);
tcmu_flush_dcache_range(mb, sizeof(*mb));
list_add_tail(&tcmu_cmd->queue_entry, &udev->inflight_queue);
set_bit(TCMU_CMD_BIT_INFLIGHT, &tcmu_cmd->flags);
/* TODO: only if FLUSH and FUA? */
uio_event_notify(&udev->uio_info);
return 0;
queue:
if (add_to_qfull_queue(tcmu_cmd)) {
*scsi_err = TCM_OUT_OF_RESOURCES;
return -1;
}
return 1;
}
static sense_reason_t
tcmu_queue_cmd(struct se_cmd *se_cmd)
{
struct se_device *se_dev = se_cmd->se_dev;
struct tcmu_dev *udev = TCMU_DEV(se_dev);
struct tcmu_cmd *tcmu_cmd;
sense_reason_t scsi_ret;
int ret;
tcmu_cmd = tcmu_alloc_cmd(se_cmd);
if (!tcmu_cmd)
return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
mutex_lock(&udev->cmdr_lock);
ret = queue_cmd_ring(tcmu_cmd, &scsi_ret);
mutex_unlock(&udev->cmdr_lock);
if (ret < 0)
tcmu_free_cmd(tcmu_cmd);
return scsi_ret;
}
static void tcmu_handle_completion(struct tcmu_cmd *cmd, struct tcmu_cmd_entry *entry)
{
struct se_cmd *se_cmd = cmd->se_cmd;
struct tcmu_dev *udev = cmd->tcmu_dev;
bool read_len_valid = false;
uint32_t read_len = se_cmd->data_length;
/*
* cmd has been completed already from timeout, just reclaim
* data area space and free cmd
*/
if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags))
goto out;
list_del_init(&cmd->queue_entry);
tcmu_cmd_reset_dbi_cur(cmd);
if (entry->hdr.uflags & TCMU_UFLAG_UNKNOWN_OP) {
pr_warn("TCMU: Userspace set UNKNOWN_OP flag on se_cmd %p\n",
cmd->se_cmd);
entry->rsp.scsi_status = SAM_STAT_CHECK_CONDITION;
goto done;
}
if (se_cmd->data_direction == DMA_FROM_DEVICE &&
(entry->hdr.uflags & TCMU_UFLAG_READ_LEN) && entry->rsp.read_len) {
read_len_valid = true;
if (entry->rsp.read_len < read_len)
read_len = entry->rsp.read_len;
}
if (entry->rsp.scsi_status == SAM_STAT_CHECK_CONDITION) {
transport_copy_sense_to_cmd(se_cmd, entry->rsp.sense_buffer);
if (!read_len_valid )
goto done;
else
se_cmd->se_cmd_flags |= SCF_TREAT_READ_AS_NORMAL;
}
if (se_cmd->se_cmd_flags & SCF_BIDI) {
/* Get Data-In buffer before clean up */
gather_data_area(udev, cmd, true, read_len);
} else if (se_cmd->data_direction == DMA_FROM_DEVICE) {
gather_data_area(udev, cmd, false, read_len);
} else if (se_cmd->data_direction == DMA_TO_DEVICE) {
/* TODO: */
} else if (se_cmd->data_direction != DMA_NONE) {
pr_warn("TCMU: data direction was %d!\n",
se_cmd->data_direction);
}
done:
if (read_len_valid) {
pr_debug("read_len = %d\n", read_len);
target_complete_cmd_with_length(cmd->se_cmd,
entry->rsp.scsi_status, read_len);
} else
target_complete_cmd(cmd->se_cmd, entry->rsp.scsi_status);
out:
cmd->se_cmd = NULL;
tcmu_cmd_free_data(cmd, cmd->dbi_cnt);
tcmu_free_cmd(cmd);
}
static void tcmu_set_next_deadline(struct list_head *queue,
struct timer_list *timer)
{
struct tcmu_cmd *tcmu_cmd, *tmp_cmd;
unsigned long deadline = 0;
list_for_each_entry_safe(tcmu_cmd, tmp_cmd, queue, queue_entry) {
if (!time_after(jiffies, tcmu_cmd->deadline)) {
deadline = tcmu_cmd->deadline;
break;
}
}
if (deadline)
mod_timer(timer, deadline);
else
del_timer(timer);
}
static unsigned int tcmu_handle_completions(struct tcmu_dev *udev)
{
struct tcmu_mailbox *mb;
struct tcmu_cmd *cmd;
int handled = 0;
if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags)) {
pr_err("ring broken, not handling completions\n");
return 0;
}
mb = udev->mb_addr;
tcmu_flush_dcache_range(mb, sizeof(*mb));
while (udev->cmdr_last_cleaned != READ_ONCE(mb->cmd_tail)) {
struct tcmu_cmd_entry *entry = (void *) mb + CMDR_OFF + udev->cmdr_last_cleaned;
tcmu_flush_dcache_range(entry, sizeof(*entry));
if (tcmu_hdr_get_op(entry->hdr.len_op) == TCMU_OP_PAD) {
UPDATE_HEAD(udev->cmdr_last_cleaned,
tcmu_hdr_get_len(entry->hdr.len_op),
udev->cmdr_size);
continue;
}
WARN_ON(tcmu_hdr_get_op(entry->hdr.len_op) != TCMU_OP_CMD);
cmd = idr_remove(&udev->commands, entry->hdr.cmd_id);
if (!cmd) {
pr_err("cmd_id %u not found, ring is broken\n",
entry->hdr.cmd_id);
set_bit(TCMU_DEV_BIT_BROKEN, &udev->flags);
break;
}
tcmu_handle_completion(cmd, entry);
UPDATE_HEAD(udev->cmdr_last_cleaned,
tcmu_hdr_get_len(entry->hdr.len_op),
udev->cmdr_size);
handled++;
}
if (mb->cmd_tail == mb->cmd_head) {
/* no more pending commands */
del_timer(&udev->cmd_timer);
if (list_empty(&udev->qfull_queue)) {
/*
* no more pending or waiting commands so try to
* reclaim blocks if needed.
*/
if (atomic_read(&global_db_count) >
tcmu_global_max_blocks)
schedule_delayed_work(&tcmu_unmap_work, 0);
}
} else if (udev->cmd_time_out) {
tcmu_set_next_deadline(&udev->inflight_queue, &udev->cmd_timer);
}
return handled;
}
static int tcmu_check_expired_cmd(int id, void *p, void *data)
{
struct tcmu_cmd *cmd = p;
struct tcmu_dev *udev = cmd->tcmu_dev;
u8 scsi_status;
struct se_cmd *se_cmd;
bool is_running;
if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags))
return 0;
if (!time_after(jiffies, cmd->deadline))
return 0;
is_running = test_bit(TCMU_CMD_BIT_INFLIGHT, &cmd->flags);
se_cmd = cmd->se_cmd;
if (is_running) {
/*
* If cmd_time_out is disabled but qfull is set deadline
* will only reflect the qfull timeout. Ignore it.
*/
if (!udev->cmd_time_out)
return 0;
set_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags);
/*
* target_complete_cmd will translate this to LUN COMM FAILURE
*/
scsi_status = SAM_STAT_CHECK_CONDITION;
list_del_init(&cmd->queue_entry);
} else {
list_del_init(&cmd->queue_entry);
idr_remove(&udev->commands, id);
tcmu_free_cmd(cmd);
scsi_status = SAM_STAT_TASK_SET_FULL;
}
pr_debug("Timing out cmd %u on dev %s that is %s.\n",
id, udev->name, is_running ? "inflight" : "queued");
target_complete_cmd(se_cmd, scsi_status);
return 0;
}
static void tcmu_device_timedout(struct tcmu_dev *udev)
{
spin_lock(&timed_out_udevs_lock);
if (list_empty(&udev->timedout_entry))
list_add_tail(&udev->timedout_entry, &timed_out_udevs);
spin_unlock(&timed_out_udevs_lock);
schedule_delayed_work(&tcmu_unmap_work, 0);
}
static void tcmu_cmd_timedout(struct timer_list *t)
{
struct tcmu_dev *udev = from_timer(udev, t, cmd_timer);
pr_debug("%s cmd timeout has expired\n", udev->name);
tcmu_device_timedout(udev);
}
static void tcmu_qfull_timedout(struct timer_list *t)
{
struct tcmu_dev *udev = from_timer(udev, t, qfull_timer);
pr_debug("%s qfull timeout has expired\n", udev->name);
tcmu_device_timedout(udev);
}
static int tcmu_attach_hba(struct se_hba *hba, u32 host_id)
{
struct tcmu_hba *tcmu_hba;
tcmu_hba = kzalloc(sizeof(struct tcmu_hba), GFP_KERNEL);
if (!tcmu_hba)
return -ENOMEM;
tcmu_hba->host_id = host_id;
hba->hba_ptr = tcmu_hba;
return 0;
}
static void tcmu_detach_hba(struct se_hba *hba)
{
kfree(hba->hba_ptr);
hba->hba_ptr = NULL;
}
static struct se_device *tcmu_alloc_device(struct se_hba *hba, const char *name)
{
struct tcmu_dev *udev;
udev = kzalloc(sizeof(struct tcmu_dev), GFP_KERNEL);
if (!udev)
return NULL;
kref_init(&udev->kref);
udev->name = kstrdup(name, GFP_KERNEL);
if (!udev->name) {
kfree(udev);
return NULL;
}
udev->hba = hba;
udev->cmd_time_out = TCMU_TIME_OUT;
udev->qfull_time_out = -1;
udev->max_blocks = DATA_BLOCK_BITS_DEF;
mutex_init(&udev->cmdr_lock);
INIT_LIST_HEAD(&udev->node);
INIT_LIST_HEAD(&udev->timedout_entry);
INIT_LIST_HEAD(&udev->qfull_queue);
INIT_LIST_HEAD(&udev->inflight_queue);
idr_init(&udev->commands);
timer_setup(&udev->qfull_timer, tcmu_qfull_timedout, 0);
timer_setup(&udev->cmd_timer, tcmu_cmd_timedout, 0);
INIT_RADIX_TREE(&udev->data_blocks, GFP_KERNEL);
return &udev->se_dev;
}
static bool run_qfull_queue(struct tcmu_dev *udev, bool fail)
{
struct tcmu_cmd *tcmu_cmd, *tmp_cmd;
LIST_HEAD(cmds);
bool drained = true;
sense_reason_t scsi_ret;
int ret;
if (list_empty(&udev->qfull_queue))
return true;
pr_debug("running %s's cmdr queue forcefail %d\n", udev->name, fail);
list_splice_init(&udev->qfull_queue, &cmds);
list_for_each_entry_safe(tcmu_cmd, tmp_cmd, &cmds, queue_entry) {
list_del_init(&tcmu_cmd->queue_entry);
pr_debug("removing cmd %u on dev %s from queue\n",
tcmu_cmd->cmd_id, udev->name);
if (fail) {
idr_remove(&udev->commands, tcmu_cmd->cmd_id);
/*
* We were not able to even start the command, so
* fail with busy to allow a retry in case runner
* was only temporarily down. If the device is being
* removed then LIO core will do the right thing and
* fail the retry.
*/
target_complete_cmd(tcmu_cmd->se_cmd, SAM_STAT_BUSY);
tcmu_free_cmd(tcmu_cmd);
continue;
}
ret = queue_cmd_ring(tcmu_cmd, &scsi_ret);
if (ret < 0) {
pr_debug("cmd %u on dev %s failed with %u\n",
tcmu_cmd->cmd_id, udev->name, scsi_ret);
idr_remove(&udev->commands, tcmu_cmd->cmd_id);
/*
* Ignore scsi_ret for now. target_complete_cmd
* drops it.
*/
target_complete_cmd(tcmu_cmd->se_cmd,
SAM_STAT_CHECK_CONDITION);
tcmu_free_cmd(tcmu_cmd);
} else if (ret > 0) {
pr_debug("ran out of space during cmdr queue run\n");
/*
* cmd was requeued, so just put all cmds back in
* the queue
*/
list_splice_tail(&cmds, &udev->qfull_queue);
drained = false;
break;
}
}
tcmu_set_next_deadline(&udev->qfull_queue, &udev->qfull_timer);
return drained;
}
static int tcmu_irqcontrol(struct uio_info *info, s32 irq_on)
{
struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
mutex_lock(&udev->cmdr_lock);
tcmu_handle_completions(udev);
run_qfull_queue(udev, false);
mutex_unlock(&udev->cmdr_lock);
return 0;
}
/*
* mmap code from uio.c. Copied here because we want to hook mmap()
* and this stuff must come along.
*/
static int tcmu_find_mem_index(struct vm_area_struct *vma)
{
struct tcmu_dev *udev = vma->vm_private_data;
struct uio_info *info = &udev->uio_info;
if (vma->vm_pgoff < MAX_UIO_MAPS) {
if (info->mem[vma->vm_pgoff].size == 0)
return -1;
return (int)vma->vm_pgoff;
}
return -1;
}
static struct page *tcmu_try_get_block_page(struct tcmu_dev *udev, uint32_t dbi)
{
struct page *page;
mutex_lock(&udev->cmdr_lock);
page = tcmu_get_block_page(udev, dbi);
if (likely(page)) {
mutex_unlock(&udev->cmdr_lock);
return page;
}
/*
* Userspace messed up and passed in a address not in the
* data iov passed to it.
*/
pr_err("Invalid addr to data block mapping (dbi %u) on device %s\n",
dbi, udev->name);
page = NULL;
mutex_unlock(&udev->cmdr_lock);
return page;
}
static vm_fault_t tcmu_vma_fault(struct vm_fault *vmf)
{
struct tcmu_dev *udev = vmf->vma->vm_private_data;
struct uio_info *info = &udev->uio_info;
struct page *page;
unsigned long offset;
void *addr;
int mi = tcmu_find_mem_index(vmf->vma);
if (mi < 0)
return VM_FAULT_SIGBUS;
/*
* We need to subtract mi because userspace uses offset = N*PAGE_SIZE
* to use mem[N].
*/
offset = (vmf->pgoff - mi) << PAGE_SHIFT;
if (offset < udev->data_off) {
/* For the vmalloc()ed cmd area pages */
addr = (void *)(unsigned long)info->mem[mi].addr + offset;
page = vmalloc_to_page(addr);
} else {
uint32_t dbi;
/* For the dynamically growing data area pages */
dbi = (offset - udev->data_off) / DATA_BLOCK_SIZE;
page = tcmu_try_get_block_page(udev, dbi);
if (!page)
return VM_FAULT_SIGBUS;
}
get_page(page);
vmf->page = page;
return 0;
}
static const struct vm_operations_struct tcmu_vm_ops = {
.fault = tcmu_vma_fault,
};
static int tcmu_mmap(struct uio_info *info, struct vm_area_struct *vma)
{
struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
vma->vm_ops = &tcmu_vm_ops;
vma->vm_private_data = udev;
/* Ensure the mmap is exactly the right size */
if (vma_pages(vma) != (udev->ring_size >> PAGE_SHIFT))
return -EINVAL;
return 0;
}
static int tcmu_open(struct uio_info *info, struct inode *inode)
{
struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
/* O_EXCL not supported for char devs, so fake it? */
if (test_and_set_bit(TCMU_DEV_BIT_OPEN, &udev->flags))
return -EBUSY;
udev->inode = inode;
kref_get(&udev->kref);
pr_debug("open\n");
return 0;
}
static void tcmu_dev_call_rcu(struct rcu_head *p)
{
struct se_device *dev = container_of(p, struct se_device, rcu_head);
struct tcmu_dev *udev = TCMU_DEV(dev);
kfree(udev->uio_info.name);
kfree(udev->name);
kfree(udev);
}
static int tcmu_check_and_free_pending_cmd(struct tcmu_cmd *cmd)
{
if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags)) {
kmem_cache_free(tcmu_cmd_cache, cmd);
return 0;
}
return -EINVAL;
}
static void tcmu_blocks_release(struct radix_tree_root *blocks,
int start, int end)
{
int i;
struct page *page;
for (i = start; i < end; i++) {
page = radix_tree_delete(blocks, i);
if (page) {
__free_page(page);
atomic_dec(&global_db_count);
}
}
}
static void tcmu_dev_kref_release(struct kref *kref)
{
struct tcmu_dev *udev = container_of(kref, struct tcmu_dev, kref);
struct se_device *dev = &udev->se_dev;
struct tcmu_cmd *cmd;
bool all_expired = true;
int i;
vfree(udev->mb_addr);
udev->mb_addr = NULL;
spin_lock_bh(&timed_out_udevs_lock);
if (!list_empty(&udev->timedout_entry))
list_del(&udev->timedout_entry);
spin_unlock_bh(&timed_out_udevs_lock);
/* Upper layer should drain all requests before calling this */
mutex_lock(&udev->cmdr_lock);
idr_for_each_entry(&udev->commands, cmd, i) {
if (tcmu_check_and_free_pending_cmd(cmd) != 0)
all_expired = false;
}
idr_destroy(&udev->commands);
WARN_ON(!all_expired);
tcmu_blocks_release(&udev->data_blocks, 0, udev->dbi_max + 1);
bitmap_free(udev->data_bitmap);
mutex_unlock(&udev->cmdr_lock);
call_rcu(&dev->rcu_head, tcmu_dev_call_rcu);
}
static int tcmu_release(struct uio_info *info, struct inode *inode)
{
struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
clear_bit(TCMU_DEV_BIT_OPEN, &udev->flags);
pr_debug("close\n");
/* release ref from open */
kref_put(&udev->kref, tcmu_dev_kref_release);
return 0;
}
static int tcmu_init_genl_cmd_reply(struct tcmu_dev *udev, int cmd)
{
struct tcmu_nl_cmd *nl_cmd = &udev->curr_nl_cmd;
if (!tcmu_kern_cmd_reply_supported)
return 0;
if (udev->nl_reply_supported <= 0)
return 0;
mutex_lock(&tcmu_nl_cmd_mutex);
if (tcmu_netlink_blocked) {
mutex_unlock(&tcmu_nl_cmd_mutex);
pr_warn("Failing nl cmd %d on %s. Interface is blocked.\n", cmd,
udev->name);
return -EAGAIN;
}
if (nl_cmd->cmd != TCMU_CMD_UNSPEC) {
mutex_unlock(&tcmu_nl_cmd_mutex);
pr_warn("netlink cmd %d already executing on %s\n",
nl_cmd->cmd, udev->name);
return -EBUSY;
}
memset(nl_cmd, 0, sizeof(*nl_cmd));
nl_cmd->cmd = cmd;
nl_cmd->udev = udev;
init_completion(&nl_cmd->complete);
INIT_LIST_HEAD(&nl_cmd->nl_list);
list_add_tail(&nl_cmd->nl_list, &tcmu_nl_cmd_list);
mutex_unlock(&tcmu_nl_cmd_mutex);
return 0;
}
static int tcmu_wait_genl_cmd_reply(struct tcmu_dev *udev)
{
struct tcmu_nl_cmd *nl_cmd = &udev->curr_nl_cmd;
int ret;
if (!tcmu_kern_cmd_reply_supported)
return 0;
if (udev->nl_reply_supported <= 0)
return 0;
pr_debug("sleeping for nl reply\n");
wait_for_completion(&nl_cmd->complete);
mutex_lock(&tcmu_nl_cmd_mutex);
nl_cmd->cmd = TCMU_CMD_UNSPEC;
ret = nl_cmd->status;
mutex_unlock(&tcmu_nl_cmd_mutex);
return ret;
}
static int tcmu_netlink_event_init(struct tcmu_dev *udev,
enum tcmu_genl_cmd cmd,
struct sk_buff **buf, void **hdr)
{
struct sk_buff *skb;
void *msg_header;
int ret = -ENOMEM;
skb = genlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
if (!skb)
return ret;
msg_header = genlmsg_put(skb, 0, 0, &tcmu_genl_family, 0, cmd);
if (!msg_header)
goto free_skb;
ret = nla_put_string(skb, TCMU_ATTR_DEVICE, udev->uio_info.name);
if (ret < 0)
goto free_skb;
ret = nla_put_u32(skb, TCMU_ATTR_MINOR, udev->uio_info.uio_dev->minor);
if (ret < 0)
goto free_skb;
ret = nla_put_u32(skb, TCMU_ATTR_DEVICE_ID, udev->se_dev.dev_index);
if (ret < 0)
goto free_skb;
*buf = skb;
*hdr = msg_header;
return ret;
free_skb:
nlmsg_free(skb);
return ret;
}
static int tcmu_netlink_event_send(struct tcmu_dev *udev,
enum tcmu_genl_cmd cmd,
struct sk_buff *skb, void *msg_header)
{
int ret;
genlmsg_end(skb, msg_header);
ret = tcmu_init_genl_cmd_reply(udev, cmd);
if (ret) {
nlmsg_free(skb);
return ret;
}
ret = genlmsg_multicast_allns(&tcmu_genl_family, skb, 0,
TCMU_MCGRP_CONFIG, GFP_KERNEL);
/* Wait during an add as the listener may not be up yet */
if (ret == 0 ||
(ret == -ESRCH && cmd == TCMU_CMD_ADDED_DEVICE))
return tcmu_wait_genl_cmd_reply(udev);
return ret;
}
static int tcmu_send_dev_add_event(struct tcmu_dev *udev)
{
struct sk_buff *skb = NULL;
void *msg_header = NULL;
int ret = 0;
ret = tcmu_netlink_event_init(udev, TCMU_CMD_ADDED_DEVICE, &skb,
&msg_header);
if (ret < 0)
return ret;
return tcmu_netlink_event_send(udev, TCMU_CMD_ADDED_DEVICE, skb,
msg_header);
}
static int tcmu_send_dev_remove_event(struct tcmu_dev *udev)
{
struct sk_buff *skb = NULL;
void *msg_header = NULL;
int ret = 0;
ret = tcmu_netlink_event_init(udev, TCMU_CMD_REMOVED_DEVICE,
&skb, &msg_header);
if (ret < 0)
return ret;
return tcmu_netlink_event_send(udev, TCMU_CMD_REMOVED_DEVICE,
skb, msg_header);
}
static int tcmu_update_uio_info(struct tcmu_dev *udev)
{
struct tcmu_hba *hba = udev->hba->hba_ptr;
struct uio_info *info;
size_t size, used;
char *str;
info = &udev->uio_info;
size = snprintf(NULL, 0, "tcm-user/%u/%s/%s", hba->host_id, udev->name,
udev->dev_config);
size += 1; /* for \0 */
str = kmalloc(size, GFP_KERNEL);
if (!str)
return -ENOMEM;
used = snprintf(str, size, "tcm-user/%u/%s", hba->host_id, udev->name);
if (udev->dev_config[0])
snprintf(str + used, size - used, "/%s", udev->dev_config);
/* If the old string exists, free it */
kfree(info->name);
info->name = str;
return 0;
}
static int tcmu_configure_device(struct se_device *dev)
{
struct tcmu_dev *udev = TCMU_DEV(dev);
struct uio_info *info;
struct tcmu_mailbox *mb;
int ret = 0;
ret = tcmu_update_uio_info(udev);
if (ret)
return ret;
info = &udev->uio_info;
mutex_lock(&udev->cmdr_lock);
udev->data_bitmap = bitmap_zalloc(udev->max_blocks, GFP_KERNEL);
mutex_unlock(&udev->cmdr_lock);
if (!udev->data_bitmap) {
ret = -ENOMEM;
goto err_bitmap_alloc;
}
udev->mb_addr = vzalloc(CMDR_SIZE);
if (!udev->mb_addr) {
ret = -ENOMEM;
goto err_vzalloc;
}
/* mailbox fits in first part of CMDR space */
udev->cmdr_size = CMDR_SIZE - CMDR_OFF;
udev->data_off = CMDR_SIZE;
udev->data_size = udev->max_blocks * DATA_BLOCK_SIZE;
udev->dbi_thresh = 0; /* Default in Idle state */
/* Initialise the mailbox of the ring buffer */
mb = udev->mb_addr;
mb->version = TCMU_MAILBOX_VERSION;
mb->flags = TCMU_MAILBOX_FLAG_CAP_OOOC | TCMU_MAILBOX_FLAG_CAP_READ_LEN;
mb->cmdr_off = CMDR_OFF;
mb->cmdr_size = udev->cmdr_size;
WARN_ON(!PAGE_ALIGNED(udev->data_off));
WARN_ON(udev->data_size % PAGE_SIZE);
WARN_ON(udev->data_size % DATA_BLOCK_SIZE);
info->version = __stringify(TCMU_MAILBOX_VERSION);
info->mem[0].name = "tcm-user command & data buffer";
info->mem[0].addr = (phys_addr_t)(uintptr_t)udev->mb_addr;
info->mem[0].size = udev->ring_size = udev->data_size + CMDR_SIZE;
info->mem[0].memtype = UIO_MEM_NONE;
info->irqcontrol = tcmu_irqcontrol;
info->irq = UIO_IRQ_CUSTOM;
info->mmap = tcmu_mmap;
info->open = tcmu_open;
info->release = tcmu_release;
ret = uio_register_device(tcmu_root_device, info);
if (ret)
goto err_register;
/* User can set hw_block_size before enable the device */
if (dev->dev_attrib.hw_block_size == 0)
dev->dev_attrib.hw_block_size = 512;
/* Other attributes can be configured in userspace */
if (!dev->dev_attrib.hw_max_sectors)
dev->dev_attrib.hw_max_sectors = 128;
if (!dev->dev_attrib.emulate_write_cache)
dev->dev_attrib.emulate_write_cache = 0;
dev->dev_attrib.hw_queue_depth = 128;
/* If user didn't explicitly disable netlink reply support, use
* module scope setting.
*/
if (udev->nl_reply_supported >= 0)
udev->nl_reply_supported = tcmu_kern_cmd_reply_supported;
/*
* Get a ref incase userspace does a close on the uio device before
* LIO has initiated tcmu_free_device.
*/
kref_get(&udev->kref);
ret = tcmu_send_dev_add_event(udev);
if (ret)
goto err_netlink;
mutex_lock(&root_udev_mutex);
list_add(&udev->node, &root_udev);
mutex_unlock(&root_udev_mutex);
return 0;
err_netlink:
kref_put(&udev->kref, tcmu_dev_kref_release);
uio_unregister_device(&udev->uio_info);
err_register:
vfree(udev->mb_addr);
udev->mb_addr = NULL;
err_vzalloc:
bitmap_free(udev->data_bitmap);
udev->data_bitmap = NULL;
err_bitmap_alloc:
kfree(info->name);
info->name = NULL;
return ret;
}
static void tcmu_free_device(struct se_device *dev)
{
struct tcmu_dev *udev = TCMU_DEV(dev);
/* release ref from init */
kref_put(&udev->kref, tcmu_dev_kref_release);
}
static void tcmu_destroy_device(struct se_device *dev)
{
struct tcmu_dev *udev = TCMU_DEV(dev);
del_timer_sync(&udev->cmd_timer);
del_timer_sync(&udev->qfull_timer);
mutex_lock(&root_udev_mutex);
list_del(&udev->node);
mutex_unlock(&root_udev_mutex);
tcmu_send_dev_remove_event(udev);
uio_unregister_device(&udev->uio_info);
/* release ref from configure */
kref_put(&udev->kref, tcmu_dev_kref_release);
}
static void tcmu_unblock_dev(struct tcmu_dev *udev)
{
mutex_lock(&udev->cmdr_lock);
clear_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags);
mutex_unlock(&udev->cmdr_lock);
}
static void tcmu_block_dev(struct tcmu_dev *udev)
{
mutex_lock(&udev->cmdr_lock);
if (test_and_set_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags))
goto unlock;
/* complete IO that has executed successfully */
tcmu_handle_completions(udev);
/* fail IO waiting to be queued */
run_qfull_queue(udev, true);
unlock:
mutex_unlock(&udev->cmdr_lock);
}
static void tcmu_reset_ring(struct tcmu_dev *udev, u8 err_level)
{
struct tcmu_mailbox *mb;
struct tcmu_cmd *cmd;
int i;
mutex_lock(&udev->cmdr_lock);
idr_for_each_entry(&udev->commands, cmd, i) {
if (!test_bit(TCMU_CMD_BIT_INFLIGHT, &cmd->flags))
continue;
pr_debug("removing cmd %u on dev %s from ring (is expired %d)\n",
cmd->cmd_id, udev->name,
test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags));
idr_remove(&udev->commands, i);
if (!test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags)) {
list_del_init(&cmd->queue_entry);
if (err_level == 1) {
/*
* Userspace was not able to start the
* command or it is retryable.
*/
target_complete_cmd(cmd->se_cmd, SAM_STAT_BUSY);
} else {
/* hard failure */
target_complete_cmd(cmd->se_cmd,
SAM_STAT_CHECK_CONDITION);
}
}
tcmu_cmd_free_data(cmd, cmd->dbi_cnt);
tcmu_free_cmd(cmd);
}
mb = udev->mb_addr;
tcmu_flush_dcache_range(mb, sizeof(*mb));
pr_debug("mb last %u head %u tail %u\n", udev->cmdr_last_cleaned,
mb->cmd_tail, mb->cmd_head);
udev->cmdr_last_cleaned = 0;
mb->cmd_tail = 0;
mb->cmd_head = 0;
tcmu_flush_dcache_range(mb, sizeof(*mb));
del_timer(&udev->cmd_timer);
mutex_unlock(&udev->cmdr_lock);
}
enum {
Opt_dev_config, Opt_dev_size, Opt_hw_block_size, Opt_hw_max_sectors,
Opt_nl_reply_supported, Opt_max_data_area_mb, Opt_err,
};
static match_table_t tokens = {
{Opt_dev_config, "dev_config=%s"},
{Opt_dev_size, "dev_size=%s"},
{Opt_hw_block_size, "hw_block_size=%d"},
{Opt_hw_max_sectors, "hw_max_sectors=%d"},
{Opt_nl_reply_supported, "nl_reply_supported=%d"},
{Opt_max_data_area_mb, "max_data_area_mb=%d"},
{Opt_err, NULL}
};
static int tcmu_set_dev_attrib(substring_t *arg, u32 *dev_attrib)
{
int val, ret;
ret = match_int(arg, &val);
if (ret < 0) {
pr_err("match_int() failed for dev attrib. Error %d.\n",
ret);
return ret;
}
if (val <= 0) {
pr_err("Invalid dev attrib value %d. Must be greater than zero.\n",
val);
return -EINVAL;
}
*dev_attrib = val;
return 0;
}
static int tcmu_set_max_blocks_param(struct tcmu_dev *udev, substring_t *arg)
{
int val, ret;
ret = match_int(arg, &val);
if (ret < 0) {
pr_err("match_int() failed for max_data_area_mb=. Error %d.\n",
ret);
return ret;
}
if (val <= 0) {
pr_err("Invalid max_data_area %d.\n", val);
return -EINVAL;
}
mutex_lock(&udev->cmdr_lock);
if (udev->data_bitmap) {
pr_err("Cannot set max_data_area_mb after it has been enabled.\n");
ret = -EINVAL;
goto unlock;
}
udev->max_blocks = TCMU_MBS_TO_BLOCKS(val);
if (udev->max_blocks > tcmu_global_max_blocks) {
pr_err("%d is too large. Adjusting max_data_area_mb to global limit of %u\n",
val, TCMU_BLOCKS_TO_MBS(tcmu_global_max_blocks));
udev->max_blocks = tcmu_global_max_blocks;
}
unlock:
mutex_unlock(&udev->cmdr_lock);
return ret;
}
static ssize_t tcmu_set_configfs_dev_params(struct se_device *dev,
const char *page, ssize_t count)
{
struct tcmu_dev *udev = TCMU_DEV(dev);
char *orig, *ptr, *opts;
substring_t args[MAX_OPT_ARGS];
int ret = 0, token;
opts = kstrdup(page, GFP_KERNEL);
if (!opts)
return -ENOMEM;
orig = opts;
while ((ptr = strsep(&opts, ",\n")) != NULL) {
if (!*ptr)
continue;
token = match_token(ptr, tokens, args);
switch (token) {
case Opt_dev_config:
if (match_strlcpy(udev->dev_config, &args[0],
TCMU_CONFIG_LEN) == 0) {
ret = -EINVAL;
break;
}
pr_debug("TCMU: Referencing Path: %s\n", udev->dev_config);
break;
case Opt_dev_size:
ret = match_u64(&args[0], &udev->dev_size);
if (ret < 0)
pr_err("match_u64() failed for dev_size=. Error %d.\n",
ret);
break;
case Opt_hw_block_size:
ret = tcmu_set_dev_attrib(&args[0],
&(dev->dev_attrib.hw_block_size));
break;
case Opt_hw_max_sectors:
ret = tcmu_set_dev_attrib(&args[0],
&(dev->dev_attrib.hw_max_sectors));
break;
case Opt_nl_reply_supported:
ret = match_int(&args[0], &udev->nl_reply_supported);
if (ret < 0)
pr_err("match_int() failed for nl_reply_supported=. Error %d.\n",
ret);
break;
case Opt_max_data_area_mb:
ret = tcmu_set_max_blocks_param(udev, &args[0]);
break;
default:
break;
}
if (ret)
break;
}
kfree(orig);
return (!ret) ? count : ret;
}
static ssize_t tcmu_show_configfs_dev_params(struct se_device *dev, char *b)
{
struct tcmu_dev *udev = TCMU_DEV(dev);
ssize_t bl = 0;
bl = sprintf(b + bl, "Config: %s ",
udev->dev_config[0] ? udev->dev_config : "NULL");
bl += sprintf(b + bl, "Size: %llu ", udev->dev_size);
bl += sprintf(b + bl, "MaxDataAreaMB: %u\n",
TCMU_BLOCKS_TO_MBS(udev->max_blocks));
return bl;
}
static sector_t tcmu_get_blocks(struct se_device *dev)
{
struct tcmu_dev *udev = TCMU_DEV(dev);
return div_u64(udev->dev_size - dev->dev_attrib.block_size,
dev->dev_attrib.block_size);
}
static sense_reason_t
tcmu_parse_cdb(struct se_cmd *cmd)
{
return passthrough_parse_cdb(cmd, tcmu_queue_cmd);
}
static ssize_t tcmu_cmd_time_out_show(struct config_item *item, char *page)
{
struct se_dev_attrib *da = container_of(to_config_group(item),
struct se_dev_attrib, da_group);
struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
return snprintf(page, PAGE_SIZE, "%lu\n", udev->cmd_time_out / MSEC_PER_SEC);
}
static ssize_t tcmu_cmd_time_out_store(struct config_item *item, const char *page,
size_t count)
{
struct se_dev_attrib *da = container_of(to_config_group(item),
struct se_dev_attrib, da_group);
struct tcmu_dev *udev = container_of(da->da_dev,
struct tcmu_dev, se_dev);
u32 val;
int ret;
if (da->da_dev->export_count) {
pr_err("Unable to set tcmu cmd_time_out while exports exist\n");
return -EINVAL;
}
ret = kstrtou32(page, 0, &val);
if (ret < 0)
return ret;
udev->cmd_time_out = val * MSEC_PER_SEC;
return count;
}
CONFIGFS_ATTR(tcmu_, cmd_time_out);
static ssize_t tcmu_qfull_time_out_show(struct config_item *item, char *page)
{
struct se_dev_attrib *da = container_of(to_config_group(item),
struct se_dev_attrib, da_group);
struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
return snprintf(page, PAGE_SIZE, "%ld\n", udev->qfull_time_out <= 0 ?
udev->qfull_time_out :
udev->qfull_time_out / MSEC_PER_SEC);
}
static ssize_t tcmu_qfull_time_out_store(struct config_item *item,
const char *page, size_t count)
{
struct se_dev_attrib *da = container_of(to_config_group(item),
struct se_dev_attrib, da_group);
struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
s32 val;
int ret;
ret = kstrtos32(page, 0, &val);
if (ret < 0)
return ret;
if (val >= 0) {
udev->qfull_time_out = val * MSEC_PER_SEC;
} else if (val == -1) {
udev->qfull_time_out = val;
} else {
printk(KERN_ERR "Invalid qfull timeout value %d\n", val);
return -EINVAL;
}
return count;
}
CONFIGFS_ATTR(tcmu_, qfull_time_out);
static ssize_t tcmu_max_data_area_mb_show(struct config_item *item, char *page)
{
struct se_dev_attrib *da = container_of(to_config_group(item),
struct se_dev_attrib, da_group);
struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
return snprintf(page, PAGE_SIZE, "%u\n",
TCMU_BLOCKS_TO_MBS(udev->max_blocks));
}
CONFIGFS_ATTR_RO(tcmu_, max_data_area_mb);
static ssize_t tcmu_dev_config_show(struct config_item *item, char *page)
{
struct se_dev_attrib *da = container_of(to_config_group(item),
struct se_dev_attrib, da_group);
struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
return snprintf(page, PAGE_SIZE, "%s\n", udev->dev_config);
}
static int tcmu_send_dev_config_event(struct tcmu_dev *udev,
const char *reconfig_data)
{
struct sk_buff *skb = NULL;
void *msg_header = NULL;
int ret = 0;
ret = tcmu_netlink_event_init(udev, TCMU_CMD_RECONFIG_DEVICE,
&skb, &msg_header);
if (ret < 0)
return ret;
ret = nla_put_string(skb, TCMU_ATTR_DEV_CFG, reconfig_data);
if (ret < 0) {
nlmsg_free(skb);
return ret;
}
return tcmu_netlink_event_send(udev, TCMU_CMD_RECONFIG_DEVICE,
skb, msg_header);
}
static ssize_t tcmu_dev_config_store(struct config_item *item, const char *page,
size_t count)
{
struct se_dev_attrib *da = container_of(to_config_group(item),
struct se_dev_attrib, da_group);
struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
int ret, len;
len = strlen(page);
if (!len || len > TCMU_CONFIG_LEN - 1)
return -EINVAL;
/* Check if device has been configured before */
if (target_dev_configured(&udev->se_dev)) {
ret = tcmu_send_dev_config_event(udev, page);
if (ret) {
pr_err("Unable to reconfigure device\n");
return ret;
}
strlcpy(udev->dev_config, page, TCMU_CONFIG_LEN);
ret = tcmu_update_uio_info(udev);
if (ret)
return ret;
return count;
}
strlcpy(udev->dev_config, page, TCMU_CONFIG_LEN);
return count;
}
CONFIGFS_ATTR(tcmu_, dev_config);
static ssize_t tcmu_dev_size_show(struct config_item *item, char *page)
{
struct se_dev_attrib *da = container_of(to_config_group(item),
struct se_dev_attrib, da_group);
struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
return snprintf(page, PAGE_SIZE, "%llu\n", udev->dev_size);
}
static int tcmu_send_dev_size_event(struct tcmu_dev *udev, u64 size)
{
struct sk_buff *skb = NULL;
void *msg_header = NULL;
int ret = 0;
ret = tcmu_netlink_event_init(udev, TCMU_CMD_RECONFIG_DEVICE,
&skb, &msg_header);
if (ret < 0)
return ret;
ret = nla_put_u64_64bit(skb, TCMU_ATTR_DEV_SIZE,
size, TCMU_ATTR_PAD);
if (ret < 0) {
nlmsg_free(skb);
return ret;
}
return tcmu_netlink_event_send(udev, TCMU_CMD_RECONFIG_DEVICE,
skb, msg_header);
}
static ssize_t tcmu_dev_size_store(struct config_item *item, const char *page,
size_t count)
{
struct se_dev_attrib *da = container_of(to_config_group(item),
struct se_dev_attrib, da_group);
struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
u64 val;
int ret;
ret = kstrtou64(page, 0, &val);
if (ret < 0)
return ret;
/* Check if device has been configured before */
if (target_dev_configured(&udev->se_dev)) {
ret = tcmu_send_dev_size_event(udev, val);
if (ret) {
pr_err("Unable to reconfigure device\n");
return ret;
}
}
udev->dev_size = val;
return count;
}
CONFIGFS_ATTR(tcmu_, dev_size);
static ssize_t tcmu_nl_reply_supported_show(struct config_item *item,
char *page)
{
struct se_dev_attrib *da = container_of(to_config_group(item),
struct se_dev_attrib, da_group);
struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
return snprintf(page, PAGE_SIZE, "%d\n", udev->nl_reply_supported);
}
static ssize_t tcmu_nl_reply_supported_store(struct config_item *item,
const char *page, size_t count)
{
struct se_dev_attrib *da = container_of(to_config_group(item),
struct se_dev_attrib, da_group);
struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
s8 val;
int ret;
ret = kstrtos8(page, 0, &val);
if (ret < 0)
return ret;
udev->nl_reply_supported = val;
return count;
}
CONFIGFS_ATTR(tcmu_, nl_reply_supported);
static ssize_t tcmu_emulate_write_cache_show(struct config_item *item,
char *page)
{
struct se_dev_attrib *da = container_of(to_config_group(item),
struct se_dev_attrib, da_group);
return snprintf(page, PAGE_SIZE, "%i\n", da->emulate_write_cache);
}
static int tcmu_send_emulate_write_cache(struct tcmu_dev *udev, u8 val)
{
struct sk_buff *skb = NULL;
void *msg_header = NULL;
int ret = 0;
ret = tcmu_netlink_event_init(udev, TCMU_CMD_RECONFIG_DEVICE,
&skb, &msg_header);
if (ret < 0)
return ret;
ret = nla_put_u8(skb, TCMU_ATTR_WRITECACHE, val);
if (ret < 0) {
nlmsg_free(skb);
return ret;
}
return tcmu_netlink_event_send(udev, TCMU_CMD_RECONFIG_DEVICE,
skb, msg_header);
}
static ssize_t tcmu_emulate_write_cache_store(struct config_item *item,
const char *page, size_t count)
{
struct se_dev_attrib *da = container_of(to_config_group(item),
struct se_dev_attrib, da_group);
struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
u8 val;
int ret;
ret = kstrtou8(page, 0, &val);
if (ret < 0)
return ret;
/* Check if device has been configured before */
if (target_dev_configured(&udev->se_dev)) {
ret = tcmu_send_emulate_write_cache(udev, val);
if (ret) {
pr_err("Unable to reconfigure device\n");
return ret;
}
}
da->emulate_write_cache = val;
return count;
}
CONFIGFS_ATTR(tcmu_, emulate_write_cache);
static ssize_t tcmu_block_dev_show(struct config_item *item, char *page)
{
struct se_device *se_dev = container_of(to_config_group(item),
struct se_device,
dev_action_group);
struct tcmu_dev *udev = TCMU_DEV(se_dev);
if (test_bit(TCMU_DEV_BIT_BLOCKED, &udev->flags))
return snprintf(page, PAGE_SIZE, "%s\n", "blocked");
else
return snprintf(page, PAGE_SIZE, "%s\n", "unblocked");
}
static ssize_t tcmu_block_dev_store(struct config_item *item, const char *page,
size_t count)
{
struct se_device *se_dev = container_of(to_config_group(item),
struct se_device,
dev_action_group);
struct tcmu_dev *udev = TCMU_DEV(se_dev);
u8 val;
int ret;
if (!target_dev_configured(&udev->se_dev)) {
pr_err("Device is not configured.\n");
return -EINVAL;
}
ret = kstrtou8(page, 0, &val);
if (ret < 0)
return ret;
if (val > 1) {
pr_err("Invalid block value %d\n", val);
return -EINVAL;
}
if (!val)
tcmu_unblock_dev(udev);
else
tcmu_block_dev(udev);
return count;
}
CONFIGFS_ATTR(tcmu_, block_dev);
static ssize_t tcmu_reset_ring_store(struct config_item *item, const char *page,
size_t count)
{
struct se_device *se_dev = container_of(to_config_group(item),
struct se_device,
dev_action_group);
struct tcmu_dev *udev = TCMU_DEV(se_dev);
u8 val;
int ret;
if (!target_dev_configured(&udev->se_dev)) {
pr_err("Device is not configured.\n");
return -EINVAL;
}
ret = kstrtou8(page, 0, &val);
if (ret < 0)
return ret;
if (val != 1 && val != 2) {
pr_err("Invalid reset ring value %d\n", val);
return -EINVAL;
}
tcmu_reset_ring(udev, val);
return count;
}
CONFIGFS_ATTR_WO(tcmu_, reset_ring);
static struct configfs_attribute *tcmu_attrib_attrs[] = {
&tcmu_attr_cmd_time_out,
&tcmu_attr_qfull_time_out,
&tcmu_attr_max_data_area_mb,
&tcmu_attr_dev_config,
&tcmu_attr_dev_size,
&tcmu_attr_emulate_write_cache,
&tcmu_attr_nl_reply_supported,
NULL,
};
static struct configfs_attribute **tcmu_attrs;
static struct configfs_attribute *tcmu_action_attrs[] = {
&tcmu_attr_block_dev,
&tcmu_attr_reset_ring,
NULL,
};
static struct target_backend_ops tcmu_ops = {
.name = "user",
.owner = THIS_MODULE,
.transport_flags = TRANSPORT_FLAG_PASSTHROUGH,
.attach_hba = tcmu_attach_hba,
.detach_hba = tcmu_detach_hba,
.alloc_device = tcmu_alloc_device,
.configure_device = tcmu_configure_device,
.destroy_device = tcmu_destroy_device,
.free_device = tcmu_free_device,
.parse_cdb = tcmu_parse_cdb,
.set_configfs_dev_params = tcmu_set_configfs_dev_params,
.show_configfs_dev_params = tcmu_show_configfs_dev_params,
.get_device_type = sbc_get_device_type,
.get_blocks = tcmu_get_blocks,
.tb_dev_action_attrs = tcmu_action_attrs,
};
static void find_free_blocks(void)
{
struct tcmu_dev *udev;
loff_t off;
u32 start, end, block, total_freed = 0;
if (atomic_read(&global_db_count) <= tcmu_global_max_blocks)
return;
mutex_lock(&root_udev_mutex);
list_for_each_entry(udev, &root_udev, node) {
mutex_lock(&udev->cmdr_lock);
if (!target_dev_configured(&udev->se_dev)) {
mutex_unlock(&udev->cmdr_lock);
continue;
}
/* Try to complete the finished commands first */
tcmu_handle_completions(udev);
/* Skip the udevs in idle */
if (!udev->dbi_thresh) {
mutex_unlock(&udev->cmdr_lock);
continue;
}
end = udev->dbi_max + 1;
block = find_last_bit(udev->data_bitmap, end);
if (block == udev->dbi_max) {
/*
* The last bit is dbi_max, so it is not possible
* reclaim any blocks.
*/
mutex_unlock(&udev->cmdr_lock);
continue;
} else if (block == end) {
/* The current udev will goto idle state */
udev->dbi_thresh = start = 0;
udev->dbi_max = 0;
} else {
udev->dbi_thresh = start = block + 1;
udev->dbi_max = block;
}
/* Here will truncate the data area from off */
off = udev->data_off + start * DATA_BLOCK_SIZE;
unmap_mapping_range(udev->inode->i_mapping, off, 0, 1);
/* Release the block pages */
tcmu_blocks_release(&udev->data_blocks, start, end);
mutex_unlock(&udev->cmdr_lock);
total_freed += end - start;
pr_debug("Freed %u blocks (total %u) from %s.\n", end - start,
total_freed, udev->name);
}
mutex_unlock(&root_udev_mutex);
if (atomic_read(&global_db_count) > tcmu_global_max_blocks)
schedule_delayed_work(&tcmu_unmap_work, msecs_to_jiffies(5000));
}
static void check_timedout_devices(void)
{
struct tcmu_dev *udev, *tmp_dev;
LIST_HEAD(devs);
spin_lock_bh(&timed_out_udevs_lock);
list_splice_init(&timed_out_udevs, &devs);
list_for_each_entry_safe(udev, tmp_dev, &devs, timedout_entry) {
list_del_init(&udev->timedout_entry);
spin_unlock_bh(&timed_out_udevs_lock);
mutex_lock(&udev->cmdr_lock);
idr_for_each(&udev->commands, tcmu_check_expired_cmd, NULL);
tcmu_set_next_deadline(&udev->inflight_queue, &udev->cmd_timer);
tcmu_set_next_deadline(&udev->qfull_queue, &udev->qfull_timer);
mutex_unlock(&udev->cmdr_lock);
spin_lock_bh(&timed_out_udevs_lock);
}
spin_unlock_bh(&timed_out_udevs_lock);
}
static void tcmu_unmap_work_fn(struct work_struct *work)
{
check_timedout_devices();
find_free_blocks();
}
static int __init tcmu_module_init(void)
{
int ret, i, k, len = 0;
BUILD_BUG_ON((sizeof(struct tcmu_cmd_entry) % TCMU_OP_ALIGN_SIZE) != 0);
INIT_DELAYED_WORK(&tcmu_unmap_work, tcmu_unmap_work_fn);
tcmu_cmd_cache = kmem_cache_create("tcmu_cmd_cache",
sizeof(struct tcmu_cmd),
__alignof__(struct tcmu_cmd),
0, NULL);
if (!tcmu_cmd_cache)
return -ENOMEM;
tcmu_root_device = root_device_register("tcm_user");
if (IS_ERR(tcmu_root_device)) {
ret = PTR_ERR(tcmu_root_device);
goto out_free_cache;
}
ret = genl_register_family(&tcmu_genl_family);
if (ret < 0) {
goto out_unreg_device;
}
for (i = 0; passthrough_attrib_attrs[i] != NULL; i++) {
len += sizeof(struct configfs_attribute *);
}
for (i = 0; tcmu_attrib_attrs[i] != NULL; i++) {
len += sizeof(struct configfs_attribute *);
}
len += sizeof(struct configfs_attribute *);
tcmu_attrs = kzalloc(len, GFP_KERNEL);
if (!tcmu_attrs) {
ret = -ENOMEM;
goto out_unreg_genl;
}
for (i = 0; passthrough_attrib_attrs[i] != NULL; i++) {
tcmu_attrs[i] = passthrough_attrib_attrs[i];
}
for (k = 0; tcmu_attrib_attrs[k] != NULL; k++) {
tcmu_attrs[i] = tcmu_attrib_attrs[k];
i++;
}
tcmu_ops.tb_dev_attrib_attrs = tcmu_attrs;
ret = transport_backend_register(&tcmu_ops);
if (ret)
goto out_attrs;
return 0;
out_attrs:
kfree(tcmu_attrs);
out_unreg_genl:
genl_unregister_family(&tcmu_genl_family);
out_unreg_device:
root_device_unregister(tcmu_root_device);
out_free_cache:
kmem_cache_destroy(tcmu_cmd_cache);
return ret;
}
static void __exit tcmu_module_exit(void)
{
cancel_delayed_work_sync(&tcmu_unmap_work);
target_backend_unregister(&tcmu_ops);
kfree(tcmu_attrs);
genl_unregister_family(&tcmu_genl_family);
root_device_unregister(tcmu_root_device);
kmem_cache_destroy(tcmu_cmd_cache);
}
MODULE_DESCRIPTION("TCM USER subsystem plugin");
MODULE_AUTHOR("Shaohua Li <shli@kernel.org>");
MODULE_AUTHOR("Andy Grover <agrover@redhat.com>");
MODULE_LICENSE("GPL");
module_init(tcmu_module_init);
module_exit(tcmu_module_exit);
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