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![Bryant G. Ly](/assets/img/avatar_default.png)
This gives tcmu the ability to handle events that can cause reconfiguration, such as resize, path changes, write_cache, etc... Signed-off-by: Bryant G. Ly <bryantly@linux.vnet.ibm.com> Reviewed-By: Mike Christie <mchristi@redhat.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
1772 lines
44 KiB
C
1772 lines
44 KiB
C
/*
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* Copyright (C) 2013 Shaohua Li <shli@kernel.org>
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* Copyright (C) 2014 Red Hat, Inc.
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* Copyright (C) 2015 Arrikto, Inc.
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* Copyright (C) 2017 Chinamobile, Inc.
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms and conditions of the GNU General Public License,
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* version 2, as published by the Free Software Foundation.
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*
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* This program is distributed in the hope it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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* more details.
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*
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* You should have received a copy of the GNU General Public License along with
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* this program; if not, write to the Free Software Foundation, Inc.,
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* 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
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*/
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#include <linux/spinlock.h>
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#include <linux/module.h>
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#include <linux/idr.h>
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#include <linux/kernel.h>
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#include <linux/timer.h>
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#include <linux/parser.h>
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#include <linux/vmalloc.h>
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#include <linux/uio_driver.h>
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#include <linux/radix-tree.h>
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#include <linux/stringify.h>
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#include <linux/bitops.h>
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#include <linux/highmem.h>
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#include <linux/configfs.h>
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#include <linux/mutex.h>
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#include <linux/kthread.h>
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#include <net/genetlink.h>
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#include <scsi/scsi_common.h>
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#include <scsi/scsi_proto.h>
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#include <target/target_core_base.h>
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#include <target/target_core_fabric.h>
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#include <target/target_core_backend.h>
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#include <linux/target_core_user.h>
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/*
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* Define a shared-memory interface for LIO to pass SCSI commands and
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* data to userspace for processing. This is to allow backends that
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* are too complex for in-kernel support to be possible.
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*
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* It uses the UIO framework to do a lot of the device-creation and
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* introspection work for us.
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*
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* See the .h file for how the ring is laid out. Note that while the
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* command ring is defined, the particulars of the data area are
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* not. Offset values in the command entry point to other locations
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* internal to the mmap()ed area. There is separate space outside the
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* command ring for data buffers. This leaves maximum flexibility for
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* moving buffer allocations, or even page flipping or other
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* allocation techniques, without altering the command ring layout.
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*
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* SECURITY:
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* The user process must be assumed to be malicious. There's no way to
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* prevent it breaking the command ring protocol if it wants, but in
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* order to prevent other issues we must only ever read *data* from
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* the shared memory area, not offsets or sizes. This applies to
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* command ring entries as well as the mailbox. Extra code needed for
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* this may have a 'UAM' comment.
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*/
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#define TCMU_TIME_OUT (30 * MSEC_PER_SEC)
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/* For cmd area, the size is fixed 8MB */
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#define CMDR_SIZE (8 * 1024 * 1024)
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/*
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* For data area, the block size is PAGE_SIZE and
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* the total size is 256K * PAGE_SIZE.
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*/
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#define DATA_BLOCK_SIZE PAGE_SIZE
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#define DATA_BLOCK_BITS (256 * 1024)
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#define DATA_SIZE (DATA_BLOCK_BITS * DATA_BLOCK_SIZE)
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#define DATA_BLOCK_INIT_BITS 128
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/* The total size of the ring is 8M + 256K * PAGE_SIZE */
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#define TCMU_RING_SIZE (CMDR_SIZE + DATA_SIZE)
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/* Default maximum of the global data blocks(512K * PAGE_SIZE) */
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#define TCMU_GLOBAL_MAX_BLOCKS (512 * 1024)
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static struct device *tcmu_root_device;
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struct tcmu_hba {
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u32 host_id;
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};
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#define TCMU_CONFIG_LEN 256
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struct tcmu_dev {
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struct list_head node;
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struct kref kref;
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struct se_device se_dev;
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char *name;
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struct se_hba *hba;
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#define TCMU_DEV_BIT_OPEN 0
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#define TCMU_DEV_BIT_BROKEN 1
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unsigned long flags;
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struct uio_info uio_info;
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struct inode *inode;
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struct tcmu_mailbox *mb_addr;
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size_t dev_size;
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u32 cmdr_size;
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u32 cmdr_last_cleaned;
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/* Offset of data area from start of mb */
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/* Must add data_off and mb_addr to get the address */
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size_t data_off;
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size_t data_size;
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wait_queue_head_t wait_cmdr;
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struct mutex cmdr_lock;
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bool waiting_global;
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uint32_t dbi_max;
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uint32_t dbi_thresh;
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DECLARE_BITMAP(data_bitmap, DATA_BLOCK_BITS);
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struct radix_tree_root data_blocks;
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struct idr commands;
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spinlock_t commands_lock;
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struct timer_list timeout;
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unsigned int cmd_time_out;
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char dev_config[TCMU_CONFIG_LEN];
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};
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#define TCMU_DEV(_se_dev) container_of(_se_dev, struct tcmu_dev, se_dev)
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#define CMDR_OFF sizeof(struct tcmu_mailbox)
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struct tcmu_cmd {
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struct se_cmd *se_cmd;
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struct tcmu_dev *tcmu_dev;
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uint16_t cmd_id;
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/* Can't use se_cmd when cleaning up expired cmds, because if
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cmd has been completed then accessing se_cmd is off limits */
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uint32_t dbi_cnt;
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uint32_t dbi_cur;
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uint32_t *dbi;
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unsigned long deadline;
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#define TCMU_CMD_BIT_EXPIRED 0
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unsigned long flags;
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};
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static struct task_struct *unmap_thread;
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static wait_queue_head_t unmap_wait;
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static DEFINE_MUTEX(root_udev_mutex);
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static LIST_HEAD(root_udev);
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static atomic_t global_db_count = ATOMIC_INIT(0);
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static struct kmem_cache *tcmu_cmd_cache;
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/* multicast group */
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enum tcmu_multicast_groups {
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TCMU_MCGRP_CONFIG,
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};
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static const struct genl_multicast_group tcmu_mcgrps[] = {
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[TCMU_MCGRP_CONFIG] = { .name = "config", },
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};
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/* Our generic netlink family */
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static struct genl_family tcmu_genl_family __ro_after_init = {
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.module = THIS_MODULE,
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.hdrsize = 0,
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.name = "TCM-USER",
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.version = 1,
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.maxattr = TCMU_ATTR_MAX,
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.mcgrps = tcmu_mcgrps,
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.n_mcgrps = ARRAY_SIZE(tcmu_mcgrps),
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.netnsok = true,
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};
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#define tcmu_cmd_set_dbi_cur(cmd, index) ((cmd)->dbi_cur = (index))
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#define tcmu_cmd_reset_dbi_cur(cmd) tcmu_cmd_set_dbi_cur(cmd, 0)
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#define tcmu_cmd_set_dbi(cmd, index) ((cmd)->dbi[(cmd)->dbi_cur++] = (index))
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#define tcmu_cmd_get_dbi(cmd) ((cmd)->dbi[(cmd)->dbi_cur++])
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static void tcmu_cmd_free_data(struct tcmu_cmd *tcmu_cmd, uint32_t len)
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{
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struct tcmu_dev *udev = tcmu_cmd->tcmu_dev;
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uint32_t i;
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for (i = 0; i < len; i++)
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clear_bit(tcmu_cmd->dbi[i], udev->data_bitmap);
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}
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static inline bool tcmu_get_empty_block(struct tcmu_dev *udev,
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struct tcmu_cmd *tcmu_cmd)
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{
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struct page *page;
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int ret, dbi;
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dbi = find_first_zero_bit(udev->data_bitmap, udev->dbi_thresh);
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if (dbi == udev->dbi_thresh)
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return false;
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page = radix_tree_lookup(&udev->data_blocks, dbi);
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if (!page) {
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if (atomic_add_return(1, &global_db_count) >
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TCMU_GLOBAL_MAX_BLOCKS) {
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atomic_dec(&global_db_count);
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return false;
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}
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/* try to get new page from the mm */
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page = alloc_page(GFP_KERNEL);
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if (!page)
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return false;
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ret = radix_tree_insert(&udev->data_blocks, dbi, page);
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if (ret) {
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__free_page(page);
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return false;
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}
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}
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if (dbi > udev->dbi_max)
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udev->dbi_max = dbi;
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set_bit(dbi, udev->data_bitmap);
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tcmu_cmd_set_dbi(tcmu_cmd, dbi);
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return true;
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}
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static bool tcmu_get_empty_blocks(struct tcmu_dev *udev,
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struct tcmu_cmd *tcmu_cmd)
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{
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int i;
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udev->waiting_global = false;
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for (i = tcmu_cmd->dbi_cur; i < tcmu_cmd->dbi_cnt; i++) {
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if (!tcmu_get_empty_block(udev, tcmu_cmd))
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goto err;
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}
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return true;
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err:
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udev->waiting_global = true;
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/* Try to wake up the unmap thread */
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wake_up(&unmap_wait);
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return false;
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}
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static inline struct page *
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tcmu_get_block_page(struct tcmu_dev *udev, uint32_t dbi)
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{
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return radix_tree_lookup(&udev->data_blocks, dbi);
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}
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static inline void tcmu_free_cmd(struct tcmu_cmd *tcmu_cmd)
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{
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kfree(tcmu_cmd->dbi);
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kmem_cache_free(tcmu_cmd_cache, tcmu_cmd);
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}
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static inline size_t tcmu_cmd_get_data_length(struct tcmu_cmd *tcmu_cmd)
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{
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struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
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size_t data_length = round_up(se_cmd->data_length, DATA_BLOCK_SIZE);
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if (se_cmd->se_cmd_flags & SCF_BIDI) {
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BUG_ON(!(se_cmd->t_bidi_data_sg && se_cmd->t_bidi_data_nents));
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data_length += round_up(se_cmd->t_bidi_data_sg->length,
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DATA_BLOCK_SIZE);
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}
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return data_length;
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}
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static inline uint32_t tcmu_cmd_get_block_cnt(struct tcmu_cmd *tcmu_cmd)
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{
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size_t data_length = tcmu_cmd_get_data_length(tcmu_cmd);
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return data_length / DATA_BLOCK_SIZE;
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}
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static struct tcmu_cmd *tcmu_alloc_cmd(struct se_cmd *se_cmd)
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{
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struct se_device *se_dev = se_cmd->se_dev;
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struct tcmu_dev *udev = TCMU_DEV(se_dev);
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struct tcmu_cmd *tcmu_cmd;
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int cmd_id;
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tcmu_cmd = kmem_cache_zalloc(tcmu_cmd_cache, GFP_KERNEL);
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if (!tcmu_cmd)
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return NULL;
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tcmu_cmd->se_cmd = se_cmd;
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tcmu_cmd->tcmu_dev = udev;
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if (udev->cmd_time_out)
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tcmu_cmd->deadline = jiffies +
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msecs_to_jiffies(udev->cmd_time_out);
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tcmu_cmd_reset_dbi_cur(tcmu_cmd);
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tcmu_cmd->dbi_cnt = tcmu_cmd_get_block_cnt(tcmu_cmd);
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tcmu_cmd->dbi = kcalloc(tcmu_cmd->dbi_cnt, sizeof(uint32_t),
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GFP_KERNEL);
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if (!tcmu_cmd->dbi) {
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kmem_cache_free(tcmu_cmd_cache, tcmu_cmd);
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return NULL;
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}
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idr_preload(GFP_KERNEL);
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spin_lock_irq(&udev->commands_lock);
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cmd_id = idr_alloc(&udev->commands, tcmu_cmd, 0,
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USHRT_MAX, GFP_NOWAIT);
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spin_unlock_irq(&udev->commands_lock);
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idr_preload_end();
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if (cmd_id < 0) {
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tcmu_free_cmd(tcmu_cmd);
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return NULL;
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}
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tcmu_cmd->cmd_id = cmd_id;
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return tcmu_cmd;
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}
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static inline void tcmu_flush_dcache_range(void *vaddr, size_t size)
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{
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unsigned long offset = offset_in_page(vaddr);
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size = round_up(size+offset, PAGE_SIZE);
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vaddr -= offset;
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while (size) {
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flush_dcache_page(virt_to_page(vaddr));
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size -= PAGE_SIZE;
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}
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}
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/*
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* Some ring helper functions. We don't assume size is a power of 2 so
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* we can't use circ_buf.h.
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*/
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static inline size_t spc_used(size_t head, size_t tail, size_t size)
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{
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int diff = head - tail;
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if (diff >= 0)
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return diff;
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else
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return size + diff;
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}
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static inline size_t spc_free(size_t head, size_t tail, size_t size)
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{
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/* Keep 1 byte unused or we can't tell full from empty */
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return (size - spc_used(head, tail, size) - 1);
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}
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static inline size_t head_to_end(size_t head, size_t size)
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{
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return size - head;
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}
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static inline void new_iov(struct iovec **iov, int *iov_cnt,
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struct tcmu_dev *udev)
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{
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struct iovec *iovec;
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if (*iov_cnt != 0)
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(*iov)++;
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(*iov_cnt)++;
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iovec = *iov;
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memset(iovec, 0, sizeof(struct iovec));
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}
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#define UPDATE_HEAD(head, used, size) smp_store_release(&head, ((head % size) + used) % size)
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/* offset is relative to mb_addr */
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static inline size_t get_block_offset_user(struct tcmu_dev *dev,
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int dbi, int remaining)
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{
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return dev->data_off + dbi * DATA_BLOCK_SIZE +
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DATA_BLOCK_SIZE - remaining;
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}
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static inline size_t iov_tail(struct tcmu_dev *udev, struct iovec *iov)
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{
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return (size_t)iov->iov_base + iov->iov_len;
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}
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static int scatter_data_area(struct tcmu_dev *udev,
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struct tcmu_cmd *tcmu_cmd, struct scatterlist *data_sg,
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unsigned int data_nents, struct iovec **iov,
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int *iov_cnt, bool copy_data)
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{
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int i, dbi;
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int block_remaining = 0;
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void *from, *to = NULL;
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size_t copy_bytes, to_offset, offset;
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struct scatterlist *sg;
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struct page *page;
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for_each_sg(data_sg, sg, data_nents, i) {
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int sg_remaining = sg->length;
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from = kmap_atomic(sg_page(sg)) + sg->offset;
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while (sg_remaining > 0) {
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if (block_remaining == 0) {
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if (to)
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kunmap_atomic(to);
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block_remaining = DATA_BLOCK_SIZE;
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dbi = tcmu_cmd_get_dbi(tcmu_cmd);
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page = tcmu_get_block_page(udev, dbi);
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to = kmap_atomic(page);
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}
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copy_bytes = min_t(size_t, sg_remaining,
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block_remaining);
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to_offset = get_block_offset_user(udev, dbi,
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block_remaining);
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offset = DATA_BLOCK_SIZE - block_remaining;
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to = (void *)(unsigned long)to + offset;
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if (*iov_cnt != 0 &&
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to_offset == iov_tail(udev, *iov)) {
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(*iov)->iov_len += copy_bytes;
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} else {
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new_iov(iov, iov_cnt, udev);
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(*iov)->iov_base = (void __user *)to_offset;
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(*iov)->iov_len = copy_bytes;
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}
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if (copy_data) {
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memcpy(to, from + sg->length - sg_remaining,
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copy_bytes);
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tcmu_flush_dcache_range(to, copy_bytes);
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}
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sg_remaining -= copy_bytes;
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block_remaining -= copy_bytes;
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}
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kunmap_atomic(from - sg->offset);
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}
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if (to)
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kunmap_atomic(to);
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return 0;
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}
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static void gather_data_area(struct tcmu_dev *udev, struct tcmu_cmd *cmd,
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bool bidi)
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{
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struct se_cmd *se_cmd = cmd->se_cmd;
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int i, dbi;
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int block_remaining = 0;
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void *from = NULL, *to;
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size_t copy_bytes, offset;
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struct scatterlist *sg, *data_sg;
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struct page *page;
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unsigned int data_nents;
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uint32_t count = 0;
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if (!bidi) {
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data_sg = se_cmd->t_data_sg;
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data_nents = se_cmd->t_data_nents;
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} else {
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/*
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* For bidi case, the first count blocks are for Data-Out
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* buffer blocks, and before gathering the Data-In buffer
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* the Data-Out buffer blocks should be discarded.
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*/
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count = DIV_ROUND_UP(se_cmd->data_length, DATA_BLOCK_SIZE);
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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) {
|
|
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);
|
|
offset = DATA_BLOCK_SIZE - block_remaining;
|
|
from = (void *)(unsigned long)from + offset;
|
|
tcmu_flush_dcache_range(from, copy_bytes);
|
|
memcpy(to + sg->length - sg_remaining, from,
|
|
copy_bytes);
|
|
|
|
sg_remaining -= copy_bytes;
|
|
block_remaining -= copy_bytes;
|
|
}
|
|
kunmap_atomic(to - sg->offset);
|
|
}
|
|
if (from)
|
|
kunmap_atomic(from);
|
|
}
|
|
|
|
static inline size_t spc_bitmap_free(unsigned long *bitmap, uint32_t thresh)
|
|
{
|
|
return DATA_BLOCK_SIZE * (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_needed) {
|
|
unsigned long blocks_left = DATA_BLOCK_BITS - udev->dbi_thresh;
|
|
unsigned long grow;
|
|
|
|
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;
|
|
}
|
|
|
|
/* Try to expand the thresh */
|
|
if (!udev->dbi_thresh) {
|
|
/* From idle state */
|
|
uint32_t init_thresh = DATA_BLOCK_INIT_BITS;
|
|
|
|
udev->dbi_thresh = max(blocks_needed, init_thresh);
|
|
} else {
|
|
/*
|
|
* Grow the data area by max(blocks needed,
|
|
* dbi_thresh / 2), but limited to the max
|
|
* DATA_BLOCK_BITS size.
|
|
*/
|
|
grow = max(blocks_needed, udev->dbi_thresh / 2);
|
|
udev->dbi_thresh += grow;
|
|
if (udev->dbi_thresh > DATA_BLOCK_BITS)
|
|
udev->dbi_thresh = DATA_BLOCK_BITS;
|
|
}
|
|
}
|
|
|
|
if (!tcmu_get_empty_blocks(udev, cmd))
|
|
return false;
|
|
|
|
return true;
|
|
}
|
|
|
|
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 sense_reason_t
|
|
tcmu_queue_cmd_ring(struct tcmu_cmd *tcmu_cmd)
|
|
{
|
|
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);
|
|
|
|
if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags))
|
|
return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
|
|
|
|
/*
|
|
* 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);
|
|
|
|
mutex_lock(&udev->cmdr_lock);
|
|
|
|
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);
|
|
mutex_unlock(&udev->cmdr_lock);
|
|
return TCM_INVALID_CDB_FIELD;
|
|
}
|
|
|
|
while (!is_ring_space_avail(udev, tcmu_cmd, command_size, data_length)) {
|
|
int ret;
|
|
DEFINE_WAIT(__wait);
|
|
|
|
prepare_to_wait(&udev->wait_cmdr, &__wait, TASK_INTERRUPTIBLE);
|
|
|
|
pr_debug("sleeping for ring space\n");
|
|
mutex_unlock(&udev->cmdr_lock);
|
|
if (udev->cmd_time_out)
|
|
ret = schedule_timeout(
|
|
msecs_to_jiffies(udev->cmd_time_out));
|
|
else
|
|
ret = schedule_timeout(msecs_to_jiffies(TCMU_TIME_OUT));
|
|
finish_wait(&udev->wait_cmdr, &__wait);
|
|
if (!ret) {
|
|
pr_warn("tcmu: command timed out\n");
|
|
return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
|
|
}
|
|
|
|
mutex_lock(&udev->cmdr_lock);
|
|
|
|
/* We dropped cmdr_lock, cmd_head is stale */
|
|
cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
|
|
}
|
|
|
|
/* 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_flush_dcache_range(entry, sizeof(*entry));
|
|
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;
|
|
|
|
UPDATE_HEAD(mb->cmd_head, pad_size, udev->cmdr_size);
|
|
|
|
cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
|
|
WARN_ON(cmd_head != 0);
|
|
}
|
|
|
|
entry = (void *) mb + CMDR_OFF + cmd_head;
|
|
tcmu_flush_dcache_range(entry, sizeof(*entry));
|
|
tcmu_hdr_set_op(&entry->hdr.len_op, TCMU_OP_CMD);
|
|
entry->hdr.cmd_id = tcmu_cmd->cmd_id;
|
|
entry->hdr.kflags = 0;
|
|
entry->hdr.uflags = 0;
|
|
|
|
/* 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);
|
|
ret = scatter_data_area(udev, tcmu_cmd, se_cmd->t_data_sg,
|
|
se_cmd->t_data_nents, &iov, &iov_cnt,
|
|
copy_to_data_area);
|
|
if (ret) {
|
|
tcmu_cmd_free_data(tcmu_cmd, tcmu_cmd->dbi_cnt);
|
|
mutex_unlock(&udev->cmdr_lock);
|
|
|
|
pr_err("tcmu: alloc and scatter data failed\n");
|
|
return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
|
|
}
|
|
entry->req.iov_cnt = iov_cnt;
|
|
entry->req.iov_dif_cnt = 0;
|
|
|
|
/* Handle BIDI commands */
|
|
if (se_cmd->se_cmd_flags & SCF_BIDI) {
|
|
iov_cnt = 0;
|
|
iov++;
|
|
ret = scatter_data_area(udev, tcmu_cmd,
|
|
se_cmd->t_bidi_data_sg,
|
|
se_cmd->t_bidi_data_nents,
|
|
&iov, &iov_cnt, false);
|
|
if (ret) {
|
|
tcmu_cmd_free_data(tcmu_cmd, tcmu_cmd->dbi_cnt);
|
|
mutex_unlock(&udev->cmdr_lock);
|
|
|
|
pr_err("tcmu: alloc and scatter bidi data failed\n");
|
|
return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
|
|
}
|
|
entry->req.iov_bidi_cnt = iov_cnt;
|
|
}
|
|
|
|
/*
|
|
* 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));
|
|
mutex_unlock(&udev->cmdr_lock);
|
|
|
|
/* TODO: only if FLUSH and FUA? */
|
|
uio_event_notify(&udev->uio_info);
|
|
|
|
if (udev->cmd_time_out)
|
|
mod_timer(&udev->timeout, round_jiffies_up(jiffies +
|
|
msecs_to_jiffies(udev->cmd_time_out)));
|
|
|
|
return TCM_NO_SENSE;
|
|
}
|
|
|
|
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 ret;
|
|
|
|
tcmu_cmd = tcmu_alloc_cmd(se_cmd);
|
|
if (!tcmu_cmd)
|
|
return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
|
|
|
|
ret = tcmu_queue_cmd_ring(tcmu_cmd);
|
|
if (ret != TCM_NO_SENSE) {
|
|
pr_err("TCMU: Could not queue command\n");
|
|
spin_lock_irq(&udev->commands_lock);
|
|
idr_remove(&udev->commands, tcmu_cmd->cmd_id);
|
|
spin_unlock_irq(&udev->commands_lock);
|
|
|
|
tcmu_free_cmd(tcmu_cmd);
|
|
}
|
|
|
|
return 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;
|
|
|
|
/*
|
|
* 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;
|
|
|
|
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;
|
|
} else if (entry->rsp.scsi_status == SAM_STAT_CHECK_CONDITION) {
|
|
memcpy(se_cmd->sense_buffer, entry->rsp.sense_buffer,
|
|
se_cmd->scsi_sense_length);
|
|
} else if (se_cmd->se_cmd_flags & SCF_BIDI) {
|
|
/* Get Data-In buffer before clean up */
|
|
gather_data_area(udev, cmd, true);
|
|
} else if (se_cmd->data_direction == DMA_FROM_DEVICE) {
|
|
gather_data_area(udev, cmd, false);
|
|
} 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);
|
|
}
|
|
|
|
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 unsigned int tcmu_handle_completions(struct tcmu_dev *udev)
|
|
{
|
|
struct tcmu_mailbox *mb;
|
|
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 != ACCESS_ONCE(mb->cmd_tail)) {
|
|
|
|
struct tcmu_cmd_entry *entry = (void *) mb + CMDR_OFF + udev->cmdr_last_cleaned;
|
|
struct tcmu_cmd *cmd;
|
|
|
|
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);
|
|
|
|
spin_lock(&udev->commands_lock);
|
|
cmd = idr_remove(&udev->commands, entry->hdr.cmd_id);
|
|
spin_unlock(&udev->commands_lock);
|
|
|
|
if (!cmd) {
|
|
pr_err("cmd_id not found, ring is broken\n");
|
|
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)
|
|
del_timer(&udev->timeout); /* no more pending cmds */
|
|
|
|
wake_up(&udev->wait_cmdr);
|
|
|
|
return handled;
|
|
}
|
|
|
|
static int tcmu_check_expired_cmd(int id, void *p, void *data)
|
|
{
|
|
struct tcmu_cmd *cmd = p;
|
|
|
|
if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags))
|
|
return 0;
|
|
|
|
if (!time_after(jiffies, cmd->deadline))
|
|
return 0;
|
|
|
|
set_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags);
|
|
target_complete_cmd(cmd->se_cmd, SAM_STAT_CHECK_CONDITION);
|
|
cmd->se_cmd = NULL;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void tcmu_device_timedout(unsigned long data)
|
|
{
|
|
struct tcmu_dev *udev = (struct tcmu_dev *)data;
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&udev->commands_lock, flags);
|
|
idr_for_each(&udev->commands, tcmu_check_expired_cmd, NULL);
|
|
spin_unlock_irqrestore(&udev->commands_lock, flags);
|
|
|
|
/* Try to wake up the ummap thread */
|
|
wake_up(&unmap_wait);
|
|
|
|
/*
|
|
* We don't need to wakeup threads on wait_cmdr since they have their
|
|
* own timeout.
|
|
*/
|
|
}
|
|
|
|
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;
|
|
|
|
init_waitqueue_head(&udev->wait_cmdr);
|
|
mutex_init(&udev->cmdr_lock);
|
|
|
|
idr_init(&udev->commands);
|
|
spin_lock_init(&udev->commands_lock);
|
|
|
|
setup_timer(&udev->timeout, tcmu_device_timedout,
|
|
(unsigned long)udev);
|
|
|
|
return &udev->se_dev;
|
|
}
|
|
|
|
static int tcmu_irqcontrol(struct uio_info *info, s32 irq_on)
|
|
{
|
|
struct tcmu_dev *tcmu_dev = container_of(info, struct tcmu_dev, uio_info);
|
|
|
|
mutex_lock(&tcmu_dev->cmdr_lock);
|
|
tcmu_handle_completions(tcmu_dev);
|
|
mutex_unlock(&tcmu_dev->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;
|
|
int ret;
|
|
|
|
mutex_lock(&udev->cmdr_lock);
|
|
page = tcmu_get_block_page(udev, dbi);
|
|
if (likely(page)) {
|
|
mutex_unlock(&udev->cmdr_lock);
|
|
return page;
|
|
}
|
|
|
|
/*
|
|
* Normally it shouldn't be here:
|
|
* Only when the userspace has touched the blocks which
|
|
* are out of the tcmu_cmd's data iov[], and will return
|
|
* one zeroed page.
|
|
*/
|
|
pr_warn("Block(%u) out of cmd's iov[] has been touched!\n", dbi);
|
|
pr_warn("Mostly it will be a bug of userspace, please have a check!\n");
|
|
|
|
if (dbi >= udev->dbi_thresh) {
|
|
/* Extern the udev->dbi_thresh to dbi + 1 */
|
|
udev->dbi_thresh = dbi + 1;
|
|
udev->dbi_max = dbi;
|
|
}
|
|
|
|
page = radix_tree_lookup(&udev->data_blocks, dbi);
|
|
if (!page) {
|
|
page = alloc_page(GFP_KERNEL | __GFP_ZERO);
|
|
if (!page) {
|
|
mutex_unlock(&udev->cmdr_lock);
|
|
return NULL;
|
|
}
|
|
|
|
ret = radix_tree_insert(&udev->data_blocks, dbi, page);
|
|
if (ret) {
|
|
mutex_unlock(&udev->cmdr_lock);
|
|
__free_page(page);
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* Since this case is rare in page fault routine, here we
|
|
* will allow the global_db_count >= TCMU_GLOBAL_MAX_BLOCKS
|
|
* to reduce possible page fault call trace.
|
|
*/
|
|
atomic_inc(&global_db_count);
|
|
}
|
|
mutex_unlock(&udev->cmdr_lock);
|
|
|
|
return page;
|
|
}
|
|
|
|
static int 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_NOPAGE;
|
|
}
|
|
|
|
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) != (TCMU_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;
|
|
|
|
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 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;
|
|
|
|
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 configure */
|
|
kref_put(&udev->kref, tcmu_dev_kref_release);
|
|
return 0;
|
|
}
|
|
|
|
static int tcmu_netlink_event(enum tcmu_genl_cmd cmd, const char *name, int minor)
|
|
{
|
|
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, name);
|
|
if (ret < 0)
|
|
goto free_skb;
|
|
|
|
ret = nla_put_u32(skb, TCMU_ATTR_MINOR, minor);
|
|
if (ret < 0)
|
|
goto free_skb;
|
|
|
|
genlmsg_end(skb, msg_header);
|
|
|
|
ret = genlmsg_multicast_allns(&tcmu_genl_family, skb, 0,
|
|
TCMU_MCGRP_CONFIG, GFP_KERNEL);
|
|
|
|
/* We don't care if no one is listening */
|
|
if (ret == -ESRCH)
|
|
ret = 0;
|
|
|
|
return ret;
|
|
free_skb:
|
|
nlmsg_free(skb);
|
|
return ret;
|
|
}
|
|
|
|
static int tcmu_configure_device(struct se_device *dev)
|
|
{
|
|
struct tcmu_dev *udev = TCMU_DEV(dev);
|
|
struct tcmu_hba *hba = udev->hba->hba_ptr;
|
|
struct uio_info *info;
|
|
struct tcmu_mailbox *mb;
|
|
size_t size;
|
|
size_t used;
|
|
int ret = 0;
|
|
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);
|
|
|
|
info->name = str;
|
|
|
|
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 = DATA_SIZE;
|
|
udev->dbi_thresh = 0; /* Default in Idle state */
|
|
udev->waiting_global = false;
|
|
|
|
/* Initialise the mailbox of the ring buffer */
|
|
mb = udev->mb_addr;
|
|
mb->version = TCMU_MAILBOX_VERSION;
|
|
mb->flags = TCMU_MAILBOX_FLAG_CAP_OOOC;
|
|
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);
|
|
|
|
INIT_RADIX_TREE(&udev->data_blocks, GFP_KERNEL);
|
|
|
|
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 = TCMU_RING_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;
|
|
|
|
/*
|
|
* 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_netlink_event(TCMU_CMD_ADDED_DEVICE, udev->uio_info.name,
|
|
udev->uio_info.uio_dev->minor);
|
|
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);
|
|
err_vzalloc:
|
|
kfree(info->name);
|
|
info->name = NULL;
|
|
|
|
return ret;
|
|
}
|
|
|
|
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 bool tcmu_dev_configured(struct tcmu_dev *udev)
|
|
{
|
|
return udev->uio_info.uio_dev ? true : false;
|
|
}
|
|
|
|
static void tcmu_blocks_release(struct tcmu_dev *udev)
|
|
{
|
|
int i;
|
|
struct page *page;
|
|
|
|
/* Try to release all block pages */
|
|
mutex_lock(&udev->cmdr_lock);
|
|
for (i = 0; i <= udev->dbi_max; i++) {
|
|
page = radix_tree_delete(&udev->data_blocks, i);
|
|
if (page) {
|
|
__free_page(page);
|
|
atomic_dec(&global_db_count);
|
|
}
|
|
}
|
|
mutex_unlock(&udev->cmdr_lock);
|
|
}
|
|
|
|
static void tcmu_free_device(struct se_device *dev)
|
|
{
|
|
struct tcmu_dev *udev = TCMU_DEV(dev);
|
|
struct tcmu_cmd *cmd;
|
|
bool all_expired = true;
|
|
int i;
|
|
|
|
del_timer_sync(&udev->timeout);
|
|
|
|
mutex_lock(&root_udev_mutex);
|
|
list_del(&udev->node);
|
|
mutex_unlock(&root_udev_mutex);
|
|
|
|
vfree(udev->mb_addr);
|
|
|
|
/* Upper layer should drain all requests before calling this */
|
|
spin_lock_irq(&udev->commands_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);
|
|
spin_unlock_irq(&udev->commands_lock);
|
|
WARN_ON(!all_expired);
|
|
|
|
tcmu_blocks_release(udev);
|
|
|
|
if (tcmu_dev_configured(udev)) {
|
|
tcmu_netlink_event(TCMU_CMD_REMOVED_DEVICE, udev->uio_info.name,
|
|
udev->uio_info.uio_dev->minor);
|
|
|
|
uio_unregister_device(&udev->uio_info);
|
|
}
|
|
|
|
/* release ref from init */
|
|
kref_put(&udev->kref, tcmu_dev_kref_release);
|
|
}
|
|
|
|
enum {
|
|
Opt_dev_config, Opt_dev_size, Opt_hw_block_size, Opt_hw_max_sectors,
|
|
Opt_err,
|
|
};
|
|
|
|
static match_table_t tokens = {
|
|
{Opt_dev_config, "dev_config=%s"},
|
|
{Opt_dev_size, "dev_size=%u"},
|
|
{Opt_hw_block_size, "hw_block_size=%u"},
|
|
{Opt_hw_max_sectors, "hw_max_sectors=%u"},
|
|
{Opt_err, NULL}
|
|
};
|
|
|
|
static int tcmu_set_dev_attrib(substring_t *arg, u32 *dev_attrib)
|
|
{
|
|
unsigned long tmp_ul;
|
|
char *arg_p;
|
|
int ret;
|
|
|
|
arg_p = match_strdup(arg);
|
|
if (!arg_p)
|
|
return -ENOMEM;
|
|
|
|
ret = kstrtoul(arg_p, 0, &tmp_ul);
|
|
kfree(arg_p);
|
|
if (ret < 0) {
|
|
pr_err("kstrtoul() failed for dev attrib\n");
|
|
return ret;
|
|
}
|
|
if (!tmp_ul) {
|
|
pr_err("dev attrib must be nonzero\n");
|
|
return -EINVAL;
|
|
}
|
|
*dev_attrib = tmp_ul;
|
|
return 0;
|
|
}
|
|
|
|
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, *arg_p;
|
|
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:
|
|
arg_p = match_strdup(&args[0]);
|
|
if (!arg_p) {
|
|
ret = -ENOMEM;
|
|
break;
|
|
}
|
|
ret = kstrtoul(arg_p, 0, (unsigned long *) &udev->dev_size);
|
|
kfree(arg_p);
|
|
if (ret < 0)
|
|
pr_err("kstrtoul() failed for dev_size=\n");
|
|
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;
|
|
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: %zu\n", udev->dev_size);
|
|
|
|
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 = container_of(da->da_dev,
|
|
struct tcmu_dev, se_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_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 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);
|
|
int val;
|
|
int ret;
|
|
|
|
ret = kstrtouint(page, 0, &val);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
da->emulate_write_cache = val;
|
|
|
|
/* Check if device has been configured before */
|
|
if (tcmu_dev_configured(udev)) {
|
|
ret = tcmu_netlink_event(TCMU_CMD_RECONFIG_DEVICE,
|
|
udev->uio_info.name,
|
|
udev->uio_info.uio_dev->minor);
|
|
if (ret) {
|
|
pr_err("Unable to reconfigure device\n");
|
|
return ret;
|
|
}
|
|
}
|
|
return count;
|
|
}
|
|
CONFIGFS_ATTR(tcmu_, emulate_write_cache);
|
|
|
|
static struct configfs_attribute **tcmu_attrs;
|
|
|
|
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,
|
|
.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_attrib_attrs = NULL,
|
|
};
|
|
|
|
static int unmap_thread_fn(void *data)
|
|
{
|
|
struct tcmu_dev *udev;
|
|
loff_t off;
|
|
uint32_t start, end, block;
|
|
struct page *page;
|
|
int i;
|
|
|
|
while (1) {
|
|
DEFINE_WAIT(__wait);
|
|
|
|
prepare_to_wait(&unmap_wait, &__wait, TASK_INTERRUPTIBLE);
|
|
schedule();
|
|
finish_wait(&unmap_wait, &__wait);
|
|
|
|
if (kthread_should_stop())
|
|
break;
|
|
|
|
mutex_lock(&root_udev_mutex);
|
|
list_for_each_entry(udev, &root_udev, node) {
|
|
mutex_lock(&udev->cmdr_lock);
|
|
|
|
/* Try to complete the finished commands first */
|
|
tcmu_handle_completions(udev);
|
|
|
|
/* Skip the udevs waiting the global pool or in idle */
|
|
if (udev->waiting_global || !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 there is
|
|
* no need to shrink 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 */
|
|
for (i = start; i < end; i++) {
|
|
page = radix_tree_delete(&udev->data_blocks, i);
|
|
if (page) {
|
|
__free_page(page);
|
|
atomic_dec(&global_db_count);
|
|
}
|
|
}
|
|
mutex_unlock(&udev->cmdr_lock);
|
|
}
|
|
|
|
/*
|
|
* Try to wake up the udevs who are waiting
|
|
* for the global data pool.
|
|
*/
|
|
list_for_each_entry(udev, &root_udev, node) {
|
|
if (udev->waiting_global)
|
|
wake_up(&udev->wait_cmdr);
|
|
}
|
|
mutex_unlock(&root_udev_mutex);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int __init tcmu_module_init(void)
|
|
{
|
|
int ret, i, len = 0;
|
|
|
|
BUILD_BUG_ON((sizeof(struct tcmu_cmd_entry) % TCMU_OP_ALIGN_SIZE) != 0);
|
|
|
|
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 *);
|
|
}
|
|
len += sizeof(struct configfs_attribute *) * 2;
|
|
|
|
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];
|
|
}
|
|
tcmu_attrs[i] = &tcmu_attr_cmd_time_out;
|
|
i++;
|
|
tcmu_attrs[i] = &tcmu_attr_emulate_write_cache;
|
|
tcmu_ops.tb_dev_attrib_attrs = tcmu_attrs;
|
|
|
|
ret = transport_backend_register(&tcmu_ops);
|
|
if (ret)
|
|
goto out_attrs;
|
|
|
|
init_waitqueue_head(&unmap_wait);
|
|
unmap_thread = kthread_run(unmap_thread_fn, NULL, "tcmu_unmap");
|
|
if (IS_ERR(unmap_thread)) {
|
|
ret = PTR_ERR(unmap_thread);
|
|
goto out_unreg_transport;
|
|
}
|
|
|
|
return 0;
|
|
|
|
out_unreg_transport:
|
|
target_backend_unregister(&tcmu_ops);
|
|
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)
|
|
{
|
|
kthread_stop(unmap_thread);
|
|
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);
|