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053c095a82
Contrary to common expectations for an "int" return, these functions return only a positive value -- if used correctly they cannot even return 0 because the message header will necessarily be in the skb. This makes the very common pattern of if (genlmsg_end(...) < 0) { ... } be a whole bunch of dead code. Many places also simply do return nlmsg_end(...); and the caller is expected to deal with it. This also commonly (at least for me) causes errors, because it is very common to write if (my_function(...)) /* error condition */ and if my_function() does "return nlmsg_end()" this is of course wrong. Additionally, there's not a single place in the kernel that actually needs the message length returned, and if anyone needs it later then it'll be very easy to just use skb->len there. Remove this, and make the functions void. This removes a bunch of dead code as described above. The patch adds lines because I did - return nlmsg_end(...); + nlmsg_end(...); + return 0; I could have preserved all the function's return values by returning skb->len, but instead I've audited all the places calling the affected functions and found that none cared. A few places actually compared the return value with <= 0 in dump functionality, but that could just be changed to < 0 with no change in behaviour, so I opted for the more efficient version. One instance of the error I've made numerous times now is also present in net/phonet/pn_netlink.c in the route_dumpit() function - it didn't check for <0 or <=0 and thus broke out of the loop every single time. I've preserved this since it will (I think) have caused the messages to userspace to be formatted differently with just a single message for every SKB returned to userspace. It's possible that this isn't needed for the tools that actually use this, but I don't even know what they are so couldn't test that changing this behaviour would be acceptable. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
1207 lines
30 KiB
C
1207 lines
30 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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*
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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/timer.h>
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#include <linux/parser.h>
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#include <scsi/scsi.h>
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#include <scsi/scsi_host.h>
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#include <linux/uio_driver.h>
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#include <net/genetlink.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 <target/target_core_backend_configfs.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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#define CMDR_SIZE (16 * 4096)
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#define DATA_SIZE (257 * 4096)
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#define TCMU_RING_SIZE (CMDR_SIZE + DATA_SIZE)
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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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/* User wants all cmds or just some */
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enum passthru_level {
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TCMU_PASS_ALL = 0,
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TCMU_PASS_IO,
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TCMU_PASS_INVALID,
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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 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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enum passthru_level pass_level;
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struct uio_info uio_info;
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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 ring from start of mb */
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size_t data_off;
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size_t data_size;
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/* Ring head + tail values. */
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/* Must add data_off and mb_addr to get the address */
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size_t data_head;
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size_t data_tail;
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wait_queue_head_t wait_cmdr;
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/* TODO should this be a mutex? */
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spinlock_t cmdr_lock;
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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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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->data_length 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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size_t data_length;
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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 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 = {
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.id = GENL_ID_GENERATE,
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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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};
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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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tcmu_cmd->data_length = se_cmd->data_length;
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tcmu_cmd->deadline = jiffies + msecs_to_jiffies(TCMU_TIME_OUT);
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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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kmem_cache_free(tcmu_cmd_cache, 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 = (unsigned long) vaddr & ~PAGE_MASK;
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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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#define UPDATE_HEAD(head, used, size) smp_store_release(&head, ((head % size) + used) % size)
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/*
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* We can't queue a command until we have space available on the cmd ring *and* space
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* space avail on the data ring.
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*
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* Called with ring lock held.
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*/
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static bool is_ring_space_avail(struct tcmu_dev *udev, size_t cmd_size, size_t data_needed)
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{
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struct tcmu_mailbox *mb = udev->mb_addr;
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size_t space;
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u32 cmd_head;
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size_t cmd_needed;
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tcmu_flush_dcache_range(mb, sizeof(*mb));
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cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
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/*
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* If cmd end-of-ring space is too small then we need space for a NOP plus
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* original cmd - cmds are internally contiguous.
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*/
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if (head_to_end(cmd_head, udev->cmdr_size) >= cmd_size)
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cmd_needed = cmd_size;
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else
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cmd_needed = cmd_size + head_to_end(cmd_head, udev->cmdr_size);
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space = spc_free(cmd_head, udev->cmdr_last_cleaned, udev->cmdr_size);
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if (space < cmd_needed) {
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pr_debug("no cmd space: %u %u %u\n", cmd_head,
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udev->cmdr_last_cleaned, udev->cmdr_size);
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return false;
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}
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space = spc_free(udev->data_head, udev->data_tail, udev->data_size);
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if (space < data_needed) {
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pr_debug("no data space: %zu %zu %zu\n", udev->data_head,
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udev->data_tail, udev->data_size);
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return false;
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}
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return true;
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}
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static int tcmu_queue_cmd_ring(struct tcmu_cmd *tcmu_cmd)
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{
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struct tcmu_dev *udev = tcmu_cmd->tcmu_dev;
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struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
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size_t base_command_size, command_size;
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struct tcmu_mailbox *mb;
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struct tcmu_cmd_entry *entry;
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int i;
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struct scatterlist *sg;
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struct iovec *iov;
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int iov_cnt = 0;
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uint32_t cmd_head;
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uint64_t cdb_off;
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if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags))
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return -EINVAL;
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/*
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* Must be a certain minimum size for response sense info, but
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* also may be larger if the iov array is large.
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*
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* iovs = sgl_nents+1, for end-of-ring case, plus another 1
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* b/c size == offsetof one-past-element.
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*/
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base_command_size = max(offsetof(struct tcmu_cmd_entry,
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req.iov[se_cmd->t_data_nents + 2]),
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sizeof(struct tcmu_cmd_entry));
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command_size = base_command_size
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+ round_up(scsi_command_size(se_cmd->t_task_cdb), TCMU_OP_ALIGN_SIZE);
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WARN_ON(command_size & (TCMU_OP_ALIGN_SIZE-1));
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spin_lock_irq(&udev->cmdr_lock);
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mb = udev->mb_addr;
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cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
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if ((command_size > (udev->cmdr_size / 2))
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|| tcmu_cmd->data_length > (udev->data_size - 1))
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pr_warn("TCMU: Request of size %zu/%zu may be too big for %u/%zu "
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"cmd/data ring buffers\n", command_size, tcmu_cmd->data_length,
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udev->cmdr_size, udev->data_size);
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while (!is_ring_space_avail(udev, command_size, tcmu_cmd->data_length)) {
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int ret;
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DEFINE_WAIT(__wait);
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prepare_to_wait(&udev->wait_cmdr, &__wait, TASK_INTERRUPTIBLE);
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pr_debug("sleeping for ring space\n");
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spin_unlock_irq(&udev->cmdr_lock);
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ret = schedule_timeout(msecs_to_jiffies(TCMU_TIME_OUT));
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finish_wait(&udev->wait_cmdr, &__wait);
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if (!ret) {
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pr_warn("tcmu: command timed out\n");
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return -ETIMEDOUT;
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}
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spin_lock_irq(&udev->cmdr_lock);
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/* We dropped cmdr_lock, cmd_head is stale */
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cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
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}
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/* Insert a PAD if end-of-ring space is too small */
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if (head_to_end(cmd_head, udev->cmdr_size) < command_size) {
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size_t pad_size = head_to_end(cmd_head, udev->cmdr_size);
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entry = (void *) mb + CMDR_OFF + cmd_head;
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tcmu_flush_dcache_range(entry, sizeof(*entry));
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tcmu_hdr_set_op(&entry->hdr, TCMU_OP_PAD);
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tcmu_hdr_set_len(&entry->hdr, pad_size);
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UPDATE_HEAD(mb->cmd_head, pad_size, udev->cmdr_size);
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cmd_head = mb->cmd_head % udev->cmdr_size; /* UAM */
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WARN_ON(cmd_head != 0);
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}
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entry = (void *) mb + CMDR_OFF + cmd_head;
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tcmu_flush_dcache_range(entry, sizeof(*entry));
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tcmu_hdr_set_op(&entry->hdr, TCMU_OP_CMD);
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tcmu_hdr_set_len(&entry->hdr, command_size);
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entry->cmd_id = tcmu_cmd->cmd_id;
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/*
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* Fix up iovecs, and handle if allocation in data ring wrapped.
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*/
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iov = &entry->req.iov[0];
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for_each_sg(se_cmd->t_data_sg, sg, se_cmd->t_data_nents, i) {
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size_t copy_bytes = min((size_t)sg->length,
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head_to_end(udev->data_head, udev->data_size));
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void *from = kmap_atomic(sg_page(sg)) + sg->offset;
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void *to = (void *) mb + udev->data_off + udev->data_head;
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if (tcmu_cmd->se_cmd->data_direction == DMA_TO_DEVICE) {
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memcpy(to, from, copy_bytes);
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tcmu_flush_dcache_range(to, copy_bytes);
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}
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/* Even iov_base is relative to mb_addr */
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iov->iov_len = copy_bytes;
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iov->iov_base = (void *) udev->data_off + udev->data_head;
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iov_cnt++;
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iov++;
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UPDATE_HEAD(udev->data_head, copy_bytes, udev->data_size);
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/* Uh oh, we wrapped the buffer. Must split sg across 2 iovs. */
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if (sg->length != copy_bytes) {
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from += copy_bytes;
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copy_bytes = sg->length - copy_bytes;
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iov->iov_len = copy_bytes;
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iov->iov_base = (void *) udev->data_off + udev->data_head;
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if (se_cmd->data_direction == DMA_TO_DEVICE) {
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to = (void *) mb + udev->data_off + udev->data_head;
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memcpy(to, from, copy_bytes);
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tcmu_flush_dcache_range(to, copy_bytes);
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}
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iov_cnt++;
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iov++;
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UPDATE_HEAD(udev->data_head, copy_bytes, udev->data_size);
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}
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kunmap_atomic(from);
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}
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entry->req.iov_cnt = iov_cnt;
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/* All offsets relative to mb_addr, not start of entry! */
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cdb_off = CMDR_OFF + cmd_head + base_command_size;
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memcpy((void *) mb + cdb_off, se_cmd->t_task_cdb, scsi_command_size(se_cmd->t_task_cdb));
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entry->req.cdb_off = cdb_off;
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tcmu_flush_dcache_range(entry, sizeof(*entry));
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UPDATE_HEAD(mb->cmd_head, command_size, udev->cmdr_size);
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tcmu_flush_dcache_range(mb, sizeof(*mb));
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spin_unlock_irq(&udev->cmdr_lock);
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/* TODO: only if FLUSH and FUA? */
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uio_event_notify(&udev->uio_info);
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mod_timer(&udev->timeout,
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round_jiffies_up(jiffies + msecs_to_jiffies(TCMU_TIME_OUT)));
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return 0;
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}
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static int tcmu_queue_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 ret;
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tcmu_cmd = tcmu_alloc_cmd(se_cmd);
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if (!tcmu_cmd)
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return -ENOMEM;
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ret = tcmu_queue_cmd_ring(tcmu_cmd);
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if (ret < 0) {
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pr_err("TCMU: Could not queue command\n");
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spin_lock_irq(&udev->commands_lock);
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idr_remove(&udev->commands, tcmu_cmd->cmd_id);
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spin_unlock_irq(&udev->commands_lock);
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kmem_cache_free(tcmu_cmd_cache, tcmu_cmd);
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}
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return ret;
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}
|
|
|
|
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;
|
|
|
|
if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags)) {
|
|
/* cmd has been completed already from timeout, just reclaim data
|
|
ring space */
|
|
UPDATE_HEAD(udev->data_tail, cmd->data_length, udev->data_size);
|
|
return;
|
|
}
|
|
|
|
if (entry->rsp.scsi_status == SAM_STAT_CHECK_CONDITION) {
|
|
memcpy(se_cmd->sense_buffer, entry->rsp.sense_buffer,
|
|
se_cmd->scsi_sense_length);
|
|
|
|
UPDATE_HEAD(udev->data_tail, cmd->data_length, udev->data_size);
|
|
}
|
|
else if (se_cmd->data_direction == DMA_FROM_DEVICE) {
|
|
struct scatterlist *sg;
|
|
int i;
|
|
|
|
/* It'd be easier to look at entry's iovec again, but UAM */
|
|
for_each_sg(se_cmd->t_data_sg, sg, se_cmd->t_data_nents, i) {
|
|
size_t copy_bytes;
|
|
void *to;
|
|
void *from;
|
|
|
|
copy_bytes = min((size_t)sg->length,
|
|
head_to_end(udev->data_tail, udev->data_size));
|
|
|
|
to = kmap_atomic(sg_page(sg)) + sg->offset;
|
|
WARN_ON(sg->length + sg->offset > PAGE_SIZE);
|
|
from = (void *) udev->mb_addr + udev->data_off + udev->data_tail;
|
|
tcmu_flush_dcache_range(from, copy_bytes);
|
|
memcpy(to, from, copy_bytes);
|
|
|
|
UPDATE_HEAD(udev->data_tail, copy_bytes, udev->data_size);
|
|
|
|
/* Uh oh, wrapped the data buffer for this sg's data */
|
|
if (sg->length != copy_bytes) {
|
|
from = (void *) udev->mb_addr + udev->data_off + udev->data_tail;
|
|
WARN_ON(udev->data_tail);
|
|
to += copy_bytes;
|
|
copy_bytes = sg->length - copy_bytes;
|
|
tcmu_flush_dcache_range(from, copy_bytes);
|
|
memcpy(to, from, copy_bytes);
|
|
|
|
UPDATE_HEAD(udev->data_tail, copy_bytes, udev->data_size);
|
|
}
|
|
|
|
kunmap_atomic(to);
|
|
}
|
|
|
|
} else if (se_cmd->data_direction == DMA_TO_DEVICE) {
|
|
UPDATE_HEAD(udev->data_tail, cmd->data_length, udev->data_size);
|
|
} else {
|
|
pr_warn("TCMU: data direction was %d!\n", se_cmd->data_direction);
|
|
}
|
|
|
|
target_complete_cmd(cmd->se_cmd, entry->rsp.scsi_status);
|
|
cmd->se_cmd = NULL;
|
|
|
|
kmem_cache_free(tcmu_cmd_cache, cmd);
|
|
}
|
|
|
|
static unsigned int tcmu_handle_completions(struct tcmu_dev *udev)
|
|
{
|
|
struct tcmu_mailbox *mb;
|
|
LIST_HEAD(cpl_cmds);
|
|
unsigned long flags;
|
|
int handled = 0;
|
|
|
|
if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags)) {
|
|
pr_err("ring broken, not handling completions\n");
|
|
return 0;
|
|
}
|
|
|
|
spin_lock_irqsave(&udev->cmdr_lock, flags);
|
|
|
|
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) == TCMU_OP_PAD) {
|
|
UPDATE_HEAD(udev->cmdr_last_cleaned, tcmu_hdr_get_len(&entry->hdr), udev->cmdr_size);
|
|
continue;
|
|
}
|
|
WARN_ON(tcmu_hdr_get_op(&entry->hdr) != TCMU_OP_CMD);
|
|
|
|
spin_lock(&udev->commands_lock);
|
|
cmd = idr_find(&udev->commands, entry->cmd_id);
|
|
if (cmd)
|
|
idr_remove(&udev->commands, cmd->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), udev->cmdr_size);
|
|
|
|
handled++;
|
|
}
|
|
|
|
if (mb->cmd_tail == mb->cmd_head)
|
|
del_timer(&udev->timeout); /* no more pending cmds */
|
|
|
|
spin_unlock_irqrestore(&udev->cmdr_lock, flags);
|
|
|
|
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(cmd->deadline, jiffies))
|
|
return 0;
|
|
|
|
set_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags);
|
|
target_complete_cmd(cmd->se_cmd, SAM_STAT_CHECK_CONDITION);
|
|
cmd->se_cmd = NULL;
|
|
|
|
kmem_cache_free(tcmu_cmd_cache, cmd);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void tcmu_device_timedout(unsigned long data)
|
|
{
|
|
struct tcmu_dev *udev = (struct tcmu_dev *)data;
|
|
unsigned long flags;
|
|
int handled;
|
|
|
|
handled = tcmu_handle_completions(udev);
|
|
|
|
pr_warn("%d completions handled from timeout\n", handled);
|
|
|
|
spin_lock_irqsave(&udev->commands_lock, flags);
|
|
idr_for_each(&udev->commands, tcmu_check_expired_cmd, NULL);
|
|
spin_unlock_irqrestore(&udev->commands_lock, flags);
|
|
|
|
/*
|
|
* 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;
|
|
|
|
udev->name = kstrdup(name, GFP_KERNEL);
|
|
if (!udev->name) {
|
|
kfree(udev);
|
|
return NULL;
|
|
}
|
|
|
|
udev->hba = hba;
|
|
|
|
init_waitqueue_head(&udev->wait_cmdr);
|
|
spin_lock_init(&udev->cmdr_lock);
|
|
|
|
idr_init(&udev->commands);
|
|
spin_lock_init(&udev->commands_lock);
|
|
|
|
setup_timer(&udev->timeout, tcmu_device_timedout,
|
|
(unsigned long)udev);
|
|
|
|
udev->pass_level = TCMU_PASS_ALL;
|
|
|
|
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);
|
|
|
|
tcmu_handle_completions(tcmu_dev);
|
|
|
|
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 int tcmu_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
|
|
{
|
|
struct tcmu_dev *udev = 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(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;
|
|
|
|
addr = (void *)(unsigned long)info->mem[mi].addr + offset;
|
|
if (info->mem[mi].memtype == UIO_MEM_LOGICAL)
|
|
page = virt_to_page(addr);
|
|
else
|
|
page = vmalloc_to_page(addr);
|
|
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;
|
|
|
|
pr_debug("open\n");
|
|
|
|
return 0;
|
|
}
|
|
|
|
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");
|
|
|
|
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(&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(TCMU_RING_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 = TCMU_RING_SIZE - CMDR_SIZE;
|
|
|
|
mb = udev->mb_addr;
|
|
mb->version = 1;
|
|
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);
|
|
|
|
info->version = "1";
|
|
|
|
info->mem[0].name = "tcm-user command & data buffer";
|
|
info->mem[0].addr = (phys_addr_t) udev->mb_addr;
|
|
info->mem[0].size = TCMU_RING_SIZE;
|
|
info->mem[0].memtype = UIO_MEM_VIRTUAL;
|
|
|
|
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;
|
|
|
|
/* Other attributes can be configured in userspace */
|
|
dev->dev_attrib.hw_block_size = 512;
|
|
dev->dev_attrib.hw_max_sectors = 128;
|
|
dev->dev_attrib.hw_queue_depth = 128;
|
|
|
|
ret = tcmu_netlink_event(TCMU_CMD_ADDED_DEVICE, udev->uio_info.name,
|
|
udev->uio_info.uio_dev->minor);
|
|
if (ret)
|
|
goto err_netlink;
|
|
|
|
return 0;
|
|
|
|
err_netlink:
|
|
uio_unregister_device(&udev->uio_info);
|
|
err_register:
|
|
vfree(udev->mb_addr);
|
|
err_vzalloc:
|
|
kfree(info->name);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int tcmu_check_pending_cmd(int id, void *p, void *data)
|
|
{
|
|
struct tcmu_cmd *cmd = p;
|
|
|
|
if (test_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags))
|
|
return 0;
|
|
return -EINVAL;
|
|
}
|
|
|
|
static void tcmu_free_device(struct se_device *dev)
|
|
{
|
|
struct tcmu_dev *udev = TCMU_DEV(dev);
|
|
int i;
|
|
|
|
del_timer_sync(&udev->timeout);
|
|
|
|
vfree(udev->mb_addr);
|
|
|
|
/* Upper layer should drain all requests before calling this */
|
|
spin_lock_irq(&udev->commands_lock);
|
|
i = idr_for_each(&udev->commands, tcmu_check_pending_cmd, NULL);
|
|
idr_destroy(&udev->commands);
|
|
spin_unlock_irq(&udev->commands_lock);
|
|
WARN_ON(i);
|
|
|
|
/* Device was configured */
|
|
if (udev->uio_info.uio_dev) {
|
|
tcmu_netlink_event(TCMU_CMD_REMOVED_DEVICE, udev->uio_info.name,
|
|
udev->uio_info.uio_dev->minor);
|
|
|
|
uio_unregister_device(&udev->uio_info);
|
|
kfree(udev->uio_info.name);
|
|
kfree(udev->name);
|
|
}
|
|
|
|
kfree(udev);
|
|
}
|
|
|
|
enum {
|
|
Opt_dev_config, Opt_dev_size, Opt_err, Opt_pass_level,
|
|
};
|
|
|
|
static match_table_t tokens = {
|
|
{Opt_dev_config, "dev_config=%s"},
|
|
{Opt_dev_size, "dev_size=%u"},
|
|
{Opt_pass_level, "pass_level=%u"},
|
|
{Opt_err, NULL}
|
|
};
|
|
|
|
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;
|
|
int arg;
|
|
|
|
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_pass_level:
|
|
match_int(args, &arg);
|
|
if (arg >= TCMU_PASS_INVALID) {
|
|
pr_warn("TCMU: Invalid pass_level: %d\n", arg);
|
|
break;
|
|
}
|
|
|
|
pr_debug("TCMU: Setting pass_level to %d\n", arg);
|
|
udev->pass_level = arg;
|
|
break;
|
|
default:
|
|
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 PassLevel: %u\n",
|
|
udev->dev_size, udev->pass_level);
|
|
|
|
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_execute_rw(struct se_cmd *se_cmd, struct scatterlist *sgl, u32 sgl_nents,
|
|
enum dma_data_direction data_direction)
|
|
{
|
|
int ret;
|
|
|
|
ret = tcmu_queue_cmd(se_cmd);
|
|
|
|
if (ret != 0)
|
|
return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
|
|
else
|
|
return TCM_NO_SENSE;
|
|
}
|
|
|
|
static sense_reason_t
|
|
tcmu_pass_op(struct se_cmd *se_cmd)
|
|
{
|
|
int ret = tcmu_queue_cmd(se_cmd);
|
|
|
|
if (ret != 0)
|
|
return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
|
|
else
|
|
return TCM_NO_SENSE;
|
|
}
|
|
|
|
static struct sbc_ops tcmu_sbc_ops = {
|
|
.execute_rw = tcmu_execute_rw,
|
|
.execute_sync_cache = tcmu_pass_op,
|
|
.execute_write_same = tcmu_pass_op,
|
|
.execute_write_same_unmap = tcmu_pass_op,
|
|
.execute_unmap = tcmu_pass_op,
|
|
};
|
|
|
|
static sense_reason_t
|
|
tcmu_parse_cdb(struct se_cmd *cmd)
|
|
{
|
|
unsigned char *cdb = cmd->t_task_cdb;
|
|
struct tcmu_dev *udev = TCMU_DEV(cmd->se_dev);
|
|
sense_reason_t ret;
|
|
|
|
switch (udev->pass_level) {
|
|
case TCMU_PASS_ALL:
|
|
/* We're just like pscsi, then */
|
|
/*
|
|
* For REPORT LUNS we always need to emulate the response, for everything
|
|
* else, pass it up.
|
|
*/
|
|
switch (cdb[0]) {
|
|
case REPORT_LUNS:
|
|
cmd->execute_cmd = spc_emulate_report_luns;
|
|
break;
|
|
case READ_6:
|
|
case READ_10:
|
|
case READ_12:
|
|
case READ_16:
|
|
case WRITE_6:
|
|
case WRITE_10:
|
|
case WRITE_12:
|
|
case WRITE_16:
|
|
case WRITE_VERIFY:
|
|
cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
|
|
/* FALLTHROUGH */
|
|
default:
|
|
cmd->execute_cmd = tcmu_pass_op;
|
|
}
|
|
ret = TCM_NO_SENSE;
|
|
break;
|
|
case TCMU_PASS_IO:
|
|
ret = sbc_parse_cdb(cmd, &tcmu_sbc_ops);
|
|
break;
|
|
default:
|
|
pr_err("Unknown tcm-user pass level %d\n", udev->pass_level);
|
|
ret = TCM_CHECK_CONDITION_ABORT_CMD;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
DEF_TB_DEFAULT_ATTRIBS(tcmu);
|
|
|
|
static struct configfs_attribute *tcmu_backend_dev_attrs[] = {
|
|
&tcmu_dev_attrib_emulate_model_alias.attr,
|
|
&tcmu_dev_attrib_emulate_dpo.attr,
|
|
&tcmu_dev_attrib_emulate_fua_write.attr,
|
|
&tcmu_dev_attrib_emulate_fua_read.attr,
|
|
&tcmu_dev_attrib_emulate_write_cache.attr,
|
|
&tcmu_dev_attrib_emulate_ua_intlck_ctrl.attr,
|
|
&tcmu_dev_attrib_emulate_tas.attr,
|
|
&tcmu_dev_attrib_emulate_tpu.attr,
|
|
&tcmu_dev_attrib_emulate_tpws.attr,
|
|
&tcmu_dev_attrib_emulate_caw.attr,
|
|
&tcmu_dev_attrib_emulate_3pc.attr,
|
|
&tcmu_dev_attrib_pi_prot_type.attr,
|
|
&tcmu_dev_attrib_hw_pi_prot_type.attr,
|
|
&tcmu_dev_attrib_pi_prot_format.attr,
|
|
&tcmu_dev_attrib_enforce_pr_isids.attr,
|
|
&tcmu_dev_attrib_is_nonrot.attr,
|
|
&tcmu_dev_attrib_emulate_rest_reord.attr,
|
|
&tcmu_dev_attrib_force_pr_aptpl.attr,
|
|
&tcmu_dev_attrib_hw_block_size.attr,
|
|
&tcmu_dev_attrib_block_size.attr,
|
|
&tcmu_dev_attrib_hw_max_sectors.attr,
|
|
&tcmu_dev_attrib_optimal_sectors.attr,
|
|
&tcmu_dev_attrib_hw_queue_depth.attr,
|
|
&tcmu_dev_attrib_queue_depth.attr,
|
|
&tcmu_dev_attrib_max_unmap_lba_count.attr,
|
|
&tcmu_dev_attrib_max_unmap_block_desc_count.attr,
|
|
&tcmu_dev_attrib_unmap_granularity.attr,
|
|
&tcmu_dev_attrib_unmap_granularity_alignment.attr,
|
|
&tcmu_dev_attrib_max_write_same_len.attr,
|
|
NULL,
|
|
};
|
|
|
|
static struct se_subsystem_api tcmu_template = {
|
|
.name = "user",
|
|
.inquiry_prod = "USER",
|
|
.inquiry_rev = TCMU_VERSION,
|
|
.owner = THIS_MODULE,
|
|
.transport_type = TRANSPORT_PLUGIN_VHBA_PDEV,
|
|
.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,
|
|
};
|
|
|
|
static int __init tcmu_module_init(void)
|
|
{
|
|
struct target_backend_cits *tbc = &tcmu_template.tb_cits;
|
|
int ret;
|
|
|
|
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;
|
|
}
|
|
|
|
target_core_setup_sub_cits(&tcmu_template);
|
|
tbc->tb_dev_attrib_cit.ct_attrs = tcmu_backend_dev_attrs;
|
|
|
|
ret = transport_subsystem_register(&tcmu_template);
|
|
if (ret)
|
|
goto out_unreg_genl;
|
|
|
|
return 0;
|
|
|
|
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)
|
|
{
|
|
transport_subsystem_release(&tcmu_template);
|
|
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);
|