2
0
mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-25 13:43:55 +08:00
linux-next/drivers/scsi/scsi_tgt_lib.c
Tejun Heo 5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00

662 lines
16 KiB
C

/*
* SCSI target lib functions
*
* Copyright (C) 2005 Mike Christie <michaelc@cs.wisc.edu>
* Copyright (C) 2005 FUJITA Tomonori <tomof@acm.org>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA
*/
#include <linux/blkdev.h>
#include <linux/hash.h>
#include <linux/module.h>
#include <linux/pagemap.h>
#include <linux/slab.h>
#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_transport.h>
#include <scsi/scsi_tgt.h>
#include "scsi_tgt_priv.h"
static struct workqueue_struct *scsi_tgtd;
static struct kmem_cache *scsi_tgt_cmd_cache;
/*
* TODO: this struct will be killed when the block layer supports large bios
* and James's work struct code is in
*/
struct scsi_tgt_cmd {
/* TODO replace work with James b's code */
struct work_struct work;
/* TODO fix limits of some drivers */
struct bio *bio;
struct list_head hash_list;
struct request *rq;
u64 itn_id;
u64 tag;
};
#define TGT_HASH_ORDER 4
#define cmd_hashfn(tag) hash_long((unsigned long) (tag), TGT_HASH_ORDER)
struct scsi_tgt_queuedata {
struct Scsi_Host *shost;
struct list_head cmd_hash[1 << TGT_HASH_ORDER];
spinlock_t cmd_hash_lock;
};
/*
* Function: scsi_host_get_command()
*
* Purpose: Allocate and setup a scsi command block and blk request
*
* Arguments: shost - scsi host
* data_dir - dma data dir
* gfp_mask- allocator flags
*
* Returns: The allocated scsi command structure.
*
* This should be called by target LLDs to get a command.
*/
struct scsi_cmnd *scsi_host_get_command(struct Scsi_Host *shost,
enum dma_data_direction data_dir,
gfp_t gfp_mask)
{
int write = (data_dir == DMA_TO_DEVICE);
struct request *rq;
struct scsi_cmnd *cmd;
struct scsi_tgt_cmd *tcmd;
/* Bail if we can't get a reference to the device */
if (!get_device(&shost->shost_gendev))
return NULL;
tcmd = kmem_cache_alloc(scsi_tgt_cmd_cache, GFP_ATOMIC);
if (!tcmd)
goto put_dev;
/*
* The blk helpers are used to the READ/WRITE requests
* transfering data from a initiator point of view. Since
* we are in target mode we want the opposite.
*/
rq = blk_get_request(shost->uspace_req_q, !write, gfp_mask);
if (!rq)
goto free_tcmd;
cmd = __scsi_get_command(shost, gfp_mask);
if (!cmd)
goto release_rq;
cmd->sc_data_direction = data_dir;
cmd->jiffies_at_alloc = jiffies;
cmd->request = rq;
cmd->cmnd = rq->cmd;
rq->special = cmd;
rq->cmd_type = REQ_TYPE_SPECIAL;
rq->cmd_flags |= REQ_TYPE_BLOCK_PC;
rq->end_io_data = tcmd;
tcmd->rq = rq;
return cmd;
release_rq:
blk_put_request(rq);
free_tcmd:
kmem_cache_free(scsi_tgt_cmd_cache, tcmd);
put_dev:
put_device(&shost->shost_gendev);
return NULL;
}
EXPORT_SYMBOL_GPL(scsi_host_get_command);
/*
* Function: scsi_host_put_command()
*
* Purpose: Free a scsi command block
*
* Arguments: shost - scsi host
* cmd - command block to free
*
* Returns: Nothing.
*
* Notes: The command must not belong to any lists.
*/
void scsi_host_put_command(struct Scsi_Host *shost, struct scsi_cmnd *cmd)
{
struct request_queue *q = shost->uspace_req_q;
struct request *rq = cmd->request;
struct scsi_tgt_cmd *tcmd = rq->end_io_data;
unsigned long flags;
kmem_cache_free(scsi_tgt_cmd_cache, tcmd);
spin_lock_irqsave(q->queue_lock, flags);
__blk_put_request(q, rq);
spin_unlock_irqrestore(q->queue_lock, flags);
__scsi_put_command(shost, cmd, &shost->shost_gendev);
}
EXPORT_SYMBOL_GPL(scsi_host_put_command);
static void cmd_hashlist_del(struct scsi_cmnd *cmd)
{
struct request_queue *q = cmd->request->q;
struct scsi_tgt_queuedata *qdata = q->queuedata;
unsigned long flags;
struct scsi_tgt_cmd *tcmd = cmd->request->end_io_data;
spin_lock_irqsave(&qdata->cmd_hash_lock, flags);
list_del(&tcmd->hash_list);
spin_unlock_irqrestore(&qdata->cmd_hash_lock, flags);
}
static void scsi_unmap_user_pages(struct scsi_tgt_cmd *tcmd)
{
blk_rq_unmap_user(tcmd->bio);
}
static void scsi_tgt_cmd_destroy(struct work_struct *work)
{
struct scsi_tgt_cmd *tcmd =
container_of(work, struct scsi_tgt_cmd, work);
struct scsi_cmnd *cmd = tcmd->rq->special;
dprintk("cmd %p %d %u\n", cmd, cmd->sc_data_direction,
rq_data_dir(cmd->request));
scsi_unmap_user_pages(tcmd);
scsi_host_put_command(scsi_tgt_cmd_to_host(cmd), cmd);
}
static void init_scsi_tgt_cmd(struct request *rq, struct scsi_tgt_cmd *tcmd,
u64 itn_id, u64 tag)
{
struct scsi_tgt_queuedata *qdata = rq->q->queuedata;
unsigned long flags;
struct list_head *head;
tcmd->itn_id = itn_id;
tcmd->tag = tag;
tcmd->bio = NULL;
INIT_WORK(&tcmd->work, scsi_tgt_cmd_destroy);
spin_lock_irqsave(&qdata->cmd_hash_lock, flags);
head = &qdata->cmd_hash[cmd_hashfn(tag)];
list_add(&tcmd->hash_list, head);
spin_unlock_irqrestore(&qdata->cmd_hash_lock, flags);
}
/*
* scsi_tgt_alloc_queue - setup queue used for message passing
* shost: scsi host
*
* This should be called by the LLD after host allocation.
* And will be released when the host is released.
*/
int scsi_tgt_alloc_queue(struct Scsi_Host *shost)
{
struct scsi_tgt_queuedata *queuedata;
struct request_queue *q;
int err, i;
/*
* Do we need to send a netlink event or should uspace
* just respond to the hotplug event?
*/
q = __scsi_alloc_queue(shost, NULL);
if (!q)
return -ENOMEM;
queuedata = kzalloc(sizeof(*queuedata), GFP_KERNEL);
if (!queuedata) {
err = -ENOMEM;
goto cleanup_queue;
}
queuedata->shost = shost;
q->queuedata = queuedata;
/*
* this is a silly hack. We should probably just queue as many
* command as is recvd to userspace. uspace can then make
* sure we do not overload the HBA
*/
q->nr_requests = shost->can_queue;
/*
* We currently only support software LLDs so this does
* not matter for now. Do we need this for the cards we support?
* If so we should make it a host template value.
*/
blk_queue_dma_alignment(q, 0);
shost->uspace_req_q = q;
for (i = 0; i < ARRAY_SIZE(queuedata->cmd_hash); i++)
INIT_LIST_HEAD(&queuedata->cmd_hash[i]);
spin_lock_init(&queuedata->cmd_hash_lock);
return 0;
cleanup_queue:
blk_cleanup_queue(q);
return err;
}
EXPORT_SYMBOL_GPL(scsi_tgt_alloc_queue);
void scsi_tgt_free_queue(struct Scsi_Host *shost)
{
int i;
unsigned long flags;
struct request_queue *q = shost->uspace_req_q;
struct scsi_cmnd *cmd;
struct scsi_tgt_queuedata *qdata = q->queuedata;
struct scsi_tgt_cmd *tcmd, *n;
LIST_HEAD(cmds);
spin_lock_irqsave(&qdata->cmd_hash_lock, flags);
for (i = 0; i < ARRAY_SIZE(qdata->cmd_hash); i++) {
list_for_each_entry_safe(tcmd, n, &qdata->cmd_hash[i],
hash_list) {
list_del(&tcmd->hash_list);
list_add(&tcmd->hash_list, &cmds);
}
}
spin_unlock_irqrestore(&qdata->cmd_hash_lock, flags);
while (!list_empty(&cmds)) {
tcmd = list_entry(cmds.next, struct scsi_tgt_cmd, hash_list);
list_del(&tcmd->hash_list);
cmd = tcmd->rq->special;
shost->hostt->eh_abort_handler(cmd);
scsi_tgt_cmd_destroy(&tcmd->work);
}
}
EXPORT_SYMBOL_GPL(scsi_tgt_free_queue);
struct Scsi_Host *scsi_tgt_cmd_to_host(struct scsi_cmnd *cmd)
{
struct scsi_tgt_queuedata *queue = cmd->request->q->queuedata;
return queue->shost;
}
EXPORT_SYMBOL_GPL(scsi_tgt_cmd_to_host);
/*
* scsi_tgt_queue_command - queue command for userspace processing
* @cmd: scsi command
* @scsilun: scsi lun
* @tag: unique value to identify this command for tmf
*/
int scsi_tgt_queue_command(struct scsi_cmnd *cmd, u64 itn_id,
struct scsi_lun *scsilun, u64 tag)
{
struct scsi_tgt_cmd *tcmd = cmd->request->end_io_data;
int err;
init_scsi_tgt_cmd(cmd->request, tcmd, itn_id, tag);
err = scsi_tgt_uspace_send_cmd(cmd, itn_id, scsilun, tag);
if (err)
cmd_hashlist_del(cmd);
return err;
}
EXPORT_SYMBOL_GPL(scsi_tgt_queue_command);
/*
* This is run from a interrupt handler normally and the unmap
* needs process context so we must queue
*/
static void scsi_tgt_cmd_done(struct scsi_cmnd *cmd)
{
struct scsi_tgt_cmd *tcmd = cmd->request->end_io_data;
dprintk("cmd %p %u\n", cmd, rq_data_dir(cmd->request));
scsi_tgt_uspace_send_status(cmd, tcmd->itn_id, tcmd->tag);
scsi_release_buffers(cmd);
queue_work(scsi_tgtd, &tcmd->work);
}
static int scsi_tgt_transfer_response(struct scsi_cmnd *cmd)
{
struct Scsi_Host *shost = scsi_tgt_cmd_to_host(cmd);
int err;
dprintk("cmd %p %u\n", cmd, rq_data_dir(cmd->request));
err = shost->hostt->transfer_response(cmd, scsi_tgt_cmd_done);
switch (err) {
case SCSI_MLQUEUE_HOST_BUSY:
case SCSI_MLQUEUE_DEVICE_BUSY:
return -EAGAIN;
}
return 0;
}
/* TODO: test this crap and replace bio_map_user with new interface maybe */
static int scsi_map_user_pages(struct scsi_tgt_cmd *tcmd, struct scsi_cmnd *cmd,
unsigned long uaddr, unsigned int len, int rw)
{
struct request_queue *q = cmd->request->q;
struct request *rq = cmd->request;
int err;
dprintk("%lx %u\n", uaddr, len);
err = blk_rq_map_user(q, rq, NULL, (void *)uaddr, len, GFP_KERNEL);
if (err) {
/*
* TODO: need to fixup sg_tablesize, max_segment_size,
* max_sectors, etc for modern HW and software drivers
* where this value is bogus.
*
* TODO2: we can alloc a reserve buffer of max size
* we can handle and do the slow copy path for really large
* IO.
*/
eprintk("Could not handle request of size %u.\n", len);
return err;
}
tcmd->bio = rq->bio;
err = scsi_init_io(cmd, GFP_KERNEL);
if (err) {
scsi_release_buffers(cmd);
goto unmap_rq;
}
/*
* we use REQ_TYPE_BLOCK_PC so scsi_init_io doesn't set the
* length for us.
*/
cmd->sdb.length = blk_rq_bytes(rq);
return 0;
unmap_rq:
scsi_unmap_user_pages(tcmd);
return err;
}
static int scsi_tgt_copy_sense(struct scsi_cmnd *cmd, unsigned long uaddr,
unsigned len)
{
char __user *p = (char __user *) uaddr;
if (copy_from_user(cmd->sense_buffer, p,
min_t(unsigned, SCSI_SENSE_BUFFERSIZE, len))) {
printk(KERN_ERR "Could not copy the sense buffer\n");
return -EIO;
}
return 0;
}
static int scsi_tgt_abort_cmd(struct Scsi_Host *shost, struct scsi_cmnd *cmd)
{
struct scsi_tgt_cmd *tcmd;
int err;
err = shost->hostt->eh_abort_handler(cmd);
if (err)
eprintk("fail to abort %p\n", cmd);
tcmd = cmd->request->end_io_data;
scsi_tgt_cmd_destroy(&tcmd->work);
return err;
}
static struct request *tgt_cmd_hash_lookup(struct request_queue *q, u64 tag)
{
struct scsi_tgt_queuedata *qdata = q->queuedata;
struct request *rq = NULL;
struct list_head *head;
struct scsi_tgt_cmd *tcmd;
unsigned long flags;
head = &qdata->cmd_hash[cmd_hashfn(tag)];
spin_lock_irqsave(&qdata->cmd_hash_lock, flags);
list_for_each_entry(tcmd, head, hash_list) {
if (tcmd->tag == tag) {
rq = tcmd->rq;
list_del(&tcmd->hash_list);
break;
}
}
spin_unlock_irqrestore(&qdata->cmd_hash_lock, flags);
return rq;
}
int scsi_tgt_kspace_exec(int host_no, u64 itn_id, int result, u64 tag,
unsigned long uaddr, u32 len, unsigned long sense_uaddr,
u32 sense_len, u8 rw)
{
struct Scsi_Host *shost;
struct scsi_cmnd *cmd;
struct request *rq;
struct scsi_tgt_cmd *tcmd;
int err = 0;
dprintk("%d %llu %d %u %lx %u\n", host_no, (unsigned long long) tag,
result, len, uaddr, rw);
/* TODO: replace with a O(1) alg */
shost = scsi_host_lookup(host_no);
if (!shost) {
printk(KERN_ERR "Could not find host no %d\n", host_no);
return -EINVAL;
}
if (!shost->uspace_req_q) {
printk(KERN_ERR "Not target scsi host %d\n", host_no);
goto done;
}
rq = tgt_cmd_hash_lookup(shost->uspace_req_q, tag);
if (!rq) {
printk(KERN_ERR "Could not find tag %llu\n",
(unsigned long long) tag);
err = -EINVAL;
goto done;
}
cmd = rq->special;
dprintk("cmd %p scb %x result %d len %d bufflen %u %u %x\n",
cmd, cmd->cmnd[0], result, len, scsi_bufflen(cmd),
rq_data_dir(rq), cmd->cmnd[0]);
if (result == TASK_ABORTED) {
scsi_tgt_abort_cmd(shost, cmd);
goto done;
}
/*
* store the userspace values here, the working values are
* in the request_* values
*/
tcmd = cmd->request->end_io_data;
cmd->result = result;
if (cmd->result == SAM_STAT_CHECK_CONDITION)
scsi_tgt_copy_sense(cmd, sense_uaddr, sense_len);
if (len) {
err = scsi_map_user_pages(rq->end_io_data, cmd, uaddr, len, rw);
if (err) {
/*
* user-space daemon bugs or OOM
* TODO: we can do better for OOM.
*/
struct scsi_tgt_queuedata *qdata;
struct list_head *head;
unsigned long flags;
eprintk("cmd %p ret %d uaddr %lx len %d rw %d\n",
cmd, err, uaddr, len, rw);
qdata = shost->uspace_req_q->queuedata;
head = &qdata->cmd_hash[cmd_hashfn(tcmd->tag)];
spin_lock_irqsave(&qdata->cmd_hash_lock, flags);
list_add(&tcmd->hash_list, head);
spin_unlock_irqrestore(&qdata->cmd_hash_lock, flags);
goto done;
}
}
err = scsi_tgt_transfer_response(cmd);
done:
scsi_host_put(shost);
return err;
}
int scsi_tgt_tsk_mgmt_request(struct Scsi_Host *shost, u64 itn_id,
int function, u64 tag, struct scsi_lun *scsilun,
void *data)
{
int err;
/* TODO: need to retry if this fails. */
err = scsi_tgt_uspace_send_tsk_mgmt(shost->host_no, itn_id,
function, tag, scsilun, data);
if (err < 0)
eprintk("The task management request lost!\n");
return err;
}
EXPORT_SYMBOL_GPL(scsi_tgt_tsk_mgmt_request);
int scsi_tgt_kspace_tsk_mgmt(int host_no, u64 itn_id, u64 mid, int result)
{
struct Scsi_Host *shost;
int err = -EINVAL;
dprintk("%d %d %llx\n", host_no, result, (unsigned long long) mid);
shost = scsi_host_lookup(host_no);
if (!shost) {
printk(KERN_ERR "Could not find host no %d\n", host_no);
return err;
}
if (!shost->uspace_req_q) {
printk(KERN_ERR "Not target scsi host %d\n", host_no);
goto done;
}
err = shost->transportt->tsk_mgmt_response(shost, itn_id, mid, result);
done:
scsi_host_put(shost);
return err;
}
int scsi_tgt_it_nexus_create(struct Scsi_Host *shost, u64 itn_id,
char *initiator)
{
int err;
/* TODO: need to retry if this fails. */
err = scsi_tgt_uspace_send_it_nexus_request(shost->host_no, itn_id, 0,
initiator);
if (err < 0)
eprintk("The i_t_neuxs request lost, %d %llx!\n",
shost->host_no, (unsigned long long)itn_id);
return err;
}
EXPORT_SYMBOL_GPL(scsi_tgt_it_nexus_create);
int scsi_tgt_it_nexus_destroy(struct Scsi_Host *shost, u64 itn_id)
{
int err;
/* TODO: need to retry if this fails. */
err = scsi_tgt_uspace_send_it_nexus_request(shost->host_no,
itn_id, 1, NULL);
if (err < 0)
eprintk("The i_t_neuxs request lost, %d %llx!\n",
shost->host_no, (unsigned long long)itn_id);
return err;
}
EXPORT_SYMBOL_GPL(scsi_tgt_it_nexus_destroy);
int scsi_tgt_kspace_it_nexus_rsp(int host_no, u64 itn_id, int result)
{
struct Scsi_Host *shost;
int err = -EINVAL;
dprintk("%d %d%llx\n", host_no, result, (unsigned long long)itn_id);
shost = scsi_host_lookup(host_no);
if (!shost) {
printk(KERN_ERR "Could not find host no %d\n", host_no);
return err;
}
if (!shost->uspace_req_q) {
printk(KERN_ERR "Not target scsi host %d\n", host_no);
goto done;
}
err = shost->transportt->it_nexus_response(shost, itn_id, result);
done:
scsi_host_put(shost);
return err;
}
static int __init scsi_tgt_init(void)
{
int err;
scsi_tgt_cmd_cache = KMEM_CACHE(scsi_tgt_cmd, 0);
if (!scsi_tgt_cmd_cache)
return -ENOMEM;
scsi_tgtd = create_workqueue("scsi_tgtd");
if (!scsi_tgtd) {
err = -ENOMEM;
goto free_kmemcache;
}
err = scsi_tgt_if_init();
if (err)
goto destroy_wq;
return 0;
destroy_wq:
destroy_workqueue(scsi_tgtd);
free_kmemcache:
kmem_cache_destroy(scsi_tgt_cmd_cache);
return err;
}
static void __exit scsi_tgt_exit(void)
{
destroy_workqueue(scsi_tgtd);
scsi_tgt_if_exit();
kmem_cache_destroy(scsi_tgt_cmd_cache);
}
module_init(scsi_tgt_init);
module_exit(scsi_tgt_exit);
MODULE_DESCRIPTION("SCSI target core");
MODULE_LICENSE("GPL");