mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-05 15:26:42 +07:00
5a0e3ad6af
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>
1122 lines
24 KiB
C
1122 lines
24 KiB
C
/*
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* bsg.c - block layer implementation of the sg v4 interface
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*
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* Copyright (C) 2004 Jens Axboe <axboe@suse.de> SUSE Labs
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* Copyright (C) 2004 Peter M. Jones <pjones@redhat.com>
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License version 2. See the file "COPYING" in the main directory of this
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* archive for more details.
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*
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*/
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/file.h>
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#include <linux/blkdev.h>
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#include <linux/poll.h>
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#include <linux/cdev.h>
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#include <linux/jiffies.h>
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#include <linux/percpu.h>
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#include <linux/uio.h>
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#include <linux/idr.h>
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#include <linux/bsg.h>
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#include <linux/smp_lock.h>
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#include <linux/slab.h>
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#include <scsi/scsi.h>
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#include <scsi/scsi_ioctl.h>
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#include <scsi/scsi_cmnd.h>
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#include <scsi/scsi_device.h>
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#include <scsi/scsi_driver.h>
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#include <scsi/sg.h>
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#define BSG_DESCRIPTION "Block layer SCSI generic (bsg) driver"
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#define BSG_VERSION "0.4"
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struct bsg_device {
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struct request_queue *queue;
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spinlock_t lock;
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struct list_head busy_list;
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struct list_head done_list;
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struct hlist_node dev_list;
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atomic_t ref_count;
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int queued_cmds;
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int done_cmds;
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wait_queue_head_t wq_done;
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wait_queue_head_t wq_free;
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char name[20];
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int max_queue;
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unsigned long flags;
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};
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enum {
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BSG_F_BLOCK = 1,
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};
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#define BSG_DEFAULT_CMDS 64
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#define BSG_MAX_DEVS 32768
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#undef BSG_DEBUG
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#ifdef BSG_DEBUG
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#define dprintk(fmt, args...) printk(KERN_ERR "%s: " fmt, __func__, ##args)
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#else
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#define dprintk(fmt, args...)
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#endif
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static DEFINE_MUTEX(bsg_mutex);
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static DEFINE_IDR(bsg_minor_idr);
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#define BSG_LIST_ARRAY_SIZE 8
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static struct hlist_head bsg_device_list[BSG_LIST_ARRAY_SIZE];
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static struct class *bsg_class;
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static int bsg_major;
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static struct kmem_cache *bsg_cmd_cachep;
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/*
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* our internal command type
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*/
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struct bsg_command {
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struct bsg_device *bd;
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struct list_head list;
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struct request *rq;
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struct bio *bio;
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struct bio *bidi_bio;
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int err;
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struct sg_io_v4 hdr;
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char sense[SCSI_SENSE_BUFFERSIZE];
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};
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static void bsg_free_command(struct bsg_command *bc)
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{
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struct bsg_device *bd = bc->bd;
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unsigned long flags;
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kmem_cache_free(bsg_cmd_cachep, bc);
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spin_lock_irqsave(&bd->lock, flags);
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bd->queued_cmds--;
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spin_unlock_irqrestore(&bd->lock, flags);
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wake_up(&bd->wq_free);
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}
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static struct bsg_command *bsg_alloc_command(struct bsg_device *bd)
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{
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struct bsg_command *bc = ERR_PTR(-EINVAL);
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spin_lock_irq(&bd->lock);
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if (bd->queued_cmds >= bd->max_queue)
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goto out;
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bd->queued_cmds++;
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spin_unlock_irq(&bd->lock);
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bc = kmem_cache_zalloc(bsg_cmd_cachep, GFP_KERNEL);
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if (unlikely(!bc)) {
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spin_lock_irq(&bd->lock);
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bd->queued_cmds--;
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bc = ERR_PTR(-ENOMEM);
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goto out;
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}
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bc->bd = bd;
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INIT_LIST_HEAD(&bc->list);
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dprintk("%s: returning free cmd %p\n", bd->name, bc);
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return bc;
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out:
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spin_unlock_irq(&bd->lock);
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return bc;
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}
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static inline struct hlist_head *bsg_dev_idx_hash(int index)
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{
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return &bsg_device_list[index & (BSG_LIST_ARRAY_SIZE - 1)];
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}
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static int bsg_io_schedule(struct bsg_device *bd)
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{
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DEFINE_WAIT(wait);
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int ret = 0;
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spin_lock_irq(&bd->lock);
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BUG_ON(bd->done_cmds > bd->queued_cmds);
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/*
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* -ENOSPC or -ENODATA? I'm going for -ENODATA, meaning "I have no
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* work to do", even though we return -ENOSPC after this same test
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* during bsg_write() -- there, it means our buffer can't have more
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* bsg_commands added to it, thus has no space left.
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*/
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if (bd->done_cmds == bd->queued_cmds) {
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ret = -ENODATA;
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goto unlock;
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}
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if (!test_bit(BSG_F_BLOCK, &bd->flags)) {
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ret = -EAGAIN;
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goto unlock;
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}
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prepare_to_wait(&bd->wq_done, &wait, TASK_UNINTERRUPTIBLE);
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spin_unlock_irq(&bd->lock);
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io_schedule();
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finish_wait(&bd->wq_done, &wait);
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return ret;
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unlock:
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spin_unlock_irq(&bd->lock);
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return ret;
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}
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static int blk_fill_sgv4_hdr_rq(struct request_queue *q, struct request *rq,
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struct sg_io_v4 *hdr, struct bsg_device *bd,
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fmode_t has_write_perm)
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{
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if (hdr->request_len > BLK_MAX_CDB) {
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rq->cmd = kzalloc(hdr->request_len, GFP_KERNEL);
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if (!rq->cmd)
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return -ENOMEM;
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}
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if (copy_from_user(rq->cmd, (void *)(unsigned long)hdr->request,
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hdr->request_len))
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return -EFAULT;
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if (hdr->subprotocol == BSG_SUB_PROTOCOL_SCSI_CMD) {
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if (blk_verify_command(rq->cmd, has_write_perm))
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return -EPERM;
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} else if (!capable(CAP_SYS_RAWIO))
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return -EPERM;
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/*
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* fill in request structure
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*/
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rq->cmd_len = hdr->request_len;
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rq->cmd_type = REQ_TYPE_BLOCK_PC;
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rq->timeout = msecs_to_jiffies(hdr->timeout);
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if (!rq->timeout)
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rq->timeout = q->sg_timeout;
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if (!rq->timeout)
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rq->timeout = BLK_DEFAULT_SG_TIMEOUT;
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if (rq->timeout < BLK_MIN_SG_TIMEOUT)
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rq->timeout = BLK_MIN_SG_TIMEOUT;
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return 0;
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}
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/*
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* Check if sg_io_v4 from user is allowed and valid
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*/
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static int
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bsg_validate_sgv4_hdr(struct request_queue *q, struct sg_io_v4 *hdr, int *rw)
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{
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int ret = 0;
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if (hdr->guard != 'Q')
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return -EINVAL;
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switch (hdr->protocol) {
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case BSG_PROTOCOL_SCSI:
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switch (hdr->subprotocol) {
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case BSG_SUB_PROTOCOL_SCSI_CMD:
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case BSG_SUB_PROTOCOL_SCSI_TRANSPORT:
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break;
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default:
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ret = -EINVAL;
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}
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break;
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default:
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ret = -EINVAL;
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}
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*rw = hdr->dout_xfer_len ? WRITE : READ;
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return ret;
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}
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/*
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* map sg_io_v4 to a request.
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*/
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static struct request *
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bsg_map_hdr(struct bsg_device *bd, struct sg_io_v4 *hdr, fmode_t has_write_perm,
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u8 *sense)
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{
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struct request_queue *q = bd->queue;
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struct request *rq, *next_rq = NULL;
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int ret, rw;
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unsigned int dxfer_len;
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void *dxferp = NULL;
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dprintk("map hdr %llx/%u %llx/%u\n", (unsigned long long) hdr->dout_xferp,
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hdr->dout_xfer_len, (unsigned long long) hdr->din_xferp,
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hdr->din_xfer_len);
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ret = bsg_validate_sgv4_hdr(q, hdr, &rw);
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if (ret)
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return ERR_PTR(ret);
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/*
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* map scatter-gather elements separately and string them to request
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*/
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rq = blk_get_request(q, rw, GFP_KERNEL);
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if (!rq)
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return ERR_PTR(-ENOMEM);
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ret = blk_fill_sgv4_hdr_rq(q, rq, hdr, bd, has_write_perm);
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if (ret)
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goto out;
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if (rw == WRITE && hdr->din_xfer_len) {
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if (!test_bit(QUEUE_FLAG_BIDI, &q->queue_flags)) {
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ret = -EOPNOTSUPP;
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goto out;
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}
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next_rq = blk_get_request(q, READ, GFP_KERNEL);
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if (!next_rq) {
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ret = -ENOMEM;
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goto out;
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}
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rq->next_rq = next_rq;
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next_rq->cmd_type = rq->cmd_type;
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dxferp = (void*)(unsigned long)hdr->din_xferp;
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ret = blk_rq_map_user(q, next_rq, NULL, dxferp,
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hdr->din_xfer_len, GFP_KERNEL);
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if (ret)
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goto out;
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}
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if (hdr->dout_xfer_len) {
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dxfer_len = hdr->dout_xfer_len;
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dxferp = (void*)(unsigned long)hdr->dout_xferp;
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} else if (hdr->din_xfer_len) {
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dxfer_len = hdr->din_xfer_len;
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dxferp = (void*)(unsigned long)hdr->din_xferp;
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} else
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dxfer_len = 0;
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if (dxfer_len) {
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ret = blk_rq_map_user(q, rq, NULL, dxferp, dxfer_len,
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GFP_KERNEL);
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if (ret)
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goto out;
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}
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rq->sense = sense;
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rq->sense_len = 0;
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return rq;
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out:
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if (rq->cmd != rq->__cmd)
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kfree(rq->cmd);
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blk_put_request(rq);
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if (next_rq) {
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blk_rq_unmap_user(next_rq->bio);
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blk_put_request(next_rq);
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}
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return ERR_PTR(ret);
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}
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/*
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* async completion call-back from the block layer, when scsi/ide/whatever
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* calls end_that_request_last() on a request
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*/
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static void bsg_rq_end_io(struct request *rq, int uptodate)
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{
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struct bsg_command *bc = rq->end_io_data;
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struct bsg_device *bd = bc->bd;
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unsigned long flags;
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dprintk("%s: finished rq %p bc %p, bio %p stat %d\n",
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bd->name, rq, bc, bc->bio, uptodate);
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bc->hdr.duration = jiffies_to_msecs(jiffies - bc->hdr.duration);
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spin_lock_irqsave(&bd->lock, flags);
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list_move_tail(&bc->list, &bd->done_list);
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bd->done_cmds++;
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spin_unlock_irqrestore(&bd->lock, flags);
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wake_up(&bd->wq_done);
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}
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/*
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* do final setup of a 'bc' and submit the matching 'rq' to the block
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* layer for io
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*/
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static void bsg_add_command(struct bsg_device *bd, struct request_queue *q,
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struct bsg_command *bc, struct request *rq)
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{
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int at_head = (0 == (bc->hdr.flags & BSG_FLAG_Q_AT_TAIL));
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/*
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* add bc command to busy queue and submit rq for io
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*/
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bc->rq = rq;
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bc->bio = rq->bio;
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if (rq->next_rq)
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bc->bidi_bio = rq->next_rq->bio;
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bc->hdr.duration = jiffies;
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spin_lock_irq(&bd->lock);
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list_add_tail(&bc->list, &bd->busy_list);
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spin_unlock_irq(&bd->lock);
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dprintk("%s: queueing rq %p, bc %p\n", bd->name, rq, bc);
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rq->end_io_data = bc;
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blk_execute_rq_nowait(q, NULL, rq, at_head, bsg_rq_end_io);
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}
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static struct bsg_command *bsg_next_done_cmd(struct bsg_device *bd)
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{
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struct bsg_command *bc = NULL;
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spin_lock_irq(&bd->lock);
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if (bd->done_cmds) {
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bc = list_first_entry(&bd->done_list, struct bsg_command, list);
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list_del(&bc->list);
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bd->done_cmds--;
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}
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spin_unlock_irq(&bd->lock);
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return bc;
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}
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/*
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* Get a finished command from the done list
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*/
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static struct bsg_command *bsg_get_done_cmd(struct bsg_device *bd)
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{
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struct bsg_command *bc;
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int ret;
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do {
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bc = bsg_next_done_cmd(bd);
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if (bc)
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break;
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if (!test_bit(BSG_F_BLOCK, &bd->flags)) {
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bc = ERR_PTR(-EAGAIN);
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break;
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}
|
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ret = wait_event_interruptible(bd->wq_done, bd->done_cmds);
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if (ret) {
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bc = ERR_PTR(-ERESTARTSYS);
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break;
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}
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} while (1);
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dprintk("%s: returning done %p\n", bd->name, bc);
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return bc;
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}
|
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|
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static int blk_complete_sgv4_hdr_rq(struct request *rq, struct sg_io_v4 *hdr,
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struct bio *bio, struct bio *bidi_bio)
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{
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int ret = 0;
|
|
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dprintk("rq %p bio %p 0x%x\n", rq, bio, rq->errors);
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/*
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* fill in all the output members
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|
*/
|
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hdr->device_status = status_byte(rq->errors);
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hdr->transport_status = host_byte(rq->errors);
|
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hdr->driver_status = driver_byte(rq->errors);
|
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hdr->info = 0;
|
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if (hdr->device_status || hdr->transport_status || hdr->driver_status)
|
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hdr->info |= SG_INFO_CHECK;
|
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hdr->response_len = 0;
|
|
|
|
if (rq->sense_len && hdr->response) {
|
|
int len = min_t(unsigned int, hdr->max_response_len,
|
|
rq->sense_len);
|
|
|
|
ret = copy_to_user((void*)(unsigned long)hdr->response,
|
|
rq->sense, len);
|
|
if (!ret)
|
|
hdr->response_len = len;
|
|
else
|
|
ret = -EFAULT;
|
|
}
|
|
|
|
if (rq->next_rq) {
|
|
hdr->dout_resid = rq->resid_len;
|
|
hdr->din_resid = rq->next_rq->resid_len;
|
|
blk_rq_unmap_user(bidi_bio);
|
|
blk_put_request(rq->next_rq);
|
|
} else if (rq_data_dir(rq) == READ)
|
|
hdr->din_resid = rq->resid_len;
|
|
else
|
|
hdr->dout_resid = rq->resid_len;
|
|
|
|
/*
|
|
* If the request generated a negative error number, return it
|
|
* (providing we aren't already returning an error); if it's
|
|
* just a protocol response (i.e. non negative), that gets
|
|
* processed above.
|
|
*/
|
|
if (!ret && rq->errors < 0)
|
|
ret = rq->errors;
|
|
|
|
blk_rq_unmap_user(bio);
|
|
if (rq->cmd != rq->__cmd)
|
|
kfree(rq->cmd);
|
|
blk_put_request(rq);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int bsg_complete_all_commands(struct bsg_device *bd)
|
|
{
|
|
struct bsg_command *bc;
|
|
int ret, tret;
|
|
|
|
dprintk("%s: entered\n", bd->name);
|
|
|
|
/*
|
|
* wait for all commands to complete
|
|
*/
|
|
ret = 0;
|
|
do {
|
|
ret = bsg_io_schedule(bd);
|
|
/*
|
|
* look for -ENODATA specifically -- we'll sometimes get
|
|
* -ERESTARTSYS when we've taken a signal, but we can't
|
|
* return until we're done freeing the queue, so ignore
|
|
* it. The signal will get handled when we're done freeing
|
|
* the bsg_device.
|
|
*/
|
|
} while (ret != -ENODATA);
|
|
|
|
/*
|
|
* discard done commands
|
|
*/
|
|
ret = 0;
|
|
do {
|
|
spin_lock_irq(&bd->lock);
|
|
if (!bd->queued_cmds) {
|
|
spin_unlock_irq(&bd->lock);
|
|
break;
|
|
}
|
|
spin_unlock_irq(&bd->lock);
|
|
|
|
bc = bsg_get_done_cmd(bd);
|
|
if (IS_ERR(bc))
|
|
break;
|
|
|
|
tret = blk_complete_sgv4_hdr_rq(bc->rq, &bc->hdr, bc->bio,
|
|
bc->bidi_bio);
|
|
if (!ret)
|
|
ret = tret;
|
|
|
|
bsg_free_command(bc);
|
|
} while (1);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int
|
|
__bsg_read(char __user *buf, size_t count, struct bsg_device *bd,
|
|
const struct iovec *iov, ssize_t *bytes_read)
|
|
{
|
|
struct bsg_command *bc;
|
|
int nr_commands, ret;
|
|
|
|
if (count % sizeof(struct sg_io_v4))
|
|
return -EINVAL;
|
|
|
|
ret = 0;
|
|
nr_commands = count / sizeof(struct sg_io_v4);
|
|
while (nr_commands) {
|
|
bc = bsg_get_done_cmd(bd);
|
|
if (IS_ERR(bc)) {
|
|
ret = PTR_ERR(bc);
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* this is the only case where we need to copy data back
|
|
* after completing the request. so do that here,
|
|
* bsg_complete_work() cannot do that for us
|
|
*/
|
|
ret = blk_complete_sgv4_hdr_rq(bc->rq, &bc->hdr, bc->bio,
|
|
bc->bidi_bio);
|
|
|
|
if (copy_to_user(buf, &bc->hdr, sizeof(bc->hdr)))
|
|
ret = -EFAULT;
|
|
|
|
bsg_free_command(bc);
|
|
|
|
if (ret)
|
|
break;
|
|
|
|
buf += sizeof(struct sg_io_v4);
|
|
*bytes_read += sizeof(struct sg_io_v4);
|
|
nr_commands--;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static inline void bsg_set_block(struct bsg_device *bd, struct file *file)
|
|
{
|
|
if (file->f_flags & O_NONBLOCK)
|
|
clear_bit(BSG_F_BLOCK, &bd->flags);
|
|
else
|
|
set_bit(BSG_F_BLOCK, &bd->flags);
|
|
}
|
|
|
|
/*
|
|
* Check if the error is a "real" error that we should return.
|
|
*/
|
|
static inline int err_block_err(int ret)
|
|
{
|
|
if (ret && ret != -ENOSPC && ret != -ENODATA && ret != -EAGAIN)
|
|
return 1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static ssize_t
|
|
bsg_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
|
|
{
|
|
struct bsg_device *bd = file->private_data;
|
|
int ret;
|
|
ssize_t bytes_read;
|
|
|
|
dprintk("%s: read %Zd bytes\n", bd->name, count);
|
|
|
|
bsg_set_block(bd, file);
|
|
|
|
bytes_read = 0;
|
|
ret = __bsg_read(buf, count, bd, NULL, &bytes_read);
|
|
*ppos = bytes_read;
|
|
|
|
if (!bytes_read || (bytes_read && err_block_err(ret)))
|
|
bytes_read = ret;
|
|
|
|
return bytes_read;
|
|
}
|
|
|
|
static int __bsg_write(struct bsg_device *bd, const char __user *buf,
|
|
size_t count, ssize_t *bytes_written,
|
|
fmode_t has_write_perm)
|
|
{
|
|
struct bsg_command *bc;
|
|
struct request *rq;
|
|
int ret, nr_commands;
|
|
|
|
if (count % sizeof(struct sg_io_v4))
|
|
return -EINVAL;
|
|
|
|
nr_commands = count / sizeof(struct sg_io_v4);
|
|
rq = NULL;
|
|
bc = NULL;
|
|
ret = 0;
|
|
while (nr_commands) {
|
|
struct request_queue *q = bd->queue;
|
|
|
|
bc = bsg_alloc_command(bd);
|
|
if (IS_ERR(bc)) {
|
|
ret = PTR_ERR(bc);
|
|
bc = NULL;
|
|
break;
|
|
}
|
|
|
|
if (copy_from_user(&bc->hdr, buf, sizeof(bc->hdr))) {
|
|
ret = -EFAULT;
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* get a request, fill in the blanks, and add to request queue
|
|
*/
|
|
rq = bsg_map_hdr(bd, &bc->hdr, has_write_perm, bc->sense);
|
|
if (IS_ERR(rq)) {
|
|
ret = PTR_ERR(rq);
|
|
rq = NULL;
|
|
break;
|
|
}
|
|
|
|
bsg_add_command(bd, q, bc, rq);
|
|
bc = NULL;
|
|
rq = NULL;
|
|
nr_commands--;
|
|
buf += sizeof(struct sg_io_v4);
|
|
*bytes_written += sizeof(struct sg_io_v4);
|
|
}
|
|
|
|
if (bc)
|
|
bsg_free_command(bc);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static ssize_t
|
|
bsg_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
|
|
{
|
|
struct bsg_device *bd = file->private_data;
|
|
ssize_t bytes_written;
|
|
int ret;
|
|
|
|
dprintk("%s: write %Zd bytes\n", bd->name, count);
|
|
|
|
bsg_set_block(bd, file);
|
|
|
|
bytes_written = 0;
|
|
ret = __bsg_write(bd, buf, count, &bytes_written,
|
|
file->f_mode & FMODE_WRITE);
|
|
|
|
*ppos = bytes_written;
|
|
|
|
/*
|
|
* return bytes written on non-fatal errors
|
|
*/
|
|
if (!bytes_written || (bytes_written && err_block_err(ret)))
|
|
bytes_written = ret;
|
|
|
|
dprintk("%s: returning %Zd\n", bd->name, bytes_written);
|
|
return bytes_written;
|
|
}
|
|
|
|
static struct bsg_device *bsg_alloc_device(void)
|
|
{
|
|
struct bsg_device *bd;
|
|
|
|
bd = kzalloc(sizeof(struct bsg_device), GFP_KERNEL);
|
|
if (unlikely(!bd))
|
|
return NULL;
|
|
|
|
spin_lock_init(&bd->lock);
|
|
|
|
bd->max_queue = BSG_DEFAULT_CMDS;
|
|
|
|
INIT_LIST_HEAD(&bd->busy_list);
|
|
INIT_LIST_HEAD(&bd->done_list);
|
|
INIT_HLIST_NODE(&bd->dev_list);
|
|
|
|
init_waitqueue_head(&bd->wq_free);
|
|
init_waitqueue_head(&bd->wq_done);
|
|
return bd;
|
|
}
|
|
|
|
static void bsg_kref_release_function(struct kref *kref)
|
|
{
|
|
struct bsg_class_device *bcd =
|
|
container_of(kref, struct bsg_class_device, ref);
|
|
struct device *parent = bcd->parent;
|
|
|
|
if (bcd->release)
|
|
bcd->release(bcd->parent);
|
|
|
|
put_device(parent);
|
|
}
|
|
|
|
static int bsg_put_device(struct bsg_device *bd)
|
|
{
|
|
int ret = 0, do_free;
|
|
struct request_queue *q = bd->queue;
|
|
|
|
mutex_lock(&bsg_mutex);
|
|
|
|
do_free = atomic_dec_and_test(&bd->ref_count);
|
|
if (!do_free) {
|
|
mutex_unlock(&bsg_mutex);
|
|
goto out;
|
|
}
|
|
|
|
hlist_del(&bd->dev_list);
|
|
mutex_unlock(&bsg_mutex);
|
|
|
|
dprintk("%s: tearing down\n", bd->name);
|
|
|
|
/*
|
|
* close can always block
|
|
*/
|
|
set_bit(BSG_F_BLOCK, &bd->flags);
|
|
|
|
/*
|
|
* correct error detection baddies here again. it's the responsibility
|
|
* of the app to properly reap commands before close() if it wants
|
|
* fool-proof error detection
|
|
*/
|
|
ret = bsg_complete_all_commands(bd);
|
|
|
|
kfree(bd);
|
|
out:
|
|
kref_put(&q->bsg_dev.ref, bsg_kref_release_function);
|
|
if (do_free)
|
|
blk_put_queue(q);
|
|
return ret;
|
|
}
|
|
|
|
static struct bsg_device *bsg_add_device(struct inode *inode,
|
|
struct request_queue *rq,
|
|
struct file *file)
|
|
{
|
|
struct bsg_device *bd;
|
|
int ret;
|
|
#ifdef BSG_DEBUG
|
|
unsigned char buf[32];
|
|
#endif
|
|
ret = blk_get_queue(rq);
|
|
if (ret)
|
|
return ERR_PTR(-ENXIO);
|
|
|
|
bd = bsg_alloc_device();
|
|
if (!bd) {
|
|
blk_put_queue(rq);
|
|
return ERR_PTR(-ENOMEM);
|
|
}
|
|
|
|
bd->queue = rq;
|
|
|
|
bsg_set_block(bd, file);
|
|
|
|
atomic_set(&bd->ref_count, 1);
|
|
mutex_lock(&bsg_mutex);
|
|
hlist_add_head(&bd->dev_list, bsg_dev_idx_hash(iminor(inode)));
|
|
|
|
strncpy(bd->name, dev_name(rq->bsg_dev.class_dev), sizeof(bd->name) - 1);
|
|
dprintk("bound to <%s>, max queue %d\n",
|
|
format_dev_t(buf, inode->i_rdev), bd->max_queue);
|
|
|
|
mutex_unlock(&bsg_mutex);
|
|
return bd;
|
|
}
|
|
|
|
static struct bsg_device *__bsg_get_device(int minor, struct request_queue *q)
|
|
{
|
|
struct bsg_device *bd;
|
|
struct hlist_node *entry;
|
|
|
|
mutex_lock(&bsg_mutex);
|
|
|
|
hlist_for_each_entry(bd, entry, bsg_dev_idx_hash(minor), dev_list) {
|
|
if (bd->queue == q) {
|
|
atomic_inc(&bd->ref_count);
|
|
goto found;
|
|
}
|
|
}
|
|
bd = NULL;
|
|
found:
|
|
mutex_unlock(&bsg_mutex);
|
|
return bd;
|
|
}
|
|
|
|
static struct bsg_device *bsg_get_device(struct inode *inode, struct file *file)
|
|
{
|
|
struct bsg_device *bd;
|
|
struct bsg_class_device *bcd;
|
|
|
|
/*
|
|
* find the class device
|
|
*/
|
|
mutex_lock(&bsg_mutex);
|
|
bcd = idr_find(&bsg_minor_idr, iminor(inode));
|
|
if (bcd)
|
|
kref_get(&bcd->ref);
|
|
mutex_unlock(&bsg_mutex);
|
|
|
|
if (!bcd)
|
|
return ERR_PTR(-ENODEV);
|
|
|
|
bd = __bsg_get_device(iminor(inode), bcd->queue);
|
|
if (bd)
|
|
return bd;
|
|
|
|
bd = bsg_add_device(inode, bcd->queue, file);
|
|
if (IS_ERR(bd))
|
|
kref_put(&bcd->ref, bsg_kref_release_function);
|
|
|
|
return bd;
|
|
}
|
|
|
|
static int bsg_open(struct inode *inode, struct file *file)
|
|
{
|
|
struct bsg_device *bd;
|
|
|
|
lock_kernel();
|
|
bd = bsg_get_device(inode, file);
|
|
unlock_kernel();
|
|
|
|
if (IS_ERR(bd))
|
|
return PTR_ERR(bd);
|
|
|
|
file->private_data = bd;
|
|
return 0;
|
|
}
|
|
|
|
static int bsg_release(struct inode *inode, struct file *file)
|
|
{
|
|
struct bsg_device *bd = file->private_data;
|
|
|
|
file->private_data = NULL;
|
|
return bsg_put_device(bd);
|
|
}
|
|
|
|
static unsigned int bsg_poll(struct file *file, poll_table *wait)
|
|
{
|
|
struct bsg_device *bd = file->private_data;
|
|
unsigned int mask = 0;
|
|
|
|
poll_wait(file, &bd->wq_done, wait);
|
|
poll_wait(file, &bd->wq_free, wait);
|
|
|
|
spin_lock_irq(&bd->lock);
|
|
if (!list_empty(&bd->done_list))
|
|
mask |= POLLIN | POLLRDNORM;
|
|
if (bd->queued_cmds >= bd->max_queue)
|
|
mask |= POLLOUT;
|
|
spin_unlock_irq(&bd->lock);
|
|
|
|
return mask;
|
|
}
|
|
|
|
static long bsg_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
|
|
{
|
|
struct bsg_device *bd = file->private_data;
|
|
int __user *uarg = (int __user *) arg;
|
|
int ret;
|
|
|
|
switch (cmd) {
|
|
/*
|
|
* our own ioctls
|
|
*/
|
|
case SG_GET_COMMAND_Q:
|
|
return put_user(bd->max_queue, uarg);
|
|
case SG_SET_COMMAND_Q: {
|
|
int queue;
|
|
|
|
if (get_user(queue, uarg))
|
|
return -EFAULT;
|
|
if (queue < 1)
|
|
return -EINVAL;
|
|
|
|
spin_lock_irq(&bd->lock);
|
|
bd->max_queue = queue;
|
|
spin_unlock_irq(&bd->lock);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* SCSI/sg ioctls
|
|
*/
|
|
case SG_GET_VERSION_NUM:
|
|
case SCSI_IOCTL_GET_IDLUN:
|
|
case SCSI_IOCTL_GET_BUS_NUMBER:
|
|
case SG_SET_TIMEOUT:
|
|
case SG_GET_TIMEOUT:
|
|
case SG_GET_RESERVED_SIZE:
|
|
case SG_SET_RESERVED_SIZE:
|
|
case SG_EMULATED_HOST:
|
|
case SCSI_IOCTL_SEND_COMMAND: {
|
|
void __user *uarg = (void __user *) arg;
|
|
return scsi_cmd_ioctl(bd->queue, NULL, file->f_mode, cmd, uarg);
|
|
}
|
|
case SG_IO: {
|
|
struct request *rq;
|
|
struct bio *bio, *bidi_bio = NULL;
|
|
struct sg_io_v4 hdr;
|
|
int at_head;
|
|
u8 sense[SCSI_SENSE_BUFFERSIZE];
|
|
|
|
if (copy_from_user(&hdr, uarg, sizeof(hdr)))
|
|
return -EFAULT;
|
|
|
|
rq = bsg_map_hdr(bd, &hdr, file->f_mode & FMODE_WRITE, sense);
|
|
if (IS_ERR(rq))
|
|
return PTR_ERR(rq);
|
|
|
|
bio = rq->bio;
|
|
if (rq->next_rq)
|
|
bidi_bio = rq->next_rq->bio;
|
|
|
|
at_head = (0 == (hdr.flags & BSG_FLAG_Q_AT_TAIL));
|
|
blk_execute_rq(bd->queue, NULL, rq, at_head);
|
|
ret = blk_complete_sgv4_hdr_rq(rq, &hdr, bio, bidi_bio);
|
|
|
|
if (copy_to_user(uarg, &hdr, sizeof(hdr)))
|
|
return -EFAULT;
|
|
|
|
return ret;
|
|
}
|
|
/*
|
|
* block device ioctls
|
|
*/
|
|
default:
|
|
#if 0
|
|
return ioctl_by_bdev(bd->bdev, cmd, arg);
|
|
#else
|
|
return -ENOTTY;
|
|
#endif
|
|
}
|
|
}
|
|
|
|
static const struct file_operations bsg_fops = {
|
|
.read = bsg_read,
|
|
.write = bsg_write,
|
|
.poll = bsg_poll,
|
|
.open = bsg_open,
|
|
.release = bsg_release,
|
|
.unlocked_ioctl = bsg_ioctl,
|
|
.owner = THIS_MODULE,
|
|
};
|
|
|
|
void bsg_unregister_queue(struct request_queue *q)
|
|
{
|
|
struct bsg_class_device *bcd = &q->bsg_dev;
|
|
|
|
if (!bcd->class_dev)
|
|
return;
|
|
|
|
mutex_lock(&bsg_mutex);
|
|
idr_remove(&bsg_minor_idr, bcd->minor);
|
|
sysfs_remove_link(&q->kobj, "bsg");
|
|
device_unregister(bcd->class_dev);
|
|
bcd->class_dev = NULL;
|
|
kref_put(&bcd->ref, bsg_kref_release_function);
|
|
mutex_unlock(&bsg_mutex);
|
|
}
|
|
EXPORT_SYMBOL_GPL(bsg_unregister_queue);
|
|
|
|
int bsg_register_queue(struct request_queue *q, struct device *parent,
|
|
const char *name, void (*release)(struct device *))
|
|
{
|
|
struct bsg_class_device *bcd;
|
|
dev_t dev;
|
|
int ret, minor;
|
|
struct device *class_dev = NULL;
|
|
const char *devname;
|
|
|
|
if (name)
|
|
devname = name;
|
|
else
|
|
devname = dev_name(parent);
|
|
|
|
/*
|
|
* we need a proper transport to send commands, not a stacked device
|
|
*/
|
|
if (!q->request_fn)
|
|
return 0;
|
|
|
|
bcd = &q->bsg_dev;
|
|
memset(bcd, 0, sizeof(*bcd));
|
|
|
|
mutex_lock(&bsg_mutex);
|
|
|
|
ret = idr_pre_get(&bsg_minor_idr, GFP_KERNEL);
|
|
if (!ret) {
|
|
ret = -ENOMEM;
|
|
goto unlock;
|
|
}
|
|
|
|
ret = idr_get_new(&bsg_minor_idr, bcd, &minor);
|
|
if (ret < 0)
|
|
goto unlock;
|
|
|
|
if (minor >= BSG_MAX_DEVS) {
|
|
printk(KERN_ERR "bsg: too many bsg devices\n");
|
|
ret = -EINVAL;
|
|
goto remove_idr;
|
|
}
|
|
|
|
bcd->minor = minor;
|
|
bcd->queue = q;
|
|
bcd->parent = get_device(parent);
|
|
bcd->release = release;
|
|
kref_init(&bcd->ref);
|
|
dev = MKDEV(bsg_major, bcd->minor);
|
|
class_dev = device_create(bsg_class, parent, dev, NULL, "%s", devname);
|
|
if (IS_ERR(class_dev)) {
|
|
ret = PTR_ERR(class_dev);
|
|
goto put_dev;
|
|
}
|
|
bcd->class_dev = class_dev;
|
|
|
|
if (q->kobj.sd) {
|
|
ret = sysfs_create_link(&q->kobj, &bcd->class_dev->kobj, "bsg");
|
|
if (ret)
|
|
goto unregister_class_dev;
|
|
}
|
|
|
|
mutex_unlock(&bsg_mutex);
|
|
return 0;
|
|
|
|
unregister_class_dev:
|
|
device_unregister(class_dev);
|
|
put_dev:
|
|
put_device(parent);
|
|
remove_idr:
|
|
idr_remove(&bsg_minor_idr, minor);
|
|
unlock:
|
|
mutex_unlock(&bsg_mutex);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(bsg_register_queue);
|
|
|
|
static struct cdev bsg_cdev;
|
|
|
|
static char *bsg_devnode(struct device *dev, mode_t *mode)
|
|
{
|
|
return kasprintf(GFP_KERNEL, "bsg/%s", dev_name(dev));
|
|
}
|
|
|
|
static int __init bsg_init(void)
|
|
{
|
|
int ret, i;
|
|
dev_t devid;
|
|
|
|
bsg_cmd_cachep = kmem_cache_create("bsg_cmd",
|
|
sizeof(struct bsg_command), 0, 0, NULL);
|
|
if (!bsg_cmd_cachep) {
|
|
printk(KERN_ERR "bsg: failed creating slab cache\n");
|
|
return -ENOMEM;
|
|
}
|
|
|
|
for (i = 0; i < BSG_LIST_ARRAY_SIZE; i++)
|
|
INIT_HLIST_HEAD(&bsg_device_list[i]);
|
|
|
|
bsg_class = class_create(THIS_MODULE, "bsg");
|
|
if (IS_ERR(bsg_class)) {
|
|
ret = PTR_ERR(bsg_class);
|
|
goto destroy_kmemcache;
|
|
}
|
|
bsg_class->devnode = bsg_devnode;
|
|
|
|
ret = alloc_chrdev_region(&devid, 0, BSG_MAX_DEVS, "bsg");
|
|
if (ret)
|
|
goto destroy_bsg_class;
|
|
|
|
bsg_major = MAJOR(devid);
|
|
|
|
cdev_init(&bsg_cdev, &bsg_fops);
|
|
ret = cdev_add(&bsg_cdev, MKDEV(bsg_major, 0), BSG_MAX_DEVS);
|
|
if (ret)
|
|
goto unregister_chrdev;
|
|
|
|
printk(KERN_INFO BSG_DESCRIPTION " version " BSG_VERSION
|
|
" loaded (major %d)\n", bsg_major);
|
|
return 0;
|
|
unregister_chrdev:
|
|
unregister_chrdev_region(MKDEV(bsg_major, 0), BSG_MAX_DEVS);
|
|
destroy_bsg_class:
|
|
class_destroy(bsg_class);
|
|
destroy_kmemcache:
|
|
kmem_cache_destroy(bsg_cmd_cachep);
|
|
return ret;
|
|
}
|
|
|
|
MODULE_AUTHOR("Jens Axboe");
|
|
MODULE_DESCRIPTION(BSG_DESCRIPTION);
|
|
MODULE_LICENSE("GPL");
|
|
|
|
device_initcall(bsg_init);
|