1 // SPDX-License-Identifier: GPL-2.0-or-later
4 * Started: Aug 9 by Lawrence Foard (entropy@world.std.com),
5 * to allow user process control of SCSI devices.
6 * Development Sponsored by Killy Corp. NY NY
8 * Original driver (sg.c):
9 * Copyright (C) 1992 Lawrence Foard
10 * Version 2 and 3 extensions to driver:
11 * Copyright (C) 1998 - 2014 Douglas Gilbert
14 static int sg_version_num = 30536; /* 2 digits for each component */
15 #define SG_VERSION_STR "3.5.36"
18 * D. P. Gilbert (dgilbert@interlog.com), notes:
19 * - scsi logging is available via SCSI_LOG_TIMEOUT macros. First
20 * the kernel/module needs to be built with CONFIG_SCSI_LOGGING
21 * (otherwise the macros compile to empty statements).
24 #include <linux/module.h>
27 #include <linux/kernel.h>
28 #include <linux/sched.h>
29 #include <linux/string.h>
31 #include <linux/errno.h>
32 #include <linux/mtio.h>
33 #include <linux/ioctl.h>
34 #include <linux/major.h>
35 #include <linux/slab.h>
36 #include <linux/fcntl.h>
37 #include <linux/init.h>
38 #include <linux/poll.h>
39 #include <linux/moduleparam.h>
40 #include <linux/cdev.h>
41 #include <linux/idr.h>
42 #include <linux/seq_file.h>
43 #include <linux/blkdev.h>
44 #include <linux/delay.h>
45 #include <linux/blktrace_api.h>
46 #include <linux/mutex.h>
47 #include <linux/atomic.h>
48 #include <linux/ratelimit.h>
49 #include <linux/uio.h>
50 #include <linux/cred.h> /* for sg_check_file_access() */
53 #include <scsi/scsi_dbg.h>
54 #include <scsi/scsi_host.h>
55 #include <scsi/scsi_driver.h>
56 #include <scsi/scsi_ioctl.h>
59 #include "scsi_logging.h"
61 #ifdef CONFIG_SCSI_PROC_FS
62 #include <linux/proc_fs.h>
63 static char *sg_version_date = "20140603";
65 static int sg_proc_init(void);
68 #define SG_ALLOW_DIO_DEF 0
70 #define SG_MAX_DEVS 32768
72 /* SG_MAX_CDB_SIZE should be 260 (spc4r37 section 3.1.30) however the type
73 * of sg_io_hdr::cmd_len can only represent 255. All SCSI commands greater
74 * than 16 bytes are "variable length" whose length is a multiple of 4
76 #define SG_MAX_CDB_SIZE 252
78 #define SG_DEFAULT_TIMEOUT mult_frac(SG_DEFAULT_TIMEOUT_USER, HZ, USER_HZ)
80 int sg_big_buff = SG_DEF_RESERVED_SIZE;
81 /* N.B. This variable is readable and writeable via
82 /proc/scsi/sg/def_reserved_size . Each time sg_open() is called a buffer
83 of this size (or less if there is not enough memory) will be reserved
84 for use by this file descriptor. [Deprecated usage: this variable is also
85 readable via /proc/sys/kernel/sg-big-buff if the sg driver is built into
86 the kernel (i.e. it is not a module).] */
87 static int def_reserved_size = -1; /* picks up init parameter */
88 static int sg_allow_dio = SG_ALLOW_DIO_DEF;
90 static int scatter_elem_sz = SG_SCATTER_SZ;
91 static int scatter_elem_sz_prev = SG_SCATTER_SZ;
93 #define SG_SECTOR_SZ 512
95 static int sg_add_device(struct device *, struct class_interface *);
96 static void sg_remove_device(struct device *, struct class_interface *);
98 static DEFINE_IDR(sg_index_idr);
99 static DEFINE_RWLOCK(sg_index_lock); /* Also used to lock
100 file descriptor list for device */
102 static struct class_interface sg_interface = {
103 .add_dev = sg_add_device,
104 .remove_dev = sg_remove_device,
107 typedef struct sg_scatter_hold { /* holding area for scsi scatter gather info */
108 unsigned short k_use_sg; /* Count of kernel scatter-gather pieces */
109 unsigned sglist_len; /* size of malloc'd scatter-gather list ++ */
110 unsigned bufflen; /* Size of (aggregate) data buffer */
113 char dio_in_use; /* 0->indirect IO (or mmap), 1->dio */
114 unsigned char cmd_opcode; /* first byte of command */
117 struct sg_device; /* forward declarations */
120 typedef struct sg_request { /* SG_MAX_QUEUE requests outstanding per file */
121 struct list_head entry; /* list entry */
122 struct sg_fd *parentfp; /* NULL -> not in use */
123 Sg_scatter_hold data; /* hold buffer, perhaps scatter list */
124 sg_io_hdr_t header; /* scsi command+info, see <scsi/sg.h> */
125 unsigned char sense_b[SCSI_SENSE_BUFFERSIZE];
126 char res_used; /* 1 -> using reserve buffer, 0 -> not ... */
127 char orphan; /* 1 -> drop on sight, 0 -> normal */
128 char sg_io_owned; /* 1 -> packet belongs to SG_IO */
129 /* done protected by rq_list_lock */
130 char done; /* 0->before bh, 1->before read, 2->read */
133 struct execute_work ew;
136 typedef struct sg_fd { /* holds the state of a file descriptor */
137 struct list_head sfd_siblings; /* protected by device's sfd_lock */
138 struct sg_device *parentdp; /* owning device */
139 wait_queue_head_t read_wait; /* queue read until command done */
140 rwlock_t rq_list_lock; /* protect access to list in req_arr */
141 struct mutex f_mutex; /* protect against changes in this fd */
142 int timeout; /* defaults to SG_DEFAULT_TIMEOUT */
143 int timeout_user; /* defaults to SG_DEFAULT_TIMEOUT_USER */
144 Sg_scatter_hold reserve; /* buffer held for this file descriptor */
145 struct list_head rq_list; /* head of request list */
146 struct fasync_struct *async_qp; /* used by asynchronous notification */
147 Sg_request req_arr[SG_MAX_QUEUE]; /* used as singly-linked list */
148 char force_packid; /* 1 -> pack_id input to read(), 0 -> ignored */
149 char cmd_q; /* 1 -> allow command queuing, 0 -> don't */
150 unsigned char next_cmd_len; /* 0: automatic, >0: use on next write() */
151 char keep_orphan; /* 0 -> drop orphan (def), 1 -> keep for read() */
152 char mmap_called; /* 0 -> mmap() never called on this fd */
153 char res_in_use; /* 1 -> 'reserve' array in use */
155 struct execute_work ew;
158 typedef struct sg_device { /* holds the state of each scsi generic device */
159 struct scsi_device *device;
160 wait_queue_head_t open_wait; /* queue open() when O_EXCL present */
161 struct mutex open_rel_lock; /* held when in open() or release() */
162 int sg_tablesize; /* adapter's max scatter-gather table size */
163 u32 index; /* device index number */
164 struct list_head sfds;
165 rwlock_t sfd_lock; /* protect access to sfd list */
166 atomic_t detaching; /* 0->device usable, 1->device detaching */
167 bool exclude; /* 1->open(O_EXCL) succeeded and is active */
168 int open_cnt; /* count of opens (perhaps < num(sfds) ) */
169 char sgdebug; /* 0->off, 1->sense, 9->dump dev, 10-> all devs */
170 char name[DISK_NAME_LEN];
171 struct cdev * cdev; /* char_dev [sysfs: /sys/cdev/major/sg<n>] */
175 /* tasklet or soft irq callback */
176 static void sg_rq_end_io(struct request *rq, blk_status_t status);
177 static int sg_start_req(Sg_request *srp, unsigned char *cmd);
178 static int sg_finish_rem_req(Sg_request * srp);
179 static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size);
180 static ssize_t sg_new_read(Sg_fd * sfp, char __user *buf, size_t count,
182 static ssize_t sg_new_write(Sg_fd *sfp, struct file *file,
183 const char __user *buf, size_t count, int blocking,
184 int read_only, int sg_io_owned, Sg_request **o_srp);
185 static int sg_common_write(Sg_fd * sfp, Sg_request * srp,
186 unsigned char *cmnd, int timeout, int blocking);
187 static int sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer);
188 static void sg_remove_scat(Sg_fd * sfp, Sg_scatter_hold * schp);
189 static void sg_build_reserve(Sg_fd * sfp, int req_size);
190 static void sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size);
191 static void sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp);
192 static Sg_fd *sg_add_sfp(Sg_device * sdp);
193 static void sg_remove_sfp(struct kref *);
194 static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id, bool *busy);
195 static Sg_request *sg_add_request(Sg_fd * sfp);
196 static int sg_remove_request(Sg_fd * sfp, Sg_request * srp);
197 static Sg_device *sg_get_dev(int dev);
198 static void sg_device_destroy(struct kref *kref);
200 #define SZ_SG_HEADER sizeof(struct sg_header)
201 #define SZ_SG_IO_HDR sizeof(sg_io_hdr_t)
202 #define SZ_SG_IOVEC sizeof(sg_iovec_t)
203 #define SZ_SG_REQ_INFO sizeof(sg_req_info_t)
205 #define sg_printk(prefix, sdp, fmt, a...) \
206 sdev_prefix_printk(prefix, (sdp)->device, (sdp)->name, fmt, ##a)
209 * The SCSI interfaces that use read() and write() as an asynchronous variant of
210 * ioctl(..., SG_IO, ...) are fundamentally unsafe, since there are lots of ways
211 * to trigger read() and write() calls from various contexts with elevated
212 * privileges. This can lead to kernel memory corruption (e.g. if these
213 * interfaces are called through splice()) and privilege escalation inside
214 * userspace (e.g. if a process with access to such a device passes a file
215 * descriptor to a SUID binary as stdin/stdout/stderr).
217 * This function provides protection for the legacy API by restricting the
220 static int sg_check_file_access(struct file *filp, const char *caller)
222 if (filp->f_cred != current_real_cred()) {
223 pr_err_once("%s: process %d (%s) changed security contexts after opening file descriptor, this is not allowed.\n",
224 caller, task_tgid_vnr(current), current->comm);
227 if (uaccess_kernel()) {
228 pr_err_once("%s: process %d (%s) called from kernel context, this is not allowed.\n",
229 caller, task_tgid_vnr(current), current->comm);
235 static int sg_allow_access(struct file *filp, unsigned char *cmd)
237 struct sg_fd *sfp = filp->private_data;
239 if (sfp->parentdp->device->type == TYPE_SCANNER)
241 if (!scsi_cmd_allowed(cmd, filp->f_mode))
247 open_wait(Sg_device *sdp, int flags)
251 if (flags & O_EXCL) {
252 while (sdp->open_cnt > 0) {
253 mutex_unlock(&sdp->open_rel_lock);
254 retval = wait_event_interruptible(sdp->open_wait,
255 (atomic_read(&sdp->detaching) ||
257 mutex_lock(&sdp->open_rel_lock);
259 if (retval) /* -ERESTARTSYS */
261 if (atomic_read(&sdp->detaching))
265 while (sdp->exclude) {
266 mutex_unlock(&sdp->open_rel_lock);
267 retval = wait_event_interruptible(sdp->open_wait,
268 (atomic_read(&sdp->detaching) ||
270 mutex_lock(&sdp->open_rel_lock);
272 if (retval) /* -ERESTARTSYS */
274 if (atomic_read(&sdp->detaching))
282 /* Returns 0 on success, else a negated errno value */
284 sg_open(struct inode *inode, struct file *filp)
286 int dev = iminor(inode);
287 int flags = filp->f_flags;
288 struct request_queue *q;
293 nonseekable_open(inode, filp);
294 if ((flags & O_EXCL) && (O_RDONLY == (flags & O_ACCMODE)))
295 return -EPERM; /* Can't lock it with read only access */
296 sdp = sg_get_dev(dev);
300 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
301 "sg_open: flags=0x%x\n", flags));
303 /* This driver's module count bumped by fops_get in <linux/fs.h> */
304 /* Prevent the device driver from vanishing while we sleep */
305 retval = scsi_device_get(sdp->device);
309 retval = scsi_autopm_get_device(sdp->device);
313 /* scsi_block_when_processing_errors() may block so bypass
314 * check if O_NONBLOCK. Permits SCSI commands to be issued
315 * during error recovery. Tread carefully. */
316 if (!((flags & O_NONBLOCK) ||
317 scsi_block_when_processing_errors(sdp->device))) {
319 /* we are in error recovery for this device */
323 mutex_lock(&sdp->open_rel_lock);
324 if (flags & O_NONBLOCK) {
325 if (flags & O_EXCL) {
326 if (sdp->open_cnt > 0) {
328 goto error_mutex_locked;
333 goto error_mutex_locked;
337 retval = open_wait(sdp, flags);
338 if (retval) /* -ERESTARTSYS or -ENODEV */
339 goto error_mutex_locked;
342 /* N.B. at this point we are holding the open_rel_lock */
346 if (sdp->open_cnt < 1) { /* no existing opens */
348 q = sdp->device->request_queue;
349 sdp->sg_tablesize = queue_max_segments(q);
351 sfp = sg_add_sfp(sdp);
353 retval = PTR_ERR(sfp);
357 filp->private_data = sfp;
359 mutex_unlock(&sdp->open_rel_lock);
363 kref_put(&sdp->d_ref, sg_device_destroy);
367 if (flags & O_EXCL) {
368 sdp->exclude = false; /* undo if error */
369 wake_up_interruptible(&sdp->open_wait);
372 mutex_unlock(&sdp->open_rel_lock);
374 scsi_autopm_put_device(sdp->device);
376 scsi_device_put(sdp->device);
380 /* Release resources associated with a successful sg_open()
381 * Returns 0 on success, else a negated errno value */
383 sg_release(struct inode *inode, struct file *filp)
388 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
390 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp, "sg_release\n"));
392 mutex_lock(&sdp->open_rel_lock);
393 scsi_autopm_put_device(sdp->device);
394 kref_put(&sfp->f_ref, sg_remove_sfp);
397 /* possibly many open()s waiting on exlude clearing, start many;
398 * only open(O_EXCL)s wait on 0==open_cnt so only start one */
400 sdp->exclude = false;
401 wake_up_interruptible_all(&sdp->open_wait);
402 } else if (0 == sdp->open_cnt) {
403 wake_up_interruptible(&sdp->open_wait);
405 mutex_unlock(&sdp->open_rel_lock);
409 static int get_sg_io_pack_id(int *pack_id, void __user *buf, size_t count)
411 struct sg_header __user *old_hdr = buf;
414 if (count >= SZ_SG_HEADER) {
415 /* negative reply_len means v3 format, otherwise v1/v2 */
416 if (get_user(reply_len, &old_hdr->reply_len))
420 return get_user(*pack_id, &old_hdr->pack_id);
422 if (in_compat_syscall() &&
423 count >= sizeof(struct compat_sg_io_hdr)) {
424 struct compat_sg_io_hdr __user *hp = buf;
426 return get_user(*pack_id, &hp->pack_id);
429 if (count >= sizeof(struct sg_io_hdr)) {
430 struct sg_io_hdr __user *hp = buf;
432 return get_user(*pack_id, &hp->pack_id);
436 /* no valid header was passed, so ignore the pack_id */
442 sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
447 int req_pack_id = -1;
450 struct sg_header *old_hdr;
454 * This could cause a response to be stranded. Close the associated
455 * file descriptor to free up any resources being held.
457 retval = sg_check_file_access(filp, __func__);
461 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
463 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
464 "sg_read: count=%d\n", (int) count));
466 if (sfp->force_packid)
467 retval = get_sg_io_pack_id(&req_pack_id, buf, count);
471 srp = sg_get_rq_mark(sfp, req_pack_id, &busy);
472 if (!srp) { /* now wait on packet to arrive */
473 if (filp->f_flags & O_NONBLOCK)
475 retval = wait_event_interruptible(sfp->read_wait,
476 ((srp = sg_get_rq_mark(sfp, req_pack_id, &busy)) ||
477 (!busy && atomic_read(&sdp->detaching))));
479 /* signal or detaching */
480 return retval ? retval : -ENODEV;
482 if (srp->header.interface_id != '\0')
483 return sg_new_read(sfp, buf, count, srp);
486 old_hdr = kzalloc(SZ_SG_HEADER, GFP_KERNEL);
490 old_hdr->reply_len = (int) hp->timeout;
491 old_hdr->pack_len = old_hdr->reply_len; /* old, strange behaviour */
492 old_hdr->pack_id = hp->pack_id;
493 old_hdr->twelve_byte =
494 ((srp->data.cmd_opcode >= 0xc0) && (12 == hp->cmd_len)) ? 1 : 0;
495 old_hdr->target_status = hp->masked_status;
496 old_hdr->host_status = hp->host_status;
497 old_hdr->driver_status = hp->driver_status;
498 if ((CHECK_CONDITION & hp->masked_status) ||
499 (srp->sense_b[0] & 0x70) == 0x70) {
500 old_hdr->driver_status = DRIVER_SENSE;
501 memcpy(old_hdr->sense_buffer, srp->sense_b,
502 sizeof (old_hdr->sense_buffer));
504 switch (hp->host_status) {
505 /* This setup of 'result' is for backward compatibility and is best
506 ignored by the user who should use target, host + driver status */
508 case DID_PASSTHROUGH:
515 old_hdr->result = EBUSY;
522 old_hdr->result = EIO;
525 old_hdr->result = (srp->sense_b[0] == 0 &&
526 hp->masked_status == GOOD) ? 0 : EIO;
529 old_hdr->result = EIO;
533 /* Now copy the result back to the user buffer. */
534 if (count >= SZ_SG_HEADER) {
535 if (copy_to_user(buf, old_hdr, SZ_SG_HEADER)) {
540 if (count > old_hdr->reply_len)
541 count = old_hdr->reply_len;
542 if (count > SZ_SG_HEADER) {
543 if (sg_read_oxfer(srp, buf, count - SZ_SG_HEADER)) {
549 count = (old_hdr->result == 0) ? 0 : -EIO;
550 sg_finish_rem_req(srp);
551 sg_remove_request(sfp, srp);
559 sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
561 sg_io_hdr_t *hp = &srp->header;
565 if (in_compat_syscall()) {
566 if (count < sizeof(struct compat_sg_io_hdr)) {
570 } else if (count < SZ_SG_IO_HDR) {
575 if ((hp->mx_sb_len > 0) && hp->sbp) {
576 if ((CHECK_CONDITION & hp->masked_status) ||
577 (srp->sense_b[0] & 0x70) == 0x70) {
578 int sb_len = SCSI_SENSE_BUFFERSIZE;
579 sb_len = (hp->mx_sb_len > sb_len) ? sb_len : hp->mx_sb_len;
580 len = 8 + (int) srp->sense_b[7]; /* Additional sense length field */
581 len = (len > sb_len) ? sb_len : len;
582 if (copy_to_user(hp->sbp, srp->sense_b, len)) {
586 hp->driver_status = DRIVER_SENSE;
590 if (hp->masked_status || hp->host_status || hp->driver_status)
591 hp->info |= SG_INFO_CHECK;
592 err = put_sg_io_hdr(hp, buf);
594 err2 = sg_finish_rem_req(srp);
595 sg_remove_request(sfp, srp);
596 return err ? : err2 ? : count;
600 sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
602 int mxsize, cmd_size, k;
603 int input_size, blocking;
604 unsigned char opcode;
608 struct sg_header old_hdr;
610 unsigned char cmnd[SG_MAX_CDB_SIZE];
613 retval = sg_check_file_access(filp, __func__);
617 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
619 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
620 "sg_write: count=%d\n", (int) count));
621 if (atomic_read(&sdp->detaching))
623 if (!((filp->f_flags & O_NONBLOCK) ||
624 scsi_block_when_processing_errors(sdp->device)))
627 if (count < SZ_SG_HEADER)
629 if (copy_from_user(&old_hdr, buf, SZ_SG_HEADER))
631 blocking = !(filp->f_flags & O_NONBLOCK);
632 if (old_hdr.reply_len < 0)
633 return sg_new_write(sfp, filp, buf, count,
634 blocking, 0, 0, NULL);
635 if (count < (SZ_SG_HEADER + 6))
636 return -EIO; /* The minimum scsi command length is 6 bytes. */
639 if (get_user(opcode, buf))
642 if (!(srp = sg_add_request(sfp))) {
643 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sdp,
644 "sg_write: queue full\n"));
647 mutex_lock(&sfp->f_mutex);
648 if (sfp->next_cmd_len > 0) {
649 cmd_size = sfp->next_cmd_len;
650 sfp->next_cmd_len = 0; /* reset so only this write() effected */
652 cmd_size = COMMAND_SIZE(opcode); /* based on SCSI command group */
653 if ((opcode >= 0xc0) && old_hdr.twelve_byte)
656 mutex_unlock(&sfp->f_mutex);
657 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
658 "sg_write: scsi opcode=0x%02x, cmd_size=%d\n", (int) opcode, cmd_size));
659 /* Determine buffer size. */
660 input_size = count - cmd_size;
661 mxsize = (input_size > old_hdr.reply_len) ? input_size : old_hdr.reply_len;
662 mxsize -= SZ_SG_HEADER;
663 input_size -= SZ_SG_HEADER;
664 if (input_size < 0) {
665 sg_remove_request(sfp, srp);
666 return -EIO; /* User did not pass enough bytes for this command. */
669 hp->interface_id = '\0'; /* indicator of old interface tunnelled */
670 hp->cmd_len = (unsigned char) cmd_size;
674 hp->dxfer_direction = (old_hdr.reply_len > SZ_SG_HEADER) ?
675 SG_DXFER_TO_FROM_DEV : SG_DXFER_TO_DEV;
677 hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
678 hp->dxfer_len = mxsize;
679 if ((hp->dxfer_direction == SG_DXFER_TO_DEV) ||
680 (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV))
681 hp->dxferp = (char __user *)buf + cmd_size;
685 hp->timeout = old_hdr.reply_len; /* structure abuse ... */
686 hp->flags = input_size; /* structure abuse ... */
687 hp->pack_id = old_hdr.pack_id;
689 if (copy_from_user(cmnd, buf, cmd_size)) {
690 sg_remove_request(sfp, srp);
694 * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
695 * but is is possible that the app intended SG_DXFER_TO_DEV, because there
696 * is a non-zero input_size, so emit a warning.
698 if (hp->dxfer_direction == SG_DXFER_TO_FROM_DEV) {
699 printk_ratelimited(KERN_WARNING
700 "sg_write: data in/out %d/%d bytes "
701 "for SCSI command 0x%x-- guessing "
702 "data in;\n program %s not setting "
703 "count and/or reply_len properly\n",
704 old_hdr.reply_len - (int)SZ_SG_HEADER,
705 input_size, (unsigned int) cmnd[0],
708 k = sg_common_write(sfp, srp, cmnd, sfp->timeout, blocking);
709 return (k < 0) ? k : count;
713 sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf,
714 size_t count, int blocking, int read_only, int sg_io_owned,
720 unsigned char cmnd[SG_MAX_CDB_SIZE];
722 unsigned long ul_timeout;
724 if (count < SZ_SG_IO_HDR)
727 sfp->cmd_q = 1; /* when sg_io_hdr seen, set command queuing on */
728 if (!(srp = sg_add_request(sfp))) {
729 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
730 "sg_new_write: queue full\n"));
733 srp->sg_io_owned = sg_io_owned;
735 if (get_sg_io_hdr(hp, buf)) {
736 sg_remove_request(sfp, srp);
739 if (hp->interface_id != 'S') {
740 sg_remove_request(sfp, srp);
743 if (hp->flags & SG_FLAG_MMAP_IO) {
744 if (hp->dxfer_len > sfp->reserve.bufflen) {
745 sg_remove_request(sfp, srp);
746 return -ENOMEM; /* MMAP_IO size must fit in reserve buffer */
748 if (hp->flags & SG_FLAG_DIRECT_IO) {
749 sg_remove_request(sfp, srp);
750 return -EINVAL; /* either MMAP_IO or DIRECT_IO (not both) */
752 if (sfp->res_in_use) {
753 sg_remove_request(sfp, srp);
754 return -EBUSY; /* reserve buffer already being used */
757 ul_timeout = msecs_to_jiffies(srp->header.timeout);
758 timeout = (ul_timeout < INT_MAX) ? ul_timeout : INT_MAX;
759 if ((!hp->cmdp) || (hp->cmd_len < 6) || (hp->cmd_len > sizeof (cmnd))) {
760 sg_remove_request(sfp, srp);
763 if (copy_from_user(cmnd, hp->cmdp, hp->cmd_len)) {
764 sg_remove_request(sfp, srp);
767 if (read_only && sg_allow_access(file, cmnd)) {
768 sg_remove_request(sfp, srp);
771 k = sg_common_write(sfp, srp, cmnd, timeout, blocking);
780 sg_common_write(Sg_fd * sfp, Sg_request * srp,
781 unsigned char *cmnd, int timeout, int blocking)
784 Sg_device *sdp = sfp->parentdp;
785 sg_io_hdr_t *hp = &srp->header;
787 srp->data.cmd_opcode = cmnd[0]; /* hold opcode of command */
789 hp->masked_status = 0;
793 hp->driver_status = 0;
795 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
796 "sg_common_write: scsi opcode=0x%02x, cmd_size=%d\n",
797 (int) cmnd[0], (int) hp->cmd_len));
799 if (hp->dxfer_len >= SZ_256M) {
800 sg_remove_request(sfp, srp);
804 k = sg_start_req(srp, cmnd);
806 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
807 "sg_common_write: start_req err=%d\n", k));
808 sg_finish_rem_req(srp);
809 sg_remove_request(sfp, srp);
810 return k; /* probably out of space --> ENOMEM */
812 if (atomic_read(&sdp->detaching)) {
814 scsi_req_free_cmd(scsi_req(srp->rq));
815 blk_put_request(srp->rq);
819 sg_finish_rem_req(srp);
820 sg_remove_request(sfp, srp);
824 hp->duration = jiffies_to_msecs(jiffies);
825 if (hp->interface_id != '\0' && /* v3 (or later) interface */
826 (SG_FLAG_Q_AT_TAIL & hp->flags))
831 srp->rq->timeout = timeout;
832 kref_get(&sfp->f_ref); /* sg_rq_end_io() does kref_put(). */
833 blk_execute_rq_nowait(NULL, srp->rq, at_head, sg_rq_end_io);
837 static int srp_done(Sg_fd *sfp, Sg_request *srp)
842 read_lock_irqsave(&sfp->rq_list_lock, flags);
844 read_unlock_irqrestore(&sfp->rq_list_lock, flags);
848 static int max_sectors_bytes(struct request_queue *q)
850 unsigned int max_sectors = queue_max_sectors(q);
852 max_sectors = min_t(unsigned int, max_sectors, INT_MAX >> 9);
854 return max_sectors << 9;
858 sg_fill_request_table(Sg_fd *sfp, sg_req_info_t *rinfo)
865 list_for_each_entry(srp, &sfp->rq_list, entry) {
866 if (val >= SG_MAX_QUEUE)
868 rinfo[val].req_state = srp->done + 1;
870 srp->header.masked_status &
871 srp->header.host_status &
872 srp->header.driver_status;
874 rinfo[val].duration =
875 srp->header.duration;
877 ms = jiffies_to_msecs(jiffies);
878 rinfo[val].duration =
879 (ms > srp->header.duration) ?
880 (ms - srp->header.duration) : 0;
882 rinfo[val].orphan = srp->orphan;
883 rinfo[val].sg_io_owned = srp->sg_io_owned;
884 rinfo[val].pack_id = srp->header.pack_id;
885 rinfo[val].usr_ptr = srp->header.usr_ptr;
891 struct compat_sg_req_info { /* used by SG_GET_REQUEST_TABLE ioctl() */
897 compat_uptr_t usr_ptr;
898 unsigned int duration;
902 static int put_compat_request_table(struct compat_sg_req_info __user *o,
903 struct sg_req_info *rinfo)
906 for (i = 0; i < SG_MAX_QUEUE; i++) {
907 if (copy_to_user(o + i, rinfo + i, offsetof(sg_req_info_t, usr_ptr)) ||
908 put_user((uintptr_t)rinfo[i].usr_ptr, &o[i].usr_ptr) ||
909 put_user(rinfo[i].duration, &o[i].duration) ||
910 put_user(rinfo[i].unused, &o[i].unused))
918 sg_ioctl_common(struct file *filp, Sg_device *sdp, Sg_fd *sfp,
919 unsigned int cmd_in, void __user *p)
922 int result, val, read_only;
924 unsigned long iflags;
926 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
927 "sg_ioctl: cmd=0x%x\n", (int) cmd_in));
928 read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
932 if (atomic_read(&sdp->detaching))
934 if (!scsi_block_when_processing_errors(sdp->device))
936 result = sg_new_write(sfp, filp, p, SZ_SG_IO_HDR,
937 1, read_only, 1, &srp);
940 result = wait_event_interruptible(sfp->read_wait,
942 write_lock_irq(&sfp->rq_list_lock);
945 write_unlock_irq(&sfp->rq_list_lock);
946 result = sg_new_read(sfp, p, SZ_SG_IO_HDR, srp);
947 return (result < 0) ? result : 0;
950 write_unlock_irq(&sfp->rq_list_lock);
951 return result; /* -ERESTARTSYS because signal hit process */
953 result = get_user(val, ip);
958 if (val >= mult_frac((s64)INT_MAX, USER_HZ, HZ))
959 val = min_t(s64, mult_frac((s64)INT_MAX, USER_HZ, HZ),
961 sfp->timeout_user = val;
962 sfp->timeout = mult_frac(val, HZ, USER_HZ);
965 case SG_GET_TIMEOUT: /* N.B. User receives timeout as return value */
966 /* strange ..., for backward compatibility */
967 return sfp->timeout_user;
968 case SG_SET_FORCE_LOW_DMA:
970 * N.B. This ioctl never worked properly, but failed to
971 * return an error value. So returning '0' to keep compability
972 * with legacy applications.
976 return put_user(0, ip);
981 if (atomic_read(&sdp->detaching))
983 memset(&v, 0, sizeof(v));
984 v.host_no = sdp->device->host->host_no;
985 v.channel = sdp->device->channel;
986 v.scsi_id = sdp->device->id;
987 v.lun = sdp->device->lun;
988 v.scsi_type = sdp->device->type;
989 v.h_cmd_per_lun = sdp->device->host->cmd_per_lun;
990 v.d_queue_depth = sdp->device->queue_depth;
991 if (copy_to_user(p, &v, sizeof(sg_scsi_id_t)))
995 case SG_SET_FORCE_PACK_ID:
996 result = get_user(val, ip);
999 sfp->force_packid = val ? 1 : 0;
1001 case SG_GET_PACK_ID:
1002 read_lock_irqsave(&sfp->rq_list_lock, iflags);
1003 list_for_each_entry(srp, &sfp->rq_list, entry) {
1004 if ((1 == srp->done) && (!srp->sg_io_owned)) {
1005 read_unlock_irqrestore(&sfp->rq_list_lock,
1007 return put_user(srp->header.pack_id, ip);
1010 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1011 return put_user(-1, ip);
1012 case SG_GET_NUM_WAITING:
1013 read_lock_irqsave(&sfp->rq_list_lock, iflags);
1015 list_for_each_entry(srp, &sfp->rq_list, entry) {
1016 if ((1 == srp->done) && (!srp->sg_io_owned))
1019 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1020 return put_user(val, ip);
1021 case SG_GET_SG_TABLESIZE:
1022 return put_user(sdp->sg_tablesize, ip);
1023 case SG_SET_RESERVED_SIZE:
1024 result = get_user(val, ip);
1029 val = min_t(int, val,
1030 max_sectors_bytes(sdp->device->request_queue));
1031 mutex_lock(&sfp->f_mutex);
1032 if (val != sfp->reserve.bufflen) {
1033 if (sfp->mmap_called ||
1035 mutex_unlock(&sfp->f_mutex);
1039 sg_remove_scat(sfp, &sfp->reserve);
1040 sg_build_reserve(sfp, val);
1042 mutex_unlock(&sfp->f_mutex);
1044 case SG_GET_RESERVED_SIZE:
1045 val = min_t(int, sfp->reserve.bufflen,
1046 max_sectors_bytes(sdp->device->request_queue));
1047 return put_user(val, ip);
1048 case SG_SET_COMMAND_Q:
1049 result = get_user(val, ip);
1052 sfp->cmd_q = val ? 1 : 0;
1054 case SG_GET_COMMAND_Q:
1055 return put_user((int) sfp->cmd_q, ip);
1056 case SG_SET_KEEP_ORPHAN:
1057 result = get_user(val, ip);
1060 sfp->keep_orphan = val;
1062 case SG_GET_KEEP_ORPHAN:
1063 return put_user((int) sfp->keep_orphan, ip);
1064 case SG_NEXT_CMD_LEN:
1065 result = get_user(val, ip);
1068 if (val > SG_MAX_CDB_SIZE)
1070 sfp->next_cmd_len = (val > 0) ? val : 0;
1072 case SG_GET_VERSION_NUM:
1073 return put_user(sg_version_num, ip);
1074 case SG_GET_ACCESS_COUNT:
1075 /* faked - we don't have a real access count anymore */
1076 val = (sdp->device ? 1 : 0);
1077 return put_user(val, ip);
1078 case SG_GET_REQUEST_TABLE:
1080 sg_req_info_t *rinfo;
1082 rinfo = kcalloc(SG_MAX_QUEUE, SZ_SG_REQ_INFO,
1086 read_lock_irqsave(&sfp->rq_list_lock, iflags);
1087 sg_fill_request_table(sfp, rinfo);
1088 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1089 #ifdef CONFIG_COMPAT
1090 if (in_compat_syscall())
1091 result = put_compat_request_table(p, rinfo);
1094 result = copy_to_user(p, rinfo,
1095 SZ_SG_REQ_INFO * SG_MAX_QUEUE);
1096 result = result ? -EFAULT : 0;
1100 case SG_EMULATED_HOST:
1101 if (atomic_read(&sdp->detaching))
1103 return put_user(sdp->device->host->hostt->emulated, ip);
1104 case SCSI_IOCTL_SEND_COMMAND:
1105 if (atomic_read(&sdp->detaching))
1107 return scsi_ioctl(sdp->device, NULL, filp->f_mode, cmd_in, p);
1109 result = get_user(val, ip);
1112 sdp->sgdebug = (char) val;
1115 return put_user(max_sectors_bytes(sdp->device->request_queue),
1118 return blk_trace_setup(sdp->device->request_queue, sdp->name,
1119 MKDEV(SCSI_GENERIC_MAJOR, sdp->index),
1122 return blk_trace_startstop(sdp->device->request_queue, 1);
1124 return blk_trace_startstop(sdp->device->request_queue, 0);
1125 case BLKTRACETEARDOWN:
1126 return blk_trace_remove(sdp->device->request_queue);
1127 case SCSI_IOCTL_GET_IDLUN:
1128 case SCSI_IOCTL_GET_BUS_NUMBER:
1129 case SCSI_IOCTL_PROBE_HOST:
1130 case SG_GET_TRANSFORM:
1132 if (atomic_read(&sdp->detaching))
1137 return -EPERM; /* don't know so take safe approach */
1141 result = scsi_ioctl_block_when_processing_errors(sdp->device,
1142 cmd_in, filp->f_flags & O_NDELAY);
1146 return -ENOIOCTLCMD;
1150 sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
1152 void __user *p = (void __user *)arg;
1157 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1160 ret = sg_ioctl_common(filp, sdp, sfp, cmd_in, p);
1161 if (ret != -ENOIOCTLCMD)
1163 return scsi_ioctl(sdp->device, NULL, filp->f_mode, cmd_in, p);
1167 sg_poll(struct file *filp, poll_table * wait)
1174 unsigned long iflags;
1176 sfp = filp->private_data;
1179 sdp = sfp->parentdp;
1182 poll_wait(filp, &sfp->read_wait, wait);
1183 read_lock_irqsave(&sfp->rq_list_lock, iflags);
1184 list_for_each_entry(srp, &sfp->rq_list, entry) {
1185 /* if any read waiting, flag it */
1186 if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
1187 res = EPOLLIN | EPOLLRDNORM;
1190 read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1192 if (atomic_read(&sdp->detaching))
1194 else if (!sfp->cmd_q) {
1196 res |= EPOLLOUT | EPOLLWRNORM;
1197 } else if (count < SG_MAX_QUEUE)
1198 res |= EPOLLOUT | EPOLLWRNORM;
1199 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1200 "sg_poll: res=0x%x\n", (__force u32) res));
1205 sg_fasync(int fd, struct file *filp, int mode)
1210 if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
1212 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1213 "sg_fasync: mode=%d\n", mode));
1215 return fasync_helper(fd, filp, mode, &sfp->async_qp);
1219 sg_vma_fault(struct vm_fault *vmf)
1221 struct vm_area_struct *vma = vmf->vma;
1223 unsigned long offset, len, sa;
1224 Sg_scatter_hold *rsv_schp;
1227 if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
1228 return VM_FAULT_SIGBUS;
1229 rsv_schp = &sfp->reserve;
1230 offset = vmf->pgoff << PAGE_SHIFT;
1231 if (offset >= rsv_schp->bufflen)
1232 return VM_FAULT_SIGBUS;
1233 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1234 "sg_vma_fault: offset=%lu, scatg=%d\n",
1235 offset, rsv_schp->k_use_sg));
1237 length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1238 for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1239 len = vma->vm_end - sa;
1240 len = (len < length) ? len : length;
1242 struct page *page = nth_page(rsv_schp->pages[k],
1243 offset >> PAGE_SHIFT);
1244 get_page(page); /* increment page count */
1246 return 0; /* success */
1252 return VM_FAULT_SIGBUS;
1255 static const struct vm_operations_struct sg_mmap_vm_ops = {
1256 .fault = sg_vma_fault,
1260 sg_mmap(struct file *filp, struct vm_area_struct *vma)
1263 unsigned long req_sz, len, sa;
1264 Sg_scatter_hold *rsv_schp;
1268 if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
1270 req_sz = vma->vm_end - vma->vm_start;
1271 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sfp->parentdp,
1272 "sg_mmap starting, vm_start=%p, len=%d\n",
1273 (void *) vma->vm_start, (int) req_sz));
1275 return -EINVAL; /* want no offset */
1276 rsv_schp = &sfp->reserve;
1277 mutex_lock(&sfp->f_mutex);
1278 if (req_sz > rsv_schp->bufflen) {
1279 ret = -ENOMEM; /* cannot map more than reserved buffer */
1284 length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
1285 for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
1286 len = vma->vm_end - sa;
1287 len = (len < length) ? len : length;
1291 sfp->mmap_called = 1;
1292 vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP;
1293 vma->vm_private_data = sfp;
1294 vma->vm_ops = &sg_mmap_vm_ops;
1296 mutex_unlock(&sfp->f_mutex);
1301 sg_rq_end_io_usercontext(struct work_struct *work)
1303 struct sg_request *srp = container_of(work, struct sg_request, ew.work);
1304 struct sg_fd *sfp = srp->parentfp;
1306 sg_finish_rem_req(srp);
1307 sg_remove_request(sfp, srp);
1308 kref_put(&sfp->f_ref, sg_remove_sfp);
1312 * This function is a "bottom half" handler that is called by the mid
1313 * level when a command is completed (or has failed).
1316 sg_rq_end_io(struct request *rq, blk_status_t status)
1318 struct sg_request *srp = rq->end_io_data;
1319 struct scsi_request *req = scsi_req(rq);
1322 unsigned long iflags;
1325 int result, resid, done = 1;
1327 if (WARN_ON(srp->done != 0))
1330 sfp = srp->parentfp;
1331 if (WARN_ON(sfp == NULL))
1334 sdp = sfp->parentdp;
1335 if (unlikely(atomic_read(&sdp->detaching)))
1336 pr_info("%s: device detaching\n", __func__);
1339 result = req->result;
1340 resid = req->resid_len;
1342 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
1343 "sg_cmd_done: pack_id=%d, res=0x%x\n",
1344 srp->header.pack_id, result));
1345 srp->header.resid = resid;
1346 ms = jiffies_to_msecs(jiffies);
1347 srp->header.duration = (ms > srp->header.duration) ?
1348 (ms - srp->header.duration) : 0;
1350 struct scsi_sense_hdr sshdr;
1352 srp->header.status = 0xff & result;
1353 srp->header.masked_status = status_byte(result);
1354 srp->header.msg_status = COMMAND_COMPLETE;
1355 srp->header.host_status = host_byte(result);
1356 srp->header.driver_status = driver_byte(result);
1357 if ((sdp->sgdebug > 0) &&
1358 ((CHECK_CONDITION == srp->header.masked_status) ||
1359 (COMMAND_TERMINATED == srp->header.masked_status)))
1360 __scsi_print_sense(sdp->device, __func__, sense,
1361 SCSI_SENSE_BUFFERSIZE);
1363 /* Following if statement is a patch supplied by Eric Youngdale */
1364 if (driver_byte(result) != 0
1365 && scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)
1366 && !scsi_sense_is_deferred(&sshdr)
1367 && sshdr.sense_key == UNIT_ATTENTION
1368 && sdp->device->removable) {
1369 /* Detected possible disc change. Set the bit - this */
1370 /* may be used if there are filesystems using this device */
1371 sdp->device->changed = 1;
1376 memcpy(srp->sense_b, req->sense, SCSI_SENSE_BUFFERSIZE);
1378 /* Rely on write phase to clean out srp status values, so no "else" */
1381 * Free the request as soon as it is complete so that its resources
1382 * can be reused without waiting for userspace to read() the
1383 * result. But keep the associated bio (if any) around until
1384 * blk_rq_unmap_user() can be called from user context.
1387 scsi_req_free_cmd(scsi_req(rq));
1388 blk_put_request(rq);
1390 write_lock_irqsave(&sfp->rq_list_lock, iflags);
1391 if (unlikely(srp->orphan)) {
1392 if (sfp->keep_orphan)
1393 srp->sg_io_owned = 0;
1398 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
1401 /* Now wake up any sg_read() that is waiting for this
1404 wake_up_interruptible(&sfp->read_wait);
1405 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
1406 kref_put(&sfp->f_ref, sg_remove_sfp);
1408 INIT_WORK(&srp->ew.work, sg_rq_end_io_usercontext);
1409 schedule_work(&srp->ew.work);
1413 static const struct file_operations sg_fops = {
1414 .owner = THIS_MODULE,
1418 .unlocked_ioctl = sg_ioctl,
1419 .compat_ioctl = compat_ptr_ioctl,
1422 .release = sg_release,
1423 .fasync = sg_fasync,
1424 .llseek = no_llseek,
1427 static struct class *sg_sysfs_class;
1429 static int sg_sysfs_valid = 0;
1432 sg_alloc(struct scsi_device *scsidp)
1434 struct request_queue *q = scsidp->request_queue;
1436 unsigned long iflags;
1440 sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
1442 sdev_printk(KERN_WARNING, scsidp, "%s: kmalloc Sg_device "
1443 "failure\n", __func__);
1444 return ERR_PTR(-ENOMEM);
1447 idr_preload(GFP_KERNEL);
1448 write_lock_irqsave(&sg_index_lock, iflags);
1450 error = idr_alloc(&sg_index_idr, sdp, 0, SG_MAX_DEVS, GFP_NOWAIT);
1452 if (error == -ENOSPC) {
1453 sdev_printk(KERN_WARNING, scsidp,
1454 "Unable to attach sg device type=%d, minor number exceeds %d\n",
1455 scsidp->type, SG_MAX_DEVS - 1);
1458 sdev_printk(KERN_WARNING, scsidp, "%s: idr "
1459 "allocation Sg_device failure: %d\n",
1466 SCSI_LOG_TIMEOUT(3, sdev_printk(KERN_INFO, scsidp,
1467 "sg_alloc: dev=%d \n", k));
1468 sprintf(sdp->name, "sg%d", k);
1469 sdp->device = scsidp;
1470 mutex_init(&sdp->open_rel_lock);
1471 INIT_LIST_HEAD(&sdp->sfds);
1472 init_waitqueue_head(&sdp->open_wait);
1473 atomic_set(&sdp->detaching, 0);
1474 rwlock_init(&sdp->sfd_lock);
1475 sdp->sg_tablesize = queue_max_segments(q);
1477 kref_init(&sdp->d_ref);
1481 write_unlock_irqrestore(&sg_index_lock, iflags);
1486 return ERR_PTR(error);
1492 sg_add_device(struct device *cl_dev, struct class_interface *cl_intf)
1494 struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1495 Sg_device *sdp = NULL;
1496 struct cdev * cdev = NULL;
1498 unsigned long iflags;
1501 cdev = cdev_alloc();
1503 pr_warn("%s: cdev_alloc failed\n", __func__);
1506 cdev->owner = THIS_MODULE;
1507 cdev->ops = &sg_fops;
1509 sdp = sg_alloc(scsidp);
1511 pr_warn("%s: sg_alloc failed\n", __func__);
1512 error = PTR_ERR(sdp);
1516 error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, sdp->index), 1);
1521 if (sg_sysfs_valid) {
1522 struct device *sg_class_member;
1524 sg_class_member = device_create(sg_sysfs_class, cl_dev->parent,
1525 MKDEV(SCSI_GENERIC_MAJOR,
1527 sdp, "%s", sdp->name);
1528 if (IS_ERR(sg_class_member)) {
1529 pr_err("%s: device_create failed\n", __func__);
1530 error = PTR_ERR(sg_class_member);
1533 error = sysfs_create_link(&scsidp->sdev_gendev.kobj,
1534 &sg_class_member->kobj, "generic");
1536 pr_err("%s: unable to make symlink 'generic' back "
1537 "to sg%d\n", __func__, sdp->index);
1539 pr_warn("%s: sg_sys Invalid\n", __func__);
1541 sdev_printk(KERN_NOTICE, scsidp, "Attached scsi generic sg%d "
1542 "type %d\n", sdp->index, scsidp->type);
1544 dev_set_drvdata(cl_dev, sdp);
1549 write_lock_irqsave(&sg_index_lock, iflags);
1550 idr_remove(&sg_index_idr, sdp->index);
1551 write_unlock_irqrestore(&sg_index_lock, iflags);
1561 sg_device_destroy(struct kref *kref)
1563 struct sg_device *sdp = container_of(kref, struct sg_device, d_ref);
1564 unsigned long flags;
1566 /* CAUTION! Note that the device can still be found via idr_find()
1567 * even though the refcount is 0. Therefore, do idr_remove() BEFORE
1568 * any other cleanup.
1571 write_lock_irqsave(&sg_index_lock, flags);
1572 idr_remove(&sg_index_idr, sdp->index);
1573 write_unlock_irqrestore(&sg_index_lock, flags);
1576 sg_printk(KERN_INFO, sdp, "sg_device_destroy\n"));
1582 sg_remove_device(struct device *cl_dev, struct class_interface *cl_intf)
1584 struct scsi_device *scsidp = to_scsi_device(cl_dev->parent);
1585 Sg_device *sdp = dev_get_drvdata(cl_dev);
1586 unsigned long iflags;
1592 /* want sdp->detaching non-zero as soon as possible */
1593 val = atomic_inc_return(&sdp->detaching);
1595 return; /* only want to do following once per device */
1597 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
1600 read_lock_irqsave(&sdp->sfd_lock, iflags);
1601 list_for_each_entry(sfp, &sdp->sfds, sfd_siblings) {
1602 wake_up_interruptible_all(&sfp->read_wait);
1603 kill_fasync(&sfp->async_qp, SIGPOLL, POLL_HUP);
1605 wake_up_interruptible_all(&sdp->open_wait);
1606 read_unlock_irqrestore(&sdp->sfd_lock, iflags);
1608 sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
1609 device_destroy(sg_sysfs_class, MKDEV(SCSI_GENERIC_MAJOR, sdp->index));
1610 cdev_del(sdp->cdev);
1613 kref_put(&sdp->d_ref, sg_device_destroy);
1616 module_param_named(scatter_elem_sz, scatter_elem_sz, int, S_IRUGO | S_IWUSR);
1617 module_param_named(def_reserved_size, def_reserved_size, int,
1619 module_param_named(allow_dio, sg_allow_dio, int, S_IRUGO | S_IWUSR);
1621 MODULE_AUTHOR("Douglas Gilbert");
1622 MODULE_DESCRIPTION("SCSI generic (sg) driver");
1623 MODULE_LICENSE("GPL");
1624 MODULE_VERSION(SG_VERSION_STR);
1625 MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR);
1627 MODULE_PARM_DESC(scatter_elem_sz, "scatter gather element "
1628 "size (default: max(SG_SCATTER_SZ, PAGE_SIZE))");
1629 MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd");
1630 MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow))");
1637 if (scatter_elem_sz < PAGE_SIZE) {
1638 scatter_elem_sz = PAGE_SIZE;
1639 scatter_elem_sz_prev = scatter_elem_sz;
1641 if (def_reserved_size >= 0)
1642 sg_big_buff = def_reserved_size;
1644 def_reserved_size = sg_big_buff;
1646 rc = register_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1650 sg_sysfs_class = class_create(THIS_MODULE, "scsi_generic");
1651 if ( IS_ERR(sg_sysfs_class) ) {
1652 rc = PTR_ERR(sg_sysfs_class);
1656 rc = scsi_register_interface(&sg_interface);
1658 #ifdef CONFIG_SCSI_PROC_FS
1660 #endif /* CONFIG_SCSI_PROC_FS */
1663 class_destroy(sg_sysfs_class);
1665 unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0), SG_MAX_DEVS);
1672 #ifdef CONFIG_SCSI_PROC_FS
1673 remove_proc_subtree("scsi/sg", NULL);
1674 #endif /* CONFIG_SCSI_PROC_FS */
1675 scsi_unregister_interface(&sg_interface);
1676 class_destroy(sg_sysfs_class);
1678 unregister_chrdev_region(MKDEV(SCSI_GENERIC_MAJOR, 0),
1680 idr_destroy(&sg_index_idr);
1684 sg_start_req(Sg_request *srp, unsigned char *cmd)
1688 struct scsi_request *req;
1689 Sg_fd *sfp = srp->parentfp;
1690 sg_io_hdr_t *hp = &srp->header;
1691 int dxfer_len = (int) hp->dxfer_len;
1692 int dxfer_dir = hp->dxfer_direction;
1693 unsigned int iov_count = hp->iovec_count;
1694 Sg_scatter_hold *req_schp = &srp->data;
1695 Sg_scatter_hold *rsv_schp = &sfp->reserve;
1696 struct request_queue *q = sfp->parentdp->device->request_queue;
1697 struct rq_map_data *md, map_data;
1698 int rw = hp->dxfer_direction == SG_DXFER_TO_DEV ? WRITE : READ;
1699 unsigned char *long_cmdp = NULL;
1701 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1702 "sg_start_req: dxfer_len=%d\n",
1705 if (hp->cmd_len > BLK_MAX_CDB) {
1706 long_cmdp = kzalloc(hp->cmd_len, GFP_KERNEL);
1714 * With scsi-mq enabled, there are a fixed number of preallocated
1715 * requests equal in number to shost->can_queue. If all of the
1716 * preallocated requests are already in use, then blk_get_request()
1717 * will sleep until an active command completes, freeing up a request.
1718 * Although waiting in an asynchronous interface is less than ideal, we
1719 * do not want to use BLK_MQ_REQ_NOWAIT here because userspace might
1720 * not expect an EWOULDBLOCK from this condition.
1722 rq = blk_get_request(q, hp->dxfer_direction == SG_DXFER_TO_DEV ?
1723 REQ_OP_DRV_OUT : REQ_OP_DRV_IN, 0);
1730 if (hp->cmd_len > BLK_MAX_CDB)
1731 req->cmd = long_cmdp;
1732 memcpy(req->cmd, cmd, hp->cmd_len);
1733 req->cmd_len = hp->cmd_len;
1736 rq->end_io_data = srp;
1737 req->retries = SG_DEFAULT_RETRIES;
1739 if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
1742 if (sg_allow_dio && hp->flags & SG_FLAG_DIRECT_IO &&
1743 dxfer_dir != SG_DXFER_UNKNOWN && !iov_count &&
1744 blk_rq_aligned(q, (unsigned long)hp->dxferp, dxfer_len))
1750 mutex_lock(&sfp->f_mutex);
1751 if (dxfer_len <= rsv_schp->bufflen &&
1753 sfp->res_in_use = 1;
1754 sg_link_reserve(sfp, srp, dxfer_len);
1755 } else if (hp->flags & SG_FLAG_MMAP_IO) {
1756 res = -EBUSY; /* sfp->res_in_use == 1 */
1757 if (dxfer_len > rsv_schp->bufflen)
1759 mutex_unlock(&sfp->f_mutex);
1762 res = sg_build_indirect(req_schp, sfp, dxfer_len);
1764 mutex_unlock(&sfp->f_mutex);
1768 mutex_unlock(&sfp->f_mutex);
1770 md->pages = req_schp->pages;
1771 md->page_order = req_schp->page_order;
1772 md->nr_entries = req_schp->k_use_sg;
1774 md->null_mapped = hp->dxferp ? 0 : 1;
1775 if (dxfer_dir == SG_DXFER_TO_FROM_DEV)
1782 struct iovec *iov = NULL;
1785 res = import_iovec(rw, hp->dxferp, iov_count, 0, &iov, &i);
1789 iov_iter_truncate(&i, hp->dxfer_len);
1790 if (!iov_iter_count(&i)) {
1795 res = blk_rq_map_user_iov(q, rq, md, &i, GFP_ATOMIC);
1798 res = blk_rq_map_user(q, rq, md, hp->dxferp,
1799 hp->dxfer_len, GFP_ATOMIC);
1805 req_schp->dio_in_use = 1;
1806 hp->info |= SG_INFO_DIRECT_IO;
1813 sg_finish_rem_req(Sg_request *srp)
1817 Sg_fd *sfp = srp->parentfp;
1818 Sg_scatter_hold *req_schp = &srp->data;
1820 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1821 "sg_finish_rem_req: res_used=%d\n",
1822 (int) srp->res_used));
1824 ret = blk_rq_unmap_user(srp->bio);
1827 scsi_req_free_cmd(scsi_req(srp->rq));
1828 blk_put_request(srp->rq);
1832 sg_unlink_reserve(sfp, srp);
1834 sg_remove_scat(sfp, req_schp);
1840 sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
1842 int sg_bufflen = tablesize * sizeof(struct page *);
1843 gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
1845 schp->pages = kzalloc(sg_bufflen, gfp_flags);
1848 schp->sglist_len = sg_bufflen;
1849 return tablesize; /* number of scat_gath elements allocated */
1853 sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
1855 int ret_sz = 0, i, k, rem_sz, num, mx_sc_elems;
1856 int sg_tablesize = sfp->parentdp->sg_tablesize;
1857 int blk_size = buff_size, order;
1858 gfp_t gfp_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN | __GFP_ZERO;
1863 ++blk_size; /* don't know why */
1864 /* round request up to next highest SG_SECTOR_SZ byte boundary */
1865 blk_size = ALIGN(blk_size, SG_SECTOR_SZ);
1866 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1867 "sg_build_indirect: buff_size=%d, blk_size=%d\n",
1868 buff_size, blk_size));
1870 /* N.B. ret_sz carried into this block ... */
1871 mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
1872 if (mx_sc_elems < 0)
1873 return mx_sc_elems; /* most likely -ENOMEM */
1875 num = scatter_elem_sz;
1876 if (unlikely(num != scatter_elem_sz_prev)) {
1877 if (num < PAGE_SIZE) {
1878 scatter_elem_sz = PAGE_SIZE;
1879 scatter_elem_sz_prev = PAGE_SIZE;
1881 scatter_elem_sz_prev = num;
1884 order = get_order(num);
1886 ret_sz = 1 << (PAGE_SHIFT + order);
1888 for (k = 0, rem_sz = blk_size; rem_sz > 0 && k < mx_sc_elems;
1889 k++, rem_sz -= ret_sz) {
1891 num = (rem_sz > scatter_elem_sz_prev) ?
1892 scatter_elem_sz_prev : rem_sz;
1894 schp->pages[k] = alloc_pages(gfp_mask, order);
1895 if (!schp->pages[k])
1898 if (num == scatter_elem_sz_prev) {
1899 if (unlikely(ret_sz > scatter_elem_sz_prev)) {
1900 scatter_elem_sz = ret_sz;
1901 scatter_elem_sz_prev = ret_sz;
1905 SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
1906 "sg_build_indirect: k=%d, num=%d, ret_sz=%d\n",
1908 } /* end of for loop */
1910 schp->page_order = order;
1912 SCSI_LOG_TIMEOUT(5, sg_printk(KERN_INFO, sfp->parentdp,
1913 "sg_build_indirect: k_use_sg=%d, rem_sz=%d\n",
1916 schp->bufflen = blk_size;
1917 if (rem_sz > 0) /* must have failed */
1921 for (i = 0; i < k; i++)
1922 __free_pages(schp->pages[i], order);
1931 sg_remove_scat(Sg_fd * sfp, Sg_scatter_hold * schp)
1933 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1934 "sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
1935 if (schp->pages && schp->sglist_len > 0) {
1936 if (!schp->dio_in_use) {
1939 for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1941 sg_printk(KERN_INFO, sfp->parentdp,
1942 "sg_remove_scat: k=%d, pg=0x%p\n",
1943 k, schp->pages[k]));
1944 __free_pages(schp->pages[k], schp->page_order);
1950 memset(schp, 0, sizeof (*schp));
1954 sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
1956 Sg_scatter_hold *schp = &srp->data;
1959 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
1960 "sg_read_oxfer: num_read_xfer=%d\n",
1962 if ((!outp) || (num_read_xfer <= 0))
1965 num = 1 << (PAGE_SHIFT + schp->page_order);
1966 for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
1967 if (num > num_read_xfer) {
1968 if (copy_to_user(outp, page_address(schp->pages[k]),
1973 if (copy_to_user(outp, page_address(schp->pages[k]),
1976 num_read_xfer -= num;
1977 if (num_read_xfer <= 0)
1987 sg_build_reserve(Sg_fd * sfp, int req_size)
1989 Sg_scatter_hold *schp = &sfp->reserve;
1991 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
1992 "sg_build_reserve: req_size=%d\n", req_size));
1994 if (req_size < PAGE_SIZE)
1995 req_size = PAGE_SIZE;
1996 if (0 == sg_build_indirect(schp, sfp, req_size))
1999 sg_remove_scat(sfp, schp);
2000 req_size >>= 1; /* divide by 2 */
2001 } while (req_size > (PAGE_SIZE / 2));
2005 sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
2007 Sg_scatter_hold *req_schp = &srp->data;
2008 Sg_scatter_hold *rsv_schp = &sfp->reserve;
2012 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sfp->parentdp,
2013 "sg_link_reserve: size=%d\n", size));
2016 num = 1 << (PAGE_SHIFT + rsv_schp->page_order);
2017 for (k = 0; k < rsv_schp->k_use_sg; k++) {
2019 req_schp->k_use_sg = k + 1;
2020 req_schp->sglist_len = rsv_schp->sglist_len;
2021 req_schp->pages = rsv_schp->pages;
2023 req_schp->bufflen = size;
2024 req_schp->page_order = rsv_schp->page_order;
2030 if (k >= rsv_schp->k_use_sg)
2031 SCSI_LOG_TIMEOUT(1, sg_printk(KERN_INFO, sfp->parentdp,
2032 "sg_link_reserve: BAD size\n"));
2036 sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
2038 Sg_scatter_hold *req_schp = &srp->data;
2040 SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, srp->parentfp->parentdp,
2041 "sg_unlink_reserve: req->k_use_sg=%d\n",
2042 (int) req_schp->k_use_sg));
2043 req_schp->k_use_sg = 0;
2044 req_schp->bufflen = 0;
2045 req_schp->pages = NULL;
2046 req_schp->page_order = 0;
2047 req_schp->sglist_len = 0;
2049 /* Called without mutex lock to avoid deadlock */
2050 sfp->res_in_use = 0;
2054 sg_get_rq_mark(Sg_fd * sfp, int pack_id, bool *busy)
2057 unsigned long iflags;
2060 write_lock_irqsave(&sfp->rq_list_lock, iflags);
2061 list_for_each_entry(resp, &sfp->rq_list, entry) {
2062 /* look for requests that are not SG_IO owned */
2063 if ((!resp->sg_io_owned) &&
2064 ((-1 == pack_id) || (resp->header.pack_id == pack_id))) {
2065 switch (resp->done) {
2066 case 0: /* request active */
2069 case 1: /* request done; response ready to return */
2070 resp->done = 2; /* guard against other readers */
2071 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2073 case 2: /* response already being returned */
2078 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2082 /* always adds to end of list */
2084 sg_add_request(Sg_fd * sfp)
2087 unsigned long iflags;
2088 Sg_request *rp = sfp->req_arr;
2090 write_lock_irqsave(&sfp->rq_list_lock, iflags);
2091 if (!list_empty(&sfp->rq_list)) {
2095 for (k = 0; k < SG_MAX_QUEUE; ++k, ++rp) {
2099 if (k >= SG_MAX_QUEUE)
2102 memset(rp, 0, sizeof (Sg_request));
2104 rp->header.duration = jiffies_to_msecs(jiffies);
2105 list_add_tail(&rp->entry, &sfp->rq_list);
2106 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2109 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2113 /* Return of 1 for found; 0 for not found */
2115 sg_remove_request(Sg_fd * sfp, Sg_request * srp)
2117 unsigned long iflags;
2120 if (!sfp || !srp || list_empty(&sfp->rq_list))
2122 write_lock_irqsave(&sfp->rq_list_lock, iflags);
2123 if (!list_empty(&srp->entry)) {
2124 list_del(&srp->entry);
2125 srp->parentfp = NULL;
2128 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2131 * If the device is detaching, wakeup any readers in case we just
2132 * removed the last response, which would leave nothing for them to
2133 * return other than -ENODEV.
2135 if (unlikely(atomic_read(&sfp->parentdp->detaching)))
2136 wake_up_interruptible_all(&sfp->read_wait);
2142 sg_add_sfp(Sg_device * sdp)
2145 unsigned long iflags;
2148 sfp = kzalloc(sizeof(*sfp), GFP_ATOMIC | __GFP_NOWARN);
2150 return ERR_PTR(-ENOMEM);
2152 init_waitqueue_head(&sfp->read_wait);
2153 rwlock_init(&sfp->rq_list_lock);
2154 INIT_LIST_HEAD(&sfp->rq_list);
2155 kref_init(&sfp->f_ref);
2156 mutex_init(&sfp->f_mutex);
2157 sfp->timeout = SG_DEFAULT_TIMEOUT;
2158 sfp->timeout_user = SG_DEFAULT_TIMEOUT_USER;
2159 sfp->force_packid = SG_DEF_FORCE_PACK_ID;
2160 sfp->cmd_q = SG_DEF_COMMAND_Q;
2161 sfp->keep_orphan = SG_DEF_KEEP_ORPHAN;
2162 sfp->parentdp = sdp;
2163 write_lock_irqsave(&sdp->sfd_lock, iflags);
2164 if (atomic_read(&sdp->detaching)) {
2165 write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2167 return ERR_PTR(-ENODEV);
2169 list_add_tail(&sfp->sfd_siblings, &sdp->sfds);
2170 write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2171 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2172 "sg_add_sfp: sfp=0x%p\n", sfp));
2173 if (unlikely(sg_big_buff != def_reserved_size))
2174 sg_big_buff = def_reserved_size;
2176 bufflen = min_t(int, sg_big_buff,
2177 max_sectors_bytes(sdp->device->request_queue));
2178 sg_build_reserve(sfp, bufflen);
2179 SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
2180 "sg_add_sfp: bufflen=%d, k_use_sg=%d\n",
2181 sfp->reserve.bufflen,
2182 sfp->reserve.k_use_sg));
2184 kref_get(&sdp->d_ref);
2185 __module_get(THIS_MODULE);
2190 sg_remove_sfp_usercontext(struct work_struct *work)
2192 struct sg_fd *sfp = container_of(work, struct sg_fd, ew.work);
2193 struct sg_device *sdp = sfp->parentdp;
2195 unsigned long iflags;
2197 /* Cleanup any responses which were never read(). */
2198 write_lock_irqsave(&sfp->rq_list_lock, iflags);
2199 while (!list_empty(&sfp->rq_list)) {
2200 srp = list_first_entry(&sfp->rq_list, Sg_request, entry);
2201 sg_finish_rem_req(srp);
2202 list_del(&srp->entry);
2203 srp->parentfp = NULL;
2205 write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
2207 if (sfp->reserve.bufflen > 0) {
2208 SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2209 "sg_remove_sfp: bufflen=%d, k_use_sg=%d\n",
2210 (int) sfp->reserve.bufflen,
2211 (int) sfp->reserve.k_use_sg));
2212 sg_remove_scat(sfp, &sfp->reserve);
2215 SCSI_LOG_TIMEOUT(6, sg_printk(KERN_INFO, sdp,
2216 "sg_remove_sfp: sfp=0x%p\n", sfp));
2219 scsi_device_put(sdp->device);
2220 kref_put(&sdp->d_ref, sg_device_destroy);
2221 module_put(THIS_MODULE);
2225 sg_remove_sfp(struct kref *kref)
2227 struct sg_fd *sfp = container_of(kref, struct sg_fd, f_ref);
2228 struct sg_device *sdp = sfp->parentdp;
2229 unsigned long iflags;
2231 write_lock_irqsave(&sdp->sfd_lock, iflags);
2232 list_del(&sfp->sfd_siblings);
2233 write_unlock_irqrestore(&sdp->sfd_lock, iflags);
2235 INIT_WORK(&sfp->ew.work, sg_remove_sfp_usercontext);
2236 schedule_work(&sfp->ew.work);
2239 #ifdef CONFIG_SCSI_PROC_FS
2241 sg_idr_max_id(int id, void *p, void *data)
2255 unsigned long iflags;
2257 read_lock_irqsave(&sg_index_lock, iflags);
2258 idr_for_each(&sg_index_idr, sg_idr_max_id, &k);
2259 read_unlock_irqrestore(&sg_index_lock, iflags);
2260 return k + 1; /* origin 1 */
2264 /* must be called with sg_index_lock held */
2265 static Sg_device *sg_lookup_dev(int dev)
2267 return idr_find(&sg_index_idr, dev);
2273 struct sg_device *sdp;
2274 unsigned long flags;
2276 read_lock_irqsave(&sg_index_lock, flags);
2277 sdp = sg_lookup_dev(dev);
2279 sdp = ERR_PTR(-ENXIO);
2280 else if (atomic_read(&sdp->detaching)) {
2281 /* If sdp->detaching, then the refcount may already be 0, in
2282 * which case it would be a bug to do kref_get().
2284 sdp = ERR_PTR(-ENODEV);
2286 kref_get(&sdp->d_ref);
2287 read_unlock_irqrestore(&sg_index_lock, flags);
2292 #ifdef CONFIG_SCSI_PROC_FS
2293 static int sg_proc_seq_show_int(struct seq_file *s, void *v);
2295 static int sg_proc_single_open_adio(struct inode *inode, struct file *file);
2296 static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
2297 size_t count, loff_t *off);
2298 static const struct proc_ops adio_proc_ops = {
2299 .proc_open = sg_proc_single_open_adio,
2300 .proc_read = seq_read,
2301 .proc_lseek = seq_lseek,
2302 .proc_write = sg_proc_write_adio,
2303 .proc_release = single_release,
2306 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file);
2307 static ssize_t sg_proc_write_dressz(struct file *filp,
2308 const char __user *buffer, size_t count, loff_t *off);
2309 static const struct proc_ops dressz_proc_ops = {
2310 .proc_open = sg_proc_single_open_dressz,
2311 .proc_read = seq_read,
2312 .proc_lseek = seq_lseek,
2313 .proc_write = sg_proc_write_dressz,
2314 .proc_release = single_release,
2317 static int sg_proc_seq_show_version(struct seq_file *s, void *v);
2318 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v);
2319 static int sg_proc_seq_show_dev(struct seq_file *s, void *v);
2320 static void * dev_seq_start(struct seq_file *s, loff_t *pos);
2321 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos);
2322 static void dev_seq_stop(struct seq_file *s, void *v);
2323 static const struct seq_operations dev_seq_ops = {
2324 .start = dev_seq_start,
2325 .next = dev_seq_next,
2326 .stop = dev_seq_stop,
2327 .show = sg_proc_seq_show_dev,
2330 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v);
2331 static const struct seq_operations devstrs_seq_ops = {
2332 .start = dev_seq_start,
2333 .next = dev_seq_next,
2334 .stop = dev_seq_stop,
2335 .show = sg_proc_seq_show_devstrs,
2338 static int sg_proc_seq_show_debug(struct seq_file *s, void *v);
2339 static const struct seq_operations debug_seq_ops = {
2340 .start = dev_seq_start,
2341 .next = dev_seq_next,
2342 .stop = dev_seq_stop,
2343 .show = sg_proc_seq_show_debug,
2349 struct proc_dir_entry *p;
2351 p = proc_mkdir("scsi/sg", NULL);
2355 proc_create("allow_dio", S_IRUGO | S_IWUSR, p, &adio_proc_ops);
2356 proc_create_seq("debug", S_IRUGO, p, &debug_seq_ops);
2357 proc_create("def_reserved_size", S_IRUGO | S_IWUSR, p, &dressz_proc_ops);
2358 proc_create_single("device_hdr", S_IRUGO, p, sg_proc_seq_show_devhdr);
2359 proc_create_seq("devices", S_IRUGO, p, &dev_seq_ops);
2360 proc_create_seq("device_strs", S_IRUGO, p, &devstrs_seq_ops);
2361 proc_create_single("version", S_IRUGO, p, sg_proc_seq_show_version);
2366 static int sg_proc_seq_show_int(struct seq_file *s, void *v)
2368 seq_printf(s, "%d\n", *((int *)s->private));
2372 static int sg_proc_single_open_adio(struct inode *inode, struct file *file)
2374 return single_open(file, sg_proc_seq_show_int, &sg_allow_dio);
2378 sg_proc_write_adio(struct file *filp, const char __user *buffer,
2379 size_t count, loff_t *off)
2384 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2386 err = kstrtoul_from_user(buffer, count, 0, &num);
2389 sg_allow_dio = num ? 1 : 0;
2393 static int sg_proc_single_open_dressz(struct inode *inode, struct file *file)
2395 return single_open(file, sg_proc_seq_show_int, &sg_big_buff);
2399 sg_proc_write_dressz(struct file *filp, const char __user *buffer,
2400 size_t count, loff_t *off)
2403 unsigned long k = ULONG_MAX;
2405 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2408 err = kstrtoul_from_user(buffer, count, 0, &k);
2411 if (k <= 1048576) { /* limit "big buff" to 1 MB */
2418 static int sg_proc_seq_show_version(struct seq_file *s, void *v)
2420 seq_printf(s, "%d\t%s [%s]\n", sg_version_num, SG_VERSION_STR,
2425 static int sg_proc_seq_show_devhdr(struct seq_file *s, void *v)
2427 seq_puts(s, "host\tchan\tid\tlun\ttype\topens\tqdepth\tbusy\tonline\n");
2431 struct sg_proc_deviter {
2436 static void * dev_seq_start(struct seq_file *s, loff_t *pos)
2438 struct sg_proc_deviter * it = kmalloc(sizeof(*it), GFP_KERNEL);
2445 it->max = sg_last_dev();
2446 if (it->index >= it->max)
2451 static void * dev_seq_next(struct seq_file *s, void *v, loff_t *pos)
2453 struct sg_proc_deviter * it = s->private;
2456 return (it->index < it->max) ? it : NULL;
2459 static void dev_seq_stop(struct seq_file *s, void *v)
2464 static int sg_proc_seq_show_dev(struct seq_file *s, void *v)
2466 struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2468 struct scsi_device *scsidp;
2469 unsigned long iflags;
2471 read_lock_irqsave(&sg_index_lock, iflags);
2472 sdp = it ? sg_lookup_dev(it->index) : NULL;
2473 if ((NULL == sdp) || (NULL == sdp->device) ||
2474 (atomic_read(&sdp->detaching)))
2475 seq_puts(s, "-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\t-1\n");
2477 scsidp = sdp->device;
2478 seq_printf(s, "%d\t%d\t%d\t%llu\t%d\t%d\t%d\t%d\t%d\n",
2479 scsidp->host->host_no, scsidp->channel,
2480 scsidp->id, scsidp->lun, (int) scsidp->type,
2482 (int) scsidp->queue_depth,
2483 (int) scsi_device_busy(scsidp),
2484 (int) scsi_device_online(scsidp));
2486 read_unlock_irqrestore(&sg_index_lock, iflags);
2490 static int sg_proc_seq_show_devstrs(struct seq_file *s, void *v)
2492 struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2494 struct scsi_device *scsidp;
2495 unsigned long iflags;
2497 read_lock_irqsave(&sg_index_lock, iflags);
2498 sdp = it ? sg_lookup_dev(it->index) : NULL;
2499 scsidp = sdp ? sdp->device : NULL;
2500 if (sdp && scsidp && (!atomic_read(&sdp->detaching)))
2501 seq_printf(s, "%8.8s\t%16.16s\t%4.4s\n",
2502 scsidp->vendor, scsidp->model, scsidp->rev);
2504 seq_puts(s, "<no active device>\n");
2505 read_unlock_irqrestore(&sg_index_lock, iflags);
2509 /* must be called while holding sg_index_lock */
2510 static void sg_proc_debug_helper(struct seq_file *s, Sg_device * sdp)
2512 int k, new_interface, blen, usg;
2515 const sg_io_hdr_t *hp;
2520 list_for_each_entry(fp, &sdp->sfds, sfd_siblings) {
2522 read_lock(&fp->rq_list_lock); /* irqs already disabled */
2523 seq_printf(s, " FD(%d): timeout=%dms bufflen=%d "
2524 "(res)sgat=%d low_dma=%d\n", k,
2525 jiffies_to_msecs(fp->timeout),
2526 fp->reserve.bufflen,
2527 (int) fp->reserve.k_use_sg, 0);
2528 seq_printf(s, " cmd_q=%d f_packid=%d k_orphan=%d closed=0\n",
2529 (int) fp->cmd_q, (int) fp->force_packid,
2530 (int) fp->keep_orphan);
2531 list_for_each_entry(srp, &fp->rq_list, entry) {
2533 new_interface = (hp->interface_id == '\0') ? 0 : 1;
2534 if (srp->res_used) {
2535 if (new_interface &&
2536 (SG_FLAG_MMAP_IO & hp->flags))
2541 if (SG_INFO_DIRECT_IO_MASK & hp->info)
2547 blen = srp->data.bufflen;
2548 usg = srp->data.k_use_sg;
2549 seq_puts(s, srp->done ?
2550 ((1 == srp->done) ? "rcv:" : "fin:")
2552 seq_printf(s, " id=%d blen=%d",
2553 srp->header.pack_id, blen);
2555 seq_printf(s, " dur=%d", hp->duration);
2557 ms = jiffies_to_msecs(jiffies);
2558 seq_printf(s, " t_o/elap=%d/%d",
2559 (new_interface ? hp->timeout :
2560 jiffies_to_msecs(fp->timeout)),
2561 (ms > hp->duration ? ms - hp->duration : 0));
2563 seq_printf(s, "ms sgat=%d op=0x%02x\n", usg,
2564 (int) srp->data.cmd_opcode);
2566 if (list_empty(&fp->rq_list))
2567 seq_puts(s, " No requests active\n");
2568 read_unlock(&fp->rq_list_lock);
2572 static int sg_proc_seq_show_debug(struct seq_file *s, void *v)
2574 struct sg_proc_deviter * it = (struct sg_proc_deviter *) v;
2576 unsigned long iflags;
2578 if (it && (0 == it->index))
2579 seq_printf(s, "max_active_device=%d def_reserved_size=%d\n",
2580 (int)it->max, sg_big_buff);
2582 read_lock_irqsave(&sg_index_lock, iflags);
2583 sdp = it ? sg_lookup_dev(it->index) : NULL;
2586 read_lock(&sdp->sfd_lock);
2587 if (!list_empty(&sdp->sfds)) {
2588 seq_printf(s, " >>> device=%s ", sdp->name);
2589 if (atomic_read(&sdp->detaching))
2590 seq_puts(s, "detaching pending close ");
2591 else if (sdp->device) {
2592 struct scsi_device *scsidp = sdp->device;
2594 seq_printf(s, "%d:%d:%d:%llu em=%d",
2595 scsidp->host->host_no,
2596 scsidp->channel, scsidp->id,
2598 scsidp->host->hostt->emulated);
2600 seq_printf(s, " sg_tablesize=%d excl=%d open_cnt=%d\n",
2601 sdp->sg_tablesize, sdp->exclude, sdp->open_cnt);
2602 sg_proc_debug_helper(s, sdp);
2604 read_unlock(&sdp->sfd_lock);
2606 read_unlock_irqrestore(&sg_index_lock, iflags);
2610 #endif /* CONFIG_SCSI_PROC_FS */
2612 module_init(init_sg);
2613 module_exit(exit_sg);