drivers/scsi/scsi_proc.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 /*
0003  * linux/drivers/scsi/scsi_proc.c
0004  *
0005  * The functions in this file provide an interface between
0006  * the PROC file system and the SCSI device drivers
0007  * It is mainly used for debugging, statistics and to pass
0008  * information directly to the lowlevel driver.
0009  *
0010  * (c) 1995 Michael Neuffer neuffer@goofy.zdv.uni-mainz.de
0011  * Version: 0.99.8   last change: 95/09/13
0012  *
0013  * generic command parser provided by:
0014  * Andreas Heilwagen <crashcar@informatik.uni-koblenz.de>
0015  *
0016  * generic_proc_info() support of xxxx_info() by:
0017  * Michael A. Griffith <grif@acm.org>
0018  */
0019
0020 #include <linux/module.h>
0021 #include <linux/init.h>
0022 #include <linux/string.h>
0023 #include <linux/mm.h>
0024 #include <linux/proc_fs.h>
0025 #include <linux/errno.h>
0026 #include <linux/blkdev.h>
0027 #include <linux/seq_file.h>
0028 #include <linux/mutex.h>
0029 #include <linux/gfp.h>
0030 #include <linux/uaccess.h>
0031
0032 #include <scsi/scsi.h>
0033 #include <scsi/scsi_device.h>
0034 #include <scsi/scsi_host.h>
0035 #include <scsi/scsi_transport.h>
0036
0037 #include "scsi_priv.h"
0038 #include "scsi_logging.h"
0039
0040
0041 /* 4K page size, but our output routines, use some slack for overruns */
0042 #define PROC_BLOCK_SIZE (3*1024)
0043
0044 static struct proc_dir_entry *proc_scsi;
0045
0046 /* Protect sht->present and sht->proc_dir */
0047 static DEFINE_MUTEX(global_host_template_mutex);
0048
0049 static ssize_t proc_scsi_host_write(struct file *file, const char __user *buf,
0050                            size_t count, loff_t *ppos)
0051 {
0052     struct Scsi_Host *shost = pde_data(file_inode(file));
0053     ssize_t ret = -ENOMEM;
0054     char *page;
0055
0056     if (count > PROC_BLOCK_SIZE)
0057         return -EOVERFLOW;
0058
0059     if (!shost->hostt->write_info)
0060         return -EINVAL;
0061
0062     page = (char *)__get_free_page(GFP_KERNEL);
0063     if (page) {
0064         ret = -EFAULT;
0065         if (copy_from_user(page, buf, count))
0066             goto out;
0067         ret = shost->hostt->write_info(shost, page, count);
0068     }
0069 out:
0070     free_page((unsigned long)page);
0071     return ret;
0072 }
0073
0074 static int proc_scsi_show(struct seq_file *m, void *v)
0075 {
0076     struct Scsi_Host *shost = m->private;
0077     return shost->hostt->show_info(m, shost);
0078 }
0079
0080 static int proc_scsi_host_open(struct inode *inode, struct file *file)
0081 {
0082     return single_open_size(file, proc_scsi_show, pde_data(inode),
0083                 4 * PAGE_SIZE);
0084 }
0085
0086 static const struct proc_ops proc_scsi_ops = {
0087     .proc_open  = proc_scsi_host_open,
0088     .proc_release   = single_release,
0089     .proc_read  = seq_read,
0090     .proc_lseek = seq_lseek,
0091     .proc_write = proc_scsi_host_write
0092 };
0093
0094 /**
0095  * scsi_proc_hostdir_add - Create directory in /proc for a scsi host
0096  * @sht: owner of this directory
0097  *
0098  * Sets sht->proc_dir to the new directory.
0099  */
0100
0101 void scsi_proc_hostdir_add(struct scsi_host_template *sht)
0102 {
0103     if (!sht->show_info)
0104         return;
0105
0106     mutex_lock(&global_host_template_mutex);
0107     if (!sht->present++) {
0108         sht->proc_dir = proc_mkdir(sht->proc_name, proc_scsi);
0109             if (!sht->proc_dir)
0110             printk(KERN_ERR "%s: proc_mkdir failed for %s\n",
0111                    __func__, sht->proc_name);
0112     }
0113     mutex_unlock(&global_host_template_mutex);
0114 }
0115
0116 /**
0117  * scsi_proc_hostdir_rm - remove directory in /proc for a scsi host
0118  * @sht: owner of directory
0119  */
0120 void scsi_proc_hostdir_rm(struct scsi_host_template *sht)
0121 {
0122     if (!sht->show_info)
0123         return;
0124
0125     mutex_lock(&global_host_template_mutex);
0126     if (!--sht->present && sht->proc_dir) {
0127         remove_proc_entry(sht->proc_name, proc_scsi);
0128         sht->proc_dir = NULL;
0129     }
0130     mutex_unlock(&global_host_template_mutex);
0131 }
0132
0133
0134 /**
0135  * scsi_proc_host_add - Add entry for this host to appropriate /proc dir
0136  * @shost: host to add
0137  */
0138 void scsi_proc_host_add(struct Scsi_Host *shost)
0139 {
0140     struct scsi_host_template *sht = shost->hostt;
0141     struct proc_dir_entry *p;
0142     char name[10];
0143
0144     if (!sht->proc_dir)
0145         return;
0146
0147     sprintf(name,"%d", shost->host_no);
0148     p = proc_create_data(name, S_IRUGO | S_IWUSR,
0149         sht->proc_dir, &proc_scsi_ops, shost);
0150     if (!p)
0151         printk(KERN_ERR "%s: Failed to register host %d in"
0152                "%s\n", __func__, shost->host_no,
0153                sht->proc_name);
0154 }
0155
0156 /**
0157  * scsi_proc_host_rm - remove this host's entry from /proc
0158  * @shost: which host
0159  */
0160 void scsi_proc_host_rm(struct Scsi_Host *shost)
0161 {
0162     char name[10];
0163
0164     if (!shost->hostt->proc_dir)
0165         return;
0166
0167     sprintf(name,"%d", shost->host_no);
0168     remove_proc_entry(name, shost->hostt->proc_dir);
0169 }
0170 /**
0171  * proc_print_scsidevice - return data about this host
0172  * @dev: A scsi device
0173  * @data: &struct seq_file to output to.
0174  *
0175  * Description: prints Host, Channel, Id, Lun, Vendor, Model, Rev, Type,
0176  * and revision.
0177  */
0178 static int proc_print_scsidevice(struct device *dev, void *data)
0179 {
0180     struct scsi_device *sdev;
0181     struct seq_file *s = data;
0182     int i;
0183
0184     if (!scsi_is_sdev_device(dev))
0185         goto out;
0186
0187     sdev = to_scsi_device(dev);
0188     seq_printf(s,
0189         "Host: scsi%d Channel: %02d Id: %02d Lun: %02llu\n  Vendor: ",
0190         sdev->host->host_no, sdev->channel, sdev->id, sdev->lun);
0191     for (i = 0; i < 8; i++) {
0192         if (sdev->vendor[i] >= 0x20)
0193             seq_putc(s, sdev->vendor[i]);
0194         else
0195             seq_putc(s, ' ');
0196     }
0197
0198     seq_puts(s, " Model: ");
0199     for (i = 0; i < 16; i++) {
0200         if (sdev->model[i] >= 0x20)
0201             seq_putc(s, sdev->model[i]);
0202         else
0203             seq_putc(s, ' ');
0204     }
0205
0206     seq_puts(s, " Rev: ");
0207     for (i = 0; i < 4; i++) {
0208         if (sdev->rev[i] >= 0x20)
0209             seq_putc(s, sdev->rev[i]);
0210         else
0211             seq_putc(s, ' ');
0212     }
0213
0214     seq_putc(s, '\n');
0215
0216     seq_printf(s, "  Type:   %s ", scsi_device_type(sdev->type));
0217     seq_printf(s, "               ANSI  SCSI revision: %02x",
0218             sdev->scsi_level - (sdev->scsi_level > 1));
0219     if (sdev->scsi_level == 2)
0220         seq_puts(s, " CCS\n");
0221     else
0222         seq_putc(s, '\n');
0223
0224 out:
0225     return 0;
0226 }
0227
0228 /**
0229  * scsi_add_single_device - Respond to user request to probe for/add device
0230  * @host: user-supplied decimal integer
0231  * @channel: user-supplied decimal integer
0232  * @id: user-supplied decimal integer
0233  * @lun: user-supplied decimal integer
0234  *
0235  * Description: called by writing "scsi add-single-device" to /proc/scsi/scsi.
0236  *
0237  * does scsi_host_lookup() and either user_scan() if that transport
0238  * type supports it, or else scsi_scan_host_selected()
0239  *
0240  * Note: this seems to be aimed exclusively at SCSI parallel busses.
0241  */
0242
0243 static int scsi_add_single_device(uint host, uint channel, uint id, uint lun)
0244 {
0245     struct Scsi_Host *shost;
0246     int error = -ENXIO;
0247
0248     shost = scsi_host_lookup(host);
0249     if (!shost)
0250         return error;
0251
0252     if (shost->transportt->user_scan)
0253         error = shost->transportt->user_scan(shost, channel, id, lun);
0254     else
0255         error = scsi_scan_host_selected(shost, channel, id, lun,
0256                         SCSI_SCAN_MANUAL);
0257     scsi_host_put(shost);
0258     return error;
0259 }
0260
0261 /**
0262  * scsi_remove_single_device - Respond to user request to remove a device
0263  * @host: user-supplied decimal integer
0264  * @channel: user-supplied decimal integer
0265  * @id: user-supplied decimal integer
0266  * @lun: user-supplied decimal integer
0267  *
0268  * Description: called by writing "scsi remove-single-device" to
0269  * /proc/scsi/scsi.  Does a scsi_device_lookup() and scsi_remove_device()
0270  */
0271 static int scsi_remove_single_device(uint host, uint channel, uint id, uint lun)
0272 {
0273     struct scsi_device *sdev;
0274     struct Scsi_Host *shost;
0275     int error = -ENXIO;
0276
0277     shost = scsi_host_lookup(host);
0278     if (!shost)
0279         return error;
0280     sdev = scsi_device_lookup(shost, channel, id, lun);
0281     if (sdev) {
0282         scsi_remove_device(sdev);
0283         scsi_device_put(sdev);
0284         error = 0;
0285     }
0286
0287     scsi_host_put(shost);
0288     return error;
0289 }
0290
0291 /**
0292  * proc_scsi_write - handle writes to /proc/scsi/scsi
0293  * @file: not used
0294  * @buf: buffer to write
0295  * @length: length of buf, at most PAGE_SIZE
0296  * @ppos: not used
0297  *
0298  * Description: this provides a legacy mechanism to add or remove devices by
0299  * Host, Channel, ID, and Lun.  To use,
0300  * "echo 'scsi add-single-device 0 1 2 3' > /proc/scsi/scsi" or
0301  * "echo 'scsi remove-single-device 0 1 2 3' > /proc/scsi/scsi" with
0302  * "0 1 2 3" replaced by the Host, Channel, Id, and Lun.
0303  *
0304  * Note: this seems to be aimed at parallel SCSI. Most modern busses (USB,
0305  * SATA, Firewire, Fibre Channel, etc) dynamically assign these values to
0306  * provide a unique identifier and nothing more.
0307  */
0308
0309
0310 static ssize_t proc_scsi_write(struct file *file, const char __user *buf,
0311                    size_t length, loff_t *ppos)
0312 {
0313     int host, channel, id, lun;
0314     char *buffer, *p;
0315     int err;
0316
0317     if (!buf || length > PAGE_SIZE)
0318         return -EINVAL;
0319
0320     buffer = (char *)__get_free_page(GFP_KERNEL);
0321     if (!buffer)
0322         return -ENOMEM;
0323
0324     err = -EFAULT;
0325     if (copy_from_user(buffer, buf, length))
0326         goto out;
0327
0328     err = -EINVAL;
0329     if (length < PAGE_SIZE)
0330         buffer[length] = '\0';
0331     else if (buffer[PAGE_SIZE-1])
0332         goto out;
0333
0334     /*
0335      * Usage: echo "scsi add-single-device 0 1 2 3" >/proc/scsi/scsi
0336      * with  "0 1 2 3" replaced by your "Host Channel Id Lun".
0337      */
0338     if (!strncmp("scsi add-single-device", buffer, 22)) {
0339         p = buffer + 23;
0340
0341         host = simple_strtoul(p, &p, 0);
0342         channel = simple_strtoul(p + 1, &p, 0);
0343         id = simple_strtoul(p + 1, &p, 0);
0344         lun = simple_strtoul(p + 1, &p, 0);
0345
0346         err = scsi_add_single_device(host, channel, id, lun);
0347
0348     /*
0349      * Usage: echo "scsi remove-single-device 0 1 2 3" >/proc/scsi/scsi
0350      * with  "0 1 2 3" replaced by your "Host Channel Id Lun".
0351      */
0352     } else if (!strncmp("scsi remove-single-device", buffer, 25)) {
0353         p = buffer + 26;
0354
0355         host = simple_strtoul(p, &p, 0);
0356         channel = simple_strtoul(p + 1, &p, 0);
0357         id = simple_strtoul(p + 1, &p, 0);
0358         lun = simple_strtoul(p + 1, &p, 0);
0359
0360         err = scsi_remove_single_device(host, channel, id, lun);
0361     }
0362
0363     /*
0364      * convert success returns so that we return the
0365      * number of bytes consumed.
0366      */
0367     if (!err)
0368         err = length;
0369
0370  out:
0371     free_page((unsigned long)buffer);
0372     return err;
0373 }
0374
0375 static inline struct device *next_scsi_device(struct device *start)
0376 {
0377     struct device *next = bus_find_next_device(&scsi_bus_type, start);
0378
0379     put_device(start);
0380     return next;
0381 }
0382
0383 static void *scsi_seq_start(struct seq_file *sfile, loff_t *pos)
0384 {
0385     struct device *dev = NULL;
0386     loff_t n = *pos;
0387
0388     while ((dev = next_scsi_device(dev))) {
0389         if (!n--)
0390             break;
0391         sfile->private++;
0392     }
0393     return dev;
0394 }
0395
0396 static void *scsi_seq_next(struct seq_file *sfile, void *v, loff_t *pos)
0397 {
0398     (*pos)++;
0399     sfile->private++;
0400     return next_scsi_device(v);
0401 }
0402
0403 static void scsi_seq_stop(struct seq_file *sfile, void *v)
0404 {
0405     put_device(v);
0406 }
0407
0408 static int scsi_seq_show(struct seq_file *sfile, void *dev)
0409 {
0410     if (!sfile->private)
0411         seq_puts(sfile, "Attached devices:\n");
0412
0413     return proc_print_scsidevice(dev, sfile);
0414 }
0415
0416 static const struct seq_operations scsi_seq_ops = {
0417     .start  = scsi_seq_start,
0418     .next   = scsi_seq_next,
0419     .stop   = scsi_seq_stop,
0420     .show   = scsi_seq_show
0421 };
0422
0423 /**
0424  * proc_scsi_open - glue function
0425  * @inode: not used
0426  * @file: passed to single_open()
0427  *
0428  * Associates proc_scsi_show with this file
0429  */
0430 static int proc_scsi_open(struct inode *inode, struct file *file)
0431 {
0432     /*
0433      * We don't really need this for the write case but it doesn't
0434      * harm either.
0435      */
0436     return seq_open(file, &scsi_seq_ops);
0437 }
0438
0439 static const struct proc_ops scsi_scsi_proc_ops = {
0440     .proc_open  = proc_scsi_open,
0441     .proc_read  = seq_read,
0442     .proc_write = proc_scsi_write,
0443     .proc_lseek = seq_lseek,
0444     .proc_release   = seq_release,
0445 };
0446
0447 /**
0448  * scsi_init_procfs - create scsi and scsi/scsi in procfs
0449  */
0450 int __init scsi_init_procfs(void)
0451 {
0452     struct proc_dir_entry *pde;
0453
0454     proc_scsi = proc_mkdir("scsi", NULL);
0455     if (!proc_scsi)
0456         goto err1;
0457
0458     pde = proc_create("scsi/scsi", 0, NULL, &scsi_scsi_proc_ops);
0459     if (!pde)
0460         goto err2;
0461
0462     return 0;
0463
0464 err2:
0465     remove_proc_entry("scsi", NULL);
0466 err1:
0467     return -ENOMEM;
0468 }
0469
0470 /**
0471  * scsi_exit_procfs - Remove scsi/scsi and scsi from procfs
0472  */
0473 void scsi_exit_procfs(void)
0474 {
0475     remove_proc_entry("scsi/scsi", NULL);
0476     remove_proc_entry("scsi", NULL);
0477 }