static struct class st_sysfs_class;
static const struct attribute_group *st_dev_groups[];
+static const struct attribute_group *st_drv_groups[];
MODULE_AUTHOR("Kai Makisara");
MODULE_DESCRIPTION("SCSI tape (st) driver");
static int st_probe(struct device *);
static int st_remove(struct device *);
-static int do_create_sysfs_files(void);
-static void do_remove_sysfs_files(void);
-
static struct scsi_driver st_template = {
.gendrv = {
.name = "st",
.owner = THIS_MODULE,
.probe = st_probe,
.remove = st_remove,
+ .groups = st_drv_groups,
},
};
kfree(streq);
}
+static void st_do_stats(struct scsi_tape *STp, struct request *req)
+{
+ ktime_t now;
+
+ now = ktime_get();
+ if (req->cmd[0] == WRITE_6) {
+ now = ktime_sub(now, STp->stats->write_time);
+ atomic64_add(ktime_to_ns(now), &STp->stats->tot_write_time);
+ atomic64_add(ktime_to_ns(now), &STp->stats->tot_io_time);
+ atomic64_inc(&STp->stats->write_cnt);
+ if (req->errors) {
+ atomic64_add(atomic_read(&STp->stats->last_write_size)
+ - STp->buffer->cmdstat.residual,
+ &STp->stats->write_byte_cnt);
+ if (STp->buffer->cmdstat.residual > 0)
+ atomic64_inc(&STp->stats->resid_cnt);
+ } else
+ atomic64_add(atomic_read(&STp->stats->last_write_size),
+ &STp->stats->write_byte_cnt);
+ } else if (req->cmd[0] == READ_6) {
+ now = ktime_sub(now, STp->stats->read_time);
+ atomic64_add(ktime_to_ns(now), &STp->stats->tot_read_time);
+ atomic64_add(ktime_to_ns(now), &STp->stats->tot_io_time);
+ atomic64_inc(&STp->stats->read_cnt);
+ if (req->errors) {
+ atomic64_add(atomic_read(&STp->stats->last_read_size)
+ - STp->buffer->cmdstat.residual,
+ &STp->stats->read_byte_cnt);
+ if (STp->buffer->cmdstat.residual > 0)
+ atomic64_inc(&STp->stats->resid_cnt);
+ } else
+ atomic64_add(atomic_read(&STp->stats->last_read_size),
+ &STp->stats->read_byte_cnt);
+ } else {
+ now = ktime_sub(now, STp->stats->other_time);
+ atomic64_add(ktime_to_ns(now), &STp->stats->tot_io_time);
+ atomic64_inc(&STp->stats->other_cnt);
+ }
+ atomic64_dec(&STp->stats->in_flight);
+}
+
static void st_scsi_execute_end(struct request *req, int uptodate)
{
struct st_request *SRpnt = req->end_io_data;
STp->buffer->cmdstat.midlevel_result = SRpnt->result = req->errors;
STp->buffer->cmdstat.residual = req->resid_len;
+ st_do_stats(STp, req);
+
tmp = SRpnt->bio;
if (SRpnt->waiting)
complete(SRpnt->waiting);
struct rq_map_data *mdata = &SRpnt->stp->buffer->map_data;
int err = 0;
int write = (data_direction == DMA_TO_DEVICE);
+ struct scsi_tape *STp = SRpnt->stp;
req = blk_get_request(SRpnt->stp->device->request_queue, write,
GFP_KERNEL);
}
}
+ atomic64_inc(&STp->stats->in_flight);
+ if (cmd[0] == WRITE_6) {
+ atomic_set(&STp->stats->last_write_size, bufflen);
+ STp->stats->write_time = ktime_get();
+ } else if (cmd[0] == READ_6) {
+ atomic_set(&STp->stats->last_read_size, bufflen);
+ STp->stats->read_time = ktime_get();
+ } else {
+ STp->stats->other_time = ktime_get();
+ }
+
SRpnt->bio = req->bio;
req->cmd_len = COMMAND_SIZE(cmd[0]);
memset(req->cmd, 0, BLK_MAX_CDB);
}
cdev->owner = THIS_MODULE;
cdev->ops = &st_fops;
+ STm->cdevs[rew] = cdev;
error = cdev_add(cdev, cdev_devno, 1);
if (error) {
pr_err("st%d: Device not attached.\n", dev_num);
goto out_free;
}
- STm->cdevs[rew] = cdev;
i = mode << (4 - ST_NBR_MODE_BITS);
snprintf(name, 10, "%s%s%s", rew ? "n" : "",
return 0;
out_free:
cdev_del(STm->cdevs[rew]);
- STm->cdevs[rew] = NULL;
out:
+ STm->cdevs[rew] = NULL;
+ STm->devs[rew] = NULL;
return error;
}
}
tpnt->index = error;
sprintf(disk->disk_name, "st%d", tpnt->index);
+ tpnt->stats = kzalloc(sizeof(struct scsi_tape_stats), GFP_KERNEL);
+ if (tpnt->stats == NULL) {
+ sdev_printk(KERN_ERR, SDp,
+ "st: Can't allocate statistics.\n");
+ goto out_idr_remove;
+ }
dev_set_drvdata(dev, tpnt);
out_remove_devs:
remove_cdevs(tpnt);
+ kfree(tpnt->stats);
+out_idr_remove:
spin_lock(&st_index_lock);
idr_remove(&st_index_idr, tpnt->index);
spin_unlock(&st_index_lock);
disk->private_data = NULL;
put_disk(disk);
+ kfree(tpnt->stats);
kfree(tpnt);
return;
}
if (err)
goto err_chrdev;
- err = do_create_sysfs_files();
- if (err)
- goto err_scsidrv;
-
return 0;
-err_scsidrv:
- scsi_unregister_driver(&st_template.gendrv);
err_chrdev:
unregister_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0),
ST_MAX_TAPE_ENTRIES);
static void __exit exit_st(void)
{
- do_remove_sysfs_files();
scsi_unregister_driver(&st_template.gendrv);
unregister_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0),
ST_MAX_TAPE_ENTRIES);
class_unregister(&st_sysfs_class);
+ idr_destroy(&st_index_idr);
printk(KERN_INFO "st: Unloaded.\n");
}
/* The sysfs driver interface. Read-only at the moment */
-static ssize_t st_try_direct_io_show(struct device_driver *ddp, char *buf)
+static ssize_t try_direct_io_show(struct device_driver *ddp, char *buf)
{
- return snprintf(buf, PAGE_SIZE, "%d\n", try_direct_io);
+ return scnprintf(buf, PAGE_SIZE, "%d\n", try_direct_io);
}
-static DRIVER_ATTR(try_direct_io, S_IRUGO, st_try_direct_io_show, NULL);
+static DRIVER_ATTR_RO(try_direct_io);
-static ssize_t st_fixed_buffer_size_show(struct device_driver *ddp, char *buf)
+static ssize_t fixed_buffer_size_show(struct device_driver *ddp, char *buf)
{
- return snprintf(buf, PAGE_SIZE, "%d\n", st_fixed_buffer_size);
+ return scnprintf(buf, PAGE_SIZE, "%d\n", st_fixed_buffer_size);
}
-static DRIVER_ATTR(fixed_buffer_size, S_IRUGO, st_fixed_buffer_size_show, NULL);
+static DRIVER_ATTR_RO(fixed_buffer_size);
-static ssize_t st_max_sg_segs_show(struct device_driver *ddp, char *buf)
+static ssize_t max_sg_segs_show(struct device_driver *ddp, char *buf)
{
- return snprintf(buf, PAGE_SIZE, "%d\n", st_max_sg_segs);
+ return scnprintf(buf, PAGE_SIZE, "%d\n", st_max_sg_segs);
}
-static DRIVER_ATTR(max_sg_segs, S_IRUGO, st_max_sg_segs_show, NULL);
+static DRIVER_ATTR_RO(max_sg_segs);
-static ssize_t st_version_show(struct device_driver *ddd, char *buf)
+static ssize_t version_show(struct device_driver *ddd, char *buf)
{
- return snprintf(buf, PAGE_SIZE, "[%s]\n", verstr);
+ return scnprintf(buf, PAGE_SIZE, "[%s]\n", verstr);
}
-static DRIVER_ATTR(version, S_IRUGO, st_version_show, NULL);
+static DRIVER_ATTR_RO(version);
-static int do_create_sysfs_files(void)
+#if DEBUG
+static ssize_t debug_flag_store(struct device_driver *ddp,
+ const char *buf, size_t count)
{
- struct device_driver *sysfs = &st_template.gendrv;
- int err;
-
- err = driver_create_file(sysfs, &driver_attr_try_direct_io);
- if (err)
- return err;
- err = driver_create_file(sysfs, &driver_attr_fixed_buffer_size);
- if (err)
- goto err_try_direct_io;
- err = driver_create_file(sysfs, &driver_attr_max_sg_segs);
- if (err)
- goto err_attr_fixed_buf;
- err = driver_create_file(sysfs, &driver_attr_version);
- if (err)
- goto err_attr_max_sg;
-
- return 0;
-
-err_attr_max_sg:
- driver_remove_file(sysfs, &driver_attr_max_sg_segs);
-err_attr_fixed_buf:
- driver_remove_file(sysfs, &driver_attr_fixed_buffer_size);
-err_try_direct_io:
- driver_remove_file(sysfs, &driver_attr_try_direct_io);
- return err;
+/* We only care what the first byte of the data is the rest is unused.
+ * if it's a '1' we turn on debug and if it's a '0' we disable it. All
+ * other values have -EINVAL returned if they are passed in.
+ */
+ if (count > 0) {
+ if (buf[0] == '0') {
+ debugging = NO_DEBUG;
+ return count;
+ } else if (buf[0] == '1') {
+ debugging = 1;
+ return count;
+ }
+ }
+ return -EINVAL;
}
-static void do_remove_sysfs_files(void)
+static ssize_t debug_flag_show(struct device_driver *ddp, char *buf)
{
- struct device_driver *sysfs = &st_template.gendrv;
-
- driver_remove_file(sysfs, &driver_attr_version);
- driver_remove_file(sysfs, &driver_attr_max_sg_segs);
- driver_remove_file(sysfs, &driver_attr_fixed_buffer_size);
- driver_remove_file(sysfs, &driver_attr_try_direct_io);
+ return scnprintf(buf, PAGE_SIZE, "%d\n", debugging);
}
+static DRIVER_ATTR_RW(debug_flag);
+#endif
+
+static struct attribute *st_drv_attrs[] = {
+ &driver_attr_try_direct_io.attr,
+ &driver_attr_fixed_buffer_size.attr,
+ &driver_attr_max_sg_segs.attr,
+ &driver_attr_version.attr,
+#if DEBUG
+ &driver_attr_debug_flag.attr,
+#endif
+ NULL,
+};
+ATTRIBUTE_GROUPS(st_drv);
/* The sysfs simple class interface */
static ssize_t
}
static DEVICE_ATTR_RO(options);
+/* Support for tape stats */
+
+/**
+ * read_cnt_show - return read count - count of reads made from tape drive
+ * @dev: struct device
+ * @attr: attribute structure
+ * @buf: buffer to return formatted data in
+ */
+static ssize_t read_cnt_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct st_modedef *STm = dev_get_drvdata(dev);
+
+ return sprintf(buf, "%lld",
+ (long long)atomic64_read(&STm->tape->stats->read_cnt));
+}
+static DEVICE_ATTR_RO(read_cnt);
+
+/**
+ * read_byte_cnt_show - return read byte count - tape drives
+ * may use blocks less than 512 bytes this gives the raw byte count of
+ * of data read from the tape drive.
+ * @dev: struct device
+ * @attr: attribute structure
+ * @buf: buffer to return formatted data in
+ */
+static ssize_t read_byte_cnt_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct st_modedef *STm = dev_get_drvdata(dev);
+
+ return sprintf(buf, "%lld",
+ (long long)atomic64_read(&STm->tape->stats->read_byte_cnt));
+}
+static DEVICE_ATTR_RO(read_byte_cnt);
+
+/**
+ * read_us_show - return read us - overall time spent waiting on reads in ns.
+ * @dev: struct device
+ * @attr: attribute structure
+ * @buf: buffer to return formatted data in
+ */
+static ssize_t read_ns_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct st_modedef *STm = dev_get_drvdata(dev);
+
+ return sprintf(buf, "%lld",
+ (long long)atomic64_read(&STm->tape->stats->tot_read_time));
+}
+static DEVICE_ATTR_RO(read_ns);
+
+/**
+ * write_cnt_show - write count - number of user calls
+ * to write(2) that have written data to tape.
+ * @dev: struct device
+ * @attr: attribute structure
+ * @buf: buffer to return formatted data in
+ */
+static ssize_t write_cnt_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct st_modedef *STm = dev_get_drvdata(dev);
+
+ return sprintf(buf, "%lld",
+ (long long)atomic64_read(&STm->tape->stats->write_cnt));
+}
+static DEVICE_ATTR_RO(write_cnt);
+
+/**
+ * write_byte_cnt_show - write byte count - raw count of
+ * bytes written to tape.
+ * @dev: struct device
+ * @attr: attribute structure
+ * @buf: buffer to return formatted data in
+ */
+static ssize_t write_byte_cnt_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct st_modedef *STm = dev_get_drvdata(dev);
+
+ return sprintf(buf, "%lld",
+ (long long)atomic64_read(&STm->tape->stats->write_byte_cnt));
+}
+static DEVICE_ATTR_RO(write_byte_cnt);
+
+/**
+ * write_ns_show - write ns - number of nanoseconds waiting on write
+ * requests to complete.
+ * @dev: struct device
+ * @attr: attribute structure
+ * @buf: buffer to return formatted data in
+ */
+static ssize_t write_ns_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct st_modedef *STm = dev_get_drvdata(dev);
+
+ return sprintf(buf, "%lld",
+ (long long)atomic64_read(&STm->tape->stats->tot_write_time));
+}
+static DEVICE_ATTR_RO(write_ns);
+
+/**
+ * in_flight_show - number of I/Os currently in flight -
+ * in most cases this will be either 0 or 1. It may be higher if someone
+ * has also issued other SCSI commands such as via an ioctl.
+ * @dev: struct device
+ * @attr: attribute structure
+ * @buf: buffer to return formatted data in
+ */
+static ssize_t in_flight_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct st_modedef *STm = dev_get_drvdata(dev);
+
+ return sprintf(buf, "%lld",
+ (long long)atomic64_read(&STm->tape->stats->in_flight));
+}
+static DEVICE_ATTR_RO(in_flight);
+
+/**
+ * io_ns_show - io wait ns - this is the number of ns spent
+ * waiting on all I/O to complete. This includes tape movement commands
+ * such as rewinding, seeking to end of file or tape, it also includes
+ * read and write. To determine the time spent on tape movement
+ * subtract the read and write ns from this value.
+ * @dev: struct device
+ * @attr: attribute structure
+ * @buf: buffer to return formatted data in
+ */
+static ssize_t io_ns_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct st_modedef *STm = dev_get_drvdata(dev);
+
+ return sprintf(buf, "%lld",
+ (long long)atomic64_read(&STm->tape->stats->tot_io_time));
+}
+static DEVICE_ATTR_RO(io_ns);
+
+/**
+ * other_cnt_show - other io count - this is the number of
+ * I/O requests other than read and write requests.
+ * Typically these are tape movement requests but will include driver
+ * tape movement. This includes only requests issued by the st driver.
+ * @dev: struct device
+ * @attr: attribute structure
+ * @buf: buffer to return formatted data in
+ */
+static ssize_t other_cnt_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct st_modedef *STm = dev_get_drvdata(dev);
+
+ return sprintf(buf, "%lld",
+ (long long)atomic64_read(&STm->tape->stats->other_cnt));
+}
+static DEVICE_ATTR_RO(other_cnt);
+
+/**
+ * resid_cnt_show - A count of the number of times we get a residual
+ * count - this should indicate someone issuing reads larger than the
+ * block size on tape.
+ * @dev: struct device
+ * @attr: attribute structure
+ * @buf: buffer to return formatted data in
+ */
+static ssize_t resid_cnt_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct st_modedef *STm = dev_get_drvdata(dev);
+
+ return sprintf(buf, "%lld",
+ (long long)atomic64_read(&STm->tape->stats->resid_cnt));
+}
+static DEVICE_ATTR_RO(resid_cnt);
+
static struct attribute *st_dev_attrs[] = {
&dev_attr_defined.attr,
&dev_attr_default_blksize.attr,
&dev_attr_options.attr,
NULL,
};
-ATTRIBUTE_GROUPS(st_dev);
+
+static struct attribute *st_stats_attrs[] = {
+ &dev_attr_read_cnt.attr,
+ &dev_attr_read_byte_cnt.attr,
+ &dev_attr_read_ns.attr,
+ &dev_attr_write_cnt.attr,
+ &dev_attr_write_byte_cnt.attr,
+ &dev_attr_write_ns.attr,
+ &dev_attr_in_flight.attr,
+ &dev_attr_io_ns.attr,
+ &dev_attr_other_cnt.attr,
+ &dev_attr_resid_cnt.attr,
+ NULL,
+};
+
+static struct attribute_group stats_group = {
+ .name = "stats",
+ .attrs = st_stats_attrs,
+};
+
+static struct attribute_group st_group = {
+ .attrs = st_dev_attrs,
+};
+
+static const struct attribute_group *st_dev_groups[] = {
+ &st_group,
+ &stats_group,
+ NULL,
+};
/* The following functions may be useful for a larger audience. */
static int sgl_map_user_pages(struct st_buffer *STbp,
Code Review / kvmfornfv.git / blobdiff