New version of statistics patch:
- Removed sysfs file containing hint for number of tape drives
- Removed disk like stat file - there is now one file per statistic as per feedback from James
- Like all other kernel stats these start at zero and keep incrementing (cannot zero them any more)
- Implemented a method where the statistics files can be frozen at a point in time to allow consistent statistics to be read from the group of statistics files (permissions on the sync file limit mean you need an euid of 0 to freeze the statistics)
- Example output of statistics directory:
# ll /sys/class/scsi_tape/st0/device/statistics
total 0
-r--r--r--. 1 root root 4096 May 3 06:32 in_flight
-r--r--r--. 1 root root 4096 May 3 06:32 io_ms
-r--r--r--. 1 root root 4096 May 3 06:32 other_cnt
-r--r--r--. 1 root root 4096 May 3 06:32 read_block_cnt
-r--r--r--. 1 root root 4096 May 3 06:32 read_byte_cnt
-r--r--r--. 1 root root 4096 May 3 06:32 read_cnt
-r--r--r--. 1 root root 4096 May 3 06:32 read_ms
-rw-rw-r--. 1 root root 4096 May 3 06:41 sync
-r--r--r--. 1 root root 4096 May 3 06:32 write_block_cnt
-r--r--r--. 1 root root 4096 May 3 06:32 write_byte_cnt
-r--r--r--. 1 root root 4096 May 3 06:32 write_cnt
-r--r--r--. 1 root root 4096 May 3 06:32 write_ms
Needs the previous patch I sent this week titled "st: clear driver data from struct device when released" to be applied before this one (the diff below is not against a vanilla 3.9 kernel it is against 3.9 with that patch applied to it to get this patch).
Signed-off-by: Shane Seymour <shane.seymour@xxxxxx>
Tested-by: Shane Seymour <shane.seymour@xxxxxx>
---
diff -uprN -X linux-3.9-vanilla/Documentation/dontdiff linux-3.9-vanilla/drivers/scsi/st.c linux-3.9/drivers/scsi/st.c
--- linux-3.9-vanilla/drivers/scsi/st.c 2013-05-03 05:46:32.000000000 +0100
+++ linux-3.9/drivers/scsi/st.c 2013-05-03 06:46:55.000000000 +0100
@@ -218,6 +218,15 @@ static DEFINE_SPINLOCK(st_index_lock);
static DEFINE_SPINLOCK(st_use_lock);
static DEFINE_IDR(st_index_idr);
+static inline void st_stats_remove_files(struct scsi_tape *);
+static inline void st_stats_create_files(struct scsi_tape *);
+static ssize_t st_tape_attr_show(struct kobject *, struct attribute *, char *);
+static ssize_t st_tape_attr_store(struct kobject *, struct attribute *,
+ const char *, size_t);
+static const struct sysfs_ops st_stats_sysfs_ops = {
+ .show = st_tape_attr_show,
+ .store = st_tape_attr_store,
+};
#include "osst_detect.h"
@@ -458,10 +467,19 @@ static void st_scsi_execute_end(struct r
struct st_request *SRpnt = req->end_io_data;
struct scsi_tape *STp = SRpnt->stp;
struct bio *tmp;
+ u64 ticks = get_jiffies_64();
STp->buffer->cmdstat.midlevel_result = SRpnt->result = req->errors;
STp->buffer->cmdstat.residual = req->resid_len;
+ STp->in_flight--;
+ ticks -= STp->stamp;
+ STp->io_ticks += ticks;
+ if (req->cmd[0] == WRITE_6)
+ STp->write_ticks += ticks;
+ else if (req->cmd[0] == READ_6)
+ STp->read_ticks += ticks;
+
tmp = SRpnt->bio;
if (SRpnt->waiting)
complete(SRpnt->waiting);
@@ -478,6 +496,7 @@ static int st_scsi_execute(struct st_req
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);
@@ -498,6 +517,18 @@ static int st_scsi_execute(struct st_req
}
}
+ if (cmd[0] == WRITE_6) {
+ STp->write_cnt++;
+ STp->write_byte_cnt += bufflen;
+ } else if (cmd[0] == READ_6) {
+ STp->read_cnt++;
+ STp->read_byte_cnt += bufflen;
+ } else {
+ STp->other_cnt++;
+ }
+ STp->stamp = get_jiffies_64();
+ STp->in_flight++;
+
SRpnt->bio = req->bio;
req->cmd_len = COMMAND_SIZE(cmd[0]);
memset(req->cmd, 0, BLK_MAX_CDB);
@@ -4048,6 +4079,14 @@ static int create_cdevs(struct scsi_tape
if (error)
return error;
}
+/* Create statistics directory under device, if it fails we dont
+ have statistics. */
+ tape->statistics = kobject_create_and_add("statistics",
+ &tape->device->sdev_gendev.kobj);
+ if (tape->statistics != 0) {
+ st_stats_create_files(tape);
+ tape->statistics->ktype->sysfs_ops = &st_stats_sysfs_ops;
+ }
return sysfs_create_link(&tape->device->sdev_gendev.kobj,
&tape->modes[0].devs[0]->kobj, "tape");
@@ -4057,6 +4096,10 @@ static void remove_cdevs(struct scsi_tap
{
int mode, rew;
sysfs_remove_link(&tape->device->sdev_gendev.kobj, "tape");
+ if (tape->statistics != 0) {
+ st_stats_remove_files(tape);
+ kobject_put(tape->statistics);
+ }
for (mode = 0; mode < ST_NBR_MODES; mode++) {
struct st_modedef *STm = &(tape->modes[mode]);
for (rew = 0; rew < 2; rew++) {
@@ -4127,6 +4170,28 @@ static int st_probe(struct device *dev)
tpnt->buffer = buffer;
tpnt->buffer->last_SRpnt = NULL;
+ tpnt->statistics = 0;
+ tpnt->read_byte_cnt = 0;
+ tpnt->write_byte_cnt = 0;
+ tpnt->read_cnt = 0;
+ tpnt->write_cnt = 0;
+ tpnt->other_cnt = 0;
+ tpnt->in_flight = 0;
+ tpnt->read_ticks = 0;
+ tpnt->write_ticks = 0;
+ tpnt->io_ticks = 0;
+ tpnt->stamp = 0;
+ tpnt->sync = 0;
+ tpnt->sync_read_byte_cnt = 0;
+ tpnt->sync_write_byte_cnt = 0;
+ tpnt->sync_in_flight = 0;
+ tpnt->sync_read_cnt = 0;
+ tpnt->sync_write_cnt = 0;
+ tpnt->sync_other_cnt = 0;
+ tpnt->sync_read_ticks = 0;
+ tpnt->sync_write_ticks = 0;
+ tpnt->sync_io_ticks = 0;
+
tpnt->inited = 0;
tpnt->dirty = 0;
tpnt->in_use = 0;
@@ -4484,6 +4549,439 @@ static struct device_attribute st_dev_at
__ATTR_NULL,
};
+/* Support for tape stats */
+
+struct tape_stats_attr {
+ struct attribute attr;
+ ssize_t (*show)(struct scsi_tape *, char *);
+ ssize_t (*store)(struct scsi_tape *, const char *, size_t);
+};
+
+#define TAPE_STATS_ATTR(_name, _mode, _show, _store) \
+struct tape_stats_attr tape_stats_attr_##_name = { \
+ .attr = {.name = __stringify(_name) , .mode = _mode }, \
+ .show = _show, \
+ .store = _store, \
+};
+
+/**
+ * st_stats_create_file - create sysfs tape stats attribute file
+ * @st: scsi_tape structure.
+ * @attr: device attribute descriptor.
+ */
+static inline int st_stats_create_file(struct scsi_tape *st,
+ const struct tape_stats_attr *attr)
+{
+ int error = 0;
+ if (st)
+ error = sysfs_create_file(st->statistics, &attr->attr);
+ return error;
+}
+
+/**
+ * st_stats_remove_file - remove sysfs atape stats attribute file.
+ * @st: scsi_tape structure.
+ * @attr: device attribute descriptor.
+ */
+static inline void st_stats_remove_file(struct scsi_tape *st,
+ const struct tape_stats_attr *attr)
+{
+ if (st)
+ sysfs_remove_file(st->statistics, &attr->attr);
+}
+
+/**
+ * st_stats_attr_show_read_cnt - return read count - count of reads made
+ * from tape drive
+ * @st: scsi_tape structure.
+ * @buf: buffer to return formatted data in
+ */
+ssize_t st_stats_attr_show_read_cnt(struct scsi_tape *st, char *buf)
+{
+ if (st->sync == 0)
+ return snprintf(buf, 4096, "%llu", st->read_cnt);
+ return snprintf(buf, 4096, "%llu", st->sync_read_cnt);
+}
+
+/**
+ * st_stats_attr_show_read_byte_cnt - 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.
+ * @st: scsi_tape structure.
+ * @buf: buffer to return formatted data in
+ */
+ssize_t st_stats_attr_show_read_byte_cnt(struct scsi_tape *st, char *buf)
+{
+ if (st->sync == 0)
+ return snprintf(buf, 4096, "%llu", st->read_byte_cnt);
+ return snprintf(buf, 4096, "%llu", st->sync_read_byte_cnt);
+}
+
+/**
+ * st_stats_attr_show_read_block_cnt - return read block count -
+ * provides disk like data for someone expecting that instead of wanting
+ * byte counts.
+ * @st: scsi_tape structure.
+ * @buf: buffer to return formatted data in
+ */
+ssize_t st_stats_attr_show_read_block_cnt(struct scsi_tape *st, char *buf)
+{
+ if (st->sync == 0)
+ return snprintf(buf, 4096, "%llu", st->read_byte_cnt >> 9);
+ return snprintf(buf, 4096, "%llu", st->sync_read_byte_cnt >> 9);
+}
+
+/**
+ * st_stats_attr_show_read_ms - return read ms - overall time spent waiting
+ * on reads in ms.
+ * @st: scsi_tape structure.
+ * @buf: buffer to return formatted data in
+ */
+ssize_t st_stats_attr_show_read_ms(struct scsi_tape *st, char *buf)
+{
+ if (st->sync == 0)
+ return snprintf(buf, 4096, "%u",
+ jiffies_to_msecs(st->read_ticks));
+ return snprintf(buf, 4096, "%u", jiffies_to_msecs(st->sync_read_ticks));
+}
+
+/**
+ * st_stats_attr_show_write_cnt - write count - number of user calls
+ * to write(2) that have written data to tape.
+ * @st: scsi_tape structure.
+ * @buf: buffer to return formatted data in
+ */
+ssize_t st_stats_attr_show_write_cnt(struct scsi_tape *st, char *buf)
+{
+ if (st->sync == 0)
+ return snprintf(buf, 4096, "%llu", st->write_cnt);
+ return snprintf(buf, 4096, "%llu", st->sync_write_cnt);
+}
+
+/**
+ * st_stats_attr_show_write_byte_cnt - write byte count - raw count of
+ * bytes written to tape.
+ * @st: scsi_tape structure.
+ * @buf: buffer to return formatted data in
+ */
+ssize_t st_stats_attr_show_write_byte_cnt(struct scsi_tape *st, char *buf)
+{
+ if (st->sync == 0)
+ return snprintf(buf, 4096, "%llu", st->write_byte_cnt);
+ return snprintf(buf, 4096, "%llu", st->sync_write_byte_cnt);
+}
+
+/**
+ * st_stats_attr_show_write_block_cnt - write block total - raw count of
+ * 512 byte blocks written to tape. This is for compatability
+ * with disk type information although it doesn't mean much for tapes since
+ * they can have a block size of less than 512 bytes.
+ * @st: scsi_tape structure.
+ * @buf: buffer to return formatted data in
+ */
+ssize_t st_stats_attr_show_write_block_cnt(struct scsi_tape *st, char *buf)
+{
+ if (st->sync == 0)
+ return snprintf(buf, 4096, "%llu", st->write_byte_cnt >> 9);
+ return snprintf(buf, 4096, "%llu", st->sync_write_byte_cnt >> 9);
+}
+
+/**
+ * st_stats_attr_show_write_ms - write ms - number of milliseconds since
+ * last open waiting on write requests to complete.
+ * @st: scsi_tape structure.
+ * @buf: buffer to return formatted data in
+ */
+ssize_t st_stats_attr_show_write_ms(struct scsi_tape *st, char *buf)
+{
+ if (st->sync == 0)
+ return snprintf(buf, 4096, "%u",
+ jiffies_to_msecs(st->write_ticks));
+ return snprintf(buf, 4096, "%u",
+ jiffies_to_msecs(st->sync_write_ticks));
+}
+
+/**
+ * st_stats_attr_show_in_flight - 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.
+ * @st: scsi_tape structure.
+ * @buf: buffer to return formatted data in
+ */
+ssize_t st_stats_attr_show_in_flight(struct scsi_tape *st, char *buf)
+{
+ if (st->sync == 0)
+ return snprintf(buf, 4096, "%llu", st->in_flight);
+ return snprintf(buf, 4096, "%llu", st->sync_in_flight);
+}
+
+/**
+ * st_stats_attr_show_io_ms - io wait ms - this is the number of ms spent
+ * waiting on other I/O to complete. This includes tape movement commands
+ * such as rewinding, seeking to end of file or tape, etc. Except in
+ * complex tape management programs these will be indirect commands issued
+ * by the driver - e.g. rewind on close.
+ * @st: scsi_tape structure.
+ * @buf: buffer to return formatted data in
+ */
+ssize_t st_stats_attr_show_io_ms(struct scsi_tape *st, char *buf)
+{
+ if (st->sync == 0)
+ return snprintf(buf, 4096, "%u",
+ jiffies_to_msecs(st->io_ticks));
+ return snprintf(buf, 4096, "%u", jiffies_to_msecs(st->sync_io_ticks));
+}
+
+/**
+ * st_stats_attr_show_other_cnt - other io count - this is the number of
+ * I/O requests that make up the time returned from st_stats_attr_show_io_ms.
+ * Typically these are tape movement requests but will include driver
+ * tape movement. This includes on requests seen by the st driver.
+ * @st: scsi_tape structure.
+ * @buf: buffer to return formatted data in
+ */
+ssize_t st_stats_attr_show_other_cnt(struct scsi_tape *st, char *buf)
+{
+ if (st->sync == 0)
+ return snprintf(buf, 4096, "%llu", st->other_cnt);
+ return snprintf(buf, 4096, "%llu", st->sync_other_cnt);
+}
+/**
+ * st_stats_attr_show_sync - if 0 is returned the stats are being read
+ * directly and are not in sync. Anyone using the sync interface should
+ * chose a random value that nobody else will use. Every time you want the
+ * stats updated you write the same value into the sync file to cause
+ * them to be copied. You can read this back when done to see if someone
+ * else has changed the sync value (i.e. someone else has caused an update
+ * to happen. You can either read them again after writing your sync
+ * value back or take the stats as they are forewarned that they may not
+ * be completely in sync.
+ * If you do not care about them being in sync you need to take some
+ * action if the sync value is non-zero as someone could have left it
+ * non-zero which means the values never change. You should write a "0"
+ * to the sync file before you read the read the other stats files.
+ * @st: scsi_tape structure.
+ * @buf: buffer to return formatted data in
+ */
+ssize_t st_stats_attr_show_sync(struct scsi_tape *st, char *buf)
+{
+ return snprintf(buf, 4096, "%llu", st->sync);
+}
+
+ssize_t st_stats_attr_store_sync(struct scsi_tape *st, const char *buf,
+ size_t len)
+{
+ if (sscanf(buf, "%llu", &st->sync) != 1)
+ st->sync = 0;
+ if (st->sync == 0)
+ return len;
+ st->sync_read_byte_cnt = st->read_byte_cnt;
+ st->sync_write_byte_cnt = st->write_byte_cnt;
+ st->sync_in_flight = st->in_flight;
+ st->sync_read_cnt = st->read_cnt;
+ st->sync_write_cnt = st->write_cnt;
+ st->sync_other_cnt = st->other_cnt;
+ st->sync_read_ticks = st->read_ticks;
+ st->sync_write_ticks = st->write_ticks;
+ st->sync_io_ticks = st->io_ticks;
+ return len;
+}
+
+TAPE_STATS_ATTR(read_cnt, S_IRUSR | S_IRGRP | S_IROTH,
+ st_stats_attr_show_read_cnt, NULL);
+TAPE_STATS_ATTR(read_byte_cnt, S_IRUSR | S_IRGRP | S_IROTH,
+ st_stats_attr_show_read_byte_cnt, NULL);
+TAPE_STATS_ATTR(read_block_cnt, S_IRUSR | S_IRGRP | S_IROTH,
+ st_stats_attr_show_read_block_cnt, NULL);
+TAPE_STATS_ATTR(read_ms, S_IRUSR | S_IRGRP | S_IROTH,
+ st_stats_attr_show_read_ms, NULL);
+TAPE_STATS_ATTR(write_cnt, S_IRUSR | S_IRGRP | S_IROTH,
+ st_stats_attr_show_write_cnt, NULL);
+TAPE_STATS_ATTR(write_byte_cnt, S_IRUSR | S_IRGRP | S_IROTH,
+ st_stats_attr_show_write_byte_cnt, NULL);
+TAPE_STATS_ATTR(write_block_cnt, S_IRUSR | S_IRGRP | S_IROTH,
+ st_stats_attr_show_write_block_cnt, NULL);
+TAPE_STATS_ATTR(write_ms, S_IRUSR | S_IRGRP | S_IROTH,
+ st_stats_attr_show_write_ms, NULL);
+TAPE_STATS_ATTR(in_flight, S_IRUSR | S_IRGRP | S_IROTH,
+ st_stats_attr_show_in_flight, NULL);
+TAPE_STATS_ATTR(io_ms, S_IRUSR | S_IRGRP | S_IROTH,
+ st_stats_attr_show_io_ms, NULL);
+TAPE_STATS_ATTR(other_cnt, S_IRUSR | S_IRGRP | S_IROTH,
+ st_stats_attr_show_other_cnt, NULL);
+TAPE_STATS_ATTR(sync, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH,
+ st_stats_attr_show_sync, st_stats_attr_store_sync);
+
+/**
+ * st_stats_create_files - register files in the device
+ * statistics directory.
+ * @st: scsi_tape structure.
+ */
+static inline void st_stats_create_files(struct scsi_tape *st)
+{
+ if (st_stats_create_file(st, &tape_stats_attr_read_cnt))
+ goto error_read_cnt;
+ if (st_stats_create_file(st, &tape_stats_attr_read_byte_cnt))
+ goto error_read_byte_cnt;
+ if (st_stats_create_file(st, &tape_stats_attr_read_block_cnt))
+ goto error_read_block_cnt;
+ if (st_stats_create_file(st, &tape_stats_attr_read_ms))
+ goto error_read_ms;
+ if (st_stats_create_file(st, &tape_stats_attr_write_cnt))
+ goto error_write_cnt;
+ if (st_stats_create_file(st, &tape_stats_attr_write_byte_cnt))
+ goto error_write_byte_cnt;
+ if (st_stats_create_file(st, &tape_stats_attr_write_block_cnt))
+ goto error_write_block_cnt;
+ if (st_stats_create_file(st, &tape_stats_attr_write_ms))
+ goto error_write_ms;
+ if (st_stats_create_file(st, &tape_stats_attr_in_flight))
+ goto error_in_flight;
+ if (st_stats_create_file(st, &tape_stats_attr_io_ms))
+ goto error_io_ms;
+ if (st_stats_create_file(st, &tape_stats_attr_other_cnt))
+ goto error_other_cnt;
+ if (st_stats_create_file(st, &tape_stats_attr_sync))
+ goto error_sync;
+ return;
+error_sync:
+ st_stats_remove_file(st, &tape_stats_attr_sync);
+error_other_cnt:
+ st_stats_remove_file(st, &tape_stats_attr_other_cnt);
+error_io_ms:
+ st_stats_remove_file(st, &tape_stats_attr_io_ms);
+error_in_flight:
+ st_stats_remove_file(st, &tape_stats_attr_in_flight);
+error_write_ms:
+ st_stats_remove_file(st, &tape_stats_attr_write_ms);
+error_write_block_cnt:
+ st_stats_remove_file(st, &tape_stats_attr_write_block_cnt);
+error_write_byte_cnt:
+ st_stats_remove_file(st, &tape_stats_attr_write_byte_cnt);
+error_write_cnt:
+ st_stats_remove_file(st, &tape_stats_attr_write_cnt);
+error_read_ms:
+ st_stats_remove_file(st, &tape_stats_attr_read_ms);
+error_read_block_cnt:
+ st_stats_remove_file(st, &tape_stats_attr_read_block_cnt);
+error_read_byte_cnt:
+ st_stats_remove_file(st, &tape_stats_attr_read_byte_cnt);
+error_read_cnt:
+ st_stats_remove_file(st, &tape_stats_attr_read_cnt);
+}
+
+#define to_tape_stats_attr(ptr) container_of(ptr, struct tape_stats_attr, attr)
+
+/**
+ * st_tape_attr_store - call functions required to implement the store
+ * functionality. Works similar to show function.
+ * @kobj: struct kobject
+ * @attr: struct attribute
+ * @buf: data provided by caller
+ * @len: length of data provided
+ */
+static ssize_t st_tape_attr_store(struct kobject *kobj, struct attribute *attr,
+ const char *buf, size_t len)
+{
+ struct kobject *ktemp = kobj->parent;
+ struct device *dev;
+ struct scsi_tape *st;
+ struct tape_stats_attr *st_attr = to_tape_stats_attr(attr);
+ ssize_t ret = -EIO;
+
+ if ((!st_attr->store) || (ktemp == 0))
+ return ret;
+ dev = kobj_to_dev(ktemp);
+ if (dev == 0)
+ return ret;
+
+ mutex_lock(&st_ref_mutex);
+ st = dev_get_drvdata(dev);
+ if (st == 0) {
+ mutex_unlock(&st_ref_mutex);
+ return ret;
+ }
+ kref_get(&st->kref);
+ mutex_unlock(&st_ref_mutex);
+
+ if (st_attr->store)
+ ret = st_attr->store(st, buf, len);
+
+ mutex_lock(&st_ref_mutex);
+ kref_put(&st->kref, scsi_tape_release);
+ mutex_unlock(&st_ref_mutex);
+
+ return ret;
+}
+
+/**
+ * st_tape_attr_show - call the functions that provide the statistics.
+ * This function makes sure that the struct scsi_tape being refered to is
+ * current and has not been deleted (e.g. during an unload of the st
+ * driver or the tape drive disappearing).
+ * @kobj: struct kobject
+ * @attr: struct attribute
+ * @buf: data being returned to caller
+ */
+static ssize_t st_tape_attr_show(struct kobject *kobj, struct attribute *attr,
+ char *buf)
+{
+ struct kobject *ktemp = kobj->parent;
+ struct device *dev;
+ struct scsi_tape *st;
+ struct tape_stats_attr *st_attr = to_tape_stats_attr(attr);
+ ssize_t ret = -EIO;
+
+/* kobject passed in is for the statistics directory. We need to look at the
+ parent kobject (part of a struct device) and from there get the struct
+ scsi_tape. If no show function return error as well. */
+ if ((!st_attr->show) || (ktemp == 0))
+ return ret;
+ dev = kobj_to_dev(ktemp);
+ if (dev == 0)
+ return ret;
+/* dev_get_drvdata must return 0 if the struct scsi_tape has been freed.
+ Holding st_ref_mutex means it cannot be freed while we check and we
+ grab a reference to the struct scsi_tape before unlocking. */
+ mutex_lock(&st_ref_mutex);
+ st = dev_get_drvdata(dev);
+ if (st == 0) {
+ mutex_unlock(&st_ref_mutex);
+ return ret;
+ }
+ kref_get(&st->kref);
+ mutex_unlock(&st_ref_mutex);
+
+ if (st_attr->show)
+ ret = st_attr->show(st, buf);
+
+ mutex_lock(&st_ref_mutex);
+ kref_put(&st->kref, scsi_tape_release);
+ mutex_unlock(&st_ref_mutex);
+
+ return ret;
+}
+
+/**
+ * st_stats_remove_files - remove the files from the statistics directory.
+ * @st: struct scsi_tape
+ */
+static inline void st_stats_remove_files(struct scsi_tape *st)
+{
+ st_stats_remove_file(st, &tape_stats_attr_other_cnt);
+ st_stats_remove_file(st, &tape_stats_attr_io_ms);
+ st_stats_remove_file(st, &tape_stats_attr_in_flight);
+ st_stats_remove_file(st, &tape_stats_attr_write_ms);
+ st_stats_remove_file(st, &tape_stats_attr_write_block_cnt);
+ st_stats_remove_file(st, &tape_stats_attr_write_byte_cnt);
+ st_stats_remove_file(st, &tape_stats_attr_write_cnt);
+ st_stats_remove_file(st, &tape_stats_attr_read_ms);
+ st_stats_remove_file(st, &tape_stats_attr_read_block_cnt);
+ st_stats_remove_file(st, &tape_stats_attr_read_byte_cnt);
+ st_stats_remove_file(st, &tape_stats_attr_read_cnt);
+ st_stats_remove_file(st, &tape_stats_attr_sync);
+}
+
/* The following functions may be useful for a larger audience. */
static int sgl_map_user_pages(struct st_buffer *STbp,
const unsigned int max_pages, unsigned long uaddr,
diff -uprN -X linux-3.9-vanilla/Documentation/dontdiff linux-3.9-vanilla/drivers/scsi/st.h linux-3.9/drivers/scsi/st.h
--- linux-3.9-vanilla/drivers/scsi/st.h 2013-04-29 01:36:01.000000000 +0100
+++ linux-3.9/drivers/scsi/st.h 2013-05-03 03:25:40.000000000 +0100
@@ -158,6 +158,29 @@ struct scsi_tape {
int max_block;
int recover_count; /* From tape opening */
int recover_reg; /* From last status call */
+/* Statistics variables */
+ struct kobject *statistics; /* Object for statistics directory */
+ u64 read_byte_cnt; /* bytes read */
+ u64 write_byte_cnt; /* bytes written */
+ u64 in_flight; /* Number of I/Os in flight */
+ u64 read_cnt; /* Count of read requests */
+ u64 write_cnt; /* Count of write requests */
+ u64 other_cnt; /* Count of other requests either implicit
+ or from user space via ioctl. */
+ u64 read_ticks; /* Ticks spent completing read requests */
+ u64 write_ticks; /* Ticks spent completing write requests */
+ u64 io_ticks; /* Ticks spent doing any I/O */
+ u64 stamp; /* holds time request was queued */
+ u64 sync; /* Are stats read in sync */
+ u64 sync_read_byte_cnt;
+ u64 sync_write_byte_cnt;
+ u64 sync_in_flight;
+ u64 sync_read_cnt;
+ u64 sync_write_cnt;
+ u64 sync_other_cnt;
+ u64 sync_read_ticks;
+ u64 sync_write_ticks;
+ u64 sync_io_ticks;
#if DEBUG
unsigned char write_pending;
--
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