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[PATCH] add sysfs attributes to scan and delete scsi_devices
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This patch against scsi-misc-2.5 adds a sysfs attribute to allow scanning
(or rescanning) and deletion of scsi_devices.

It also allows scanning of entire hosts, channels, or targets.

It adds a per-host scan attribute, and a per scsi_device delete attribute.
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Patrick Mansfield authored and James Bottomley committed Aug 14, 2003
1 parent 8e47b96 commit 7973cbd
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Showing 4 changed files with 168 additions and 48 deletions.
8 changes: 8 additions & 0 deletions drivers/scsi/scsi_priv.h
Original file line number Diff line number Diff line change
Expand Up @@ -41,6 +41,12 @@
#define SCSI_SENSE_VALID(scmd) \
(((scmd)->sense_buffer[0] & 0x70) == 0x70)

/*
* Special value for scanning to specify scanning or rescanning of all
* possible channels, (target) ids, or luns on a given shost.
*/
#define SCAN_WILD_CARD ~0

/*
* scsi_target: representation of a scsi target, for now, this is only
* used for single_lun devices. If no one has active IO to the target,
Expand Down Expand Up @@ -109,6 +115,8 @@ extern void scsi_exit_procfs(void);
#endif /* CONFIG_PROC_FS */

/* scsi_scan.c */
int scsi_scan_host_selected(struct Scsi_Host *, unsigned int, unsigned int,
unsigned int, int);
extern void scsi_forget_host(struct Scsi_Host *);
extern void scsi_free_sdev(struct scsi_device *);
extern void scsi_rescan_device(struct device *);
Expand Down
10 changes: 1 addition & 9 deletions drivers/scsi/scsi_proc.c
Original file line number Diff line number Diff line change
Expand Up @@ -189,21 +189,13 @@ static int proc_print_scsidevice(struct device *dev, void *data)
static int scsi_add_single_device(uint host, uint channel, uint id, uint lun)
{
struct Scsi_Host *shost;
struct scsi_device *sdev;
int error = -ENXIO;

shost = scsi_host_lookup(host);
if (IS_ERR(shost))
return PTR_ERR(shost);

if (!scsi_find_device(shost, channel, id, lun)) {
sdev = scsi_add_device(shost, channel, id, lun);
if (IS_ERR(sdev))
error = PTR_ERR(sdev);
else
error = 0;
}

error = scsi_scan_host_selected(shost, channel, id, lun, 1);
scsi_host_put(shost);
return error;
}
Expand Down
126 changes: 88 additions & 38 deletions drivers/scsi/scsi_scan.c
Original file line number Diff line number Diff line change
Expand Up @@ -676,13 +676,32 @@ static int scsi_add_lun(struct scsi_device *sdev, char *inq_result, int *bflags)
**/
static int scsi_probe_and_add_lun(struct Scsi_Host *host,
uint channel, uint id, uint lun, int *bflagsp,
struct scsi_device **sdevp)
struct scsi_device **sdevp, int rescan)
{
struct scsi_device *sdev;
struct scsi_request *sreq;
unsigned char *result;
int bflags, res = SCSI_SCAN_NO_RESPONSE;

/*
* The rescan flag is used as an optimization, the first scan of a
* host adapter calls into here with rescan == 0.
*/
if (rescan) {
sdev = scsi_find_device(host, channel, id, lun);
if (sdev) {
SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO
"scsi scan: device exists on <%d:%d:%d:%d>\n",
host->host_no, channel, id, lun));
if (sdevp)
*sdevp = sdev;
if (bflagsp)
*bflagsp = scsi_get_device_flags(sdev->vendor,
sdev->model);
return SCSI_SCAN_LUN_PRESENT;
}
}

sdev = scsi_alloc_sdev(host, channel, id, lun);
if (!sdev)
goto out;
Expand Down Expand Up @@ -757,7 +776,7 @@ static int scsi_probe_and_add_lun(struct Scsi_Host *host,
* Modifies sdevscan->lun.
**/
static void scsi_sequential_lun_scan(struct Scsi_Host *shost, uint channel,
uint id, int bflags, int lun0_res, int scsi_level)
uint id, int bflags, int lun0_res, int scsi_level, int rescan)
{
unsigned int sparse_lun, lun, max_dev_lun;

Expand Down Expand Up @@ -826,7 +845,8 @@ static void scsi_sequential_lun_scan(struct Scsi_Host *shost, uint channel,
*/
for (lun = 1; lun < max_dev_lun; ++lun)
if ((scsi_probe_and_add_lun(shost, channel, id, lun,
NULL, NULL) != SCSI_SCAN_LUN_PRESENT) && !sparse_lun)
NULL, NULL, rescan) != SCSI_SCAN_LUN_PRESENT) &&
!sparse_lun)
return;
}

Expand Down Expand Up @@ -877,7 +897,8 @@ static int scsilun_to_int(struct scsi_lun *scsilun)
* 0: scan completed (or no memory, so further scanning is futile)
* 1: no report lun scan, or not configured
**/
static int scsi_report_lun_scan(struct scsi_device *sdev, int bflags)
static int scsi_report_lun_scan(struct scsi_device *sdev, int bflags,
int rescan)
{
char devname[64];
unsigned char scsi_cmd[MAX_COMMAND_SIZE];
Expand Down Expand Up @@ -1031,7 +1052,7 @@ static int scsi_report_lun_scan(struct scsi_device *sdev, int bflags)
int res;

res = scsi_probe_and_add_lun(sdev->host, sdev->channel,
sdev->id, lun, NULL, NULL);
sdev->id, lun, NULL, NULL, rescan);
if (res == SCSI_SCAN_NO_RESPONSE) {
/*
* Got some results, but now none, abort.
Expand All @@ -1057,7 +1078,7 @@ static int scsi_report_lun_scan(struct scsi_device *sdev, int bflags)
return 0;
}
#else
# define scsi_report_lun_scan(sdev, blags) (1)
# define scsi_report_lun_scan(sdev, blags, rescan) (1)
#endif /* CONFIG_SCSI_REPORT_LUNS */

struct scsi_device *scsi_add_device(struct Scsi_Host *shost,
Expand All @@ -1066,7 +1087,7 @@ struct scsi_device *scsi_add_device(struct Scsi_Host *shost,
struct scsi_device *sdev;
int res;

res = scsi_probe_and_add_lun(shost, channel, id, lun, NULL, &sdev);
res = scsi_probe_and_add_lun(shost, channel, id, lun, NULL, &sdev, 1);
if (res != SCSI_SCAN_LUN_PRESENT)
sdev = ERR_PTR(-ENODEV);
return sdev;
Expand Down Expand Up @@ -1103,7 +1124,7 @@ void scsi_rescan_device(struct device *dev)
* sequential scan of LUNs on the target id.
**/
static void scsi_scan_target(struct Scsi_Host *shost, unsigned int channel,
unsigned int id)
unsigned int id, unsigned int lun, int rescan)
{
int bflags = 0;
int res;
Expand All @@ -1115,19 +1136,29 @@ static void scsi_scan_target(struct Scsi_Host *shost, unsigned int channel,
*/
return;

if (lun != SCAN_WILD_CARD) {
/*
* Scan for a specific host/chan/id/lun.
*/
scsi_probe_and_add_lun(shost, channel, id, lun, NULL, NULL,
rescan);
return;
}

/*
* Scan LUN 0, if there is some response, scan further. Ideally, we
* would not configure LUN 0 until all LUNs are scanned.
*/
res = scsi_probe_and_add_lun(shost, channel, id, 0, &bflags, &sdev);
res = scsi_probe_and_add_lun(shost, channel, id, 0, &bflags, &sdev,
rescan);
if (res == SCSI_SCAN_LUN_PRESENT) {
if (scsi_report_lun_scan(sdev, bflags) != 0)
if (scsi_report_lun_scan(sdev, bflags, rescan) != 0)
/*
* The REPORT LUN did not scan the target,
* do a sequential scan.
*/
scsi_sequential_lun_scan(shost, channel, id, bflags,
res, sdev->scsi_level);
res, sdev->scsi_level, rescan);
} else if (res == SCSI_SCAN_TARGET_PRESENT) {
/*
* There's a target here, but lun 0 is offline so we
Expand All @@ -1136,47 +1167,66 @@ static void scsi_scan_target(struct Scsi_Host *shost, unsigned int channel,
* a default scsi level of SCSI_2
*/
scsi_sequential_lun_scan(shost, channel, id, BLIST_SPARSELUN,
SCSI_SCAN_TARGET_PRESENT, SCSI_2);
SCSI_SCAN_TARGET_PRESENT, SCSI_2, rescan);
}
}

/**
* scsi_scan_host - scan the given adapter
* @shost: adapter to scan
*
* Description:
* Iterate and call scsi_scan_target to scan all possible target id's
* on all possible channels.
**/
void scsi_scan_host(struct Scsi_Host *shost)
static void scsi_scan_channel(struct Scsi_Host *shost, unsigned int channel,
unsigned int id, unsigned int lun, int rescan)
{
uint channel, id, order_id;
uint order_id;

/*
* The sdevscan host, channel, id and lun are filled in as
* needed to scan.
*/
for (channel = 0; channel <= shost->max_channel; channel++) {
/*
* XXX adapter drivers when possible (FCP, iSCSI)
* could modify max_id to match the current max,
* not the absolute max.
*
* XXX add a shost id iterator, so for example,
* the FC ID can be the same as a target id
* without a huge overhead of sparse id's.
*/
if (id == SCAN_WILD_CARD)
for (id = 0; id < shost->max_id; ++id) {
/*
* XXX adapter drivers when possible (FCP, iSCSI)
* could modify max_id to match the current max,
* not the absolute max.
*
* XXX add a shost id iterator, so for example,
* the FC ID can be the same as a target id
* without a huge overhead of sparse id's.
*/
if (shost->reverse_ordering)
/*
* Scan from high to low id.
*/
order_id = shost->max_id - id - 1;
else
order_id = id;
scsi_scan_target(shost, channel, order_id);
scsi_scan_target(shost, channel, order_id, lun, rescan);
}
}
else
scsi_scan_target(shost, channel, id, lun, rescan);
}

int scsi_scan_host_selected(struct Scsi_Host *shost, unsigned int channel,
unsigned int id, unsigned int lun, int rescan)
{
SCSI_LOG_SCAN_BUS(3, printk (KERN_INFO "%s: <%u:%u:%u:%u>\n",
__FUNCTION__, shost->host_no, channel, id, lun));

if (((channel != SCAN_WILD_CARD) && (channel > shost->max_channel)) ||
((id != SCAN_WILD_CARD) && (id > shost->max_id)) ||
((lun != SCAN_WILD_CARD) && (lun > shost->max_lun)))
return -EINVAL;

if (channel == SCAN_WILD_CARD)
for (channel = 0; channel <= shost->max_channel; channel++)
scsi_scan_channel(shost, channel, id, lun, rescan);
else
scsi_scan_channel(shost, channel, id, lun, rescan);
return 0;
}

/**
* scsi_scan_host - scan the given adapter
* @shost: adapter to scan
**/
void scsi_scan_host(struct Scsi_Host *shost)
{
scsi_scan_host_selected(shost, SCAN_WILD_CARD, SCAN_WILD_CARD,
SCAN_WILD_CARD, 0);
}

void scsi_forget_host(struct Scsi_Host *shost)
Expand Down
72 changes: 71 additions & 1 deletion drivers/scsi/scsi_sysfs.c
Original file line number Diff line number Diff line change
Expand Up @@ -15,6 +15,43 @@
#include "hosts.h"

#include "scsi_priv.h"
#include "scsi_logging.h"

static int check_set(unsigned int *val, char *src)
{
char *last;

if (strncmp(src, "-", 20) == 0) {
*val = SCAN_WILD_CARD;
} else {
/*
* Doesn't check for int overflow
*/
*val = simple_strtoul(src, &last, 0);
if (*last != '\0')
return 1;
}
return 0;
}

static int scsi_scan(struct Scsi_Host *shost, const char *str)
{
char s1[15], s2[15], s3[15], junk;
unsigned int channel, id, lun;
int res;

res = sscanf(str, "%10s %10s %10s %c", s1, s2, s3, &junk);
if (res != 3)
return -EINVAL;
if (check_set(&channel, s1))
return -EINVAL;
if (check_set(&id, s2))
return -EINVAL;
if (check_set(&lun, s3))
return -EINVAL;
res = scsi_scan_host_selected(shost, channel, id, lun, 1);
return res;
}

/*
* shost_show_function: macro to create an attr function that can be used to
Expand All @@ -39,6 +76,20 @@ static CLASS_DEVICE_ATTR(field, S_IRUGO, show_##field, NULL)
/*
* Create the actual show/store functions and data structures.
*/

static ssize_t store_scan(struct class_device *class_dev, const char *buf,
size_t count)
{
struct Scsi_Host *shost = class_to_shost(class_dev);
int res;

res = scsi_scan(shost, buf);
if (res == 0)
res = count;
return res;
};
static CLASS_DEVICE_ATTR(scan, S_IWUSR, NULL, store_scan);

shost_rd_attr(unique_id, "%u\n");
shost_rd_attr(host_busy, "%hu\n");
shost_rd_attr(cmd_per_lun, "%hd\n");
Expand All @@ -51,6 +102,7 @@ static struct class_device_attribute *scsi_sysfs_shost_attrs[] = {
&class_device_attr_cmd_per_lun,
&class_device_attr_sg_tablesize,
&class_device_attr_unchecked_isa_dma,
&class_device_attr_scan,
NULL
};

Expand Down Expand Up @@ -89,7 +141,6 @@ struct bus_type scsi_bus_type = {
.match = scsi_bus_match,
};


int scsi_sysfs_register(void)
{
int error;
Expand Down Expand Up @@ -210,6 +261,24 @@ store_rescan_field (struct device *dev, const char *buf, size_t count)

static DEVICE_ATTR(rescan, S_IWUSR, NULL, store_rescan_field)

static ssize_t sdev_store_delete(struct device *dev, const char *buf,
size_t count)
{
struct scsi_device *sdev = to_scsi_device(dev);
int res = count;

if (sdev->access_count)
/*
* FIXME and scsi_proc.c: racey use of access_count,
* possibly add a new arg to scsi_remove_device.
*/
res = -EBUSY;
else
scsi_remove_device(sdev);
return res;
};
static DEVICE_ATTR(delete, S_IWUSR, NULL, sdev_store_delete);

/* Default template for device attributes. May NOT be modified */
static struct device_attribute *scsi_sysfs_sdev_attrs[] = {
&dev_attr_device_blocked,
Expand All @@ -222,6 +291,7 @@ static struct device_attribute *scsi_sysfs_sdev_attrs[] = {
&dev_attr_rev,
&dev_attr_online,
&dev_attr_rescan,
&dev_attr_delete,
NULL
};

Expand Down

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