linux_old1/drivers/scsi/scsi_dh.c

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/*
* SCSI device handler infrastruture.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
* Copyright IBM Corporation, 2007
* Authors:
* Chandra Seetharaman <sekharan@us.ibm.com>
* Mike Anderson <andmike@linux.vnet.ibm.com>
*/
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 16:04:11 +08:00
#include <linux/slab.h>
#include <linux/module.h>
#include <scsi/scsi_dh.h>
#include "scsi_priv.h"
static DEFINE_SPINLOCK(list_lock);
static LIST_HEAD(scsi_dh_list);
struct scsi_dh_blist {
const char *vendor;
const char *model;
const char *driver;
};
static const struct scsi_dh_blist scsi_dh_blist[] = {
{"DGC", "RAID", "clariion" },
{"DGC", "DISK", "clariion" },
{"DGC", "VRAID", "clariion" },
{"COMPAQ", "MSA1000 VOLUME", "hp_sw" },
{"COMPAQ", "HSV110", "hp_sw" },
{"HP", "HSV100", "hp_sw"},
{"DEC", "HSG80", "hp_sw"},
{"IBM", "1722", "rdac", },
{"IBM", "1724", "rdac", },
{"IBM", "1726", "rdac", },
{"IBM", "1742", "rdac", },
{"IBM", "1745", "rdac", },
{"IBM", "1746", "rdac", },
{"IBM", "1813", "rdac", },
{"IBM", "1814", "rdac", },
{"IBM", "1815", "rdac", },
{"IBM", "1818", "rdac", },
{"IBM", "3526", "rdac", },
{"SGI", "TP9", "rdac", },
{"SGI", "IS", "rdac", },
{"STK", "OPENstorage D280", "rdac", },
{"STK", "FLEXLINE 380", "rdac", },
{"SUN", "CSM", "rdac", },
{"SUN", "LCSM100", "rdac", },
{"SUN", "STK6580_6780", "rdac", },
{"SUN", "SUN_6180", "rdac", },
{"SUN", "ArrayStorage", "rdac", },
{"DELL", "MD3", "rdac", },
{"NETAPP", "INF-01-00", "rdac", },
{"LSI", "INF-01-00", "rdac", },
{"ENGENIO", "INF-01-00", "rdac", },
{NULL, NULL, NULL },
};
static const char *
scsi_dh_find_driver(struct scsi_device *sdev)
{
const struct scsi_dh_blist *b;
if (scsi_device_tpgs(sdev))
return "alua";
for (b = scsi_dh_blist; b->vendor; b++) {
if (!strncmp(sdev->vendor, b->vendor, strlen(b->vendor)) &&
!strncmp(sdev->model, b->model, strlen(b->model))) {
return b->driver;
}
}
return NULL;
}
static struct scsi_device_handler *__scsi_dh_lookup(const char *name)
{
struct scsi_device_handler *tmp, *found = NULL;
spin_lock(&list_lock);
list_for_each_entry(tmp, &scsi_dh_list, list) {
if (!strncmp(tmp->name, name, strlen(tmp->name))) {
found = tmp;
break;
}
}
spin_unlock(&list_lock);
return found;
}
static struct scsi_device_handler *scsi_dh_lookup(const char *name)
{
struct scsi_device_handler *dh;
dh = __scsi_dh_lookup(name);
if (!dh) {
request_module(name);
dh = __scsi_dh_lookup(name);
}
return dh;
}
/*
* scsi_dh_handler_attach - Attach a device handler to a device
* @sdev - SCSI device the device handler should attach to
* @scsi_dh - The device handler to attach
*/
static int scsi_dh_handler_attach(struct scsi_device *sdev,
struct scsi_device_handler *scsi_dh)
{
int error;
if (!try_module_get(scsi_dh->module))
return -EINVAL;
error = scsi_dh->attach(sdev);
if (error) {
sdev_printk(KERN_ERR, sdev, "%s: Attach failed (%d)\n",
scsi_dh->name, error);
module_put(scsi_dh->module);
} else
sdev->handler = scsi_dh;
return error;
}
/*
* scsi_dh_handler_detach - Detach a device handler from a device
* @sdev - SCSI device the device handler should be detached from
*/
static void scsi_dh_handler_detach(struct scsi_device *sdev)
{
sdev->handler->detach(sdev);
sdev_printk(KERN_NOTICE, sdev, "%s: Detached\n", sdev->handler->name);
module_put(sdev->handler->module);
}
/*
* Functions for sysfs attribute 'dh_state'
*/
static ssize_t
store_dh_state(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct scsi_device *sdev = to_scsi_device(dev);
struct scsi_device_handler *scsi_dh;
int err = -EINVAL;
if (sdev->sdev_state == SDEV_CANCEL ||
sdev->sdev_state == SDEV_DEL)
return -ENODEV;
if (!sdev->handler) {
/*
* Attach to a device handler
*/
scsi_dh = scsi_dh_lookup(buf);
if (!scsi_dh)
return err;
err = scsi_dh_handler_attach(sdev, scsi_dh);
} else {
if (!strncmp(buf, "detach", 6)) {
/*
* Detach from a device handler
*/
scsi_dh_handler_detach(sdev);
err = 0;
} else if (!strncmp(buf, "activate", 8)) {
/*
* Activate a device handler
*/
if (sdev->handler->activate)
err = sdev->handler->activate(sdev, NULL, NULL);
else
err = 0;
}
}
return err<0?err:count;
}
static ssize_t
show_dh_state(struct device *dev, struct device_attribute *attr, char *buf)
{
struct scsi_device *sdev = to_scsi_device(dev);
if (!sdev->handler)
return snprintf(buf, 20, "detached\n");
return snprintf(buf, 20, "%s\n", sdev->handler->name);
}
static struct device_attribute scsi_dh_state_attr =
__ATTR(dh_state, S_IRUGO | S_IWUSR, show_dh_state,
store_dh_state);
int scsi_dh_add_device(struct scsi_device *sdev)
{
struct scsi_device_handler *devinfo = NULL;
const char *drv;
int err;
err = device_create_file(&sdev->sdev_gendev, &scsi_dh_state_attr);
if (err)
return err;
drv = scsi_dh_find_driver(sdev);
if (drv)
devinfo = scsi_dh_lookup(drv);
if (devinfo)
err = scsi_dh_handler_attach(sdev, devinfo);
return err;
}
void scsi_dh_remove_device(struct scsi_device *sdev)
{
if (sdev->handler)
scsi_dh_handler_detach(sdev);
device_remove_file(&sdev->sdev_gendev, &scsi_dh_state_attr);
}
/*
* scsi_register_device_handler - register a device handler personality
* module.
* @scsi_dh - device handler to be registered.
*
* Returns 0 on success, -EBUSY if handler already registered.
*/
int scsi_register_device_handler(struct scsi_device_handler *scsi_dh)
{
if (__scsi_dh_lookup(scsi_dh->name))
return -EBUSY;
if (!scsi_dh->attach || !scsi_dh->detach)
return -EINVAL;
spin_lock(&list_lock);
list_add(&scsi_dh->list, &scsi_dh_list);
spin_unlock(&list_lock);
printk(KERN_INFO "%s: device handler registered\n", scsi_dh->name);
return SCSI_DH_OK;
}
EXPORT_SYMBOL_GPL(scsi_register_device_handler);
/*
* scsi_unregister_device_handler - register a device handler personality
* module.
* @scsi_dh - device handler to be unregistered.
*
* Returns 0 on success, -ENODEV if handler not registered.
*/
int scsi_unregister_device_handler(struct scsi_device_handler *scsi_dh)
{
if (!__scsi_dh_lookup(scsi_dh->name))
return -ENODEV;
spin_lock(&list_lock);
list_del(&scsi_dh->list);
spin_unlock(&list_lock);
printk(KERN_INFO "%s: device handler unregistered\n", scsi_dh->name);
return SCSI_DH_OK;
}
EXPORT_SYMBOL_GPL(scsi_unregister_device_handler);
static struct scsi_device *get_sdev_from_queue(struct request_queue *q)
{
struct scsi_device *sdev;
unsigned long flags;
spin_lock_irqsave(q->queue_lock, flags);
sdev = q->queuedata;
if (!sdev || !get_device(&sdev->sdev_gendev))
sdev = NULL;
spin_unlock_irqrestore(q->queue_lock, flags);
return sdev;
}
/*
* scsi_dh_activate - activate the path associated with the scsi_device
* corresponding to the given request queue.
* Returns immediately without waiting for activation to be completed.
* @q - Request queue that is associated with the scsi_device to be
* activated.
* @fn - Function to be called upon completion of the activation.
* Function fn is called with data (below) and the error code.
* Function fn may be called from the same calling context. So,
* do not hold the lock in the caller which may be needed in fn.
* @data - data passed to the function fn upon completion.
*
*/
int scsi_dh_activate(struct request_queue *q, activate_complete fn, void *data)
{
struct scsi_device *sdev;
int err = SCSI_DH_NOSYS;
sdev = get_sdev_from_queue(q);
if (!sdev) {
if (fn)
fn(data, err);
return err;
}
if (!sdev->handler)
goto out_fn;
if (sdev->sdev_state == SDEV_CANCEL ||
[SCSI] scsi_dh: propagate SCSI device deletion Currently, when scsi_dh_activate() returns with an error (e.g. SCSI_DH_NOSYS) the activate_complete callback is not called and the error is not propagated to DM mpath. When a SCSI device attached to a device handler is deleted, userland processes currently performing I/O on the device will have their I/O hang forever. - Set SCSI_DH_NOSYS error when the handler is in the process of being deleted (e.g. the SCSI device is in a SDEV_CANCEL or SDEV_DEL state). - Set SCSI_DH_DEV_OFFLINED error when device is in SDEV_OFFLINE state. - Call the activate_complete callback function directly from scsi_dh_activate if an error has been set (when either the scsi_dh internal data has already been deleted or is in the process of being deleted). The patch was tested in an iSCSI environment, RDAC H/W handler and multipath. In the following reproduction process, dd will I/O hang forever and the only way to release it will be to reboot the machine: 1) Perform I/O on a multipath device: dd if=/dev/dm-0 of=/dev/zero bs=8k count=1000000 & 2) Delete all slave SCSI devices contained in the mpath device: I) In an iSCSI environment, the easiest way to do this is by stopping iSCSI: /etc/init.d/iscsi stop II) Another way to delete the devices is by applying the following bash scriptlet: dm_devs=$(ls /sys/block/ | grep dm- | xargs) for dm_dev in $dm_devs; do devices=$(ls /sys/block/$dm_dev/slaves) for device in $devices; do echo 1 > /sys/block/$device/device/delete done done NOTE: when DM mpath's fail_path uses blk_abort_queue this scsi_dh change isn't strictly required. However, DM mpath's call to blk_abort_queue will soon be reverted because it has proven to be unsafe due to a race (between blk_abort_queue and scsi_request_fn) that can lead to list corruption. Therefore we cannot rely on blk_abort_queue via fail_path, but even if we could this scsi_dh change is still preferrable. Signed-off-by: Menny Hamburger <Menny_Hamburger@Dell.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Reviewed-by: Babu Moger <babu.moger@lsi.com> Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2010-12-17 03:57:07 +08:00
sdev->sdev_state == SDEV_DEL)
goto out_fn;
err = SCSI_DH_DEV_OFFLINED;
if (sdev->sdev_state == SDEV_OFFLINE)
goto out_fn;
if (sdev->handler->activate)
err = sdev->handler->activate(sdev, fn, data);
out_put_device:
put_device(&sdev->sdev_gendev);
return err;
out_fn:
if (fn)
fn(data, err);
goto out_put_device;
}
EXPORT_SYMBOL_GPL(scsi_dh_activate);
/*
* scsi_dh_set_params - set the parameters for the device as per the
* string specified in params.
* @q - Request queue that is associated with the scsi_device for
* which the parameters to be set.
* @params - parameters in the following format
* "no_of_params\0param1\0param2\0param3\0...\0"
* for example, string for 2 parameters with value 10 and 21
* is specified as "2\010\021\0".
*/
int scsi_dh_set_params(struct request_queue *q, const char *params)
{
struct scsi_device *sdev;
int err = -SCSI_DH_NOSYS;
sdev = get_sdev_from_queue(q);
if (!sdev)
return err;
if (sdev->handler && sdev->handler->set_params)
err = sdev->handler->set_params(sdev, params);
put_device(&sdev->sdev_gendev);
return err;
}
EXPORT_SYMBOL_GPL(scsi_dh_set_params);
/*
* scsi_dh_attach - Attach device handler
* @q - Request queue that is associated with the scsi_device
* the handler should be attached to
* @name - name of the handler to attach
*/
int scsi_dh_attach(struct request_queue *q, const char *name)
{
struct scsi_device *sdev;
struct scsi_device_handler *scsi_dh;
int err = 0;
sdev = get_sdev_from_queue(q);
if (!sdev)
return -ENODEV;
scsi_dh = scsi_dh_lookup(name);
if (!scsi_dh) {
err = -EINVAL;
goto out_put_device;
}
if (sdev->handler) {
if (sdev->handler != scsi_dh)
err = -EBUSY;
goto out_put_device;
}
err = scsi_dh_handler_attach(sdev, scsi_dh);
out_put_device:
put_device(&sdev->sdev_gendev);
return err;
}
EXPORT_SYMBOL_GPL(scsi_dh_attach);
/*
* scsi_dh_attached_handler_name - Get attached device handler's name
* @q - Request queue that is associated with the scsi_device
* that may have a device handler attached
* @gfp - the GFP mask used in the kmalloc() call when allocating memory
*
* Returns name of attached handler, NULL if no handler is attached.
* Caller must take care to free the returned string.
*/
const char *scsi_dh_attached_handler_name(struct request_queue *q, gfp_t gfp)
{
struct scsi_device *sdev;
const char *handler_name = NULL;
sdev = get_sdev_from_queue(q);
if (!sdev)
return NULL;
if (sdev->handler)
handler_name = kstrdup(sdev->handler->name, gfp);
put_device(&sdev->sdev_gendev);
return handler_name;
}
EXPORT_SYMBOL_GPL(scsi_dh_attached_handler_name);