linux/drivers/scsi/scsi.c

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/*
* scsi.c Copyright (C) 1992 Drew Eckhardt
* Copyright (C) 1993, 1994, 1995, 1999 Eric Youngdale
* Copyright (C) 2002, 2003 Christoph Hellwig
*
* generic mid-level SCSI driver
* Initial versions: Drew Eckhardt
* Subsequent revisions: Eric Youngdale
*
* <drew@colorado.edu>
*
* Bug correction thanks go to :
* Rik Faith <faith@cs.unc.edu>
* Tommy Thorn <tthorn>
* Thomas Wuensche <tw@fgb1.fgb.mw.tu-muenchen.de>
*
* Modified by Eric Youngdale eric@andante.org or ericy@gnu.ai.mit.edu to
* add scatter-gather, multiple outstanding request, and other
* enhancements.
*
* Native multichannel, wide scsi, /proc/scsi and hot plugging
* support added by Michael Neuffer <mike@i-connect.net>
*
* Added request_module("scsi_hostadapter") for kerneld:
* (Put an "alias scsi_hostadapter your_hostadapter" in /etc/modprobe.conf)
* Bjorn Ekwall <bj0rn@blox.se>
* (changed to kmod)
*
* Major improvements to the timeout, abort, and reset processing,
* as well as performance modifications for large queue depths by
* Leonard N. Zubkoff <lnz@dandelion.com>
*
* Converted cli() code to spinlocks, Ingo Molnar
*
* Jiffies wrap fixes (host->resetting), 3 Dec 1998 Andrea Arcangeli
*
* out_of_space hacks, D. Gilbert (dpg) 990608
*/
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/kernel.h>
#include <linux/timer.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/blkdev.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/completion.h>
#include <linux/unistd.h>
#include <linux/spinlock.h>
#include <linux/kmod.h>
#include <linux/interrupt.h>
#include <linux/notifier.h>
#include <linux/cpu.h>
#include <linux/mutex.h>
#include <linux/async.h>
#include <asm/unaligned.h>
#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_dbg.h>
#include <scsi/scsi_device.h>
Revert "scsi: revert "[SCSI] Get rid of scsi_cmnd->done"" This reverts commit ac40532ef0b8649e6f7f83859ea0de1c4ed08a19, which gets us back the original cleanup of 6f5391c283d7fdcf24bf40786ea79061919d1e1d. It turns out that the bug that was triggered by that commit was apparently not actually triggered by that commit at all, and just the testing conditions had changed enough to make it appear to be due to it. The real problem seems to have been found by Peter Osterlund: "pktcdvd sets it [block device size] when opening the /dev/pktcdvd device, but when the drive is later opened as /dev/scd0, there is nothing that sets it back. (Btw, 40944 is possible if the disk is a CDRW that was formatted with "cdrwtool -m 10236".) The problem is that pktcdvd opens the cd device in non-blocking mode when pktsetup is run, and doesn't close it again until pktsetup -d is run. The effect is that if you meanwhile open the cd device, blkdev.c:do_open() doesn't call bd_set_size() because bdev->bd_openers is non-zero." In particular, to repeat the bug (regardless of whether commit 6f5391c283d7fdcf24bf40786ea79061919d1e1d is applied or not): " 1. Start with an empty drive. 2. pktsetup 0 /dev/scd0 3. Insert a CD containing an isofs filesystem. 4. mount /dev/pktcdvd/0 /mnt/tmp 5. umount /mnt/tmp 6. Press the eject button. 7. Insert a DVD containing a non-writable filesystem. 8. mount /dev/scd0 /mnt/tmp 9. find /mnt/tmp -type f -print0 | xargs -0 sha1sum >/dev/null 10. If the DVD contains data beyond the physical size of a CD, you get I/O errors in the terminal, and dmesg reports lots of "attempt to access beyond end of device" errors." which in turn is because the nested open after the media change won't cause the size to be set properly (because the original open still holds the block device, and we only do the bd_set_size() when we don't have other people holding the device open). The proper fix for that is probably to just do something like bdev->bd_inode->i_size = (loff_t)get_capacity(disk)<<9; in fs/block_dev.c:do_open() even for the cases where we're not the original opener (but *not* call bd_set_size(), since that will also change the block size of the device). Cc: Peter Osterlund <petero2@telia.com> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Cc: Matthew Wilcox <matthew@wil.cx> Cc: Ingo Molnar <mingo@elte.hu> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-01-06 18:17:12 +00:00
#include <scsi/scsi_driver.h>
#include <scsi/scsi_eh.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_tcq.h>
#include "scsi_priv.h"
#include "scsi_logging.h"
#define CREATE_TRACE_POINTS
#include <trace/events/scsi.h>
static void scsi_done(struct scsi_cmnd *cmd);
/*
* Definitions and constants.
*/
/*
* Note - the initial logging level can be set here to log events at boot time.
* After the system is up, you may enable logging via the /proc interface.
*/
unsigned int scsi_logging_level;
#if defined(CONFIG_SCSI_LOGGING)
EXPORT_SYMBOL(scsi_logging_level);
#endif
/* sd, scsi core and power management need to coordinate flushing async actions */
ASYNC_DOMAIN(scsi_sd_probe_domain);
[SCSI] sd: limit the scope of the async probe domain sd injects and synchronizes probe work on the global kernel-wide domain. This runs into conflict with PM that wants to perform resume actions in async context: [ 494.237079] INFO: task kworker/u:3:554 blocked for more than 120 seconds. [ 494.294396] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 494.360809] kworker/u:3 D 0000000000000000 0 554 2 0x00000000 [ 494.420739] ffff88012e4d3af0 0000000000000046 ffff88013200c160 ffff88012e4d3fd8 [ 494.484392] ffff88012e4d3fd8 0000000000012500 ffff8801394ea0b0 ffff88013200c160 [ 494.548038] ffff88012e4d3ae0 00000000000001e3 ffffffff81a249e0 ffff8801321c5398 [ 494.611685] Call Trace: [ 494.632649] [<ffffffff8149dd25>] schedule+0x5a/0x5c [ 494.674687] [<ffffffff8104b968>] async_synchronize_cookie_domain+0xb6/0x112 [ 494.734177] [<ffffffff810461ff>] ? __init_waitqueue_head+0x50/0x50 [ 494.787134] [<ffffffff8131a224>] ? scsi_remove_target+0x48/0x48 [ 494.837900] [<ffffffff8104b9d9>] async_synchronize_cookie+0x15/0x17 [ 494.891567] [<ffffffff8104ba49>] async_synchronize_full+0x54/0x70 <-- here we wait for async contexts to complete [ 494.943783] [<ffffffff8104b9f5>] ? async_synchronize_full_domain+0x1a/0x1a [ 495.002547] [<ffffffffa00114b1>] sd_remove+0x2c/0xa2 [sd_mod] [ 495.051861] [<ffffffff812fe94f>] __device_release_driver+0x86/0xcf [ 495.104807] [<ffffffff812fe9bd>] device_release_driver+0x25/0x32 <-- here we take device_lock() [ 853.511341] INFO: task kworker/u:4:549 blocked for more than 120 seconds. [ 853.568693] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 853.635119] kworker/u:4 D ffff88013097b5d0 0 549 2 0x00000000 [ 853.695129] ffff880132773c40 0000000000000046 ffff880130790000 ffff880132773fd8 [ 853.758990] ffff880132773fd8 0000000000012500 ffff88013288a0b0 ffff880130790000 [ 853.822796] 0000000000000246 0000000000000040 ffff88013097b5c8 ffff880130790000 [ 853.886633] Call Trace: [ 853.907631] [<ffffffff8149dd25>] schedule+0x5a/0x5c [ 853.949670] [<ffffffff8149cc44>] __mutex_lock_common+0x220/0x351 [ 854.001225] [<ffffffff81304bd7>] ? device_resume+0x58/0x1c4 [ 854.049082] [<ffffffff81304bd7>] ? device_resume+0x58/0x1c4 [ 854.097011] [<ffffffff8149ce48>] mutex_lock_nested+0x2f/0x36 <-- here we wait for device_lock() [ 854.145591] [<ffffffff81304bd7>] device_resume+0x58/0x1c4 [ 854.192066] [<ffffffff81304d61>] async_resume+0x1e/0x45 [ 854.237019] [<ffffffff8104bc93>] async_run_entry_fn+0xc6/0x173 <-- ...while running in async context Provide a 'scsi_sd_probe_domain' so that async probe actions actions can be flushed without regard for the state of PM, and allow for the resume path to handle devices that have transitioned from SDEV_QUIESCE to SDEV_DEL prior to resume. Acked-by: Alan Stern <stern@rowland.harvard.edu> [alan: uplevel scsi_sd_probe_domain, clarify scsi_device_resume] Signed-off-by: Dan Williams <dan.j.williams@intel.com> [jejb: remove unneeded config guards in include file] Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2012-03-23 00:05:11 +00:00
EXPORT_SYMBOL(scsi_sd_probe_domain);
scsi: async sd resume async_schedule() sd resume work to allow disks and other devices to resume in parallel. This moves the entirety of scsi_device resume to an async context to ensure that scsi_device_resume() remains ordered with respect to the completion of the start/stop command. For the duration of the resume, new command submissions (that do not originate from the scsi-core) will be deferred (BLKPREP_DEFER). It adds a new ASYNC_DOMAIN_EXCLUSIVE(scsi_sd_pm_domain) as a container of these operations. Like scsi_sd_probe_domain it is flushed at sd_remove() time to ensure async ops do not continue past the end-of-life of the sdev. The implementation explicitly refrains from reusing scsi_sd_probe_domain directly for this purpose as it is flushed at the end of dpm_resume(), potentially defeating some of the benefit. Given sdevs are quiesced it is permissible for these resume operations to bleed past the async_synchronize_full() calls made by the driver core. We defer the resolution of which pm callback to call until scsi_dev_type_{suspend|resume} time and guarantee that the callback parameter is never NULL. With this in place the type of resume operation is encoded in the async function identifier. There is a concern that async resume could trigger PSU overload. In the enterprise, storage enclosures enforce staggered spin-up regardless of what the kernel does making async scanning safe by default. Outside of that context a user can disable asynchronous scanning via a kernel command line or CONFIG_SCSI_SCAN_ASYNC. Honor that setting when deciding whether to do resume asynchronously. Inspired by Todd's analysis and initial proposal [2]: https://01.org/suspendresume/blogs/tebrandt/2013/hard-disk-resume-optimization-simpler-approach Cc: Len Brown <len.brown@intel.com> Cc: Phillip Susi <psusi@ubuntu.com> [alan: bug fix and clean up suggestion] Acked-by: Alan Stern <stern@rowland.harvard.edu> Suggested-by: Todd Brandt <todd.e.brandt@linux.intel.com> [djbw: kick all resume work to the async queue] Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2014-04-10 22:30:35 +00:00
/*
* Separate domain (from scsi_sd_probe_domain) to maximize the benefit of
* asynchronous system resume operations. It is marked 'exclusive' to avoid
* being included in the async_synchronize_full() that is invoked by
* dpm_resume()
*/
ASYNC_DOMAIN_EXCLUSIVE(scsi_sd_pm_domain);
EXPORT_SYMBOL(scsi_sd_pm_domain);
/* NB: These are exposed through /proc/scsi/scsi and form part of the ABI.
* You may not alter any existing entry (although adding new ones is
* encouraged once assigned by ANSI/INCITS T10
*/
static const char *const scsi_device_types[] = {
"Direct-Access ",
"Sequential-Access",
"Printer ",
"Processor ",
"WORM ",
"CD-ROM ",
"Scanner ",
"Optical Device ",
"Medium Changer ",
"Communications ",
"ASC IT8 ",
"ASC IT8 ",
"RAID ",
"Enclosure ",
"Direct-Access-RBC",
"Optical card ",
"Bridge controller",
"Object storage ",
"Automation/Drive ",
};
/**
* scsi_device_type - Return 17 char string indicating device type.
* @type: type number to look up
*/
const char * scsi_device_type(unsigned type)
{
if (type == 0x1e)
return "Well-known LUN ";
if (type == 0x1f)
return "No Device ";
if (type >= ARRAY_SIZE(scsi_device_types))
return "Unknown ";
return scsi_device_types[type];
}
EXPORT_SYMBOL(scsi_device_type);
struct scsi_host_cmd_pool {
struct kmem_cache *cmd_slab;
struct kmem_cache *sense_slab;
unsigned int users;
char *cmd_name;
char *sense_name;
unsigned int slab_flags;
gfp_t gfp_mask;
};
static struct scsi_host_cmd_pool scsi_cmd_pool = {
.cmd_name = "scsi_cmd_cache",
.sense_name = "scsi_sense_cache",
.slab_flags = SLAB_HWCACHE_ALIGN,
};
static struct scsi_host_cmd_pool scsi_cmd_dma_pool = {
.cmd_name = "scsi_cmd_cache(DMA)",
.sense_name = "scsi_sense_cache(DMA)",
.slab_flags = SLAB_HWCACHE_ALIGN|SLAB_CACHE_DMA,
.gfp_mask = __GFP_DMA,
};
static DEFINE_MUTEX(host_cmd_pool_mutex);
/**
* scsi_host_free_command - internal function to release a command
* @shost: host to free the command for
* @cmd: command to release
*
* the command must previously have been allocated by
* scsi_host_alloc_command.
*/
static void
scsi_host_free_command(struct Scsi_Host *shost, struct scsi_cmnd *cmd)
{
struct scsi_host_cmd_pool *pool = shost->cmd_pool;
if (cmd->prot_sdb)
kmem_cache_free(scsi_sdb_cache, cmd->prot_sdb);
kmem_cache_free(pool->sense_slab, cmd->sense_buffer);
kmem_cache_free(pool->cmd_slab, cmd);
}
/**
* scsi_host_alloc_command - internal function to allocate command
* @shost: SCSI host whose pool to allocate from
* @gfp_mask: mask for the allocation
*
* Returns a fully allocated command with sense buffer and protection
* data buffer (where applicable) or NULL on failure
*/
static struct scsi_cmnd *
scsi_host_alloc_command(struct Scsi_Host *shost, gfp_t gfp_mask)
{
struct scsi_host_cmd_pool *pool = shost->cmd_pool;
struct scsi_cmnd *cmd;
cmd = kmem_cache_zalloc(pool->cmd_slab, gfp_mask | pool->gfp_mask);
if (!cmd)
goto fail;
cmd->sense_buffer = kmem_cache_alloc(pool->sense_slab,
gfp_mask | pool->gfp_mask);
if (!cmd->sense_buffer)
goto fail_free_cmd;
if (scsi_host_get_prot(shost) >= SHOST_DIX_TYPE0_PROTECTION) {
cmd->prot_sdb = kmem_cache_zalloc(scsi_sdb_cache, gfp_mask);
if (!cmd->prot_sdb)
goto fail_free_sense;
}
return cmd;
fail_free_sense:
kmem_cache_free(pool->sense_slab, cmd->sense_buffer);
fail_free_cmd:
kmem_cache_free(pool->cmd_slab, cmd);
fail:
return NULL;
}
/**
* __scsi_get_command - Allocate a struct scsi_cmnd
* @shost: host to transmit command
* @gfp_mask: allocation mask
*
* Description: allocate a struct scsi_cmd from host's slab, recycling from the
* host's free_list if necessary.
*/
static struct scsi_cmnd *
__scsi_get_command(struct Scsi_Host *shost, gfp_t gfp_mask)
{
struct scsi_cmnd *cmd = scsi_host_alloc_command(shost, gfp_mask);
scsi: fix sense_slab/bio swapping livelock Since 2.6.25-rc7, I've been seeing an occasional livelock on one x86_64 machine, copying kernel trees to tmpfs, paging out to swap. Signature: 6000 pages under writeback but never getting written; most tasks of interest trying to reclaim, but each get_swap_bio waiting for a bio in mempool_alloc's io_schedule_timeout(5*HZ); every five seconds an atomic page allocation failure report from kblockd failing to allocate a sense_buffer in __scsi_get_command. __scsi_get_command has a (one item) free_list to protect against this, but rc1's [SCSI] use dynamically allocated sense buffer de25deb18016f66dcdede165d07654559bb332bc upset that slightly. When it fails to allocate from the separate sense_slab, instead of giving up, it must fall back to the command free_list, which is sure to have a sense_buffer attached. Either my earlier -rc testing missed this, or there's some recent contributory factor. One very significant factor is SLUB, which merges slab caches when it can, and on 64-bit happens to merge both bio cache and sense_slab cache into kmalloc's 128-byte cache: so that under this swapping load, bios above are liable to gobble up all the slots needed for scsi_cmnd sense_buffers below. That's disturbing behaviour, and I tried a few things to fix it. Adding a no-op constructor to the sense_slab inhibits SLUB from merging it, and stops all the allocation failures I was seeing; but it's rather a hack, and perhaps in different configurations we have other caches on the swapout path which are ill-merged. Another alternative is to revert the separate sense_slab, using cache-line-aligned sense_buffer allocated beyond scsi_cmnd from the one kmem_cache; but that might waste more memory, and is only a way of diverting around the known problem. While I don't like seeing the allocation failures, and hate the idea of all those bios piled up above a scsi host working one by one, it does seem to emerge fairly soon with the livelock fix. So lacking better ideas, stick with that one clear fix for now. Signed-off-by: Hugh Dickins <hugh@veritas.com> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: Christoph Lameter <clameter@sgi.com> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Peter Zijlstra <a.p.ziljstra@chello.nl> Cc: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-06 22:56:57 +00:00
if (unlikely(!cmd)) {
unsigned long flags;
spin_lock_irqsave(&shost->free_list_lock, flags);
if (likely(!list_empty(&shost->free_list))) {
cmd = list_entry(shost->free_list.next,
struct scsi_cmnd, list);
list_del_init(&cmd->list);
}
spin_unlock_irqrestore(&shost->free_list_lock, flags);
if (cmd) {
void *buf, *prot;
buf = cmd->sense_buffer;
prot = cmd->prot_sdb;
memset(cmd, 0, sizeof(*cmd));
cmd->sense_buffer = buf;
cmd->prot_sdb = prot;
}
}
return cmd;
}
/**
* scsi_get_command - Allocate and setup a scsi command block
* @dev: parent scsi device
* @gfp_mask: allocator flags
*
* Returns: The allocated scsi command structure.
*/
struct scsi_cmnd *scsi_get_command(struct scsi_device *dev, gfp_t gfp_mask)
{
struct scsi_cmnd *cmd = __scsi_get_command(dev->host, gfp_mask);
unsigned long flags;
if (unlikely(cmd == NULL))
return NULL;
cmd->device = dev;
INIT_LIST_HEAD(&cmd->list);
INIT_DELAYED_WORK(&cmd->abort_work, scmd_eh_abort_handler);
spin_lock_irqsave(&dev->list_lock, flags);
list_add_tail(&cmd->list, &dev->cmd_list);
spin_unlock_irqrestore(&dev->list_lock, flags);
cmd->jiffies_at_alloc = jiffies;
return cmd;
}
/**
* __scsi_put_command - Free a struct scsi_cmnd
* @shost: dev->host
* @cmd: Command to free
*/
static void __scsi_put_command(struct Scsi_Host *shost, struct scsi_cmnd *cmd)
{
unsigned long flags;
if (unlikely(list_empty(&shost->free_list))) {
spin_lock_irqsave(&shost->free_list_lock, flags);
if (list_empty(&shost->free_list)) {
list_add(&cmd->list, &shost->free_list);
cmd = NULL;
}
spin_unlock_irqrestore(&shost->free_list_lock, flags);
}
if (likely(cmd != NULL))
scsi_host_free_command(shost, cmd);
}
/**
* scsi_put_command - Free a scsi command block
* @cmd: command block to free
*
* Returns: Nothing.
*
* Notes: The command must not belong to any lists.
*/
void scsi_put_command(struct scsi_cmnd *cmd)
{
unsigned long flags;
/* serious error if the command hasn't come from a device list */
spin_lock_irqsave(&cmd->device->list_lock, flags);
BUG_ON(list_empty(&cmd->list));
list_del_init(&cmd->list);
spin_unlock_irqrestore(&cmd->device->list_lock, flags);
BUG_ON(delayed_work_pending(&cmd->abort_work));
__scsi_put_command(cmd->device->host, cmd);
}
static struct scsi_host_cmd_pool *
scsi_find_host_cmd_pool(struct Scsi_Host *shost)
{
if (shost->hostt->cmd_size)
return shost->hostt->cmd_pool;
if (shost->unchecked_isa_dma)
return &scsi_cmd_dma_pool;
return &scsi_cmd_pool;
}
static void
scsi_free_host_cmd_pool(struct scsi_host_cmd_pool *pool)
{
kfree(pool->sense_name);
kfree(pool->cmd_name);
kfree(pool);
}
static struct scsi_host_cmd_pool *
scsi_alloc_host_cmd_pool(struct Scsi_Host *shost)
{
struct scsi_host_template *hostt = shost->hostt;
struct scsi_host_cmd_pool *pool;
pool = kzalloc(sizeof(*pool), GFP_KERNEL);
if (!pool)
return NULL;
pool->cmd_name = kasprintf(GFP_KERNEL, "%s_cmd", hostt->name);
pool->sense_name = kasprintf(GFP_KERNEL, "%s_sense", hostt->name);
if (!pool->cmd_name || !pool->sense_name) {
scsi_free_host_cmd_pool(pool);
return NULL;
}
pool->slab_flags = SLAB_HWCACHE_ALIGN;
if (shost->unchecked_isa_dma) {
pool->slab_flags |= SLAB_CACHE_DMA;
pool->gfp_mask = __GFP_DMA;
}
return pool;
}
static struct scsi_host_cmd_pool *
scsi_get_host_cmd_pool(struct Scsi_Host *shost)
{
struct scsi_host_template *hostt = shost->hostt;
struct scsi_host_cmd_pool *retval = NULL, *pool;
size_t cmd_size = sizeof(struct scsi_cmnd) + hostt->cmd_size;
/*
* Select a command slab for this host and create it if not
* yet existent.
*/
mutex_lock(&host_cmd_pool_mutex);
pool = scsi_find_host_cmd_pool(shost);
if (!pool) {
pool = scsi_alloc_host_cmd_pool(shost);
if (!pool)
goto out;
}
if (!pool->users) {
pool->cmd_slab = kmem_cache_create(pool->cmd_name, cmd_size, 0,
pool->slab_flags, NULL);
if (!pool->cmd_slab)
goto out_free_pool;
pool->sense_slab = kmem_cache_create(pool->sense_name,
SCSI_SENSE_BUFFERSIZE, 0,
pool->slab_flags, NULL);
if (!pool->sense_slab)
goto out_free_slab;
}
pool->users++;
retval = pool;
out:
mutex_unlock(&host_cmd_pool_mutex);
return retval;
out_free_slab:
kmem_cache_destroy(pool->cmd_slab);
out_free_pool:
if (hostt->cmd_size)
scsi_free_host_cmd_pool(pool);
goto out;
}
static void scsi_put_host_cmd_pool(struct Scsi_Host *shost)
{
struct scsi_host_template *hostt = shost->hostt;
struct scsi_host_cmd_pool *pool;
mutex_lock(&host_cmd_pool_mutex);
pool = scsi_find_host_cmd_pool(shost);
/*
* This may happen if a driver has a mismatched get and put
* of the command pool; the driver should be implicated in
* the stack trace
*/
BUG_ON(pool->users == 0);
if (!--pool->users) {
kmem_cache_destroy(pool->cmd_slab);
kmem_cache_destroy(pool->sense_slab);
if (hostt->cmd_size)
scsi_free_host_cmd_pool(pool);
}
mutex_unlock(&host_cmd_pool_mutex);
}
/**
* scsi_setup_command_freelist - Setup the command freelist for a scsi host.
* @shost: host to allocate the freelist for.
*
* Description: The command freelist protects against system-wide out of memory
* deadlock by preallocating one SCSI command structure for each host, so the
* system can always write to a swap file on a device associated with that host.
*
* Returns: Nothing.
*/
int scsi_setup_command_freelist(struct Scsi_Host *shost)
{
const gfp_t gfp_mask = shost->unchecked_isa_dma ? GFP_DMA : GFP_KERNEL;
struct scsi_cmnd *cmd;
spin_lock_init(&shost->free_list_lock);
INIT_LIST_HEAD(&shost->free_list);
shost->cmd_pool = scsi_get_host_cmd_pool(shost);
if (!shost->cmd_pool)
return -ENOMEM;
/*
* Get one backup command for this host.
*/
cmd = scsi_host_alloc_command(shost, gfp_mask);
if (!cmd) {
scsi_put_host_cmd_pool(shost);
shost->cmd_pool = NULL;
return -ENOMEM;
}
list_add(&cmd->list, &shost->free_list);
return 0;
}
/**
* scsi_destroy_command_freelist - Release the command freelist for a scsi host.
* @shost: host whose freelist is going to be destroyed
*/
void scsi_destroy_command_freelist(struct Scsi_Host *shost)
{
/*
* If cmd_pool is NULL the free list was not initialized, so
* do not attempt to release resources.
*/
if (!shost->cmd_pool)
return;
while (!list_empty(&shost->free_list)) {
struct scsi_cmnd *cmd;
cmd = list_entry(shost->free_list.next, struct scsi_cmnd, list);
list_del_init(&cmd->list);
scsi_host_free_command(shost, cmd);
}
shost->cmd_pool = NULL;
scsi_put_host_cmd_pool(shost);
}
#ifdef CONFIG_SCSI_LOGGING
void scsi_log_send(struct scsi_cmnd *cmd)
{
unsigned int level;
/*
* If ML QUEUE log level is greater than or equal to:
*
* 1: nothing (match completion)
*
* 2: log opcode + command of all commands
*
* 3: same as 2 plus dump cmd address
*
* 4: same as 3 plus dump extra junk
*/
if (unlikely(scsi_logging_level)) {
level = SCSI_LOG_LEVEL(SCSI_LOG_MLQUEUE_SHIFT,
SCSI_LOG_MLQUEUE_BITS);
if (level > 1) {
scmd_printk(KERN_INFO, cmd, "Send: ");
if (level > 2)
printk("0x%p ", cmd);
printk("\n");
scsi_print_command(cmd);
if (level > 3) {
printk(KERN_INFO "buffer = 0x%p, bufflen = %d,"
Revert "scsi: revert "[SCSI] Get rid of scsi_cmnd->done"" This reverts commit ac40532ef0b8649e6f7f83859ea0de1c4ed08a19, which gets us back the original cleanup of 6f5391c283d7fdcf24bf40786ea79061919d1e1d. It turns out that the bug that was triggered by that commit was apparently not actually triggered by that commit at all, and just the testing conditions had changed enough to make it appear to be due to it. The real problem seems to have been found by Peter Osterlund: "pktcdvd sets it [block device size] when opening the /dev/pktcdvd device, but when the drive is later opened as /dev/scd0, there is nothing that sets it back. (Btw, 40944 is possible if the disk is a CDRW that was formatted with "cdrwtool -m 10236".) The problem is that pktcdvd opens the cd device in non-blocking mode when pktsetup is run, and doesn't close it again until pktsetup -d is run. The effect is that if you meanwhile open the cd device, blkdev.c:do_open() doesn't call bd_set_size() because bdev->bd_openers is non-zero." In particular, to repeat the bug (regardless of whether commit 6f5391c283d7fdcf24bf40786ea79061919d1e1d is applied or not): " 1. Start with an empty drive. 2. pktsetup 0 /dev/scd0 3. Insert a CD containing an isofs filesystem. 4. mount /dev/pktcdvd/0 /mnt/tmp 5. umount /mnt/tmp 6. Press the eject button. 7. Insert a DVD containing a non-writable filesystem. 8. mount /dev/scd0 /mnt/tmp 9. find /mnt/tmp -type f -print0 | xargs -0 sha1sum >/dev/null 10. If the DVD contains data beyond the physical size of a CD, you get I/O errors in the terminal, and dmesg reports lots of "attempt to access beyond end of device" errors." which in turn is because the nested open after the media change won't cause the size to be set properly (because the original open still holds the block device, and we only do the bd_set_size() when we don't have other people holding the device open). The proper fix for that is probably to just do something like bdev->bd_inode->i_size = (loff_t)get_capacity(disk)<<9; in fs/block_dev.c:do_open() even for the cases where we're not the original opener (but *not* call bd_set_size(), since that will also change the block size of the device). Cc: Peter Osterlund <petero2@telia.com> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Cc: Matthew Wilcox <matthew@wil.cx> Cc: Ingo Molnar <mingo@elte.hu> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-01-06 18:17:12 +00:00
" queuecommand 0x%p\n",
scsi_sglist(cmd), scsi_bufflen(cmd),
cmd->device->host->hostt->queuecommand);
}
}
}
}
void scsi_log_completion(struct scsi_cmnd *cmd, int disposition)
{
unsigned int level;
/*
* If ML COMPLETE log level is greater than or equal to:
*
* 1: log disposition, result, opcode + command, and conditionally
* sense data for failures or non SUCCESS dispositions.
*
* 2: same as 1 but for all command completions.
*
* 3: same as 2 plus dump cmd address
*
* 4: same as 3 plus dump extra junk
*/
if (unlikely(scsi_logging_level)) {
level = SCSI_LOG_LEVEL(SCSI_LOG_MLCOMPLETE_SHIFT,
SCSI_LOG_MLCOMPLETE_BITS);
if (((level > 0) && (cmd->result || disposition != SUCCESS)) ||
(level > 1)) {
scmd_printk(KERN_INFO, cmd, "Done: ");
if (level > 2)
printk("0x%p ", cmd);
/*
* Dump truncated values, so we usually fit within
* 80 chars.
*/
switch (disposition) {
case SUCCESS:
printk("SUCCESS\n");
break;
case NEEDS_RETRY:
printk("RETRY\n");
break;
case ADD_TO_MLQUEUE:
printk("MLQUEUE\n");
break;
case FAILED:
printk("FAILED\n");
break;
case TIMEOUT_ERROR:
/*
* If called via scsi_times_out.
*/
printk("TIMEOUT\n");
break;
default:
printk("UNKNOWN\n");
}
scsi_print_result(cmd);
scsi_print_command(cmd);
if (status_byte(cmd->result) & CHECK_CONDITION)
scsi_print_sense("", cmd);
if (level > 3)
scmd_printk(KERN_INFO, cmd,
"scsi host busy %d failed %d\n",
cmd->device->host->host_busy,
cmd->device->host->host_failed);
}
}
}
#endif
/**
* scsi_cmd_get_serial - Assign a serial number to a command
* @host: the scsi host
* @cmd: command to assign serial number to
*
* Description: a serial number identifies a request for error recovery
* and debugging purposes. Protected by the Host_Lock of host.
*/
void scsi_cmd_get_serial(struct Scsi_Host *host, struct scsi_cmnd *cmd)
{
cmd->serial_number = host->cmd_serial_number++;
if (cmd->serial_number == 0)
cmd->serial_number = host->cmd_serial_number++;
}
EXPORT_SYMBOL(scsi_cmd_get_serial);
/**
* scsi_dispatch_command - Dispatch a command to the low-level driver.
* @cmd: command block we are dispatching.
*
* Return: nonzero return request was rejected and device's queue needs to be
* plugged.
*/
int scsi_dispatch_cmd(struct scsi_cmnd *cmd)
{
struct Scsi_Host *host = cmd->device->host;
int rtn = 0;
atomic_inc(&cmd->device->iorequest_cnt);
/* check if the device is still usable */
if (unlikely(cmd->device->sdev_state == SDEV_DEL)) {
/* in SDEV_DEL we error all commands. DID_NO_CONNECT
* returns an immediate error upwards, and signals
* that the device is no longer present */
cmd->result = DID_NO_CONNECT << 16;
scsi_done(cmd);
/* return 0 (because the command has been processed) */
goto out;
}
/* Check to see if the scsi lld made this device blocked. */
if (unlikely(scsi_device_blocked(cmd->device))) {
/*
* in blocked state, the command is just put back on
* the device queue. The suspend state has already
* blocked the queue so future requests should not
* occur until the device transitions out of the
* suspend state.
*/
scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY);
SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd,
"queuecommand : device blocked\n"));
/*
* NOTE: rtn is still zero here because we don't need the
* queue to be plugged on return (it's already stopped)
*/
goto out;
}
/*
* If SCSI-2 or lower, store the LUN value in cmnd.
*/
if (cmd->device->scsi_level <= SCSI_2 &&
cmd->device->scsi_level != SCSI_UNKNOWN) {
cmd->cmnd[1] = (cmd->cmnd[1] & 0x1f) |
(cmd->device->lun << 5 & 0xe0);
}
scsi_log_send(cmd);
/*
* Before we queue this command, check if the command
* length exceeds what the host adapter can handle.
*/
if (cmd->cmd_len > cmd->device->host->max_cmd_len) {
SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd,
"queuecommand : command too long. "
"cdb_size=%d host->max_cmd_len=%d\n",
cmd->cmd_len, cmd->device->host->max_cmd_len));
cmd->result = (DID_ABORT << 16);
scsi_done(cmd);
goto out;
}
if (unlikely(host->shost_state == SHOST_DEL)) {
cmd->result = (DID_NO_CONNECT << 16);
scsi_done(cmd);
} else {
trace_scsi_dispatch_cmd_start(cmd);
cmd->scsi_done = scsi_done;
rtn = host->hostt->queuecommand(host, cmd);
}
if (rtn) {
trace_scsi_dispatch_cmd_error(cmd, rtn);
[SCSI] Add helper code so transport classes/driver can control queueing (v3) SCSI-ml manages the queueing limits for the device and host, but does not do so at the target level. However something something similar can come in userful when a driver is transitioning a transport object to the the blocked state, becuase at that time we do not want to queue io and we do not want the queuecommand to be called again. The patch adds code similar to the exisiting SCSI_ML_*BUSY handlers. You can now return SCSI_MLQUEUE_TARGET_BUSY when we hit a transport level queueing issue like the hw cannot allocate some resource at the iscsi session/connection level, or the target has temporarily closed or shrunk the queueing window, or if we are transitioning to the blocked state. bnx2i, when they rework their firmware according to netdev developers requests, will also need to be able to limit queueing at this level. bnx2i will hook into libiscsi, but will allocate a scsi host per netdevice/hba, so unlike pure software iscsi/iser which is allocating a host per session, it cannot set the scsi_host->can_queue and return SCSI_MLQUEUE_HOST_BUSY to reflect queueing limits on the transport. The iscsi class/driver can also set a scsi_target->can_queue value which reflects the max commands the driver/class can support. For iscsi this reflects the number of commands we can support for each session due to session/connection hw limits, driver limits, and to also reflect the session/targets's queueing window. Changes: v1 - initial patch. v2 - Fix scsi_run_queue handling of multiple blocked targets. Previously we would break from the main loop if a device was added back on the starved list. We now run over the list and check if any target is blocked. v3 - Rediff for scsi-misc. Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-08-17 20:24:38 +00:00
if (rtn != SCSI_MLQUEUE_DEVICE_BUSY &&
rtn != SCSI_MLQUEUE_TARGET_BUSY)
rtn = SCSI_MLQUEUE_HOST_BUSY;
SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd,
"queuecommand : request rejected\n"));
[SCSI] Add helper code so transport classes/driver can control queueing (v3) SCSI-ml manages the queueing limits for the device and host, but does not do so at the target level. However something something similar can come in userful when a driver is transitioning a transport object to the the blocked state, becuase at that time we do not want to queue io and we do not want the queuecommand to be called again. The patch adds code similar to the exisiting SCSI_ML_*BUSY handlers. You can now return SCSI_MLQUEUE_TARGET_BUSY when we hit a transport level queueing issue like the hw cannot allocate some resource at the iscsi session/connection level, or the target has temporarily closed or shrunk the queueing window, or if we are transitioning to the blocked state. bnx2i, when they rework their firmware according to netdev developers requests, will also need to be able to limit queueing at this level. bnx2i will hook into libiscsi, but will allocate a scsi host per netdevice/hba, so unlike pure software iscsi/iser which is allocating a host per session, it cannot set the scsi_host->can_queue and return SCSI_MLQUEUE_HOST_BUSY to reflect queueing limits on the transport. The iscsi class/driver can also set a scsi_target->can_queue value which reflects the max commands the driver/class can support. For iscsi this reflects the number of commands we can support for each session due to session/connection hw limits, driver limits, and to also reflect the session/targets's queueing window. Changes: v1 - initial patch. v2 - Fix scsi_run_queue handling of multiple blocked targets. Previously we would break from the main loop if a device was added back on the starved list. We now run over the list and check if any target is blocked. v3 - Rediff for scsi-misc. Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-08-17 20:24:38 +00:00
scsi_queue_insert(cmd, rtn);
}
out:
return rtn;
}
/**
* scsi_done - Invoke completion on finished SCSI command.
* @cmd: The SCSI Command for which a low-level device driver (LLDD) gives
* ownership back to SCSI Core -- i.e. the LLDD has finished with it.
*
* Description: This function is the mid-level's (SCSI Core) interrupt routine,
* which regains ownership of the SCSI command (de facto) from a LLDD, and
* calls blk_complete_request() for further processing.
*
* This function is interrupt context safe.
*/
static void scsi_done(struct scsi_cmnd *cmd)
{
trace_scsi_dispatch_cmd_done(cmd);
blk_complete_request(cmd->request);
}
/**
* scsi_finish_command - cleanup and pass command back to upper layer
* @cmd: the command
*
* Description: Pass command off to upper layer for finishing of I/O
* request, waking processes that are waiting on results,
* etc.
*/
void scsi_finish_command(struct scsi_cmnd *cmd)
{
struct scsi_device *sdev = cmd->device;
[SCSI] Add helper code so transport classes/driver can control queueing (v3) SCSI-ml manages the queueing limits for the device and host, but does not do so at the target level. However something something similar can come in userful when a driver is transitioning a transport object to the the blocked state, becuase at that time we do not want to queue io and we do not want the queuecommand to be called again. The patch adds code similar to the exisiting SCSI_ML_*BUSY handlers. You can now return SCSI_MLQUEUE_TARGET_BUSY when we hit a transport level queueing issue like the hw cannot allocate some resource at the iscsi session/connection level, or the target has temporarily closed or shrunk the queueing window, or if we are transitioning to the blocked state. bnx2i, when they rework their firmware according to netdev developers requests, will also need to be able to limit queueing at this level. bnx2i will hook into libiscsi, but will allocate a scsi host per netdevice/hba, so unlike pure software iscsi/iser which is allocating a host per session, it cannot set the scsi_host->can_queue and return SCSI_MLQUEUE_HOST_BUSY to reflect queueing limits on the transport. The iscsi class/driver can also set a scsi_target->can_queue value which reflects the max commands the driver/class can support. For iscsi this reflects the number of commands we can support for each session due to session/connection hw limits, driver limits, and to also reflect the session/targets's queueing window. Changes: v1 - initial patch. v2 - Fix scsi_run_queue handling of multiple blocked targets. Previously we would break from the main loop if a device was added back on the starved list. We now run over the list and check if any target is blocked. v3 - Rediff for scsi-misc. Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-08-17 20:24:38 +00:00
struct scsi_target *starget = scsi_target(sdev);
struct Scsi_Host *shost = sdev->host;
Revert "scsi: revert "[SCSI] Get rid of scsi_cmnd->done"" This reverts commit ac40532ef0b8649e6f7f83859ea0de1c4ed08a19, which gets us back the original cleanup of 6f5391c283d7fdcf24bf40786ea79061919d1e1d. It turns out that the bug that was triggered by that commit was apparently not actually triggered by that commit at all, and just the testing conditions had changed enough to make it appear to be due to it. The real problem seems to have been found by Peter Osterlund: "pktcdvd sets it [block device size] when opening the /dev/pktcdvd device, but when the drive is later opened as /dev/scd0, there is nothing that sets it back. (Btw, 40944 is possible if the disk is a CDRW that was formatted with "cdrwtool -m 10236".) The problem is that pktcdvd opens the cd device in non-blocking mode when pktsetup is run, and doesn't close it again until pktsetup -d is run. The effect is that if you meanwhile open the cd device, blkdev.c:do_open() doesn't call bd_set_size() because bdev->bd_openers is non-zero." In particular, to repeat the bug (regardless of whether commit 6f5391c283d7fdcf24bf40786ea79061919d1e1d is applied or not): " 1. Start with an empty drive. 2. pktsetup 0 /dev/scd0 3. Insert a CD containing an isofs filesystem. 4. mount /dev/pktcdvd/0 /mnt/tmp 5. umount /mnt/tmp 6. Press the eject button. 7. Insert a DVD containing a non-writable filesystem. 8. mount /dev/scd0 /mnt/tmp 9. find /mnt/tmp -type f -print0 | xargs -0 sha1sum >/dev/null 10. If the DVD contains data beyond the physical size of a CD, you get I/O errors in the terminal, and dmesg reports lots of "attempt to access beyond end of device" errors." which in turn is because the nested open after the media change won't cause the size to be set properly (because the original open still holds the block device, and we only do the bd_set_size() when we don't have other people holding the device open). The proper fix for that is probably to just do something like bdev->bd_inode->i_size = (loff_t)get_capacity(disk)<<9; in fs/block_dev.c:do_open() even for the cases where we're not the original opener (but *not* call bd_set_size(), since that will also change the block size of the device). Cc: Peter Osterlund <petero2@telia.com> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Cc: Matthew Wilcox <matthew@wil.cx> Cc: Ingo Molnar <mingo@elte.hu> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-01-06 18:17:12 +00:00
struct scsi_driver *drv;
unsigned int good_bytes;
scsi_device_unbusy(sdev);
/*
* Clear the flags which say that the device/host is no longer
* capable of accepting new commands. These are set in scsi_queue.c
* for both the queue full condition on a device, and for a
* host full condition on the host.
*
* XXX(hch): What about locking?
*/
shost->host_blocked = 0;
[SCSI] Add helper code so transport classes/driver can control queueing (v3) SCSI-ml manages the queueing limits for the device and host, but does not do so at the target level. However something something similar can come in userful when a driver is transitioning a transport object to the the blocked state, becuase at that time we do not want to queue io and we do not want the queuecommand to be called again. The patch adds code similar to the exisiting SCSI_ML_*BUSY handlers. You can now return SCSI_MLQUEUE_TARGET_BUSY when we hit a transport level queueing issue like the hw cannot allocate some resource at the iscsi session/connection level, or the target has temporarily closed or shrunk the queueing window, or if we are transitioning to the blocked state. bnx2i, when they rework their firmware according to netdev developers requests, will also need to be able to limit queueing at this level. bnx2i will hook into libiscsi, but will allocate a scsi host per netdevice/hba, so unlike pure software iscsi/iser which is allocating a host per session, it cannot set the scsi_host->can_queue and return SCSI_MLQUEUE_HOST_BUSY to reflect queueing limits on the transport. The iscsi class/driver can also set a scsi_target->can_queue value which reflects the max commands the driver/class can support. For iscsi this reflects the number of commands we can support for each session due to session/connection hw limits, driver limits, and to also reflect the session/targets's queueing window. Changes: v1 - initial patch. v2 - Fix scsi_run_queue handling of multiple blocked targets. Previously we would break from the main loop if a device was added back on the starved list. We now run over the list and check if any target is blocked. v3 - Rediff for scsi-misc. Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-08-17 20:24:38 +00:00
starget->target_blocked = 0;
sdev->device_blocked = 0;
/*
* If we have valid sense information, then some kind of recovery
* must have taken place. Make a note of this.
*/
if (SCSI_SENSE_VALID(cmd))
cmd->result |= (DRIVER_SENSE << 24);
SCSI_LOG_MLCOMPLETE(4, sdev_printk(KERN_INFO, sdev,
"Notifying upper driver of completion "
"(result %x)\n", cmd->result));
good_bytes = scsi_bufflen(cmd);
Revert "scsi: revert "[SCSI] Get rid of scsi_cmnd->done"" This reverts commit ac40532ef0b8649e6f7f83859ea0de1c4ed08a19, which gets us back the original cleanup of 6f5391c283d7fdcf24bf40786ea79061919d1e1d. It turns out that the bug that was triggered by that commit was apparently not actually triggered by that commit at all, and just the testing conditions had changed enough to make it appear to be due to it. The real problem seems to have been found by Peter Osterlund: "pktcdvd sets it [block device size] when opening the /dev/pktcdvd device, but when the drive is later opened as /dev/scd0, there is nothing that sets it back. (Btw, 40944 is possible if the disk is a CDRW that was formatted with "cdrwtool -m 10236".) The problem is that pktcdvd opens the cd device in non-blocking mode when pktsetup is run, and doesn't close it again until pktsetup -d is run. The effect is that if you meanwhile open the cd device, blkdev.c:do_open() doesn't call bd_set_size() because bdev->bd_openers is non-zero." In particular, to repeat the bug (regardless of whether commit 6f5391c283d7fdcf24bf40786ea79061919d1e1d is applied or not): " 1. Start with an empty drive. 2. pktsetup 0 /dev/scd0 3. Insert a CD containing an isofs filesystem. 4. mount /dev/pktcdvd/0 /mnt/tmp 5. umount /mnt/tmp 6. Press the eject button. 7. Insert a DVD containing a non-writable filesystem. 8. mount /dev/scd0 /mnt/tmp 9. find /mnt/tmp -type f -print0 | xargs -0 sha1sum >/dev/null 10. If the DVD contains data beyond the physical size of a CD, you get I/O errors in the terminal, and dmesg reports lots of "attempt to access beyond end of device" errors." which in turn is because the nested open after the media change won't cause the size to be set properly (because the original open still holds the block device, and we only do the bd_set_size() when we don't have other people holding the device open). The proper fix for that is probably to just do something like bdev->bd_inode->i_size = (loff_t)get_capacity(disk)<<9; in fs/block_dev.c:do_open() even for the cases where we're not the original opener (but *not* call bd_set_size(), since that will also change the block size of the device). Cc: Peter Osterlund <petero2@telia.com> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Cc: Matthew Wilcox <matthew@wil.cx> Cc: Ingo Molnar <mingo@elte.hu> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-01-06 18:17:12 +00:00
if (cmd->request->cmd_type != REQ_TYPE_BLOCK_PC) {
int old_good_bytes = good_bytes;
Revert "scsi: revert "[SCSI] Get rid of scsi_cmnd->done"" This reverts commit ac40532ef0b8649e6f7f83859ea0de1c4ed08a19, which gets us back the original cleanup of 6f5391c283d7fdcf24bf40786ea79061919d1e1d. It turns out that the bug that was triggered by that commit was apparently not actually triggered by that commit at all, and just the testing conditions had changed enough to make it appear to be due to it. The real problem seems to have been found by Peter Osterlund: "pktcdvd sets it [block device size] when opening the /dev/pktcdvd device, but when the drive is later opened as /dev/scd0, there is nothing that sets it back. (Btw, 40944 is possible if the disk is a CDRW that was formatted with "cdrwtool -m 10236".) The problem is that pktcdvd opens the cd device in non-blocking mode when pktsetup is run, and doesn't close it again until pktsetup -d is run. The effect is that if you meanwhile open the cd device, blkdev.c:do_open() doesn't call bd_set_size() because bdev->bd_openers is non-zero." In particular, to repeat the bug (regardless of whether commit 6f5391c283d7fdcf24bf40786ea79061919d1e1d is applied or not): " 1. Start with an empty drive. 2. pktsetup 0 /dev/scd0 3. Insert a CD containing an isofs filesystem. 4. mount /dev/pktcdvd/0 /mnt/tmp 5. umount /mnt/tmp 6. Press the eject button. 7. Insert a DVD containing a non-writable filesystem. 8. mount /dev/scd0 /mnt/tmp 9. find /mnt/tmp -type f -print0 | xargs -0 sha1sum >/dev/null 10. If the DVD contains data beyond the physical size of a CD, you get I/O errors in the terminal, and dmesg reports lots of "attempt to access beyond end of device" errors." which in turn is because the nested open after the media change won't cause the size to be set properly (because the original open still holds the block device, and we only do the bd_set_size() when we don't have other people holding the device open). The proper fix for that is probably to just do something like bdev->bd_inode->i_size = (loff_t)get_capacity(disk)<<9; in fs/block_dev.c:do_open() even for the cases where we're not the original opener (but *not* call bd_set_size(), since that will also change the block size of the device). Cc: Peter Osterlund <petero2@telia.com> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Cc: Matthew Wilcox <matthew@wil.cx> Cc: Ingo Molnar <mingo@elte.hu> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-01-06 18:17:12 +00:00
drv = scsi_cmd_to_driver(cmd);
if (drv->done)
good_bytes = drv->done(cmd);
/*
* USB may not give sense identifying bad sector and
* simply return a residue instead, so subtract off the
* residue if drv->done() error processing indicates no
* change to the completion length.
*/
if (good_bytes == old_good_bytes)
good_bytes -= scsi_get_resid(cmd);
Revert "scsi: revert "[SCSI] Get rid of scsi_cmnd->done"" This reverts commit ac40532ef0b8649e6f7f83859ea0de1c4ed08a19, which gets us back the original cleanup of 6f5391c283d7fdcf24bf40786ea79061919d1e1d. It turns out that the bug that was triggered by that commit was apparently not actually triggered by that commit at all, and just the testing conditions had changed enough to make it appear to be due to it. The real problem seems to have been found by Peter Osterlund: "pktcdvd sets it [block device size] when opening the /dev/pktcdvd device, but when the drive is later opened as /dev/scd0, there is nothing that sets it back. (Btw, 40944 is possible if the disk is a CDRW that was formatted with "cdrwtool -m 10236".) The problem is that pktcdvd opens the cd device in non-blocking mode when pktsetup is run, and doesn't close it again until pktsetup -d is run. The effect is that if you meanwhile open the cd device, blkdev.c:do_open() doesn't call bd_set_size() because bdev->bd_openers is non-zero." In particular, to repeat the bug (regardless of whether commit 6f5391c283d7fdcf24bf40786ea79061919d1e1d is applied or not): " 1. Start with an empty drive. 2. pktsetup 0 /dev/scd0 3. Insert a CD containing an isofs filesystem. 4. mount /dev/pktcdvd/0 /mnt/tmp 5. umount /mnt/tmp 6. Press the eject button. 7. Insert a DVD containing a non-writable filesystem. 8. mount /dev/scd0 /mnt/tmp 9. find /mnt/tmp -type f -print0 | xargs -0 sha1sum >/dev/null 10. If the DVD contains data beyond the physical size of a CD, you get I/O errors in the terminal, and dmesg reports lots of "attempt to access beyond end of device" errors." which in turn is because the nested open after the media change won't cause the size to be set properly (because the original open still holds the block device, and we only do the bd_set_size() when we don't have other people holding the device open). The proper fix for that is probably to just do something like bdev->bd_inode->i_size = (loff_t)get_capacity(disk)<<9; in fs/block_dev.c:do_open() even for the cases where we're not the original opener (but *not* call bd_set_size(), since that will also change the block size of the device). Cc: Peter Osterlund <petero2@telia.com> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Cc: Matthew Wilcox <matthew@wil.cx> Cc: Ingo Molnar <mingo@elte.hu> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-01-06 18:17:12 +00:00
}
scsi_io_completion(cmd, good_bytes);
}
/**
* scsi_adjust_queue_depth - Let low level drivers change a device's queue depth
* @sdev: SCSI Device in question
* @tagged: Do we use tagged queueing (non-0) or do we treat
* this device as an untagged device (0)
* @tags: Number of tags allowed if tagged queueing enabled,
* or number of commands the low level driver can
* queue up in non-tagged mode (as per cmd_per_lun).
*
* Returns: Nothing
*
* Lock Status: None held on entry
*
* Notes: Low level drivers may call this at any time and we will do
* the right thing depending on whether or not the device is
* currently active and whether or not it even has the
* command blocks built yet.
*/
void scsi_adjust_queue_depth(struct scsi_device *sdev, int tagged, int tags)
{
unsigned long flags;
/*
* refuse to set tagged depth to an unworkable size
*/
if (tags <= 0)
return;
spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
/*
* Check to see if the queue is managed by the block layer.
* If it is, and we fail to adjust the depth, exit.
*
* Do not resize the tag map if it is a host wide share bqt,
* because the size should be the hosts's can_queue. If there
* is more IO than the LLD's can_queue (so there are not enuogh
* tags) request_fn's host queue ready check will handle it.
*/
if (!sdev->host->bqt) {
if (blk_queue_tagged(sdev->request_queue) &&
blk_queue_resize_tags(sdev->request_queue, tags) != 0)
goto out;
}
sdev->queue_depth = tags;
switch (tagged) {
case MSG_ORDERED_TAG:
sdev->ordered_tags = 1;
sdev->simple_tags = 1;
break;
case MSG_SIMPLE_TAG:
sdev->ordered_tags = 0;
sdev->simple_tags = 1;
break;
default:
sdev_printk(KERN_WARNING, sdev,
"scsi_adjust_queue_depth, bad queue type, "
"disabled\n");
case 0:
sdev->ordered_tags = sdev->simple_tags = 0;
sdev->queue_depth = tags;
break;
}
out:
spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
}
EXPORT_SYMBOL(scsi_adjust_queue_depth);
/**
* scsi_track_queue_full - track QUEUE_FULL events to adjust queue depth
* @sdev: SCSI Device in question
* @depth: Current number of outstanding SCSI commands on this device,
* not counting the one returned as QUEUE_FULL.
*
* Description: This function will track successive QUEUE_FULL events on a
* specific SCSI device to determine if and when there is a
* need to adjust the queue depth on the device.
*
* Returns: 0 - No change needed, >0 - Adjust queue depth to this new depth,
* -1 - Drop back to untagged operation using host->cmd_per_lun
* as the untagged command depth
*
* Lock Status: None held on entry
*
* Notes: Low level drivers may call this at any time and we will do
* "The Right Thing." We are interrupt context safe.
*/
int scsi_track_queue_full(struct scsi_device *sdev, int depth)
{
[SCSI] add queue_depth ramp up code Current FC HBA queue_depth ramp up code depends on last queue full time. The sdev already has last_queue_full_time field to track last queue full time but stored value is truncated by last four bits. So this patch updates last_queue_full_time without truncating last 4 bits to store full value and then updates its only current usages in scsi_track_queue_full to ignore last four bits to keep current usages same while also use this field in added ramp up code. Adds scsi_handle_queue_ramp_up to ramp up queue_depth on successful completion of IO. The scsi_handle_queue_ramp_up will do ramp up on all luns of a target, just same as ramp down done on all luns on a target. The ramp up is skipped in case the change_queue_depth is not supported by LLD or already reached to added max_queue_depth. Updates added max_queue_depth on every new update to default queue_depth value. The ramp up is also skipped if lapsed time since either last queue ramp up or down is less than LLD specified queue_ramp_up_period. Adds queue_ramp_up_period to sysfs but only if change_queue_depth is supported since ramp up and queue_ramp_up_period is needed only in case change_queue_depth is supported first. Initializes queue_ramp_up_period to 120HZ jiffies as initial default value, it is same as used in existing lpfc and qla2xxx. -v2 Combined all ramp code into this single patch. -v3 Moves max_queue_depth initialization after slave_configure is called from after slave_alloc calling done. Also adjusted max_queue_depth check to skip ramp up if current queue_depth is >= max_queue_depth. -v4 Changes sdev->queue_ramp_up_period unit to ms when using sysfs i/f to store or show its value. Signed-off-by: Vasu Dev <vasu.dev@intel.com> Tested-by: Christof Schmitt <christof.schmitt@de.ibm.com> Tested-by: Giridhar Malavali <giridhar.malavali@qlogic.com> Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2009-10-22 22:46:33 +00:00
/*
* Don't let QUEUE_FULLs on the same
* jiffies count, they could all be from
* same event.
*/
if ((jiffies >> 4) == (sdev->last_queue_full_time >> 4))
return 0;
[SCSI] add queue_depth ramp up code Current FC HBA queue_depth ramp up code depends on last queue full time. The sdev already has last_queue_full_time field to track last queue full time but stored value is truncated by last four bits. So this patch updates last_queue_full_time without truncating last 4 bits to store full value and then updates its only current usages in scsi_track_queue_full to ignore last four bits to keep current usages same while also use this field in added ramp up code. Adds scsi_handle_queue_ramp_up to ramp up queue_depth on successful completion of IO. The scsi_handle_queue_ramp_up will do ramp up on all luns of a target, just same as ramp down done on all luns on a target. The ramp up is skipped in case the change_queue_depth is not supported by LLD or already reached to added max_queue_depth. Updates added max_queue_depth on every new update to default queue_depth value. The ramp up is also skipped if lapsed time since either last queue ramp up or down is less than LLD specified queue_ramp_up_period. Adds queue_ramp_up_period to sysfs but only if change_queue_depth is supported since ramp up and queue_ramp_up_period is needed only in case change_queue_depth is supported first. Initializes queue_ramp_up_period to 120HZ jiffies as initial default value, it is same as used in existing lpfc and qla2xxx. -v2 Combined all ramp code into this single patch. -v3 Moves max_queue_depth initialization after slave_configure is called from after slave_alloc calling done. Also adjusted max_queue_depth check to skip ramp up if current queue_depth is >= max_queue_depth. -v4 Changes sdev->queue_ramp_up_period unit to ms when using sysfs i/f to store or show its value. Signed-off-by: Vasu Dev <vasu.dev@intel.com> Tested-by: Christof Schmitt <christof.schmitt@de.ibm.com> Tested-by: Giridhar Malavali <giridhar.malavali@qlogic.com> Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2009-10-22 22:46:33 +00:00
sdev->last_queue_full_time = jiffies;
if (sdev->last_queue_full_depth != depth) {
sdev->last_queue_full_count = 1;
sdev->last_queue_full_depth = depth;
} else {
sdev->last_queue_full_count++;
}
if (sdev->last_queue_full_count <= 10)
return 0;
if (sdev->last_queue_full_depth < 8) {
/* Drop back to untagged */
scsi_adjust_queue_depth(sdev, 0, sdev->host->cmd_per_lun);
return -1;
}
if (sdev->ordered_tags)
scsi_adjust_queue_depth(sdev, MSG_ORDERED_TAG, depth);
else
scsi_adjust_queue_depth(sdev, MSG_SIMPLE_TAG, depth);
return depth;
}
EXPORT_SYMBOL(scsi_track_queue_full);
/**
* scsi_vpd_inquiry - Request a device provide us with a VPD page
* @sdev: The device to ask
* @buffer: Where to put the result
* @page: Which Vital Product Data to return
* @len: The length of the buffer
*
* This is an internal helper function. You probably want to use
* scsi_get_vpd_page instead.
*
* Returns size of the vpd page on success or a negative error number.
*/
static int scsi_vpd_inquiry(struct scsi_device *sdev, unsigned char *buffer,
u8 page, unsigned len)
{
int result;
unsigned char cmd[16];
if (len < 4)
return -EINVAL;
cmd[0] = INQUIRY;
cmd[1] = 1; /* EVPD */
cmd[2] = page;
cmd[3] = len >> 8;
cmd[4] = len & 0xff;
cmd[5] = 0; /* Control byte */
/*
* I'm not convinced we need to try quite this hard to get VPD, but
* all the existing users tried this hard.
*/
result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer,
len, NULL, 30 * HZ, 3, NULL);
if (result)
return -EIO;
/* Sanity check that we got the page back that we asked for */
if (buffer[1] != page)
return -EIO;
return get_unaligned_be16(&buffer[2]) + 4;
}
/**
* scsi_get_vpd_page - Get Vital Product Data from a SCSI device
* @sdev: The device to ask
* @page: Which Vital Product Data to return
* @buf: where to store the VPD
* @buf_len: number of bytes in the VPD buffer area
*
* SCSI devices may optionally supply Vital Product Data. Each 'page'
* of VPD is defined in the appropriate SCSI document (eg SPC, SBC).
* If the device supports this VPD page, this routine returns a pointer
* to a buffer containing the data from that page. The caller is
* responsible for calling kfree() on this pointer when it is no longer
* needed. If we cannot retrieve the VPD page this routine returns %NULL.
*/
int scsi_get_vpd_page(struct scsi_device *sdev, u8 page, unsigned char *buf,
int buf_len)
{
int i, result;
if (sdev->skip_vpd_pages)
goto fail;
/* Ask for all the pages supported by this device */
result = scsi_vpd_inquiry(sdev, buf, 0, buf_len);
if (result < 4)
goto fail;
/* If the user actually wanted this page, we can skip the rest */
if (page == 0)
return 0;
for (i = 4; i < min(result, buf_len); i++)
if (buf[i] == page)
goto found;
if (i < result && i >= buf_len)
/* ran off the end of the buffer, give us benefit of doubt */
goto found;
/* The device claims it doesn't support the requested page */
goto fail;
found:
result = scsi_vpd_inquiry(sdev, buf, page, buf_len);
if (result < 0)
goto fail;
return 0;
fail:
return -EINVAL;
}
EXPORT_SYMBOL_GPL(scsi_get_vpd_page);
/**
* scsi_attach_vpd - Attach Vital Product Data to a SCSI device structure
* @sdev: The device to ask
*
* Attach the 'Device Identification' VPD page (0x83) and the
* 'Unit Serial Number' VPD page (0x80) to a SCSI device
* structure. This information can be used to identify the device
* uniquely.
*/
void scsi_attach_vpd(struct scsi_device *sdev)
{
int result, i;
int vpd_len = SCSI_VPD_PG_LEN;
int pg80_supported = 0;
int pg83_supported = 0;
unsigned char *vpd_buf;
if (sdev->skip_vpd_pages)
return;
retry_pg0:
vpd_buf = kmalloc(vpd_len, GFP_KERNEL);
if (!vpd_buf)
return;
/* Ask for all the pages supported by this device */
result = scsi_vpd_inquiry(sdev, vpd_buf, 0, vpd_len);
if (result < 0) {
kfree(vpd_buf);
return;
}
if (result > vpd_len) {
vpd_len = result;
kfree(vpd_buf);
goto retry_pg0;
}
for (i = 4; i < result; i++) {
if (vpd_buf[i] == 0x80)
pg80_supported = 1;
if (vpd_buf[i] == 0x83)
pg83_supported = 1;
}
kfree(vpd_buf);
vpd_len = SCSI_VPD_PG_LEN;
if (pg80_supported) {
retry_pg80:
vpd_buf = kmalloc(vpd_len, GFP_KERNEL);
if (!vpd_buf)
return;
result = scsi_vpd_inquiry(sdev, vpd_buf, 0x80, vpd_len);
if (result < 0) {
kfree(vpd_buf);
return;
}
if (result > vpd_len) {
vpd_len = result;
kfree(vpd_buf);
goto retry_pg80;
}
sdev->vpd_pg80_len = result;
sdev->vpd_pg80 = vpd_buf;
vpd_len = SCSI_VPD_PG_LEN;
}
if (pg83_supported) {
retry_pg83:
vpd_buf = kmalloc(vpd_len, GFP_KERNEL);
if (!vpd_buf)
return;
result = scsi_vpd_inquiry(sdev, vpd_buf, 0x83, vpd_len);
if (result < 0) {
kfree(vpd_buf);
return;
}
if (result > vpd_len) {
vpd_len = result;
kfree(vpd_buf);
goto retry_pg83;
}
sdev->vpd_pg83_len = result;
sdev->vpd_pg83 = vpd_buf;
}
}
/**
* scsi_report_opcode - Find out if a given command opcode is supported
* @sdev: scsi device to query
* @buffer: scratch buffer (must be at least 20 bytes long)
* @len: length of buffer
* @opcode: opcode for command to look up
*
* Uses the REPORT SUPPORTED OPERATION CODES to look up the given
* opcode. Returns -EINVAL if RSOC fails, 0 if the command opcode is
* unsupported and 1 if the device claims to support the command.
*/
int scsi_report_opcode(struct scsi_device *sdev, unsigned char *buffer,
unsigned int len, unsigned char opcode)
{
unsigned char cmd[16];
struct scsi_sense_hdr sshdr;
int result;
if (sdev->no_report_opcodes || sdev->scsi_level < SCSI_SPC_3)
return -EINVAL;
memset(cmd, 0, 16);
cmd[0] = MAINTENANCE_IN;
cmd[1] = MI_REPORT_SUPPORTED_OPERATION_CODES;
cmd[2] = 1; /* One command format */
cmd[3] = opcode;
put_unaligned_be32(len, &cmd[6]);
memset(buffer, 0, len);
result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer, len,
&sshdr, 30 * HZ, 3, NULL);
if (result && scsi_sense_valid(&sshdr) &&
sshdr.sense_key == ILLEGAL_REQUEST &&
(sshdr.asc == 0x20 || sshdr.asc == 0x24) && sshdr.ascq == 0x00)
return -EINVAL;
if ((buffer[1] & 3) == 3) /* Command supported */
return 1;
return 0;
}
EXPORT_SYMBOL(scsi_report_opcode);
/**
* scsi_device_get - get an additional reference to a scsi_device
* @sdev: device to get a reference to
*
* Description: Gets a reference to the scsi_device and increments the use count
* of the underlying LLDD module. You must hold host_lock of the
* parent Scsi_Host or already have a reference when calling this.
*/
int scsi_device_get(struct scsi_device *sdev)
{
if (sdev->sdev_state == SDEV_DEL)
return -ENXIO;
if (!get_device(&sdev->sdev_gendev))
return -ENXIO;
/* We can fail this if we're doing SCSI operations
* from module exit (like cache flush) */
try_module_get(sdev->host->hostt->module);
return 0;
}
EXPORT_SYMBOL(scsi_device_get);
/**
* scsi_device_put - release a reference to a scsi_device
* @sdev: device to release a reference on.
*
* Description: Release a reference to the scsi_device and decrements the use
* count of the underlying LLDD module. The device is freed once the last
* user vanishes.
*/
void scsi_device_put(struct scsi_device *sdev)
{
#ifdef CONFIG_MODULE_UNLOAD
struct module *module = sdev->host->hostt->module;
/* The module refcount will be zero if scsi_device_get()
* was called from a module removal routine */
if (module && module_refcount(module) != 0)
module_put(module);
#endif
put_device(&sdev->sdev_gendev);
}
EXPORT_SYMBOL(scsi_device_put);
/* helper for shost_for_each_device, see that for documentation */
struct scsi_device *__scsi_iterate_devices(struct Scsi_Host *shost,
struct scsi_device *prev)
{
struct list_head *list = (prev ? &prev->siblings : &shost->__devices);
struct scsi_device *next = NULL;
unsigned long flags;
spin_lock_irqsave(shost->host_lock, flags);
while (list->next != &shost->__devices) {
next = list_entry(list->next, struct scsi_device, siblings);
/* skip devices that we can't get a reference to */
if (!scsi_device_get(next))
break;
next = NULL;
list = list->next;
}
spin_unlock_irqrestore(shost->host_lock, flags);
if (prev)
scsi_device_put(prev);
return next;
}
EXPORT_SYMBOL(__scsi_iterate_devices);
/**
* starget_for_each_device - helper to walk all devices of a target
* @starget: target whose devices we want to iterate over.
* @data: Opaque passed to each function call.
* @fn: Function to call on each device
*
* This traverses over each device of @starget. The devices have
* a reference that must be released by scsi_host_put when breaking
* out of the loop.
*/
void starget_for_each_device(struct scsi_target *starget, void *data,
void (*fn)(struct scsi_device *, void *))
{
struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
struct scsi_device *sdev;
shost_for_each_device(sdev, shost) {
if ((sdev->channel == starget->channel) &&
(sdev->id == starget->id))
fn(sdev, data);
}
}
EXPORT_SYMBOL(starget_for_each_device);
/**
* __starget_for_each_device - helper to walk all devices of a target (UNLOCKED)
* @starget: target whose devices we want to iterate over.
* @data: parameter for callback @fn()
* @fn: callback function that is invoked for each device
*
* This traverses over each device of @starget. It does _not_
* take a reference on the scsi_device, so the whole loop must be
* protected by shost->host_lock.
*
* Note: The only reason why drivers would want to use this is because
* they need to access the device list in irq context. Otherwise you
* really want to use starget_for_each_device instead.
**/
void __starget_for_each_device(struct scsi_target *starget, void *data,
void (*fn)(struct scsi_device *, void *))
{
struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
struct scsi_device *sdev;
__shost_for_each_device(sdev, shost) {
if ((sdev->channel == starget->channel) &&
(sdev->id == starget->id))
fn(sdev, data);
}
}
EXPORT_SYMBOL(__starget_for_each_device);
/**
* __scsi_device_lookup_by_target - find a device given the target (UNLOCKED)
* @starget: SCSI target pointer
* @lun: SCSI Logical Unit Number
*
* Description: Looks up the scsi_device with the specified @lun for a given
* @starget. The returned scsi_device does not have an additional
* reference. You must hold the host's host_lock over this call and
* any access to the returned scsi_device. A scsi_device in state
* SDEV_DEL is skipped.
*
* Note: The only reason why drivers should use this is because
* they need to access the device list in irq context. Otherwise you
* really want to use scsi_device_lookup_by_target instead.
**/
struct scsi_device *__scsi_device_lookup_by_target(struct scsi_target *starget,
u64 lun)
{
struct scsi_device *sdev;
list_for_each_entry(sdev, &starget->devices, same_target_siblings) {
if (sdev->sdev_state == SDEV_DEL)
continue;
if (sdev->lun ==lun)
return sdev;
}
return NULL;
}
EXPORT_SYMBOL(__scsi_device_lookup_by_target);
/**
* scsi_device_lookup_by_target - find a device given the target
* @starget: SCSI target pointer
* @lun: SCSI Logical Unit Number
*
* Description: Looks up the scsi_device with the specified @lun for a given
* @starget. The returned scsi_device has an additional reference that
* needs to be released with scsi_device_put once you're done with it.
**/
struct scsi_device *scsi_device_lookup_by_target(struct scsi_target *starget,
u64 lun)
{
struct scsi_device *sdev;
struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
unsigned long flags;
spin_lock_irqsave(shost->host_lock, flags);
sdev = __scsi_device_lookup_by_target(starget, lun);
if (sdev && scsi_device_get(sdev))
sdev = NULL;
spin_unlock_irqrestore(shost->host_lock, flags);
return sdev;
}
EXPORT_SYMBOL(scsi_device_lookup_by_target);
/**
* __scsi_device_lookup - find a device given the host (UNLOCKED)
* @shost: SCSI host pointer
* @channel: SCSI channel (zero if only one channel)
* @id: SCSI target number (physical unit number)
* @lun: SCSI Logical Unit Number
*
* Description: Looks up the scsi_device with the specified @channel, @id, @lun
* for a given host. The returned scsi_device does not have an additional
* reference. You must hold the host's host_lock over this call and any access
* to the returned scsi_device.
*
* Note: The only reason why drivers would want to use this is because
* they need to access the device list in irq context. Otherwise you
* really want to use scsi_device_lookup instead.
**/
struct scsi_device *__scsi_device_lookup(struct Scsi_Host *shost,
uint channel, uint id, u64 lun)
{
struct scsi_device *sdev;
list_for_each_entry(sdev, &shost->__devices, siblings) {
if (sdev->channel == channel && sdev->id == id &&
sdev->lun ==lun)
return sdev;
}
return NULL;
}
EXPORT_SYMBOL(__scsi_device_lookup);
/**
* scsi_device_lookup - find a device given the host
* @shost: SCSI host pointer
* @channel: SCSI channel (zero if only one channel)
* @id: SCSI target number (physical unit number)
* @lun: SCSI Logical Unit Number
*
* Description: Looks up the scsi_device with the specified @channel, @id, @lun
* for a given host. The returned scsi_device has an additional reference that
* needs to be released with scsi_device_put once you're done with it.
**/
struct scsi_device *scsi_device_lookup(struct Scsi_Host *shost,
uint channel, uint id, u64 lun)
{
struct scsi_device *sdev;
unsigned long flags;
spin_lock_irqsave(shost->host_lock, flags);
sdev = __scsi_device_lookup(shost, channel, id, lun);
if (sdev && scsi_device_get(sdev))
sdev = NULL;
spin_unlock_irqrestore(shost->host_lock, flags);
return sdev;
}
EXPORT_SYMBOL(scsi_device_lookup);
MODULE_DESCRIPTION("SCSI core");
MODULE_LICENSE("GPL");
module_param(scsi_logging_level, int, S_IRUGO|S_IWUSR);
MODULE_PARM_DESC(scsi_logging_level, "a bit mask of logging levels");
static int __init init_scsi(void)
{
int error;
error = scsi_init_queue();
if (error)
return error;
error = scsi_init_procfs();
if (error)
goto cleanup_queue;
error = scsi_init_devinfo();
if (error)
goto cleanup_procfs;
error = scsi_init_hosts();
if (error)
goto cleanup_devlist;
error = scsi_init_sysctl();
if (error)
goto cleanup_hosts;
error = scsi_sysfs_register();
if (error)
goto cleanup_sysctl;
[SCSI] SCSI and FC Transport: add netlink support for posting of transport events This patch formally adds support for the posting of FC events via netlink. It is a followup to the original RFC at: http://marc.theaimsgroup.com/?l=linux-scsi&m=114530667923464&w=2 and the initial posting at: http://marc.theaimsgroup.com/?l=linux-scsi&m=115507374832500&w=2 The patch has been updated to optimize the send path, per the discussions in the initial posting. Per discussions at the Storage Summit and at OLS, we are to use netlink for async events from transports. Also per discussions, to avoid a netlink protocol per transport, I've create a single NETLINK_SCSITRANSPORT protocol, which can then be used by all transports. This patch: - Creates new files scsi_netlink.c and scsi_netlink.h, which contains the single and shared definitions for the SCSI Transport. It is tied into the base SCSI subsystem intialization. Contains a single interface routine, scsi_send_transport_event(), for a transport to send an event (via multicast to a protocol specific group). - Creates a new scsi_netlink_fc.h file, which contains the FC netlink event messages - Adds 3 new routines to the fc transport: fc_get_event_number() - to get a FC event # fc_host_post_event() - to send a simple FC event (32 bits of data) fc_host_post_vendor_event() - to send a Vendor unique event, with arbitrary amounts of data. Note: the separation of event number allows for a LLD to send a standard event, followed by vendor-specific data for the event. Note: This patch assumes 2 prior fc transport patches have been installed: http://marc.theaimsgroup.com/?l=linux-scsi&m=115555807316329&w=2 http://marc.theaimsgroup.com/?l=linux-scsi&m=115581614930261&w=2 Sorry - next time I'll do something like making these individual patches of the same posting when I know they'll be posted closely together. Signed-off-by: James Smart <James.Smart@emulex.com> Tidy up configuration not to make SCSI always select NET Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2006-08-18 21:30:09 +00:00
scsi_netlink_init();
printk(KERN_NOTICE "SCSI subsystem initialized\n");
return 0;
cleanup_sysctl:
scsi_exit_sysctl();
cleanup_hosts:
scsi_exit_hosts();
cleanup_devlist:
scsi_exit_devinfo();
cleanup_procfs:
scsi_exit_procfs();
cleanup_queue:
scsi_exit_queue();
printk(KERN_ERR "SCSI subsystem failed to initialize, error = %d\n",
-error);
return error;
}
static void __exit exit_scsi(void)
{
[SCSI] SCSI and FC Transport: add netlink support for posting of transport events This patch formally adds support for the posting of FC events via netlink. It is a followup to the original RFC at: http://marc.theaimsgroup.com/?l=linux-scsi&m=114530667923464&w=2 and the initial posting at: http://marc.theaimsgroup.com/?l=linux-scsi&m=115507374832500&w=2 The patch has been updated to optimize the send path, per the discussions in the initial posting. Per discussions at the Storage Summit and at OLS, we are to use netlink for async events from transports. Also per discussions, to avoid a netlink protocol per transport, I've create a single NETLINK_SCSITRANSPORT protocol, which can then be used by all transports. This patch: - Creates new files scsi_netlink.c and scsi_netlink.h, which contains the single and shared definitions for the SCSI Transport. It is tied into the base SCSI subsystem intialization. Contains a single interface routine, scsi_send_transport_event(), for a transport to send an event (via multicast to a protocol specific group). - Creates a new scsi_netlink_fc.h file, which contains the FC netlink event messages - Adds 3 new routines to the fc transport: fc_get_event_number() - to get a FC event # fc_host_post_event() - to send a simple FC event (32 bits of data) fc_host_post_vendor_event() - to send a Vendor unique event, with arbitrary amounts of data. Note: the separation of event number allows for a LLD to send a standard event, followed by vendor-specific data for the event. Note: This patch assumes 2 prior fc transport patches have been installed: http://marc.theaimsgroup.com/?l=linux-scsi&m=115555807316329&w=2 http://marc.theaimsgroup.com/?l=linux-scsi&m=115581614930261&w=2 Sorry - next time I'll do something like making these individual patches of the same posting when I know they'll be posted closely together. Signed-off-by: James Smart <James.Smart@emulex.com> Tidy up configuration not to make SCSI always select NET Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2006-08-18 21:30:09 +00:00
scsi_netlink_exit();
scsi_sysfs_unregister();
scsi_exit_sysctl();
scsi_exit_hosts();
scsi_exit_devinfo();
scsi_exit_procfs();
scsi_exit_queue();
async_unregister_domain(&scsi_sd_probe_domain);
}
subsys_initcall(init_scsi);
module_exit(exit_scsi);