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libata-eh.c
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/*
* libata-eh.c - libata error handling
*
* Maintained by: Jeff Garzik <[email protected]>
* Please ALWAYS copy [email protected]
* on emails.
*
* Copyright 2006 Tejun Heo <[email protected]>
*
*
* 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, 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; see the file COPYING. If not, write to
* the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139,
* USA.
*
*
* libata documentation is available via 'make {ps|pdf}docs',
* as Documentation/DocBook/libata.*
*
* Hardware documentation available from http://www.t13.org/ and
* http://www.sata-io.org/
*
*/
#include <linux/kernel.h>
#include <linux/blkdev.h>
#include <linux/export.h>
#include <linux/pci.h>
#include <scsi/scsi.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_eh.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_dbg.h>
#include "../scsi/scsi_transport_api.h"
#include <linux/libata.h>
#include "libata.h"
enum {
/* speed down verdicts */
ATA_EH_SPDN_NCQ_OFF = (1 << 0),
ATA_EH_SPDN_SPEED_DOWN = (1 << 1),
ATA_EH_SPDN_FALLBACK_TO_PIO = (1 << 2),
ATA_EH_SPDN_KEEP_ERRORS = (1 << 3),
/* error flags */
ATA_EFLAG_IS_IO = (1 << 0),
ATA_EFLAG_DUBIOUS_XFER = (1 << 1),
ATA_EFLAG_OLD_ER = (1 << 31),
/* error categories */
ATA_ECAT_NONE = 0,
ATA_ECAT_ATA_BUS = 1,
ATA_ECAT_TOUT_HSM = 2,
ATA_ECAT_UNK_DEV = 3,
ATA_ECAT_DUBIOUS_NONE = 4,
ATA_ECAT_DUBIOUS_ATA_BUS = 5,
ATA_ECAT_DUBIOUS_TOUT_HSM = 6,
ATA_ECAT_DUBIOUS_UNK_DEV = 7,
ATA_ECAT_NR = 8,
ATA_EH_CMD_DFL_TIMEOUT = 5000,
/* always put at least this amount of time between resets */
ATA_EH_RESET_COOL_DOWN = 5000,
/* Waiting in ->prereset can never be reliable. It's
* sometimes nice to wait there but it can't be depended upon;
* otherwise, we wouldn't be resetting. Just give it enough
* time for most drives to spin up.
*/
ATA_EH_PRERESET_TIMEOUT = 10000,
ATA_EH_FASTDRAIN_INTERVAL = 3000,
ATA_EH_UA_TRIES = 5,
/* probe speed down parameters, see ata_eh_schedule_probe() */
ATA_EH_PROBE_TRIAL_INTERVAL = 60000, /* 1 min */
ATA_EH_PROBE_TRIALS = 2,
};
/* The following table determines how we sequence resets. Each entry
* represents timeout for that try. The first try can be soft or
* hardreset. All others are hardreset if available. In most cases
* the first reset w/ 10sec timeout should succeed. Following entries
* are mostly for error handling, hotplug and retarded devices.
*/
static const unsigned long ata_eh_reset_timeouts[] = {
10000, /* most drives spin up by 10sec */
10000, /* > 99% working drives spin up before 20sec */
35000, /* give > 30 secs of idleness for retarded devices */
5000, /* and sweet one last chance */
ULONG_MAX, /* > 1 min has elapsed, give up */
};
static const unsigned long ata_eh_identify_timeouts[] = {
5000, /* covers > 99% of successes and not too boring on failures */
10000, /* combined time till here is enough even for media access */
30000, /* for true idiots */
ULONG_MAX,
};
static const unsigned long ata_eh_flush_timeouts[] = {
15000, /* be generous with flush */
15000, /* ditto */
30000, /* and even more generous */
ULONG_MAX,
};
static const unsigned long ata_eh_other_timeouts[] = {
5000, /* same rationale as identify timeout */
10000, /* ditto */
/* but no merciful 30sec for other commands, it just isn't worth it */
ULONG_MAX,
};
struct ata_eh_cmd_timeout_ent {
const u8 *commands;
const unsigned long *timeouts;
};
/* The following table determines timeouts to use for EH internal
* commands. Each table entry is a command class and matches the
* commands the entry applies to and the timeout table to use.
*
* On the retry after a command timed out, the next timeout value from
* the table is used. If the table doesn't contain further entries,
* the last value is used.
*
* ehc->cmd_timeout_idx keeps track of which timeout to use per
* command class, so if SET_FEATURES times out on the first try, the
* next try will use the second timeout value only for that class.
*/
#define CMDS(cmds...) (const u8 []){ cmds, 0 }
static const struct ata_eh_cmd_timeout_ent
ata_eh_cmd_timeout_table[ATA_EH_CMD_TIMEOUT_TABLE_SIZE] = {
{ .commands = CMDS(ATA_CMD_ID_ATA, ATA_CMD_ID_ATAPI),
.timeouts = ata_eh_identify_timeouts, },
{ .commands = CMDS(ATA_CMD_READ_NATIVE_MAX, ATA_CMD_READ_NATIVE_MAX_EXT),
.timeouts = ata_eh_other_timeouts, },
{ .commands = CMDS(ATA_CMD_SET_MAX, ATA_CMD_SET_MAX_EXT),
.timeouts = ata_eh_other_timeouts, },
{ .commands = CMDS(ATA_CMD_SET_FEATURES),
.timeouts = ata_eh_other_timeouts, },
{ .commands = CMDS(ATA_CMD_INIT_DEV_PARAMS),
.timeouts = ata_eh_other_timeouts, },
{ .commands = CMDS(ATA_CMD_FLUSH, ATA_CMD_FLUSH_EXT),
.timeouts = ata_eh_flush_timeouts },
};
#undef CMDS
static void __ata_port_freeze(struct ata_port *ap);
#ifdef CONFIG_PM
static void ata_eh_handle_port_suspend(struct ata_port *ap);
static void ata_eh_handle_port_resume(struct ata_port *ap);
#else /* CONFIG_PM */
static void ata_eh_handle_port_suspend(struct ata_port *ap)
{ }
static void ata_eh_handle_port_resume(struct ata_port *ap)
{ }
#endif /* CONFIG_PM */
static void __ata_ehi_pushv_desc(struct ata_eh_info *ehi, const char *fmt,
va_list args)
{
ehi->desc_len += vscnprintf(ehi->desc + ehi->desc_len,
ATA_EH_DESC_LEN - ehi->desc_len,
fmt, args);
}
/**
* __ata_ehi_push_desc - push error description without adding separator
* @ehi: target EHI
* @fmt: printf format string
*
* Format string according to @fmt and append it to @ehi->desc.
*
* LOCKING:
* spin_lock_irqsave(host lock)
*/
void __ata_ehi_push_desc(struct ata_eh_info *ehi, const char *fmt, ...)
{
va_list args;
va_start(args, fmt);
__ata_ehi_pushv_desc(ehi, fmt, args);
va_end(args);
}
/**
* ata_ehi_push_desc - push error description with separator
* @ehi: target EHI
* @fmt: printf format string
*
* Format string according to @fmt and append it to @ehi->desc.
* If @ehi->desc is not empty, ", " is added in-between.
*
* LOCKING:
* spin_lock_irqsave(host lock)
*/
void ata_ehi_push_desc(struct ata_eh_info *ehi, const char *fmt, ...)
{
va_list args;
if (ehi->desc_len)
__ata_ehi_push_desc(ehi, ", ");
va_start(args, fmt);
__ata_ehi_pushv_desc(ehi, fmt, args);
va_end(args);
}
/**
* ata_ehi_clear_desc - clean error description
* @ehi: target EHI
*
* Clear @ehi->desc.
*
* LOCKING:
* spin_lock_irqsave(host lock)
*/
void ata_ehi_clear_desc(struct ata_eh_info *ehi)
{
ehi->desc[0] = '\0';
ehi->desc_len = 0;
}
/**
* ata_port_desc - append port description
* @ap: target ATA port
* @fmt: printf format string
*
* Format string according to @fmt and append it to port
* description. If port description is not empty, " " is added
* in-between. This function is to be used while initializing
* ata_host. The description is printed on host registration.
*
* LOCKING:
* None.
*/
void ata_port_desc(struct ata_port *ap, const char *fmt, ...)
{
va_list args;
WARN_ON(!(ap->pflags & ATA_PFLAG_INITIALIZING));
if (ap->link.eh_info.desc_len)
__ata_ehi_push_desc(&ap->link.eh_info, " ");
va_start(args, fmt);
__ata_ehi_pushv_desc(&ap->link.eh_info, fmt, args);
va_end(args);
}
#ifdef CONFIG_PCI
/**
* ata_port_pbar_desc - append PCI BAR description
* @ap: target ATA port
* @bar: target PCI BAR
* @offset: offset into PCI BAR
* @name: name of the area
*
* If @offset is negative, this function formats a string which
* contains the name, address, size and type of the BAR and
* appends it to the port description. If @offset is zero or
* positive, only name and offsetted address is appended.
*
* LOCKING:
* None.
*/
void ata_port_pbar_desc(struct ata_port *ap, int bar, ssize_t offset,
const char *name)
{
struct pci_dev *pdev = to_pci_dev(ap->host->dev);
char *type = "";
unsigned long long start, len;
if (pci_resource_flags(pdev, bar) & IORESOURCE_MEM)
type = "m";
else if (pci_resource_flags(pdev, bar) & IORESOURCE_IO)
type = "i";
start = (unsigned long long)pci_resource_start(pdev, bar);
len = (unsigned long long)pci_resource_len(pdev, bar);
if (offset < 0)
ata_port_desc(ap, "%s %s%llu@0x%llx", name, type, len, start);
else
ata_port_desc(ap, "%s 0x%llx", name,
start + (unsigned long long)offset);
}
#endif /* CONFIG_PCI */
static int ata_lookup_timeout_table(u8 cmd)
{
int i;
for (i = 0; i < ATA_EH_CMD_TIMEOUT_TABLE_SIZE; i++) {
const u8 *cur;
for (cur = ata_eh_cmd_timeout_table[i].commands; *cur; cur++)
if (*cur == cmd)
return i;
}
return -1;
}
/**
* ata_internal_cmd_timeout - determine timeout for an internal command
* @dev: target device
* @cmd: internal command to be issued
*
* Determine timeout for internal command @cmd for @dev.
*
* LOCKING:
* EH context.
*
* RETURNS:
* Determined timeout.
*/
unsigned long ata_internal_cmd_timeout(struct ata_device *dev, u8 cmd)
{
struct ata_eh_context *ehc = &dev->link->eh_context;
int ent = ata_lookup_timeout_table(cmd);
int idx;
if (ent < 0)
return ATA_EH_CMD_DFL_TIMEOUT;
idx = ehc->cmd_timeout_idx[dev->devno][ent];
return ata_eh_cmd_timeout_table[ent].timeouts[idx];
}
/**
* ata_internal_cmd_timed_out - notification for internal command timeout
* @dev: target device
* @cmd: internal command which timed out
*
* Notify EH that internal command @cmd for @dev timed out. This
* function should be called only for commands whose timeouts are
* determined using ata_internal_cmd_timeout().
*
* LOCKING:
* EH context.
*/
void ata_internal_cmd_timed_out(struct ata_device *dev, u8 cmd)
{
struct ata_eh_context *ehc = &dev->link->eh_context;
int ent = ata_lookup_timeout_table(cmd);
int idx;
if (ent < 0)
return;
idx = ehc->cmd_timeout_idx[dev->devno][ent];
if (ata_eh_cmd_timeout_table[ent].timeouts[idx + 1] != ULONG_MAX)
ehc->cmd_timeout_idx[dev->devno][ent]++;
}
static void ata_ering_record(struct ata_ering *ering, unsigned int eflags,
unsigned int err_mask)
{
struct ata_ering_entry *ent;
WARN_ON(!err_mask);
ering->cursor++;
ering->cursor %= ATA_ERING_SIZE;
ent = &ering->ring[ering->cursor];
ent->eflags = eflags;
ent->err_mask = err_mask;
ent->timestamp = get_jiffies_64();
}
static struct ata_ering_entry *ata_ering_top(struct ata_ering *ering)
{
struct ata_ering_entry *ent = &ering->ring[ering->cursor];
if (ent->err_mask)
return ent;
return NULL;
}
int ata_ering_map(struct ata_ering *ering,
int (*map_fn)(struct ata_ering_entry *, void *),
void *arg)
{
int idx, rc = 0;
struct ata_ering_entry *ent;
idx = ering->cursor;
do {
ent = &ering->ring[idx];
if (!ent->err_mask)
break;
rc = map_fn(ent, arg);
if (rc)
break;
idx = (idx - 1 + ATA_ERING_SIZE) % ATA_ERING_SIZE;
} while (idx != ering->cursor);
return rc;
}
static int ata_ering_clear_cb(struct ata_ering_entry *ent, void *void_arg)
{
ent->eflags |= ATA_EFLAG_OLD_ER;
return 0;
}
static void ata_ering_clear(struct ata_ering *ering)
{
ata_ering_map(ering, ata_ering_clear_cb, NULL);
}
static unsigned int ata_eh_dev_action(struct ata_device *dev)
{
struct ata_eh_context *ehc = &dev->link->eh_context;
return ehc->i.action | ehc->i.dev_action[dev->devno];
}
static void ata_eh_clear_action(struct ata_link *link, struct ata_device *dev,
struct ata_eh_info *ehi, unsigned int action)
{
struct ata_device *tdev;
if (!dev) {
ehi->action &= ~action;
ata_for_each_dev(tdev, link, ALL)
ehi->dev_action[tdev->devno] &= ~action;
} else {
/* doesn't make sense for port-wide EH actions */
WARN_ON(!(action & ATA_EH_PERDEV_MASK));
/* break ehi->action into ehi->dev_action */
if (ehi->action & action) {
ata_for_each_dev(tdev, link, ALL)
ehi->dev_action[tdev->devno] |=
ehi->action & action;
ehi->action &= ~action;
}
/* turn off the specified per-dev action */
ehi->dev_action[dev->devno] &= ~action;
}
}
/**
* ata_eh_acquire - acquire EH ownership
* @ap: ATA port to acquire EH ownership for
*
* Acquire EH ownership for @ap. This is the basic exclusion
* mechanism for ports sharing a host. Only one port hanging off
* the same host can claim the ownership of EH.
*
* LOCKING:
* EH context.
*/
void ata_eh_acquire(struct ata_port *ap)
{
mutex_lock(&ap->host->eh_mutex);
WARN_ON_ONCE(ap->host->eh_owner);
ap->host->eh_owner = current;
}
/**
* ata_eh_release - release EH ownership
* @ap: ATA port to release EH ownership for
*
* Release EH ownership for @ap if the caller. The caller must
* have acquired EH ownership using ata_eh_acquire() previously.
*
* LOCKING:
* EH context.
*/
void ata_eh_release(struct ata_port *ap)
{
WARN_ON_ONCE(ap->host->eh_owner != current);
ap->host->eh_owner = NULL;
mutex_unlock(&ap->host->eh_mutex);
}
/**
* ata_scsi_timed_out - SCSI layer time out callback
* @cmd: timed out SCSI command
*
* Handles SCSI layer timeout. We race with normal completion of
* the qc for @cmd. If the qc is already gone, we lose and let
* the scsi command finish (EH_HANDLED). Otherwise, the qc has
* timed out and EH should be invoked. Prevent ata_qc_complete()
* from finishing it by setting EH_SCHEDULED and return
* EH_NOT_HANDLED.
*
* TODO: kill this function once old EH is gone.
*
* LOCKING:
* Called from timer context
*
* RETURNS:
* EH_HANDLED or EH_NOT_HANDLED
*/
enum blk_eh_timer_return ata_scsi_timed_out(struct scsi_cmnd *cmd)
{
struct Scsi_Host *host = cmd->device->host;
struct ata_port *ap = ata_shost_to_port(host);
unsigned long flags;
struct ata_queued_cmd *qc;
enum blk_eh_timer_return ret;
DPRINTK("ENTER\n");
if (ap->ops->error_handler) {
ret = BLK_EH_NOT_HANDLED;
goto out;
}
ret = BLK_EH_HANDLED;
spin_lock_irqsave(ap->lock, flags);
qc = ata_qc_from_tag(ap, ap->link.active_tag);
if (qc) {
WARN_ON(qc->scsicmd != cmd);
qc->flags |= ATA_QCFLAG_EH_SCHEDULED;
qc->err_mask |= AC_ERR_TIMEOUT;
ret = BLK_EH_NOT_HANDLED;
}
spin_unlock_irqrestore(ap->lock, flags);
out:
DPRINTK("EXIT, ret=%d\n", ret);
return ret;
}
static void ata_eh_unload(struct ata_port *ap)
{
struct ata_link *link;
struct ata_device *dev;
unsigned long flags;
/* Restore SControl IPM and SPD for the next driver and
* disable attached devices.
*/
ata_for_each_link(link, ap, PMP_FIRST) {
sata_scr_write(link, SCR_CONTROL, link->saved_scontrol & 0xff0);
ata_for_each_dev(dev, link, ALL)
ata_dev_disable(dev);
}
/* freeze and set UNLOADED */
spin_lock_irqsave(ap->lock, flags);
ata_port_freeze(ap); /* won't be thawed */
ap->pflags &= ~ATA_PFLAG_EH_PENDING; /* clear pending from freeze */
ap->pflags |= ATA_PFLAG_UNLOADED;
spin_unlock_irqrestore(ap->lock, flags);
}
/**
* ata_scsi_error - SCSI layer error handler callback
* @host: SCSI host on which error occurred
*
* Handles SCSI-layer-thrown error events.
*
* LOCKING:
* Inherited from SCSI layer (none, can sleep)
*
* RETURNS:
* Zero.
*/
void ata_scsi_error(struct Scsi_Host *host)
{
struct ata_port *ap = ata_shost_to_port(host);
unsigned long flags;
LIST_HEAD(eh_work_q);
DPRINTK("ENTER\n");
spin_lock_irqsave(host->host_lock, flags);
list_splice_init(&host->eh_cmd_q, &eh_work_q);
spin_unlock_irqrestore(host->host_lock, flags);
ata_scsi_cmd_error_handler(host, ap, &eh_work_q);
/* If we timed raced normal completion and there is nothing to
recover nr_timedout == 0 why exactly are we doing error recovery ? */
ata_scsi_port_error_handler(host, ap);
/* finish or retry handled scmd's and clean up */
WARN_ON(host->host_failed || !list_empty(&eh_work_q));
DPRINTK("EXIT\n");
}
/**
* ata_scsi_cmd_error_handler - error callback for a list of commands
* @host: scsi host containing the port
* @ap: ATA port within the host
* @eh_work_q: list of commands to process
*
* process the given list of commands and return those finished to the
* ap->eh_done_q. This function is the first part of the libata error
* handler which processes a given list of failed commands.
*/
void ata_scsi_cmd_error_handler(struct Scsi_Host *host, struct ata_port *ap,
struct list_head *eh_work_q)
{
int i;
unsigned long flags;
/* make sure sff pio task is not running */
ata_sff_flush_pio_task(ap);
/* synchronize with host lock and sort out timeouts */
/* For new EH, all qcs are finished in one of three ways -
* normal completion, error completion, and SCSI timeout.
* Both completions can race against SCSI timeout. When normal
* completion wins, the qc never reaches EH. When error
* completion wins, the qc has ATA_QCFLAG_FAILED set.
*
* When SCSI timeout wins, things are a bit more complex.
* Normal or error completion can occur after the timeout but
* before this point. In such cases, both types of
* completions are honored. A scmd is determined to have
* timed out iff its associated qc is active and not failed.
*/
if (ap->ops->error_handler) {
struct scsi_cmnd *scmd, *tmp;
int nr_timedout = 0;
spin_lock_irqsave(ap->lock, flags);
/* This must occur under the ap->lock as we don't want
a polled recovery to race the real interrupt handler
The lost_interrupt handler checks for any completed but
non-notified command and completes much like an IRQ handler.
We then fall into the error recovery code which will treat
this as if normal completion won the race */
if (ap->ops->lost_interrupt)
ap->ops->lost_interrupt(ap);
list_for_each_entry_safe(scmd, tmp, eh_work_q, eh_entry) {
struct ata_queued_cmd *qc;
for (i = 0; i < ATA_MAX_QUEUE; i++) {
qc = __ata_qc_from_tag(ap, i);
if (qc->flags & ATA_QCFLAG_ACTIVE &&
qc->scsicmd == scmd)
break;
}
if (i < ATA_MAX_QUEUE) {
/* the scmd has an associated qc */
if (!(qc->flags & ATA_QCFLAG_FAILED)) {
/* which hasn't failed yet, timeout */
qc->err_mask |= AC_ERR_TIMEOUT;
qc->flags |= ATA_QCFLAG_FAILED;
nr_timedout++;
}
} else {
/* Normal completion occurred after
* SCSI timeout but before this point.
* Successfully complete it.
*/
scmd->retries = scmd->allowed;
scsi_eh_finish_cmd(scmd, &ap->eh_done_q);
}
}
/* If we have timed out qcs. They belong to EH from
* this point but the state of the controller is
* unknown. Freeze the port to make sure the IRQ
* handler doesn't diddle with those qcs. This must
* be done atomically w.r.t. setting QCFLAG_FAILED.
*/
if (nr_timedout)
__ata_port_freeze(ap);
spin_unlock_irqrestore(ap->lock, flags);
/* initialize eh_tries */
ap->eh_tries = ATA_EH_MAX_TRIES;
} else
spin_unlock_wait(ap->lock);
}
EXPORT_SYMBOL(ata_scsi_cmd_error_handler);
/**
* ata_scsi_port_error_handler - recover the port after the commands
* @host: SCSI host containing the port
* @ap: the ATA port
*
* Handle the recovery of the port @ap after all the commands
* have been recovered.
*/
void ata_scsi_port_error_handler(struct Scsi_Host *host, struct ata_port *ap)
{
unsigned long flags;
/* invoke error handler */
if (ap->ops->error_handler) {
struct ata_link *link;
/* acquire EH ownership */
ata_eh_acquire(ap);
repeat:
/* kill fast drain timer */
del_timer_sync(&ap->fastdrain_timer);
/* process port resume request */
ata_eh_handle_port_resume(ap);
/* fetch & clear EH info */
spin_lock_irqsave(ap->lock, flags);
ata_for_each_link(link, ap, HOST_FIRST) {
struct ata_eh_context *ehc = &link->eh_context;
struct ata_device *dev;
memset(&link->eh_context, 0, sizeof(link->eh_context));
link->eh_context.i = link->eh_info;
memset(&link->eh_info, 0, sizeof(link->eh_info));
ata_for_each_dev(dev, link, ENABLED) {
int devno = dev->devno;
ehc->saved_xfer_mode[devno] = dev->xfer_mode;
if (ata_ncq_enabled(dev))
ehc->saved_ncq_enabled |= 1 << devno;
}
}
ap->pflags |= ATA_PFLAG_EH_IN_PROGRESS;
ap->pflags &= ~ATA_PFLAG_EH_PENDING;
ap->excl_link = NULL; /* don't maintain exclusion over EH */
spin_unlock_irqrestore(ap->lock, flags);
/* invoke EH, skip if unloading or suspended */
if (!(ap->pflags & (ATA_PFLAG_UNLOADING | ATA_PFLAG_SUSPENDED)))
ap->ops->error_handler(ap);
else {
/* if unloading, commence suicide */
if ((ap->pflags & ATA_PFLAG_UNLOADING) &&
!(ap->pflags & ATA_PFLAG_UNLOADED))
ata_eh_unload(ap);
ata_eh_finish(ap);
}
/* process port suspend request */
ata_eh_handle_port_suspend(ap);
/* Exception might have happened after ->error_handler
* recovered the port but before this point. Repeat
* EH in such case.
*/
spin_lock_irqsave(ap->lock, flags);
if (ap->pflags & ATA_PFLAG_EH_PENDING) {
if (--ap->eh_tries) {
spin_unlock_irqrestore(ap->lock, flags);
goto repeat;
}
ata_port_err(ap,
"EH pending after %d tries, giving up\n",
ATA_EH_MAX_TRIES);
ap->pflags &= ~ATA_PFLAG_EH_PENDING;
}
/* this run is complete, make sure EH info is clear */
ata_for_each_link(link, ap, HOST_FIRST)
memset(&link->eh_info, 0, sizeof(link->eh_info));
/* end eh (clear host_eh_scheduled) while holding
* ap->lock such that if exception occurs after this
* point but before EH completion, SCSI midlayer will
* re-initiate EH.
*/
ap->ops->end_eh(ap);
spin_unlock_irqrestore(ap->lock, flags);
ata_eh_release(ap);
} else {
WARN_ON(ata_qc_from_tag(ap, ap->link.active_tag) == NULL);
ap->ops->eng_timeout(ap);
}
scsi_eh_flush_done_q(&ap->eh_done_q);
/* clean up */
spin_lock_irqsave(ap->lock, flags);
if (ap->pflags & ATA_PFLAG_LOADING)
ap->pflags &= ~ATA_PFLAG_LOADING;
else if (ap->pflags & ATA_PFLAG_SCSI_HOTPLUG)
schedule_delayed_work(&ap->hotplug_task, 0);
if (ap->pflags & ATA_PFLAG_RECOVERED)
ata_port_info(ap, "EH complete\n");
ap->pflags &= ~(ATA_PFLAG_SCSI_HOTPLUG | ATA_PFLAG_RECOVERED);
/* tell wait_eh that we're done */
ap->pflags &= ~ATA_PFLAG_EH_IN_PROGRESS;
wake_up_all(&ap->eh_wait_q);
spin_unlock_irqrestore(ap->lock, flags);
}
EXPORT_SYMBOL_GPL(ata_scsi_port_error_handler);
/**
* ata_port_wait_eh - Wait for the currently pending EH to complete
* @ap: Port to wait EH for
*
* Wait until the currently pending EH is complete.
*
* LOCKING:
* Kernel thread context (may sleep).
*/
void ata_port_wait_eh(struct ata_port *ap)
{
unsigned long flags;
DEFINE_WAIT(wait);
retry:
spin_lock_irqsave(ap->lock, flags);
while (ap->pflags & (ATA_PFLAG_EH_PENDING | ATA_PFLAG_EH_IN_PROGRESS)) {
prepare_to_wait(&ap->eh_wait_q, &wait, TASK_UNINTERRUPTIBLE);
spin_unlock_irqrestore(ap->lock, flags);
schedule();
spin_lock_irqsave(ap->lock, flags);
}
finish_wait(&ap->eh_wait_q, &wait);
spin_unlock_irqrestore(ap->lock, flags);
/* make sure SCSI EH is complete */
if (scsi_host_in_recovery(ap->scsi_host)) {
ata_msleep(ap, 10);
goto retry;
}
}
EXPORT_SYMBOL_GPL(ata_port_wait_eh);
static int ata_eh_nr_in_flight(struct ata_port *ap)
{
unsigned int tag;
int nr = 0;
/* count only non-internal commands */
for (tag = 0; tag < ATA_MAX_QUEUE - 1; tag++)
if (ata_qc_from_tag(ap, tag))
nr++;
return nr;
}
void ata_eh_fastdrain_timerfn(unsigned long arg)
{
struct ata_port *ap = (void *)arg;
unsigned long flags;
int cnt;
spin_lock_irqsave(ap->lock, flags);
cnt = ata_eh_nr_in_flight(ap);
/* are we done? */
if (!cnt)
goto out_unlock;
if (cnt == ap->fastdrain_cnt) {
unsigned int tag;
/* No progress during the last interval, tag all
* in-flight qcs as timed out and freeze the port.
*/
for (tag = 0; tag < ATA_MAX_QUEUE - 1; tag++) {
struct ata_queued_cmd *qc = ata_qc_from_tag(ap, tag);
if (qc)
qc->err_mask |= AC_ERR_TIMEOUT;
}
ata_port_freeze(ap);
} else {
/* some qcs have finished, give it another chance */
ap->fastdrain_cnt = cnt;
ap->fastdrain_timer.expires =
ata_deadline(jiffies, ATA_EH_FASTDRAIN_INTERVAL);
add_timer(&ap->fastdrain_timer);
}
out_unlock:
spin_unlock_irqrestore(ap->lock, flags);
}
/**
* ata_eh_set_pending - set ATA_PFLAG_EH_PENDING and activate fast drain
* @ap: target ATA port
* @fastdrain: activate fast drain
*
* Set ATA_PFLAG_EH_PENDING and activate fast drain if @fastdrain
* is non-zero and EH wasn't pending before. Fast drain ensures
* that EH kicks in in timely manner.
*
* LOCKING:
* spin_lock_irqsave(host lock)
*/
static void ata_eh_set_pending(struct ata_port *ap, int fastdrain)
{
int cnt;
/* already scheduled? */
if (ap->pflags & ATA_PFLAG_EH_PENDING)
return;
ap->pflags |= ATA_PFLAG_EH_PENDING;
if (!fastdrain)
return;
/* do we have in-flight qcs? */
cnt = ata_eh_nr_in_flight(ap);
if (!cnt)
return;
/* activate fast drain */
ap->fastdrain_cnt = cnt;
ap->fastdrain_timer.expires =
ata_deadline(jiffies, ATA_EH_FASTDRAIN_INTERVAL);
add_timer(&ap->fastdrain_timer);
}
/**
* ata_qc_schedule_eh - schedule qc for error handling
* @qc: command to schedule error handling for
*
* Schedule error handling for @qc. EH will kick in as soon as
* other commands are drained.
*
* LOCKING:
* spin_lock_irqsave(host lock)
*/
void ata_qc_schedule_eh(struct ata_queued_cmd *qc)
{
struct ata_port *ap = qc->ap;
struct request_queue *q = qc->scsicmd->device->request_queue;
unsigned long flags;
WARN_ON(!ap->ops->error_handler);
qc->flags |= ATA_QCFLAG_FAILED;
ata_eh_set_pending(ap, 1);
/* The following will fail if timeout has already expired.
* ata_scsi_error() takes care of such scmds on EH entry.
* Note that ATA_QCFLAG_FAILED is unconditionally set after
* this function completes.
*/
spin_lock_irqsave(q->queue_lock, flags);
blk_abort_request(qc->scsicmd->request);
spin_unlock_irqrestore(q->queue_lock, flags);
}
/**
* ata_std_sched_eh - non-libsas ata_ports issue eh with this common routine
* @ap: ATA port to schedule EH for
*
* LOCKING: inherited from ata_port_schedule_eh
* spin_lock_irqsave(host lock)
*/
void ata_std_sched_eh(struct ata_port *ap)
{
WARN_ON(!ap->ops->error_handler);
if (ap->pflags & ATA_PFLAG_INITIALIZING)
return;