linux/fs/xfs/xfs_sysfs.c
Brian Foster 9dbddd7b0c xfs: resurrect debug mode drop buffered writes mechanism
A debug mode write failure mechanism was introduced to XFS in commit
801cc4e17a ("xfs: debug mode forced buffered write failure") to
facilitate targeted testing of delalloc indirect reservation management
from userspace. This code was subsequently rendered ineffective by the
move to iomap based buffered writes in commit 68a9f5e700 ("xfs:
implement iomap based buffered write path"). This likely went unnoticed
because the associated userspace code had not made it into xfstests.

Resurrect this mechanism to facilitate effective indlen reservation
testing from xfstests. The move to iomap based buffered writes relocated
the hook this mechanism needs to return write failure from XFS to
generic code. The failure trigger must remain in XFS. Given that
limitation, convert this from a write failure mechanism to one that
simply drops writes without returning failure to userspace. Rename all
"fail_writes" references to "drop_writes" to illustrate the point. This
is more hacky than preferred, but still triggers the XFS error handling
behavior required to drive the indlen tests. This is only available in
DEBUG mode and for testing purposes only.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-02-16 17:19:15 -08:00

680 lines
14 KiB
C

/*
* Copyright (c) 2014 Red Hat, Inc.
* All Rights Reserved.
*
* 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.
*
* This program is distributed in the hope that it would be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "xfs.h"
#include "xfs_shared.h"
#include "xfs_format.h"
#include "xfs_log_format.h"
#include "xfs_trans_resv.h"
#include "xfs_sysfs.h"
#include "xfs_log.h"
#include "xfs_log_priv.h"
#include "xfs_stats.h"
#include "xfs_mount.h"
struct xfs_sysfs_attr {
struct attribute attr;
ssize_t (*show)(struct kobject *kobject, char *buf);
ssize_t (*store)(struct kobject *kobject, const char *buf,
size_t count);
};
static inline struct xfs_sysfs_attr *
to_attr(struct attribute *attr)
{
return container_of(attr, struct xfs_sysfs_attr, attr);
}
#define XFS_SYSFS_ATTR_RW(name) \
static struct xfs_sysfs_attr xfs_sysfs_attr_##name = __ATTR_RW(name)
#define XFS_SYSFS_ATTR_RO(name) \
static struct xfs_sysfs_attr xfs_sysfs_attr_##name = __ATTR_RO(name)
#define XFS_SYSFS_ATTR_WO(name) \
static struct xfs_sysfs_attr xfs_sysfs_attr_##name = __ATTR_WO(name)
#define ATTR_LIST(name) &xfs_sysfs_attr_##name.attr
STATIC ssize_t
xfs_sysfs_object_show(
struct kobject *kobject,
struct attribute *attr,
char *buf)
{
struct xfs_sysfs_attr *xfs_attr = to_attr(attr);
return xfs_attr->show ? xfs_attr->show(kobject, buf) : 0;
}
STATIC ssize_t
xfs_sysfs_object_store(
struct kobject *kobject,
struct attribute *attr,
const char *buf,
size_t count)
{
struct xfs_sysfs_attr *xfs_attr = to_attr(attr);
return xfs_attr->store ? xfs_attr->store(kobject, buf, count) : 0;
}
static const struct sysfs_ops xfs_sysfs_ops = {
.show = xfs_sysfs_object_show,
.store = xfs_sysfs_object_store,
};
/*
* xfs_mount kobject. The mp kobject also serves as the per-mount parent object
* that is identified by the fsname under sysfs.
*/
static inline struct xfs_mount *
to_mp(struct kobject *kobject)
{
struct xfs_kobj *kobj = to_kobj(kobject);
return container_of(kobj, struct xfs_mount, m_kobj);
}
#ifdef DEBUG
STATIC ssize_t
drop_writes_store(
struct kobject *kobject,
const char *buf,
size_t count)
{
struct xfs_mount *mp = to_mp(kobject);
int ret;
int val;
ret = kstrtoint(buf, 0, &val);
if (ret)
return ret;
if (val == 1)
mp->m_drop_writes = true;
else if (val == 0)
mp->m_drop_writes = false;
else
return -EINVAL;
return count;
}
STATIC ssize_t
drop_writes_show(
struct kobject *kobject,
char *buf)
{
struct xfs_mount *mp = to_mp(kobject);
return snprintf(buf, PAGE_SIZE, "%d\n", mp->m_drop_writes ? 1 : 0);
}
XFS_SYSFS_ATTR_RW(drop_writes);
#endif /* DEBUG */
static struct attribute *xfs_mp_attrs[] = {
#ifdef DEBUG
ATTR_LIST(drop_writes),
#endif
NULL,
};
struct kobj_type xfs_mp_ktype = {
.release = xfs_sysfs_release,
.sysfs_ops = &xfs_sysfs_ops,
.default_attrs = xfs_mp_attrs,
};
#ifdef DEBUG
/* debug */
STATIC ssize_t
log_recovery_delay_store(
struct kobject *kobject,
const char *buf,
size_t count)
{
int ret;
int val;
ret = kstrtoint(buf, 0, &val);
if (ret)
return ret;
if (val < 0 || val > 60)
return -EINVAL;
xfs_globals.log_recovery_delay = val;
return count;
}
STATIC ssize_t
log_recovery_delay_show(
struct kobject *kobject,
char *buf)
{
return snprintf(buf, PAGE_SIZE, "%d\n", xfs_globals.log_recovery_delay);
}
XFS_SYSFS_ATTR_RW(log_recovery_delay);
static struct attribute *xfs_dbg_attrs[] = {
ATTR_LIST(log_recovery_delay),
NULL,
};
struct kobj_type xfs_dbg_ktype = {
.release = xfs_sysfs_release,
.sysfs_ops = &xfs_sysfs_ops,
.default_attrs = xfs_dbg_attrs,
};
#endif /* DEBUG */
/* stats */
static inline struct xstats *
to_xstats(struct kobject *kobject)
{
struct xfs_kobj *kobj = to_kobj(kobject);
return container_of(kobj, struct xstats, xs_kobj);
}
STATIC ssize_t
stats_show(
struct kobject *kobject,
char *buf)
{
struct xstats *stats = to_xstats(kobject);
return xfs_stats_format(stats->xs_stats, buf);
}
XFS_SYSFS_ATTR_RO(stats);
STATIC ssize_t
stats_clear_store(
struct kobject *kobject,
const char *buf,
size_t count)
{
int ret;
int val;
struct xstats *stats = to_xstats(kobject);
ret = kstrtoint(buf, 0, &val);
if (ret)
return ret;
if (val != 1)
return -EINVAL;
xfs_stats_clearall(stats->xs_stats);
return count;
}
XFS_SYSFS_ATTR_WO(stats_clear);
static struct attribute *xfs_stats_attrs[] = {
ATTR_LIST(stats),
ATTR_LIST(stats_clear),
NULL,
};
struct kobj_type xfs_stats_ktype = {
.release = xfs_sysfs_release,
.sysfs_ops = &xfs_sysfs_ops,
.default_attrs = xfs_stats_attrs,
};
/* xlog */
static inline struct xlog *
to_xlog(struct kobject *kobject)
{
struct xfs_kobj *kobj = to_kobj(kobject);
return container_of(kobj, struct xlog, l_kobj);
}
STATIC ssize_t
log_head_lsn_show(
struct kobject *kobject,
char *buf)
{
int cycle;
int block;
struct xlog *log = to_xlog(kobject);
spin_lock(&log->l_icloglock);
cycle = log->l_curr_cycle;
block = log->l_curr_block;
spin_unlock(&log->l_icloglock);
return snprintf(buf, PAGE_SIZE, "%d:%d\n", cycle, block);
}
XFS_SYSFS_ATTR_RO(log_head_lsn);
STATIC ssize_t
log_tail_lsn_show(
struct kobject *kobject,
char *buf)
{
int cycle;
int block;
struct xlog *log = to_xlog(kobject);
xlog_crack_atomic_lsn(&log->l_tail_lsn, &cycle, &block);
return snprintf(buf, PAGE_SIZE, "%d:%d\n", cycle, block);
}
XFS_SYSFS_ATTR_RO(log_tail_lsn);
STATIC ssize_t
reserve_grant_head_show(
struct kobject *kobject,
char *buf)
{
int cycle;
int bytes;
struct xlog *log = to_xlog(kobject);
xlog_crack_grant_head(&log->l_reserve_head.grant, &cycle, &bytes);
return snprintf(buf, PAGE_SIZE, "%d:%d\n", cycle, bytes);
}
XFS_SYSFS_ATTR_RO(reserve_grant_head);
STATIC ssize_t
write_grant_head_show(
struct kobject *kobject,
char *buf)
{
int cycle;
int bytes;
struct xlog *log = to_xlog(kobject);
xlog_crack_grant_head(&log->l_write_head.grant, &cycle, &bytes);
return snprintf(buf, PAGE_SIZE, "%d:%d\n", cycle, bytes);
}
XFS_SYSFS_ATTR_RO(write_grant_head);
#ifdef DEBUG
STATIC ssize_t
log_badcrc_factor_store(
struct kobject *kobject,
const char *buf,
size_t count)
{
struct xlog *log = to_xlog(kobject);
int ret;
uint32_t val;
ret = kstrtouint(buf, 0, &val);
if (ret)
return ret;
log->l_badcrc_factor = val;
return count;
}
STATIC ssize_t
log_badcrc_factor_show(
struct kobject *kobject,
char *buf)
{
struct xlog *log = to_xlog(kobject);
return snprintf(buf, PAGE_SIZE, "%d\n", log->l_badcrc_factor);
}
XFS_SYSFS_ATTR_RW(log_badcrc_factor);
#endif /* DEBUG */
static struct attribute *xfs_log_attrs[] = {
ATTR_LIST(log_head_lsn),
ATTR_LIST(log_tail_lsn),
ATTR_LIST(reserve_grant_head),
ATTR_LIST(write_grant_head),
#ifdef DEBUG
ATTR_LIST(log_badcrc_factor),
#endif
NULL,
};
struct kobj_type xfs_log_ktype = {
.release = xfs_sysfs_release,
.sysfs_ops = &xfs_sysfs_ops,
.default_attrs = xfs_log_attrs,
};
/*
* Metadata IO error configuration
*
* The sysfs structure here is:
* ...xfs/<dev>/error/<class>/<errno>/<error_attrs>
*
* where <class> allows us to discriminate between data IO and metadata IO,
* and any other future type of IO (e.g. special inode or directory error
* handling) we care to support.
*/
static inline struct xfs_error_cfg *
to_error_cfg(struct kobject *kobject)
{
struct xfs_kobj *kobj = to_kobj(kobject);
return container_of(kobj, struct xfs_error_cfg, kobj);
}
static inline struct xfs_mount *
err_to_mp(struct kobject *kobject)
{
struct xfs_kobj *kobj = to_kobj(kobject);
return container_of(kobj, struct xfs_mount, m_error_kobj);
}
static ssize_t
max_retries_show(
struct kobject *kobject,
char *buf)
{
int retries;
struct xfs_error_cfg *cfg = to_error_cfg(kobject);
if (cfg->max_retries == XFS_ERR_RETRY_FOREVER)
retries = -1;
else
retries = cfg->max_retries;
return snprintf(buf, PAGE_SIZE, "%d\n", retries);
}
static ssize_t
max_retries_store(
struct kobject *kobject,
const char *buf,
size_t count)
{
struct xfs_error_cfg *cfg = to_error_cfg(kobject);
int ret;
int val;
ret = kstrtoint(buf, 0, &val);
if (ret)
return ret;
if (val < -1)
return -EINVAL;
if (val == -1)
cfg->max_retries = XFS_ERR_RETRY_FOREVER;
else
cfg->max_retries = val;
return count;
}
XFS_SYSFS_ATTR_RW(max_retries);
static ssize_t
retry_timeout_seconds_show(
struct kobject *kobject,
char *buf)
{
int timeout;
struct xfs_error_cfg *cfg = to_error_cfg(kobject);
if (cfg->retry_timeout == XFS_ERR_RETRY_FOREVER)
timeout = -1;
else
timeout = jiffies_to_msecs(cfg->retry_timeout) / MSEC_PER_SEC;
return snprintf(buf, PAGE_SIZE, "%d\n", timeout);
}
static ssize_t
retry_timeout_seconds_store(
struct kobject *kobject,
const char *buf,
size_t count)
{
struct xfs_error_cfg *cfg = to_error_cfg(kobject);
int ret;
int val;
ret = kstrtoint(buf, 0, &val);
if (ret)
return ret;
/* 1 day timeout maximum, -1 means infinite */
if (val < -1 || val > 86400)
return -EINVAL;
if (val == -1)
cfg->retry_timeout = XFS_ERR_RETRY_FOREVER;
else {
cfg->retry_timeout = msecs_to_jiffies(val * MSEC_PER_SEC);
ASSERT(msecs_to_jiffies(val * MSEC_PER_SEC) < LONG_MAX);
}
return count;
}
XFS_SYSFS_ATTR_RW(retry_timeout_seconds);
static ssize_t
fail_at_unmount_show(
struct kobject *kobject,
char *buf)
{
struct xfs_mount *mp = err_to_mp(kobject);
return snprintf(buf, PAGE_SIZE, "%d\n", mp->m_fail_unmount);
}
static ssize_t
fail_at_unmount_store(
struct kobject *kobject,
const char *buf,
size_t count)
{
struct xfs_mount *mp = err_to_mp(kobject);
int ret;
int val;
ret = kstrtoint(buf, 0, &val);
if (ret)
return ret;
if (val < 0 || val > 1)
return -EINVAL;
mp->m_fail_unmount = val;
return count;
}
XFS_SYSFS_ATTR_RW(fail_at_unmount);
static struct attribute *xfs_error_attrs[] = {
ATTR_LIST(max_retries),
ATTR_LIST(retry_timeout_seconds),
NULL,
};
static struct kobj_type xfs_error_cfg_ktype = {
.release = xfs_sysfs_release,
.sysfs_ops = &xfs_sysfs_ops,
.default_attrs = xfs_error_attrs,
};
static struct kobj_type xfs_error_ktype = {
.release = xfs_sysfs_release,
.sysfs_ops = &xfs_sysfs_ops,
};
/*
* Error initialization tables. These need to be ordered in the same
* order as the enums used to index the array. All class init tables need to
* define a "default" behaviour as the first entry, all other entries can be
* empty.
*/
struct xfs_error_init {
char *name;
int max_retries;
int retry_timeout; /* in seconds */
};
static const struct xfs_error_init xfs_error_meta_init[XFS_ERR_ERRNO_MAX] = {
{ .name = "default",
.max_retries = XFS_ERR_RETRY_FOREVER,
.retry_timeout = XFS_ERR_RETRY_FOREVER,
},
{ .name = "EIO",
.max_retries = XFS_ERR_RETRY_FOREVER,
.retry_timeout = XFS_ERR_RETRY_FOREVER,
},
{ .name = "ENOSPC",
.max_retries = XFS_ERR_RETRY_FOREVER,
.retry_timeout = XFS_ERR_RETRY_FOREVER,
},
{ .name = "ENODEV",
.max_retries = 0, /* We can't recover from devices disappearing */
.retry_timeout = 0,
},
};
static int
xfs_error_sysfs_init_class(
struct xfs_mount *mp,
int class,
const char *parent_name,
struct xfs_kobj *parent_kobj,
const struct xfs_error_init init[])
{
struct xfs_error_cfg *cfg;
int error;
int i;
ASSERT(class < XFS_ERR_CLASS_MAX);
error = xfs_sysfs_init(parent_kobj, &xfs_error_ktype,
&mp->m_error_kobj, parent_name);
if (error)
return error;
for (i = 0; i < XFS_ERR_ERRNO_MAX; i++) {
cfg = &mp->m_error_cfg[class][i];
error = xfs_sysfs_init(&cfg->kobj, &xfs_error_cfg_ktype,
parent_kobj, init[i].name);
if (error)
goto out_error;
cfg->max_retries = init[i].max_retries;
if (init[i].retry_timeout == XFS_ERR_RETRY_FOREVER)
cfg->retry_timeout = XFS_ERR_RETRY_FOREVER;
else
cfg->retry_timeout = msecs_to_jiffies(
init[i].retry_timeout * MSEC_PER_SEC);
}
return 0;
out_error:
/* unwind the entries that succeeded */
for (i--; i >= 0; i--) {
cfg = &mp->m_error_cfg[class][i];
xfs_sysfs_del(&cfg->kobj);
}
xfs_sysfs_del(parent_kobj);
return error;
}
int
xfs_error_sysfs_init(
struct xfs_mount *mp)
{
int error;
/* .../xfs/<dev>/error/ */
error = xfs_sysfs_init(&mp->m_error_kobj, &xfs_error_ktype,
&mp->m_kobj, "error");
if (error)
return error;
error = sysfs_create_file(&mp->m_error_kobj.kobject,
ATTR_LIST(fail_at_unmount));
if (error)
goto out_error;
/* .../xfs/<dev>/error/metadata/ */
error = xfs_error_sysfs_init_class(mp, XFS_ERR_METADATA,
"metadata", &mp->m_error_meta_kobj,
xfs_error_meta_init);
if (error)
goto out_error;
return 0;
out_error:
xfs_sysfs_del(&mp->m_error_kobj);
return error;
}
void
xfs_error_sysfs_del(
struct xfs_mount *mp)
{
struct xfs_error_cfg *cfg;
int i, j;
for (i = 0; i < XFS_ERR_CLASS_MAX; i++) {
for (j = 0; j < XFS_ERR_ERRNO_MAX; j++) {
cfg = &mp->m_error_cfg[i][j];
xfs_sysfs_del(&cfg->kobj);
}
}
xfs_sysfs_del(&mp->m_error_meta_kobj);
xfs_sysfs_del(&mp->m_error_kobj);
}
struct xfs_error_cfg *
xfs_error_get_cfg(
struct xfs_mount *mp,
int error_class,
int error)
{
struct xfs_error_cfg *cfg;
if (error < 0)
error = -error;
switch (error) {
case EIO:
cfg = &mp->m_error_cfg[error_class][XFS_ERR_EIO];
break;
case ENOSPC:
cfg = &mp->m_error_cfg[error_class][XFS_ERR_ENOSPC];
break;
case ENODEV:
cfg = &mp->m_error_cfg[error_class][XFS_ERR_ENODEV];
break;
default:
cfg = &mp->m_error_cfg[error_class][XFS_ERR_DEFAULT];
break;
}
return cfg;
}