linux/drivers/block/aoe/aoeblk.c
Ed Cashin fea1b13973 aoe: do not BUG if memory pressure prevented debugfs file creation
If the system has trouble allocating memory for the creation of the aoe
debugfs directory or of a file inside it, the debugfs member of an aoedev
can be NULL.

Do not treat a NULL debugfs pointer as a BUG on aoedev shutdown, avoiding
the user impact of an unecessary panic.

Signed-off-by: Ed Cashin <ecashin@coraid.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11 15:59:28 -07:00

465 lines
11 KiB
C

/* Copyright (c) 2013 Coraid, Inc. See COPYING for GPL terms. */
/*
* aoeblk.c
* block device routines
*/
#include <linux/kernel.h>
#include <linux/hdreg.h>
#include <linux/blkdev.h>
#include <linux/backing-dev.h>
#include <linux/fs.h>
#include <linux/ioctl.h>
#include <linux/slab.h>
#include <linux/ratelimit.h>
#include <linux/genhd.h>
#include <linux/netdevice.h>
#include <linux/mutex.h>
#include <linux/export.h>
#include <linux/moduleparam.h>
#include <linux/debugfs.h>
#include <scsi/sg.h>
#include "aoe.h"
static DEFINE_MUTEX(aoeblk_mutex);
static struct kmem_cache *buf_pool_cache;
static struct dentry *aoe_debugfs_dir;
/* GPFS needs a larger value than the default. */
static int aoe_maxsectors;
module_param(aoe_maxsectors, int, 0644);
MODULE_PARM_DESC(aoe_maxsectors,
"When nonzero, set the maximum number of sectors per I/O request");
static ssize_t aoedisk_show_state(struct device *dev,
struct device_attribute *attr, char *page)
{
struct gendisk *disk = dev_to_disk(dev);
struct aoedev *d = disk->private_data;
return snprintf(page, PAGE_SIZE,
"%s%s\n",
(d->flags & DEVFL_UP) ? "up" : "down",
(d->flags & DEVFL_KICKME) ? ",kickme" :
(d->nopen && !(d->flags & DEVFL_UP)) ? ",closewait" : "");
/* I'd rather see nopen exported so we can ditch closewait */
}
static ssize_t aoedisk_show_mac(struct device *dev,
struct device_attribute *attr, char *page)
{
struct gendisk *disk = dev_to_disk(dev);
struct aoedev *d = disk->private_data;
struct aoetgt *t = d->targets[0];
if (t == NULL)
return snprintf(page, PAGE_SIZE, "none\n");
return snprintf(page, PAGE_SIZE, "%pm\n", t->addr);
}
static ssize_t aoedisk_show_netif(struct device *dev,
struct device_attribute *attr, char *page)
{
struct gendisk *disk = dev_to_disk(dev);
struct aoedev *d = disk->private_data;
struct net_device *nds[8], **nd, **nnd, **ne;
struct aoetgt **t, **te;
struct aoeif *ifp, *e;
char *p;
memset(nds, 0, sizeof nds);
nd = nds;
ne = nd + ARRAY_SIZE(nds);
t = d->targets;
te = t + d->ntargets;
for (; t < te && *t; t++) {
ifp = (*t)->ifs;
e = ifp + NAOEIFS;
for (; ifp < e && ifp->nd; ifp++) {
for (nnd = nds; nnd < nd; nnd++)
if (*nnd == ifp->nd)
break;
if (nnd == nd && nd != ne)
*nd++ = ifp->nd;
}
}
ne = nd;
nd = nds;
if (*nd == NULL)
return snprintf(page, PAGE_SIZE, "none\n");
for (p = page; nd < ne; nd++)
p += snprintf(p, PAGE_SIZE - (p-page), "%s%s",
p == page ? "" : ",", (*nd)->name);
p += snprintf(p, PAGE_SIZE - (p-page), "\n");
return p-page;
}
/* firmware version */
static ssize_t aoedisk_show_fwver(struct device *dev,
struct device_attribute *attr, char *page)
{
struct gendisk *disk = dev_to_disk(dev);
struct aoedev *d = disk->private_data;
return snprintf(page, PAGE_SIZE, "0x%04x\n", (unsigned int) d->fw_ver);
}
static ssize_t aoedisk_show_payload(struct device *dev,
struct device_attribute *attr, char *page)
{
struct gendisk *disk = dev_to_disk(dev);
struct aoedev *d = disk->private_data;
return snprintf(page, PAGE_SIZE, "%lu\n", d->maxbcnt);
}
static int aoedisk_debugfs_show(struct seq_file *s, void *ignored)
{
struct aoedev *d;
struct aoetgt **t, **te;
struct aoeif *ifp, *ife;
unsigned long flags;
char c;
d = s->private;
seq_printf(s, "rttavg: %d rttdev: %d\n",
d->rttavg >> RTTSCALE,
d->rttdev >> RTTDSCALE);
seq_printf(s, "nskbpool: %d\n", skb_queue_len(&d->skbpool));
seq_printf(s, "kicked: %ld\n", d->kicked);
seq_printf(s, "maxbcnt: %ld\n", d->maxbcnt);
seq_printf(s, "ref: %ld\n", d->ref);
spin_lock_irqsave(&d->lock, flags);
t = d->targets;
te = t + d->ntargets;
for (; t < te && *t; t++) {
c = '\t';
seq_printf(s, "falloc: %ld\n", (*t)->falloc);
seq_printf(s, "ffree: %p\n",
list_empty(&(*t)->ffree) ? NULL : (*t)->ffree.next);
seq_printf(s, "%pm:%d:%d:%d\n", (*t)->addr, (*t)->nout,
(*t)->maxout, (*t)->nframes);
seq_printf(s, "\tssthresh:%d\n", (*t)->ssthresh);
seq_printf(s, "\ttaint:%d\n", (*t)->taint);
seq_printf(s, "\tr:%d\n", (*t)->rpkts);
seq_printf(s, "\tw:%d\n", (*t)->wpkts);
ifp = (*t)->ifs;
ife = ifp + ARRAY_SIZE((*t)->ifs);
for (; ifp->nd && ifp < ife; ifp++) {
seq_printf(s, "%c%s", c, ifp->nd->name);
c = ',';
}
seq_puts(s, "\n");
}
spin_unlock_irqrestore(&d->lock, flags);
return 0;
}
static int aoe_debugfs_open(struct inode *inode, struct file *file)
{
return single_open(file, aoedisk_debugfs_show, inode->i_private);
}
static DEVICE_ATTR(state, S_IRUGO, aoedisk_show_state, NULL);
static DEVICE_ATTR(mac, S_IRUGO, aoedisk_show_mac, NULL);
static DEVICE_ATTR(netif, S_IRUGO, aoedisk_show_netif, NULL);
static struct device_attribute dev_attr_firmware_version = {
.attr = { .name = "firmware-version", .mode = S_IRUGO },
.show = aoedisk_show_fwver,
};
static DEVICE_ATTR(payload, S_IRUGO, aoedisk_show_payload, NULL);
static struct attribute *aoe_attrs[] = {
&dev_attr_state.attr,
&dev_attr_mac.attr,
&dev_attr_netif.attr,
&dev_attr_firmware_version.attr,
&dev_attr_payload.attr,
NULL,
};
static const struct attribute_group attr_group = {
.attrs = aoe_attrs,
};
static const struct file_operations aoe_debugfs_fops = {
.open = aoe_debugfs_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
static void
aoedisk_add_debugfs(struct aoedev *d)
{
struct dentry *entry;
char *p;
if (aoe_debugfs_dir == NULL)
return;
p = strchr(d->gd->disk_name, '/');
if (p == NULL)
p = d->gd->disk_name;
else
p++;
BUG_ON(*p == '\0');
entry = debugfs_create_file(p, 0444, aoe_debugfs_dir, d,
&aoe_debugfs_fops);
if (IS_ERR_OR_NULL(entry)) {
pr_info("aoe: cannot create debugfs file for %s\n",
d->gd->disk_name);
return;
}
BUG_ON(d->debugfs);
d->debugfs = entry;
}
void
aoedisk_rm_debugfs(struct aoedev *d)
{
debugfs_remove(d->debugfs);
d->debugfs = NULL;
}
static int
aoedisk_add_sysfs(struct aoedev *d)
{
return sysfs_create_group(&disk_to_dev(d->gd)->kobj, &attr_group);
}
void
aoedisk_rm_sysfs(struct aoedev *d)
{
sysfs_remove_group(&disk_to_dev(d->gd)->kobj, &attr_group);
}
static int
aoeblk_open(struct block_device *bdev, fmode_t mode)
{
struct aoedev *d = bdev->bd_disk->private_data;
ulong flags;
if (!virt_addr_valid(d)) {
pr_crit("aoe: invalid device pointer in %s\n",
__func__);
WARN_ON(1);
return -ENODEV;
}
if (!(d->flags & DEVFL_UP) || d->flags & DEVFL_TKILL)
return -ENODEV;
mutex_lock(&aoeblk_mutex);
spin_lock_irqsave(&d->lock, flags);
if (d->flags & DEVFL_UP && !(d->flags & DEVFL_TKILL)) {
d->nopen++;
spin_unlock_irqrestore(&d->lock, flags);
mutex_unlock(&aoeblk_mutex);
return 0;
}
spin_unlock_irqrestore(&d->lock, flags);
mutex_unlock(&aoeblk_mutex);
return -ENODEV;
}
static void
aoeblk_release(struct gendisk *disk, fmode_t mode)
{
struct aoedev *d = disk->private_data;
ulong flags;
spin_lock_irqsave(&d->lock, flags);
if (--d->nopen == 0) {
spin_unlock_irqrestore(&d->lock, flags);
aoecmd_cfg(d->aoemajor, d->aoeminor);
return;
}
spin_unlock_irqrestore(&d->lock, flags);
}
static void
aoeblk_request(struct request_queue *q)
{
struct aoedev *d;
struct request *rq;
d = q->queuedata;
if ((d->flags & DEVFL_UP) == 0) {
pr_info_ratelimited("aoe: device %ld.%d is not up\n",
d->aoemajor, d->aoeminor);
while ((rq = blk_peek_request(q))) {
blk_start_request(rq);
aoe_end_request(d, rq, 1);
}
return;
}
aoecmd_work(d);
}
static int
aoeblk_getgeo(struct block_device *bdev, struct hd_geometry *geo)
{
struct aoedev *d = bdev->bd_disk->private_data;
if ((d->flags & DEVFL_UP) == 0) {
printk(KERN_ERR "aoe: disk not up\n");
return -ENODEV;
}
geo->cylinders = d->geo.cylinders;
geo->heads = d->geo.heads;
geo->sectors = d->geo.sectors;
return 0;
}
static int
aoeblk_ioctl(struct block_device *bdev, fmode_t mode, uint cmd, ulong arg)
{
struct aoedev *d;
if (!arg)
return -EINVAL;
d = bdev->bd_disk->private_data;
if ((d->flags & DEVFL_UP) == 0) {
pr_err("aoe: disk not up\n");
return -ENODEV;
}
if (cmd == HDIO_GET_IDENTITY) {
if (!copy_to_user((void __user *) arg, &d->ident,
sizeof(d->ident)))
return 0;
return -EFAULT;
}
/* udev calls scsi_id, which uses SG_IO, resulting in noise */
if (cmd != SG_IO)
pr_info("aoe: unknown ioctl 0x%x\n", cmd);
return -ENOTTY;
}
static const struct block_device_operations aoe_bdops = {
.open = aoeblk_open,
.release = aoeblk_release,
.ioctl = aoeblk_ioctl,
.getgeo = aoeblk_getgeo,
.owner = THIS_MODULE,
};
/* alloc_disk and add_disk can sleep */
void
aoeblk_gdalloc(void *vp)
{
struct aoedev *d = vp;
struct gendisk *gd;
mempool_t *mp;
struct request_queue *q;
enum { KB = 1024, MB = KB * KB, READ_AHEAD = 2 * MB, };
ulong flags;
int late = 0;
spin_lock_irqsave(&d->lock, flags);
if (d->flags & DEVFL_GDALLOC
&& !(d->flags & DEVFL_TKILL)
&& !(d->flags & DEVFL_GD_NOW))
d->flags |= DEVFL_GD_NOW;
else
late = 1;
spin_unlock_irqrestore(&d->lock, flags);
if (late)
return;
gd = alloc_disk(AOE_PARTITIONS);
if (gd == NULL) {
pr_err("aoe: cannot allocate disk structure for %ld.%d\n",
d->aoemajor, d->aoeminor);
goto err;
}
mp = mempool_create(MIN_BUFS, mempool_alloc_slab, mempool_free_slab,
buf_pool_cache);
if (mp == NULL) {
printk(KERN_ERR "aoe: cannot allocate bufpool for %ld.%d\n",
d->aoemajor, d->aoeminor);
goto err_disk;
}
q = blk_init_queue(aoeblk_request, &d->lock);
if (q == NULL) {
pr_err("aoe: cannot allocate block queue for %ld.%d\n",
d->aoemajor, d->aoeminor);
goto err_mempool;
}
spin_lock_irqsave(&d->lock, flags);
WARN_ON(!(d->flags & DEVFL_GD_NOW));
WARN_ON(!(d->flags & DEVFL_GDALLOC));
WARN_ON(d->flags & DEVFL_TKILL);
WARN_ON(d->gd);
WARN_ON(d->flags & DEVFL_UP);
blk_queue_max_hw_sectors(q, BLK_DEF_MAX_SECTORS);
q->backing_dev_info.name = "aoe";
q->backing_dev_info.ra_pages = READ_AHEAD / PAGE_CACHE_SIZE;
d->bufpool = mp;
d->blkq = gd->queue = q;
q->queuedata = d;
d->gd = gd;
if (aoe_maxsectors)
blk_queue_max_hw_sectors(q, aoe_maxsectors);
gd->major = AOE_MAJOR;
gd->first_minor = d->sysminor;
gd->fops = &aoe_bdops;
gd->private_data = d;
set_capacity(gd, d->ssize);
snprintf(gd->disk_name, sizeof gd->disk_name, "etherd/e%ld.%d",
d->aoemajor, d->aoeminor);
d->flags &= ~DEVFL_GDALLOC;
d->flags |= DEVFL_UP;
spin_unlock_irqrestore(&d->lock, flags);
add_disk(gd);
aoedisk_add_sysfs(d);
aoedisk_add_debugfs(d);
spin_lock_irqsave(&d->lock, flags);
WARN_ON(!(d->flags & DEVFL_GD_NOW));
d->flags &= ~DEVFL_GD_NOW;
spin_unlock_irqrestore(&d->lock, flags);
return;
err_mempool:
mempool_destroy(mp);
err_disk:
put_disk(gd);
err:
spin_lock_irqsave(&d->lock, flags);
d->flags &= ~DEVFL_GD_NOW;
schedule_work(&d->work);
spin_unlock_irqrestore(&d->lock, flags);
}
void
aoeblk_exit(void)
{
debugfs_remove_recursive(aoe_debugfs_dir);
aoe_debugfs_dir = NULL;
kmem_cache_destroy(buf_pool_cache);
}
int __init
aoeblk_init(void)
{
buf_pool_cache = kmem_cache_create("aoe_bufs",
sizeof(struct buf),
0, 0, NULL);
if (buf_pool_cache == NULL)
return -ENOMEM;
aoe_debugfs_dir = debugfs_create_dir("aoe", NULL);
if (IS_ERR_OR_NULL(aoe_debugfs_dir)) {
pr_info("aoe: cannot create debugfs directory\n");
aoe_debugfs_dir = NULL;
}
return 0;
}