linux_dsm_epyc7002/drivers/block/aoe/aoeblk.c
Arnd Bergmann 6e9624b8ca block: push down BKL into .open and .release
The open and release block_device_operations are currently
called with the BKL held. In order to change that, we must
first make sure that all drivers that currently rely
on this have no regressions.

This blindly pushes the BKL into all .open and .release
operations for all block drivers to prepare for the
next step. The drivers can subsequently replace the BKL
with their own locks or remove it completely when it can
be shown that it is not needed.

The functions blkdev_get and blkdev_put are the only
remaining users of the big kernel lock in the block
layer, besides a few uses in the ioctl code, none
of which need to serialize with blkdev_{get,put}.

Most of these two functions is also under the protection
of bdev->bd_mutex, including the actual calls to
->open and ->release, and the common code does not
access any global data structures that need the BKL.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-07 18:25:34 +02:00

333 lines
7.5 KiB
C

/* Copyright (c) 2007 Coraid, Inc. See COPYING for GPL terms. */
/*
* aoeblk.c
* block device routines
*/
#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/genhd.h>
#include <linux/netdevice.h>
#include <linux/smp_lock.h>
#include "aoe.h"
static struct kmem_cache *buf_pool_cache;
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 + 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 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 struct attribute *aoe_attrs[] = {
&dev_attr_state.attr,
&dev_attr_mac.attr,
&dev_attr_netif.attr,
&dev_attr_firmware_version.attr,
NULL,
};
static const struct attribute_group attr_group = {
.attrs = aoe_attrs,
};
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;
lock_kernel();
spin_lock_irqsave(&d->lock, flags);
if (d->flags & DEVFL_UP) {
d->nopen++;
spin_unlock_irqrestore(&d->lock, flags);
unlock_kernel();
return 0;
}
spin_unlock_irqrestore(&d->lock, flags);
unlock_kernel();
return -ENODEV;
}
static int
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 0;
}
spin_unlock_irqrestore(&d->lock, flags);
return 0;
}
static int
aoeblk_make_request(struct request_queue *q, struct bio *bio)
{
struct sk_buff_head queue;
struct aoedev *d;
struct buf *buf;
ulong flags;
blk_queue_bounce(q, &bio);
if (bio == NULL) {
printk(KERN_ERR "aoe: bio is NULL\n");
BUG();
return 0;
}
d = bio->bi_bdev->bd_disk->private_data;
if (d == NULL) {
printk(KERN_ERR "aoe: bd_disk->private_data is NULL\n");
BUG();
bio_endio(bio, -ENXIO);
return 0;
} else if (bio->bi_rw & REQ_HARDBARRIER) {
bio_endio(bio, -EOPNOTSUPP);
return 0;
} else if (bio->bi_io_vec == NULL) {
printk(KERN_ERR "aoe: bi_io_vec is NULL\n");
BUG();
bio_endio(bio, -ENXIO);
return 0;
}
buf = mempool_alloc(d->bufpool, GFP_NOIO);
if (buf == NULL) {
printk(KERN_INFO "aoe: buf allocation failure\n");
bio_endio(bio, -ENOMEM);
return 0;
}
memset(buf, 0, sizeof(*buf));
INIT_LIST_HEAD(&buf->bufs);
buf->stime = jiffies;
buf->bio = bio;
buf->resid = bio->bi_size;
buf->sector = bio->bi_sector;
buf->bv = &bio->bi_io_vec[bio->bi_idx];
buf->bv_resid = buf->bv->bv_len;
WARN_ON(buf->bv_resid == 0);
buf->bv_off = buf->bv->bv_offset;
spin_lock_irqsave(&d->lock, flags);
if ((d->flags & DEVFL_UP) == 0) {
printk(KERN_INFO "aoe: device %ld.%d is not up\n",
d->aoemajor, d->aoeminor);
spin_unlock_irqrestore(&d->lock, flags);
mempool_free(buf, d->bufpool);
bio_endio(bio, -ENXIO);
return 0;
}
list_add_tail(&buf->bufs, &d->bufq);
aoecmd_work(d);
__skb_queue_head_init(&queue);
skb_queue_splice_init(&d->sendq, &queue);
spin_unlock_irqrestore(&d->lock, flags);
aoenet_xmit(&queue);
return 0;
}
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 const struct block_device_operations aoe_bdops = {
.open = aoeblk_open,
.release = aoeblk_release,
.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;
ulong flags;
gd = alloc_disk(AOE_PARTITIONS);
if (gd == NULL) {
printk(KERN_ERR
"aoe: cannot allocate disk structure for %ld.%d\n",
d->aoemajor, d->aoeminor);
goto err;
}
d->bufpool = mempool_create_slab_pool(MIN_BUFS, buf_pool_cache);
if (d->bufpool == NULL) {
printk(KERN_ERR "aoe: cannot allocate bufpool for %ld.%d\n",
d->aoemajor, d->aoeminor);
goto err_disk;
}
d->blkq = blk_alloc_queue(GFP_KERNEL);
if (!d->blkq)
goto err_mempool;
blk_queue_make_request(d->blkq, aoeblk_make_request);
d->blkq->backing_dev_info.name = "aoe";
if (bdi_init(&d->blkq->backing_dev_info))
goto err_blkq;
spin_lock_irqsave(&d->lock, flags);
gd->major = AOE_MAJOR;
gd->first_minor = d->sysminor * AOE_PARTITIONS;
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);
gd->queue = d->blkq;
d->gd = gd;
d->flags &= ~DEVFL_GDALLOC;
d->flags |= DEVFL_UP;
spin_unlock_irqrestore(&d->lock, flags);
add_disk(gd);
aoedisk_add_sysfs(d);
return;
err_blkq:
blk_cleanup_queue(d->blkq);
d->blkq = NULL;
err_mempool:
mempool_destroy(d->bufpool);
err_disk:
put_disk(gd);
err:
spin_lock_irqsave(&d->lock, flags);
d->flags &= ~DEVFL_GDALLOC;
spin_unlock_irqrestore(&d->lock, flags);
}
void
aoeblk_exit(void)
{
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;
return 0;
}