alistair23-linux/fs/nfs/blocklayout/dev.c
Benjamin Coddington b3dce6a2f0 pnfs/blocklayout: handle transient devices
PNFS block/SCSI layouts should gracefully handle cases where block devices
are not available when a layout is retrieved, or the block devices are
removed while the client holds a layout.

While setting up a layout segment, keep a record of an unavailable or
un-parsable block device in cache with a flag so that subsequent layouts do
not spam the server with GETDEVINFO.  We can reuse the current
NFS_DEVICEID_UNAVAILABLE handling with one variation: instead of reusing
the device, we will discard it and send a fresh GETDEVINFO after the
timeout, since the lookup and validation of the device occurs within the
GETDEVINFO response handling.

A lookup of a layout segment that references an unavailable device will
return a segment with the NFS_LSEG_UNAVAILABLE flag set.  This will allow
the pgio layer to mark the layout with the appropriate fail bit, which
forces subsequent IO to the MDS, and prevents spamming the server with
LAYOUTGET, LAYOUTRETURN.

Finally, when IO to a block device fails, look up the block device(s)
referenced by the pgio header, and mark them as unavailable.

Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2018-01-14 23:06:29 -05:00

549 lines
13 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2014-2016 Christoph Hellwig.
*/
#include <linux/sunrpc/svc.h>
#include <linux/blkdev.h>
#include <linux/nfs4.h>
#include <linux/nfs_fs.h>
#include <linux/nfs_xdr.h>
#include <linux/pr.h>
#include "blocklayout.h"
#define NFSDBG_FACILITY NFSDBG_PNFS_LD
static void
bl_free_device(struct pnfs_block_dev *dev)
{
if (dev->nr_children) {
int i;
for (i = 0; i < dev->nr_children; i++)
bl_free_device(&dev->children[i]);
kfree(dev->children);
} else {
if (dev->pr_registered) {
const struct pr_ops *ops =
dev->bdev->bd_disk->fops->pr_ops;
int error;
error = ops->pr_register(dev->bdev, dev->pr_key, 0,
false);
if (error)
pr_err("failed to unregister PR key.\n");
}
if (dev->bdev)
blkdev_put(dev->bdev, FMODE_READ | FMODE_WRITE);
}
}
void
bl_free_deviceid_node(struct nfs4_deviceid_node *d)
{
struct pnfs_block_dev *dev =
container_of(d, struct pnfs_block_dev, node);
bl_free_device(dev);
kfree_rcu(dev, node.rcu);
}
static int
nfs4_block_decode_volume(struct xdr_stream *xdr, struct pnfs_block_volume *b)
{
__be32 *p;
int i;
p = xdr_inline_decode(xdr, 4);
if (!p)
return -EIO;
b->type = be32_to_cpup(p++);
switch (b->type) {
case PNFS_BLOCK_VOLUME_SIMPLE:
p = xdr_inline_decode(xdr, 4);
if (!p)
return -EIO;
b->simple.nr_sigs = be32_to_cpup(p++);
if (!b->simple.nr_sigs || b->simple.nr_sigs > PNFS_BLOCK_MAX_UUIDS) {
dprintk("Bad signature count: %d\n", b->simple.nr_sigs);
return -EIO;
}
b->simple.len = 4 + 4;
for (i = 0; i < b->simple.nr_sigs; i++) {
p = xdr_inline_decode(xdr, 8 + 4);
if (!p)
return -EIO;
p = xdr_decode_hyper(p, &b->simple.sigs[i].offset);
b->simple.sigs[i].sig_len = be32_to_cpup(p++);
if (b->simple.sigs[i].sig_len > PNFS_BLOCK_UUID_LEN) {
pr_info("signature too long: %d\n",
b->simple.sigs[i].sig_len);
return -EIO;
}
p = xdr_inline_decode(xdr, b->simple.sigs[i].sig_len);
if (!p)
return -EIO;
memcpy(&b->simple.sigs[i].sig, p,
b->simple.sigs[i].sig_len);
b->simple.len += 8 + 4 + \
(XDR_QUADLEN(b->simple.sigs[i].sig_len) << 2);
}
break;
case PNFS_BLOCK_VOLUME_SLICE:
p = xdr_inline_decode(xdr, 8 + 8 + 4);
if (!p)
return -EIO;
p = xdr_decode_hyper(p, &b->slice.start);
p = xdr_decode_hyper(p, &b->slice.len);
b->slice.volume = be32_to_cpup(p++);
break;
case PNFS_BLOCK_VOLUME_CONCAT:
p = xdr_inline_decode(xdr, 4);
if (!p)
return -EIO;
b->concat.volumes_count = be32_to_cpup(p++);
if (b->concat.volumes_count > PNFS_BLOCK_MAX_DEVICES) {
dprintk("Too many volumes: %d\n", b->concat.volumes_count);
return -EIO;
}
p = xdr_inline_decode(xdr, b->concat.volumes_count * 4);
if (!p)
return -EIO;
for (i = 0; i < b->concat.volumes_count; i++)
b->concat.volumes[i] = be32_to_cpup(p++);
break;
case PNFS_BLOCK_VOLUME_STRIPE:
p = xdr_inline_decode(xdr, 8 + 4);
if (!p)
return -EIO;
p = xdr_decode_hyper(p, &b->stripe.chunk_size);
b->stripe.volumes_count = be32_to_cpup(p++);
if (b->stripe.volumes_count > PNFS_BLOCK_MAX_DEVICES) {
dprintk("Too many volumes: %d\n", b->stripe.volumes_count);
return -EIO;
}
p = xdr_inline_decode(xdr, b->stripe.volumes_count * 4);
if (!p)
return -EIO;
for (i = 0; i < b->stripe.volumes_count; i++)
b->stripe.volumes[i] = be32_to_cpup(p++);
break;
case PNFS_BLOCK_VOLUME_SCSI:
p = xdr_inline_decode(xdr, 4 + 4 + 4);
if (!p)
return -EIO;
b->scsi.code_set = be32_to_cpup(p++);
b->scsi.designator_type = be32_to_cpup(p++);
b->scsi.designator_len = be32_to_cpup(p++);
p = xdr_inline_decode(xdr, b->scsi.designator_len);
if (!p)
return -EIO;
if (b->scsi.designator_len > 256)
return -EIO;
memcpy(&b->scsi.designator, p, b->scsi.designator_len);
p = xdr_inline_decode(xdr, 8);
if (!p)
return -EIO;
p = xdr_decode_hyper(p, &b->scsi.pr_key);
break;
default:
dprintk("unknown volume type!\n");
return -EIO;
}
return 0;
}
static bool bl_map_simple(struct pnfs_block_dev *dev, u64 offset,
struct pnfs_block_dev_map *map)
{
map->start = dev->start;
map->len = dev->len;
map->disk_offset = dev->disk_offset;
map->bdev = dev->bdev;
return true;
}
static bool bl_map_concat(struct pnfs_block_dev *dev, u64 offset,
struct pnfs_block_dev_map *map)
{
int i;
for (i = 0; i < dev->nr_children; i++) {
struct pnfs_block_dev *child = &dev->children[i];
if (child->start > offset ||
child->start + child->len <= offset)
continue;
child->map(child, offset - child->start, map);
return true;
}
dprintk("%s: ran off loop!\n", __func__);
return false;
}
static bool bl_map_stripe(struct pnfs_block_dev *dev, u64 offset,
struct pnfs_block_dev_map *map)
{
struct pnfs_block_dev *child;
u64 chunk;
u32 chunk_idx;
u64 disk_offset;
chunk = div_u64(offset, dev->chunk_size);
div_u64_rem(chunk, dev->nr_children, &chunk_idx);
if (chunk_idx > dev->nr_children) {
dprintk("%s: invalid chunk idx %d (%lld/%lld)\n",
__func__, chunk_idx, offset, dev->chunk_size);
/* error, should not happen */
return false;
}
/* truncate offset to the beginning of the stripe */
offset = chunk * dev->chunk_size;
/* disk offset of the stripe */
disk_offset = div_u64(offset, dev->nr_children);
child = &dev->children[chunk_idx];
child->map(child, disk_offset, map);
map->start += offset;
map->disk_offset += disk_offset;
map->len = dev->chunk_size;
return true;
}
static int
bl_parse_deviceid(struct nfs_server *server, struct pnfs_block_dev *d,
struct pnfs_block_volume *volumes, int idx, gfp_t gfp_mask);
static int
bl_parse_simple(struct nfs_server *server, struct pnfs_block_dev *d,
struct pnfs_block_volume *volumes, int idx, gfp_t gfp_mask)
{
struct pnfs_block_volume *v = &volumes[idx];
struct block_device *bdev;
dev_t dev;
dev = bl_resolve_deviceid(server, v, gfp_mask);
if (!dev)
return -EIO;
bdev = blkdev_get_by_dev(dev, FMODE_READ | FMODE_WRITE, NULL);
if (IS_ERR(bdev)) {
printk(KERN_WARNING "pNFS: failed to open device %d:%d (%ld)\n",
MAJOR(dev), MINOR(dev), PTR_ERR(bdev));
return PTR_ERR(bdev);
}
d->bdev = bdev;
d->len = i_size_read(d->bdev->bd_inode);
d->map = bl_map_simple;
printk(KERN_INFO "pNFS: using block device %s\n",
d->bdev->bd_disk->disk_name);
return 0;
}
static bool
bl_validate_designator(struct pnfs_block_volume *v)
{
switch (v->scsi.designator_type) {
case PS_DESIGNATOR_EUI64:
if (v->scsi.code_set != PS_CODE_SET_BINARY)
return false;
if (v->scsi.designator_len != 8 &&
v->scsi.designator_len != 10 &&
v->scsi.designator_len != 16)
return false;
return true;
case PS_DESIGNATOR_NAA:
if (v->scsi.code_set != PS_CODE_SET_BINARY)
return false;
if (v->scsi.designator_len != 8 &&
v->scsi.designator_len != 16)
return false;
return true;
case PS_DESIGNATOR_T10:
case PS_DESIGNATOR_NAME:
pr_err("pNFS: unsupported designator "
"(code set %d, type %d, len %d.\n",
v->scsi.code_set,
v->scsi.designator_type,
v->scsi.designator_len);
return false;
default:
pr_err("pNFS: invalid designator "
"(code set %d, type %d, len %d.\n",
v->scsi.code_set,
v->scsi.designator_type,
v->scsi.designator_len);
return false;
}
}
/*
* Try to open the udev path for the WWN. At least on Debian the udev
* by-id path will always point to the dm-multipath device if one exists.
*/
static struct block_device *
bl_open_udev_path(struct pnfs_block_volume *v)
{
struct block_device *bdev;
const char *devname;
devname = kasprintf(GFP_KERNEL, "/dev/disk/by-id/wwn-0x%*phN",
v->scsi.designator_len, v->scsi.designator);
if (!devname)
return ERR_PTR(-ENOMEM);
bdev = blkdev_get_by_path(devname, FMODE_READ | FMODE_WRITE, NULL);
if (IS_ERR(bdev)) {
pr_warn("pNFS: failed to open device %s (%ld)\n",
devname, PTR_ERR(bdev));
}
kfree(devname);
return bdev;
}
/*
* Try to open the RH/Fedora specific dm-mpath udev path for this WWN, as the
* wwn- links will only point to the first discovered SCSI device there.
*/
static struct block_device *
bl_open_dm_mpath_udev_path(struct pnfs_block_volume *v)
{
struct block_device *bdev;
const char *devname;
devname = kasprintf(GFP_KERNEL,
"/dev/disk/by-id/dm-uuid-mpath-%d%*phN",
v->scsi.designator_type,
v->scsi.designator_len, v->scsi.designator);
if (!devname)
return ERR_PTR(-ENOMEM);
bdev = blkdev_get_by_path(devname, FMODE_READ | FMODE_WRITE, NULL);
kfree(devname);
return bdev;
}
static int
bl_parse_scsi(struct nfs_server *server, struct pnfs_block_dev *d,
struct pnfs_block_volume *volumes, int idx, gfp_t gfp_mask)
{
struct pnfs_block_volume *v = &volumes[idx];
struct block_device *bdev;
const struct pr_ops *ops;
int error;
if (!bl_validate_designator(v))
return -EINVAL;
bdev = bl_open_dm_mpath_udev_path(v);
if (IS_ERR(bdev))
bdev = bl_open_udev_path(v);
if (IS_ERR(bdev))
return PTR_ERR(bdev);
d->bdev = bdev;
d->len = i_size_read(d->bdev->bd_inode);
d->map = bl_map_simple;
d->pr_key = v->scsi.pr_key;
pr_info("pNFS: using block device %s (reservation key 0x%llx)\n",
d->bdev->bd_disk->disk_name, d->pr_key);
ops = d->bdev->bd_disk->fops->pr_ops;
if (!ops) {
pr_err("pNFS: block device %s does not support reservations.",
d->bdev->bd_disk->disk_name);
error = -EINVAL;
goto out_blkdev_put;
}
error = ops->pr_register(d->bdev, 0, d->pr_key, true);
if (error) {
pr_err("pNFS: failed to register key for block device %s.",
d->bdev->bd_disk->disk_name);
goto out_blkdev_put;
}
d->pr_registered = true;
return 0;
out_blkdev_put:
blkdev_put(d->bdev, FMODE_READ | FMODE_WRITE);
return error;
}
static int
bl_parse_slice(struct nfs_server *server, struct pnfs_block_dev *d,
struct pnfs_block_volume *volumes, int idx, gfp_t gfp_mask)
{
struct pnfs_block_volume *v = &volumes[idx];
int ret;
ret = bl_parse_deviceid(server, d, volumes, v->slice.volume, gfp_mask);
if (ret)
return ret;
d->disk_offset = v->slice.start;
d->len = v->slice.len;
return 0;
}
static int
bl_parse_concat(struct nfs_server *server, struct pnfs_block_dev *d,
struct pnfs_block_volume *volumes, int idx, gfp_t gfp_mask)
{
struct pnfs_block_volume *v = &volumes[idx];
u64 len = 0;
int ret, i;
d->children = kcalloc(v->concat.volumes_count,
sizeof(struct pnfs_block_dev), GFP_KERNEL);
if (!d->children)
return -ENOMEM;
for (i = 0; i < v->concat.volumes_count; i++) {
ret = bl_parse_deviceid(server, &d->children[i],
volumes, v->concat.volumes[i], gfp_mask);
if (ret)
return ret;
d->nr_children++;
d->children[i].start += len;
len += d->children[i].len;
}
d->len = len;
d->map = bl_map_concat;
return 0;
}
static int
bl_parse_stripe(struct nfs_server *server, struct pnfs_block_dev *d,
struct pnfs_block_volume *volumes, int idx, gfp_t gfp_mask)
{
struct pnfs_block_volume *v = &volumes[idx];
u64 len = 0;
int ret, i;
d->children = kcalloc(v->stripe.volumes_count,
sizeof(struct pnfs_block_dev), GFP_KERNEL);
if (!d->children)
return -ENOMEM;
for (i = 0; i < v->stripe.volumes_count; i++) {
ret = bl_parse_deviceid(server, &d->children[i],
volumes, v->stripe.volumes[i], gfp_mask);
if (ret)
return ret;
d->nr_children++;
len += d->children[i].len;
}
d->len = len;
d->chunk_size = v->stripe.chunk_size;
d->map = bl_map_stripe;
return 0;
}
static int
bl_parse_deviceid(struct nfs_server *server, struct pnfs_block_dev *d,
struct pnfs_block_volume *volumes, int idx, gfp_t gfp_mask)
{
switch (volumes[idx].type) {
case PNFS_BLOCK_VOLUME_SIMPLE:
return bl_parse_simple(server, d, volumes, idx, gfp_mask);
case PNFS_BLOCK_VOLUME_SLICE:
return bl_parse_slice(server, d, volumes, idx, gfp_mask);
case PNFS_BLOCK_VOLUME_CONCAT:
return bl_parse_concat(server, d, volumes, idx, gfp_mask);
case PNFS_BLOCK_VOLUME_STRIPE:
return bl_parse_stripe(server, d, volumes, idx, gfp_mask);
case PNFS_BLOCK_VOLUME_SCSI:
return bl_parse_scsi(server, d, volumes, idx, gfp_mask);
default:
dprintk("unsupported volume type: %d\n", volumes[idx].type);
return -EIO;
}
}
struct nfs4_deviceid_node *
bl_alloc_deviceid_node(struct nfs_server *server, struct pnfs_device *pdev,
gfp_t gfp_mask)
{
struct nfs4_deviceid_node *node = NULL;
struct pnfs_block_volume *volumes;
struct pnfs_block_dev *top;
struct xdr_stream xdr;
struct xdr_buf buf;
struct page *scratch;
int nr_volumes, ret, i;
__be32 *p;
scratch = alloc_page(gfp_mask);
if (!scratch)
goto out;
xdr_init_decode_pages(&xdr, &buf, pdev->pages, pdev->pglen);
xdr_set_scratch_buffer(&xdr, page_address(scratch), PAGE_SIZE);
p = xdr_inline_decode(&xdr, sizeof(__be32));
if (!p)
goto out_free_scratch;
nr_volumes = be32_to_cpup(p++);
volumes = kcalloc(nr_volumes, sizeof(struct pnfs_block_volume),
gfp_mask);
if (!volumes)
goto out_free_scratch;
for (i = 0; i < nr_volumes; i++) {
ret = nfs4_block_decode_volume(&xdr, &volumes[i]);
if (ret < 0)
goto out_free_volumes;
}
top = kzalloc(sizeof(*top), gfp_mask);
if (!top)
goto out_free_volumes;
ret = bl_parse_deviceid(server, top, volumes, nr_volumes - 1, gfp_mask);
node = &top->node;
nfs4_init_deviceid_node(node, server, &pdev->dev_id);
if (ret)
nfs4_mark_deviceid_unavailable(node);
out_free_volumes:
kfree(volumes);
out_free_scratch:
__free_page(scratch);
out:
return node;
}