tmp_suning_uos_patched/fs/nfs/pnfs_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

365 lines
9.6 KiB
C

/*
* Device operations for the pnfs client.
*
* Copyright (c) 2002
* The Regents of the University of Michigan
* All Rights Reserved
*
* Dean Hildebrand <dhildebz@umich.edu>
* Garth Goodson <Garth.Goodson@netapp.com>
*
* Permission is granted to use, copy, create derivative works, and
* redistribute this software and such derivative works for any purpose,
* so long as the name of the University of Michigan is not used in
* any advertising or publicity pertaining to the use or distribution
* of this software without specific, written prior authorization. If
* the above copyright notice or any other identification of the
* University of Michigan is included in any copy of any portion of
* this software, then the disclaimer below must also be included.
*
* This software is provided as is, without representation or warranty
* of any kind either express or implied, including without limitation
* the implied warranties of merchantability, fitness for a particular
* purpose, or noninfringement. The Regents of the University of
* Michigan shall not be liable for any damages, including special,
* indirect, incidental, or consequential damages, with respect to any
* claim arising out of or in connection with the use of the software,
* even if it has been or is hereafter advised of the possibility of
* such damages.
*/
#include <linux/export.h>
#include <linux/nfs_fs.h>
#include "nfs4session.h"
#include "internal.h"
#include "pnfs.h"
#define NFSDBG_FACILITY NFSDBG_PNFS
/*
* Device ID RCU cache. A device ID is unique per server and layout type.
*/
#define NFS4_DEVICE_ID_HASH_BITS 5
#define NFS4_DEVICE_ID_HASH_SIZE (1 << NFS4_DEVICE_ID_HASH_BITS)
#define NFS4_DEVICE_ID_HASH_MASK (NFS4_DEVICE_ID_HASH_SIZE - 1)
static struct hlist_head nfs4_deviceid_cache[NFS4_DEVICE_ID_HASH_SIZE];
static DEFINE_SPINLOCK(nfs4_deviceid_lock);
#ifdef NFS_DEBUG
void
nfs4_print_deviceid(const struct nfs4_deviceid *id)
{
u32 *p = (u32 *)id;
dprintk("%s: device id= [%x%x%x%x]\n", __func__,
p[0], p[1], p[2], p[3]);
}
EXPORT_SYMBOL_GPL(nfs4_print_deviceid);
#endif
static inline u32
nfs4_deviceid_hash(const struct nfs4_deviceid *id)
{
unsigned char *cptr = (unsigned char *)id->data;
unsigned int nbytes = NFS4_DEVICEID4_SIZE;
u32 x = 0;
while (nbytes--) {
x *= 37;
x += *cptr++;
}
return x & NFS4_DEVICE_ID_HASH_MASK;
}
static struct nfs4_deviceid_node *
_lookup_deviceid(const struct pnfs_layoutdriver_type *ld,
const struct nfs_client *clp, const struct nfs4_deviceid *id,
long hash)
{
struct nfs4_deviceid_node *d;
hlist_for_each_entry_rcu(d, &nfs4_deviceid_cache[hash], node)
if (d->ld == ld && d->nfs_client == clp &&
!memcmp(&d->deviceid, id, sizeof(*id))) {
if (atomic_read(&d->ref))
return d;
else
continue;
}
return NULL;
}
static struct nfs4_deviceid_node *
nfs4_get_device_info(struct nfs_server *server,
const struct nfs4_deviceid *dev_id,
struct rpc_cred *cred, gfp_t gfp_flags)
{
struct nfs4_deviceid_node *d = NULL;
struct pnfs_device *pdev = NULL;
struct page **pages = NULL;
u32 max_resp_sz;
int max_pages;
int rc, i;
/*
* Use the session max response size as the basis for setting
* GETDEVICEINFO's maxcount
*/
max_resp_sz = server->nfs_client->cl_session->fc_attrs.max_resp_sz;
if (server->pnfs_curr_ld->max_deviceinfo_size &&
server->pnfs_curr_ld->max_deviceinfo_size < max_resp_sz)
max_resp_sz = server->pnfs_curr_ld->max_deviceinfo_size;
max_pages = nfs_page_array_len(0, max_resp_sz);
dprintk("%s: server %p max_resp_sz %u max_pages %d\n",
__func__, server, max_resp_sz, max_pages);
pdev = kzalloc(sizeof(*pdev), gfp_flags);
if (!pdev)
return NULL;
pages = kcalloc(max_pages, sizeof(struct page *), gfp_flags);
if (!pages)
goto out_free_pdev;
for (i = 0; i < max_pages; i++) {
pages[i] = alloc_page(gfp_flags);
if (!pages[i])
goto out_free_pages;
}
memcpy(&pdev->dev_id, dev_id, sizeof(*dev_id));
pdev->layout_type = server->pnfs_curr_ld->id;
pdev->pages = pages;
pdev->pgbase = 0;
pdev->pglen = max_resp_sz;
pdev->mincount = 0;
pdev->maxcount = max_resp_sz - nfs41_maxgetdevinfo_overhead;
rc = nfs4_proc_getdeviceinfo(server, pdev, cred);
dprintk("%s getdevice info returns %d\n", __func__, rc);
if (rc)
goto out_free_pages;
/*
* Found new device, need to decode it and then add it to the
* list of known devices for this mountpoint.
*/
d = server->pnfs_curr_ld->alloc_deviceid_node(server, pdev,
gfp_flags);
if (d && pdev->nocache)
set_bit(NFS_DEVICEID_NOCACHE, &d->flags);
out_free_pages:
for (i = 0; i < max_pages; i++)
__free_page(pages[i]);
kfree(pages);
out_free_pdev:
kfree(pdev);
dprintk("<-- %s d %p\n", __func__, d);
return d;
}
/*
* Lookup a deviceid in cache and get a reference count on it if found
*
* @clp nfs_client associated with deviceid
* @id deviceid to look up
*/
static struct nfs4_deviceid_node *
__nfs4_find_get_deviceid(struct nfs_server *server,
const struct nfs4_deviceid *id, long hash)
{
struct nfs4_deviceid_node *d;
rcu_read_lock();
d = _lookup_deviceid(server->pnfs_curr_ld, server->nfs_client, id,
hash);
if (d != NULL && !atomic_inc_not_zero(&d->ref))
d = NULL;
rcu_read_unlock();
return d;
}
struct nfs4_deviceid_node *
nfs4_find_get_deviceid(struct nfs_server *server,
const struct nfs4_deviceid *id, struct rpc_cred *cred,
gfp_t gfp_mask)
{
long hash = nfs4_deviceid_hash(id);
struct nfs4_deviceid_node *d, *new;
d = __nfs4_find_get_deviceid(server, id, hash);
if (d)
return d;
new = nfs4_get_device_info(server, id, cred, gfp_mask);
if (!new)
return new;
spin_lock(&nfs4_deviceid_lock);
d = __nfs4_find_get_deviceid(server, id, hash);
if (d) {
spin_unlock(&nfs4_deviceid_lock);
server->pnfs_curr_ld->free_deviceid_node(new);
return d;
}
hlist_add_head_rcu(&new->node, &nfs4_deviceid_cache[hash]);
atomic_inc(&new->ref);
spin_unlock(&nfs4_deviceid_lock);
return new;
}
EXPORT_SYMBOL_GPL(nfs4_find_get_deviceid);
/*
* Remove a deviceid from cache
*
* @clp nfs_client associated with deviceid
* @id the deviceid to unhash
*
* @ret the unhashed node, if found and dereferenced to zero, NULL otherwise.
*/
void
nfs4_delete_deviceid(const struct pnfs_layoutdriver_type *ld,
const struct nfs_client *clp, const struct nfs4_deviceid *id)
{
struct nfs4_deviceid_node *d;
spin_lock(&nfs4_deviceid_lock);
rcu_read_lock();
d = _lookup_deviceid(ld, clp, id, nfs4_deviceid_hash(id));
rcu_read_unlock();
if (!d) {
spin_unlock(&nfs4_deviceid_lock);
return;
}
hlist_del_init_rcu(&d->node);
clear_bit(NFS_DEVICEID_NOCACHE, &d->flags);
spin_unlock(&nfs4_deviceid_lock);
/* balance the initial ref set in pnfs_insert_deviceid */
nfs4_put_deviceid_node(d);
}
EXPORT_SYMBOL_GPL(nfs4_delete_deviceid);
void
nfs4_init_deviceid_node(struct nfs4_deviceid_node *d, struct nfs_server *server,
const struct nfs4_deviceid *id)
{
INIT_HLIST_NODE(&d->node);
INIT_HLIST_NODE(&d->tmpnode);
d->ld = server->pnfs_curr_ld;
d->nfs_client = server->nfs_client;
d->flags = 0;
d->deviceid = *id;
atomic_set(&d->ref, 1);
}
EXPORT_SYMBOL_GPL(nfs4_init_deviceid_node);
/*
* Dereference a deviceid node and delete it when its reference count drops
* to zero.
*
* @d deviceid node to put
*
* return true iff the node was deleted
* Note that since the test for d->ref == 0 is sufficient to establish
* that the node is no longer hashed in the global device id cache.
*/
bool
nfs4_put_deviceid_node(struct nfs4_deviceid_node *d)
{
if (test_bit(NFS_DEVICEID_NOCACHE, &d->flags)) {
if (atomic_add_unless(&d->ref, -1, 2))
return false;
nfs4_delete_deviceid(d->ld, d->nfs_client, &d->deviceid);
}
if (!atomic_dec_and_test(&d->ref))
return false;
d->ld->free_deviceid_node(d);
return true;
}
EXPORT_SYMBOL_GPL(nfs4_put_deviceid_node);
void
nfs4_mark_deviceid_unavailable(struct nfs4_deviceid_node *node)
{
node->timestamp_unavailable = jiffies;
set_bit(NFS_DEVICEID_UNAVAILABLE, &node->flags);
}
EXPORT_SYMBOL_GPL(nfs4_mark_deviceid_unavailable);
bool
nfs4_test_deviceid_unavailable(struct nfs4_deviceid_node *node)
{
if (test_bit(NFS_DEVICEID_UNAVAILABLE, &node->flags)) {
unsigned long start, end;
end = jiffies;
start = end - PNFS_DEVICE_RETRY_TIMEOUT;
if (time_in_range(node->timestamp_unavailable, start, end))
return true;
clear_bit(NFS_DEVICEID_UNAVAILABLE, &node->flags);
}
return false;
}
EXPORT_SYMBOL_GPL(nfs4_test_deviceid_unavailable);
static void
_deviceid_purge_client(const struct nfs_client *clp, long hash)
{
struct nfs4_deviceid_node *d;
HLIST_HEAD(tmp);
spin_lock(&nfs4_deviceid_lock);
rcu_read_lock();
hlist_for_each_entry_rcu(d, &nfs4_deviceid_cache[hash], node)
if (d->nfs_client == clp && atomic_read(&d->ref)) {
hlist_del_init_rcu(&d->node);
hlist_add_head(&d->tmpnode, &tmp);
clear_bit(NFS_DEVICEID_NOCACHE, &d->flags);
}
rcu_read_unlock();
spin_unlock(&nfs4_deviceid_lock);
if (hlist_empty(&tmp))
return;
while (!hlist_empty(&tmp)) {
d = hlist_entry(tmp.first, struct nfs4_deviceid_node, tmpnode);
hlist_del(&d->tmpnode);
nfs4_put_deviceid_node(d);
}
}
void
nfs4_deviceid_purge_client(const struct nfs_client *clp)
{
long h;
if (!(clp->cl_exchange_flags & EXCHGID4_FLAG_USE_PNFS_MDS))
return;
for (h = 0; h < NFS4_DEVICE_ID_HASH_SIZE; h++)
_deviceid_purge_client(clp, h);
}
/*
* Stop use of all deviceids associated with an nfs_client
*/
void
nfs4_deviceid_mark_client_invalid(struct nfs_client *clp)
{
struct nfs4_deviceid_node *d;
int i;
rcu_read_lock();
for (i = 0; i < NFS4_DEVICE_ID_HASH_SIZE; i ++){
hlist_for_each_entry_rcu(d, &nfs4_deviceid_cache[i], node)
if (d->nfs_client == clp)
set_bit(NFS_DEVICEID_INVALID, &d->flags);
}
rcu_read_unlock();
}