/*
* pNFS functions to call and manage layout drivers.
*
* Copyright (c) 2002 [year of first publication]
* The Regents of the University of Michigan
* All Rights Reserved
*
* Dean Hildebrand <dhildebz@umich.edu>
*
* 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/nfs_fs.h>
#include "internal.h"
#include "pnfs.h"
#define NFSDBG_FACILITY NFSDBG_PNFS
/* Locking:
*
* pnfs_spinlock:
* protects pnfs_modules_tbl.
*/
static DEFINE_SPINLOCK(pnfs_spinlock);
/*
* pnfs_modules_tbl holds all pnfs modules
*/
static LIST_HEAD(pnfs_modules_tbl);
/* Return the registered pnfs layout driver module matching given id */
static struct pnfs_layoutdriver_type *
find_pnfs_driver_locked(u32 id)
{
struct pnfs_layoutdriver_type *local;
list_for_each_entry(local, &pnfs_modules_tbl, pnfs_tblid)
if (local->id == id)
goto out;
local = NULL;
out:
dprintk("%s: Searching for id %u, found %p\n", __func__, id, local);
return local;
}
static struct pnfs_layoutdriver_type *
find_pnfs_driver(u32 id)
{
struct pnfs_layoutdriver_type *local;
spin_lock(&pnfs_spinlock);
local = find_pnfs_driver_locked(id);
spin_unlock(&pnfs_spinlock);
return local;
}
void
unset_pnfs_layoutdriver(struct nfs_server *nfss)
{
if (nfss->pnfs_curr_ld) {
nfss->pnfs_curr_ld->clear_layoutdriver(nfss);
module_put(nfss->pnfs_curr_ld->owner);
}
nfss->pnfs_curr_ld = NULL;
}
/*
* Try to set the server's pnfs module to the pnfs layout type specified by id.
* Currently only one pNFS layout driver per filesystem is supported.
*
* @id layout type. Zero (illegal layout type) indicates pNFS not in use.
*/
void
set_pnfs_layoutdriver(struct nfs_server *server, u32 id)
{
struct pnfs_layoutdriver_type *ld_type = NULL;
if (id == 0)
goto out_no_driver;
if (!(server->nfs_client->cl_exchange_flags &
(EXCHGID4_FLAG_USE_NON_PNFS | EXCHGID4_FLAG_USE_PNFS_MDS))) {
printk(KERN_ERR "%s: id %u cl_exchange_flags 0x%x\n", __func__,
id, server->nfs_client->cl_exchange_flags);
goto out_no_driver;
}
ld_type = find_pnfs_driver(id);
if (!ld_type) {
request_module("%s-%u", LAYOUT_NFSV4_1_MODULE_PREFIX, id);
ld_type = find_pnfs_driver(id);
if (!ld_type) {
dprintk("%s: No pNFS module found for %u.\n",
__func__, id);
goto out_no_driver;
}
}
if (!try_module_get(ld_type->owner)) {
dprintk("%s: Could not grab reference on module\n", __func__);
goto out_no_driver;
}
server->pnfs_curr_ld = ld_type;
if (ld_type->set_layoutdriver(server)) {
printk(KERN_ERR
"%s: Error initializing mount point for layout driver %u.\n",
__func__, id);
module_put(ld_type->owner);
goto out_no_driver;
}
dprintk("%s: pNFS module for %u set\n", __func__, id);
return;
out_no_driver:
dprintk("%s: Using NFSv4 I/O\n", __func__);
server->pnfs_curr_ld = NULL;
}
int
pnfs_register_layoutdriver(struct pnfs_layoutdriver_type *ld_type)
{
int status = -EINVAL;
struct pnfs_layoutdriver_type *tmp;
if (ld_type->id == 0) {
printk(KERN_ERR "%s id 0 is reserved\n", __func__);
return status;
}
if (!ld_type->alloc_lseg || !ld_type->free_lseg) {
printk(KERN_ERR "%s Layout driver must provide "
"alloc_lseg and free_lseg.\n", __func__);
return status;
}
spin_lock(&pnfs_spinlock);
tmp = find_pnfs_driver_locked(ld_type->id);
if (!tmp) {
list_add(&ld_type->pnfs_tblid, &pnfs_modules_tbl);
status = 0;
dprintk("%s Registering id:%u name:%s\n", __func__, ld_type->id,
ld_type->name);
} else {
printk(KERN_ERR "%s Module with id %d already loaded!\n",
__func__, ld_type->id);
}
spin_unlock(&pnfs_spinlock);
return status;
}
EXPORT_SYMBOL_GPL(pnfs_register_layoutdriver);
void
pnfs_unregister_layoutdriver(struct pnfs_layoutdriver_type *ld_type)
{
dprintk("%s Deregistering id:%u\n", __func__, ld_type->id);
spin_lock(&pnfs_spinlock);
list_del(&ld_type->pnfs_tblid);
spin_unlock(&pnfs_spinlock);
}
EXPORT_SYMBOL_GPL(pnfs_unregister_layoutdriver);
/*
* pNFS client layout cache
*/
static void
get_layout_hdr_locked(struct pnfs_layout_hdr *lo)
{
assert_spin_locked(&lo->plh_inode->i_lock);
lo->plh_refcount++;
}
static void
put_layout_hdr_locked(struct pnfs_layout_hdr *lo)
{
assert_spin_locked(&lo->plh_inode->i_lock);
BUG_ON(lo->plh_refcount == 0);
lo->plh_refcount--;
if (!lo->plh_refcount) {
dprintk("%s: freeing layout cache %p\n", __func__, lo);
BUG_ON(!list_empty(&lo->plh_layouts));
NFS_I(lo->plh_inode)->layout = NULL;
kfree(lo);
}
}
void
put_layout_hdr(struct inode *inode)
{
spin_lock(&inode->i_lock);
put_layout_hdr_locked(NFS_I(inode)->layout);
spin_unlock(&inode->i_lock);
}
static void
init_lseg(struct pnfs_layout_hdr *lo, struct pnfs_layout_segment *lseg)
{
INIT_LIST_HEAD(&lseg->pls_list);
atomic_set(&lseg->pls_refcount, 1);
smp_mb();
set_bit(NFS_LSEG_VALID, &lseg->pls_flags);
lseg->pls_layout = lo;
}
static void free_lseg(struct pnfs_layout_segment *lseg)
{
struct inode *ino = lseg->pls_layout->plh_inode;
NFS_SERVER(ino)->pnfs_curr_ld->free_lseg(lseg);
/* Matched by get_layout_hdr in pnfs_insert_layout */
put_layout_hdr(ino);
}
/* The use of tmp_list is necessary because pnfs_curr_ld->free_lseg
* could sleep, so must be called outside of the lock.
* Returns 1 if object was removed, otherwise return 0.
*/
static int
put_lseg_locked(struct pnfs_layout_segment *lseg,
struct list_head *tmp_list)
{
dprintk("%s: lseg %p ref %d valid %d\n", __func__, lseg,
atomic_read(&lseg->pls_refcount),
test_bit(NFS_LSEG_VALID, &lseg->pls_flags));
if (atomic_dec_and_test(&lseg->pls_refcount)) {
struct inode *ino = lseg->pls_layout->plh_inode;
BUG_ON(test_bit(NFS_LSEG_VALID, &lseg->pls_flags));
list_del(&lseg->pls_list);
if (list_empty(&lseg->pls_layout->plh_segs)) {
struct nfs_client *clp;
clp = NFS_SERVER(ino)->nfs_client;
spin_lock(&clp->cl_lock);
/* List does not take a reference, so no need for put here */
list_del_init(&lseg->pls_layout->plh_layouts);
spin_unlock(&clp->cl_lock);
}
list_add(&lseg->pls_list, tmp_list);
return 1;
}
return 0;
}
static bool
should_free_lseg(u32 lseg_iomode, u32 recall_iomode)
{
return (recall_iomode == IOMODE_ANY ||
lseg_iomode == recall_iomode);
}
/* Returns 1 if lseg is removed from list, 0 otherwise */
static int mark_lseg_invalid(struct pnfs_layout_segment *lseg,
struct list_head *tmp_list)
{
int rv = 0;
if (test_and_clear_bit(NFS_LSEG_VALID, &lseg->pls_flags)) {
/* Remove the reference keeping the lseg in the
* list. It will now be removed when all
* outstanding io is finished.
*/
rv = put_lseg_locked(lseg, tmp_list);
}
return rv;
}
/* Returns count of number of matching invalid lsegs remaining in list
* after call.
*/
static int
mark_matching_lsegs_invalid(struct pnfs_layout_hdr *lo,
struct list_head *tmp_list,
u32 iomode)
{
struct pnfs_layout_segment *lseg, *next;
int invalid = 0, removed = 0;
dprintk("%s:Begin lo %p\n", __func__, lo);
list_for_each_entry_safe(lseg, next, &lo->plh_segs, pls_list)
if (should_free_lseg(lseg->pls_range.iomode, iomode)) {
dprintk("%s: freeing lseg %p iomode %d "
"offset %llu length %llu\n", __func__,
lseg, lseg->pls_range.iomode, lseg->pls_range.offset,
lseg->pls_range.length);
invalid++;
removed += mark_lseg_invalid(lseg, tmp_list);
}
dprintk("%s:Return %i\n", __func__, invalid - removed);
return invalid - removed;
}
static void
pnfs_free_lseg_list(struct list_head *free_me)
{
struct pnfs_layout_segment *lseg, *tmp;
list_for_each_entry_safe(lseg, tmp, free_me, pls_list) {
list_del(&lseg->pls_list);
free_lseg(lseg);
}
}
void
pnfs_destroy_layout(struct nfs_inode *nfsi)
{
struct pnfs_layout_hdr *lo;
LIST_HEAD(tmp_list);
spin_lock(&nfsi->vfs_inode.i_lock);
lo = nfsi->layout;
if (lo) {
set_bit(NFS_LAYOUT_DESTROYED, &nfsi->layout->plh_flags);
mark_matching_lsegs_invalid(lo, &tmp_list, IOMODE_ANY);
/* Matched by refcount set to 1 in alloc_init_layout_hdr */
put_layout_hdr_locked(lo);
}
spin_unlock(&nfsi->vfs_inode.i_lock);
pnfs_free_lseg_list(&tmp_list);
}
/*
* Called by the state manger to remove all layouts established under an
* expired lease.
*/
void
pnfs_destroy_all_layouts(struct nfs_client *clp)
{
struct pnfs_layout_hdr *lo;
LIST_HEAD(tmp_list);
spin_lock(&clp->cl_lock);
list_splice_init(&clp->cl_layouts, &tmp_list);
spin_unlock(&clp->cl_lock);
while (!list_empty(&tmp_list)) {
lo = list_entry(tmp_list.next, struct pnfs_layout_hdr,
plh_layouts);
dprintk("%s freeing layout for inode %lu\n", __func__,
lo->plh_inode->i_ino);
pnfs_destroy_layout(NFS_I(lo->plh_inode));
}
}
/* update lo->plh_stateid with new if is more recent */
static void
pnfs_set_layout_stateid(struct pnfs_layout_hdr *lo,
const nfs4_stateid *new)
{
u32 oldseq, newseq;
oldseq = be32_to_cpu(lo->plh_stateid.stateid.seqid);
newseq = be32_to_cpu(new->stateid.seqid);
if ((int)(newseq - oldseq) > 0)
memcpy(&lo->plh_stateid, &new->stateid, sizeof(new->stateid));
}
int
pnfs_choose_layoutget_stateid(nfs4_stateid *dst, struct pnfs_layout_hdr *lo,
struct nfs4_state *open_state)
{
int status = 0;
dprintk("--> %s\n", __func__);
spin_lock(&lo->plh_inode->i_lock);
if (list_empty(&lo->plh_segs)) {
int seq;
do {
seq = read_seqbegin(&open_state->seqlock);
memcpy(dst->data, open_state->stateid.data,
sizeof(open_state->stateid.data));
} while (read_seqretry(&open_state->seqlock, seq));
} else
memcpy(dst->data, lo->plh_stateid.data, sizeof(lo->plh_stateid.data));
spin_unlock(&lo->plh_inode->i_lock);
dprintk("<-- %s\n", __func__);
return status;
}
/*
* Get layout from server.
* for now, assume that whole file layouts are requested.
* arg->offset: 0
* arg->length: all ones
*/
static struct pnfs_layout_segment *
send_layoutget(struct pnfs_layout_hdr *lo,
struct nfs_open_context *ctx,
u32 iomode)
{
struct inode *ino = lo->plh_inode;
struct nfs_server *server = NFS_SERVER(ino);
struct nfs4_layoutget *lgp;
struct pnfs_layout_segment *lseg = NULL;
dprintk("--> %s\n", __func__);
BUG_ON(ctx == NULL);
lgp = kzalloc(sizeof(*lgp), GFP_KERNEL);
if (lgp == NULL) {
put_layout_hdr(lo->plh_inode);
return NULL;
}
lgp->args.minlength = NFS4_MAX_UINT64;
lgp->args.maxcount = PNFS_LAYOUT_MAXSIZE;
lgp->args.range.iomode = iomode;
lgp->args.range.offset = 0;
lgp->args.range.length = NFS4_MAX_UINT64;
lgp->args.type = server->pnfs_curr_ld->id;
lgp->args.inode = ino;
lgp->args.ctx = get_nfs_open_context(ctx);
lgp->lsegpp = &lseg;
/* Synchronously retrieve layout information from server and
* store in lseg.
*/
nfs4_proc_layoutget(lgp);
if (!lseg) {
/* remember that LAYOUTGET failed and suspend trying */
set_bit(lo_fail_bit(iomode), &lo->plh_flags);
}
return lseg;
}
/*
* Compare two layout segments for sorting into layout cache.
* We want to preferentially return RW over RO layouts, so ensure those
* are seen first.
*/
static s64
cmp_layout(u32 iomode1, u32 iomode2)
{
/* read > read/write */
return (int)(iomode2 == IOMODE_READ) - (int)(iomode1 == IOMODE_READ);
}
static void
pnfs_insert_layout(struct pnfs_layout_hdr *lo,
struct pnfs_layout_segment *lseg)
{
struct pnfs_layout_segment *lp;
int found = 0;
dprintk("%s:Begin\n", __func__);
assert_spin_locked(&lo->plh_inode->i_lock);
if (list_empty(&lo->plh_segs)) {
struct nfs_client *clp = NFS_SERVER(lo->plh_inode)->nfs_client;
spin_lock(&clp->cl_lock);
BUG_ON(!list_empty(&lo->plh_layouts));
list_add_tail(&lo->plh_layouts, &clp->cl_layouts);
spin_unlock(&clp->cl_lock);
}
list_for_each_entry(lp, &lo->plh_segs, pls_list) {
if (cmp_layout(lp->pls_range.iomode, lseg->pls_range.iomode) > 0)
continue;
list_add_tail(&lseg->pls_list, &lp->pls_list);
dprintk("%s: inserted lseg %p "
"iomode %d offset %llu length %llu before "
"lp %p iomode %d offset %llu length %llu\n",
__func__, lseg, lseg->pls_range.iomode,
lseg->pls_range.offset, lseg->pls_range.length,
lp, lp->pls_range.iomode, lp->pls_range.offset,
lp->pls_range.length);
found = 1;
break;
}
if (!found) {
list_add_tail(&lseg->pls_list, &lo->plh_segs);
dprintk("%s: inserted lseg %p "
"iomode %d offset %llu length %llu at tail\n",
__func__, lseg, lseg->pls_range.iomode,
lseg->pls_range.offset, lseg->pls_range.length);
}
get_layout_hdr_locked(lo);
dprintk("%s:Return\n", __func__);
}
static struct pnfs_layout_hdr *
alloc_init_layout_hdr(struct inode *ino)
{
struct pnfs_layout_hdr *lo;
lo = kzalloc(sizeof(struct pnfs_layout_hdr), GFP_KERNEL);
if (!lo)
return NULL;
lo->plh_refcount = 1;
INIT_LIST_HEAD(&lo->plh_layouts);
INIT_LIST_HEAD(&lo->plh_segs);
lo->plh_inode = ino;
return lo;
}
static struct pnfs_layout_hdr *
pnfs_find_alloc_layout(struct inode *ino)
{
struct nfs_inode *nfsi = NFS_I(ino);
struct pnfs_layout_hdr *new = NULL;
dprintk("%s Begin ino=%p layout=%p\n", __func__, ino, nfsi->layout);
assert_spin_locked(&ino->i_lock);
if (nfsi->layout) {
if (test_bit(NFS_LAYOUT_DESTROYED, &nfsi->layout->plh_flags))
return NULL;
else
return nfsi->layout;
}
spin_unlock(&ino->i_lock);
new = alloc_init_layout_hdr(ino);
spin_lock(&ino->i_lock);
if (likely(nfsi->layout == NULL)) /* Won the race? */
nfsi->layout = new;
else
kfree(new);
return nfsi->layout;
}
/*
* iomode matching rules:
* iomode lseg match
* ----- ----- -----
* ANY READ true
* ANY RW true
* RW READ false
* RW RW true
* READ READ true
* READ RW true
*/
static int
is_matching_lseg(struct pnfs_layout_segment *lseg, u32 iomode)
{
return (iomode != IOMODE_RW || lseg->pls_range.iomode == IOMODE_RW);
}
/*
* lookup range in layout
*/
static struct pnfs_layout_segment *
pnfs_has_layout(struct pnfs_layout_hdr *lo, u32 iomode)
{
struct pnfs_layout_segment *lseg, *ret = NULL;
dprintk("%s:Begin\n", __func__);
assert_spin_locked(&lo->plh_inode->i_lock);
list_for_each_entry(lseg, &lo->plh_segs, pls_list) {
if (test_bit(NFS_LSEG_VALID, &lseg->pls_flags) &&
is_matching_lseg(lseg, iomode)) {
ret = lseg;
break;
}
if (cmp_layout(iomode, lseg->pls_range.iomode) > 0)
break;
}
dprintk("%s:Return lseg %p ref %d\n",
__func__, ret, ret ? atomic_read(&ret->pls_refcount) : 0);
return ret;
}
/*
* Layout segment is retreived from the server if not cached.
* The appropriate layout segment is referenced and returned to the caller.
*/
struct pnfs_layout_segment *
pnfs_update_layout(struct inode *ino,
struct nfs_open_context *ctx,
enum pnfs_iomode iomode)
{
struct nfs_inode *nfsi = NFS_I(ino);
struct pnfs_layout_hdr *lo;
struct pnfs_layout_segment *lseg = NULL;
if (!pnfs_enabled_sb(NFS_SERVER(ino)))
return NULL;
spin_lock(&ino->i_lock);
lo = pnfs_find_alloc_layout(ino);
if (lo == NULL) {
dprintk("%s ERROR: can't get pnfs_layout_hdr\n", __func__);
goto out_unlock;
}
/* Check to see if the layout for the given range already exists */
lseg = pnfs_has_layout(lo, iomode);
if (lseg) {
dprintk("%s: Using cached lseg %p for iomode %d)\n",
__func__, lseg, iomode);
goto out_unlock;
}
/* if LAYOUTGET already failed once we don't try again */
if (test_bit(lo_fail_bit(iomode), &nfsi->layout->plh_flags))
goto out_unlock;
get_layout_hdr_locked(lo); /* Matched in nfs4_layoutget_release */
spin_unlock(&ino->i_lock);
lseg = send_layoutget(lo, ctx, iomode);
out:
dprintk("%s end, state 0x%lx lseg %p\n", __func__,
nfsi->layout->plh_flags, lseg);
return lseg;
out_unlock:
spin_unlock(&ino->i_lock);
goto out;
}
int
pnfs_layout_process(struct nfs4_layoutget *lgp)
{
struct pnfs_layout_hdr *lo = NFS_I(lgp->args.inode)->layout;
struct nfs4_layoutget_res *res = &lgp->res;
struct pnfs_layout_segment *lseg;
struct inode *ino = lo->plh_inode;
int status = 0;
/* Inject layout blob into I/O device driver */
lseg = NFS_SERVER(ino)->pnfs_curr_ld->alloc_lseg(lo, res);
if (!lseg || IS_ERR(lseg)) {
if (!lseg)
status = -ENOMEM;
else
status = PTR_ERR(lseg);
dprintk("%s: Could not allocate layout: error %d\n",
__func__, status);
goto out;
}
spin_lock(&ino->i_lock);
init_lseg(lo, lseg);
lseg->pls_range = res->range;
*lgp->lsegpp = lseg;
pnfs_insert_layout(lo, lseg);
/* Done processing layoutget. Set the layout stateid */
pnfs_set_layout_stateid(lo, &res->stateid);
spin_unlock(&ino->i_lock);
out:
return status;
}
/*
* Device ID cache. Currently supports one layout type per struct nfs_client.
* Add layout type to the lookup key to expand to support multiple types.
*/
int
pnfs_alloc_init_deviceid_cache(struct nfs_client *clp,
void (*free_callback)(struct pnfs_deviceid_node *))
{
struct pnfs_deviceid_cache *c;
c = kzalloc(sizeof(struct pnfs_deviceid_cache), GFP_KERNEL);
if (!c)
return -ENOMEM;
spin_lock(&clp->cl_lock);
if (clp->cl_devid_cache != NULL) {
atomic_inc(&clp->cl_devid_cache->dc_ref);
dprintk("%s [kref [%d]]\n", __func__,
atomic_read(&clp->cl_devid_cache->dc_ref));
kfree(c);
} else {
/* kzalloc initializes hlists */
spin_lock_init(&c->dc_lock);
atomic_set(&c->dc_ref, 1);
c->dc_free_callback = free_callback;
clp->cl_devid_cache = c;
dprintk("%s [new]\n", __func__);
}
spin_unlock(&clp->cl_lock);
return 0;
}
EXPORT_SYMBOL_GPL(pnfs_alloc_init_deviceid_cache);
/*
* Called from pnfs_layoutdriver_type->free_lseg
* last layout segment reference frees deviceid
*/
void
pnfs_put_deviceid(struct pnfs_deviceid_cache *c,
struct pnfs_deviceid_node *devid)
{
struct nfs4_deviceid *id = &devid->de_id;
struct pnfs_deviceid_node *d;
struct hlist_node *n;
long h = nfs4_deviceid_hash(id);
dprintk("%s [%d]\n", __func__, atomic_read(&devid->de_ref));
if (!atomic_dec_and_lock(&devid->de_ref, &c->dc_lock))
return;
hlist_for_each_entry_rcu(d, n, &c->dc_deviceids[h], de_node)
if (!memcmp(&d->de_id, id, sizeof(*id))) {
hlist_del_rcu(&d->de_node);
spin_unlock(&c->dc_lock);
synchronize_rcu();
c->dc_free_callback(devid);
return;
}
spin_unlock(&c->dc_lock);
/* Why wasn't it found in the list? */
BUG();
}
EXPORT_SYMBOL_GPL(pnfs_put_deviceid);
/* Find and reference a deviceid */
struct pnfs_deviceid_node *
pnfs_find_get_deviceid(struct pnfs_deviceid_cache *c, struct nfs4_deviceid *id)
{
struct pnfs_deviceid_node *d;
struct hlist_node *n;
long hash = nfs4_deviceid_hash(id);
dprintk("--> %s hash %ld\n", __func__, hash);
rcu_read_lock();
hlist_for_each_entry_rcu(d, n, &c->dc_deviceids[hash], de_node) {
if (!memcmp(&d->de_id, id, sizeof(*id))) {
if (!atomic_inc_not_zero(&d->de_ref)) {
goto fail;
} else {
rcu_read_unlock();
return d;
}
}
}
fail:
rcu_read_unlock();
return NULL;
}
EXPORT_SYMBOL_GPL(pnfs_find_get_deviceid);
/*
* Add a deviceid to the cache.
* GETDEVICEINFOs for same deviceid can race. If deviceid is found, discard new
*/
struct pnfs_deviceid_node *
pnfs_add_deviceid(struct pnfs_deviceid_cache *c, struct pnfs_deviceid_node *new)
{
struct pnfs_deviceid_node *d;
long hash = nfs4_deviceid_hash(&new->de_id);
dprintk("--> %s hash %ld\n", __func__, hash);
spin_lock(&c->dc_lock);
d = pnfs_find_get_deviceid(c, &new->de_id);
if (d) {
spin_unlock(&c->dc_lock);
dprintk("%s [discard]\n", __func__);
c->dc_free_callback(new);
return d;
}
INIT_HLIST_NODE(&new->de_node);
atomic_set(&new->de_ref, 1);
hlist_add_head_rcu(&new->de_node, &c->dc_deviceids[hash]);
spin_unlock(&c->dc_lock);
dprintk("%s [new]\n", __func__);
return new;
}
EXPORT_SYMBOL_GPL(pnfs_add_deviceid);
void
pnfs_put_deviceid_cache(struct nfs_client *clp)
{
struct pnfs_deviceid_cache *local = clp->cl_devid_cache;
dprintk("--> %s cl_devid_cache %p\n", __func__, clp->cl_devid_cache);
if (atomic_dec_and_lock(&local->dc_ref, &clp->cl_lock)) {
int i;
/* Verify cache is empty */
for (i = 0; i < NFS4_DEVICE_ID_HASH_SIZE; i++)
BUG_ON(!hlist_empty(&local->dc_deviceids[i]));
clp->cl_devid_cache = NULL;
spin_unlock(&clp->cl_lock);
kfree(local);
}
}
EXPORT_SYMBOL_GPL(pnfs_put_deviceid_cache);
