diff options
Diffstat (limited to 'kernel/fs/nfs/pnfs_dev.c')
| -rw-r--r-- | kernel/fs/nfs/pnfs_dev.c | 365 |
1 files changed, 365 insertions, 0 deletions
diff --git a/kernel/fs/nfs/pnfs_dev.c b/kernel/fs/nfs/pnfs_dev.c new file mode 100644 index 000000000..2961fcd7a --- /dev/null +++ b/kernel/fs/nfs/pnfs_dev.c @@ -0,0 +1,365 @@ +/* + * 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) + +#define PNFS_DEVICE_RETRY_TIMEOUT (120*HZ) + +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(); +} |