diff options
Diffstat (limited to 'fs/nfs/filelayout/filelayoutdev.c')
| -rw-r--r-- | fs/nfs/filelayout/filelayoutdev.c | 843 |
1 files changed, 843 insertions, 0 deletions
diff --git a/fs/nfs/filelayout/filelayoutdev.c b/fs/nfs/filelayout/filelayoutdev.c new file mode 100644 index 00000000000..44bf0140a4c --- /dev/null +++ b/fs/nfs/filelayout/filelayoutdev.c @@ -0,0 +1,843 @@ +/* + * Device operations for the pnfs nfs4 file layout driver. + * + * 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/nfs_fs.h> +#include <linux/vmalloc.h> +#include <linux/module.h> +#include <linux/sunrpc/addr.h> + +#include "../internal.h" +#include "../nfs4session.h" +#include "filelayout.h" + +#define NFSDBG_FACILITY NFSDBG_PNFS_LD + +static unsigned int dataserver_timeo = NFS4_DEF_DS_TIMEO; +static unsigned int dataserver_retrans = NFS4_DEF_DS_RETRANS; + +/* + * Data server cache + * + * Data servers can be mapped to different device ids. + * nfs4_pnfs_ds reference counting + * - set to 1 on allocation + * - incremented when a device id maps a data server already in the cache. + * - decremented when deviceid is removed from the cache. + */ +static DEFINE_SPINLOCK(nfs4_ds_cache_lock); +static LIST_HEAD(nfs4_data_server_cache); + +/* Debug routines */ +void +print_ds(struct nfs4_pnfs_ds *ds) +{ + if (ds == NULL) { + printk("%s NULL device\n", __func__); + return; + } + printk(" ds %s\n" + " ref count %d\n" + " client %p\n" + " cl_exchange_flags %x\n", + ds->ds_remotestr, + atomic_read(&ds->ds_count), ds->ds_clp, + ds->ds_clp ? ds->ds_clp->cl_exchange_flags : 0); +} + +static bool +same_sockaddr(struct sockaddr *addr1, struct sockaddr *addr2) +{ + struct sockaddr_in *a, *b; + struct sockaddr_in6 *a6, *b6; + + if (addr1->sa_family != addr2->sa_family) + return false; + + switch (addr1->sa_family) { + case AF_INET: + a = (struct sockaddr_in *)addr1; + b = (struct sockaddr_in *)addr2; + + if (a->sin_addr.s_addr == b->sin_addr.s_addr && + a->sin_port == b->sin_port) + return true; + break; + + case AF_INET6: + a6 = (struct sockaddr_in6 *)addr1; + b6 = (struct sockaddr_in6 *)addr2; + + /* LINKLOCAL addresses must have matching scope_id */ + if (ipv6_addr_src_scope(&a6->sin6_addr) == + IPV6_ADDR_SCOPE_LINKLOCAL && + a6->sin6_scope_id != b6->sin6_scope_id) + return false; + + if (ipv6_addr_equal(&a6->sin6_addr, &b6->sin6_addr) && + a6->sin6_port == b6->sin6_port) + return true; + break; + + default: + dprintk("%s: unhandled address family: %u\n", + __func__, addr1->sa_family); + return false; + } + + return false; +} + +static bool +_same_data_server_addrs_locked(const struct list_head *dsaddrs1, + const struct list_head *dsaddrs2) +{ + struct nfs4_pnfs_ds_addr *da1, *da2; + + /* step through both lists, comparing as we go */ + for (da1 = list_first_entry(dsaddrs1, typeof(*da1), da_node), + da2 = list_first_entry(dsaddrs2, typeof(*da2), da_node); + da1 != NULL && da2 != NULL; + da1 = list_entry(da1->da_node.next, typeof(*da1), da_node), + da2 = list_entry(da2->da_node.next, typeof(*da2), da_node)) { + if (!same_sockaddr((struct sockaddr *)&da1->da_addr, + (struct sockaddr *)&da2->da_addr)) + return false; + } + if (da1 == NULL && da2 == NULL) + return true; + + return false; +} + +/* + * Lookup DS by addresses. nfs4_ds_cache_lock is held + */ +static struct nfs4_pnfs_ds * +_data_server_lookup_locked(const struct list_head *dsaddrs) +{ + struct nfs4_pnfs_ds *ds; + + list_for_each_entry(ds, &nfs4_data_server_cache, ds_node) + if (_same_data_server_addrs_locked(&ds->ds_addrs, dsaddrs)) + return ds; + return NULL; +} + +/* + * Create an rpc connection to the nfs4_pnfs_ds data server + * Currently only supports IPv4 and IPv6 addresses + */ +static int +nfs4_ds_connect(struct nfs_server *mds_srv, struct nfs4_pnfs_ds *ds) +{ + struct nfs_client *clp = ERR_PTR(-EIO); + struct nfs4_pnfs_ds_addr *da; + int status = 0; + + dprintk("--> %s DS %s au_flavor %d\n", __func__, ds->ds_remotestr, + mds_srv->nfs_client->cl_rpcclient->cl_auth->au_flavor); + + list_for_each_entry(da, &ds->ds_addrs, da_node) { + dprintk("%s: DS %s: trying address %s\n", + __func__, ds->ds_remotestr, da->da_remotestr); + + clp = nfs4_set_ds_client(mds_srv->nfs_client, + (struct sockaddr *)&da->da_addr, + da->da_addrlen, IPPROTO_TCP, + dataserver_timeo, dataserver_retrans); + if (!IS_ERR(clp)) + break; + } + + if (IS_ERR(clp)) { + status = PTR_ERR(clp); + goto out; + } + + status = nfs4_init_ds_session(clp, mds_srv->nfs_client->cl_lease_time); + if (status) + goto out_put; + + smp_wmb(); + ds->ds_clp = clp; + dprintk("%s [new] addr: %s\n", __func__, ds->ds_remotestr); +out: + return status; +out_put: + nfs_put_client(clp); + goto out; +} + +static void +destroy_ds(struct nfs4_pnfs_ds *ds) +{ + struct nfs4_pnfs_ds_addr *da; + + dprintk("--> %s\n", __func__); + ifdebug(FACILITY) + print_ds(ds); + + if (ds->ds_clp) + nfs_put_client(ds->ds_clp); + + while (!list_empty(&ds->ds_addrs)) { + da = list_first_entry(&ds->ds_addrs, + struct nfs4_pnfs_ds_addr, + da_node); + list_del_init(&da->da_node); + kfree(da->da_remotestr); + kfree(da); + } + + kfree(ds->ds_remotestr); + kfree(ds); +} + +void +nfs4_fl_free_deviceid(struct nfs4_file_layout_dsaddr *dsaddr) +{ + struct nfs4_pnfs_ds *ds; + int i; + + nfs4_print_deviceid(&dsaddr->id_node.deviceid); + + for (i = 0; i < dsaddr->ds_num; i++) { + ds = dsaddr->ds_list[i]; + if (ds != NULL) { + if (atomic_dec_and_lock(&ds->ds_count, + &nfs4_ds_cache_lock)) { + list_del_init(&ds->ds_node); + spin_unlock(&nfs4_ds_cache_lock); + destroy_ds(ds); + } + } + } + kfree(dsaddr->stripe_indices); + kfree(dsaddr); +} + +/* + * Create a string with a human readable address and port to avoid + * complicated setup around many dprinks. + */ +static char * +nfs4_pnfs_remotestr(struct list_head *dsaddrs, gfp_t gfp_flags) +{ + struct nfs4_pnfs_ds_addr *da; + char *remotestr; + size_t len; + char *p; + + len = 3; /* '{', '}' and eol */ + list_for_each_entry(da, dsaddrs, da_node) { + len += strlen(da->da_remotestr) + 1; /* string plus comma */ + } + + remotestr = kzalloc(len, gfp_flags); + if (!remotestr) + return NULL; + + p = remotestr; + *(p++) = '{'; + len--; + list_for_each_entry(da, dsaddrs, da_node) { + size_t ll = strlen(da->da_remotestr); + + if (ll > len) + goto out_err; + + memcpy(p, da->da_remotestr, ll); + p += ll; + len -= ll; + + if (len < 1) + goto out_err; + (*p++) = ','; + len--; + } + if (len < 2) + goto out_err; + *(p++) = '}'; + *p = '\0'; + return remotestr; +out_err: + kfree(remotestr); + return NULL; +} + +static struct nfs4_pnfs_ds * +nfs4_pnfs_ds_add(struct list_head *dsaddrs, gfp_t gfp_flags) +{ + struct nfs4_pnfs_ds *tmp_ds, *ds = NULL; + char *remotestr; + + if (list_empty(dsaddrs)) { + dprintk("%s: no addresses defined\n", __func__); + goto out; + } + + ds = kzalloc(sizeof(*ds), gfp_flags); + if (!ds) + goto out; + + /* this is only used for debugging, so it's ok if its NULL */ + remotestr = nfs4_pnfs_remotestr(dsaddrs, gfp_flags); + + spin_lock(&nfs4_ds_cache_lock); + tmp_ds = _data_server_lookup_locked(dsaddrs); + if (tmp_ds == NULL) { + INIT_LIST_HEAD(&ds->ds_addrs); + list_splice_init(dsaddrs, &ds->ds_addrs); + ds->ds_remotestr = remotestr; + atomic_set(&ds->ds_count, 1); + INIT_LIST_HEAD(&ds->ds_node); + ds->ds_clp = NULL; + list_add(&ds->ds_node, &nfs4_data_server_cache); + dprintk("%s add new data server %s\n", __func__, + ds->ds_remotestr); + } else { + kfree(remotestr); + kfree(ds); + atomic_inc(&tmp_ds->ds_count); + dprintk("%s data server %s found, inc'ed ds_count to %d\n", + __func__, tmp_ds->ds_remotestr, + atomic_read(&tmp_ds->ds_count)); + ds = tmp_ds; + } + spin_unlock(&nfs4_ds_cache_lock); +out: + return ds; +} + +/* + * Currently only supports ipv4, ipv6 and one multi-path address. + */ +static struct nfs4_pnfs_ds_addr * +decode_ds_addr(struct net *net, struct xdr_stream *streamp, gfp_t gfp_flags) +{ + struct nfs4_pnfs_ds_addr *da = NULL; + char *buf, *portstr; + __be16 port; + int nlen, rlen; + int tmp[2]; + __be32 *p; + char *netid, *match_netid; + size_t len, match_netid_len; + char *startsep = ""; + char *endsep = ""; + + + /* r_netid */ + p = xdr_inline_decode(streamp, 4); + if (unlikely(!p)) + goto out_err; + nlen = be32_to_cpup(p++); + + p = xdr_inline_decode(streamp, nlen); + if (unlikely(!p)) + goto out_err; + + netid = kmalloc(nlen+1, gfp_flags); + if (unlikely(!netid)) + goto out_err; + + netid[nlen] = '\0'; + memcpy(netid, p, nlen); + + /* r_addr: ip/ip6addr with port in dec octets - see RFC 5665 */ + p = xdr_inline_decode(streamp, 4); + if (unlikely(!p)) + goto out_free_netid; + rlen = be32_to_cpup(p); + + p = xdr_inline_decode(streamp, rlen); + if (unlikely(!p)) + goto out_free_netid; + + /* port is ".ABC.DEF", 8 chars max */ + if (rlen > INET6_ADDRSTRLEN + IPV6_SCOPE_ID_LEN + 8) { + dprintk("%s: Invalid address, length %d\n", __func__, + rlen); + goto out_free_netid; + } + buf = kmalloc(rlen + 1, gfp_flags); + if (!buf) { + dprintk("%s: Not enough memory\n", __func__); + goto out_free_netid; + } + buf[rlen] = '\0'; + memcpy(buf, p, rlen); + + /* replace port '.' with '-' */ + portstr = strrchr(buf, '.'); + if (!portstr) { + dprintk("%s: Failed finding expected dot in port\n", + __func__); + goto out_free_buf; + } + *portstr = '-'; + + /* find '.' between address and port */ + portstr = strrchr(buf, '.'); + if (!portstr) { + dprintk("%s: Failed finding expected dot between address and " + "port\n", __func__); + goto out_free_buf; + } + *portstr = '\0'; + + da = kzalloc(sizeof(*da), gfp_flags); + if (unlikely(!da)) + goto out_free_buf; + + INIT_LIST_HEAD(&da->da_node); + + if (!rpc_pton(net, buf, portstr-buf, (struct sockaddr *)&da->da_addr, + sizeof(da->da_addr))) { + dprintk("%s: error parsing address %s\n", __func__, buf); + goto out_free_da; + } + + portstr++; + sscanf(portstr, "%d-%d", &tmp[0], &tmp[1]); + port = htons((tmp[0] << 8) | (tmp[1])); + + switch (da->da_addr.ss_family) { + case AF_INET: + ((struct sockaddr_in *)&da->da_addr)->sin_port = port; + da->da_addrlen = sizeof(struct sockaddr_in); + match_netid = "tcp"; + match_netid_len = 3; + break; + + case AF_INET6: + ((struct sockaddr_in6 *)&da->da_addr)->sin6_port = port; + da->da_addrlen = sizeof(struct sockaddr_in6); + match_netid = "tcp6"; + match_netid_len = 4; + startsep = "["; + endsep = "]"; + break; + + default: + dprintk("%s: unsupported address family: %u\n", + __func__, da->da_addr.ss_family); + goto out_free_da; + } + + if (nlen != match_netid_len || strncmp(netid, match_netid, nlen)) { + dprintk("%s: ERROR: r_netid \"%s\" != \"%s\"\n", + __func__, netid, match_netid); + goto out_free_da; + } + + /* save human readable address */ + len = strlen(startsep) + strlen(buf) + strlen(endsep) + 7; + da->da_remotestr = kzalloc(len, gfp_flags); + + /* NULL is ok, only used for dprintk */ + if (da->da_remotestr) + snprintf(da->da_remotestr, len, "%s%s%s:%u", startsep, + buf, endsep, ntohs(port)); + + dprintk("%s: Parsed DS addr %s\n", __func__, da->da_remotestr); + kfree(buf); + kfree(netid); + return da; + +out_free_da: + kfree(da); +out_free_buf: + dprintk("%s: Error parsing DS addr: %s\n", __func__, buf); + kfree(buf); +out_free_netid: + kfree(netid); +out_err: + return NULL; +} + +/* Decode opaque device data and return the result */ +static struct nfs4_file_layout_dsaddr* +decode_device(struct inode *ino, struct pnfs_device *pdev, gfp_t gfp_flags) +{ + int i; + u32 cnt, num; + u8 *indexp; + __be32 *p; + u8 *stripe_indices; + u8 max_stripe_index; + struct nfs4_file_layout_dsaddr *dsaddr = NULL; + struct xdr_stream stream; + struct xdr_buf buf; + struct page *scratch; + struct list_head dsaddrs; + struct nfs4_pnfs_ds_addr *da; + + /* set up xdr stream */ + scratch = alloc_page(gfp_flags); + if (!scratch) + goto out_err; + + xdr_init_decode_pages(&stream, &buf, pdev->pages, pdev->pglen); + xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE); + + /* Get the stripe count (number of stripe index) */ + p = xdr_inline_decode(&stream, 4); + if (unlikely(!p)) + goto out_err_free_scratch; + + cnt = be32_to_cpup(p); + dprintk("%s stripe count %d\n", __func__, cnt); + if (cnt > NFS4_PNFS_MAX_STRIPE_CNT) { + printk(KERN_WARNING "NFS: %s: stripe count %d greater than " + "supported maximum %d\n", __func__, + cnt, NFS4_PNFS_MAX_STRIPE_CNT); + goto out_err_free_scratch; + } + + /* read stripe indices */ + stripe_indices = kcalloc(cnt, sizeof(u8), gfp_flags); + if (!stripe_indices) + goto out_err_free_scratch; + + p = xdr_inline_decode(&stream, cnt << 2); + if (unlikely(!p)) + goto out_err_free_stripe_indices; + + indexp = &stripe_indices[0]; + max_stripe_index = 0; + for (i = 0; i < cnt; i++) { + *indexp = be32_to_cpup(p++); + max_stripe_index = max(max_stripe_index, *indexp); + indexp++; + } + + /* Check the multipath list count */ + p = xdr_inline_decode(&stream, 4); + if (unlikely(!p)) + goto out_err_free_stripe_indices; + + num = be32_to_cpup(p); + dprintk("%s ds_num %u\n", __func__, num); + if (num > NFS4_PNFS_MAX_MULTI_CNT) { + printk(KERN_WARNING "NFS: %s: multipath count %d greater than " + "supported maximum %d\n", __func__, + num, NFS4_PNFS_MAX_MULTI_CNT); + goto out_err_free_stripe_indices; + } + + /* validate stripe indices are all < num */ + if (max_stripe_index >= num) { + printk(KERN_WARNING "NFS: %s: stripe index %u >= num ds %u\n", + __func__, max_stripe_index, num); + goto out_err_free_stripe_indices; + } + + dsaddr = kzalloc(sizeof(*dsaddr) + + (sizeof(struct nfs4_pnfs_ds *) * (num - 1)), + gfp_flags); + if (!dsaddr) + goto out_err_free_stripe_indices; + + dsaddr->stripe_count = cnt; + dsaddr->stripe_indices = stripe_indices; + stripe_indices = NULL; + dsaddr->ds_num = num; + nfs4_init_deviceid_node(&dsaddr->id_node, + NFS_SERVER(ino)->pnfs_curr_ld, + NFS_SERVER(ino)->nfs_client, + &pdev->dev_id); + + INIT_LIST_HEAD(&dsaddrs); + + for (i = 0; i < dsaddr->ds_num; i++) { + int j; + u32 mp_count; + + p = xdr_inline_decode(&stream, 4); + if (unlikely(!p)) + goto out_err_free_deviceid; + + mp_count = be32_to_cpup(p); /* multipath count */ + for (j = 0; j < mp_count; j++) { + da = decode_ds_addr(NFS_SERVER(ino)->nfs_client->cl_net, + &stream, gfp_flags); + if (da) + list_add_tail(&da->da_node, &dsaddrs); + } + if (list_empty(&dsaddrs)) { + dprintk("%s: no suitable DS addresses found\n", + __func__); + goto out_err_free_deviceid; + } + + dsaddr->ds_list[i] = nfs4_pnfs_ds_add(&dsaddrs, gfp_flags); + if (!dsaddr->ds_list[i]) + goto out_err_drain_dsaddrs; + + /* If DS was already in cache, free ds addrs */ + while (!list_empty(&dsaddrs)) { + da = list_first_entry(&dsaddrs, + struct nfs4_pnfs_ds_addr, + da_node); + list_del_init(&da->da_node); + kfree(da->da_remotestr); + kfree(da); + } + } + + __free_page(scratch); + return dsaddr; + +out_err_drain_dsaddrs: + while (!list_empty(&dsaddrs)) { + da = list_first_entry(&dsaddrs, struct nfs4_pnfs_ds_addr, + da_node); + list_del_init(&da->da_node); + kfree(da->da_remotestr); + kfree(da); + } +out_err_free_deviceid: + nfs4_fl_free_deviceid(dsaddr); + /* stripe_indicies was part of dsaddr */ + goto out_err_free_scratch; +out_err_free_stripe_indices: + kfree(stripe_indices); +out_err_free_scratch: + __free_page(scratch); +out_err: + dprintk("%s ERROR: returning NULL\n", __func__); + return NULL; +} + +/* + * Decode the opaque device specified in 'dev' and add it to the cache of + * available devices. + */ +static struct nfs4_file_layout_dsaddr * +decode_and_add_device(struct inode *inode, struct pnfs_device *dev, gfp_t gfp_flags) +{ + struct nfs4_deviceid_node *d; + struct nfs4_file_layout_dsaddr *n, *new; + + new = decode_device(inode, dev, gfp_flags); + if (!new) { + printk(KERN_WARNING "NFS: %s: Could not decode or add device\n", + __func__); + return NULL; + } + + d = nfs4_insert_deviceid_node(&new->id_node); + n = container_of(d, struct nfs4_file_layout_dsaddr, id_node); + if (n != new) { + nfs4_fl_free_deviceid(new); + return n; + } + + return new; +} + +/* + * Retrieve the information for dev_id, add it to the list + * of available devices, and return it. + */ +struct nfs4_file_layout_dsaddr * +filelayout_get_device_info(struct inode *inode, + struct nfs4_deviceid *dev_id, + struct rpc_cred *cred, + gfp_t gfp_flags) +{ + struct pnfs_device *pdev = NULL; + u32 max_resp_sz; + int max_pages; + struct page **pages = NULL; + struct nfs4_file_layout_dsaddr *dsaddr = NULL; + int rc, i; + struct nfs_server *server = NFS_SERVER(inode); + + /* + * 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; + max_pages = nfs_page_array_len(0, max_resp_sz); + dprintk("%s inode %p max_resp_sz %u max_pages %d\n", + __func__, inode, max_resp_sz, max_pages); + + pdev = kzalloc(sizeof(struct pnfs_device), gfp_flags); + if (pdev == NULL) + return NULL; + + pages = kzalloc(max_pages * sizeof(struct page *), gfp_flags); + if (pages == NULL) { + kfree(pdev); + return NULL; + } + for (i = 0; i < max_pages; i++) { + pages[i] = alloc_page(gfp_flags); + if (!pages[i]) + goto out_free; + } + + memcpy(&pdev->dev_id, dev_id, sizeof(*dev_id)); + pdev->layout_type = LAYOUT_NFSV4_1_FILES; + 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; + + /* + * Found new device, need to decode it and then add it to the + * list of known devices for this mountpoint. + */ + dsaddr = decode_and_add_device(inode, pdev, gfp_flags); +out_free: + for (i = 0; i < max_pages; i++) + __free_page(pages[i]); + kfree(pages); + kfree(pdev); + dprintk("<-- %s dsaddr %p\n", __func__, dsaddr); + return dsaddr; +} + +void +nfs4_fl_put_deviceid(struct nfs4_file_layout_dsaddr *dsaddr) +{ + nfs4_put_deviceid_node(&dsaddr->id_node); +} + +/* + * Want res = (offset - layout->pattern_offset)/ layout->stripe_unit + * Then: ((res + fsi) % dsaddr->stripe_count) + */ +u32 +nfs4_fl_calc_j_index(struct pnfs_layout_segment *lseg, loff_t offset) +{ + struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg); + u64 tmp; + + tmp = offset - flseg->pattern_offset; + do_div(tmp, flseg->stripe_unit); + tmp += flseg->first_stripe_index; + return do_div(tmp, flseg->dsaddr->stripe_count); +} + +u32 +nfs4_fl_calc_ds_index(struct pnfs_layout_segment *lseg, u32 j) +{ + return FILELAYOUT_LSEG(lseg)->dsaddr->stripe_indices[j]; +} + +struct nfs_fh * +nfs4_fl_select_ds_fh(struct pnfs_layout_segment *lseg, u32 j) +{ + struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg); + u32 i; + + if (flseg->stripe_type == STRIPE_SPARSE) { + if (flseg->num_fh == 1) + i = 0; + else if (flseg->num_fh == 0) + /* Use the MDS OPEN fh set in nfs_read_rpcsetup */ + return NULL; + else + i = nfs4_fl_calc_ds_index(lseg, j); + } else + i = j; + return flseg->fh_array[i]; +} + +static void nfs4_wait_ds_connect(struct nfs4_pnfs_ds *ds) +{ + might_sleep(); + wait_on_bit(&ds->ds_state, NFS4DS_CONNECTING, + nfs_wait_bit_killable, TASK_KILLABLE); +} + +static void nfs4_clear_ds_conn_bit(struct nfs4_pnfs_ds *ds) +{ + smp_mb__before_atomic(); + clear_bit(NFS4DS_CONNECTING, &ds->ds_state); + smp_mb__after_atomic(); + wake_up_bit(&ds->ds_state, NFS4DS_CONNECTING); +} + + +struct nfs4_pnfs_ds * +nfs4_fl_prepare_ds(struct pnfs_layout_segment *lseg, u32 ds_idx) +{ + struct nfs4_file_layout_dsaddr *dsaddr = FILELAYOUT_LSEG(lseg)->dsaddr; + struct nfs4_pnfs_ds *ds = dsaddr->ds_list[ds_idx]; + struct nfs4_deviceid_node *devid = FILELAYOUT_DEVID_NODE(lseg); + struct nfs4_pnfs_ds *ret = ds; + + if (ds == NULL) { + printk(KERN_ERR "NFS: %s: No data server for offset index %d\n", + __func__, ds_idx); + filelayout_mark_devid_invalid(devid); + goto out; + } + smp_rmb(); + if (ds->ds_clp) + goto out_test_devid; + + if (test_and_set_bit(NFS4DS_CONNECTING, &ds->ds_state) == 0) { + struct nfs_server *s = NFS_SERVER(lseg->pls_layout->plh_inode); + int err; + + err = nfs4_ds_connect(s, ds); + if (err) + nfs4_mark_deviceid_unavailable(devid); + nfs4_clear_ds_conn_bit(ds); + } else { + /* Either ds is connected, or ds is NULL */ + nfs4_wait_ds_connect(ds); + } +out_test_devid: + if (filelayout_test_devid_unavailable(devid)) + ret = NULL; +out: + return ret; +} + +module_param(dataserver_retrans, uint, 0644); +MODULE_PARM_DESC(dataserver_retrans, "The number of times the NFSv4.1 client " + "retries a request before it attempts further " + " recovery action."); +module_param(dataserver_timeo, uint, 0644); +MODULE_PARM_DESC(dataserver_timeo, "The time (in tenths of a second) the " + "NFSv4.1 client waits for a response from a " + " data server before it retries an NFS request."); |