diff options
Diffstat (limited to 'fs/nfs/pnfs_nfs.c')
| -rw-r--r-- | fs/nfs/pnfs_nfs.c | 242 |
1 files changed, 242 insertions, 0 deletions
diff --git a/fs/nfs/pnfs_nfs.c b/fs/nfs/pnfs_nfs.c index fd2a2f0e8cbb..3bb2b74cf600 100644 --- a/fs/nfs/pnfs_nfs.c +++ b/fs/nfs/pnfs_nfs.c @@ -13,6 +13,8 @@ #include "internal.h" #include "pnfs.h" +#define NFSDBG_FACILITY NFSDBG_PNFS + static void pnfs_generic_fenceme(struct inode *inode, struct pnfs_layout_hdr *lo) { @@ -290,3 +292,243 @@ out: return PNFS_ATTEMPTED; } EXPORT_SYMBOL_GPL(pnfs_generic_commit_pagelist); + +/* + * 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 */ +static void +print_ds(struct nfs4_pnfs_ds *ds) +{ + if (ds == NULL) { + printk(KERN_WARNING "%s NULL device\n", __func__); + return; + } + printk(KERN_WARNING " 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; +} + +static void destroy_ds(struct nfs4_pnfs_ds *ds) +{ + struct nfs4_pnfs_ds_addr *da; + + dprintk("--> %s\n", __func__); + ifdebug(FACILITY) + print_ds(ds); + + 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_pnfs_ds_put(struct nfs4_pnfs_ds *ds) +{ + 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); + } +} +EXPORT_SYMBOL_GPL(nfs4_pnfs_ds_put); + +/* + * 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; +} + +/* + * Given a list of multipath struct nfs4_pnfs_ds_addr, add it to ds cache if + * uncached and return cached struct nfs4_pnfs_ds. + */ +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; +} +EXPORT_SYMBOL_GPL(nfs4_pnfs_ds_add); |