From 587bc7255d26ca80b58026881db5fb3bf770cc43 Mon Sep 17 00:00:00 2001 From: Olga Kornievskaia Date: Tue, 8 Jun 2021 15:59:19 -0400 Subject: [PATCH] sunrpc: add dst_attr attributes to the sysfs xprt directory Allow to query and set the destination's address of a transport. Setting of the destination address is allowed only for TCP or RDMA based connections. Signed-off-by: Olga Kornievskaia Signed-off-by: Trond Myklebust --- include/linux/sunrpc/xprt.h | 1 + net/sunrpc/sysfs.c | 105 ++++++++++++++++++++++++++++++++++++ net/sunrpc/xprt.c | 4 +- net/sunrpc/xprtmultipath.c | 2 - 4 files changed, 109 insertions(+), 3 deletions(-) diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h index 8360db664e5f..13a4eaf385cf 100644 --- a/include/linux/sunrpc/xprt.h +++ b/include/linux/sunrpc/xprt.h @@ -414,6 +414,7 @@ void xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie); bool xprt_lock_connect(struct rpc_xprt *, struct rpc_task *, void *); void xprt_unlock_connect(struct rpc_xprt *, void *); +void xprt_release_write(struct rpc_xprt *, struct rpc_task *); /* * Reserved bit positions in xprt->state diff --git a/net/sunrpc/sysfs.c b/net/sunrpc/sysfs.c index 20f75708594f..402924bbd743 100644 --- a/net/sunrpc/sysfs.c +++ b/net/sunrpc/sysfs.c @@ -4,8 +4,23 @@ */ #include #include +#include + #include "sysfs.h" +struct xprt_addr { + const char *addr; + struct rcu_head rcu; +}; + +static void free_xprt_addr(struct rcu_head *head) +{ + struct xprt_addr *addr = container_of(head, struct xprt_addr, rcu); + + kfree(addr->addr); + kfree(addr); +} + static struct kset *rpc_sunrpc_kset; static struct kobject *rpc_sunrpc_client_kobj, *rpc_sunrpc_xprt_switch_kobj; @@ -43,6 +58,87 @@ static struct kobject *rpc_sysfs_object_alloc(const char *name, return NULL; } +static inline struct rpc_xprt * +rpc_sysfs_xprt_kobj_get_xprt(struct kobject *kobj) +{ + struct rpc_sysfs_xprt *x = container_of(kobj, + struct rpc_sysfs_xprt, kobject); + + return xprt_get(x->xprt); +} + +static ssize_t rpc_sysfs_xprt_dstaddr_show(struct kobject *kobj, + struct kobj_attribute *attr, + char *buf) +{ + struct rpc_xprt *xprt = rpc_sysfs_xprt_kobj_get_xprt(kobj); + ssize_t ret; + + if (!xprt) + return 0; + ret = sprintf(buf, "%s\n", xprt->address_strings[RPC_DISPLAY_ADDR]); + xprt_put(xprt); + return ret + 1; +} + +static ssize_t rpc_sysfs_xprt_dstaddr_store(struct kobject *kobj, + struct kobj_attribute *attr, + const char *buf, size_t count) +{ + struct rpc_xprt *xprt = rpc_sysfs_xprt_kobj_get_xprt(kobj); + struct sockaddr *saddr; + char *dst_addr; + int port; + struct xprt_addr *saved_addr; + size_t buf_len; + + if (!xprt) + return 0; + if (!(xprt->xprt_class->ident == XPRT_TRANSPORT_TCP || + xprt->xprt_class->ident == XPRT_TRANSPORT_RDMA)) { + xprt_put(xprt); + return -EOPNOTSUPP; + } + + if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE)) { + count = -EINTR; + goto out_put; + } + saddr = (struct sockaddr *)&xprt->addr; + port = rpc_get_port(saddr); + + /* buf_len is the len until the first occurence of either + * '\n' or '\0' + */ + buf_len = strcspn(buf, "\n"); + + dst_addr = kstrndup(buf, buf_len, GFP_KERNEL); + if (!dst_addr) + goto out_err; + saved_addr = kzalloc(sizeof(*saved_addr), GFP_KERNEL); + if (!saved_addr) + goto out_err_free; + saved_addr->addr = + rcu_dereference_raw(xprt->address_strings[RPC_DISPLAY_ADDR]); + rcu_assign_pointer(xprt->address_strings[RPC_DISPLAY_ADDR], dst_addr); + call_rcu(&saved_addr->rcu, free_xprt_addr); + xprt->addrlen = rpc_pton(xprt->xprt_net, buf, buf_len, saddr, + sizeof(*saddr)); + rpc_set_port(saddr, port); + + xprt_force_disconnect(xprt); +out: + xprt_release_write(xprt, NULL); +out_put: + xprt_put(xprt); + return count; +out_err_free: + kfree(dst_addr); +out_err: + count = -ENOMEM; + goto out; +} + int rpc_sysfs_init(void) { rpc_sunrpc_kset = kset_create_and_add("sunrpc", NULL, kernel_kobj); @@ -106,6 +202,14 @@ static const void *rpc_sysfs_xprt_namespace(struct kobject *kobj) kobject)->xprt->xprt_net; } +static struct kobj_attribute rpc_sysfs_xprt_dstaddr = __ATTR(dstaddr, + 0644, rpc_sysfs_xprt_dstaddr_show, rpc_sysfs_xprt_dstaddr_store); + +static struct attribute *rpc_sysfs_xprt_attrs[] = { + &rpc_sysfs_xprt_dstaddr.attr, + NULL, +}; + static struct kobj_type rpc_sysfs_client_type = { .release = rpc_sysfs_client_release, .sysfs_ops = &kobj_sysfs_ops, @@ -120,6 +224,7 @@ static struct kobj_type rpc_sysfs_xprt_switch_type = { static struct kobj_type rpc_sysfs_xprt_type = { .release = rpc_sysfs_xprt_release, + .default_attrs = rpc_sysfs_xprt_attrs, .sysfs_ops = &kobj_sysfs_ops, .namespace = rpc_sysfs_xprt_namespace, }; diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c index 20b9bd705014..fb6db09725c7 100644 --- a/net/sunrpc/xprt.c +++ b/net/sunrpc/xprt.c @@ -55,6 +55,7 @@ #include #include "sunrpc.h" +#include "sysfs.h" /* * Local variables @@ -443,7 +444,7 @@ void xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task) } EXPORT_SYMBOL_GPL(xprt_release_xprt_cong); -static inline void xprt_release_write(struct rpc_xprt *xprt, struct rpc_task *task) +void xprt_release_write(struct rpc_xprt *xprt, struct rpc_task *task) { if (xprt->snd_task != task) return; @@ -1812,6 +1813,7 @@ void xprt_free(struct rpc_xprt *xprt) put_net(xprt->xprt_net); xprt_free_all_slots(xprt); xprt_free_id(xprt); + rpc_sysfs_xprt_destroy(xprt); kfree_rcu(xprt, rcu); } EXPORT_SYMBOL_GPL(xprt_free); diff --git a/net/sunrpc/xprtmultipath.c b/net/sunrpc/xprtmultipath.c index e7973c1ff70c..07e76ae1028a 100644 --- a/net/sunrpc/xprtmultipath.c +++ b/net/sunrpc/xprtmultipath.c @@ -86,7 +86,6 @@ void rpc_xprt_switch_remove_xprt(struct rpc_xprt_switch *xps, spin_lock(&xps->xps_lock); xprt_switch_remove_xprt_locked(xps, xprt); spin_unlock(&xps->xps_lock); - rpc_sysfs_xprt_destroy(xprt); xprt_put(xprt); } @@ -155,7 +154,6 @@ static void xprt_switch_free_entries(struct rpc_xprt_switch *xps) struct rpc_xprt, xprt_switch); xprt_switch_remove_xprt_locked(xps, xprt); spin_unlock(&xps->xps_lock); - rpc_sysfs_xprt_destroy(xprt); xprt_put(xprt); spin_lock(&xps->xps_lock); } -- 2.20.1