Ricardo Labiaga | fb7a0b9 | 2009-04-01 09:23:00 -0400 | [diff] [blame] | 1 | /****************************************************************************** |
| 2 | |
| 3 | (c) 2007 Network Appliance, Inc. All Rights Reserved. |
| 4 | (c) 2009 NetApp. All Rights Reserved. |
| 5 | |
| 6 | NetApp provides this source code under the GPL v2 License. |
| 7 | The GPL v2 license is available at |
| 8 | http://opensource.org/licenses/gpl-license.php. |
| 9 | |
| 10 | THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 11 | "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 12 | LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| 13 | A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR |
| 14 | CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
| 15 | EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
| 16 | PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR |
| 17 | PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF |
| 18 | LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING |
| 19 | NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS |
| 20 | SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 21 | |
| 22 | ******************************************************************************/ |
| 23 | |
| 24 | #include <linux/tcp.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 25 | #include <linux/slab.h> |
Ricardo Labiaga | fb7a0b9 | 2009-04-01 09:23:00 -0400 | [diff] [blame] | 26 | #include <linux/sunrpc/xprt.h> |
Paul Gortmaker | bc3b2d7 | 2011-07-15 11:47:34 -0400 | [diff] [blame] | 27 | #include <linux/export.h> |
Trond Myklebust | 09acfea | 2012-03-11 15:22:54 -0400 | [diff] [blame] | 28 | #include <linux/sunrpc/bc_xprt.h> |
Ricardo Labiaga | fb7a0b9 | 2009-04-01 09:23:00 -0400 | [diff] [blame] | 29 | |
Jeff Layton | f895b25 | 2014-11-17 16:58:04 -0500 | [diff] [blame] | 30 | #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) |
Ricardo Labiaga | fb7a0b9 | 2009-04-01 09:23:00 -0400 | [diff] [blame] | 31 | #define RPCDBG_FACILITY RPCDBG_TRANS |
| 32 | #endif |
| 33 | |
Ricardo Labiaga | fb7a0b9 | 2009-04-01 09:23:00 -0400 | [diff] [blame] | 34 | /* |
| 35 | * Helper routines that track the number of preallocation elements |
| 36 | * on the transport. |
| 37 | */ |
| 38 | static inline int xprt_need_to_requeue(struct rpc_xprt *xprt) |
| 39 | { |
| 40 | return xprt->bc_alloc_count > 0; |
| 41 | } |
| 42 | |
| 43 | static inline void xprt_inc_alloc_count(struct rpc_xprt *xprt, unsigned int n) |
| 44 | { |
| 45 | xprt->bc_alloc_count += n; |
| 46 | } |
| 47 | |
| 48 | static inline int xprt_dec_alloc_count(struct rpc_xprt *xprt, unsigned int n) |
| 49 | { |
| 50 | return xprt->bc_alloc_count -= n; |
| 51 | } |
| 52 | |
| 53 | /* |
| 54 | * Free the preallocated rpc_rqst structure and the memory |
| 55 | * buffers hanging off of it. |
| 56 | */ |
| 57 | static void xprt_free_allocation(struct rpc_rqst *req) |
| 58 | { |
| 59 | struct xdr_buf *xbufp; |
| 60 | |
| 61 | dprintk("RPC: free allocations for req= %p\n", req); |
Weston Andros Adamson | f30dfbb | 2012-10-23 10:43:33 -0400 | [diff] [blame] | 62 | WARN_ON_ONCE(test_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state)); |
Trond Myklebust | 88de6af | 2015-06-01 15:10:25 -0400 | [diff] [blame] | 63 | xbufp = &req->rq_rcv_buf; |
Ricardo Labiaga | fb7a0b9 | 2009-04-01 09:23:00 -0400 | [diff] [blame] | 64 | free_page((unsigned long)xbufp->head[0].iov_base); |
| 65 | xbufp = &req->rq_snd_buf; |
| 66 | free_page((unsigned long)xbufp->head[0].iov_base); |
Ricardo Labiaga | fb7a0b9 | 2009-04-01 09:23:00 -0400 | [diff] [blame] | 67 | kfree(req); |
| 68 | } |
| 69 | |
Trond Myklebust | 1dddda8 | 2015-06-01 15:05:38 -0400 | [diff] [blame^] | 70 | static int xprt_alloc_xdr_buf(struct xdr_buf *buf, gfp_t gfp_flags) |
| 71 | { |
| 72 | struct page *page; |
| 73 | /* Preallocate one XDR receive buffer */ |
| 74 | page = alloc_page(gfp_flags); |
| 75 | if (page == NULL) |
| 76 | return -ENOMEM; |
| 77 | buf->head[0].iov_base = page_address(page); |
| 78 | buf->head[0].iov_len = PAGE_SIZE; |
| 79 | buf->tail[0].iov_base = NULL; |
| 80 | buf->tail[0].iov_len = 0; |
| 81 | buf->page_len = 0; |
| 82 | buf->len = 0; |
| 83 | buf->buflen = PAGE_SIZE; |
| 84 | return 0; |
| 85 | } |
| 86 | |
| 87 | static |
| 88 | struct rpc_rqst *xprt_alloc_bc_req(struct rpc_xprt *xprt, gfp_t gfp_flags) |
| 89 | { |
| 90 | struct rpc_rqst *req; |
| 91 | |
| 92 | /* Pre-allocate one backchannel rpc_rqst */ |
| 93 | req = kzalloc(sizeof(*req), gfp_flags); |
| 94 | if (req == NULL) |
| 95 | return NULL; |
| 96 | |
| 97 | req->rq_xprt = xprt; |
| 98 | INIT_LIST_HEAD(&req->rq_list); |
| 99 | INIT_LIST_HEAD(&req->rq_bc_list); |
| 100 | |
| 101 | /* Preallocate one XDR receive buffer */ |
| 102 | if (xprt_alloc_xdr_buf(&req->rq_rcv_buf, gfp_flags) < 0) { |
| 103 | printk(KERN_ERR "Failed to create bc receive xbuf\n"); |
| 104 | goto out_free; |
| 105 | } |
| 106 | req->rq_rcv_buf.len = PAGE_SIZE; |
| 107 | |
| 108 | /* Preallocate one XDR send buffer */ |
| 109 | if (xprt_alloc_xdr_buf(&req->rq_snd_buf, gfp_flags) < 0) { |
| 110 | printk(KERN_ERR "Failed to create bc snd xbuf\n"); |
| 111 | goto out_free; |
| 112 | } |
| 113 | return req; |
| 114 | out_free: |
| 115 | xprt_free_allocation(req); |
| 116 | return NULL; |
| 117 | } |
| 118 | |
Ricardo Labiaga | fb7a0b9 | 2009-04-01 09:23:00 -0400 | [diff] [blame] | 119 | /* |
| 120 | * Preallocate up to min_reqs structures and related buffers for use |
| 121 | * by the backchannel. This function can be called multiple times |
| 122 | * when creating new sessions that use the same rpc_xprt. The |
| 123 | * preallocated buffers are added to the pool of resources used by |
| 124 | * the rpc_xprt. Anyone of these resources may be used used by an |
| 125 | * incoming callback request. It's up to the higher levels in the |
| 126 | * stack to enforce that the maximum number of session slots is not |
| 127 | * being exceeded. |
| 128 | * |
| 129 | * Some callback arguments can be large. For example, a pNFS server |
| 130 | * using multiple deviceids. The list can be unbound, but the client |
| 131 | * has the ability to tell the server the maximum size of the callback |
| 132 | * requests. Each deviceID is 16 bytes, so allocate one page |
| 133 | * for the arguments to have enough room to receive a number of these |
| 134 | * deviceIDs. The NFS client indicates to the pNFS server that its |
| 135 | * callback requests can be up to 4096 bytes in size. |
| 136 | */ |
| 137 | int xprt_setup_backchannel(struct rpc_xprt *xprt, unsigned int min_reqs) |
| 138 | { |
Trond Myklebust | 1dddda8 | 2015-06-01 15:05:38 -0400 | [diff] [blame^] | 139 | struct rpc_rqst *req; |
Ricardo Labiaga | fb7a0b9 | 2009-04-01 09:23:00 -0400 | [diff] [blame] | 140 | struct list_head tmp_list; |
| 141 | int i; |
| 142 | |
| 143 | dprintk("RPC: setup backchannel transport\n"); |
| 144 | |
| 145 | /* |
| 146 | * We use a temporary list to keep track of the preallocated |
| 147 | * buffers. Once we're done building the list we splice it |
| 148 | * into the backchannel preallocation list off of the rpc_xprt |
| 149 | * struct. This helps minimize the amount of time the list |
| 150 | * lock is held on the rpc_xprt struct. It also makes cleanup |
| 151 | * easier in case of memory allocation errors. |
| 152 | */ |
| 153 | INIT_LIST_HEAD(&tmp_list); |
| 154 | for (i = 0; i < min_reqs; i++) { |
| 155 | /* Pre-allocate one backchannel rpc_rqst */ |
Trond Myklebust | 1dddda8 | 2015-06-01 15:05:38 -0400 | [diff] [blame^] | 156 | req = xprt_alloc_bc_req(xprt, GFP_KERNEL); |
Ricardo Labiaga | fb7a0b9 | 2009-04-01 09:23:00 -0400 | [diff] [blame] | 157 | if (req == NULL) { |
| 158 | printk(KERN_ERR "Failed to create bc rpc_rqst\n"); |
| 159 | goto out_free; |
| 160 | } |
| 161 | |
| 162 | /* Add the allocated buffer to the tmp list */ |
| 163 | dprintk("RPC: adding req= %p\n", req); |
| 164 | list_add(&req->rq_bc_pa_list, &tmp_list); |
Ricardo Labiaga | fb7a0b9 | 2009-04-01 09:23:00 -0400 | [diff] [blame] | 165 | } |
| 166 | |
| 167 | /* |
| 168 | * Add the temporary list to the backchannel preallocation list |
| 169 | */ |
| 170 | spin_lock_bh(&xprt->bc_pa_lock); |
| 171 | list_splice(&tmp_list, &xprt->bc_pa_list); |
| 172 | xprt_inc_alloc_count(xprt, min_reqs); |
| 173 | spin_unlock_bh(&xprt->bc_pa_lock); |
| 174 | |
| 175 | dprintk("RPC: setup backchannel transport done\n"); |
| 176 | return 0; |
| 177 | |
| 178 | out_free: |
| 179 | /* |
| 180 | * Memory allocation failed, free the temporary list |
| 181 | */ |
Trond Myklebust | 1dddda8 | 2015-06-01 15:05:38 -0400 | [diff] [blame^] | 182 | while (!list_empty(&tmp_list)) { |
| 183 | req = list_first_entry(&tmp_list, |
| 184 | struct rpc_rqst, |
| 185 | rq_bc_pa_list); |
Trond Myklebust | 6283567 | 2014-02-11 13:56:54 -0500 | [diff] [blame] | 186 | list_del(&req->rq_bc_pa_list); |
Ricardo Labiaga | fb7a0b9 | 2009-04-01 09:23:00 -0400 | [diff] [blame] | 187 | xprt_free_allocation(req); |
Trond Myklebust | 6283567 | 2014-02-11 13:56:54 -0500 | [diff] [blame] | 188 | } |
Ricardo Labiaga | fb7a0b9 | 2009-04-01 09:23:00 -0400 | [diff] [blame] | 189 | |
| 190 | dprintk("RPC: setup backchannel transport failed\n"); |
Weston Andros Adamson | d24bab9 | 2012-11-01 11:21:53 -0400 | [diff] [blame] | 191 | return -ENOMEM; |
Ricardo Labiaga | fb7a0b9 | 2009-04-01 09:23:00 -0400 | [diff] [blame] | 192 | } |
Trond Myklebust | 0d961aa | 2011-07-13 19:24:15 -0400 | [diff] [blame] | 193 | EXPORT_SYMBOL_GPL(xprt_setup_backchannel); |
Ricardo Labiaga | fb7a0b9 | 2009-04-01 09:23:00 -0400 | [diff] [blame] | 194 | |
Ben Hutchings | 2c53040 | 2012-07-10 10:55:09 +0000 | [diff] [blame] | 195 | /** |
| 196 | * xprt_destroy_backchannel - Destroys the backchannel preallocated structures. |
| 197 | * @xprt: the transport holding the preallocated strucures |
| 198 | * @max_reqs the maximum number of preallocated structures to destroy |
| 199 | * |
Ricardo Labiaga | fb7a0b9 | 2009-04-01 09:23:00 -0400 | [diff] [blame] | 200 | * Since these structures may have been allocated by multiple calls |
| 201 | * to xprt_setup_backchannel, we only destroy up to the maximum number |
| 202 | * of reqs specified by the caller. |
Ricardo Labiaga | fb7a0b9 | 2009-04-01 09:23:00 -0400 | [diff] [blame] | 203 | */ |
| 204 | void xprt_destroy_backchannel(struct rpc_xprt *xprt, unsigned int max_reqs) |
| 205 | { |
| 206 | struct rpc_rqst *req = NULL, *tmp = NULL; |
| 207 | |
| 208 | dprintk("RPC: destroy backchannel transport\n"); |
| 209 | |
Weston Andros Adamson | c4ded8d | 2012-10-23 10:43:34 -0400 | [diff] [blame] | 210 | if (max_reqs == 0) |
| 211 | goto out; |
| 212 | |
Ricardo Labiaga | fb7a0b9 | 2009-04-01 09:23:00 -0400 | [diff] [blame] | 213 | spin_lock_bh(&xprt->bc_pa_lock); |
| 214 | xprt_dec_alloc_count(xprt, max_reqs); |
| 215 | list_for_each_entry_safe(req, tmp, &xprt->bc_pa_list, rq_bc_pa_list) { |
| 216 | dprintk("RPC: req=%p\n", req); |
Trond Myklebust | 6283567 | 2014-02-11 13:56:54 -0500 | [diff] [blame] | 217 | list_del(&req->rq_bc_pa_list); |
Ricardo Labiaga | fb7a0b9 | 2009-04-01 09:23:00 -0400 | [diff] [blame] | 218 | xprt_free_allocation(req); |
| 219 | if (--max_reqs == 0) |
| 220 | break; |
| 221 | } |
| 222 | spin_unlock_bh(&xprt->bc_pa_lock); |
| 223 | |
Weston Andros Adamson | c4ded8d | 2012-10-23 10:43:34 -0400 | [diff] [blame] | 224 | out: |
Ricardo Labiaga | fb7a0b9 | 2009-04-01 09:23:00 -0400 | [diff] [blame] | 225 | dprintk("RPC: backchannel list empty= %s\n", |
| 226 | list_empty(&xprt->bc_pa_list) ? "true" : "false"); |
| 227 | } |
Trond Myklebust | 0d961aa | 2011-07-13 19:24:15 -0400 | [diff] [blame] | 228 | EXPORT_SYMBOL_GPL(xprt_destroy_backchannel); |
Ricardo Labiaga | fb7a0b9 | 2009-04-01 09:23:00 -0400 | [diff] [blame] | 229 | |
Trond Myklebust | 2ea2449 | 2014-02-10 11:18:39 -0500 | [diff] [blame] | 230 | static struct rpc_rqst *xprt_alloc_bc_request(struct rpc_xprt *xprt, __be32 xid) |
Ricardo Labiaga | fb7a0b9 | 2009-04-01 09:23:00 -0400 | [diff] [blame] | 231 | { |
Trond Myklebust | 2ea2449 | 2014-02-10 11:18:39 -0500 | [diff] [blame] | 232 | struct rpc_rqst *req = NULL; |
Ricardo Labiaga | fb7a0b9 | 2009-04-01 09:23:00 -0400 | [diff] [blame] | 233 | |
| 234 | dprintk("RPC: allocate a backchannel request\n"); |
Trond Myklebust | 2ea2449 | 2014-02-10 11:18:39 -0500 | [diff] [blame] | 235 | if (list_empty(&xprt->bc_pa_list)) |
| 236 | goto not_found; |
Ricardo Labiaga | fb7a0b9 | 2009-04-01 09:23:00 -0400 | [diff] [blame] | 237 | |
Trond Myklebust | 2ea2449 | 2014-02-10 11:18:39 -0500 | [diff] [blame] | 238 | req = list_first_entry(&xprt->bc_pa_list, struct rpc_rqst, |
| 239 | rq_bc_pa_list); |
| 240 | req->rq_reply_bytes_recvd = 0; |
| 241 | req->rq_bytes_sent = 0; |
| 242 | memcpy(&req->rq_private_buf, &req->rq_rcv_buf, |
Ricardo Labiaga | fb7a0b9 | 2009-04-01 09:23:00 -0400 | [diff] [blame] | 243 | sizeof(req->rq_private_buf)); |
Trond Myklebust | 2ea2449 | 2014-02-10 11:18:39 -0500 | [diff] [blame] | 244 | req->rq_xid = xid; |
| 245 | req->rq_connect_cookie = xprt->connect_cookie; |
| 246 | not_found: |
Ricardo Labiaga | fb7a0b9 | 2009-04-01 09:23:00 -0400 | [diff] [blame] | 247 | dprintk("RPC: backchannel req=%p\n", req); |
| 248 | return req; |
| 249 | } |
| 250 | |
| 251 | /* |
| 252 | * Return the preallocated rpc_rqst structure and XDR buffers |
| 253 | * associated with this rpc_task. |
| 254 | */ |
| 255 | void xprt_free_bc_request(struct rpc_rqst *req) |
| 256 | { |
| 257 | struct rpc_xprt *xprt = req->rq_xprt; |
| 258 | |
| 259 | dprintk("RPC: free backchannel req=%p\n", req); |
| 260 | |
Trond Myklebust | 2ea2449 | 2014-02-10 11:18:39 -0500 | [diff] [blame] | 261 | req->rq_connect_cookie = xprt->connect_cookie - 1; |
Peter Zijlstra | 4e857c5 | 2014-03-17 18:06:10 +0100 | [diff] [blame] | 262 | smp_mb__before_atomic(); |
Weston Andros Adamson | f30dfbb | 2012-10-23 10:43:33 -0400 | [diff] [blame] | 263 | WARN_ON_ONCE(!test_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state)); |
Ricardo Labiaga | fb7a0b9 | 2009-04-01 09:23:00 -0400 | [diff] [blame] | 264 | clear_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state); |
Peter Zijlstra | 4e857c5 | 2014-03-17 18:06:10 +0100 | [diff] [blame] | 265 | smp_mb__after_atomic(); |
Ricardo Labiaga | fb7a0b9 | 2009-04-01 09:23:00 -0400 | [diff] [blame] | 266 | |
| 267 | if (!xprt_need_to_requeue(xprt)) { |
| 268 | /* |
| 269 | * The last remaining session was destroyed while this |
| 270 | * entry was in use. Free the entry and don't attempt |
| 271 | * to add back to the list because there is no need to |
| 272 | * have anymore preallocated entries. |
| 273 | */ |
| 274 | dprintk("RPC: Last session removed req=%p\n", req); |
| 275 | xprt_free_allocation(req); |
| 276 | return; |
| 277 | } |
| 278 | |
| 279 | /* |
| 280 | * Return it to the list of preallocations so that it |
| 281 | * may be reused by a new callback request. |
| 282 | */ |
| 283 | spin_lock_bh(&xprt->bc_pa_lock); |
Trond Myklebust | 2ea2449 | 2014-02-10 11:18:39 -0500 | [diff] [blame] | 284 | list_add_tail(&req->rq_bc_pa_list, &xprt->bc_pa_list); |
Ricardo Labiaga | fb7a0b9 | 2009-04-01 09:23:00 -0400 | [diff] [blame] | 285 | spin_unlock_bh(&xprt->bc_pa_lock); |
| 286 | } |
| 287 | |
Trond Myklebust | 2ea2449 | 2014-02-10 11:18:39 -0500 | [diff] [blame] | 288 | /* |
| 289 | * One or more rpc_rqst structure have been preallocated during the |
| 290 | * backchannel setup. Buffer space for the send and private XDR buffers |
| 291 | * has been preallocated as well. Use xprt_alloc_bc_request to allocate |
| 292 | * to this request. Use xprt_free_bc_request to return it. |
| 293 | * |
| 294 | * We know that we're called in soft interrupt context, grab the spin_lock |
| 295 | * since there is no need to grab the bottom half spin_lock. |
| 296 | * |
| 297 | * Return an available rpc_rqst, otherwise NULL if non are available. |
| 298 | */ |
| 299 | struct rpc_rqst *xprt_lookup_bc_request(struct rpc_xprt *xprt, __be32 xid) |
| 300 | { |
| 301 | struct rpc_rqst *req; |
| 302 | |
| 303 | spin_lock(&xprt->bc_pa_lock); |
| 304 | list_for_each_entry(req, &xprt->bc_pa_list, rq_bc_pa_list) { |
| 305 | if (req->rq_connect_cookie != xprt->connect_cookie) |
| 306 | continue; |
| 307 | if (req->rq_xid == xid) |
| 308 | goto found; |
| 309 | } |
| 310 | req = xprt_alloc_bc_request(xprt, xid); |
| 311 | found: |
| 312 | spin_unlock(&xprt->bc_pa_lock); |
| 313 | return req; |
| 314 | } |
| 315 | |
| 316 | /* |
| 317 | * Add callback request to callback list. The callback |
| 318 | * service sleeps on the sv_cb_waitq waiting for new |
| 319 | * requests. Wake it up after adding enqueing the |
| 320 | * request. |
| 321 | */ |
| 322 | void xprt_complete_bc_request(struct rpc_rqst *req, uint32_t copied) |
| 323 | { |
| 324 | struct rpc_xprt *xprt = req->rq_xprt; |
| 325 | struct svc_serv *bc_serv = xprt->bc_serv; |
| 326 | |
Chuck Lever | 813b00d | 2015-02-13 13:08:25 -0500 | [diff] [blame] | 327 | spin_lock(&xprt->bc_pa_lock); |
| 328 | list_del(&req->rq_bc_pa_list); |
| 329 | spin_unlock(&xprt->bc_pa_lock); |
| 330 | |
Trond Myklebust | 2ea2449 | 2014-02-10 11:18:39 -0500 | [diff] [blame] | 331 | req->rq_private_buf.len = copied; |
| 332 | set_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state); |
| 333 | |
| 334 | dprintk("RPC: add callback request to list\n"); |
| 335 | spin_lock(&bc_serv->sv_cb_lock); |
Trond Myklebust | 2ea2449 | 2014-02-10 11:18:39 -0500 | [diff] [blame] | 336 | list_add(&req->rq_bc_list, &bc_serv->sv_cb_list); |
| 337 | wake_up(&bc_serv->sv_cb_waitq); |
| 338 | spin_unlock(&bc_serv->sv_cb_lock); |
| 339 | } |
| 340 | |