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TOMOYO Linux Cross Reference
Linux/fs/nfs/filelayout/filelayout.c

Version: ~ [ linux-5.2-rc1 ] ~ [ linux-5.1.2 ] ~ [ linux-5.0.16 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.43 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.119 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.176 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.179 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.139 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.67 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.39.4 ] ~ [ linux-2.6.38.8 ] ~ [ linux-2.6.37.6 ] ~ [ linux-2.6.36.4 ] ~ [ linux-2.6.35.14 ] ~ [ linux-2.6.34.15 ] ~ [ linux-2.6.33.20 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
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  1 /*
  2  *  Module for the pnfs nfs4 file layout driver.
  3  *  Defines all I/O and Policy interface operations, plus code
  4  *  to register itself with the pNFS client.
  5  *
  6  *  Copyright (c) 2002
  7  *  The Regents of the University of Michigan
  8  *  All Rights Reserved
  9  *
 10  *  Dean Hildebrand <dhildebz@umich.edu>
 11  *
 12  *  Permission is granted to use, copy, create derivative works, and
 13  *  redistribute this software and such derivative works for any purpose,
 14  *  so long as the name of the University of Michigan is not used in
 15  *  any advertising or publicity pertaining to the use or distribution
 16  *  of this software without specific, written prior authorization. If
 17  *  the above copyright notice or any other identification of the
 18  *  University of Michigan is included in any copy of any portion of
 19  *  this software, then the disclaimer below must also be included.
 20  *
 21  *  This software is provided as is, without representation or warranty
 22  *  of any kind either express or implied, including without limitation
 23  *  the implied warranties of merchantability, fitness for a particular
 24  *  purpose, or noninfringement.  The Regents of the University of
 25  *  Michigan shall not be liable for any damages, including special,
 26  *  indirect, incidental, or consequential damages, with respect to any
 27  *  claim arising out of or in connection with the use of the software,
 28  *  even if it has been or is hereafter advised of the possibility of
 29  *  such damages.
 30  */
 31 
 32 #include <linux/nfs_fs.h>
 33 #include <linux/nfs_page.h>
 34 #include <linux/module.h>
 35 #include <linux/backing-dev.h>
 36 
 37 #include <linux/sunrpc/metrics.h>
 38 
 39 #include "../nfs4session.h"
 40 #include "../internal.h"
 41 #include "../delegation.h"
 42 #include "filelayout.h"
 43 #include "../nfs4trace.h"
 44 
 45 #define NFSDBG_FACILITY         NFSDBG_PNFS_LD
 46 
 47 MODULE_LICENSE("GPL");
 48 MODULE_AUTHOR("Dean Hildebrand <dhildebz@umich.edu>");
 49 MODULE_DESCRIPTION("The NFSv4 file layout driver");
 50 
 51 #define FILELAYOUT_POLL_RETRY_MAX     (15*HZ)
 52 
 53 static loff_t
 54 filelayout_get_dense_offset(struct nfs4_filelayout_segment *flseg,
 55                             loff_t offset)
 56 {
 57         u32 stripe_width = flseg->stripe_unit * flseg->dsaddr->stripe_count;
 58         u64 stripe_no;
 59         u32 rem;
 60 
 61         offset -= flseg->pattern_offset;
 62         stripe_no = div_u64(offset, stripe_width);
 63         div_u64_rem(offset, flseg->stripe_unit, &rem);
 64 
 65         return stripe_no * flseg->stripe_unit + rem;
 66 }
 67 
 68 /* This function is used by the layout driver to calculate the
 69  * offset of the file on the dserver based on whether the
 70  * layout type is STRIPE_DENSE or STRIPE_SPARSE
 71  */
 72 static loff_t
 73 filelayout_get_dserver_offset(struct pnfs_layout_segment *lseg, loff_t offset)
 74 {
 75         struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg);
 76 
 77         switch (flseg->stripe_type) {
 78         case STRIPE_SPARSE:
 79                 return offset;
 80 
 81         case STRIPE_DENSE:
 82                 return filelayout_get_dense_offset(flseg, offset);
 83         }
 84 
 85         BUG();
 86 }
 87 
 88 static void filelayout_reset_write(struct nfs_pgio_header *hdr)
 89 {
 90         struct rpc_task *task = &hdr->task;
 91 
 92         if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
 93                 dprintk("%s Reset task %5u for i/o through MDS "
 94                         "(req %s/%llu, %u bytes @ offset %llu)\n", __func__,
 95                         hdr->task.tk_pid,
 96                         hdr->inode->i_sb->s_id,
 97                         (unsigned long long)NFS_FILEID(hdr->inode),
 98                         hdr->args.count,
 99                         (unsigned long long)hdr->args.offset);
100 
101                 task->tk_status = pnfs_write_done_resend_to_mds(hdr);
102         }
103 }
104 
105 static void filelayout_reset_read(struct nfs_pgio_header *hdr)
106 {
107         struct rpc_task *task = &hdr->task;
108 
109         if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
110                 dprintk("%s Reset task %5u for i/o through MDS "
111                         "(req %s/%llu, %u bytes @ offset %llu)\n", __func__,
112                         hdr->task.tk_pid,
113                         hdr->inode->i_sb->s_id,
114                         (unsigned long long)NFS_FILEID(hdr->inode),
115                         hdr->args.count,
116                         (unsigned long long)hdr->args.offset);
117 
118                 task->tk_status = pnfs_read_done_resend_to_mds(hdr);
119         }
120 }
121 
122 static int filelayout_async_handle_error(struct rpc_task *task,
123                                          struct nfs4_state *state,
124                                          struct nfs_client *clp,
125                                          struct pnfs_layout_segment *lseg)
126 {
127         struct pnfs_layout_hdr *lo = lseg->pls_layout;
128         struct inode *inode = lo->plh_inode;
129         struct nfs4_deviceid_node *devid = FILELAYOUT_DEVID_NODE(lseg);
130         struct nfs4_slot_table *tbl = &clp->cl_session->fc_slot_table;
131 
132         if (task->tk_status >= 0)
133                 return 0;
134 
135         switch (task->tk_status) {
136         /* DS session errors */
137         case -NFS4ERR_BADSESSION:
138         case -NFS4ERR_BADSLOT:
139         case -NFS4ERR_BAD_HIGH_SLOT:
140         case -NFS4ERR_DEADSESSION:
141         case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
142         case -NFS4ERR_SEQ_FALSE_RETRY:
143         case -NFS4ERR_SEQ_MISORDERED:
144                 dprintk("%s ERROR %d, Reset session. Exchangeid "
145                         "flags 0x%x\n", __func__, task->tk_status,
146                         clp->cl_exchange_flags);
147                 nfs4_schedule_session_recovery(clp->cl_session, task->tk_status);
148                 break;
149         case -NFS4ERR_DELAY:
150         case -NFS4ERR_GRACE:
151                 rpc_delay(task, FILELAYOUT_POLL_RETRY_MAX);
152                 break;
153         case -NFS4ERR_RETRY_UNCACHED_REP:
154                 break;
155         /* Invalidate Layout errors */
156         case -NFS4ERR_ACCESS:
157         case -NFS4ERR_PNFS_NO_LAYOUT:
158         case -ESTALE:           /* mapped NFS4ERR_STALE */
159         case -EBADHANDLE:       /* mapped NFS4ERR_BADHANDLE */
160         case -EISDIR:           /* mapped NFS4ERR_ISDIR */
161         case -NFS4ERR_FHEXPIRED:
162         case -NFS4ERR_WRONG_TYPE:
163                 dprintk("%s Invalid layout error %d\n", __func__,
164                         task->tk_status);
165                 /*
166                  * Destroy layout so new i/o will get a new layout.
167                  * Layout will not be destroyed until all current lseg
168                  * references are put. Mark layout as invalid to resend failed
169                  * i/o and all i/o waiting on the slot table to the MDS until
170                  * layout is destroyed and a new valid layout is obtained.
171                  */
172                 pnfs_destroy_layout(NFS_I(inode));
173                 rpc_wake_up(&tbl->slot_tbl_waitq);
174                 goto reset;
175         /* RPC connection errors */
176         case -ECONNREFUSED:
177         case -EHOSTDOWN:
178         case -EHOSTUNREACH:
179         case -ENETUNREACH:
180         case -EIO:
181         case -ETIMEDOUT:
182         case -EPIPE:
183                 dprintk("%s DS connection error %d\n", __func__,
184                         task->tk_status);
185                 nfs4_mark_deviceid_unavailable(devid);
186                 pnfs_error_mark_layout_for_return(inode, lseg);
187                 pnfs_set_lo_fail(lseg);
188                 rpc_wake_up(&tbl->slot_tbl_waitq);
189                 /* fall through */
190         default:
191 reset:
192                 dprintk("%s Retry through MDS. Error %d\n", __func__,
193                         task->tk_status);
194                 return -NFS4ERR_RESET_TO_MDS;
195         }
196         task->tk_status = 0;
197         return -EAGAIN;
198 }
199 
200 /* NFS_PROTO call done callback routines */
201 
202 static int filelayout_read_done_cb(struct rpc_task *task,
203                                 struct nfs_pgio_header *hdr)
204 {
205         int err;
206 
207         trace_nfs4_pnfs_read(hdr, task->tk_status);
208         err = filelayout_async_handle_error(task, hdr->args.context->state,
209                                             hdr->ds_clp, hdr->lseg);
210 
211         switch (err) {
212         case -NFS4ERR_RESET_TO_MDS:
213                 filelayout_reset_read(hdr);
214                 return task->tk_status;
215         case -EAGAIN:
216                 rpc_restart_call_prepare(task);
217                 return -EAGAIN;
218         }
219 
220         return 0;
221 }
222 
223 /*
224  * We reference the rpc_cred of the first WRITE that triggers the need for
225  * a LAYOUTCOMMIT, and use it to send the layoutcommit compound.
226  * rfc5661 is not clear about which credential should be used.
227  */
228 static void
229 filelayout_set_layoutcommit(struct nfs_pgio_header *hdr)
230 {
231         loff_t end_offs = 0;
232 
233         if (FILELAYOUT_LSEG(hdr->lseg)->commit_through_mds ||
234             hdr->res.verf->committed == NFS_FILE_SYNC)
235                 return;
236         if (hdr->res.verf->committed == NFS_DATA_SYNC)
237                 end_offs = hdr->mds_offset + (loff_t)hdr->res.count;
238 
239         /* Note: if the write is unstable, don't set end_offs until commit */
240         pnfs_set_layoutcommit(hdr->inode, hdr->lseg, end_offs);
241         dprintk("%s inode %lu pls_end_pos %lu\n", __func__, hdr->inode->i_ino,
242                 (unsigned long) NFS_I(hdr->inode)->layout->plh_lwb);
243 }
244 
245 bool
246 filelayout_test_devid_unavailable(struct nfs4_deviceid_node *node)
247 {
248         return filelayout_test_devid_invalid(node) ||
249                 nfs4_test_deviceid_unavailable(node);
250 }
251 
252 static bool
253 filelayout_reset_to_mds(struct pnfs_layout_segment *lseg)
254 {
255         struct nfs4_deviceid_node *node = FILELAYOUT_DEVID_NODE(lseg);
256 
257         return filelayout_test_devid_unavailable(node);
258 }
259 
260 /*
261  * Call ops for the async read/write cases
262  * In the case of dense layouts, the offset needs to be reset to its
263  * original value.
264  */
265 static void filelayout_read_prepare(struct rpc_task *task, void *data)
266 {
267         struct nfs_pgio_header *hdr = data;
268 
269         if (unlikely(test_bit(NFS_CONTEXT_BAD, &hdr->args.context->flags))) {
270                 rpc_exit(task, -EIO);
271                 return;
272         }
273         if (filelayout_reset_to_mds(hdr->lseg)) {
274                 dprintk("%s task %u reset io to MDS\n", __func__, task->tk_pid);
275                 filelayout_reset_read(hdr);
276                 rpc_exit(task, 0);
277                 return;
278         }
279         hdr->pgio_done_cb = filelayout_read_done_cb;
280 
281         if (nfs4_setup_sequence(hdr->ds_clp,
282                         &hdr->args.seq_args,
283                         &hdr->res.seq_res,
284                         task))
285                 return;
286         if (nfs4_set_rw_stateid(&hdr->args.stateid, hdr->args.context,
287                         hdr->args.lock_context, FMODE_READ) == -EIO)
288                 rpc_exit(task, -EIO); /* lost lock, terminate I/O */
289 }
290 
291 static void filelayout_read_call_done(struct rpc_task *task, void *data)
292 {
293         struct nfs_pgio_header *hdr = data;
294 
295         dprintk("--> %s task->tk_status %d\n", __func__, task->tk_status);
296 
297         if (test_bit(NFS_IOHDR_REDO, &hdr->flags) &&
298             task->tk_status == 0) {
299                 nfs41_sequence_done(task, &hdr->res.seq_res);
300                 return;
301         }
302 
303         /* Note this may cause RPC to be resent */
304         hdr->mds_ops->rpc_call_done(task, data);
305 }
306 
307 static void filelayout_read_count_stats(struct rpc_task *task, void *data)
308 {
309         struct nfs_pgio_header *hdr = data;
310 
311         rpc_count_iostats(task, NFS_SERVER(hdr->inode)->client->cl_metrics);
312 }
313 
314 static int filelayout_write_done_cb(struct rpc_task *task,
315                                 struct nfs_pgio_header *hdr)
316 {
317         int err;
318 
319         trace_nfs4_pnfs_write(hdr, task->tk_status);
320         err = filelayout_async_handle_error(task, hdr->args.context->state,
321                                             hdr->ds_clp, hdr->lseg);
322 
323         switch (err) {
324         case -NFS4ERR_RESET_TO_MDS:
325                 filelayout_reset_write(hdr);
326                 return task->tk_status;
327         case -EAGAIN:
328                 rpc_restart_call_prepare(task);
329                 return -EAGAIN;
330         }
331 
332         filelayout_set_layoutcommit(hdr);
333 
334         /* zero out the fattr */
335         hdr->fattr.valid = 0;
336         if (task->tk_status >= 0)
337                 nfs_writeback_update_inode(hdr);
338 
339         return 0;
340 }
341 
342 static int filelayout_commit_done_cb(struct rpc_task *task,
343                                      struct nfs_commit_data *data)
344 {
345         int err;
346 
347         trace_nfs4_pnfs_commit_ds(data, task->tk_status);
348         err = filelayout_async_handle_error(task, NULL, data->ds_clp,
349                                             data->lseg);
350 
351         switch (err) {
352         case -NFS4ERR_RESET_TO_MDS:
353                 pnfs_generic_prepare_to_resend_writes(data);
354                 return -EAGAIN;
355         case -EAGAIN:
356                 rpc_restart_call_prepare(task);
357                 return -EAGAIN;
358         }
359 
360         pnfs_set_layoutcommit(data->inode, data->lseg, data->lwb);
361 
362         return 0;
363 }
364 
365 static void filelayout_write_prepare(struct rpc_task *task, void *data)
366 {
367         struct nfs_pgio_header *hdr = data;
368 
369         if (unlikely(test_bit(NFS_CONTEXT_BAD, &hdr->args.context->flags))) {
370                 rpc_exit(task, -EIO);
371                 return;
372         }
373         if (filelayout_reset_to_mds(hdr->lseg)) {
374                 dprintk("%s task %u reset io to MDS\n", __func__, task->tk_pid);
375                 filelayout_reset_write(hdr);
376                 rpc_exit(task, 0);
377                 return;
378         }
379         if (nfs4_setup_sequence(hdr->ds_clp,
380                         &hdr->args.seq_args,
381                         &hdr->res.seq_res,
382                         task))
383                 return;
384         if (nfs4_set_rw_stateid(&hdr->args.stateid, hdr->args.context,
385                         hdr->args.lock_context, FMODE_WRITE) == -EIO)
386                 rpc_exit(task, -EIO); /* lost lock, terminate I/O */
387 }
388 
389 static void filelayout_write_call_done(struct rpc_task *task, void *data)
390 {
391         struct nfs_pgio_header *hdr = data;
392 
393         if (test_bit(NFS_IOHDR_REDO, &hdr->flags) &&
394             task->tk_status == 0) {
395                 nfs41_sequence_done(task, &hdr->res.seq_res);
396                 return;
397         }
398 
399         /* Note this may cause RPC to be resent */
400         hdr->mds_ops->rpc_call_done(task, data);
401 }
402 
403 static void filelayout_write_count_stats(struct rpc_task *task, void *data)
404 {
405         struct nfs_pgio_header *hdr = data;
406 
407         rpc_count_iostats(task, NFS_SERVER(hdr->inode)->client->cl_metrics);
408 }
409 
410 static void filelayout_commit_prepare(struct rpc_task *task, void *data)
411 {
412         struct nfs_commit_data *wdata = data;
413 
414         nfs4_setup_sequence(wdata->ds_clp,
415                         &wdata->args.seq_args,
416                         &wdata->res.seq_res,
417                         task);
418 }
419 
420 static void filelayout_commit_count_stats(struct rpc_task *task, void *data)
421 {
422         struct nfs_commit_data *cdata = data;
423 
424         rpc_count_iostats(task, NFS_SERVER(cdata->inode)->client->cl_metrics);
425 }
426 
427 static const struct rpc_call_ops filelayout_read_call_ops = {
428         .rpc_call_prepare = filelayout_read_prepare,
429         .rpc_call_done = filelayout_read_call_done,
430         .rpc_count_stats = filelayout_read_count_stats,
431         .rpc_release = pnfs_generic_rw_release,
432 };
433 
434 static const struct rpc_call_ops filelayout_write_call_ops = {
435         .rpc_call_prepare = filelayout_write_prepare,
436         .rpc_call_done = filelayout_write_call_done,
437         .rpc_count_stats = filelayout_write_count_stats,
438         .rpc_release = pnfs_generic_rw_release,
439 };
440 
441 static const struct rpc_call_ops filelayout_commit_call_ops = {
442         .rpc_call_prepare = filelayout_commit_prepare,
443         .rpc_call_done = pnfs_generic_write_commit_done,
444         .rpc_count_stats = filelayout_commit_count_stats,
445         .rpc_release = pnfs_generic_commit_release,
446 };
447 
448 static enum pnfs_try_status
449 filelayout_read_pagelist(struct nfs_pgio_header *hdr)
450 {
451         struct pnfs_layout_segment *lseg = hdr->lseg;
452         struct nfs4_pnfs_ds *ds;
453         struct rpc_clnt *ds_clnt;
454         loff_t offset = hdr->args.offset;
455         u32 j, idx;
456         struct nfs_fh *fh;
457 
458         dprintk("--> %s ino %lu pgbase %u req %zu@%llu\n",
459                 __func__, hdr->inode->i_ino,
460                 hdr->args.pgbase, (size_t)hdr->args.count, offset);
461 
462         /* Retrieve the correct rpc_client for the byte range */
463         j = nfs4_fl_calc_j_index(lseg, offset);
464         idx = nfs4_fl_calc_ds_index(lseg, j);
465         ds = nfs4_fl_prepare_ds(lseg, idx);
466         if (!ds)
467                 return PNFS_NOT_ATTEMPTED;
468 
469         ds_clnt = nfs4_find_or_create_ds_client(ds->ds_clp, hdr->inode);
470         if (IS_ERR(ds_clnt))
471                 return PNFS_NOT_ATTEMPTED;
472 
473         dprintk("%s USE DS: %s cl_count %d\n", __func__,
474                 ds->ds_remotestr, refcount_read(&ds->ds_clp->cl_count));
475 
476         /* No multipath support. Use first DS */
477         refcount_inc(&ds->ds_clp->cl_count);
478         hdr->ds_clp = ds->ds_clp;
479         hdr->ds_commit_idx = idx;
480         fh = nfs4_fl_select_ds_fh(lseg, j);
481         if (fh)
482                 hdr->args.fh = fh;
483 
484         hdr->args.offset = filelayout_get_dserver_offset(lseg, offset);
485         hdr->mds_offset = offset;
486 
487         /* Perform an asynchronous read to ds */
488         nfs_initiate_pgio(ds_clnt, hdr, hdr->cred,
489                           NFS_PROTO(hdr->inode), &filelayout_read_call_ops,
490                           0, RPC_TASK_SOFTCONN);
491         return PNFS_ATTEMPTED;
492 }
493 
494 /* Perform async writes. */
495 static enum pnfs_try_status
496 filelayout_write_pagelist(struct nfs_pgio_header *hdr, int sync)
497 {
498         struct pnfs_layout_segment *lseg = hdr->lseg;
499         struct nfs4_pnfs_ds *ds;
500         struct rpc_clnt *ds_clnt;
501         loff_t offset = hdr->args.offset;
502         u32 j, idx;
503         struct nfs_fh *fh;
504 
505         /* Retrieve the correct rpc_client for the byte range */
506         j = nfs4_fl_calc_j_index(lseg, offset);
507         idx = nfs4_fl_calc_ds_index(lseg, j);
508         ds = nfs4_fl_prepare_ds(lseg, idx);
509         if (!ds)
510                 return PNFS_NOT_ATTEMPTED;
511 
512         ds_clnt = nfs4_find_or_create_ds_client(ds->ds_clp, hdr->inode);
513         if (IS_ERR(ds_clnt))
514                 return PNFS_NOT_ATTEMPTED;
515 
516         dprintk("%s ino %lu sync %d req %zu@%llu DS: %s cl_count %d\n",
517                 __func__, hdr->inode->i_ino, sync, (size_t) hdr->args.count,
518                 offset, ds->ds_remotestr, refcount_read(&ds->ds_clp->cl_count));
519 
520         hdr->pgio_done_cb = filelayout_write_done_cb;
521         refcount_inc(&ds->ds_clp->cl_count);
522         hdr->ds_clp = ds->ds_clp;
523         hdr->ds_commit_idx = idx;
524         fh = nfs4_fl_select_ds_fh(lseg, j);
525         if (fh)
526                 hdr->args.fh = fh;
527         hdr->args.offset = filelayout_get_dserver_offset(lseg, offset);
528 
529         /* Perform an asynchronous write */
530         nfs_initiate_pgio(ds_clnt, hdr, hdr->cred,
531                           NFS_PROTO(hdr->inode), &filelayout_write_call_ops,
532                           sync, RPC_TASK_SOFTCONN);
533         return PNFS_ATTEMPTED;
534 }
535 
536 static int
537 filelayout_check_deviceid(struct pnfs_layout_hdr *lo,
538                           struct nfs4_filelayout_segment *fl,
539                           gfp_t gfp_flags)
540 {
541         struct nfs4_deviceid_node *d;
542         struct nfs4_file_layout_dsaddr *dsaddr;
543         int status = -EINVAL;
544 
545         /* Is the deviceid already set? If so, we're good. */
546         if (fl->dsaddr != NULL)
547                 return 0;
548 
549         /* find and reference the deviceid */
550         d = nfs4_find_get_deviceid(NFS_SERVER(lo->plh_inode), &fl->deviceid,
551                         lo->plh_lc_cred, gfp_flags);
552         if (d == NULL)
553                 goto out;
554 
555         dsaddr = container_of(d, struct nfs4_file_layout_dsaddr, id_node);
556         /* Found deviceid is unavailable */
557         if (filelayout_test_devid_unavailable(&dsaddr->id_node))
558                 goto out_put;
559 
560         if (fl->first_stripe_index >= dsaddr->stripe_count) {
561                 dprintk("%s Bad first_stripe_index %u\n",
562                                 __func__, fl->first_stripe_index);
563                 goto out_put;
564         }
565 
566         if ((fl->stripe_type == STRIPE_SPARSE &&
567             fl->num_fh > 1 && fl->num_fh != dsaddr->ds_num) ||
568             (fl->stripe_type == STRIPE_DENSE &&
569             fl->num_fh != dsaddr->stripe_count)) {
570                 dprintk("%s num_fh %u not valid for given packing\n",
571                         __func__, fl->num_fh);
572                 goto out_put;
573         }
574         status = 0;
575 
576         /*
577          * Atomic compare and xchange to ensure we don't scribble
578          * over a non-NULL pointer.
579          */
580         if (cmpxchg(&fl->dsaddr, NULL, dsaddr) != NULL)
581                 goto out_put;
582 out:
583         return status;
584 out_put:
585         nfs4_fl_put_deviceid(dsaddr);
586         goto out;
587 }
588 
589 /*
590  * filelayout_check_layout()
591  *
592  * Make sure layout segment parameters are sane WRT the device.
593  * At this point no generic layer initialization of the lseg has occurred,
594  * and nothing has been added to the layout_hdr cache.
595  *
596  */
597 static int
598 filelayout_check_layout(struct pnfs_layout_hdr *lo,
599                         struct nfs4_filelayout_segment *fl,
600                         struct nfs4_layoutget_res *lgr,
601                         gfp_t gfp_flags)
602 {
603         int status = -EINVAL;
604 
605         dprintk("--> %s\n", __func__);
606 
607         /* FIXME: remove this check when layout segment support is added */
608         if (lgr->range.offset != 0 ||
609             lgr->range.length != NFS4_MAX_UINT64) {
610                 dprintk("%s Only whole file layouts supported. Use MDS i/o\n",
611                         __func__);
612                 goto out;
613         }
614 
615         if (fl->pattern_offset > lgr->range.offset) {
616                 dprintk("%s pattern_offset %lld too large\n",
617                                 __func__, fl->pattern_offset);
618                 goto out;
619         }
620 
621         if (!fl->stripe_unit) {
622                 dprintk("%s Invalid stripe unit (%u)\n",
623                         __func__, fl->stripe_unit);
624                 goto out;
625         }
626 
627         status = 0;
628 out:
629         dprintk("--> %s returns %d\n", __func__, status);
630         return status;
631 }
632 
633 static void _filelayout_free_lseg(struct nfs4_filelayout_segment *fl)
634 {
635         int i;
636 
637         if (fl->fh_array) {
638                 for (i = 0; i < fl->num_fh; i++) {
639                         if (!fl->fh_array[i])
640                                 break;
641                         kfree(fl->fh_array[i]);
642                 }
643                 kfree(fl->fh_array);
644         }
645         kfree(fl);
646 }
647 
648 static int
649 filelayout_decode_layout(struct pnfs_layout_hdr *flo,
650                          struct nfs4_filelayout_segment *fl,
651                          struct nfs4_layoutget_res *lgr,
652                          gfp_t gfp_flags)
653 {
654         struct xdr_stream stream;
655         struct xdr_buf buf;
656         struct page *scratch;
657         __be32 *p;
658         uint32_t nfl_util;
659         int i;
660 
661         dprintk("%s: set_layout_map Begin\n", __func__);
662 
663         scratch = alloc_page(gfp_flags);
664         if (!scratch)
665                 return -ENOMEM;
666 
667         xdr_init_decode_pages(&stream, &buf, lgr->layoutp->pages, lgr->layoutp->len);
668         xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE);
669 
670         /* 20 = ufl_util (4), first_stripe_index (4), pattern_offset (8),
671          * num_fh (4) */
672         p = xdr_inline_decode(&stream, NFS4_DEVICEID4_SIZE + 20);
673         if (unlikely(!p))
674                 goto out_err;
675 
676         memcpy(&fl->deviceid, p, sizeof(fl->deviceid));
677         p += XDR_QUADLEN(NFS4_DEVICEID4_SIZE);
678         nfs4_print_deviceid(&fl->deviceid);
679 
680         nfl_util = be32_to_cpup(p++);
681         if (nfl_util & NFL4_UFLG_COMMIT_THRU_MDS)
682                 fl->commit_through_mds = 1;
683         if (nfl_util & NFL4_UFLG_DENSE)
684                 fl->stripe_type = STRIPE_DENSE;
685         else
686                 fl->stripe_type = STRIPE_SPARSE;
687         fl->stripe_unit = nfl_util & ~NFL4_UFLG_MASK;
688 
689         fl->first_stripe_index = be32_to_cpup(p++);
690         p = xdr_decode_hyper(p, &fl->pattern_offset);
691         fl->num_fh = be32_to_cpup(p++);
692 
693         dprintk("%s: nfl_util 0x%X num_fh %u fsi %u po %llu\n",
694                 __func__, nfl_util, fl->num_fh, fl->first_stripe_index,
695                 fl->pattern_offset);
696 
697         /* Note that a zero value for num_fh is legal for STRIPE_SPARSE.
698          * Futher checking is done in filelayout_check_layout */
699         if (fl->num_fh >
700             max(NFS4_PNFS_MAX_STRIPE_CNT, NFS4_PNFS_MAX_MULTI_CNT))
701                 goto out_err;
702 
703         if (fl->num_fh > 0) {
704                 fl->fh_array = kcalloc(fl->num_fh, sizeof(fl->fh_array[0]),
705                                        gfp_flags);
706                 if (!fl->fh_array)
707                         goto out_err;
708         }
709 
710         for (i = 0; i < fl->num_fh; i++) {
711                 /* Do we want to use a mempool here? */
712                 fl->fh_array[i] = kmalloc(sizeof(struct nfs_fh), gfp_flags);
713                 if (!fl->fh_array[i])
714                         goto out_err;
715 
716                 p = xdr_inline_decode(&stream, 4);
717                 if (unlikely(!p))
718                         goto out_err;
719                 fl->fh_array[i]->size = be32_to_cpup(p++);
720                 if (sizeof(struct nfs_fh) < fl->fh_array[i]->size) {
721                         printk(KERN_ERR "NFS: Too big fh %d received %d\n",
722                                i, fl->fh_array[i]->size);
723                         goto out_err;
724                 }
725 
726                 p = xdr_inline_decode(&stream, fl->fh_array[i]->size);
727                 if (unlikely(!p))
728                         goto out_err;
729                 memcpy(fl->fh_array[i]->data, p, fl->fh_array[i]->size);
730                 dprintk("DEBUG: %s: fh len %d\n", __func__,
731                         fl->fh_array[i]->size);
732         }
733 
734         __free_page(scratch);
735         return 0;
736 
737 out_err:
738         __free_page(scratch);
739         return -EIO;
740 }
741 
742 static void
743 filelayout_free_lseg(struct pnfs_layout_segment *lseg)
744 {
745         struct nfs4_filelayout_segment *fl = FILELAYOUT_LSEG(lseg);
746 
747         dprintk("--> %s\n", __func__);
748         if (fl->dsaddr != NULL)
749                 nfs4_fl_put_deviceid(fl->dsaddr);
750         /* This assumes a single RW lseg */
751         if (lseg->pls_range.iomode == IOMODE_RW) {
752                 struct nfs4_filelayout *flo;
753 
754                 flo = FILELAYOUT_FROM_HDR(lseg->pls_layout);
755                 flo->commit_info.nbuckets = 0;
756                 kfree(flo->commit_info.buckets);
757                 flo->commit_info.buckets = NULL;
758         }
759         _filelayout_free_lseg(fl);
760 }
761 
762 static int
763 filelayout_alloc_commit_info(struct pnfs_layout_segment *lseg,
764                              struct nfs_commit_info *cinfo,
765                              gfp_t gfp_flags)
766 {
767         struct nfs4_filelayout_segment *fl = FILELAYOUT_LSEG(lseg);
768         struct pnfs_commit_bucket *buckets;
769         int size, i;
770 
771         if (fl->commit_through_mds)
772                 return 0;
773 
774         size = (fl->stripe_type == STRIPE_SPARSE) ?
775                 fl->dsaddr->ds_num : fl->dsaddr->stripe_count;
776 
777         if (cinfo->ds->nbuckets >= size) {
778                 /* This assumes there is only one IOMODE_RW lseg.  What
779                  * we really want to do is have a layout_hdr level
780                  * dictionary of <multipath_list4, fh> keys, each
781                  * associated with a struct list_head, populated by calls
782                  * to filelayout_write_pagelist().
783                  * */
784                 return 0;
785         }
786 
787         buckets = kcalloc(size, sizeof(struct pnfs_commit_bucket),
788                           gfp_flags);
789         if (!buckets)
790                 return -ENOMEM;
791         for (i = 0; i < size; i++) {
792                 INIT_LIST_HEAD(&buckets[i].written);
793                 INIT_LIST_HEAD(&buckets[i].committing);
794                 /* mark direct verifier as unset */
795                 buckets[i].direct_verf.committed = NFS_INVALID_STABLE_HOW;
796         }
797 
798         spin_lock(&cinfo->inode->i_lock);
799         if (cinfo->ds->nbuckets >= size)
800                 goto out;
801         for (i = 0; i < cinfo->ds->nbuckets; i++) {
802                 list_splice(&cinfo->ds->buckets[i].written,
803                             &buckets[i].written);
804                 list_splice(&cinfo->ds->buckets[i].committing,
805                             &buckets[i].committing);
806                 buckets[i].direct_verf.committed =
807                         cinfo->ds->buckets[i].direct_verf.committed;
808                 buckets[i].wlseg = cinfo->ds->buckets[i].wlseg;
809                 buckets[i].clseg = cinfo->ds->buckets[i].clseg;
810         }
811         swap(cinfo->ds->buckets, buckets);
812         cinfo->ds->nbuckets = size;
813 out:
814         spin_unlock(&cinfo->inode->i_lock);
815         kfree(buckets);
816         return 0;
817 }
818 
819 static struct pnfs_layout_segment *
820 filelayout_alloc_lseg(struct pnfs_layout_hdr *layoutid,
821                       struct nfs4_layoutget_res *lgr,
822                       gfp_t gfp_flags)
823 {
824         struct nfs4_filelayout_segment *fl;
825         int rc;
826 
827         dprintk("--> %s\n", __func__);
828         fl = kzalloc(sizeof(*fl), gfp_flags);
829         if (!fl)
830                 return NULL;
831 
832         rc = filelayout_decode_layout(layoutid, fl, lgr, gfp_flags);
833         if (rc != 0 || filelayout_check_layout(layoutid, fl, lgr, gfp_flags)) {
834                 _filelayout_free_lseg(fl);
835                 return NULL;
836         }
837         return &fl->generic_hdr;
838 }
839 
840 /*
841  * filelayout_pg_test(). Called by nfs_can_coalesce_requests()
842  *
843  * Return 0 if @req cannot be coalesced into @pgio, otherwise return the number
844  * of bytes (maximum @req->wb_bytes) that can be coalesced.
845  */
846 static size_t
847 filelayout_pg_test(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev,
848                    struct nfs_page *req)
849 {
850         unsigned int size;
851         u64 p_stripe, r_stripe;
852         u32 stripe_offset;
853         u64 segment_offset = pgio->pg_lseg->pls_range.offset;
854         u32 stripe_unit = FILELAYOUT_LSEG(pgio->pg_lseg)->stripe_unit;
855 
856         /* calls nfs_generic_pg_test */
857         size = pnfs_generic_pg_test(pgio, prev, req);
858         if (!size)
859                 return 0;
860 
861         /* see if req and prev are in the same stripe */
862         if (prev) {
863                 p_stripe = (u64)req_offset(prev) - segment_offset;
864                 r_stripe = (u64)req_offset(req) - segment_offset;
865                 do_div(p_stripe, stripe_unit);
866                 do_div(r_stripe, stripe_unit);
867 
868                 if (p_stripe != r_stripe)
869                         return 0;
870         }
871 
872         /* calculate remaining bytes in the current stripe */
873         div_u64_rem((u64)req_offset(req) - segment_offset,
874                         stripe_unit,
875                         &stripe_offset);
876         WARN_ON_ONCE(stripe_offset > stripe_unit);
877         if (stripe_offset >= stripe_unit)
878                 return 0;
879         return min(stripe_unit - (unsigned int)stripe_offset, size);
880 }
881 
882 static struct pnfs_layout_segment *
883 fl_pnfs_update_layout(struct inode *ino,
884                       struct nfs_open_context *ctx,
885                       loff_t pos,
886                       u64 count,
887                       enum pnfs_iomode iomode,
888                       bool strict_iomode,
889                       gfp_t gfp_flags)
890 {
891         struct pnfs_layout_segment *lseg = NULL;
892         struct pnfs_layout_hdr *lo;
893         struct nfs4_filelayout_segment *fl;
894         int status;
895 
896         lseg = pnfs_update_layout(ino, ctx, pos, count, iomode, strict_iomode,
897                                   gfp_flags);
898         if (IS_ERR_OR_NULL(lseg))
899                 goto out;
900 
901         lo = NFS_I(ino)->layout;
902         fl = FILELAYOUT_LSEG(lseg);
903 
904         status = filelayout_check_deviceid(lo, fl, gfp_flags);
905         if (status) {
906                 pnfs_put_lseg(lseg);
907                 lseg = ERR_PTR(status);
908         }
909 out:
910         return lseg;
911 }
912 
913 static void
914 filelayout_pg_init_read(struct nfs_pageio_descriptor *pgio,
915                         struct nfs_page *req)
916 {
917         pnfs_generic_pg_check_layout(pgio);
918         if (!pgio->pg_lseg) {
919                 pgio->pg_lseg = fl_pnfs_update_layout(pgio->pg_inode,
920                                                       req->wb_context,
921                                                       0,
922                                                       NFS4_MAX_UINT64,
923                                                       IOMODE_READ,
924                                                       false,
925                                                       GFP_KERNEL);
926                 if (IS_ERR(pgio->pg_lseg)) {
927                         pgio->pg_error = PTR_ERR(pgio->pg_lseg);
928                         pgio->pg_lseg = NULL;
929                         return;
930                 }
931         }
932         /* If no lseg, fall back to read through mds */
933         if (pgio->pg_lseg == NULL)
934                 nfs_pageio_reset_read_mds(pgio);
935 }
936 
937 static void
938 filelayout_pg_init_write(struct nfs_pageio_descriptor *pgio,
939                          struct nfs_page *req)
940 {
941         struct nfs_commit_info cinfo;
942         int status;
943 
944         pnfs_generic_pg_check_layout(pgio);
945         if (!pgio->pg_lseg) {
946                 pgio->pg_lseg = fl_pnfs_update_layout(pgio->pg_inode,
947                                                       req->wb_context,
948                                                       0,
949                                                       NFS4_MAX_UINT64,
950                                                       IOMODE_RW,
951                                                       false,
952                                                       GFP_NOFS);
953                 if (IS_ERR(pgio->pg_lseg)) {
954                         pgio->pg_error = PTR_ERR(pgio->pg_lseg);
955                         pgio->pg_lseg = NULL;
956                         return;
957                 }
958         }
959 
960         /* If no lseg, fall back to write through mds */
961         if (pgio->pg_lseg == NULL)
962                 goto out_mds;
963         nfs_init_cinfo(&cinfo, pgio->pg_inode, pgio->pg_dreq);
964         status = filelayout_alloc_commit_info(pgio->pg_lseg, &cinfo, GFP_NOFS);
965         if (status < 0) {
966                 pnfs_put_lseg(pgio->pg_lseg);
967                 pgio->pg_lseg = NULL;
968                 goto out_mds;
969         }
970         return;
971 out_mds:
972         nfs_pageio_reset_write_mds(pgio);
973 }
974 
975 static const struct nfs_pageio_ops filelayout_pg_read_ops = {
976         .pg_init = filelayout_pg_init_read,
977         .pg_test = filelayout_pg_test,
978         .pg_doio = pnfs_generic_pg_readpages,
979         .pg_cleanup = pnfs_generic_pg_cleanup,
980 };
981 
982 static const struct nfs_pageio_ops filelayout_pg_write_ops = {
983         .pg_init = filelayout_pg_init_write,
984         .pg_test = filelayout_pg_test,
985         .pg_doio = pnfs_generic_pg_writepages,
986         .pg_cleanup = pnfs_generic_pg_cleanup,
987 };
988 
989 static u32 select_bucket_index(struct nfs4_filelayout_segment *fl, u32 j)
990 {
991         if (fl->stripe_type == STRIPE_SPARSE)
992                 return nfs4_fl_calc_ds_index(&fl->generic_hdr, j);
993         else
994                 return j;
995 }
996 
997 static void
998 filelayout_mark_request_commit(struct nfs_page *req,
999                                struct pnfs_layout_segment *lseg,
1000                                struct nfs_commit_info *cinfo,
1001                                u32 ds_commit_idx)
1002 
1003 {
1004         struct nfs4_filelayout_segment *fl = FILELAYOUT_LSEG(lseg);
1005         u32 i, j;
1006 
1007         if (fl->commit_through_mds) {
1008                 nfs_request_add_commit_list(req, cinfo);
1009         } else {
1010                 /* Note that we are calling nfs4_fl_calc_j_index on each page
1011                  * that ends up being committed to a data server.  An attractive
1012                  * alternative is to add a field to nfs_write_data and nfs_page
1013                  * to store the value calculated in filelayout_write_pagelist
1014                  * and just use that here.
1015                  */
1016                 j = nfs4_fl_calc_j_index(lseg, req_offset(req));
1017                 i = select_bucket_index(fl, j);
1018                 pnfs_layout_mark_request_commit(req, lseg, cinfo, i);
1019         }
1020 }
1021 
1022 static u32 calc_ds_index_from_commit(struct pnfs_layout_segment *lseg, u32 i)
1023 {
1024         struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg);
1025 
1026         if (flseg->stripe_type == STRIPE_SPARSE)
1027                 return i;
1028         else
1029                 return nfs4_fl_calc_ds_index(lseg, i);
1030 }
1031 
1032 static struct nfs_fh *
1033 select_ds_fh_from_commit(struct pnfs_layout_segment *lseg, u32 i)
1034 {
1035         struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg);
1036 
1037         if (flseg->stripe_type == STRIPE_SPARSE) {
1038                 if (flseg->num_fh == 1)
1039                         i = 0;
1040                 else if (flseg->num_fh == 0)
1041                         /* Use the MDS OPEN fh set in nfs_read_rpcsetup */
1042                         return NULL;
1043         }
1044         return flseg->fh_array[i];
1045 }
1046 
1047 static int filelayout_initiate_commit(struct nfs_commit_data *data, int how)
1048 {
1049         struct pnfs_layout_segment *lseg = data->lseg;
1050         struct nfs4_pnfs_ds *ds;
1051         struct rpc_clnt *ds_clnt;
1052         u32 idx;
1053         struct nfs_fh *fh;
1054 
1055         idx = calc_ds_index_from_commit(lseg, data->ds_commit_index);
1056         ds = nfs4_fl_prepare_ds(lseg, idx);
1057         if (!ds)
1058                 goto out_err;
1059 
1060         ds_clnt = nfs4_find_or_create_ds_client(ds->ds_clp, data->inode);
1061         if (IS_ERR(ds_clnt))
1062                 goto out_err;
1063 
1064         dprintk("%s ino %lu, how %d cl_count %d\n", __func__,
1065                 data->inode->i_ino, how, refcount_read(&ds->ds_clp->cl_count));
1066         data->commit_done_cb = filelayout_commit_done_cb;
1067         refcount_inc(&ds->ds_clp->cl_count);
1068         data->ds_clp = ds->ds_clp;
1069         fh = select_ds_fh_from_commit(lseg, data->ds_commit_index);
1070         if (fh)
1071                 data->args.fh = fh;
1072         return nfs_initiate_commit(ds_clnt, data, NFS_PROTO(data->inode),
1073                                    &filelayout_commit_call_ops, how,
1074                                    RPC_TASK_SOFTCONN);
1075 out_err:
1076         pnfs_generic_prepare_to_resend_writes(data);
1077         pnfs_generic_commit_release(data);
1078         return -EAGAIN;
1079 }
1080 
1081 /* filelayout_search_commit_reqs - Search lists in @cinfo for the head reqest
1082  *                                 for @page
1083  * @cinfo - commit info for current inode
1084  * @page - page to search for matching head request
1085  *
1086  * Returns a the head request if one is found, otherwise returns NULL.
1087  */
1088 static struct nfs_page *
1089 filelayout_search_commit_reqs(struct nfs_commit_info *cinfo, struct page *page)
1090 {
1091         struct nfs_page *freq, *t;
1092         struct pnfs_commit_bucket *b;
1093         int i;
1094 
1095         /* Linearly search the commit lists for each bucket until a matching
1096          * request is found */
1097         for (i = 0, b = cinfo->ds->buckets; i < cinfo->ds->nbuckets; i++, b++) {
1098                 list_for_each_entry_safe(freq, t, &b->written, wb_list) {
1099                         if (freq->wb_page == page)
1100                                 return freq->wb_head;
1101                 }
1102                 list_for_each_entry_safe(freq, t, &b->committing, wb_list) {
1103                         if (freq->wb_page == page)
1104                                 return freq->wb_head;
1105                 }
1106         }
1107 
1108         return NULL;
1109 }
1110 
1111 static int
1112 filelayout_commit_pagelist(struct inode *inode, struct list_head *mds_pages,
1113                            int how, struct nfs_commit_info *cinfo)
1114 {
1115         return pnfs_generic_commit_pagelist(inode, mds_pages, how, cinfo,
1116                                             filelayout_initiate_commit);
1117 }
1118 
1119 static struct nfs4_deviceid_node *
1120 filelayout_alloc_deviceid_node(struct nfs_server *server,
1121                 struct pnfs_device *pdev, gfp_t gfp_flags)
1122 {
1123         struct nfs4_file_layout_dsaddr *dsaddr;
1124 
1125         dsaddr = nfs4_fl_alloc_deviceid_node(server, pdev, gfp_flags);
1126         if (!dsaddr)
1127                 return NULL;
1128         return &dsaddr->id_node;
1129 }
1130 
1131 static void
1132 filelayout_free_deviceid_node(struct nfs4_deviceid_node *d)
1133 {
1134         nfs4_fl_free_deviceid(container_of(d, struct nfs4_file_layout_dsaddr, id_node));
1135 }
1136 
1137 static struct pnfs_layout_hdr *
1138 filelayout_alloc_layout_hdr(struct inode *inode, gfp_t gfp_flags)
1139 {
1140         struct nfs4_filelayout *flo;
1141 
1142         flo = kzalloc(sizeof(*flo), gfp_flags);
1143         return flo != NULL ? &flo->generic_hdr : NULL;
1144 }
1145 
1146 static void
1147 filelayout_free_layout_hdr(struct pnfs_layout_hdr *lo)
1148 {
1149         kfree(FILELAYOUT_FROM_HDR(lo));
1150 }
1151 
1152 static struct pnfs_ds_commit_info *
1153 filelayout_get_ds_info(struct inode *inode)
1154 {
1155         struct pnfs_layout_hdr *layout = NFS_I(inode)->layout;
1156 
1157         if (layout == NULL)
1158                 return NULL;
1159         else
1160                 return &FILELAYOUT_FROM_HDR(layout)->commit_info;
1161 }
1162 
1163 static struct pnfs_layoutdriver_type filelayout_type = {
1164         .id                     = LAYOUT_NFSV4_1_FILES,
1165         .name                   = "LAYOUT_NFSV4_1_FILES",
1166         .owner                  = THIS_MODULE,
1167         .alloc_layout_hdr       = filelayout_alloc_layout_hdr,
1168         .free_layout_hdr        = filelayout_free_layout_hdr,
1169         .alloc_lseg             = filelayout_alloc_lseg,
1170         .free_lseg              = filelayout_free_lseg,
1171         .pg_read_ops            = &filelayout_pg_read_ops,
1172         .pg_write_ops           = &filelayout_pg_write_ops,
1173         .get_ds_info            = &filelayout_get_ds_info,
1174         .mark_request_commit    = filelayout_mark_request_commit,
1175         .clear_request_commit   = pnfs_generic_clear_request_commit,
1176         .scan_commit_lists      = pnfs_generic_scan_commit_lists,
1177         .recover_commit_reqs    = pnfs_generic_recover_commit_reqs,
1178         .search_commit_reqs     = filelayout_search_commit_reqs,
1179         .commit_pagelist        = filelayout_commit_pagelist,
1180         .read_pagelist          = filelayout_read_pagelist,
1181         .write_pagelist         = filelayout_write_pagelist,
1182         .alloc_deviceid_node    = filelayout_alloc_deviceid_node,
1183         .free_deviceid_node     = filelayout_free_deviceid_node,
1184         .sync                   = pnfs_nfs_generic_sync,
1185 };
1186 
1187 static int __init nfs4filelayout_init(void)
1188 {
1189         printk(KERN_INFO "%s: NFSv4 File Layout Driver Registering...\n",
1190                __func__);
1191         return pnfs_register_layoutdriver(&filelayout_type);
1192 }
1193 
1194 static void __exit nfs4filelayout_exit(void)
1195 {
1196         printk(KERN_INFO "%s: NFSv4 File Layout Driver Unregistering...\n",
1197                __func__);
1198         pnfs_unregister_layoutdriver(&filelayout_type);
1199 }
1200 
1201 MODULE_ALIAS("nfs-layouttype4-1");
1202 
1203 module_init(nfs4filelayout_init);
1204 module_exit(nfs4filelayout_exit);
1205 

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