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

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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 nfs_server *mds_server = NFS_SERVER(inode);
130         struct nfs4_deviceid_node *devid = FILELAYOUT_DEVID_NODE(lseg);
131         struct nfs_client *mds_client = mds_server->nfs_client;
132         struct nfs4_slot_table *tbl = &clp->cl_session->fc_slot_table;
133 
134         if (task->tk_status >= 0)
135                 return 0;
136 
137         switch (task->tk_status) {
138         /* MDS state errors */
139         case -NFS4ERR_DELEG_REVOKED:
140         case -NFS4ERR_ADMIN_REVOKED:
141         case -NFS4ERR_BAD_STATEID:
142         case -NFS4ERR_OPENMODE:
143                 if (state == NULL)
144                         break;
145                 if (nfs4_schedule_stateid_recovery(mds_server, state) < 0)
146                         goto out_bad_stateid;
147                 goto wait_on_recovery;
148         case -NFS4ERR_EXPIRED:
149                 if (state != NULL) {
150                         if (nfs4_schedule_stateid_recovery(mds_server, state) < 0)
151                                 goto out_bad_stateid;
152                 }
153                 nfs4_schedule_lease_recovery(mds_client);
154                 goto wait_on_recovery;
155         /* DS session errors */
156         case -NFS4ERR_BADSESSION:
157         case -NFS4ERR_BADSLOT:
158         case -NFS4ERR_BAD_HIGH_SLOT:
159         case -NFS4ERR_DEADSESSION:
160         case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
161         case -NFS4ERR_SEQ_FALSE_RETRY:
162         case -NFS4ERR_SEQ_MISORDERED:
163                 dprintk("%s ERROR %d, Reset session. Exchangeid "
164                         "flags 0x%x\n", __func__, task->tk_status,
165                         clp->cl_exchange_flags);
166                 nfs4_schedule_session_recovery(clp->cl_session, task->tk_status);
167                 break;
168         case -NFS4ERR_DELAY:
169         case -NFS4ERR_GRACE:
170                 rpc_delay(task, FILELAYOUT_POLL_RETRY_MAX);
171                 break;
172         case -NFS4ERR_RETRY_UNCACHED_REP:
173                 break;
174         /* Invalidate Layout errors */
175         case -NFS4ERR_PNFS_NO_LAYOUT:
176         case -ESTALE:           /* mapped NFS4ERR_STALE */
177         case -EBADHANDLE:       /* mapped NFS4ERR_BADHANDLE */
178         case -EISDIR:           /* mapped NFS4ERR_ISDIR */
179         case -NFS4ERR_FHEXPIRED:
180         case -NFS4ERR_WRONG_TYPE:
181                 dprintk("%s Invalid layout error %d\n", __func__,
182                         task->tk_status);
183                 /*
184                  * Destroy layout so new i/o will get a new layout.
185                  * Layout will not be destroyed until all current lseg
186                  * references are put. Mark layout as invalid to resend failed
187                  * i/o and all i/o waiting on the slot table to the MDS until
188                  * layout is destroyed and a new valid layout is obtained.
189                  */
190                 pnfs_destroy_layout(NFS_I(inode));
191                 rpc_wake_up(&tbl->slot_tbl_waitq);
192                 goto reset;
193         /* RPC connection errors */
194         case -ECONNREFUSED:
195         case -EHOSTDOWN:
196         case -EHOSTUNREACH:
197         case -ENETUNREACH:
198         case -EIO:
199         case -ETIMEDOUT:
200         case -EPIPE:
201                 dprintk("%s DS connection error %d\n", __func__,
202                         task->tk_status);
203                 nfs4_mark_deviceid_unavailable(devid);
204                 pnfs_error_mark_layout_for_return(inode, lseg);
205                 pnfs_set_lo_fail(lseg);
206                 rpc_wake_up(&tbl->slot_tbl_waitq);
207                 /* fall through */
208         default:
209 reset:
210                 dprintk("%s Retry through MDS. Error %d\n", __func__,
211                         task->tk_status);
212                 return -NFS4ERR_RESET_TO_MDS;
213         }
214 out:
215         task->tk_status = 0;
216         return -EAGAIN;
217 out_bad_stateid:
218         task->tk_status = -EIO;
219         return 0;
220 wait_on_recovery:
221         rpc_sleep_on(&mds_client->cl_rpcwaitq, task, NULL);
222         if (test_bit(NFS4CLNT_MANAGER_RUNNING, &mds_client->cl_state) == 0)
223                 rpc_wake_up_queued_task(&mds_client->cl_rpcwaitq, task);
224         goto out;
225 }
226 
227 /* NFS_PROTO call done callback routines */
228 
229 static int filelayout_read_done_cb(struct rpc_task *task,
230                                 struct nfs_pgio_header *hdr)
231 {
232         int err;
233 
234         trace_nfs4_pnfs_read(hdr, task->tk_status);
235         err = filelayout_async_handle_error(task, hdr->args.context->state,
236                                             hdr->ds_clp, hdr->lseg);
237 
238         switch (err) {
239         case -NFS4ERR_RESET_TO_MDS:
240                 filelayout_reset_read(hdr);
241                 return task->tk_status;
242         case -EAGAIN:
243                 rpc_restart_call_prepare(task);
244                 return -EAGAIN;
245         }
246 
247         return 0;
248 }
249 
250 /*
251  * We reference the rpc_cred of the first WRITE that triggers the need for
252  * a LAYOUTCOMMIT, and use it to send the layoutcommit compound.
253  * rfc5661 is not clear about which credential should be used.
254  */
255 static void
256 filelayout_set_layoutcommit(struct nfs_pgio_header *hdr)
257 {
258 
259         if (FILELAYOUT_LSEG(hdr->lseg)->commit_through_mds ||
260             hdr->res.verf->committed != NFS_DATA_SYNC)
261                 return;
262 
263         pnfs_set_layoutcommit(hdr->inode, hdr->lseg,
264                         hdr->mds_offset + hdr->res.count);
265         dprintk("%s inode %lu pls_end_pos %lu\n", __func__, hdr->inode->i_ino,
266                 (unsigned long) NFS_I(hdr->inode)->layout->plh_lwb);
267 }
268 
269 bool
270 filelayout_test_devid_unavailable(struct nfs4_deviceid_node *node)
271 {
272         return filelayout_test_devid_invalid(node) ||
273                 nfs4_test_deviceid_unavailable(node);
274 }
275 
276 static bool
277 filelayout_reset_to_mds(struct pnfs_layout_segment *lseg)
278 {
279         struct nfs4_deviceid_node *node = FILELAYOUT_DEVID_NODE(lseg);
280 
281         return filelayout_test_devid_unavailable(node);
282 }
283 
284 /*
285  * Call ops for the async read/write cases
286  * In the case of dense layouts, the offset needs to be reset to its
287  * original value.
288  */
289 static void filelayout_read_prepare(struct rpc_task *task, void *data)
290 {
291         struct nfs_pgio_header *hdr = data;
292 
293         if (unlikely(test_bit(NFS_CONTEXT_BAD, &hdr->args.context->flags))) {
294                 rpc_exit(task, -EIO);
295                 return;
296         }
297         if (filelayout_reset_to_mds(hdr->lseg)) {
298                 dprintk("%s task %u reset io to MDS\n", __func__, task->tk_pid);
299                 filelayout_reset_read(hdr);
300                 rpc_exit(task, 0);
301                 return;
302         }
303         hdr->pgio_done_cb = filelayout_read_done_cb;
304 
305         if (nfs41_setup_sequence(hdr->ds_clp->cl_session,
306                         &hdr->args.seq_args,
307                         &hdr->res.seq_res,
308                         task))
309                 return;
310         if (nfs4_set_rw_stateid(&hdr->args.stateid, hdr->args.context,
311                         hdr->args.lock_context, FMODE_READ) == -EIO)
312                 rpc_exit(task, -EIO); /* lost lock, terminate I/O */
313 }
314 
315 static void filelayout_read_call_done(struct rpc_task *task, void *data)
316 {
317         struct nfs_pgio_header *hdr = data;
318 
319         dprintk("--> %s task->tk_status %d\n", __func__, task->tk_status);
320 
321         if (test_bit(NFS_IOHDR_REDO, &hdr->flags) &&
322             task->tk_status == 0) {
323                 nfs41_sequence_done(task, &hdr->res.seq_res);
324                 return;
325         }
326 
327         /* Note this may cause RPC to be resent */
328         hdr->mds_ops->rpc_call_done(task, data);
329 }
330 
331 static void filelayout_read_count_stats(struct rpc_task *task, void *data)
332 {
333         struct nfs_pgio_header *hdr = data;
334 
335         rpc_count_iostats(task, NFS_SERVER(hdr->inode)->client->cl_metrics);
336 }
337 
338 static int filelayout_write_done_cb(struct rpc_task *task,
339                                 struct nfs_pgio_header *hdr)
340 {
341         int err;
342 
343         trace_nfs4_pnfs_write(hdr, task->tk_status);
344         err = filelayout_async_handle_error(task, hdr->args.context->state,
345                                             hdr->ds_clp, hdr->lseg);
346 
347         switch (err) {
348         case -NFS4ERR_RESET_TO_MDS:
349                 filelayout_reset_write(hdr);
350                 return task->tk_status;
351         case -EAGAIN:
352                 rpc_restart_call_prepare(task);
353                 return -EAGAIN;
354         }
355 
356         filelayout_set_layoutcommit(hdr);
357         return 0;
358 }
359 
360 static int filelayout_commit_done_cb(struct rpc_task *task,
361                                      struct nfs_commit_data *data)
362 {
363         int err;
364 
365         trace_nfs4_pnfs_commit_ds(data, task->tk_status);
366         err = filelayout_async_handle_error(task, NULL, data->ds_clp,
367                                             data->lseg);
368 
369         switch (err) {
370         case -NFS4ERR_RESET_TO_MDS:
371                 pnfs_generic_prepare_to_resend_writes(data);
372                 return -EAGAIN;
373         case -EAGAIN:
374                 rpc_restart_call_prepare(task);
375                 return -EAGAIN;
376         }
377 
378         pnfs_set_layoutcommit(data->inode, data->lseg, data->lwb);
379 
380         return 0;
381 }
382 
383 static void filelayout_write_prepare(struct rpc_task *task, void *data)
384 {
385         struct nfs_pgio_header *hdr = data;
386 
387         if (unlikely(test_bit(NFS_CONTEXT_BAD, &hdr->args.context->flags))) {
388                 rpc_exit(task, -EIO);
389                 return;
390         }
391         if (filelayout_reset_to_mds(hdr->lseg)) {
392                 dprintk("%s task %u reset io to MDS\n", __func__, task->tk_pid);
393                 filelayout_reset_write(hdr);
394                 rpc_exit(task, 0);
395                 return;
396         }
397         if (nfs41_setup_sequence(hdr->ds_clp->cl_session,
398                         &hdr->args.seq_args,
399                         &hdr->res.seq_res,
400                         task))
401                 return;
402         if (nfs4_set_rw_stateid(&hdr->args.stateid, hdr->args.context,
403                         hdr->args.lock_context, FMODE_WRITE) == -EIO)
404                 rpc_exit(task, -EIO); /* lost lock, terminate I/O */
405 }
406 
407 static void filelayout_write_call_done(struct rpc_task *task, void *data)
408 {
409         struct nfs_pgio_header *hdr = data;
410 
411         if (test_bit(NFS_IOHDR_REDO, &hdr->flags) &&
412             task->tk_status == 0) {
413                 nfs41_sequence_done(task, &hdr->res.seq_res);
414                 return;
415         }
416 
417         /* Note this may cause RPC to be resent */
418         hdr->mds_ops->rpc_call_done(task, data);
419 }
420 
421 static void filelayout_write_count_stats(struct rpc_task *task, void *data)
422 {
423         struct nfs_pgio_header *hdr = data;
424 
425         rpc_count_iostats(task, NFS_SERVER(hdr->inode)->client->cl_metrics);
426 }
427 
428 static void filelayout_commit_prepare(struct rpc_task *task, void *data)
429 {
430         struct nfs_commit_data *wdata = data;
431 
432         nfs41_setup_sequence(wdata->ds_clp->cl_session,
433                         &wdata->args.seq_args,
434                         &wdata->res.seq_res,
435                         task);
436 }
437 
438 static void filelayout_commit_count_stats(struct rpc_task *task, void *data)
439 {
440         struct nfs_commit_data *cdata = data;
441 
442         rpc_count_iostats(task, NFS_SERVER(cdata->inode)->client->cl_metrics);
443 }
444 
445 static const struct rpc_call_ops filelayout_read_call_ops = {
446         .rpc_call_prepare = filelayout_read_prepare,
447         .rpc_call_done = filelayout_read_call_done,
448         .rpc_count_stats = filelayout_read_count_stats,
449         .rpc_release = pnfs_generic_rw_release,
450 };
451 
452 static const struct rpc_call_ops filelayout_write_call_ops = {
453         .rpc_call_prepare = filelayout_write_prepare,
454         .rpc_call_done = filelayout_write_call_done,
455         .rpc_count_stats = filelayout_write_count_stats,
456         .rpc_release = pnfs_generic_rw_release,
457 };
458 
459 static const struct rpc_call_ops filelayout_commit_call_ops = {
460         .rpc_call_prepare = filelayout_commit_prepare,
461         .rpc_call_done = pnfs_generic_write_commit_done,
462         .rpc_count_stats = filelayout_commit_count_stats,
463         .rpc_release = pnfs_generic_commit_release,
464 };
465 
466 static enum pnfs_try_status
467 filelayout_read_pagelist(struct nfs_pgio_header *hdr)
468 {
469         struct pnfs_layout_segment *lseg = hdr->lseg;
470         struct nfs4_pnfs_ds *ds;
471         struct rpc_clnt *ds_clnt;
472         loff_t offset = hdr->args.offset;
473         u32 j, idx;
474         struct nfs_fh *fh;
475 
476         dprintk("--> %s ino %lu pgbase %u req %Zu@%llu\n",
477                 __func__, hdr->inode->i_ino,
478                 hdr->args.pgbase, (size_t)hdr->args.count, offset);
479 
480         /* Retrieve the correct rpc_client for the byte range */
481         j = nfs4_fl_calc_j_index(lseg, offset);
482         idx = nfs4_fl_calc_ds_index(lseg, j);
483         ds = nfs4_fl_prepare_ds(lseg, idx);
484         if (!ds)
485                 return PNFS_NOT_ATTEMPTED;
486 
487         ds_clnt = nfs4_find_or_create_ds_client(ds->ds_clp, hdr->inode);
488         if (IS_ERR(ds_clnt))
489                 return PNFS_NOT_ATTEMPTED;
490 
491         dprintk("%s USE DS: %s cl_count %d\n", __func__,
492                 ds->ds_remotestr, atomic_read(&ds->ds_clp->cl_count));
493 
494         /* No multipath support. Use first DS */
495         atomic_inc(&ds->ds_clp->cl_count);
496         hdr->ds_clp = ds->ds_clp;
497         hdr->ds_commit_idx = idx;
498         fh = nfs4_fl_select_ds_fh(lseg, j);
499         if (fh)
500                 hdr->args.fh = fh;
501 
502         hdr->args.offset = filelayout_get_dserver_offset(lseg, offset);
503         hdr->mds_offset = offset;
504 
505         /* Perform an asynchronous read to ds */
506         nfs_initiate_pgio(ds_clnt, hdr, hdr->cred,
507                           NFS_PROTO(hdr->inode), &filelayout_read_call_ops,
508                           0, RPC_TASK_SOFTCONN);
509         return PNFS_ATTEMPTED;
510 }
511 
512 /* Perform async writes. */
513 static enum pnfs_try_status
514 filelayout_write_pagelist(struct nfs_pgio_header *hdr, int sync)
515 {
516         struct pnfs_layout_segment *lseg = hdr->lseg;
517         struct nfs4_pnfs_ds *ds;
518         struct rpc_clnt *ds_clnt;
519         loff_t offset = hdr->args.offset;
520         u32 j, idx;
521         struct nfs_fh *fh;
522 
523         /* Retrieve the correct rpc_client for the byte range */
524         j = nfs4_fl_calc_j_index(lseg, offset);
525         idx = nfs4_fl_calc_ds_index(lseg, j);
526         ds = nfs4_fl_prepare_ds(lseg, idx);
527         if (!ds)
528                 return PNFS_NOT_ATTEMPTED;
529 
530         ds_clnt = nfs4_find_or_create_ds_client(ds->ds_clp, hdr->inode);
531         if (IS_ERR(ds_clnt))
532                 return PNFS_NOT_ATTEMPTED;
533 
534         dprintk("%s ino %lu sync %d req %Zu@%llu DS: %s cl_count %d\n",
535                 __func__, hdr->inode->i_ino, sync, (size_t) hdr->args.count,
536                 offset, ds->ds_remotestr, atomic_read(&ds->ds_clp->cl_count));
537 
538         hdr->pgio_done_cb = filelayout_write_done_cb;
539         atomic_inc(&ds->ds_clp->cl_count);
540         hdr->ds_clp = ds->ds_clp;
541         hdr->ds_commit_idx = idx;
542         fh = nfs4_fl_select_ds_fh(lseg, j);
543         if (fh)
544                 hdr->args.fh = fh;
545         hdr->args.offset = filelayout_get_dserver_offset(lseg, offset);
546 
547         /* Perform an asynchronous write */
548         nfs_initiate_pgio(ds_clnt, hdr, hdr->cred,
549                           NFS_PROTO(hdr->inode), &filelayout_write_call_ops,
550                           sync, RPC_TASK_SOFTCONN);
551         return PNFS_ATTEMPTED;
552 }
553 
554 /*
555  * filelayout_check_layout()
556  *
557  * Make sure layout segment parameters are sane WRT the device.
558  * At this point no generic layer initialization of the lseg has occurred,
559  * and nothing has been added to the layout_hdr cache.
560  *
561  */
562 static int
563 filelayout_check_layout(struct pnfs_layout_hdr *lo,
564                         struct nfs4_filelayout_segment *fl,
565                         struct nfs4_layoutget_res *lgr,
566                         struct nfs4_deviceid *id,
567                         gfp_t gfp_flags)
568 {
569         struct nfs4_deviceid_node *d;
570         struct nfs4_file_layout_dsaddr *dsaddr;
571         int status = -EINVAL;
572 
573         dprintk("--> %s\n", __func__);
574 
575         /* FIXME: remove this check when layout segment support is added */
576         if (lgr->range.offset != 0 ||
577             lgr->range.length != NFS4_MAX_UINT64) {
578                 dprintk("%s Only whole file layouts supported. Use MDS i/o\n",
579                         __func__);
580                 goto out;
581         }
582 
583         if (fl->pattern_offset > lgr->range.offset) {
584                 dprintk("%s pattern_offset %lld too large\n",
585                                 __func__, fl->pattern_offset);
586                 goto out;
587         }
588 
589         if (!fl->stripe_unit) {
590                 dprintk("%s Invalid stripe unit (%u)\n",
591                         __func__, fl->stripe_unit);
592                 goto out;
593         }
594 
595         /* find and reference the deviceid */
596         d = nfs4_find_get_deviceid(NFS_SERVER(lo->plh_inode), id,
597                         lo->plh_lc_cred, gfp_flags);
598         if (d == NULL)
599                 goto out;
600 
601         dsaddr = container_of(d, struct nfs4_file_layout_dsaddr, id_node);
602         /* Found deviceid is unavailable */
603         if (filelayout_test_devid_unavailable(&dsaddr->id_node))
604                 goto out_put;
605 
606         fl->dsaddr = dsaddr;
607 
608         if (fl->first_stripe_index >= dsaddr->stripe_count) {
609                 dprintk("%s Bad first_stripe_index %u\n",
610                                 __func__, fl->first_stripe_index);
611                 goto out_put;
612         }
613 
614         if ((fl->stripe_type == STRIPE_SPARSE &&
615             fl->num_fh > 1 && fl->num_fh != dsaddr->ds_num) ||
616             (fl->stripe_type == STRIPE_DENSE &&
617             fl->num_fh != dsaddr->stripe_count)) {
618                 dprintk("%s num_fh %u not valid for given packing\n",
619                         __func__, fl->num_fh);
620                 goto out_put;
621         }
622 
623         status = 0;
624 out:
625         dprintk("--> %s returns %d\n", __func__, status);
626         return status;
627 out_put:
628         nfs4_fl_put_deviceid(dsaddr);
629         goto out;
630 }
631 
632 static void _filelayout_free_lseg(struct nfs4_filelayout_segment *fl)
633 {
634         int i;
635 
636         if (fl->fh_array) {
637                 for (i = 0; i < fl->num_fh; i++) {
638                         if (!fl->fh_array[i])
639                                 break;
640                         kfree(fl->fh_array[i]);
641                 }
642                 kfree(fl->fh_array);
643         }
644         kfree(fl);
645 }
646 
647 static int
648 filelayout_decode_layout(struct pnfs_layout_hdr *flo,
649                          struct nfs4_filelayout_segment *fl,
650                          struct nfs4_layoutget_res *lgr,
651                          struct nfs4_deviceid *id,
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(id, p, sizeof(*id));
677         p += XDR_QUADLEN(NFS4_DEVICEID4_SIZE);
678         nfs4_print_deviceid(id);
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         nfs4_fl_put_deviceid(fl->dsaddr);
749         /* This assumes a single RW lseg */
750         if (lseg->pls_range.iomode == IOMODE_RW) {
751                 struct nfs4_filelayout *flo;
752 
753                 flo = FILELAYOUT_FROM_HDR(lseg->pls_layout);
754                 flo->commit_info.nbuckets = 0;
755                 kfree(flo->commit_info.buckets);
756                 flo->commit_info.buckets = NULL;
757         }
758         _filelayout_free_lseg(fl);
759 }
760 
761 static int
762 filelayout_alloc_commit_info(struct pnfs_layout_segment *lseg,
763                              struct nfs_commit_info *cinfo,
764                              gfp_t gfp_flags)
765 {
766         struct nfs4_filelayout_segment *fl = FILELAYOUT_LSEG(lseg);
767         struct pnfs_commit_bucket *buckets;
768         int size, i;
769 
770         if (fl->commit_through_mds)
771                 return 0;
772 
773         size = (fl->stripe_type == STRIPE_SPARSE) ?
774                 fl->dsaddr->ds_num : fl->dsaddr->stripe_count;
775 
776         if (cinfo->ds->nbuckets >= size) {
777                 /* This assumes there is only one IOMODE_RW lseg.  What
778                  * we really want to do is have a layout_hdr level
779                  * dictionary of <multipath_list4, fh> keys, each
780                  * associated with a struct list_head, populated by calls
781                  * to filelayout_write_pagelist().
782                  * */
783                 return 0;
784         }
785 
786         buckets = kcalloc(size, sizeof(struct pnfs_commit_bucket),
787                           gfp_flags);
788         if (!buckets)
789                 return -ENOMEM;
790         for (i = 0; i < size; i++) {
791                 INIT_LIST_HEAD(&buckets[i].written);
792                 INIT_LIST_HEAD(&buckets[i].committing);
793                 /* mark direct verifier as unset */
794                 buckets[i].direct_verf.committed = NFS_INVALID_STABLE_HOW;
795         }
796 
797         spin_lock(&cinfo->inode->i_lock);
798         if (cinfo->ds->nbuckets >= size)
799                 goto out;
800         for (i = 0; i < cinfo->ds->nbuckets; i++) {
801                 list_splice(&cinfo->ds->buckets[i].written,
802                             &buckets[i].written);
803                 list_splice(&cinfo->ds->buckets[i].committing,
804                             &buckets[i].committing);
805                 buckets[i].direct_verf.committed =
806                         cinfo->ds->buckets[i].direct_verf.committed;
807                 buckets[i].wlseg = cinfo->ds->buckets[i].wlseg;
808                 buckets[i].clseg = cinfo->ds->buckets[i].clseg;
809         }
810         swap(cinfo->ds->buckets, buckets);
811         cinfo->ds->nbuckets = size;
812 out:
813         spin_unlock(&cinfo->inode->i_lock);
814         kfree(buckets);
815         return 0;
816 }
817 
818 static struct pnfs_layout_segment *
819 filelayout_alloc_lseg(struct pnfs_layout_hdr *layoutid,
820                       struct nfs4_layoutget_res *lgr,
821                       gfp_t gfp_flags)
822 {
823         struct nfs4_filelayout_segment *fl;
824         int rc;
825         struct nfs4_deviceid id;
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, &id, gfp_flags);
833         if (rc != 0 || filelayout_check_layout(layoutid, fl, lgr, &id, 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 void
883 filelayout_pg_init_read(struct nfs_pageio_descriptor *pgio,
884                         struct nfs_page *req)
885 {
886         if (!pgio->pg_lseg) {
887                 pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
888                                            req->wb_context,
889                                            0,
890                                            NFS4_MAX_UINT64,
891                                            IOMODE_READ,
892                                            false,
893                                            GFP_KERNEL);
894                 if (IS_ERR(pgio->pg_lseg)) {
895                         pgio->pg_error = PTR_ERR(pgio->pg_lseg);
896                         pgio->pg_lseg = NULL;
897                         return;
898                 }
899         }
900         /* If no lseg, fall back to read through mds */
901         if (pgio->pg_lseg == NULL)
902                 nfs_pageio_reset_read_mds(pgio);
903 }
904 
905 static void
906 filelayout_pg_init_write(struct nfs_pageio_descriptor *pgio,
907                          struct nfs_page *req)
908 {
909         struct nfs_commit_info cinfo;
910         int status;
911 
912         if (!pgio->pg_lseg) {
913                 pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
914                                            req->wb_context,
915                                            0,
916                                            NFS4_MAX_UINT64,
917                                            IOMODE_RW,
918                                            false,
919                                            GFP_NOFS);
920                 if (IS_ERR(pgio->pg_lseg)) {
921                         pgio->pg_error = PTR_ERR(pgio->pg_lseg);
922                         pgio->pg_lseg = NULL;
923                         return;
924                 }
925         }
926 
927         /* If no lseg, fall back to write through mds */
928         if (pgio->pg_lseg == NULL)
929                 goto out_mds;
930         nfs_init_cinfo(&cinfo, pgio->pg_inode, pgio->pg_dreq);
931         status = filelayout_alloc_commit_info(pgio->pg_lseg, &cinfo, GFP_NOFS);
932         if (status < 0) {
933                 pnfs_put_lseg(pgio->pg_lseg);
934                 pgio->pg_lseg = NULL;
935                 goto out_mds;
936         }
937         return;
938 out_mds:
939         nfs_pageio_reset_write_mds(pgio);
940 }
941 
942 static const struct nfs_pageio_ops filelayout_pg_read_ops = {
943         .pg_init = filelayout_pg_init_read,
944         .pg_test = filelayout_pg_test,
945         .pg_doio = pnfs_generic_pg_readpages,
946         .pg_cleanup = pnfs_generic_pg_cleanup,
947 };
948 
949 static const struct nfs_pageio_ops filelayout_pg_write_ops = {
950         .pg_init = filelayout_pg_init_write,
951         .pg_test = filelayout_pg_test,
952         .pg_doio = pnfs_generic_pg_writepages,
953         .pg_cleanup = pnfs_generic_pg_cleanup,
954 };
955 
956 static u32 select_bucket_index(struct nfs4_filelayout_segment *fl, u32 j)
957 {
958         if (fl->stripe_type == STRIPE_SPARSE)
959                 return nfs4_fl_calc_ds_index(&fl->generic_hdr, j);
960         else
961                 return j;
962 }
963 
964 static void
965 filelayout_mark_request_commit(struct nfs_page *req,
966                                struct pnfs_layout_segment *lseg,
967                                struct nfs_commit_info *cinfo,
968                                u32 ds_commit_idx)
969 
970 {
971         struct nfs4_filelayout_segment *fl = FILELAYOUT_LSEG(lseg);
972         u32 i, j;
973 
974         if (fl->commit_through_mds) {
975                 nfs_request_add_commit_list(req, cinfo);
976         } else {
977                 /* Note that we are calling nfs4_fl_calc_j_index on each page
978                  * that ends up being committed to a data server.  An attractive
979                  * alternative is to add a field to nfs_write_data and nfs_page
980                  * to store the value calculated in filelayout_write_pagelist
981                  * and just use that here.
982                  */
983                 j = nfs4_fl_calc_j_index(lseg, req_offset(req));
984                 i = select_bucket_index(fl, j);
985                 pnfs_layout_mark_request_commit(req, lseg, cinfo, i);
986         }
987 }
988 
989 static u32 calc_ds_index_from_commit(struct pnfs_layout_segment *lseg, u32 i)
990 {
991         struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg);
992 
993         if (flseg->stripe_type == STRIPE_SPARSE)
994                 return i;
995         else
996                 return nfs4_fl_calc_ds_index(lseg, i);
997 }
998 
999 static struct nfs_fh *
1000 select_ds_fh_from_commit(struct pnfs_layout_segment *lseg, u32 i)
1001 {
1002         struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg);
1003 
1004         if (flseg->stripe_type == STRIPE_SPARSE) {
1005                 if (flseg->num_fh == 1)
1006                         i = 0;
1007                 else if (flseg->num_fh == 0)
1008                         /* Use the MDS OPEN fh set in nfs_read_rpcsetup */
1009                         return NULL;
1010         }
1011         return flseg->fh_array[i];
1012 }
1013 
1014 static int filelayout_initiate_commit(struct nfs_commit_data *data, int how)
1015 {
1016         struct pnfs_layout_segment *lseg = data->lseg;
1017         struct nfs4_pnfs_ds *ds;
1018         struct rpc_clnt *ds_clnt;
1019         u32 idx;
1020         struct nfs_fh *fh;
1021 
1022         idx = calc_ds_index_from_commit(lseg, data->ds_commit_index);
1023         ds = nfs4_fl_prepare_ds(lseg, idx);
1024         if (!ds)
1025                 goto out_err;
1026 
1027         ds_clnt = nfs4_find_or_create_ds_client(ds->ds_clp, data->inode);
1028         if (IS_ERR(ds_clnt))
1029                 goto out_err;
1030 
1031         dprintk("%s ino %lu, how %d cl_count %d\n", __func__,
1032                 data->inode->i_ino, how, atomic_read(&ds->ds_clp->cl_count));
1033         data->commit_done_cb = filelayout_commit_done_cb;
1034         atomic_inc(&ds->ds_clp->cl_count);
1035         data->ds_clp = ds->ds_clp;
1036         fh = select_ds_fh_from_commit(lseg, data->ds_commit_index);
1037         if (fh)
1038                 data->args.fh = fh;
1039         return nfs_initiate_commit(ds_clnt, data, NFS_PROTO(data->inode),
1040                                    &filelayout_commit_call_ops, how,
1041                                    RPC_TASK_SOFTCONN);
1042 out_err:
1043         pnfs_generic_prepare_to_resend_writes(data);
1044         pnfs_generic_commit_release(data);
1045         return -EAGAIN;
1046 }
1047 
1048 /* filelayout_search_commit_reqs - Search lists in @cinfo for the head reqest
1049  *                                 for @page
1050  * @cinfo - commit info for current inode
1051  * @page - page to search for matching head request
1052  *
1053  * Returns a the head request if one is found, otherwise returns NULL.
1054  */
1055 static struct nfs_page *
1056 filelayout_search_commit_reqs(struct nfs_commit_info *cinfo, struct page *page)
1057 {
1058         struct nfs_page *freq, *t;
1059         struct pnfs_commit_bucket *b;
1060         int i;
1061 
1062         /* Linearly search the commit lists for each bucket until a matching
1063          * request is found */
1064         for (i = 0, b = cinfo->ds->buckets; i < cinfo->ds->nbuckets; i++, b++) {
1065                 list_for_each_entry_safe(freq, t, &b->written, wb_list) {
1066                         if (freq->wb_page == page)
1067                                 return freq->wb_head;
1068                 }
1069                 list_for_each_entry_safe(freq, t, &b->committing, wb_list) {
1070                         if (freq->wb_page == page)
1071                                 return freq->wb_head;
1072                 }
1073         }
1074 
1075         return NULL;
1076 }
1077 
1078 static int
1079 filelayout_commit_pagelist(struct inode *inode, struct list_head *mds_pages,
1080                            int how, struct nfs_commit_info *cinfo)
1081 {
1082         return pnfs_generic_commit_pagelist(inode, mds_pages, how, cinfo,
1083                                             filelayout_initiate_commit);
1084 }
1085 
1086 static struct nfs4_deviceid_node *
1087 filelayout_alloc_deviceid_node(struct nfs_server *server,
1088                 struct pnfs_device *pdev, gfp_t gfp_flags)
1089 {
1090         struct nfs4_file_layout_dsaddr *dsaddr;
1091 
1092         dsaddr = nfs4_fl_alloc_deviceid_node(server, pdev, gfp_flags);
1093         if (!dsaddr)
1094                 return NULL;
1095         return &dsaddr->id_node;
1096 }
1097 
1098 static void
1099 filelayout_free_deviceid_node(struct nfs4_deviceid_node *d)
1100 {
1101         nfs4_fl_free_deviceid(container_of(d, struct nfs4_file_layout_dsaddr, id_node));
1102 }
1103 
1104 static struct pnfs_layout_hdr *
1105 filelayout_alloc_layout_hdr(struct inode *inode, gfp_t gfp_flags)
1106 {
1107         struct nfs4_filelayout *flo;
1108 
1109         flo = kzalloc(sizeof(*flo), gfp_flags);
1110         return flo != NULL ? &flo->generic_hdr : NULL;
1111 }
1112 
1113 static void
1114 filelayout_free_layout_hdr(struct pnfs_layout_hdr *lo)
1115 {
1116         kfree(FILELAYOUT_FROM_HDR(lo));
1117 }
1118 
1119 static struct pnfs_ds_commit_info *
1120 filelayout_get_ds_info(struct inode *inode)
1121 {
1122         struct pnfs_layout_hdr *layout = NFS_I(inode)->layout;
1123 
1124         if (layout == NULL)
1125                 return NULL;
1126         else
1127                 return &FILELAYOUT_FROM_HDR(layout)->commit_info;
1128 }
1129 
1130 static struct pnfs_layoutdriver_type filelayout_type = {
1131         .id                     = LAYOUT_NFSV4_1_FILES,
1132         .name                   = "LAYOUT_NFSV4_1_FILES",
1133         .owner                  = THIS_MODULE,
1134         .alloc_layout_hdr       = filelayout_alloc_layout_hdr,
1135         .free_layout_hdr        = filelayout_free_layout_hdr,
1136         .alloc_lseg             = filelayout_alloc_lseg,
1137         .free_lseg              = filelayout_free_lseg,
1138         .pg_read_ops            = &filelayout_pg_read_ops,
1139         .pg_write_ops           = &filelayout_pg_write_ops,
1140         .get_ds_info            = &filelayout_get_ds_info,
1141         .mark_request_commit    = filelayout_mark_request_commit,
1142         .clear_request_commit   = pnfs_generic_clear_request_commit,
1143         .scan_commit_lists      = pnfs_generic_scan_commit_lists,
1144         .recover_commit_reqs    = pnfs_generic_recover_commit_reqs,
1145         .search_commit_reqs     = filelayout_search_commit_reqs,
1146         .commit_pagelist        = filelayout_commit_pagelist,
1147         .read_pagelist          = filelayout_read_pagelist,
1148         .write_pagelist         = filelayout_write_pagelist,
1149         .alloc_deviceid_node    = filelayout_alloc_deviceid_node,
1150         .free_deviceid_node     = filelayout_free_deviceid_node,
1151         .sync                   = pnfs_nfs_generic_sync,
1152 };
1153 
1154 static int __init nfs4filelayout_init(void)
1155 {
1156         printk(KERN_INFO "%s: NFSv4 File Layout Driver Registering...\n",
1157                __func__);
1158         return pnfs_register_layoutdriver(&filelayout_type);
1159 }
1160 
1161 static void __exit nfs4filelayout_exit(void)
1162 {
1163         printk(KERN_INFO "%s: NFSv4 File Layout Driver Unregistering...\n",
1164                __func__);
1165         pnfs_unregister_layoutdriver(&filelayout_type);
1166 }
1167 
1168 MODULE_ALIAS("nfs-layouttype4-1");
1169 
1170 module_init(nfs4filelayout_init);
1171 module_exit(nfs4filelayout_exit);
1172 

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