ARM: mvebu: use new bindings for existing crypto devices
[linux/fpc-iii.git] / fs / nfs / pagelist.c
blob7c5718ba625e28ff661868dd2d32fb438042a7bb
1 /*
2 * linux/fs/nfs/pagelist.c
4 * A set of helper functions for managing NFS read and write requests.
5 * The main purpose of these routines is to provide support for the
6 * coalescing of several requests into a single RPC call.
8 * Copyright 2000, 2001 (c) Trond Myklebust <trond.myklebust@fys.uio.no>
12 #include <linux/slab.h>
13 #include <linux/file.h>
14 #include <linux/sched.h>
15 #include <linux/sunrpc/clnt.h>
16 #include <linux/nfs.h>
17 #include <linux/nfs3.h>
18 #include <linux/nfs4.h>
19 #include <linux/nfs_page.h>
20 #include <linux/nfs_fs.h>
21 #include <linux/nfs_mount.h>
22 #include <linux/export.h>
24 #include "internal.h"
25 #include "pnfs.h"
27 #define NFSDBG_FACILITY NFSDBG_PAGECACHE
29 static struct kmem_cache *nfs_page_cachep;
30 static const struct rpc_call_ops nfs_pgio_common_ops;
32 static bool nfs_pgarray_set(struct nfs_page_array *p, unsigned int pagecount)
34 p->npages = pagecount;
35 if (pagecount <= ARRAY_SIZE(p->page_array))
36 p->pagevec = p->page_array;
37 else {
38 p->pagevec = kcalloc(pagecount, sizeof(struct page *), GFP_KERNEL);
39 if (!p->pagevec)
40 p->npages = 0;
42 return p->pagevec != NULL;
45 struct nfs_pgio_mirror *
46 nfs_pgio_current_mirror(struct nfs_pageio_descriptor *desc)
48 return nfs_pgio_has_mirroring(desc) ?
49 &desc->pg_mirrors[desc->pg_mirror_idx] :
50 &desc->pg_mirrors[0];
52 EXPORT_SYMBOL_GPL(nfs_pgio_current_mirror);
54 void nfs_pgheader_init(struct nfs_pageio_descriptor *desc,
55 struct nfs_pgio_header *hdr,
56 void (*release)(struct nfs_pgio_header *hdr))
58 struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
61 hdr->req = nfs_list_entry(mirror->pg_list.next);
62 hdr->inode = desc->pg_inode;
63 hdr->cred = hdr->req->wb_context->cred;
64 hdr->io_start = req_offset(hdr->req);
65 hdr->good_bytes = mirror->pg_count;
66 hdr->dreq = desc->pg_dreq;
67 hdr->layout_private = desc->pg_layout_private;
68 hdr->release = release;
69 hdr->completion_ops = desc->pg_completion_ops;
70 if (hdr->completion_ops->init_hdr)
71 hdr->completion_ops->init_hdr(hdr);
73 hdr->pgio_mirror_idx = desc->pg_mirror_idx;
75 EXPORT_SYMBOL_GPL(nfs_pgheader_init);
77 void nfs_set_pgio_error(struct nfs_pgio_header *hdr, int error, loff_t pos)
79 spin_lock(&hdr->lock);
80 if (!test_and_set_bit(NFS_IOHDR_ERROR, &hdr->flags)
81 || pos < hdr->io_start + hdr->good_bytes) {
82 clear_bit(NFS_IOHDR_EOF, &hdr->flags);
83 hdr->good_bytes = pos - hdr->io_start;
84 hdr->error = error;
86 spin_unlock(&hdr->lock);
89 static inline struct nfs_page *
90 nfs_page_alloc(void)
92 struct nfs_page *p = kmem_cache_zalloc(nfs_page_cachep, GFP_NOIO);
93 if (p)
94 INIT_LIST_HEAD(&p->wb_list);
95 return p;
98 static inline void
99 nfs_page_free(struct nfs_page *p)
101 kmem_cache_free(nfs_page_cachep, p);
104 static void
105 nfs_iocounter_inc(struct nfs_io_counter *c)
107 atomic_inc(&c->io_count);
110 static void
111 nfs_iocounter_dec(struct nfs_io_counter *c)
113 if (atomic_dec_and_test(&c->io_count)) {
114 clear_bit(NFS_IO_INPROGRESS, &c->flags);
115 smp_mb__after_atomic();
116 wake_up_bit(&c->flags, NFS_IO_INPROGRESS);
120 static int
121 __nfs_iocounter_wait(struct nfs_io_counter *c)
123 wait_queue_head_t *wq = bit_waitqueue(&c->flags, NFS_IO_INPROGRESS);
124 DEFINE_WAIT_BIT(q, &c->flags, NFS_IO_INPROGRESS);
125 int ret = 0;
127 do {
128 prepare_to_wait(wq, &q.wait, TASK_KILLABLE);
129 set_bit(NFS_IO_INPROGRESS, &c->flags);
130 if (atomic_read(&c->io_count) == 0)
131 break;
132 ret = nfs_wait_bit_killable(&q.key);
133 } while (atomic_read(&c->io_count) != 0 && !ret);
134 finish_wait(wq, &q.wait);
135 return ret;
139 * nfs_iocounter_wait - wait for i/o to complete
140 * @c: nfs_io_counter to use
142 * returns -ERESTARTSYS if interrupted by a fatal signal.
143 * Otherwise returns 0 once the io_count hits 0.
146 nfs_iocounter_wait(struct nfs_io_counter *c)
148 if (atomic_read(&c->io_count) == 0)
149 return 0;
150 return __nfs_iocounter_wait(c);
154 * nfs_page_group_lock - lock the head of the page group
155 * @req - request in group that is to be locked
156 * @nonblock - if true don't block waiting for lock
158 * this lock must be held if modifying the page group list
160 * return 0 on success, < 0 on error: -EDELAY if nonblocking or the
161 * result from wait_on_bit_lock
163 * NOTE: calling with nonblock=false should always have set the
164 * lock bit (see fs/buffer.c and other uses of wait_on_bit_lock
165 * with TASK_UNINTERRUPTIBLE), so there is no need to check the result.
168 nfs_page_group_lock(struct nfs_page *req, bool nonblock)
170 struct nfs_page *head = req->wb_head;
172 WARN_ON_ONCE(head != head->wb_head);
174 if (!test_and_set_bit(PG_HEADLOCK, &head->wb_flags))
175 return 0;
177 if (!nonblock)
178 return wait_on_bit_lock(&head->wb_flags, PG_HEADLOCK,
179 TASK_UNINTERRUPTIBLE);
181 return -EAGAIN;
185 * nfs_page_group_lock_wait - wait for the lock to clear, but don't grab it
186 * @req - a request in the group
188 * This is a blocking call to wait for the group lock to be cleared.
190 void
191 nfs_page_group_lock_wait(struct nfs_page *req)
193 struct nfs_page *head = req->wb_head;
195 WARN_ON_ONCE(head != head->wb_head);
197 wait_on_bit(&head->wb_flags, PG_HEADLOCK,
198 TASK_UNINTERRUPTIBLE);
202 * nfs_page_group_unlock - unlock the head of the page group
203 * @req - request in group that is to be unlocked
205 void
206 nfs_page_group_unlock(struct nfs_page *req)
208 struct nfs_page *head = req->wb_head;
210 WARN_ON_ONCE(head != head->wb_head);
212 smp_mb__before_atomic();
213 clear_bit(PG_HEADLOCK, &head->wb_flags);
214 smp_mb__after_atomic();
215 wake_up_bit(&head->wb_flags, PG_HEADLOCK);
219 * nfs_page_group_sync_on_bit_locked
221 * must be called with page group lock held
223 static bool
224 nfs_page_group_sync_on_bit_locked(struct nfs_page *req, unsigned int bit)
226 struct nfs_page *head = req->wb_head;
227 struct nfs_page *tmp;
229 WARN_ON_ONCE(!test_bit(PG_HEADLOCK, &head->wb_flags));
230 WARN_ON_ONCE(test_and_set_bit(bit, &req->wb_flags));
232 tmp = req->wb_this_page;
233 while (tmp != req) {
234 if (!test_bit(bit, &tmp->wb_flags))
235 return false;
236 tmp = tmp->wb_this_page;
239 /* true! reset all bits */
240 tmp = req;
241 do {
242 clear_bit(bit, &tmp->wb_flags);
243 tmp = tmp->wb_this_page;
244 } while (tmp != req);
246 return true;
250 * nfs_page_group_sync_on_bit - set bit on current request, but only
251 * return true if the bit is set for all requests in page group
252 * @req - request in page group
253 * @bit - PG_* bit that is used to sync page group
255 bool nfs_page_group_sync_on_bit(struct nfs_page *req, unsigned int bit)
257 bool ret;
259 nfs_page_group_lock(req, false);
260 ret = nfs_page_group_sync_on_bit_locked(req, bit);
261 nfs_page_group_unlock(req);
263 return ret;
267 * nfs_page_group_init - Initialize the page group linkage for @req
268 * @req - a new nfs request
269 * @prev - the previous request in page group, or NULL if @req is the first
270 * or only request in the group (the head).
272 static inline void
273 nfs_page_group_init(struct nfs_page *req, struct nfs_page *prev)
275 struct inode *inode;
276 WARN_ON_ONCE(prev == req);
278 if (!prev) {
279 /* a head request */
280 req->wb_head = req;
281 req->wb_this_page = req;
282 } else {
283 /* a subrequest */
284 WARN_ON_ONCE(prev->wb_this_page != prev->wb_head);
285 WARN_ON_ONCE(!test_bit(PG_HEADLOCK, &prev->wb_head->wb_flags));
286 req->wb_head = prev->wb_head;
287 req->wb_this_page = prev->wb_this_page;
288 prev->wb_this_page = req;
290 /* All subrequests take a ref on the head request until
291 * nfs_page_group_destroy is called */
292 kref_get(&req->wb_head->wb_kref);
294 /* grab extra ref and bump the request count if head request
295 * has extra ref from the write/commit path to handle handoff
296 * between write and commit lists. */
297 if (test_bit(PG_INODE_REF, &prev->wb_head->wb_flags)) {
298 inode = page_file_mapping(req->wb_page)->host;
299 set_bit(PG_INODE_REF, &req->wb_flags);
300 kref_get(&req->wb_kref);
301 spin_lock(&inode->i_lock);
302 NFS_I(inode)->nrequests++;
303 spin_unlock(&inode->i_lock);
309 * nfs_page_group_destroy - sync the destruction of page groups
310 * @req - request that no longer needs the page group
312 * releases the page group reference from each member once all
313 * members have called this function.
315 static void
316 nfs_page_group_destroy(struct kref *kref)
318 struct nfs_page *req = container_of(kref, struct nfs_page, wb_kref);
319 struct nfs_page *tmp, *next;
321 /* subrequests must release the ref on the head request */
322 if (req->wb_head != req)
323 nfs_release_request(req->wb_head);
325 if (!nfs_page_group_sync_on_bit(req, PG_TEARDOWN))
326 return;
328 tmp = req;
329 do {
330 next = tmp->wb_this_page;
331 /* unlink and free */
332 tmp->wb_this_page = tmp;
333 tmp->wb_head = tmp;
334 nfs_free_request(tmp);
335 tmp = next;
336 } while (tmp != req);
340 * nfs_create_request - Create an NFS read/write request.
341 * @ctx: open context to use
342 * @page: page to write
343 * @last: last nfs request created for this page group or NULL if head
344 * @offset: starting offset within the page for the write
345 * @count: number of bytes to read/write
347 * The page must be locked by the caller. This makes sure we never
348 * create two different requests for the same page.
349 * User should ensure it is safe to sleep in this function.
351 struct nfs_page *
352 nfs_create_request(struct nfs_open_context *ctx, struct page *page,
353 struct nfs_page *last, unsigned int offset,
354 unsigned int count)
356 struct nfs_page *req;
357 struct nfs_lock_context *l_ctx;
359 if (test_bit(NFS_CONTEXT_BAD, &ctx->flags))
360 return ERR_PTR(-EBADF);
361 /* try to allocate the request struct */
362 req = nfs_page_alloc();
363 if (req == NULL)
364 return ERR_PTR(-ENOMEM);
366 /* get lock context early so we can deal with alloc failures */
367 l_ctx = nfs_get_lock_context(ctx);
368 if (IS_ERR(l_ctx)) {
369 nfs_page_free(req);
370 return ERR_CAST(l_ctx);
372 req->wb_lock_context = l_ctx;
373 nfs_iocounter_inc(&l_ctx->io_count);
375 /* Initialize the request struct. Initially, we assume a
376 * long write-back delay. This will be adjusted in
377 * update_nfs_request below if the region is not locked. */
378 req->wb_page = page;
379 req->wb_index = page_file_index(page);
380 page_cache_get(page);
381 req->wb_offset = offset;
382 req->wb_pgbase = offset;
383 req->wb_bytes = count;
384 req->wb_context = get_nfs_open_context(ctx);
385 kref_init(&req->wb_kref);
386 nfs_page_group_init(req, last);
387 return req;
391 * nfs_unlock_request - Unlock request and wake up sleepers.
392 * @req:
394 void nfs_unlock_request(struct nfs_page *req)
396 if (!NFS_WBACK_BUSY(req)) {
397 printk(KERN_ERR "NFS: Invalid unlock attempted\n");
398 BUG();
400 smp_mb__before_atomic();
401 clear_bit(PG_BUSY, &req->wb_flags);
402 smp_mb__after_atomic();
403 wake_up_bit(&req->wb_flags, PG_BUSY);
407 * nfs_unlock_and_release_request - Unlock request and release the nfs_page
408 * @req:
410 void nfs_unlock_and_release_request(struct nfs_page *req)
412 nfs_unlock_request(req);
413 nfs_release_request(req);
417 * nfs_clear_request - Free up all resources allocated to the request
418 * @req:
420 * Release page and open context resources associated with a read/write
421 * request after it has completed.
423 static void nfs_clear_request(struct nfs_page *req)
425 struct page *page = req->wb_page;
426 struct nfs_open_context *ctx = req->wb_context;
427 struct nfs_lock_context *l_ctx = req->wb_lock_context;
429 if (page != NULL) {
430 page_cache_release(page);
431 req->wb_page = NULL;
433 if (l_ctx != NULL) {
434 nfs_iocounter_dec(&l_ctx->io_count);
435 nfs_put_lock_context(l_ctx);
436 req->wb_lock_context = NULL;
438 if (ctx != NULL) {
439 put_nfs_open_context(ctx);
440 req->wb_context = NULL;
445 * nfs_release_request - Release the count on an NFS read/write request
446 * @req: request to release
448 * Note: Should never be called with the spinlock held!
450 void nfs_free_request(struct nfs_page *req)
452 WARN_ON_ONCE(req->wb_this_page != req);
454 /* extra debug: make sure no sync bits are still set */
455 WARN_ON_ONCE(test_bit(PG_TEARDOWN, &req->wb_flags));
456 WARN_ON_ONCE(test_bit(PG_UNLOCKPAGE, &req->wb_flags));
457 WARN_ON_ONCE(test_bit(PG_UPTODATE, &req->wb_flags));
458 WARN_ON_ONCE(test_bit(PG_WB_END, &req->wb_flags));
459 WARN_ON_ONCE(test_bit(PG_REMOVE, &req->wb_flags));
461 /* Release struct file and open context */
462 nfs_clear_request(req);
463 nfs_page_free(req);
466 void nfs_release_request(struct nfs_page *req)
468 kref_put(&req->wb_kref, nfs_page_group_destroy);
472 * nfs_wait_on_request - Wait for a request to complete.
473 * @req: request to wait upon.
475 * Interruptible by fatal signals only.
476 * The user is responsible for holding a count on the request.
479 nfs_wait_on_request(struct nfs_page *req)
481 return wait_on_bit_io(&req->wb_flags, PG_BUSY,
482 TASK_UNINTERRUPTIBLE);
486 * nfs_generic_pg_test - determine if requests can be coalesced
487 * @desc: pointer to descriptor
488 * @prev: previous request in desc, or NULL
489 * @req: this request
491 * Returns zero if @req can be coalesced into @desc, otherwise it returns
492 * the size of the request.
494 size_t nfs_generic_pg_test(struct nfs_pageio_descriptor *desc,
495 struct nfs_page *prev, struct nfs_page *req)
497 struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
500 if (mirror->pg_count > mirror->pg_bsize) {
501 /* should never happen */
502 WARN_ON_ONCE(1);
503 return 0;
507 * Limit the request size so that we can still allocate a page array
508 * for it without upsetting the slab allocator.
510 if (((mirror->pg_count + req->wb_bytes) >> PAGE_SHIFT) *
511 sizeof(struct page) > PAGE_SIZE)
512 return 0;
514 return min(mirror->pg_bsize - mirror->pg_count, (size_t)req->wb_bytes);
516 EXPORT_SYMBOL_GPL(nfs_generic_pg_test);
518 struct nfs_pgio_header *nfs_pgio_header_alloc(const struct nfs_rw_ops *ops)
520 struct nfs_pgio_header *hdr = ops->rw_alloc_header();
522 if (hdr) {
523 INIT_LIST_HEAD(&hdr->pages);
524 spin_lock_init(&hdr->lock);
525 hdr->rw_ops = ops;
527 return hdr;
529 EXPORT_SYMBOL_GPL(nfs_pgio_header_alloc);
532 * nfs_pgio_header_free - Free a read or write header
533 * @hdr: The header to free
535 void nfs_pgio_header_free(struct nfs_pgio_header *hdr)
537 hdr->rw_ops->rw_free_header(hdr);
539 EXPORT_SYMBOL_GPL(nfs_pgio_header_free);
542 * nfs_pgio_data_destroy - make @hdr suitable for reuse
544 * Frees memory and releases refs from nfs_generic_pgio, so that it may
545 * be called again.
547 * @hdr: A header that has had nfs_generic_pgio called
549 void nfs_pgio_data_destroy(struct nfs_pgio_header *hdr)
551 if (hdr->args.context)
552 put_nfs_open_context(hdr->args.context);
553 if (hdr->page_array.pagevec != hdr->page_array.page_array)
554 kfree(hdr->page_array.pagevec);
556 EXPORT_SYMBOL_GPL(nfs_pgio_data_destroy);
559 * nfs_pgio_rpcsetup - Set up arguments for a pageio call
560 * @hdr: The pageio hdr
561 * @count: Number of bytes to read
562 * @offset: Initial offset
563 * @how: How to commit data (writes only)
564 * @cinfo: Commit information for the call (writes only)
566 static void nfs_pgio_rpcsetup(struct nfs_pgio_header *hdr,
567 unsigned int count, unsigned int offset,
568 int how, struct nfs_commit_info *cinfo)
570 struct nfs_page *req = hdr->req;
572 /* Set up the RPC argument and reply structs
573 * NB: take care not to mess about with hdr->commit et al. */
575 hdr->args.fh = NFS_FH(hdr->inode);
576 hdr->args.offset = req_offset(req) + offset;
577 /* pnfs_set_layoutcommit needs this */
578 hdr->mds_offset = hdr->args.offset;
579 hdr->args.pgbase = req->wb_pgbase + offset;
580 hdr->args.pages = hdr->page_array.pagevec;
581 hdr->args.count = count;
582 hdr->args.context = get_nfs_open_context(req->wb_context);
583 hdr->args.lock_context = req->wb_lock_context;
584 hdr->args.stable = NFS_UNSTABLE;
585 switch (how & (FLUSH_STABLE | FLUSH_COND_STABLE)) {
586 case 0:
587 break;
588 case FLUSH_COND_STABLE:
589 if (nfs_reqs_to_commit(cinfo))
590 break;
591 default:
592 hdr->args.stable = NFS_FILE_SYNC;
595 hdr->res.fattr = &hdr->fattr;
596 hdr->res.count = count;
597 hdr->res.eof = 0;
598 hdr->res.verf = &hdr->verf;
599 nfs_fattr_init(&hdr->fattr);
603 * nfs_pgio_prepare - Prepare pageio hdr to go over the wire
604 * @task: The current task
605 * @calldata: pageio header to prepare
607 static void nfs_pgio_prepare(struct rpc_task *task, void *calldata)
609 struct nfs_pgio_header *hdr = calldata;
610 int err;
611 err = NFS_PROTO(hdr->inode)->pgio_rpc_prepare(task, hdr);
612 if (err)
613 rpc_exit(task, err);
616 int nfs_initiate_pgio(struct rpc_clnt *clnt, struct nfs_pgio_header *hdr,
617 struct rpc_cred *cred, const struct nfs_rpc_ops *rpc_ops,
618 const struct rpc_call_ops *call_ops, int how, int flags)
620 struct rpc_task *task;
621 struct rpc_message msg = {
622 .rpc_argp = &hdr->args,
623 .rpc_resp = &hdr->res,
624 .rpc_cred = cred,
626 struct rpc_task_setup task_setup_data = {
627 .rpc_client = clnt,
628 .task = &hdr->task,
629 .rpc_message = &msg,
630 .callback_ops = call_ops,
631 .callback_data = hdr,
632 .workqueue = nfsiod_workqueue,
633 .flags = RPC_TASK_ASYNC | flags,
635 int ret = 0;
637 hdr->rw_ops->rw_initiate(hdr, &msg, rpc_ops, &task_setup_data, how);
639 dprintk("NFS: initiated pgio call "
640 "(req %s/%llu, %u bytes @ offset %llu)\n",
641 hdr->inode->i_sb->s_id,
642 (unsigned long long)NFS_FILEID(hdr->inode),
643 hdr->args.count,
644 (unsigned long long)hdr->args.offset);
646 task = rpc_run_task(&task_setup_data);
647 if (IS_ERR(task)) {
648 ret = PTR_ERR(task);
649 goto out;
651 if (how & FLUSH_SYNC) {
652 ret = rpc_wait_for_completion_task(task);
653 if (ret == 0)
654 ret = task->tk_status;
656 rpc_put_task(task);
657 out:
658 return ret;
660 EXPORT_SYMBOL_GPL(nfs_initiate_pgio);
663 * nfs_pgio_error - Clean up from a pageio error
664 * @desc: IO descriptor
665 * @hdr: pageio header
667 static int nfs_pgio_error(struct nfs_pageio_descriptor *desc,
668 struct nfs_pgio_header *hdr)
670 struct nfs_pgio_mirror *mirror;
671 u32 midx;
673 set_bit(NFS_IOHDR_REDO, &hdr->flags);
674 nfs_pgio_data_destroy(hdr);
675 hdr->completion_ops->completion(hdr);
676 /* TODO: Make sure it's right to clean up all mirrors here
677 * and not just hdr->pgio_mirror_idx */
678 for (midx = 0; midx < desc->pg_mirror_count; midx++) {
679 mirror = &desc->pg_mirrors[midx];
680 desc->pg_completion_ops->error_cleanup(&mirror->pg_list);
682 return -ENOMEM;
686 * nfs_pgio_release - Release pageio data
687 * @calldata: The pageio header to release
689 static void nfs_pgio_release(void *calldata)
691 struct nfs_pgio_header *hdr = calldata;
692 nfs_pgio_data_destroy(hdr);
693 hdr->completion_ops->completion(hdr);
696 static void nfs_pageio_mirror_init(struct nfs_pgio_mirror *mirror,
697 unsigned int bsize)
699 INIT_LIST_HEAD(&mirror->pg_list);
700 mirror->pg_bytes_written = 0;
701 mirror->pg_count = 0;
702 mirror->pg_bsize = bsize;
703 mirror->pg_base = 0;
704 mirror->pg_recoalesce = 0;
708 * nfs_pageio_init - initialise a page io descriptor
709 * @desc: pointer to descriptor
710 * @inode: pointer to inode
711 * @pg_ops: pointer to pageio operations
712 * @compl_ops: pointer to pageio completion operations
713 * @rw_ops: pointer to nfs read/write operations
714 * @bsize: io block size
715 * @io_flags: extra parameters for the io function
717 void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
718 struct inode *inode,
719 const struct nfs_pageio_ops *pg_ops,
720 const struct nfs_pgio_completion_ops *compl_ops,
721 const struct nfs_rw_ops *rw_ops,
722 size_t bsize,
723 int io_flags)
725 struct nfs_pgio_mirror *new;
726 int i;
728 desc->pg_moreio = 0;
729 desc->pg_inode = inode;
730 desc->pg_ops = pg_ops;
731 desc->pg_completion_ops = compl_ops;
732 desc->pg_rw_ops = rw_ops;
733 desc->pg_ioflags = io_flags;
734 desc->pg_error = 0;
735 desc->pg_lseg = NULL;
736 desc->pg_dreq = NULL;
737 desc->pg_layout_private = NULL;
738 desc->pg_bsize = bsize;
740 desc->pg_mirror_count = 1;
741 desc->pg_mirror_idx = 0;
743 if (pg_ops->pg_get_mirror_count) {
744 /* until we have a request, we don't have an lseg and no
745 * idea how many mirrors there will be */
746 new = kcalloc(NFS_PAGEIO_DESCRIPTOR_MIRROR_MAX,
747 sizeof(struct nfs_pgio_mirror), GFP_KERNEL);
748 desc->pg_mirrors_dynamic = new;
749 desc->pg_mirrors = new;
751 for (i = 0; i < NFS_PAGEIO_DESCRIPTOR_MIRROR_MAX; i++)
752 nfs_pageio_mirror_init(&desc->pg_mirrors[i], bsize);
753 } else {
754 desc->pg_mirrors_dynamic = NULL;
755 desc->pg_mirrors = desc->pg_mirrors_static;
756 nfs_pageio_mirror_init(&desc->pg_mirrors[0], bsize);
759 EXPORT_SYMBOL_GPL(nfs_pageio_init);
762 * nfs_pgio_result - Basic pageio error handling
763 * @task: The task that ran
764 * @calldata: Pageio header to check
766 static void nfs_pgio_result(struct rpc_task *task, void *calldata)
768 struct nfs_pgio_header *hdr = calldata;
769 struct inode *inode = hdr->inode;
771 dprintk("NFS: %s: %5u, (status %d)\n", __func__,
772 task->tk_pid, task->tk_status);
774 if (hdr->rw_ops->rw_done(task, hdr, inode) != 0)
775 return;
776 if (task->tk_status < 0)
777 nfs_set_pgio_error(hdr, task->tk_status, hdr->args.offset);
778 else
779 hdr->rw_ops->rw_result(task, hdr);
783 * Create an RPC task for the given read or write request and kick it.
784 * The page must have been locked by the caller.
786 * It may happen that the page we're passed is not marked dirty.
787 * This is the case if nfs_updatepage detects a conflicting request
788 * that has been written but not committed.
790 int nfs_generic_pgio(struct nfs_pageio_descriptor *desc,
791 struct nfs_pgio_header *hdr)
793 struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
795 struct nfs_page *req;
796 struct page **pages,
797 *last_page;
798 struct list_head *head = &mirror->pg_list;
799 struct nfs_commit_info cinfo;
800 unsigned int pagecount, pageused;
802 pagecount = nfs_page_array_len(mirror->pg_base, mirror->pg_count);
803 if (!nfs_pgarray_set(&hdr->page_array, pagecount))
804 return nfs_pgio_error(desc, hdr);
806 nfs_init_cinfo(&cinfo, desc->pg_inode, desc->pg_dreq);
807 pages = hdr->page_array.pagevec;
808 last_page = NULL;
809 pageused = 0;
810 while (!list_empty(head)) {
811 req = nfs_list_entry(head->next);
812 nfs_list_remove_request(req);
813 nfs_list_add_request(req, &hdr->pages);
815 if (!last_page || last_page != req->wb_page) {
816 pageused++;
817 if (pageused > pagecount)
818 break;
819 *pages++ = last_page = req->wb_page;
822 if (WARN_ON_ONCE(pageused != pagecount))
823 return nfs_pgio_error(desc, hdr);
825 if ((desc->pg_ioflags & FLUSH_COND_STABLE) &&
826 (desc->pg_moreio || nfs_reqs_to_commit(&cinfo)))
827 desc->pg_ioflags &= ~FLUSH_COND_STABLE;
829 /* Set up the argument struct */
830 nfs_pgio_rpcsetup(hdr, mirror->pg_count, 0, desc->pg_ioflags, &cinfo);
831 desc->pg_rpc_callops = &nfs_pgio_common_ops;
832 return 0;
834 EXPORT_SYMBOL_GPL(nfs_generic_pgio);
836 static int nfs_generic_pg_pgios(struct nfs_pageio_descriptor *desc)
838 struct nfs_pgio_mirror *mirror;
839 struct nfs_pgio_header *hdr;
840 int ret;
842 mirror = nfs_pgio_current_mirror(desc);
844 hdr = nfs_pgio_header_alloc(desc->pg_rw_ops);
845 if (!hdr) {
846 /* TODO: make sure this is right with mirroring - or
847 * should it back out all mirrors? */
848 desc->pg_completion_ops->error_cleanup(&mirror->pg_list);
849 return -ENOMEM;
851 nfs_pgheader_init(desc, hdr, nfs_pgio_header_free);
852 ret = nfs_generic_pgio(desc, hdr);
853 if (ret == 0)
854 ret = nfs_initiate_pgio(NFS_CLIENT(hdr->inode),
855 hdr,
856 hdr->cred,
857 NFS_PROTO(hdr->inode),
858 desc->pg_rpc_callops,
859 desc->pg_ioflags, 0);
860 return ret;
864 * nfs_pageio_setup_mirroring - determine if mirroring is to be used
865 * by calling the pg_get_mirror_count op
867 static int nfs_pageio_setup_mirroring(struct nfs_pageio_descriptor *pgio,
868 struct nfs_page *req)
870 int mirror_count = 1;
872 if (!pgio->pg_ops->pg_get_mirror_count)
873 return 0;
875 mirror_count = pgio->pg_ops->pg_get_mirror_count(pgio, req);
877 if (!mirror_count || mirror_count > NFS_PAGEIO_DESCRIPTOR_MIRROR_MAX)
878 return -EINVAL;
880 if (WARN_ON_ONCE(!pgio->pg_mirrors_dynamic))
881 return -EINVAL;
883 pgio->pg_mirror_count = mirror_count;
885 return 0;
889 * nfs_pageio_stop_mirroring - stop using mirroring (set mirror count to 1)
891 void nfs_pageio_stop_mirroring(struct nfs_pageio_descriptor *pgio)
893 pgio->pg_mirror_count = 1;
894 pgio->pg_mirror_idx = 0;
897 static void nfs_pageio_cleanup_mirroring(struct nfs_pageio_descriptor *pgio)
899 pgio->pg_mirror_count = 1;
900 pgio->pg_mirror_idx = 0;
901 pgio->pg_mirrors = pgio->pg_mirrors_static;
902 kfree(pgio->pg_mirrors_dynamic);
903 pgio->pg_mirrors_dynamic = NULL;
906 static bool nfs_match_open_context(const struct nfs_open_context *ctx1,
907 const struct nfs_open_context *ctx2)
909 return ctx1->cred == ctx2->cred && ctx1->state == ctx2->state;
912 static bool nfs_match_lock_context(const struct nfs_lock_context *l1,
913 const struct nfs_lock_context *l2)
915 return l1->lockowner.l_owner == l2->lockowner.l_owner
916 && l1->lockowner.l_pid == l2->lockowner.l_pid;
920 * nfs_can_coalesce_requests - test two requests for compatibility
921 * @prev: pointer to nfs_page
922 * @req: pointer to nfs_page
924 * The nfs_page structures 'prev' and 'req' are compared to ensure that the
925 * page data area they describe is contiguous, and that their RPC
926 * credentials, NFSv4 open state, and lockowners are the same.
928 * Return 'true' if this is the case, else return 'false'.
930 static bool nfs_can_coalesce_requests(struct nfs_page *prev,
931 struct nfs_page *req,
932 struct nfs_pageio_descriptor *pgio)
934 size_t size;
935 struct file_lock_context *flctx;
937 if (prev) {
938 if (!nfs_match_open_context(req->wb_context, prev->wb_context))
939 return false;
940 flctx = d_inode(req->wb_context->dentry)->i_flctx;
941 if (flctx != NULL &&
942 !(list_empty_careful(&flctx->flc_posix) &&
943 list_empty_careful(&flctx->flc_flock)) &&
944 !nfs_match_lock_context(req->wb_lock_context,
945 prev->wb_lock_context))
946 return false;
947 if (req_offset(req) != req_offset(prev) + prev->wb_bytes)
948 return false;
949 if (req->wb_page == prev->wb_page) {
950 if (req->wb_pgbase != prev->wb_pgbase + prev->wb_bytes)
951 return false;
952 } else {
953 if (req->wb_pgbase != 0 ||
954 prev->wb_pgbase + prev->wb_bytes != PAGE_CACHE_SIZE)
955 return false;
958 size = pgio->pg_ops->pg_test(pgio, prev, req);
959 WARN_ON_ONCE(size > req->wb_bytes);
960 if (size && size < req->wb_bytes)
961 req->wb_bytes = size;
962 return size > 0;
966 * nfs_pageio_do_add_request - Attempt to coalesce a request into a page list.
967 * @desc: destination io descriptor
968 * @req: request
970 * Returns true if the request 'req' was successfully coalesced into the
971 * existing list of pages 'desc'.
973 static int nfs_pageio_do_add_request(struct nfs_pageio_descriptor *desc,
974 struct nfs_page *req)
976 struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
978 struct nfs_page *prev = NULL;
980 if (mirror->pg_count != 0) {
981 prev = nfs_list_entry(mirror->pg_list.prev);
982 } else {
983 if (desc->pg_ops->pg_init)
984 desc->pg_ops->pg_init(desc, req);
985 mirror->pg_base = req->wb_pgbase;
987 if (!nfs_can_coalesce_requests(prev, req, desc))
988 return 0;
989 nfs_list_remove_request(req);
990 nfs_list_add_request(req, &mirror->pg_list);
991 mirror->pg_count += req->wb_bytes;
992 return 1;
996 * Helper for nfs_pageio_add_request and nfs_pageio_complete
998 static void nfs_pageio_doio(struct nfs_pageio_descriptor *desc)
1000 struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
1003 if (!list_empty(&mirror->pg_list)) {
1004 int error = desc->pg_ops->pg_doio(desc);
1005 if (error < 0)
1006 desc->pg_error = error;
1007 else
1008 mirror->pg_bytes_written += mirror->pg_count;
1010 if (list_empty(&mirror->pg_list)) {
1011 mirror->pg_count = 0;
1012 mirror->pg_base = 0;
1017 * nfs_pageio_add_request - Attempt to coalesce a request into a page list.
1018 * @desc: destination io descriptor
1019 * @req: request
1021 * This may split a request into subrequests which are all part of the
1022 * same page group.
1024 * Returns true if the request 'req' was successfully coalesced into the
1025 * existing list of pages 'desc'.
1027 static int __nfs_pageio_add_request(struct nfs_pageio_descriptor *desc,
1028 struct nfs_page *req)
1030 struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
1032 struct nfs_page *subreq;
1033 unsigned int bytes_left = 0;
1034 unsigned int offset, pgbase;
1036 nfs_page_group_lock(req, false);
1038 subreq = req;
1039 bytes_left = subreq->wb_bytes;
1040 offset = subreq->wb_offset;
1041 pgbase = subreq->wb_pgbase;
1043 do {
1044 if (!nfs_pageio_do_add_request(desc, subreq)) {
1045 /* make sure pg_test call(s) did nothing */
1046 WARN_ON_ONCE(subreq->wb_bytes != bytes_left);
1047 WARN_ON_ONCE(subreq->wb_offset != offset);
1048 WARN_ON_ONCE(subreq->wb_pgbase != pgbase);
1050 nfs_page_group_unlock(req);
1051 desc->pg_moreio = 1;
1052 nfs_pageio_doio(desc);
1053 if (desc->pg_error < 0)
1054 return 0;
1055 if (mirror->pg_recoalesce)
1056 return 0;
1057 /* retry add_request for this subreq */
1058 nfs_page_group_lock(req, false);
1059 continue;
1062 /* check for buggy pg_test call(s) */
1063 WARN_ON_ONCE(subreq->wb_bytes + subreq->wb_pgbase > PAGE_SIZE);
1064 WARN_ON_ONCE(subreq->wb_bytes > bytes_left);
1065 WARN_ON_ONCE(subreq->wb_bytes == 0);
1067 bytes_left -= subreq->wb_bytes;
1068 offset += subreq->wb_bytes;
1069 pgbase += subreq->wb_bytes;
1071 if (bytes_left) {
1072 subreq = nfs_create_request(req->wb_context,
1073 req->wb_page,
1074 subreq, pgbase, bytes_left);
1075 if (IS_ERR(subreq))
1076 goto err_ptr;
1077 nfs_lock_request(subreq);
1078 subreq->wb_offset = offset;
1079 subreq->wb_index = req->wb_index;
1081 } while (bytes_left > 0);
1083 nfs_page_group_unlock(req);
1084 return 1;
1085 err_ptr:
1086 desc->pg_error = PTR_ERR(subreq);
1087 nfs_page_group_unlock(req);
1088 return 0;
1091 static int nfs_do_recoalesce(struct nfs_pageio_descriptor *desc)
1093 struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
1094 LIST_HEAD(head);
1096 do {
1097 list_splice_init(&mirror->pg_list, &head);
1098 mirror->pg_bytes_written -= mirror->pg_count;
1099 mirror->pg_count = 0;
1100 mirror->pg_base = 0;
1101 mirror->pg_recoalesce = 0;
1103 while (!list_empty(&head)) {
1104 struct nfs_page *req;
1106 req = list_first_entry(&head, struct nfs_page, wb_list);
1107 nfs_list_remove_request(req);
1108 if (__nfs_pageio_add_request(desc, req))
1109 continue;
1110 if (desc->pg_error < 0) {
1111 list_splice_tail(&head, &mirror->pg_list);
1112 mirror->pg_recoalesce = 1;
1113 return 0;
1115 break;
1117 } while (mirror->pg_recoalesce);
1118 return 1;
1121 static int nfs_pageio_add_request_mirror(struct nfs_pageio_descriptor *desc,
1122 struct nfs_page *req)
1124 int ret;
1126 do {
1127 ret = __nfs_pageio_add_request(desc, req);
1128 if (ret)
1129 break;
1130 if (desc->pg_error < 0)
1131 break;
1132 ret = nfs_do_recoalesce(desc);
1133 } while (ret);
1135 return ret;
1138 int nfs_pageio_add_request(struct nfs_pageio_descriptor *desc,
1139 struct nfs_page *req)
1141 u32 midx;
1142 unsigned int pgbase, offset, bytes;
1143 struct nfs_page *dupreq, *lastreq;
1145 pgbase = req->wb_pgbase;
1146 offset = req->wb_offset;
1147 bytes = req->wb_bytes;
1149 nfs_pageio_setup_mirroring(desc, req);
1151 for (midx = 0; midx < desc->pg_mirror_count; midx++) {
1152 if (midx) {
1153 nfs_page_group_lock(req, false);
1155 /* find the last request */
1156 for (lastreq = req->wb_head;
1157 lastreq->wb_this_page != req->wb_head;
1158 lastreq = lastreq->wb_this_page)
1161 dupreq = nfs_create_request(req->wb_context,
1162 req->wb_page, lastreq, pgbase, bytes);
1164 if (IS_ERR(dupreq)) {
1165 nfs_page_group_unlock(req);
1166 return 0;
1169 nfs_lock_request(dupreq);
1170 nfs_page_group_unlock(req);
1171 dupreq->wb_offset = offset;
1172 dupreq->wb_index = req->wb_index;
1173 } else
1174 dupreq = req;
1176 if (nfs_pgio_has_mirroring(desc))
1177 desc->pg_mirror_idx = midx;
1178 if (!nfs_pageio_add_request_mirror(desc, dupreq))
1179 return 0;
1182 return 1;
1186 * nfs_pageio_complete_mirror - Complete I/O on the current mirror of an
1187 * nfs_pageio_descriptor
1188 * @desc: pointer to io descriptor
1189 * @mirror_idx: pointer to mirror index
1191 static void nfs_pageio_complete_mirror(struct nfs_pageio_descriptor *desc,
1192 u32 mirror_idx)
1194 struct nfs_pgio_mirror *mirror = &desc->pg_mirrors[mirror_idx];
1195 u32 restore_idx = desc->pg_mirror_idx;
1197 if (nfs_pgio_has_mirroring(desc))
1198 desc->pg_mirror_idx = mirror_idx;
1199 for (;;) {
1200 nfs_pageio_doio(desc);
1201 if (!mirror->pg_recoalesce)
1202 break;
1203 if (!nfs_do_recoalesce(desc))
1204 break;
1206 desc->pg_mirror_idx = restore_idx;
1210 * nfs_pageio_resend - Transfer requests to new descriptor and resend
1211 * @hdr - the pgio header to move request from
1212 * @desc - the pageio descriptor to add requests to
1214 * Try to move each request (nfs_page) from @hdr to @desc then attempt
1215 * to send them.
1217 * Returns 0 on success and < 0 on error.
1219 int nfs_pageio_resend(struct nfs_pageio_descriptor *desc,
1220 struct nfs_pgio_header *hdr)
1222 LIST_HEAD(failed);
1224 desc->pg_dreq = hdr->dreq;
1225 while (!list_empty(&hdr->pages)) {
1226 struct nfs_page *req = nfs_list_entry(hdr->pages.next);
1228 nfs_list_remove_request(req);
1229 if (!nfs_pageio_add_request(desc, req))
1230 nfs_list_add_request(req, &failed);
1232 nfs_pageio_complete(desc);
1233 if (!list_empty(&failed)) {
1234 list_move(&failed, &hdr->pages);
1235 return -EIO;
1237 return 0;
1239 EXPORT_SYMBOL_GPL(nfs_pageio_resend);
1242 * nfs_pageio_complete - Complete I/O then cleanup an nfs_pageio_descriptor
1243 * @desc: pointer to io descriptor
1245 void nfs_pageio_complete(struct nfs_pageio_descriptor *desc)
1247 u32 midx;
1249 for (midx = 0; midx < desc->pg_mirror_count; midx++)
1250 nfs_pageio_complete_mirror(desc, midx);
1252 if (desc->pg_ops->pg_cleanup)
1253 desc->pg_ops->pg_cleanup(desc);
1254 nfs_pageio_cleanup_mirroring(desc);
1258 * nfs_pageio_cond_complete - Conditional I/O completion
1259 * @desc: pointer to io descriptor
1260 * @index: page index
1262 * It is important to ensure that processes don't try to take locks
1263 * on non-contiguous ranges of pages as that might deadlock. This
1264 * function should be called before attempting to wait on a locked
1265 * nfs_page. It will complete the I/O if the page index 'index'
1266 * is not contiguous with the existing list of pages in 'desc'.
1268 void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *desc, pgoff_t index)
1270 struct nfs_pgio_mirror *mirror;
1271 struct nfs_page *prev;
1272 u32 midx;
1274 for (midx = 0; midx < desc->pg_mirror_count; midx++) {
1275 mirror = &desc->pg_mirrors[midx];
1276 if (!list_empty(&mirror->pg_list)) {
1277 prev = nfs_list_entry(mirror->pg_list.prev);
1278 if (index != prev->wb_index + 1)
1279 nfs_pageio_complete_mirror(desc, midx);
1284 int __init nfs_init_nfspagecache(void)
1286 nfs_page_cachep = kmem_cache_create("nfs_page",
1287 sizeof(struct nfs_page),
1288 0, SLAB_HWCACHE_ALIGN,
1289 NULL);
1290 if (nfs_page_cachep == NULL)
1291 return -ENOMEM;
1293 return 0;
1296 void nfs_destroy_nfspagecache(void)
1298 kmem_cache_destroy(nfs_page_cachep);
1301 static const struct rpc_call_ops nfs_pgio_common_ops = {
1302 .rpc_call_prepare = nfs_pgio_prepare,
1303 .rpc_call_done = nfs_pgio_result,
1304 .rpc_release = nfs_pgio_release,
1307 const struct nfs_pageio_ops nfs_pgio_rw_ops = {
1308 .pg_test = nfs_generic_pg_test,
1309 .pg_doio = nfs_generic_pg_pgios,