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>
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
;
38 p
->pagevec
= kcalloc(pagecount
, sizeof(struct page
*), GFP_KERNEL
);
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
] :
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
;
86 spin_unlock(&hdr
->lock
);
89 static inline struct nfs_page
*
92 struct nfs_page
*p
= kmem_cache_zalloc(nfs_page_cachep
, GFP_NOIO
);
94 INIT_LIST_HEAD(&p
->wb_list
);
99 nfs_page_free(struct nfs_page
*p
)
101 kmem_cache_free(nfs_page_cachep
, p
);
105 nfs_iocounter_inc(struct nfs_io_counter
*c
)
107 atomic_inc(&c
->io_count
);
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
);
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
);
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)
132 ret
= nfs_wait_bit_killable(&q
.key
);
133 } while (atomic_read(&c
->io_count
) != 0 && !ret
);
134 finish_wait(wq
, &q
.wait
);
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)
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
))
178 return wait_on_bit_lock(&head
->wb_flags
, PG_HEADLOCK
,
179 TASK_UNINTERRUPTIBLE
);
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.
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
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
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
;
234 if (!test_bit(bit
, &tmp
->wb_flags
))
236 tmp
= tmp
->wb_this_page
;
239 /* true! reset all bits */
242 clear_bit(bit
, &tmp
->wb_flags
);
243 tmp
= tmp
->wb_this_page
;
244 } while (tmp
!= req
);
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
)
259 nfs_page_group_lock(req
, false);
260 ret
= nfs_page_group_sync_on_bit_locked(req
, bit
);
261 nfs_page_group_unlock(req
);
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).
273 nfs_page_group_init(struct nfs_page
*req
, struct nfs_page
*prev
)
276 WARN_ON_ONCE(prev
== req
);
281 req
->wb_this_page
= req
;
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.
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
))
330 next
= tmp
->wb_this_page
;
331 /* unlink and free */
332 tmp
->wb_this_page
= tmp
;
334 nfs_free_request(tmp
);
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.
352 nfs_create_request(struct nfs_open_context
*ctx
, struct page
*page
,
353 struct nfs_page
*last
, unsigned int offset
,
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();
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
);
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. */
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
);
391 * nfs_unlock_request - Unlock request and wake up sleepers.
394 void nfs_unlock_request(struct nfs_page
*req
)
396 if (!NFS_WBACK_BUSY(req
)) {
397 printk(KERN_ERR
"NFS: Invalid unlock attempted\n");
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
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
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
;
430 page_cache_release(page
);
434 nfs_iocounter_dec(&l_ctx
->io_count
);
435 nfs_put_lock_context(l_ctx
);
436 req
->wb_lock_context
= 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
);
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
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 */
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
)
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();
523 INIT_LIST_HEAD(&hdr
->pages
);
524 spin_lock_init(&hdr
->lock
);
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
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
)) {
588 case FLUSH_COND_STABLE
:
589 if (nfs_reqs_to_commit(cinfo
))
592 hdr
->args
.stable
= NFS_FILE_SYNC
;
595 hdr
->res
.fattr
= &hdr
->fattr
;
596 hdr
->res
.count
= count
;
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
;
611 err
= NFS_PROTO(hdr
->inode
)->pgio_rpc_prepare(task
, hdr
);
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
,
626 struct rpc_task_setup task_setup_data
= {
630 .callback_ops
= call_ops
,
631 .callback_data
= hdr
,
632 .workqueue
= nfsiod_workqueue
,
633 .flags
= RPC_TASK_ASYNC
| flags
,
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
),
644 (unsigned long long)hdr
->args
.offset
);
646 task
= rpc_run_task(&task_setup_data
);
651 if (how
& FLUSH_SYNC
) {
652 ret
= rpc_wait_for_completion_task(task
);
654 ret
= task
->tk_status
;
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
;
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
);
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
,
699 INIT_LIST_HEAD(&mirror
->pg_list
);
700 mirror
->pg_bytes_written
= 0;
701 mirror
->pg_count
= 0;
702 mirror
->pg_bsize
= bsize
;
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
,
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
,
725 struct nfs_pgio_mirror
*new;
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
;
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
);
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)
776 if (task
->tk_status
< 0)
777 nfs_set_pgio_error(hdr
, task
->tk_status
, hdr
->args
.offset
);
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
;
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
;
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
) {
817 if (pageused
> pagecount
)
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
;
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
;
842 mirror
= nfs_pgio_current_mirror(desc
);
844 hdr
= nfs_pgio_header_alloc(desc
->pg_rw_ops
);
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
);
851 nfs_pgheader_init(desc
, hdr
, nfs_pgio_header_free
);
852 ret
= nfs_generic_pgio(desc
, hdr
);
854 ret
= nfs_initiate_pgio(NFS_CLIENT(hdr
->inode
),
857 NFS_PROTO(hdr
->inode
),
858 desc
->pg_rpc_callops
,
859 desc
->pg_ioflags
, 0);
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
)
875 mirror_count
= pgio
->pg_ops
->pg_get_mirror_count(pgio
, req
);
877 if (!mirror_count
|| mirror_count
> NFS_PAGEIO_DESCRIPTOR_MIRROR_MAX
)
880 if (WARN_ON_ONCE(!pgio
->pg_mirrors_dynamic
))
883 pgio
->pg_mirror_count
= mirror_count
;
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
)
935 struct file_lock_context
*flctx
;
938 if (!nfs_match_open_context(req
->wb_context
, prev
->wb_context
))
940 flctx
= d_inode(req
->wb_context
->dentry
)->i_flctx
;
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
))
947 if (req_offset(req
) != req_offset(prev
) + prev
->wb_bytes
)
949 if (req
->wb_page
== prev
->wb_page
) {
950 if (req
->wb_pgbase
!= prev
->wb_pgbase
+ prev
->wb_bytes
)
953 if (req
->wb_pgbase
!= 0 ||
954 prev
->wb_pgbase
+ prev
->wb_bytes
!= PAGE_CACHE_SIZE
)
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
;
966 * nfs_pageio_do_add_request - Attempt to coalesce a request into a page list.
967 * @desc: destination io descriptor
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
);
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
))
989 nfs_list_remove_request(req
);
990 nfs_list_add_request(req
, &mirror
->pg_list
);
991 mirror
->pg_count
+= req
->wb_bytes
;
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
);
1006 desc
->pg_error
= error
;
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
1021 * This may split a request into subrequests which are all part of the
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);
1039 bytes_left
= subreq
->wb_bytes
;
1040 offset
= subreq
->wb_offset
;
1041 pgbase
= subreq
->wb_pgbase
;
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)
1055 if (mirror
->pg_recoalesce
)
1057 /* retry add_request for this subreq */
1058 nfs_page_group_lock(req
, false);
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
;
1072 subreq
= nfs_create_request(req
->wb_context
,
1074 subreq
, pgbase
, bytes_left
);
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
);
1086 desc
->pg_error
= PTR_ERR(subreq
);
1087 nfs_page_group_unlock(req
);
1091 static int nfs_do_recoalesce(struct nfs_pageio_descriptor
*desc
)
1093 struct nfs_pgio_mirror
*mirror
= nfs_pgio_current_mirror(desc
);
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
))
1110 if (desc
->pg_error
< 0) {
1111 list_splice_tail(&head
, &mirror
->pg_list
);
1112 mirror
->pg_recoalesce
= 1;
1117 } while (mirror
->pg_recoalesce
);
1121 static int nfs_pageio_add_request_mirror(struct nfs_pageio_descriptor
*desc
,
1122 struct nfs_page
*req
)
1127 ret
= __nfs_pageio_add_request(desc
, req
);
1130 if (desc
->pg_error
< 0)
1132 ret
= nfs_do_recoalesce(desc
);
1138 int nfs_pageio_add_request(struct nfs_pageio_descriptor
*desc
,
1139 struct nfs_page
*req
)
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
++) {
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
);
1169 nfs_lock_request(dupreq
);
1170 nfs_page_group_unlock(req
);
1171 dupreq
->wb_offset
= offset
;
1172 dupreq
->wb_index
= req
->wb_index
;
1176 if (nfs_pgio_has_mirroring(desc
))
1177 desc
->pg_mirror_idx
= midx
;
1178 if (!nfs_pageio_add_request_mirror(desc
, dupreq
))
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
,
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
;
1200 nfs_pageio_doio(desc
);
1201 if (!mirror
->pg_recoalesce
)
1203 if (!nfs_do_recoalesce(desc
))
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
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
)
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
);
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
)
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
;
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
,
1290 if (nfs_page_cachep
== NULL
)
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
,