blob: 7913961aff225995fda011973ed048276ae826e9 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/fs/nfs/pagelist.c
3 *
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.
7 *
8 * Copyright 2000, 2001 (c) Trond Myklebust <trond.myklebust@fys.uio.no>
9 *
10 */
11
Linus Torvalds1da177e2005-04-16 15:20:36 -070012#include <linux/slab.h>
13#include <linux/file.h>
Alexey Dobriyane8edc6e2007-05-21 01:22:52 +040014#include <linux/sched.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070015#include <linux/sunrpc/clnt.h>
16#include <linux/nfs3.h>
17#include <linux/nfs4.h>
18#include <linux/nfs_page.h>
19#include <linux/nfs_fs.h>
20#include <linux/nfs_mount.h>
21
Trond Myklebust8d5658c2007-04-10 09:26:35 -040022#include "internal.h"
Fred Isamanbae724e2011-03-01 01:34:15 +000023#include "pnfs.h"
Trond Myklebust8d5658c2007-04-10 09:26:35 -040024
Christoph Lametere18b8902006-12-06 20:33:20 -080025static struct kmem_cache *nfs_page_cachep;
Linus Torvalds1da177e2005-04-16 15:20:36 -070026
27static inline struct nfs_page *
28nfs_page_alloc(void)
29{
Jesper Juhl72895b12010-12-09 23:17:15 +010030 struct nfs_page *p = kmem_cache_zalloc(nfs_page_cachep, GFP_KERNEL);
31 if (p)
Linus Torvalds1da177e2005-04-16 15:20:36 -070032 INIT_LIST_HEAD(&p->wb_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -070033 return p;
34}
35
36static inline void
37nfs_page_free(struct nfs_page *p)
38{
39 kmem_cache_free(nfs_page_cachep, p);
40}
41
42/**
43 * nfs_create_request - Create an NFS read/write request.
44 * @file: file descriptor to use
45 * @inode: inode to which the request is attached
46 * @page: page to write
47 * @offset: starting offset within the page for the write
48 * @count: number of bytes to read/write
49 *
50 * The page must be locked by the caller. This makes sure we never
Jason Uhlenkotta19b89c2007-04-26 17:25:51 -070051 * create two different requests for the same page.
Linus Torvalds1da177e2005-04-16 15:20:36 -070052 * User should ensure it is safe to sleep in this function.
53 */
54struct nfs_page *
55nfs_create_request(struct nfs_open_context *ctx, struct inode *inode,
56 struct page *page,
57 unsigned int offset, unsigned int count)
58{
Linus Torvalds1da177e2005-04-16 15:20:36 -070059 struct nfs_page *req;
60
Trond Myklebust18eb8842010-05-13 12:51:02 -040061 /* try to allocate the request struct */
62 req = nfs_page_alloc();
63 if (req == NULL)
64 return ERR_PTR(-ENOMEM);
Linus Torvalds1da177e2005-04-16 15:20:36 -070065
Jeff Layton015f0212010-10-28 10:10:37 -040066 /* get lock context early so we can deal with alloc failures */
67 req->wb_lock_context = nfs_get_lock_context(ctx);
68 if (req->wb_lock_context == NULL) {
69 nfs_page_free(req);
70 return ERR_PTR(-ENOMEM);
71 }
72
Linus Torvalds1da177e2005-04-16 15:20:36 -070073 /* Initialize the request struct. Initially, we assume a
74 * long write-back delay. This will be adjusted in
75 * update_nfs_request below if the region is not locked. */
76 req->wb_page = page;
77 atomic_set(&req->wb_complete, 0);
78 req->wb_index = page->index;
79 page_cache_get(page);
Trond Myklebustcd52ed32006-03-20 13:44:04 -050080 BUG_ON(PagePrivate(page));
81 BUG_ON(!PageLocked(page));
82 BUG_ON(page->mapping->host != inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -070083 req->wb_offset = offset;
84 req->wb_pgbase = offset;
85 req->wb_bytes = count;
Linus Torvalds1da177e2005-04-16 15:20:36 -070086 req->wb_context = get_nfs_open_context(ctx);
Trond Myklebustc03b4022007-06-17 13:26:38 -040087 kref_init(&req->wb_kref);
Linus Torvalds1da177e2005-04-16 15:20:36 -070088 return req;
89}
90
91/**
92 * nfs_unlock_request - Unlock request and wake up sleepers.
93 * @req:
94 */
95void nfs_unlock_request(struct nfs_page *req)
96{
97 if (!NFS_WBACK_BUSY(req)) {
98 printk(KERN_ERR "NFS: Invalid unlock attempted\n");
99 BUG();
100 }
101 smp_mb__before_clear_bit();
102 clear_bit(PG_BUSY, &req->wb_flags);
103 smp_mb__after_clear_bit();
Trond Myklebust464a98b2005-06-22 17:16:21 +0000104 wake_up_bit(&req->wb_flags, PG_BUSY);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105 nfs_release_request(req);
106}
107
108/**
Trond Myklebust9fd367f2007-06-17 15:10:24 -0400109 * nfs_set_page_tag_locked - Tag a request as locked
Trond Myklebustc6a556b2005-06-22 17:16:30 +0000110 * @req:
111 */
Trond Myklebustacee4782008-01-22 17:13:07 -0500112int nfs_set_page_tag_locked(struct nfs_page *req)
Trond Myklebustc6a556b2005-06-22 17:16:30 +0000113{
Trond Myklebustacee4782008-01-22 17:13:07 -0500114 if (!nfs_lock_request_dontget(req))
Trond Myklebustc6a556b2005-06-22 17:16:30 +0000115 return 0;
Trond Myklebust2df485a2010-12-07 22:39:17 -0500116 if (test_bit(PG_MAPPED, &req->wb_flags))
Trond Myklebustbb6fbc42010-03-11 09:19:35 -0500117 radix_tree_tag_set(&NFS_I(req->wb_context->path.dentry->d_inode)->nfs_page_tree, req->wb_index, NFS_PAGE_TAG_LOCKED);
Trond Myklebustc6a556b2005-06-22 17:16:30 +0000118 return 1;
119}
120
121/**
Trond Myklebust9fd367f2007-06-17 15:10:24 -0400122 * nfs_clear_page_tag_locked - Clear request tag and wake up sleepers
Trond Myklebustc6a556b2005-06-22 17:16:30 +0000123 */
Trond Myklebust9fd367f2007-06-17 15:10:24 -0400124void nfs_clear_page_tag_locked(struct nfs_page *req)
Trond Myklebustc6a556b2005-06-22 17:16:30 +0000125{
Trond Myklebust2df485a2010-12-07 22:39:17 -0500126 if (test_bit(PG_MAPPED, &req->wb_flags)) {
Trond Myklebustbb6fbc42010-03-11 09:19:35 -0500127 struct inode *inode = req->wb_context->path.dentry->d_inode;
128 struct nfs_inode *nfsi = NFS_I(inode);
129
Trond Myklebust587142f2007-07-02 09:57:54 -0400130 spin_lock(&inode->i_lock);
Trond Myklebust9fd367f2007-06-17 15:10:24 -0400131 radix_tree_tag_clear(&nfsi->nfs_page_tree, req->wb_index, NFS_PAGE_TAG_LOCKED);
Trond Myklebustacee4782008-01-22 17:13:07 -0500132 nfs_unlock_request(req);
Trond Myklebust587142f2007-07-02 09:57:54 -0400133 spin_unlock(&inode->i_lock);
Trond Myklebustacee4782008-01-22 17:13:07 -0500134 } else
135 nfs_unlock_request(req);
Trond Myklebustc6a556b2005-06-22 17:16:30 +0000136}
137
Trond Myklebust4d65c522011-03-25 14:15:11 -0400138/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139 * nfs_clear_request - Free up all resources allocated to the request
140 * @req:
141 *
Trond Myklebustbb6fbc42010-03-11 09:19:35 -0500142 * Release page and open context resources associated with a read/write
143 * request after it has completed.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144 */
Trond Myklebust4d65c522011-03-25 14:15:11 -0400145static void nfs_clear_request(struct nfs_page *req)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146{
Trond Myklebustcd52ed32006-03-20 13:44:04 -0500147 struct page *page = req->wb_page;
Trond Myklebustbb6fbc42010-03-11 09:19:35 -0500148 struct nfs_open_context *ctx = req->wb_context;
Trond Myklebustf11ac8d2010-06-25 16:35:53 -0400149 struct nfs_lock_context *l_ctx = req->wb_lock_context;
Trond Myklebustbb6fbc42010-03-11 09:19:35 -0500150
Trond Myklebustcd52ed32006-03-20 13:44:04 -0500151 if (page != NULL) {
Trond Myklebustcd52ed32006-03-20 13:44:04 -0500152 page_cache_release(page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153 req->wb_page = NULL;
154 }
Trond Myklebustf11ac8d2010-06-25 16:35:53 -0400155 if (l_ctx != NULL) {
156 nfs_put_lock_context(l_ctx);
157 req->wb_lock_context = NULL;
158 }
Trond Myklebustbb6fbc42010-03-11 09:19:35 -0500159 if (ctx != NULL) {
160 put_nfs_open_context(ctx);
161 req->wb_context = NULL;
162 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163}
164
165
166/**
167 * nfs_release_request - Release the count on an NFS read/write request
168 * @req: request to release
169 *
170 * Note: Should never be called with the spinlock held!
171 */
Trond Myklebustc03b4022007-06-17 13:26:38 -0400172static void nfs_free_request(struct kref *kref)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173{
Trond Myklebustc03b4022007-06-17 13:26:38 -0400174 struct nfs_page *req = container_of(kref, struct nfs_page, wb_kref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175
Trond Myklebustbb6fbc42010-03-11 09:19:35 -0500176 /* Release struct file and open context */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700177 nfs_clear_request(req);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178 nfs_page_free(req);
179}
180
Trond Myklebustc03b4022007-06-17 13:26:38 -0400181void nfs_release_request(struct nfs_page *req)
182{
183 kref_put(&req->wb_kref, nfs_free_request);
184}
185
Trond Myklebust9f557cd2010-02-03 08:27:22 -0500186static int nfs_wait_bit_uninterruptible(void *word)
187{
188 io_schedule();
189 return 0;
190}
191
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192/**
193 * nfs_wait_on_request - Wait for a request to complete.
194 * @req: request to wait upon.
195 *
Matthew Wilcox150030b2007-12-06 16:24:39 -0500196 * Interruptible by fatal signals only.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197 * The user is responsible for holding a count on the request.
198 */
199int
200nfs_wait_on_request(struct nfs_page *req)
201{
Trond Myklebust9f557cd2010-02-03 08:27:22 -0500202 return wait_on_bit(&req->wb_flags, PG_BUSY,
203 nfs_wait_bit_uninterruptible,
204 TASK_UNINTERRUPTIBLE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205}
206
Boaz Harrosh5b36c7d2011-05-29 11:45:39 +0300207static bool nfs_generic_pg_test(struct nfs_pageio_descriptor *desc, struct nfs_page *prev, struct nfs_page *req)
208{
209 /*
210 * FIXME: ideally we should be able to coalesce all requests
211 * that are not block boundary aligned, but currently this
212 * is problematic for the case of bsize < PAGE_CACHE_SIZE,
213 * since nfs_flush_multi and nfs_pagein_multi assume you
214 * can have only one struct nfs_page.
215 */
216 if (desc->pg_bsize < PAGE_SIZE)
217 return 0;
218
219 return desc->pg_count + req->wb_bytes <= desc->pg_bsize;
220}
221
Linus Torvalds1da177e2005-04-16 15:20:36 -0700222/**
Trond Myklebustd8a5ad72007-04-02 18:48:28 -0400223 * nfs_pageio_init - initialise a page io descriptor
224 * @desc: pointer to descriptor
Trond Myklebustbcb71bb2007-04-02 18:48:28 -0400225 * @inode: pointer to inode
226 * @doio: pointer to io function
227 * @bsize: io block size
228 * @io_flags: extra parameters for the io function
Trond Myklebustd8a5ad72007-04-02 18:48:28 -0400229 */
Trond Myklebustbcb71bb2007-04-02 18:48:28 -0400230void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
231 struct inode *inode,
Fred Isamanc76069b2011-03-03 15:13:48 +0000232 int (*doio)(struct nfs_pageio_descriptor *),
Trond Myklebust84dde762007-05-04 14:44:06 -0400233 size_t bsize,
Trond Myklebustbcb71bb2007-04-02 18:48:28 -0400234 int io_flags)
Trond Myklebustd8a5ad72007-04-02 18:48:28 -0400235{
236 INIT_LIST_HEAD(&desc->pg_list);
Trond Myklebustbcb71bb2007-04-02 18:48:28 -0400237 desc->pg_bytes_written = 0;
Trond Myklebustd8a5ad72007-04-02 18:48:28 -0400238 desc->pg_count = 0;
239 desc->pg_bsize = bsize;
240 desc->pg_base = 0;
Trond Myklebustb31268a2011-03-21 17:02:00 -0400241 desc->pg_moreio = 0;
Trond Myklebustbcb71bb2007-04-02 18:48:28 -0400242 desc->pg_inode = inode;
243 desc->pg_doio = doio;
244 desc->pg_ioflags = io_flags;
245 desc->pg_error = 0;
Fred Isaman94ad1c82011-03-01 01:34:14 +0000246 desc->pg_lseg = NULL;
Boaz Harrosh5b36c7d2011-05-29 11:45:39 +0300247 desc->pg_test = nfs_generic_pg_test;
Benny Halevydfed2062011-05-25 20:25:22 +0300248 pnfs_pageio_init(desc, inode);
Trond Myklebustd8a5ad72007-04-02 18:48:28 -0400249}
250
251/**
252 * nfs_can_coalesce_requests - test two requests for compatibility
253 * @prev: pointer to nfs_page
254 * @req: pointer to nfs_page
255 *
256 * The nfs_page structures 'prev' and 'req' are compared to ensure that the
257 * page data area they describe is contiguous, and that their RPC
258 * credentials, NFSv4 open state, and lockowners are the same.
259 *
260 * Return 'true' if this is the case, else return 'false'.
261 */
Benny Halevy18ad0a92011-05-25 21:03:56 +0300262static bool nfs_can_coalesce_requests(struct nfs_page *prev,
263 struct nfs_page *req,
264 struct nfs_pageio_descriptor *pgio)
Trond Myklebustd8a5ad72007-04-02 18:48:28 -0400265{
266 if (req->wb_context->cred != prev->wb_context->cred)
Benny Halevy18ad0a92011-05-25 21:03:56 +0300267 return false;
Trond Myklebustf11ac8d2010-06-25 16:35:53 -0400268 if (req->wb_lock_context->lockowner != prev->wb_lock_context->lockowner)
Benny Halevy18ad0a92011-05-25 21:03:56 +0300269 return false;
Trond Myklebustd8a5ad72007-04-02 18:48:28 -0400270 if (req->wb_context->state != prev->wb_context->state)
Benny Halevy18ad0a92011-05-25 21:03:56 +0300271 return false;
Trond Myklebustd8a5ad72007-04-02 18:48:28 -0400272 if (req->wb_index != (prev->wb_index + 1))
Benny Halevy18ad0a92011-05-25 21:03:56 +0300273 return false;
Trond Myklebustd8a5ad72007-04-02 18:48:28 -0400274 if (req->wb_pgbase != 0)
Benny Halevy18ad0a92011-05-25 21:03:56 +0300275 return false;
Trond Myklebustd8a5ad72007-04-02 18:48:28 -0400276 if (prev->wb_pgbase + prev->wb_bytes != PAGE_CACHE_SIZE)
Benny Halevy18ad0a92011-05-25 21:03:56 +0300277 return false;
Boaz Harrosh5b36c7d2011-05-29 11:45:39 +0300278 return pgio->pg_test(pgio, prev, req);
Trond Myklebustd8a5ad72007-04-02 18:48:28 -0400279}
280
281/**
Trond Myklebustbcb71bb2007-04-02 18:48:28 -0400282 * nfs_pageio_do_add_request - Attempt to coalesce a request into a page list.
Trond Myklebustd8a5ad72007-04-02 18:48:28 -0400283 * @desc: destination io descriptor
284 * @req: request
285 *
286 * Returns true if the request 'req' was successfully coalesced into the
287 * existing list of pages 'desc'.
288 */
Trond Myklebustbcb71bb2007-04-02 18:48:28 -0400289static int nfs_pageio_do_add_request(struct nfs_pageio_descriptor *desc,
290 struct nfs_page *req)
Trond Myklebustd8a5ad72007-04-02 18:48:28 -0400291{
Trond Myklebustd8a5ad72007-04-02 18:48:28 -0400292 if (desc->pg_count != 0) {
293 struct nfs_page *prev;
294
Trond Myklebustd8a5ad72007-04-02 18:48:28 -0400295 prev = nfs_list_entry(desc->pg_list.prev);
Fred Isaman94ad1c82011-03-01 01:34:14 +0000296 if (!nfs_can_coalesce_requests(prev, req, desc))
Trond Myklebustd8a5ad72007-04-02 18:48:28 -0400297 return 0;
Boaz Harrosh5b36c7d2011-05-29 11:45:39 +0300298 } else {
Trond Myklebustd8a5ad72007-04-02 18:48:28 -0400299 desc->pg_base = req->wb_pgbase;
Boaz Harrosh5b36c7d2011-05-29 11:45:39 +0300300 }
Trond Myklebustd8a5ad72007-04-02 18:48:28 -0400301 nfs_list_remove_request(req);
302 nfs_list_add_request(req, &desc->pg_list);
Boaz Harrosh5b36c7d2011-05-29 11:45:39 +0300303 desc->pg_count += req->wb_bytes;
Trond Myklebustd8a5ad72007-04-02 18:48:28 -0400304 return 1;
305}
306
Trond Myklebustbcb71bb2007-04-02 18:48:28 -0400307/*
308 * Helper for nfs_pageio_add_request and nfs_pageio_complete
309 */
310static void nfs_pageio_doio(struct nfs_pageio_descriptor *desc)
311{
312 if (!list_empty(&desc->pg_list)) {
Fred Isamanc76069b2011-03-03 15:13:48 +0000313 int error = desc->pg_doio(desc);
Trond Myklebustbcb71bb2007-04-02 18:48:28 -0400314 if (error < 0)
315 desc->pg_error = error;
316 else
317 desc->pg_bytes_written += desc->pg_count;
318 }
319 if (list_empty(&desc->pg_list)) {
320 desc->pg_count = 0;
321 desc->pg_base = 0;
322 }
323}
324
325/**
326 * nfs_pageio_add_request - Attempt to coalesce a request into a page list.
327 * @desc: destination io descriptor
328 * @req: request
329 *
330 * Returns true if the request 'req' was successfully coalesced into the
331 * existing list of pages 'desc'.
332 */
Trond Myklebust8b09bee2007-04-02 18:48:28 -0400333int nfs_pageio_add_request(struct nfs_pageio_descriptor *desc,
334 struct nfs_page *req)
Trond Myklebustbcb71bb2007-04-02 18:48:28 -0400335{
336 while (!nfs_pageio_do_add_request(desc, req)) {
Trond Myklebustb31268a2011-03-21 17:02:00 -0400337 desc->pg_moreio = 1;
Trond Myklebustbcb71bb2007-04-02 18:48:28 -0400338 nfs_pageio_doio(desc);
339 if (desc->pg_error < 0)
340 return 0;
Trond Myklebustb31268a2011-03-21 17:02:00 -0400341 desc->pg_moreio = 0;
Trond Myklebustbcb71bb2007-04-02 18:48:28 -0400342 }
343 return 1;
344}
345
Trond Myklebustd8a5ad72007-04-02 18:48:28 -0400346/**
Trond Myklebustbcb71bb2007-04-02 18:48:28 -0400347 * nfs_pageio_complete - Complete I/O on an nfs_pageio_descriptor
348 * @desc: pointer to io descriptor
349 */
350void nfs_pageio_complete(struct nfs_pageio_descriptor *desc)
351{
352 nfs_pageio_doio(desc);
353}
354
Trond Myklebust7fe7f842007-05-20 10:18:27 -0400355/**
356 * nfs_pageio_cond_complete - Conditional I/O completion
357 * @desc: pointer to io descriptor
358 * @index: page index
359 *
360 * It is important to ensure that processes don't try to take locks
361 * on non-contiguous ranges of pages as that might deadlock. This
362 * function should be called before attempting to wait on a locked
363 * nfs_page. It will complete the I/O if the page index 'index'
364 * is not contiguous with the existing list of pages in 'desc'.
365 */
366void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *desc, pgoff_t index)
367{
368 if (!list_empty(&desc->pg_list)) {
369 struct nfs_page *prev = nfs_list_entry(desc->pg_list.prev);
370 if (index != prev->wb_index + 1)
371 nfs_pageio_doio(desc);
372 }
373}
374
Trond Myklebust3da28eb2005-06-22 17:16:31 +0000375#define NFS_SCAN_MAXENTRIES 16
376/**
Linus Torvalds1da177e2005-04-16 15:20:36 -0700377 * nfs_scan_list - Scan a list for matching requests
Trond Myklebustd2ccddf2006-05-31 01:13:38 -0400378 * @nfsi: NFS inode
Linus Torvalds1da177e2005-04-16 15:20:36 -0700379 * @dst: Destination list
380 * @idx_start: lower bound of page->index to scan
381 * @npages: idx_start + npages sets the upper bound to scan.
Trond Myklebust5c369682007-06-17 15:27:42 -0400382 * @tag: tag to scan for
Linus Torvalds1da177e2005-04-16 15:20:36 -0700383 *
384 * Moves elements from one of the inode request lists.
385 * If the number of requests is set to 0, the entire address_space
386 * starting at index idx_start, is scanned.
387 * The requests are *not* checked to ensure that they form a contiguous set.
Trond Myklebust587142f2007-07-02 09:57:54 -0400388 * You must be holding the inode's i_lock when calling this function
Linus Torvalds1da177e2005-04-16 15:20:36 -0700389 */
Trond Myklebust5c369682007-06-17 15:27:42 -0400390int nfs_scan_list(struct nfs_inode *nfsi,
Trond Myklebustca52fec2007-04-17 17:22:13 -0400391 struct list_head *dst, pgoff_t idx_start,
Trond Myklebust5c369682007-06-17 15:27:42 -0400392 unsigned int npages, int tag)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700393{
Trond Myklebustd2ccddf2006-05-31 01:13:38 -0400394 struct nfs_page *pgvec[NFS_SCAN_MAXENTRIES];
395 struct nfs_page *req;
Trond Myklebustca52fec2007-04-17 17:22:13 -0400396 pgoff_t idx_end;
Trond Myklebustd2ccddf2006-05-31 01:13:38 -0400397 int found, i;
398 int res;
Fred Isamana861a1e2011-03-23 13:27:51 +0000399 struct list_head *list;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700400
401 res = 0;
402 if (npages == 0)
403 idx_end = ~0;
404 else
405 idx_end = idx_start + npages - 1;
406
Trond Myklebustd2ccddf2006-05-31 01:13:38 -0400407 for (;;) {
Trond Myklebust5c369682007-06-17 15:27:42 -0400408 found = radix_tree_gang_lookup_tag(&nfsi->nfs_page_tree,
Trond Myklebustd2ccddf2006-05-31 01:13:38 -0400409 (void **)&pgvec[0], idx_start,
Trond Myklebust5c369682007-06-17 15:27:42 -0400410 NFS_SCAN_MAXENTRIES, tag);
Trond Myklebustd2ccddf2006-05-31 01:13:38 -0400411 if (found <= 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700412 break;
Trond Myklebustd2ccddf2006-05-31 01:13:38 -0400413 for (i = 0; i < found; i++) {
414 req = pgvec[i];
415 if (req->wb_index > idx_end)
416 goto out;
417 idx_start = req->wb_index + 1;
Trond Myklebust9fd367f2007-06-17 15:10:24 -0400418 if (nfs_set_page_tag_locked(req)) {
Trond Myklebustacee4782008-01-22 17:13:07 -0500419 kref_get(&req->wb_kref);
Trond Myklebust5c369682007-06-17 15:27:42 -0400420 radix_tree_tag_clear(&nfsi->nfs_page_tree,
421 req->wb_index, tag);
Fred Isamana861a1e2011-03-23 13:27:51 +0000422 list = pnfs_choose_commit_list(req, dst);
423 nfs_list_add_request(req, list);
Trond Myklebustd2ccddf2006-05-31 01:13:38 -0400424 res++;
Trond Myklebustdce34ce2007-06-17 15:47:53 -0400425 if (res == INT_MAX)
426 goto out;
Trond Myklebustd2ccddf2006-05-31 01:13:38 -0400427 }
428 }
Trond Myklebustedc05fc2007-06-17 16:02:34 -0400429 /* for latency reduction */
Trond Myklebust587142f2007-07-02 09:57:54 -0400430 cond_resched_lock(&nfsi->vfs_inode.i_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700431 }
Trond Myklebustd2ccddf2006-05-31 01:13:38 -0400432out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700433 return res;
434}
435
David Howellsf7b422b2006-06-09 09:34:33 -0400436int __init nfs_init_nfspagecache(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700437{
438 nfs_page_cachep = kmem_cache_create("nfs_page",
439 sizeof(struct nfs_page),
440 0, SLAB_HWCACHE_ALIGN,
Paul Mundt20c2df82007-07-20 10:11:58 +0900441 NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700442 if (nfs_page_cachep == NULL)
443 return -ENOMEM;
444
445 return 0;
446}
447
David Brownell266bee82006-06-27 12:59:15 -0700448void nfs_destroy_nfspagecache(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700449{
Alexey Dobriyan1a1d92c2006-09-27 01:49:40 -0700450 kmem_cache_destroy(nfs_page_cachep);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700451}
452