blob: a5e5d9899d56fa622c1156609b406ee953527d6c [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/fs/nfs/read.c
3 *
4 * Block I/O for NFS
5 *
6 * Partial copy of Linus' read cache modifications to fs/nfs/file.c
7 * modified for async RPC by okir@monad.swb.de
Linus Torvalds1da177e2005-04-16 15:20:36 -07008 */
9
Linus Torvalds1da177e2005-04-16 15:20:36 -070010#include <linux/time.h>
11#include <linux/kernel.h>
12#include <linux/errno.h>
13#include <linux/fcntl.h>
14#include <linux/stat.h>
15#include <linux/mm.h>
16#include <linux/slab.h>
17#include <linux/pagemap.h>
18#include <linux/sunrpc/clnt.h>
19#include <linux/nfs_fs.h>
20#include <linux/nfs_page.h>
Andy Adamson64419a92011-03-01 01:34:16 +000021#include <linux/module.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070022
Andy Adamsonf11c88a2009-04-01 09:22:25 -040023#include "nfs4_fs.h"
Trond Myklebust49a70f22006-12-05 00:35:38 -050024#include "internal.h"
Chuck Lever91d5b472006-03-20 13:44:14 -050025#include "iostat.h"
David Howells9a9fc1c2009-04-03 16:42:44 +010026#include "fscache.h"
Chuck Lever91d5b472006-03-20 13:44:14 -050027
Linus Torvalds1da177e2005-04-16 15:20:36 -070028#define NFSDBG_FACILITY NFSDBG_PAGECACHE
29
Trond Myklebust1751c362011-06-10 13:30:23 -040030static const struct nfs_pageio_ops nfs_pageio_read_ops;
Fred Isaman4db6e0b2012-04-20 14:47:46 -040031static const struct rpc_call_ops nfs_read_common_ops;
Fred Isaman061ae2e2012-04-20 14:47:48 -040032static const struct nfs_pgio_completion_ops nfs_async_read_completion_ops;
Linus Torvalds1da177e2005-04-16 15:20:36 -070033
Christoph Lametere18b8902006-12-06 20:33:20 -080034static struct kmem_cache *nfs_rdata_cachep;
Linus Torvalds1da177e2005-04-16 15:20:36 -070035
Trond Myklebust1385b812012-05-04 13:54:24 -040036struct nfs_read_header *nfs_readhdr_alloc(void)
Trond Myklebust3feb2d42006-03-20 13:44:37 -050037{
Fred Isaman4db6e0b2012-04-20 14:47:46 -040038 struct nfs_read_header *rhdr;
Trond Myklebust3feb2d42006-03-20 13:44:37 -050039
Fred Isaman4db6e0b2012-04-20 14:47:46 -040040 rhdr = kmem_cache_zalloc(nfs_rdata_cachep, GFP_KERNEL);
41 if (rhdr) {
42 struct nfs_pgio_header *hdr = &rhdr->header;
Fred Isamancd841602012-04-20 14:47:44 -040043
44 INIT_LIST_HEAD(&hdr->pages);
Fred Isaman4db6e0b2012-04-20 14:47:46 -040045 INIT_LIST_HEAD(&hdr->rpc_list);
46 spin_lock_init(&hdr->lock);
47 atomic_set(&hdr->refcnt, 0);
Trond Myklebust3feb2d42006-03-20 13:44:37 -050048 }
Fred Isaman4db6e0b2012-04-20 14:47:46 -040049 return rhdr;
50}
Bryan Schumaker89d77c82012-07-30 16:05:25 -040051EXPORT_SYMBOL_GPL(nfs_readhdr_alloc);
Fred Isaman4db6e0b2012-04-20 14:47:46 -040052
Fred Isaman584aa812012-04-20 14:47:51 -040053static struct nfs_read_data *nfs_readdata_alloc(struct nfs_pgio_header *hdr,
54 unsigned int pagecount)
Fred Isaman4db6e0b2012-04-20 14:47:46 -040055{
56 struct nfs_read_data *data, *prealloc;
57
58 prealloc = &container_of(hdr, struct nfs_read_header, header)->rpc_data;
59 if (prealloc->header == NULL)
60 data = prealloc;
61 else
62 data = kzalloc(sizeof(*data), GFP_KERNEL);
63 if (!data)
64 goto out;
65
66 if (nfs_pgarray_set(&data->pages, pagecount)) {
67 data->header = hdr;
68 atomic_inc(&hdr->refcnt);
69 } else {
70 if (data != prealloc)
71 kfree(data);
72 data = NULL;
73 }
74out:
75 return data;
Trond Myklebust3feb2d42006-03-20 13:44:37 -050076}
77
Fred Isamancd841602012-04-20 14:47:44 -040078void nfs_readhdr_free(struct nfs_pgio_header *hdr)
Trond Myklebust3feb2d42006-03-20 13:44:37 -050079{
Fred Isamancd841602012-04-20 14:47:44 -040080 struct nfs_read_header *rhdr = container_of(hdr, struct nfs_read_header, header);
81
82 kmem_cache_free(nfs_rdata_cachep, rhdr);
Trond Myklebust3feb2d42006-03-20 13:44:37 -050083}
Bryan Schumaker89d77c82012-07-30 16:05:25 -040084EXPORT_SYMBOL_GPL(nfs_readhdr_free);
Trond Myklebust3feb2d42006-03-20 13:44:37 -050085
Trond Myklebust493292d2011-07-13 15:58:28 -040086void nfs_readdata_release(struct nfs_read_data *rdata)
Linus Torvalds1da177e2005-04-16 15:20:36 -070087{
Fred Isaman4db6e0b2012-04-20 14:47:46 -040088 struct nfs_pgio_header *hdr = rdata->header;
89 struct nfs_read_header *read_header = container_of(hdr, struct nfs_read_header, header);
90
Trond Myklebust383ba712008-02-19 20:04:20 -050091 put_nfs_open_context(rdata->args.context);
Fred Isaman30dd3742012-04-20 14:47:45 -040092 if (rdata->pages.pagevec != rdata->pages.page_array)
93 kfree(rdata->pages.pagevec);
Trond Myklebust6db6dd72013-01-04 12:47:04 -050094 if (rdata == &read_header->rpc_data) {
Fred Isaman4db6e0b2012-04-20 14:47:46 -040095 rdata->header = NULL;
Trond Myklebust6db6dd72013-01-04 12:47:04 -050096 rdata = NULL;
97 }
Fred Isaman4db6e0b2012-04-20 14:47:46 -040098 if (atomic_dec_and_test(&hdr->refcnt))
Fred Isaman061ae2e2012-04-20 14:47:48 -040099 hdr->completion_ops->completion(hdr);
Trond Myklebust6db6dd72013-01-04 12:47:04 -0500100 /* Note: we only free the rpc_task after callbacks are done.
101 * See the comment in rpc_free_task() for why
102 */
103 kfree(rdata);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104}
Bryan Schumaker89d77c82012-07-30 16:05:25 -0400105EXPORT_SYMBOL_GPL(nfs_readdata_release);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106
107static
Linus Torvalds1da177e2005-04-16 15:20:36 -0700108int nfs_return_empty_page(struct page *page)
109{
Christoph Lametereebd2aa2008-02-04 22:28:29 -0800110 zero_user(page, 0, PAGE_CACHE_SIZE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111 SetPageUptodate(page);
112 unlock_page(page);
113 return 0;
114}
115
Bryan Schumaker1abb50882012-06-20 15:53:47 -0400116void nfs_pageio_init_read(struct nfs_pageio_descriptor *pgio,
Fred Isaman061ae2e2012-04-20 14:47:48 -0400117 struct inode *inode,
118 const struct nfs_pgio_completion_ops *compl_ops)
Trond Myklebust1751c362011-06-10 13:30:23 -0400119{
Fred Isaman061ae2e2012-04-20 14:47:48 -0400120 nfs_pageio_init(pgio, inode, &nfs_pageio_read_ops, compl_ops,
Trond Myklebust1751c362011-06-10 13:30:23 -0400121 NFS_SERVER(inode)->rsize, 0);
122}
Bryan Schumakerddda8e02012-07-30 16:05:23 -0400123EXPORT_SYMBOL_GPL(nfs_pageio_init_read);
Trond Myklebust1751c362011-06-10 13:30:23 -0400124
Trond Myklebust493292d2011-07-13 15:58:28 -0400125void nfs_pageio_reset_read_mds(struct nfs_pageio_descriptor *pgio)
126{
127 pgio->pg_ops = &nfs_pageio_read_ops;
128 pgio->pg_bsize = NFS_SERVER(pgio->pg_inode)->rsize;
129}
Trond Myklebust1f945352011-07-13 15:59:57 -0400130EXPORT_SYMBOL_GPL(nfs_pageio_reset_read_mds);
Trond Myklebust493292d2011-07-13 15:58:28 -0400131
David Howellsf42b2932009-04-03 16:42:44 +0100132int nfs_readpage_async(struct nfs_open_context *ctx, struct inode *inode,
133 struct page *page)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135 struct nfs_page *new;
136 unsigned int len;
Fred Isamanc76069b2011-03-03 15:13:48 +0000137 struct nfs_pageio_descriptor pgio;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700138
Trond Myklebust49a70f22006-12-05 00:35:38 -0500139 len = nfs_page_length(page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140 if (len == 0)
141 return nfs_return_empty_page(page);
142 new = nfs_create_request(ctx, inode, page, 0, len);
143 if (IS_ERR(new)) {
144 unlock_page(page);
145 return PTR_ERR(new);
146 }
147 if (len < PAGE_CACHE_SIZE)
Christoph Lametereebd2aa2008-02-04 22:28:29 -0800148 zero_user_segment(page, len, PAGE_CACHE_SIZE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149
Bryan Schumaker1abb50882012-06-20 15:53:47 -0400150 NFS_PROTO(inode)->read_pageio_init(&pgio, inode, &nfs_async_read_completion_ops);
Trond Myklebustd8007d42011-06-10 13:30:23 -0400151 nfs_pageio_add_request(&pgio, new);
Trond Myklebust1751c362011-06-10 13:30:23 -0400152 nfs_pageio_complete(&pgio);
Andy Adamson2701d082012-05-24 13:13:24 -0400153 NFS_I(inode)->read_io += pgio.pg_bytes_written;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700154 return 0;
155}
156
157static void nfs_readpage_release(struct nfs_page *req)
158{
Al Viro3d4ff432011-06-22 18:40:12 -0400159 struct inode *d_inode = req->wb_context->dentry->d_inode;
David Howells7f8e05f2009-04-03 16:42:45 +0100160
161 if (PageUptodate(req->wb_page))
162 nfs_readpage_to_fscache(d_inode, req->wb_page, 0);
163
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164 unlock_page(req->wb_page);
165
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166 dprintk("NFS: read done (%s/%Ld %d@%Ld)\n",
Al Viro3d4ff432011-06-22 18:40:12 -0400167 req->wb_context->dentry->d_inode->i_sb->s_id,
168 (long long)NFS_FILEID(req->wb_context->dentry->d_inode),
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169 req->wb_bytes,
170 (long long)req_offset(req));
Nick Wilson10d2c462005-09-22 21:44:28 -0700171 nfs_release_request(req);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172}
173
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400174/* Note io was page aligned */
Fred Isaman061ae2e2012-04-20 14:47:48 -0400175static void nfs_read_completion(struct nfs_pgio_header *hdr)
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400176{
177 unsigned long bytes = 0;
178
179 if (test_bit(NFS_IOHDR_REDO, &hdr->flags))
180 goto out;
Trond Myklebust4bd8b012012-05-01 12:49:58 -0400181 while (!list_empty(&hdr->pages)) {
182 struct nfs_page *req = nfs_list_entry(hdr->pages.next);
183 struct page *page = req->wb_page;
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400184
Trond Myklebust4bd8b012012-05-01 12:49:58 -0400185 if (test_bit(NFS_IOHDR_EOF, &hdr->flags)) {
186 if (bytes > hdr->good_bytes)
187 zero_user(page, 0, PAGE_SIZE);
188 else if (hdr->good_bytes - bytes < PAGE_SIZE)
189 zero_user_segment(page,
190 hdr->good_bytes & ~PAGE_MASK,
191 PAGE_SIZE);
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400192 }
Trond Myklebust4bd8b012012-05-01 12:49:58 -0400193 bytes += req->wb_bytes;
194 if (test_bit(NFS_IOHDR_ERROR, &hdr->flags)) {
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400195 if (bytes <= hdr->good_bytes)
Trond Myklebust4bd8b012012-05-01 12:49:58 -0400196 SetPageUptodate(page);
197 } else
198 SetPageUptodate(page);
199 nfs_list_remove_request(req);
200 nfs_readpage_release(req);
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400201 }
202out:
203 hdr->release(hdr);
204}
205
Fred Isamanc5996c42012-04-20 14:47:41 -0400206int nfs_initiate_read(struct rpc_clnt *clnt,
207 struct nfs_read_data *data,
Andy Adamson9f0ec1762012-04-27 17:53:44 -0400208 const struct rpc_call_ops *call_ops, int flags)
Andy Adamson64419a92011-03-01 01:34:16 +0000209{
Fred Isamancd841602012-04-20 14:47:44 -0400210 struct inode *inode = data->header->inode;
Andy Adamson64419a92011-03-01 01:34:16 +0000211 int swap_flags = IS_SWAPFILE(inode) ? NFS_RPC_SWAPFLAGS : 0;
212 struct rpc_task *task;
213 struct rpc_message msg = {
214 .rpc_argp = &data->args,
215 .rpc_resp = &data->res,
Fred Isamancd841602012-04-20 14:47:44 -0400216 .rpc_cred = data->header->cred,
Andy Adamson64419a92011-03-01 01:34:16 +0000217 };
218 struct rpc_task_setup task_setup_data = {
219 .task = &data->task,
220 .rpc_client = clnt,
221 .rpc_message = &msg,
222 .callback_ops = call_ops,
223 .callback_data = data,
224 .workqueue = nfsiod_workqueue,
Andy Adamson9f0ec1762012-04-27 17:53:44 -0400225 .flags = RPC_TASK_ASYNC | swap_flags | flags,
Andy Adamson64419a92011-03-01 01:34:16 +0000226 };
227
228 /* Set up the initial task struct. */
229 NFS_PROTO(inode)->read_setup(data, &msg);
230
231 dprintk("NFS: %5u initiated read call (req %s/%lld, %u bytes @ "
232 "offset %llu)\n",
233 data->task.tk_pid,
234 inode->i_sb->s_id,
235 (long long)NFS_FILEID(inode),
236 data->args.count,
237 (unsigned long long)data->args.offset);
238
239 task = rpc_run_task(&task_setup_data);
240 if (IS_ERR(task))
241 return PTR_ERR(task);
242 rpc_put_task(task);
243 return 0;
244}
Andy Adamsondc70d7b2011-03-01 01:34:19 +0000245EXPORT_SYMBOL_GPL(nfs_initiate_read);
Andy Adamson64419a92011-03-01 01:34:16 +0000246
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247/*
248 * Set up the NFS read request struct
249 */
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400250static void nfs_read_rpcsetup(struct nfs_read_data *data,
Trond Myklebust6e4efd52011-07-12 13:42:02 -0400251 unsigned int count, unsigned int offset)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252{
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400253 struct nfs_page *req = data->header->req;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400255 data->args.fh = NFS_FH(data->header->inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700256 data->args.offset = req_offset(req) + offset;
257 data->args.pgbase = req->wb_pgbase + offset;
Fred Isaman30dd3742012-04-20 14:47:45 -0400258 data->args.pages = data->pages.pagevec;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700259 data->args.count = count;
Trond Myklebust383ba712008-02-19 20:04:20 -0500260 data->args.context = get_nfs_open_context(req->wb_context);
Trond Myklebustf11ac8d2010-06-25 16:35:53 -0400261 data->args.lock_context = req->wb_lock_context;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262
263 data->res.fattr = &data->fattr;
264 data->res.count = count;
265 data->res.eof = 0;
Trond Myklebust0e574af2005-10-27 22:12:38 -0400266 nfs_fattr_init(&data->fattr);
Trond Myklebust6e4efd52011-07-12 13:42:02 -0400267}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700268
Trond Myklebust6e4efd52011-07-12 13:42:02 -0400269static int nfs_do_read(struct nfs_read_data *data,
Trond Myklebust493292d2011-07-13 15:58:28 -0400270 const struct rpc_call_ops *call_ops)
Trond Myklebust6e4efd52011-07-12 13:42:02 -0400271{
Fred Isamancd841602012-04-20 14:47:44 -0400272 struct inode *inode = data->header->inode;
Trond Myklebust6e4efd52011-07-12 13:42:02 -0400273
Andy Adamson9f0ec1762012-04-27 17:53:44 -0400274 return nfs_initiate_read(NFS_CLIENT(inode), data, call_ops, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700275}
276
Trond Myklebust275acaa2011-07-12 13:42:02 -0400277static int
278nfs_do_multiple_reads(struct list_head *head,
Trond Myklebust493292d2011-07-13 15:58:28 -0400279 const struct rpc_call_ops *call_ops)
Trond Myklebust275acaa2011-07-12 13:42:02 -0400280{
281 struct nfs_read_data *data;
282 int ret = 0;
283
284 while (!list_empty(head)) {
285 int ret2;
286
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400287 data = list_first_entry(head, struct nfs_read_data, list);
Trond Myklebust275acaa2011-07-12 13:42:02 -0400288 list_del_init(&data->list);
289
Trond Myklebust493292d2011-07-13 15:58:28 -0400290 ret2 = nfs_do_read(data, call_ops);
Trond Myklebust275acaa2011-07-12 13:42:02 -0400291 if (ret == 0)
292 ret = ret2;
293 }
294 return ret;
295}
296
Fred Isaman061ae2e2012-04-20 14:47:48 -0400297static void
Linus Torvalds1da177e2005-04-16 15:20:36 -0700298nfs_async_read_error(struct list_head *head)
299{
300 struct nfs_page *req;
301
302 while (!list_empty(head)) {
303 req = nfs_list_entry(head->next);
304 nfs_list_remove_request(req);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700305 nfs_readpage_release(req);
306 }
307}
308
Fred Isaman061ae2e2012-04-20 14:47:48 -0400309static const struct nfs_pgio_completion_ops nfs_async_read_completion_ops = {
310 .error_cleanup = nfs_async_read_error,
311 .completion = nfs_read_completion,
312};
313
Trond Myklebust25b11dc2012-05-01 12:07:22 -0400314static void nfs_pagein_error(struct nfs_pageio_descriptor *desc,
315 struct nfs_pgio_header *hdr)
316{
317 set_bit(NFS_IOHDR_REDO, &hdr->flags);
318 while (!list_empty(&hdr->rpc_list)) {
319 struct nfs_read_data *data = list_first_entry(&hdr->rpc_list,
320 struct nfs_read_data, list);
321 list_del(&data->list);
322 nfs_readdata_release(data);
323 }
324 desc->pg_completion_ops->error_cleanup(&desc->pg_list);
325}
326
Linus Torvalds1da177e2005-04-16 15:20:36 -0700327/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700328 * Generate multiple requests to fill a single page.
329 *
330 * We optimize to reduce the number of read operations on the wire. If we
331 * detect that we're reading a page, or an area of a page, that is past the
332 * end of file, we do not generate NFS read operations but just clear the
333 * parts of the page that would have come back zero from the server anyway.
334 *
335 * We rely on the cached value of i_size to make this determination; another
336 * client can fill pages on the server past our cached end-of-file, but we
337 * won't see the new data until our attribute cache is updated. This is more
338 * or less conventional NFS client behavior.
339 */
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400340static int nfs_pagein_multi(struct nfs_pageio_descriptor *desc,
341 struct nfs_pgio_header *hdr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700342{
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400343 struct nfs_page *req = hdr->req;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700344 struct page *page = req->wb_page;
345 struct nfs_read_data *data;
Trond Myklebustd0979712011-07-12 13:42:02 -0400346 size_t rsize = desc->pg_bsize, nbytes;
Trond Myklebuste9f7bee2006-09-08 09:48:54 -0700347 unsigned int offset;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700348
Trond Myklebust275acaa2011-07-12 13:42:02 -0400349 offset = 0;
Fred Isamanc76069b2011-03-03 15:13:48 +0000350 nbytes = desc->pg_count;
Trond Myklebuste9f7bee2006-09-08 09:48:54 -0700351 do {
352 size_t len = min(nbytes,rsize);
353
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400354 data = nfs_readdata_alloc(hdr, 1);
Trond Myklebust25b11dc2012-05-01 12:07:22 -0400355 if (!data) {
356 nfs_pagein_error(desc, hdr);
357 return -ENOMEM;
358 }
Fred Isaman30dd3742012-04-20 14:47:45 -0400359 data->pages.pagevec[0] = page;
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400360 nfs_read_rpcsetup(data, len, offset);
361 list_add(&data->list, &hdr->rpc_list);
Trond Myklebuste9f7bee2006-09-08 09:48:54 -0700362 nbytes -= len;
Trond Myklebust275acaa2011-07-12 13:42:02 -0400363 offset += len;
Trond Myklebust9146ab52012-05-01 11:21:43 -0400364 } while (nbytes != 0);
Trond Myklebust25b11dc2012-05-01 12:07:22 -0400365
366 nfs_list_remove_request(req);
367 nfs_list_add_request(req, &hdr->pages);
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400368 desc->pg_rpc_callops = &nfs_read_common_ops;
Trond Myklebust9146ab52012-05-01 11:21:43 -0400369 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700370}
371
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400372static int nfs_pagein_one(struct nfs_pageio_descriptor *desc,
373 struct nfs_pgio_header *hdr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700374{
375 struct nfs_page *req;
376 struct page **pages;
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400377 struct nfs_read_data *data;
Fred Isamanc76069b2011-03-03 15:13:48 +0000378 struct list_head *head = &desc->pg_list;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700379
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400380 data = nfs_readdata_alloc(hdr, nfs_page_array_len(desc->pg_base,
381 desc->pg_count));
382 if (!data) {
Trond Myklebust25b11dc2012-05-01 12:07:22 -0400383 nfs_pagein_error(desc, hdr);
Trond Myklebust9146ab52012-05-01 11:21:43 -0400384 return -ENOMEM;
Fred Isamanbae724e2011-03-01 01:34:15 +0000385 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700386
Fred Isaman30dd3742012-04-20 14:47:45 -0400387 pages = data->pages.pagevec;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700388 while (!list_empty(head)) {
389 req = nfs_list_entry(head->next);
390 nfs_list_remove_request(req);
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400391 nfs_list_add_request(req, &hdr->pages);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700392 *pages++ = req->wb_page;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700393 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700394
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400395 nfs_read_rpcsetup(data, desc->pg_count, 0);
396 list_add(&data->list, &hdr->rpc_list);
397 desc->pg_rpc_callops = &nfs_read_common_ops;
Trond Myklebust9146ab52012-05-01 11:21:43 -0400398 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700399}
400
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400401int nfs_generic_pagein(struct nfs_pageio_descriptor *desc,
402 struct nfs_pgio_header *hdr)
Trond Myklebust493292d2011-07-13 15:58:28 -0400403{
404 if (desc->pg_bsize < PAGE_CACHE_SIZE)
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400405 return nfs_pagein_multi(desc, hdr);
406 return nfs_pagein_one(desc, hdr);
Trond Myklebust493292d2011-07-13 15:58:28 -0400407}
Bryan Schumaker89d77c82012-07-30 16:05:25 -0400408EXPORT_SYMBOL_GPL(nfs_generic_pagein);
Trond Myklebust493292d2011-07-13 15:58:28 -0400409
410static int nfs_generic_pg_readpages(struct nfs_pageio_descriptor *desc)
Trond Myklebust1751c362011-06-10 13:30:23 -0400411{
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400412 struct nfs_read_header *rhdr;
413 struct nfs_pgio_header *hdr;
Trond Myklebust275acaa2011-07-12 13:42:02 -0400414 int ret;
415
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400416 rhdr = nfs_readhdr_alloc();
417 if (!rhdr) {
Fred Isaman061ae2e2012-04-20 14:47:48 -0400418 desc->pg_completion_ops->error_cleanup(&desc->pg_list);
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400419 return -ENOMEM;
420 }
421 hdr = &rhdr->header;
422 nfs_pgheader_init(desc, hdr, nfs_readhdr_free);
423 atomic_inc(&hdr->refcnt);
424 ret = nfs_generic_pagein(desc, hdr);
Trond Myklebust50828d72011-07-12 13:42:02 -0400425 if (ret == 0)
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400426 ret = nfs_do_multiple_reads(&hdr->rpc_list,
427 desc->pg_rpc_callops);
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400428 if (atomic_dec_and_test(&hdr->refcnt))
Fred Isaman061ae2e2012-04-20 14:47:48 -0400429 hdr->completion_ops->completion(hdr);
Trond Myklebust275acaa2011-07-12 13:42:02 -0400430 return ret;
Trond Myklebust1751c362011-06-10 13:30:23 -0400431}
Trond Myklebust1751c362011-06-10 13:30:23 -0400432
433static const struct nfs_pageio_ops nfs_pageio_read_ops = {
434 .pg_test = nfs_generic_pg_test,
435 .pg_doio = nfs_generic_pg_readpages,
436};
437
Linus Torvalds1da177e2005-04-16 15:20:36 -0700438/*
Trond Myklebust0b671302006-11-14 16:12:23 -0500439 * This is the callback from RPC telling us whether a reply was
440 * received or some error occurred (timeout or socket shutdown).
441 */
442int nfs_readpage_result(struct rpc_task *task, struct nfs_read_data *data)
443{
Fred Isamancd841602012-04-20 14:47:44 -0400444 struct inode *inode = data->header->inode;
Trond Myklebust0b671302006-11-14 16:12:23 -0500445 int status;
446
Harvey Harrison3110ff82008-05-02 13:42:44 -0700447 dprintk("NFS: %s: %5u, (status %d)\n", __func__, task->tk_pid,
Trond Myklebust0b671302006-11-14 16:12:23 -0500448 task->tk_status);
449
Fred Isamancd841602012-04-20 14:47:44 -0400450 status = NFS_PROTO(inode)->read_done(task, data);
Trond Myklebust0b671302006-11-14 16:12:23 -0500451 if (status != 0)
452 return status;
453
Fred Isamancd841602012-04-20 14:47:44 -0400454 nfs_add_stats(inode, NFSIOS_SERVERREADBYTES, data->res.count);
Trond Myklebust0b671302006-11-14 16:12:23 -0500455
456 if (task->tk_status == -ESTALE) {
Fred Isamancd841602012-04-20 14:47:44 -0400457 set_bit(NFS_INO_STALE, &NFS_I(inode)->flags);
458 nfs_mark_for_revalidate(inode);
Trond Myklebust0b671302006-11-14 16:12:23 -0500459 }
Trond Myklebust0b671302006-11-14 16:12:23 -0500460 return 0;
461}
462
Trond Myklebustfdd1e742008-04-15 16:33:58 -0400463static void nfs_readpage_retry(struct rpc_task *task, struct nfs_read_data *data)
Trond Myklebust0b671302006-11-14 16:12:23 -0500464{
465 struct nfs_readargs *argp = &data->args;
466 struct nfs_readres *resp = &data->res;
467
Trond Myklebust0b671302006-11-14 16:12:23 -0500468 /* This is a short read! */
Fred Isamancd841602012-04-20 14:47:44 -0400469 nfs_inc_stats(data->header->inode, NFSIOS_SHORTREAD);
Trond Myklebust0b671302006-11-14 16:12:23 -0500470 /* Has the server at least made some progress? */
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400471 if (resp->count == 0) {
472 nfs_set_pgio_error(data->header, -EIO, argp->offset);
Trond Myklebustd61e6122009-12-05 19:32:19 -0500473 return;
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400474 }
Trond Myklebust0b671302006-11-14 16:12:23 -0500475 /* Yes, so retry the read at the end of the data */
Andy Adamsoncbdabc7f2011-03-01 01:34:20 +0000476 data->mds_offset += resp->count;
Trond Myklebust0b671302006-11-14 16:12:23 -0500477 argp->offset += resp->count;
478 argp->pgbase += resp->count;
479 argp->count -= resp->count;
Trond Myklebustd00c5d42011-10-19 12:17:29 -0700480 rpc_restart_call_prepare(task);
Trond Myklebust0b671302006-11-14 16:12:23 -0500481}
482
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400483static void nfs_readpage_result_common(struct rpc_task *task, void *calldata)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700484{
Trond Myklebustec06c092006-03-20 13:44:27 -0500485 struct nfs_read_data *data = calldata;
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400486 struct nfs_pgio_header *hdr = data->header;
487
488 /* Note the only returns of nfs_readpage_result are 0 and -EAGAIN */
Trond Myklebustec06c092006-03-20 13:44:27 -0500489 if (nfs_readpage_result(task, data) != 0)
490 return;
Trond Myklebustfdd1e742008-04-15 16:33:58 -0400491 if (task->tk_status < 0)
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400492 nfs_set_pgio_error(hdr, task->tk_status, data->args.offset);
493 else if (data->res.eof) {
494 loff_t bound;
Trond Myklebust0b671302006-11-14 16:12:23 -0500495
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400496 bound = data->args.offset + data->res.count;
497 spin_lock(&hdr->lock);
498 if (bound < hdr->io_start + hdr->good_bytes) {
499 set_bit(NFS_IOHDR_EOF, &hdr->flags);
500 clear_bit(NFS_IOHDR_ERROR, &hdr->flags);
501 hdr->good_bytes = bound - hdr->io_start;
502 }
503 spin_unlock(&hdr->lock);
504 } else if (data->res.count != data->args.count)
505 nfs_readpage_retry(task, data);
Trond Myklebustfdd1e742008-04-15 16:33:58 -0400506}
507
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400508static void nfs_readpage_release_common(void *calldata)
Trond Myklebustfdd1e742008-04-15 16:33:58 -0400509{
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400510 nfs_readdata_release(calldata);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700511}
512
Andy Adamsonf11c88a2009-04-01 09:22:25 -0400513void nfs_read_prepare(struct rpc_task *task, void *calldata)
514{
515 struct nfs_read_data *data = calldata;
Fred Isamancd841602012-04-20 14:47:44 -0400516 NFS_PROTO(data->header->inode)->read_rpc_prepare(task, data);
Andy Adamsonf11c88a2009-04-01 09:22:25 -0400517}
Andy Adamsonf11c88a2009-04-01 09:22:25 -0400518
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400519static const struct rpc_call_ops nfs_read_common_ops = {
Andy Adamsonf11c88a2009-04-01 09:22:25 -0400520 .rpc_call_prepare = nfs_read_prepare,
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400521 .rpc_call_done = nfs_readpage_result_common,
522 .rpc_release = nfs_readpage_release_common,
Trond Myklebustec06c092006-03-20 13:44:27 -0500523};
524
Linus Torvalds1da177e2005-04-16 15:20:36 -0700525/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700526 * Read a page over NFS.
527 * We read the page synchronously in the following case:
528 * - The error flag is set for this page. This happens only when a
529 * previous async read operation failed.
530 */
531int nfs_readpage(struct file *file, struct page *page)
532{
533 struct nfs_open_context *ctx;
Mel Gormand56b4dd2012-07-31 16:45:06 -0700534 struct inode *inode = page_file_mapping(page)->host;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700535 int error;
536
537 dprintk("NFS: nfs_readpage (%p %ld@%lu)\n",
Mel Gormand56b4dd2012-07-31 16:45:06 -0700538 page, PAGE_CACHE_SIZE, page_file_index(page));
Chuck Lever91d5b472006-03-20 13:44:14 -0500539 nfs_inc_stats(inode, NFSIOS_VFSREADPAGE);
540 nfs_add_stats(inode, NFSIOS_READPAGES, 1);
541
Linus Torvalds1da177e2005-04-16 15:20:36 -0700542 /*
543 * Try to flush any pending writes to the file..
544 *
545 * NOTE! Because we own the page lock, there cannot
546 * be any new pending writes generated at this point
547 * for this page (other pages can be written to).
548 */
549 error = nfs_wb_page(inode, page);
550 if (error)
Trond Myklebustde05a0c2007-05-20 13:05:05 -0400551 goto out_unlock;
552 if (PageUptodate(page))
553 goto out_unlock;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700554
Trond Myklebust5f004cf2006-09-14 14:03:14 -0400555 error = -ESTALE;
556 if (NFS_STALE(inode))
Trond Myklebustde05a0c2007-05-20 13:05:05 -0400557 goto out_unlock;
Trond Myklebust5f004cf2006-09-14 14:03:14 -0400558
Linus Torvalds1da177e2005-04-16 15:20:36 -0700559 if (file == NULL) {
Trond Myklebustcf1308f2006-11-19 16:44:52 -0500560 error = -EBADF;
Trond Myklebustd5308382005-11-04 15:33:38 -0500561 ctx = nfs_find_open_context(inode, NULL, FMODE_READ);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700562 if (ctx == NULL)
Trond Myklebustde05a0c2007-05-20 13:05:05 -0400563 goto out_unlock;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700564 } else
Trond Myklebustcd3758e2007-08-10 17:44:32 -0400565 ctx = get_nfs_open_context(nfs_file_open_context(file));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700566
David Howells9a9fc1c2009-04-03 16:42:44 +0100567 if (!IS_SYNC(inode)) {
568 error = nfs_readpage_from_fscache(ctx, inode, page);
569 if (error == 0)
570 goto out;
571 }
572
Trond Myklebust8e0969f2006-12-13 15:23:44 -0500573 error = nfs_readpage_async(ctx, inode, page);
574
David Howells9a9fc1c2009-04-03 16:42:44 +0100575out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700576 put_nfs_open_context(ctx);
577 return error;
Trond Myklebustde05a0c2007-05-20 13:05:05 -0400578out_unlock:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700579 unlock_page(page);
580 return error;
581}
582
583struct nfs_readdesc {
Trond Myklebust8b09bee2007-04-02 18:48:28 -0400584 struct nfs_pageio_descriptor *pgio;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700585 struct nfs_open_context *ctx;
586};
587
588static int
589readpage_async_filler(void *data, struct page *page)
590{
591 struct nfs_readdesc *desc = (struct nfs_readdesc *)data;
Mel Gormand56b4dd2012-07-31 16:45:06 -0700592 struct inode *inode = page_file_mapping(page)->host;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700593 struct nfs_page *new;
594 unsigned int len;
Trond Myklebustde05a0c2007-05-20 13:05:05 -0400595 int error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700596
Trond Myklebust49a70f22006-12-05 00:35:38 -0500597 len = nfs_page_length(page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700598 if (len == 0)
599 return nfs_return_empty_page(page);
Trond Myklebustde05a0c2007-05-20 13:05:05 -0400600
Linus Torvalds1da177e2005-04-16 15:20:36 -0700601 new = nfs_create_request(desc->ctx, inode, page, 0, len);
Trond Myklebustde05a0c2007-05-20 13:05:05 -0400602 if (IS_ERR(new))
603 goto out_error;
604
Linus Torvalds1da177e2005-04-16 15:20:36 -0700605 if (len < PAGE_CACHE_SIZE)
Christoph Lametereebd2aa2008-02-04 22:28:29 -0800606 zero_user_segment(page, len, PAGE_CACHE_SIZE);
Fred Isamanf8512ad2008-03-19 11:24:39 -0400607 if (!nfs_pageio_add_request(desc->pgio, new)) {
608 error = desc->pgio->pg_error;
609 goto out_unlock;
610 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700611 return 0;
Trond Myklebustde05a0c2007-05-20 13:05:05 -0400612out_error:
613 error = PTR_ERR(new);
Trond Myklebustde05a0c2007-05-20 13:05:05 -0400614out_unlock:
615 unlock_page(page);
616 return error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700617}
618
619int nfs_readpages(struct file *filp, struct address_space *mapping,
620 struct list_head *pages, unsigned nr_pages)
621{
Trond Myklebust8b09bee2007-04-02 18:48:28 -0400622 struct nfs_pageio_descriptor pgio;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700623 struct nfs_readdesc desc = {
Trond Myklebust8b09bee2007-04-02 18:48:28 -0400624 .pgio = &pgio,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700625 };
626 struct inode *inode = mapping->host;
Trond Myklebust8b09bee2007-04-02 18:48:28 -0400627 unsigned long npages;
Trond Myklebust5f004cf2006-09-14 14:03:14 -0400628 int ret = -ESTALE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700629
630 dprintk("NFS: nfs_readpages (%s/%Ld %d)\n",
631 inode->i_sb->s_id,
632 (long long)NFS_FILEID(inode),
633 nr_pages);
Chuck Lever91d5b472006-03-20 13:44:14 -0500634 nfs_inc_stats(inode, NFSIOS_VFSREADPAGES);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700635
Trond Myklebust5f004cf2006-09-14 14:03:14 -0400636 if (NFS_STALE(inode))
637 goto out;
638
Linus Torvalds1da177e2005-04-16 15:20:36 -0700639 if (filp == NULL) {
Trond Myklebustd5308382005-11-04 15:33:38 -0500640 desc.ctx = nfs_find_open_context(inode, NULL, FMODE_READ);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700641 if (desc.ctx == NULL)
642 return -EBADF;
643 } else
Trond Myklebustcd3758e2007-08-10 17:44:32 -0400644 desc.ctx = get_nfs_open_context(nfs_file_open_context(filp));
David Howells9a9fc1c2009-04-03 16:42:44 +0100645
646 /* attempt to read as many of the pages as possible from the cache
647 * - this returns -ENOBUFS immediately if the cookie is negative
648 */
649 ret = nfs_readpages_from_fscache(desc.ctx, inode, mapping,
650 pages, &nr_pages);
651 if (ret == 0)
652 goto read_complete; /* all pages were read */
653
Bryan Schumaker1abb50882012-06-20 15:53:47 -0400654 NFS_PROTO(inode)->read_pageio_init(&pgio, inode, &nfs_async_read_completion_ops);
Trond Myklebust8b09bee2007-04-02 18:48:28 -0400655
Linus Torvalds1da177e2005-04-16 15:20:36 -0700656 ret = read_cache_pages(mapping, pages, readpage_async_filler, &desc);
Trond Myklebust8b09bee2007-04-02 18:48:28 -0400657
658 nfs_pageio_complete(&pgio);
Andy Adamson2701d082012-05-24 13:13:24 -0400659 NFS_I(inode)->read_io += pgio.pg_bytes_written;
Trond Myklebust8b09bee2007-04-02 18:48:28 -0400660 npages = (pgio.pg_bytes_written + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
661 nfs_add_stats(inode, NFSIOS_READPAGES, npages);
David Howells9a9fc1c2009-04-03 16:42:44 +0100662read_complete:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700663 put_nfs_open_context(desc.ctx);
Trond Myklebust5f004cf2006-09-14 14:03:14 -0400664out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700665 return ret;
666}
667
David Howellsf7b422b2006-06-09 09:34:33 -0400668int __init nfs_init_readpagecache(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700669{
670 nfs_rdata_cachep = kmem_cache_create("nfs_read_data",
Fred Isamancd841602012-04-20 14:47:44 -0400671 sizeof(struct nfs_read_header),
Linus Torvalds1da177e2005-04-16 15:20:36 -0700672 0, SLAB_HWCACHE_ALIGN,
Paul Mundt20c2df82007-07-20 10:11:58 +0900673 NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700674 if (nfs_rdata_cachep == NULL)
675 return -ENOMEM;
676
Linus Torvalds1da177e2005-04-16 15:20:36 -0700677 return 0;
678}
679
David Brownell266bee82006-06-27 12:59:15 -0700680void nfs_destroy_readpagecache(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700681{
Alexey Dobriyan1a1d92c2006-09-27 01:49:40 -0700682 kmem_cache_destroy(nfs_rdata_cachep);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700683}