blob: eb31e23e7defa5a1cdb494aae35b18ccd3a30a0f [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"
Christoph Hellwigfab5fc22014-04-16 15:07:22 +020027#include "pnfs.h"
Chuck Lever91d5b472006-03-20 13:44:14 -050028
Linus Torvalds1da177e2005-04-16 15:20:36 -070029#define NFSDBG_FACILITY NFSDBG_PAGECACHE
30
Fred Isaman061ae2e2012-04-20 14:47:48 -040031static const struct nfs_pgio_completion_ops nfs_async_read_completion_ops;
Anna Schumaker4a0de552014-05-06 09:12:30 -040032static const struct nfs_rw_ops nfs_rw_read_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
Weston Andros Adamson1e7f3a42014-06-09 11:48:33 -040036static struct nfs_pgio_header *nfs_readhdr_alloc(void)
Trond Myklebust3feb2d42006-03-20 13:44:37 -050037{
Anna Schumaker4a0de552014-05-06 09:12:30 -040038 return kmem_cache_zalloc(nfs_rdata_cachep, GFP_KERNEL);
Fred Isaman4db6e0b2012-04-20 14:47:46 -040039}
40
Weston Andros Adamson1e7f3a42014-06-09 11:48:33 -040041static void nfs_readhdr_free(struct nfs_pgio_header *rhdr)
Trond Myklebust3feb2d42006-03-20 13:44:37 -050042{
Fred Isamancd841602012-04-20 14:47:44 -040043 kmem_cache_free(nfs_rdata_cachep, rhdr);
Trond Myklebust3feb2d42006-03-20 13:44:37 -050044}
45
Linus Torvalds1da177e2005-04-16 15:20:36 -070046static
Linus Torvalds1da177e2005-04-16 15:20:36 -070047int nfs_return_empty_page(struct page *page)
48{
Christoph Lametereebd2aa2008-02-04 22:28:29 -080049 zero_user(page, 0, PAGE_CACHE_SIZE);
Linus Torvalds1da177e2005-04-16 15:20:36 -070050 SetPageUptodate(page);
51 unlock_page(page);
52 return 0;
53}
54
Bryan Schumaker1abb50882012-06-20 15:53:47 -040055void nfs_pageio_init_read(struct nfs_pageio_descriptor *pgio,
Christoph Hellwigfab5fc22014-04-16 15:07:22 +020056 struct inode *inode, bool force_mds,
Fred Isaman061ae2e2012-04-20 14:47:48 -040057 const struct nfs_pgio_completion_ops *compl_ops)
Trond Myklebust1751c362011-06-10 13:30:23 -040058{
Christoph Hellwigfab5fc22014-04-16 15:07:22 +020059 struct nfs_server *server = NFS_SERVER(inode);
Anna Schumaker41d8d5b2014-05-06 09:12:40 -040060 const struct nfs_pageio_ops *pg_ops = &nfs_pgio_rw_ops;
Christoph Hellwigfab5fc22014-04-16 15:07:22 +020061
62#ifdef CONFIG_NFS_V4_1
63 if (server->pnfs_curr_ld && !force_mds)
64 pg_ops = server->pnfs_curr_ld->pg_read_ops;
65#endif
Anna Schumaker4a0de552014-05-06 09:12:30 -040066 nfs_pageio_init(pgio, inode, pg_ops, compl_ops, &nfs_rw_read_ops,
67 server->rsize, 0);
Trond Myklebust1751c362011-06-10 13:30:23 -040068}
Bryan Schumakerddda8e02012-07-30 16:05:23 -040069EXPORT_SYMBOL_GPL(nfs_pageio_init_read);
Trond Myklebust1751c362011-06-10 13:30:23 -040070
Trond Myklebust493292d2011-07-13 15:58:28 -040071void nfs_pageio_reset_read_mds(struct nfs_pageio_descriptor *pgio)
72{
Weston Andros Adamsona7d42dd2014-09-19 10:55:07 -040073 struct nfs_pgio_mirror *mirror;
74
Kinglong Mee6f29b9b2015-09-20 23:03:28 +080075 if (pgio->pg_ops && pgio->pg_ops->pg_cleanup)
76 pgio->pg_ops->pg_cleanup(pgio);
77
Anna Schumaker41d8d5b2014-05-06 09:12:40 -040078 pgio->pg_ops = &nfs_pgio_rw_ops;
Weston Andros Adamsona7d42dd2014-09-19 10:55:07 -040079
80 /* read path should never have more than one mirror */
81 WARN_ON_ONCE(pgio->pg_mirror_count != 1);
82
83 mirror = &pgio->pg_mirrors[0];
84 mirror->pg_bsize = NFS_SERVER(pgio->pg_inode)->rsize;
Trond Myklebust493292d2011-07-13 15:58:28 -040085}
Trond Myklebust1f945352011-07-13 15:59:57 -040086EXPORT_SYMBOL_GPL(nfs_pageio_reset_read_mds);
Trond Myklebust493292d2011-07-13 15:58:28 -040087
Peng Tao0bcbf032015-12-05 15:57:31 +080088static void nfs_readpage_release(struct nfs_page *req)
89{
90 struct inode *inode = d_inode(req->wb_context->dentry);
91
92 dprintk("NFS: read done (%s/%llu %d@%lld)\n", inode->i_sb->s_id,
93 (unsigned long long)NFS_FILEID(inode), req->wb_bytes,
94 (long long)req_offset(req));
95
96 if (nfs_page_group_sync_on_bit(req, PG_UNLOCKPAGE)) {
97 if (PageUptodate(req->wb_page))
98 nfs_readpage_to_fscache(inode, req->wb_page, 0);
99
100 unlock_page(req->wb_page);
101 }
102 nfs_release_request(req);
103}
104
David Howellsf42b2932009-04-03 16:42:44 +0100105int nfs_readpage_async(struct nfs_open_context *ctx, struct inode *inode,
106 struct page *page)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700108 struct nfs_page *new;
109 unsigned int len;
Fred Isamanc76069b2011-03-03 15:13:48 +0000110 struct nfs_pageio_descriptor pgio;
Weston Andros Adamsona7d42dd2014-09-19 10:55:07 -0400111 struct nfs_pgio_mirror *pgm;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112
Trond Myklebust49a70f22006-12-05 00:35:38 -0500113 len = nfs_page_length(page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114 if (len == 0)
115 return nfs_return_empty_page(page);
Weston Andros Adamson2bfc6e52014-05-15 11:56:45 -0400116 new = nfs_create_request(ctx, page, NULL, 0, len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117 if (IS_ERR(new)) {
118 unlock_page(page);
119 return PTR_ERR(new);
120 }
121 if (len < PAGE_CACHE_SIZE)
Christoph Lametereebd2aa2008-02-04 22:28:29 -0800122 zero_user_segment(page, len, PAGE_CACHE_SIZE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123
Christoph Hellwigfab5fc22014-04-16 15:07:22 +0200124 nfs_pageio_init_read(&pgio, inode, false,
125 &nfs_async_read_completion_ops);
Peng Tao0bcbf032015-12-05 15:57:31 +0800126 if (!nfs_pageio_add_request(&pgio, new)) {
127 nfs_list_remove_request(new);
128 nfs_readpage_release(new);
129 }
Trond Myklebust1751c362011-06-10 13:30:23 -0400130 nfs_pageio_complete(&pgio);
Weston Andros Adamsona7d42dd2014-09-19 10:55:07 -0400131
132 /* It doesn't make sense to do mirrored reads! */
133 WARN_ON_ONCE(pgio.pg_mirror_count != 1);
134
135 pgm = &pgio.pg_mirrors[0];
136 NFS_I(inode)->read_io += pgm->pg_bytes_written;
137
Peng Taod600ad12015-12-04 02:57:48 +0800138 return pgio.pg_error < 0 ? pgio.pg_error : 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139}
140
Weston Andros Adamson67d03382014-05-15 11:56:46 -0400141static void nfs_page_group_set_uptodate(struct nfs_page *req)
142{
143 if (nfs_page_group_sync_on_bit(req, PG_UPTODATE))
144 SetPageUptodate(req->wb_page);
145}
146
Fred Isaman061ae2e2012-04-20 14:47:48 -0400147static void nfs_read_completion(struct nfs_pgio_header *hdr)
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400148{
149 unsigned long bytes = 0;
150
151 if (test_bit(NFS_IOHDR_REDO, &hdr->flags))
152 goto out;
Trond Myklebust4bd8b012012-05-01 12:49:58 -0400153 while (!list_empty(&hdr->pages)) {
154 struct nfs_page *req = nfs_list_entry(hdr->pages.next);
155 struct page *page = req->wb_page;
Weston Andros Adamson68072992014-05-15 11:56:57 -0400156 unsigned long start = req->wb_pgbase;
157 unsigned long end = req->wb_pgbase + req->wb_bytes;
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400158
Trond Myklebust4bd8b012012-05-01 12:49:58 -0400159 if (test_bit(NFS_IOHDR_EOF, &hdr->flags)) {
Weston Andros Adamson68072992014-05-15 11:56:57 -0400160 /* note: regions of the page not covered by a
161 * request are zeroed in nfs_readpage_async /
162 * readpage_async_filler */
163 if (bytes > hdr->good_bytes) {
164 /* nothing in this request was good, so zero
165 * the full extent of the request */
166 zero_user_segment(page, start, end);
167
168 } else if (hdr->good_bytes - bytes < req->wb_bytes) {
169 /* part of this request has good bytes, but
170 * not all. zero the bad bytes */
171 start += hdr->good_bytes - bytes;
172 WARN_ON(start < req->wb_pgbase);
173 zero_user_segment(page, start, end);
174 }
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400175 }
Trond Myklebust4bd8b012012-05-01 12:49:58 -0400176 bytes += req->wb_bytes;
177 if (test_bit(NFS_IOHDR_ERROR, &hdr->flags)) {
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400178 if (bytes <= hdr->good_bytes)
Weston Andros Adamson67d03382014-05-15 11:56:46 -0400179 nfs_page_group_set_uptodate(req);
Trond Myklebust4bd8b012012-05-01 12:49:58 -0400180 } else
Weston Andros Adamson67d03382014-05-15 11:56:46 -0400181 nfs_page_group_set_uptodate(req);
Trond Myklebust4bd8b012012-05-01 12:49:58 -0400182 nfs_list_remove_request(req);
183 nfs_readpage_release(req);
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400184 }
185out:
186 hdr->release(hdr);
187}
188
Weston Andros Adamsond45f60c2014-06-09 11:48:35 -0400189static void nfs_initiate_read(struct nfs_pgio_header *hdr,
190 struct rpc_message *msg,
Tom Haynesabde71f2014-06-09 13:12:20 -0700191 const struct nfs_rpc_ops *rpc_ops,
Anna Schumaker1ed26f32014-05-06 09:12:37 -0400192 struct rpc_task_setup *task_setup_data, int how)
Andy Adamson64419a92011-03-01 01:34:16 +0000193{
Weston Andros Adamsond45f60c2014-06-09 11:48:35 -0400194 struct inode *inode = hdr->inode;
Andy Adamson64419a92011-03-01 01:34:16 +0000195 int swap_flags = IS_SWAPFILE(inode) ? NFS_RPC_SWAPFLAGS : 0;
Andy Adamson64419a92011-03-01 01:34:16 +0000196
Anna Schumaker1ed26f32014-05-06 09:12:37 -0400197 task_setup_data->flags |= swap_flags;
Tom Haynesabde71f2014-06-09 13:12:20 -0700198 rpc_ops->read_setup(hdr, msg);
Andy Adamson64419a92011-03-01 01:34:16 +0000199}
200
Fred Isaman061ae2e2012-04-20 14:47:48 -0400201static void
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202nfs_async_read_error(struct list_head *head)
203{
204 struct nfs_page *req;
205
206 while (!list_empty(head)) {
207 req = nfs_list_entry(head->next);
208 nfs_list_remove_request(req);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209 nfs_readpage_release(req);
210 }
211}
212
Fred Isaman061ae2e2012-04-20 14:47:48 -0400213static const struct nfs_pgio_completion_ops nfs_async_read_completion_ops = {
214 .error_cleanup = nfs_async_read_error,
215 .completion = nfs_read_completion,
216};
217
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218/*
Trond Myklebust0b671302006-11-14 16:12:23 -0500219 * This is the callback from RPC telling us whether a reply was
220 * received or some error occurred (timeout or socket shutdown).
221 */
Weston Andros Adamsond45f60c2014-06-09 11:48:35 -0400222static int nfs_readpage_done(struct rpc_task *task,
223 struct nfs_pgio_header *hdr,
Anna Schumaker0eecb212014-05-06 09:12:32 -0400224 struct inode *inode)
Trond Myklebust0b671302006-11-14 16:12:23 -0500225{
Weston Andros Adamsond45f60c2014-06-09 11:48:35 -0400226 int status = NFS_PROTO(inode)->read_done(task, hdr);
Trond Myklebust0b671302006-11-14 16:12:23 -0500227 if (status != 0)
228 return status;
229
Weston Andros Adamsond45f60c2014-06-09 11:48:35 -0400230 nfs_add_stats(inode, NFSIOS_SERVERREADBYTES, hdr->res.count);
Trond Myklebust0b671302006-11-14 16:12:23 -0500231
232 if (task->tk_status == -ESTALE) {
Fred Isamancd841602012-04-20 14:47:44 -0400233 set_bit(NFS_INO_STALE, &NFS_I(inode)->flags);
234 nfs_mark_for_revalidate(inode);
Trond Myklebust0b671302006-11-14 16:12:23 -0500235 }
Trond Myklebust0b671302006-11-14 16:12:23 -0500236 return 0;
237}
238
Weston Andros Adamsond45f60c2014-06-09 11:48:35 -0400239static void nfs_readpage_retry(struct rpc_task *task,
240 struct nfs_pgio_header *hdr)
Trond Myklebust0b671302006-11-14 16:12:23 -0500241{
Weston Andros Adamsond45f60c2014-06-09 11:48:35 -0400242 struct nfs_pgio_args *argp = &hdr->args;
243 struct nfs_pgio_res *resp = &hdr->res;
Trond Myklebust0b671302006-11-14 16:12:23 -0500244
Trond Myklebust0b671302006-11-14 16:12:23 -0500245 /* This is a short read! */
Weston Andros Adamsond45f60c2014-06-09 11:48:35 -0400246 nfs_inc_stats(hdr->inode, NFSIOS_SHORTREAD);
Trond Myklebust0b671302006-11-14 16:12:23 -0500247 /* Has the server at least made some progress? */
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400248 if (resp->count == 0) {
Weston Andros Adamsond45f60c2014-06-09 11:48:35 -0400249 nfs_set_pgio_error(hdr, -EIO, argp->offset);
Trond Myklebustd61e6122009-12-05 19:32:19 -0500250 return;
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400251 }
Kinglong Meef8417b482015-10-16 17:23:29 +0800252
253 /* For non rpc-based layout drivers, retry-through-MDS */
254 if (!task->tk_ops) {
255 hdr->pnfs_error = -EAGAIN;
256 return;
257 }
258
Weston Andros Adamsond45f60c2014-06-09 11:48:35 -0400259 /* Yes, so retry the read at the end of the hdr */
260 hdr->mds_offset += resp->count;
Trond Myklebust0b671302006-11-14 16:12:23 -0500261 argp->offset += resp->count;
262 argp->pgbase += resp->count;
263 argp->count -= resp->count;
Trond Myklebustd00c5d42011-10-19 12:17:29 -0700264 rpc_restart_call_prepare(task);
Trond Myklebust0b671302006-11-14 16:12:23 -0500265}
266
Weston Andros Adamsond45f60c2014-06-09 11:48:35 -0400267static void nfs_readpage_result(struct rpc_task *task,
268 struct nfs_pgio_header *hdr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700269{
Weston Andros Adamsond45f60c2014-06-09 11:48:35 -0400270 if (hdr->res.eof) {
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400271 loff_t bound;
Trond Myklebust0b671302006-11-14 16:12:23 -0500272
Weston Andros Adamsond45f60c2014-06-09 11:48:35 -0400273 bound = hdr->args.offset + hdr->res.count;
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400274 spin_lock(&hdr->lock);
275 if (bound < hdr->io_start + hdr->good_bytes) {
276 set_bit(NFS_IOHDR_EOF, &hdr->flags);
277 clear_bit(NFS_IOHDR_ERROR, &hdr->flags);
278 hdr->good_bytes = bound - hdr->io_start;
279 }
280 spin_unlock(&hdr->lock);
Kinglong Meef8417b482015-10-16 17:23:29 +0800281 } else if (hdr->res.count < hdr->args.count)
Weston Andros Adamsond45f60c2014-06-09 11:48:35 -0400282 nfs_readpage_retry(task, hdr);
Trond Myklebustfdd1e742008-04-15 16:33:58 -0400283}
284
Linus Torvalds1da177e2005-04-16 15:20:36 -0700285/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700286 * Read a page over NFS.
287 * We read the page synchronously in the following case:
288 * - The error flag is set for this page. This happens only when a
289 * previous async read operation failed.
290 */
291int nfs_readpage(struct file *file, struct page *page)
292{
293 struct nfs_open_context *ctx;
Mel Gormand56b4dd2012-07-31 16:45:06 -0700294 struct inode *inode = page_file_mapping(page)->host;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700295 int error;
296
297 dprintk("NFS: nfs_readpage (%p %ld@%lu)\n",
Mel Gormand56b4dd2012-07-31 16:45:06 -0700298 page, PAGE_CACHE_SIZE, page_file_index(page));
Chuck Lever91d5b472006-03-20 13:44:14 -0500299 nfs_inc_stats(inode, NFSIOS_VFSREADPAGE);
Nicolas Iooss3708f842015-04-16 18:48:39 +0800300 nfs_add_stats(inode, NFSIOS_READPAGES, 1);
Chuck Lever91d5b472006-03-20 13:44:14 -0500301
Linus Torvalds1da177e2005-04-16 15:20:36 -0700302 /*
303 * Try to flush any pending writes to the file..
304 *
305 * NOTE! Because we own the page lock, there cannot
306 * be any new pending writes generated at this point
307 * for this page (other pages can be written to).
308 */
309 error = nfs_wb_page(inode, page);
310 if (error)
Trond Myklebustde05a0c2007-05-20 13:05:05 -0400311 goto out_unlock;
312 if (PageUptodate(page))
313 goto out_unlock;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700314
Trond Myklebust5f004cf2006-09-14 14:03:14 -0400315 error = -ESTALE;
316 if (NFS_STALE(inode))
Trond Myklebustde05a0c2007-05-20 13:05:05 -0400317 goto out_unlock;
Trond Myklebust5f004cf2006-09-14 14:03:14 -0400318
Linus Torvalds1da177e2005-04-16 15:20:36 -0700319 if (file == NULL) {
Trond Myklebustcf1308f2006-11-19 16:44:52 -0500320 error = -EBADF;
Trond Myklebustd5308382005-11-04 15:33:38 -0500321 ctx = nfs_find_open_context(inode, NULL, FMODE_READ);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700322 if (ctx == NULL)
Trond Myklebustde05a0c2007-05-20 13:05:05 -0400323 goto out_unlock;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700324 } else
Trond Myklebustcd3758e2007-08-10 17:44:32 -0400325 ctx = get_nfs_open_context(nfs_file_open_context(file));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700326
David Howells9a9fc1c2009-04-03 16:42:44 +0100327 if (!IS_SYNC(inode)) {
328 error = nfs_readpage_from_fscache(ctx, inode, page);
329 if (error == 0)
330 goto out;
331 }
332
Trond Myklebust8e0969f2006-12-13 15:23:44 -0500333 error = nfs_readpage_async(ctx, inode, page);
334
David Howells9a9fc1c2009-04-03 16:42:44 +0100335out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336 put_nfs_open_context(ctx);
337 return error;
Trond Myklebustde05a0c2007-05-20 13:05:05 -0400338out_unlock:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700339 unlock_page(page);
340 return error;
341}
342
343struct nfs_readdesc {
Trond Myklebust8b09bee2007-04-02 18:48:28 -0400344 struct nfs_pageio_descriptor *pgio;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700345 struct nfs_open_context *ctx;
346};
347
348static int
349readpage_async_filler(void *data, struct page *page)
350{
351 struct nfs_readdesc *desc = (struct nfs_readdesc *)data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700352 struct nfs_page *new;
353 unsigned int len;
Trond Myklebustde05a0c2007-05-20 13:05:05 -0400354 int error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700355
Trond Myklebust49a70f22006-12-05 00:35:38 -0500356 len = nfs_page_length(page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700357 if (len == 0)
358 return nfs_return_empty_page(page);
Trond Myklebustde05a0c2007-05-20 13:05:05 -0400359
Weston Andros Adamson2bfc6e52014-05-15 11:56:45 -0400360 new = nfs_create_request(desc->ctx, page, NULL, 0, len);
Trond Myklebustde05a0c2007-05-20 13:05:05 -0400361 if (IS_ERR(new))
362 goto out_error;
363
Linus Torvalds1da177e2005-04-16 15:20:36 -0700364 if (len < PAGE_CACHE_SIZE)
Christoph Lametereebd2aa2008-02-04 22:28:29 -0800365 zero_user_segment(page, len, PAGE_CACHE_SIZE);
Fred Isamanf8512ad2008-03-19 11:24:39 -0400366 if (!nfs_pageio_add_request(desc->pgio, new)) {
Peng Tao0bcbf032015-12-05 15:57:31 +0800367 nfs_list_remove_request(new);
368 nfs_readpage_release(new);
Fred Isamanf8512ad2008-03-19 11:24:39 -0400369 error = desc->pgio->pg_error;
370 goto out_unlock;
371 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700372 return 0;
Trond Myklebustde05a0c2007-05-20 13:05:05 -0400373out_error:
374 error = PTR_ERR(new);
Trond Myklebustde05a0c2007-05-20 13:05:05 -0400375out_unlock:
376 unlock_page(page);
377 return error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700378}
379
380int nfs_readpages(struct file *filp, struct address_space *mapping,
381 struct list_head *pages, unsigned nr_pages)
382{
Trond Myklebust8b09bee2007-04-02 18:48:28 -0400383 struct nfs_pageio_descriptor pgio;
Weston Andros Adamsona7d42dd2014-09-19 10:55:07 -0400384 struct nfs_pgio_mirror *pgm;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700385 struct nfs_readdesc desc = {
Trond Myklebust8b09bee2007-04-02 18:48:28 -0400386 .pgio = &pgio,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700387 };
388 struct inode *inode = mapping->host;
Trond Myklebust8b09bee2007-04-02 18:48:28 -0400389 unsigned long npages;
Trond Myklebust5f004cf2006-09-14 14:03:14 -0400390 int ret = -ESTALE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700391
Niels de Vos1e8968c2013-12-17 18:20:16 +0100392 dprintk("NFS: nfs_readpages (%s/%Lu %d)\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700393 inode->i_sb->s_id,
Niels de Vos1e8968c2013-12-17 18:20:16 +0100394 (unsigned long long)NFS_FILEID(inode),
Linus Torvalds1da177e2005-04-16 15:20:36 -0700395 nr_pages);
Chuck Lever91d5b472006-03-20 13:44:14 -0500396 nfs_inc_stats(inode, NFSIOS_VFSREADPAGES);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700397
Trond Myklebust5f004cf2006-09-14 14:03:14 -0400398 if (NFS_STALE(inode))
399 goto out;
400
Linus Torvalds1da177e2005-04-16 15:20:36 -0700401 if (filp == NULL) {
Trond Myklebustd5308382005-11-04 15:33:38 -0500402 desc.ctx = nfs_find_open_context(inode, NULL, FMODE_READ);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700403 if (desc.ctx == NULL)
404 return -EBADF;
405 } else
Trond Myklebustcd3758e2007-08-10 17:44:32 -0400406 desc.ctx = get_nfs_open_context(nfs_file_open_context(filp));
David Howells9a9fc1c2009-04-03 16:42:44 +0100407
408 /* attempt to read as many of the pages as possible from the cache
409 * - this returns -ENOBUFS immediately if the cookie is negative
410 */
411 ret = nfs_readpages_from_fscache(desc.ctx, inode, mapping,
412 pages, &nr_pages);
413 if (ret == 0)
414 goto read_complete; /* all pages were read */
415
Christoph Hellwigfab5fc22014-04-16 15:07:22 +0200416 nfs_pageio_init_read(&pgio, inode, false,
417 &nfs_async_read_completion_ops);
Trond Myklebust8b09bee2007-04-02 18:48:28 -0400418
Linus Torvalds1da177e2005-04-16 15:20:36 -0700419 ret = read_cache_pages(mapping, pages, readpage_async_filler, &desc);
Trond Myklebust8b09bee2007-04-02 18:48:28 -0400420 nfs_pageio_complete(&pgio);
Weston Andros Adamsona7d42dd2014-09-19 10:55:07 -0400421
422 /* It doesn't make sense to do mirrored reads! */
423 WARN_ON_ONCE(pgio.pg_mirror_count != 1);
424
425 pgm = &pgio.pg_mirrors[0];
426 NFS_I(inode)->read_io += pgm->pg_bytes_written;
427 npages = (pgm->pg_bytes_written + PAGE_CACHE_SIZE - 1) >>
428 PAGE_CACHE_SHIFT;
Trond Myklebust8b09bee2007-04-02 18:48:28 -0400429 nfs_add_stats(inode, NFSIOS_READPAGES, npages);
David Howells9a9fc1c2009-04-03 16:42:44 +0100430read_complete:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700431 put_nfs_open_context(desc.ctx);
Trond Myklebust5f004cf2006-09-14 14:03:14 -0400432out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700433 return ret;
434}
435
David Howellsf7b422b2006-06-09 09:34:33 -0400436int __init nfs_init_readpagecache(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700437{
438 nfs_rdata_cachep = kmem_cache_create("nfs_read_data",
Weston Andros Adamson1e7f3a42014-06-09 11:48:33 -0400439 sizeof(struct nfs_pgio_header),
Linus Torvalds1da177e2005-04-16 15:20:36 -0700440 0, SLAB_HWCACHE_ALIGN,
Paul Mundt20c2df82007-07-20 10:11:58 +0900441 NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700442 if (nfs_rdata_cachep == NULL)
443 return -ENOMEM;
444
Linus Torvalds1da177e2005-04-16 15:20:36 -0700445 return 0;
446}
447
David Brownell266bee82006-06-27 12:59:15 -0700448void nfs_destroy_readpagecache(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700449{
Alexey Dobriyan1a1d92c2006-09-27 01:49:40 -0700450 kmem_cache_destroy(nfs_rdata_cachep);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700451}
Anna Schumaker4a0de552014-05-06 09:12:30 -0400452
453static const struct nfs_rw_ops nfs_rw_read_ops = {
Anna Schumakera4cdda52014-05-06 09:12:31 -0400454 .rw_mode = FMODE_READ,
Anna Schumaker4a0de552014-05-06 09:12:30 -0400455 .rw_alloc_header = nfs_readhdr_alloc,
456 .rw_free_header = nfs_readhdr_free,
Anna Schumaker0eecb212014-05-06 09:12:32 -0400457 .rw_done = nfs_readpage_done,
458 .rw_result = nfs_readpage_result,
Anna Schumaker1ed26f32014-05-06 09:12:37 -0400459 .rw_initiate = nfs_initiate_read,
Anna Schumaker4a0de552014-05-06 09:12:30 -0400460};