blob: 0a5e33f33b5c83c73e69f1bab538bbb254175c16 [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
David Howellsf42b2932009-04-03 16:42:44 +010088int nfs_readpage_async(struct nfs_open_context *ctx, struct inode *inode,
89 struct page *page)
Linus Torvalds1da177e2005-04-16 15:20:36 -070090{
Linus Torvalds1da177e2005-04-16 15:20:36 -070091 struct nfs_page *new;
92 unsigned int len;
Fred Isamanc76069b2011-03-03 15:13:48 +000093 struct nfs_pageio_descriptor pgio;
Weston Andros Adamsona7d42dd2014-09-19 10:55:07 -040094 struct nfs_pgio_mirror *pgm;
Linus Torvalds1da177e2005-04-16 15:20:36 -070095
Trond Myklebust49a70f22006-12-05 00:35:38 -050096 len = nfs_page_length(page);
Linus Torvalds1da177e2005-04-16 15:20:36 -070097 if (len == 0)
98 return nfs_return_empty_page(page);
Weston Andros Adamson2bfc6e52014-05-15 11:56:45 -040099 new = nfs_create_request(ctx, page, NULL, 0, len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100 if (IS_ERR(new)) {
101 unlock_page(page);
102 return PTR_ERR(new);
103 }
104 if (len < PAGE_CACHE_SIZE)
Christoph Lametereebd2aa2008-02-04 22:28:29 -0800105 zero_user_segment(page, len, PAGE_CACHE_SIZE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106
Christoph Hellwigfab5fc22014-04-16 15:07:22 +0200107 nfs_pageio_init_read(&pgio, inode, false,
108 &nfs_async_read_completion_ops);
Trond Myklebustd8007d42011-06-10 13:30:23 -0400109 nfs_pageio_add_request(&pgio, new);
Trond Myklebust1751c362011-06-10 13:30:23 -0400110 nfs_pageio_complete(&pgio);
Weston Andros Adamsona7d42dd2014-09-19 10:55:07 -0400111
112 /* It doesn't make sense to do mirrored reads! */
113 WARN_ON_ONCE(pgio.pg_mirror_count != 1);
114
115 pgm = &pgio.pg_mirrors[0];
116 NFS_I(inode)->read_io += pgm->pg_bytes_written;
117
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118 return 0;
119}
120
121static void nfs_readpage_release(struct nfs_page *req)
122{
David Howells2b0143b2015-03-17 22:25:59 +0000123 struct inode *inode = d_inode(req->wb_context->dentry);
David Howells7f8e05f2009-04-03 16:42:45 +0100124
David Howells88e7fbd2015-03-04 16:38:26 +0000125 dprintk("NFS: read done (%s/%llu %d@%lld)\n", inode->i_sb->s_id,
126 (unsigned long long)NFS_FILEID(inode), req->wb_bytes,
Weston Andros Adamson67d03382014-05-15 11:56:46 -0400127 (long long)req_offset(req));
David Howells7f8e05f2009-04-03 16:42:45 +0100128
Weston Andros Adamson67d03382014-05-15 11:56:46 -0400129 if (nfs_page_group_sync_on_bit(req, PG_UNLOCKPAGE)) {
130 if (PageUptodate(req->wb_page))
David Howells88e7fbd2015-03-04 16:38:26 +0000131 nfs_readpage_to_fscache(inode, req->wb_page, 0);
Weston Andros Adamson67d03382014-05-15 11:56:46 -0400132
133 unlock_page(req->wb_page);
134 }
Nick Wilson10d2c462005-09-22 21:44:28 -0700135 nfs_release_request(req);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136}
137
Weston Andros Adamson67d03382014-05-15 11:56:46 -0400138static void nfs_page_group_set_uptodate(struct nfs_page *req)
139{
140 if (nfs_page_group_sync_on_bit(req, PG_UPTODATE))
141 SetPageUptodate(req->wb_page);
142}
143
Fred Isaman061ae2e2012-04-20 14:47:48 -0400144static void nfs_read_completion(struct nfs_pgio_header *hdr)
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400145{
146 unsigned long bytes = 0;
147
148 if (test_bit(NFS_IOHDR_REDO, &hdr->flags))
149 goto out;
Trond Myklebust4bd8b012012-05-01 12:49:58 -0400150 while (!list_empty(&hdr->pages)) {
151 struct nfs_page *req = nfs_list_entry(hdr->pages.next);
152 struct page *page = req->wb_page;
Weston Andros Adamson68072992014-05-15 11:56:57 -0400153 unsigned long start = req->wb_pgbase;
154 unsigned long end = req->wb_pgbase + req->wb_bytes;
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400155
Trond Myklebust4bd8b012012-05-01 12:49:58 -0400156 if (test_bit(NFS_IOHDR_EOF, &hdr->flags)) {
Weston Andros Adamson68072992014-05-15 11:56:57 -0400157 /* note: regions of the page not covered by a
158 * request are zeroed in nfs_readpage_async /
159 * readpage_async_filler */
160 if (bytes > hdr->good_bytes) {
161 /* nothing in this request was good, so zero
162 * the full extent of the request */
163 zero_user_segment(page, start, end);
164
165 } else if (hdr->good_bytes - bytes < req->wb_bytes) {
166 /* part of this request has good bytes, but
167 * not all. zero the bad bytes */
168 start += hdr->good_bytes - bytes;
169 WARN_ON(start < req->wb_pgbase);
170 zero_user_segment(page, start, end);
171 }
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400172 }
Trond Myklebust4bd8b012012-05-01 12:49:58 -0400173 bytes += req->wb_bytes;
174 if (test_bit(NFS_IOHDR_ERROR, &hdr->flags)) {
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400175 if (bytes <= hdr->good_bytes)
Weston Andros Adamson67d03382014-05-15 11:56:46 -0400176 nfs_page_group_set_uptodate(req);
Trond Myklebust4bd8b012012-05-01 12:49:58 -0400177 } else
Weston Andros Adamson67d03382014-05-15 11:56:46 -0400178 nfs_page_group_set_uptodate(req);
Trond Myklebust4bd8b012012-05-01 12:49:58 -0400179 nfs_list_remove_request(req);
180 nfs_readpage_release(req);
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400181 }
182out:
183 hdr->release(hdr);
184}
185
Weston Andros Adamsond45f60c2014-06-09 11:48:35 -0400186static void nfs_initiate_read(struct nfs_pgio_header *hdr,
187 struct rpc_message *msg,
Tom Haynesabde71f2014-06-09 13:12:20 -0700188 const struct nfs_rpc_ops *rpc_ops,
Anna Schumaker1ed26f32014-05-06 09:12:37 -0400189 struct rpc_task_setup *task_setup_data, int how)
Andy Adamson64419a92011-03-01 01:34:16 +0000190{
Weston Andros Adamsond45f60c2014-06-09 11:48:35 -0400191 struct inode *inode = hdr->inode;
Andy Adamson64419a92011-03-01 01:34:16 +0000192 int swap_flags = IS_SWAPFILE(inode) ? NFS_RPC_SWAPFLAGS : 0;
Andy Adamson64419a92011-03-01 01:34:16 +0000193
Anna Schumaker1ed26f32014-05-06 09:12:37 -0400194 task_setup_data->flags |= swap_flags;
Tom Haynesabde71f2014-06-09 13:12:20 -0700195 rpc_ops->read_setup(hdr, msg);
Andy Adamson64419a92011-03-01 01:34:16 +0000196}
197
Fred Isaman061ae2e2012-04-20 14:47:48 -0400198static void
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199nfs_async_read_error(struct list_head *head)
200{
201 struct nfs_page *req;
202
203 while (!list_empty(head)) {
204 req = nfs_list_entry(head->next);
205 nfs_list_remove_request(req);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206 nfs_readpage_release(req);
207 }
208}
209
Fred Isaman061ae2e2012-04-20 14:47:48 -0400210static const struct nfs_pgio_completion_ops nfs_async_read_completion_ops = {
211 .error_cleanup = nfs_async_read_error,
212 .completion = nfs_read_completion,
213};
214
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215/*
Trond Myklebust0b671302006-11-14 16:12:23 -0500216 * This is the callback from RPC telling us whether a reply was
217 * received or some error occurred (timeout or socket shutdown).
218 */
Weston Andros Adamsond45f60c2014-06-09 11:48:35 -0400219static int nfs_readpage_done(struct rpc_task *task,
220 struct nfs_pgio_header *hdr,
Anna Schumaker0eecb212014-05-06 09:12:32 -0400221 struct inode *inode)
Trond Myklebust0b671302006-11-14 16:12:23 -0500222{
Weston Andros Adamsond45f60c2014-06-09 11:48:35 -0400223 int status = NFS_PROTO(inode)->read_done(task, hdr);
Trond Myklebust0b671302006-11-14 16:12:23 -0500224 if (status != 0)
225 return status;
226
Weston Andros Adamsond45f60c2014-06-09 11:48:35 -0400227 nfs_add_stats(inode, NFSIOS_SERVERREADBYTES, hdr->res.count);
Trond Myklebust0b671302006-11-14 16:12:23 -0500228
229 if (task->tk_status == -ESTALE) {
Fred Isamancd841602012-04-20 14:47:44 -0400230 set_bit(NFS_INO_STALE, &NFS_I(inode)->flags);
231 nfs_mark_for_revalidate(inode);
Trond Myklebust0b671302006-11-14 16:12:23 -0500232 }
Trond Myklebust0b671302006-11-14 16:12:23 -0500233 return 0;
234}
235
Weston Andros Adamsond45f60c2014-06-09 11:48:35 -0400236static void nfs_readpage_retry(struct rpc_task *task,
237 struct nfs_pgio_header *hdr)
Trond Myklebust0b671302006-11-14 16:12:23 -0500238{
Weston Andros Adamsond45f60c2014-06-09 11:48:35 -0400239 struct nfs_pgio_args *argp = &hdr->args;
240 struct nfs_pgio_res *resp = &hdr->res;
Trond Myklebust0b671302006-11-14 16:12:23 -0500241
Trond Myklebust0b671302006-11-14 16:12:23 -0500242 /* This is a short read! */
Weston Andros Adamsond45f60c2014-06-09 11:48:35 -0400243 nfs_inc_stats(hdr->inode, NFSIOS_SHORTREAD);
Trond Myklebust0b671302006-11-14 16:12:23 -0500244 /* Has the server at least made some progress? */
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400245 if (resp->count == 0) {
Weston Andros Adamsond45f60c2014-06-09 11:48:35 -0400246 nfs_set_pgio_error(hdr, -EIO, argp->offset);
Trond Myklebustd61e6122009-12-05 19:32:19 -0500247 return;
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400248 }
Kinglong Meef8417b482015-10-16 17:23:29 +0800249
250 /* For non rpc-based layout drivers, retry-through-MDS */
251 if (!task->tk_ops) {
252 hdr->pnfs_error = -EAGAIN;
253 return;
254 }
255
Weston Andros Adamsond45f60c2014-06-09 11:48:35 -0400256 /* Yes, so retry the read at the end of the hdr */
257 hdr->mds_offset += resp->count;
Trond Myklebust0b671302006-11-14 16:12:23 -0500258 argp->offset += resp->count;
259 argp->pgbase += resp->count;
260 argp->count -= resp->count;
Trond Myklebustd00c5d42011-10-19 12:17:29 -0700261 rpc_restart_call_prepare(task);
Trond Myklebust0b671302006-11-14 16:12:23 -0500262}
263
Weston Andros Adamsond45f60c2014-06-09 11:48:35 -0400264static void nfs_readpage_result(struct rpc_task *task,
265 struct nfs_pgio_header *hdr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700266{
Weston Andros Adamsond45f60c2014-06-09 11:48:35 -0400267 if (hdr->res.eof) {
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400268 loff_t bound;
Trond Myklebust0b671302006-11-14 16:12:23 -0500269
Weston Andros Adamsond45f60c2014-06-09 11:48:35 -0400270 bound = hdr->args.offset + hdr->res.count;
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400271 spin_lock(&hdr->lock);
272 if (bound < hdr->io_start + hdr->good_bytes) {
273 set_bit(NFS_IOHDR_EOF, &hdr->flags);
274 clear_bit(NFS_IOHDR_ERROR, &hdr->flags);
275 hdr->good_bytes = bound - hdr->io_start;
276 }
277 spin_unlock(&hdr->lock);
Kinglong Meef8417b482015-10-16 17:23:29 +0800278 } else if (hdr->res.count < hdr->args.count)
Weston Andros Adamsond45f60c2014-06-09 11:48:35 -0400279 nfs_readpage_retry(task, hdr);
Trond Myklebustfdd1e742008-04-15 16:33:58 -0400280}
281
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700283 * Read a page over NFS.
284 * We read the page synchronously in the following case:
285 * - The error flag is set for this page. This happens only when a
286 * previous async read operation failed.
287 */
288int nfs_readpage(struct file *file, struct page *page)
289{
290 struct nfs_open_context *ctx;
Mel Gormand56b4dd2012-07-31 16:45:06 -0700291 struct inode *inode = page_file_mapping(page)->host;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292 int error;
293
294 dprintk("NFS: nfs_readpage (%p %ld@%lu)\n",
Mel Gormand56b4dd2012-07-31 16:45:06 -0700295 page, PAGE_CACHE_SIZE, page_file_index(page));
Chuck Lever91d5b472006-03-20 13:44:14 -0500296 nfs_inc_stats(inode, NFSIOS_VFSREADPAGE);
Nicolas Iooss3708f842015-04-16 18:48:39 +0800297 nfs_add_stats(inode, NFSIOS_READPAGES, 1);
Chuck Lever91d5b472006-03-20 13:44:14 -0500298
Linus Torvalds1da177e2005-04-16 15:20:36 -0700299 /*
300 * Try to flush any pending writes to the file..
301 *
302 * NOTE! Because we own the page lock, there cannot
303 * be any new pending writes generated at this point
304 * for this page (other pages can be written to).
305 */
306 error = nfs_wb_page(inode, page);
307 if (error)
Trond Myklebustde05a0c2007-05-20 13:05:05 -0400308 goto out_unlock;
309 if (PageUptodate(page))
310 goto out_unlock;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700311
Trond Myklebust5f004cf2006-09-14 14:03:14 -0400312 error = -ESTALE;
313 if (NFS_STALE(inode))
Trond Myklebustde05a0c2007-05-20 13:05:05 -0400314 goto out_unlock;
Trond Myklebust5f004cf2006-09-14 14:03:14 -0400315
Linus Torvalds1da177e2005-04-16 15:20:36 -0700316 if (file == NULL) {
Trond Myklebustcf1308f2006-11-19 16:44:52 -0500317 error = -EBADF;
Trond Myklebustd5308382005-11-04 15:33:38 -0500318 ctx = nfs_find_open_context(inode, NULL, FMODE_READ);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700319 if (ctx == NULL)
Trond Myklebustde05a0c2007-05-20 13:05:05 -0400320 goto out_unlock;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700321 } else
Trond Myklebustcd3758e2007-08-10 17:44:32 -0400322 ctx = get_nfs_open_context(nfs_file_open_context(file));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700323
David Howells9a9fc1c2009-04-03 16:42:44 +0100324 if (!IS_SYNC(inode)) {
325 error = nfs_readpage_from_fscache(ctx, inode, page);
326 if (error == 0)
327 goto out;
328 }
329
Trond Myklebust8e0969f2006-12-13 15:23:44 -0500330 error = nfs_readpage_async(ctx, inode, page);
331
David Howells9a9fc1c2009-04-03 16:42:44 +0100332out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700333 put_nfs_open_context(ctx);
334 return error;
Trond Myklebustde05a0c2007-05-20 13:05:05 -0400335out_unlock:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336 unlock_page(page);
337 return error;
338}
339
340struct nfs_readdesc {
Trond Myklebust8b09bee2007-04-02 18:48:28 -0400341 struct nfs_pageio_descriptor *pgio;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700342 struct nfs_open_context *ctx;
343};
344
345static int
346readpage_async_filler(void *data, struct page *page)
347{
348 struct nfs_readdesc *desc = (struct nfs_readdesc *)data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700349 struct nfs_page *new;
350 unsigned int len;
Trond Myklebustde05a0c2007-05-20 13:05:05 -0400351 int error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700352
Trond Myklebust49a70f22006-12-05 00:35:38 -0500353 len = nfs_page_length(page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700354 if (len == 0)
355 return nfs_return_empty_page(page);
Trond Myklebustde05a0c2007-05-20 13:05:05 -0400356
Weston Andros Adamson2bfc6e52014-05-15 11:56:45 -0400357 new = nfs_create_request(desc->ctx, page, NULL, 0, len);
Trond Myklebustde05a0c2007-05-20 13:05:05 -0400358 if (IS_ERR(new))
359 goto out_error;
360
Linus Torvalds1da177e2005-04-16 15:20:36 -0700361 if (len < PAGE_CACHE_SIZE)
Christoph Lametereebd2aa2008-02-04 22:28:29 -0800362 zero_user_segment(page, len, PAGE_CACHE_SIZE);
Fred Isamanf8512ad2008-03-19 11:24:39 -0400363 if (!nfs_pageio_add_request(desc->pgio, new)) {
364 error = desc->pgio->pg_error;
365 goto out_unlock;
366 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700367 return 0;
Trond Myklebustde05a0c2007-05-20 13:05:05 -0400368out_error:
369 error = PTR_ERR(new);
Trond Myklebustde05a0c2007-05-20 13:05:05 -0400370out_unlock:
371 unlock_page(page);
372 return error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700373}
374
375int nfs_readpages(struct file *filp, struct address_space *mapping,
376 struct list_head *pages, unsigned nr_pages)
377{
Trond Myklebust8b09bee2007-04-02 18:48:28 -0400378 struct nfs_pageio_descriptor pgio;
Weston Andros Adamsona7d42dd2014-09-19 10:55:07 -0400379 struct nfs_pgio_mirror *pgm;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700380 struct nfs_readdesc desc = {
Trond Myklebust8b09bee2007-04-02 18:48:28 -0400381 .pgio = &pgio,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700382 };
383 struct inode *inode = mapping->host;
Trond Myklebust8b09bee2007-04-02 18:48:28 -0400384 unsigned long npages;
Trond Myklebust5f004cf2006-09-14 14:03:14 -0400385 int ret = -ESTALE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700386
Niels de Vos1e8968c2013-12-17 18:20:16 +0100387 dprintk("NFS: nfs_readpages (%s/%Lu %d)\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700388 inode->i_sb->s_id,
Niels de Vos1e8968c2013-12-17 18:20:16 +0100389 (unsigned long long)NFS_FILEID(inode),
Linus Torvalds1da177e2005-04-16 15:20:36 -0700390 nr_pages);
Chuck Lever91d5b472006-03-20 13:44:14 -0500391 nfs_inc_stats(inode, NFSIOS_VFSREADPAGES);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700392
Trond Myklebust5f004cf2006-09-14 14:03:14 -0400393 if (NFS_STALE(inode))
394 goto out;
395
Linus Torvalds1da177e2005-04-16 15:20:36 -0700396 if (filp == NULL) {
Trond Myklebustd5308382005-11-04 15:33:38 -0500397 desc.ctx = nfs_find_open_context(inode, NULL, FMODE_READ);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700398 if (desc.ctx == NULL)
399 return -EBADF;
400 } else
Trond Myklebustcd3758e2007-08-10 17:44:32 -0400401 desc.ctx = get_nfs_open_context(nfs_file_open_context(filp));
David Howells9a9fc1c2009-04-03 16:42:44 +0100402
403 /* attempt to read as many of the pages as possible from the cache
404 * - this returns -ENOBUFS immediately if the cookie is negative
405 */
406 ret = nfs_readpages_from_fscache(desc.ctx, inode, mapping,
407 pages, &nr_pages);
408 if (ret == 0)
409 goto read_complete; /* all pages were read */
410
Christoph Hellwigfab5fc22014-04-16 15:07:22 +0200411 nfs_pageio_init_read(&pgio, inode, false,
412 &nfs_async_read_completion_ops);
Trond Myklebust8b09bee2007-04-02 18:48:28 -0400413
Linus Torvalds1da177e2005-04-16 15:20:36 -0700414 ret = read_cache_pages(mapping, pages, readpage_async_filler, &desc);
Trond Myklebust8b09bee2007-04-02 18:48:28 -0400415 nfs_pageio_complete(&pgio);
Weston Andros Adamsona7d42dd2014-09-19 10:55:07 -0400416
417 /* It doesn't make sense to do mirrored reads! */
418 WARN_ON_ONCE(pgio.pg_mirror_count != 1);
419
420 pgm = &pgio.pg_mirrors[0];
421 NFS_I(inode)->read_io += pgm->pg_bytes_written;
422 npages = (pgm->pg_bytes_written + PAGE_CACHE_SIZE - 1) >>
423 PAGE_CACHE_SHIFT;
Trond Myklebust8b09bee2007-04-02 18:48:28 -0400424 nfs_add_stats(inode, NFSIOS_READPAGES, npages);
David Howells9a9fc1c2009-04-03 16:42:44 +0100425read_complete:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700426 put_nfs_open_context(desc.ctx);
Trond Myklebust5f004cf2006-09-14 14:03:14 -0400427out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700428 return ret;
429}
430
David Howellsf7b422b2006-06-09 09:34:33 -0400431int __init nfs_init_readpagecache(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700432{
433 nfs_rdata_cachep = kmem_cache_create("nfs_read_data",
Weston Andros Adamson1e7f3a42014-06-09 11:48:33 -0400434 sizeof(struct nfs_pgio_header),
Linus Torvalds1da177e2005-04-16 15:20:36 -0700435 0, SLAB_HWCACHE_ALIGN,
Paul Mundt20c2df82007-07-20 10:11:58 +0900436 NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700437 if (nfs_rdata_cachep == NULL)
438 return -ENOMEM;
439
Linus Torvalds1da177e2005-04-16 15:20:36 -0700440 return 0;
441}
442
David Brownell266bee82006-06-27 12:59:15 -0700443void nfs_destroy_readpagecache(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700444{
Alexey Dobriyan1a1d92c2006-09-27 01:49:40 -0700445 kmem_cache_destroy(nfs_rdata_cachep);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700446}
Anna Schumaker4a0de552014-05-06 09:12:30 -0400447
448static const struct nfs_rw_ops nfs_rw_read_ops = {
Anna Schumakera4cdda52014-05-06 09:12:31 -0400449 .rw_mode = FMODE_READ,
Anna Schumaker4a0de552014-05-06 09:12:30 -0400450 .rw_alloc_header = nfs_readhdr_alloc,
451 .rw_free_header = nfs_readhdr_free,
Anna Schumaker0eecb212014-05-06 09:12:32 -0400452 .rw_done = nfs_readpage_done,
453 .rw_result = nfs_readpage_result,
Anna Schumaker1ed26f32014-05-06 09:12:37 -0400454 .rw_initiate = nfs_initiate_read,
Anna Schumaker4a0de552014-05-06 09:12:30 -0400455};