blob: 568ecf0a880f1145aedb69a1d93241b5eba300e0 [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
Anna Schumaker41d8d5b2014-05-06 09:12:40 -040075 pgio->pg_ops = &nfs_pgio_rw_ops;
Weston Andros Adamsona7d42dd2014-09-19 10:55:07 -040076
77 /* read path should never have more than one mirror */
78 WARN_ON_ONCE(pgio->pg_mirror_count != 1);
79
80 mirror = &pgio->pg_mirrors[0];
81 mirror->pg_bsize = NFS_SERVER(pgio->pg_inode)->rsize;
Trond Myklebust493292d2011-07-13 15:58:28 -040082}
Trond Myklebust1f945352011-07-13 15:59:57 -040083EXPORT_SYMBOL_GPL(nfs_pageio_reset_read_mds);
Trond Myklebust493292d2011-07-13 15:58:28 -040084
David Howellsf42b2932009-04-03 16:42:44 +010085int nfs_readpage_async(struct nfs_open_context *ctx, struct inode *inode,
86 struct page *page)
Linus Torvalds1da177e2005-04-16 15:20:36 -070087{
Linus Torvalds1da177e2005-04-16 15:20:36 -070088 struct nfs_page *new;
89 unsigned int len;
Fred Isamanc76069b2011-03-03 15:13:48 +000090 struct nfs_pageio_descriptor pgio;
Weston Andros Adamsona7d42dd2014-09-19 10:55:07 -040091 struct nfs_pgio_mirror *pgm;
Linus Torvalds1da177e2005-04-16 15:20:36 -070092
Trond Myklebust49a70f22006-12-05 00:35:38 -050093 len = nfs_page_length(page);
Linus Torvalds1da177e2005-04-16 15:20:36 -070094 if (len == 0)
95 return nfs_return_empty_page(page);
Weston Andros Adamson2bfc6e52014-05-15 11:56:45 -040096 new = nfs_create_request(ctx, page, NULL, 0, len);
Linus Torvalds1da177e2005-04-16 15:20:36 -070097 if (IS_ERR(new)) {
98 unlock_page(page);
99 return PTR_ERR(new);
100 }
101 if (len < PAGE_CACHE_SIZE)
Christoph Lametereebd2aa2008-02-04 22:28:29 -0800102 zero_user_segment(page, len, PAGE_CACHE_SIZE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103
Christoph Hellwigfab5fc22014-04-16 15:07:22 +0200104 nfs_pageio_init_read(&pgio, inode, false,
105 &nfs_async_read_completion_ops);
Trond Myklebustd8007d42011-06-10 13:30:23 -0400106 nfs_pageio_add_request(&pgio, new);
Trond Myklebust1751c362011-06-10 13:30:23 -0400107 nfs_pageio_complete(&pgio);
Weston Andros Adamsona7d42dd2014-09-19 10:55:07 -0400108
109 /* It doesn't make sense to do mirrored reads! */
110 WARN_ON_ONCE(pgio.pg_mirror_count != 1);
111
112 pgm = &pgio.pg_mirrors[0];
113 NFS_I(inode)->read_io += pgm->pg_bytes_written;
114
Linus Torvalds1da177e2005-04-16 15:20:36 -0700115 return 0;
116}
117
118static void nfs_readpage_release(struct nfs_page *req)
119{
Al Viro3d4ff432011-06-22 18:40:12 -0400120 struct inode *d_inode = req->wb_context->dentry->d_inode;
David Howells7f8e05f2009-04-03 16:42:45 +0100121
Weston Andros Adamson67d03382014-05-15 11:56:46 -0400122 dprintk("NFS: read done (%s/%llu %d@%lld)\n", d_inode->i_sb->s_id,
123 (unsigned long long)NFS_FILEID(d_inode), req->wb_bytes,
124 (long long)req_offset(req));
David Howells7f8e05f2009-04-03 16:42:45 +0100125
Weston Andros Adamson67d03382014-05-15 11:56:46 -0400126 if (nfs_page_group_sync_on_bit(req, PG_UNLOCKPAGE)) {
127 if (PageUptodate(req->wb_page))
128 nfs_readpage_to_fscache(d_inode, req->wb_page, 0);
129
130 unlock_page(req->wb_page);
131 }
Nick Wilson10d2c462005-09-22 21:44:28 -0700132 nfs_release_request(req);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133}
134
Weston Andros Adamson67d03382014-05-15 11:56:46 -0400135static void nfs_page_group_set_uptodate(struct nfs_page *req)
136{
137 if (nfs_page_group_sync_on_bit(req, PG_UPTODATE))
138 SetPageUptodate(req->wb_page);
139}
140
Fred Isaman061ae2e2012-04-20 14:47:48 -0400141static void nfs_read_completion(struct nfs_pgio_header *hdr)
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400142{
143 unsigned long bytes = 0;
144
145 if (test_bit(NFS_IOHDR_REDO, &hdr->flags))
146 goto out;
Trond Myklebust4bd8b012012-05-01 12:49:58 -0400147 while (!list_empty(&hdr->pages)) {
148 struct nfs_page *req = nfs_list_entry(hdr->pages.next);
149 struct page *page = req->wb_page;
Weston Andros Adamson68072992014-05-15 11:56:57 -0400150 unsigned long start = req->wb_pgbase;
151 unsigned long end = req->wb_pgbase + req->wb_bytes;
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400152
Trond Myklebust4bd8b012012-05-01 12:49:58 -0400153 if (test_bit(NFS_IOHDR_EOF, &hdr->flags)) {
Weston Andros Adamson68072992014-05-15 11:56:57 -0400154 /* note: regions of the page not covered by a
155 * request are zeroed in nfs_readpage_async /
156 * readpage_async_filler */
157 if (bytes > hdr->good_bytes) {
158 /* nothing in this request was good, so zero
159 * the full extent of the request */
160 zero_user_segment(page, start, end);
161
162 } else if (hdr->good_bytes - bytes < req->wb_bytes) {
163 /* part of this request has good bytes, but
164 * not all. zero the bad bytes */
165 start += hdr->good_bytes - bytes;
166 WARN_ON(start < req->wb_pgbase);
167 zero_user_segment(page, start, end);
168 }
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400169 }
Trond Myklebust4bd8b012012-05-01 12:49:58 -0400170 bytes += req->wb_bytes;
171 if (test_bit(NFS_IOHDR_ERROR, &hdr->flags)) {
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400172 if (bytes <= hdr->good_bytes)
Weston Andros Adamson67d03382014-05-15 11:56:46 -0400173 nfs_page_group_set_uptodate(req);
Trond Myklebust4bd8b012012-05-01 12:49:58 -0400174 } else
Weston Andros Adamson67d03382014-05-15 11:56:46 -0400175 nfs_page_group_set_uptodate(req);
Trond Myklebust4bd8b012012-05-01 12:49:58 -0400176 nfs_list_remove_request(req);
177 nfs_readpage_release(req);
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400178 }
179out:
180 hdr->release(hdr);
181}
182
Weston Andros Adamsond45f60c2014-06-09 11:48:35 -0400183static void nfs_initiate_read(struct nfs_pgio_header *hdr,
184 struct rpc_message *msg,
Tom Haynesabde71f2014-06-09 13:12:20 -0700185 const struct nfs_rpc_ops *rpc_ops,
Anna Schumaker1ed26f32014-05-06 09:12:37 -0400186 struct rpc_task_setup *task_setup_data, int how)
Andy Adamson64419a92011-03-01 01:34:16 +0000187{
Weston Andros Adamsond45f60c2014-06-09 11:48:35 -0400188 struct inode *inode = hdr->inode;
Andy Adamson64419a92011-03-01 01:34:16 +0000189 int swap_flags = IS_SWAPFILE(inode) ? NFS_RPC_SWAPFLAGS : 0;
Andy Adamson64419a92011-03-01 01:34:16 +0000190
Anna Schumaker1ed26f32014-05-06 09:12:37 -0400191 task_setup_data->flags |= swap_flags;
Tom Haynesabde71f2014-06-09 13:12:20 -0700192 rpc_ops->read_setup(hdr, msg);
Andy Adamson64419a92011-03-01 01:34:16 +0000193}
194
Fred Isaman061ae2e2012-04-20 14:47:48 -0400195static void
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196nfs_async_read_error(struct list_head *head)
197{
198 struct nfs_page *req;
199
200 while (!list_empty(head)) {
201 req = nfs_list_entry(head->next);
202 nfs_list_remove_request(req);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203 nfs_readpage_release(req);
204 }
205}
206
Fred Isaman061ae2e2012-04-20 14:47:48 -0400207static const struct nfs_pgio_completion_ops nfs_async_read_completion_ops = {
208 .error_cleanup = nfs_async_read_error,
209 .completion = nfs_read_completion,
210};
211
Linus Torvalds1da177e2005-04-16 15:20:36 -0700212/*
Trond Myklebust0b671302006-11-14 16:12:23 -0500213 * This is the callback from RPC telling us whether a reply was
214 * received or some error occurred (timeout or socket shutdown).
215 */
Weston Andros Adamsond45f60c2014-06-09 11:48:35 -0400216static int nfs_readpage_done(struct rpc_task *task,
217 struct nfs_pgio_header *hdr,
Anna Schumaker0eecb212014-05-06 09:12:32 -0400218 struct inode *inode)
Trond Myklebust0b671302006-11-14 16:12:23 -0500219{
Weston Andros Adamsond45f60c2014-06-09 11:48:35 -0400220 int status = NFS_PROTO(inode)->read_done(task, hdr);
Trond Myklebust0b671302006-11-14 16:12:23 -0500221 if (status != 0)
222 return status;
223
Weston Andros Adamsond45f60c2014-06-09 11:48:35 -0400224 nfs_add_stats(inode, NFSIOS_SERVERREADBYTES, hdr->res.count);
Trond Myklebust0b671302006-11-14 16:12:23 -0500225
226 if (task->tk_status == -ESTALE) {
Fred Isamancd841602012-04-20 14:47:44 -0400227 set_bit(NFS_INO_STALE, &NFS_I(inode)->flags);
228 nfs_mark_for_revalidate(inode);
Trond Myklebust0b671302006-11-14 16:12:23 -0500229 }
Trond Myklebust0b671302006-11-14 16:12:23 -0500230 return 0;
231}
232
Weston Andros Adamsond45f60c2014-06-09 11:48:35 -0400233static void nfs_readpage_retry(struct rpc_task *task,
234 struct nfs_pgio_header *hdr)
Trond Myklebust0b671302006-11-14 16:12:23 -0500235{
Weston Andros Adamsond45f60c2014-06-09 11:48:35 -0400236 struct nfs_pgio_args *argp = &hdr->args;
237 struct nfs_pgio_res *resp = &hdr->res;
Trond Myklebust0b671302006-11-14 16:12:23 -0500238
Trond Myklebust0b671302006-11-14 16:12:23 -0500239 /* This is a short read! */
Weston Andros Adamsond45f60c2014-06-09 11:48:35 -0400240 nfs_inc_stats(hdr->inode, NFSIOS_SHORTREAD);
Trond Myklebust0b671302006-11-14 16:12:23 -0500241 /* Has the server at least made some progress? */
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400242 if (resp->count == 0) {
Weston Andros Adamsond45f60c2014-06-09 11:48:35 -0400243 nfs_set_pgio_error(hdr, -EIO, argp->offset);
Trond Myklebustd61e6122009-12-05 19:32:19 -0500244 return;
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400245 }
Weston Andros Adamsond45f60c2014-06-09 11:48:35 -0400246 /* Yes, so retry the read at the end of the hdr */
247 hdr->mds_offset += resp->count;
Trond Myklebust0b671302006-11-14 16:12:23 -0500248 argp->offset += resp->count;
249 argp->pgbase += resp->count;
250 argp->count -= resp->count;
Trond Myklebustd00c5d42011-10-19 12:17:29 -0700251 rpc_restart_call_prepare(task);
Trond Myklebust0b671302006-11-14 16:12:23 -0500252}
253
Weston Andros Adamsond45f60c2014-06-09 11:48:35 -0400254static void nfs_readpage_result(struct rpc_task *task,
255 struct nfs_pgio_header *hdr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700256{
Weston Andros Adamsond45f60c2014-06-09 11:48:35 -0400257 if (hdr->res.eof) {
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400258 loff_t bound;
Trond Myklebust0b671302006-11-14 16:12:23 -0500259
Weston Andros Adamsond45f60c2014-06-09 11:48:35 -0400260 bound = hdr->args.offset + hdr->res.count;
Fred Isaman4db6e0b2012-04-20 14:47:46 -0400261 spin_lock(&hdr->lock);
262 if (bound < hdr->io_start + hdr->good_bytes) {
263 set_bit(NFS_IOHDR_EOF, &hdr->flags);
264 clear_bit(NFS_IOHDR_ERROR, &hdr->flags);
265 hdr->good_bytes = bound - hdr->io_start;
266 }
267 spin_unlock(&hdr->lock);
Weston Andros Adamsond45f60c2014-06-09 11:48:35 -0400268 } else if (hdr->res.count != hdr->args.count)
269 nfs_readpage_retry(task, hdr);
Trond Myklebustfdd1e742008-04-15 16:33:58 -0400270}
271
Linus Torvalds1da177e2005-04-16 15:20:36 -0700272/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700273 * Read a page over NFS.
274 * We read the page synchronously in the following case:
275 * - The error flag is set for this page. This happens only when a
276 * previous async read operation failed.
277 */
278int nfs_readpage(struct file *file, struct page *page)
279{
280 struct nfs_open_context *ctx;
Mel Gormand56b4dd2012-07-31 16:45:06 -0700281 struct inode *inode = page_file_mapping(page)->host;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282 int error;
283
284 dprintk("NFS: nfs_readpage (%p %ld@%lu)\n",
Mel Gormand56b4dd2012-07-31 16:45:06 -0700285 page, PAGE_CACHE_SIZE, page_file_index(page));
Chuck Lever91d5b472006-03-20 13:44:14 -0500286 nfs_inc_stats(inode, NFSIOS_VFSREADPAGE);
Li RongQing5a254d02014-11-23 12:47:17 +0800287 nfs_inc_stats(inode, NFSIOS_READPAGES);
Chuck Lever91d5b472006-03-20 13:44:14 -0500288
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289 /*
290 * Try to flush any pending writes to the file..
291 *
292 * NOTE! Because we own the page lock, there cannot
293 * be any new pending writes generated at this point
294 * for this page (other pages can be written to).
295 */
296 error = nfs_wb_page(inode, page);
297 if (error)
Trond Myklebustde05a0c2007-05-20 13:05:05 -0400298 goto out_unlock;
299 if (PageUptodate(page))
300 goto out_unlock;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301
Trond Myklebust5f004cf2006-09-14 14:03:14 -0400302 error = -ESTALE;
303 if (NFS_STALE(inode))
Trond Myklebustde05a0c2007-05-20 13:05:05 -0400304 goto out_unlock;
Trond Myklebust5f004cf2006-09-14 14:03:14 -0400305
Linus Torvalds1da177e2005-04-16 15:20:36 -0700306 if (file == NULL) {
Trond Myklebustcf1308f2006-11-19 16:44:52 -0500307 error = -EBADF;
Trond Myklebustd5308382005-11-04 15:33:38 -0500308 ctx = nfs_find_open_context(inode, NULL, FMODE_READ);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700309 if (ctx == NULL)
Trond Myklebustde05a0c2007-05-20 13:05:05 -0400310 goto out_unlock;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700311 } else
Trond Myklebustcd3758e2007-08-10 17:44:32 -0400312 ctx = get_nfs_open_context(nfs_file_open_context(file));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700313
David Howells9a9fc1c2009-04-03 16:42:44 +0100314 if (!IS_SYNC(inode)) {
315 error = nfs_readpage_from_fscache(ctx, inode, page);
316 if (error == 0)
317 goto out;
318 }
319
Trond Myklebust8e0969f2006-12-13 15:23:44 -0500320 error = nfs_readpage_async(ctx, inode, page);
321
David Howells9a9fc1c2009-04-03 16:42:44 +0100322out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700323 put_nfs_open_context(ctx);
324 return error;
Trond Myklebustde05a0c2007-05-20 13:05:05 -0400325out_unlock:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700326 unlock_page(page);
327 return error;
328}
329
330struct nfs_readdesc {
Trond Myklebust8b09bee2007-04-02 18:48:28 -0400331 struct nfs_pageio_descriptor *pgio;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700332 struct nfs_open_context *ctx;
333};
334
335static int
336readpage_async_filler(void *data, struct page *page)
337{
338 struct nfs_readdesc *desc = (struct nfs_readdesc *)data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700339 struct nfs_page *new;
340 unsigned int len;
Trond Myklebustde05a0c2007-05-20 13:05:05 -0400341 int error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700342
Trond Myklebust49a70f22006-12-05 00:35:38 -0500343 len = nfs_page_length(page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700344 if (len == 0)
345 return nfs_return_empty_page(page);
Trond Myklebustde05a0c2007-05-20 13:05:05 -0400346
Weston Andros Adamson2bfc6e52014-05-15 11:56:45 -0400347 new = nfs_create_request(desc->ctx, page, NULL, 0, len);
Trond Myklebustde05a0c2007-05-20 13:05:05 -0400348 if (IS_ERR(new))
349 goto out_error;
350
Linus Torvalds1da177e2005-04-16 15:20:36 -0700351 if (len < PAGE_CACHE_SIZE)
Christoph Lametereebd2aa2008-02-04 22:28:29 -0800352 zero_user_segment(page, len, PAGE_CACHE_SIZE);
Fred Isamanf8512ad2008-03-19 11:24:39 -0400353 if (!nfs_pageio_add_request(desc->pgio, new)) {
354 error = desc->pgio->pg_error;
355 goto out_unlock;
356 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700357 return 0;
Trond Myklebustde05a0c2007-05-20 13:05:05 -0400358out_error:
359 error = PTR_ERR(new);
Trond Myklebustde05a0c2007-05-20 13:05:05 -0400360out_unlock:
361 unlock_page(page);
362 return error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700363}
364
365int nfs_readpages(struct file *filp, struct address_space *mapping,
366 struct list_head *pages, unsigned nr_pages)
367{
Trond Myklebust8b09bee2007-04-02 18:48:28 -0400368 struct nfs_pageio_descriptor pgio;
Weston Andros Adamsona7d42dd2014-09-19 10:55:07 -0400369 struct nfs_pgio_mirror *pgm;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700370 struct nfs_readdesc desc = {
Trond Myklebust8b09bee2007-04-02 18:48:28 -0400371 .pgio = &pgio,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700372 };
373 struct inode *inode = mapping->host;
Trond Myklebust8b09bee2007-04-02 18:48:28 -0400374 unsigned long npages;
Trond Myklebust5f004cf2006-09-14 14:03:14 -0400375 int ret = -ESTALE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700376
Niels de Vos1e8968c2013-12-17 18:20:16 +0100377 dprintk("NFS: nfs_readpages (%s/%Lu %d)\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700378 inode->i_sb->s_id,
Niels de Vos1e8968c2013-12-17 18:20:16 +0100379 (unsigned long long)NFS_FILEID(inode),
Linus Torvalds1da177e2005-04-16 15:20:36 -0700380 nr_pages);
Chuck Lever91d5b472006-03-20 13:44:14 -0500381 nfs_inc_stats(inode, NFSIOS_VFSREADPAGES);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700382
Trond Myklebust5f004cf2006-09-14 14:03:14 -0400383 if (NFS_STALE(inode))
384 goto out;
385
Linus Torvalds1da177e2005-04-16 15:20:36 -0700386 if (filp == NULL) {
Trond Myklebustd5308382005-11-04 15:33:38 -0500387 desc.ctx = nfs_find_open_context(inode, NULL, FMODE_READ);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700388 if (desc.ctx == NULL)
389 return -EBADF;
390 } else
Trond Myklebustcd3758e2007-08-10 17:44:32 -0400391 desc.ctx = get_nfs_open_context(nfs_file_open_context(filp));
David Howells9a9fc1c2009-04-03 16:42:44 +0100392
393 /* attempt to read as many of the pages as possible from the cache
394 * - this returns -ENOBUFS immediately if the cookie is negative
395 */
396 ret = nfs_readpages_from_fscache(desc.ctx, inode, mapping,
397 pages, &nr_pages);
398 if (ret == 0)
399 goto read_complete; /* all pages were read */
400
Christoph Hellwigfab5fc22014-04-16 15:07:22 +0200401 nfs_pageio_init_read(&pgio, inode, false,
402 &nfs_async_read_completion_ops);
Trond Myklebust8b09bee2007-04-02 18:48:28 -0400403
Linus Torvalds1da177e2005-04-16 15:20:36 -0700404 ret = read_cache_pages(mapping, pages, readpage_async_filler, &desc);
Trond Myklebust8b09bee2007-04-02 18:48:28 -0400405 nfs_pageio_complete(&pgio);
Weston Andros Adamsona7d42dd2014-09-19 10:55:07 -0400406
407 /* It doesn't make sense to do mirrored reads! */
408 WARN_ON_ONCE(pgio.pg_mirror_count != 1);
409
410 pgm = &pgio.pg_mirrors[0];
411 NFS_I(inode)->read_io += pgm->pg_bytes_written;
412 npages = (pgm->pg_bytes_written + PAGE_CACHE_SIZE - 1) >>
413 PAGE_CACHE_SHIFT;
Trond Myklebust8b09bee2007-04-02 18:48:28 -0400414 nfs_add_stats(inode, NFSIOS_READPAGES, npages);
David Howells9a9fc1c2009-04-03 16:42:44 +0100415read_complete:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700416 put_nfs_open_context(desc.ctx);
Trond Myklebust5f004cf2006-09-14 14:03:14 -0400417out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700418 return ret;
419}
420
David Howellsf7b422b2006-06-09 09:34:33 -0400421int __init nfs_init_readpagecache(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700422{
423 nfs_rdata_cachep = kmem_cache_create("nfs_read_data",
Weston Andros Adamson1e7f3a42014-06-09 11:48:33 -0400424 sizeof(struct nfs_pgio_header),
Linus Torvalds1da177e2005-04-16 15:20:36 -0700425 0, SLAB_HWCACHE_ALIGN,
Paul Mundt20c2df82007-07-20 10:11:58 +0900426 NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700427 if (nfs_rdata_cachep == NULL)
428 return -ENOMEM;
429
Linus Torvalds1da177e2005-04-16 15:20:36 -0700430 return 0;
431}
432
David Brownell266bee82006-06-27 12:59:15 -0700433void nfs_destroy_readpagecache(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700434{
Alexey Dobriyan1a1d92c2006-09-27 01:49:40 -0700435 kmem_cache_destroy(nfs_rdata_cachep);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700436}
Anna Schumaker4a0de552014-05-06 09:12:30 -0400437
438static const struct nfs_rw_ops nfs_rw_read_ops = {
Anna Schumakera4cdda52014-05-06 09:12:31 -0400439 .rw_mode = FMODE_READ,
Anna Schumaker4a0de552014-05-06 09:12:30 -0400440 .rw_alloc_header = nfs_readhdr_alloc,
441 .rw_free_header = nfs_readhdr_free,
Anna Schumaker0eecb212014-05-06 09:12:32 -0400442 .rw_done = nfs_readpage_done,
443 .rw_result = nfs_readpage_result,
Anna Schumaker1ed26f32014-05-06 09:12:37 -0400444 .rw_initiate = nfs_initiate_read,
Anna Schumaker4a0de552014-05-06 09:12:30 -0400445};