blob: 555013034f7a899e2d03268a6571e01d096e8cee [file] [log] [blame]
Yehuda Sadeh3d14c5d2010-04-06 15:14:15 -07001#include <linux/ceph/ceph_debug.h>
2
3#include <linux/module.h>
4#include <linux/sched.h>
5#include <linux/slab.h>
6#include <linux/file.h>
7#include <linux/namei.h>
8#include <linux/writeback.h>
9
10#include <linux/ceph/libceph.h>
11
12/*
13 * build a vector of user pages
14 */
Alex Elderb3248142013-02-06 13:11:38 -060015struct page **ceph_get_direct_page_vector(const void __user *data,
Henry C Changb6aa5902010-12-15 20:45:41 -080016 int num_pages, bool write_page)
Yehuda Sadeh3d14c5d2010-04-06 15:14:15 -070017{
18 struct page **pages;
Sage Weil38815b72011-03-02 16:55:21 -080019 int got = 0;
20 int rc = 0;
Yehuda Sadeh3d14c5d2010-04-06 15:14:15 -070021
22 pages = kmalloc(sizeof(*pages) * num_pages, GFP_NOFS);
23 if (!pages)
24 return ERR_PTR(-ENOMEM);
25
26 down_read(&current->mm->mmap_sem);
Sage Weil38815b72011-03-02 16:55:21 -080027 while (got < num_pages) {
28 rc = get_user_pages(current, current->mm,
29 (unsigned long)data + ((unsigned long)got * PAGE_SIZE),
30 num_pages - got, write_page, 0, pages + got, NULL);
31 if (rc < 0)
32 break;
33 BUG_ON(rc == 0);
34 got += rc;
35 }
Yehuda Sadeh3d14c5d2010-04-06 15:14:15 -070036 up_read(&current->mm->mmap_sem);
Sage Weil38815b72011-03-02 16:55:21 -080037 if (rc < 0)
Yehuda Sadeh3d14c5d2010-04-06 15:14:15 -070038 goto fail;
39 return pages;
40
41fail:
Sage Weil38815b72011-03-02 16:55:21 -080042 ceph_put_page_vector(pages, got, false);
Yehuda Sadeh3d14c5d2010-04-06 15:14:15 -070043 return ERR_PTR(rc);
44}
45EXPORT_SYMBOL(ceph_get_direct_page_vector);
46
Henry C Changb6aa5902010-12-15 20:45:41 -080047void ceph_put_page_vector(struct page **pages, int num_pages, bool dirty)
Yehuda Sadeh3d14c5d2010-04-06 15:14:15 -070048{
49 int i;
50
Henry C Changb6aa5902010-12-15 20:45:41 -080051 for (i = 0; i < num_pages; i++) {
52 if (dirty)
53 set_page_dirty_lock(pages[i]);
Yehuda Sadeh3d14c5d2010-04-06 15:14:15 -070054 put_page(pages[i]);
Henry C Changb6aa5902010-12-15 20:45:41 -080055 }
Al Viro2b777c92014-04-03 22:31:22 -040056 if (is_vmalloc_addr(pages))
57 vfree(pages);
58 else
59 kfree(pages);
Yehuda Sadeh3d14c5d2010-04-06 15:14:15 -070060}
61EXPORT_SYMBOL(ceph_put_page_vector);
62
63void ceph_release_page_vector(struct page **pages, int num_pages)
64{
65 int i;
66
67 for (i = 0; i < num_pages; i++)
68 __free_pages(pages[i], 0);
69 kfree(pages);
70}
71EXPORT_SYMBOL(ceph_release_page_vector);
72
73/*
74 * allocate a vector new pages
75 */
76struct page **ceph_alloc_page_vector(int num_pages, gfp_t flags)
77{
78 struct page **pages;
79 int i;
80
81 pages = kmalloc(sizeof(*pages) * num_pages, flags);
82 if (!pages)
83 return ERR_PTR(-ENOMEM);
84 for (i = 0; i < num_pages; i++) {
85 pages[i] = __page_cache_alloc(flags);
86 if (pages[i] == NULL) {
87 ceph_release_page_vector(pages, i);
88 return ERR_PTR(-ENOMEM);
89 }
90 }
91 return pages;
92}
93EXPORT_SYMBOL(ceph_alloc_page_vector);
94
95/*
96 * copy user data into a page vector
97 */
98int ceph_copy_user_to_page_vector(struct page **pages,
Alex Elderb3248142013-02-06 13:11:38 -060099 const void __user *data,
Yehuda Sadeh3d14c5d2010-04-06 15:14:15 -0700100 loff_t off, size_t len)
101{
102 int i = 0;
103 int po = off & ~PAGE_CACHE_MASK;
104 int left = len;
105 int l, bad;
106
107 while (left > 0) {
108 l = min_t(int, PAGE_CACHE_SIZE-po, left);
109 bad = copy_from_user(page_address(pages[i]) + po, data, l);
110 if (bad == l)
111 return -EFAULT;
112 data += l - bad;
113 left -= l - bad;
114 po += l - bad;
115 if (po == PAGE_CACHE_SIZE) {
116 po = 0;
117 i++;
118 }
119 }
120 return len;
121}
122EXPORT_SYMBOL(ceph_copy_user_to_page_vector);
123
Alex Elder903bb322013-02-06 13:11:38 -0600124void ceph_copy_to_page_vector(struct page **pages,
Alex Elderb3248142013-02-06 13:11:38 -0600125 const void *data,
Yehuda Sadeh3d14c5d2010-04-06 15:14:15 -0700126 loff_t off, size_t len)
127{
128 int i = 0;
129 size_t po = off & ~PAGE_CACHE_MASK;
130 size_t left = len;
Yehuda Sadeh3d14c5d2010-04-06 15:14:15 -0700131
132 while (left > 0) {
Alex Elder903bb322013-02-06 13:11:38 -0600133 size_t l = min_t(size_t, PAGE_CACHE_SIZE-po, left);
134
Yehuda Sadeh3d14c5d2010-04-06 15:14:15 -0700135 memcpy(page_address(pages[i]) + po, data, l);
136 data += l;
137 left -= l;
138 po += l;
139 if (po == PAGE_CACHE_SIZE) {
140 po = 0;
141 i++;
142 }
143 }
Yehuda Sadeh3d14c5d2010-04-06 15:14:15 -0700144}
145EXPORT_SYMBOL(ceph_copy_to_page_vector);
146
Alex Elder903bb322013-02-06 13:11:38 -0600147void ceph_copy_from_page_vector(struct page **pages,
Alex Elderb3248142013-02-06 13:11:38 -0600148 void *data,
Yehuda Sadeh3d14c5d2010-04-06 15:14:15 -0700149 loff_t off, size_t len)
150{
151 int i = 0;
152 size_t po = off & ~PAGE_CACHE_MASK;
153 size_t left = len;
Yehuda Sadeh3d14c5d2010-04-06 15:14:15 -0700154
155 while (left > 0) {
Alex Elder903bb322013-02-06 13:11:38 -0600156 size_t l = min_t(size_t, PAGE_CACHE_SIZE-po, left);
157
Yehuda Sadeh3d14c5d2010-04-06 15:14:15 -0700158 memcpy(data, page_address(pages[i]) + po, l);
159 data += l;
160 left -= l;
161 po += l;
162 if (po == PAGE_CACHE_SIZE) {
163 po = 0;
164 i++;
165 }
166 }
Yehuda Sadeh3d14c5d2010-04-06 15:14:15 -0700167}
168EXPORT_SYMBOL(ceph_copy_from_page_vector);
169
170/*
Yehuda Sadeh3d14c5d2010-04-06 15:14:15 -0700171 * Zero an extent within a page vector. Offset is relative to the
172 * start of the first page.
173 */
174void ceph_zero_page_vector_range(int off, int len, struct page **pages)
175{
176 int i = off >> PAGE_CACHE_SHIFT;
177
178 off &= ~PAGE_CACHE_MASK;
179
180 dout("zero_page_vector_page %u~%u\n", off, len);
181
182 /* leading partial page? */
183 if (off) {
184 int end = min((int)PAGE_CACHE_SIZE, off + len);
185 dout("zeroing %d %p head from %d\n", i, pages[i],
186 (int)off);
187 zero_user_segment(pages[i], off, end);
188 len -= (end - off);
189 i++;
190 }
191 while (len >= PAGE_CACHE_SIZE) {
192 dout("zeroing %d %p len=%d\n", i, pages[i], len);
193 zero_user_segment(pages[i], 0, PAGE_CACHE_SIZE);
194 len -= PAGE_CACHE_SIZE;
195 i++;
196 }
197 /* trailing partial page? */
198 if (len) {
199 dout("zeroing %d %p tail to %d\n", i, pages[i], (int)len);
200 zero_user_segment(pages[i], 0, len);
201 }
202}
203EXPORT_SYMBOL(ceph_zero_page_vector_range);
204