1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/ceph/ceph_debug.h>
3
4 #include <linux/module.h>
5 #include <linux/sched.h>
6 #include <linux/slab.h>
7 #include <linux/file.h>
8 #include <linux/namei.h>
9 #include <linux/writeback.h>
10
11 #include <linux/ceph/libceph.h>
12
13 void ceph_put_page_vector(struct page **pages, int num_pages, bool dirty)
14 {
15 int i;
16
17 for (i = 0; i < num_pages; i++) {
18 if (dirty)
19 set_page_dirty_lock(pages[i]);
20 put_page(pages[i]);
21 }
22 kvfree(pages);
23 }
24 EXPORT_SYMBOL(ceph_put_page_vector);
25
26 void ceph_release_page_vector(struct page **pages, int num_pages)
27 {
28 int i;
29
30 for (i = 0; i < num_pages; i++)
31 __free_pages(pages[i], 0);
32 kfree(pages);
33 }
34 EXPORT_SYMBOL(ceph_release_page_vector);
35
36 /*
37 * allocate a vector new pages
38 */
39 struct page **ceph_alloc_page_vector(int num_pages, gfp_t flags)
40 {
41 struct page **pages;
42 int i;
43
44 pages = kmalloc_array(num_pages, sizeof(*pages), flags);
45 if (!pages)
46 return ERR_PTR(-ENOMEM);
47 for (i = 0; i < num_pages; i++) {
48 pages[i] = __page_cache_alloc(flags);
49 if (pages[i] == NULL) {
50 ceph_release_page_vector(pages, i);
51 return ERR_PTR(-ENOMEM);
52 }
53 }
54 return pages;
55 }
56 EXPORT_SYMBOL(ceph_alloc_page_vector);
57
58 /*
59 * copy user data into a page vector
60 */
61 int ceph_copy_user_to_page_vector(struct page **pages,
62 const void __user *data,
63 loff_t off, size_t len)
64 {
65 int i = 0;
66 int po = off & ~PAGE_MASK;
67 int left = len;
68 int l, bad;
69
70 while (left > 0) {
71 l = min_t(int, PAGE_SIZE-po, left);
72 bad = copy_from_user(page_address(pages[i]) + po, data, l);
73 if (bad == l)
74 return -EFAULT;
75 data += l - bad;
76 left -= l - bad;
77 po += l - bad;
78 if (po == PAGE_SIZE) {
79 po = 0;
80 i++;
81 }
82 }
83 return len;
84 }
85 EXPORT_SYMBOL(ceph_copy_user_to_page_vector);
86
87 void ceph_copy_to_page_vector(struct page **pages,
88 const void *data,
89 loff_t off, size_t len)
90 {
91 int i = 0;
92 size_t po = off & ~PAGE_MASK;
93 size_t left = len;
94
95 while (left > 0) {
96 size_t l = min_t(size_t, PAGE_SIZE-po, left);
97
98 memcpy(page_address(pages[i]) + po, data, l);
99 data += l;
100 left -= l;
101 po += l;
102 if (po == PAGE_SIZE) {
103 po = 0;
104 i++;
105 }
106 }
107 }
108 EXPORT_SYMBOL(ceph_copy_to_page_vector);
109
110 void ceph_copy_from_page_vector(struct page **pages,
111 void *data,
112 loff_t off, size_t len)
113 {
114 int i = 0;
115 size_t po = off & ~PAGE_MASK;
116 size_t left = len;
117
118 while (left > 0) {
119 size_t l = min_t(size_t, PAGE_SIZE-po, left);
120
121 memcpy(data, page_address(pages[i]) + po, l);
122 data += l;
123 left -= l;
124 po += l;
125 if (po == PAGE_SIZE) {
126 po = 0;
127 i++;
128 }
129 }
130 }
131 EXPORT_SYMBOL(ceph_copy_from_page_vector);
132
133 /*
134 * Zero an extent within a page vector. Offset is relative to the
135 * start of the first page.
136 */
137 void ceph_zero_page_vector_range(int off, int len, struct page **pages)
138 {
139 int i = off >> PAGE_SHIFT;
140
141 off &= ~PAGE_MASK;
142
143 dout("zero_page_vector_page %u~%u\n", off, len);
144
145 /* leading partial page? */
146 if (off) {
147 int end = min((int)PAGE_SIZE, off + len);
148 dout("zeroing %d %p head from %d\n", i, pages[i],
149 (int)off);
150 zero_user_segment(pages[i], off, end);
151 len -= (end - off);
152 i++;
153 }
154 while (len >= PAGE_SIZE) {
155 dout("zeroing %d %p len=%d\n", i, pages[i], len);
156 zero_user_segment(pages[i], 0, PAGE_SIZE);
157 len -= PAGE_SIZE;
158 i++;
159 }
160 /* trailing partial page? */
161 if (len) {
162 dout("zeroing %d %p tail to %d\n", i, pages[i], (int)len);
163 zero_user_segment(pages[i], 0, len);
164 }
165 }
166 EXPORT_SYMBOL(ceph_zero_page_vector_range);
167
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