projects/linux·blob master · refs

101 lines · 2.1 KiB

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
13void ceph_release_page_vector(struct page **pages, int num_pages)
14{
15 int i;
16
17 for (i = 0; i < num_pages; i++)
18 __free_pages(pages[i], 0);
19 kfree(pages);
20}
21EXPORT_SYMBOL(ceph_release_page_vector);
22
23/*
24 * allocate a vector new pages
25 */
26struct page **ceph_alloc_page_vector(int num_pages, gfp_t flags)
27{
28 struct page **pages;
29 int i;
30
31 pages = kmalloc_objs(*pages, num_pages, flags);
32 if (!pages)
33 return ERR_PTR(-ENOMEM);
34 for (i = 0; i < num_pages; i++) {
35 pages[i] = __page_cache_alloc(flags);
36 if (pages[i] == NULL) {
37 ceph_release_page_vector(pages, i);
38 return ERR_PTR(-ENOMEM);
39 }
40 }
41 return pages;
42}
43EXPORT_SYMBOL(ceph_alloc_page_vector);
44
45void ceph_copy_from_page_vector(struct page **pages,
46 void *data,
47 loff_t off, size_t len)
48{
49 int i = 0;
50 size_t po = off & ~PAGE_MASK;
51 size_t left = len;
52
53 while (left > 0) {
54 size_t l = min_t(size_t, PAGE_SIZE-po, left);
55
56 memcpy(data, page_address(pages[i]) + po, l);
57 data += l;
58 left -= l;
59 po += l;
60 if (po == PAGE_SIZE) {
61 po = 0;
62 i++;
63 }
64 }
65}
66EXPORT_SYMBOL(ceph_copy_from_page_vector);
67
68/*
69 * Zero an extent within a page vector. Offset is relative to the
70 * start of the first page.
71 */
72void ceph_zero_page_vector_range(int off, int len, struct page **pages)
73{
74 int i = off >> PAGE_SHIFT;
75
76 off &= ~PAGE_MASK;
77
78 dout("zero_page_vector_page %u~%u\n", off, len);
79
80 /* leading partial page? */
81 if (off) {
82 int end = min((int)PAGE_SIZE, off + len);
83 dout("zeroing %d %p head from %d\n", i, pages[i],
84 (int)off);
85 zero_user_segment(pages[i], off, end);
86 len -= (end - off);
87 i++;
88 }
89 while (len >= PAGE_SIZE) {
90 dout("zeroing %d %p len=%d\n", i, pages[i], len);
91 zero_user_segment(pages[i], 0, PAGE_SIZE);
92 len -= PAGE_SIZE;
93 i++;
94 }
95 /* trailing partial page? */
96 if (len) {
97 dout("zeroing %d %p tail to %d\n", i, pages[i], (int)len);
98 zero_user_segment(pages[i], 0, len);
99 }
100}
101EXPORT_SYMBOL(ceph_zero_page_vector_range);