1 #include <linux/ceph/ceph_debug.h>
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>
10 #include <linux/ceph/libceph.h>
13 * build a vector of user pages
15 struct page **ceph_get_direct_page_vector(const char __user *data,
21 pages = kmalloc(sizeof(*pages) * num_pages, GFP_NOFS);
23 return ERR_PTR(-ENOMEM);
25 down_read(¤t->mm->mmap_sem);
26 rc = get_user_pages(current, current->mm, (unsigned long)data,
27 num_pages, 0, 0, pages, NULL);
28 up_read(¤t->mm->mmap_sem);
37 EXPORT_SYMBOL(ceph_get_direct_page_vector);
39 void ceph_put_page_vector(struct page **pages, int num_pages)
43 for (i = 0; i < num_pages; i++)
47 EXPORT_SYMBOL(ceph_put_page_vector);
49 void ceph_release_page_vector(struct page **pages, int num_pages)
53 for (i = 0; i < num_pages; i++)
54 __free_pages(pages[i], 0);
57 EXPORT_SYMBOL(ceph_release_page_vector);
60 * allocate a vector new pages
62 struct page **ceph_alloc_page_vector(int num_pages, gfp_t flags)
67 pages = kmalloc(sizeof(*pages) * num_pages, flags);
69 return ERR_PTR(-ENOMEM);
70 for (i = 0; i < num_pages; i++) {
71 pages[i] = __page_cache_alloc(flags);
72 if (pages[i] == NULL) {
73 ceph_release_page_vector(pages, i);
74 return ERR_PTR(-ENOMEM);
79 EXPORT_SYMBOL(ceph_alloc_page_vector);
82 * copy user data into a page vector
84 int ceph_copy_user_to_page_vector(struct page **pages,
85 const char __user *data,
86 loff_t off, size_t len)
89 int po = off & ~PAGE_CACHE_MASK;
94 l = min_t(int, PAGE_CACHE_SIZE-po, left);
95 bad = copy_from_user(page_address(pages[i]) + po, data, l);
101 if (po == PAGE_CACHE_SIZE) {
108 EXPORT_SYMBOL(ceph_copy_user_to_page_vector);
110 int ceph_copy_to_page_vector(struct page **pages,
112 loff_t off, size_t len)
115 size_t po = off & ~PAGE_CACHE_MASK;
120 l = min_t(size_t, PAGE_CACHE_SIZE-po, left);
121 memcpy(page_address(pages[i]) + po, data, l);
125 if (po == PAGE_CACHE_SIZE) {
132 EXPORT_SYMBOL(ceph_copy_to_page_vector);
134 int ceph_copy_from_page_vector(struct page **pages,
136 loff_t off, size_t len)
139 size_t po = off & ~PAGE_CACHE_MASK;
144 l = min_t(size_t, PAGE_CACHE_SIZE-po, left);
145 memcpy(data, page_address(pages[i]) + po, l);
149 if (po == PAGE_CACHE_SIZE) {
156 EXPORT_SYMBOL(ceph_copy_from_page_vector);
159 * copy user data from a page vector into a user pointer
161 int ceph_copy_page_vector_to_user(struct page **pages,
163 loff_t off, size_t len)
166 int po = off & ~PAGE_CACHE_MASK;
171 l = min_t(int, left, PAGE_CACHE_SIZE-po);
172 bad = copy_to_user(data, page_address(pages[i]) + po, l);
179 if (po == PAGE_CACHE_SIZE)
186 EXPORT_SYMBOL(ceph_copy_page_vector_to_user);
189 * Zero an extent within a page vector. Offset is relative to the
190 * start of the first page.
192 void ceph_zero_page_vector_range(int off, int len, struct page **pages)
194 int i = off >> PAGE_CACHE_SHIFT;
196 off &= ~PAGE_CACHE_MASK;
198 dout("zero_page_vector_page %u~%u\n", off, len);
200 /* leading partial page? */
202 int end = min((int)PAGE_CACHE_SIZE, off + len);
203 dout("zeroing %d %p head from %d\n", i, pages[i],
205 zero_user_segment(pages[i], off, end);
209 while (len >= PAGE_CACHE_SIZE) {
210 dout("zeroing %d %p len=%d\n", i, pages[i], len);
211 zero_user_segment(pages[i], 0, PAGE_CACHE_SIZE);
212 len -= PAGE_CACHE_SIZE;
215 /* trailing partial page? */
217 dout("zeroing %d %p tail to %d\n", i, pages[i], (int)len);
218 zero_user_segment(pages[i], 0, len);
221 EXPORT_SYMBOL(ceph_zero_page_vector_range);