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 void __user *data,
16 int num_pages, bool write_page)
22 pages = kmalloc(sizeof(*pages) * num_pages, GFP_NOFS);
24 return ERR_PTR(-ENOMEM);
26 down_read(¤t->mm->mmap_sem);
27 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);
36 up_read(¤t->mm->mmap_sem);
42 ceph_put_page_vector(pages, got, false);
45 EXPORT_SYMBOL(ceph_get_direct_page_vector);
47 void ceph_put_page_vector(struct page **pages, int num_pages, bool dirty)
51 for (i = 0; i < num_pages; i++) {
53 set_page_dirty_lock(pages[i]);
56 if (is_vmalloc_addr(pages))
61 EXPORT_SYMBOL(ceph_put_page_vector);
63 void ceph_release_page_vector(struct page **pages, int num_pages)
67 for (i = 0; i < num_pages; i++)
68 __free_pages(pages[i], 0);
71 EXPORT_SYMBOL(ceph_release_page_vector);
74 * allocate a vector new pages
76 struct page **ceph_alloc_page_vector(int num_pages, gfp_t flags)
81 pages = kmalloc(sizeof(*pages) * num_pages, flags);
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);
93 EXPORT_SYMBOL(ceph_alloc_page_vector);
96 * copy user data into a page vector
98 int ceph_copy_user_to_page_vector(struct page **pages,
99 const void __user *data,
100 loff_t off, size_t len)
103 int po = off & ~PAGE_CACHE_MASK;
108 l = min_t(int, PAGE_CACHE_SIZE-po, left);
109 bad = copy_from_user(page_address(pages[i]) + po, data, l);
115 if (po == PAGE_CACHE_SIZE) {
122 EXPORT_SYMBOL(ceph_copy_user_to_page_vector);
124 void ceph_copy_to_page_vector(struct page **pages,
126 loff_t off, size_t len)
129 size_t po = off & ~PAGE_CACHE_MASK;
133 size_t l = min_t(size_t, PAGE_CACHE_SIZE-po, left);
135 memcpy(page_address(pages[i]) + po, data, l);
139 if (po == PAGE_CACHE_SIZE) {
145 EXPORT_SYMBOL(ceph_copy_to_page_vector);
147 void ceph_copy_from_page_vector(struct page **pages,
149 loff_t off, size_t len)
152 size_t po = off & ~PAGE_CACHE_MASK;
156 size_t l = min_t(size_t, PAGE_CACHE_SIZE-po, left);
158 memcpy(data, page_address(pages[i]) + po, l);
162 if (po == PAGE_CACHE_SIZE) {
168 EXPORT_SYMBOL(ceph_copy_from_page_vector);
171 * Zero an extent within a page vector. Offset is relative to the
172 * start of the first page.
174 void ceph_zero_page_vector_range(int off, int len, struct page **pages)
176 int i = off >> PAGE_CACHE_SHIFT;
178 off &= ~PAGE_CACHE_MASK;
180 dout("zero_page_vector_page %u~%u\n", off, len);
182 /* leading partial page? */
184 int end = min((int)PAGE_CACHE_SIZE, off + len);
185 dout("zeroing %d %p head from %d\n", i, pages[i],
187 zero_user_segment(pages[i], off, end);
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;
197 /* trailing partial page? */
199 dout("zeroing %d %p tail to %d\n", i, pages[i], (int)len);
200 zero_user_segment(pages[i], 0, len);
203 EXPORT_SYMBOL(ceph_zero_page_vector_range);