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 while (got
< num_pages
) {
27 rc
= get_user_pages_unlocked(current
, current
->mm
,
28 (unsigned long)data
+ ((unsigned long)got
* PAGE_SIZE
),
29 num_pages
- got
, write_page
, 0, pages
+ got
);
40 ceph_put_page_vector(pages
, got
, false);
43 EXPORT_SYMBOL(ceph_get_direct_page_vector
);
45 void ceph_put_page_vector(struct page
**pages
, int num_pages
, bool dirty
)
49 for (i
= 0; i
< num_pages
; i
++) {
51 set_page_dirty_lock(pages
[i
]);
54 if (is_vmalloc_addr(pages
))
59 EXPORT_SYMBOL(ceph_put_page_vector
);
61 void ceph_release_page_vector(struct page
**pages
, int num_pages
)
65 for (i
= 0; i
< num_pages
; i
++)
66 __free_pages(pages
[i
], 0);
69 EXPORT_SYMBOL(ceph_release_page_vector
);
72 * allocate a vector new pages
74 struct page
**ceph_alloc_page_vector(int num_pages
, gfp_t flags
)
79 pages
= kmalloc(sizeof(*pages
) * num_pages
, flags
);
81 return ERR_PTR(-ENOMEM
);
82 for (i
= 0; i
< num_pages
; i
++) {
83 pages
[i
] = __page_cache_alloc(flags
);
84 if (pages
[i
] == NULL
) {
85 ceph_release_page_vector(pages
, i
);
86 return ERR_PTR(-ENOMEM
);
91 EXPORT_SYMBOL(ceph_alloc_page_vector
);
94 * copy user data into a page vector
96 int ceph_copy_user_to_page_vector(struct page
**pages
,
97 const void __user
*data
,
98 loff_t off
, size_t len
)
101 int po
= off
& ~PAGE_CACHE_MASK
;
106 l
= min_t(int, PAGE_CACHE_SIZE
-po
, left
);
107 bad
= copy_from_user(page_address(pages
[i
]) + po
, data
, l
);
113 if (po
== PAGE_CACHE_SIZE
) {
120 EXPORT_SYMBOL(ceph_copy_user_to_page_vector
);
122 void ceph_copy_to_page_vector(struct page
**pages
,
124 loff_t off
, size_t len
)
127 size_t po
= off
& ~PAGE_CACHE_MASK
;
131 size_t l
= min_t(size_t, PAGE_CACHE_SIZE
-po
, left
);
133 memcpy(page_address(pages
[i
]) + po
, data
, l
);
137 if (po
== PAGE_CACHE_SIZE
) {
143 EXPORT_SYMBOL(ceph_copy_to_page_vector
);
145 void ceph_copy_from_page_vector(struct page
**pages
,
147 loff_t off
, size_t len
)
150 size_t po
= off
& ~PAGE_CACHE_MASK
;
154 size_t l
= min_t(size_t, PAGE_CACHE_SIZE
-po
, left
);
156 memcpy(data
, page_address(pages
[i
]) + po
, l
);
160 if (po
== PAGE_CACHE_SIZE
) {
166 EXPORT_SYMBOL(ceph_copy_from_page_vector
);
169 * Zero an extent within a page vector. Offset is relative to the
170 * start of the first page.
172 void ceph_zero_page_vector_range(int off
, int len
, struct page
**pages
)
174 int i
= off
>> PAGE_CACHE_SHIFT
;
176 off
&= ~PAGE_CACHE_MASK
;
178 dout("zero_page_vector_page %u~%u\n", off
, len
);
180 /* leading partial page? */
182 int end
= min((int)PAGE_CACHE_SIZE
, off
+ len
);
183 dout("zeroing %d %p head from %d\n", i
, pages
[i
],
185 zero_user_segment(pages
[i
], off
, end
);
189 while (len
>= PAGE_CACHE_SIZE
) {
190 dout("zeroing %d %p len=%d\n", i
, pages
[i
], len
);
191 zero_user_segment(pages
[i
], 0, PAGE_CACHE_SIZE
);
192 len
-= PAGE_CACHE_SIZE
;
195 /* trailing partial page? */
197 dout("zeroing %d %p tail to %d\n", i
, pages
[i
], (int)len
);
198 zero_user_segment(pages
[i
], 0, len
);
201 EXPORT_SYMBOL(ceph_zero_page_vector_range
);