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TOMOYO Linux Cross Reference
Linux/net/ceph/pagevec.c

Version: ~ [ linux-5.7-rc7 ] ~ [ linux-5.6.14 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.42 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.124 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.181 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.224 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.224 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.84 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
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  1 #include <linux/ceph/ceph_debug.h>
  2 
  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>
  9 
 10 #include <linux/ceph/libceph.h>
 11 
 12 /*
 13  * build a vector of user pages
 14  */
 15 struct page **ceph_get_direct_page_vector(const void __user *data,
 16                                           int num_pages, bool write_page)
 17 {
 18         struct page **pages;
 19         int got = 0;
 20         int rc = 0;
 21 
 22         pages = kmalloc(sizeof(*pages) * num_pages, GFP_NOFS);
 23         if (!pages)
 24                 return ERR_PTR(-ENOMEM);
 25 
 26         down_read(&current->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);
 31                 if (rc < 0)
 32                         break;
 33                 BUG_ON(rc == 0);
 34                 got += rc;
 35         }
 36         up_read(&current->mm->mmap_sem);
 37         if (rc < 0)
 38                 goto fail;
 39         return pages;
 40 
 41 fail:
 42         ceph_put_page_vector(pages, got, false);
 43         return ERR_PTR(rc);
 44 }
 45 EXPORT_SYMBOL(ceph_get_direct_page_vector);
 46 
 47 void ceph_put_page_vector(struct page **pages, int num_pages, bool dirty)
 48 {
 49         int i;
 50 
 51         for (i = 0; i < num_pages; i++) {
 52                 if (dirty)
 53                         set_page_dirty_lock(pages[i]);
 54                 put_page(pages[i]);
 55         }
 56         kfree(pages);
 57 }
 58 EXPORT_SYMBOL(ceph_put_page_vector);
 59 
 60 void ceph_release_page_vector(struct page **pages, int num_pages)
 61 {
 62         int i;
 63 
 64         for (i = 0; i < num_pages; i++)
 65                 __free_pages(pages[i], 0);
 66         kfree(pages);
 67 }
 68 EXPORT_SYMBOL(ceph_release_page_vector);
 69 
 70 /*
 71  * allocate a vector new pages
 72  */
 73 struct page **ceph_alloc_page_vector(int num_pages, gfp_t flags)
 74 {
 75         struct page **pages;
 76         int i;
 77 
 78         pages = kmalloc(sizeof(*pages) * num_pages, flags);
 79         if (!pages)
 80                 return ERR_PTR(-ENOMEM);
 81         for (i = 0; i < num_pages; i++) {
 82                 pages[i] = __page_cache_alloc(flags);
 83                 if (pages[i] == NULL) {
 84                         ceph_release_page_vector(pages, i);
 85                         return ERR_PTR(-ENOMEM);
 86                 }
 87         }
 88         return pages;
 89 }
 90 EXPORT_SYMBOL(ceph_alloc_page_vector);
 91 
 92 /*
 93  * copy user data into a page vector
 94  */
 95 int ceph_copy_user_to_page_vector(struct page **pages,
 96                                          const void __user *data,
 97                                          loff_t off, size_t len)
 98 {
 99         int i = 0;
100         int po = off & ~PAGE_CACHE_MASK;
101         int left = len;
102         int l, bad;
103 
104         while (left > 0) {
105                 l = min_t(int, PAGE_CACHE_SIZE-po, left);
106                 bad = copy_from_user(page_address(pages[i]) + po, data, l);
107                 if (bad == l)
108                         return -EFAULT;
109                 data += l - bad;
110                 left -= l - bad;
111                 po += l - bad;
112                 if (po == PAGE_CACHE_SIZE) {
113                         po = 0;
114                         i++;
115                 }
116         }
117         return len;
118 }
119 EXPORT_SYMBOL(ceph_copy_user_to_page_vector);
120 
121 void ceph_copy_to_page_vector(struct page **pages,
122                                     const void *data,
123                                     loff_t off, size_t len)
124 {
125         int i = 0;
126         size_t po = off & ~PAGE_CACHE_MASK;
127         size_t left = len;
128 
129         while (left > 0) {
130                 size_t l = min_t(size_t, PAGE_CACHE_SIZE-po, left);
131 
132                 memcpy(page_address(pages[i]) + po, data, l);
133                 data += l;
134                 left -= l;
135                 po += l;
136                 if (po == PAGE_CACHE_SIZE) {
137                         po = 0;
138                         i++;
139                 }
140         }
141 }
142 EXPORT_SYMBOL(ceph_copy_to_page_vector);
143 
144 void ceph_copy_from_page_vector(struct page **pages,
145                                     void *data,
146                                     loff_t off, size_t len)
147 {
148         int i = 0;
149         size_t po = off & ~PAGE_CACHE_MASK;
150         size_t left = len;
151 
152         while (left > 0) {
153                 size_t l = min_t(size_t, PAGE_CACHE_SIZE-po, left);
154 
155                 memcpy(data, page_address(pages[i]) + po, l);
156                 data += l;
157                 left -= l;
158                 po += l;
159                 if (po == PAGE_CACHE_SIZE) {
160                         po = 0;
161                         i++;
162                 }
163         }
164 }
165 EXPORT_SYMBOL(ceph_copy_from_page_vector);
166 
167 /*
168  * copy user data from a page vector into a user pointer
169  */
170 int ceph_copy_page_vector_to_user(struct page **pages,
171                                          void __user *data,
172                                          loff_t off, size_t len)
173 {
174         int i = 0;
175         int po = off & ~PAGE_CACHE_MASK;
176         int left = len;
177         int l, bad;
178 
179         while (left > 0) {
180                 l = min_t(int, left, PAGE_CACHE_SIZE-po);
181                 bad = copy_to_user(data, page_address(pages[i]) + po, l);
182                 if (bad == l)
183                         return -EFAULT;
184                 data += l - bad;
185                 left -= l - bad;
186                 if (po) {
187                         po += l - bad;
188                         if (po == PAGE_CACHE_SIZE)
189                                 po = 0;
190                 }
191                 i++;
192         }
193         return len;
194 }
195 EXPORT_SYMBOL(ceph_copy_page_vector_to_user);
196 
197 /*
198  * Zero an extent within a page vector.  Offset is relative to the
199  * start of the first page.
200  */
201 void ceph_zero_page_vector_range(int off, int len, struct page **pages)
202 {
203         int i = off >> PAGE_CACHE_SHIFT;
204 
205         off &= ~PAGE_CACHE_MASK;
206 
207         dout("zero_page_vector_page %u~%u\n", off, len);
208 
209         /* leading partial page? */
210         if (off) {
211                 int end = min((int)PAGE_CACHE_SIZE, off + len);
212                 dout("zeroing %d %p head from %d\n", i, pages[i],
213                      (int)off);
214                 zero_user_segment(pages[i], off, end);
215                 len -= (end - off);
216                 i++;
217         }
218         while (len >= PAGE_CACHE_SIZE) {
219                 dout("zeroing %d %p len=%d\n", i, pages[i], len);
220                 zero_user_segment(pages[i], 0, PAGE_CACHE_SIZE);
221                 len -= PAGE_CACHE_SIZE;
222                 i++;
223         }
224         /* trailing partial page? */
225         if (len) {
226                 dout("zeroing %d %p tail to %d\n", i, pages[i], (int)len);
227                 zero_user_segment(pages[i], 0, len);
228         }
229 }
230 EXPORT_SYMBOL(ceph_zero_page_vector_range);
231 
232 

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