net/ceph/pagevec.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 #include <linux/ceph/ceph_debug.h>
0003
0004 #include <linux/module.h>
0005 #include <linux/sched.h>
0006 #include <linux/slab.h>
0007 #include <linux/file.h>
0008 #include <linux/namei.h>
0009 #include <linux/writeback.h>
0010
0011 #include <linux/ceph/libceph.h>
0012
0013 void ceph_put_page_vector(struct page **pages, int num_pages, bool dirty)
0014 {
0015     int i;
0016
0017     for (i = 0; i < num_pages; i++) {
0018         if (dirty)
0019             set_page_dirty_lock(pages[i]);
0020         put_page(pages[i]);
0021     }
0022     kvfree(pages);
0023 }
0024 EXPORT_SYMBOL(ceph_put_page_vector);
0025
0026 void ceph_release_page_vector(struct page **pages, int num_pages)
0027 {
0028     int i;
0029
0030     for (i = 0; i < num_pages; i++)
0031         __free_pages(pages[i], 0);
0032     kfree(pages);
0033 }
0034 EXPORT_SYMBOL(ceph_release_page_vector);
0035
0036 /*
0037  * allocate a vector new pages
0038  */
0039 struct page **ceph_alloc_page_vector(int num_pages, gfp_t flags)
0040 {
0041     struct page **pages;
0042     int i;
0043
0044     pages = kmalloc_array(num_pages, sizeof(*pages), flags);
0045     if (!pages)
0046         return ERR_PTR(-ENOMEM);
0047     for (i = 0; i < num_pages; i++) {
0048         pages[i] = __page_cache_alloc(flags);
0049         if (pages[i] == NULL) {
0050             ceph_release_page_vector(pages, i);
0051             return ERR_PTR(-ENOMEM);
0052         }
0053     }
0054     return pages;
0055 }
0056 EXPORT_SYMBOL(ceph_alloc_page_vector);
0057
0058 /*
0059  * copy user data into a page vector
0060  */
0061 int ceph_copy_user_to_page_vector(struct page **pages,
0062                      const void __user *data,
0063                      loff_t off, size_t len)
0064 {
0065     int i = 0;
0066     int po = off & ~PAGE_MASK;
0067     int left = len;
0068     int l, bad;
0069
0070     while (left > 0) {
0071         l = min_t(int, PAGE_SIZE-po, left);
0072         bad = copy_from_user(page_address(pages[i]) + po, data, l);
0073         if (bad == l)
0074             return -EFAULT;
0075         data += l - bad;
0076         left -= l - bad;
0077         po += l - bad;
0078         if (po == PAGE_SIZE) {
0079             po = 0;
0080             i++;
0081         }
0082     }
0083     return len;
0084 }
0085 EXPORT_SYMBOL(ceph_copy_user_to_page_vector);
0086
0087 void ceph_copy_to_page_vector(struct page **pages,
0088                     const void *data,
0089                     loff_t off, size_t len)
0090 {
0091     int i = 0;
0092     size_t po = off & ~PAGE_MASK;
0093     size_t left = len;
0094
0095     while (left > 0) {
0096         size_t l = min_t(size_t, PAGE_SIZE-po, left);
0097
0098         memcpy(page_address(pages[i]) + po, data, l);
0099         data += l;
0100         left -= l;
0101         po += l;
0102         if (po == PAGE_SIZE) {
0103             po = 0;
0104             i++;
0105         }
0106     }
0107 }
0108 EXPORT_SYMBOL(ceph_copy_to_page_vector);
0109
0110 void ceph_copy_from_page_vector(struct page **pages,
0111                     void *data,
0112                     loff_t off, size_t len)
0113 {
0114     int i = 0;
0115     size_t po = off & ~PAGE_MASK;
0116     size_t left = len;
0117
0118     while (left > 0) {
0119         size_t l = min_t(size_t, PAGE_SIZE-po, left);
0120
0121         memcpy(data, page_address(pages[i]) + po, l);
0122         data += l;
0123         left -= l;
0124         po += l;
0125         if (po == PAGE_SIZE) {
0126             po = 0;
0127             i++;
0128         }
0129     }
0130 }
0131 EXPORT_SYMBOL(ceph_copy_from_page_vector);
0132
0133 /*
0134  * Zero an extent within a page vector.  Offset is relative to the
0135  * start of the first page.
0136  */
0137 void ceph_zero_page_vector_range(int off, int len, struct page **pages)
0138 {
0139     int i = off >> PAGE_SHIFT;
0140
0141     off &= ~PAGE_MASK;
0142
0143     dout("zero_page_vector_page %u~%u\n", off, len);
0144
0145     /* leading partial page? */
0146     if (off) {
0147         int end = min((int)PAGE_SIZE, off + len);
0148         dout("zeroing %d %p head from %d\n", i, pages[i],
0149              (int)off);
0150         zero_user_segment(pages[i], off, end);
0151         len -= (end - off);
0152         i++;
0153     }
0154     while (len >= PAGE_SIZE) {
0155         dout("zeroing %d %p len=%d\n", i, pages[i], len);
0156         zero_user_segment(pages[i], 0, PAGE_SIZE);
0157         len -= PAGE_SIZE;
0158         i++;
0159     }
0160     /* trailing partial page? */
0161     if (len) {
0162         dout("zeroing %d %p tail to %d\n", i, pages[i], (int)len);
0163         zero_user_segment(pages[i], 0, len);
0164     }
0165 }
0166 EXPORT_SYMBOL(ceph_zero_page_vector_range);