1 // SPDX-License-Identifier: GPL-2.0 2 #include <linux/ceph/ceph_debug.h> 3 4 #include <linux/module.h> 5 #include <linux/sched.h> 6 #include <linux/slab.h> 7 #include <linux/file.h> 8 #include <linux/namei.h> 9 #include <linux/writeback.h> 10 11 #include <linux/ceph/libceph.h> 12 13 void ceph_put_page_vector(struct page **pages, int num_pages, bool dirty) 14 { 15 int i; 16 17 for (i = 0; i < num_pages; i++) { 18 if (dirty) 19 set_page_dirty_lock(pages[i]); 20 put_page(pages[i]); 21 } 22 kvfree(pages); 23 } 24 EXPORT_SYMBOL(ceph_put_page_vector); 25 26 void ceph_release_page_vector(struct page **pages, int num_pages) 27 { 28 int i; 29 30 for (i = 0; i < num_pages; i++) 31 __free_pages(pages[i], 0); 32 kfree(pages); 33 } 34 EXPORT_SYMBOL(ceph_release_page_vector); 35 36 /* 37 * allocate a vector new pages 38 */ 39 struct page **ceph_alloc_page_vector(int num_pages, gfp_t flags) 40 { 41 struct page **pages; 42 int i; 43 44 pages = kmalloc_array(num_pages, sizeof(*pages), flags); 45 if (!pages) 46 return ERR_PTR(-ENOMEM); 47 for (i = 0; i < num_pages; i++) { 48 pages[i] = __page_cache_alloc(flags); 49 if (pages[i] == NULL) { 50 ceph_release_page_vector(pages, i); 51 return ERR_PTR(-ENOMEM); 52 } 53 } 54 return pages; 55 } 56 EXPORT_SYMBOL(ceph_alloc_page_vector); 57 58 /* 59 * copy user data into a page vector 60 */ 61 int ceph_copy_user_to_page_vector(struct page **pages, 62 const void __user *data, 63 loff_t off, size_t len) 64 { 65 int i = 0; 66 int po = off & ~PAGE_MASK; 67 int left = len; 68 int l, bad; 69 70 while (left > 0) { 71 l = min_t(int, PAGE_SIZE-po, left); 72 bad = copy_from_user(page_address(pages[i]) + po, data, l); 73 if (bad == l) 74 return -EFAULT; 75 data += l - bad; 76 left -= l - bad; 77 po += l - bad; 78 if (po == PAGE_SIZE) { 79 po = 0; 80 i++; 81 } 82 } 83 return len; 84 } 85 EXPORT_SYMBOL(ceph_copy_user_to_page_vector); 86 87 void ceph_copy_to_page_vector(struct page **pages, 88 const void *data, 89 loff_t off, size_t len) 90 { 91 int i = 0; 92 size_t po = off & ~PAGE_MASK; 93 size_t left = len; 94 95 while (left > 0) { 96 size_t l = min_t(size_t, PAGE_SIZE-po, left); 97 98 memcpy(page_address(pages[i]) + po, data, l); 99 data += l; 100 left -= l; 101 po += l; 102 if (po == PAGE_SIZE) { 103 po = 0; 104 i++; 105 } 106 } 107 } 108 EXPORT_SYMBOL(ceph_copy_to_page_vector); 109 110 void ceph_copy_from_page_vector(struct page **pages, 111 void *data, 112 loff_t off, size_t len) 113 { 114 int i = 0; 115 size_t po = off & ~PAGE_MASK; 116 size_t left = len; 117 118 while (left > 0) { 119 size_t l = min_t(size_t, PAGE_SIZE-po, left); 120 121 memcpy(data, page_address(pages[i]) + po, l); 122 data += l; 123 left -= l; 124 po += l; 125 if (po == PAGE_SIZE) { 126 po = 0; 127 i++; 128 } 129 } 130 } 131 EXPORT_SYMBOL(ceph_copy_from_page_vector); 132 133 /* 134 * Zero an extent within a page vector. Offset is relative to the 135 * start of the first page. 136 */ 137 void ceph_zero_page_vector_range(int off, int len, struct page **pages) 138 { 139 int i = off >> PAGE_SHIFT; 140 141 off &= ~PAGE_MASK; 142 143 dout("zero_page_vector_page %u~%u\n", off, len); 144 145 /* leading partial page? */ 146 if (off) { 147 int end = min((int)PAGE_SIZE, off + len); 148 dout("zeroing %d %p head from %d\n", i, pages[i], 149 (int)off); 150 zero_user_segment(pages[i], off, end); 151 len -= (end - off); 152 i++; 153 } 154 while (len >= PAGE_SIZE) { 155 dout("zeroing %d %p len=%d\n", i, pages[i], len); 156 zero_user_segment(pages[i], 0, PAGE_SIZE); 157 len -= PAGE_SIZE; 158 i++; 159 } 160 /* trailing partial page? */ 161 if (len) { 162 dout("zeroing %d %p tail to %d\n", i, pages[i], (int)len); 163 zero_user_segment(pages[i], 0, len); 164 } 165 } 166 EXPORT_SYMBOL(ceph_zero_page_vector_range); 167