pagevec.c

  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
 13void 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}
 24EXPORT_SYMBOL(ceph_put_page_vector);
 25
 26void 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}
 34EXPORT_SYMBOL(ceph_release_page_vector);
 35
 36/*
 37 * allocate a vector new pages
 38 */
 39struct 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}
 56EXPORT_SYMBOL(ceph_alloc_page_vector);
 57
 58void ceph_copy_from_page_vector(struct page **pages,
 59				    void *data,
 60				    loff_t off, size_t len)
 61{
 62	int i = 0;
 63	size_t po = off & ~PAGE_MASK;
 64	size_t left = len;
 65
 66	while (left > 0) {
 67		size_t l = min_t(size_t, PAGE_SIZE-po, left);
 68
 69		memcpy(data, page_address(pages[i]) + po, l);
 70		data += l;
 71		left -= l;
 72		po += l;
 73		if (po == PAGE_SIZE) {
 74			po = 0;
 75			i++;
 76		}
 77	}
 78}
 79EXPORT_SYMBOL(ceph_copy_from_page_vector);
 80
 81/*
 82 * Zero an extent within a page vector.  Offset is relative to the
 83 * start of the first page.
 84 */
 85void ceph_zero_page_vector_range(int off, int len, struct page **pages)
 86{
 87	int i = off >> PAGE_SHIFT;
 88
 89	off &= ~PAGE_MASK;
 90
 91	dout("zero_page_vector_page %u~%u\n", off, len);
 92
 93	/* leading partial page? */
 94	if (off) {
 95		int end = min((int)PAGE_SIZE, off + len);
 96		dout("zeroing %d %p head from %d\n", i, pages[i],
 97		     (int)off);
 98		zero_user_segment(pages[i], off, end);
 99		len -= (end - off);
100		i++;
101	}
102	while (len >= PAGE_SIZE) {
103		dout("zeroing %d %p len=%d\n", i, pages[i], len);
104		zero_user_segment(pages[i], 0, PAGE_SIZE);
105		len -= PAGE_SIZE;
106		i++;
107	}
108	/* trailing partial page? */
109	if (len) {
110		dout("zeroing %d %p tail to %d\n", i, pages[i], (int)len);
111		zero_user_segment(pages[i], 0, len);
112	}
113}
114EXPORT_SYMBOL(ceph_zero_page_vector_range);