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- #include <linux/ceph/ceph_debug.h>
- #include <linux/module.h>
- #include <linux/sched.h>
- #include <linux/slab.h>
- #include <linux/file.h>
- #include <linux/namei.h>
- #include <linux/writeback.h>
- #include <linux/ceph/libceph.h>
- /*
- * build a vector of user pages
- */
- struct page **ceph_get_direct_page_vector(const void __user *data,
- int num_pages, bool write_page)
- {
- struct page **pages;
- int got = 0;
- int rc = 0;
- pages = kmalloc(sizeof(*pages) * num_pages, GFP_NOFS);
- if (!pages)
- return ERR_PTR(-ENOMEM);
- while (got < num_pages) {
- rc = get_user_pages_unlocked(
- (unsigned long)data + ((unsigned long)got * PAGE_SIZE),
- num_pages - got, pages + got, write_page ? FOLL_WRITE : 0);
- if (rc < 0)
- break;
- BUG_ON(rc == 0);
- got += rc;
- }
- if (rc < 0)
- goto fail;
- return pages;
- fail:
- ceph_put_page_vector(pages, got, false);
- return ERR_PTR(rc);
- }
- EXPORT_SYMBOL(ceph_get_direct_page_vector);
- void ceph_put_page_vector(struct page **pages, int num_pages, bool dirty)
- {
- int i;
- for (i = 0; i < num_pages; i++) {
- if (dirty)
- set_page_dirty_lock(pages[i]);
- put_page(pages[i]);
- }
- kvfree(pages);
- }
- EXPORT_SYMBOL(ceph_put_page_vector);
- void ceph_release_page_vector(struct page **pages, int num_pages)
- {
- int i;
- for (i = 0; i < num_pages; i++)
- __free_pages(pages[i], 0);
- kfree(pages);
- }
- EXPORT_SYMBOL(ceph_release_page_vector);
- /*
- * allocate a vector new pages
- */
- struct page **ceph_alloc_page_vector(int num_pages, gfp_t flags)
- {
- struct page **pages;
- int i;
- pages = kmalloc(sizeof(*pages) * num_pages, flags);
- if (!pages)
- return ERR_PTR(-ENOMEM);
- for (i = 0; i < num_pages; i++) {
- pages[i] = __page_cache_alloc(flags);
- if (pages[i] == NULL) {
- ceph_release_page_vector(pages, i);
- return ERR_PTR(-ENOMEM);
- }
- }
- return pages;
- }
- EXPORT_SYMBOL(ceph_alloc_page_vector);
- /*
- * copy user data into a page vector
- */
- int ceph_copy_user_to_page_vector(struct page **pages,
- const void __user *data,
- loff_t off, size_t len)
- {
- int i = 0;
- int po = off & ~PAGE_MASK;
- int left = len;
- int l, bad;
- while (left > 0) {
- l = min_t(int, PAGE_SIZE-po, left);
- bad = copy_from_user(page_address(pages[i]) + po, data, l);
- if (bad == l)
- return -EFAULT;
- data += l - bad;
- left -= l - bad;
- po += l - bad;
- if (po == PAGE_SIZE) {
- po = 0;
- i++;
- }
- }
- return len;
- }
- EXPORT_SYMBOL(ceph_copy_user_to_page_vector);
- void ceph_copy_to_page_vector(struct page **pages,
- const void *data,
- loff_t off, size_t len)
- {
- int i = 0;
- size_t po = off & ~PAGE_MASK;
- size_t left = len;
- while (left > 0) {
- size_t l = min_t(size_t, PAGE_SIZE-po, left);
- memcpy(page_address(pages[i]) + po, data, l);
- data += l;
- left -= l;
- po += l;
- if (po == PAGE_SIZE) {
- po = 0;
- i++;
- }
- }
- }
- EXPORT_SYMBOL(ceph_copy_to_page_vector);
- void ceph_copy_from_page_vector(struct page **pages,
- void *data,
- loff_t off, size_t len)
- {
- int i = 0;
- size_t po = off & ~PAGE_MASK;
- size_t left = len;
- while (left > 0) {
- size_t l = min_t(size_t, PAGE_SIZE-po, left);
- memcpy(data, page_address(pages[i]) + po, l);
- data += l;
- left -= l;
- po += l;
- if (po == PAGE_SIZE) {
- po = 0;
- i++;
- }
- }
- }
- EXPORT_SYMBOL(ceph_copy_from_page_vector);
- /*
- * Zero an extent within a page vector. Offset is relative to the
- * start of the first page.
- */
- void ceph_zero_page_vector_range(int off, int len, struct page **pages)
- {
- int i = off >> PAGE_SHIFT;
- off &= ~PAGE_MASK;
- dout("zero_page_vector_page %u~%u\n", off, len);
- /* leading partial page? */
- if (off) {
- int end = min((int)PAGE_SIZE, off + len);
- dout("zeroing %d %p head from %d\n", i, pages[i],
- (int)off);
- zero_user_segment(pages[i], off, end);
- len -= (end - off);
- i++;
- }
- while (len >= PAGE_SIZE) {
- dout("zeroing %d %p len=%d\n", i, pages[i], len);
- zero_user_segment(pages[i], 0, PAGE_SIZE);
- len -= PAGE_SIZE;
- i++;
- }
- /* trailing partial page? */
- if (len) {
- dout("zeroing %d %p tail to %d\n", i, pages[i], (int)len);
- zero_user_segment(pages[i], 0, len);
- }
- }
- EXPORT_SYMBOL(ceph_zero_page_vector_range);
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