959 lines
21 KiB
C
959 lines
21 KiB
C
#include <linux/export.h>
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#include <linux/uio.h>
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#include <linux/pagemap.h>
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#include <linux/slab.h>
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#include <linux/vmalloc.h>
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static size_t copy_to_iter_iovec(void *from, size_t bytes, struct iov_iter *i)
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{
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size_t skip, copy, left, wanted;
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const struct iovec *iov;
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char __user *buf;
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if (unlikely(bytes > i->count))
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bytes = i->count;
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if (unlikely(!bytes))
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return 0;
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wanted = bytes;
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iov = i->iov;
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skip = i->iov_offset;
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buf = iov->iov_base + skip;
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copy = min(bytes, iov->iov_len - skip);
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left = __copy_to_user(buf, from, copy);
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copy -= left;
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skip += copy;
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from += copy;
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bytes -= copy;
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while (unlikely(!left && bytes)) {
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iov++;
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buf = iov->iov_base;
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copy = min(bytes, iov->iov_len);
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left = __copy_to_user(buf, from, copy);
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copy -= left;
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skip = copy;
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from += copy;
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bytes -= copy;
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}
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if (skip == iov->iov_len) {
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iov++;
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skip = 0;
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}
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i->count -= wanted - bytes;
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i->nr_segs -= iov - i->iov;
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i->iov = iov;
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i->iov_offset = skip;
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return wanted - bytes;
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}
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static size_t copy_from_iter_iovec(void *to, size_t bytes, struct iov_iter *i)
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{
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size_t skip, copy, left, wanted;
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const struct iovec *iov;
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char __user *buf;
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if (unlikely(bytes > i->count))
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bytes = i->count;
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if (unlikely(!bytes))
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return 0;
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wanted = bytes;
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iov = i->iov;
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skip = i->iov_offset;
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buf = iov->iov_base + skip;
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copy = min(bytes, iov->iov_len - skip);
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left = __copy_from_user(to, buf, copy);
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copy -= left;
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skip += copy;
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to += copy;
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bytes -= copy;
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while (unlikely(!left && bytes)) {
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iov++;
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buf = iov->iov_base;
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copy = min(bytes, iov->iov_len);
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left = __copy_from_user(to, buf, copy);
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copy -= left;
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skip = copy;
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to += copy;
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bytes -= copy;
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}
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if (skip == iov->iov_len) {
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iov++;
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skip = 0;
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}
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i->count -= wanted - bytes;
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i->nr_segs -= iov - i->iov;
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i->iov = iov;
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i->iov_offset = skip;
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return wanted - bytes;
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}
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static size_t copy_page_to_iter_iovec(struct page *page, size_t offset, size_t bytes,
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struct iov_iter *i)
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{
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size_t skip, copy, left, wanted;
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const struct iovec *iov;
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char __user *buf;
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void *kaddr, *from;
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if (unlikely(bytes > i->count))
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bytes = i->count;
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if (unlikely(!bytes))
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return 0;
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wanted = bytes;
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iov = i->iov;
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skip = i->iov_offset;
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buf = iov->iov_base + skip;
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copy = min(bytes, iov->iov_len - skip);
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if (!fault_in_pages_writeable(buf, copy)) {
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kaddr = kmap_atomic(page);
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from = kaddr + offset;
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/* first chunk, usually the only one */
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left = __copy_to_user_inatomic(buf, from, copy);
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copy -= left;
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skip += copy;
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from += copy;
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bytes -= copy;
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while (unlikely(!left && bytes)) {
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iov++;
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buf = iov->iov_base;
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copy = min(bytes, iov->iov_len);
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left = __copy_to_user_inatomic(buf, from, copy);
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copy -= left;
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skip = copy;
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from += copy;
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bytes -= copy;
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}
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if (likely(!bytes)) {
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kunmap_atomic(kaddr);
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goto done;
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}
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offset = from - kaddr;
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buf += copy;
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kunmap_atomic(kaddr);
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copy = min(bytes, iov->iov_len - skip);
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}
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/* Too bad - revert to non-atomic kmap */
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kaddr = kmap(page);
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from = kaddr + offset;
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left = __copy_to_user(buf, from, copy);
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copy -= left;
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skip += copy;
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from += copy;
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bytes -= copy;
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while (unlikely(!left && bytes)) {
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iov++;
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buf = iov->iov_base;
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copy = min(bytes, iov->iov_len);
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left = __copy_to_user(buf, from, copy);
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copy -= left;
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skip = copy;
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from += copy;
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bytes -= copy;
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}
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kunmap(page);
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done:
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if (skip == iov->iov_len) {
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iov++;
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skip = 0;
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}
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i->count -= wanted - bytes;
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i->nr_segs -= iov - i->iov;
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i->iov = iov;
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i->iov_offset = skip;
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return wanted - bytes;
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}
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static size_t copy_page_from_iter_iovec(struct page *page, size_t offset, size_t bytes,
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struct iov_iter *i)
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{
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size_t skip, copy, left, wanted;
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const struct iovec *iov;
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char __user *buf;
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void *kaddr, *to;
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if (unlikely(bytes > i->count))
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bytes = i->count;
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if (unlikely(!bytes))
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return 0;
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wanted = bytes;
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iov = i->iov;
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skip = i->iov_offset;
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buf = iov->iov_base + skip;
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copy = min(bytes, iov->iov_len - skip);
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if (!fault_in_pages_readable(buf, copy)) {
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kaddr = kmap_atomic(page);
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to = kaddr + offset;
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/* first chunk, usually the only one */
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left = __copy_from_user_inatomic(to, buf, copy);
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copy -= left;
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skip += copy;
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to += copy;
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bytes -= copy;
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while (unlikely(!left && bytes)) {
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iov++;
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buf = iov->iov_base;
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copy = min(bytes, iov->iov_len);
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left = __copy_from_user_inatomic(to, buf, copy);
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copy -= left;
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skip = copy;
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to += copy;
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bytes -= copy;
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}
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if (likely(!bytes)) {
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kunmap_atomic(kaddr);
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goto done;
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}
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offset = to - kaddr;
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buf += copy;
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kunmap_atomic(kaddr);
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copy = min(bytes, iov->iov_len - skip);
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}
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/* Too bad - revert to non-atomic kmap */
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kaddr = kmap(page);
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to = kaddr + offset;
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left = __copy_from_user(to, buf, copy);
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copy -= left;
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skip += copy;
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to += copy;
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bytes -= copy;
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while (unlikely(!left && bytes)) {
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iov++;
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buf = iov->iov_base;
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copy = min(bytes, iov->iov_len);
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left = __copy_from_user(to, buf, copy);
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copy -= left;
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skip = copy;
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to += copy;
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bytes -= copy;
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}
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kunmap(page);
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done:
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if (skip == iov->iov_len) {
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iov++;
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skip = 0;
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}
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i->count -= wanted - bytes;
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i->nr_segs -= iov - i->iov;
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i->iov = iov;
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i->iov_offset = skip;
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return wanted - bytes;
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}
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static size_t zero_iovec(size_t bytes, struct iov_iter *i)
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{
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size_t skip, copy, left, wanted;
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const struct iovec *iov;
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char __user *buf;
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if (unlikely(bytes > i->count))
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bytes = i->count;
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if (unlikely(!bytes))
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return 0;
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wanted = bytes;
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iov = i->iov;
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skip = i->iov_offset;
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buf = iov->iov_base + skip;
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copy = min(bytes, iov->iov_len - skip);
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left = __clear_user(buf, copy);
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copy -= left;
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skip += copy;
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bytes -= copy;
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while (unlikely(!left && bytes)) {
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iov++;
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buf = iov->iov_base;
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copy = min(bytes, iov->iov_len);
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left = __clear_user(buf, copy);
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copy -= left;
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skip = copy;
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bytes -= copy;
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}
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if (skip == iov->iov_len) {
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iov++;
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skip = 0;
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}
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i->count -= wanted - bytes;
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i->nr_segs -= iov - i->iov;
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i->iov = iov;
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i->iov_offset = skip;
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return wanted - bytes;
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}
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static size_t __iovec_copy_from_user_inatomic(char *vaddr,
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const struct iovec *iov, size_t base, size_t bytes)
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{
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size_t copied = 0, left = 0;
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while (bytes) {
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char __user *buf = iov->iov_base + base;
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int copy = min(bytes, iov->iov_len - base);
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base = 0;
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left = __copy_from_user_inatomic(vaddr, buf, copy);
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copied += copy;
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bytes -= copy;
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vaddr += copy;
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iov++;
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if (unlikely(left))
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break;
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}
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return copied - left;
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}
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/*
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* Copy as much as we can into the page and return the number of bytes which
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* were successfully copied. If a fault is encountered then return the number of
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* bytes which were copied.
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*/
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static size_t copy_from_user_atomic_iovec(struct page *page,
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struct iov_iter *i, unsigned long offset, size_t bytes)
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{
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char *kaddr;
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size_t copied;
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kaddr = kmap_atomic(page);
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if (likely(i->nr_segs == 1)) {
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int left;
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char __user *buf = i->iov->iov_base + i->iov_offset;
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left = __copy_from_user_inatomic(kaddr + offset, buf, bytes);
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copied = bytes - left;
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} else {
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copied = __iovec_copy_from_user_inatomic(kaddr + offset,
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i->iov, i->iov_offset, bytes);
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}
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kunmap_atomic(kaddr);
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return copied;
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}
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static void advance_iovec(struct iov_iter *i, size_t bytes)
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{
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BUG_ON(i->count < bytes);
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if (likely(i->nr_segs == 1)) {
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i->iov_offset += bytes;
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i->count -= bytes;
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} else {
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const struct iovec *iov = i->iov;
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size_t base = i->iov_offset;
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unsigned long nr_segs = i->nr_segs;
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/*
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* The !iov->iov_len check ensures we skip over unlikely
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* zero-length segments (without overruning the iovec).
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*/
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while (bytes || unlikely(i->count && !iov->iov_len)) {
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int copy;
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copy = min(bytes, iov->iov_len - base);
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BUG_ON(!i->count || i->count < copy);
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i->count -= copy;
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bytes -= copy;
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base += copy;
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if (iov->iov_len == base) {
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iov++;
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nr_segs--;
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base = 0;
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}
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}
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i->iov = iov;
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i->iov_offset = base;
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i->nr_segs = nr_segs;
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}
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}
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/*
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* Fault in the first iovec of the given iov_iter, to a maximum length
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* of bytes. Returns 0 on success, or non-zero if the memory could not be
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* accessed (ie. because it is an invalid address).
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*
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* writev-intensive code may want this to prefault several iovecs -- that
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* would be possible (callers must not rely on the fact that _only_ the
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* first iovec will be faulted with the current implementation).
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*/
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int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes)
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{
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if (!(i->type & ITER_BVEC)) {
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char __user *buf = i->iov->iov_base + i->iov_offset;
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bytes = min(bytes, i->iov->iov_len - i->iov_offset);
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return fault_in_pages_readable(buf, bytes);
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}
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return 0;
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}
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EXPORT_SYMBOL(iov_iter_fault_in_readable);
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static unsigned long alignment_iovec(const struct iov_iter *i)
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{
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const struct iovec *iov = i->iov;
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unsigned long res;
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size_t size = i->count;
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size_t n;
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if (!size)
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return 0;
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res = (unsigned long)iov->iov_base + i->iov_offset;
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n = iov->iov_len - i->iov_offset;
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if (n >= size)
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return res | size;
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size -= n;
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res |= n;
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while (size > (++iov)->iov_len) {
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res |= (unsigned long)iov->iov_base | iov->iov_len;
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size -= iov->iov_len;
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}
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res |= (unsigned long)iov->iov_base | size;
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return res;
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}
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void iov_iter_init(struct iov_iter *i, int direction,
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const struct iovec *iov, unsigned long nr_segs,
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size_t count)
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{
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/* It will get better. Eventually... */
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if (segment_eq(get_fs(), KERNEL_DS))
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direction |= ITER_KVEC;
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i->type = direction;
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i->iov = iov;
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i->nr_segs = nr_segs;
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i->iov_offset = 0;
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i->count = count;
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}
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EXPORT_SYMBOL(iov_iter_init);
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static ssize_t get_pages_iovec(struct iov_iter *i,
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struct page **pages, size_t maxsize, unsigned maxpages,
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size_t *start)
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{
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size_t offset = i->iov_offset;
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const struct iovec *iov = i->iov;
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size_t len;
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unsigned long addr;
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int n;
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int res;
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len = iov->iov_len - offset;
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if (len > i->count)
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len = i->count;
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if (len > maxsize)
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len = maxsize;
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addr = (unsigned long)iov->iov_base + offset;
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len += *start = addr & (PAGE_SIZE - 1);
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if (len > maxpages * PAGE_SIZE)
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len = maxpages * PAGE_SIZE;
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addr &= ~(PAGE_SIZE - 1);
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n = (len + PAGE_SIZE - 1) / PAGE_SIZE;
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res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, pages);
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if (unlikely(res < 0))
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return res;
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return (res == n ? len : res * PAGE_SIZE) - *start;
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}
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static ssize_t get_pages_alloc_iovec(struct iov_iter *i,
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struct page ***pages, size_t maxsize,
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size_t *start)
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{
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size_t offset = i->iov_offset;
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const struct iovec *iov = i->iov;
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size_t len;
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unsigned long addr;
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void *p;
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int n;
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int res;
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len = iov->iov_len - offset;
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if (len > i->count)
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len = i->count;
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if (len > maxsize)
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len = maxsize;
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addr = (unsigned long)iov->iov_base + offset;
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len += *start = addr & (PAGE_SIZE - 1);
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addr &= ~(PAGE_SIZE - 1);
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n = (len + PAGE_SIZE - 1) / PAGE_SIZE;
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p = kmalloc(n * sizeof(struct page *), GFP_KERNEL);
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if (!p)
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p = vmalloc(n * sizeof(struct page *));
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if (!p)
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return -ENOMEM;
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res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, p);
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if (unlikely(res < 0)) {
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kvfree(p);
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return res;
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}
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*pages = p;
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return (res == n ? len : res * PAGE_SIZE) - *start;
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}
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static int iov_iter_npages_iovec(const struct iov_iter *i, int maxpages)
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{
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size_t offset = i->iov_offset;
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size_t size = i->count;
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const struct iovec *iov = i->iov;
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int npages = 0;
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int n;
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for (n = 0; size && n < i->nr_segs; n++, iov++) {
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unsigned long addr = (unsigned long)iov->iov_base + offset;
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size_t len = iov->iov_len - offset;
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offset = 0;
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if (unlikely(!len)) /* empty segment */
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continue;
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if (len > size)
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len = size;
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npages += (addr + len + PAGE_SIZE - 1) / PAGE_SIZE
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- addr / PAGE_SIZE;
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if (npages >= maxpages) /* don't bother going further */
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return maxpages;
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size -= len;
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offset = 0;
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}
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return min(npages, maxpages);
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}
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static void memcpy_from_page(char *to, struct page *page, size_t offset, size_t len)
|
|
{
|
|
char *from = kmap_atomic(page);
|
|
memcpy(to, from + offset, len);
|
|
kunmap_atomic(from);
|
|
}
|
|
|
|
static void memcpy_to_page(struct page *page, size_t offset, char *from, size_t len)
|
|
{
|
|
char *to = kmap_atomic(page);
|
|
memcpy(to + offset, from, len);
|
|
kunmap_atomic(to);
|
|
}
|
|
|
|
static void memzero_page(struct page *page, size_t offset, size_t len)
|
|
{
|
|
char *addr = kmap_atomic(page);
|
|
memset(addr + offset, 0, len);
|
|
kunmap_atomic(addr);
|
|
}
|
|
|
|
static size_t copy_to_iter_bvec(void *from, size_t bytes, struct iov_iter *i)
|
|
{
|
|
size_t skip, copy, wanted;
|
|
const struct bio_vec *bvec;
|
|
|
|
if (unlikely(bytes > i->count))
|
|
bytes = i->count;
|
|
|
|
if (unlikely(!bytes))
|
|
return 0;
|
|
|
|
wanted = bytes;
|
|
bvec = i->bvec;
|
|
skip = i->iov_offset;
|
|
copy = min_t(size_t, bytes, bvec->bv_len - skip);
|
|
|
|
memcpy_to_page(bvec->bv_page, skip + bvec->bv_offset, from, copy);
|
|
skip += copy;
|
|
from += copy;
|
|
bytes -= copy;
|
|
while (bytes) {
|
|
bvec++;
|
|
copy = min(bytes, (size_t)bvec->bv_len);
|
|
memcpy_to_page(bvec->bv_page, bvec->bv_offset, from, copy);
|
|
skip = copy;
|
|
from += copy;
|
|
bytes -= copy;
|
|
}
|
|
if (skip == bvec->bv_len) {
|
|
bvec++;
|
|
skip = 0;
|
|
}
|
|
i->count -= wanted - bytes;
|
|
i->nr_segs -= bvec - i->bvec;
|
|
i->bvec = bvec;
|
|
i->iov_offset = skip;
|
|
return wanted - bytes;
|
|
}
|
|
|
|
static size_t copy_from_iter_bvec(void *to, size_t bytes, struct iov_iter *i)
|
|
{
|
|
size_t skip, copy, wanted;
|
|
const struct bio_vec *bvec;
|
|
|
|
if (unlikely(bytes > i->count))
|
|
bytes = i->count;
|
|
|
|
if (unlikely(!bytes))
|
|
return 0;
|
|
|
|
wanted = bytes;
|
|
bvec = i->bvec;
|
|
skip = i->iov_offset;
|
|
|
|
copy = min(bytes, bvec->bv_len - skip);
|
|
|
|
memcpy_from_page(to, bvec->bv_page, bvec->bv_offset + skip, copy);
|
|
|
|
to += copy;
|
|
skip += copy;
|
|
bytes -= copy;
|
|
|
|
while (bytes) {
|
|
bvec++;
|
|
copy = min(bytes, (size_t)bvec->bv_len);
|
|
memcpy_from_page(to, bvec->bv_page, bvec->bv_offset, copy);
|
|
skip = copy;
|
|
to += copy;
|
|
bytes -= copy;
|
|
}
|
|
if (skip == bvec->bv_len) {
|
|
bvec++;
|
|
skip = 0;
|
|
}
|
|
i->count -= wanted;
|
|
i->nr_segs -= bvec - i->bvec;
|
|
i->bvec = bvec;
|
|
i->iov_offset = skip;
|
|
return wanted;
|
|
}
|
|
|
|
static size_t copy_page_to_iter_bvec(struct page *page, size_t offset,
|
|
size_t bytes, struct iov_iter *i)
|
|
{
|
|
void *kaddr = kmap_atomic(page);
|
|
size_t wanted = copy_to_iter_bvec(kaddr + offset, bytes, i);
|
|
kunmap_atomic(kaddr);
|
|
return wanted;
|
|
}
|
|
|
|
static size_t copy_page_from_iter_bvec(struct page *page, size_t offset,
|
|
size_t bytes, struct iov_iter *i)
|
|
{
|
|
void *kaddr = kmap_atomic(page);
|
|
size_t wanted = copy_from_iter_bvec(kaddr + offset, bytes, i);
|
|
kunmap_atomic(kaddr);
|
|
return wanted;
|
|
}
|
|
|
|
static size_t zero_bvec(size_t bytes, struct iov_iter *i)
|
|
{
|
|
size_t skip, copy, wanted;
|
|
const struct bio_vec *bvec;
|
|
|
|
if (unlikely(bytes > i->count))
|
|
bytes = i->count;
|
|
|
|
if (unlikely(!bytes))
|
|
return 0;
|
|
|
|
wanted = bytes;
|
|
bvec = i->bvec;
|
|
skip = i->iov_offset;
|
|
copy = min_t(size_t, bytes, bvec->bv_len - skip);
|
|
|
|
memzero_page(bvec->bv_page, skip + bvec->bv_offset, copy);
|
|
skip += copy;
|
|
bytes -= copy;
|
|
while (bytes) {
|
|
bvec++;
|
|
copy = min(bytes, (size_t)bvec->bv_len);
|
|
memzero_page(bvec->bv_page, bvec->bv_offset, copy);
|
|
skip = copy;
|
|
bytes -= copy;
|
|
}
|
|
if (skip == bvec->bv_len) {
|
|
bvec++;
|
|
skip = 0;
|
|
}
|
|
i->count -= wanted - bytes;
|
|
i->nr_segs -= bvec - i->bvec;
|
|
i->bvec = bvec;
|
|
i->iov_offset = skip;
|
|
return wanted - bytes;
|
|
}
|
|
|
|
static size_t copy_from_user_bvec(struct page *page,
|
|
struct iov_iter *i, unsigned long offset, size_t bytes)
|
|
{
|
|
char *kaddr;
|
|
size_t left;
|
|
const struct bio_vec *bvec;
|
|
size_t base = i->iov_offset;
|
|
|
|
kaddr = kmap_atomic(page);
|
|
for (left = bytes, bvec = i->bvec; left; bvec++, base = 0) {
|
|
size_t copy = min(left, bvec->bv_len - base);
|
|
if (!bvec->bv_len)
|
|
continue;
|
|
memcpy_from_page(kaddr + offset, bvec->bv_page,
|
|
bvec->bv_offset + base, copy);
|
|
offset += copy;
|
|
left -= copy;
|
|
}
|
|
kunmap_atomic(kaddr);
|
|
return bytes;
|
|
}
|
|
|
|
static void advance_bvec(struct iov_iter *i, size_t bytes)
|
|
{
|
|
BUG_ON(i->count < bytes);
|
|
|
|
if (likely(i->nr_segs == 1)) {
|
|
i->iov_offset += bytes;
|
|
i->count -= bytes;
|
|
} else {
|
|
const struct bio_vec *bvec = i->bvec;
|
|
size_t base = i->iov_offset;
|
|
unsigned long nr_segs = i->nr_segs;
|
|
|
|
/*
|
|
* The !iov->iov_len check ensures we skip over unlikely
|
|
* zero-length segments (without overruning the iovec).
|
|
*/
|
|
while (bytes || unlikely(i->count && !bvec->bv_len)) {
|
|
int copy;
|
|
|
|
copy = min(bytes, bvec->bv_len - base);
|
|
BUG_ON(!i->count || i->count < copy);
|
|
i->count -= copy;
|
|
bytes -= copy;
|
|
base += copy;
|
|
if (bvec->bv_len == base) {
|
|
bvec++;
|
|
nr_segs--;
|
|
base = 0;
|
|
}
|
|
}
|
|
i->bvec = bvec;
|
|
i->iov_offset = base;
|
|
i->nr_segs = nr_segs;
|
|
}
|
|
}
|
|
|
|
static unsigned long alignment_bvec(const struct iov_iter *i)
|
|
{
|
|
const struct bio_vec *bvec = i->bvec;
|
|
unsigned long res;
|
|
size_t size = i->count;
|
|
size_t n;
|
|
|
|
if (!size)
|
|
return 0;
|
|
|
|
res = bvec->bv_offset + i->iov_offset;
|
|
n = bvec->bv_len - i->iov_offset;
|
|
if (n >= size)
|
|
return res | size;
|
|
size -= n;
|
|
res |= n;
|
|
while (size > (++bvec)->bv_len) {
|
|
res |= bvec->bv_offset | bvec->bv_len;
|
|
size -= bvec->bv_len;
|
|
}
|
|
res |= bvec->bv_offset | size;
|
|
return res;
|
|
}
|
|
|
|
static ssize_t get_pages_bvec(struct iov_iter *i,
|
|
struct page **pages, size_t maxsize, unsigned maxpages,
|
|
size_t *start)
|
|
{
|
|
const struct bio_vec *bvec = i->bvec;
|
|
size_t len = bvec->bv_len - i->iov_offset;
|
|
if (len > i->count)
|
|
len = i->count;
|
|
if (len > maxsize)
|
|
len = maxsize;
|
|
/* can't be more than PAGE_SIZE */
|
|
*start = bvec->bv_offset + i->iov_offset;
|
|
|
|
get_page(*pages = bvec->bv_page);
|
|
|
|
return len;
|
|
}
|
|
|
|
static ssize_t get_pages_alloc_bvec(struct iov_iter *i,
|
|
struct page ***pages, size_t maxsize,
|
|
size_t *start)
|
|
{
|
|
const struct bio_vec *bvec = i->bvec;
|
|
size_t len = bvec->bv_len - i->iov_offset;
|
|
if (len > i->count)
|
|
len = i->count;
|
|
if (len > maxsize)
|
|
len = maxsize;
|
|
*start = bvec->bv_offset + i->iov_offset;
|
|
|
|
*pages = kmalloc(sizeof(struct page *), GFP_KERNEL);
|
|
if (!*pages)
|
|
return -ENOMEM;
|
|
|
|
get_page(**pages = bvec->bv_page);
|
|
|
|
return len;
|
|
}
|
|
|
|
static int iov_iter_npages_bvec(const struct iov_iter *i, int maxpages)
|
|
{
|
|
size_t offset = i->iov_offset;
|
|
size_t size = i->count;
|
|
const struct bio_vec *bvec = i->bvec;
|
|
int npages = 0;
|
|
int n;
|
|
|
|
for (n = 0; size && n < i->nr_segs; n++, bvec++) {
|
|
size_t len = bvec->bv_len - offset;
|
|
offset = 0;
|
|
if (unlikely(!len)) /* empty segment */
|
|
continue;
|
|
if (len > size)
|
|
len = size;
|
|
npages++;
|
|
if (npages >= maxpages) /* don't bother going further */
|
|
return maxpages;
|
|
size -= len;
|
|
offset = 0;
|
|
}
|
|
return min(npages, maxpages);
|
|
}
|
|
|
|
size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes,
|
|
struct iov_iter *i)
|
|
{
|
|
if (i->type & ITER_BVEC)
|
|
return copy_page_to_iter_bvec(page, offset, bytes, i);
|
|
else
|
|
return copy_page_to_iter_iovec(page, offset, bytes, i);
|
|
}
|
|
EXPORT_SYMBOL(copy_page_to_iter);
|
|
|
|
size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes,
|
|
struct iov_iter *i)
|
|
{
|
|
if (i->type & ITER_BVEC)
|
|
return copy_page_from_iter_bvec(page, offset, bytes, i);
|
|
else
|
|
return copy_page_from_iter_iovec(page, offset, bytes, i);
|
|
}
|
|
EXPORT_SYMBOL(copy_page_from_iter);
|
|
|
|
size_t copy_to_iter(void *addr, size_t bytes, struct iov_iter *i)
|
|
{
|
|
if (i->type & ITER_BVEC)
|
|
return copy_to_iter_bvec(addr, bytes, i);
|
|
else
|
|
return copy_to_iter_iovec(addr, bytes, i);
|
|
}
|
|
EXPORT_SYMBOL(copy_to_iter);
|
|
|
|
size_t copy_from_iter(void *addr, size_t bytes, struct iov_iter *i)
|
|
{
|
|
if (i->type & ITER_BVEC)
|
|
return copy_from_iter_bvec(addr, bytes, i);
|
|
else
|
|
return copy_from_iter_iovec(addr, bytes, i);
|
|
}
|
|
EXPORT_SYMBOL(copy_from_iter);
|
|
|
|
size_t iov_iter_zero(size_t bytes, struct iov_iter *i)
|
|
{
|
|
if (i->type & ITER_BVEC) {
|
|
return zero_bvec(bytes, i);
|
|
} else {
|
|
return zero_iovec(bytes, i);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(iov_iter_zero);
|
|
|
|
size_t iov_iter_copy_from_user_atomic(struct page *page,
|
|
struct iov_iter *i, unsigned long offset, size_t bytes)
|
|
{
|
|
if (i->type & ITER_BVEC)
|
|
return copy_from_user_bvec(page, i, offset, bytes);
|
|
else
|
|
return copy_from_user_atomic_iovec(page, i, offset, bytes);
|
|
}
|
|
EXPORT_SYMBOL(iov_iter_copy_from_user_atomic);
|
|
|
|
void iov_iter_advance(struct iov_iter *i, size_t size)
|
|
{
|
|
if (i->type & ITER_BVEC)
|
|
advance_bvec(i, size);
|
|
else
|
|
advance_iovec(i, size);
|
|
}
|
|
EXPORT_SYMBOL(iov_iter_advance);
|
|
|
|
/*
|
|
* Return the count of just the current iov_iter segment.
|
|
*/
|
|
size_t iov_iter_single_seg_count(const struct iov_iter *i)
|
|
{
|
|
if (i->nr_segs == 1)
|
|
return i->count;
|
|
else if (i->type & ITER_BVEC)
|
|
return min(i->count, i->bvec->bv_len - i->iov_offset);
|
|
else
|
|
return min(i->count, i->iov->iov_len - i->iov_offset);
|
|
}
|
|
EXPORT_SYMBOL(iov_iter_single_seg_count);
|
|
|
|
unsigned long iov_iter_alignment(const struct iov_iter *i)
|
|
{
|
|
if (i->type & ITER_BVEC)
|
|
return alignment_bvec(i);
|
|
else
|
|
return alignment_iovec(i);
|
|
}
|
|
EXPORT_SYMBOL(iov_iter_alignment);
|
|
|
|
ssize_t iov_iter_get_pages(struct iov_iter *i,
|
|
struct page **pages, size_t maxsize, unsigned maxpages,
|
|
size_t *start)
|
|
{
|
|
if (i->type & ITER_BVEC)
|
|
return get_pages_bvec(i, pages, maxsize, maxpages, start);
|
|
else
|
|
return get_pages_iovec(i, pages, maxsize, maxpages, start);
|
|
}
|
|
EXPORT_SYMBOL(iov_iter_get_pages);
|
|
|
|
ssize_t iov_iter_get_pages_alloc(struct iov_iter *i,
|
|
struct page ***pages, size_t maxsize,
|
|
size_t *start)
|
|
{
|
|
if (i->type & ITER_BVEC)
|
|
return get_pages_alloc_bvec(i, pages, maxsize, start);
|
|
else
|
|
return get_pages_alloc_iovec(i, pages, maxsize, start);
|
|
}
|
|
EXPORT_SYMBOL(iov_iter_get_pages_alloc);
|
|
|
|
int iov_iter_npages(const struct iov_iter *i, int maxpages)
|
|
{
|
|
if (i->type & ITER_BVEC)
|
|
return iov_iter_npages_bvec(i, maxpages);
|
|
else
|
|
return iov_iter_npages_iovec(i, maxpages);
|
|
}
|
|
EXPORT_SYMBOL(iov_iter_npages);
|