#include <linux/pagemap.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
-
-static size_t copy_to_iter_iovec(void *from, size_t bytes, struct iov_iter *i)
-{
- size_t skip, copy, left, wanted;
- const struct iovec *iov;
- char __user *buf;
-
- if (unlikely(bytes > i->count))
- bytes = i->count;
-
- if (unlikely(!bytes))
- return 0;
-
- wanted = bytes;
- iov = i->iov;
- skip = i->iov_offset;
- buf = iov->iov_base + skip;
- copy = min(bytes, iov->iov_len - skip);
-
- left = __copy_to_user(buf, from, copy);
- copy -= left;
- skip += copy;
- from += copy;
- bytes -= copy;
- while (unlikely(!left && bytes)) {
- iov++;
- buf = iov->iov_base;
- copy = min(bytes, iov->iov_len);
- left = __copy_to_user(buf, from, copy);
- copy -= left;
- skip = copy;
- from += copy;
- bytes -= copy;
- }
-
- if (skip == iov->iov_len) {
- iov++;
- skip = 0;
- }
- i->count -= wanted - bytes;
- i->nr_segs -= iov - i->iov;
- i->iov = iov;
- i->iov_offset = skip;
- return wanted - bytes;
-}
-
-static size_t copy_from_iter_iovec(void *to, size_t bytes, struct iov_iter *i)
-{
- size_t skip, copy, left, wanted;
- const struct iovec *iov;
- char __user *buf;
-
- if (unlikely(bytes > i->count))
- bytes = i->count;
-
- if (unlikely(!bytes))
- return 0;
-
- wanted = bytes;
- iov = i->iov;
- skip = i->iov_offset;
- buf = iov->iov_base + skip;
- copy = min(bytes, iov->iov_len - skip);
-
- left = __copy_from_user(to, buf, copy);
- copy -= left;
- skip += copy;
- to += copy;
- bytes -= copy;
- while (unlikely(!left && bytes)) {
- iov++;
- buf = iov->iov_base;
- copy = min(bytes, iov->iov_len);
- left = __copy_from_user(to, buf, copy);
- copy -= left;
- skip = copy;
- to += copy;
- bytes -= copy;
- }
-
- if (skip == iov->iov_len) {
- iov++;
- skip = 0;
- }
- i->count -= wanted - bytes;
- i->nr_segs -= iov - i->iov;
- i->iov = iov;
- i->iov_offset = skip;
- return wanted - bytes;
+#include <net/checksum.h>
+
+#define iterate_iovec(i, n, __v, __p, skip, STEP) { \
+ size_t left; \
+ size_t wanted = n; \
+ __p = i->iov; \
+ __v.iov_len = min(n, __p->iov_len - skip); \
+ if (likely(__v.iov_len)) { \
+ __v.iov_base = __p->iov_base + skip; \
+ left = (STEP); \
+ __v.iov_len -= left; \
+ skip += __v.iov_len; \
+ n -= __v.iov_len; \
+ } else { \
+ left = 0; \
+ } \
+ while (unlikely(!left && n)) { \
+ __p++; \
+ __v.iov_len = min(n, __p->iov_len); \
+ if (unlikely(!__v.iov_len)) \
+ continue; \
+ __v.iov_base = __p->iov_base; \
+ left = (STEP); \
+ __v.iov_len -= left; \
+ skip = __v.iov_len; \
+ n -= __v.iov_len; \
+ } \
+ n = wanted - n; \
+}
+
+#define iterate_kvec(i, n, __v, __p, skip, STEP) { \
+ size_t wanted = n; \
+ __p = i->kvec; \
+ __v.iov_len = min(n, __p->iov_len - skip); \
+ if (likely(__v.iov_len)) { \
+ __v.iov_base = __p->iov_base + skip; \
+ (void)(STEP); \
+ skip += __v.iov_len; \
+ n -= __v.iov_len; \
+ } \
+ while (unlikely(n)) { \
+ __p++; \
+ __v.iov_len = min(n, __p->iov_len); \
+ if (unlikely(!__v.iov_len)) \
+ continue; \
+ __v.iov_base = __p->iov_base; \
+ (void)(STEP); \
+ skip = __v.iov_len; \
+ n -= __v.iov_len; \
+ } \
+ n = wanted; \
+}
+
+#define iterate_bvec(i, n, __v, __p, skip, STEP) { \
+ size_t wanted = n; \
+ __p = i->bvec; \
+ __v.bv_len = min_t(size_t, n, __p->bv_len - skip); \
+ if (likely(__v.bv_len)) { \
+ __v.bv_page = __p->bv_page; \
+ __v.bv_offset = __p->bv_offset + skip; \
+ (void)(STEP); \
+ skip += __v.bv_len; \
+ n -= __v.bv_len; \
+ } \
+ while (unlikely(n)) { \
+ __p++; \
+ __v.bv_len = min_t(size_t, n, __p->bv_len); \
+ if (unlikely(!__v.bv_len)) \
+ continue; \
+ __v.bv_page = __p->bv_page; \
+ __v.bv_offset = __p->bv_offset; \
+ (void)(STEP); \
+ skip = __v.bv_len; \
+ n -= __v.bv_len; \
+ } \
+ n = wanted; \
+}
+
+#define iterate_all_kinds(i, n, v, I, B, K) { \
+ size_t skip = i->iov_offset; \
+ if (unlikely(i->type & ITER_BVEC)) { \
+ const struct bio_vec *bvec; \
+ struct bio_vec v; \
+ iterate_bvec(i, n, v, bvec, skip, (B)) \
+ } else if (unlikely(i->type & ITER_KVEC)) { \
+ const struct kvec *kvec; \
+ struct kvec v; \
+ iterate_kvec(i, n, v, kvec, skip, (K)) \
+ } else { \
+ const struct iovec *iov; \
+ struct iovec v; \
+ iterate_iovec(i, n, v, iov, skip, (I)) \
+ } \
+}
+
+#define iterate_and_advance(i, n, v, I, B, K) { \
+ size_t skip = i->iov_offset; \
+ if (unlikely(i->type & ITER_BVEC)) { \
+ const struct bio_vec *bvec; \
+ struct bio_vec v; \
+ iterate_bvec(i, n, v, bvec, skip, (B)) \
+ if (skip == bvec->bv_len) { \
+ bvec++; \
+ skip = 0; \
+ } \
+ i->nr_segs -= bvec - i->bvec; \
+ i->bvec = bvec; \
+ } else if (unlikely(i->type & ITER_KVEC)) { \
+ const struct kvec *kvec; \
+ struct kvec v; \
+ iterate_kvec(i, n, v, kvec, skip, (K)) \
+ if (skip == kvec->iov_len) { \
+ kvec++; \
+ skip = 0; \
+ } \
+ i->nr_segs -= kvec - i->kvec; \
+ i->kvec = kvec; \
+ } else { \
+ const struct iovec *iov; \
+ struct iovec v; \
+ iterate_iovec(i, n, v, iov, skip, (I)) \
+ if (skip == iov->iov_len) { \
+ iov++; \
+ skip = 0; \
+ } \
+ i->nr_segs -= iov - i->iov; \
+ i->iov = iov; \
+ } \
+ i->count -= n; \
+ i->iov_offset = skip; \
}
static size_t copy_page_to_iter_iovec(struct page *page, size_t offset, size_t bytes,
return wanted - bytes;
}
-static size_t zero_iovec(size_t bytes, struct iov_iter *i)
-{
- size_t skip, copy, left, wanted;
- const struct iovec *iov;
- char __user *buf;
-
- if (unlikely(bytes > i->count))
- bytes = i->count;
-
- if (unlikely(!bytes))
- return 0;
-
- wanted = bytes;
- iov = i->iov;
- skip = i->iov_offset;
- buf = iov->iov_base + skip;
- copy = min(bytes, iov->iov_len - skip);
-
- left = __clear_user(buf, copy);
- copy -= left;
- skip += copy;
- bytes -= copy;
-
- while (unlikely(!left && bytes)) {
- iov++;
- buf = iov->iov_base;
- copy = min(bytes, iov->iov_len);
- left = __clear_user(buf, copy);
- copy -= left;
- skip = copy;
- bytes -= copy;
- }
-
- if (skip == iov->iov_len) {
- iov++;
- skip = 0;
- }
- i->count -= wanted - bytes;
- i->nr_segs -= iov - i->iov;
- i->iov = iov;
- i->iov_offset = skip;
- return wanted - bytes;
-}
-
-static size_t __iovec_copy_from_user_inatomic(char *vaddr,
- const struct iovec *iov, size_t base, size_t bytes)
-{
- size_t copied = 0, left = 0;
-
- while (bytes) {
- char __user *buf = iov->iov_base + base;
- int copy = min(bytes, iov->iov_len - base);
-
- base = 0;
- left = __copy_from_user_inatomic(vaddr, buf, copy);
- copied += copy;
- bytes -= copy;
- vaddr += copy;
- iov++;
-
- if (unlikely(left))
- break;
- }
- return copied - left;
-}
-
-/*
- * Copy as much as we can into the page and return the number of bytes which
- * were successfully copied. If a fault is encountered then return the number of
- * bytes which were copied.
- */
-static size_t copy_from_user_atomic_iovec(struct page *page,
- struct iov_iter *i, unsigned long offset, size_t bytes)
-{
- char *kaddr;
- size_t copied;
-
- kaddr = kmap_atomic(page);
- if (likely(i->nr_segs == 1)) {
- int left;
- char __user *buf = i->iov->iov_base + i->iov_offset;
- left = __copy_from_user_inatomic(kaddr + offset, buf, bytes);
- copied = bytes - left;
- } else {
- copied = __iovec_copy_from_user_inatomic(kaddr + offset,
- i->iov, i->iov_offset, bytes);
- }
- kunmap_atomic(kaddr);
-
- return copied;
-}
-
-static void advance_iovec(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 iovec *iov = i->iov;
- 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 && !iov->iov_len)) {
- int copy;
-
- copy = min(bytes, iov->iov_len - base);
- BUG_ON(!i->count || i->count < copy);
- i->count -= copy;
- bytes -= copy;
- base += copy;
- if (iov->iov_len == base) {
- iov++;
- nr_segs--;
- base = 0;
- }
- }
- i->iov = iov;
- i->iov_offset = base;
- i->nr_segs = nr_segs;
- }
-}
-
/*
* Fault in the first iovec of the given iov_iter, to a maximum length
* of bytes. Returns 0 on success, or non-zero if the memory could not be
*/
int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes)
{
- if (!(i->type & ITER_BVEC)) {
+ if (!(i->type & (ITER_BVEC|ITER_KVEC))) {
char __user *buf = i->iov->iov_base + i->iov_offset;
bytes = min(bytes, i->iov->iov_len - i->iov_offset);
return fault_in_pages_readable(buf, bytes);
}
EXPORT_SYMBOL(iov_iter_fault_in_readable);
-static unsigned long alignment_iovec(const struct iov_iter *i)
-{
- const struct iovec *iov = i->iov;
- unsigned long res;
- size_t size = i->count;
- size_t n;
-
- if (!size)
- return 0;
-
- res = (unsigned long)iov->iov_base + i->iov_offset;
- n = iov->iov_len - i->iov_offset;
- if (n >= size)
- return res | size;
- size -= n;
- res |= n;
- while (size > (++iov)->iov_len) {
- res |= (unsigned long)iov->iov_base | iov->iov_len;
- size -= iov->iov_len;
- }
- res |= (unsigned long)iov->iov_base | size;
- return res;
-}
-
void iov_iter_init(struct iov_iter *i, int direction,
const struct iovec *iov, unsigned long nr_segs,
size_t count)
{
/* It will get better. Eventually... */
- if (segment_eq(get_fs(), KERNEL_DS))
+ if (segment_eq(get_fs(), KERNEL_DS)) {
direction |= ITER_KVEC;
- i->type = direction;
- i->iov = iov;
+ i->type = direction;
+ i->kvec = (struct kvec *)iov;
+ } else {
+ i->type = direction;
+ i->iov = iov;
+ }
i->nr_segs = nr_segs;
i->iov_offset = 0;
i->count = count;
}
EXPORT_SYMBOL(iov_iter_init);
-static ssize_t get_pages_iovec(struct iov_iter *i,
- struct page **pages, size_t maxsize, unsigned maxpages,
- size_t *start)
-{
- size_t offset = i->iov_offset;
- const struct iovec *iov = i->iov;
- size_t len;
- unsigned long addr;
- int n;
- int res;
-
- len = iov->iov_len - offset;
- if (len > i->count)
- len = i->count;
- if (len > maxsize)
- len = maxsize;
- addr = (unsigned long)iov->iov_base + offset;
- len += *start = addr & (PAGE_SIZE - 1);
- if (len > maxpages * PAGE_SIZE)
- len = maxpages * PAGE_SIZE;
- addr &= ~(PAGE_SIZE - 1);
- n = (len + PAGE_SIZE - 1) / PAGE_SIZE;
- res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, pages);
- if (unlikely(res < 0))
- return res;
- return (res == n ? len : res * PAGE_SIZE) - *start;
-}
-
-static ssize_t get_pages_alloc_iovec(struct iov_iter *i,
- struct page ***pages, size_t maxsize,
- size_t *start)
-{
- size_t offset = i->iov_offset;
- const struct iovec *iov = i->iov;
- size_t len;
- unsigned long addr;
- void *p;
- int n;
- int res;
-
- len = iov->iov_len - offset;
- if (len > i->count)
- len = i->count;
- if (len > maxsize)
- len = maxsize;
- addr = (unsigned long)iov->iov_base + offset;
- len += *start = addr & (PAGE_SIZE - 1);
- addr &= ~(PAGE_SIZE - 1);
- n = (len + PAGE_SIZE - 1) / PAGE_SIZE;
-
- p = kmalloc(n * sizeof(struct page *), GFP_KERNEL);
- if (!p)
- p = vmalloc(n * sizeof(struct page *));
- if (!p)
- return -ENOMEM;
-
- res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, p);
- if (unlikely(res < 0)) {
- kvfree(p);
- return res;
- }
- *pages = p;
- return (res == n ? len : res * PAGE_SIZE) - *start;
-}
-
-static int iov_iter_npages_iovec(const struct iov_iter *i, int maxpages)
-{
- size_t offset = i->iov_offset;
- size_t size = i->count;
- const struct iovec *iov = i->iov;
- int npages = 0;
- int n;
-
- for (n = 0; size && n < i->nr_segs; n++, iov++) {
- unsigned long addr = (unsigned long)iov->iov_base + offset;
- size_t len = iov->iov_len - offset;
- offset = 0;
- if (unlikely(!len)) /* empty segment */
- continue;
- if (len > size)
- len = size;
- npages += (addr + len + PAGE_SIZE - 1) / PAGE_SIZE
- - addr / PAGE_SIZE;
- if (npages >= maxpages) /* don't bother going further */
- return maxpages;
- size -= len;
- offset = 0;
- }
- return min(npages, maxpages);
-}
-
static void memcpy_from_page(char *to, struct page *page, size_t offset, size_t len)
{
char *from = kmap_atomic(page);
kunmap_atomic(addr);
}
-static size_t copy_to_iter_bvec(void *from, size_t bytes, struct iov_iter *i)
+size_t copy_to_iter(void *addr, size_t bytes, struct iov_iter *i)
{
- size_t skip, copy, wanted;
- const struct bio_vec *bvec;
-
+ char *from = addr;
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);
+ iterate_and_advance(i, bytes, v,
+ __copy_to_user(v.iov_base, (from += v.iov_len) - v.iov_len,
+ v.iov_len),
+ memcpy_to_page(v.bv_page, v.bv_offset,
+ (from += v.bv_len) - v.bv_len, v.bv_len),
+ memcpy(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len)
+ )
- 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;
+ return bytes;
}
+EXPORT_SYMBOL(copy_to_iter);
-static size_t copy_from_iter_bvec(void *to, size_t bytes, struct iov_iter *i)
+size_t copy_from_iter(void *addr, size_t bytes, struct iov_iter *i)
{
- size_t skip, copy, wanted;
- const struct bio_vec *bvec;
-
+ char *to = addr;
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;
-}
+ iterate_and_advance(i, bytes, v,
+ __copy_from_user((to += v.iov_len) - v.iov_len, v.iov_base,
+ v.iov_len),
+ memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page,
+ v.bv_offset, v.bv_len),
+ memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len)
+ )
-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;
+ return bytes;
}
+EXPORT_SYMBOL(copy_from_iter);
-static size_t zero_bvec(size_t bytes, struct iov_iter *i)
+size_t copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i)
{
- size_t skip, copy, wanted;
- const struct bio_vec *bvec;
-
+ char *to = addr;
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);
+ iterate_and_advance(i, bytes, v,
+ __copy_from_user_nocache((to += v.iov_len) - v.iov_len,
+ v.iov_base, v.iov_len),
+ memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page,
+ v.bv_offset, v.bv_len),
+ memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len)
+ )
- 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);
-}
+EXPORT_SYMBOL(copy_from_iter_nocache);
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
+ if (i->type & (ITER_BVEC|ITER_KVEC)) {
+ void *kaddr = kmap_atomic(page);
+ size_t wanted = copy_to_iter(kaddr + offset, bytes, i);
+ kunmap_atomic(kaddr);
+ return wanted;
+ } 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
+ if (i->type & (ITER_BVEC|ITER_KVEC)) {
+ void *kaddr = kmap_atomic(page);
+ size_t wanted = copy_from_iter(kaddr + offset, bytes, i);
+ kunmap_atomic(kaddr);
+ return wanted;
+ } 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)
+size_t iov_iter_zero(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);
+ if (unlikely(bytes > i->count))
+ bytes = i->count;
-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);
+ if (unlikely(!bytes))
+ return 0;
-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);
- }
+ iterate_and_advance(i, bytes, v,
+ __clear_user(v.iov_base, v.iov_len),
+ memzero_page(v.bv_page, v.bv_offset, v.bv_len),
+ memset(v.iov_base, 0, v.iov_len)
+ )
+
+ return bytes;
}
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);
+ char *kaddr = kmap_atomic(page), *p = kaddr + offset;
+ iterate_all_kinds(i, bytes, v,
+ __copy_from_user_inatomic((p += v.iov_len) - v.iov_len,
+ v.iov_base, v.iov_len),
+ memcpy_from_page((p += v.bv_len) - v.bv_len, v.bv_page,
+ v.bv_offset, v.bv_len),
+ memcpy((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len)
+ )
+ kunmap_atomic(kaddr);
+ return 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);
+ iterate_and_advance(i, size, v, 0, 0, 0)
}
EXPORT_SYMBOL(iov_iter_advance);
if (i->nr_segs == 1)
return i->count;
else if (i->type & ITER_BVEC)
- return min(i->count, i->iov->iov_len - i->iov_offset);
- else
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);
+void iov_iter_kvec(struct iov_iter *i, int direction,
+ const struct kvec *iov, unsigned long nr_segs,
+ size_t count)
+{
+ BUG_ON(!(direction & ITER_KVEC));
+ i->type = direction;
+ i->kvec = (struct kvec *)iov;
+ i->nr_segs = nr_segs;
+ i->iov_offset = 0;
+ i->count = count;
+}
+EXPORT_SYMBOL(iov_iter_kvec);
+
unsigned long iov_iter_alignment(const struct iov_iter *i)
{
- if (i->type & ITER_BVEC)
- return alignment_bvec(i);
- else
- return alignment_iovec(i);
+ unsigned long res = 0;
+ size_t size = i->count;
+
+ if (!size)
+ return 0;
+
+ iterate_all_kinds(i, size, v,
+ (res |= (unsigned long)v.iov_base | v.iov_len, 0),
+ res |= v.bv_offset | v.bv_len,
+ res |= (unsigned long)v.iov_base | v.iov_len
+ )
+ return res;
}
EXPORT_SYMBOL(iov_iter_alignment);
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);
+ if (maxsize > i->count)
+ maxsize = i->count;
+
+ if (!maxsize)
+ return 0;
+
+ iterate_all_kinds(i, maxsize, v, ({
+ unsigned long addr = (unsigned long)v.iov_base;
+ size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1));
+ int n;
+ int res;
+
+ if (len > maxpages * PAGE_SIZE)
+ len = maxpages * PAGE_SIZE;
+ addr &= ~(PAGE_SIZE - 1);
+ n = DIV_ROUND_UP(len, PAGE_SIZE);
+ res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, pages);
+ if (unlikely(res < 0))
+ return res;
+ return (res == n ? len : res * PAGE_SIZE) - *start;
+ 0;}),({
+ /* can't be more than PAGE_SIZE */
+ *start = v.bv_offset;
+ get_page(*pages = v.bv_page);
+ return v.bv_len;
+ }),({
+ return -EFAULT;
+ })
+ )
+ return 0;
}
EXPORT_SYMBOL(iov_iter_get_pages);
+static struct page **get_pages_array(size_t n)
+{
+ struct page **p = kmalloc(n * sizeof(struct page *), GFP_KERNEL);
+ if (!p)
+ p = vmalloc(n * sizeof(struct page *));
+ return p;
+}
+
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);
+ struct page **p;
+
+ if (maxsize > i->count)
+ maxsize = i->count;
+
+ if (!maxsize)
+ return 0;
+
+ iterate_all_kinds(i, maxsize, v, ({
+ unsigned long addr = (unsigned long)v.iov_base;
+ size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1));
+ int n;
+ int res;
+
+ addr &= ~(PAGE_SIZE - 1);
+ n = DIV_ROUND_UP(len, PAGE_SIZE);
+ p = get_pages_array(n);
+ if (!p)
+ return -ENOMEM;
+ res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, p);
+ if (unlikely(res < 0)) {
+ kvfree(p);
+ return res;
+ }
+ *pages = p;
+ return (res == n ? len : res * PAGE_SIZE) - *start;
+ 0;}),({
+ /* can't be more than PAGE_SIZE */
+ *start = v.bv_offset;
+ *pages = p = get_pages_array(1);
+ if (!p)
+ return -ENOMEM;
+ get_page(*p = v.bv_page);
+ return v.bv_len;
+ }),({
+ return -EFAULT;
+ })
+ )
+ return 0;
}
EXPORT_SYMBOL(iov_iter_get_pages_alloc);
+size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum,
+ struct iov_iter *i)
+{
+ char *to = addr;
+ __wsum sum, next;
+ size_t off = 0;
+ if (unlikely(bytes > i->count))
+ bytes = i->count;
+
+ if (unlikely(!bytes))
+ return 0;
+
+ sum = *csum;
+ iterate_and_advance(i, bytes, v, ({
+ int err = 0;
+ next = csum_and_copy_from_user(v.iov_base,
+ (to += v.iov_len) - v.iov_len,
+ v.iov_len, 0, &err);
+ if (!err) {
+ sum = csum_block_add(sum, next, off);
+ off += v.iov_len;
+ }
+ err ? v.iov_len : 0;
+ }), ({
+ char *p = kmap_atomic(v.bv_page);
+ next = csum_partial_copy_nocheck(p + v.bv_offset,
+ (to += v.bv_len) - v.bv_len,
+ v.bv_len, 0);
+ kunmap_atomic(p);
+ sum = csum_block_add(sum, next, off);
+ off += v.bv_len;
+ }),({
+ next = csum_partial_copy_nocheck(v.iov_base,
+ (to += v.iov_len) - v.iov_len,
+ v.iov_len, 0);
+ sum = csum_block_add(sum, next, off);
+ off += v.iov_len;
+ })
+ )
+ *csum = sum;
+ return bytes;
+}
+EXPORT_SYMBOL(csum_and_copy_from_iter);
+
+size_t csum_and_copy_to_iter(void *addr, size_t bytes, __wsum *csum,
+ struct iov_iter *i)
+{
+ char *from = addr;
+ __wsum sum, next;
+ size_t off = 0;
+ if (unlikely(bytes > i->count))
+ bytes = i->count;
+
+ if (unlikely(!bytes))
+ return 0;
+
+ sum = *csum;
+ iterate_and_advance(i, bytes, v, ({
+ int err = 0;
+ next = csum_and_copy_to_user((from += v.iov_len) - v.iov_len,
+ v.iov_base,
+ v.iov_len, 0, &err);
+ if (!err) {
+ sum = csum_block_add(sum, next, off);
+ off += v.iov_len;
+ }
+ err ? v.iov_len : 0;
+ }), ({
+ char *p = kmap_atomic(v.bv_page);
+ next = csum_partial_copy_nocheck((from += v.bv_len) - v.bv_len,
+ p + v.bv_offset,
+ v.bv_len, 0);
+ kunmap_atomic(p);
+ sum = csum_block_add(sum, next, off);
+ off += v.bv_len;
+ }),({
+ next = csum_partial_copy_nocheck((from += v.iov_len) - v.iov_len,
+ v.iov_base,
+ v.iov_len, 0);
+ sum = csum_block_add(sum, next, off);
+ off += v.iov_len;
+ })
+ )
+ *csum = sum;
+ return bytes;
+}
+EXPORT_SYMBOL(csum_and_copy_to_iter);
+
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);
+ size_t size = i->count;
+ int npages = 0;
+
+ if (!size)
+ return 0;
+
+ iterate_all_kinds(i, size, v, ({
+ unsigned long p = (unsigned long)v.iov_base;
+ npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE)
+ - p / PAGE_SIZE;
+ if (npages >= maxpages)
+ return maxpages;
+ 0;}),({
+ npages++;
+ if (npages >= maxpages)
+ return maxpages;
+ }),({
+ unsigned long p = (unsigned long)v.iov_base;
+ npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE)
+ - p / PAGE_SIZE;
+ if (npages >= maxpages)
+ return maxpages;
+ })
+ )
+ return npages;
}
EXPORT_SYMBOL(iov_iter_npages);
projects / cascardo / linux.git / blobdiff