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-rw-r--r--lib/iov_iter.c203
1 files changed, 151 insertions, 52 deletions
diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index 691a52b634fe..e68604ae3ced 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -73,19 +73,21 @@
}
#define iterate_all_kinds(i, n, v, I, B, K) { \
- size_t skip = i->iov_offset; \
- if (unlikely(i->type & ITER_BVEC)) { \
- struct bio_vec v; \
- struct bvec_iter __bi; \
- iterate_bvec(i, n, v, __bi, 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)) \
+ if (likely(n)) { \
+ size_t skip = i->iov_offset; \
+ if (unlikely(i->type & ITER_BVEC)) { \
+ struct bio_vec v; \
+ struct bvec_iter __bi; \
+ iterate_bvec(i, n, v, __bi, 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)) \
+ } \
} \
}
@@ -569,6 +571,31 @@ size_t copy_from_iter(void *addr, size_t bytes, struct iov_iter *i)
}
EXPORT_SYMBOL(copy_from_iter);
+bool copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i)
+{
+ char *to = addr;
+ if (unlikely(i->type & ITER_PIPE)) {
+ WARN_ON(1);
+ return false;
+ }
+ if (unlikely(i->count < bytes))
+ return false;
+
+ iterate_all_kinds(i, bytes, v, ({
+ if (__copy_from_user((to += v.iov_len) - v.iov_len,
+ v.iov_base, v.iov_len))
+ return false;
+ 0;}),
+ 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)
+ )
+
+ iov_iter_advance(i, bytes);
+ return true;
+}
+EXPORT_SYMBOL(copy_from_iter_full);
+
size_t copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i)
{
char *to = addr;
@@ -588,6 +615,30 @@ size_t copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i)
}
EXPORT_SYMBOL(copy_from_iter_nocache);
+bool copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i)
+{
+ char *to = addr;
+ if (unlikely(i->type & ITER_PIPE)) {
+ WARN_ON(1);
+ return false;
+ }
+ if (unlikely(i->count < bytes))
+ return false;
+ iterate_all_kinds(i, bytes, v, ({
+ if (__copy_from_user_nocache((to += v.iov_len) - v.iov_len,
+ v.iov_base, v.iov_len))
+ return false;
+ 0;}),
+ 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)
+ )
+
+ iov_iter_advance(i, bytes);
+ return true;
+}
+EXPORT_SYMBOL(copy_from_iter_full_nocache);
+
size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes,
struct iov_iter *i)
{
@@ -679,43 +730,50 @@ size_t iov_iter_copy_from_user_atomic(struct page *page,
}
EXPORT_SYMBOL(iov_iter_copy_from_user_atomic);
+static inline void pipe_truncate(struct iov_iter *i)
+{
+ struct pipe_inode_info *pipe = i->pipe;
+ if (pipe->nrbufs) {
+ size_t off = i->iov_offset;
+ int idx = i->idx;
+ int nrbufs = (idx - pipe->curbuf) & (pipe->buffers - 1);
+ if (off) {
+ pipe->bufs[idx].len = off - pipe->bufs[idx].offset;
+ idx = next_idx(idx, pipe);
+ nrbufs++;
+ }
+ while (pipe->nrbufs > nrbufs) {
+ pipe_buf_release(pipe, &pipe->bufs[idx]);
+ idx = next_idx(idx, pipe);
+ pipe->nrbufs--;
+ }
+ }
+}
+
static void pipe_advance(struct iov_iter *i, size_t size)
{
struct pipe_inode_info *pipe = i->pipe;
- struct pipe_buffer *buf;
- int idx = i->idx;
- size_t off = i->iov_offset, orig_sz;
-
if (unlikely(i->count < size))
size = i->count;
- orig_sz = size;
-
if (size) {
+ struct pipe_buffer *buf;
+ size_t off = i->iov_offset, left = size;
+ int idx = i->idx;
if (off) /* make it relative to the beginning of buffer */
- size += off - pipe->bufs[idx].offset;
+ left += off - pipe->bufs[idx].offset;
while (1) {
buf = &pipe->bufs[idx];
- if (size <= buf->len)
+ if (left <= buf->len)
break;
- size -= buf->len;
+ left -= buf->len;
idx = next_idx(idx, pipe);
}
- buf->len = size;
i->idx = idx;
- off = i->iov_offset = buf->offset + size;
+ i->iov_offset = buf->offset + left;
}
- if (off)
- idx = next_idx(idx, pipe);
- if (pipe->nrbufs) {
- int unused = (pipe->curbuf + pipe->nrbufs) & (pipe->buffers - 1);
- /* [curbuf,unused) is in use. Free [idx,unused) */
- while (idx != unused) {
- pipe_buf_release(pipe, &pipe->bufs[idx]);
- idx = next_idx(idx, pipe);
- pipe->nrbufs--;
- }
- }
- i->count -= orig_sz;
+ i->count -= size;
+ /* ... and discard everything past that point */
+ pipe_truncate(i);
}
void iov_iter_advance(struct iov_iter *i, size_t size)
@@ -775,6 +833,7 @@ void iov_iter_pipe(struct iov_iter *i, int direction,
size_t count)
{
BUG_ON(direction != ITER_PIPE);
+ WARN_ON(pipe->nrbufs == pipe->buffers);
i->type = direction;
i->pipe = pipe;
i->idx = (pipe->curbuf + pipe->nrbufs) & (pipe->buffers - 1);
@@ -788,11 +847,8 @@ unsigned long iov_iter_alignment(const struct iov_iter *i)
unsigned long res = 0;
size_t size = i->count;
- if (!size)
- return 0;
-
if (unlikely(i->type & ITER_PIPE)) {
- if (i->iov_offset && allocated(&i->pipe->bufs[i->idx]))
+ if (size && i->iov_offset && allocated(&i->pipe->bufs[i->idx]))
return size | i->iov_offset;
return size;
}
@@ -807,10 +863,8 @@ EXPORT_SYMBOL(iov_iter_alignment);
unsigned long iov_iter_gap_alignment(const struct iov_iter *i)
{
- unsigned long res = 0;
+ unsigned long res = 0;
size_t size = i->count;
- if (!size)
- return 0;
if (unlikely(i->type & ITER_PIPE)) {
WARN_ON(1);
@@ -825,7 +879,7 @@ unsigned long iov_iter_gap_alignment(const struct iov_iter *i)
(res |= (!res ? 0 : (unsigned long)v.iov_base) |
(size != v.iov_len ? size : 0))
);
- return res;
+ return res;
}
EXPORT_SYMBOL(iov_iter_gap_alignment);
@@ -859,6 +913,9 @@ static ssize_t pipe_get_pages(struct iov_iter *i,
size_t capacity;
int idx;
+ if (!maxsize)
+ return 0;
+
if (!sanity(i))
return -EFAULT;
@@ -877,9 +934,6 @@ ssize_t iov_iter_get_pages(struct iov_iter *i,
if (maxsize > i->count)
maxsize = i->count;
- if (!maxsize)
- return 0;
-
if (unlikely(i->type & ITER_PIPE))
return pipe_get_pages(i, pages, maxsize, maxpages, start);
iterate_all_kinds(i, maxsize, v, ({
@@ -926,6 +980,9 @@ static ssize_t pipe_get_pages_alloc(struct iov_iter *i,
int idx;
int npages;
+ if (!maxsize)
+ return 0;
+
if (!sanity(i))
return -EFAULT;
@@ -957,9 +1014,6 @@ ssize_t iov_iter_get_pages_alloc(struct iov_iter *i,
if (maxsize > i->count)
maxsize = i->count;
- if (!maxsize)
- return 0;
-
if (unlikely(i->type & ITER_PIPE))
return pipe_get_pages_alloc(i, pages, maxsize, start);
iterate_all_kinds(i, maxsize, v, ({
@@ -1009,7 +1063,7 @@ size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum,
}
iterate_and_advance(i, bytes, v, ({
int err = 0;
- next = csum_and_copy_from_user(v.iov_base,
+ next = csum_and_copy_from_user(v.iov_base,
(to += v.iov_len) - v.iov_len,
v.iov_len, 0, &err);
if (!err) {
@@ -1038,6 +1092,51 @@ size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum,
}
EXPORT_SYMBOL(csum_and_copy_from_iter);
+bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum,
+ struct iov_iter *i)
+{
+ char *to = addr;
+ __wsum sum, next;
+ size_t off = 0;
+ sum = *csum;
+ if (unlikely(i->type & ITER_PIPE)) {
+ WARN_ON(1);
+ return false;
+ }
+ if (unlikely(i->count < bytes))
+ return false;
+ iterate_all_kinds(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)
+ return false;
+ sum = csum_block_add(sum, next, off);
+ off += 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;
+ iov_iter_advance(i, bytes);
+ return true;
+}
+EXPORT_SYMBOL(csum_and_copy_from_iter_full);
+
size_t csum_and_copy_to_iter(const void *addr, size_t bytes, __wsum *csum,
struct iov_iter *i)
{
@@ -1052,7 +1151,7 @@ size_t csum_and_copy_to_iter(const void *addr, size_t bytes, __wsum *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_base,
v.iov_len, 0, &err);
if (!err) {
sum = csum_block_add(sum, next, off);
generated by cgit v1.2.3 (git 2.25.1) at 2025-03-26 16:26:09 +0000