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-rw-r--r--Documentation/filesystems/porting.rst9
-rw-r--r--fs/btrfs/file.c23
-rw-r--r--fs/fuse/file.c4
-rw-r--r--fs/iomap/buffered-io.c35
-rw-r--r--fs/ntfs/file.c33
-rw-r--r--include/linux/uio.h66
-rw-r--r--include/net/checksum.h14
-rw-r--r--lib/iov_iter.c1231
-rw-r--r--mm/filemap.c36
9 files changed, 643 insertions, 808 deletions
diff --git a/Documentation/filesystems/porting.rst b/Documentation/filesystems/porting.rst
index 0302035781be..43b492d08dec 100644
--- a/Documentation/filesystems/porting.rst
+++ b/Documentation/filesystems/porting.rst
@@ -890,3 +890,12 @@ been called or returned with non -EIOCBQUEUED code.
mnt_want_write_file() can now only be paired with mnt_drop_write_file(),
whereas previously it could be paired with mnt_drop_write() as well.
+
+---
+
+**mandatory**
+
+iov_iter_copy_from_user_atomic() is gone; use copy_page_from_iter_atomic().
+The difference is copy_page_from_iter_atomic() advances the iterator and
+you don't need iov_iter_advance() after it. However, if you decide to use
+only a part of obtained data, you should do iov_iter_revert().
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 28a05ba47060..ee34497500e1 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -399,7 +399,7 @@ static noinline int btrfs_copy_from_user(loff_t pos, size_t write_bytes,
/*
* Copy data from userspace to the current page
*/
- copied = iov_iter_copy_from_user_atomic(page, i, offset, count);
+ copied = copy_page_from_iter_atomic(page, offset, count, i);
/* Flush processor's dcache for this page */
flush_dcache_page(page);
@@ -413,20 +413,19 @@ static noinline int btrfs_copy_from_user(loff_t pos, size_t write_bytes,
* The rest of the btrfs_file_write code will fall
* back to page at a time copies after we return 0.
*/
- if (!PageUptodate(page) && copied < count)
- copied = 0;
+ if (unlikely(copied < count)) {
+ if (!PageUptodate(page)) {
+ iov_iter_revert(i, copied);
+ copied = 0;
+ }
+ if (!copied)
+ break;
+ }
- iov_iter_advance(i, copied);
write_bytes -= copied;
total_copied += copied;
-
- /* Return to btrfs_file_write_iter to fault page */
- if (unlikely(copied == 0))
- break;
-
- if (copied < PAGE_SIZE - offset) {
- offset += copied;
- } else {
+ offset += copied;
+ if (offset == PAGE_SIZE) {
pg++;
offset = 0;
}
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 09ef2a4d25ed..4722fa31a185 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -1171,14 +1171,12 @@ static ssize_t fuse_fill_write_pages(struct fuse_io_args *ia,
if (mapping_writably_mapped(mapping))
flush_dcache_page(page);
- tmp = iov_iter_copy_from_user_atomic(page, ii, offset, bytes);
+ tmp = copy_page_from_iter_atomic(page, offset, bytes, ii);
flush_dcache_page(page);
- iov_iter_advance(ii, tmp);
if (!tmp) {
unlock_page(page);
put_page(page);
- bytes = min(bytes, iov_iter_single_seg_count(ii));
goto again;
}
diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index 0065781935c7..41da4f14c00b 100644
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -746,10 +746,6 @@ again:
* Otherwise there's a nasty deadlock on copying from the
* same page as we're writing to, without it being marked
* up-to-date.
- *
- * Not only is this an optimisation, but it is also required
- * to check that the address is actually valid, when atomic
- * usercopies are used, below.
*/
if (unlikely(iov_iter_fault_in_readable(i, bytes))) {
status = -EFAULT;
@@ -764,30 +760,29 @@ again:
if (mapping_writably_mapped(inode->i_mapping))
flush_dcache_page(page);
- copied = iov_iter_copy_from_user_atomic(page, i, offset, bytes);
+ copied = copy_page_from_iter_atomic(page, offset, bytes, i);
- copied = iomap_write_end(inode, pos, bytes, copied, page, iomap,
+ status = iomap_write_end(inode, pos, bytes, copied, page, iomap,
srcmap);
- cond_resched();
+ if (unlikely(copied != status))
+ iov_iter_revert(i, copied - status);
- iov_iter_advance(i, copied);
- if (unlikely(copied == 0)) {
+ cond_resched();
+ if (unlikely(status == 0)) {
/*
- * If we were unable to copy any data at all, we must
- * fall back to a single segment length write.
- *
- * If we didn't fallback here, we could livelock
- * because not all segments in the iov can be copied at
- * once without a pagefault.
+ * A short copy made iomap_write_end() reject the
+ * thing entirely. Might be memory poisoning
+ * halfway through, might be a race with munmap,
+ * might be severe memory pressure.
*/
- bytes = min_t(unsigned long, PAGE_SIZE - offset,
- iov_iter_single_seg_count(i));
+ if (copied)
+ bytes = copied;
goto again;
}
- pos += copied;
- written += copied;
- length -= copied;
+ pos += status;
+ written += status;
+ length -= status;
balance_dirty_pages_ratelimited(inode->i_mapping);
} while (iov_iter_count(i) && length);
diff --git a/fs/ntfs/file.c b/fs/ntfs/file.c
index e5aab265dff1..ab4f3362466d 100644
--- a/fs/ntfs/file.c
+++ b/fs/ntfs/file.c
@@ -1684,20 +1684,17 @@ static size_t ntfs_copy_from_user_iter(struct page **pages, unsigned nr_pages,
{
struct page **last_page = pages + nr_pages;
size_t total = 0;
- struct iov_iter data = *i;
unsigned len, copied;
do {
len = PAGE_SIZE - ofs;
if (len > bytes)
len = bytes;
- copied = iov_iter_copy_from_user_atomic(*pages, &data, ofs,
- len);
+ copied = copy_page_from_iter_atomic(*pages, ofs, len, i);
total += copied;
bytes -= copied;
if (!bytes)
break;
- iov_iter_advance(&data, copied);
if (copied < len)
goto err;
ofs = 0;
@@ -1866,34 +1863,24 @@ again:
if (likely(copied == bytes)) {
status = ntfs_commit_pages_after_write(pages, do_pages,
pos, bytes);
- if (!status)
- status = bytes;
}
do {
unlock_page(pages[--do_pages]);
put_page(pages[do_pages]);
} while (do_pages);
- if (unlikely(status < 0))
+ if (unlikely(status < 0)) {
+ iov_iter_revert(i, copied);
break;
- copied = status;
+ }
cond_resched();
- if (unlikely(!copied)) {
- size_t sc;
-
- /*
- * We failed to copy anything. Fall back to single
- * segment length write.
- *
- * This is needed to avoid possible livelock in the
- * case that all segments in the iov cannot be copied
- * at once without a pagefault.
- */
- sc = iov_iter_single_seg_count(i);
- if (bytes > sc)
- bytes = sc;
+ if (unlikely(copied < bytes)) {
+ iov_iter_revert(i, copied);
+ if (copied)
+ bytes = copied;
+ else if (bytes > PAGE_SIZE - ofs)
+ bytes = PAGE_SIZE - ofs;
goto again;
}
- iov_iter_advance(i, copied);
pos += copied;
written += copied;
balance_dirty_pages_ratelimited(mapping);
diff --git a/include/linux/uio.h b/include/linux/uio.h
index d3ec87706d75..82c3c3e819e0 100644
--- a/include/linux/uio.h
+++ b/include/linux/uio.h
@@ -19,21 +19,17 @@ struct kvec {
enum iter_type {
/* iter types */
- ITER_IOVEC = 4,
- ITER_KVEC = 8,
- ITER_BVEC = 16,
- ITER_PIPE = 32,
- ITER_DISCARD = 64,
- ITER_XARRAY = 128,
+ ITER_IOVEC,
+ ITER_KVEC,
+ ITER_BVEC,
+ ITER_PIPE,
+ ITER_XARRAY,
+ ITER_DISCARD,
};
struct iov_iter {
- /*
- * Bit 0 is the read/write bit, set if we're writing.
- * Bit 1 is the BVEC_FLAG_NO_REF bit, set if type is a bvec and
- * the caller isn't expecting to drop a page reference when done.
- */
- unsigned int type;
+ u8 iter_type;
+ bool data_source;
size_t iov_offset;
size_t count;
union {
@@ -55,7 +51,7 @@ struct iov_iter {
static inline enum iter_type iov_iter_type(const struct iov_iter *i)
{
- return i->type & ~(READ | WRITE);
+ return i->iter_type;
}
static inline bool iter_is_iovec(const struct iov_iter *i)
@@ -90,7 +86,7 @@ static inline bool iov_iter_is_xarray(const struct iov_iter *i)
static inline unsigned char iov_iter_rw(const struct iov_iter *i)
{
- return i->type & (READ | WRITE);
+ return i->data_source ? WRITE : READ;
}
/*
@@ -119,11 +115,11 @@ static inline struct iovec iov_iter_iovec(const struct iov_iter *iter)
};
}
-size_t iov_iter_copy_from_user_atomic(struct page *page,
- struct iov_iter *i, unsigned long offset, size_t bytes);
+size_t copy_page_from_iter_atomic(struct page *page, unsigned offset,
+ size_t bytes, struct iov_iter *i);
void iov_iter_advance(struct iov_iter *i, size_t bytes);
void iov_iter_revert(struct iov_iter *i, size_t bytes);
-int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes);
+int iov_iter_fault_in_readable(const struct iov_iter *i, size_t bytes);
size_t iov_iter_single_seg_count(const struct iov_iter *i);
size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes,
struct iov_iter *i);
@@ -132,9 +128,7 @@ size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes,
size_t _copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i);
size_t _copy_from_iter(void *addr, size_t bytes, struct iov_iter *i);
-bool _copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i);
size_t _copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i);
-bool _copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i);
static __always_inline __must_check
size_t copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i)
@@ -157,10 +151,11 @@ size_t copy_from_iter(void *addr, size_t bytes, struct iov_iter *i)
static __always_inline __must_check
bool copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i)
{
- if (unlikely(!check_copy_size(addr, bytes, false)))
- return false;
- else
- return _copy_from_iter_full(addr, bytes, i);
+ size_t copied = copy_from_iter(addr, bytes, i);
+ if (likely(copied == bytes))
+ return true;
+ iov_iter_revert(i, copied);
+ return false;
}
static __always_inline __must_check
@@ -175,10 +170,11 @@ size_t copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i)
static __always_inline __must_check
bool copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i)
{
- if (unlikely(!check_copy_size(addr, bytes, false)))
- return false;
- else
- return _copy_from_iter_full_nocache(addr, bytes, i);
+ size_t copied = copy_from_iter_nocache(addr, bytes, i);
+ if (likely(copied == bytes))
+ return true;
+ iov_iter_revert(i, copied);
+ return false;
}
#ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE
@@ -278,7 +274,17 @@ struct csum_state {
size_t csum_and_copy_to_iter(const void *addr, size_t bytes, void *csstate, struct iov_iter *i);
size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, struct iov_iter *i);
-bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum, struct iov_iter *i);
+
+static __always_inline __must_check
+bool csum_and_copy_from_iter_full(void *addr, size_t bytes,
+ __wsum *csum, struct iov_iter *i)
+{
+ size_t copied = csum_and_copy_from_iter(addr, bytes, csum, i);
+ if (likely(copied == bytes))
+ return true;
+ iov_iter_revert(i, copied);
+ return false;
+}
size_t hash_and_copy_to_iter(const void *addr, size_t bytes, void *hashp,
struct iov_iter *i);
@@ -294,8 +300,4 @@ ssize_t __import_iovec(int type, const struct iovec __user *uvec,
int import_single_range(int type, void __user *buf, size_t len,
struct iovec *iov, struct iov_iter *i);
-int iov_iter_for_each_range(struct iov_iter *i, size_t bytes,
- int (*f)(struct kvec *vec, void *context),
- void *context);
-
#endif
diff --git a/include/net/checksum.h b/include/net/checksum.h
index 0d05b9e8690b..5b96d5bd6e54 100644
--- a/include/net/checksum.h
+++ b/include/net/checksum.h
@@ -80,16 +80,18 @@ static inline __sum16 csum16_sub(__sum16 csum, __be16 addend)
return csum16_add(csum, ~addend);
}
-static inline __wsum
-csum_block_add(__wsum csum, __wsum csum2, int offset)
+static inline __wsum csum_shift(__wsum sum, int offset)
{
- u32 sum = (__force u32)csum2;
-
/* rotate sum to align it with a 16b boundary */
if (offset & 1)
- sum = ror32(sum, 8);
+ return (__force __wsum)ror32((__force u32)sum, 8);
+ return sum;
+}
- return csum_add(csum, (__force __wsum)sum);
+static inline __wsum
+csum_block_add(__wsum csum, __wsum csum2, int offset)
+{
+ return csum_add(csum, csum_shift(csum2, offset));
}
static inline __wsum
diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index c701b7a187f2..97e04c5dbeef 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -16,170 +16,137 @@
#define PIPE_PARANOIA /* for now */
-#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, __bi, skip, STEP) { \
- struct bvec_iter __start; \
- __start.bi_size = n; \
- __start.bi_bvec_done = skip; \
- __start.bi_idx = 0; \
- for_each_bvec(__v, i->bvec, __bi, __start) { \
- (void)(STEP); \
- } \
-}
-
-#define iterate_xarray(i, n, __v, skip, STEP) { \
+/* covers iovec and kvec alike */
+#define iterate_iovec(i, n, base, len, off, __p, STEP) { \
+ size_t off = 0; \
+ size_t skip = i->iov_offset; \
+ do { \
+ len = min(n, __p->iov_len - skip); \
+ if (likely(len)) { \
+ base = __p->iov_base + skip; \
+ len -= (STEP); \
+ off += len; \
+ skip += len; \
+ n -= len; \
+ if (skip < __p->iov_len) \
+ break; \
+ } \
+ __p++; \
+ skip = 0; \
+ } while (n); \
+ i->iov_offset = skip; \
+ n = off; \
+}
+
+#define iterate_bvec(i, n, base, len, off, p, STEP) { \
+ size_t off = 0; \
+ unsigned skip = i->iov_offset; \
+ while (n) { \
+ unsigned offset = p->bv_offset + skip; \
+ unsigned left; \
+ void *kaddr = kmap_local_page(p->bv_page + \
+ offset / PAGE_SIZE); \
+ base = kaddr + offset % PAGE_SIZE; \
+ len = min(min(n, (size_t)(p->bv_len - skip)), \
+ (size_t)(PAGE_SIZE - offset % PAGE_SIZE)); \
+ left = (STEP); \
+ kunmap_local(kaddr); \
+ len -= left; \
+ off += len; \
+ skip += len; \
+ if (skip == p->bv_len) { \
+ skip = 0; \
+ p++; \
+ } \
+ n -= len; \
+ if (left) \
+ break; \
+ } \
+ i->iov_offset = skip; \
+ n = off; \
+}
+
+#define iterate_xarray(i, n, base, len, __off, STEP) { \
+ __label__ __out; \
+ size_t __off = 0; \
struct page *head = NULL; \
- size_t wanted = n, seg, offset; \
- loff_t start = i->xarray_start + skip; \
- pgoff_t index = start >> PAGE_SHIFT; \
+ loff_t start = i->xarray_start + i->iov_offset; \
+ unsigned offset = start % PAGE_SIZE; \
+ pgoff_t index = start / PAGE_SIZE; \
int j; \
\
XA_STATE(xas, i->xarray, index); \
\
- rcu_read_lock(); \
- xas_for_each(&xas, head, ULONG_MAX) { \
- if (xas_retry(&xas, head)) \
- continue; \
- if (WARN_ON(xa_is_value(head))) \
- break; \
- if (WARN_ON(PageHuge(head))) \
- break; \
+ rcu_read_lock(); \
+ xas_for_each(&xas, head, ULONG_MAX) { \
+ unsigned left; \
+ if (xas_retry(&xas, head)) \
+ continue; \
+ if (WARN_ON(xa_is_value(head))) \
+ break; \
+ if (WARN_ON(PageHuge(head))) \
+ break; \
for (j = (head->index < index) ? index - head->index : 0; \
- j < thp_nr_pages(head); j++) { \
- __v.bv_page = head + j; \
- offset = (i->xarray_start + skip) & ~PAGE_MASK; \
- seg = PAGE_SIZE - offset; \
- __v.bv_offset = offset; \
- __v.bv_len = min(n, seg); \
- (void)(STEP); \
- n -= __v.bv_len; \
- skip += __v.bv_len; \
- if (n == 0) \
- break; \
- } \
- if (n == 0) \
- break; \
- } \
- rcu_read_unlock(); \
- n = wanted - n; \
-}
-
-#define iterate_all_kinds(i, n, v, I, B, K, X) { \
- 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 if (unlikely(i->type & ITER_DISCARD)) { \
- } else if (unlikely(i->type & ITER_XARRAY)) { \
- struct bio_vec v; \
- iterate_xarray(i, n, v, skip, (X)); \
- } else { \
- const struct iovec *iov; \
- struct iovec v; \
- iterate_iovec(i, n, v, iov, skip, (I)) \
+ j < thp_nr_pages(head); j++) { \
+ void *kaddr = kmap_local_page(head + j); \
+ base = kaddr + offset; \
+ len = PAGE_SIZE - offset; \
+ len = min(n, len); \
+ left = (STEP); \
+ kunmap_local(kaddr); \
+ len -= left; \
+ __off += len; \
+ n -= len; \
+ if (left || n == 0) \
+ goto __out; \
+ offset = 0; \
} \
} \
+__out: \
+ rcu_read_unlock(); \
+ i->iov_offset += __off; \
+ n = __off; \
}
-#define iterate_and_advance(i, n, v, I, B, K, X) { \
+#define __iterate_and_advance(i, n, base, len, off, I, K) { \
if (unlikely(i->count < n)) \
n = i->count; \
- if (i->count) { \
- size_t skip = i->iov_offset; \
- if (unlikely(i->type & ITER_BVEC)) { \
+ if (likely(n)) { \
+ if (likely(iter_is_iovec(i))) { \
+ const struct iovec *iov = i->iov; \
+ void __user *base; \
+ size_t len; \
+ iterate_iovec(i, n, base, len, off, \
+ iov, (I)) \
+ i->nr_segs -= iov - i->iov; \
+ i->iov = iov; \
+ } else if (iov_iter_is_bvec(i)) { \
const struct bio_vec *bvec = i->bvec; \
- struct bio_vec v; \
- struct bvec_iter __bi; \
- iterate_bvec(i, n, v, __bi, skip, (B)) \
- i->bvec = __bvec_iter_bvec(i->bvec, __bi); \
- i->nr_segs -= i->bvec - bvec; \
- skip = __bi.bi_bvec_done; \
- } 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; \
- } \
+ void *base; \
+ size_t len; \
+ iterate_bvec(i, n, base, len, off, \
+ bvec, (K)) \
+ i->nr_segs -= bvec - i->bvec; \
+ i->bvec = bvec; \
+ } else if (iov_iter_is_kvec(i)) { \
+ const struct kvec *kvec = i->kvec; \
+ void *base; \
+ size_t len; \
+ iterate_iovec(i, n, base, len, off, \
+ kvec, (K)) \
i->nr_segs -= kvec - i->kvec; \
i->kvec = kvec; \
- } else if (unlikely(i->type & ITER_DISCARD)) { \
- skip += n; \
- } else if (unlikely(i->type & ITER_XARRAY)) { \
- struct bio_vec v; \
- iterate_xarray(i, n, v, skip, (X)) \
- } 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; \
+ } else if (iov_iter_is_xarray(i)) { \
+ void *base; \
+ size_t len; \
+ iterate_xarray(i, n, base, len, off, \
+ (K)) \
} \
i->count -= n; \
- i->iov_offset = skip; \
} \
}
+#define iterate_and_advance(i, n, base, len, off, I, K) \
+ __iterate_and_advance(i, n, base, len, off, I, ((void)(K),0))
static int copyout(void __user *to, const void *from, size_t n)
{
@@ -469,19 +436,25 @@ out:
* Return 0 on success, or non-zero if the memory could not be accessed (i.e.
* because it is an invalid address).
*/
-int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes)
+int iov_iter_fault_in_readable(const struct iov_iter *i, size_t bytes)
{
- size_t skip = i->iov_offset;
- const struct iovec *iov;
- int err;
- struct iovec v;
+ if (iter_is_iovec(i)) {
+ const struct iovec *p;
+ size_t skip;
- if (!(i->type & (ITER_BVEC|ITER_KVEC))) {
- iterate_iovec(i, bytes, v, iov, skip, ({
- err = fault_in_pages_readable(v.iov_base, v.iov_len);
+ if (bytes > i->count)
+ bytes = i->count;
+ for (p = i->iov, skip = i->iov_offset; bytes; p++, skip = 0) {
+ size_t len = min(bytes, p->iov_len - skip);
+ int err;
+
+ if (unlikely(!len))
+ continue;
+ err = fault_in_pages_readable(p->iov_base + skip, len);
if (unlikely(err))
- return err;
- 0;}))
+ return err;
+ bytes -= len;
+ }
}
return 0;
}
@@ -492,19 +465,15 @@ void iov_iter_init(struct iov_iter *i, unsigned int direction,
size_t count)
{
WARN_ON(direction & ~(READ | WRITE));
- direction &= READ | WRITE;
-
- /* It will get better. Eventually... */
- if (uaccess_kernel()) {
- i->type = ITER_KVEC | direction;
- i->kvec = (struct kvec *)iov;
- } else {
- i->type = ITER_IOVEC | direction;
- i->iov = iov;
- }
- i->nr_segs = nr_segs;
- i->iov_offset = 0;
- i->count = count;
+ WARN_ON_ONCE(uaccess_kernel());
+ *i = (struct iov_iter) {
+ .iter_type = ITER_IOVEC,
+ .data_source = direction,
+ .iov = iov,
+ .nr_segs = nr_segs,
+ .iov_offset = 0,
+ .count = count
+ };
}
EXPORT_SYMBOL(iov_iter_init);
@@ -613,55 +582,45 @@ static __wsum csum_and_memcpy(void *to, const void *from, size_t len,
}
static size_t csum_and_copy_to_pipe_iter(const void *addr, size_t bytes,
- struct csum_state *csstate,
- struct iov_iter *i)
+ struct iov_iter *i, __wsum *sump)
{
struct pipe_inode_info *pipe = i->pipe;
unsigned int p_mask = pipe->ring_size - 1;
- __wsum sum = csstate->csum;
- size_t off = csstate->off;
+ __wsum sum = *sump;
+ size_t off = 0;
unsigned int i_head;
- size_t n, r;
+ size_t r;
if (!sanity(i))
return 0;
- bytes = n = push_pipe(i, bytes, &i_head, &r);
- if (unlikely(!n))
- return 0;
- do {
- size_t chunk = min_t(size_t, n, PAGE_SIZE - r);
- char *p = kmap_atomic(pipe->bufs[i_head & p_mask].page);
- sum = csum_and_memcpy(p + r, addr, chunk, sum, off);
- kunmap_atomic(p);
+ bytes = push_pipe(i, bytes, &i_head, &r);
+ while (bytes) {
+ size_t chunk = min_t(size_t, bytes, PAGE_SIZE - r);
+ char *p = kmap_local_page(pipe->bufs[i_head & p_mask].page);
+ sum = csum_and_memcpy(p + r, addr + off, chunk, sum, off);
+ kunmap_local(p);
i->head = i_head;
i->iov_offset = r + chunk;
- n -= chunk;
+ bytes -= chunk;
off += chunk;
- addr += chunk;
r = 0;
i_head++;
- } while (n);
- i->count -= bytes;
- csstate->csum = sum;
- csstate->off = off;
- return bytes;
+ }
+ *sump = sum;
+ i->count -= off;
+ return off;
}
size_t _copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i)
{
- const char *from = addr;
if (unlikely(iov_iter_is_pipe(i)))
return copy_pipe_to_iter(addr, bytes, i);
if (iter_is_iovec(i))
might_fault();
- iterate_and_advance(i, bytes, v,
- copyout(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(v.bv_page, v.bv_offset,
- (from += v.bv_len) - v.bv_len, v.bv_len)
+ iterate_and_advance(i, bytes, base, len, off,
+ copyout(base, addr + off, len),
+ memcpy(base, addr + off, len)
)
return bytes;
@@ -678,19 +637,6 @@ static int copyout_mc(void __user *to, const void *from, size_t n)
return n;
}
-static unsigned long copy_mc_to_page(struct page *page, size_t offset,
- const char *from, size_t len)
-{
- unsigned long ret;
- char *to;
-
- to = kmap_atomic(page);
- ret = copy_mc_to_kernel(to + offset, from, len);
- kunmap_atomic(to);
-
- return ret;
-}
-
static size_t copy_mc_pipe_to_iter(const void *addr, size_t bytes,
struct iov_iter *i)
{
@@ -702,25 +648,23 @@ static size_t copy_mc_pipe_to_iter(const void *addr, size_t bytes,
if (!sanity(i))
return 0;
- bytes = n = push_pipe(i, bytes, &i_head, &off);
- if (unlikely(!n))
- return 0;
- do {
+ n = push_pipe(i, bytes, &i_head, &off);
+ while (n) {
size_t chunk = min_t(size_t, n, PAGE_SIZE - off);
+ char *p = kmap_local_page(pipe->bufs[i_head & p_mask].page);
unsigned long rem;
-
- rem = copy_mc_to_page(pipe->bufs[i_head & p_mask].page,
- off, addr, chunk);
+ rem = copy_mc_to_kernel(p + off, addr + xfer, chunk);
+ chunk -= rem;
+ kunmap_local(p);
i->head = i_head;
- i->iov_offset = off + chunk - rem;
- xfer += chunk - rem;
+ i->iov_offset = off + chunk;
+ xfer += chunk;
if (rem)
break;
n -= chunk;
- addr += chunk;
off = 0;
i_head++;
- } while (n);
+ }
i->count -= xfer;
return xfer;
}
@@ -750,46 +694,13 @@ static size_t copy_mc_pipe_to_iter(const void *addr, size_t bytes,
*/
size_t _copy_mc_to_iter(const void *addr, size_t bytes, struct iov_iter *i)
{
- const char *from = addr;
- unsigned long rem, curr_addr, s_addr = (unsigned long) addr;
-
if (unlikely(iov_iter_is_pipe(i)))
return copy_mc_pipe_to_iter(addr, bytes, i);
if (iter_is_iovec(i))
might_fault();
- iterate_and_advance(i, bytes, v,
- copyout_mc(v.iov_base, (from += v.iov_len) - v.iov_len,
- v.iov_len),
- ({
- rem = copy_mc_to_page(v.bv_page, v.bv_offset,
- (from += v.bv_len) - v.bv_len, v.bv_len);
- if (rem) {
- curr_addr = (unsigned long) from;
- bytes = curr_addr - s_addr - rem;
- return bytes;
- }
- }),
- ({
- rem = copy_mc_to_kernel(v.iov_base, (from += v.iov_len)
- - v.iov_len, v.iov_len);
- if (rem) {
- curr_addr = (unsigned long) from;
- bytes = curr_addr - s_addr - rem;
- return bytes;
- }
- }),
- ({
- rem = copy_mc_to_page(v.bv_page, v.bv_offset,
- (from += v.bv_len) - v.bv_len, v.bv_len);
- if (rem) {
- curr_addr = (unsigned long) from;
- bytes = curr_addr - s_addr - rem;
- rcu_read_unlock();
- i->iov_offset += bytes;
- i->count -= bytes;
- return bytes;
- }
- })
+ __iterate_and_advance(i, bytes, base, len, off,
+ copyout_mc(base, addr + off, len),
+ copy_mc_to_kernel(base, addr + off, len)
)
return bytes;
@@ -799,70 +710,30 @@ EXPORT_SYMBOL_GPL(_copy_mc_to_iter);
size_t _copy_from_iter(void *addr, size_t bytes, struct iov_iter *i)
{
- char *to = addr;
if (unlikely(iov_iter_is_pipe(i))) {
WARN_ON(1);
return 0;
}
if (iter_is_iovec(i))
might_fault();
- iterate_and_advance(i, bytes, v,
- copyin((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),
- memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page,
- v.bv_offset, v.bv_len)
+ iterate_and_advance(i, bytes, base, len, off,
+ copyin(addr + off, base, len),
+ memcpy(addr + off, base, len)
)
return bytes;
}
EXPORT_SYMBOL(_copy_from_iter);
-bool _copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i)
-{
- char *to = addr;
- if (unlikely(iov_iter_is_pipe(i))) {
- WARN_ON(1);
- return false;
- }
- if (unlikely(i->count < bytes))
- return false;
-
- if (iter_is_iovec(i))
- might_fault();
- iterate_all_kinds(i, bytes, v, ({
- if (copyin((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),
- memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page,
- v.bv_offset, v.bv_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;
if (unlikely(iov_iter_is_pipe(i))) {
WARN_ON(1);
return 0;
}
- iterate_and_advance(i, bytes, v,
- __copy_from_user_inatomic_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),
- memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page,
- v.bv_offset, v.bv_len)
+ iterate_and_advance(i, bytes, base, len, off,
+ __copy_from_user_inatomic_nocache(addr + off, base, len),
+ memcpy(addr + off, base, len)
)
return bytes;
@@ -886,20 +757,13 @@ EXPORT_SYMBOL(_copy_from_iter_nocache);
*/
size_t _copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i)
{
- char *to = addr;
if (unlikely(iov_iter_is_pipe(i))) {
WARN_ON(1);
return 0;
}
- iterate_and_advance(i, bytes, v,
- __copy_from_user_flushcache((to += v.iov_len) - v.iov_len,
- v.iov_base, v.iov_len),
- memcpy_page_flushcache((to += v.bv_len) - v.bv_len, v.bv_page,
- v.bv_offset, v.bv_len),
- memcpy_flushcache((to += v.iov_len) - v.iov_len, v.iov_base,
- v.iov_len),
- memcpy_page_flushcache((to += v.bv_len) - v.bv_len, v.bv_page,
- v.bv_offset, v.bv_len)
+ iterate_and_advance(i, bytes, base, len, off,
+ __copy_from_user_flushcache(addr + off, base, len),
+ memcpy_flushcache(addr + off, base, len)
)
return bytes;
@@ -907,32 +771,6 @@ size_t _copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i)
EXPORT_SYMBOL_GPL(_copy_from_iter_flushcache);
#endif
-bool _copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i)
-{
- char *to = addr;
- if (unlikely(iov_iter_is_pipe(i))) {
- WARN_ON(1);
- return false;
- }
- if (unlikely(i->count < bytes))
- return false;
- iterate_all_kinds(i, bytes, v, ({
- if (__copy_from_user_inatomic_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),
- memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page,
- v.bv_offset, v.bv_len)
- )
-
- iov_iter_advance(i, bytes);
- return true;
-}
-EXPORT_SYMBOL(_copy_from_iter_full_nocache);
-
static inline bool page_copy_sane(struct page *page, size_t offset, size_t n)
{
struct page *head;
@@ -957,22 +795,51 @@ static inline bool page_copy_sane(struct page *page, size_t offset, size_t n)
return false;
}
+static size_t __copy_page_to_iter(struct page *page, size_t offset, size_t bytes,
+ struct iov_iter *i)
+{
+ if (likely(iter_is_iovec(i)))
+ return copy_page_to_iter_iovec(page, offset, bytes, i);
+ if (iov_iter_is_bvec(i) || iov_iter_is_kvec(i) || iov_iter_is_xarray(i)) {
+ void *kaddr = kmap_local_page(page);
+ size_t wanted = _copy_to_iter(kaddr + offset, bytes, i);
+ kunmap_local(kaddr);
+ return wanted;
+ }
+ if (iov_iter_is_pipe(i))
+ return copy_page_to_iter_pipe(page, offset, bytes, i);
+ if (unlikely(iov_iter_is_discard(i))) {
+ if (unlikely(i->count < bytes))
+ bytes = i->count;
+ i->count -= bytes;
+ return bytes;
+ }
+ WARN_ON(1);
+ return 0;
+}
+
size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes,
struct iov_iter *i)
{
+ size_t res = 0;
if (unlikely(!page_copy_sane(page, offset, bytes)))
return 0;
- if (i->type & (ITER_BVEC | ITER_KVEC | ITER_XARRAY)) {
- void *kaddr = kmap_atomic(page);
- size_t wanted = copy_to_iter(kaddr + offset, bytes, i);
- kunmap_atomic(kaddr);
- return wanted;
- } else if (unlikely(iov_iter_is_discard(i)))
- return bytes;
- else if (likely(!iov_iter_is_pipe(i)))
- return copy_page_to_iter_iovec(page, offset, bytes, i);
- else
- return copy_page_to_iter_pipe(page, offset, bytes, i);
+ page += offset / PAGE_SIZE; // first subpage
+ offset %= PAGE_SIZE;
+ while (1) {
+ size_t n = __copy_page_to_iter(page, offset,
+ min(bytes, (size_t)PAGE_SIZE - offset), i);
+ res += n;
+ bytes -= n;
+ if (!bytes || !n)
+ break;
+ offset += n;
+ if (offset == PAGE_SIZE) {
+ page++;
+ offset = 0;
+ }
+ }
+ return res;
}
EXPORT_SYMBOL(copy_page_to_iter);
@@ -981,17 +848,16 @@ size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes,
{
if (unlikely(!page_copy_sane(page, offset, bytes)))
return 0;
- if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) {
- WARN_ON(1);
- return 0;
- }
- if (i->type & (ITER_BVEC | ITER_KVEC | ITER_XARRAY)) {
- void *kaddr = kmap_atomic(page);
+ if (likely(iter_is_iovec(i)))
+ return copy_page_from_iter_iovec(page, offset, bytes, i);
+ if (iov_iter_is_bvec(i) || iov_iter_is_kvec(i) || iov_iter_is_xarray(i)) {
+ void *kaddr = kmap_local_page(page);
size_t wanted = _copy_from_iter(kaddr + offset, bytes, i);
- kunmap_atomic(kaddr);
+ kunmap_local(kaddr);
return wanted;
- } else
- return copy_page_from_iter_iovec(page, offset, bytes, i);
+ }
+ WARN_ON(1);
+ return 0;
}
EXPORT_SYMBOL(copy_page_from_iter);
@@ -1011,7 +877,9 @@ static size_t pipe_zero(size_t bytes, struct iov_iter *i)
do {
size_t chunk = min_t(size_t, n, PAGE_SIZE - off);
- memzero_page(pipe->bufs[i_head & p_mask].page, off, chunk);
+ char *p = kmap_local_page(pipe->bufs[i_head & p_mask].page);
+ memset(p + off, 0, chunk);
+ kunmap_local(p);
i->head = i_head;
i->iov_offset = off + chunk;
n -= chunk;
@@ -1026,19 +894,17 @@ size_t iov_iter_zero(size_t bytes, struct iov_iter *i)
{
if (unlikely(iov_iter_is_pipe(i)))
return pipe_zero(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),
- memzero_page(v.bv_page, v.bv_offset, v.bv_len)
+ iterate_and_advance(i, bytes, base, len, count,
+ clear_user(base, len),
+ memset(base, 0, 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)
+size_t copy_page_from_iter_atomic(struct page *page, unsigned offset, size_t bytes,
+ struct iov_iter *i)
{
char *kaddr = kmap_atomic(page), *p = kaddr + offset;
if (unlikely(!page_copy_sane(page, offset, bytes))) {
@@ -1050,18 +916,14 @@ size_t iov_iter_copy_from_user_atomic(struct page *page,
WARN_ON(1);
return 0;
}
- iterate_all_kinds(i, bytes, v,
- copyin((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),
- memcpy_from_page((p += v.bv_len) - v.bv_len, v.bv_page,
- v.bv_offset, v.bv_len)
+ iterate_and_advance(i, bytes, base, len, off,
+ copyin(p + off, base, len),
+ memcpy(p + off, base, len)
)
kunmap_atomic(kaddr);
return bytes;
}
-EXPORT_SYMBOL(iov_iter_copy_from_user_atomic);
+EXPORT_SYMBOL(copy_page_from_iter_atomic);
static inline void pipe_truncate(struct iov_iter *i)
{
@@ -1092,8 +954,6 @@ static inline void pipe_truncate(struct iov_iter *i)
static void pipe_advance(struct iov_iter *i, size_t size)
{
struct pipe_inode_info *pipe = i->pipe;
- if (unlikely(i->count < size))
- size = i->count;
if (size) {
struct pipe_buffer *buf;
unsigned int p_mask = pipe->ring_size - 1;
@@ -1132,27 +992,42 @@ static void iov_iter_bvec_advance(struct iov_iter *i, size_t size)
i->iov_offset = bi.bi_bvec_done;
}
-void iov_iter_advance(struct iov_iter *i, size_t size)
+static void iov_iter_iovec_advance(struct iov_iter *i, size_t size)
{
- if (unlikely(iov_iter_is_pipe(i))) {
- pipe_advance(i, size);
- return;
- }
- if (unlikely(iov_iter_is_discard(i))) {
- i->count -= size;
+ const struct iovec *iov, *end;
+
+ if (!i->count)
return;
+ i->count -= size;
+
+ size += i->iov_offset; // from beginning of current segment
+ for (iov = i->iov, end = iov + i->nr_segs; iov < end; iov++) {
+ if (likely(size < iov->iov_len))
+ break;
+ size -= iov->iov_len;
}
- if (unlikely(iov_iter_is_xarray(i))) {
- size = min(size, i->count);
+ i->iov_offset = size;
+ i->nr_segs -= iov - i->iov;
+ i->iov = iov;
+}
+
+void iov_iter_advance(struct iov_iter *i, size_t size)
+{
+ if (unlikely(i->count < size))
+ size = i->count;
+ if (likely(iter_is_iovec(i) || iov_iter_is_kvec(i))) {
+ /* iovec and kvec have identical layouts */
+ iov_iter_iovec_advance(i, size);
+ } else if (iov_iter_is_bvec(i)) {
+ iov_iter_bvec_advance(i, size);
+ } else if (iov_iter_is_pipe(i)) {
+ pipe_advance(i, size);
+ } else if (unlikely(iov_iter_is_xarray(i))) {
i->iov_offset += size;
i->count -= size;
- return;
- }
- if (iov_iter_is_bvec(i)) {
- iov_iter_bvec_advance(i, size);
- return;
+ } else if (iov_iter_is_discard(i)) {
+ i->count -= size;
}
- iterate_and_advance(i, size, v, 0, 0, 0, 0)
}
EXPORT_SYMBOL(iov_iter_advance);
@@ -1234,16 +1109,13 @@ EXPORT_SYMBOL(iov_iter_revert);
*/
size_t iov_iter_single_seg_count(const struct iov_iter *i)
{
- if (unlikely(iov_iter_is_pipe(i)))
- return i->count; // it is a silly place, anyway
- if (i->nr_segs == 1)
- return i->count;
- if (unlikely(iov_iter_is_discard(i) || iov_iter_is_xarray(i)))
- return i->count;
- if (iov_iter_is_bvec(i))
- return min(i->count, i->bvec->bv_len - i->iov_offset);
- else
- return min(i->count, i->iov->iov_len - i->iov_offset);
+ if (i->nr_segs > 1) {
+ if (likely(iter_is_iovec(i) || iov_iter_is_kvec(i)))
+ return min(i->count, i->iov->iov_len - i->iov_offset);
+ if (iov_iter_is_bvec(i))
+ return min(i->count, i->bvec->bv_len - i->iov_offset);
+ }
+ return i->count;
}
EXPORT_SYMBOL(iov_iter_single_seg_count);
@@ -1252,11 +1124,14 @@ void iov_iter_kvec(struct iov_iter *i, unsigned int direction,
size_t count)
{
WARN_ON(direction & ~(READ | WRITE));
- i->type = ITER_KVEC | (direction & (READ | WRITE));
- i->kvec = kvec;
- i->nr_segs = nr_segs;
- i->iov_offset = 0;
- i->count = count;
+ *i = (struct iov_iter){
+ .iter_type = ITER_KVEC,
+ .data_source = direction,
+ .kvec = kvec,
+ .nr_segs = nr_segs,
+ .iov_offset = 0,
+ .count = count
+ };
}
EXPORT_SYMBOL(iov_iter_kvec);
@@ -1265,11 +1140,14 @@ void iov_iter_bvec(struct iov_iter *i, unsigned int direction,
size_t count)
{
WARN_ON(direction & ~(READ | WRITE));
- i->type = ITER_BVEC | (direction & (READ | WRITE));
- i->bvec = bvec;
- i->nr_segs = nr_segs;
- i->iov_offset = 0;
- i->count = count;
+ *i = (struct iov_iter){
+ .iter_type = ITER_BVEC,
+ .data_source = direction,
+ .bvec = bvec,
+ .nr_segs = nr_segs,
+ .iov_offset = 0,
+ .count = count
+ };
}
EXPORT_SYMBOL(iov_iter_bvec);
@@ -1279,12 +1157,15 @@ void iov_iter_pipe(struct iov_iter *i, unsigned int direction,
{
BUG_ON(direction != READ);
WARN_ON(pipe_full(pipe->head, pipe->tail, pipe->ring_size));
- i->type = ITER_PIPE | READ;
- i->pipe = pipe;
- i->head = pipe->head;
- i->iov_offset = 0;
- i->count = count;
- i->start_head = i->head;
+ *i = (struct iov_iter){
+ .iter_type = ITER_PIPE,
+ .data_source = false,
+ .pipe = pipe,
+ .head = pipe->head,
+ .start_head = pipe->head,
+ .iov_offset = 0,
+ .count = count
+ };
}
EXPORT_SYMBOL(iov_iter_pipe);
@@ -1305,11 +1186,14 @@ void iov_iter_xarray(struct iov_iter *i, unsigned int direction,
struct xarray *xarray, loff_t start, size_t count)
{
BUG_ON(direction & ~1);
- i->type = ITER_XARRAY | (direction & (READ | WRITE));
- i->xarray = xarray;
- i->xarray_start = start;
- i->count = count;
- i->iov_offset = 0;
+ *i = (struct iov_iter) {
+ .iter_type = ITER_XARRAY,
+ .data_source = direction,
+ .xarray = xarray,
+ .xarray_start = start,
+ .count = count,
+ .iov_offset = 0
+ };
}
EXPORT_SYMBOL(iov_iter_xarray);
@@ -1325,56 +1209,103 @@ EXPORT_SYMBOL(iov_iter_xarray);
void iov_iter_discard(struct iov_iter *i, unsigned int direction, size_t count)
{
BUG_ON(direction != READ);
- i->type = ITER_DISCARD | READ;
- i->count = count;
- i->iov_offset = 0;
+ *i = (struct iov_iter){
+ .iter_type = ITER_DISCARD,
+ .data_source = false,
+ .count = count,
+ .iov_offset = 0
+ };
}
EXPORT_SYMBOL(iov_iter_discard);
-unsigned long iov_iter_alignment(const struct iov_iter *i)
+static unsigned long iov_iter_alignment_iovec(const struct iov_iter *i)
{
unsigned long res = 0;
size_t size = i->count;
+ size_t skip = i->iov_offset;
+ unsigned k;
+
+ for (k = 0; k < i->nr_segs; k++, skip = 0) {
+ size_t len = i->iov[k].iov_len - skip;
+ if (len) {
+ res |= (unsigned long)i->iov[k].iov_base + skip;
+ if (len > size)
+ len = size;
+ res |= len;
+ size -= len;
+ if (!size)
+ break;
+ }
+ }
+ return res;
+}
- if (unlikely(iov_iter_is_pipe(i))) {
+static unsigned long iov_iter_alignment_bvec(const struct iov_iter *i)
+{
+ unsigned res = 0;
+ size_t size = i->count;
+ unsigned skip = i->iov_offset;
+ unsigned k;
+
+ for (k = 0; k < i->nr_segs; k++, skip = 0) {
+ size_t len = i->bvec[k].bv_len - skip;
+ res |= (unsigned long)i->bvec[k].bv_offset + skip;
+ if (len > size)
+ len = size;
+ res |= len;
+ size -= len;
+ if (!size)
+ break;
+ }
+ return res;
+}
+
+unsigned long iov_iter_alignment(const struct iov_iter *i)
+{
+ /* iovec and kvec have identical layouts */
+ if (likely(iter_is_iovec(i) || iov_iter_is_kvec(i)))
+ return iov_iter_alignment_iovec(i);
+
+ if (iov_iter_is_bvec(i))
+ return iov_iter_alignment_bvec(i);
+
+ if (iov_iter_is_pipe(i)) {
unsigned int p_mask = i->pipe->ring_size - 1;
+ size_t size = i->count;
if (size && i->iov_offset && allocated(&i->pipe->bufs[i->head & p_mask]))
return size | i->iov_offset;
return size;
}
- if (unlikely(iov_iter_is_xarray(i)))
+
+ if (iov_iter_is_xarray(i))
return (i->xarray_start + i->iov_offset) | i->count;
- 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,
- res |= v.bv_offset | v.bv_len
- )
- return res;
+
+ return 0;
}
EXPORT_SYMBOL(iov_iter_alignment);
unsigned long iov_iter_gap_alignment(const struct iov_iter *i)
{
unsigned long res = 0;
+ unsigned long v = 0;
size_t size = i->count;
+ unsigned k;
- if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) {
- WARN_ON(1);
+ if (WARN_ON(!iter_is_iovec(i)))
return ~0U;
- }
- iterate_all_kinds(i, size, v,
- (res |= (!res ? 0 : (unsigned long)v.iov_base) |
- (size != v.iov_len ? size : 0), 0),
- (res |= (!res ? 0 : (unsigned long)v.bv_offset) |
- (size != v.bv_len ? size : 0)),
- (res |= (!res ? 0 : (unsigned long)v.iov_base) |
- (size != v.iov_len ? size : 0)),
- (res |= (!res ? 0 : (unsigned long)v.bv_offset) |
- (size != v.bv_len ? size : 0))
- );
+ for (k = 0; k < i->nr_segs; k++) {
+ if (i->iov[k].iov_len) {
+ unsigned long base = (unsigned long)i->iov[k].iov_base;
+ if (v) // if not the first one
+ res |= base | v; // this start | previous end
+ v = base + i->iov[k].iov_len;
+ if (size <= i->iov[k].iov_len)
+ break;
+ size -= i->iov[k].iov_len;
+ }
+ }
return res;
}
EXPORT_SYMBOL(iov_iter_gap_alignment);
@@ -1409,9 +1340,6 @@ static ssize_t pipe_get_pages(struct iov_iter *i,
unsigned int iter_head, npages;
size_t capacity;
- if (!maxsize)
- return 0;
-
if (!sanity(i))
return -EFAULT;
@@ -1492,29 +1420,67 @@ static ssize_t iter_xarray_get_pages(struct iov_iter *i,
return actual;
}
+/* must be done on non-empty ITER_IOVEC one */
+static unsigned long first_iovec_segment(const struct iov_iter *i,
+ size_t *size, size_t *start,
+ size_t maxsize, unsigned maxpages)
+{
+ size_t skip;
+ long k;
+
+ for (k = 0, skip = i->iov_offset; k < i->nr_segs; k++, skip = 0) {
+ unsigned long addr = (unsigned long)i->iov[k].iov_base + skip;
+ size_t len = i->iov[k].iov_len - skip;
+
+ if (unlikely(!len))
+ continue;
+ if (len > maxsize)
+ len = maxsize;
+ len += (*start = addr % PAGE_SIZE);
+ if (len > maxpages * PAGE_SIZE)
+ len = maxpages * PAGE_SIZE;
+ *size = len;
+ return addr & PAGE_MASK;
+ }
+ BUG(); // if it had been empty, we wouldn't get called
+}
+
+/* must be done on non-empty ITER_BVEC one */
+static struct page *first_bvec_segment(const struct iov_iter *i,
+ size_t *size, size_t *start,
+ size_t maxsize, unsigned maxpages)
+{
+ struct page *page;
+ size_t skip = i->iov_offset, len;
+
+ len = i->bvec->bv_len - skip;
+ if (len > maxsize)
+ len = maxsize;
+ skip += i->bvec->bv_offset;
+ page = i->bvec->bv_page + skip / PAGE_SIZE;
+ len += (*start = skip % PAGE_SIZE);
+ if (len > maxpages * PAGE_SIZE)
+ len = maxpages * PAGE_SIZE;
+ *size = len;
+ return page;
+}
+
ssize_t iov_iter_get_pages(struct iov_iter *i,
struct page **pages, size_t maxsize, unsigned maxpages,
size_t *start)
{
+ size_t len;
+ int n, res;
+
if (maxsize > i->count)
maxsize = i->count;
+ if (!maxsize)
+ return 0;
- if (unlikely(iov_iter_is_pipe(i)))
- return pipe_get_pages(i, pages, maxsize, maxpages, start);
- if (unlikely(iov_iter_is_xarray(i)))
- return iter_xarray_get_pages(i, pages, maxsize, maxpages, start);
- if (unlikely(iov_iter_is_discard(i)))
- return -EFAULT;
-
- 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 (likely(iter_is_iovec(i))) {
+ unsigned long addr;
- if (len > maxpages * PAGE_SIZE)
- len = maxpages * PAGE_SIZE;
- addr &= ~(PAGE_SIZE - 1);
+ addr = first_iovec_segment(i, &len, start, maxsize, maxpages);
n = DIV_ROUND_UP(len, PAGE_SIZE);
res = get_user_pages_fast(addr, n,
iov_iter_rw(i) != WRITE ? FOLL_WRITE : 0,
@@ -1522,17 +1488,21 @@ ssize_t iov_iter_get_pages(struct iov_iter *i,
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;
- }),
- 0
- )
- return 0;
+ }
+ if (iov_iter_is_bvec(i)) {
+ struct page *page;
+
+ page = first_bvec_segment(i, &len, start, maxsize, maxpages);
+ n = DIV_ROUND_UP(len, PAGE_SIZE);
+ while (n--)
+ get_page(*pages++ = page++);
+ return len - *start;
+ }
+ if (iov_iter_is_pipe(i))
+ return pipe_get_pages(i, pages, maxsize, maxpages, start);
+ if (iov_iter_is_xarray(i))
+ return iter_xarray_get_pages(i, pages, maxsize, maxpages, start);
+ return -EFAULT;
}
EXPORT_SYMBOL(iov_iter_get_pages);
@@ -1549,9 +1519,6 @@ static ssize_t pipe_get_pages_alloc(struct iov_iter *i,
unsigned int iter_head, npages;
ssize_t n;
- if (!maxsize)
- return 0;
-
if (!sanity(i))
return -EFAULT;
@@ -1624,24 +1591,18 @@ ssize_t iov_iter_get_pages_alloc(struct iov_iter *i,
size_t *start)
{
struct page **p;
+ size_t len;
+ int n, res;
if (maxsize > i->count)
maxsize = i->count;
+ if (!maxsize)
+ return 0;
- if (unlikely(iov_iter_is_pipe(i)))
- return pipe_get_pages_alloc(i, pages, maxsize, start);
- if (unlikely(iov_iter_is_xarray(i)))
- return iter_xarray_get_pages_alloc(i, pages, maxsize, start);
- if (unlikely(iov_iter_is_discard(i)))
- return -EFAULT;
-
- 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 (likely(iter_is_iovec(i))) {
+ unsigned long addr;
- addr &= ~(PAGE_SIZE - 1);
+ addr = first_iovec_segment(i, &len, start, maxsize, ~0U);
n = DIV_ROUND_UP(len, PAGE_SIZE);
p = get_pages_array(n);
if (!p)
@@ -1654,61 +1615,42 @@ ssize_t iov_iter_get_pages_alloc(struct iov_iter *i,
}
*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 (iov_iter_is_bvec(i)) {
+ struct page *page;
+
+ page = first_bvec_segment(i, &len, start, maxsize, ~0U);
+ n = DIV_ROUND_UP(len, PAGE_SIZE);
+ *pages = p = get_pages_array(n);
if (!p)
return -ENOMEM;
- get_page(*p = v.bv_page);
- return v.bv_len;
- }),({
- return -EFAULT;
- }), 0
- )
- return 0;
+ while (n--)
+ get_page(*p++ = page++);
+ return len - *start;
+ }
+ if (iov_iter_is_pipe(i))
+ return pipe_get_pages_alloc(i, pages, maxsize, start);
+ if (iov_iter_is_xarray(i))
+ return iter_xarray_get_pages_alloc(i, pages, maxsize, start);
+ return -EFAULT;
}
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;
sum = *csum;
if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) {
WARN_ON(1);
return 0;
}
- iterate_and_advance(i, bytes, v, ({
- next = csum_and_copy_from_user(v.iov_base,
- (to += v.iov_len) - v.iov_len,
- v.iov_len);
- if (next) {
- sum = csum_block_add(sum, next, off);
- off += v.iov_len;
- }
- next ? 0 : v.iov_len;
- }), ({
- char *p = kmap_atomic(v.bv_page);
- sum = csum_and_memcpy((to += v.bv_len) - v.bv_len,
- p + v.bv_offset, v.bv_len,
- sum, off);
- kunmap_atomic(p);
- off += v.bv_len;
- }),({
- sum = csum_and_memcpy((to += v.iov_len) - v.iov_len,
- v.iov_base, v.iov_len,
- sum, off);
- off += v.iov_len;
+ iterate_and_advance(i, bytes, base, len, off, ({
+ next = csum_and_copy_from_user(base, addr + off, len);
+ sum = csum_block_add(sum, next, off);
+ next ? 0 : len;
}), ({
- char *p = kmap_atomic(v.bv_page);
- sum = csum_and_memcpy((to += v.bv_len) - v.bv_len,
- p + v.bv_offset, v.bv_len,
- sum, off);
- kunmap_atomic(p);
- off += v.bv_len;
+ sum = csum_and_memcpy(addr + off, base, len, sum, off);
})
)
*csum = sum;
@@ -1716,104 +1658,30 @@ 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(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) {
- WARN_ON(1);
- return false;
- }
- if (unlikely(i->count < bytes))
- return false;
- iterate_all_kinds(i, bytes, v, ({
- next = csum_and_copy_from_user(v.iov_base,
- (to += v.iov_len) - v.iov_len,
- v.iov_len);
- if (!next)
- return false;
- sum = csum_block_add(sum, next, off);
- off += v.iov_len;
- 0;
- }), ({
- char *p = kmap_atomic(v.bv_page);
- sum = csum_and_memcpy((to += v.bv_len) - v.bv_len,
- p + v.bv_offset, v.bv_len,
- sum, off);
- kunmap_atomic(p);
- off += v.bv_len;
- }),({
- sum = csum_and_memcpy((to += v.iov_len) - v.iov_len,
- v.iov_base, v.iov_len,
- sum, off);
- off += v.iov_len;
- }), ({
- char *p = kmap_atomic(v.bv_page);
- sum = csum_and_memcpy((to += v.bv_len) - v.bv_len,
- p + v.bv_offset, v.bv_len,
- sum, off);
- kunmap_atomic(p);
- off += v.bv_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, void *_csstate,
struct iov_iter *i)
{
struct csum_state *csstate = _csstate;
- const char *from = addr;
__wsum sum, next;
- size_t off;
-
- if (unlikely(iov_iter_is_pipe(i)))
- return csum_and_copy_to_pipe_iter(addr, bytes, _csstate, i);
- sum = csstate->csum;
- off = csstate->off;
if (unlikely(iov_iter_is_discard(i))) {
WARN_ON(1); /* for now */
return 0;
}
- iterate_and_advance(i, bytes, v, ({
- next = csum_and_copy_to_user((from += v.iov_len) - v.iov_len,
- v.iov_base,
- v.iov_len);
- if (next) {
- sum = csum_block_add(sum, next, off);
- off += v.iov_len;
- }
- next ? 0 : v.iov_len;
- }), ({
- char *p = kmap_atomic(v.bv_page);
- sum = csum_and_memcpy(p + v.bv_offset,
- (from += v.bv_len) - v.bv_len,
- v.bv_len, sum, off);
- kunmap_atomic(p);
- off += v.bv_len;
- }),({
- sum = csum_and_memcpy(v.iov_base,
- (from += v.iov_len) - v.iov_len,
- v.iov_len, sum, off);
- off += v.iov_len;
+
+ sum = csum_shift(csstate->csum, csstate->off);
+ if (unlikely(iov_iter_is_pipe(i)))
+ bytes = csum_and_copy_to_pipe_iter(addr, bytes, i, &sum);
+ else iterate_and_advance(i, bytes, base, len, off, ({
+ next = csum_and_copy_to_user(addr + off, base, len);
+ sum = csum_block_add(sum, next, off);
+ next ? 0 : len;
}), ({
- char *p = kmap_atomic(v.bv_page);
- sum = csum_and_memcpy(p + v.bv_offset,
- (from += v.bv_len) - v.bv_len,
- v.bv_len, sum, off);
- kunmap_atomic(p);
- off += v.bv_len;
+ sum = csum_and_memcpy(base, addr + off, len, sum, off);
})
)
- csstate->csum = sum;
- csstate->off = off;
+ csstate->csum = csum_shift(sum, csstate->off);
+ csstate->off += bytes;
return bytes;
}
EXPORT_SYMBOL(csum_and_copy_to_iter);
@@ -1837,19 +1705,56 @@ size_t hash_and_copy_to_iter(const void *addr, size_t bytes, void *hashp,
}
EXPORT_SYMBOL(hash_and_copy_to_iter);
-int iov_iter_npages(const struct iov_iter *i, int maxpages)
+static int iov_npages(const struct iov_iter *i, int maxpages)
{
- size_t size = i->count;
+ size_t skip = i->iov_offset, size = i->count;
+ const struct iovec *p;
int npages = 0;
- if (!size)
- return 0;
- if (unlikely(iov_iter_is_discard(i)))
- return 0;
+ for (p = i->iov; size; skip = 0, p++) {
+ unsigned offs = offset_in_page(p->iov_base + skip);
+ size_t len = min(p->iov_len - skip, size);
- if (unlikely(iov_iter_is_pipe(i))) {
- struct pipe_inode_info *pipe = i->pipe;
+ if (len) {
+ size -= len;
+ npages += DIV_ROUND_UP(offs + len, PAGE_SIZE);
+ if (unlikely(npages > maxpages))
+ return maxpages;
+ }
+ }
+ return npages;
+}
+
+static int bvec_npages(const struct iov_iter *i, int maxpages)
+{
+ size_t skip = i->iov_offset, size = i->count;
+ const struct bio_vec *p;
+ int npages = 0;
+
+ for (p = i->bvec; size; skip = 0, p++) {
+ unsigned offs = (p->bv_offset + skip) % PAGE_SIZE;
+ size_t len = min(p->bv_len - skip, size);
+
+ size -= len;
+ npages += DIV_ROUND_UP(offs + len, PAGE_SIZE);
+ if (unlikely(npages > maxpages))
+ return maxpages;
+ }
+ return npages;
+}
+
+int iov_iter_npages(const struct iov_iter *i, int maxpages)
+{
+ if (unlikely(!i->count))
+ return 0;
+ /* iovec and kvec have identical layouts */
+ if (likely(iter_is_iovec(i) || iov_iter_is_kvec(i)))
+ return iov_npages(i, maxpages);
+ if (iov_iter_is_bvec(i))
+ return bvec_npages(i, maxpages);
+ if (iov_iter_is_pipe(i)) {
unsigned int iter_head;
+ int npages;
size_t off;
if (!sanity(i))
@@ -1857,44 +1762,15 @@ int iov_iter_npages(const struct iov_iter *i, int maxpages)
data_start(i, &iter_head, &off);
/* some of this one + all after this one */
- npages = pipe_space_for_user(iter_head, pipe->tail, pipe);
- if (npages >= maxpages)
- return maxpages;
- } else if (unlikely(iov_iter_is_xarray(i))) {
- unsigned offset;
-
- offset = (i->xarray_start + i->iov_offset) & ~PAGE_MASK;
-
- npages = 1;
- if (size > PAGE_SIZE - offset) {
- size -= PAGE_SIZE - offset;
- npages += size >> PAGE_SHIFT;
- size &= ~PAGE_MASK;
- if (size)
- npages++;
- }
- if (npages >= maxpages)
- return maxpages;
- } else 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;
- }),
- 0
- )
- return npages;
+ npages = pipe_space_for_user(iter_head, i->pipe->tail, i->pipe);
+ return min(npages, maxpages);
+ }
+ if (iov_iter_is_xarray(i)) {
+ unsigned offset = (i->xarray_start + i->iov_offset) % PAGE_SIZE;
+ int npages = DIV_ROUND_UP(offset + i->count, PAGE_SIZE);
+ return min(npages, maxpages);
+ }
+ return 0;
}
EXPORT_SYMBOL(iov_iter_npages);
@@ -2093,30 +1969,3 @@ int import_single_range(int rw, void __user *buf, size_t len,
return 0;
}
EXPORT_SYMBOL(import_single_range);
-
-int iov_iter_for_each_range(struct iov_iter *i, size_t bytes,
- int (*f)(struct kvec *vec, void *context),
- void *context)
-{
- struct kvec w;
- int err = -EINVAL;
- if (!bytes)
- return 0;
-
- iterate_all_kinds(i, bytes, v, -EINVAL, ({
- w.iov_base = kmap(v.bv_page) + v.bv_offset;
- w.iov_len = v.bv_len;
- err = f(&w, context);
- kunmap(v.bv_page);
- err;}), ({
- w = v;
- err = f(&w, context);}), ({
- w.iov_base = kmap(v.bv_page) + v.bv_offset;
- w.iov_len = v.bv_len;
- err = f(&w, context);
- kunmap(v.bv_page);
- err;})
- )
- return err;
-}
-EXPORT_SYMBOL(iov_iter_for_each_range);
diff --git a/mm/filemap.c b/mm/filemap.c
index ac82a93d4f38..d1458ecf2f51 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -3642,10 +3642,6 @@ again:
* Otherwise there's a nasty deadlock on copying from the
* same page as we're writing to, without it being marked
* up-to-date.
- *
- * Not only is this an optimisation, but it is also required
- * to check that the address is actually valid, when atomic
- * usercopies are used, below.
*/
if (unlikely(iov_iter_fault_in_readable(i, bytes))) {
status = -EFAULT;
@@ -3665,33 +3661,31 @@ again:
if (mapping_writably_mapped(mapping))
flush_dcache_page(page);
- copied = iov_iter_copy_from_user_atomic(page, i, offset, bytes);
+ copied = copy_page_from_iter_atomic(page, offset, bytes, i);
flush_dcache_page(page);
status = a_ops->write_end(file, mapping, pos, bytes, copied,
page, fsdata);
- if (unlikely(status < 0))
- break;
- copied = status;
-
+ if (unlikely(status != copied)) {
+ iov_iter_revert(i, copied - max(status, 0L));
+ if (unlikely(status < 0))
+ break;
+ }
cond_resched();
- iov_iter_advance(i, copied);
- if (unlikely(copied == 0)) {
+ if (unlikely(status == 0)) {
/*
- * If we were unable to copy any data at all, we must
- * fall back to a single segment length write.
- *
- * If we didn't fallback here, we could livelock
- * because not all segments in the iov can be copied at
- * once without a pagefault.
+ * A short copy made ->write_end() reject the
+ * thing entirely. Might be memory poisoning
+ * halfway through, might be a race with munmap,
+ * might be severe memory pressure.
*/
- bytes = min_t(unsigned long, PAGE_SIZE - offset,
- iov_iter_single_seg_count(i));
+ if (copied)
+ bytes = copied;
goto again;
}
- pos += copied;
- written += copied;
+ pos += status;
+ written += status;
balance_dirty_pages_ratelimited(mapping);
} while (iov_iter_count(i));
generated by cgit v1.2.3 (git 2.39.0) at 2024-12-28 15:49:32 +0300