1 files changed, 39 insertions, 33 deletions

diff --git a/include/linux/uio.h b/include/linux/uio.h
index d3ec87706d75..5265024e8b90 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 {
@@ -51,11 +47,12 @@ struct iov_iter {
 		};
 		loff_t xarray_start;
 	};
+	size_t truncated;
 };
 
 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 +87,7 @@ 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 +116,11 @@ 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 +129,7 @@ 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 +152,11 @@ 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 +171,11 @@ 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
@@ -258,8 +255,10 @@ static inline void iov_iter_truncate(struct iov_iter *i, u64 count)
 	 * conversion in assignement is by definition greater than all
 	 * values of size_t, including old i->count.
 	 */
-	if (i->count > count)
+	if (i->count > count) {
+		i->truncated += i->count - count;
 		i->count = count;
+	}
 }
 
 /*
@@ -268,6 +267,7 @@ static inline void iov_iter_truncate(struct iov_iter *i, u64 count)
  */
 static inline void iov_iter_reexpand(struct iov_iter *i, size_t count)
 {
+	i->truncated -= count - i->count;
 	i->count = count;
 }
 
@@ -278,7 +278,17 @@ 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 +304,4 @@ 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