[PATCH v5 2/9] iov_iter: Use the direction in the iterator functions

David Howells
2023-01-11T14:32:12Z

Use the direction in the iterator functions rather than READ/WRITE.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Al Viro <viro@zeniv.linux.org.uk>
Link: https://lore.kernel.org/r/167305162465.1521586.18077838937455153675.stgit@warthog.procyon.org.uk/ # v4
---

include/linux/uio.h | 22 +++++++++++-----------
lib/iov_iter.c | 46 +++++++++++++++++++++++-----------------------
2 files changed, 34 insertions(+), 34 deletions(-)

diff --git a/include/linux/uio.h b/include/linux/uio.h
index 4b0f4a773d90..acb1ae3324ed 100644
--- a/include/linux/uio.h
+++ b/include/linux/uio.h
@@ -261,16 +261,16 @@ bool iov_iter_is_aligned(const struct iov_iter *i, unsigned addr_mask,
unsigned len_mask);
unsigned long iov_iter_alignment(const struct iov_iter *i);
unsigned long iov_iter_gap_alignment(const struct iov_iter *i);
-void iov_iter_init(struct iov_iter *i, unsigned int direction, const struct iovec *iov,
+void iov_iter_init(struct iov_iter *i, enum iter_dir direction, const struct iovec *iov,
unsigned long nr_segs, size_t count);
-void iov_iter_kvec(struct iov_iter *i, unsigned int direction, const struct kvec *kvec,
+void iov_iter_kvec(struct iov_iter *i, enum iter_dir direction, const struct kvec *kvec,
unsigned long nr_segs, size_t count);
-void iov_iter_bvec(struct iov_iter *i, unsigned int direction, const struct bio_vec *bvec,
+void iov_iter_bvec(struct iov_iter *i, enum iter_dir direction, const struct bio_vec *bvec,
unsigned long nr_segs, size_t count);
-void iov_iter_pipe(struct iov_iter *i, unsigned int direction, struct pipe_inode_info *pipe,
+void iov_iter_pipe(struct iov_iter *i, enum iter_dir direction, struct pipe_inode_info *pipe,
size_t count);
-void iov_iter_discard(struct iov_iter *i, unsigned int direction, size_t count);
-void iov_iter_xarray(struct iov_iter *i, unsigned int direction, struct xarray *xarray,
+void iov_iter_discard(struct iov_iter *i, enum iter_dir direction, size_t count);
+void iov_iter_xarray(struct iov_iter *i, enum iter_dir direction, struct xarray *xarray,
loff_t start, size_t count);
ssize_t iov_iter_get_pages(struct iov_iter *i, struct page **pages,
size_t maxsize, unsigned maxpages, size_t *start,
@@ -360,19 +360,19 @@ size_t hash_and_copy_to_iter(const void *addr, size_t bytes, void *hashp,
struct iovec *iovec_from_user(const struct iovec __user *uvector,
unsigned long nr_segs, unsigned long fast_segs,
struct iovec *fast_iov, bool compat);
-ssize_t import_iovec(int type, const struct iovec __user *uvec,
+ssize_t import_iovec(enum iter_dir direction, const struct iovec __user *uvec,
unsigned nr_segs, unsigned fast_segs, struct iovec **iovp,
struct iov_iter *i);
-ssize_t __import_iovec(int type, const struct iovec __user *uvec,
+ssize_t __import_iovec(enum iter_dir direction, const struct iovec __user *uvec,
unsigned nr_segs, unsigned fast_segs, struct iovec **iovp,
struct iov_iter *i, bool compat);
-int import_single_range(int type, void __user *buf, size_t len,
+int import_single_range(enum iter_dir direction, void __user *buf, size_t len,
struct iovec *iov, struct iov_iter *i);

-static inline void iov_iter_ubuf(struct iov_iter *i, unsigned int direction,
+static inline void iov_iter_ubuf(struct iov_iter *i, enum iter_dir direction,
void __user *buf, size_t count)
{
- WARN_ON(direction & ~(READ | WRITE));
+ WARN_ON(!iov_iter_dir_valid(direction));
*i = (struct iov_iter) {
.iter_type = ITER_UBUF,
.user_backed = true,
diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index f9a3ff37ecd1..fec1c5513197 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -421,11 +421,11 @@ size_t fault_in_iov_iter_writeable(const struct iov_iter *i, size_t size)
}
EXPORT_SYMBOL(fault_in_iov_iter_writeable);

-void iov_iter_init(struct iov_iter *i, unsigned int direction,
+void iov_iter_init(struct iov_iter *i, enum iter_dir direction,
const struct iovec *iov, unsigned long nr_segs,
size_t count)
{
- WARN_ON(direction & ~(READ | WRITE));
+ WARN_ON(!iov_iter_dir_valid(direction));
*i = (struct iov_iter) {
.iter_type = ITER_IOVEC,
.nofault = false,
@@ -994,11 +994,11 @@ size_t iov_iter_single_seg_count(const struct iov_iter *i)
}
EXPORT_SYMBOL(iov_iter_single_seg_count);

-void iov_iter_kvec(struct iov_iter *i, unsigned int direction,
+void iov_iter_kvec(struct iov_iter *i, enum iter_dir direction,
const struct kvec *kvec, unsigned long nr_segs,
size_t count)
{
- WARN_ON(direction & ~(READ | WRITE));
+ WARN_ON(!iov_iter_dir_valid(direction));
*i = (struct iov_iter){
.iter_type = ITER_KVEC,
.data_source = direction,
@@ -1010,11 +1010,11 @@ void iov_iter_kvec(struct iov_iter *i, unsigned int direction,
}
EXPORT_SYMBOL(iov_iter_kvec);

-void iov_iter_bvec(struct iov_iter *i, unsigned int direction,
+void iov_iter_bvec(struct iov_iter *i, enum iter_dir direction,
const struct bio_vec *bvec, unsigned long nr_segs,
size_t count)
{
- WARN_ON(direction & ~(READ | WRITE));
+ WARN_ON(!iov_iter_dir_valid(direction));
*i = (struct iov_iter){
.iter_type = ITER_BVEC,
.data_source = direction,
@@ -1026,15 +1026,15 @@ void iov_iter_bvec(struct iov_iter *i, unsigned int direction,
}
EXPORT_SYMBOL(iov_iter_bvec);

-void iov_iter_pipe(struct iov_iter *i, unsigned int direction,
+void iov_iter_pipe(struct iov_iter *i, enum iter_dir direction,
struct pipe_inode_info *pipe,
size_t count)
{
- BUG_ON(direction != READ);
+ BUG_ON(direction != ITER_DEST);
WARN_ON(pipe_full(pipe->head, pipe->tail, pipe->ring_size));
*i = (struct iov_iter){
.iter_type = ITER_PIPE,
- .data_source = false,
+ .data_source = ITER_DEST,
.pipe = pipe,
.head = pipe->head,
.start_head = pipe->head,
@@ -1057,10 +1057,10 @@ EXPORT_SYMBOL(iov_iter_pipe);
* from evaporation, either by taking a ref on them or locking them by the
* caller.
*/
-void iov_iter_xarray(struct iov_iter *i, unsigned int direction,
+void iov_iter_xarray(struct iov_iter *i, enum iter_dir direction,
struct xarray *xarray, loff_t start, size_t count)
{
- BUG_ON(direction & ~1);
+ WARN_ON(!iov_iter_dir_valid(direction));
*i = (struct iov_iter) {
.iter_type = ITER_XARRAY,
.data_source = direction,
@@ -1079,14 +1079,14 @@ EXPORT_SYMBOL(iov_iter_xarray);
* @count: The size of the I/O buffer in bytes.
*
* Set up an I/O iterator that just discards everything that's written to it.
- * It's only available as a READ iterator.
+ * It's only available as a destination iterator.
*/
-void iov_iter_discard(struct iov_iter *i, unsigned int direction, size_t count)
+void iov_iter_discard(struct iov_iter *i, enum iter_dir direction, size_t count)
{
- BUG_ON(direction != READ);
+ BUG_ON(direction != ITER_DEST);
*i = (struct iov_iter){
.iter_type = ITER_DISCARD,
- .data_source = false,
+ .data_source = ITER_DEST,
.count = count,
.iov_offset = 0
};
@@ -1447,7 +1447,7 @@ static ssize_t __iov_iter_get_pages_alloc(struct iov_iter *i,
unsigned long addr;
int res;

- if (iov_iter_rw(i) != WRITE)
+ if (iov_iter_is_dest(i))
gup_flags |= FOLL_WRITE;
if (i->nofault)
gup_flags |= FOLL_NOFAULT;
@@ -1784,7 +1784,7 @@ struct iovec *iovec_from_user(const struct iovec __user *uvec,
return iov;
}

-ssize_t __import_iovec(int type, const struct iovec __user *uvec,
+ssize_t __import_iovec(enum iter_dir direction, const struct iovec __user *uvec,
unsigned nr_segs, unsigned fast_segs, struct iovec **iovp,
struct iov_iter *i, bool compat)
{
@@ -1823,7 +1823,7 @@ ssize_t __import_iovec(int type, const struct iovec __user *uvec,
total_len += len;
}

- iov_iter_init(i, type, iov, nr_segs, total_len);
+ iov_iter_init(i, direction, iov, nr_segs, total_len);
if (iov == *iovp)
*iovp = NULL;
else
@@ -1836,7 +1836,7 @@ ssize_t __import_iovec(int type, const struct iovec __user *uvec,
* into the kernel, check that it is valid, and initialize a new
* &struct iov_iter iterator to access it.
*
- * @type: One of %READ or %WRITE.
+ * @direction: One of %ITER_SOURCE or %ITER_DEST.
* @uvec: Pointer to the userspace array.
* @nr_segs: Number of elements in userspace array.
* @fast_segs: Number of elements in @iov.
@@ -1853,16 +1853,16 @@ ssize_t __import_iovec(int type, const struct iovec __user *uvec,
*
* Return: Negative error code on error, bytes imported on success
*/
-ssize_t import_iovec(int type, const struct iovec __user *uvec,
+ssize_t import_iovec(enum iter_dir direction, const struct iovec __user *uvec,
unsigned nr_segs, unsigned fast_segs,
struct iovec **iovp, struct iov_iter *i)
{
- return __import_iovec(type, uvec, nr_segs, fast_segs, iovp, i,
+ return __import_iovec(direction, uvec, nr_segs, fast_segs, iovp, i,
in_compat_syscall());
}
EXPORT_SYMBOL(import_iovec);

-int import_single_range(int rw, void __user *buf, size_t len,
+int import_single_range(enum iter_dir direction, void __user *buf, size_t len,
struct iovec *iov, struct iov_iter *i)
{
if (len > MAX_RW_COUNT)
@@ -1872,7 +1872,7 @@ int import_single_range(int rw, void __user *buf, size_t len,

iov->iov_base = buf;
iov->iov_len = len;
- iov_iter_init(i, rw, iov, 1, len);
+ iov_iter_init(i, direction, iov, 1, len);
return 0;
}
EXPORT_SYMBOL(import_single_range);