[PATCH 09/29] iov_iter: Split copy_from_iter_full()

From: David Howells
Date: Sat Nov 21 2020 - 09:15:24 EST


Split copy_from_iter_full() by type.

Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
---

lib/iov_iter.c | 59 +++++++++++++++++++++++++++++++++++++++-----------------
1 file changed, 41 insertions(+), 18 deletions(-)

diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index 934193627540..3dba665a1ee9 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -923,32 +923,55 @@ static size_t no_copy_from_iter(void *addr, size_t bytes, struct iov_iter *i)
return bytes;
}

-static bool xxx_copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i)
+static bool iovec_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, ({
+ might_fault();
+ iterate_over_iovec(i, bytes, v, ({
if (copyin((to += v.iov_len) - v.iov_len,
- v.iov_base, v.iov_len))
+ v.iov_base, v.iov_len))
return false;
- 0;}),
+ 0;}));
+ iov_iter_advance(i, bytes);
+ return true;
+}
+
+static bool bvec_copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i)
+{
+ char *to = addr;
+
+ if (unlikely(i->count < bytes))
+ return false;
+ iterate_over_bvec(i, bytes, v,
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)
- )
+ v.bv_offset, v.bv_len));
+ iov_iter_advance(i, bytes);
+ return true;
+}
+
+static bool kvec_copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i)
+{
+ char *to = addr;

+ if (unlikely(i->count < bytes))
+ return false;
+
+ iterate_over_kvec(i, bytes, v,
+ memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len));
iov_iter_advance(i, bytes);
return true;
}

+static bool no_copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i)
+{
+ WARN_ON(1);
+ return false;
+}
+
static size_t xxx_copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i)
{
char *to = addr;
@@ -1985,7 +2008,7 @@ static const struct iov_iter_ops iovec_iter_ops = {
.copy_page_from_iter = xxx_copy_page_from_iter,
.copy_to_iter = iovec_copy_to_iter,
.copy_from_iter = iovec_copy_from_iter,
- .copy_from_iter_full = xxx_copy_from_iter_full,
+ .copy_from_iter_full = iovec_copy_from_iter_full,
.copy_from_iter_nocache = xxx_copy_from_iter_nocache,
.copy_from_iter_full_nocache = xxx_copy_from_iter_full_nocache,
#ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE
@@ -2019,7 +2042,7 @@ static const struct iov_iter_ops kvec_iter_ops = {
.copy_page_from_iter = xxx_copy_page_from_iter,
.copy_to_iter = kvec_copy_to_iter,
.copy_from_iter = kvec_copy_from_iter,
- .copy_from_iter_full = xxx_copy_from_iter_full,
+ .copy_from_iter_full = kvec_copy_from_iter_full,
.copy_from_iter_nocache = xxx_copy_from_iter_nocache,
.copy_from_iter_full_nocache = xxx_copy_from_iter_full_nocache,
#ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE
@@ -2053,7 +2076,7 @@ static const struct iov_iter_ops bvec_iter_ops = {
.copy_page_from_iter = xxx_copy_page_from_iter,
.copy_to_iter = bvec_copy_to_iter,
.copy_from_iter = bvec_copy_from_iter,
- .copy_from_iter_full = xxx_copy_from_iter_full,
+ .copy_from_iter_full = bvec_copy_from_iter_full,
.copy_from_iter_nocache = xxx_copy_from_iter_nocache,
.copy_from_iter_full_nocache = xxx_copy_from_iter_full_nocache,
#ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE
@@ -2087,7 +2110,7 @@ static const struct iov_iter_ops pipe_iter_ops = {
.copy_page_from_iter = xxx_copy_page_from_iter,
.copy_to_iter = pipe_copy_to_iter,
.copy_from_iter = no_copy_from_iter,
- .copy_from_iter_full = xxx_copy_from_iter_full,
+ .copy_from_iter_full = no_copy_from_iter_full,
.copy_from_iter_nocache = xxx_copy_from_iter_nocache,
.copy_from_iter_full_nocache = xxx_copy_from_iter_full_nocache,
#ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE
@@ -2121,7 +2144,7 @@ static const struct iov_iter_ops discard_iter_ops = {
.copy_page_from_iter = xxx_copy_page_from_iter,
.copy_to_iter = discard_copy_to_iter,
.copy_from_iter = no_copy_from_iter,
- .copy_from_iter_full = xxx_copy_from_iter_full,
+ .copy_from_iter_full = no_copy_from_iter_full,
.copy_from_iter_nocache = xxx_copy_from_iter_nocache,
.copy_from_iter_full_nocache = xxx_copy_from_iter_full_nocache,
#ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE