Merge branch 'work.iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull iov_iter cleanups from Al Viro.

* 'work.iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fold checks into iterate_and_advance()
  rw_verify_area(): saner calling conventions
  aio: remove a pointless assignment

1 files changed, 36 insertions, 68 deletions

diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index ca5316e0087b..28cb4315fe57 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -99,40 +99,44 @@
 }
 
 #define iterate_and_advance(i, n, v, I, B, K) {                 \
-        size_t skip = i->iov_offset;                            \
-        if (unlikely(i->type & ITER_BVEC)) {                    \
-                const struct bio_vec *bvec;                     \
-                struct bio_vec v;                               \
-                iterate_bvec(i, n, v, bvec, skip, (B))          \
-                if (skip == bvec->bv_len) {                     \
-                        bvec++;                                 \
-                        skip = 0;                               \
-                }                                               \
-                i->nr_segs -= bvec - i->bvec;                   \
-                i->bvec = bvec;                                 \
-        } 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;                               \
-                }                                               \
-                i->nr_segs -= kvec - i->kvec;                   \
-                i->kvec = kvec;                                 \
-        } else {                                                \
-                const struct iovec *iov;                        \
-                struct iovec v;                                 \
-                iterate_iovec(i, n, v, iov, skip, (I))          \
-                if (skip == iov->iov_len) {                     \
-                        iov++;                                  \
-                        skip = 0;                               \
+        if (unlikely(i->count < n))                             \
+                n = i->count;                                   \
+        if (n) {                                                \
+                size_t skip = i->iov_offset;                    \
+                if (unlikely(i->type & ITER_BVEC)) {            \
+                        const struct bio_vec *bvec;             \
+                        struct bio_vec v;                       \
+                        iterate_bvec(i, n, v, bvec, skip, (B))  \
+                        if (skip == bvec->bv_len) {             \
+                                bvec++;                         \
+                                skip = 0;                       \
+                        }                                       \
+                        i->nr_segs -= bvec - i->bvec;           \
+                        i->bvec = bvec;                         \
+                } 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;                       \
+                        }                                       \
+                        i->nr_segs -= kvec - i->kvec;           \
+                        i->kvec = kvec;                         \
+                } 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;                           \
                 }                                               \
-                i->nr_segs -= iov - i->iov;                     \
-                i->iov = iov;                                   \
+                i->count -= n;                                  \
+                i->iov_offset = skip;                           \
         }                                                       \
-        i->count -= n;                                          \
-        i->iov_offset = skip;                                   \
 }
 
 static size_t copy_page_to_iter_iovec(struct page *page, size_t offset, size_t bytes,
@@ -386,12 +390,6 @@ static void memzero_page(struct page *page, size_t offset, size_t len)
 size_t copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i)
 {
         const char *from = addr;
-        if (unlikely(bytes > i->count))
-                bytes = i->count;
-
-        if (unlikely(!bytes))
-                return 0;
-
         iterate_and_advance(i, bytes, v,
                 __copy_to_user(v.iov_base, (from += v.iov_len) - v.iov_len,
                                v.iov_len),
@@ -407,12 +405,6 @@ EXPORT_SYMBOL(copy_to_iter);
 size_t copy_from_iter(void *addr, size_t bytes, struct iov_iter *i)
 {
         char *to = addr;
-        if (unlikely(bytes > i->count))
-                bytes = i->count;
-
-        if (unlikely(!bytes))
-                return 0;
-
         iterate_and_advance(i, bytes, v,
                 __copy_from_user((to += v.iov_len) - v.iov_len, v.iov_base,
                                  v.iov_len),
@@ -428,12 +420,6 @@ EXPORT_SYMBOL(copy_from_iter);
 size_t copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i)
 {
         char *to = addr;
-        if (unlikely(bytes > i->count))
-                bytes = i->count;
-
-        if (unlikely(!bytes))
-                return 0;
-
         iterate_and_advance(i, bytes, v,
                 __copy_from_user_nocache((to += v.iov_len) - v.iov_len,
                                          v.iov_base, v.iov_len),
@@ -474,12 +460,6 @@ EXPORT_SYMBOL(copy_page_from_iter);
 
 size_t iov_iter_zero(size_t bytes, struct iov_iter *i)
 {
-        if (unlikely(bytes > i->count))
-                bytes = i->count;
-
-        if (unlikely(!bytes))
-                return 0;
-
         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),
@@ -685,12 +665,6 @@ size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum,
         char *to = addr;
         __wsum sum, next;
         size_t off = 0;
-        if (unlikely(bytes > i->count))
-                bytes = i->count;
-
-        if (unlikely(!bytes))
-                return 0;
-
         sum = *csum;
         iterate_and_advance(i, bytes, v, ({
                 int err = 0;
@@ -729,12 +703,6 @@ size_t csum_and_copy_to_iter(const void *addr, size_t bytes, __wsum *csum,
         const char *from = addr;
         __wsum sum, next;
         size_t off = 0;
-        if (unlikely(bytes > i->count))
-                bytes = i->count;
-
-        if (unlikely(!bytes))
-                return 0;
-
         sum = *csum;
         iterate_and_advance(i, bytes, v, ({
                 int err = 0;