diff options
| author | Al Viro <viro@zeniv.linux.org.uk> | 2021-04-22 14:50:39 -0400 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2021-06-10 11:45:08 -0400 |
| commit | 8cd54c1c848031a87820e58d772166ffdf8c08c0 (patch) | |
| tree | 3945e5cf8c6639ec53c30da0cc9784adefec58d5 /include/linux/uio.h | |
| parent | 556351c1c09ad6511bc2eaa2c214992192f50410 (diff) | |
iov_iter: separate direction from flavour
Instead of having them mixed in iter->type, use separate ->iter_type
and ->data_source (u8 and bool resp.) And don't bother with (pseudo-)
bitmap for the former - microoptimizations from being able to check
if the flavour is one of two values are not worth the confusion for
optimizer. It can't prove that we never get e.g. ITER_IOVEC | ITER_PIPE,
so we end up with extra headache.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'include/linux/uio.h')
| -rw-r--r-- | include/linux/uio.h | 24 |
1 files changed, 10 insertions, 14 deletions
diff --git a/include/linux/uio.h b/include/linux/uio.h index 68079e2f34eb..ad76eef356b0 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; } /* |