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author | Al Viro <viro@zeniv.linux.org.uk> | 2014-03-05 13:50:45 -0500 |
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committer | Al Viro <viro@zeniv.linux.org.uk> | 2014-05-06 17:32:47 -0400 |
commit | 886a39115005ced8b15ab067c9c2a8d546b40a5e (patch) | |
tree | cb72af0480369f31a449aa7a8451d407315c2bf3 /mm | |
parent | 26978b8b4d83c46f4310b253db70fa9e65149e7c (diff) | |
download | linux-886a39115005ced8b15ab067c9c2a8d546b40a5e.tar.bz2 |
new primitive: iov_iter_alignment()
returns the value aligned as badly as the worst remaining segment
in iov_iter is. Use instead of open-coded equivalents.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'mm')
-rw-r--r-- | mm/iov_iter.c | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/mm/iov_iter.c b/mm/iov_iter.c index 22ec1ef068a8..2f762cc21080 100644 --- a/mm/iov_iter.c +++ b/mm/iov_iter.c @@ -195,3 +195,28 @@ size_t iov_iter_single_seg_count(const struct iov_iter *i) return min(i->count, iov->iov_len - i->iov_offset); } EXPORT_SYMBOL(iov_iter_single_seg_count); + +unsigned long iov_iter_alignment(const struct iov_iter *i) +{ + const struct iovec *iov = i->iov; + unsigned long res; + size_t size = i->count; + size_t n; + + if (!size) + return 0; + + res = (unsigned long)iov->iov_base + i->iov_offset; + n = iov->iov_len - i->iov_offset; + if (n >= size) + return res | size; + size -= n; + res |= n; + while (size > (++iov)->iov_len) { + res |= (unsigned long)iov->iov_base | iov->iov_len; + size -= iov->iov_len; + } + res |= (unsigned long)iov->iov_base | size; + return res; +} +EXPORT_SYMBOL(iov_iter_alignment); |