diff options
author | Dave Airlie <airlied@redhat.com> | 2017-04-19 11:07:14 +1000 |
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committer | Dave Airlie <airlied@redhat.com> | 2017-04-19 11:07:14 +1000 |
commit | 856ee92e8602bd86d34388ac08381c5cb3918756 (patch) | |
tree | c3bed2bf85214f78239724adb34a1c2d6ec8444d /lib | |
parent | a6a5c983b35e579071370d4eb2b4ed8ad5c18da9 (diff) | |
parent | 4f7d029b9bf009fbee76bb10c0c4351a1870d2f3 (diff) |
Merge tag 'v4.11-rc7' into drm-next
Backmerge Linux 4.11-rc7 from Linus tree, to fix some
conflicts that were causing problems with the rerere cache
in drm-tip.
Diffstat (limited to 'lib')
-rw-r--r-- | lib/iov_iter.c | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/lib/iov_iter.c b/lib/iov_iter.c index e68604ae3ced..60abc44385b7 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -786,6 +786,68 @@ void iov_iter_advance(struct iov_iter *i, size_t size) } EXPORT_SYMBOL(iov_iter_advance); +void iov_iter_revert(struct iov_iter *i, size_t unroll) +{ + if (!unroll) + return; + i->count += unroll; + if (unlikely(i->type & ITER_PIPE)) { + struct pipe_inode_info *pipe = i->pipe; + int idx = i->idx; + size_t off = i->iov_offset; + while (1) { + size_t n = off - pipe->bufs[idx].offset; + if (unroll < n) { + off -= (n - unroll); + break; + } + unroll -= n; + if (!unroll && idx == i->start_idx) { + off = 0; + break; + } + if (!idx--) + idx = pipe->buffers - 1; + off = pipe->bufs[idx].offset + pipe->bufs[idx].len; + } + i->iov_offset = off; + i->idx = idx; + pipe_truncate(i); + return; + } + if (unroll <= i->iov_offset) { + i->iov_offset -= unroll; + return; + } + unroll -= i->iov_offset; + if (i->type & ITER_BVEC) { + const struct bio_vec *bvec = i->bvec; + while (1) { + size_t n = (--bvec)->bv_len; + i->nr_segs++; + if (unroll <= n) { + i->bvec = bvec; + i->iov_offset = n - unroll; + return; + } + unroll -= n; + } + } else { /* same logics for iovec and kvec */ + const struct iovec *iov = i->iov; + while (1) { + size_t n = (--iov)->iov_len; + i->nr_segs++; + if (unroll <= n) { + i->iov = iov; + i->iov_offset = n - unroll; + return; + } + unroll -= n; + } + } +} +EXPORT_SYMBOL(iov_iter_revert); + /* * Return the count of just the current iov_iter segment. */ @@ -839,6 +901,7 @@ void iov_iter_pipe(struct iov_iter *i, int direction, i->idx = (pipe->curbuf + pipe->nrbufs) & (pipe->buffers - 1); i->iov_offset = 0; i->count = count; + i->start_idx = i->idx; } EXPORT_SYMBOL(iov_iter_pipe); |