diff options
Diffstat (limited to 'lib/iov_iter.c')
| -rw-r--r-- | lib/iov_iter.c | 69 |
1 files changed, 66 insertions, 3 deletions
diff --git a/lib/iov_iter.c b/lib/iov_iter.c index e68604ae3ced..4952311422c1 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -413,7 +413,7 @@ void iov_iter_init(struct iov_iter *i, int direction, size_t count) { /* It will get better. Eventually... */ - if (segment_eq(get_fs(), KERNEL_DS)) { + if (uaccess_kernel()) { direction |= ITER_KVEC; i->type = direction; i->kvec = (struct kvec *)iov; @@ -604,7 +604,7 @@ size_t copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i) return 0; } iterate_and_advance(i, bytes, v, - __copy_from_user_nocache((to += v.iov_len) - v.iov_len, + __copy_from_user_inatomic_nocache((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len), memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, v.bv_offset, v.bv_len), @@ -625,7 +625,7 @@ bool copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i) if (unlikely(i->count < bytes)) return false; iterate_all_kinds(i, bytes, v, ({ - if (__copy_from_user_nocache((to += v.iov_len) - v.iov_len, + if (__copy_from_user_inatomic_nocache((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len)) return false; 0;}), @@ -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 -= 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); |