diff options
| -rw-r--r-- | mm/filemap.c | 9 | ||||
| -rw-r--r-- | mm/filemap.h | 4 |
2 files changed, 10 insertions, 3 deletions
diff --git a/mm/filemap.c b/mm/filemap.c index 4082b3b3cea..648f2c0c8e1 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -2125,6 +2125,12 @@ generic_file_buffered_write(struct kiocb *iocb, const struct iovec *iov, break; } + if (unlikely(bytes == 0)) { + status = 0; + copied = 0; + goto zero_length_segment; + } + status = a_ops->prepare_write(file, page, offset, offset+bytes); if (unlikely(status)) { loff_t isize = i_size_read(inode); @@ -2154,7 +2160,8 @@ generic_file_buffered_write(struct kiocb *iocb, const struct iovec *iov, page_cache_release(page); continue; } - if (likely(copied > 0)) { +zero_length_segment: + if (likely(copied >= 0)) { if (!status) status = copied; diff --git a/mm/filemap.h b/mm/filemap.h index 536979fb4ba..3f2a343c601 100644 --- a/mm/filemap.h +++ b/mm/filemap.h @@ -88,7 +88,7 @@ filemap_set_next_iovec(const struct iovec **iovp, size_t *basep, size_t bytes) const struct iovec *iov = *iovp; size_t base = *basep; - while (bytes) { + do { int copy = min(bytes, iov->iov_len - base); bytes -= copy; @@ -97,7 +97,7 @@ filemap_set_next_iovec(const struct iovec **iovp, size_t *basep, size_t bytes) iov++; base = 0; } - } + } while (bytes); *iovp = iov; *basep = base; } |