From: Andrew Morton Revert 81b0c8713385ce1b1b9058e916edcf9561ad76d6. This was a bugfix against 6527c2bdf1f833cc18e8f42bd97973d583e4aa83, which we also revert. Signed-off-by: Andrew Morton --- mm/filemap.c | 9 +-------- mm/filemap.h | 4 ++-- 2 files changed, 3 insertions(+), 10 deletions(-) diff -puN mm/filemap.c~revert-generic_file_buffered_write-handle-zero-length-iovec-segments mm/filemap.c --- a/mm/filemap.c~revert-generic_file_buffered_write-handle-zero-length-iovec-segments +++ a/mm/filemap.c @@ -2123,12 +2123,6 @@ generic_file_buffered_write(struct kiocb 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); @@ -2158,8 +2152,7 @@ generic_file_buffered_write(struct kiocb page_cache_release(page); continue; } -zero_length_segment: - if (likely(copied >= 0)) { + if (likely(copied > 0)) { if (!status) status = copied; diff -puN mm/filemap.h~revert-generic_file_buffered_write-handle-zero-length-iovec-segments mm/filemap.h --- a/mm/filemap.h~revert-generic_file_buffered_write-handle-zero-length-iovec-segments +++ a/mm/filemap.h @@ -87,7 +87,7 @@ filemap_set_next_iovec(const struct iove const struct iovec *iov = *iovp; size_t base = *basep; - do { + while (bytes) { int copy = min(bytes, iov->iov_len - base); bytes -= copy; @@ -96,7 +96,7 @@ filemap_set_next_iovec(const struct iove iov++; base = 0; } - } while (bytes); + } *iovp = iov; *basep = base; } _