In MD's resync I/O path, there are lots of direct access to bio's bvec table. This patchset kills almost all, and the conversion is quite straightforward. One root cause of direct access to bvec table is that resync I/O uses the bio's bvec to manage pages. In V1, as suggested by Shaohua, a new approach is used to manage these pages for resync I/O, turns out code becomes more clean and readable. Once direct access to bvec table in MD is cleaned up, we may make multipage bvec moving on. V2: - remove the patch for introducing/applying bio_remove_last_page() V1: - allocate page array to manage resync pages Thanks, Ming Ming Lei (13): block: introduce bio_segments_all() md: raid1/raid10: don't handle failure of bio_add_page() md: move two macros into md.h md: prepare for managing resync I/O pages in clean way md: raid1: simplify r1buf_pool_free() md: raid1: don't use bio's vec table to manage resync pages md: raid1: retrieve page from pre-allocated resync page array md: raid1: use bio helper in process_checks() md: raid1: use bio_segments_all() md: raid10: refactor code of read reshape's .bi_end_io md: raid10: don't use bio's vec table to manage resync pages md: raid10: retrieve page from preallocated resync page array md: raid10: avoid direct access to bvec table in handle_reshape_read_error drivers/md/md.h | 59 ++++++++++++++ drivers/md/raid1.c | 140 ++++++++++++++++++--------------- drivers/md/raid10.c | 220 ++++++++++++++++++++++++++++------------------------ include/linux/bio.h | 7 ++ 4 files changed, 263 insertions(+), 163 deletions(-) -- 2.7.4