user/sven/linux.git/include/linux/bvec.h, branch v5.4.171

block: allow for_each_bvec to support zero len bvec

2020-09-09T17:12:34Z

commit 7e24969022cbd61ddc586f14824fc205661bb124 upstream. Block layer usually doesn't support or allow zero-length bvec. Since commit 1bdc76aea115 ("iov_iter: use bvec iterator to implement iterate_bvec()"), iterate_bvec() switches to bvec iterator. However, Al mentioned that 'Zero-length segments are not disallowed' in iov_iter. Fixes for_each_bvec() so that it can move on after seeing one zero length bvec. Fixes: 1bdc76aea115 ("iov_iter: use bvec iterator to implement iterate_bvec()") Reported-by: syzbot Signed-off-by: Ming Lei Tested-by: Tetsuo Handa Cc: Al Viro Cc: Matthew Wilcox Cc: Link: https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg2262077.html Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

block: fix mismerge in bvec_advance

2019-05-07T14:39:02Z

When Jens merged my commit to only allow contiguous page structs in a bio_vec with Ming's 5.1 fix to ensue the bvec length didn't overflow we failed to keep the removal of the expensive nth_page calls. This commits adds them back as intended. Fixes: 5c61ee2cd586 ("Merge tag 'v5.1-rc6' into for-5.2/block") Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe

block: switch all files cleared marked as GPLv2 to SPDX tags

2019-04-30T22:11:57Z

All these files have some form of the usual GPLv2 boilerplate. Switch them to use SPDX tags instead. Reviewed-by: Chaitanya Kulkarni Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe

Merge tag 'v5.1-rc6' into for-5.2/block

2019-04-22T15:47:36Z

Pull in v5.1-rc6 to resolve two conflicts. One is in BFQ, in just a comment, and is trivial. The other one is a conflict due to a later fix in the bio multi-page work, and needs a bit more care. * tag 'v5.1-rc6': (770 commits) Linux 5.1-rc6 block: make sure that bvec length can't be overflow block: kill all_q_node in request_queue x86/cpu/intel: Lower the "ENERGY_PERF_BIAS: Set to normal" message's log priority coredump: fix race condition between mmget_not_zero()/get_task_mm() and core dumping mm/kmemleak.c: fix unused-function warning init: initialize jump labels before command line option parsing kernel/watchdog_hld.c: hard lockup message should end with a newline kcov: improve CONFIG_ARCH_HAS_KCOV help text mm: fix inactive list balancing between NUMA nodes and cgroups mm/hotplug: treat CMA pages as unmovable proc: fixup proc-pid-vm test proc: fix map_files test on F29 mm/vmstat.c: fix /proc/vmstat format for CONFIG_DEBUG_TLBFLUSH=y CONFIG_SMP=n mm/memory_hotplug: do not unlock after failing to take the device_hotplug_lock mm: swapoff: shmem_unuse() stop eviction without igrab() mm: swapoff: take notice of completion sooner mm: swapoff: remove too limiting SWAP_UNUSE_MAX_TRIES mm: swapoff: shmem_find_swap_entries() filter out other types slab: store tagged freelist for off-slab slabmgmt ... Signed-off-by: Jens Axboe

block: make sure that bvec length can't be overflow

2019-04-19T17:32:14Z

bvec->bv_offset may be bigger than PAGE_SIZE sometimes, such as, when one bio is splitted in the middle of one bvec via bio_split(), and bi_iter.bi_bvec_done is used to build offset of the 1st bvec of remained bio. And the remained bio's bvec may be re-submitted to fs layer via ITER_IBVEC, such as loop and nvme-loop. So we have to make sure that every bvec's offset is less than PAGE_SIZE from bio_for_each_segment_all() because some drivers(loop, nvme-loop) passes the splitted bvec to fs layer via ITER_BVEC. This patch fixes this issue reported by Zhang Yi When running nvme/011. Cc: Christoph Hellwig Cc: Yi Zhang Reported-by: Yi Zhang Reviewed-by: Christoph Hellwig Fixes: 6dc4f100c175 ("block: allow bio_for_each_segment_all() to iterate over multi-page bvec") Signed-off-by: Ming Lei Signed-off-by: Jens Axboe

block: only allow contiguous page structs in a bio_vec

2019-04-12T15:06:42Z

We currently have to call nth_page when iterating over pages inside a bio_vec. Jens complained a while ago that this is fairly expensive. To mitigate this we can check that that the actual page structures are contiguous when adding them to the bio, and just do check pointer arithmetics later on. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe

block: change how we get page references in bio_iov_iter_get_pages

2019-04-12T15:06:40Z

Instead of needing a special macro to iterate over all pages in a bvec just do a second passs over the whole bio. This also matches what we do on the release side. The release side helper is moved up to where we need the get helper to clearly express the symmetry. Reviewed-by: Ming Lei Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe

block: don't use for-inside-for in bio_for_each_segment_all

2019-04-08T14:19:41Z

Commit 6dc4f100c175 ("block: allow bio_for_each_segment_all() to iterate over multi-page bvec") changes bio_for_each_segment_all() to use for-inside-for. This way breaks all bio_for_each_segment_all() call with error out branch via 'break', since now 'break' can only break from the inner loop. Fixes this issue by implementing bio_for_each_segment_all() via single 'for' loop, and now the logic is very similar with normal bvec iterator. Cc: Qu Wenruo Cc: linux-btrfs@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org Cc: Omar Sandoval Reviewed-by: Johannes Thumshirn Reported-and-Tested-by: Qu Wenruo Fixes: 6dc4f100c175 ("block: allow bio_for_each_segment_all() to iterate over multi-page bvec") Reviewed-by: Christoph Hellwig Signed-off-by: Ming Lei Signed-off-by: Jens Axboe

block: optimize bvec iteration in bvec_iter_advance

2019-02-28T20:49:22Z

There is no need to only iterate in chunks of PAGE_SIZE or less in bvec_iter_advance, given that the callers pass in the chunk length that they are operating on - either that already is less than PAGE_SIZE because they do classic page-based iteration, or it is larger because the caller operates on multi-page bvecs. This should help shaving off a few cycles of the I/O hot path. Reviewed-by: Johannes Thumshirn Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe

block: introduce mp_bvec_for_each_page() for iterating over page

2019-02-28T12:56:03Z

mp_bvec_for_each_segment() is a bit big for the iteration, so introduce a light-weight helper for iterating over pages, then 32bytes stack space can be saved. Signed-off-by: Ming Lei Signed-off-by: Jens Axboe