user/sven/linux.git/include/linux/bio.h, branch v4.6.5

mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros

2016-04-04T17:41:08Z

PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time ago with promise that one day it will be possible to implement page cache with bigger chunks than PAGE_SIZE. This promise never materialized. And unlikely will. We have many places where PAGE_CACHE_SIZE assumed to be equal to PAGE_SIZE. And it's constant source of confusion on whether PAGE_CACHE_* or PAGE_* constant should be used in a particular case, especially on the border between fs and mm. Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much breakage to be doable. Let's stop pretending that pages in page cache are special. They are not. The changes are pretty straight-forward: - << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> ; - >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> ; - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN}; - page_cache_get() -> get_page(); - page_cache_release() -> put_page(); This patch contains automated changes generated with coccinelle using script below. For some reason, coccinelle doesn't patch header files. I've called spatch for them manually. The only adjustment after coccinelle is revert of changes to PAGE_CAHCE_ALIGN definition: we are going to drop it later. There are few places in the code where coccinelle didn't reach. I'll fix them manually in a separate patch. Comments and documentation also will be addressed with the separate patch. virtual patch @@ expression E; @@ - E << (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ expression E; @@ - E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ @@ - PAGE_CACHE_SHIFT + PAGE_SHIFT @@ @@ - PAGE_CACHE_SIZE + PAGE_SIZE @@ @@ - PAGE_CACHE_MASK + PAGE_MASK @@ expression E; @@ - PAGE_CACHE_ALIGN(E) + PAGE_ALIGN(E) @@ expression E; @@ - page_cache_get(E) + get_page(E) @@ expression E; @@ - page_cache_release(E) + put_page(E) Signed-off-by: Kirill A. Shutemov Acked-by: Michal Hocko Signed-off-by: Linus Torvalds

block: don't optimize for non-cloned bio in bio_get_last_bvec()

2016-03-12T21:12:10Z

For !BIO_CLONED bio, we can use .bi_vcnt safely, but it doesn't mean we can just simply return .bi_io_vec[.bi_vcnt - 1] because the start postion may have been moved in the middle of the bvec, such as splitting in the middle of bvec. Fixes: 7bcd79ac50d9(block: bio: introduce helpers to get the 1st and last bvec) Cc: stable@vger.kernel.org Reported-by: Kent Overstreet Signed-off-by: Ming Lei Signed-off-by: Jens Axboe

block: bio: introduce helpers to get the 1st and last bvec

2016-03-03T21:42:49Z

The bio passed to bio_will_gap() may be fast cloned from upper layer(dm, md, bcache, fs, ...), or from bio splitting in block core. Unfortunately bio_will_gap() just figures out the last bvec via 'bi_io_vec[prev->bi_vcnt - 1]' directly, and this way is obviously wrong. This patch introduces two helpers for getting the first and last bvec of one bio for fixing the issue. Cc: stable@vger.kernel.org Reported-by: Sagi Grimberg Reviewed-by: Sagi Grimberg Reviewed-by: Christoph Hellwig Signed-off-by: Ming Lei Signed-off-by: Jens Axboe

blk-integrity: empty implementation when disabled

2015-12-03T16:32:21Z

This patch moves the blk_integrity_payload definition outside the CONFIG_BLK_DEV_INTERITY dependency and provides empty function implementations when the kernel configuration disables integrity extensions. This simplifies drivers that make use of these to map user data so they don't need to repeat the same configuration checks. Signed-off-by: Keith Busch Updated by Jens to pass an error pointer return from bio_integrity_alloc(), otherwise if CONFIG_BLK_DEV_INTEGRITY isn't set, we return a weird ENOMEM from __nvme_submit_user_cmd() if a meta buffer is set. Signed-off-by: Jens Axboe

block: Replace SG_GAPS with new queue limits mask

2015-08-19T21:26:02Z

The SG_GAPS queue flag caused checks for bio vector alignment against PAGE_SIZE, but the device may have different constraints. This patch adds a queue limits so a driver with such constraints can set to allow requests that would have been unnecessarily split. The new gaps check takes the request_queue as a parameter to simplify the logic around invoking this function. This new limit makes the queue flag redundant, so removing it and all usage. Device-mappers will inherit the correct settings through blk_stack_limits(). Signed-off-by: Keith Busch Reviewed-by: Martin K. Petersen Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe

block: remove bio_get_nr_vecs()

2015-08-13T18:32:04Z

We can always fill up the bio now, no need to estimate the possible size based on queue parameters. Acked-by: Steven Whitehouse Signed-off-by: Kent Overstreet [hch: rebased and wrote a changelog] Signed-off-by: Christoph Hellwig Signed-off-by: Ming Lin Signed-off-by: Jens Axboe

block: shrink struct bio down to 2 cache lines again

2015-07-29T14:55:25Z

Commit bcf2843b3f8f added ->bi_error to cleanup the error passing for struct bio, but that ended up adding 4 bytes and a 4 byte hole to the size of struct bio. For a clean config, that bumped it from 128 bytes, to 136 bytes, on x86-64. The ->bi_flags member is currently an unsigned long, but it fits easily within an int. Change it to an unsigned int, adjust the the pool offset code, and move ->bi_error into the new hole. Then we end up with a 128 byte bio again. Change the bio flag set/clear to use cmpxchg to ensure we don't lose any flags when manipulating them. Signed-off-by: Jens Axboe

block: manipulate bio->bi_flags through helpers

2015-07-29T14:55:20Z

Some places use helpers now, others don't. We only have the 'is set' helper, add helpers for setting and clearing flags too. It was a bit of a mess of atomic vs non-atomic access. With BIO_UPTODATE gone, we don't have any risk of concurrent access to the flags. So relax the restriction and don't make any of them atomic. The flags that do have serialization issues (reffed and chained), we already handle those separately. Signed-off-by: Jens Axboe

block: add a bi_error field to struct bio

2015-07-29T14:55:15Z

Currently we have two different ways to signal an I/O error on a BIO: (1) by clearing the BIO_UPTODATE flag (2) by returning a Linux errno value to the bi_end_io callback The first one has the drawback of only communicating a single possible error (-EIO), and the second one has the drawback of not beeing persistent when bios are queued up, and are not passed along from child to parent bio in the ever more popular chaining scenario. Having both mechanisms available has the additional drawback of utterly confusing driver authors and introducing bugs where various I/O submitters only deal with one of them, and the others have to add boilerplate code to deal with both kinds of error returns. So add a new bi_error field to store an errno value directly in struct bio and remove the existing mechanisms to clean all this up. Signed-off-by: Christoph Hellwig Reviewed-by: Hannes Reinecke Reviewed-by: NeilBrown Signed-off-by: Jens Axboe

blkcg: implement bio_associate_blkcg()

2015-06-02T14:33:34Z

Currently, a bio can only be associated with the io_context and blkcg of %current using bio_associate_current(). This is too restrictive for cgroup writeback support. Implement bio_associate_blkcg() which associates a bio with the specified blkcg. bio_associate_blkcg() leaves the io_context unassociated. bio_associate_current() is updated so that it considers a bio as already associated if it has a blkcg_css, instead of an io_context, associated with it. Signed-off-by: Tejun Heo Cc: Jens Axboe Cc: Vivek Goyal Signed-off-by: Jens Axboe