This document is completely out of date and extremely misleading. In
general the existing kerneldoc comment serve as a much better
documentation of the still existing functionality, while the history
blurbs are pretty much irrelevant today.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20220215081047.3693582-1-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Since commit 7eaceacc ("block: remove per-queue plugging"), kernel
has removed blk_run_address_space(), blk_unplug() and sync_buffer(),
and moved to on-stack plugging. The document has been obsolete for
years.
Given that there is no obvious counterparts in the new mechinism to
replace old APIs, this patch drops the content directly.
Signed-off-by: NBarry Song <song.bao.hua@hisilicon.com>
Link: https://lore.kernel.org/r/20220207074931.20067-1-song.bao.hua@hisilicon.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

Partition include/linux/blk-cgroup.h into two parts: one is public part,
the other is block layer private part.

Suggested by Christoph Hellwig.
Signed-off-by: NMing Lei <ming.lei@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220211101149.2368042-4-ming.lei@redhat.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

q->blkg_list is only used by blkcg code, so move it into
blkcg_init_queue.
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBart Van Assche <bvanassche@acm.org>
Signed-off-by: NMing Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20220211101149.2368042-3-ming.lei@redhat.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

No one uses THROTL_IOPS_MAX any more, so remove it.
Signed-off-by: NMing Lei <ming.lei@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220211101149.2368042-2-ming.lei@redhat.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

Currently, rasdaemon uses the existing tracepoint block_rq_complete
and filters out non-error cases in order to capture block disk errors.

But there are a few problems with this approach:

1. Even kernel trace filter could do the filtering work, there is
   still some overhead after we enable this tracepoint.

2. The filter is merely based on errno, which does not align with kernel
   logic to check the errors for print_req_error().

3. block_rq_complete only provides dev major and minor to identify
   the block device, it is not convenient to use in user-space.

So introduce a new tracepoint block_rq_error just for the error case.
With this patch, rasdaemon could switch to block_rq_error.

Since the new tracepoint has the similar implementation with
block_rq_complete, so move the existing code from TRACE_EVENT
block_rq_complete() into new event class block_rq_completion(). Then add
event for block_rq_complete and block_rq_err respectively from the newly
created event class per the suggestion from Chaitanya Kulkarni.

Cc: Jens Axboe <axboe@kernel.dk>
Cc: Christoph Hellwig <hch@infradead.org>
Reviewed-by: NSteven Rostedt <rostedt@goodmis.org>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NChaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: NYang Shi <shy828301@gmail.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220210225222.260069-1-shy828301@gmail.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

Since __sbitmap_queue_get_shallow() was introduced in commit c05e6673
("sbitmap: add sbitmap_get_shallow() operation"), it has not been used.

Delete __sbitmap_queue_get_shallow() and rename public
__sbitmap_queue_get_shallow() -> sbitmap_queue_get_shallow() as it is odd
to have public __foo but no foo at all.
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Link: https://lore.kernel.org/r/1644322024-105340-1-git-send-email-john.garry@huawei.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

Only the last sbitmap_word can have different depth, and all the others
must have same depth of 1U << sb->shift, so not necessary to store it in
sbitmap_word, and it can be retrieved easily and efficiently by adding
one internal helper of __map_depth(sb, index).

Remove 'depth' field from sbitmap_word, then the annotation of
____cacheline_aligned_in_smp for 'word' isn't needed any more.

Not see performance effect when running high parallel IOPS test on
null_blk.

This way saves us one cacheline(usually 64 words) per each sbitmap_word.

Cc: Martin Wilck <martin.wilck@suse.com>
Signed-off-by: NMing Lei <ming.lei@redhat.com>
Reviewed-by: NMartin Wilck <mwilck@suse.com>
Reviewed-by: NJohn Garry <john.garry@huawei.com>
Link: https://lore.kernel.org/r/20220110072945.347535-1-ming.lei@redhat.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

Pass a block_device to bio_clone_fast and __bio_clone_fast and give
the functions more suitable names.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMike Snitzer <snitzer@redhat.com>
Link: https://lore.kernel.org/r/20220202160109.108149-14-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

All callers of __bio_clone_fast initialize the bio first.  Move that
initialization into __bio_clone_fast instead.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMike Snitzer <snitzer@redhat.com>
Link: https://lore.kernel.org/r/20220202160109.108149-13-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Replace open coded bio_clone_fast implementations with the actual helper.
Note that the bio allocated as part of the dm_io structure in alloc_io
will only actually be used later in alloc_tio, making this earlier
cloning of the information safe.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMike Snitzer <snitzer@redhat.com>
Link: https://lore.kernel.org/r/20220202160109.108149-12-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

__bio_clone_fast should also clone integrity and crypto data, as a clone
without those is incomplete.  Right now the only caller that can actually
support crypto and integrity data (dm) does it manually for the one
callchain that supports these, but we better do it properly in the core.

Note that all callers except for the above mentioned one also don't need
to handle failure at all, given that the integrity and crypto clones are
based on mempool allocations that won't fail for sleeping allocations.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMike Snitzer <snitzer@redhat.com>
Link: https://lore.kernel.org/r/20220202160109.108149-11-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Fold __remap_to_origin_clear_discard into the two callers to prepare
for bio cloning refactoring.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMike Snitzer <snitzer@redhat.com>
Link: https://lore.kernel.org/r/20220202160109.108149-10-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Most targets just need a single flush bio.  Open code that case in
__send_duplicate_bios without the need to add the bio to a list.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMike Snitzer <snitzer@redhat.com>
Link: https://lore.kernel.org/r/20220202160109.108149-9-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Return the clone bio embedded into the tio as that is what the callers
actually want.  Similar for the free side.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMike Snitzer <snitzer@redhat.com>
Link: https://lore.kernel.org/r/20220202160109.108149-8-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

This simplifies the callers a bit.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMike Snitzer <snitzer@redhat.com>
Link: https://lore.kernel.org/r/20220202160109.108149-7-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Move the call to __bio_clone_fast and the assignment of ->len_ptr from
the callers into alloc_tio to prepare for changes to the bio clone API.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMike Snitzer <snitzer@redhat.com>
Link: https://lore.kernel.org/r/20220202160109.108149-6-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Fold __send_duplicate_bios into its only caller to prepare for
refactoring.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMike Snitzer <snitzer@redhat.com>
Link: https://lore.kernel.org/r/20220202160109.108149-5-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Fold clone_bio into its only caller to prepare for refactoring.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMike Snitzer <snitzer@redhat.com>
Link: https://lore.kernel.org/r/20220202160109.108149-4-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Add a helper to stop open coding the container_of operations to get
from the clone bio to the tio structure.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMike Snitzer <snitzer@redhat.com>
Link: https://lore.kernel.org/r/20220202160109.108149-3-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Make sure the newly allocated bio has the correct bi_bdev set from the
start.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMike Snitzer <snitzer@redhat.com>
Link: https://lore.kernel.org/r/20220202160109.108149-2-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Call bio_associate_blkg just like bio_set_dev did in the callers before
the conversion to set the block device in bio_reset.

Fixes: a7c50c94 ("block: pass a block_device and opf to bio_reset")
Reported-by: syzbot+2b3f18414c37b42dcc94@syzkaller.appspotmail.com
Tested-by: syzbot+2b3f18414c37b42dcc94@syzkaller.appspotmail.com
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Tested-by: NChaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220204071934.168469-1-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

The new error message for such case looks like

[  172.809565] device offline error, dev sda, sector 3138208 ...

which will not be confused with regular I/O error (BLK_STS_IOERR).
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NSong Liu <song@kernel.org>
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20220203192827.1370270-4-song@kernel.orgSigned-off-by: NJens Axboe <axboe@kernel.dk>

Change the user visible return value for BLK_STS_OFFLINE to -ENODEV, which
is more descriptive than existing -EIO.
Signed-off-by: NSong Liu <song@kernel.org>
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20220203192827.1370270-3-song@kernel.orgSigned-off-by: NJens Axboe <axboe@kernel.dk>

Currently, drivers reports BLK_STS_IOERR for devices that are not full
online or being removed. This behavior could cause confusion for users,
as they are not really I/O errors from the device.

Solve this issue with a new state BLK_STS_OFFLINE, which reports "device
offline error" in dmesg instead of "I/O error".

EIO is intentionally kept to not change user visible return value.
Signed-off-by: NSong Liu <song@kernel.org>
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20220203192827.1370270-2-song@kernel.orgSigned-off-by: NJens Axboe <axboe@kernel.dk>

This code triggers a Smatch warning:

    fs/ntfs3/fsntfs.c:1606 ntfs_bio_fill_1()
    warn: variable dereferenced before check 'bio' (see line 1591)

The "bio" pointer cannot be NULL so there is no need to check.
Originally there was more extensive NULL checking but it was removed
because bio_alloc() will never fail if it is allowed to sleep.

Remove this check as well.

Fixes: 39146b6f ("ntfs3: remove ntfs_alloc_bio")
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220128140922.GA29766@kiliSigned-off-by: NJens Axboe <axboe@kernel.dk>

Return statements in functions returning bool should use true/false
instead of 1/0.

./block/bio.c:1081:9-10: WARNING: return of 0/1 in function
'bio_add_folio' with return type bool.
Reported-by: NAbaci Robot <abaci@linux.alibaba.com>
Signed-off-by: NJiapeng Chong <jiapeng.chong@linux.alibaba.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220128043454.68927-1-jiapeng.chong@linux.alibaba.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

bio.h is part of the block layer, so list it in the MAINTAINERS file
as such.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220127064221.1314477-1-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Document the actually existing parameter name.
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220127064125.1314347-1-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Rename blk_flush_plug to __blk_flush_plug and add a wrapper that includes
the NULL check instead of open coding that check everywhere.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220127070549.1377856-2-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

blk_needs_flush_plug fails to account for the cb_list, which needs
flushing as well.  Remove it and just check if there is a plug instead
of poking into the internals of the plug structure.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220127070549.1377856-1-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Pass the block_device that we plan to use this bio for and the
operation to bio_reset to optimize the assigment.  A NULL block_device
can be passed, both for the passthrough case on a raw request_queue and
to temporarily avoid refactoring some nasty code.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220124091107.642561-20-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Pass the block_device that we plan to use this bio for and the
operation to bio_init to optimize the assignment.  A NULL block_device
can be passed, both for the passthrough case on a raw request_queue and
to temporarily avoid refactoring some nasty code.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220124091107.642561-19-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Pass the block_device and operation that we plan to use this bio for to
bio_alloc to optimize the assignment.  NULL/0 can be passed, both for the
passthrough case on a raw request_queue and to temporarily avoid
refactoring some nasty code.

Also move the gfp_mask argument after the nr_vecs argument for a much
more logical calling convention matching what most of the kernel does.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220124091107.642561-18-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Pass the block_device and operation that we plan to use this bio for to
bio_alloc_kiocb to optimize the assigment.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220124091107.642561-17-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Pass the block_device and operation that we plan to use this bio for to
bio_alloc_bioset to optimize the assigment.  NULL/0 can be passed, both
for the passthrough case on a raw request_queue and to temporarily avoid
refactoring some nasty code.

Also move the gfp_mask argument after the nr_vecs argument for a much
more logical calling convention matching what most of the kernel does.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220124091107.642561-16-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

All callers need to set the block_device and operation, so lift that into
the common code.
Signed-off-by: NChaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220124091107.642561-15-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Keep blk_next_bio next to the core bio infrastructure.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220124091107.642561-14-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Remove handling of NULL returns from sleeping bio_alloc calls given that
those can't fail.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220124091107.642561-13-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

Only the priv field of rnbd_dev_blk_io is used, so store the value of
that in bio->bi_private directly and remove the entire bio_set overhead.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJack Wang <jinpu.wang@ionos.com>
Link: https://lore.kernel.org/r/20220124091107.642561-12-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>