block: fix "check bi_size overflow before merge"

This partially reverts commit e3a5d8e386c3fb973fa75f2403622a8f3640ec06.

Commit e3a5d8e386c3 ("check bi_size overflow before merge") adds a bio_full

block: fix "check bi_size overflow before merge"

This partially reverts commit e3a5d8e386c3fb973fa75f2403622a8f3640ec06.

Commit e3a5d8e386c3 ("check bi_size overflow before merge") adds a bio_full
check to __bio_try_merge_page. This will cause __bio_try_merge_page to fail
when the last bi_io_vec has been reached. Instead, what we want here is only
the bi_size overflow check.

Fixes: e3a5d8e386c3 ("block: check bi_size overflow before merge")
Cc: stable@vger.kernel.org # v5.4+
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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block: fix memleak of bio integrity data

7c20f11680a4 ("bio-integrity: stop abusing bi_end_io") moves
bio_integrity_free from bio_uninit() to bio_integrity_verify_fn()
and bio_endio(). This way look

block: fix memleak of bio integrity data

7c20f11680a4 ("bio-integrity: stop abusing bi_end_io") moves
bio_integrity_free from bio_uninit() to bio_integrity_verify_fn()
and bio_endio(). This way looks wrong because bio may be freed
without calling bio_endio(), for example, blk_rq_unprep_clone() is
called from dm_mq_queue_rq() when the underlying queue of dm-mpath
is busy.

So memory leak of bio integrity data is caused by commit 7c20f11680a4.

Fixes this issue by re-adding bio_integrity_free() to bio_uninit().

Fixes: 7c20f11680a4 ("bio-integrity: stop abusing bi_end_io")
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by Justin Tee <justin.tee@broadcom.com>

Add commit log, and simplify/fix the original patch wroten by Justin.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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block: check bi_size overflow before merge

__bio_try_merge_page() may merge a page to bio without bio_full() check
and cause bi_size overflow.

The overflow typically ends up with sd_init_command()

block: check bi_size overflow before merge

__bio_try_merge_page() may merge a page to bio without bio_full() check
and cause bi_size overflow.

The overflow typically ends up with sd_init_command() warning on zero
segment request with call trace like this:

------------[ cut here ]------------
WARNING: CPU: 2 PID: 1986 at drivers/scsi/scsi_lib.c:1025 scsi_init_io+0x156/0x180
CPU: 2 PID: 1986 Comm: kworker/2:1H Kdump: loaded Not tainted 5.4.0-rc7 #1
Workqueue: kblockd blk_mq_run_work_fn
RIP: 0010:scsi_init_io+0x156/0x180
RSP: 0018:ffffa11487663bf0 EFLAGS: 00010246
RAX: 00000000002be0a0 RBX: ffff8e6e9ff30118 RCX: 0000000000000000
RDX: 00000000ffffffe1 RSI: 0000000000000000 RDI: ffff8e6e9ff30118
RBP: ffffa11487663c18 R08: ffffa11487663d28 R09: ffff8e6e9ff30150
R10: 0000000000000001 R11: 0000000000000000 R12: ffff8e6e9ff30000
R13: 0000000000000001 R14: ffff8e74a1cf1800 R15: ffff8e6e9ff30000
FS: 0000000000000000(0000) GS:ffff8e6ea7680000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fff18cf0fe8 CR3: 0000000659f0a001 CR4: 00000000001606e0
Call Trace:
sd_init_command+0x326/0xb40 [sd_mod]
scsi_queue_rq+0x502/0xaa0
? blk_mq_get_driver_tag+0xe7/0x120
blk_mq_dispatch_rq_list+0x256/0x5a0
? elv_rb_del+0x24/0x30
? deadline_remove_request+0x7b/0xc0
blk_mq_do_dispatch_sched+0xa3/0x140
blk_mq_sched_dispatch_requests+0xfb/0x170
__blk_mq_run_hw_queue+0x81/0x130
blk_mq_run_work_fn+0x1b/0x20
process_one_work+0x179/0x390
worker_thread+0x4f/0x3e0
kthread+0x105/0x140
? max_active_store+0x80/0x80
? kthread_bind+0x20/0x20
ret_from_fork+0x35/0x40
---[ end trace f9036abf5af4a4d3 ]---
blk_update_request: I/O error, dev sdd, sector 2875552 op 0x1:(WRITE) flags 0x0 phys_seg 0 prio class 0
XFS (sdd1): writeback error on sector 2875552

__bio_try_merge_page() should check the overflow before actually doing
merge.

Fixes: 07173c3ec276c ("block: enable multipage bvecs")
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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block: move same page handling from __bio_add_pc_page to the callers

Hiding page refcount manipulation inside a low-level bio helper is
somewhat awkward. Instead return the same page information to

block: move same page handling from __bio_add_pc_page to the callers

Hiding page refcount manipulation inside a low-level bio helper is
somewhat awkward. Instead return the same page information to the
callers, where it fits in much better.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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block: create a bio_try_merge_pc_page helper

Passsthrough bio handling should be the same as normal bio handling,
except that we need to take hardware limitations into account. Thus
use the common

block: create a bio_try_merge_pc_page helper

Passsthrough bio handling should be the same as normal bio handling,
except that we need to take hardware limitations into account. Thus
use the common try_merge implementation after checking the hardware
limits. This changes behavior in that we now also check segment
and dma boundary settings for same page merges, which is a little
more work but has no effect as those need to be larger than the
page size.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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block: improve the gap check in __bio_add_pc_page

If we can add more data into an existing segment we do not create a gap
per definition, so move the check for a gap after the attempt to merge
into

block: improve the gap check in __bio_add_pc_page

If we can add more data into an existing segment we do not create a gap
per definition, so move the check for a gap after the attempt to merge
into the segment.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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block: annotate refault stalls from IO submission

psi tracks the time tasks wait for refaulting pages to become
uptodate, but it does not track the time spent submitting the IO. The
submission part

block: annotate refault stalls from IO submission

psi tracks the time tasks wait for refaulting pages to become
uptodate, but it does not track the time spent submitting the IO. The
submission part can be significant if backing storage is contended or
when cgroup throttling (io.latency) is in effect - a lot of time is
spent in submit_bio(). In that case, we underreport memory pressure.

Annotate submit_bio() to account submission time as memory stall when
the bio is reading userspace workingset pages.

Tested-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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block: stop exporting bio_map_kern

Now that there no module users left of bio_map_kern, stop exporting the
symbol.

Reviewed-by: Javier González <javier@javigon.com>
Reviewed-by: Christoph Hellwig <

block: stop exporting bio_map_kern

Now that there no module users left of bio_map_kern, stop exporting the
symbol.

Reviewed-by: Javier González <javier@javigon.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Hans Holmberg <hans@owltronix.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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block: Document the bio splitting functions

Since what the bio splitting functions do is nontrivial, document these
functions.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Cc: Christoph Hel

block: Document the bio splitting functions

Since what the bio splitting functions do is nontrivial, document these
functions.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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block: Allow mapping of vmalloc-ed buffers

To allow the SCSI subsystem scsi_execute_req() function to issue
requests using large buffers that are better allocated with vmalloc()
rather than kmalloc(

block: Allow mapping of vmalloc-ed buffers

To allow the SCSI subsystem scsi_execute_req() function to issue
requests using large buffers that are better allocated with vmalloc()
rather than kmalloc(), modify bio_map_kern() to allow passing a buffer
allocated with vmalloc().

To do so, detect vmalloc-ed buffers using is_vmalloc_addr(). For
vmalloc-ed buffers, flush the buffer using flush_kernel_vmap_range(),
use vmalloc_to_page() instead of virt_to_page() to obtain the pages of
the buffer, and invalidate the buffer addresses with
invalidate_kernel_vmap_range() on completion of read BIOs. This last
point is executed using the function bio_invalidate_vmalloc_pages()
which is defined only if the architecture defines
ARCH_HAS_FLUSH_KERNEL_DCACHE_PAGE, that is, if the architecture
actually needs the invalidation done.

Fixes: 515ce6061312 ("scsi: sd_zbc: Fix sd_zbc_report_zones() buffer allocation")
Fixes: e76239a3748c ("block: add a report_zones method")
Cc: stable@vger.kernel.org
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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block: fix .bi_size overflow

'bio->bi_iter.bi_size' is 'unsigned int', which at most hold 4G - 1
bytes.

Before 07173c3ec276 ("block: enable multipage bvecs"), one bio can
include very limited pages

block: fix .bi_size overflow

'bio->bi_iter.bi_size' is 'unsigned int', which at most hold 4G - 1
bytes.

Before 07173c3ec276 ("block: enable multipage bvecs"), one bio can
include very limited pages, and usually at most 256, so the fs bio
size won't be bigger than 1M bytes most of times.

Since we support multi-page bvec, in theory one fs bio really can
be added > 1M pages, especially in case of hugepage, or big writeback
with too many dirty pages. Then there is chance in which .bi_size
is overflowed.

Fixes this issue by using bio_full() to check if the added segment may
overflow .bi_size.

Cc: Liu Yiding <liuyd.fnst@cn.fujitsu.com>
Cc: kernel test robot <rong.a.chen@intel.com>
Cc: "Darrick J. Wong" <darrick.wong@oracle.com>
Cc: linux-xfs@vger.kernel.org
Cc: linux-fsdevel@vger.kernel.org
Cc: stable@vger.kernel.org
Fixes: 07173c3ec276 ("block: enable multipage bvecs")
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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block: never take page references for ITER_BVEC

If we pass pages through an iov_iter we always already have a reference
in the caller. Thus remove the ITER_BVEC_FLAG_NO_REF and don't take
reference

block: never take page references for ITER_BVEC

If we pass pages through an iov_iter we always already have a reference
in the caller. Thus remove the ITER_BVEC_FLAG_NO_REF and don't take
reference to pages by default for bvec backed iov_iters.

Reviewed-by: Minwoo Im <minwoo.im.dev@gmail.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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block: use bio_release_pages in bio_map_user_iov

Use bio_release_pages instead of open coding it.

Reviewed-by: Minwoo Im <minwoo.im.dev@gmail.com>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarn

block: use bio_release_pages in bio_map_user_iov

Use bio_release_pages instead of open coding it.

Reviewed-by: Minwoo Im <minwoo.im.dev@gmail.com>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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block: use bio_release_pages in bio_unmap_user

Use bio_release_pages instead of open coding it.

Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Minwoo Im <minwoo.im.dev@gm

block: use bio_release_pages in bio_unmap_user

Use bio_release_pages instead of open coding it.

Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Minwoo Im <minwoo.im.dev@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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block: optionally mark pages dirty in bio_release_pages

A lot of callers of bio_release_pages also want to mark the released
pages as dirty. Add a mark_dirty parameter to avoid a second
relatively

block: optionally mark pages dirty in bio_release_pages

A lot of callers of bio_release_pages also want to mark the released
pages as dirty. Add a mark_dirty parameter to avoid a second
relatively expensive bio_for_each_segment_all loop.

Reviewed-by: Minwoo Im <minwoo.im.dev@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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block: move the BIO_NO_PAGE_REF check into bio_release_pages

Move the BIO_NO_PAGE_REF check into bio_release_pages instead of
duplicating it in both callers.

Also make the function available outsid

block: move the BIO_NO_PAGE_REF check into bio_release_pages

Move the BIO_NO_PAGE_REF check into bio_release_pages instead of
duplicating it in both callers.

Also make the function available outside of bio.c so that we can
reuse it in other direct I/O implementations.

Reviewed-by: Minwoo Im <minwoo.im.dev@gmail.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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block: Remove unused code

bio_flush_dcache_pages() is unused. Remove it.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe

block: Remove unused code

bio_flush_dcache_pages() is unused. Remove it.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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block: remove the bi_phys_segments field in struct bio

We only need the number of segments in the blk-mq submission path.
Remove the field from struct bio, and return it from a variant of
blk_queue_

block: remove the bi_phys_segments field in struct bio

We only need the number of segments in the blk-mq submission path.
Remove the field from struct bio, and return it from a variant of
blk_queue_split instead of that it can passed as an argument to
those functions that need the value.

This also means we stop recounting segments except for cloning
and partial segments.

To keep the number of arguments in this how path down remove
pointless struct request_queue arguments from any of the functions
that had it and grew a nr_segs argument.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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block: fix page leak when merging to same page

When multiple iovecs reference the same page, each get_user_page call
will add a reference to the page. But once we've created the bio that
informatio

block: fix page leak when merging to same page

When multiple iovecs reference the same page, each get_user_page call
will add a reference to the page. But once we've created the bio that
information gets lost and only a single reference will be dropped after
I/O completion. Use the same_page information returned from
__bio_try_merge_page to drop additional references to pages that were
already present in the bio.

Based on a patch from Ming Lei.

Link: https://lkml.org/lkml/2019/4/23/64
Fixes: 576ed913 ("block: use bio_add_page in bio_iov_iter_get_pages")
Reported-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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block: return from __bio_try_merge_page if merging occured in the same page

We currently have an input same_page parameter to __bio_try_merge_page
to prohibit merging in the same page. The rational

block: return from __bio_try_merge_page if merging occured in the same page

We currently have an input same_page parameter to __bio_try_merge_page
to prohibit merging in the same page. The rationale for that is that
some callers need to account for every page added to a bio. Instead of
letting these callers call twice into the merge code to account for the
new vs existing page cases, just turn the paramter into an output one that
returns if a merge in the same page occured and let them act accordingly.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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block: bio: Use struct_size() in kmalloc()

One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory f

block: bio: Use struct_size() in kmalloc()

One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:

struct bio_map_data {
...
struct iovec iov[];
};

instance = kmalloc(sizeof(sizeof(struct bio_map_data) + sizeof(struct iovec) *
count, GFP_KERNEL);

Instead of leaving these open-coded and prone to type mistakes, we can
now use the new struct_size() helper:

instance = kmalloc(struct_size(instance, iov, count), GFP_KERNEL);

This code was detected with the help of Coccinelle.

Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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

All these files have some form of the usual GPLv2 boilerplate. Switch
them to use SPDX tags instead.

Reviewed-by: Chaitanya Kulkarni <c

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

All these files have some form of the usual GPLv2 boilerplate. Switch
them to use SPDX tags instead.

Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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block: clean up __bio_add_pc_page a bit

Share the bi_size update by moving the done label up, and duplicate
the bv_len update in the two callers to get rid of the bvec_merge
label.

Signed-off-by: C

block: clean up __bio_add_pc_page a bit

Share the bi_size update by moving the done label up, and duplicate
the bv_len update in the two callers to get rid of the bvec_merge
label.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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block: remove bogus comments in __bio_add_pc_page

We are never called with file system pages by defintions for the
passthrough interface, and we also never undo any addition later
these days.

Signe

block: remove bogus comments in __bio_add_pc_page

We are never called with file system pages by defintions for the
passthrough interface, and we also never undo any addition later
these days.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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block: remove the __bio_add_pc_page export

The same page optimization is a rather odd corner case, which is not
used outside bio.c and which really should not be used outside of bio.c
either - we ha

block: remove the __bio_add_pc_page export

The same page optimization is a rather odd corner case, which is not
used outside bio.c and which really should not be used outside of bio.c
either - we have better highlevel helpers like the rq/bio mapping
helpers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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