bcache: fix variable length array abuse in btree_iter

commit 3a861560ccb35f2a4f0a4b8207fa7c2a35fc7f31 upstream.

btree_iter is used in two ways: either allocated on the stack with a
fixed size MAX_B

bcache: fix variable length array abuse in btree_iter

commit 3a861560ccb35f2a4f0a4b8207fa7c2a35fc7f31 upstream.

btree_iter is used in two ways: either allocated on the stack with a
fixed size MAX_BSETS, or from a mempool with a dynamic size based on the
specific cache set. Previously, the struct had a fixed-length array of
size MAX_BSETS which was indexed out-of-bounds for the dynamically-sized
iterators, which causes UBSAN to complain.

This patch uses the same approach as in bcachefs's sort_iter and splits
the iterator into a btree_iter with a flexible array member and a
btree_iter_stack which embeds a btree_iter as well as a fixed-length
data array.

Cc: stable@vger.kernel.org
Closes: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2039368
Signed-off-by: Matthew Mirvish <matthew@mm12.xyz>
Signed-off-by: Coly Li <colyli@suse.de>
Link: https://lore.kernel.org/r/20240509011117.2697-3-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

bcache: fix variable length array abuse in btree_iter

commit 3a861560ccb35f2a4f0a4b8207fa7c2a35fc7f31 upstream.

btree_iter is used in two ways: either allocated on the stack with a
fixed size MAX_B

bcache: fix variable length array abuse in btree_iter

commit 3a861560ccb35f2a4f0a4b8207fa7c2a35fc7f31 upstream.

btree_iter is used in two ways: either allocated on the stack with a
fixed size MAX_BSETS, or from a mempool with a dynamic size based on the
specific cache set. Previously, the struct had a fixed-length array of
size MAX_BSETS which was indexed out-of-bounds for the dynamically-sized
iterators, which causes UBSAN to complain.

This patch uses the same approach as in bcachefs's sort_iter and splits
the iterator into a btree_iter with a flexible array member and a
btree_iter_stack which embeds a btree_iter as well as a fixed-length
data array.

Cc: stable@vger.kernel.org
Closes: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2039368
Signed-off-by: Matthew Mirvish <matthew@mm12.xyz>
Signed-off-by: Coly Li <colyli@suse.de>
Link: https://lore.kernel.org/r/20240509011117.2697-3-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

bcache: fix variable length array abuse in btree_iter

commit 3a861560ccb35f2a4f0a4b8207fa7c2a35fc7f31 upstream.

btree_iter is used in two ways: either allocated on the stack with a
fixed size MAX_B

bcache: fix variable length array abuse in btree_iter

commit 3a861560ccb35f2a4f0a4b8207fa7c2a35fc7f31 upstream.

btree_iter is used in two ways: either allocated on the stack with a
fixed size MAX_BSETS, or from a mempool with a dynamic size based on the
specific cache set. Previously, the struct had a fixed-length array of
size MAX_BSETS which was indexed out-of-bounds for the dynamically-sized
iterators, which causes UBSAN to complain.

This patch uses the same approach as in bcachefs's sort_iter and splits
the iterator into a btree_iter with a flexible array member and a
btree_iter_stack which embeds a btree_iter as well as a fixed-length
data array.

Cc: stable@vger.kernel.org
Closes: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2039368
Signed-off-by: Matthew Mirvish <matthew@mm12.xyz>
Signed-off-by: Coly Li <colyli@suse.de>
Link: https://lore.kernel.org/r/20240509011117.2697-3-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

bcache: fix variable length array abuse in btree_iter

commit 3a861560ccb35f2a4f0a4b8207fa7c2a35fc7f31 upstream.

btree_iter is used in two ways: either allocated on the stack with a
fixed size MAX_B

bcache: fix variable length array abuse in btree_iter

commit 3a861560ccb35f2a4f0a4b8207fa7c2a35fc7f31 upstream.

btree_iter is used in two ways: either allocated on the stack with a
fixed size MAX_BSETS, or from a mempool with a dynamic size based on the
specific cache set. Previously, the struct had a fixed-length array of
size MAX_BSETS which was indexed out-of-bounds for the dynamically-sized
iterators, which causes UBSAN to complain.

This patch uses the same approach as in bcachefs's sort_iter and splits
the iterator into a btree_iter with a flexible array member and a
btree_iter_stack which embeds a btree_iter as well as a fixed-length
data array.

Cc: stable@vger.kernel.org
Closes: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2039368
Signed-off-by: Matthew Mirvish <matthew@mm12.xyz>
Signed-off-by: Coly Li <colyli@suse.de>
Link: https://lore.kernel.org/r/20240509011117.2697-3-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

bcache: fix variable length array abuse in btree_iter

commit 3a861560ccb35f2a4f0a4b8207fa7c2a35fc7f31 upstream.

btree_iter is used in two ways: either allocated on the stack with a
fixed size MAX_B

bcache: fix variable length array abuse in btree_iter

commit 3a861560ccb35f2a4f0a4b8207fa7c2a35fc7f31 upstream.

btree_iter is used in two ways: either allocated on the stack with a
fixed size MAX_BSETS, or from a mempool with a dynamic size based on the
specific cache set. Previously, the struct had a fixed-length array of
size MAX_BSETS which was indexed out-of-bounds for the dynamically-sized
iterators, which causes UBSAN to complain.

This patch uses the same approach as in bcachefs's sort_iter and splits
the iterator into a btree_iter with a flexible array member and a
btree_iter_stack which embeds a btree_iter as well as a fixed-length
data array.

Cc: stable@vger.kernel.org
Closes: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2039368
Signed-off-by: Matthew Mirvish <matthew@mm12.xyz>
Signed-off-by: Coly Li <colyli@suse.de>
Link: https://lore.kernel.org/r/20240509011117.2697-3-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

bcache: avoid NULL checking to c->root in run_cache_set()

[ Upstream commit 3eba5e0b2422aec3c9e79822029599961fdcab97 ]

In run_cache_set() after c->root returned from bch_btree_node_get(), it
is che

bcache: avoid NULL checking to c->root in run_cache_set()

[ Upstream commit 3eba5e0b2422aec3c9e79822029599961fdcab97 ]

In run_cache_set() after c->root returned from bch_btree_node_get(), it
is checked by IS_ERR_OR_NULL(). Indeed it is unncessary to check NULL
because bch_btree_node_get() will not return NULL pointer to caller.

This patch replaces IS_ERR_OR_NULL() by IS_ERR() for the above reason.

Signed-off-by: Coly Li <colyli@suse.de>
Link: https://lore.kernel.org/r/20231120052503.6122-11-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>

show more ...

bcache: avoid oversize memory allocation by small stripe_size

[ Upstream commit baf8fb7e0e5ec54ea0839f0c534f2cdcd79bea9c ]

Arraies bcache->stripe_sectors_dirty and bcache->full_dirty_stripes are
us

bcache: avoid oversize memory allocation by small stripe_size

[ Upstream commit baf8fb7e0e5ec54ea0839f0c534f2cdcd79bea9c ]

Arraies bcache->stripe_sectors_dirty and bcache->full_dirty_stripes are
used for dirty data writeback, their sizes are decided by backing device
capacity and stripe size. Larger backing device capacity or smaller
stripe size make these two arraies occupies more dynamic memory space.

Currently bcache->stripe_size is directly inherited from
queue->limits.io_opt of underlying storage device. For normal hard
drives, its limits.io_opt is 0, and bcache sets the corresponding
stripe_size to 1TB (1<<31 sectors), it works fine 10+ years. But for
devices do declare value for queue->limits.io_opt, small stripe_size
(comparing to 1TB) becomes an issue for oversize memory allocations of
bcache->stripe_sectors_dirty and bcache->full_dirty_stripes, while the
capacity of hard drives gets much larger in recent decade.

For example a raid5 array assembled by three 20TB hardrives, the raid
device capacity is 40TB with typical 512KB limits.io_opt. After the math
calculation in bcache code, these two arraies will occupy 400MB dynamic
memory. Even worse Andrea Tomassetti reports that a 4KB limits.io_opt is
declared on a new 2TB hard drive, then these two arraies request 2GB and
512MB dynamic memory from kzalloc(). The result is that bcache device
always fails to initialize on his system.

To avoid the oversize memory allocation, bcache->stripe_size should not
directly inherited by queue->limits.io_opt from the underlying device.
This patch defines BCH_MIN_STRIPE_SZ (4MB) as minimal bcache stripe size
and set bcache device's stripe size against the declared limits.io_opt
value from the underlying storage device,
- If the declared limits.io_opt > BCH_MIN_STRIPE_SZ, bcache device will
set its stripe size directly by this limits.io_opt value.
- If the declared limits.io_opt < BCH_MIN_STRIPE_SZ, bcache device will
set its stripe size by a value multiplying limits.io_opt and euqal or
large than BCH_MIN_STRIPE_SZ.

Then the minimal stripe size of a bcache device will always be >= 4MB.
For a 40TB raid5 device with 512KB limits.io_opt, memory occupied by
bcache->stripe_sectors_dirty and bcache->full_dirty_stripes will be 50MB
in total. For a 2TB hard drive with 4KB limits.io_opt, memory occupied
by these two arraies will be 2.5MB in total.

Such mount of memory allocated for bcache->stripe_sectors_dirty and
bcache->full_dirty_stripes is reasonable for most of storage devices.

Reported-by: Andrea Tomassetti <andrea.tomassetti-opensource@devo.com>
Signed-off-by: Coly Li <colyli@suse.de>
Reviewed-by: Eric Wheeler <bcache@lists.ewheeler.net>
Link: https://lore.kernel.org/r/20231120052503.6122-2-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>

show more ...

bcache: Fix bcache device claiming

Commit 2736e8eeb0cc ("block: use the holder as indication for exclusive
opens") introduced a change that blkdev_put() has to get exclusive
holder of the bdev as an

bcache: Fix bcache device claiming

Commit 2736e8eeb0cc ("block: use the holder as indication for exclusive
opens") introduced a change that blkdev_put() has to get exclusive
holder of the bdev as an argument. However it overlooked that
register_bdev() and register_cache() overwrite the bdev->bd_holder field
in the block device to point to the real owning object which was not
available at the time we called blkdev_get_by_path(). Messing with bdev
internals like this is a layering violation and it also causes
blkdev_put() to issue warning about mismatching holders.

Fix bcache to reopen the block device with appropriate holder once it is
available which also restores the behavior that multiple bcache caches
cannot claim the same device which was broken by commit 29499ab060fe
("bcache: don't pass a stack address to blkdev_get_by_path").

Fixes: 2736e8eeb0cc ("block: use the holder as indication for exclusive opens")
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Kent Overstreet <kent.overstreet@linux.dev>
Acked-by: Coly Li <colyli@suse.de>
Link: https://lore.kernel.org/r/20230622164658.12861-2-jack@suse.cz
Signed-off-by: Jens Axboe <axboe@kernel.dk>

show more ...

bcache: Alloc holder object before async registration

Allocate holder object (cache or cached_dev) before offloading the
rest of the startup to async work. This will allow us to open the block
block

bcache: Alloc holder object before async registration

Allocate holder object (cache or cached_dev) before offloading the
rest of the startup to async work. This will allow us to open the block
block device with proper holder.

Signed-off-by: Jan Kara <jack@suse.cz>
Acked-by: Coly Li <colyli@suse.de>
Reviewed-by: Kent Overstreet <kent.overstreet@linux.dev>
Link: https://lore.kernel.org/r/20230622164658.12861-1-jack@suse.cz
Signed-off-by: Jens Axboe <axboe@kernel.dk>

show more ...

bcache: Remove unnecessary NULL point check in node allocations

Due to the previous fix of __bch_btree_node_alloc, the return value will
never be a NULL pointer. So IS_ERR is enough to handle the fa

bcache: Remove unnecessary NULL point check in node allocations

Due to the previous fix of __bch_btree_node_alloc, the return value will
never be a NULL pointer. So IS_ERR is enough to handle the failure
situation. Fix it by replacing IS_ERR_OR_NULL check by an IS_ERR check.

Fixes: cafe56359144 ("bcache: A block layer cache")
Cc: stable@vger.kernel.org
Signed-off-by: Zheng Wang <zyytlz.wz@163.com>
Signed-off-by: Coly Li <colyli@suse.de>
Link: https://lore.kernel.org/r/20230615121223.22502-5-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

show more ...

block: replace fmode_t with a block-specific type for block open flags

The only overlap between the block open flags mapped into the fmode_t and
other uses of fmode_t are FMODE_READ and FMODE_WRITE.

block: replace fmode_t with a block-specific type for block open flags

The only overlap between the block open flags mapped into the fmode_t and
other uses of fmode_t are FMODE_READ and FMODE_WRITE. Define a new
blk_mode_t instead for use in blkdev_get_by_{dev,path}, ->open and
->ioctl and stop abusing fmode_t.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jack Wang <jinpu.wang@ionos.com> [rnbd]
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Link: https://lore.kernel.org/r/20230608110258.189493-28-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

show more ...

block: use the holder as indication for exclusive opens

The current interface for exclusive opens is rather confusing as it
requires both the FMODE_EXCL flag and a holder. Remove the need to pass
F

block: use the holder as indication for exclusive opens

The current interface for exclusive opens is rather confusing as it
requires both the FMODE_EXCL flag and a holder. Remove the need to pass
FMODE_EXCL and just key off the exclusive open off a non-NULL holder.

For blkdev_put this requires adding the holder argument, which provides
better debug checking that only the holder actually releases the hold,
but at the same time allows removing the now superfluous mode argument.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Christian Brauner <brauner@kernel.org>
Acked-by: David Sterba <dsterba@suse.com> [btrfs]
Acked-by: Jack Wang <jinpu.wang@ionos.com> [rnbd]
Link: https://lore.kernel.org/r/20230608110258.189493-16-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

show more ...

bcache: don't pass a stack address to blkdev_get_by_path

sb is just an on-stack pointer that can easily be reused by other calls.
Switch to use the bcache-wide bcache_kobj instead as there is no nee

bcache: don't pass a stack address to blkdev_get_by_path

sb is just an on-stack pointer that can easily be reused by other calls.
Switch to use the bcache-wide bcache_kobj instead as there is no need to
claim per-bcache device anyway.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20230608110258.189493-13-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

show more ...

block: remove the unused mode argument to ->release

The mode argument to the ->release block_device_operation is never used,
so remove it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by:

block: remove the unused mode argument to ->release

The mode argument to the ->release block_device_operation is never used,
so remove it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Christian Brauner <brauner@kernel.org>
Acked-by: Jack Wang <jinpu.wang@ionos.com> [rnbd]
Link: https://lore.kernel.org/r/20230608110258.189493-10-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

show more ...

block: pass a gendisk to ->open

->open is only called on the whole device. Make that explicit by
passing a gendisk instead of the block_device.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Review

block: pass a gendisk to ->open

->open is only called on the whole device. Make that explicit by
passing a gendisk instead of the block_device.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Christian Brauner <brauner@kernel.org>
Acked-by: Jack Wang <jinpu.wang@ionos.com> [rnbd]
Link: https://lore.kernel.org/r/20230608110258.189493-9-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

show more ...

block: introduce holder ops

Add a new blk_holder_ops structure, which is passed to blkdev_get_by_* and
installed in the block_device for exclusive claims. It will be used to
allow the block layer t

block: introduce holder ops

Add a new blk_holder_ops structure, which is passed to blkdev_get_by_* and
installed in the block_device for exclusive claims. It will be used to
allow the block layer to call back into the user of the block device for
thing like notification of a removed device or a device resize.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Link: https://lore.kernel.org/r/20230601094459.1350643-10-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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block/drivers: remove dead clear of random flag

QUEUE_FLAG_ADD_RANDOM is not set before we clear it for "null_blk",
"brd", "nbd", "zram", and "bcache" since by default we don't set
"QUEUE_FLAG_ADD_R

block/drivers: remove dead clear of random flag

QUEUE_FLAG_ADD_RANDOM is not set before we clear it for "null_blk",
"brd", "nbd", "zram", and "bcache" since by default we don't set
"QUEUE_FLAG_ADD_RANDOM" to MQ ops.

Remove dead clear of QUEUE_FLAG_ADD_RANDOM in above listed drivers.

Signed-off-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> #zram
Link: https://lore.kernel.org/r/20230424234628.45544-2-kch@nvidia.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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md/bcache: Combine two prio_io() arguments

Improve uniformity in the kernel of handling of request operation and
flags by passing these as a single argument.

Cc: Coly Li <colyli@suse.de>
Cc: Mingzh

md/bcache: Combine two prio_io() arguments

Improve uniformity in the kernel of handling of request operation and
flags by passing these as a single argument.

Cc: Coly Li <colyli@suse.de>
Cc: Mingzhe Zou <mingzhe.zou@easystack.cn>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20220714180729.1065367-34-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

show more ...

md/bcache: Combine two uuid_io() arguments

Improve uniformity in the kernel of handling of request operation and
flags by passing these as a single argument.

Cc: Coly Li <colyli@suse.de>
Cc: Mingzh

md/bcache: Combine two uuid_io() arguments

Improve uniformity in the kernel of handling of request operation and
flags by passing these as a single argument.

Cc: Coly Li <colyli@suse.de>
Cc: Mingzhe Zou <mingzhe.zou@easystack.cn>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20220714180729.1065367-33-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

show more ...

block: remove blk_cleanup_disk

blk_cleanup_disk is nothing but a trivial wrapper for put_disk now,
so remove it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@sus

block: remove blk_cleanup_disk

blk_cleanup_disk is nothing but a trivial wrapper for put_disk now,
so remove it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20220619060552.1850436-7-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

show more ...

bcache: avoid journal no-space deadlock by reserving 1 journal bucket

The journal no-space deadlock was reported time to time. Such deadlock
can happen in the following situation.

When all journal

bcache: avoid journal no-space deadlock by reserving 1 journal bucket

The journal no-space deadlock was reported time to time. Such deadlock
can happen in the following situation.

When all journal buckets are fully filled by active jset with heavy
write I/O load, the cache set registration (after a reboot) will load
all active jsets and inserting them into the btree again (which is
called journal replay). If a journaled bkey is inserted into a btree
node and results btree node split, new journal request might be
triggered. For example, the btree grows one more level after the node
split, then the root node record in cache device super block will be
upgrade by bch_journal_meta() from bch_btree_set_root(). But there is no
space in journal buckets, the journal replay has to wait for new journal
bucket to be reclaimed after at least one journal bucket replayed. This
is one example that how the journal no-space deadlock happens.

The solution to avoid the deadlock is to reserve 1 journal bucket in
run time, and only permit the reserved journal bucket to be used during
cache set registration procedure for things like journal replay. Then
the journal space will never be fully filled, there is no chance for
journal no-space deadlock to happen anymore.

This patch adds a new member "bool do_reserve" in struct journal, it is
inititalized to 0 (false) when struct journal is allocated, and set to
1 (true) by bch_journal_space_reserve() when all initialization done in
run_cache_set(). In the run time when journal_reclaim() tries to
allocate a new journal bucket, free_journal_buckets() is called to check
whether there are enough free journal buckets to use. If there is only
1 free journal bucket and journal->do_reserve is 1 (true), the last
bucket is reserved and free_journal_buckets() will return 0 to indicate
no free journal bucket. Then journal_reclaim() will give up, and try
next time to see whetheer there is free journal bucket to allocate. By
this method, there is always 1 jouranl bucket reserved in run time.

During the cache set registration, journal->do_reserve is 0 (false), so
the reserved journal bucket can be used to avoid the no-space deadlock.

Reported-by: Nikhil Kshirsagar <nkshirsagar@gmail.com>
Signed-off-by: Coly Li <colyli@suse.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20220524102336.10684-5-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

show more ...

block: remove QUEUE_FLAG_DISCARD

Just use a non-zero max_discard_sectors as an indicator for discard
support, similar to what is done for write zeroes.

The only places where needs special attention

block: remove QUEUE_FLAG_DISCARD

Just use a non-zero max_discard_sectors as an indicator for discard
support, similar to what is done for write zeroes.

The only places where needs special attention is the RAID5 driver,
which must clear discard support for security reasons by default,
even if the default stacking rules would allow for it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com> [drbd]
Acked-by: Jan Höppner <hoeppner@linux.ibm.com> [s390]
Acked-by: Coly Li <colyli@suse.de> [bcache]
Acked-by: David Sterba <dsterba@suse.com> [btrfs]
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220415045258.199825-25-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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block: pass a block_device and opf to bio_init

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, bo

block: pass a block_device and opf to bio_init

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: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220124091107.642561-19-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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block: remove genhd.h

There is no good reason to keep genhd.h separate from the main blkdev.h
header that includes it. So fold the contents of genhd.h into blkdev.h
and remove genhd.h entirely.

Si

block: remove genhd.h

There is no good reason to keep genhd.h separate from the main blkdev.h
header that includes it. So fold the contents of genhd.h into blkdev.h
and remove genhd.h entirely.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20220124093913.742411-4-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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bcache: fix NULL pointer reference in cached_dev_detach_finish

Commit 0259d4498ba4 ("bcache: move calc_cached_dev_sectors to proper
place on backing device detach") tries to fix calc_cached_dev_sect

bcache: fix NULL pointer reference in cached_dev_detach_finish

Commit 0259d4498ba4 ("bcache: move calc_cached_dev_sectors to proper
place on backing device detach") tries to fix calc_cached_dev_sectors
when bcache device detaches, but now we have:

cached_dev_detach_finish
...
bcache_device_detach(&dc->disk);
...
closure_put(&d->c->caching);
d->c = NULL; [*explicitly set dc->disk.c to NULL*]
list_move(&dc->list, &uncached_devices);
calc_cached_dev_sectors(dc->disk.c); [*passing a NULL pointer*]
...

Upper codeflows shows how bug happens, this patch fix the problem by
caching dc->disk.c beforehand, and cache_set won't be freed under us
because c->caching closure at least holds a reference count and closure
callback __cache_set_unregister only being called by bch_cache_set_stop
which using closure_queue(&c->caching), that means c->caching closure
callback for destroying cache_set won't be trigger by previous
closure_put(&d->c->caching).
So at this stage(while cached_dev_detach_finish is calling) it's safe to
access cache_set dc->disk.c.

Fixes: 0259d4498ba4 ("bcache: move calc_cached_dev_sectors to proper place on backing device detach")
Signed-off-by: Lin Feng <linf@wangsu.com>
Signed-off-by: Coly Li <colyli@suse.de>
Link: https://lore.kernel.org/r/20211112053629.3437-2-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

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