linux.git/drivers/md/bcache, branch v5.17.6

bcache: fixup multiple threads crash

2022-04-08T11:57:28+00:00

commit 887554ab96588de2917b6c8c73e552da082e5368 upstream.

When multiple threads to check btree nodes in parallel, the main
thread wait for all threads to stop or CACHE_SET_IO_DISABLE flag:

wait_event_interruptible(check_state->wait,
                         atomic_read(&check_state->started) == 0 ||
                         test_bit(CACHE_SET_IO_DISABLE, &c->flags));

However, the bch_btree_node_read and bch_btree_node_read_done
maybe call bch_cache_set_error, then the CACHE_SET_IO_DISABLE
will be set. If the flag already set, the main thread return
error. At the same time, maybe some threads still running and
read NULL pointer, the kernel will crash.

This patch change the event wait condition, the main thread must
wait for all threads to stop.

Fixes: 8e7102273f597 ("bcache: make bch_btree_check() to be multithreaded")
Signed-off-by: Mingzhe Zou 
Cc: stable@vger.kernel.org # v5.7+
Signed-off-by: Coly Li 
Signed-off-by: Greg Kroah-Hartman

bcache: fix NULL pointer reference in cached_dev_detach_finish

2021-12-15T03:32:54+00:00

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 
Signed-off-by: Coly Li 
Link: https://lore.kernel.org/r/20211112053629.3437-2-colyli@suse.de
Signed-off-by: Jens Axboe

Merge tag 'for-5.16/drivers-2021-11-09' of git://git.kernel.dk/linux-block

2021-11-09T19:24:08+00:00

Pull more block driver updates from Jens Axboe:

 - Last series adding error handling support for add_disk() in drivers.
   After this one, and once the SCSI side has been merged, we can
   finally annotate add_disk() as must_check. (Luis)

 - bcache fixes (Coly)

 - zram fixes (Ming)

 - ataflop locking fix (Tetsuo)

 - nbd fixes (Ye, Yu)

 - MD merge via Song
      - Cleanup (Yang)
      - sysfs fix (Guoqing)

 - Misc fixes (Geert, Wu, luo)

* tag 'for-5.16/drivers-2021-11-09' of git://git.kernel.dk/linux-block: (34 commits)
  bcache: Revert "bcache: use bvec_virt"
  ataflop: Add missing semicolon to return statement
  floppy: address add_disk() error handling on probe
  ataflop: address add_disk() error handling on probe
  block: update __register_blkdev() probe documentation
  ataflop: remove ataflop_probe_lock mutex
  mtd/ubi/block: add error handling support for add_disk()
  block/sunvdc: add error handling support for add_disk()
  z2ram: add error handling support for add_disk()
  nvdimm/pmem: use add_disk() error handling
  nvdimm/pmem: cleanup the disk if pmem_release_disk() is yet assigned
  nvdimm/blk: add error handling support for add_disk()
  nvdimm/blk: avoid calling del_gendisk() on early failures
  nvdimm/btt: add error handling support for add_disk()
  nvdimm/btt: use goto error labels on btt_blk_init()
  loop: Remove duplicate assignments
  drbd: Fix double free problem in drbd_create_device
  nvdimm/btt: do not call del_gendisk() if not needed
  bcache: fix use-after-free problem in bcache_device_free()
  zram: replace fsync_bdev with sync_blockdev
  ...

bcache: Revert "bcache: use bvec_virt"

2021-11-08T13:23:17+00:00

This reverts commit 2fd3e5efe791946be0957c8e1eed9560b541fe46.

The above commit replaces page_address(bv->bv_page) by bvec_virt(bv) to
avoid directly access to bv->bv_page, but in situation bv->bv_offset is
not zero and page_address(bv->bv_page) is not equal to bvec_virt(bv). In
such case a memory corruption may happen because memory in next page is
tainted by following line in do_btree_node_write(),
	memcpy(bvec_virt(bv), addr, PAGE_SIZE);

This patch reverts the mentioned commit to avoid the memory corruption.

Fixes: 2fd3e5efe791 ("bcache: use bvec_virt")
Signed-off-by: Coly Li 
Cc: Christoph Hellwig 
Cc: stable@vger.kernel.org # 5.15
Signed-off-by: Christoph Hellwig 
Link: https://lore.kernel.org/r/20211103151041.70516-1-colyli@suse.de
Signed-off-by: Jens Axboe

bcache: fix use-after-free problem in bcache_device_free()

2021-11-03T12:00:29+00:00

In bcache_device_free(), pointer disk is referenced still in
ida_simple_remove() after blk_cleanup_disk() gets called on this
pointer. This may cause a potential panic by use-after-free on the
disk pointer.

This patch fixes the problem by calling blk_cleanup_disk() after
ida_simple_remove().

Fixes: bc70852fd104 ("bcache: convert to blk_alloc_disk/blk_cleanup_disk")
Signed-off-by: Coly Li 
Cc: Christoph Hellwig 
Cc: Hannes Reinecke 
Cc: Ulf Hansson 
Cc: stable@vger.kernel.org # v5.14+
Reviewed-by: Christoph Hellwig 
Link: https://lore.kernel.org/r/20211103064917.67383-1-colyli@suse.de
Signed-off-by: Jens Axboe

Merge tag 'for-5.16/bdev-size-2021-10-29' of git://git.kernel.dk/linux-block

2021-11-01T16:50:37+00:00

Pull bdev size cleanups from Jens Axboe:
 "Clean up the bdev size handling with new bdev_nr_bytes() helper"

* tag 'for-5.16/bdev-size-2021-10-29' of git://git.kernel.dk/linux-block: (34 commits)
  partitions/ibm: use bdev_nr_sectors instead of open coding it
  partitions/efi: use bdev_nr_bytes instead of open coding it
  block/ioctl: use bdev_nr_sectors and bdev_nr_bytes
  block: cache inode size in bdev
  udf: use sb_bdev_nr_blocks
  reiserfs: use sb_bdev_nr_blocks
  ntfs: use sb_bdev_nr_blocks
  jfs: use sb_bdev_nr_blocks
  ext4: use sb_bdev_nr_blocks
  block: add a sb_bdev_nr_blocks helper
  block: use bdev_nr_bytes instead of open coding it in blkdev_fallocate
  squashfs: use bdev_nr_bytes instead of open coding it
  reiserfs: use bdev_nr_bytes instead of open coding it
  pstore/blk: use bdev_nr_bytes instead of open coding it
  ntfs3: use bdev_nr_bytes instead of open coding it
  nilfs2: use bdev_nr_bytes instead of open coding it
  nfs/blocklayout: use bdev_nr_bytes instead of open coding it
  jfs: use bdev_nr_bytes instead of open coding it
  hfsplus: use bdev_nr_sectors instead of open coding it
  hfs: use bdev_nr_sectors instead of open coding it
  ...

bcache: replace snprintf in show functions with sysfs_emit

2021-10-29T12:43:21+00:00

coccicheck complains about the use of snprintf() in sysfs show functions.

Fix the following coccicheck warning:
drivers/md/bcache/sysfs.h:54:12-20: WARNING: use scnprintf or sprintf.

Implement sysfs_print() by sysfs_emit() and remove snprint() since no one
uses it any more.

Suggested-by: Coly Li 
Signed-off-by: Qing Wang 
Signed-off-by: Coly Li 
Link: https://lore.kernel.org/r/20211029060930.119923-3-colyli@suse.de
Signed-off-by: Jens Axboe

bcache: move uapi header bcache.h to bcache code directory

2021-10-29T12:43:21+00:00

The header file include/uapi/linux/bcache.h is not really a user space
API heaer. This file defines the ondisk format of bcache internal meta
data but no one includes it from user space, bcache-tools has its own
copy of this header with minor modification.

Therefore, this patch moves include/uapi/linux/bcache.h to bcache code
directory as drivers/md/bcache/bcache_ondisk.h.

Suggested-by: Arnd Bergmann 
Suggested-by: Christoph Hellwig 
Signed-off-by: Coly Li 
Link: https://lore.kernel.org/r/20211029060930.119923-2-colyli@suse.de
Signed-off-by: Jens Axboe

bcache: add error handling support for add_disk()

2021-10-21T15:00:56+00:00

We never checked for errors on add_disk() as this function
returned void. Now that this is fixed, use the shiny new
error handling.

This driver doesn't do any unwinding with blk_cleanup_disk()
even on errors after add_disk() and so we follow that
tradition.

Acked-by: Coly Li 
Signed-off-by: Luis Chamberlain 
Link: https://lore.kernel.org/r/20211015233028.2167651-5-mcgrof@kernel.org
Signed-off-by: Jens Axboe

bcache: remove bch_crc64_update

2021-10-20T14:40:54+00:00

bch_crc64_update is an entirely pointless wrapper around crc64_be.

Signed-off-by: Christoph Hellwig 
Signed-off-by: Coly Li 
Link: https://lore.kernel.org/r/20211020143812.6403-9-colyli@suse.de
Signed-off-by: Jens Axboe