commit c0e473a0d2 upstream.
With the new large sector size support, it's now the case that
set_blocksize can change i_blksize and the folio order in a manner that
conflicts with a concurrent reader and causes a kernel crash.
Specifically, let's say that udev-worker calls libblkid to detect the
labels on a block device. The read call can create an order-0 folio to
read the first 4096 bytes from the disk. But then udev is preempted.
Next, someone tries to mount an 8k-sectorsize filesystem from the same
block device. The filesystem calls set_blksize, which sets i_blksize to
8192 and the minimum folio order to 1.
Now udev resumes, still holding the order-0 folio it allocated. It then
tries to schedule a read bio and do_mpage_readahead tries to create
bufferheads for the folio. Unfortunately, blocks_per_folio == 0 because
the page size is 4096 but the blocksize is 8192 so no bufferheads are
attached and the bh walk never sets bdev. We then submit the bio with a
NULL block device and crash.
Therefore, truncate the page cache after flushing but before updating
i_blksize. However, that's not enough -- we also need to lock out file
IO and page faults during the update. Take both the i_rwsem and the
invalidate_lock in exclusive mode for invalidations, and in shared mode
for read/write operations.
I don't know if this is the correct fix, but xfs/259 found it.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Tested-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Link: https://lore.kernel.org/r/174543795699.4139148.2086129139322431423.stgit@frogsfrogsfrogs
Signed-off-by: Jens Axboe <axboe@kernel.dk>
[use bdev->bd_inode instead & fix small contextual changes]
Signed-off-by: Mahmoud Adam <mngyadam@amazon.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 1898efcdbe ]
Propagate the per-queue stable_write flags into each bdev inode in bdev_add.
This makes sure devices that require stable writes have it set for I/O
on the block device node as well.
Note that this doesn't cover the case of a flag changing on a live device
yet. We should handle that as well, but I plan to cover it as part of a
more general rework of how changing runtime paramters on block devices
works.
Fixes: 1cb039f3dc ("bdi: replace BDI_CAP_STABLE_WRITES with a queue and a sb flag")
Reported-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20231025141020.192413-3-hch@lst.de
Tested-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Add support for STATX_DIOALIGN to block devices, so that direct I/O
alignment restrictions are exposed to userspace in a generic way.
Note that this breaks the tradition of stat operating only on the block
device node, not the block device itself. However, it was felt that
doing this is preferable, in order to make the interface useful and
avoid needing separate interfaces for regular files and block devices.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Link: https://lore.kernel.org/r/20220827065851.135710-3-ebiggers@kernel.org
Pull exfat updates from Namjae Jeon:
- fix referencing wrong parent directory information during rename
- introduce a sys_tz mount option to use system timezone
- improve performance while zeroing a cluster with dirsync mount option
- fix slab-out-bounds in exat_clear_bitmap() reported from syzbot
* tag 'exfat-for-5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/linkinjeon/exfat:
exfat: check if cluster num is valid
exfat: reduce block requests when zeroing a cluster
block: add sync_blockdev_range()
exfat: introduce mount option 'sys_tz'
exfat: fix referencing wrong parent directory information after renaming
All manipulation of bd_openers is under disk->open_mutex and will remain
so for the foreseeable future. But at least one place reads it without
the lock (blkdev_get) and there are more to be added. So make sure the
compiler does not do turn the increments and decrements into non-atomic
sequences by using an atomic_t.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20220330052917.2566582-6-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
As Luis reported, losetup currently doesn't properly create the loop
device without this if the device node already exists because old
scripts created it manually. So default to y for now and remove the
aggressive removal schedule.
Reported-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220225181440.1351591-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
disk->fops->owner is grabbed in blkdev_get_no_open() after the disk
kobject refcount is increased. This way can't make sure that
disk->fops->owner is still alive since del_gendisk() still can move
on if the kobject refcount of disk is grabbed by open() and
disk->fops->open() isn't called yet.
Fixes the issue by moving try_module_get() into blkdev_get_by_dev()
with ->open_mutex() held, then we can drain the in-progress open()
in del_gendisk(). Meantime new open() won't succeed because disk
becomes not alive.
This way is reasonable because blkdev_get_no_open() needn't to touch
disk->fops or defined callbacks.
Cc: Christoph Hellwig <hch@lst.de>
Cc: czhong@redhat.com
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20211111020343.316126-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
