- 13 Aug, 2021 7 commits
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Christoph Hellwig authored
nbd_index_mutex is currently held over add_disk and inside ->open, which leads to lock order reversals. Refactor the device creation code path so that nbd_dev_add is called without nbd_index_mutex lock held and only takes it for the IDR insertation. Signed-off-by:
Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20210811124428.2368491-7-hch@lst.de [axboe: fix whitespace] Reviewed-by:
Josef Bacik <josef@toxicpanda.com> Signed-off-by:
Jens Axboe <axboe@kernel.dk>
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Christoph Hellwig authored
Use idr_for_each_entry instead of the awkward callback to find an existing device for the index == -1 case, and de-duplicate the device allocation if no existing device was found. Signed-off-by:
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Christoph Hellwig authored
Return the device we just allocated instead of doing an extra search for it in the caller. Signed-off-by:
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Christoph Hellwig authored
Fold nbd_del_disk and remove the pointless NULL check on ->disk given that it is always set for a successfully allocated nbd_device structure. Signed-off-by:
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Christoph Hellwig authored
Share common code for the synchronous and workqueue based device removal, and remove the pointless use of refcount_dec_and_mutex_lock. Signed-off-by:
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Hou Tao authored
Now open_mutex is used to synchronize partition operations (e.g, blk_drop_partitions() and blkdev_reread_part()), however it makes nbd driver broken, because nbd may call del_gendisk() in nbd_release() or nbd_genl_disconnect() if NBD_CFLAG_DESTROY_ON_DISCONNECT is enabled, and deadlock occurs, as shown below: // AB-BA dead-lock nbd_genl_disconnect blkdev_open nbd_disconnect_and_put lock bd_mutex // last ref nbd_put lock nbd_index_mutex del_gendisk nbd_open try lock nbd_index_mutex try lock bd_mutex or // AA dead-lock nbd_release lock bd_mutex nbd_put try lock bd_mutex Instead of fixing block layer (e.g, introduce another lock), fixing the nbd driver to call del_gendisk() in a kworker when NBD_DESTROY_ON_DISCONNECT is enabled. When NBD_DESTROY_ON_DISCONNECT is disabled, nbd device will always be destroy through module removal, and there is no risky of deadlock. To ensure the reuse of nbd index succeeds, moving the calling of idr_remove() after del_gendisk(), so if the reused index is not found in nbd_index_idr, the old disk must have been deleted. And reusing the existing destroy_complete mechanism to ensure nbd_genl_connect() will wait for the completion of del_gendisk(). Also adding a new workqueue for nbd removal, so nbd_cleanup() can ensure all removals complete before exits. Reported-by: syzbot+0fe7752e52337864d29b@syzkaller.appspotmail.com Fixes: c76f48eb ("block: take bd_mutex around delete_partitions in del_gendisk") Signed-off-by:Hou Tao <houtao1@huawei.com> Signed-off-by:
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Baokun Li authored
If user specify a large enough value of NBD blocks option, it may trigger signed integer overflow which may lead to nbd->config->bytesize becomes a large or small value, zero in particular. UBSAN: Undefined behaviour in drivers/block/nbd.c:325:31 signed integer overflow: 1024 * 4611686155866341414 cannot be represented in type 'long long int' [...] Call trace: [...] handle_overflow+0x188/0x1dc lib/ubsan.c:192 __ubsan_handle_mul_overflow+0x34/0x44 lib/ubsan.c:213 nbd_size_set drivers/block/nbd.c:325 [inline] __nbd_ioctl drivers/block/nbd.c:1342 [inline] nbd_ioctl+0x998/0xa10 drivers/block/nbd.c:1395 __blkdev_driver_ioctl block/ioctl.c:311 [inline] [...] Although it is not a big deal, still silence the UBSAN by limit the input value. Reported-by:
Hulk Robot <hulkci@huawei.com> Signed-off-by:
Baokun Li <libaokun1@huawei.com> Reviewed-by:
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- 10 Aug, 2021 1 commit
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Colin Ian King authored
The variable err is being assigned a value that is never read, the assignment is redundant and can be removed. Addresses-Coverity: ("Unused value") Signed-off-by:Colin Ian King <colin.king@canonical.com> Reviewed-by:
Boris Ostrovsky <boris.ostrovsky@oracle.com> Link: https://lore.kernel.org/r/20210806110601.11386-1-colin.king@canonical.comSigned-off-by:
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- 02 Aug, 2021 32 commits
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Md Haris Iqbal authored
sysfs_emit function was added to be aware of the PAGE_SIZE maximum of the temporary buffer used for outputting sysfs content, so there is no possible overruns. So replace the uses of any s*printf functions for the sysfs show functions with sysfs_emit. Signed-off-by:
Md Haris Iqbal <haris.iqbal@ionos.com> Signed-off-by:
Jack Wang <jinpu.wang@ionos.com> Link: https://lore.kernel.org/r/20210726115950.470543-3-jinpu.wang@ionos.comSigned-off-by:
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Gioh Kim authored
This patch replaces put_cpu_var with put_cpu_ptr because get_cpu_ptr should be paired with put_cpu_ptr. Signed-off-by:
Gioh Kim <gi-oh.kim@ionos.com> Signed-off-by:
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Damien Le Moal authored
In block/blk-mq-sysfs.c, struct blk_mq_ctx_sysfs_entry is not used to define any attribute since the "mq" sysfs directory contains only sub-directories (no attribute files). As a result, blk_mq_sysfs_show(), blk_mq_sysfs_store(), and struct sysfs_ops blk_mq_sysfs_ops are all unused and unnecessary. Remove all this unused code. Signed-off-by:
Damien Le Moal <damien.lemoal@wdc.com> Link: https://lore.kernel.org/r/20210713081837.524422-1-damien.lemoal@wdc.comSigned-off-by:
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Matteo Croce authored
Make the loop device raise a DISK_MEDIA_CHANGE event on attach or detach. # udevadm monitor -up |grep -e DISK_MEDIA_CHANGE -e DEVNAME & # losetup -f zero [ 7.454235] loop0: detected capacity change from 0 to 16384 DISK_MEDIA_CHANGE=1 DEVNAME=/dev/loop0 DEVNAME=/dev/loop0 DEVNAME=/dev/loop0 # losetup -f zero [ 10.205245] loop1: detected capacity change from 0 to 16384 DISK_MEDIA_CHANGE=1 DEVNAME=/dev/loop1 DEVNAME=/dev/loop1 DEVNAME=/dev/loop1 # losetup -f zero2 [ 13.532368] loop2: detected capacity change from 0 to 40960 DISK_MEDIA_CHANGE=1 DEVNAME=/dev/loop2 DEVNAME=/dev/loop2 # losetup -D DEVNAME=/dev/loop1 DISK_MEDIA_CHANGE=1 DEVNAME=/dev/loop1 DEVNAME=/dev/loop2 DISK_MEDIA_CHANGE=1 DEVNAME=/dev/loop2 DEVNAME=/dev/loop0 DISK_MEDIA_CHANGE=1 DEVNAME=/dev/loop0 Signed-off-by:
Matteo Croce <mcroce@microsoft.com> Reviewed-by:
Luca Boccassi <bluca@debian.org> Link: https://lore.kernel.org/r/20210712230530.29323-7-mcroce@linux.microsoft.comSigned-off-by:
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Matteo Croce authored
Refactor disk_check_events() and move some code into disk_event_uevent(). Then add disk_force_media_change(), a helper which will be used by devices to force issuing a DISK_EVENT_MEDIA_CHANGE event. Co-developed-by:
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Matteo Croce authored
Add a new sysfs handle to export the new diskseq value. Place it in <sysfs>/block/<disk>/diskseq and document it. $ grep . /sys/class/block/*/diskseq /sys/class/block/loop0/diskseq:13 /sys/class/block/loop1/diskseq:14 /sys/class/block/loop2/diskseq:5 /sys/class/block/loop3/diskseq:6 /sys/class/block/ram0/diskseq:1 /sys/class/block/ram1/diskseq:2 /sys/class/block/vda/diskseq:7 Reviewed-by: -
Matteo Croce authored
Add a new BLKGETDISKSEQ ioctl which retrieves the disk sequence number from the genhd structure. # ./getdiskseq /dev/loop* /dev/loop0: 13 /dev/loop0p1: 13 /dev/loop0p2: 13 /dev/loop0p3: 13 /dev/loop1: 14 /dev/loop1p1: 14 /dev/loop1p2: 14 /dev/loop2: 5 /dev/loop3: 6 Reviewed-by: -
Matteo Croce authored
Export the newly introduced diskseq in uevents: $ udevadm info /sys/class/block/* |grep -e DEVNAME -e DISKSEQ E: DEVNAME=/dev/loop0 E: DISKSEQ=1 E: DEVNAME=/dev/loop1 E: DISKSEQ=2 E: DEVNAME=/dev/loop2 E: DISKSEQ=3 E: DEVNAME=/dev/loop3 E: DISKSEQ=4 E: DEVNAME=/dev/loop4 E: DISKSEQ=5 E: DEVNAME=/dev/loop5 E: DISKSEQ=6 E: DEVNAME=/dev/loop6 E: DISKSEQ=7 E: DEVNAME=/dev/loop7 E: DISKSEQ=8 E: DEVNAME=/dev/nvme0n1 E: DISKSEQ=9 E: DEVNAME=/dev/nvme0n1p1 E: DISKSEQ=9 E: DEVNAME=/dev/nvme0n1p2 E: DISKSEQ=9 E: DEVNAME=/dev/nvme0n1p3 E: DISKSEQ=9 E: DEVNAME=/dev/nvme0n1p4 E: DISKSEQ=9 E: DEVNAME=/dev/nvme0n1p5 E: DISKSEQ=9 E: DEVNAME=/dev/sda E: DISKSEQ=10 E: DEVNAME=/dev/sda1 E: DISKSEQ=10 E: DEVNAME=/dev/sda2 E: DISKSEQ=10 Reviewed-by: -
Matteo Croce authored
Associating uevents with block devices in userspace is difficult and racy: the uevent netlink socket is lossy, and on slow and overloaded systems has a very high latency. Block devices do not have exclusive owners in userspace, any process can set one up (e.g. loop devices). Moreover, device names can be reused (e.g. loop0 can be reused again and again). A userspace process setting up a block device and watching for its events cannot thus reliably tell whether an event relates to the device it just set up or another earlier instance with the same name. Being able to set a UUID on a loop device would solve the race conditions. But it does not allow to derive orderings from uevents: if you see a uevent with a UUID that does not match the device you are waiting for, you cannot tell whether it's because the right uevent has not arrived yet, or it was already sent and you missed it. So you cannot tell whether you should wait for it or not. Associating a unique, monotonically increasing sequential number to the lifetime of each block device, which can be retrieved with an ioctl immediately upon setting it up, allows to solve the race conditions with uevents, and also allows userspace processes to know whether they should wait for the uevent they need or if it was dropped and thus they should move on. Additionally, increment the disk sequence number when the media change, i.e. on DISK_EVENT_MEDIA_CHANGE event. Reviewed-by:
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Christoph Hellwig authored
cmdline-parser.c is only used by the cmdline faux partition format, so merge the code into that and avoid an indirect call. Signed-off-by:
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Christoph Hellwig authored
Remove the disk_name function now that all users are gone. Signed-off-by:
Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/20210727062518.122108-7-hch@lst.deSigned-off-by:
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Christoph Hellwig authored
disk_name for partition 0 just copies out the disk_name field. Replace the call to disk_name with a %s format specifier. Signed-off-by:
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Christoph Hellwig authored
Printk ->disk_name directly for the disk and use the %pg format specifier for the block device, which is equivalent to a bdevname call. Signed-off-by:
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Christoph Hellwig authored
Simplify printing the partition name by using the %pg format specifier that is equivalent to a bdevname call. Signed-off-by:
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Christoph Hellwig authored
Simplify printing the partition name by using the %pg format specifier that is equivalent to a bdevname call. Signed-off-by:
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Abd-Alrhman Masalkhi authored
I have compiled the kernel with a cross compiler "hppa-linux-gnu-" v9.3.0 on x86-64 host machine. I got the following warning: block/genhd.c: In function ‘diskstats_show’: block/genhd.c:1227:1: warning: the frame size of 1688 bytes is larger than 1280 bytes [-Wframe-larger-than=] 1227 | } By Reduced the stack footprint by using the %pg printk specifier instead of disk_name to remove the need for the on-stack buffer. Signed-off-by:
Abd-Alrhman Masalkhi <abd.masalkhi@gmail.com> Signed-off-by:
Hannes Reinecke <hare@suse.de> Reviewed-by:
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Christoph Hellwig authored
Now that we've stopped using inode references for anything meaninful in the block layer get rid of the helper to put it and just open code the call to iput on the block_device inode. Signed-off-by:
Chaitanya Kulkarni <ckulkarnilinux@gmail.com> Link: https://lore.kernel.org/r/20210722075402.983367-10-hch@lst.deSigned-off-by:
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Christoph Hellwig authored
All callers are gone, and no one should grab a pure inode reference to a block device anymore. Signed-off-by:
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Christoph Hellwig authored
The whole device block device won't be removed while the disk is still alive, so don't bother to grab a reference to it. Signed-off-by:
Ming Lei <ming.lei@rehat.com> Reviewed-by:
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Christoph Hellwig authored
Instead of acquiring an inode reference on open make sure partitions always hold device model references to the disk while alive, and switch open to grab only a device model reference to the opened block device. If that is a partition the disk reference is transitively held by the partition already. Link: https://lore.kernel.org/r/20210722075402.983367-6-hch@lst.deSigned-off-by:
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Christoph Hellwig authored
Move the allocation of bd_meta_info after initializing the struct device to avoid the special bdput error handling path. Signed-off-by:
Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20210722075402.983367-5-hch@lst.deSigned-off-by:
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Christoph Hellwig authored
Unhash the whole device inode early in del_gendisk. This allows to remove the first GENHD_FL_UP check in the open path as we simply won't find a just removed inode. The second non-racy check after taking open_mutex is still kept. Signed-off-by:
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Christoph Hellwig authored
Add a lockdep assert instead of the outdated locking comment. Signed-off-by:
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Christoph Hellwig authored
Using local kmaps slightly reduces the chances to stray writes, and the bvec interface cleans up the code a little bit. Signed-off-by:
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Christoph Hellwig authored
Using local kmaps slightly reduces the chances to stray writes, and the bvec interface cleans up the code a little bit. Signed-off-by:
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Christoph Hellwig authored
Rewrite the actual bounce buffering loop in __blk_queue_bounce to that the memcpy_to_bvec helper can be used to perform the data copies. Signed-off-by:
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Christoph Hellwig authored
Use memcpy_from_bvec instead of open coding the logic. Signed-off-by:
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Christoph Hellwig authored
Use memcpy_to_bvec instead of opencoding the logic. Signed-off-by:
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Christoph Hellwig authored
Use the proper helpers instead of open coding the copy. Signed-off-by:
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Christoph Hellwig authored
These two helpers are entirely unused now. Signed-off-by:
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Christoph Hellwig authored
Use the bvec helpers instead of open coding the copy. Signed-off-by:
Geoff Levand <geoff@infradead.org> Link: https://lore.kernel.org/r/20210727055646.118787-9-hch@lst.deSigned-off-by:
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Christoph Hellwig authored
There is no need to disable interrupts in bio_copy_block, and the local only mappings helps to avoid any sort of problems with stray writes into the bio data. Signed-off-by:
Ira Weiny <ira.weiny@intel.com> Link: https://lore.kernel.org/r/20210727055646.118787-8-hch@lst.deSigned-off-by:
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