linux/block/ioctl.c, branch v6.7

fs: Avoid grabbing sb->s_umount under bdev->bd_holder_lock

2023-10-28T11:29:22Z

The implementation of bdev holder operations such as fs_bdev_mark_dead() and fs_bdev_sync() grab sb->s_umount semaphore under bdev->bd_holder_lock. This is problematic because it leads to disk->open_mutex -> sb->s_umount lock ordering which is counterintuitive (usually we grab higher level (e.g. filesystem) locks first and lower level (e.g. block layer) locks later) and indeed makes lockdep complain about possible locking cycles whenever we open a block device while holding sb->s_umount semaphore. Implement a function bdev_super_lock_shared() which safely transitions from holding bdev->bd_holder_lock to holding sb->s_umount on alive superblock without introducing the problematic lock dependency. We use this function fs_bdev_sync() and fs_bdev_mark_dead(). Signed-off-by: Jan Kara Link: https://lore.kernel.org/r/20231018152924.3858-1-jack@suse.cz Link: https://lore.kernel.org/r/20231017184823.1383356-1-hch@lst.de Reviewed-by: Christoph Hellwig Signed-off-by: Christian Brauner

block: Use bdev_open_by_dev() in disk_scan_partitions() and blkdev_bszset()

2023-10-28T11:29:16Z

Convert disk_scan_partitions() and blkdev_bszset() to use bdev_open_by_dev(). Acked-by: Christoph Hellwig Reviewed-by: Christian Brauner Signed-off-by: Jan Kara Link: https://lore.kernel.org/r/20230927093442.25915-3-jack@suse.cz Signed-off-by: Christian Brauner

block: don't add or resize partition on the disk with GENHD_FL_NO_PART

2023-08-31T14:00:35Z

Commit a33df75c6328 ("block: use an xarray for disk->part_tbl") remove disk_expand_part_tbl() in add_partition(), which means all kinds of devices will support extended dynamic `dev_t`. However, some devices with GENHD_FL_NO_PART are not expected to add or resize partition. Fix this by adding check of GENHD_FL_NO_PART before add or resize partition. Fixes: a33df75c6328 ("block: use an xarray for disk->part_tbl") Signed-off-by: Li Lingfeng Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20230831075900.1725842-1-lilingfeng@huaweicloud.com Signed-off-by: Jens Axboe

block: call into the file system for ioctl BLKFLSBUF

2023-08-21T12:35:32Z

BLKFLSBUF is a historic ioctl that is called on a file handle to a block device and syncs either the file system mounted on that block device if there is one, or otherwise the just the data on the block device. Replace the get_super based syncing with a holder operation to remove the last usage of get_super, and to also support syncing the file system if the block device is not the main block device stored in s_dev. Signed-off-by: Christoph Hellwig Reviewed-by: Josef Bacik Message-Id: <20230811100828.1897174-16-hch@lst.de> Signed-off-by: Christian Brauner

block: fine-granular CAP_SYS_ADMIN for Persistent Reservation

2023-06-20T18:49:23Z

Allow of unprivileged Persistent Reservation operations on devices if the write permission check on the device node has passed. brw-rw---- 1 root disk 259, 0 Jun 13 07:09 /dev/nvme0n1 In the example above, the "disk" group of nvme0n1 is also allowed to make reservations on the device even without CAP_SYS_ADMIN. Signed-off-by: Jingbo Xu Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20230613084008.93795-3-jefflexu@linux.alibaba.com Signed-off-by: Jens Axboe

block: disallow Persistent Reservation on partitions

2023-06-20T18:49:23Z

Refuse Persistent Reservation operations on partitions as reservation on partitions doesn't make sense. Besides, introduce blkdev_pr_allowed() helper, where more policies could be placed here later. Signed-off-by: Jingbo Xu Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20230613084008.93795-2-jefflexu@linux.alibaba.com Signed-off-by: Jens Axboe

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

2023-06-12T14:04:05Z

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 Acked-by: Jack Wang [rnbd] Reviewed-by: Hannes Reinecke Reviewed-by: Christian Brauner Link: https://lore.kernel.org/r/20230608110258.189493-28-hch@lst.de Signed-off-by: Jens Axboe

block: remove unused fmode_t arguments from ioctl handlers

2023-06-12T14:04:04Z

A few ioctl handlers have fmode_t arguments that are entirely unused, remove them. Signed-off-by: Christoph Hellwig Acked-by: Christian Brauner Reviewed-by: Hannes Reinecke Link: https://lore.kernel.org/r/20230608110258.189493-27-hch@lst.de Signed-off-by: Jens Axboe

block: use the holder as indication for exclusive opens

2023-06-12T14:04:04Z

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 Reviewed-by: Hannes Reinecke Acked-by: Christian Brauner Acked-by: David Sterba [btrfs] Acked-by: Jack Wang [rnbd] Link: https://lore.kernel.org/r/20230608110258.189493-16-hch@lst.de Signed-off-by: Jens Axboe

block: introduce holder ops

2023-06-05T16:53:04Z

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 Reviewed-by: Jan Kara Acked-by: Dave Chinner Reviewed-by: Dave Chinner Link: https://lore.kernel.org/r/20230601094459.1350643-10-hch@lst.de Signed-off-by: Jens Axboe