kernel/linux.git/block/genhd.c, branch v5.3.1

block: fix sysfs module parameters directory path in comment

2019-07-16T16:16:33+00:00

The runtime configurable module parameter files are located under /sys/module/MODULENAME/parameters, not /sys/module/MODULENAME. Cc: Jens Axboe Signed-off-by: Akinobu Mita Signed-off-by: Jens Axboe

block: genhd: Use struct_size() helper

2019-06-15T07:46:09+00:00

Make use of the struct_size() helper instead of an open-coded version in order to avoid any potential type mistakes, in particular in the context in which this code is being used. So, replace the following form: sizeof(*new_ptbl) + target * sizeof(new_ptbl->part[0]) with: struct_size(new_ptbl, part, target) Also, notice that variable size is unnecessary, hence it is removed. This code was detected with the help of Coccinelle. Signed-off-by: Gustavo A. R. Silva Signed-off-by: Jens Axboe

block: Convert blk_invalidate_devt() header into a non-kernel-doc header

2019-05-31T21:12:34+00:00

This patch avoids that the kernel-doc tool warns about this function header when building with W=1. Reviewed-by: Chaitanya Kulkarni Signed-off-by: Bart Van Assche Signed-off-by: Jens Axboe

block: add SPDX tags to block layer files missing licensing information

2019-04-30T22:12:03+00:00

Various block layer files do not have any licensing information at all. Add SPDX tags for the default kernel GPLv2 license to those. Reviewed-by: Chaitanya Kulkarni Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe

block: fix use-after-free on gendisk

2019-04-22T15:48:12+00:00

commit 2da78092dda "block: Fix dev_t minor allocation lifetime" specifically moved blk_free_devt(dev->devt) call to part_release() to avoid reallocating device number before the device is fully shutdown. However, it can cause use-after-free on gendisk in get_gendisk(). We use md device as example to show the race scenes: Process1 Worker Process2 md_free blkdev_open del_gendisk add delete_partition_work_fn() to wq __blkdev_get get_gendisk put_disk disk_release kfree(disk) find part from ext_devt_idr get_disk_and_module(disk) cause use after free delete_partition_work_fn put_device(part) part_release remove part from ext_devt_idr Before is removed from ext_devt_idr by delete_partition_work_fn(), we can find the devt and then access gendisk by hd_struct pointer. But, if we access the gendisk after it have been freed, it can cause in use-after-freeon gendisk in get_gendisk(). We fix this by adding a new helper blk_invalidate_devt() in delete_partition() and del_gendisk(). It replaces hd_struct pointer in idr with value 'NULL', and deletes the entry from idr in part_release() as we do now. Thanks to Jan Kara for providing the solution and more clear comments for the code. Fixes: 2da78092dda1 ("block: Fix dev_t minor allocation lifetime") Cc: Al Viro Reviewed-by: Bart Van Assche Reviewed-by: Keith Busch Reviewed-by: Jan Kara Suggested-by: Jan Kara Signed-off-by: Yufen Yu Signed-off-by: Jens Axboe

block: check_events: don't bother with events if unsupported

2019-04-12T19:35:28+00:00

Drivers now report to the block layer if they support media change events. If this is not the case, there's no need to allocate the event structure, and all event handling code can effectively be skipped. This simplifies code flow in particular for non-removable sd devices. This effectively reverts commit 75e3f3ee3c64 ("block: always allocate genhd->ev if check_events is implemented"). The sysfs files for the events are kept in place even if no events are supported, as user space may rely on them being present. The only difference is that an error code is now returned if the user tries to set poll_msecs. Reviewed-by: Hannes Reinecke Reviewed-by: Christoph Hellwig Signed-off-by: Martin Wilck Signed-off-by: Jens Axboe

block: disk_events: introduce event flags

2019-04-12T19:35:24+00:00

Currently, an empty disk->events field tells the block layer not to forward media change events to user space. This was done in commit 7c88a168da80 ("block: don't propagate unlisted DISK_EVENTs to userland") in order to avoid events from "fringe" drivers to be forwarded to user space. By doing so, the block layer lost the information which events were supported by a particular block device, and most importantly, whether or not a given device supports media change events at all. Prepare for not interpreting the "events" field this way in the future any more. This is done by adding an additional field "event_flags" to struct gendisk, and two flag bits that can be set to have the device treated like one that had the "events" field set to a non-zero value before. This applies only to the sd and sr drivers, which are changed to set the new flags. The new flags are DISK_EVENT_FLAG_POLL to enforce polling of the device for synchronous events, and DISK_EVENT_FLAG_UEVENT to tell the blocklayer to generate udev events from kernel events. In order to add the event_flags field to struct gendisk, the events field is converted to an "unsigned short"; it doesn't need to hold values bigger than 2 anyway. This patch doesn't change behavior. Reviewed-by: Christoph Hellwig Signed-off-by: Martin Wilck Signed-off-by: Jens Axboe

block: genhd: remove async_events field

2019-04-12T19:35:22+00:00

The async_events field, intended to be used for drivers that support asynchronous notifications about disk events (aka media change events), isn't currently used by any driver, and apparently that has been that way for a long time (if not forever). Remove it. Reviewed-by: Hannes Reinecke Reviewed-by: Christoph Hellwig Signed-off-by: Martin Wilck Signed-off-by: Jens Axboe

block: Replace function name in string with func

2019-02-28T21:09:08+00:00

Replace hard coded function name register_blkdev with __func__, to improve robustness and to conform to the Linux kernel coding style. Issue found using checkpatch. Signed-off-by: Keyur Patel Signed-off-by: Jens Axboe

block: fix NULL pointer dereference in register_disk

2019-02-28T21:01:36+00:00

If __device_add_disk-->bdi_register_owner-->bdi_register--> bdi_register_va-->device_create_vargs fails, bdi->dev is still NULL, __device_add_disk-->register_disk will visit bdi->dev->kobj. This patch fixes that. Signed-off-by: zhengbin Signed-off-by: Jens Axboe