kernel/drivers/s390/block/dasd_genhd.c, branch linux-4.3.y

s390/block/dasd: remove obsolete while -EBUSY loop

2015-05-20T15:06:17Z

With the mutex_trylock bit gone from blkdev_reread_part(), the retry logic in dasd_scan_partitions() shouldn't be necessary. CC: Christoph Hellwig CC: Jens Axboe CC: Tejun Heo CC: Alexander Viro CC: Markus Pargmann CC: Stefan Weinhuber CC: Stefan Haberland CC: Sebastian Ott CC: Fabian Frederick CC: Ming Lei CC: David Herrmann CC: Andrew Morton CC: Peter Zijlstra CC: nbd-general@lists.sourceforge.net CC: linux-s390@vger.kernel.org Reviewed-by: Christoph Hellwig Acked-by: Sebastian Ott Signed-off-by: Ming Lei Signed-off-by: Jarod Wilson Signed-off-by: Jens Axboe

block: dasd_genhd: convert to blkdev_reread_part

2015-05-20T15:06:15Z

Also remove the obsolete comment. Reviewed-by: Christoph Hellwig Tested-by: Jarod Wilson Acked-by: Jarod Wilson Acked-by: Sebastian Ott Signed-off-by: Ming Lei Signed-off-by: Jens Axboe

s390/dasd: retry partition detection

2014-11-28T08:47:42Z

In case somebody attempted to open the device during online processing the partition detection ioctl may have failed. Added a retry loop to avoid not detected partitions. Signed-off-by: Stefan Haberland Signed-off-by: Martin Schwidefsky

s390/dasd: fix memory leak caused by dangling references to request_queue

2013-12-02T14:31:06Z

After the call to del_gendisk, the gendisk still holds a reference to its request_queue. We must not modify the gendisks queue pointer before the put_disk call, or the gendisk_release function cannot release the reference and the memory for the request_queue structure is lost. Signed-off-by: Stefan Weinhuber Signed-off-by: Martin Schwidefsky

s390/comments: unify copyright messages and remove file names

2012-07-20T09:15:04Z

Remove the file name from the comment at top of many files. In most cases the file name was wrong anyway, so it's rather pointless. Also unify the IBM copyright statement. We did have a lot of sightly different statements and wanted to change them one after another whenever a file gets touched. However that never happened. Instead people start to take the old/"wrong" statements to use as a template for new files. So unify all of them in one go. Signed-off-by: Heiko Carstens

[S390] dasd: fix race between open and offline

2011-04-20T08:15:43Z

The dasd_open function uses the private_data pointer of the gendisk to find the dasd_block structure that matches the gendisk. When a DASD device is set offline, we set the private_data pointer of the gendisk to NULL and later remove the dasd_block structure, but there is still a small race window, in which dasd_open could first read a pointer from the private_data field and then try to use it, after the structure has already been freed. To close this race window, we will store a pointer to the dasd_devmap structure of the base device in the private_data field. The devmap entries are not deleted, and we already have proper locking and reference counting in place, so that we can safely get from a devmap pointer to the dasd_device and dasd_block structures of the device. Signed-off-by: Stefan Weinhuber Signed-off-by: Martin Schwidefsky

block: make blkdev_get/put() handle exclusive access

2010-11-13T10:55:17Z

Over time, block layer has accumulated a set of APIs dealing with bdev open, close, claim and release. * blkdev_get/put() are the primary open and close functions. * bd_claim/release() deal with exclusive open. * open/close_bdev_exclusive() are combination of open and claim and the other way around, respectively. * bd_link/unlink_disk_holder() to create and remove holder/slave symlinks. * open_by_devnum() wraps bdget() + blkdev_get(). The interface is a bit confusing and the decoupling of open and claim makes it impossible to properly guarantee exclusive access as in-kernel open + claim sequence can disturb the existing exclusive open even before the block layer knows the current open if for another exclusive access. Reorganize the interface such that, * blkdev_get() is extended to include exclusive access management. @holder argument is added and, if is @FMODE_EXCL specified, it will gain exclusive access atomically w.r.t. other exclusive accesses. * blkdev_put() is similarly extended. It now takes @mode argument and if @FMODE_EXCL is set, it releases an exclusive access. Also, when the last exclusive claim is released, the holder/slave symlinks are removed automatically. * bd_claim/release() and close_bdev_exclusive() are no longer necessary and either made static or removed. * bd_link_disk_holder() remains the same but bd_unlink_disk_holder() is no longer necessary and removed. * open_bdev_exclusive() becomes a simple wrapper around lookup_bdev() and blkdev_get(). It also has an unexpected extra bdev_read_only() test which probably should be moved into blkdev_get(). * open_by_devnum() is modified to take @holder argument and pass it to blkdev_get(). Most of bdev open/close operations are unified into blkdev_get/put() and most exclusive accesses are tested atomically at the open time (as it should). This cleans up code and removes some, both valid and invalid, but unnecessary all the same, corner cases. open_bdev_exclusive() and open_by_devnum() can use further cleanup - rename to blkdev_get_by_path() and blkdev_get_by_devt() and drop special features. Well, let's leave them for another day. Most conversions are straight-forward. drbd conversion is a bit more involved as there was some reordering, but the logic should stay the same. Signed-off-by: Tejun Heo Acked-by: Neil Brown Acked-by: Ryusuke Konishi Acked-by: Mike Snitzer Acked-by: Philipp Reisner Cc: Peter Osterlund Cc: Martin Schwidefsky Cc: Heiko Carstens Cc: Jan Kara Cc: Andrew Morton Cc: Andreas Dilger Cc: "Theodore Ts'o" Cc: Mark Fasheh Cc: Joel Becker Cc: Alex Elder Cc: Christoph Hellwig Cc: dm-devel@redhat.com Cc: drbd-dev@lists.linbit.com Cc: Leo Chen Cc: Scott Branden Cc: Chris Mason Cc: Steven Whitehouse Cc: Dave Kleikamp Cc: Joern Engel Cc: reiserfs-devel@vger.kernel.org Cc: Alexander Viro

[S390] dasd: automatic recognition of read-only devices

2010-03-08T11:26:27Z

In z/VM it is possible to attach a device as read-only. To prevent unintentional write requests and subsequent I/O errors, we can detect this configuration using the z/VM DIAG 210 interface and set the respective linux block device to read-only as well. Signed-off-by: Stefan Weinhuber Signed-off-by: Martin Schwidefsky

[S390] dasd: fix online/offline race

2010-02-26T21:37:32Z

Setting a DASD online and offline in quick succession may cause a kernel panic or let the chhccwdev command wait forever. The Online process is split into two parts. After the first part is finished the offline process may be called. This may result in a situation where the second online processing part tries to set the DASD offline as well. Use a mutex to protect online and offline against each other. Also correct some checking. Signed-off-by: Stefan Haberland Signed-off-by: Martin Schwidefsky

[S390] dasd: message cleanup

2009-03-26T14:24:05Z

Moved some Messages into s390 debug feature and changed remaining messages to use the dev_xxx and pr_xxx macros. Signed-off-by: Stefan Haberland Signed-off-by: Martin Schwidefsky