| Age | Commit message (Collapse) | Author |
|---|
|
After a bit of poking around wondering why my 32-bit user-space can't
seem to send a proper ioctl(BLKPG) to an MTD on my 64-bit kernel
(ARM64), I noticed that struct blkpg_ioctl_arg is actually pretty
unsuitable for use in the ioctl() ABI, due to its use of raw pointers,
and its lack of alignment/packing restrictions (32-bit arch'es tend to
pack the 4 fields into 4 32-bit words, whereas 64-bit arch'es would add
padding after the third int, and make this 6 32-bit words).
Anyway, this means BLKPG deserves some special compat_ioctl handling. Do
the conversion in a small shim for MTD.
block/compat_ioctl.c already has compat support for the block subsystem,
but it does so by a re-marshalling data to/from user-space (see
compat_blkpg_ioctl()). Personally, I think this approach is cleaner.
Tested only on MTD, with an ARM32 user space on an ARM64 kernel.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
|
|
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Michael Kerrisk <mtk.manpages@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Dave Jones <davej@redhat.com>
|
|
Add a new operation code (BLKPG_RESIZE_PARTITION) to the BLKPG ioctl that
allows altering the size of an existing partition, even if it is currently
in use.
This patch converts hd_struct->nr_sects into sequence counter because
One might extend a partition while IO is happening to it and update of
nr_sects can be non-atomic on 32bit machines with 64bit sector_t. This
can lead to issues like reading inconsistent size of a partition. Sequence
counter have been used so that readers don't have to take bdev mutex lock
as we call sector_in_part() very frequently.
Now all the access to hd_struct->nr_sects should happen using sequence
counter read/update helper functions part_nr_sects_read/part_nr_sects_write.
There is one exception though, set_capacity()/get_capacity(). I think
theoritically race should exist there too but this patch does not
modify set_capacity()/get_capacity() due to sheer number of call sites
and I am afraid that change might break something. I have left that as a
TODO item. We can handle it later if need be. This patch does not introduce
any new races as such w.r.t set_capacity()/get_capacity().
v2: Add CONFIG_LBDAF test to UP preempt case as suggested by Phillip.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Phillip Susi <psusi@ubuntu.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
|
|
|
|
From: Christoph Hellwig <hch@lst.de>
partition_name() is a variant of __bdevname() that caches results and
returns a pointrer to kmalloc()ed data instead of printing into a buffer.
Due to it's caching it gets utterly confused when the name for a dev_t
changes (can happen easily now with device mapper and probably in the
future with dynamic dev_t users).
It's only used by the raid code and most calls are through a wrapper,
bdev_partition_name() which takes a struct block_device * that maybe be
NULL.
The patch below changes the bdev_partition_name() to call bdevname() if
possible and the other calls where we really have nothing more than a dev_t
to __bdevname.
Btw, it would be nice if someone who knows the md code a bit better than me
could remove bdev_partition_name() in favour of direct calls to bdevname()
where possible - that would also get rid of the returns pointer to string
on stack issue that this patch can't fix yet.
|
|
guts of blkpg.c and blkdev_ioctl() sanitized up and moved into a new
file - drivers/block/ioctl.c. blkpg.c is gone.
|
|
partition_name() moved from md.c to partitions/check.c; disk_name() is not
exported anymore; partition_name() takes dev_t instead of kdev_t.
|
|
|
|
|
