linux-stable.git/drivers/char/raw.c, branch linux-3.17.y

blkdev_aio_write() - turn into blkdev_write_iter()

2014-05-06T21:38:01+00:00

Signed-off-by: Al Viro

switch simple generic_file_aio_read() users to ->read_iter()

2014-05-06T21:37:55+00:00

Signed-off-by: Al Viro

raw: test against runtime value of max_raw_minors

2014-02-07T16:29:46+00:00

bind_get() checks the device number it is called with. It uses
MAX_RAW_MINORS for the upper bound. But MAX_RAW_MINORS is set at compile
time while the actual number of raw devices can be set at runtime. This
means the test can either be too strict or too lenient. And if the test
ends up being too lenient bind_get() might try to access memory beyond
what was allocated for "raw_devices".

So check against the runtime value (max_raw_minors) in this function.

Signed-off-by: Paul Bolle 
Acked-by: Jan Kara 
Cc: stable 
Signed-off-by: Greg Kroah-Hartman

new helper: file_inode(file)

2013-02-23T04:31:31+00:00

Signed-off-by: Al Viro

blockdev: remove bd_block_size_semaphore again

2012-11-29T18:52:19+00:00

This reverts the block-device direct access code to the previous
unlocked code, now that fs/buffer.c no longer needs external locking.

With this, fs/block_dev.c is back to the original version, apart from a
whitespace cleanup that I didn't want to revert.

Signed-off-by: Linus Torvalds

Fix a crash when block device is read and block size is changed at the same time

2012-09-26T05:46:40+00:00

The kernel may crash when block size is changed and I/O is issued
simultaneously.

Because some subsystems (udev or lvm) may read any block device anytime,
the bug actually puts any code that changes a block device size in
jeopardy.

The crash can be reproduced if you place "msleep(1000)" to
blkdev_get_blocks just before "bh->b_size = max_blocks <<
inode->i_blkbits;".
Then, run "dd if=/dev/ram0 of=/dev/null bs=4k count=1 iflag=direct"
While it is waiting in msleep, run "blockdev --setbsz 2048 /dev/ram0"
You get a BUG.

The direct and non-direct I/O is written with the assumption that block
size does not change. It doesn't seem practical to fix these crashes
one-by-one there may be many crash possibilities when block size changes
at a certain place and it is impossible to find them all and verify the
code.

This patch introduces a new rw-lock bd_block_size_semaphore. The lock is
taken for read during I/O. It is taken for write when changing block
size. Consequently, block size can't be changed while I/O is being
submitted.

For asynchronous I/O, the patch only prevents block size change while
the I/O is being submitted. The block size can change when the I/O is in
progress or when the I/O is being finished. This is acceptable because
there are no accesses to block size when asynchronous I/O is being
finished.

The patch prevents block size changing while the device is mapped with
mmap.

Signed-off-by: Mikulas Patocka 
Signed-off-by: Jens Axboe

switch device_get_devnode() and ->devnode() to umode_t *

2012-01-04T03:54:55+00:00

both callers of device_get_devnode() are only interested in lower 16bits
and nobody tries to return anything wider than 16bit anyway.

Signed-off-by: Al Viro

char: Convert vmalloc/memset to vzalloc

2011-09-15T11:55:03+00:00

Signed-off-by: Joe Perches 
Signed-off-by: Jiri Kosina

RAW driver: Remove call to kobject_put().

2011-05-07T00:52:32+00:00

If cdev_add() fails, there is no justification for subsequently
calling kobject_put().

Signed-off-by: Robert P. J. Day 
Signed-off-by: Greg Kroah-Hartman

Allow setting of number of raw devices as a module parameter

2011-05-07T00:52:31+00:00

Allow setting of maximal number of raw devices as a module parameter. This
requires changing of static array into a vmalloced one (the array is going to
be too large for kmalloc).

Signed-off-by: Jan Kara 
Signed-off-by: Greg Kroah-Hartman