linux-stable.git/drivers/block, branch v4.4.261

rsxx: Return -EFAULT if copy_to_user() fails

2021-03-11T12:46:35+00:00

[ Upstream commit 77516d25f54912a7baedeeac1b1b828b6f285152 ]

The copy_to_user() function returns the number of bytes remaining but
we want to return -EFAULT to the user if it can't complete the copy.
The "st" variable only holds zero on success or negative error codes on
failure so the type should be int.

Fixes: 36f988e978f8 ("rsxx: Adding in debugfs entries.")
Signed-off-by: Dan Carpenter 
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

zsmalloc: account the number of compacted pages correctly

2021-03-07T10:24:22+00:00

commit 2395928158059b8f9858365fce7713ce7fef62e4 upstream.

There exists multiple path may do zram compaction concurrently.
1. auto-compaction triggered during memory reclaim
2. userspace utils write zram/compaction node

So, multiple threads may call zs_shrinker_scan/zs_compact concurrently.
But pages_compacted is a per zsmalloc pool variable and modification
of the variable is not serialized(through under class->lock).
There are two issues here:
1. the pages_compacted may not equal to total number of pages
freed(due to concurrently add).
2. zs_shrinker_scan may not return the correct number of pages
freed(issued by current shrinker).

The fix is simple:
1. account the number of pages freed in zs_compact locally.
2. use actomic variable pages_compacted to accumulate total number.

Link: https://lkml.kernel.org/r/20210202122235.26885-1-wu-yan@tcl.com
Fixes: 860c707dca155a56 ("zsmalloc: account the number of compacted pages")
Signed-off-by: Rokudo Yan 
Cc: Minchan Kim 
Cc: Sergey Senozhatsky 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

floppy: reintroduce O_NDELAY fix

2021-03-03T15:44:22+00:00

commit 8a0c014cd20516ade9654fc13b51345ec58e7be8 upstream.

This issue was originally fixed in 09954bad4 ("floppy: refactor open()
flags handling").

The fix as a side-effect, however, introduce issue for open(O_ACCMODE)
that is being used for ioctl-only open. I wrote a fix for that, but
instead of it being merged, full revert of 09954bad4 was performed,
re-introducing the O_NDELAY / O_NONBLOCK issue, and it strikes again.

This is a forward-port of the original fix to current codebase; the
original submission had the changelog below:

====
Commit 09954bad4 ("floppy: refactor open() flags handling"), as a
side-effect, causes open(/dev/fdX, O_ACCMODE) to fail. It turns out that
this is being used setfdprm userspace for ioctl-only open().

Reintroduce back the original behavior wrt !(FMODE_READ|FMODE_WRITE)
modes, while still keeping the original O_NDELAY bug fixed.

Link: https://lore.kernel.org/r/nycvar.YFH.7.76.2101221209060.5622@cbobk.fhfr.pm
Cc: stable@vger.kernel.org
Reported-by: Wim Osterholt 
Tested-by: Wim Osterholt 
Reported-and-tested-by: Kurt Garloff 
Fixes: 09954bad4 ("floppy: refactor open() flags handling")
Fixes: f2791e7ead ("Revert "floppy: refactor open() flags handling"")
Signed-off-by: Jiri Kosina 
Signed-off-by: Denis Efremov 
Signed-off-by: Greg Kroah-Hartman

block: Move SECTOR_SIZE and SECTOR_SHIFT definitions into

2021-03-03T15:44:21+00:00

commit 233bde21aa43516baa013ef7ac33f3427056db3e upstream.

It happens often while I'm preparing a patch for a block driver that
I'm wondering: is a definition of SECTOR_SIZE and/or SECTOR_SHIFT
available for this driver? Do I have to introduce definitions of these
constants before I can use these constants? To avoid this confusion,
move the existing definitions of SECTOR_SIZE and SECTOR_SHIFT into the
 header file such that these become available for all
block drivers. Make the SECTOR_SIZE definition in the uapi msdos_fs.h
header file conditional to avoid that including that header file after
 causes the compiler to complain about a SECTOR_SIZE
redefinition.

Note: the SECTOR_SIZE / SECTOR_SHIFT / SECTOR_BITS definitions have
not been removed from uapi header files nor from NAND drivers in
which these constants are used for another purpose than converting
block layer offsets and sizes into a number of sectors.

Cc: David S. Miller 
Cc: Mike Snitzer 
Cc: Dan Williams 
Cc: Minchan Kim 
Cc: Nitin Gupta 
Reviewed-by: Sergey Senozhatsky 
Reviewed-by: Christoph Hellwig 
Reviewed-by: Johannes Thumshirn 
Reviewed-by: Martin K. Petersen 
Signed-off-by: Bart Van Assche 
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

xen-blkback: fix error handling in xen_blkbk_map()

2021-02-23T12:58:14+00:00

commit 871997bc9e423f05c7da7c9178e62dde5df2a7f8 upstream.

The function uses a goto-based loop, which may lead to an earlier error
getting discarded by a later iteration. Exit this ad-hoc loop when an
error was encountered.

The out-of-memory error path additionally fails to fill a structure
field looked at by xen_blkbk_unmap_prepare() before inspecting the
handle which does get properly set (to BLKBACK_INVALID_HANDLE).

Since the earlier exiting from the ad-hoc loop requires the same field
filling (invalidation) as that on the out-of-memory path, fold both
paths. While doing so, drop the pr_alert(), as extra log messages aren't
going to help the situation (the kernel will log oom conditions already
anyway).

This is XSA-365.

Signed-off-by: Jan Beulich 
Reviewed-by: Juergen Gross 
Reviewed-by: Julien Grall 
Signed-off-by: Juergen Gross 
Signed-off-by: Greg Kroah-Hartman

xen-blkback: don't "handle" error by BUG()

2021-02-23T12:58:14+00:00

commit 5a264285ed1cd32e26d9de4f3c8c6855e467fd63 upstream.

In particular -ENOMEM may come back here, from set_foreign_p2m_mapping().
Don't make problems worse, the more that handling elsewhere (together
with map's status fields now indicating whether a mapping wasn't even
attempted, and hence has to be considered failed) doesn't require this
odd way of dealing with errors.

This is part of XSA-362.

Signed-off-by: Jan Beulich 
Cc: stable@vger.kernel.org
Reviewed-by: Juergen Gross 
Signed-off-by: Juergen Gross 
Signed-off-by: Greg Kroah-Hartman

xen-blkback: set ring->xenblkd to NULL after kthread_stop()

2021-01-30T12:25:57+00:00

commit 1c728719a4da6e654afb9cc047164755072ed7c9 upstream.

When xen_blkif_disconnect() is called, the kernel thread behind the
block interface is stopped by calling kthread_stop(ring->xenblkd).
The ring->xenblkd thread pointer being non-NULL determines if the
thread has been already stopped.
Normally, the thread's function xen_blkif_schedule() sets the
ring->xenblkd to NULL, when the thread's main loop ends.

However, when the thread has not been started yet (i.e.
wake_up_process() has not been called on it), the xen_blkif_schedule()
function would not be called yet.

In such case the kthread_stop() call returns -EINTR and the
ring->xenblkd remains dangling.
When this happens, any consecutive call to xen_blkif_disconnect (for
example in frontend_changed() callback) leads to a kernel crash in
kthread_stop() (e.g. NULL pointer dereference in exit_creds()).

This is XSA-350.

Cc:  # 4.12
Fixes: a24fa22ce22a ("xen/blkback: don't use xen_blkif_get() in xen-blkback kthread")
Reported-by: Olivier Benjamin 
Reported-by: Pawel Wieczorkiewicz 
Signed-off-by: Pawel Wieczorkiewicz 
Reviewed-by: Julien Grall 
Reviewed-by: Juergen Gross 
Signed-off-by: Juergen Gross 
[iwamatsu: change from ring to blkif]
Signed-off-by: Nobuhiro Iwamatsu 
Signed-off-by: Greg Kroah-Hartman

block: rsxx: select CONFIG_CRC32

2021-01-17T12:55:14+00:00

commit 36a106a4c1c100d55ba3d32a21ef748cfcd4fa99 upstream.

Without crc32, the driver fails to link:

arm-linux-gnueabi-ld: drivers/block/rsxx/config.o: in function `rsxx_load_config':
config.c:(.text+0x124): undefined reference to `crc32_le'

Fixes: 8722ff8cdbfa ("block: IBM RamSan 70/80 device driver")
Signed-off-by: Arnd Bergmann 
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

xen/xenbus: Add 'will_handle' callback support in xenbus_watch_path()

2020-12-29T12:42:45+00:00

commit 2e85d32b1c865bec703ce0c962221a5e955c52c2 upstream.

Some code does not directly make 'xenbus_watch' object and call
'register_xenbus_watch()' but use 'xenbus_watch_path()' instead.  This
commit adds support of 'will_handle' callback in the
'xenbus_watch_path()' and it's wrapper, 'xenbus_watch_pathfmt()'.

This is part of XSA-349

Cc: stable@vger.kernel.org
Signed-off-by: SeongJae Park 
Reported-by: Michael Kurth 
Reported-by: Pawel Wieczorkiewicz 
Reviewed-by: Juergen Gross 
Signed-off-by: Juergen Gross 
Signed-off-by: Greg Kroah-Hartman

xen/blkback: use lateeoi irq binding

2020-11-18T17:25:03+00:00

commit 01263a1fabe30b4d542f34c7e2364a22587ddaf2 upstream.

In order to reduce the chance for the system becoming unresponsive due
to event storms triggered by a misbehaving blkfront use the lateeoi
irq binding for blkback and unmask the event channel only after
processing all pending requests.

As the thread processing requests is used to do purging work in regular
intervals an EOI may be sent only after having received an event. If
there was no pending I/O request flag the EOI as spurious.

This is part of XSA-332.

Cc: stable@vger.kernel.org
Reported-by: Julien Grall 
Signed-off-by: Juergen Gross 
Reviewed-by: Jan Beulich 
Reviewed-by: Wei Liu 
Signed-off-by: Greg Kroah-Hartman