platform/kernel/linux-exynos.git
13 years agoMerge branch 'apei-release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb...
Linus Torvalds [Thu, 4 Aug 2011 07:53:27 +0000 (21:53 -1000)]
Merge branch 'apei-release' of git://git./linux/kernel/git/lenb/linux-acpi-2.6

* 'apei-release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6:
  ACPI, APEI, EINJ Param support is disabled by default
  APEI GHES: 32-bit buildfix
  ACPI: APEI build fix
  ACPI, APEI, GHES: Add hardware memory error recovery support
  HWPoison: add memory_failure_queue()
  ACPI, APEI, GHES, Error records content based throttle
  ACPI, APEI, GHES, printk support for recoverable error via NMI
  lib, Make gen_pool memory allocator lockless
  lib, Add lock-less NULL terminated single list
  Add Kconfig option ARCH_HAVE_NMI_SAFE_CMPXCHG
  ACPI, APEI, Add WHEA _OSC support
  ACPI, APEI, Add APEI bit support in generic _OSC call
  ACPI, APEI, GHES, Support disable GHES at boot time
  ACPI, APEI, GHES, Prevent GHES to be built as module
  ACPI, APEI, Use apei_exec_run_optional in APEI EINJ and ERST
  ACPI, APEI, Add apei_exec_run_optional
  ACPI, APEI, GHES, Do not ratelimit fatal error printk before panic
  ACPI, APEI, ERST, Fix erst-dbg long record reading issue
  ACPI, APEI, ERST, Prevent erst_dbg from loading if ERST is disabled

13 years agoMerge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target...
Linus Torvalds [Thu, 4 Aug 2011 01:12:09 +0000 (15:12 -1000)]
Merge branch 'for-next' of git://git./linux/kernel/git/nab/target-pending

* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending:
  tcm_fc: Handle DDP/SW fc_frame_payload_get failures in ft_recv_write_data
  target: Fix bug for transport_generic_wait_for_tasks with direct operation
  target: iscsi_target depends on NET
  target: Fix WRITE_SAME_16 lba assignment breakage
  MAINTAINERS: Add target-devel list for drivers/target/
  iscsi-target: Fix CONFIG_SMP=n and CONFIG_MODULES=n build failure
  iscsi-target: Fix snprintf usage with MAX_PORTAL_LEN
  iscsi-target: Fix uninitialized usage of cmd->pad_bytes
  iscsi-target: strlen() doesn't count the terminator
  iscsi-target: Fix NULL dereference on allocation failure

13 years agoMerge branch 'devicetree/next' of git://git.secretlab.ca/git/linux-2.6
Linus Torvalds [Thu, 4 Aug 2011 01:10:30 +0000 (15:10 -1000)]
Merge branch 'devicetree/next' of git://git.secretlab.ca/git/linux-2.6

* 'devicetree/next' of git://git.secretlab.ca/git/linux-2.6:
  dt: add of_alias_scan and of_alias_get_id

13 years agoMerge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
Linus Torvalds [Thu, 4 Aug 2011 01:09:10 +0000 (15:09 -1000)]
Merge branch 'for_linus' of git://git./linux/kernel/git/tytso/ext4

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: use kzalloc in ext4_kzalloc()

13 years agoshm: optimize exit_shm()
Vasiliy Kulikov [Wed, 3 Aug 2011 18:28:26 +0000 (22:28 +0400)]
shm: optimize exit_shm()

We may optimistically check .in_use == 0 without holding the rw_mutex:
it's the common case, and if it's zero, there certainly won't be any
segments associated with us.

After taking the lock, the idr_for_each() will do the right thing, so we
could now drop the re-check inside the lock without any real cost.  But
it won't hurt.

Signed-off-by: Vasiliy Kulikov <segoon@openwall.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
13 years agoshm: fix wrong tests
Vasiliy Kulikov [Wed, 3 Aug 2011 18:26:55 +0000 (22:26 +0400)]
shm: fix wrong tests

Commit 4c677e2eefdb ("shm: optimize locking and ipc_namespace getting")
introduced a copy-paste bug.  Due to the bug cycle optimizations were
disabled.

Signed-off-by: Vasiliy Kulikov <segoon@openwall.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
13 years agotmpfs: expand "help" to explain value of TMPFS_POSIX_ACL
Robert P. J. Day [Wed, 3 Aug 2011 23:21:29 +0000 (16:21 -0700)]
tmpfs: expand "help" to explain value of TMPFS_POSIX_ACL

Expand the fs/Kconfig "help" info to clarify why it's a bad idea to
deselect the TMPFS_POSIX_ACL config variable.

Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Acked-by: Randy Dunlap <rdunlap@xenotime.net>
Acked-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
13 years agomm: clarify the radix_tree exceptional cases
Hugh Dickins [Wed, 3 Aug 2011 23:21:28 +0000 (16:21 -0700)]
mm: clarify the radix_tree exceptional cases

Make the radix_tree exceptional cases, mostly in filemap.c, clearer.

It's hard to devise a suitable snappy name that illuminates the use by
shmem/tmpfs for swap, while keeping filemap/pagecache/radix_tree
generality.  And akpm points out that /* radix_tree_deref_retry(page) */
comments look like calls that have been commented out for unknown
reason.

Skirt the naming difficulty by rearranging these blocks to handle the
transient radix_tree_deref_retry(page) case first; then just explain the
remaining shmem/tmpfs swap case in a comment.

Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
13 years agotmpfs radix_tree: locate_item to speed up swapoff
Hugh Dickins [Wed, 3 Aug 2011 23:21:27 +0000 (16:21 -0700)]
tmpfs radix_tree: locate_item to speed up swapoff

We have already acknowledged that swapoff of a tmpfs file is slower than
it was before conversion to the generic radix_tree: a little slower
there will be acceptable, if the hotter paths are faster.

But it was a shock to find swapoff of a 500MB file 20 times slower on my
laptop, taking 10 minutes; and at that rate it significantly slows down
my testing.

Now, most of that turned out to be overhead from PROVE_LOCKING and
PROVE_RCU: without those it was only 4 times slower than before; and
more realistic tests on other machines don't fare as badly.

I've tried a number of things to improve it, including tagging the swap
entries, then doing lookup by tag: I'd expected that to halve the time,
but in practice it's erratic, and often counter-productive.

The only change I've so far found to make a consistent improvement, is
to short-circuit the way we go back and forth, gang lookup packing
entries into the array supplied, then shmem scanning that array for the
target entry.  Scanning in place doubles the speed, so it's now only
twice as slow as before (or three times slower when the PROVEs are on).

So, add radix_tree_locate_item() as an expedient, once-off,
single-caller hack to do the lookup directly in place.  #ifdef it on
CONFIG_SHMEM and CONFIG_SWAP, as much to document its limited
applicability as save space in other configurations.  And, sadly,
#include sched.h for cond_resched().

Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
13 years agomm: a few small updates for radix-swap
Hugh Dickins [Wed, 3 Aug 2011 23:21:27 +0000 (16:21 -0700)]
mm: a few small updates for radix-swap

Remove PageSwapBacked (!page_is_file_cache) cases from
add_to_page_cache_locked() and add_to_page_cache_lru(): those pages now
go through shmem_add_to_page_cache().

Remove a comment on maximum tmpfs size from fsstack_copy_inode_size(),
and add a comment on swap entries to invalidate_mapping_pages().

And mincore_page() uses find_get_page() on what might be shmem or a
tmpfs file: allow for a radix_tree_exceptional_entry(), and proceed to
find_get_page() on swapper_space if so (oh, swapper_space needs #ifdef).

Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
13 years agotmpfs: use kmemdup for short symlinks
Hugh Dickins [Wed, 3 Aug 2011 23:21:26 +0000 (16:21 -0700)]
tmpfs: use kmemdup for short symlinks

But we've not yet removed the old swp_entry_t i_direct[16] from
shmem_inode_info.  That's because it was still being shared with the
inline symlink.  Remove it now (saving 64 or 128 bytes from shmem inode
size), and use kmemdup() for short symlinks, say, those up to 128 bytes.

I wonder why mpol_free_shared_policy() is done in shmem_destroy_inode()
rather than shmem_evict_inode(), where we usually do such freeing? I
guess it doesn't matter, and I'm not into NUMA mpol testing right now.

Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
13 years agotmpfs: convert shmem_writepage and enable swap
Hugh Dickins [Wed, 3 Aug 2011 23:21:25 +0000 (16:21 -0700)]
tmpfs: convert shmem_writepage and enable swap

Convert shmem_writepage() to use shmem_delete_from_page_cache() to use
shmem_radix_tree_replace() to substitute swap entry for page pointer
atomically in the radix tree.

As with shmem_add_to_page_cache(), it's not entirely satisfactory to be
copying such code from delete_from_swap_cache, but again judged easier
to sell than making its other callers go through the extras.

Remove the toy implementation's shmem_put_swap() and shmem_get_swap(),
now unreferenced, and the hack to disable swap: it's now good to go.

The way things have worked out, info->lock no longer helps to guard the
shmem_swaplist: we increment swapped under shmem_swaplist_mutex only.
That global mutex exclusion between shmem_writepage() and shmem_unuse()
is not pretty, and we ought to find another way; but it's been forced on
us by recent race discoveries, not a consequence of this patchset.

And what has become of the WARN_ON_ONCE(1) free_swap_and_cache() if a
swap entry was found already present? That's no longer possible, the
(unknown) one inserting this page into filecache would hit the swap
entry occupying that slot.

Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
13 years agotmpfs: convert mem_cgroup shmem to radix-swap
Hugh Dickins [Wed, 3 Aug 2011 23:21:24 +0000 (16:21 -0700)]
tmpfs: convert mem_cgroup shmem to radix-swap

Remove mem_cgroup_shmem_charge_fallback(): it was only required when we
had to move swappage to filecache with GFP_NOWAIT.

Remove the GFP_NOWAIT special case from mem_cgroup_cache_charge(), by
moving its call out from shmem_add_to_page_cache() to two of thats three
callers.  But leave it doing mem_cgroup_uncharge_cache_page() on error:
although asymmetrical, it's easier for all 3 callers to handle.

These two changes would also be appropriate if anyone were to start
using shmem_read_mapping_page_gfp() with GFP_NOWAIT.

Remove mem_cgroup_get_shmem_target(): mc_handle_file_pte() can test
radix_tree_exceptional_entry() to get what it needs for itself.

Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
13 years agotmpfs: convert shmem_getpage_gfp to radix-swap
Hugh Dickins [Wed, 3 Aug 2011 23:21:24 +0000 (16:21 -0700)]
tmpfs: convert shmem_getpage_gfp to radix-swap

Convert shmem_getpage_gfp(), the engine-room of shmem, to expect page or
swap entry returned from radix tree by find_lock_page().

Whereas the repetitive old method proceeded mainly under info->lock,
dropping and repeating whenever one of the conditions needed was not
met, now we can proceed without it, leaving shmem_add_to_page_cache() to
check for a race.

This way there is no need to preallocate a page, no need for an early
radix_tree_preload(), no need for mem_cgroup_shmem_charge_fallback().

Move the error unwinding down to the bottom instead of repeating it
throughout.  ENOSPC handling is a little different from before: there is
no longer any race between find_lock_page() and finding swap, but we can
arrive at ENOSPC before calling shmem_recalc_inode(), which might
occasionally discover freed space.

Be stricter to check i_size before returning.  info->lock is used for
little but alloced, swapped, i_blocks updates.  Move i_blocks updates
out from under the max_blocks check, so even an unlimited size=0 mount
can show accurate du.

Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
13 years agotmpfs: convert shmem_unuse_inode to radix-swap
Hugh Dickins [Wed, 3 Aug 2011 23:21:23 +0000 (16:21 -0700)]
tmpfs: convert shmem_unuse_inode to radix-swap

Convert shmem_unuse_inode() to use a lockless gang lookup of the radix
tree, searching for matching swap.

This is somewhat slower than the old method: because of repeated radix
tree descents, because of copying entries up, but probably most because
the old method noted and skipped once a vector page was cleared of swap.
Perhaps we can devise a use of radix tree tagging to achieve that later.

shmem_add_to_page_cache() uses shmem_radix_tree_replace() to compensate
for the lockless lookup by checking that the expected entry is in place,
under lock.  It is not very satisfactory to be copying this much from
add_to_page_cache_locked(), but I think easier to sell than insisting
that every caller of add_to_page_cache*() go through the extras.

Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
13 years agotmpfs: convert shmem_truncate_range to radix-swap
Hugh Dickins [Wed, 3 Aug 2011 23:21:22 +0000 (16:21 -0700)]
tmpfs: convert shmem_truncate_range to radix-swap

Disable the toy swapping implementation in shmem_writepage() - it's hard
to support two schemes at once - and convert shmem_truncate_range() to a
lockless gang lookup of swap entries along with pages, freeing both.

Since the second loop tightens its noose until all entries of either
kind have been squeezed out (and we shall make sure that there's not an
instant when neither is visible), there is no longer a need for yet
another pass below.

shmem_radix_tree_replace() compensates for the lockless lookup by
checking that the expected entry is in place, under lock, before
replacing it.  Here it just deletes, but will be used in later patches
to substitute swap entry for page or page for swap entry.

Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
13 years agotmpfs: copy truncate_inode_pages_range
Hugh Dickins [Wed, 3 Aug 2011 23:21:21 +0000 (16:21 -0700)]
tmpfs: copy truncate_inode_pages_range

Bring truncate.c's code for truncate_inode_pages_range() inline into
shmem_truncate_range(), replacing its first call (there's a followup
call below, but leave that one, it will disappear next).

Don't play with it yet, apart from leaving out the cleancache flush, and
(importantly) the nrpages == 0 skip, and moving shmem_setattr()'s
partial page preparation into its partial page handling.

Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
13 years agotmpfs: miscellaneous trivial cleanups
Hugh Dickins [Wed, 3 Aug 2011 23:21:21 +0000 (16:21 -0700)]
tmpfs: miscellaneous trivial cleanups

While it's at its least, make a number of boring nitpicky cleanups to
shmem.c, mostly for consistency of variable naming.  Things like "swap"
instead of "entry", "pgoff_t index" instead of "unsigned long idx".

And since everything else here is prefixed "shmem_", better change
init_tmpfs() to shmem_init().

Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
13 years agotmpfs: demolish old swap vector support
Hugh Dickins [Wed, 3 Aug 2011 23:21:20 +0000 (16:21 -0700)]
tmpfs: demolish old swap vector support

The maximum size of a shmem/tmpfs file has been limited by the maximum
size of its triple-indirect swap vector.  With 4kB page size, maximum
filesize was just over 2TB on a 32-bit kernel, but sadly one eighth of
that on a 64-bit kernel.  (With 8kB page size, maximum filesize was just
over 4TB on a 64-bit kernel, but 16TB on a 32-bit kernel,
MAX_LFS_FILESIZE being then more restrictive than swap vector layout.)

It's a shame that tmpfs should be more restrictive than ramfs, and this
limitation has now been noticed.  Add another level to the swap vector?
No, it became obscure and hard to maintain, once I complicated it to
make use of highmem pages nine years ago: better choose another way.

Surely, if 2.4 had had the radix tree pagecache introduced in 2.5, then
tmpfs would never have invented its own peculiar radix tree: we would
have fitted swap entries into the common radix tree instead, in much the
same way as we fit swap entries into page tables.

And why should each file have a separate radix tree for its pages and
for its swap entries? The swap entries are required precisely where and
when the pages are not.  We want to put them together in a single radix
tree: which can then avoid much of the locking which was needed to
prevent them from being exchanged underneath us.

This also avoids the waste of memory devoted to swap vectors, first in
the shmem_inode itself, then at least two more pages once a file grew
beyond 16 data pages (pages accounted by df and du, but not by memcg).
Allocated upfront, to avoid allocation when under swapping pressure, but
pure waste when CONFIG_SWAP is not set - I have never spattered around
the ifdefs to prevent that, preferring this move to sharing the common
radix tree instead.

There are three downsides to sharing the radix tree.  One, that it binds
tmpfs more tightly to the rest of mm, either requiring knowledge of swap
entries in radix tree there, or duplication of its code here in shmem.c.
I believe that the simplications and memory savings (and probable higher
performance, not yet measured) justify that.

Two, that on HIGHMEM systems with SWAP enabled, it's the lowmem radix
nodes that cannot be freed under memory pressure - whereas before it was
the less precious highmem swap vector pages that could not be freed.
I'm hoping that 64-bit has now been accessible for long enough, that the
highmem argument has grown much less persuasive.

Three, that swapoff is slower than it used to be on tmpfs files, since
it's using a simple generic mechanism not tailored to it: I find this
noticeable, and shall want to improve, but maybe nobody else will
notice.

So...  now remove most of the old swap vector code from shmem.c.  But,
for the moment, keep the simple i_direct vector of 16 pages, with simple
accessors shmem_put_swap() and shmem_get_swap(), as a toy implementation
to help mark where swap needs to be handled in subsequent patches.

Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
13 years agomm: let swap use exceptional entries
Hugh Dickins [Wed, 3 Aug 2011 23:21:19 +0000 (16:21 -0700)]
mm: let swap use exceptional entries

If swap entries are to be stored along with struct page pointers in a
radix tree, they need to be distinguished as exceptional entries.

Most of the handling of swap entries in radix tree will be contained in
shmem.c, but a few functions in filemap.c's common code need to check
for their appearance: find_get_page(), find_lock_page(),
find_get_pages() and find_get_pages_contig().

So as not to slow their fast paths, tuck those checks inside the
existing checks for unlikely radix_tree_deref_slot(); except for
find_lock_page(), where it is an added test.  And make it a BUG in
find_get_pages_tag(), which is not applied to tmpfs files.

A part of the reason for eliminating shmem_readpage() earlier, was to
minimize the places where common code would need to allow for swap
entries.

The swp_entry_t known to swapfile.c must be massaged into a slightly
different form when stored in the radix tree, just as it gets massaged
into a pte_t when stored in page tables.

In an i386 kernel this limits its information (type and page offset) to
30 bits: given 32 "types" of swapfile and 4kB pagesize, that's a maximum
swapfile size of 128GB.  Which is less than the 512GB we previously
allowed with X86_PAE (where the swap entry can occupy the entire upper
32 bits of a pte_t), but not a new limitation on 32-bit without PAE; and
there's not a new limitation on 64-bit (where swap filesize is already
limited to 16TB by a 32-bit page offset).  Thirty areas of 128GB is
probably still enough swap for a 64GB 32-bit machine.

Provide swp_to_radix_entry() and radix_to_swp_entry() conversions, and
enforce filesize limit in read_swap_header(), just as for ptes.

Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
13 years agoradix_tree: exceptional entries and indices
Hugh Dickins [Wed, 3 Aug 2011 23:21:18 +0000 (16:21 -0700)]
radix_tree: exceptional entries and indices

A patchset to extend tmpfs to MAX_LFS_FILESIZE by abandoning its
peculiar swap vector, instead keeping a file's swap entries in the same
radix tree as its struct page pointers: thus saving memory, and
simplifying its code and locking.

This patch:

The radix_tree is used by several subsystems for different purposes.  A
major use is to store the struct page pointers of a file's pagecache for
memory management.  But what if mm wanted to store something other than
page pointers there too?

The low bit of a radix_tree entry is already used to denote an indirect
pointer, for internal use, and the unlikely radix_tree_deref_retry()
case.

Define the next bit as denoting an exceptional entry, and supply inline
functions radix_tree_exception() to return non-0 in either unlikely
case, and radix_tree_exceptional_entry() to return non-0 in the second
case.

If a subsystem already uses radix_tree with that bit set, no problem: it
does not affect internal workings at all, but is defined for the
convenience of those storing well-aligned pointers in the radix_tree.

The radix_tree_gang_lookups have an implicit assumption that the caller
can deduce the offset of each entry returned e.g.  by the page->index of
a struct page.  But that may not be feasible for some kinds of item to
be stored there.

radix_tree_gang_lookup_slot() allow for an optional indices argument,
output array in which to return those offsets.  The same could be added
to other radix_tree_gang_lookups, but for now keep it to the only one
for which we need it.

Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
13 years agodrivers/video/backlight/aat2870_bl.c: make it buildable as a module
Andrew Morton [Wed, 3 Aug 2011 23:21:17 +0000 (16:21 -0700)]
drivers/video/backlight/aat2870_bl.c: make it buildable as a module

i386 allmodconfig:

  drivers/built-in.o: In function `aat2870_bl_remove':
  aat2870_bl.c:(.text+0x414f9): undefined reference to `backlight_device_unregister'
  drivers/built-in.o: In function `aat2870_bl_probe':
  aat2870_bl.c:(.text+0x418fc): undefined reference to `backlight_device_register'
  aat2870_bl.c:(.text+0x41a31): undefined reference to `backlight_device_unregiste

Cc: Jin Park <jinyoungp@nvidia.com>
Cc: Samuel Ortiz <sameo@linux.intel.com>
Cc: Axel Lin <axel.lin@gmail.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
13 years agodrivers/video/backlight/aat2870_bl.c: fix setting max_current
Axel Lin [Wed, 3 Aug 2011 23:21:17 +0000 (16:21 -0700)]
drivers/video/backlight/aat2870_bl.c: fix setting max_current

 - Current implementation tests wrong value for setting
   aat2870_bl->max_current.

 - In the current implementation, we cannot differentiate between 2 cases:

   a) if pdata->max_current is not set , or

   b) pdata->max_current is set to AAT2870_CURRENT_0_45 (which is also 0).

   Fix it by setting AAT2870_CURRENT_0_45 to be 1 and adjust the equation in
   aat2870_brightness() accordingly.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Samuel Ortiz <sameo@linux.intel.com>
Tested-by: Jin Park <jinyoungp@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
13 years agodrivers/video/backlight/aat2870_bl.c: fix error checking for backlight_device_register
Axel Lin [Wed, 3 Aug 2011 23:21:16 +0000 (16:21 -0700)]
drivers/video/backlight/aat2870_bl.c: fix error checking for backlight_device_register

backlight_device_register() returns ERR_PTR() on error.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Jin Park <jinyoungp@nvidia.com>
Cc: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
13 years agocris: add missing declaration of kgdb_init() and breakpoint()
WANG Cong [Wed, 3 Aug 2011 23:21:15 +0000 (16:21 -0700)]
cris: add missing declaration of kgdb_init() and breakpoint()

Fix:

  arch/cris/arch-v10/kernel/irq.c:239: error: implicit declaration of function 'kgdb_init'
  arch/cris/arch-v10/kernel/irq.c:240: error: implicit declaration of function 'breakpoint'

Declare these two functions.

Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
13 years agocris: fix the prototype of sync_serial_ioctl()
WANG Cong [Wed, 3 Aug 2011 23:21:14 +0000 (16:21 -0700)]
cris: fix the prototype of sync_serial_ioctl()

Fix:

  arch/cris/arch-v10/drivers/sync_serial.c:961: error: conflicting types for 'sync_serial_ioctl'

Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
13 years agocris: fix a build error in sync_serial_open()
WANG Cong [Wed, 3 Aug 2011 23:21:14 +0000 (16:21 -0700)]
cris: fix a build error in sync_serial_open()

Fix:

  arch/cris/arch-v10/drivers/sync_serial.c:628: error: 'ret' undeclared (first use in this function)

'ret' should be 'err'.

Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
13 years agocris: fix a build error in kernel/fork.c
WANG Cong [Wed, 3 Aug 2011 23:21:12 +0000 (16:21 -0700)]
cris: fix a build error in kernel/fork.c

Fix this error:

  kernel/fork.c:267: error: implicit declaration of function 'alloc_thread_info_node'

This is due to renaming alloc_thread_info() to alloc_thread_info_node().

[akpm@linux-foundation.org: coding-style fixes]
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
13 years agotpm_tis: fix build when ACPI is not enabled
Randy Dunlap [Wed, 3 Aug 2011 23:21:11 +0000 (16:21 -0700)]
tpm_tis: fix build when ACPI is not enabled

Fix tpm_tis.c build when CONFIG_ACPI is not enabled by providing a stub
function.  Fixes many build errors/warnings:

  drivers/char/tpm/tpm_tis.c:89: error: dereferencing pointer to incomplete type
  drivers/char/tpm/tpm_tis.c:89: warning: type defaults to 'int' in declaration of 'type name'
  drivers/char/tpm/tpm_tis.c:89: error: request for member 'list' in something not a structure or union
  ...

Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Cc: Leendert van Doorn <leendert@watson.ibm.com>
Cc: James Morris <jmorris@namei.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
13 years agomm: page_alloc: increase __GFP_BITS_SHIFT to include __GFP_OTHER_NODE
Johannes Weiner [Wed, 3 Aug 2011 23:21:09 +0000 (16:21 -0700)]
mm: page_alloc: increase __GFP_BITS_SHIFT to include __GFP_OTHER_NODE

__GFP_OTHER_NODE is used for NUMA allocations on behalf of other nodes.
It's supposed to be passed through from the page allocator to
zone_statistics(), but it never gets there as gfp_allowed_mask is not
wide enough and masks out the flag early in the allocation path.

The result is an accounting glitch where successful NUMA allocations
by-agent are not properly attributed as local.

Increase __GFP_BITS_SHIFT so that it includes __GFP_OTHER_NODE.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Andi Kleen <ak@linux.intel.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
13 years agoramoops: update module parameters
Sergiu Iordache [Wed, 3 Aug 2011 23:21:09 +0000 (16:21 -0700)]
ramoops: update module parameters

Update the module parameters when platform data is used.  This means
that they can be read from /sys/module/ramoops/parameters in order to
parse the memory area.

Signed-off-by: Sergiu Iordache <sergiu@chromium.org>
Cc: Marco Stornelli <marco.stornelli@gmail.com>
Cc: Seiji Aguchi <seiji.aguchi@hds.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
13 years agoDocumentation: add pointer to name_to_dev_t for root= values
Will Drewry [Wed, 3 Aug 2011 23:21:08 +0000 (16:21 -0700)]
Documentation: add pointer to name_to_dev_t for root= values

Update kernel-parameters.txt to point users to the authoritative comment
for name_to_dev_t.  In addition, updates other places where some
name_to_dev_t behavior was discussed.  All other references to root=
appear to be for explicit sample usage or just side comments when
discussing other kernel parameters.

Signed-off-by: Will Drewry <wad@chromium.org>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
13 years agofs/dcache.c: fix new kernel-doc warning
Randy Dunlap [Wed, 3 Aug 2011 23:21:07 +0000 (16:21 -0700)]
fs/dcache.c: fix new kernel-doc warning

Fix new kernel-doc warning in fs/dcache.c:

  Warning(fs/dcache.c:797): No description found for parameter 'sb'

Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
13 years agoida: simplified functions for id allocation
Rusty Russell [Wed, 3 Aug 2011 23:21:06 +0000 (16:21 -0700)]
ida: simplified functions for id allocation

The current hyper-optimized functions are overkill if you simply want to
allocate an id for a device.  Create versions which use an internal
lock.

In followup patches, numerous drivers are converted to use this
interface.

Thanks to Tejun for feedback.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
13 years agotaskstats: add_del_listener() should ignore !valid listeners
Oleg Nesterov [Wed, 3 Aug 2011 23:21:05 +0000 (16:21 -0700)]
taskstats: add_del_listener() should ignore !valid listeners

When send_cpu_listeners() finds the orphaned listener it marks it as
!valid and drops listeners->sem.  Before it takes this sem for writing,
s->pid can be reused and add_del_listener() can wrongly try to re-use
this entry.

Change add_del_listener() to check ->valid = T.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Vasiliy Kulikov <segoon@openwall.com>
Acked-by: Balbir Singh <bsingharora@gmail.com>
Cc: Jerome Marchand <jmarchan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
13 years agotaskstats: add_del_listener() shouldn't use the wrong node
Oleg Nesterov [Wed, 3 Aug 2011 23:21:04 +0000 (16:21 -0700)]
taskstats: add_del_listener() shouldn't use the wrong node

1. Commit 26c4caea9d69 "don't allow duplicate entries in listener mode"
   changed add_del_listener(REGISTER) so that "next_cpu:" can reuse the
   listener allocated for the previous cpu, this doesn't look exactly
   right even if minor.

   Change the code to kfree() in the already-registered case, this case
   is unlikely anyway so the extra kmalloc_node() shouldn't hurt but
   looke more correct and clean.

2. use the plain list_for_each_entry() instead of _safe() to scan
   listeners->list.

3. Remove the unneeded INIT_LIST_HEAD(&s->list), we are going to
   list_add(&s->list).

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Vasiliy Kulikov <segoon@openwall.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Reviewed-by: Jerome Marchand <jmarchan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
13 years agortc-omap: fix initialization of control register
Daniel Glöckner [Wed, 3 Aug 2011 23:21:02 +0000 (16:21 -0700)]
rtc-omap: fix initialization of control register

As the comment explains, the intention of the code is to clear the
OMAP_RTC_CTRL_MODE_12_24 bit, but instead it only clears the
OMAP_RTC_CTRL_SPLIT and OMAP_RTC_CTRL_AUTO_COMP bits, which should be
kept.  OMAP_RTC_CTRL_DISABLE, OMAP_RTC_CTRL_SET_32_COUNTER,
OMAP_RTC_CTRL_TEST, and OMAP_RTC_CTRL_ROUND_30S are also better off
being cleared.

Signed-off-by: Daniel Glöckner <dg@emlix.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
13 years agofault-injection: add ability to export fault_attr in arbitrary directory
Akinobu Mita [Wed, 3 Aug 2011 23:21:01 +0000 (16:21 -0700)]
fault-injection: add ability to export fault_attr in arbitrary directory

init_fault_attr_dentries() is used to export fault_attr via debugfs.
But it can only export it in debugfs root directory.

Per Forlin is working on mmc_fail_request which adds support to inject
data errors after a completed host transfer in MMC subsystem.

The fault_attr for mmc_fail_request should be defined per mmc host and
export it in debugfs directory per mmc host like
/sys/kernel/debug/mmc0/mmc_fail_request.

init_fault_attr_dentries() doesn't help for mmc_fail_request.  So this
introduces fault_create_debugfs_attr() which is able to create a
directory in the arbitrary directory and replace
init_fault_attr_dentries().

[akpm@linux-foundation.org: extraneous semicolon, per Randy]
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Tested-by: Per Forlin <per.forlin@linaro.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
13 years agoext4: use kzalloc in ext4_kzalloc()
Mathias Krause [Wed, 3 Aug 2011 18:57:11 +0000 (14:57 -0400)]
ext4: use kzalloc in ext4_kzalloc()

Commit 9933fc0i (ext4: introduce ext4_kvmalloc(), ext4_kzalloc(), and
ext4_kvfree()) intruduced wrappers around k*alloc/vmalloc but introduced
a typo for ext4_kzalloc() by not using kzalloc() but kmalloc().

Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
13 years agoMerge branch 'apei' into apei-release
Len Brown [Wed, 3 Aug 2011 15:30:42 +0000 (11:30 -0400)]
Merge branch 'apei' into apei-release

Some trivial conflicts due to other various merges
adding to the end of common lists sooner than this one.

arch/ia64/Kconfig
arch/powerpc/Kconfig
arch/x86/Kconfig
lib/Kconfig
lib/Makefile

Signed-off-by: Len Brown <len.brown@intel.com>
13 years agoACPI, APEI, EINJ Param support is disabled by default
Huang Ying [Wed, 20 Jul 2011 08:09:29 +0000 (16:09 +0800)]
ACPI, APEI, EINJ Param support is disabled by default

EINJ parameter support is only usable for some specific BIOS.
Originally, it is expected to have no harm for BIOS does not support
it.  But now, we found it will cause issue (memory overwriting) for
some BIOS.  So param support is disabled by default and only enabled
when newly added module parameter named "param_extension" is
explicitly specified.

Signed-off-by: Huang Ying <ying.huang@intel.com>
Cc: Matthew Garrett <mjg@redhat.com>
Acked-by: Don Zickus <dzickus@redhat.com>
Acked-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
13 years agoAPEI GHES: 32-bit buildfix
Len Brown [Tue, 2 Aug 2011 22:00:21 +0000 (18:00 -0400)]
APEI GHES: 32-bit buildfix

drivers/acpi/apei/ghes.c:542: warning: integer overflow in expression
drivers/acpi/apei/ghes.c:619: warning: integer overflow in expression

ghes.c:(.text+0x46289): undefined reference to `__udivdi3'
  in function ghes_estatus_cache_add().

Reported-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Len Brown <len.brown@intel.com>
13 years agoACPI: APEI build fix
Len Brown [Sat, 16 Jul 2011 22:14:21 +0000 (18:14 -0400)]
ACPI: APEI build fix

as GHES is optional...

When # CONFIG_ACPI_APEI_GHES is not set:

(.init.text+0x4c22): undefined reference to `ghes_disable'

Reported-by: Randy Dunlap <rdunlap@xenotime.net>
Acked-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Len Brown <len.brown@intel.com>
13 years agoACPI, APEI, GHES: Add hardware memory error recovery support
Huang Ying [Wed, 13 Jul 2011 05:14:28 +0000 (13:14 +0800)]
ACPI, APEI, GHES: Add hardware memory error recovery support

memory_failure_queue() is called when recoverable memory errors are
notified by firmware to do the recovery work.

Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
13 years agoHWPoison: add memory_failure_queue()
Huang Ying [Wed, 13 Jul 2011 05:14:27 +0000 (13:14 +0800)]
HWPoison: add memory_failure_queue()

memory_failure() is the entry point for HWPoison memory error
recovery.  It must be called in process context.  But commonly
hardware memory errors are notified via MCE or NMI, so some delayed
execution mechanism must be used.  In MCE handler, a work queue + ring
buffer mechanism is used.

In addition to MCE, now APEI (ACPI Platform Error Interface) GHES
(Generic Hardware Error Source) can be used to report memory errors
too.  To add support to APEI GHES memory recovery, a mechanism similar
to that of MCE is implemented.  memory_failure_queue() is the new
entry point that can be called in IRQ context.  The next step is to
make MCE handler uses this interface too.

Signed-off-by: Huang Ying <ying.huang@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
13 years agoACPI, APEI, GHES, Error records content based throttle
Huang Ying [Wed, 13 Jul 2011 05:14:26 +0000 (13:14 +0800)]
ACPI, APEI, GHES, Error records content based throttle

printk is used by GHES to report hardware errors.  Ratelimit is
enforced on the printk to avoid too many hardware error reports in
kernel log.  Because there may be thousands or even millions of
corrected hardware errors during system running.

Currently, a simple scheme is used.  That is, the total number of
hardware error reporting is ratelimited.  This may cause some issues
in practice.

For example, there are two kinds of hardware errors occurred in
system.  One is corrected memory error, because the fault memory
address is accessed frequently, there may be hundreds error report
per-second.  The other is corrected PCIe AER error, it will be
reported once per-second.  Because they share one ratelimit control
structure, it is highly possible that only memory error is reported.

To avoid the above issue, an error record content based throttle
algorithm is implemented in the patch.  Where after the first
successful reporting, all error records that are same are throttled for
some time, to let other kinds of error records have the opportunity to
be reported.

In above example, the memory errors will be throttled for some time,
after being printked.  Then the PCIe AER error will be printked
successfully.

Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
13 years agoACPI, APEI, GHES, printk support for recoverable error via NMI
Huang Ying [Wed, 13 Jul 2011 05:14:25 +0000 (13:14 +0800)]
ACPI, APEI, GHES, printk support for recoverable error via NMI

Some APEI GHES recoverable errors are reported via NMI, but printk is
not safe in NMI context.

To solve the issue, a lock-less memory allocator is used to allocate
memory in NMI handler, save the error record into the allocated
memory, put the error record into a lock-less list.  On the other
hand, an irq_work is used to delay the operation from NMI context to
IRQ context.  The irq_work IRQ handler will remove nodes from
lock-less list, printk the error record and do some further processing
include recovery operation, then free the memory.

Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
13 years agolib, Make gen_pool memory allocator lockless
Huang Ying [Wed, 13 Jul 2011 05:14:24 +0000 (13:14 +0800)]
lib, Make gen_pool memory allocator lockless

This version of the gen_pool memory allocator supports lockless
operation.

This makes it safe to use in NMI handlers and other special
unblockable contexts that could otherwise deadlock on locks.  This is
implemented by using atomic operations and retries on any conflicts.
The disadvantage is that there may be livelocks in extreme cases.  For
better scalability, one gen_pool allocator can be used for each CPU.

The lockless operation only works if there is enough memory available.
If new memory is added to the pool a lock has to be still taken.  So
any user relying on locklessness has to ensure that sufficient memory
is preallocated.

The basic atomic operation of this allocator is cmpxchg on long.  On
architectures that don't have NMI-safe cmpxchg implementation, the
allocator can NOT be used in NMI handler.  So code uses the allocator
in NMI handler should depend on CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG.

Signed-off-by: Huang Ying <ying.huang@intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
13 years agolib, Add lock-less NULL terminated single list
Huang Ying [Wed, 13 Jul 2011 05:14:23 +0000 (13:14 +0800)]
lib, Add lock-less NULL terminated single list

Cmpxchg is used to implement adding new entry to the list, deleting
all entries from the list, deleting first entry of the list and some
other operations.

Because this is a single list, so the tail can not be accessed in O(1).

If there are multiple producers and multiple consumers, llist_add can
be used in producers and llist_del_all can be used in consumers.  They
can work simultaneously without lock.  But llist_del_first can not be
used here.  Because llist_del_first depends on list->first->next does
not changed if list->first is not changed during its operation, but
llist_del_first, llist_add, llist_add (or llist_del_all, llist_add,
llist_add) sequence in another consumer may violate that.

If there are multiple producers and one consumer, llist_add can be
used in producers and llist_del_all or llist_del_first can be used in
the consumer.

This can be summarized as follow:

           |   add    | del_first |  del_all
 add       |    -     |     -     |     -
 del_first |          |     L     |     L
 del_all   |          |           |     -

Where "-" stands for no lock is needed, while "L" stands for lock is
needed.

The list entries deleted via llist_del_all can be traversed with
traversing function such as llist_for_each etc.  But the list entries
can not be traversed safely before deleted from the list.  The order
of deleted entries is from the newest to the oldest added one.  If you
want to traverse from the oldest to the newest, you must reverse the
order by yourself before traversing.

The basic atomic operation of this list is cmpxchg on long.  On
architectures that don't have NMI-safe cmpxchg implementation, the
list can NOT be used in NMI handler.  So code uses the list in NMI
handler should depend on CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG.

Signed-off-by: Huang Ying <ying.huang@intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
13 years agoAdd Kconfig option ARCH_HAVE_NMI_SAFE_CMPXCHG
Huang Ying [Wed, 13 Jul 2011 05:14:22 +0000 (13:14 +0800)]
Add Kconfig option ARCH_HAVE_NMI_SAFE_CMPXCHG

cmpxchg() is widely used by lockless code, including NMI-safe lockless
code.  But on some architectures, the cmpxchg() implementation is not
NMI-safe, on these architectures the lockless code may need a
spin_trylock_irqsave() based implementation.

This patch adds a Kconfig option: ARCH_HAVE_NMI_SAFE_CMPXCHG, so that
NMI-safe lockless code can depend on it or provide different
implementation according to it.

On many architectures, cmpxchg is only NMI-safe for several specific
operand sizes. So, ARCH_HAVE_NMI_SAFE_CMPXCHG define in this patch
only guarantees cmpxchg is NMI-safe for sizeof(unsigned long).

Signed-off-by: Huang Ying <ying.huang@intel.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Acked-by: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Chris Metcalf <cmetcalf@tilera.com>
Acked-by: Richard Henderson <rth@twiddle.net>
CC: Mikael Starvik <starvik@axis.com>
Acked-by: David Howells <dhowells@redhat.com>
CC: Yoshinori Sato <ysato@users.sourceforge.jp>
CC: Tony Luck <tony.luck@intel.com>
CC: Hirokazu Takata <takata@linux-m32r.org>
CC: Geert Uytterhoeven <geert@linux-m68k.org>
CC: Michal Simek <monstr@monstr.eu>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
CC: Kyle McMartin <kyle@mcmartin.ca>
CC: Martin Schwidefsky <schwidefsky@de.ibm.com>
CC: Chen Liqin <liqin.chen@sunplusct.com>
CC: "David S. Miller" <davem@davemloft.net>
CC: Ingo Molnar <mingo@redhat.com>
CC: Chris Zankel <chris@zankel.net>
Signed-off-by: Len Brown <len.brown@intel.com>
13 years agodt: add of_alias_scan and of_alias_get_id
Shawn Guo [Wed, 3 Aug 2011 10:28:14 +0000 (11:28 +0100)]
dt: add of_alias_scan and of_alias_get_id

The patch adds function of_alias_scan to populate a global lookup
table with the properties of 'aliases' node and function
of_alias_get_id for drivers to find alias id from the lookup table.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
[grant.likely: add locking and rework parse loop]
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
13 years agotcm_fc: Handle DDP/SW fc_frame_payload_get failures in ft_recv_write_data
Kiran Patil [Wed, 3 Aug 2011 09:20:01 +0000 (09:20 +0000)]
tcm_fc: Handle DDP/SW fc_frame_payload_get failures in ft_recv_write_data

Problem: HW DDP context was not invalidated in case of ABORTS, etc...
This leads to the problem where memory pages which are used for DDP
as user descriptor could get reused for some other purpose (such as to
satisfy new memory allocation request either by kernel or user mode threads)
and since HW DDP context was not invalidated, HW continue to write to
those pages, hence causing memory corruption.

Fix: Either on incoming ABORTS or due to exchange time out, allowed the
target to cleanup HW DDP context if it was setup for respective ft_cmd.
Added new function to perform this cleanup, furthur it can be enhanced
for other cleanup activity.  Fix ft_recv_write_data() to properly handle
fc_frame_payload_get to return pointer to payload if it exist. If there is
no payload which is most common case (+ve case in case if DDP is working
as expected, it will return NULL. Yes, scope of buf is limited to printk.
Invalidation of HW context (which is done inside ft_invl_hw_context() is
necessary in SUCCESS and FAILURE case of DDP. Hence invalidation is DONE
as long as there was DDP setup (whether it worked correctly or not,

NOTE: For some reason, if there is any error w.r.t DDP such as out of
order packet reception, HW simply post the full packet in rx queue.

Signed-off-by: Kiran Patil <kiran.patil@intel.com>
Cc: Robert W Love <robert.w.love@intel.com>
Signed-off-by: Nicholas A. Bellinger <nab@linux-iscsi.org>
13 years agoMerge branch 'pstore-efi' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6
Linus Torvalds [Wed, 3 Aug 2011 07:18:39 +0000 (21:18 -1000)]
Merge branch 'pstore-efi' of git://git./linux/kernel/git/aegl/linux-2.6

* 'pstore-efi' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6:
  efivars: fix warnings when CONFIG_PSTORE=n

13 years agoMerge branch 'tools-release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb...
Linus Torvalds [Wed, 3 Aug 2011 07:17:39 +0000 (21:17 -1000)]
Merge branch 'tools-release' of git://git./linux/kernel/git/lenb/linux-idle-2.6

* 'tools-release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-idle-2.6:
  tools/power turbostat: fit output into 80 columns on snb-ep
  tools/power x86_energy_perf_policy: fix print of uninitialized string

13 years agoMerge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux...
Linus Torvalds [Wed, 3 Aug 2011 07:17:02 +0000 (21:17 -1000)]
Merge branch 'release' of git://git./linux/kernel/git/lenb/linux-acpi-2.6

* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6: (28 commits)
  ACPI:  delete stale reference in kernel-parameters.txt
  ACPI: add missing _OSI strings
  ACPI: remove NID_INVAL
  thermal: make THERMAL_HWMON implementation fully internal
  thermal: split hwmon lookup to a separate function
  thermal: hide CONFIG_THERMAL_HWMON
  ACPI print OSI(Linux) warning only once
  ACPI: DMI workaround for Asus A8N-SLI Premium and Asus A8N-SLI DELUX
  ACPI / Battery: propagate sysfs error in acpi_battery_add()
  ACPI / Battery: avoid acpi_battery_add() use-after-free
  ACPI: introduce "acpi_rsdp=" parameter for kdump
  ACPI: constify ops structs
  ACPI: fix CONFIG_X86_REROUTE_FOR_BROKEN_BOOT_IRQS
  ACPI: fix 80 char overflow
  ACPI / Battery: Resolve the race condition in the sysfs_remove_battery()
  ACPI / Battery: Add the check before refresh sysfs in the battery_notify()
  ACPI / Battery: Add the hibernation process in the battery_notify()
  ACPI / Battery: Rename acpi_battery_quirks2 with acpi_battery_quirks
  ACPI / Battery: Change 16-bit signed negative battery current into correct value
  ACPI / Battery: Add the power unit macro
  ...

13 years agoMerge git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile
Linus Torvalds [Wed, 3 Aug 2011 07:16:11 +0000 (21:16 -1000)]
Merge git://git./linux/kernel/git/cmetcalf/linux-tile

* git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile:
  arch/tile/mm/init.c: trivial: use BUG_ON
  arch/tile: remove useless set_fixmap_nocache() macro
  arch/tile: add hypervisor-based character driver for SPI flash ROM
  ioctl-number.txt: add the tile hardwall ioctl range
  tile: use generic-y format for one-line asm-generic headers
  clocksource: tile: convert to use clocksource_register_hz

13 years agoMerge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs...
Linus Torvalds [Wed, 3 Aug 2011 07:14:05 +0000 (21:14 -1000)]
Merge branch 'for-linus' of git://git./linux/kernel/git/mason/btrfs-unstable

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable: (31 commits)
  Btrfs: don't call writepages from within write_full_page
  Btrfs: Remove unused variable 'last_index' in file.c
  Btrfs: clean up for find_first_extent_bit()
  Btrfs: clean up for wait_extent_bit()
  Btrfs: clean up for insert_state()
  Btrfs: remove unused members from struct extent_state
  Btrfs: clean up code for merging extent maps
  Btrfs: clean up code for extent_map lookup
  Btrfs: clean up search_extent_mapping()
  Btrfs: remove redundant code for dir item lookup
  Btrfs: make acl functions really no-op if acl is not enabled
  Btrfs: remove remaining ref-cache code
  Btrfs: remove a BUG_ON() in btrfs_commit_transaction()
  Btrfs: use wait_event()
  Btrfs: check the nodatasum flag when writing compressed files
  Btrfs: copy string correctly in INO_LOOKUP ioctl
  Btrfs: don't print the leaf if we had an error
  btrfs: make btrfs_set_root_node void
  Btrfs: fix oops while writing data to SSD partitions
  Btrfs: Protect the readonly flag of block group
  ...

Fix up trivial conflicts (due to acl and writeback cleanups) in
 - fs/btrfs/acl.c
 - fs/btrfs/ctree.h
 - fs/btrfs/extent_io.c

13 years agoMerge branch 'devicetree/next' of git://git.secretlab.ca/git/linux-2.6
Linus Torvalds [Wed, 3 Aug 2011 06:49:57 +0000 (20:49 -1000)]
Merge branch 'devicetree/next' of git://git.secretlab.ca/git/linux-2.6

* 'devicetree/next' of git://git.secretlab.ca/git/linux-2.6:
  MAINTAINERS: Add keyword match for of_match_table to device tree section
  of: constify property name parameters for helper functions
  input: xilinx_ps2: Add missing of_address.h header
  of: address: use resource_size helper

13 years agoMerge branch 'spi/next' of git://git.secretlab.ca/git/linux-2.6
Linus Torvalds [Wed, 3 Aug 2011 06:49:38 +0000 (20:49 -1000)]
Merge branch 'spi/next' of git://git.secretlab.ca/git/linux-2.6

* 'spi/next' of git://git.secretlab.ca/git/linux-2.6:
  spi/pl022: remove function cannot exit

13 years agoMerge git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dm
Linus Torvalds [Wed, 3 Aug 2011 06:49:21 +0000 (20:49 -1000)]
Merge git://git./linux/kernel/git/agk/linux-2.6-dm

* git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dm: (34 commits)
  dm table: set flush capability based on underlying devices
  dm crypt: optionally support discard requests
  dm raid: add md raid1 support
  dm raid: support metadata devices
  dm raid: add write_mostly parameter
  dm raid: add region_size parameter
  dm raid: improve table parameters documentation
  dm ioctl: forbid multiple device specifiers
  dm ioctl: introduce __get_dev_cell
  dm ioctl: fill in device parameters in more ioctls
  dm flakey: add corrupt_bio_byte feature
  dm flakey: add drop_writes
  dm flakey: support feature args
  dm flakey: use dm_target_offset and support discards
  dm table: share target argument parsing functions
  dm snapshot: skip reading origin when overwriting complete chunk
  dm: ignore merge_bvec for snapshots when safe
  dm table: clean dm_get_device and move exports
  dm raid: tidy includes
  dm ioctl: prevent empty message
  ...

13 years agoMerge git://git.kernel.org/pub/scm/linux/kernel/git/wim/linux-watchdog
Linus Torvalds [Wed, 3 Aug 2011 06:48:47 +0000 (20:48 -1000)]
Merge git://git./linux/kernel/git/wim/linux-watchdog

* git://git.kernel.org/pub/scm/linux/kernel/git/wim/linux-watchdog:
  watchdog: Cleanup WATCHDOG_CORE help text
  watchdog: Fix POST failure on ASUS P5N32-E SLI and similar boards
  watchdog: shwdt: fix usage of mod_timer

13 years agoMerge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6
Linus Torvalds [Wed, 3 Aug 2011 06:48:22 +0000 (20:48 -1000)]
Merge branch 'for-linus' of git://git./linux/kernel/git/tiwai/sound-2.6

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6:
  ALSA: asihpi - Clarify adapter index validity check
  ALSA: asihpi - Don't leak firmware if mem alloc fails
  ALSA: rtctimer.c needs module.h
  ASoC: Fix txx9aclc.c build
  ALSA: hdspm - Add firmware revision 0xcc for RME MADI
  ALSA: hdspm - Fix reported external sample rate on RME MADI and MADIface
  ALSA: hdspm - Provide MADI speed mode selector on RME MADI and MADIface
  ALSA: sound/core/pcm_compat.c: adjust array index

13 years agotools/power turbostat: fit output into 80 columns on snb-ep
Len Brown [Sun, 31 Jul 2011 22:19:33 +0000 (18:19 -0400)]
tools/power turbostat: fit output into 80 columns on snb-ep

Reduce columns for package number to 1.
If you can afford more than 9 packages,
you can also afford a terminal with more than 80 columns:-)

Also shave a column also off the package C-states

Signed-off-by: Len Brown <len.brown@intel.com>
13 years agoefivars: fix warnings when CONFIG_PSTORE=n
Tony Luck [Tue, 2 Aug 2011 22:08:30 +0000 (15:08 -0700)]
efivars: fix warnings when CONFIG_PSTORE=n

drivers/firmware/efivars.c:161: warning: â€˜utf16_strlen’ defined but not used
utf16_strlen() is only used inside CONFIG_PSTORE - make this "static inline"
to shut the compiler up [thanks to hpa for the suggestion].

drivers/firmware/efivars.c:602: warning: initialization from incompatible pointer type
Between v1 and v2 of this patch series we decided to make the "part" number
unsigned - but missed fixing the stub version of efi_pstore_write()

Acked-by: Matthew Garrett <mjg@redhat.com>
Acked-by: Mike Waychison <mikew@google.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
13 years agoMerge branches 'acpica', 'battery', 'boot-irqs', 'bz-24492', 'bz-9528', 'from-akpm...
Len Brown [Tue, 2 Aug 2011 21:22:09 +0000 (17:22 -0400)]
Merge branches 'acpica', 'battery', 'boot-irqs', 'bz-24492', 'bz-9528', 'from-akpm', 'kexec-param' and 'misc' into release

Conflicts:
Documentation/kernel-parameters.txt

Signed-off-by: Len Brown <len.brown@intel.com>
13 years agoACPI: delete stale reference in kernel-parameters.txt
Len Brown [Tue, 2 Aug 2011 21:15:33 +0000 (17:15 -0400)]
ACPI:  delete stale reference in kernel-parameters.txt

Says for acpi=
                        See also Documentation/power/pm.txt, pci=noacpi

but this file does not exist

Reported-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Len Brown <len.brown@intel.com>
13 years agoarch/tile/mm/init.c: trivial: use BUG_ON
Julia Lawall [Tue, 2 Aug 2011 10:35:04 +0000 (12:35 +0200)]
arch/tile/mm/init.c: trivial: use BUG_ON

Use BUG_ON(x) rather than if(x) BUG();

The semantic patch that fixes this problem is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@ identifier x; @@
-if (x) BUG();
+BUG_ON(x);

@@ identifier x; @@
-if (!x) BUG();
+BUG_ON(!x);
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
13 years agoMerge tag 'v3.0' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux...
Chris Metcalf [Tue, 2 Aug 2011 20:14:02 +0000 (16:14 -0400)]
Merge tag 'v3.0' of git://git./linux/kernel/git/torvalds/linux-2.6 into for-linus

13 years agoACPI: add missing _OSI strings
Shaohua Li [Thu, 28 Jul 2011 20:48:43 +0000 (13:48 -0700)]
ACPI: add missing _OSI strings

Linux supports some optional features, but it should notify the BIOS about
them via the _OSI method.  Currently Linux doesn't notify any, which might
make such features not work because the BIOS doesn't know about them.

Jarosz has a system which needs this to make ACPI processor aggregator
device work.

Reported-by: "Jarosz, Sebastian" <sebastian.jarosz@intel.com>
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Acked-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
13 years agoACPI: remove NID_INVAL
David Rientjes [Thu, 28 Jul 2011 20:48:43 +0000 (13:48 -0700)]
ACPI: remove NID_INVAL

b552a8c56db8 ("ACPI: remove NID_INVAL") removed the left over uses of
NID_INVAL, but didn't actually remove the definition.  Remove it.

Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
13 years agothermal: make THERMAL_HWMON implementation fully internal
Jean Delvare [Thu, 28 Jul 2011 20:48:42 +0000 (13:48 -0700)]
thermal: make THERMAL_HWMON implementation fully internal

THERMAL_HWMON is implemented inside the thermal_sys driver and has no
effect on drivers implementing thermal zones, so they shouldn't see
anything related to it in <linux/thermal.h>.  Making the THERMAL_HWMON
implementation fully internal has two advantages beyond the cleaner
design:

* This avoids rebuilding all thermal drivers if the THERMAL_HWMON
  implementation changes, or if CONFIG_THERMAL_HWMON gets enabled or
  disabled.

* This avoids breaking the thermal kABI in these cases too, which should
  make distributions happy.

The only drawback I can see is slightly higher memory fragmentation, as
the number of kzalloc() calls will increase by one per thermal zone.  But
I doubt it will be a problem in practice, as I've never seen a system with
more than two thermal zones.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Rene Herman <rene.herman@gmail.com>
Acked-by: Guenter Roeck <guenter.roeck@ericsson.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
13 years agothermal: split hwmon lookup to a separate function
Jean Delvare [Thu, 28 Jul 2011 20:48:41 +0000 (13:48 -0700)]
thermal: split hwmon lookup to a separate function

We'll soon need to reuse it.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Rene Herman <rene.herman@gmail.com>
Acked-by: Guenter Roeck <guenter.roeck@ericsson.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
13 years agothermal: hide CONFIG_THERMAL_HWMON
Jean Delvare [Thu, 28 Jul 2011 20:48:40 +0000 (13:48 -0700)]
thermal: hide CONFIG_THERMAL_HWMON

It's about time to revert 16d752397301b9 ("thermal: Create
CONFIG_THERMAL_HWMON=n").  Anybody running a kernel >= 2.6.40 would also
be running a recent enough version of lm-sensors.

Actually having CONFIG_THERMAL_HWMON is pretty convenient so instead of
dropping it, we keep it but hide it.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Rene Herman <rene.herman@gmail.com>
Acked-by: Guenter Roeck <guenter.roeck@ericsson.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
13 years agoMAINTAINERS: Add keyword match for of_match_table to device tree section
Mark Brown [Tue, 2 Aug 2011 05:13:26 +0000 (14:13 +0900)]
MAINTAINERS: Add keyword match for of_match_table to device tree section

If a patch is working with an of_match_table it's probably adding an OF
binding to a driver in which case the binding ought to be reviewed by the
device tree folks to make sure that things like the device matches are set
up correctly.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
13 years agoof: constify property name parameters for helper functions
Jamie Iles [Tue, 2 Aug 2011 14:45:07 +0000 (15:45 +0100)]
of: constify property name parameters for helper functions

The helper functions for reading u32 integers, u32 arrays and strings
should have the property name as a const pointer.

Cc: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Jamie Iles <jamie@jamieiles.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
13 years agospi/pl022: remove function cannot exit
Linus Walleij [Tue, 2 Aug 2011 09:29:24 +0000 (11:29 +0200)]
spi/pl022: remove function cannot exit

The remove function in the PL022 driver cannot abort the remove
function any way, so restructure the code so as not to make that
assumption. Remove will now proceed no matter whether it can
stop the transfer queue or not.

Reported-by: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
13 years agodm table: set flush capability based on underlying devices
Mike Snitzer [Tue, 2 Aug 2011 11:32:08 +0000 (12:32 +0100)]
dm table: set flush capability based on underlying devices

DM has always advertised both REQ_FLUSH and REQ_FUA flush capabilities
regardless of whether or not a given DM device's underlying devices
also advertised a need for them.

Block's flush-merge changes from 2.6.39 have proven to be more costly
for DM devices.  Performance regressions have been reported even when
DM's underlying devices do not advertise that they have a write cache.

Fix the performance regressions by configuring a DM device's flushing
capabilities based on those of the underlying devices' capabilities.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
13 years agodm crypt: optionally support discard requests
Milan Broz [Tue, 2 Aug 2011 11:32:08 +0000 (12:32 +0100)]
dm crypt: optionally support discard requests

Add optional parameter field to dmcrypt table and support
"allow_discards" option.

Discard requests bypass crypt queue processing. Bio is simple remapped
to underlying device.

Note that discard will be never enabled by default because of security
consequences.  It is up to the administrator to enable it for encrypted
devices.

(Note that userspace cryptsetup does not understand new optional
parameters yet.  Support for this will come later.  Until then, you
should use 'dmsetup' to enable and disable this.)

Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
13 years agodm raid: add md raid1 support
Jonathan Brassow [Tue, 2 Aug 2011 11:32:07 +0000 (12:32 +0100)]
dm raid: add md raid1 support

Support the MD RAID1 personality through dm-raid.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
13 years agodm raid: support metadata devices
Jonathan Brassow [Tue, 2 Aug 2011 11:32:07 +0000 (12:32 +0100)]
dm raid: support metadata devices

Add the ability to parse and use metadata devices to dm-raid.  Although
not strictly required, without the metadata devices, many features of
RAID are unavailable.  They are used to store a superblock and bitmap.

The role, or position in the array, of each device must be recorded in
its superblock.  This is to help with fault handling, array reshaping,
and sanity checks.  RAID 4/5/6 devices must be loaded in a specific order:
in this way, the 'array_position' field helps validate the correctness
of the mapping when it is loaded.  It can be used during reshaping to
identify which devices are added/removed.  Fault handling is impossible
without this field.  For example, when a device fails it is recorded in
the superblock.  If this is a RAID1 device and the offending device is
removed from the array, there must be a way during subsequent array
assembly to determine that the failed device was the one removed.  This
is done by correlating the 'array_position' field and the bit-field
variable 'failed_devices'.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
13 years agodm raid: add write_mostly parameter
Jonathan Brassow [Tue, 2 Aug 2011 11:32:07 +0000 (12:32 +0100)]
dm raid: add write_mostly parameter

Add the write_mostly parameter to RAID1 dm-raid tables.

This allows the user to set the WriteMostly flag on a RAID1 device that
should normally be avoided for read I/O.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
13 years agodm raid: add region_size parameter
Jonathan Brassow [Tue, 2 Aug 2011 11:32:07 +0000 (12:32 +0100)]
dm raid: add region_size parameter

Allow the user to specify the region_size.

Ensures that the supplied value meets md's constraints, viz. the number of
regions does not exceed 2^21.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
13 years agodm raid: improve table parameters documentation
Jonathan Brassow [Tue, 2 Aug 2011 11:32:06 +0000 (12:32 +0100)]
dm raid: improve table parameters documentation

Add more information about some dm-raid table parameters and clarify how
parameters are printed when 'dmsetup table' is issued.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
13 years agodm ioctl: forbid multiple device specifiers
Mikulas Patocka [Tue, 2 Aug 2011 11:32:06 +0000 (12:32 +0100)]
dm ioctl: forbid multiple device specifiers

Exactly one of name, uuid or device must be specified when referencing
an existing device.  This removes the ambiguity (risking the wrong
device being updated) if two conflicting parameters were specified.
Previously one parameter got used and any others were ignored silently.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
13 years agodm ioctl: introduce __get_dev_cell
Mikulas Patocka [Tue, 2 Aug 2011 11:32:06 +0000 (12:32 +0100)]
dm ioctl: introduce __get_dev_cell

Move logic to find device based on major/minor number to a separate
function __get_dev_cell (similar to __get_uuid_cell and __get_name_cell).
This makes the function __find_device_hash_cell more straightforward.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
13 years agodm ioctl: fill in device parameters in more ioctls
Mikulas Patocka [Tue, 2 Aug 2011 11:32:06 +0000 (12:32 +0100)]
dm ioctl: fill in device parameters in more ioctls

Move parameter filling from find_device to __find_device_hash_cell.

This patch causes ioctls using __find_device_hash_cell
(DM_DEV_REMOVE_CMD, DM_DEV_SUSPEND_CMD - resume, DM_TABLE_CLEAR_CMD)
to return device parameters, bringing them into line with the other
ioctls.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
13 years agodm flakey: add corrupt_bio_byte feature
Mike Snitzer [Tue, 2 Aug 2011 11:32:06 +0000 (12:32 +0100)]
dm flakey: add corrupt_bio_byte feature

Add corrupt_bio_byte feature to simulate corruption by overwriting a byte at a
specified position with a specified value during intervals when the device is
"down".

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
13 years agodm flakey: add drop_writes
Mike Snitzer [Tue, 2 Aug 2011 11:32:05 +0000 (12:32 +0100)]
dm flakey: add drop_writes

Add 'drop_writes' option to drop writes silently while the
device is 'down'.  Reads are not touched.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
13 years agodm flakey: support feature args
Mike Snitzer [Tue, 2 Aug 2011 11:32:05 +0000 (12:32 +0100)]
dm flakey: support feature args

Add the ability to specify arbitrary feature flags when creating a
flakey target.  This code uses the same target argument helpers that
the multipath target does.

Also remove the superfluous 'dm-flakey' prefixes from the error messages,
as they already contain the prefix 'flakey'.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
13 years agodm flakey: use dm_target_offset and support discards
Mike Snitzer [Tue, 2 Aug 2011 11:32:05 +0000 (12:32 +0100)]
dm flakey: use dm_target_offset and support discards

Use dm_target_offset() and support discards.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
13 years agodm table: share target argument parsing functions
Mike Snitzer [Tue, 2 Aug 2011 11:32:04 +0000 (12:32 +0100)]
dm table: share target argument parsing functions

Move multipath target argument parsing code into dm-table so other
targets can share it.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
13 years agodm snapshot: skip reading origin when overwriting complete chunk
Mikulas Patocka [Tue, 2 Aug 2011 11:32:04 +0000 (12:32 +0100)]
dm snapshot: skip reading origin when overwriting complete chunk

If we write a full chunk in the snapshot, skip reading the origin device
because the whole chunk will be overwritten anyway.

This patch changes the snapshot write logic when a full chunk is written.
In this case:
  1. allocate the exception
  2. dispatch the bio (but don't report the bio completion to device mapper)
  3. write the exception record
  4. report bio completed

Callbacks must be done through the kcopyd thread, because callbacks must not
race with each other.  So we create two new functions:

  dm_kcopyd_prepare_callback: allocate a job structure and prepare the callback.
  (This function must not be called from interrupt context.)

  dm_kcopyd_do_callback: submit callback.
  (This function may be called from interrupt context.)

Performance test (on snapshots with 4k chunk size):
  without the patch:
    non-direct-io sequential write (dd):    17.7MB/s
    direct-io sequential write (dd):        20.9MB/s
    non-direct-io random write (mkfs.ext2): 0.44s

  with the patch:
    non-direct-io sequential write (dd):    26.5MB/s
    direct-io sequential write (dd):        33.2MB/s
    non-direct-io random write (mkfs.ext2): 0.27s

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
13 years agodm: ignore merge_bvec for snapshots when safe
Mikulas Patocka [Tue, 2 Aug 2011 11:32:04 +0000 (12:32 +0100)]
dm: ignore merge_bvec for snapshots when safe

Add a new flag DMF_MERGE_IS_OPTIONAL to struct mapped_device to indicate
whether the device can accept bios larger than the size its merge
function returns.  When set, use this to send large bios to snapshots
which can split them if necessary.  Snapshot I/O may be significantly
fragmented and this approach seems to improve peformance.

Before the patch, dm_set_device_limits restricted bio size to page size
if the underlying device had a merge function and the target didn't
provide a merge function.  After the patch, dm_set_device_limits
restricts bio size to page size if the underlying device has a merge
function, doesn't have DMF_MERGE_IS_OPTIONAL flag and the target doesn't
provide a merge function.

The snapshot target can't provide a merge function because when the merge
function is called, it is impossible to determine where the bio will be
remapped.  Previously this led us to impose a 4k limit, which we can
now remove if the snapshot store is located on a device without a merge
function.  Together with another patch for optimizing full chunk writes,
it improves performance from 29MB/s to 40MB/s when writing to the
filesystem on snapshot store.

If the snapshot store is placed on a non-dm device with a merge function
(such as md-raid), device mapper still limits all bios to page size.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
13 years agodm table: clean dm_get_device and move exports
Mike Snitzer [Tue, 2 Aug 2011 11:32:04 +0000 (12:32 +0100)]
dm table: clean dm_get_device and move exports

There is no need for __table_get_device to be factored out.
Also move the exports to the end of their respective functions.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
13 years agodm raid: tidy includes
Alasdair G Kergon [Tue, 2 Aug 2011 11:32:03 +0000 (12:32 +0100)]
dm raid: tidy includes

A dm target only needs to use include/linux dm headers.

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
13 years agodm ioctl: prevent empty message
Alasdair G Kergon [Tue, 2 Aug 2011 11:32:03 +0000 (12:32 +0100)]
dm ioctl: prevent empty message

Detect invalid empty messages in core dm instead of requiring every target to
check this.

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
13 years agodm raid: cleanup parameter handling
Jonathan Brassow [Tue, 2 Aug 2011 11:32:03 +0000 (12:32 +0100)]
dm raid: cleanup parameter handling

Re-order the parameters so they are handled consistently in the same order
where defined, parsed and output.

Only include rebuild parameters in the STATUSTYPE_TABLE output if they were
supplied in the original table line.

Correct the parameter count when outputting rebuild: there are two words,
not one.

Use case-independent checks for keywords (as in other device-mapper targets).

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
13 years agodm snapshot: style cleanups
Jonathan Brassow [Tue, 2 Aug 2011 11:32:03 +0000 (12:32 +0100)]
dm snapshot: style cleanups

Coding style cleanups.

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
13 years agodm snapshot: remove unused definitions
Mikulas Patocka [Tue, 2 Aug 2011 11:32:03 +0000 (12:32 +0100)]
dm snapshot: remove unused definitions

Remove a couple of unused #defines.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
13 years agodm kcopyd: remove nr_pages field from job structure
Mikulas Patocka [Tue, 2 Aug 2011 11:32:02 +0000 (12:32 +0100)]
dm kcopyd: remove nr_pages field from job structure

The nr_pages field in struct kcopyd_job is only used temporarily in
run_pages_job() to count the number of required pages.
We can use a local variable instead.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>