If we load the null_blk module with bs=8k we get following oops:
[ 3819.812190] BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
[ 3819.812387] IP: [<ffffffff81170aa5>] create_empty_buffers+0x28/0xaf
[ 3819.812527] PGD 219244067 PUD 215a06067 PMD 0
[ 3819.812640] Oops: 0000 [#1] SMP
[ 3819.812772] Modules linked in: null_blk(+)

 Fix that by resetting block size to PAGE_SIZE if it is greater than PAGE_SIZE
Reported-by: NSumanth <sumantk2@linux.vnet.ibm.com>
Signed-off-by: NRaghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Reviewed-by: NMatias Bjorling <m@bjorling.me>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

If power is removed during a secure erase, the drive will end up in a
security locked condition.  This patch causes the driver to identify,
log, and flag the security lock state.  IOs are prevented from
submission to the drive until the locked state is addressed with a
secure erase.

Bumped version number to reflect this capability.
Signed-off-by: NSam Bradshaw <sbradshaw@micron.com>
Signed-off-by: NAsai Thambi S P <asamymuthupa@micron.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

The mtip32xx driver makes a high order dma memory allocation to store a
command index table, some dedicated buffers, and a command header & SGL
blob.  This allocation can fail with a surprise insert under low &
fragmented memory conditions.

This patch breaks these regions up into separate low order allocations
and increases the maximum number of segments a single command SGL can
have.  We wanted to allow at least 256 segments for 1 MB direct IO.
Since the command header occupies the first 0x80 bytes of the SGL blob,
that meant we needed two 4k pages to contain the header and SGL.  The
two pages allow up to 504 SGL segments.
Signed-off-by: NSam Bradshaw <sbradshaw@micron.com>
Signed-off-by: NAsai Thambi S P <asamymuthupa@micron.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Merge branch 'for-jens' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/linux-block into for-3.14/drivers

Discard requests are ignored if the encryption is enabled for the given
loop device.  Update comment to match the code, and similar comments
elsewhere in the file.
Signed-off-by: NOlaf Hering <olaf@aepfle.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

pci_driver.probe should return a meaningful errno, not -1.

Cc: Jens Axboe <axboe@kernel.dk>
Cc: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

The test here can underflow so we pass bogus lengths to the hardware.
It's a static checker fix and I don't know the impact.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

The driver core clears the driver data to NULL after device_release or on
probe failure.  Thus, it is not needed to manually clear the device driver
data to NULL.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Use module_pci_driver() macro which makes the code smaller and simpler.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

In case reading of block 0 during open() fails, it is not the right thing
to let open() succeed.

Fix this by introducing FD_OPEN_SHOULD_FAIL_BIT flag, and setting it in
case the bio callback encounters an error while trying to read block 0.

As a bonus, this works around certain broken userspace (blkid), which is
not able to properly handle read()s returning IO errors. Hence be nice to
those, and bail out during open() already; if block 0 is not readable,
read()s are not going to provide any meaningful data anyway.
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Signed-off-by: NKent Overstreet <kmo@daterainc.com>

We need to return -EINTR after a split because we invalidated iterators
(and freed the btree node) - but if we were finished inserting, we don't
want to redo the traversal.
Signed-off-by: NKent Overstreet <kmo@daterainc.com>

When deciding what order to reuse buckets we take into account both the bucket's
priority (which indicates lru order) and also the amount of live data in that
bucket. The way they were scaled together wasn't as correct as it could be...
this patch improves and documents it.
Signed-off-by: NKent Overstreet <kmo@daterainc.com>

Checks if two keys have equivalent header fields.
(good enough for replacement or merging)

Used in bch_bkey_try_merge, and replacing a key
in the btree.
Signed-off-by: NNicholas Swenson <nks@daterainc.com>
Signed-off-by: NKent Overstreet <kmo@daterainc.com>

Added generic header checks to bch_bkey_try_merge,
which then calls the bkey specific function

Removed extraneous checks from bch_extent_merge
Signed-off-by: NNicholas Swenson <nks@daterainc.com>

Now handling overlapping extents/keys is a method that's specific to what the
btree node contains.
Signed-off-by: NKent Overstreet <kmo@daterainc.com>

More work to disentangle various code from struct btree
Signed-off-by: NKent Overstreet <kmo@daterainc.com>

More work to disentangle various code from struct btree
Signed-off-by: NKent Overstreet <kmo@daterainc.com>

More work to disentangle bset.c from struct btree
Signed-off-by: NKent Overstreet <kmo@daterainc.com>

We're in the process of turning bset.c into library code, so none of the code in
that file should know about struct cache_set or struct btree - so, move the
btree traversal part of the stats code to sysfs.c.
Signed-off-by: NKent Overstreet <kmo@daterainc.com>

Helper function to explicitly check how much space is free in a btree node
Signed-off-by: NKent Overstreet <kmo@daterainc.com>

Soon, bset.c won't need to depend on struct btree.
Signed-off-by: NKent Overstreet <kmo@daterainc.com>

Signed-off-by: NKent Overstreet <kmo@daterainc.com>

More work to disentangle bset.c from the rest of the code:
Signed-off-by: NKent Overstreet <kmo@daterainc.com>

More disentangling bset.c from the rest of the bcache code - soon, the
sorting routines won't have any dependencies on any outside structs.
Signed-off-by: NKent Overstreet <kmo@daterainc.com>

Only use extent comparison for comparing extents, so we're not using
START_KEY() on other key types (i.e. btree pointers)
Signed-off-by: NKent Overstreet <kmo@daterainc.com>

More refactoring:

node() -> bset_bkey_idx()
end() -> bset_bkey_last()
Signed-off-by: NKent Overstreet <kmo@daterainc.com>

Getting away from KEY_PTRS and moving toward KEY_U64s - and getting rid of magic
2s

Also - split out the part that checks against journal entry size so as to avoid
a dependancy on struct cache_set in bset.c
Signed-off-by: NKent Overstreet <kmo@daterainc.com>

In the process of disentagling/libraryizing bset.c from the rest of the
bcache code.
Signed-off-by: NKent Overstreet <kmo@daterainc.com>

It was a single element mempool before, it's slightly cleaner to just use a real
mempool.
Signed-off-by: NKent Overstreet <kmo@daterainc.com>

Used this fixed code to find and fix the bug fixed by
a4d885097b0ac0cd1337f171f2d4b83e946094d4.
Signed-off-by: NKent Overstreet <kmo@daterainc.com>

That was a terrible name for a macro, add some better helpers to replace it.
Signed-off-by: NKent Overstreet <kmo@daterainc.com>

Signed-off-by: NKent Overstreet <kmo@daterainc.com>

Now that we've got code for raid5/6 stripe awareness, bcache just needs
to know about the stripes and when writing partial stripes is expensive
- we probably don't want to enable this optimization for raid1 or 10,
even though they have stripes. So add a flag to queue_limits.
Signed-off-by: NKent Overstreet <kmo@daterainc.com>

This error path shouldn't have been hit in practice.. and we've got reworked
reserve code coming soon so that it shouldn't _ever_ be bit... but if we've got
code for this error path it should be correct.
Signed-off-by: NKent Overstreet <kmo@daterainc.com>

We need a reserve for allocating buckets for new btree nodes - and now that
we've got multiple btrees, it really needs to be per btree.

This reworks the reserves so we've got separate freelists for each reserve
instead of watermarks, which seems to make things a bit cleaner, and it adds
some code so that btree_split() can make sure the reserve is available before it
starts.
Signed-off-by: NKent Overstreet <kmo@daterainc.com>

Also flesh out the documentation a bit
Signed-off-by: NKent Overstreet <kmo@daterainc.com>

Signed-off-by: NKent Overstreet <kmo@daterainc.com>

Another minor performance optimization
Signed-off-by: NKent Overstreet <kmo@daterainc.com>

Unnecessary since a bucket that has dirty pointers pointing to it can
never be invalidated - and skipping it is a measurable performance
boost, since the bucket gen will usually be a cache miss.
Signed-off-by: NKent Overstreet <kmo@daterainc.com>