linux.git/drivers/md/dm-thin.c, branch v4.10

block: rename bio bi_rw to bi_opf

2016-08-07T20:41:02+00:00

Since commit 63a4cc24867d, bio->bi_rw contains flags in the lower
portion and the op code in the higher portions. This means that
old code that relies on manually setting bi_rw is most likely
going to be broken. Instead of letting that brokeness linger,
rename the member, to force old and out-of-tree code to break
at compile time instead of at runtime.

No intended functional changes in this commit.

Signed-off-by: Jens Axboe

dm thin: fix a race condition between discarding and provisioning a block

2016-07-20T16:43:35+00:00

The discard passdown was being issued after the block was unmapped,
which meant the block could be reprovisioned whilst the passdown discard
was still in flight.

We can only identify unshared blocks (safe to do a passdown a discard
to) once they're unmapped and their ref count hits zero.  Block ref
counts are now used to guard against concurrent allocation of these
blocks that are being discarded.  So now we unmap the block, issue
passdown discards, and the immediately increment ref counts for regions
that have been discarded via passed down (this is safe because
allocation occurs within the same thread).  We then decrement ref counts
once the passdown discard IO is complete -- signaling these blocks may
now be allocated.

This fixes the potential for corruption that was reported here:
https://www.redhat.com/archives/dm-devel/2016-June/msg00311.html

Reported-by: Dennis Yang 
Signed-off-by: Joe Thornber 
Signed-off-by: Mike Snitzer

block, drivers, fs: rename REQ_FLUSH to REQ_PREFLUSH

2016-06-07T19:41:38+00:00

To avoid confusion between REQ_OP_FLUSH, which is handled by
request_fn drivers, and upper layers requesting the block layer
perform a flush sequence along with possibly a WRITE, this patch
renames REQ_FLUSH to REQ_PREFLUSH.

Signed-off-by: Mike Christie 
Reviewed-by: Christoph Hellwig 
Reviewed-by: Hannes Reinecke 
Signed-off-by: Jens Axboe

dm: use bio op accessors

2016-06-07T19:41:38+00:00

Separate the op from the rq_flag_bits and have dm
set/get the bio using bio_set_op_attrs/bio_op.

Signed-off-by: Mike Christie 
Reviewed-by: Hannes Reinecke 
Signed-off-by: Jens Axboe

block discard: use bio set op accessor

2016-06-07T19:41:38+00:00

This converts the block issue discard helper and users to use
the bio_set_op_attrs accessor and only pass in the operation flags
like REQ_SEQURE.

Signed-off-by: Mike Christie 
Reviewed-by: Hannes Reinecke 
Signed-off-by: Jens Axboe

block/fs/drivers: remove rw argument from submit_bio

2016-06-07T19:41:38+00:00

This has callers of submit_bio/submit_bio_wait set the bio->bi_rw
instead of passing it in. This makes that use the same as
generic_make_request and how we set the other bio fields.

Signed-off-by: Mike Christie 

Fixed up fs/ext4/crypto.c

Signed-off-by: Jens Axboe

dm thin: unroll issue_discard() to create longer discard bio chains

2016-05-13T13:04:20+00:00

There is little benefit to doing this but it does structure DM thinp's
code to more cleanly use the __blkdev_issue_discard() interface --
particularly in passdown_double_checking_shared_status().

Signed-off-by: Joe Thornber 
Signed-off-by: Mike Snitzer

dm thin: use __blkdev_issue_discard for async discard support

2016-05-13T13:03:52+00:00

With commit 38f25255330 ("block: add __blkdev_issue_discard") DM thinp
no longer needs to carry its own async discard method.

Signed-off-by: Mike Snitzer 
Acked-by: Joe Thornber 
Reviewed-by: Christoph Hellwig

dm thin: remove __bio_inc_remaining() and switch to using bio_inc_remaining()

2016-05-13T13:03:52+00:00

DM thinp's use of bio_inc_remaining() is critical to ensure the original
parent discard bio isn't completed before sub-discards have.  DM thinp
needs this due to the extra quiescing that occurs, via multiple DM thinp
mappings, while processing large discards.  As such DM thinp must build
the async discard bio chain after some delay -- so bio_inc_remaining()
is used to enable DM thinp to take a reference on the original parent
discard bio for each mapping.  This allows the immediate use of
bio_endio() on that discard bio; but with the understanding that the
actual completion won't occur until each of the sub-discards'
per-mapping references are dropped.

Signed-off-by: Mike Snitzer 
Acked-by: Joe Thornber

dm thin: Remove return statement from void function

2016-05-05T19:25:50+00:00

Return statement at the end of a void function is useless.

The Coccinelle semantic patch used to make this change is as follows:
//
@@
identifier f;
expression e;
@@
void f(...) {
<...
- return
  e;
...>
}
//

Signed-off-by: Amitoj Kaur Chawla 
Signed-off-by: Mike Snitzer