linux-stable.git/block/blk-lib.c, branch v4.7.2

block: missing bio_put following submit_bio_wait

2016-06-07T16:47:48+00:00

submit_bio_wait() gives the caller an opportunity to examine
struct bio and so expects the caller to issue the put_bio()

This fixes a memory leak reported by a few people in 4.7-rc2
kmemleak report after 9082e87bfbf8 ("block: remove struct bio_batch")

Signed-off-by: Shaun Tancheff 
Tested-by: Catalin Marinas 
Tested-by: Larry Finger@lwfinger.net
Tested-by: David Drysdale 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Jens Axboe

block: reinstate early return of -EOPNOTSUPP from blkdev_issue_discard

2016-05-05T19:03:26+00:00

Commit 38f25255330 ("block: add __blkdev_issue_discard") incorrectly
disallowed the early return of -EOPNOTSUPP if the device doesn't support
discard (or secure discard).  This early return of -EOPNOTSUPP has
always been part of blkdev_issue_discard() interface so there isn't a
good reason to break that behaviour -- especially when it can be easily
reinstated.

The nuance of allowing early return of -EOPNOTSUPP vs disallowing late
return of -EOPNOTSUPP is: if the overall device never advertised support
for discards and one is issued to the device it is beneficial to inform
the caller that discards are not supported via -EOPNOTSUPP.  But if a
device advertises discard support it means that at least a subset of the
device does have discard support -- but it could be that discards issued
to some regions of a stacked device will not be supported.  In that case
the late return of -EOPNOTSUPP must be disallowed.

Fixes: 38f25255330 ("block: add __blkdev_issue_discard")
Signed-off-by: Mike Snitzer 
Signed-off-by: Jens Axboe

block: add __blkdev_issue_discard

2016-05-02T15:19:46+00:00

This is a version of blkdev_issue_discard which doesn't wait for
the I/O to complete, but instead allows the caller to submit
the final bio and/or chain it to others.

Signed-off-by: Christoph Hellwig 
Signed-off-by: Ming Lin 
Signed-off-by: Sagi Grimberg 
Reviewed-by: Ming Lei 
Signed-off-by: Jens Axboe

block: remove struct bio_batch

2016-05-02T15:19:43+00:00

It can be replaced with a combination of bio_chain and submit_bio_wait.

Signed-off-by: Christoph Hellwig 
Signed-off-by: Ming Lin 
Signed-off-by: Sagi Grimberg 
Reviewed-by: Ming Lei 
Signed-off-by: Jens Axboe

block: re-add discard_granularity and alignment checks

2015-10-28T00:12:58+00:00

In commit b49a087("block: remove split code in
blkdev_issue_{discard,write_same}"), discard_granularity and alignment
checks were removed. Ideally, with bio late splitting, the upper layers
shouldn't need to depend on device's limits.

Christoph reported a discard regression on the HGST Ultrastar SN100 NVMe
device when mkfs.xfs. We have not found the root cause yet.

This patch re-adds discard_granularity and alignment checks by reverting
the related changes in commit b49a087. The good thing is now we can
remove the 2G discard size cap and just use UINT_MAX to avoid bi_size
overflow.

Reviewed-by: Christoph Hellwig 
Tested-by: Christoph Hellwig 
Signed-off-by: Ming Lin 
Reviewed-by: Mike Snitzer 
Signed-off-by: Jens Axboe

block: remove split code in blkdev_issue_{discard,write_same}

2015-08-13T18:31:47+00:00

The split code in blkdev_issue_{discard,write_same} can go away
now that any driver that cares does the split. We have to make
sure bio size doesn't overflow.

For discard, we set max discard sectors to (1<<31)>>9 to ensure
it doesn't overflow bi_size and hopefully it is of the proper
granularity as long as the granularity is a power of two.

Acked-by: Christoph Hellwig 
Signed-off-by: Ming Lin 
Signed-off-by: Jens Axboe

block: add a bi_error field to struct bio

2015-07-29T14:55:15+00:00

Currently we have two different ways to signal an I/O error on a BIO:

 (1) by clearing the BIO_UPTODATE flag
 (2) by returning a Linux errno value to the bi_end_io callback

The first one has the drawback of only communicating a single possible
error (-EIO), and the second one has the drawback of not beeing persistent
when bios are queued up, and are not passed along from child to parent
bio in the ever more popular chaining scenario.  Having both mechanisms
available has the additional drawback of utterly confusing driver authors
and introducing bugs where various I/O submitters only deal with one of
them, and the others have to add boilerplate code to deal with both kinds
of error returns.

So add a new bi_error field to store an errno value directly in struct
bio and remove the existing mechanisms to clean all this up.

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

block: Quiesce zeroout wrapper

2015-02-05T17:14:54+00:00

blkdev_issue_zeroout() printed a warning if a device failed a discard or
write same request despite advertising support for these. That's fine
for SCSI since we'll disable these commands if we get an error back from
the disk saying that they are not supported. And consequently the
warning only gets printed once.

There are other types of block devices that support discard, however,
and these may return -EOPNOTSUPP for each command but leave discard
enabled in the queue limits. This will cause a warning message for every
blkdev_issue_zeroout() invocation.

Remove the offending warning messages.

Reported-by: Sedat Dilek 
Signed-off-by: Martin K. Petersen 
Tested-by: Sedat Dilek 
Signed-off-by: Jens Axboe

block: Add discard flag to blkdev_issue_zeroout() function

2015-01-21T17:41:46+00:00

blkdev_issue_discard() will zero a given block range. This is done by
way of explicit writing, thus provisioning or allocating the blocks on
disk.

There are use cases where the desired behavior is to zero the blocks but
unprovision them if possible. The blocks must deterministically contain
zeroes when they are subsequently read back.

This patch adds a flag to blkdev_issue_zeroout() that provides this
variant. If the discard flag is set and a block device guarantees
discard_zeroes_data we will use REQ_DISCARD to clear the block range. If
the device does not support discard_zeroes_data or if the discard
request fails we will fall back to first REQ_WRITE_SAME and then a
regular REQ_WRITE.

Also update the callers of blkdev_issue_zero() to reflect the new flag
and make sb_issue_zeroout() prefer the discard approach.

Signed-off-by: Martin K. Petersen 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Jens Axboe

block/blk-lib.c: make __blkdev_issue_zeroout static

2014-05-26T23:39:09+00:00

__blkdev_issue_zeroout is only used in blk-lib.c

Cc: Jens Axboe 
Cc: Andrew Morton 
Signed-off-by: Fabian Frederick 
Signed-off-by: Jens Axboe