<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/md/dm-thin.c, branch v4.3</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>dm thin: fix missing pool reference count decrement in pool_ctr error path</title>
<updated>2015-10-13T16:20:55+00:00</updated>
<author>
<name>Mike Snitzer</name>
<email>snitzer@redhat.com</email>
</author>
<published>2015-10-13T16:04:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=ba30670f4d5292c4e7f7980bbd5071f7c4794cdd'/>
<id>ba30670f4d5292c4e7f7980bbd5071f7c4794cdd</id>
<content type='text'>
Fixes: ac8c3f3df ("dm thin: generate event when metadata threshold passed")
Signed-off-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
Cc: stable@vger.kernel.org # 3.10+
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Fixes: ac8c3f3df ("dm thin: generate event when metadata threshold passed")
Signed-off-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
Cc: stable@vger.kernel.org # 3.10+
</pre>
</div>
</content>
</entry>
<entry>
<title>dm thin: disable discard support for thin devices if pool's is disabled</title>
<updated>2015-09-14T01:32:10+00:00</updated>
<author>
<name>Mike Snitzer</name>
<email>snitzer@redhat.com</email>
</author>
<published>2015-09-08T12:56:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=216076705d6ac291d42e0f8dd85e6a0da98c0fa3'/>
<id>216076705d6ac291d42e0f8dd85e6a0da98c0fa3</id>
<content type='text'>
If the pool is configured with 'ignore_discard' its discard support is
disabled.  The pool's thin devices should also have queue_limits that
reflect discards are disabled.

Fixes: 34fbcf62 ("dm thin: range discard support")
Signed-off-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
Cc: stable@vger.kernel.org # 4.1+
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
If the pool is configured with 'ignore_discard' its discard support is
disabled.  The pool's thin devices should also have queue_limits that
reflect discards are disabled.

Fixes: 34fbcf62 ("dm thin: range discard support")
Signed-off-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
Cc: stable@vger.kernel.org # 4.1+
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'dm-4.3-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm</title>
<updated>2015-09-02T23:35:26+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2015-09-02T23:35:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=1e1a4e8f439113b7820bc7150569f685e1cc2b43'/>
<id>1e1a4e8f439113b7820bc7150569f685e1cc2b43</id>
<content type='text'>
Pull device mapper update from Mike Snitzer:

 - a couple small cleanups in dm-cache, dm-verity, persistent-data's
   dm-btree, and DM core.

 - a 4.1-stable fix for dm-cache that fixes the leaking of deferred bio
   prison cells

 - a 4.2-stable fix that adds feature reporting for the dm-stats
   features added in 4.2

 - improve DM-snapshot to not invalidate the on-disk snapshot if
   snapshot device write overflow occurs; but a write overflow triggered
   through the origin device will still invalidate the snapshot.

 - optimize DM-thinp's async discard submission a bit now that late bio
   splitting has been included in block core.

 - switch DM-cache's SMQ policy lock from using a mutex to a spinlock;
   improves performance on very low latency devices (eg. NVMe SSD).

 - document DM RAID 4/5/6's discard support

[ I did not pull the slab changes, which weren't appropriate for this
  tree, and weren't obviously the right thing to do anyway.  At the very
  least they need some discussion and explanation before getting merged.

  Because not pulling the actual tagged commit but doing a partial pull
  instead, this merge commit thus also obviously is missing the git
  signature from the original tag ]

* tag 'dm-4.3-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm cache: fix use after freeing migrations
  dm cache: small cleanups related to deferred prison cell cleanup
  dm cache: fix leaking of deferred bio prison cells
  dm raid: document RAID 4/5/6 discard support
  dm stats: report precise_timestamps and histogram in @stats_list output
  dm thin: optimize async discard submission
  dm snapshot: don't invalidate on-disk image on snapshot write overflow
  dm: remove unlikely() before IS_ERR()
  dm: do not override error code returned from dm_get_device()
  dm: test return value for DM_MAPIO_SUBMITTED
  dm verity: remove unused mempool
  dm cache: move wake_waker() from free_migrations() to where it is needed
  dm btree remove: remove unused function get_nr_entries()
  dm btree: remove unused "dm_block_t root" parameter in btree_split_sibling()
  dm cache policy smq: change the mutex to a spinlock
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull device mapper update from Mike Snitzer:

 - a couple small cleanups in dm-cache, dm-verity, persistent-data's
   dm-btree, and DM core.

 - a 4.1-stable fix for dm-cache that fixes the leaking of deferred bio
   prison cells

 - a 4.2-stable fix that adds feature reporting for the dm-stats
   features added in 4.2

 - improve DM-snapshot to not invalidate the on-disk snapshot if
   snapshot device write overflow occurs; but a write overflow triggered
   through the origin device will still invalidate the snapshot.

 - optimize DM-thinp's async discard submission a bit now that late bio
   splitting has been included in block core.

 - switch DM-cache's SMQ policy lock from using a mutex to a spinlock;
   improves performance on very low latency devices (eg. NVMe SSD).

 - document DM RAID 4/5/6's discard support

[ I did not pull the slab changes, which weren't appropriate for this
  tree, and weren't obviously the right thing to do anyway.  At the very
  least they need some discussion and explanation before getting merged.

  Because not pulling the actual tagged commit but doing a partial pull
  instead, this merge commit thus also obviously is missing the git
  signature from the original tag ]

* tag 'dm-4.3-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm cache: fix use after freeing migrations
  dm cache: small cleanups related to deferred prison cell cleanup
  dm cache: fix leaking of deferred bio prison cells
  dm raid: document RAID 4/5/6 discard support
  dm stats: report precise_timestamps and histogram in @stats_list output
  dm thin: optimize async discard submission
  dm snapshot: don't invalidate on-disk image on snapshot write overflow
  dm: remove unlikely() before IS_ERR()
  dm: do not override error code returned from dm_get_device()
  dm: test return value for DM_MAPIO_SUBMITTED
  dm verity: remove unused mempool
  dm cache: move wake_waker() from free_migrations() to where it is needed
  dm btree remove: remove unused function get_nr_entries()
  dm btree: remove unused "dm_block_t root" parameter in btree_split_sibling()
  dm cache policy smq: change the mutex to a spinlock
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'for-4.3/core' of git://git.kernel.dk/linux-block</title>
<updated>2015-09-02T20:10:25+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2015-09-02T20:10:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=1081230b748de8f03f37f80c53dfa89feda9b8de'/>
<id>1081230b748de8f03f37f80c53dfa89feda9b8de</id>
<content type='text'>
Pull core block updates from Jens Axboe:
 "This first core part of the block IO changes contains:

   - Cleanup of the bio IO error signaling from Christoph.  We used to
     rely on the uptodate bit and passing around of an error, now we
     store the error in the bio itself.

   - Improvement of the above from myself, by shrinking the bio size
     down again to fit in two cachelines on x86-64.

   - Revert of the max_hw_sectors cap removal from a revision again,
     from Jeff Moyer.  This caused performance regressions in various
     tests.  Reinstate the limit, bump it to a more reasonable size
     instead.

   - Make /sys/block/&lt;dev&gt;/queue/discard_max_bytes writeable, by me.
     Most devices have huge trim limits, which can cause nasty latencies
     when deleting files.  Enable the admin to configure the size down.
     We will look into having a more sane default instead of UINT_MAX
     sectors.

   - Improvement of the SGP gaps logic from Keith Busch.

   - Enable the block core to handle arbitrarily sized bios, which
     enables a nice simplification of bio_add_page() (which is an IO hot
     path).  From Kent.

   - Improvements to the partition io stats accounting, making it
     faster.  From Ming Lei.

   - Also from Ming Lei, a basic fixup for overflow of the sysfs pending
     file in blk-mq, as well as a fix for a blk-mq timeout race
     condition.

   - Ming Lin has been carrying Kents above mentioned patches forward
     for a while, and testing them.  Ming also did a few fixes around
     that.

   - Sasha Levin found and fixed a use-after-free problem introduced by
     the bio-&gt;bi_error changes from Christoph.

   - Small blk cgroup cleanup from Viresh Kumar"

* 'for-4.3/core' of git://git.kernel.dk/linux-block: (26 commits)
  blk: Fix bio_io_vec index when checking bvec gaps
  block: Replace SG_GAPS with new queue limits mask
  block: bump BLK_DEF_MAX_SECTORS to 2560
  Revert "block: remove artifical max_hw_sectors cap"
  blk-mq: fix race between timeout and freeing request
  blk-mq: fix buffer overflow when reading sysfs file of 'pending'
  Documentation: update notes in biovecs about arbitrarily sized bios
  block: remove bio_get_nr_vecs()
  fs: use helper bio_add_page() instead of open coding on bi_io_vec
  block: kill merge_bvec_fn() completely
  md/raid5: get rid of bio_fits_rdev()
  md/raid5: split bio for chunk_aligned_read
  block: remove split code in blkdev_issue_{discard,write_same}
  btrfs: remove bio splitting and merge_bvec_fn() calls
  bcache: remove driver private bio splitting code
  block: simplify bio_add_page()
  block: make generic_make_request handle arbitrarily sized bios
  blk-cgroup: Drop unlikely before IS_ERR(_OR_NULL)
  block: don't access bio-&gt;bi_error after bio_put()
  block: shrink struct bio down to 2 cache lines again
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull core block updates from Jens Axboe:
 "This first core part of the block IO changes contains:

   - Cleanup of the bio IO error signaling from Christoph.  We used to
     rely on the uptodate bit and passing around of an error, now we
     store the error in the bio itself.

   - Improvement of the above from myself, by shrinking the bio size
     down again to fit in two cachelines on x86-64.

   - Revert of the max_hw_sectors cap removal from a revision again,
     from Jeff Moyer.  This caused performance regressions in various
     tests.  Reinstate the limit, bump it to a more reasonable size
     instead.

   - Make /sys/block/&lt;dev&gt;/queue/discard_max_bytes writeable, by me.
     Most devices have huge trim limits, which can cause nasty latencies
     when deleting files.  Enable the admin to configure the size down.
     We will look into having a more sane default instead of UINT_MAX
     sectors.

   - Improvement of the SGP gaps logic from Keith Busch.

   - Enable the block core to handle arbitrarily sized bios, which
     enables a nice simplification of bio_add_page() (which is an IO hot
     path).  From Kent.

   - Improvements to the partition io stats accounting, making it
     faster.  From Ming Lei.

   - Also from Ming Lei, a basic fixup for overflow of the sysfs pending
     file in blk-mq, as well as a fix for a blk-mq timeout race
     condition.

   - Ming Lin has been carrying Kents above mentioned patches forward
     for a while, and testing them.  Ming also did a few fixes around
     that.

   - Sasha Levin found and fixed a use-after-free problem introduced by
     the bio-&gt;bi_error changes from Christoph.

   - Small blk cgroup cleanup from Viresh Kumar"

* 'for-4.3/core' of git://git.kernel.dk/linux-block: (26 commits)
  blk: Fix bio_io_vec index when checking bvec gaps
  block: Replace SG_GAPS with new queue limits mask
  block: bump BLK_DEF_MAX_SECTORS to 2560
  Revert "block: remove artifical max_hw_sectors cap"
  blk-mq: fix race between timeout and freeing request
  blk-mq: fix buffer overflow when reading sysfs file of 'pending'
  Documentation: update notes in biovecs about arbitrarily sized bios
  block: remove bio_get_nr_vecs()
  fs: use helper bio_add_page() instead of open coding on bi_io_vec
  block: kill merge_bvec_fn() completely
  md/raid5: get rid of bio_fits_rdev()
  md/raid5: split bio for chunk_aligned_read
  block: remove split code in blkdev_issue_{discard,write_same}
  btrfs: remove bio splitting and merge_bvec_fn() calls
  bcache: remove driver private bio splitting code
  block: simplify bio_add_page()
  block: make generic_make_request handle arbitrarily sized bios
  blk-cgroup: Drop unlikely before IS_ERR(_OR_NULL)
  block: don't access bio-&gt;bi_error after bio_put()
  block: shrink struct bio down to 2 cache lines again
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>dm thin: optimize async discard submission</title>
<updated>2015-08-18T15:36:11+00:00</updated>
<author>
<name>Mike Snitzer</name>
<email>snitzer@redhat.com</email>
</author>
<published>2015-08-18T14:31:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=84f8bd86cc8977c344df572169f7ec10b8188cfa'/>
<id>84f8bd86cc8977c344df572169f7ec10b8188cfa</id>
<content type='text'>
__blkdev_issue_discard_async() doesn't need to worry about further
splitting because the upper layer blkdev_issue_discard() will have
already handled splitting bios such that the bi_size isn't
overflowed.

Signed-off-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
Acked-by: Joe Thornber &lt;ejt@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
__blkdev_issue_discard_async() doesn't need to worry about further
splitting because the upper layer blkdev_issue_discard() will have
already handled splitting bios such that the bi_size isn't
overflowed.

Signed-off-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
Acked-by: Joe Thornber &lt;ejt@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>block: kill merge_bvec_fn() completely</title>
<updated>2015-08-13T18:31:57+00:00</updated>
<author>
<name>Kent Overstreet</name>
<email>kent.overstreet@gmail.com</email>
</author>
<published>2015-04-28T06:48:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=8ae126660fddbeebb9251a174e6fa45b6ad8f932'/>
<id>8ae126660fddbeebb9251a174e6fa45b6ad8f932</id>
<content type='text'>
As generic_make_request() is now able to handle arbitrarily sized bios,
it's no longer necessary for each individual block driver to define its
own -&gt;merge_bvec_fn() callback. Remove every invocation completely.

Cc: Jens Axboe &lt;axboe@kernel.dk&gt;
Cc: Lars Ellenberg &lt;drbd-dev@lists.linbit.com&gt;
Cc: drbd-user@lists.linbit.com
Cc: Jiri Kosina &lt;jkosina@suse.cz&gt;
Cc: Yehuda Sadeh &lt;yehuda@inktank.com&gt;
Cc: Sage Weil &lt;sage@inktank.com&gt;
Cc: Alex Elder &lt;elder@kernel.org&gt;
Cc: ceph-devel@vger.kernel.org
Cc: Alasdair Kergon &lt;agk@redhat.com&gt;
Cc: Mike Snitzer &lt;snitzer@redhat.com&gt;
Cc: dm-devel@redhat.com
Cc: Neil Brown &lt;neilb@suse.de&gt;
Cc: linux-raid@vger.kernel.org
Cc: Christoph Hellwig &lt;hch@infradead.org&gt;
Cc: "Martin K. Petersen" &lt;martin.petersen@oracle.com&gt;
Acked-by: NeilBrown &lt;neilb@suse.de&gt; (for the 'md' bits)
Acked-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
Signed-off-by: Kent Overstreet &lt;kent.overstreet@gmail.com&gt;
[dpark: also remove -&gt;merge_bvec_fn() in dm-thin as well as
 dm-era-target, and resolve merge conflicts]
Signed-off-by: Dongsu Park &lt;dpark@posteo.net&gt;
Signed-off-by: Ming Lin &lt;ming.l@ssi.samsung.com&gt;
Signed-off-by: Jens Axboe &lt;axboe@fb.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
As generic_make_request() is now able to handle arbitrarily sized bios,
it's no longer necessary for each individual block driver to define its
own -&gt;merge_bvec_fn() callback. Remove every invocation completely.

Cc: Jens Axboe &lt;axboe@kernel.dk&gt;
Cc: Lars Ellenberg &lt;drbd-dev@lists.linbit.com&gt;
Cc: drbd-user@lists.linbit.com
Cc: Jiri Kosina &lt;jkosina@suse.cz&gt;
Cc: Yehuda Sadeh &lt;yehuda@inktank.com&gt;
Cc: Sage Weil &lt;sage@inktank.com&gt;
Cc: Alex Elder &lt;elder@kernel.org&gt;
Cc: ceph-devel@vger.kernel.org
Cc: Alasdair Kergon &lt;agk@redhat.com&gt;
Cc: Mike Snitzer &lt;snitzer@redhat.com&gt;
Cc: dm-devel@redhat.com
Cc: Neil Brown &lt;neilb@suse.de&gt;
Cc: linux-raid@vger.kernel.org
Cc: Christoph Hellwig &lt;hch@infradead.org&gt;
Cc: "Martin K. Petersen" &lt;martin.petersen@oracle.com&gt;
Acked-by: NeilBrown &lt;neilb@suse.de&gt; (for the 'md' bits)
Acked-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
Signed-off-by: Kent Overstreet &lt;kent.overstreet@gmail.com&gt;
[dpark: also remove -&gt;merge_bvec_fn() in dm-thin as well as
 dm-era-target, and resolve merge conflicts]
Signed-off-by: Dongsu Park &lt;dpark@posteo.net&gt;
Signed-off-by: Ming Lin &lt;ming.l@ssi.samsung.com&gt;
Signed-off-by: Jens Axboe &lt;axboe@fb.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>block: add a bi_error field to struct bio</title>
<updated>2015-07-29T14:55:15+00:00</updated>
<author>
<name>Christoph Hellwig</name>
<email>hch@lst.de</email>
</author>
<published>2015-07-20T13:29:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=4246a0b63bd8f56a1469b12eafeb875b1041a451'/>
<id>4246a0b63bd8f56a1469b12eafeb875b1041a451</id>
<content type='text'>
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 &lt;hch@lst.de&gt;
Reviewed-by: Hannes Reinecke &lt;hare@suse.de&gt;
Reviewed-by: NeilBrown &lt;neilb@suse.com&gt;
Signed-off-by: Jens Axboe &lt;axboe@fb.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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 &lt;hch@lst.de&gt;
Reviewed-by: Hannes Reinecke &lt;hare@suse.de&gt;
Reviewed-by: NeilBrown &lt;neilb@suse.com&gt;
Signed-off-by: Jens Axboe &lt;axboe@fb.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>dm thin: return -ENOSPC when erroring retry list due to out of data space</title>
<updated>2015-07-26T21:39:19+00:00</updated>
<author>
<name>Mike Snitzer</name>
<email>snitzer@redhat.com</email>
</author>
<published>2015-07-21T17:20:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=0a927c2f02a2437a57679527e42ab7cbfa14efb1'/>
<id>0a927c2f02a2437a57679527e42ab7cbfa14efb1</id>
<content type='text'>
Otherwise -EIO would be returned when -ENOSPC should be used
consistently.

Signed-off-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Otherwise -EIO would be returned when -ENOSPC should be used
consistently.

Signed-off-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>dm thin: display 'needs_check' in status if it is set</title>
<updated>2015-07-16T14:23:50+00:00</updated>
<author>
<name>Mike Snitzer</name>
<email>snitzer@redhat.com</email>
</author>
<published>2015-07-15T15:40:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=e4c78e210daea17f82f12037005df225e22189b9'/>
<id>e4c78e210daea17f82f12037005df225e22189b9</id>
<content type='text'>
There is currently no way to see that the needs_check flag has been set
in the metadata.  Display 'needs_check' in the thin-pool status if it is
set in the thinp metadata.

Also, update thinp documentation.

Signed-off-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
There is currently no way to see that the needs_check flag has been set
in the metadata.  Display 'needs_check' in the thin-pool status if it is
set in the thinp metadata.

Also, update thinp documentation.

Signed-off-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>dm thin: stay in out-of-data-space mode once no_space_timeout expires</title>
<updated>2015-07-16T14:23:49+00:00</updated>
<author>
<name>Mike Snitzer</name>
<email>snitzer@redhat.com</email>
</author>
<published>2015-07-15T20:52:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=bcc696fac11fe13e59dda5aaec6322a25b7c9a3a'/>
<id>bcc696fac11fe13e59dda5aaec6322a25b7c9a3a</id>
<content type='text'>
This fixes an issue where running out of data space would cause the
thin-pool's metadata to become read-only.  There was no reason to make
metadata read-only -- calling set_pool_mode() with PM_READ_ONLY was a
misguided way to error all queued and future write IOs.  We can
accomplish the same by degrading from PM_OUT_OF_DATA_SPACE to
PM_OUT_OF_DATA_SPACE with error_if_no_space enabled.

Otherwise, the use of PM_READ_ONLY could cause a race where commit() was
started before the PM_READ_ONLY transition but dm_pool_commit_metadata()
would go on to fail because the block manager had transitioned to
read-only.  The return of -EPERM from dm_pool_commit_metadata(), due to
attempting to commit while in read-only mode, caused the thin-pool to
set 'needs_check' because a metadata_operation_failed().  This needless
cascade of failures makes life for users more difficult than needed.

Reported-by: Vivek Goyal &lt;vgoyal@redhat.com&gt;
Signed-off-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
</content>
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<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This fixes an issue where running out of data space would cause the
thin-pool's metadata to become read-only.  There was no reason to make
metadata read-only -- calling set_pool_mode() with PM_READ_ONLY was a
misguided way to error all queued and future write IOs.  We can
accomplish the same by degrading from PM_OUT_OF_DATA_SPACE to
PM_OUT_OF_DATA_SPACE with error_if_no_space enabled.

Otherwise, the use of PM_READ_ONLY could cause a race where commit() was
started before the PM_READ_ONLY transition but dm_pool_commit_metadata()
would go on to fail because the block manager had transitioned to
read-only.  The return of -EPERM from dm_pool_commit_metadata(), due to
attempting to commit while in read-only mode, caused the thin-pool to
set 'needs_check' because a metadata_operation_failed().  This needless
cascade of failures makes life for users more difficult than needed.

Reported-by: Vivek Goyal &lt;vgoyal@redhat.com&gt;
Signed-off-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
</pre>
</div>
</content>
</entry>
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