linux-stable.git/drivers/md, branch v3.18.6

dm cache: fix missing ERR_PTR returns and handling

2015-02-06T06:36:06+00:00

commit 766a78882ddf79b162243649d7dfdbac1fb6fb88 upstream.

Commit 9b1cc9f251 ("dm cache: share cache-metadata object across
inactive and active DM tables") mistakenly ignored the use of ERR_PTR
returns.  Restore missing IS_ERR checks and ERR_PTR returns where
appropriate.

Reported-by: Dan Carpenter 
Signed-off-by: Joe Thornber 
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

dm thin: don't allow messages to be sent to a pool target in READ_ONLY or FAIL mode

2015-02-06T06:36:06+00:00

commit 2a7eaea02b99b6e267b1e89c79acc6e9a51cee3b upstream.

You can't modify the metadata in these modes.  It's better to fail these
messages immediately than let the block-manager deny write locks on
metadata blocks.  Otherwise these failed metadata changes will trigger
'needs_check' to get set in the metadata superblock -- requiring repair
using the thin_check utility.

Signed-off-by: Joe Thornber 
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

dm cache: fix problematic dual use of a single migration count variable

2015-01-30T01:40:44+00:00

commit a59db67656021fa212e9b95a583f13c34eb67cd9 upstream.

Introduce a new variable to count the number of allocated migration
structures.  The existing variable cache->nr_migrations became
overloaded.  It was used to:

 i) track of the number of migrations in flight for the purposes of
    quiescing during suspend.

 ii) to estimate the amount of background IO occuring.

Recent discard changes meant that REQ_DISCARD bios are processed with
a migration.  Discards are not background IO so nr_migrations was not
incremented.  However this could cause quiescing to complete early.

(i) is now handled with a new variable cache->nr_allocated_migrations.
cache->nr_migrations has been renamed cache->nr_io_migrations.
cleanup_migration() is now called free_io_migration(), since it
decrements that variable.

Also, remove the unused cache->next_migration variable that got replaced
with with prealloc_structs a while ago.

Signed-off-by: Joe Thornber 
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

dm cache: share cache-metadata object across inactive and active DM tables

2015-01-30T01:40:44+00:00

commit 9b1cc9f251affdd27f29fe46d0989ba76c33faf6 upstream.

If a DM table is reloaded with an inactive table when the device is not
suspended (normal procedure for LVM2), then there will be two dm-bufio
objects that can diverge.  This can lead to a situation where the
inactive table uses bufio to read metadata at the same time the active
table writes metadata -- resulting in the inactive table having stale
metadata buffers once it is promoted to the active table slot.

Fix this by using reference counting and a global list of cache metadata
objects to ensure there is only one metadata object per metadata device.

Signed-off-by: Joe Thornber 
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

dm: fix missed error code if .end_io isn't implemented by target_type

2015-01-27T16:29:39+00:00

commit 5164bece1673cdf04782f8ed3fba70743700f5da upstream.

In bio-based DM's clone_endio(), when target_type doesn't implement
.end_io (e.g. linear) r will be always be initialized 0.  So if a
WRITE SAME bio fails WRITE SAME will not be disabled as intended.

Fix this by initializing r to error, rather than 0, in clone_endio().

Signed-off-by: Alex Chen 
Signed-off-by: Mike Snitzer 
Fixes: 7eee4ae2db ("dm: disable WRITE SAME if it fails")
Signed-off-by: Greg Kroah-Hartman

md/raid5: fetch_block must fetch all the blocks handle_stripe_dirtying wants.

2015-01-16T14:59:51+00:00

commit 108cef3aa41669610e1836fe638812dd067d72de upstream.

It is critical that fetch_block() and handle_stripe_dirtying()
are consistent in their analysis of what needs to be loaded.
Otherwise raid5 can wait forever for a block that won't be loaded.

Currently when writing to a RAID5 that is resyncing, to a location
beyond the resync offset, handle_stripe_dirtying chooses a
reconstruct-write cycle, but fetch_block() assumes a
read-modify-write, and a lockup can happen.

So treat that case just like RAID6, just as we do in
handle_stripe_dirtying.  RAID6 always does reconstruct-write.

This bug was introduced when the behaviour of handle_stripe_dirtying
was changed in 3.7, so the patch is suitable for any kernel since,
though it will need careful merging for some versions.

Fixes: a7854487cd7128a30a7f4f5259de9f67d5efb95f
Reported-by: Henry Cai 
Signed-off-by: NeilBrown 
Signed-off-by: Greg Kroah-Hartman

dm thin: fix a race in thin_dtr

2015-01-08T18:30:19+00:00

commit 17181fb7a0c3a279196c0eeb2caba65a1519614b upstream.

As long as struct thin_c is in the list, anyone can grab a reference of
it.  Consequently, we must wait for the reference count to drop to zero
*after* we remove the structure from the list, not before.

Signed-off-by: Mikulas Patocka 
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

dm thin: fix missing out-of-data-space to write mode transition if blocks are released

2015-01-08T18:30:19+00:00

commit 2c43fd26e46734430122b8d2ad3024bb532df3ef upstream.

Discard bios and thin device deletion have the potential to release data
blocks.  If the thin-pool is in out-of-data-space mode, and blocks were
released, transition the thin-pool back to full write mode.

The correct time to do this is just after the thin-pool metadata commit.
It cannot be done before the commit because the space maps will not
allow immediate reuse of the data blocks in case there's a rollback
following power failure.

Signed-off-by: Joe Thornber 
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

dm thin: fix inability to discard blocks when in out-of-data-space mode

2015-01-08T18:30:19+00:00

commit 45ec9bd0fd7abf8705e7cf12205ff69fe9d51181 upstream.

When the pool was in PM_OUT_OF_SPACE mode its process_prepared_discard
function pointer was incorrectly being set to
process_prepared_discard_passdown rather than process_prepared_discard.

This incorrect function pointer meant the discard was being passed down,
but not effecting the mapping.  As such any discard that was issued, in
an attempt to reclaim blocks, would not successfully free data space.

Reported-by: Eric Sandeen 
Signed-off-by: Joe Thornber 
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

dm space map metadata: fix sm_bootstrap_get_nr_blocks()

2015-01-08T18:30:19+00:00

commit c1c6156fe4d4577444b769d7edd5dd503e57bbc9 upstream.

This function isn't right and it causes a static checker warning:

	drivers/md/dm-thin.c:3016 maybe_resize_data_dev()
	error: potentially using uninitialized 'sb_data_size'.

It should set "*count" and return zero on success the same as the
sm_metadata_get_nr_blocks() function does earlier.

Fixes: 3241b1d3e0aa ('dm: add persistent data library')
Signed-off-by: Dan Carpenter 
Acked-by: Joe Thornber 
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman