dm: Fix typo in error message

Remove the redundant "i" at the beginning of the error message. This "i"
came from commit 1c1318866928 ("dm: prefer
'"%s...", __func__'"), the "i" is accidentally left.

dm: Fix typo in error message

Remove the redundant "i" at the beginning of the error message. This "i"
came from commit 1c1318866928 ("dm: prefer
'"%s...", __func__'"), the "i" is accidentally left.

Signed-off-by: Ssuhung Yeh <[email protected]>
Signed-off-by: Mikulas Patocka <[email protected]>
Fixes: 1c1318866928 ("dm: prefer '"%s...", __func__'")
Cc: [email protected] # v6.3+

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dm: Constify struct dm_block_validator

'struct dm_block_validator' are not modified in these drivers.

Constifying this structure moves some data to a read-only section, so
increase overall security

dm: Constify struct dm_block_validator

'struct dm_block_validator' are not modified in these drivers.

Constifying this structure moves some data to a read-only section, so
increase overall security.

On a x86_64, with allmodconfig, as an example:

Before:
======
text data bss dec hex filename
32047 920 16 32983 80d7 drivers/md/dm-cache-metadata.o

After:
=====
text data bss dec hex filename
32075 896 16 32987 80db drivers/md/dm-cache-metadata.o

Signed-off-by: Christophe JAILLET <[email protected]>
Signed-off-by: Mikulas Patocka <[email protected]>

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dm: avoid useless 'else' after 'break' or return'

Signed-off-by: Heinz Mauelshagen <[email protected]>
Signed-off-by: Mike Snitzer <[email protected]>

dm: prefer '"%s...", __func__'

Signed-off-by: Heinz Mauelshagen <[email protected]>
Signed-off-by: Mike Snitzer <[email protected]>

dm: add missing empty lines

Signed-off-by: Heinz Mauelshagen <[email protected]>
Signed-off-by: Mike Snitzer <[email protected]>

dm: address indent/space issues

Signed-off-by: Heinz Mauelshagen <[email protected]>
Signed-off-by: Mike Snitzer <[email protected]>

dm: change "unsigned" to "unsigned int"

Signed-off-by: Heinz Mauelshagen <[email protected]>
Signed-off-by: Mike Snitzer <[email protected]>

dm: add missing SPDX-License-Indentifiers

'GPL-2.0-only' is used instead of 'GPL-2.0' because SPDX has
deprecated its use.

Suggested-by: John Wiele <[email protected]>
Signed-off-by: Heinz Mauelsha

dm: add missing SPDX-License-Indentifiers

'GPL-2.0-only' is used instead of 'GPL-2.0' because SPDX has
deprecated its use.

Suggested-by: John Wiele <[email protected]>
Signed-off-by: Heinz Mauelshagen <[email protected]>
Signed-off-by: Mike Snitzer <[email protected]>

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dm space map common: add bounds check to sm_ll_lookup_bitmap()

Corrupted metadata could warrant returning error from sm_ll_lookup_bitmap().

Signed-off-by: Joe Thornber <[email protected]>
Signed-off-b

dm space map common: add bounds check to sm_ll_lookup_bitmap()

Corrupted metadata could warrant returning error from sm_ll_lookup_bitmap().

Signed-off-by: Joe Thornber <[email protected]>
Signed-off-by: Mike Snitzer <[email protected]>

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dm space map disk: cache a small number of index entries

The disk space map stores it's index entries in a btree, these are
accessed very frequently, so having a few cached makes a big difference
to

dm space map disk: cache a small number of index entries

The disk space map stores it's index entries in a btree, these are
accessed very frequently, so having a few cached makes a big difference
to performance.

With this change provisioning a new block takes roughly 20% less cpu.

Signed-off-by: Joe Thornber <[email protected]>
Signed-off-by: Mike Snitzer <[email protected]>

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dm space maps: improve performance with inc/dec on ranges of blocks

When we break sharing on btree nodes we typically need to increment
the reference counts to every value held in the node. This ca

dm space maps: improve performance with inc/dec on ranges of blocks

When we break sharing on btree nodes we typically need to increment
the reference counts to every value held in the node. This can
cause a lot of repeated calls to the space maps. Fix this by changing
the interface to the space map inc/dec methods to take ranges of
adjacent blocks to be operated on.

For installations that are using a lot of snapshots this will reduce
cpu overhead of fundamental operations such as provisioning a new block,
or deleting a snapshot, by as much as 10 times.

Signed-off-by: Joe Thornber <[email protected]>
Signed-off-by: Mike Snitzer <[email protected]>

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dm space map common: fix division bug in sm_ll_find_free_block()

This division bug meant the search for free metadata space could skip
the final allocation bitmap's worth of entries. Fix affects DM

dm space map common: fix division bug in sm_ll_find_free_block()

This division bug meant the search for free metadata space could skip
the final allocation bitmap's worth of entries. Fix affects DM thinp,
cache and era targets.

Cc: [email protected]
Signed-off-by: Joe Thornber <[email protected]>
Tested-by: Ming-Hung Tsai <[email protected]>
Signed-off-by: Mike Snitzer <[email protected]>

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dm space map common: fix to ensure new block isn't already in use

The space-maps track the reference counts for disk blocks allocated by
both the thin-provisioning and cache targets. There are vari

dm space map common: fix to ensure new block isn't already in use

The space-maps track the reference counts for disk blocks allocated by
both the thin-provisioning and cache targets. There are variants for
tracking metadata blocks and data blocks.

Transactionality is implemented by never touching blocks from the
previous transaction, so we can rollback in the event of a crash.

When allocating a new block we need to ensure the block is free (has
reference count of 0) in both the current and previous transaction.
Prior to this fix we were doing this by searching for a free block in
the previous transaction, and relying on a 'begin' counter to track
where the last allocation in the current transaction was. This
'begin' field was not being updated in all code paths (eg, increment
of a data block reference count due to breaking sharing of a neighbour
block in the same btree leaf).

This fix keeps the 'begin' field, but now it's just a hint to speed up
the search. Instead the current transaction is searched for a free
block, and then the old transaction is double checked to ensure it's
free. Much simpler.

This fixes reports of sm_disk_new_block()'s BUG_ON() triggering when
DM thin-provisioning's snapshots are heavily used.

Reported-by: Eric Wheeler <[email protected]>
Cc: [email protected]
Signed-off-by: Joe Thornber <[email protected]>
Signed-off-by: Mike Snitzer <[email protected]>

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dm space map common: remove check for impossible sm_find_free() return value

The function sm_find_free() just returns -ENOSPC and 0.
So remove lone caller's check for some other error.

Signed-off-b

dm space map common: remove check for impossible sm_find_free() return value

The function sm_find_free() just returns -ENOSPC and 0.
So remove lone caller's check for some other error.

Signed-off-by: ZhangXiaoxu <[email protected]>
Signed-off-by: Mike Snitzer <[email protected]>

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dm space map common: zero entire ll_disk

Otherwise, memory that is allocated (and potentially not previously
zeroed) will get written to disk as part of the space maps.

Signed-off-by: Mike Snitzer

dm space map common: zero entire ll_disk

Otherwise, memory that is allocated (and potentially not previously
zeroed) will get written to disk as part of the space maps.

Signed-off-by: Mike Snitzer <[email protected]>

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dm: Avoid namespace collision with bitmap API

bitmap API (include/linux/bitmap.h) has 'bitmap' prefix for its methods.

On the other hand DM bitmap API is special case.
Adding 'dm' prefix to it to a

dm: Avoid namespace collision with bitmap API

bitmap API (include/linux/bitmap.h) has 'bitmap' prefix for its methods.

On the other hand DM bitmap API is special case.
Adding 'dm' prefix to it to avoid potential name space collision.

No functional changes intended.

Suggested-by: Mike Snitzer <[email protected]>
Signed-off-by: Andy Shevchenko <[email protected]>
Acked-by: Mike Snitzer <[email protected]>
Signed-off-by: Dmitry Torokhov <[email protected]>

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dm space map common: memcpy the disk root to ensure it's arch aligned

The metadata_space_map_root passed to sm_ll_open_metadata() may or may
not be arch aligned, use memcpy to ensure it is. This is

dm space map common: memcpy the disk root to ensure it's arch aligned

The metadata_space_map_root passed to sm_ll_open_metadata() may or may
not be arch aligned, use memcpy to ensure it is. This is not a fast
path so the extra memcpy doesn't hurt us.

Long-term it'd be better to use the kernel's alignment infrastructure to
remove the memcpy()s that are littered across persistent-data (btree,
array, space-maps, etc).

Signed-off-by: Joe Thornber <[email protected]>
Signed-off-by: Mike Snitzer <[email protected]>

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dm space map: always set ev if sm_ll_mutate() succeeds

If no block was allocated or freed, sm_ll_mutate() wasn't setting
*ev, leaving the variable unitialized. sm_ll_insert(),
sm_disk_inc_block(), a

dm space map: always set ev if sm_ll_mutate() succeeds

If no block was allocated or freed, sm_ll_mutate() wasn't setting
*ev, leaving the variable unitialized. sm_ll_insert(),
sm_disk_inc_block(), and sm_disk_new_block() all check ev to see
if there was an allocation event in sm_ll_mutate(), possibly
reading unitialized data.

If no allocation event occured, sm_ll_mutate() should set *ev
to SM_NONE.

Signed-off-by: Benjamin Marzinski <[email protected]>
Acked-by: Joe Thornber <[email protected]>
Signed-off-by: Mike Snitzer <[email protected]>

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dm space map metadata: skip useless memcpy in metadata_ll_init_index()

When metadata_ll_init_index() is called by sm_ll_new_metadata(),
ll->mi_le hasn't been initialized yet. So, when
metadata_ll_in

dm space map metadata: skip useless memcpy in metadata_ll_init_index()

When metadata_ll_init_index() is called by sm_ll_new_metadata(),
ll->mi_le hasn't been initialized yet. So, when
metadata_ll_init_index() copies the contents of ll->mi_le into the
newly allocated bitmap_root, it is just copying garbage. ll->mi_le
will be allocated later in sm_ll_extend() and copied into the
bitmap_root, in sm_ll_commit().

Signed-off-by: Benjamin Marzinski <[email protected]>
Signed-off-by: Mike Snitzer <[email protected]>

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dm persistent data: eliminate unnecessary return values

dm_bm_unlock and dm_tm_unlock return an integer value but the returned
value is always 0. The calling code sometimes checks the return value

dm persistent data: eliminate unnecessary return values

dm_bm_unlock and dm_tm_unlock return an integer value but the returned
value is always 0. The calling code sometimes checks the return value
and sometimes doesn't.

Eliminate these unnecessary return values and also the checks for them.

Signed-off-by: Mikulas Patocka <[email protected]>
Signed-off-by: Mike Snitzer <[email protected]>

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dm space map common: make sure new space is used during extend

When extending a low level space map we should update nr_blocks at
the start so the new space is used for the index entries.

Otherwise

dm space map common: make sure new space is used during extend

When extending a low level space map we should update nr_blocks at
the start so the new space is used for the index entries.

Otherwise extend can fail, e.g.: sm_metadata_extend call sequence
that fails:
-> sm_ll_extend
-> dm_tm_new_block -> dm_sm_new_block -> sm_bootstrap_new_block
=> returns -ENOSPC because smm->begin == smm->ll.nr_blocks

Signed-off-by: Joe Thornber <[email protected]>
Signed-off-by: Mike Snitzer <[email protected]>
Cc: [email protected]

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dm space map: disallow decrementing a reference count below zero

The old behaviour, returning -EINVAL if a ref_count of 0 would be
decremented, was removed in commit f722063 ("dm space map: optimise

dm space map: disallow decrementing a reference count below zero

The old behaviour, returning -EINVAL if a ref_count of 0 would be
decremented, was removed in commit f722063 ("dm space map: optimise
sm_ll_dec and sm_ll_inc"). To fix this regression we return an error
code from the mutator function pointer passed to sm_ll_mutate() and have
dec_ref_count() return -EINVAL if the old ref_count is 0.

Add a DMERR to reflect the potential seriousness of this error.

Also, add missing dm_tm_unlock() to sm_ll_mutate()'s error path.

With this fix the following dmts regression test now passes:
dmtest run --suite cache -n /metadata_use_kernel/

The next patch fixes the higher-level dm-array code that exposed this
regression.

Signed-off-by: Joe Thornber <[email protected]>
Signed-off-by: Mike Snitzer <[email protected]>
Cc: [email protected] # 3.12+

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dm space map: optimise sm_ll_dec and sm_ll_inc

Prior to this patch these methods did a lookup followed by an insert.
Instead they now call a common mutate function that adjusts the value
according t

dm space map: optimise sm_ll_dec and sm_ll_inc

Prior to this patch these methods did a lookup followed by an insert.
Instead they now call a common mutate function that adjusts the value
according to a callback function. This avoids traversing the data
structures twice and hence improves performance.

Also factor out sm_ll_lookup_big_ref_count() for use by both
sm_ll_lookup() and sm_ll_mutate().

Signed-off-by: Joe Thornber <[email protected]>
Signed-off-by: Mike Snitzer <[email protected]>
Signed-off-by: Alasdair G Kergon <[email protected]>

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dm persistent data: use DMERR_LIMIT for errors

Nearly all of persistent-data is in the IO path so throttle error
messages with DMERR_LIMIT to limit the amount logged when
something has gone wrong.

dm persistent data: use DMERR_LIMIT for errors

Nearly all of persistent-data is in the IO path so throttle error
messages with DMERR_LIMIT to limit the amount logged when
something has gone wrong.

Signed-off-by: Mike Snitzer <[email protected]>
Signed-off-by: Alasdair G Kergon <[email protected]>

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dm persistent data: convert to use le32_add_cpu

Convert cpu_to_le32(le32_to_cpu(E1) + E2) to use le32_add_cpu().

dpatch engine is used to auto generate this patch.
(https://github.com/weiyj/dpatch)

dm persistent data: convert to use le32_add_cpu

Convert cpu_to_le32(le32_to_cpu(E1) + E2) to use le32_add_cpu().

dpatch engine is used to auto generate this patch.
(https://github.com/weiyj/dpatch)

Signed-off-by: Wei Yongjun <[email protected]>
Signed-off-by: Alasdair G Kergon <[email protected]>

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