linux.git/drivers/md/dm-raid.c, branch v4.18

dm raid: don't use 'const' in function return

2018-06-22T18:51:12+00:00

A newly introduced function has 'const int' as the return type,
but as "make W=1" reports, that has no meaning:

drivers/md/dm-raid.c:510:18: error: type qualifiers ignored on function return type [-Werror=ignored-qualifiers]

This changes the return type to plain 'int'.

Signed-off-by: Arnd Bergmann 
Fixes: 33e53f06850f ("dm raid: introduce extended superblock and new raid types to support takeover/reshaping")
Signed-off-by: Mike Snitzer 
Fixes: 552aa679f2657431 ("dm raid: use rs_is_raid*()")
Signed-off-by: Geert Uytterhoeven 
Signed-off-by: Mike Snitzer

treewide: Use struct_size() for kmalloc()-family

2018-06-06T18:15:43+00:00

One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:

struct foo {
    int stuff;
    void *entry[];
};

instance = kmalloc(sizeof(struct foo) + sizeof(void *) * count, GFP_KERNEL);

Instead of leaving these open-coded and prone to type mistakes, we can
now use the new struct_size() helper:

instance = kmalloc(struct_size(instance, entry, count), GFP_KERNEL);

This patch makes the changes for kmalloc()-family (and kvmalloc()-family)
uses. It was done via automatic conversion with manual review for the
"CHECKME" non-standard cases noted below, using the following Coccinelle
script:

// pkey_cache = kmalloc(sizeof *pkey_cache + tprops->pkey_tbl_len *
//                      sizeof *pkey_cache->table, GFP_KERNEL);
@@
identifier alloc =~ "kmalloc|kzalloc|kvmalloc|kvzalloc";
expression GFP;
identifier VAR, ELEMENT;
expression COUNT;
@@

- alloc(sizeof(*VAR) + COUNT * sizeof(*VAR->ELEMENT), GFP)
+ alloc(struct_size(VAR, ELEMENT, COUNT), GFP)

// mr = kzalloc(sizeof(*mr) + m * sizeof(mr->map[0]), GFP_KERNEL);
@@
identifier alloc =~ "kmalloc|kzalloc|kvmalloc|kvzalloc";
expression GFP;
identifier VAR, ELEMENT;
expression COUNT;
@@

- alloc(sizeof(*VAR) + COUNT * sizeof(VAR->ELEMENT[0]), GFP)
+ alloc(struct_size(VAR, ELEMENT, COUNT), GFP)

// Same pattern, but can't trivially locate the trailing element name,
// or variable name.
@@
identifier alloc =~ "kmalloc|kzalloc|kvmalloc|kvzalloc";
expression GFP;
expression SOMETHING, COUNT, ELEMENT;
@@

- alloc(sizeof(SOMETHING) + COUNT * sizeof(ELEMENT), GFP)
+ alloc(CHECKME_struct_size(&SOMETHING, ELEMENT, COUNT), GFP)

Signed-off-by: Kees Cook

dm raid: fix parse_raid_params() variable range issue

2018-04-04T16:12:37+00:00

parse_raid_params() compares variable "int value" with INT_MAX.

E.g. related Coverity report excerpt:
   CID 1364818 (#2 of 3): Operands don't affect result (CONSTANT_EXPRESSION_RESULT) [select issue]
1433                        if (value > INT_MAX) {

Fix by changing checks to avoid INT_MAX.

Whilst on it, avoid unnecessary checks against constants
and add check for sane recovery speed min/max.

Signed-off-by: Heinz Mauelshagen 
Signed-off-by: Mike Snitzer

dm raid: fix nosync status

2018-04-03T19:04:19+00:00

Fix a race for "nosync" activations providing "aa.." device health
characters and "0/N" sync ratio rather than "AA..." and "N/N".  Occurs
when status for the raid set is retrieved during resume before the MD
sync thread starts and clears the MD_RECOVERY_NEEDED flag.

Cc: stable@vger.kernel.org # 4.16+
Signed-off-by: Heinz Mauelshagen 
Signed-off-by: Mike Snitzer

dm: allow targets to return output from messages they are sent

2018-04-03T19:04:10+00:00

Could be useful for a target to return stats or other information.
If a target does DMEMIT() anything to @result from its .message method
then it must return 1 to the caller.

Signed-off-By: Mike Snitzer

dm raid: fix incorrect sync_ratio when degraded

2018-03-07T01:23:57+00:00

Upstream commit 4102d9de6d375 ("dm raid: fix rs_get_progress()
synchronization state/ratio") in combination with commit 7c29744ecce
("dm raid: simplify rs_get_progress()") introduced a regression by
incorrectly reporting a sync_ratio of 0 for degraded raid sets.  This
caused lvm2 to fail to repair raid legs automatically.

Fix by identifying the degraded state by checking the MD_RECOVERY_INTR
flag and returning mddev->recovery_cp in case it is set.

MD sets recovery = [ MD_RECOVERY_RECOVER MD_RECOVERY_INTR
MD_RECOVERY_NEEDED ] when a RAID member fails.  It then shuts down any
sync thread that is running and leaves us with all MD_RECOVERY_* flags
cleared.  The bug occurs if a status is requested in the short time it
takes to shut down any sync thread and clear the flags, because we were
keying in on the MD_RECOVERY_NEEDED - understanding it to be the initial
phase of a “recover” sync thread.  However, this is an incorrect
interpretation if MD_RECOVERY_INTR is also set.

This also explains why the bug only happened when automatic repair was
enabled and not a normal ‘manual’ method.  It is impossible to react
quick enough to hit the problematic window without it being automated.

Fix passes automatic repair tests.

Fixes: 7c29744ecce ("dm raid: simplify rs_get_progress()")
Signed-off-by: Jonathan Brassow 
Signed-off-by: Heinz Mauelshagen 
Signed-off-by: Mike Snitzer

Merge tag 'for-4.16/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

2018-01-31T19:05:47+00:00

Pull device mapper updates from Mike Snitzer:

- DM core fixes to ensure that bio submission follows a depth-first
tree walk; this is critical to allow forward progress without the
need to use the bioset's BIOSET_NEED_RESCUER.

- Remove DM core's BIOSET_NEED_RESCUER based dm_offload infrastructure.

- DM core cleanups and improvements to make bio-based DM more efficient
(e.g. reduced memory footprint as well leveraging per-bio-data more).

- Introduce new bio-based mode (DM_TYPE_NVME_BIO_BASED) that leverages
the more direct IO submission path in the block layer; this mode is
used by DM multipath and also optimizes targets like DM thin-pool
that stack directly on NVMe data device.

- DM multipath improvements to factor out legacy SCSI-only (e.g.
scsi_dh) code paths to allow for more optimized support for NVMe
multipath.

- A fix for DM multipath path selectors (service-time and queue-length)
to select paths in a more balanced way; largely academic but doesn't
hurt.

- Numerous DM raid target fixes and improvements.

- Add a new DM "unstriped" target that enables Intel to workaround
firmware limitations in some NVMe drives that are striped internally
(this target also works when stacked above the DM "striped" target).

- Various Documentation fixes and improvements.

- Misc cleanups and fixes across various DM infrastructure and targets
(e.g. bufio, flakey, log-writes, snapshot).

* tag 'for-4.16/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (69 commits)
dm cache: Documentation: update default migration_throttling value
dm mpath selector: more evenly distribute ties
dm unstripe: fix target length versus number of stripes size check
dm thin: fix trailing semicolon in __remap_and_issue_shared_cell
dm table: fix NVMe bio-based dm_table_determine_type() validation
dm: various cleanups to md->queue initialization code
dm mpath: delay the retry of a request if the target responded as busy
dm mpath: return DM_MAPIO_DELAY_REQUEUE if QUEUE_IO or PG_INIT_REQUIRED
dm mpath: return DM_MAPIO_REQUEUE on blk-mq rq allocation failure
dm log writes: fix max length used for kstrndup
dm: backfill missing calls to mutex_destroy()
dm snapshot: use mutex instead of rw_semaphore
dm flakey: check for null arg_name in parse_features()
dm thin: extend thinpool status format string with omitted fields
dm thin: fixes in thin-provisioning.txt
dm thin: document representation of when there is none
dm thin: fix documentation relative to low water mark threshold
dm cache: be consistent in specifying sectors and SI units in cache.txt
dm cache: delete obsoleted paragraph in cache.txt
dm cache: fix grammar in cache-policies.txt
...

dm raid: make raid_sets symbol static

2018-01-17T14:16:05+00:00

Fixes the following sparse warning:

drivers/md/dm-raid.c:33:1: warning:
 symbol 'raid_sets' was not declared. Should it be static?

Signed-off-by: Wei Yongjun 
Signed-off-by: Mike Snitzer

dm raid: use rs_is_raid*()

2017-12-13T17:15:47+00:00

Cleanup, no functional change.

Signed-off-by: Heinz Mauelshagen 
Signed-off-by: Mike Snitzer

dm raid: simplify rs_get_progress()

2017-12-13T16:59:21+00:00

No need to calculate the reshaping progress because
mddev->curr_resync_completed holds it.

Signed-off-by: Heinz Mauelshagen 
Signed-off-by: Mike Snitzer