Man page - pmempool_feature_query(3)

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Package: libpmempool-dev
apt-get install libpmempool-dev

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libpmempool-dev

Manual

NAME
SYNOPSIS
DESCRIPTION
COMPATIBILITY
DISCLAIMER
RETURN VALUE
SEE ALSO

NAME

pmempool_feature_query (), pmempool_feature_enable (), pmempool_feature_disable () - toggle or query pool set features

SYNOPSIS

#include <libpmempool.h>

int pmempool_feature_query(const char *path, enum pmempool_feature feature, unsigned flags);

int pmempool_feature_enable(const char *path, enum pmempool_feature feature, unsigned flags);


int pmempool_feature_disable(const char *path, enum pmempool_feature feature, unsigned flags);

DESCRIPTION

The feature argument accepts following values:

	•		PMEMPOOL_FEAT_SINGLEHDR - only the first part in each replica contains the pool part internal metadata. This value can be used only with pmempool_feature_query (). It can not be enabled or disabled. For details see poolset (5).
	•		PMEMPOOL_FEAT_CKSUM_2K - only the first 2KiB of pool part internal metadata is checksummed. Other features may depend on this one to store additional metadata in otherwise unused second 2KiB part of a header. When PMEMPOOL_FEAT_CKSUM_2K is disabled whole 4KiB is checksummed.
	•		PMEMPOOL_FEAT_SHUTDOWN_STATE - enables additional check performed during pool open which verifies pool consistency in the presence of dirty shutdown. PMEMPOOL_FEAT_CKSUM_2K has to be enabled prior to PMEMPOOL_FEAT_SHUTDOWN_STATE otherwise enabling PMEMPOOL_FEAT_SHUTDOWN_STATE will fail.
	•		PMEMPOOL_FEAT_CHECK_BAD_BLOCKS - enables checking bad blocks performed during opening a pool and fixing bad blocks performed by pmempool-sync during syncing a pool. For details see pmempool-feature (1).

The pmempool_feature_query () function checks state of feature in the pool set pointed by path .

The pmempool_feature_enable () function enables feature in the pool set pointed by path .

The pmempool_feature_disable () function disables feature in the pool set pointed by path .

COMPATIBILITY

Poolsets with features not defined in this document (e.g. enabled by the newer software version) are not supported.

DISCLAIMER

pmempool_feature_query (), pmempool_feature_enable () and pmempool_feature_disable () are not fail safe.

RETURN VALUE

On success, pmempool_feature_query () returns 0 if feature is disabled or 1 if it is enabled. On error, it returns -1 and sets errno accordingly.

On success, pmempool_feature_enable () returns 0. On error, it returns -1 and sets errno accordingly.

On success, pmempool_feature_disable () returns 0. On error, it returns -1 and sets errno accordingly.

If non zero flags are provided errno is set to EINVAL and function returns -1.