4.2 stratafs.mutation.refused

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Event type: stratafs.mutation.refused
Defined in: stratafs.evman
Tier: standard
Gating: none — every arrangement refusal is recorded
Cardinality: one record per occurrence

The record that a mutation was refused because of how the mount is arranged, rather than because of an access check. Software writing where it cannot, or an arrangement that does not admit an operation someone expected — a mismatch between intent and configuration that is otherwise visible only as an error returned to a caller who may discard it.

The record is written through KACS, so its emitter.class is kacs.

The refusals that count are one explicit list: EROFS, EXDEV, ENOTDIR, EISDIR, ENOTEMPTY, EEXIST and EINVAL. Call sites cover every mutating path.

EACCES is deliberately absent. A refusal produced by an access check is recorded by the mechanism that performed it, so StrataFS does not duplicate it. Looking here for a permission denial finds nothing — look at kacs.audit.access.checked.

There is one exception, and it is deliberate. A refused deferred deletion is recorded on any non-zero result, including one refused by an access check, because by the time a deferred deletion fails there is nobody left to receive the error. Rollbacks arrive under this type with the same flag set: a create or link whose outer bookkeeping failed and whose lower object could not be removed again, and a failed publication rollback after a copy-up.

Resolution, revalidation and enumeration record nothing at all. They happen on every path operation, reveal nothing the resulting access check does not, and recording them would produce volume out of all proportion to their significance.

4.2.1 Fields #

Field	Type	Presence	Meaning
`object.file.path-relative`	`str.path`	optional	Absent only from a reduced record: when the memory for the full record could not be had, the kernel writes the record without its paths rather than lose it.
`operation.name`	`str.enum`	required	StrataFS names its own operations, and the set is disjoint from the `file.` names an already-open handle uses. Values here (open set): `copy-file-range` · `copy-up-publication-rollback` · `create` · `create-rollback` · `fallocate` · `link` · `link-rollback` · `mmap` · `remap-file-range` · `removexattr` · `rename` · `rmdir` · `setattr` · `setxattr` · `splice-write` · `supersede` · `supersede-removal` · `tmpfile` · `truncate` · `unlink` · `write`.
`source.stratum.index`	`uint`	optional	Absent when the refusal was raised before any provider was determined.
`source.stratum.path`	`str.path`	optional	Present exactly when `source.stratum.index` is, except in a reduced record, which carries no paths.
`outcome.errno`	`int.errno`	required	The error the operation failed with, as a negative errno.
`outcome.deferred`	`bool`	required	Whether the refusal was deferred — set on rollbacks and on deferred deletions, which are the records where no caller remained to be told.

Every record also carries the header fields of the envelope, which no payload repeats.

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