hesela.devFIEMAP
A Linux ioctl interface that reports file extent mappings and associated state flags over a requested logical byte range.
FIEMAP_FLAG_SYNC synchronizes before mapping, so the query can alter the observed state. DELALLOC also sets UNKNOWN; UNWRITTEN instead describes allocated zero-reading storage. Mappings can change between calls and are not permission to access a mounted filesystem through its block device. Record request flags and check for a full output buffer. Hesela's linked observation compares unsynchronized queries with explicit fsync and FIEMAP synchronization.
Relations
- related
- file-extent, delayed-allocation, unwritten-extent, fsync