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[[!meta title="file_sync"]]

    routine file_sync (
    	file: file_t;
    	RPT
    	wait: int;
    	omit_metadata: int);

Sync the individual file.  If `omit_metadata` is set, then it is only necessary
for the server to updated the actual contents of the file, not any associated
metadata.

# Implementation Examples

Servers that either don't keep any unsynchronized state (or don't have a
backing store at all) can simply `return 0`.  Examples: [[translator/nfs]].

## [[libtrivfs]]

Pass the call through to the underlying node.

### [[storeio]] / [[streamio]]

Instead of to the underlying node, pass the call through to the backend
(device).

## [[libnetfs]]

Invoke `netfs_attempt_sync`.

## [[libdiskfs]]

Invoke `diskfs_file_update`.

# Usage Examples

## [[glibc]]

  * `fdatasync`

    `file_syncfs (FD, true, true)` -- invoke it on the passed file descriptor,
    do wait for completion, do allow omitting to update the associated
    metadata.

  * `fsync`

    `file_syncfs (FD, true, false)` -- invoke it on the passed file descriptor,
    do wait for completion, don't allow omitting to update the associated
    metadata.