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33 .\" @(#)fsync.2 8.1 (Berkeley) 6/4/93
41 .Nd "synchronise changes to a file"
47 .Fn fdatasync "int fd"
54 causes all modified data and attributes of the file referenced by
57 to be moved to a permanent storage device.
58 This normally results in all in-core modified copies
59 of buffers for the associated file to be written to a disk.
63 system call causes all modified data of
65 to be moved to a permanent storage device.
68 the system call does not guarantee that file attributes or
69 metadata necessary to access the file are committed to the permanent storage.
74 should be used by programs that require a file to be
75 in a known state, for example, in building a simple transaction
77 If the file metadata has already been committed, using
79 can be more efficient than
86 calls are cancellation points.
100 is not a valid descriptor.
105 refers to a socket, not to a file.
107 An I/O error occurred while reading from or writing to the file system.
109 Corrupted data was detected while reading from the file system.
119 system call appeared in
123 system call appeared in
128 system call currently does not guarantee that enqueued
130 requests for the file referenced by
132 are completed before the syscall returns.