xref: /linux-6.15/include/uapi/linux/falloc.h (revision 00f5e619)
1 #ifndef _UAPI_FALLOC_H_
2 #define _UAPI_FALLOC_H_
3 
4 #define FALLOC_FL_KEEP_SIZE	0x01 /* default is extend size */
5 #define FALLOC_FL_PUNCH_HOLE	0x02 /* de-allocates range */
6 #define FALLOC_FL_NO_HIDE_STALE	0x04 /* reserved codepoint */
7 
8 /*
9  * FALLOC_FL_COLLAPSE_RANGE is used to remove a range of a file
10  * without leaving a hole in the file. The contents of the file beyond
11  * the range being removed is appended to the start offset of the range
12  * being removed (i.e. the hole that was punched is "collapsed"),
13  * resulting in a file layout that looks like the range that was
14  * removed never existed. As such collapsing a range of a file changes
15  * the size of the file, reducing it by the same length of the range
16  * that has been removed by the operation.
17  *
18  * Different filesystems may implement different limitations on the
19  * granularity of the operation. Most will limit operations to
20  * filesystem block size boundaries, but this boundary may be larger or
21  * smaller depending on the filesystem and/or the configuration of the
22  * filesystem or file.
23  *
24  * Attempting to collapse a range that crosses the end of the file is
25  * considered an illegal operation - just use ftruncate(2) if you need
26  * to collapse a range that crosses EOF.
27  */
28 #define FALLOC_FL_COLLAPSE_RANGE	0x08
29 
30 #endif /* _UAPI_FALLOC_H_ */
31