1607ca46eSDavid Howells #ifndef _UAPI_FALLOC_H_ 2607ca46eSDavid Howells #define _UAPI_FALLOC_H_ 3607ca46eSDavid Howells 4607ca46eSDavid Howells #define FALLOC_FL_KEEP_SIZE 0x01 /* default is extend size */ 5607ca46eSDavid Howells #define FALLOC_FL_PUNCH_HOLE 0x02 /* de-allocates range */ 6607ca46eSDavid Howells #define FALLOC_FL_NO_HIDE_STALE 0x04 /* reserved codepoint */ 7607ca46eSDavid Howells 8*00f5e619SNamjae Jeon /* 9*00f5e619SNamjae Jeon * FALLOC_FL_COLLAPSE_RANGE is used to remove a range of a file 10*00f5e619SNamjae Jeon * without leaving a hole in the file. The contents of the file beyond 11*00f5e619SNamjae Jeon * the range being removed is appended to the start offset of the range 12*00f5e619SNamjae Jeon * being removed (i.e. the hole that was punched is "collapsed"), 13*00f5e619SNamjae Jeon * resulting in a file layout that looks like the range that was 14*00f5e619SNamjae Jeon * removed never existed. As such collapsing a range of a file changes 15*00f5e619SNamjae Jeon * the size of the file, reducing it by the same length of the range 16*00f5e619SNamjae Jeon * that has been removed by the operation. 17*00f5e619SNamjae Jeon * 18*00f5e619SNamjae Jeon * Different filesystems may implement different limitations on the 19*00f5e619SNamjae Jeon * granularity of the operation. Most will limit operations to 20*00f5e619SNamjae Jeon * filesystem block size boundaries, but this boundary may be larger or 21*00f5e619SNamjae Jeon * smaller depending on the filesystem and/or the configuration of the 22*00f5e619SNamjae Jeon * filesystem or file. 23*00f5e619SNamjae Jeon * 24*00f5e619SNamjae Jeon * Attempting to collapse a range that crosses the end of the file is 25*00f5e619SNamjae Jeon * considered an illegal operation - just use ftruncate(2) if you need 26*00f5e619SNamjae Jeon * to collapse a range that crosses EOF. 27*00f5e619SNamjae Jeon */ 28*00f5e619SNamjae Jeon #define FALLOC_FL_COLLAPSE_RANGE 0x08 29607ca46eSDavid Howells 30607ca46eSDavid Howells #endif /* _UAPI_FALLOC_H_ */ 31