diff options
Diffstat (limited to 'include/uapi')
| -rw-r--r-- | include/uapi/linux/falloc.h | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/include/uapi/linux/falloc.h b/include/uapi/linux/falloc.h index 990c4ccf8b61..5ff562ddac0b 100644 --- a/include/uapi/linux/falloc.h +++ b/include/uapi/linux/falloc.h @@ -5,5 +5,26 @@ #define FALLOC_FL_PUNCH_HOLE 0x02 /* de-allocates range */ #define FALLOC_FL_NO_HIDE_STALE 0x04 /* reserved codepoint */ +/* + * FALLOC_FL_COLLAPSE_RANGE is used to remove a range of a file + * without leaving a hole in the file. The contents of the file beyond + * the range being removed is appended to the start offset of the range + * being removed (i.e. the hole that was punched is "collapsed"), + * resulting in a file layout that looks like the range that was + * removed never existed. As such collapsing a range of a file changes + * the size of the file, reducing it by the same length of the range + * that has been removed by the operation. + * + * Different filesystems may implement different limitations on the + * granularity of the operation. Most will limit operations to + * filesystem block size boundaries, but this boundary may be larger or + * smaller depending on the filesystem and/or the configuration of the + * filesystem or file. + * + * Attempting to collapse a range that crosses the end of the file is + * considered an illegal operation - just use ftruncate(2) if you need + * to collapse a range that crosses EOF. + */ +#define FALLOC_FL_COLLAPSE_RANGE 0x08 #endif /* _UAPI_FALLOC_H_ */ |