linux_dsm_epyc7002/include/uapi/linux/falloc.h
Namjae Jeon dd46c78778 fs: Add support FALLOC_FL_INSERT_RANGE for fallocate
FALLOC_FL_INSERT_RANGE command is the opposite command of
FALLOC_FL_COLLAPSE_RANGE that is needed for someone who wants to add
some data in the middle of file.

FALLOC_FL_INSERT_RANGE will create space for writing new data within
a file after shifting extents to right as given length. This command
also has same limitations as FALLOC_FL_COLLAPSE_RANGE in that
operations need to be filesystem block boundary aligned and cannot
cross the current EOF.

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Ashish Sangwan <a.sangwan@samsung.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-03-25 15:07:05 +11:00

62 lines
2.7 KiB
C

#ifndef _UAPI_FALLOC_H_
#define _UAPI_FALLOC_H_
#define FALLOC_FL_KEEP_SIZE 0x01 /* default is extend size */
#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
/*
* FALLOC_FL_ZERO_RANGE is used to convert a range of file to zeros preferably
* without issuing data IO. Blocks should be preallocated for the regions that
* span holes in the file, and the entire range is preferable converted to
* unwritten extents - even though file system may choose to zero out the
* extent or do whatever which will result in reading zeros from the range
* while the range remains allocated for the file.
*
* This can be also used to preallocate blocks past EOF in the same way as
* with fallocate. Flag FALLOC_FL_KEEP_SIZE should cause the inode
* size to remain the same.
*/
#define FALLOC_FL_ZERO_RANGE 0x10
/*
* FALLOC_FL_INSERT_RANGE is use to insert space within the file size without
* overwriting any existing data. The contents of the file beyond offset are
* shifted towards right by len bytes to create a hole. As such, this
* operation will increase the size of the file by len bytes.
*
* 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 insert space using this flag at OR beyond the end of
* the file is considered an illegal operation - just use ftruncate(2) or
* fallocate(2) with mode 0 for such type of operations.
*/
#define FALLOC_FL_INSERT_RANGE 0x20
#endif /* _UAPI_FALLOC_H_ */