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1/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */2#ifndef _UAPI_FALLOC_H_3#define _UAPI_FALLOC_H_4 5#define FALLOC_FL_ALLOCATE_RANGE 0x00 /* allocate range */6#define FALLOC_FL_KEEP_SIZE 0x01 /* default is extend size */7#define FALLOC_FL_PUNCH_HOLE 0x02 /* de-allocates range */8#define FALLOC_FL_NO_HIDE_STALE 0x04 /* reserved codepoint */9 10/*11 * FALLOC_FL_COLLAPSE_RANGE is used to remove a range of a file12 * without leaving a hole in the file. The contents of the file beyond13 * the range being removed is appended to the start offset of the range14 * being removed (i.e. the hole that was punched is "collapsed"),15 * resulting in a file layout that looks like the range that was16 * removed never existed. As such collapsing a range of a file changes17 * the size of the file, reducing it by the same length of the range18 * that has been removed by the operation.19 *20 * Different filesystems may implement different limitations on the21 * granularity of the operation. Most will limit operations to22 * filesystem block size boundaries, but this boundary may be larger or23 * smaller depending on the filesystem and/or the configuration of the24 * filesystem or file.25 *26 * Attempting to collapse a range that crosses the end of the file is27 * considered an illegal operation - just use ftruncate(2) if you need28 * to collapse a range that crosses EOF.29 */30#define FALLOC_FL_COLLAPSE_RANGE 0x0831 32/*33 * FALLOC_FL_ZERO_RANGE is used to convert a range of file to zeros preferably34 * without issuing data IO. Blocks should be preallocated for the regions that35 * span holes in the file, and the entire range is preferable converted to36 * unwritten extents - even though file system may choose to zero out the37 * extent or do whatever which will result in reading zeros from the range38 * while the range remains allocated for the file.39 *40 * This can be also used to preallocate blocks past EOF in the same way as41 * with fallocate. Flag FALLOC_FL_KEEP_SIZE should cause the inode42 * size to remain the same.43 */44#define FALLOC_FL_ZERO_RANGE 0x1045 46/*47 * FALLOC_FL_INSERT_RANGE is use to insert space within the file size without48 * overwriting any existing data. The contents of the file beyond offset are49 * shifted towards right by len bytes to create a hole. As such, this50 * operation will increase the size of the file by len bytes.51 *52 * Different filesystems may implement different limitations on the granularity53 * of the operation. Most will limit operations to filesystem block size54 * boundaries, but this boundary may be larger or smaller depending on55 * the filesystem and/or the configuration of the filesystem or file.56 *57 * Attempting to insert space using this flag at OR beyond the end of58 * the file is considered an illegal operation - just use ftruncate(2) or59 * fallocate(2) with mode 0 for such type of operations.60 */61#define FALLOC_FL_INSERT_RANGE 0x2062 63/*64 * FALLOC_FL_UNSHARE_RANGE is used to unshare shared blocks within the65 * file size without overwriting any existing data. The purpose of this66 * call is to preemptively reallocate any blocks that are subject to67 * copy-on-write.68 *69 * Different filesystems may implement different limitations on the70 * granularity of the operation. Most will limit operations to filesystem71 * block size boundaries, but this boundary may be larger or smaller72 * depending on the filesystem and/or the configuration of the filesystem73 * or file.74 *75 * This flag can only be used with allocate-mode fallocate, which is76 * to say that it cannot be used with the punch, zero, collapse, or77 * insert range modes.78 */79#define FALLOC_FL_UNSHARE_RANGE 0x4080 81#endif /* _UAPI_FALLOC_H_ */82