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6f52b16c | 1 | /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ |
607ca46e DH |
2 | #ifndef _UAPI_FALLOC_H_ |
3 | #define _UAPI_FALLOC_H_ | |
4 | ||
5 | #define FALLOC_FL_KEEP_SIZE 0x01 /* default is extend size */ | |
6 | #define FALLOC_FL_PUNCH_HOLE 0x02 /* de-allocates range */ | |
7 | #define FALLOC_FL_NO_HIDE_STALE 0x04 /* reserved codepoint */ | |
8 | ||
00f5e619 NJ |
9 | /* |
10 | * FALLOC_FL_COLLAPSE_RANGE is used to remove a range of a file | |
11 | * without leaving a hole in the file. The contents of the file beyond | |
12 | * the range being removed is appended to the start offset of the range | |
13 | * being removed (i.e. the hole that was punched is "collapsed"), | |
14 | * resulting in a file layout that looks like the range that was | |
15 | * removed never existed. As such collapsing a range of a file changes | |
16 | * the size of the file, reducing it by the same length of the range | |
17 | * that has been removed by the operation. | |
18 | * | |
19 | * Different filesystems may implement different limitations on the | |
20 | * granularity of the operation. Most will limit operations to | |
21 | * filesystem block size boundaries, but this boundary may be larger or | |
22 | * smaller depending on the filesystem and/or the configuration of the | |
23 | * filesystem or file. | |
24 | * | |
25 | * Attempting to collapse a range that crosses the end of the file is | |
26 | * considered an illegal operation - just use ftruncate(2) if you need | |
27 | * to collapse a range that crosses EOF. | |
28 | */ | |
29 | #define FALLOC_FL_COLLAPSE_RANGE 0x08 | |
607ca46e | 30 | |
409332b6 LC |
31 | /* |
32 | * FALLOC_FL_ZERO_RANGE is used to convert a range of file to zeros preferably | |
33 | * without issuing data IO. Blocks should be preallocated for the regions that | |
34 | * span holes in the file, and the entire range is preferable converted to | |
35 | * unwritten extents - even though file system may choose to zero out the | |
36 | * extent or do whatever which will result in reading zeros from the range | |
37 | * while the range remains allocated for the file. | |
38 | * | |
39 | * This can be also used to preallocate blocks past EOF in the same way as | |
40 | * with fallocate. Flag FALLOC_FL_KEEP_SIZE should cause the inode | |
41 | * size to remain the same. | |
42 | */ | |
43 | #define FALLOC_FL_ZERO_RANGE 0x10 | |
44 | ||
dd46c787 NJ |
45 | /* |
46 | * FALLOC_FL_INSERT_RANGE is use to insert space within the file size without | |
47 | * overwriting any existing data. The contents of the file beyond offset are | |
48 | * shifted towards right by len bytes to create a hole. As such, this | |
49 | * operation will increase the size of the file by len bytes. | |
50 | * | |
51 | * Different filesystems may implement different limitations on the granularity | |
52 | * of the operation. Most will limit operations to filesystem block size | |
53 | * boundaries, but this boundary may be larger or smaller depending on | |
54 | * the filesystem and/or the configuration of the filesystem or file. | |
55 | * | |
56 | * Attempting to insert space using this flag at OR beyond the end of | |
57 | * the file is considered an illegal operation - just use ftruncate(2) or | |
58 | * fallocate(2) with mode 0 for such type of operations. | |
59 | */ | |
60 | #define FALLOC_FL_INSERT_RANGE 0x20 | |
61 | ||
71be6b49 DW |
62 | /* |
63 | * FALLOC_FL_UNSHARE_RANGE is used to unshare shared blocks within the | |
64 | * file size without overwriting any existing data. The purpose of this | |
65 | * call is to preemptively reallocate any blocks that are subject to | |
66 | * copy-on-write. | |
67 | * | |
68 | * Different filesystems may implement different limitations on the | |
69 | * granularity of the operation. Most will limit operations to filesystem | |
70 | * block size boundaries, but this boundary may be larger or smaller | |
71 | * depending on the filesystem and/or the configuration of the filesystem | |
72 | * or file. | |
73 | * | |
74 | * This flag can only be used with allocate-mode fallocate, which is | |
75 | * to say that it cannot be used with the punch, zero, collapse, or | |
76 | * insert range modes. | |
77 | */ | |
78 | #define FALLOC_FL_UNSHARE_RANGE 0x40 | |
79 | ||
607ca46e | 80 | #endif /* _UAPI_FALLOC_H_ */ |