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607ca46e DH |
1 | #ifndef _UAPI_FALLOC_H_ |
2 | #define _UAPI_FALLOC_H_ | |
3 | ||
4 | #define FALLOC_FL_KEEP_SIZE 0x01 /* default is extend size */ | |
5 | #define FALLOC_FL_PUNCH_HOLE 0x02 /* de-allocates range */ | |
6 | #define FALLOC_FL_NO_HIDE_STALE 0x04 /* reserved codepoint */ | |
7 | ||
00f5e619 NJ |
8 | /* |
9 | * FALLOC_FL_COLLAPSE_RANGE is used to remove a range of a file | |
10 | * without leaving a hole in the file. The contents of the file beyond | |
11 | * the range being removed is appended to the start offset of the range | |
12 | * being removed (i.e. the hole that was punched is "collapsed"), | |
13 | * resulting in a file layout that looks like the range that was | |
14 | * removed never existed. As such collapsing a range of a file changes | |
15 | * the size of the file, reducing it by the same length of the range | |
16 | * that has been removed by the operation. | |
17 | * | |
18 | * Different filesystems may implement different limitations on the | |
19 | * granularity of the operation. Most will limit operations to | |
20 | * filesystem block size boundaries, but this boundary may be larger or | |
21 | * smaller depending on the filesystem and/or the configuration of the | |
22 | * filesystem or file. | |
23 | * | |
24 | * Attempting to collapse a range that crosses the end of the file is | |
25 | * considered an illegal operation - just use ftruncate(2) if you need | |
26 | * to collapse a range that crosses EOF. | |
27 | */ | |
28 | #define FALLOC_FL_COLLAPSE_RANGE 0x08 | |
607ca46e | 29 | |
409332b6 LC |
30 | /* |
31 | * FALLOC_FL_ZERO_RANGE is used to convert a range of file to zeros preferably | |
32 | * without issuing data IO. Blocks should be preallocated for the regions that | |
33 | * span holes in the file, and the entire range is preferable converted to | |
34 | * unwritten extents - even though file system may choose to zero out the | |
35 | * extent or do whatever which will result in reading zeros from the range | |
36 | * while the range remains allocated for the file. | |
37 | * | |
38 | * This can be also used to preallocate blocks past EOF in the same way as | |
39 | * with fallocate. Flag FALLOC_FL_KEEP_SIZE should cause the inode | |
40 | * size to remain the same. | |
41 | */ | |
42 | #define FALLOC_FL_ZERO_RANGE 0x10 | |
43 | ||
dd46c787 NJ |
44 | /* |
45 | * FALLOC_FL_INSERT_RANGE is use to insert space within the file size without | |
46 | * overwriting any existing data. The contents of the file beyond offset are | |
47 | * shifted towards right by len bytes to create a hole. As such, this | |
48 | * operation will increase the size of the file by len bytes. | |
49 | * | |
50 | * Different filesystems may implement different limitations on the granularity | |
51 | * of the operation. Most will limit operations to filesystem block size | |
52 | * boundaries, but this boundary may be larger or smaller depending on | |
53 | * the filesystem and/or the configuration of the filesystem or file. | |
54 | * | |
55 | * Attempting to insert space using this flag at OR beyond the end of | |
56 | * the file is considered an illegal operation - just use ftruncate(2) or | |
57 | * fallocate(2) with mode 0 for such type of operations. | |
58 | */ | |
59 | #define FALLOC_FL_INSERT_RANGE 0x20 | |
60 | ||
607ca46e | 61 | #endif /* _UAPI_FALLOC_H_ */ |