fallocate
Implemented in Antinomie 0.7.0 · Syscall list
Synopsis
Section titled “Synopsis”long fallocate(int fd, int mode, loff_t offset, loff_t len);| Number (x86-64) | 285 |
| ABI | common |
| Kernel entry point | sys_fallocate |
This is the raw kernel prototype from the pinned Linux 6.12.94 schema, not the libc wrapper.
Description
Section titled “Description”Preallocates, deallocates, punches holes in or collapses the disk space of a file range.
Arguments
Section titled “Arguments”| Name | Type | Meaning |
|---|---|---|
fd (arg0) |
int |
File descriptor to operate on. |
mode (arg1) |
int |
Permission bits (and, for some calls, the file type) for a file or directory being created or changed. |
offset (arg2) |
loff_t |
Value of type loff_t. |
len (arg3) |
loff_t |
Length in bytes. |
Return value
Section titled “Return value”On success: 0.
In an Antinomie trace the Return column and the ret filter field show the raw kernel return value. On failure that is the negative errno, for example -2 for ENOENT, not the -1 plus errno that the libc wrapper gives. syscall.errno holds the positive errno and syscall.success is false.
Common errors
Section titled “Common errors”| Raw return | Name | Meaning |
|---|---|---|
-9 |
EBADF |
A file descriptor is not valid for this operation. |
-28 |
ENOSPC |
There is no space left on the device. |
-95 |
EOPNOTSUPP |
The operation is not supported. |
Man page
Section titled “Man page”Captured by Antinomie
Section titled “Captured by Antinomie”Coverage mark: Implemented. All arguments are plain values, recorded as the raw argument words at entry. There is no pointee to copy and no known gap.
Every call is recorded as an Entry record (the six argument words and the pointees copied at entry) and an Exit record (the return value and the pointees copied at exit).
Arguments
Section titled “Arguments”| Argument | When | How | Recorded field key | Condition |
|---|---|---|---|---|
fd (arg0) |
Entry | raw scalar word | args.0, args.fd |
|
mode (arg1) |
Entry | raw scalar word; Syscall Trace also decodes it into flag names (fallocate group), listing unknown bits separately |
args.1, args.mode |
|
offset (arg2) |
Entry | raw scalar word | args.2, args.offset |
|
len (arg3) |
Entry | raw scalar word | args.3, args.len |
Filter fields
Section titled “Filter fields”- Result:
ret,syscall.errno,syscall.success,syscall.duration_ns. - Argument words:
args.fd(arg0),args.mode(arg1),args.offset(arg2),args.len(arg3);args.0toargs.5by position.
See Syscall Trace filter for the full syntax.
For what the capture statuses mean, see Capture statuses. For what is never recorded, see Known gaps.