ioctl_xfs_ag_geometry(2)

Usage

#include <xfs/xfs_fs.h>

int ioctl(int fd, XFS_IOC_AG_GEOMETRY, struct xfs_ag_geometry *arg);

Overview

This XFS ioctl retrieves the geometry information for a given allocation group. The geometry information is conveyed in a structure of the following form:

struct xfs_ag_geometry {
	uint32_t  ag_number;
	uint32_t  ag_length;
	uint32_t  ag_freeblks;
	uint32_t  ag_icount;
	uint32_t  ag_ifree;
	uint32_t  ag_sick;
	uint32_t  ag_checked;
	uint32_t  ag_flags;
	uint64_t  ag_reserved[12];
};

ag_number: The caller must set this field to the index of the allocation group that the caller wishes to learn about.

ag_length: The length of the allocation group is returned in this field, in units of filesystem blocks.

ag_freeblks: The number of free blocks in the allocation group is returned in this field, in units of filesystem blocks.

ag_icount: The number of inode records allocated in this allocation group is returned in this field.

ag_ifree: The number of unused inode records (of the space allocated) in this allocation group is returned in this field.

ag_flags: The caller can set this field to change the operational behavior of the ioctl. Currently no flags are defined, so this field must be zero.

ag_reserved: All reserved fields will be set to zero on return.

The fields ag_sick and ag_checked indicate the relative health of various allocation group metadata:

•: If a given sick flag is set in ag_sick, then that piece of metadata has been observed to be damaged. The same bit will be set in ag_checked.

•: If a given sick flag is set in ag_checked and is not set in ag_sick, then that piece of metadata has been checked and is not faulty.

•: If a given sick flag is not set in ag_checked, then no conclusion can be made.

The following flags apply to these fields:

`XFS_AG_GEOM_SICK_SB`	Allocation group superblock.
`XFS_AG_GEOM_SICK_AGF`	Free space header.
`XFS_AG_GEOM_SICK_AGFL`	Free space reserve list.
`XFS_AG_GEOM_SICK_AGI`	Inode header.
`XFS_AG_GEOM_SICK_BNOBT or XFS_AG_GEOM_SICK_CNTBT`	Free space btrees.
`XFS_AG_GEOM_SICK_INOBT or XFS_AG_GEOM_SICK_FINOBT`	Inode btrees.
`XFS_AG_GEOM_SICK_RMAPBT`	Reverse mapping btree.
`XFS_AG_GEOM_SICK_REFCNTBT`	Reference count btree.

Return value

On error, -1 is returned, and errno is set to indicate the error.

Errors

Error codes can be one of, but are not limited to, the following:

`EFSBADCRC`	Metadata checksum validation failed while performing the query.
`EFSCORRUPTED`	Metadata corruption was encountered while performing the query.
`EINVAL`	The specified allocation group number is not valid for this filesystem.
`EIO`	An I/O error was encountered while performing the query.

Releases

Unchanged in 4 releases since Debian 11 (Bullseye).

11–Arch

Referred to by