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   ioctl_xfs_ag_geometry    ( 2 )

запросить информацию о геометрии группы размещения XFS (query XFS allocation group geometry information)

Имя (Name)

ioctl_xfs_ag_geometry - query XFS allocation group geometry information


Синопсис (Synopsis)

#include <xfs/xfs_fs.h>

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


Описание (Description)

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.


Возвращаемое значение (Return value)

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


Ошибки (Error)

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.


Стандарты (Conforming to)

This API is specific to XFS filesystem on the Linux kernel.


Смотри также (See also)

ioctl(2)