ioctl_xfs_scrubv_metadata - Man Page

#include <xfs/xfs_fs.h>

int ioctl(int dest_fd, XFS_IOC_SCRUBV_METADATA, struct xfs_scrub_vec_head *arg);

This XFS ioctl asks the kernel driver to examine several pieces of filesystem metadata for errors or suboptimal metadata. Multiple scrub types can be invoked to target a single filesystem object. See ioctl_xfs_scrub_metadata(2) for a discussion of metadata validation, and documentation of the various XFS_SCRUB_TYPE and XFS_SCRUB_FLAGS values referenced below.

The types and location of the metadata to scrub are conveyed as a vector with a header of the following form:

struct xfs_scrub_vec_head {
	__u64 svh_ino;
	__u32 svh_gen;
	__u32 svh_agno;
	__u32 svh_flags;
	__u16 svh_rest_us;
	__u16 svh_nr;
	__u64 svh_reserved;
	__u64 svh_vectors;
};

The field svh_ino, svh_gen, and svh_agno correspond to the sm_ino, sm_gen, and sm_agno fields of the regular scrub ioctl. Exactly one filesystem object can be specified in a single call. The kernel will proceed with each vector in svh_vectors until progress is no longer possible.

The field svh_rest_us specifies an amount of time to pause between each scrub invocation to give the system a chance to process other requests.

The field svh_nr specifies the number of vectors in the svh_vectors array.

The field svh_vectors is a pointer to an array of struct xfs_scrub_vec structures.

The field svh_reserved must be zero.

Each vector has the following form:

struct xfs_scrub_vec {
	__u32 sv_type;
	__u32 sv_flags;
	__s32 sv_ret;
	__u32 sv_reserved;
};

The fields sv_type and sv_flags indicate the type of metadata to check and the behavioral changes that userspace will permit of the kernel. The sv_flags field will be updated upon completion of the scrub call. See the documentation of XFS_SCRUB_TYPE_* and XFS_SCRUB_[IO]FLAG_* values in ioctl_xfs_scrub_metadata(2) for a detailed description of their purpose.

If a vector's sv_type field is set to the value XFS_SCRUB_TYPE_BARRIER, the kernel will stop processing vectors and return to userspace if a scrubber flags corruption by setting one of the XFS_SCRUB_OFLAG_* values in sv_flags or returns an operation error in sv_ret. Otherwise, the kernel returns only after processing all vectors.

The sv_ret field is set to the return value of the scrub function. See the Return Value section of the ioctl_xfs_scrub_metadata(2) manual page for more information.

The sv_reserved field must be zero.

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

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

EINVAL

One or more of the arguments specified is invalid.

EINTR

The operation was interrupted.

ENOMEM

There was not sufficient memory to perform the scrub or repair operation.

EFAULT

A memory fault was encountered while reading or writing the vector.

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

These operations may block other filesystem operations for a long time. A calling process can stop the operation by being sent a fatal signal, but non-fatal signals are blocked.

ioctl(2) ioctl_xfs_scrub_metadata(2) xfs_scrub(8) xfs_repair(8)