|
NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | CONFORMING TO | NOTES | SEE ALSO | COLOPHON |
IOCTL-XFS-SCRUB-METADATA(2) System Calls Manual IOCTL-XFS-SCRUB-METADATA(2)
ioctl_xfs_scrub_metadata - check XFS filesystem metadata
#include <xfs/xfs_fs.h>
int ioctl(int dest_fd, XFS_IOC_SCRUB_METADATA, struct
xfs_scrub_metadata *arg);
This XFS ioctl asks the kernel driver to examine a piece of
filesystem metadata for errors or suboptimal metadata. Examination
includes running metadata verifiers, checking records for obviously
incorrect or impossible values, and cross-referencing each record
with any other available metadata in the filesystem. This ioctl can
also try to repair or optimize metadata, though this may block normal
filesystem operations for a long period of time. The type and
location of the metadata to scrub is conveyed in a structure of the
following form:
struct xfs_scrub_metadata {
__u32 sm_type;
__u32 sm_flags;
__u64 sm_ino;
__u32 sm_gen;
__u32 sm_agno;
__u64 sm_reserved[5];
};
The field sm_reserved must be zero.
The field sm_type indicates the type of metadata to check:
XFS_SCRUB_TYPE_PROBE
Probe the kernel to see if it is willing to try to check
or repair this filesystem. sm_agno, sm_ino, and sm_gen
must be zero.
XFS_SCRUB_TYPE_SB
XFS_SCRUB_TYPE_AGF
XFS_SCRUB_TYPE_AGFL
XFS_SCRUB_TYPE_AGI
Examine a given allocation group's superblock, free space
header, free block list, or inode header, respectively.
Headers are checked for obviously incorrect values and
cross-referenced against the allocation group's metadata
btrees, if possible. The allocation group number must be
given in sm_agno. sm_ino and sm_gen must be zero.
XFS_SCRUB_TYPE_BNOBT
XFS_SCRUB_TYPE_CNTBT
XFS_SCRUB_TYPE_INOBT
XFS_SCRUB_TYPE_FINOBT
XFS_SCRUB_TYPE_RMAPBT
XFS_SCRUB_TYPE_REFCNTBT
Examine a given allocation group's two free space btrees,
two inode btrees, reverse mapping btrees, or reference
count btrees, respectively. Records are checked for
obviously incorrect values and cross-referenced with other
allocation group metadata records to ensure that there are
no conflicts. The allocation group number must be given
in sm_agno. sm_ino and sm_gen must be zero.
XFS_SCRUB_TYPE_INODE
Examine a given inode record for obviously incorrect
values and discrepancies with the rest of filesystem
metadata. Parent pointers are checked for impossible
inode values and are then followed up to the parent
directory to ensure that the linkage is correct. The
inode to examine may be specified either through sm_ino
and sm_gen; if not specified, then the file described by
dest_fd will be examined. sm_agno must be zero.
XFS_SCRUB_TYPE_BMBTD
XFS_SCRUB_TYPE_BMBTA
XFS_SCRUB_TYPE_BMBTC
XFS_SCRUB_TYPE_PARENT
Examine a given inode's data block map, extended attribute
block map, copy on write block map, or parent inode
pointer. Inode records are examined for obviously
incorrect values and discrepancies with the three block
map types. The block maps are checked for obviously wrong
values and cross-referenced with the allocation group
space extent metadata for discrepancies. The inode to
examine can be specified in the same manner as
XFS_SCRUB_TYPE_INODE.
XFS_SCRUB_TYPE_XATTR
Examine the extended attribute records and indices of a
given inode for incorrect pointers and other signs of
damage. The inode to examine can be specified in the same
manner as XFS_SCRUB_TYPE_INODE.
XFS_SCRUB_TYPE_DIR
Examine the entries in a given directory for invalid data
or dangling pointers. The directory to examine can be
specified in the same manner as XFS_SCRUB_TYPE_INODE.
XFS_SCRUB_TYPE_SYMLINK
Examine the target of a symbolic link for obvious pathname
problems. The link to examine can be specified in the
same manner as XFS_SCRUB_TYPE_INODE.
XFS_SCRUB_TYPE_RTBITMAP
XFS_SCRUB_TYPE_RTSUM
Examine the realtime block bitmap and realtime summary
inodes for corruption.
XFS_SCRUB_TYPE_UQUOTA
XFS_SCRUB_TYPE_GQUOTA
XFS_SCRUB_TYPE_PQUOTA
Examine all user, group, or project quota records for
corruption.
XFS_SCRUB_TYPE_FSCOUNTERS
Examine all filesystem summary counters (free blocks,
inode count, free inode count) for errors.
The field sm_flags control the behavior of the scrub operation and
provide more information about the outcome of the operation. If none
of the XFS_SCRUB_OFLAG_* flags are set upon return, the metadata is
clean.
XFS_SCRUB_IFLAG_REPAIR
If the caller sets this flag, the kernel driver will
examine the metadata and try to fix all problems and to
optimize metadata when possible. If no errors occur
during the repair operation, the check is performed a
second time to determine whether the repair succeeded. If
errors occur, the call returns an error status
immediately.
XFS_SCRUB_OFLAG_CORRUPT
The metadata was corrupt when the call returned. If
XFS_SCRUB_IFLAG_REPAIR was specified, then an attempted
repair failed to fix the problem. Unmount the filesystem
and run xfs_repair to fix the filesystem.
XFS_SCRUB_OFLAG_PREEN
The metadata is ok, but some aspect of the metadata could
be optimized to increase performance. Call again with
XFS_SCRUB_IFLAG_REPAIR to optimize the metadata.
XFS_SCRUB_OFLAG_XFAIL
Filesystem errors were encountered when accessing other
metadata to cross-reference the records attached to this
metadata object.
XFS_SCRUB_OFLAG_XCORRUPT
Discrepancies were found when cross-referencing the
records attached to this metadata object against all other
available metadata in the system.
XFS_SCRUB_OFLAG_INCOMPLETE
The checker was unable to complete its check of all
records.
XFS_SCRUB_OFLAG_WARNING
The checker encountered a metadata object with potentially
problematic records. However, the records were not
obviously corrupt.
For metadata checkers that operate on inodes or inode metadata, the
fields sm_ino and sm_gen are the inode number and generation number
of the inode to check. If the inode number is zero, the inode
represented by dest_fd is used instead. If the generation number of
the inode does not match sm_gen, the call will return an error code
for the invalid argument. The sm_agno field must be zero.
For metadata checkers that operate on allocation group metadata, the
field sm_agno indicates the allocation group in which to find the
metadata. The sm_ino and sm_gen fields must be zero.
For metadata checkers that operate on filesystem-wide metadata, no
further arguments are required. sm_agno, sm_ino, and sm_gen must all
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:
EBUSY The filesystem object is busy; the operation will have to be
tried again.
EFSCORRUPTED
Severe filesystem corruption was detected and could not be
repaired. Unmount the filesystem and run xfs_repair to fix
the filesystem.
EINVAL One or more of the arguments specified is invalid.
ENOENT The specified metadata object does not exist. For example,
this error code is returned for a XFS_SCRUB_TYPE_REFCNTBT
request on a filesystem that does not support reflink.
ENOMEM There was not sufficient memory to perform the scrub or repair
operation. Some operations (most notably reference count
checking) require large amounts of memory.
ENOSPC There is not enough free disk space to attempt a repair.
ENOTRECOVERABLE
Filesystem was mounted in norecovery mode and therefore has an
unclean log. Neither scrub nor repair operations can be
attempted with an unclean log.
ENOTTY Online scrubbing or repair were not enabled.
EOPNOTSUPP
Repairs of the requested metadata object are not supported.
EROFS Filesystem is read-only and a repair was requested.
ESHUTDOWN
Filesystem is shut down due to previous errors.
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) xfs_scrub(8) xfs_repair(8)
This page is part of the xfsprogs (utilities for XFS filesystems)
project. Information about the project can be found at
⟨http://xfs.org/⟩. If you have a bug report for this manual page,
send it to linux-xfs@vger.kernel.org. This page was obtained from
the project's upstream Git repository
⟨https://git.kernel.org/pub/scm/fs/xfs/xfsprogs-dev.git⟩ on
2020-08-13. (At that time, the date of the most recent commit that
was found in the repository was 2020-07-24.) If you discover any
rendering problems in this HTML version of the page, or you believe
there is a better or more up-to-date source for the page, or you have
corrections or improvements to the information in this COLOPHON
(which is not part of the original manual page), send a mail to
man-pages@man7.org
XFS 2017-12-01 IOCTL-XFS-SCRUB-METADATA(2)
Pages that refer to this page: xfsctl(3)
Copyright and license for this manual page