NAME | SYNOPSIS | DESCRIPTION | FILESYSTEM FEATURE FLAGS | RETURN VALUE | ERRORS | CONFORMING TO | SEE ALSO | COLOPHON

IOCTL-XFS-FSOP-GEOMETRY(2)   System Calls Manual  IOCTL-XFS-FSOP-GEOMETRY(2)

NAME         top

       ioctl_xfs_fsop_geometry - report XFS filesystem layout and features

SYNOPSIS         top

       #include <xfs/xfs_fs.h>

       int ioctl(int fd, XFS_IOC_FSOP_GEOMETRY, struct xfs_fsop_geom*arg);
       int ioctl(int fd, XFS_IOC_FSOP_GEOMETRY_V1, struct xfs_fsop_geom_v1
       *arg);

DESCRIPTION         top

       Report the details of an XFS filesystem layout, features, and other
       descriptive items.  This information is conveyed in a structure of
       the following form:

           struct xfs_fsop_geom {
                __u32         blocksize;
                __u32         rtextsize;
                __u32         agblocks;
                __u32         agcount;
                __u32         logblocks;
                __u32         sectsize;
                __u32         inodesize;
                __u32         imaxpct;
                __u64         datablocks;
                __u64         rtblocks;
                __u64         rtextents;
                __u64         logstart;
                unsigned char uuid[16];
                __u32         sunit;
                __u32         swidth;
                __s32         version;
                __u32         flags;
                __u32         logsectsize;
                __u32         rtsectsize;
                __u32         dirblocksize;
                /* struct xfs_fsop_geom_v1 stops here. */

                __u32         logsunit;
           };

       blocksize is the size of a fundamental filesystem block, in bytes.

       rtextsize is the size of an extent on the realtime volume, in bytes.

       agblocks is the size of an allocation group, in units of filesystem
       blocks.

       agcount is the number of allocation groups in the filesystem.

       logblocks is the size of the log, in units of filesystem blocks.

       sectsize is the smallest amount of data that can be written to the
       data device atomically, in bytes.

       inodesize is the size of an inode record, in bytes.

       imaxpct is the maximum percentage of the filesystem that can be
       allocated to inode record blocks.

       datablocks is the size of the data device, in units of filesystem
       blocks.

       rtblocks is the size of the realtime device, in units of filesystem
       blocks.

       rtextents is the number of extents that can be allocated on the
       realtime device.

       logstart is the start of the log, in units of filesystem blocks.  If
       the filesystem has an external log, this will be zero.

       uuid is the universal unique identifier of the filesystem.

       sunit is what the filesystem has been told is the size of a RAID
       stripe unit on the underlying data device, in filesystem blocks.

       swidth is what the filesystem has been told is the width of a RAID
       stripe on the underlying data device, in units of RAID stripe units.

       version is the version of this structure.  This value will be
       XFS_FSOP_GEOM_VERSION.

       flags tell us what features are enabled on the filesystem.  Refer to
       the section FILESYSTEM FEATURE FLAGS below for more information about
       each feature.

       logsectsize is the smallest amount of data that can be written to the
       log device atomically, in bytes.

       rtsectsize is the smallest amount of data that can be written to the
       realtime device atomically, in bytes.

       dirblocksize is the size of directory blocks, in bytes.

       logsunit is what the filesystem has been told is the size of a RAID
       stripe unit on the underlying log device, in filesystem blocks.  This
       field is meaningful only if the flag XFS_FSOP_GEOM_FLAGS_LOGV2 is
       set.

FILESYSTEM FEATURE FLAGS         top

       Filesystem features are reported to userspace as a combination the
       following flags:

       XFS_FSOP_GEOM_FLAGS_ATTR
              Extended attributes are present.

       XFS_FSOP_GEOM_FLAGS_NLINK
              Files on this filesystem support up to 2^32 hard links.  If
              this flag is not set, files on this filesystem support only up
              to 2^16 hard links.

       XFS_FSOP_GEOM_FLAGS_QUOTA
              Quotas are enabled.

       XFS_FSOP_GEOM_FLAGS_IALIGN
              Inodes are aligned for better performance.

       XFS_FSOP_GEOM_FLAGS_DALIGN
              Filesystem tries to align data block allocations to RAID
              stripe units for better performance.

       XFS_FSOP_GEOM_FLAGS_SHARED
              Unused.

       XFS_FSOP_GEOM_FLAGS_EXTFLG
              Filesystem supports unwritten extents.

       XFS_FSOP_GEOM_FLAGS_DIRV2
              Directories are in version 2 format and maintain free space
              data for better performance.  Version 1 format directories are
              no longer supported.

       XFS_FSOP_GEOM_FLAGS_LOGV2
              Log uses the V2 format.

       XFS_FSOP_GEOM_FLAGS_SECTOR
              The log device has a sector size larger than 512 bytes.

       XFS_FSOP_GEOM_FLAGS_ATTR2
              Filesystem contains V2 extended attributes.

       XFS_FSOP_GEOM_FLAGS_PROJID32
              Project IDs can be as large as 2^32.  If this flag is not set,
              the filesystem supports only 2^16 project IDs.

       XFS_FSOP_GEOM_FLAGS_DIRV2CI
              Case-insensitive lookups are supported on directories.

       XFS_FSOP_GEOM_FLAGS_LAZYSB
              On-disk superblock counters are updated only at unmount time.

       XFS_FSOP_GEOM_FLAGS_V5SB
              Metadata blocks are self describing and contain checksums.

       XFS_FSOP_GEOM_FLAGS_FTYPE
              Directories contain inode types in directory entries.

       XFS_FSOP_GEOM_FLAGS_FINOBT
              Filesystem maintains an index of free inodes.

       XFS_FSOP_GEOM_FLAGS_SPINODES
              Filesystem may allocate discontiguous inode chunks when free
              space is fragmented.

       XFS_FSOP_GEOM_FLAGS_RMAPBT
              Filesystem stores reverse mappings of blocks to owners.

       XFS_FSOP_GEOM_FLAGS_REFLINK
              Filesystem supports sharing blocks between files.

RETURN VALUE         top

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

ERRORS         top

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

       EFAULT The kernel was not able to copy into the userspace buffer.

       EFSBADCRC
              Metadata checksum validation failed while performing the
              query.

       EFSCORRUPTED
              Metadata corruption was encountered while performing the
              query.

       EIO    An I/O error was encountered while performing the query.

CONFORMING TO         top

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

SEE ALSO         top

       ioctl(2)

COLOPHON         top

       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
       2019-07-28.  (At that time, the date of the most recent commit that
       was found in the repository was 2019-07-19.)  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                              2019-06-17       IOCTL-XFS-FSOP-GEOMETRY(2)

Pages that refer to this page: xfsctl(3)