Provided by: xfslibs-dev_5.10.0-2ubuntu3_amd64 bug

NAME

       ioctl_xfs_fsgeometry - report XFS filesystem layout and features

SYNOPSIS

       #include <xfs/xfs_fs.h>

       int ioctl(int fd, XFS_IOC_FSGEOMETRY, struct xfs_fsop_geom *arg);
       int ioctl(int fd, XFS_IOC_FSGEOMETRY_V4, struct xfs_fsop_geom_v4 *arg);
       int ioctl(int fd, XFS_IOC_FSGEOMETRY_V1, struct xfs_fsop_geom_v1 *arg);

DESCRIPTION

       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;
                /* struct xfs_fsop_geom_v4 stops here. */

                __u32         sick;
                __u32         checked;
                __u64         reserved[17];
           };

       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.

       The fields sick and checked indicate  the  relative  health  of  various  whole-filesystem
       metadata.  Please see the section XFS METADATA HEALTH REPORTING for more details.

       reserved is set to zero.

FILESYSTEM FEATURE FLAGS

       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.

XFS METADATA HEALTH REPORTING

       The  online  filesystem  checking  utility scans metadata and records what it finds in the
       kernel incore state.  The following scheme is used for userspace to read the incore health
       status of the filesystem:

       · If a given sick flag is set in sick, then that piece of metadata has been observed to be
         damaged.  The same bit should be set in checked.

       · If a given sick flag is set in checked but is not  set  in  sick,  then  that  piece  of
         metadata has been checked and is not faulty.

       · If a given sick flag is not set in checked, then no conclusion can be made.

       The following flags apply to these fields:

           XFS_FSOP_GEOM_SICK_COUNTERS
                  Inode and space summary counters.

           XFS_FSOP_GEOM_SICK_UQUOTA
                  User quota information.

           XFS_FSOP_GEOM_SICK_GQUOTA
                  Group quota information.

           XFS_FSOP_GEOM_SICK_PQUOTA
                  Project quota information.

           XFS_FSOP_GEOM_SICK_RT_BITMAP
                  Free space bitmap for the realtime device.

           XFS_FSOP_GEOM_SICK_RT_SUMMARY
                  Free space summary for the realtime device.

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:

       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

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

SEE ALSO

       ioctl(2)