Provided by: xfsprogs_3.1.7_amd64 bug


       xfs_bmap - print block mapping for an XFS file


       xfs_bmap [ -adlpv ] [ -n num_extents ] file


       xfs_bmap  prints the map of disk blocks used by files in an XFS filesystem.  The map lists
       each extent used by the file, as well as  regions  in  the  file  that  do  not  have  any
       corresponding blocks (holes).  Each line of the listings takes the following form:

              extent: [startoffset..endoffset]: startblock..endblock

       Holes  are  marked  by replacing the startblock..endblock with hole.  All the file offsets
       and disk blocks are in units of 512-byte blocks, no matter  what  the  filesystem's  block
       size is.


       -a     If this option is specified, information about the file's attribute fork is printed
              instead of the default data fork.

       -d     If portions of the file have been migrated offline by a DMAPI application, a  DMAPI
              read  event  will  be generated to bring those portions back online before the disk
              block map is printed.  However if the -d option is used, no DMAPI read  event  will
              be generated for a DMAPI file and offline portions will be reported as holes.

       -l     If this option is used, then

                   <nblocks>  blocks

              will  be  appended  to each line.  nblocks is the length of the extent described on
              the line in units of 512-byte blocks.

              This flag has no effect if the -v option is used.

       -n num_extents
              If this option is given, xfs_bmap obtains the extent list of the file in groups  of
              num_extents  extents.  In  the  absence  of -n, xfs_bmap queries the system for the
              number of extents in the file and uses that value to compute the group size.

       -p     If this option is used, xfs_bmap obtains all unwritten (preallocated) extents  that
              do  not  contain written data. With the -v option, the flags column will show which
              extents are preallocated/unwritten.

       -v     Shows verbose information. When this flag  is  specified,  additional  AG  specific
              information is appended to each line in the following form:

                   agno (startagoffset..endagoffset) nblocks flags

              A second -v option will print out the flags legend.


       xfs_fsr(8), xfs(5).