inode_vxfs(4) inode_vxfs(4)
NAME [Toc] [Back]
inode_vxfs - format of a VxFS file system inode
SYNOPSIS [Toc] [Back]
#include <sys/types.h>
#include <sys/fs/vx_inode.h>
DESCRIPTION [Toc] [Back]
A VxFS inode is typically 256 bytes in length, but an inode can also
be 512 bytes. You specify the inode size with mkfs.
An inode entry has the following format:
i_mode The mode and type of file.
i_nlink The number of links to the file.
i_uid The inode owner.
i_gid The inode group.
i_size The size in bytes of the file. Eight bytes are
allocated.
i_atime Time of last access, in struct timeval format.
i_mtime Time of last modification, in struct timeval format.
i_ctime Time of last inode change, in struct timeval format.
i_aflags These flags control the allocation and extension of
files:
VX_AF_IBAD If set, the inode is invalid. Cleared
when fsck is run.
VX_AF_NOEXTEND If set, the file cannot be extended
after the current reservation is
exceeded. The reservation can be
increased by the VX_SETEXT ioctl, but
the file is not automatically extended.
VX_AF_NOGROW If set, the file cannot be extended
after the current reservation is
exceeded. This flag is typically set
because an I/O error occurred while
extending a file. Cleared on truncation
or when setext is run.
VX_AF_ALIGN If set, the file must be allocated in
extents of a fixed size and alignment.
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If an extent of i_fixextsize blocks
aligned on an i_fixextsize boundary
cannot be found, then the allocation
fails. The alignment is relative to the
beginning of the allocation unit.
i_orgtype Mapping type. Indicates how to interpret the inode
mapping area. Currently there are four supported
mapping types:
IORG_NONE Mapping area is unused. IORG_NONE is
used for files that have no associated
data storage. Because there is no need
for either extents or immediate data,
the mapping area is unused. Block and
character special files, for example,
use this organization type.
IORG_EXT4 Mapping area consists of an array of
32-bit extent block addresses and sizes.
IORG_IMMED Mapping area itself is a data block.
This mapping is referred to as Immediate
Inode Data.
IORG_TYPED Mapping area consists of typed-extent
structures.
i_eopflags Extended inode operation flag area.
i_eopdata Extended inode operation data area.
i_ftarea This field is a union. The contents are determined by
file type.
For devices, the following field is supported:
i_rdev The device number of a block or
character special device.
For directories, the following field is supported:
i_dotdot The parent directory inode inumber if
the inode is a directory. This
replaces the standard ``..'' (dot
dot) entry in the first directory
block. VxFS does not have explicit
``.'' (dot ) and ``..'' (dot dot)
entries.
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inode_vxfs(4) inode_vxfs(4)
For regular files, the following fields are supported:
i_reserve The number of data blocks reserved
for exclusive use by the file
(preallocation). A preallocation can
be requested using an ioctl. See
vxfsio(7).
i_fixextsize Set when the inode has a fixed extent
size. The default is to have a
variable extent size allocation
policy. A fixed extent size may be
specified using ioctl. See vxfsio(7).
For structural files, the following fields are
supported:
i_matchino (Version 2 and later disk layouts
only.) The inode number of the
``matching'' inode. For replicated
files, this is the inode of the
replica. For extent map
reorganization files, this is the
inode of the file being reorganized.
i_fsetindex (Version 2 and later disk layouts
only.) The index of the fileset
associated with the inode.
i_blocks The number of blocks allocated to the file, including
the blocks allocated for indirect address extents.
i_gen The generation number. A serial number which
increments whenever the inode is freed and reallocated.
This provides a ``handle'' for stateless servers such
as NFS.
i_vversion The number of times the inode metadata is modified.
This field is a 64-bit number.
ic_org The mapping area. This field is a union based on the
value of i_orgtype and the file system type.
For the VxFS IORG_IMMED organization type, the
following structure is used:
i_immed
The immediate inode data area, NIMMED_N (currently
96) bytes in length (see fs_immedlen). Any
directory or symbolic link which is less than or
equal to 96 bytes in length is stored directly in
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the inode.
For the VxFS IORG_EXT4 organization type, the following
structure is used:
i_ies
Indirect extent size. The size, in blocks, of the
indirect data extents in the file.
i_ie Array of indirect address extents. There are
NIADDR indirect address extents. The indirect
address extents are 8192 bytes long. Each
indirect address extent may contain up to 2048
extent addresses.
The first indirect address extent is for single
indirection. With single indirection, each entry
in the indirect address extent indicates the
starting block number of a data extent.
The second indirect address extent is a double
indirect address extent. With double indirection,
each entry in the indirect address extent
indicates the starting block number of a single
indirect address extent.
i_dext
An array of structures containing the direct
extent addresses and sizes. Up to NDADDR_N direct
extents are supported. Because there is a
variable length extent allocation policy, each
direct extent can have a different size. Each
structure contains the following elements:
i_de Direct extent address.
i_des Direct extent size.
i_iattrino
(Version 2 and later disk layouts.) Indirect
attribute inode. Identifies the inode in the
attribute fileset that contains indirect attribute
references.
The remaining bytes of the inode are reserved for
extended attribute records. Their format is:
length
The length of the attribute record. If this
is not a multiple of 4 bytes, the start of
the next attribute record is found by
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rounding the length up to a 4 byte boundary.
format
The format of the data layout of the
remainder of the attribute record. Each
attribute consists of a class identifying the
attribute's administrative domain, a subclass
identifying the attribute within the
administrative domain, and data. The valid
record formats are:
ATTR_EXTIMMED [Toc] [Back]
Extends the immediate data area so that
files larger than 96 bytes can be stored
directly in the inode.
ATTR_IMMED [Toc] [Back]
The attribute is stored directly in the
inode. The fields in the rest of this
record are:
class The class of the attribute.
subclass The subclass of the attribute.
data The attribute data.
ATTR_DIRECT [Toc] [Back]
When attributes are too large to store
directly in the inode, each attribute is
stored in its own file. ATTR_DIRECT
lists each attribute along with the
inode number corresponding to the file
in which the attribute is stored. The
number of entries in the list is
determined by the length of the record.
The fields in each entry are:
class The class of the attribute.
subclass The subclass of the attribute.
length The length of the attribute
data. This allows attribute
operations to check the length
of an attribute without
reading the attribute inode.
inumber The inode number of the file
containing the attribute data.
The inode is part of the
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inode_vxfs(4) inode_vxfs(4)
attribute fileset.
The attribute records in the inode terminate with
a record that has a format of zero (for
compatibility with file systems that have the last
80 bytes of all inodes set to NULL).
SEE ALSO [Toc] [Back]
setext(1M), stat(2), fs_vxfs(4), vxfsio(7).
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