IBM 10 SP1 EAL4 Benutzerhandbuch
Figure 5-9 shows how for a file on the ext3 file system, inode_operations map to
ext3_file_inode_operations.
ext3_file_inode_operations.
Similarly, for directory, symlink, and special-file types of objects, inode operations map to
ext3_dir_inode_operations, ext3_symlink_inode_operations, and
ext3_special_inode_operations, respectively.
ext3_dir_inode_operations, ext3_symlink_inode_operations, and
ext3_special_inode_operations, respectively.
ext3_truncate() is the entry point for truncating a file. The ext3_truncate() routine is invoked
when VFS calls to the sys_truncate() routine are diverted based on the ext3 inode’s inode operation
vector i_op of the ext3 inode. This routine prevents the truncation of inodes whose extended attributes
mark them as being append-only or immutable.
5.1.2.2 ISO 9660 file system for CD-ROM
The SLES kernel supports the ISO 9660 file system for CD-ROM. Refer to the HOWTO document by
Martin Hinner on the Linux Documentation Project Web site for a detailed specification of the ISO 9660 file
system: http://www.tldp.org/HOWTO/Filesystems-HOWTO.html.
Martin Hinner on the Linux Documentation Project Web site for a detailed specification of the ISO 9660 file
system: http://www.tldp.org/HOWTO/Filesystems-HOWTO.html.
5.1.2.2.1 Data structures and algorithms
The following data structures and inode operations implement the file system on the SLES kernel.
•
vfs_permission(): Because the file system is a read-only file system, there are no object reuse
implications with respect to allocating data blocks. The discretionary access check is performed at
the VFS layer with the vfs_permission() routine, which grants permission based on a process’s
implications with respect to allocating data blocks. The discretionary access check is performed at
the VFS layer with the vfs_permission() routine, which grants permission based on a process’s
fsuid field.
•
isofs_sb_info: The CD-ROM file system super block isofs_sb_info stores file system-specific
information, such as the number of inodes, number of zones, maximum size, and fields for the mount
command line option to prohibit the execution of suid programs.
information, such as the number of inodes, number of zones, maximum size, and fields for the mount
command line option to prohibit the execution of suid programs.
•
iso_inode_info: The iso_inode_info is in-core inode information for CD-ROM file objects.
iso_inode_info stores information, such as file format, extent location, and a link to the next inode.
iso_inode_info stores information, such as file format, extent location, and a link to the next inode.
•
isofs_lookup(): The isofs_lookup() on inode is called when the pathname translation routine is
diverted from the VFS layer to the isofs layer. isofs_lookup() sets the inode operation vector
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Figure 5-9: Access control on ext3 file system