Returns information about a file.
| vp | Points to the vnode to be queried. |
| cmd | Specifies the command parameter. |
| bufp | Points to the buffer for the information. |
| length | Specifies the length of the buffer. |
| crp | Specifies user's credentials. |
The vn_finfo entry point is used to query a file system. It is used primarily to implement the pathconf and fpathonf subroutines. The command parameter defines what type of query is being done. The query commands and the associated data structures are defined in <sys/finfo.h>. If the file system does not support the particular query, it should return ENOSYS.
File systems that do not define GFS_VERSION421 in their gfs flags do not need to supply a vn_finfo entry point. If the command is FI_PATHCONF, then the logical file system returns generic pathconf information. If the query is other than FI_PATHCONF, then the request fails with EINVAL.
The vn_finfo entry point can be called from the process environment only.
| Zero | Indicates a successful operation. |
| Nonzero | Indicates that the operation failed; return values should be chosen from the /usr/include/sys/errno.h file. |
The pathconf subroutine, fpathconf subroutine.
Virtual File System Overview, Logical File System Overview, Understanding Virtual Nodes (V-nodes) in AIX Kernel Extensions and Device Support Programming Concepts, and Virtual File System Kernel Extensions Overview.
List of Virtual File System Operations.