.\" $NetBSD: puffs_ops.3,v 1.21.4.2 2009/04/12 02:24:16 snj Exp $ .\" .\" Copyright (c) 2007 Antti Kantee. All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" .\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE .\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" .Dd December 16, 2007 .Dt PUFFS_OPS 3 .Os .Sh NAME .Nm puffs_ops .Nd puffs callback operations .Sh LIBRARY .Lb libpuffs .Sh SYNOPSIS .In puffs.h .Ft int .Fo puffs_fs_statvfs .Fa "struct puffs_usermount *pu" "struct statvfs *sbp" .Fc .Ft int .Fo puffs_fs_sync .Fa "struct puffs_usermount *pu" "int waitfor" "const struct puffs_cred *pcr" .Fc .Ft int .Fo puffs_fs_fhtonode .Fa "struct puffs_usermount *pu" "void *fid" "size_t fidsize" .Fa "struct puffs_newinfo *pni" .Fc .Ft int .Fo puffs_fs_nodetofh .Fa "struct puffs_usermount *pu" "puffs_cooie_t cookie" "void *fid" .Fa "size_t *fidsize" .Fc .Ft void .Fn puffs_fs_suspend "struct puffs_usermount *pu" "int status" .Ft int .Fo puffs_fs_unmount .Fa "struct puffs_usermount *pu" "int flags" .Fc .Ft int .Fo puffs_node_lookup .Fa "struct puffs_usermount *pu" "puffs_cookie_t opc" .Fa "struct puffs_newinfo *pni" "const struct puffs_cn *pcn" .Fc .Ft int .Fo puffs_node_create .Fa "struct puffs_usermount *pu" "puffs_cookie_t opc" .Fa "struct puffs_newinfo *pni" "const struct puffs_cn *pcn" .Fa "const struct vattr *vap" .Fc .Ft int .Fo puffs_node_mknod .Fa "struct puffs_usermount *pu" "puffs_cookie_t opc" .Fa "struct puffs_newinfo *pni" "const struct puffs_cn *pcn" .Fa "const struct vattr *vap" .Fc .Ft int .Fo puffs_node_open .Fa "struct puffs_usermount *pu" "puffs_cookie_t opc" "int mode" .Fa "const struct puffs_cred *pcr" .Fc .Ft int .Fo puffs_node_close .Fa "struct puffs_usermount *pu" "puffs_cookie_t opc" "int flags" .Fa "const struct puffs_cred *pcr" .Fc .Ft int .Fo puffs_node_access .Fa "struct puffs_usermount *pu" "puffs_cookie_t opc" "int mode" .Fa "const struct puffs_cred *pcr" .Fc .Ft int .Fo puffs_node_getattr .Fa "struct puffs_usermount *pu" "puffs_cookie_t opc" "struct vattr *vap" .Fa "const struct puffs_cred *pcr" .Fc .Ft int .Fo puffs_node_setattr .Fa "struct puffs_usermount *pu" "puffs_cookie_t opc" "const struct vattr *vap" .Fa "const struct puffs_cred *pcr" .Fc .Ft int .Fo puffs_node_poll .Fa "struct puffs_usermount *pu" "puffs_cookie_t opc" "int *events" .Fc .Ft int .Fo puffs_node_mmap .Fa "struct puffs_usermount *pu" "puffs_cookie_t opc" "int flags" .Fa "const struct puffs_cred *pcr" .Fc .Ft int .Fo puffs_node_fsync .Fa "struct puffs_usermount *pu" "puffs_cookie_t opc" .Fa "const struct puffs_cred *pcr" "int flags" "off_t offlo" "off_t offhi" .Fc .Ft int .Fo puffs_node_seek .Fa "struct puffs_usermount *pu" "puffs_cookie_t opc" "off_t oldoff" .Fa "off_t newoff" "const struct puffs_cred *pcr" .Fc .Ft int .Fo puffs_node_remove .Fa "struct puffs_usermount *pu" "puffs_cookie_t opc" "puffs_cookie_t targ" .Fa "const struct puffs_cn *pcn" .Fc .Ft int .Fo puffs_node_link .Fa "struct puffs_usermount *pu" "puffs_cookie_t opc" "puffs_cookie_t targ" .Fa "const struct puffs_cn *pcn" .Fc .Ft int .Fo puffs_node_rename .Fa "struct puffs_usermount *pu" "puffs_cookie_t opc" "puffs_cookie_t src" .Fa "const struct puffs_cn *pcn_src" "puffs_cookie_t targ_dir" .Fa "puffs_cookie_t targ" "const struct puffs_cn *pcn_targ" .Fc .Ft int .Fo puffs_node_mkdir .Fa "struct puffs_usermount *pu" "puffs_cookie_t opc" .Fa "struct puffs_newinfo *pni" "const struct puffs_cn *pcn" .Fa "const struct vattr *vap" .Fc .Ft int .Fo puffs_node_rmdir .Fa "struct puffs_usermount *pu" "puffs_cookie_t opc" "puffs_cookie_t targ" .Fa "const struct puffs_cn *pcn" .Fc .Ft int .Fo puffs_node_readdir .Fa "struct puffs_usermount *pu" "puffs_cookie_t opc" "struct dirent *dent" .Fa "off_t *readoff" "size_t *reslen" "const struct puffs_cred *pcr" .Fa "int *eofflag" "off_t *cookies" "size_t *ncookies" .Fc .Ft int .Fo puffs_node_symlink .Fa "struct puffs_usermount *pu" "puffs_cookie_t opc" .Fa "struct puffs_newinfo *pni" .Fa "const struct puffs_cn *pcn_src" "const struct vattr *vap" .Fa "const char *link_target" .Fc .Ft int .Fo puffs_node_readlink .Fa "struct puffs_usermount *pu" "puffs_cookie_t opc" .Fa "const struct puffs_cred *pcr" "char *link" "size_t *linklen" .Fc .Ft int .Fo puffs_node_read .Fa "struct puffs_usermount *pu" "puffs_cookie_t opc" "uint8_t *buf" .Fa "off_t offset" "size_t *resid" "const struct puffs_cred *pcr" "int ioflag" .Fc .Ft int .Fo puffs_node_write .Fa "struct puffs_usermount *pu" "puffs_cookie_t opc" "uint8_t *buf" .Fa "off_t offset" "size_t *resid" "const struct puffs_cred *pcr" "int ioflag" .Fc .Ft int .Fn puffs_node_print "struct puffs_usermount *pu" "puffs_cookie_t opc" .Ft int .Fo puffs_node_reclaim .Fa "struct puffs_usermount *pu" "puffs_cookie_t opc" .Fc .Ft int .Fo puffs_node_inactive .Fa "struct puffs_usermount *pu" "puffs_cookie_t opc" .Fc .Ft void .Fn puffs_setback "struct puffs_cc *pcc" "int op" .Ft void .Fn puffs_newinfo_setcookie "struct puffs_newinfo *pni" "puffs_cookie_t cookie" .Ft void .Fn puffs_newinfo_setvtype "struct puffs_newinfo *pni" "enum vtype vtype" .Ft void .Fn puffs_newinfo_setsize "struct puffs_newinfo *pni" "voff_t size" .Ft void .Fn puffs_newinfo_setrdev "struct puffs_newinfo *pni" "dev_t rdev" .Sh DESCRIPTION The operations .Nm puffs requires to function can be divided into two categories: file system callbacks and node callbacks. The former affect the entire file system while the latter are targeted at a file or a directory and a file. They are roughly equivalent to the vfs and vnode operations in the kernel. .Pp All callbacks can be prototyped with the file system name and operation name using the macro .Fn PUFFSOP_PROTOS fsname . .Ss File system callbacks (puffs_fs) .Bl -tag -width xxxx .It Fn puffs_fs_statvfs "pu" "sbp" The following fields of the argument .Fa sbp need to be filled: .Bd -literal * unsigned long f_bsize; file system block size * unsigned long f_frsize; fundamental file system block size * fsblkcnt_t f_blocks; number of blocks in file system, * (in units of f_frsize) * * fsblkcnt_t f_bfree; free blocks avail in file system * fsblkcnt_t f_bavail; free blocks avail to non-root * fsblkcnt_t f_bresvd; blocks reserved for root * fsfilcnt_t f_files; total file nodes in file system * fsfilcnt_t f_ffree; free file nodes in file system * fsfilcnt_t f_favail; free file nodes avail to non-root * fsfilcnt_t f_fresvd; file nodes reserved for root .Ed .It Fn puffs_fs_sync "pu" "waitfor" "pcr" All the dirty buffers that have been cached at the file server level including metadata should be committed to stable storage. The .Fa waitfor parameter affects the operation. Possible values are: .Bl -tag -width XMNT_NOWAITX .It Dv MNT_WAIT Wait for all I/O for complete until returning. .It Dv MNT_NOWAIT Initiate I/O, but do not wait for completion. .It Dv MNT_LAZY Synchorize data not synchoronized by the file system syncer, i.e. data not written when .Fn node_fsync is called with .Dv FSYNC_LAZY . .El .Pp The credentials for the initiator of the sync operation are present in .Fa pcr and will usually be either file system or kernel credentials, but might also be user credentials. However, most of the time it is advisable to sync regardless of the credentials of the caller. .It Fn puffs_fs_fhtonode "pu" "fid" "fidsize" "pni" Translates a file handle .Fa fid to a node. The parameter .Fa fidsize indicates how large the file handle is. In case the file system's handles are static length, this parameter can be ignored as the kernel guarantees all file handles passed to the file server are of correct length. For dynamic length handles the field should be examined and .Er EINVAL returned in case the file handle length is not correct. .Pp This function provides essentially the same information to the kernel as .Fn puffs_node_lookup . The information is necessary for creating a new vnode corresponding to the file handle. .It Fn puffs_fs_nodetofh "pu" "cookie" "fid" "fidsize" Create a file handle from the node described by .Fa cookie . The file handle should contain enough information to reliably identify the node even after reboots and the pathname/inode being replaced by another file. If this is not possible, it is up to the author of the file system to act responsibly and decide if the file system can support file handles at all. .Pp For file systems which want dynamic length file handles, this function must check if the file handle space indicated by .Fa fidsize is large enough to accommodate the file handle for the node. If not, it must fill in the correct size and return .Er E2BIG . In either case, the handle length should be supplied to the kernel in .Fa fidsize . File systems with static length handles can ignore the size parameter as the kernel always supplies the correct size buffer. .It Fn puffs_fs_suspend "pu" "status" Called when file system suspension reaches various phases. See .Xr puffs_suspend 3 for more information. .It Fn puffs_fs_unmount "pu" "flags" Unmount the file system. The kernel has assumedly flushed all cached data when this callback is executed. If the file system cannot currently be safely be unmounted, for whatever reason, the kernel will honor an error value and not forcibly unmount. However, if the flag .Dv MNT_FORCE is not honored by the file server, the kernel will forcibly unmount the file system. .El .Ss Node callbacks These operations operate in the level of individual files. The file cookie is always provided as the second argument .Fa opc . If the operation is for a file, it will be the cookie of the file. The case the operation involves a directory (such as .Dq create file in directory ) , the cookie will be for the directory. Some operations take additional cookies to describe the rest of the operands. The return value 0 signals success, else an appropriate errno value should be returned. Please note that neither this list nor the descriptions are complete. .Bl -tag -width xxxx .It Fn puffs_node_lookup "pu" "opc" "pni" "pcn" This function is used to locate nodes, or in other words translate pathname components to file system data structures. The implementation should match the name in .Fa pcn against the existing entries in the directory provided by the cookie .Fa opc . If found, the cookie for the located node should be set in .Fa pni using .Fn puffs_newinfo_setcookie . Additionally, the vnode type and size (latter applicable to regular files only) should be set using .Fn puffs_newinfo_setvtype and .Fn puffs_newinfo_setsize , respectively. If the located entry is a block device or character device file, the dev_t for the entry should be set using .Fn puffs_newinfo_setrdev . .Pp The type of operation is found from .Va pcn-\*[Gt]pcn_nameiop : .Bl -tag -width XPUFFSLOOKUP_LOOKUPX .It Dv PUFFSLOOKUP_LOOKUP Normal lookup operation. .It Dv PUFFSLOOKUP_CREATE Lookup to create a node. .It Dv PUFFSLOOKUP_DELETE Lookup for node deletion. .It Dv PUFFSLOOKUP_RENAME Lookup for the target of a rename operation (source will be looked up using .Dv PUFFSLOOKUP_DELETE ) . .El .Pp The final component from a pathname lookup usually requires special treatment. It can be identified by looking at the .Va pcn-\*[Gt]pcn_flags fields for the flag .Dv PUFFSLOOKUP_ISLASTCN . For example, in most cases the lookup operation will want to check if a delete, rename or create operation has enough credentials to perform the operation. .Pp The return value 0 signals a found node and a nonzero value signals an errno. As a special case, .Er ENOENT signals "success" for cases where the lookup operation is .Dv PUFFSLOOKUP_CREATE or .Dv PUFFSLOOKUP_RENAME . Failure in these cases can be signalled by returning another appropriate error code, for example .Er EACCESS . .Pp Usually a null-terminated string for the next pathname component is provided in .Ar pcn-\*[Gt]pcn_name . In case the file system is using the option .Dv PUFFS_KFLAG_LOOKUP_FULLPNBUF , the remainder of the complete pathname under lookup is found in the same location. .Ar pcn-\*[Gt]pcn_namelen always specifies the length of the next component. If operating with a full path, the file system is allowed to consume more than the next component's length in node lookup. This is done by setting .Ar pcn-\*[Gt]pcn_consume to indicate the amount of .Em extra characters in addition to .Ar pcn-\*[Gt]pcn_namelen processed. .It Fn puffs_node_create "pu" "opc" "pni" "pcn" "va" .It Fn puffs_node_mkdir "pu" "opc" "pni" "pcn" "va" .It Fn puffs_node_mknod "pu" "opc" "pni" "pcn" "va" A file node is created in the directory denoted by the cookie .Fa opc by any of the above callbacks. The name of the new file can be found from .Fa pcn and the attributes are specified by .Fa va and the cookie for the newly created node should be set in .Fa pni . The only difference between these three is that they create a regular file, directory and device special file, respectively. .Pp In case of mknod, the device identifier can be found in .Fa va-\*[Gt]va_rdev . .It Fn puffs_node_open "pu" "opc" "mode" "pcr" Open the node denoted by the cookie .Fa opc . The parameter .Fa mode specifies the flags that .Xr open 2 was called with, e.g. .Dv O_APPEND and .Dv O_NONBLOCK . .It Fn puffs_node_close "pu" "opc" "flags" "pcr" Close a node. The parameter .Fa flags parameter describes the flags that the file was opened with. .It Fn puffs_node_access "pu" "opc" "mode" "pcr" Check if the credentials of .Fa pcr have the right to perform the operation specified by .Fa mode onto the node .Fa opc . The argument .Fa mode can specify read, write or execute by .Dv PUFFS_VREAD , .Dv PUFFS_VWRITE , and .Dv PUFFS_VEXEC , respectively. .It Fn puffs_node_getattr "pu" "opc" "va" "pcr" The attributes of the node specified by .Fa opc must be copied to the space pointed by .Fa va . .It Fn puffs_node_setattr "pu" "opc" "va" "pcr" The attributes for the node specified by .Fa opc must be set to those contained in .Fa va . Only fields of .Fa va which contain a value different from .Dv PUFFS_VNOVAL (typecast to the field's type!) contain a valid value. .It Fn puffs_node_poll "pu" "opc" "events" Poll for events on node .Ar opc . If .Xr poll 2 events specified in .Ar events are available, the function should set the bitmask to match available events and return immediately. Otherwise, the function should block (yield) until some events in .Ar events become available and only then set the .Ar events bitmask and return. .Pp In case this function returns an error, .Dv POLLERR (or it's .Xr select 2 equivalent) will be delivered to the calling process. .Pp .Em NOTE! The system call interface for .Fn poll contains a timeout parameter. At this level, however, the timeout is not supplied. In case input does not arrive, the file system should periodically unblock and return 0 new events to avoid hanging forever. This will hopefully be better supported by libpuffs in the future. .It Fn puffs_node_mmap "pu" "opc" "flags" "pcr" Called when a regular file is being memory mapped by .Xr mmap 2 . .Fa flags is currently always 0. .It Fn puffs_node_fsync "pu" "opc" "pcr" "flags" "offlo" "offhi" Sychronize a node's contents onto stable storage. This is necessary only if the file server caches some information before committing it. The parameter .Fa flags specifies the minimum level of sychronization required (XXX: they are not yet available). The parameters .Fa offlo and .Fa offhi specify the data offsets requiring to be synced. A high offset of 0 means sync from .Fa offlo to the end of the file. .It Fn puffs_node_seek "pu" "opc" "oldoff" "newoff" "pcr" Test if the node .Ar opc is seekable to the location .Ar newoff . The argument .Ar oldoff specifies the offset we are starting the seek from. Most file systems dealing only with regular will choose to not implement this. However, it is useful for example in cases where files are unseekable streams. .It Fn puffs_node_remove "pu" "opc" "targ" "pcn" .It Fn puffs_node_rmdir "pu" "opc" "targ" "pcn" Remove the node .Fa targ from the directory indicated by .Fa opc . The directory entry name to be removed is provided by .Fa pcn . The rmdir operation removes only directories, while the remove operation removes all other types except directories. .Pp It is paramount to note that the file system may not remove the node data structures at this point, only the directory entry and prevent lookups from finding the node again. This is to retain the .Ux open file semantics. The data may be removed only when .Fn puffs_node_reclaim is called for the node, as this assures there are no further users. .It Fn puffs_node_link "pu" "opc" "targ" "pcn" Create a hard link for the node .Fa targ into the directory .Fa opc . The argument .Fa pcn provides the directory entry name for the new link. .It Fn puffs_node_rename "pu" "src_dir" "src" "pcn_src" "targ_dir" "targ" "pcn_targ" Rename the node .Fa src with the name specified by .Fa pcn_src from the directory .Fa src_dir . The target directory and target name are given by .Fa targ_dir and .Fa pcn_targ , respectively. .Em If the target node already exists, it is specified by .Fa targ and must be replaced atomically. Otherwise .Fa targ is gives as .Dv NULL . .Pp It is legal to replace a directory node by another directory node with the means of rename if the target directory is empty, otherwise .Er ENOTEMPTY should be returned. All other types can replace all other types. In case a rename between incompatible types is attempted, the errors .Er ENOTDIR or .Er EISDIR should be returned, depending on the target type. .It Fn puffs_node_readdir "pu" "opc" "dent" "readoff" "reslen" "pcr" "eofflag" "cookies" "ncookies" To read directory entries, .Fn puffs_node_readdir is called. It should store directories as .Va struct dirent in the space pointed to by .Fa dent . The amount of space available is given by .Fa reslen and before returning it should be set to the amount of space .Em remaining in the buffer. The argument .Fa offset is used to specify the offset to the directory. Its intepretation is up to the file system and it should be set to signal the continuation point when there is no more room for the next entry in .Fa dent . It is most performant to return the maximal amount of directory entries each call. It is easiest to generate directory entries by using .Fn puffs_nextdent , which also automatically advances the necessary pointers. .Pp In case end-of-directory is reached, .Fa eofflag should be set to one. Note that even a new call to readdir may start where .Fa readoff points to end-of-directory. .Pp If the file system supports file handles, the arguments .Fa cookies and .Fa ncookies must be filled out. .Fa cookies is a vector for offsets corresponding to read offsets. One cookie should be filled out for each directory entry. The value of the cookie should equal the offset of the .Em next directory entry, i.e. which offset should be passed to readdir for the first entry read to be the entry following the current one. .Fa ncookies is the number of slots for cookies in the cookie vector upon entry to the function and must be set to the amount of cookies stored in the vector (i.e. amount of directory entries read) upon exit. There is always enough space in the cookie vector for the maximal number of entries that will fit into the directory entry buffer. For filling out the vector, the helper function .Fn PUFFS_STORE_DCOOKIE cookies ncookies offset can be used. This properly checks against .Fa cookies being .Dv NULL . Note that .Fa ncookies must be initialized to zero before the first call to .Fn PUFFS_STORE_DCOOKIE . .It Fn puffs_node_symlink "pu" "opc" "pni" "pcn_src" "va" "link_target" Create a symbolic link into the directory .Fa opc with the name in .Fa pcn_src and the initial attributes in .Fa va . The argument .Ar link_target contains a null-terminated string for the link target. The created node cookie should be set in .Fa pni . .It Fn puffs_node_readlink "pu" "opc" "pcr" "link" "linklen" Read the target of a symbolic link .Fa opc . The result is placed in the buffer pointed to by .Fa link . This buffer's length is given in .Fa linklen and it must be updated to reflect the real link length. A terminating nul character should not be put into the buffer and .Em "must not" be included in the link length. .It Fn puffs_node_read "pu" "opc" "buf" "offset" "resid" "pcr" "ioflag" Read the contents of a file .Fa opc . It will gather the data from .Fa offset in the file and read the number .Fa resid octets. The buffer is guaranteed to have this much space. The amount of data requested by .Fa resid should be read, except in the case of eof-of-file or an error. The parameter .Fa resid should be set to indicate the amount of request NOT completed. In the normal case this should be 0. .It Fn puffs_node_write "pu" "opc" "buf" "offset" "resid" "pcr" "ioflag" .Fn puffs_node_write Write data to a file .Fa opc at .Fa offset and extend the file if necessary. The number of octets written is indicated by .Fa resid ; everything must be written or an error will be generated. The parameter must be set to indicate the amount of data NOT written. In case the flag .Dv PUFFS_IO_APPEND is specified, the data should be appended to the end of the file. .It Fn puffs_node_print "pu" "opc" Print information about node. This is used only for kernel-initiated diagnostic purposes. .It Fn puffs_node_reclaim "pu" "opc" The kernel will no longer reference the cookie and resources associated with it may be freed. In case the file .Fa opc has a link count of zero, it may be safely removed now. .It Fn puffs_node_inactive "pu" "opc" The node .Fa opc has lost its last reference in the kernel. However, the cookie must still remain valid until .Fn puffs_node_reclaim is called. .It Fn puffs_setback "pcc" "op" Issue a "setback" operation which will be handled when the request response is returned to the kernel. Currently this can be only called from mmap, open, remove and rmdir. The valid parameters for .Ar op are .Dv PUFFS_SETBACK_INACT_N1 and .Dv PUFFS_SETBACK_INACT_N2 . These signal that a file system mounted with .Dv PUFFS_KFLAG_IAONDEMAND should call the file system inactive method for the specified node. The node number 1 always means the operation cookie .Ar opc , while the node number 2 can be used to specify the second node argument present in some methods, e.g. remove. .It Fn puffs_newinfo_setcookie pni cookie Set cookie for node provided by this method to .Ar cookie . .It Fn puffs_newinfo_setvtype pni vtype Set the type of the newly located node to .Ar vtype . This call is valid only for .Fn lookup and .Fn fhtonode . .It Fn puffs_newinfo_setsize pni size Set the size of the newly located node to .Ar size . If left unset, the value defaults to 0. This call is valid only for .Fn lookup and .Fn fhtovp . .It Fn puffs_newinfo_setrdev pni rdev Set the type of the newly located node to .Ar vtype . This call is valid only for .Fn lookup and .Fn fhtovp producing device type nodes. .El .Sh SEE ALSO .Xr puffs 3 , .Xr vfsops 9 , .Xr vnodeops 9