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Diffstat (limited to 'lib/libsys/getfh.2')
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diff --git a/lib/libsys/getfh.2 b/lib/libsys/getfh.2 new file mode 100644 index 000000000000..d16a34da4f28 --- /dev/null +++ b/lib/libsys/getfh.2 @@ -0,0 +1,232 @@ +.\" Copyright (c) 1989, 1991, 1993 +.\" The Regents of the University of California. All rights reserved. +.\" Copyright (c) 2018 Gandi +.\" +.\" 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. +.\" 3. Neither the name of the University nor the names of its contributors +.\" may be used to endorse or promote products derived from this software +.\" without specific prior written permission. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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 November 30, 2022 +.Dt GETFH 2 +.Os +.Sh NAME +.Nm getfh , +.Nm lgetfh , +.Nm getfhat +.Nd get file handle +.Sh LIBRARY +.Lb libc +.Sh SYNOPSIS +.In sys/param.h +.In sys/mount.h +.Ft int +.Fn getfh "const char *path" "fhandle_t *fhp" +.Ft int +.Fn lgetfh "const char *path" "fhandle_t *fhp" +.Ft int +.Fn getfhat "int fd" "const char *path" "fhandle_t *fhp" "int flag" +.Sh DESCRIPTION +The +.Fn getfh +system call +returns a file handle for the specified file or directory +in the file handle pointed to by +.Fa fhp . +.Pp +The +.Fn lgetfh +system call is like +.Fn getfh +except in the case where the named file is a symbolic link, +in which case +.Fn lgetfh +returns information about the link, +while +.Fn getfh +returns information about the file the link references. +.Pp +The +.Fn getfhat +system call is equivalent to +.Fn getfh +and +.Fn lgetfh +except when the +.Fa path +specifies a relative path. +For +.Fn getfhat +and relative +.Fa path , +the status is retrieved from a file relative to +the directory associated with the file descriptor +.Fa fd +instead of the current working directory. +.Pp +The values for the +.Fa flag +are constructed by a bitwise-inclusive OR of flags from this list, +defined in +.In fcntl.h : +.Bl -tag -width indent +.It Dv AT_SYMLINK_NOFOLLOW +If +.Fa path +names a symbolic link, the status of the symbolic link is returned. +.It Dv AT_RESOLVE_BENEATH +Only walk paths below the directory specified by the +.Ar fd +descriptor. +See the description of the +.Dv O_RESOLVE_BENEATH +flag in the +.Xr open 2 +manual page. +.El +.Pp +If +.Fn getfhat +is passed the special value +.Dv AT_FDCWD +in the +.Fa fd +parameter, the current working directory is used and the behavior is +identical to a call to +.Fn getfth +or +.Fn lgetfh +respectively, depending on whether or not the +.Dv AT_SYMLINK_NOFOLLOW +bit is set in +.Fa flag . +.Pp +When +.Fn getfhat +is called with an absolute +.Fa path , +it ignores the +.Fa fd +argument. +.Pp +These system calls are restricted to the superuser. +.Sh RETURN VALUES +.Rv -std +.Sh ERRORS +The +.Fn getfh +and +.Fn lgetfh +system calls +fail if one or more of the following are true: +.Bl -tag -width Er +.It Bq Er EPERM +The caller does not have appropriate privilege to perform the operation. +.It Bq Er ENOTDIR +A component of the path prefix of +.Fa path +is not a directory. +.It Bq Er ENAMETOOLONG +The length of a component of +.Fa path +exceeds 255 characters, +or the length of +.Fa path +exceeds 1023 characters. +.It Bq Er ENOENT +The file referred to by +.Fa path +does not exist. +.It Bq Er EACCES +Search permission is denied for a component of the path prefix of +.Fa path . +.It Bq Er ELOOP +Too many symbolic links were encountered in translating +.Fa path . +.It Bq Er EFAULT +The +.Fa fhp +argument +points to an invalid address. +.It Bq Er EFAULT +The +.Fa path +argument +points to an invalid address. +.It Bq Er EIO +An +.Tn I/O +error occurred while reading from or writing to the file system. +.It Bq Er EINTEGRITY +Corrupted data was detected while reading from the file system. +.It Bq Er ESTALE +The file handle +.Fa fhp +is no longer valid. +.El +.Pp +In addition to the errors returned by +.Fn getfh , +and +.Fn lgetfh , +the +.Fn getfhat +system call may fail if: +.Bl -tag -width Er +.It Bq Er EBADF +The +.Fa path +argument does not specify an absolute path and the +.Fa fd +argument, is neither +.Dv AT_FDCWD +nor a valid file descriptor open for searching. +.It Bq Er EINVAL +The value of the +.Fa flag +argument is not valid. +.It Bq Er ENOTDIR +The +.Fa path +argument is not an absolute path and +.Fa fd +is neither +.Dv AT_FDCWD +nor a file descriptor associated with a directory. +.El +.Sh SEE ALSO +.Xr fhopen 2 , +.Xr open 2 , +.Xr stat 2 +.Sh HISTORY +The +.Fn getfh +system call first appeared in +.Bx 4.4 . +The +.Fn lgetfh +system call first appeared in +.Fx 5.3 . +The +.Fn getfhat +system call first appeared in +.Fx 12.1 . |