'\" t
.\"     Title: generic_permission
.\"    Author: [FIXME: author] [see http://docbook.sf.net/el/author]
.\" Generator: DocBook XSL Stylesheets v1.79.1 <http://docbook.sf.net/>
.\"      Date: January 2017
.\"    Manual: The Linux VFS
.\"    Source: Kernel Hackers Manual 4.8.15
.\"  Language: English
.\"
.TH "GENERIC_PERMISSION" "9" "January 2017" "Kernel Hackers Manual 4\&.8\&." "The Linux VFS"
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.SH "NAME"
generic_permission \- check for access rights on a Posix\-like filesystem
.SH "SYNOPSIS"
.HP \w'int\ generic_permission('u
.BI "int generic_permission(struct\ inode\ *\ " "inode" ", int\ " "mask" ");"
.SH "ARGUMENTS"
.PP
\fIinode\fR
.RS 4
inode to check access rights for
.RE
.PP
\fImask\fR
.RS 4
right to check for (\fBMAY_READ\fR,
\fBMAY_WRITE\fR,
\fBMAY_EXEC\fR, \&.\&.\&.)
.RE
.SH "DESCRIPTION"
.PP
Used to check for read/write/execute permissions on a file\&. We use
\(lqfsuid\(rq
for this, letting us set arbitrary permissions for filesystem access without changing the
\(lqnormal\(rq
uids which are used for other things\&.
.PP
generic_permission is rcu\-walk aware\&. It returns \-ECHILD in case an rcu\-walk request cannot be satisfied (eg\&. requires blocking or too much complexity)\&. It would then be called again in ref\-walk mode\&.
.SH "COPYRIGHT"
.br