'\" t
.\"     Title: filemap_fault
.\"    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: Memory Management in Linux
.\"    Source: Kernel Hackers Manual 4.8.15
.\"  Language: English
.\"
.TH "FILEMAP_FAULT" "9" "January 2017" "Kernel Hackers Manual 4\&.8\&." "Memory Management in Linux"
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.SH "NAME"
filemap_fault \- read in file data for page fault handling
.SH "SYNOPSIS"
.HP \w'int\ filemap_fault('u
.BI "int filemap_fault(struct\ vm_area_struct\ *\ " "vma" ", struct\ vm_fault\ *\ " "vmf" ");"
.SH "ARGUMENTS"
.PP
\fIvma\fR
.RS 4
vma in which the fault was taken
.RE
.PP
\fIvmf\fR
.RS 4
struct vm_fault containing details of the fault
.RE
.SH "DESCRIPTION"
.PP
\fBfilemap_fault\fR
is invoked via the vma operations vector for a mapped memory region to read in file data during a page fault\&.
.PP
The goto\*(Aqs are kind of ugly, but this streamlines the normal case of having it in the page cache, and handles the special cases reasonably without having a lot of duplicated code\&.
.PP
vma\->vm_mm\->mmap_sem must be held on entry\&.
.PP
If our return value has VM_FAULT_RETRY set, it\*(Aqs because
\fBlock_page_or_retry\fR
returned 0\&. The mmap_sem has usually been released in this case\&. See
\fB__lock_page_or_retry\fR
for the exception\&.
.PP
If our return value does not have VM_FAULT_RETRY set, the mmap_sem has not been released\&.
.PP
We never return with VM_FAULT_RETRY and a bit from VM_FAULT_ERROR set\&.
.SH "COPYRIGHT"
.br