Page MenuHomeFreeBSD
Files F139038778

D10579.diff
No OneTemporary
Actions

D10579.diff
View Options

Index: head/share/man/man9/VOP_GETPAGES.9
===================================================================
--- head/share/man/man9/VOP_GETPAGES.9
+++ head/share/man/man9/VOP_GETPAGES.9
@@ -29,7 +29,7 @@
.\"
.\" $FreeBSD$
.\"
-.Dd December 16, 2015
+.Dd May 7, 2017
.Dt VOP_GETPAGES 9
.Os
.Sh NAME
@@ -41,9 +41,21 @@
.In sys/vnode.h
.In vm/vm.h
.Ft int
-.Fn VOP_GETPAGES "struct vnode *vp" "vm_page_t *ma" "int count" "int *rbehind" "int *rahead"
+.Fo VOP_GETPAGES
+.Fa "struct vnode *vp"
+.Fa "vm_page_t *ma"
+.Fa "int count"
+.Fa "int *rbehind"
+.Fa "int *rahead"
+.Fc
.Ft int
-.Fn VOP_PUTPAGES "struct vnode *vp" "vm_page_t *ma" "int count" "int sync" "int *rtvals"
+.Fo VOP_PUTPAGES
+.Fa "struct vnode *vp"
+.Fa "vm_page_t *ma"
+.Fa "int bytecount"
+.Fa "int flags"
+.Fa "int *rtvals"
+.Fc
.Sh DESCRIPTION
The
.Fn VOP_GETPAGES
@@ -70,10 +82,32 @@
Pointer to the first element of an array of pages representing a
contiguous region of the file to be read or written.
.It Fa count
-The number of bytes that should be read into the pages of the array.
-.It Fa sync
+The length of the
+.Fa ma
+array.
+.It Fa bytecount
+The number of bytes that should be written from the pages of the array.
+.It Fa flags
+A bitfield of flags affecting the function operation.
+If
.Dv VM_PAGER_PUT_SYNC
-if the write should be synchronous.
+is set, the write should be synchronous; control must not be returned
+to the caller until after the write is finished.
+If
+.Dv VM_PAGER_PUT_INVAL
+is set, the pages are to be invalidated after being written.
+If
+.Dv VM_PAGER_PUT_NOREUSE
+is set, the I/O performed should set the IO_NOREUSE flag, to indicate
+to the filesystem that pages should be marked for fast reuse if needed.
+This could occur via a call to
+.Xr vm_page_deactivate_noreuse 9 ,
+which puts such pages onto the head of the inactive queue.
+If
+.Dv VM_PAGER_CLUSTER_OK
+is set, writes may be performed asynchronously, so that related writes
+can be coalesced for efficiency, e.g.,
+using the clustering mechanism of the buffer cache.
.It Fa rtvals
An array of VM system result codes indicating the status of each
page written by
@@ -127,32 +161,33 @@
.Pp
The
.Fn VOP_GETPAGES
-method is expected to release any pages in
+method must populate and validate all requested pages in order to
+return success.
+It is expected to release any pages in
.Fa ma
that it does not successfully handle, by calling
.Xr vm_page_free 9 .
When it succeeds,
.Fn VOP_GETPAGES
must set the valid bits appropriately.
+Upon entry to
+.Fn VOP_GETPAGES ,
+all pages in
+.Fa ma
+are busied exclusively.
+Upon successful return, the pages must all be busied exclusively
+as well, but pages may be unbusied during processing.
+The filesystem is responsible for activating paged-out pages, but this
+does not necessarily need to be done within
.Fn VOP_GETPAGES
-must keep
-.Fa reqpage
-busy.
-It must unbusy all other successfully handled pages and put them
-on appropriate page queue(s).
-For example,
-.Fn VOP_GETPAGES
-may either activate a page (if its wanted bit is set)
-or deactivate it (otherwise), and finally call
-.Xr vm_page_xunbusy 9
-to arouse any threads currently waiting for the page to be faulted in.
+depending on the architecture of the particular filesystem.
.Sh RETURN VALUES
-If it successfully reads
-.Fa ma[reqpage] ,
+If it successfully reads all pages in
+.Fa ma ,
.Fn VOP_GETPAGES
returns
.Dv VM_PAGER_OK ;
-otherwise,
+otherwise, it returns
.Dv VM_PAGER_ERROR .
By convention, the return value of
.Fn VOP_PUTPAGES

File Metadata

Mime Type
text/plain
Expires
Sun, Dec 7, 9:50 PM (4 h, 59 m)
Storage Engine
blob
Storage Format
Raw Data
Storage Handle
26805199
Default Alt Text
D10579.diff (3 KB)

Event Timeline