Author: bjk (doc committer) Date: Sun May 7 19:01:08 2017 New Revision: 317910 URL: https://svnweb.freebsd.org/changeset/base/317910
Log: Bring VOP_GETPAGES.9 more up-to-date Attempt to catch up to the KPI changes from r292373, and perform some other tidying while in the area. Reviewed by: kib Differential Revision: https://reviews.freebsd.org/D10579 Modified: head/share/man/man9/VOP_GETPAGES.9 Modified: head/share/man/man9/VOP_GETPAGES.9 ============================================================================== --- head/share/man/man9/VOP_GETPAGES.9 Sun May 7 17:21:22 2017 (r317909) +++ head/share/man/man9/VOP_GETPAGES.9 Sun May 7 19:01:08 2017 (r317910) @@ -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 @@ The file to access. 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 @@ The page was not handled by this request .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 _______________________________________________ svn-src-all@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
