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Add the posix_fadvise(2) system call. It is somewhat similar to

Browse Source 
madvise(2) except that it operates on a file descriptor instead of a
memory region.  It is currently only supported on regular files.

Just as with madvise(2), the advice given to posix_fadvise(2) can be
divided into two types.  The first type provide hints about data access
patterns and are used in the file read and write routines to modify the
I/O flags passed down to VOP_READ() and VOP_WRITE().  These modes are
thus filesystem independent.  Note that to ease implementation (and
since this API is only advisory anyway), only a single non-normal
range is allowed per file descriptor.

The second type of hints are used to hint to the OS that data will or
will not be used.  These hints are implemented via a new VOP_ADVISE().
A default implementation is provided which does nothing for the WILLNEED
request and attempts to move any clean pages to the cache page queue for
the DONTNEED request.  This latter case required two other changes.
First, a new V_CLEANONLY flag was added to vinvalbuf().  This requests
vinvalbuf() to only flush clean buffers for the vnode from the buffer
cache and to not remove any backing pages from the vnode.  This is
used to ensure clean pages are not wired into the buffer cache before
attempting to move them to the cache page queue.  The second change adds
a new vm_object_page_cache() method.  This method is somewhat similar to
vm_object_page_remove() except that instead of freeing each page in the
specified range, it attempts to move clean pages to the cache queue if
possible.

To preserve the ABI of struct file, the f_cdevpriv pointer is now reused
in a union to point to the currently active advice region if one is
present for regular files.

Reviewed by:	jilles, kib, arch@
Approved by:	re (kib)
MFC after:	1 month
This commit is contained in:
jhb 2011-11-04 04:02:50 +00:00
parent 1e2d8c9d67
commit 78c075174e
18 changed files with 511 additions and 24 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
lib/libc/sys/Makefile.inc
View File

@ -96,7 +96,8 @@ MAN+= abort2.2 accept.2 access.2 acct.2 adjtime.2 \
mq_setattr.2 \
msgctl.2 msgget.2 msgrcv.2 msgsnd.2 \
msync.2 munmap.2 nanosleep.2 nfssvc.2 ntp_adjtime.2 open.2 \
pathconf.2 pdfork.2 pipe.2 poll.2 posix_fallocate.2 posix_openpt.2 profil.2 \
pathconf.2 pdfork.2 pipe.2 poll.2 posix_fadvise.2 posix_fallocate.2 \
posix_openpt.2 profil.2 \
pselect.2 ptrace.2 quotactl.2 \
read.2 readlink.2 reboot.2 recv.2 rename.2 revoke.2 rfork.2 rmdir.2 \
rtprio.2

4
lib/libc/sys/Symbol.map
View File

@ -378,6 +378,10 @@ FBSD_1.2 {
setloginclass;
};
FBSD_1.3 {
posix_fadvise;
};
FBSDprivate_1.0 {
___acl_aclcheck_fd;
__sys___acl_aclcheck_fd;

3
lib/libc/sys/madvise.2
View File

@ -169,7 +169,8 @@ was specified and the process does not have superuser privileges.
.Xr mincore 2 ,
.Xr mprotect 2 ,
.Xr msync 2 ,
.Xr munmap 2
.Xr munmap 2 ,
.Xr posix_fadvise 2
.Sh STANDARDS
The
.Fn posix_madvise

139
lib/libc/sys/posix_fadvise.2 Normal file
View File

@ -0,0 +1,139 @@
.\" Copyright (c) 1991, 1993
.\" The Regents of the University of California. All rights reserved.
.\"
.\" 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.
.\" 4. 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.
.\"
.\" @(#)madvise.2 8.1 (Berkeley) 6/9/93
.\" $FreeBSD$
.\"
.Dd October 26, 2011
.Dt POSIX_FADVISE 2
.Os
.Sh NAME
.Nm posix_fadvise
.Nd give advice about use of file data
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In fcntl.h
.Ft int
.Fn posix_fadvise "int fd" "off_t offset" "off_t len" "int advice"
.Sh DESCRIPTION
The
.Fn posix_fadvise
system call
allows a process to describe to the system its data access behavior for an
open file descriptor
.Fa fd .
The advice covers the data starting at offset
.Fa offset
and continuing for
.Fa len
bytes.
If
.Fa len
is zero,
all data from
.Fa offset
to the end of the file is covered.
.Pp
The behavior is specified by the
.Fa advice
parameter and may be one of:
.Bl -tag -width POSIX_FADV_SEQUENTIAL
.It Dv POSIX_FADV_NORMAL
Tells the system to revert to the default data access behavior.
.It Dv POSIX_FADV_RANDOM
Is a hint that file data will be accessed randomly,
and prefetching is likely not advantageous.
.It Dv POSIX_FADV_SEQUENTIAL
Tells the system that file data will be accessed sequentially.
This currently does nothing as the default behavior uses heuristics to
detect sequential behavior.
.It Dv POSIX_FADV_WILLNEED
Tells the system that the specified data will be accessed in the near future.
The system may initiate an asychronous read of the data if it is not already
present in memory.
.It Dv POSIX_FADV_DONTNEED
Tells the system that the specified data will not be accessed in the near
future.
The system may decrease the in-memory priority of clean data within the
specified range and future access to this data may require a read operation.
.It Dv POSIX_FADV_NOREUSE
Tells the system that the specified data will only be accessed once and
then not reused.
Accesses to data within the specified range are treated as if the file
descriptor has the
.Dv O_DIRECT
flag enabled.
.El
.Pp
.Sh RETURN VALUES
.Rv -std posix_fadvise
.Sh ERRORS
The
.Fn posix_fadvise
system call will fail if:
.Bl -tag -width Er
.It Bq Er EBADF
The
.Fa fd
argument is not a valid file descriptor.
.It Bq Er EINVAL
The
.Fa advice
argument is not valid.
.It Bq Er EINVAL
The
.Fa offset
or
.Fa len
arguments are negative,
or
.Fa offset
+
.Fa len
is greater than the maximum file size.
.It Bq Er ENODEV
The
.Fa fd
argument does not refer to a regular file.
.It Bq Er ESPIPE
The
.Fa fd
argument is associated with a pipe or FIFO.
.El
.Sh SEE ALSO
.Xr madvise 2
.Sh STANDARDS
The
.Fn posix_fadvise
interface conforms to
.St -p1003.1-2001 .
.Sh HISTORY
The
.Fn posix_fadvise
system call first appeared in
.Fx 10.0 .

13
sys/compat/freebsd32/freebsd32_misc.c
View File

@ -2835,3 +2835,16 @@ freebsd32_posix_fallocate(struct thread *td,
ap.len = PAIR32TO64(off_t, uap->len);
return (sys_posix_fallocate(td, &ap));
}
int
freebsd32_posix_fadvise(struct thread *td,
struct freebsd32_posix_fadvise_args *uap)
{
struct posix_fadvise_args ap;
ap.fd = uap->fd;
ap.offset = PAIR32TO64(off_t, uap->offset);
ap.len = PAIR32TO64(off_t, uap->len);
ap.advice = uap->advice;
return (sys_posix_fadvise(td, &ap));
}

5
sys/compat/freebsd32/syscalls.master
View File

@ -991,4 +991,7 @@
530 AUE_NULL STD { int freebsd32_posix_fallocate(int fd,\
uint32_t offset1, uint32_t offset2,\
uint32_t len1, uint32_t len2); }
531 AUE_NULL UNIMPL posix_fadvise
531 AUE_NULL STD { int freebsd32_posix_fadvise(int fd, \
uint32_t offset1, uint32_t offset2,\
uint32_t len1, uint32_t len2, \
int advice); }

3
sys/kern/syscalls.master
View File

@ -947,6 +947,7 @@
size_t outbuflen); }
530 AUE_NULL STD { int posix_fallocate(int fd, \
off_t offset, off_t len); }
531 AUE_NULL UNIMPL posix_fadvise
531 AUE_NULL STD { int posix_fadvise(int fd, off_t offset, \
off_t len, int advice); }
; Please copy any additions and changes to the following compatability tables:
; sys/compat/freebsd32/syscalls.master

53
sys/kern/vfs_default.c
View File

@ -96,6 +96,7 @@ struct vop_vector default_vnodeops = {
.vop_access = vop_stdaccess,
.vop_accessx = vop_stdaccessx,
.vop_advise = vop_stdadvise,
.vop_advlock = vop_stdadvlock,
.vop_advlockasync = vop_stdadvlockasync,
.vop_advlockpurge = vop_stdadvlockpurge,
@ -984,6 +985,58 @@ vop_stdallocate(struct vop_allocate_args *ap)
return (error);
}
int
vop_stdadvise(struct vop_advise_args *ap)
{
struct vnode *vp;
off_t start, end;
int error, vfslocked;
vp = ap->a_vp;
switch (ap->a_advice) {
case POSIX_FADV_WILLNEED:
/*
* Do nothing for now. Filesystems should provide a
* custom method which starts an asynchronous read of
* the requested region.
*/
error = 0;
break;
case POSIX_FADV_DONTNEED:
/*
* Flush any open FS buffers and then remove pages
* from the backing VM object. Using vinvalbuf() here
* is a bit heavy-handed as it flushes all buffers for
* the given vnode, not just the buffers covering the
* requested range.
*/
error = 0;
vfslocked = VFS_LOCK_GIANT(vp->v_mount);
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
if (vp->v_iflag & VI_DOOMED) {
VOP_UNLOCK(vp, 0);
VFS_UNLOCK_GIANT(vfslocked);
break;
}
vinvalbuf(vp, V_CLEANONLY, 0, 0);
if (vp->v_object != NULL) {
start = trunc_page(ap->a_start);
end = round_page(ap->a_end);
VM_OBJECT_LOCK(vp->v_object);
vm_object_page_cache(vp->v_object, OFF_TO_IDX(start),
OFF_TO_IDX(end));
VM_OBJECT_UNLOCK(vp->v_object);
}
VOP_UNLOCK(vp, 0);
VFS_UNLOCK_GIANT(vfslocked);
break;
default:
error = EINVAL;
break;
}
return (error);
}
/*
* vfs default ops
* used to fill the vfs function table to get reasonable default return values.

7
sys/kern/vfs_subr.c
View File

@ -1191,7 +1191,7 @@ bufobj_invalbuf(struct bufobj *bo, int flags, int slpflag, int slptimeo)
do {
error = flushbuflist(&bo->bo_clean,
flags, bo, slpflag, slptimeo);
if (error == 0)
if (error == 0 && !(flags & V_CLEANONLY))
error = flushbuflist(&bo->bo_dirty,
flags, bo, slpflag, slptimeo);
if (error != 0 && error != EAGAIN) {
@ -1220,7 +1220,8 @@ bufobj_invalbuf(struct bufobj *bo, int flags, int slpflag, int slptimeo)
/*
* Destroy the copy in the VM cache, too.
*/
if (bo->bo_object != NULL && (flags & (V_ALT | V_NORMAL)) == 0) {
if (bo->bo_object != NULL &&
(flags & (V_ALT | V_NORMAL | V_CLEANONLY)) == 0) {
VM_OBJECT_LOCK(bo->bo_object);
vm_object_page_remove(bo->bo_object, 0, 0, (flags & V_SAVE) ?
OBJPR_CLEANONLY : 0);
@ -1229,7 +1230,7 @@ bufobj_invalbuf(struct bufobj *bo, int flags, int slpflag, int slptimeo)
#ifdef INVARIANTS
BO_LOCK(bo);
if ((flags & (V_ALT | V_NORMAL)) == 0 &&
if ((flags & (V_ALT | V_NORMAL | V_CLEANONLY)) == 0 &&
(bo->bo_dirty.bv_cnt > 0 || bo->bo_clean.bv_cnt > 0))
panic("vinvalbuf: flush failed");
BO_UNLOCK(bo);

134
sys/kern/vfs_syscalls.c
View File

@ -86,6 +86,8 @@ __FBSDID("$FreeBSD$");
#include <vm/vm_page.h>
#include <vm/uma.h>
static MALLOC_DEFINE(M_FADVISE, "fadvise", "posix_fadvise(2) information");
SDT_PROVIDER_DEFINE(vfs);
SDT_PROBE_DEFINE(vfs, , stat, mode, mode);
SDT_PROBE_ARGTYPE(vfs, , stat, mode, 0, "char *");
@ -4845,3 +4847,135 @@ sys_posix_fallocate(struct thread *td, struct posix_fallocate_args *uap)
return (kern_posix_fallocate(td, uap->fd, uap->offset, uap->len));
}
/*
* Unlike madvise(2), we do not make a best effort to remember every
* possible caching hint. Instead, we remember the last setting with
* the exception that we will allow POSIX_FADV_NORMAL to adjust the
* region of any current setting.
*/
int
sys_posix_fadvise(struct thread *td, struct posix_fadvise_args *uap)
{
struct fadvise_info *fa, *new;
struct file *fp;
struct vnode *vp;
off_t end;
int error;
if (uap->offset < 0 || uap->len < 0 ||
uap->offset > OFF_MAX - uap->len)
return (EINVAL);
switch (uap->advice) {
case POSIX_FADV_SEQUENTIAL:
case POSIX_FADV_RANDOM:
case POSIX_FADV_NOREUSE:
new = malloc(sizeof(*fa), M_FADVISE, M_WAITOK);
break;
case POSIX_FADV_NORMAL:
case POSIX_FADV_WILLNEED:
case POSIX_FADV_DONTNEED:
new = NULL;
break;
default:
return (EINVAL);
}
/* XXX: CAP_POSIX_FADVISE? */
error = fget(td, uap->fd, 0, &fp);
if (error != 0)
goto out;
switch (fp->f_type) {
case DTYPE_VNODE:
break;
case DTYPE_PIPE:
case DTYPE_FIFO:
error = ESPIPE;
goto out;
default:
error = ENODEV;
goto out;
}
vp = fp->f_vnode;
if (vp->v_type != VREG) {
error = ENODEV;
goto out;
}
if (uap->len == 0)
end = OFF_MAX;
else
end = uap->offset + uap->len - 1;
switch (uap->advice) {
case POSIX_FADV_SEQUENTIAL:
case POSIX_FADV_RANDOM:
case POSIX_FADV_NOREUSE:
/*
* Try to merge any existing non-standard region with
* this new region if possible, otherwise create a new
* non-standard region for this request.
*/
mtx_pool_lock(mtxpool_sleep, fp);
fa = fp->f_advice;
if (fa != NULL && fa->fa_advice == uap->advice &&
((fa->fa_start <= end && fa->fa_end >= uap->offset) ||
(end != OFF_MAX && fa->fa_start == end + 1) ||
(fa->fa_end != OFF_MAX && fa->fa_end + 1 == uap->offset))) {
if (uap->offset < fa->fa_start)
fa->fa_start = uap->offset;
if (end > fa->fa_end)
fa->fa_end = end;
} else {
new->fa_advice = uap->advice;
new->fa_start = uap->offset;
new->fa_end = end;
fp->f_advice = new;
new = fa;
}
mtx_pool_unlock(mtxpool_sleep, fp);
break;
case POSIX_FADV_NORMAL:
/*
* If a the "normal" region overlaps with an existing
* non-standard region, trim or remove the
* non-standard region.
*/
mtx_pool_lock(mtxpool_sleep, fp);
fa = fp->f_advice;
if (fa != NULL) {
if (uap->offset <= fa->fa_start &&
end >= fa->fa_end) {
new = fa;
fp->f_advice = NULL;
} else if (uap->offset <= fa->fa_start &&
end >= fa->fa_start)
fa->fa_start = end + 1;
else if (uap->offset <= fa->fa_end &&
end >= fa->fa_end)
fa->fa_end = uap->offset - 1;
else if (uap->offset >= fa->fa_start &&
end <= fa->fa_end) {
/*
* If the "normal" region is a middle
* portion of the existing
* non-standard region, just remove
* the whole thing rather than picking
* one side or the other to
* preserve.
*/
new = fa;
fp->f_advice = NULL;
}
}
mtx_pool_unlock(mtxpool_sleep, fp);
break;
case POSIX_FADV_WILLNEED:
case POSIX_FADV_DONTNEED:
error = VOP_ADVISE(vp, uap->offset, end, uap->advice);
break;
}
out:
if (fp != NULL)
fdrop(fp, td);
free(new, M_FADVISE);
return (error);
}

76
sys/kern/vfs_vnops.c
View File

@ -518,7 +518,7 @@ vn_read(fp, uio, active_cred, flags, td)
struct vnode *vp;
int error, ioflag;
struct mtx *mtxp;
int vfslocked;
int advice, vfslocked;
KASSERT(uio->uio_td == td, ("uio_td %p is not td %p",
uio->uio_td, td));
@ -529,27 +529,48 @@ vn_read(fp, uio, active_cred, flags, td)
ioflag |= IO_NDELAY;
if (fp->f_flag & O_DIRECT)
ioflag |= IO_DIRECT;
advice = POSIX_FADV_NORMAL;
vfslocked = VFS_LOCK_GIANT(vp->v_mount);
/*
* According to McKusick the vn lock was protecting f_offset here.
* It is now protected by the FOFFSET_LOCKED flag.
*/
if ((flags & FOF_OFFSET) == 0) {
if ((flags & FOF_OFFSET) == 0 || fp->f_advice != NULL) {
mtxp = mtx_pool_find(mtxpool_sleep, fp);
mtx_lock(mtxp);
while(fp->f_vnread_flags & FOFFSET_LOCKED) {
fp->f_vnread_flags |= FOFFSET_LOCK_WAITING;
msleep(&fp->f_vnread_flags, mtxp, PUSER -1,
"vnread offlock", 0);
if ((flags & FOF_OFFSET) == 0) {
while (fp->f_vnread_flags & FOFFSET_LOCKED) {
fp->f_vnread_flags |= FOFFSET_LOCK_WAITING;
msleep(&fp->f_vnread_flags, mtxp, PUSER -1,
"vnread offlock", 0);
}
fp->f_vnread_flags |= FOFFSET_LOCKED;
uio->uio_offset = fp->f_offset;
}
fp->f_vnread_flags |= FOFFSET_LOCKED;
if (fp->f_advice != NULL &&
uio->uio_offset >= fp->f_advice->fa_start &&
uio->uio_offset + uio->uio_resid <= fp->f_advice->fa_end)
advice = fp->f_advice->fa_advice;
mtx_unlock(mtxp);
vn_lock(vp, LK_SHARED | LK_RETRY);
uio->uio_offset = fp->f_offset;
} else
vn_lock(vp, LK_SHARED | LK_RETRY);
}
vn_lock(vp, LK_SHARED | LK_RETRY);
ioflag |= sequential_heuristic(uio, fp);
switch (advice) {
case POSIX_FADV_NORMAL:
case POSIX_FADV_SEQUENTIAL:
ioflag |= sequential_heuristic(uio, fp);
break;
case POSIX_FADV_RANDOM:
/* Disable read-ahead for random I/O. */
break;
case POSIX_FADV_NOREUSE:
/*
* Request the underlying FS to discard the buffers
* and pages after the I/O is complete.
*/
ioflag |= IO_DIRECT;
break;
}
#ifdef MAC
error = mac_vnode_check_read(active_cred, fp->f_cred, vp);
@ -584,7 +605,8 @@ vn_write(fp, uio, active_cred, flags, td)
struct vnode *vp;
struct mount *mp;
int error, ioflag, lock_flags;
int vfslocked;
struct mtx *mtxp;
int advice, vfslocked;
KASSERT(uio->uio_td == td, ("uio_td %p is not td %p",
uio->uio_td, td));
@ -618,7 +640,33 @@ vn_write(fp, uio, active_cred, flags, td)
vn_lock(vp, lock_flags | LK_RETRY);
if ((flags & FOF_OFFSET) == 0)
uio->uio_offset = fp->f_offset;
ioflag |= sequential_heuristic(uio, fp);
advice = POSIX_FADV_NORMAL;
if (fp->f_advice != NULL) {
mtxp = mtx_pool_find(mtxpool_sleep, fp);
mtx_lock(mtxp);
if (fp->f_advice != NULL &&
uio->uio_offset >= fp->f_advice->fa_start &&
uio->uio_offset + uio->uio_resid <= fp->f_advice->fa_end)
advice = fp->f_advice->fa_advice;
mtx_unlock(mtxp);
}
switch (advice) {
case POSIX_FADV_NORMAL:
case POSIX_FADV_SEQUENTIAL:
ioflag |= sequential_heuristic(uio, fp);
break;
case POSIX_FADV_RANDOM:
/* XXX: Is this correct? */
break;
case POSIX_FADV_NOREUSE:
/*
* Request the underlying FS to discard the buffers
* and pages after the I/O is complete.
*/
ioflag |= IO_DIRECT;
break;
}
#ifdef MAC
error = mac_vnode_check_write(active_cred, fp->f_cred, vp);
if (error == 0)

9
sys/kern/vnode_if.src
View File

@ -628,3 +628,12 @@ vop_allocate {
INOUT off_t *offset;
INOUT off_t *len;
};
%% advise vp U U U
vop_advise {
IN struct vnode *vp;
IN off_t start;
IN off_t end;
IN int advice;
};

11
sys/sys/fcntl.h
View File

@ -277,9 +277,17 @@ struct oflock {
#define LOCK_UN 0x08 /* unlock file */
#endif
#if __POSIX_VISIBLE >= 200112
/*
* XXX missing posix_fadvise() and POSIX_FADV_* macros.
* Advice to posix_fadvise
*/
#define POSIX_FADV_NORMAL 0 /* no special treatment */
#define POSIX_FADV_RANDOM 1 /* expect random page references */
#define POSIX_FADV_SEQUENTIAL 2 /* expect sequential page references */
#define POSIX_FADV_WILLNEED 3 /* will need these pages */
#define POSIX_FADV_DONTNEED 4 /* dont need these pages */
#define POSIX_FADV_NOREUSE 5 /* access data only once */
#endif
#ifndef _KERNEL
__BEGIN_DECLS
@ -293,6 +301,7 @@ int flock(int, int);
int openat(int, const char *, int, ...);
#endif
#if __BSD_VISIBLE || __POSIX_VISIBLE >= 200112
int posix_fadvise(int, off_t, off_t, int);
int posix_fallocate(int, off_t, off_t);
#endif
__END_DECLS

15
sys/sys/file.h
View File

@ -122,6 +122,12 @@ struct fileops {
* none not locked
*/
struct fadvise_info {
int fa_advice; /* (f) FADV_* type. */
off_t fa_start; /* (f) Region start. */
off_t fa_end; /* (f) Region end. */
};
struct file {
void *f_data; /* file descriptor specific data */
struct fileops *f_ops; /* File operations */
@ -136,7 +142,11 @@ struct file {
*/
int f_seqcount; /* Count of sequential accesses. */
off_t f_nextoff; /* next expected read/write offset. */
struct cdev_privdata *f_cdevpriv; /* (d) Private data for the cdev. */
union {
struct cdev_privdata *fvn_cdevpriv;
/* (d) Private data for the cdev. */
struct fadvise_info *fvn_advice;
} f_vnun;
/*
* DFLAG_SEEKABLE specific fields
*/
@ -147,6 +157,9 @@ struct file {
void *f_label; /* Place-holder for MAC label. */
};
#define f_cdevpriv f_vnun.fvn_cdevpriv
#define f_advice f_vnun.fvn_advice
#define FOFFSET_LOCKED 0x1
#define FOFFSET_LOCK_WAITING 0x2

2
sys/sys/param.h
View File

@ -58,7 +58,7 @@
* in the range 5 to 9.
*/
#undef __FreeBSD_version
#define __FreeBSD_version 1000000 /* Master, propagated to newvers */
#define __FreeBSD_version 1000001 /* Master, propagated to newvers */
#ifdef _KERNEL
#define P_OSREL_SIGWAIT 700000

2
sys/sys/vnode.h
View File

@ -384,6 +384,7 @@ extern int vttoif_tab[];
#define V_SAVE 0x0001 /* vinvalbuf: sync file first */
#define V_ALT 0x0002 /* vinvalbuf: invalidate only alternate bufs */
#define V_NORMAL 0x0004 /* vinvalbuf: invalidate only regular bufs */
#define V_CLEANONLY 0x0008 /* vinvalbuf: invalidate only clean bufs */
#define REVOKEALL 0x0001 /* vop_revoke: revoke all aliases */
#define V_WAIT 0x0001 /* vn_start_write: sleep for suspend */
#define V_NOWAIT 0x0002 /* vn_start_write: don't sleep for suspend */
@ -685,6 +686,7 @@ int vop_stdunlock(struct vop_unlock_args *);
int vop_nopoll(struct vop_poll_args *);
int vop_stdaccess(struct vop_access_args *ap);
int vop_stdaccessx(struct vop_accessx_args *ap);
int vop_stdadvise(struct vop_advise_args *ap);
int vop_stdadvlock(struct vop_advlock_args *ap);
int vop_stdadvlockasync(struct vop_advlockasync_args *ap);
int vop_stdadvlockpurge(struct vop_advlockpurge_args *ap);

54
sys/vm/vm_object.c
View File

@ -1862,6 +1862,60 @@ vm_object_page_remove(vm_object_t object, vm_pindex_t start, vm_pindex_t end,
vm_page_cache_free(object, start, end);
}
/*
* vm_object_page_cache:
*
* For the given object, attempt to move the specified clean
* pages to the cache queue. If a page is wired for any reason,
* then it will not be changed. Pages are specified by the given
* range ["start", "end"). As a special case, if "end" is zero,
* then the range extends from "start" to the end of the object.
* Any mappings to the specified pages are removed before the
* pages are moved to the cache queue.
*
* This operation should only be performed on objects that
* contain managed pages.
*
* The object must be locked.
*/
void
vm_object_page_cache(vm_object_t object, vm_pindex_t start, vm_pindex_t end)
{
struct mtx *mtx, *new_mtx;
vm_page_t p, next;
VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
KASSERT((object->type != OBJT_DEVICE && object->type != OBJT_SG &&
object->type != OBJT_PHYS),
("vm_object_page_cache: illegal object %p", object));
if (object->resident_page_count == 0)
return;
p = vm_page_find_least(object, start);
/*
* Here, the variable "p" is either (1) the page with the least pindex
* greater than or equal to the parameter "start" or (2) NULL.
*/
mtx = NULL;
for (; p != NULL && (p->pindex < end || end == 0); p = next) {
next = TAILQ_NEXT(p, listq);
/*
* Avoid releasing and reacquiring the same page lock.
*/
new_mtx = vm_page_lockptr(p);
if (mtx != new_mtx) {
if (mtx != NULL)
mtx_unlock(mtx);
mtx = new_mtx;
mtx_lock(mtx);
}
vm_page_try_to_cache(p);
}
if (mtx != NULL)
mtx_unlock(mtx);
}
/*
* Populate the specified range of the object with valid pages. Returns
* TRUE if the range is successfully populated and FALSE otherwise.

2
sys/vm/vm_object.h
View File

@ -223,6 +223,8 @@ void vm_object_destroy (vm_object_t);
void vm_object_terminate (vm_object_t);
void vm_object_set_writeable_dirty (vm_object_t);
void vm_object_init (void);
void vm_object_page_cache(vm_object_t object, vm_pindex_t start,
vm_pindex_t end);
void vm_object_page_clean(vm_object_t object, vm_ooffset_t start,
vm_ooffset_t end, int flags);
void vm_object_page_remove(vm_object_t object, vm_pindex_t start,