Differential D25024 Diff 73424 head/sys/kern/vfs_vnops.c

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head/sys/kern/vfs_vnops.c

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}		}

/*		/*
* Heuristic to detect sequential operation.		* Heuristic to detect sequential operation.
*/		*/
static int		static int
sequential_heuristic(struct uio uio, struct file fp)		sequential_heuristic(struct uio uio, struct file fp)
{		{
		enum uio_rw rw;

ASSERT_VOP_LOCKED(fp->f_vnode, __func__);		ASSERT_VOP_LOCKED(fp->f_vnode, __func__);

		rw = uio->uio_rw;
if (fp->f_flag & FRDAHEAD)		if (fp->f_flag & FRDAHEAD)
return (fp->f_seqcount << IO_SEQSHIFT);		return (fp->f_seqcount[rw] << IO_SEQSHIFT);

/*		/*
* Offset 0 is handled specially. open() sets f_seqcount to 1 so		* Offset 0 is handled specially. open() sets f_seqcount to 1 so
* that the first I/O is normally considered to be slightly		* that the first I/O is normally considered to be slightly
* sequential. Seeking to offset 0 doesn't change sequentiality		* sequential. Seeking to offset 0 doesn't change sequentiality
* unless previous seeks have reduced f_seqcount to 0, in which		* unless previous seeks have reduced f_seqcount to 0, in which
* case offset 0 is not special.		* case offset 0 is not special.
*/		*/
if ((uio->uio_offset == 0 && fp->f_seqcount > 0) \|\|		if ((uio->uio_offset == 0 && fp->f_seqcount[rw] > 0) \|\|
uio->uio_offset == fp->f_nextoff) {		uio->uio_offset == fp->f_nextoff[rw]) {
/*		/*
* f_seqcount is in units of fixed-size blocks so that it		* f_seqcount is in units of fixed-size blocks so that it
* depends mainly on the amount of sequential I/O and not		* depends mainly on the amount of sequential I/O and not
* much on the number of sequential I/O's. The fixed size		* much on the number of sequential I/O's. The fixed size
* of 16384 is hard-coded here since it is (not quite) just		* of 16384 is hard-coded here since it is (not quite) just
* a magic size that works well here. This size is more		* a magic size that works well here. This size is more
* closely related to the best I/O size for real disks than		* closely related to the best I/O size for real disks than
* to any block size used by software.		* to any block size used by software.
*/		*/
if (uio->uio_resid >= IO_SEQMAX * 16384)		if (uio->uio_resid >= IO_SEQMAX * 16384)
fp->f_seqcount = IO_SEQMAX;		fp->f_seqcount[rw] = IO_SEQMAX;
else {		else {
fp->f_seqcount += howmany(uio->uio_resid, 16384);		fp->f_seqcount[rw] += howmany(uio->uio_resid, 16384);
if (fp->f_seqcount > IO_SEQMAX)		if (fp->f_seqcount[rw] > IO_SEQMAX)
fp->f_seqcount = IO_SEQMAX;		fp->f_seqcount[rw] = IO_SEQMAX;
}		}
return (fp->f_seqcount << IO_SEQSHIFT);		return (fp->f_seqcount[rw] << IO_SEQSHIFT);
}		}

/* Not sequential. Quickly draw-down sequentiality. */		/* Not sequential. Quickly draw-down sequentiality. */
if (fp->f_seqcount > 1)		if (fp->f_seqcount[rw] > 1)
fp->f_seqcount = 1;		fp->f_seqcount[rw] = 1;
else		else
fp->f_seqcount = 0;		fp->f_seqcount[rw] = 0;
return (0);		return (0);
}		}

/*		/*
* Package up an I/O request on a vnode into a uio and do it.		* Package up an I/O request on a vnode into a uio and do it.
*/		*/
int		int
vn_rdwr(enum uio_rw rw, struct vnode vp, void base, int len, off_t offset,		vn_rdwr(enum uio_rw rw, struct vnode vp, void base, int len, off_t offset,
▲ Show 20 Lines • Show All 191 Lines • ▼ Show 20 Lines
{		{
volatile short *flagsp;		volatile short *flagsp;
short state;		short state;

KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed"));		KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed"));

if ((flags & FOF_NOUPDATE) == 0)		if ((flags & FOF_NOUPDATE) == 0)
atomic_store_long(&fp->f_offset, val);		atomic_store_long(&fp->f_offset, val);
if ((flags & FOF_NEXTOFF) != 0)		if ((flags & FOF_NEXTOFF_R) != 0)
fp->f_nextoff = val;		fp->f_nextoff[UIO_READ] = val;
		if ((flags & FOF_NEXTOFF_W) != 0)
		fp->f_nextoff[UIO_WRITE] = val;

if ((flags & FOF_NOLOCK) != 0)		if ((flags & FOF_NOLOCK) != 0)
return;		return;

flagsp = &fp->f_vnread_flags;		flagsp = &fp->f_vnread_flags;
state = atomic_load_16(flagsp);		state = atomic_load_16(flagsp);
if ((state & FOFFSET_LOCK_WAITING) == 0 &&		if ((state & FOFFSET_LOCK_WAITING) == 0 &&
atomic_cmpset_rel_16(flagsp, state, 0))		atomic_cmpset_rel_16(flagsp, state, 0))
Show All 36 Lines	foffset_unlock(struct file *fp, off_t val, int flags)
struct mtx *mtxp;		struct mtx *mtxp;

KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed"));		KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed"));

mtxp = mtx_pool_find(mtxpool_sleep, fp);		mtxp = mtx_pool_find(mtxpool_sleep, fp);
mtx_lock(mtxp);		mtx_lock(mtxp);
if ((flags & FOF_NOUPDATE) == 0)		if ((flags & FOF_NOUPDATE) == 0)
fp->f_offset = val;		fp->f_offset = val;
if ((flags & FOF_NEXTOFF) != 0)		if ((flags & FOF_NEXTOFF_R) != 0)
fp->f_nextoff = val;		fp->f_nextoff[UIO_READ] = val;
		if ((flags & FOF_NEXTOFF_W) != 0)
		fp->f_nextoff[UIO_WRITE] = val;
if ((flags & FOF_NOLOCK) == 0) {		if ((flags & FOF_NOLOCK) == 0) {
KASSERT((fp->f_vnread_flags & FOFFSET_LOCKED) != 0,		KASSERT((fp->f_vnread_flags & FOFFSET_LOCKED) != 0,
("Lost FOFFSET_LOCKED"));		("Lost FOFFSET_LOCKED"));
if (fp->f_vnread_flags & FOFFSET_LOCK_WAITING)		if (fp->f_vnread_flags & FOFFSET_LOCK_WAITING)
wakeup(&fp->f_vnread_flags);		wakeup(&fp->f_vnread_flags);
fp->f_vnread_flags = 0;		fp->f_vnread_flags = 0;
}		}
mtx_unlock(mtxp);		mtx_unlock(mtxp);
▲ Show 20 Lines • Show All 72 Lines • ▼ Show 20 Lines	vn_read(struct file fp, struct uio uio, struct ucred *active_cred, int flags,
}		}
orig_offset = uio->uio_offset;		orig_offset = uio->uio_offset;

#ifdef MAC		#ifdef MAC
error = mac_vnode_check_read(active_cred, fp->f_cred, vp);		error = mac_vnode_check_read(active_cred, fp->f_cred, vp);
if (error == 0)		if (error == 0)
#endif		#endif
error = VOP_READ(vp, uio, ioflag, fp->f_cred);		error = VOP_READ(vp, uio, ioflag, fp->f_cred);
fp->f_nextoff = uio->uio_offset;		fp->f_nextoff[UIO_READ] = uio->uio_offset;
VOP_UNLOCK(vp);		VOP_UNLOCK(vp);
if (error == 0 && advice == POSIX_FADV_NOREUSE &&		if (error == 0 && advice == POSIX_FADV_NOREUSE &&
orig_offset != uio->uio_offset)		orig_offset != uio->uio_offset)
/*		/*
* Use POSIX_FADV_DONTNEED to flush pages and buffers		* Use POSIX_FADV_DONTNEED to flush pages and buffers
* for the backing file after a POSIX_FADV_NOREUSE		* for the backing file after a POSIX_FADV_NOREUSE
* read(2).		* read(2).
*/		*/
▲ Show 20 Lines • Show All 58 Lines • ▼ Show 20 Lines	vn_write(struct file fp, struct uio uio, struct ucred *active_cred, int flags,
}		}
orig_offset = uio->uio_offset;		orig_offset = uio->uio_offset;

#ifdef MAC		#ifdef MAC
error = mac_vnode_check_write(active_cred, fp->f_cred, vp);		error = mac_vnode_check_write(active_cred, fp->f_cred, vp);
if (error == 0)		if (error == 0)
#endif		#endif
error = VOP_WRITE(vp, uio, ioflag, fp->f_cred);		error = VOP_WRITE(vp, uio, ioflag, fp->f_cred);
fp->f_nextoff = uio->uio_offset;		fp->f_nextoff[UIO_WRITE] = uio->uio_offset;
VOP_UNLOCK(vp);		VOP_UNLOCK(vp);
if (vp->v_type != VCHR)		if (vp->v_type != VCHR)
vn_finished_write(mp);		vn_finished_write(mp);
if (error == 0 && advice == POSIX_FADV_NOREUSE &&		if (error == 0 && advice == POSIX_FADV_NOREUSE &&
orig_offset != uio->uio_offset)		orig_offset != uio->uio_offset)
/*		/*
* Use POSIX_FADV_DONTNEED to flush pages and buffers		* Use POSIX_FADV_DONTNEED to flush pages and buffers
* for the backing file after a POSIX_FADV_NOREUSE		* for the backing file after a POSIX_FADV_NOREUSE
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