Check suspendability on the mountpoint returned by VOP_GETWRITEMOUNT.

This obviates the need for a MNTK_SUSPENDABLE flag, since passthrough
filesystems like nullfs and unionfs no longer need to inherit this
information from their lower layer(s). This change also restores the
pre-r273336 behaviour of using the presence of a susp_clean VFS method to
request suspension support.

Reviewed by:	kib, mjg
Differential Revision:	https://reviews.freebsd.org/D2937
This commit is contained in:
Mark Johnston 2015-07-05 22:37:33 +00:00
parent 010ba3842c
commit 5f34e93c58
6 changed files with 33 additions and 37 deletions

View File

@ -199,7 +199,7 @@ nullfs_mount(struct mount *mp)
}
mp->mnt_kern_flag |= MNTK_LOOKUP_EXCL_DOTDOT;
mp->mnt_kern_flag |= lowerrootvp->v_mount->mnt_kern_flag &
(MNTK_SUSPENDABLE | MNTK_USES_BCACHE);
MNTK_USES_BCACHE;
MNT_IUNLOCK(mp);
mp->mnt_data = xmp;
vfs_getnewfsid(mp);

View File

@ -75,6 +75,7 @@ static int tmpfs_root(struct mount *, int flags, struct vnode **);
static int tmpfs_fhtovp(struct mount *, struct fid *, int,
struct vnode **);
static int tmpfs_statfs(struct mount *, struct statfs *);
static void tmpfs_susp_clean(struct mount *);
static const char *tmpfs_opts[] = {
"from", "size", "maxfilesize", "inodes", "uid", "gid", "mode", "export",
@ -256,7 +257,7 @@ tmpfs_mount(struct mount *mp)
MNT_ILOCK(mp);
mp->mnt_flag |= MNT_LOCAL;
mp->mnt_kern_flag |= MNTK_LOOKUP_SHARED | MNTK_SUSPENDABLE;
mp->mnt_kern_flag |= MNTK_LOOKUP_SHARED;
MNT_IUNLOCK(mp);
mp->mnt_data = tmp;
@ -462,6 +463,14 @@ tmpfs_sync(struct mount *mp, int waitfor)
return (0);
}
/*
* The presence of a susp_clean method tells the VFS to track writes.
*/
static void
tmpfs_susp_clean(struct mount *mp __unused)
{
}
/*
* tmpfs vfs operations.
*/
@ -473,5 +482,6 @@ struct vfsops tmpfs_vfsops = {
.vfs_statfs = tmpfs_statfs,
.vfs_fhtovp = tmpfs_fhtovp,
.vfs_sync = tmpfs_sync,
.vfs_susp_clean = tmpfs_susp_clean,
};
VFS_SET(tmpfs_vfsops, tmpfs, VFCF_JAIL);

View File

@ -294,9 +294,6 @@ unionfs_domount(struct mount *mp)
if ((ump->um_lowervp->v_mount->mnt_flag & MNT_LOCAL) &&
(ump->um_uppervp->v_mount->mnt_flag & MNT_LOCAL))
mp->mnt_flag |= MNT_LOCAL;
if ((ump->um_uppervp->v_mount->mnt_kern_flag & MNTK_SUSPENDABLE) != 0)
mp->mnt_kern_flag |= MNTK_SUSPENDABLE;
MNT_IUNLOCK(mp);
/*

View File

@ -1589,22 +1589,10 @@ vn_closefile(fp, td)
}
static bool
vn_suspendable_mp(struct mount *mp)
vn_suspendable(struct mount *mp)
{
return ((mp->mnt_kern_flag & MNTK_SUSPENDABLE) != 0);
}
static bool
vn_suspendable(struct vnode *vp, struct mount **mpp)
{
if (vp != NULL)
*mpp = vp->v_mount;
if (*mpp == NULL)
return (false);
return (vn_suspendable_mp(*mpp));
return (mp->mnt_op->vfs_susp_clean != NULL);
}
/*
@ -1657,11 +1645,6 @@ vn_start_write(struct vnode *vp, struct mount **mpp, int flags)
KASSERT((flags & V_MNTREF) == 0 || (*mpp != NULL && vp == NULL),
("V_MNTREF requires mp"));
if (!vn_suspendable(vp, mpp)) {
if ((flags & V_MNTREF) != 0)
vfs_rel(*mpp);
return (0);
}
error = 0;
/*
@ -1679,6 +1662,12 @@ vn_start_write(struct vnode *vp, struct mount **mpp, int flags)
if ((mp = *mpp) == NULL)
return (0);
if (!vn_suspendable(mp)) {
if (vp != NULL || (flags & V_MNTREF) != 0)
vfs_rel(mp);
return (0);
}
/*
* VOP_GETWRITEMOUNT() returns with the mp refcount held through
* a vfs_ref().
@ -1708,11 +1697,6 @@ vn_start_secondary_write(struct vnode *vp, struct mount **mpp, int flags)
KASSERT((flags & V_MNTREF) == 0 || (*mpp != NULL && vp == NULL),
("V_MNTREF requires mp"));
if (!vn_suspendable(vp, mpp)) {
if ((flags & V_MNTREF) != 0)
vfs_rel(*mpp);
return (0);
}
retry:
if (vp != NULL) {
@ -1730,6 +1714,12 @@ vn_start_secondary_write(struct vnode *vp, struct mount **mpp, int flags)
if ((mp = *mpp) == NULL)
return (0);
if (!vn_suspendable(mp)) {
if (vp != NULL || (flags & V_MNTREF) != 0)
vfs_rel(mp);
return (0);
}
/*
* VOP_GETWRITEMOUNT() returns with the mp refcount held through
* a vfs_ref().
@ -1772,7 +1762,7 @@ void
vn_finished_write(mp)
struct mount *mp;
{
if (mp == NULL || !vn_suspendable_mp(mp))
if (mp == NULL || !vn_suspendable(mp))
return;
MNT_ILOCK(mp);
MNT_REL(mp);
@ -1795,7 +1785,7 @@ void
vn_finished_secondary_write(mp)
struct mount *mp;
{
if (mp == NULL || !vn_suspendable_mp(mp))
if (mp == NULL || !vn_suspendable(mp))
return;
MNT_ILOCK(mp);
MNT_REL(mp);
@ -1818,7 +1808,7 @@ vfs_write_suspend(struct mount *mp, int flags)
{
int error;
MPASS(vn_suspendable_mp(mp));
MPASS(vn_suspendable(mp));
MNT_ILOCK(mp);
if (mp->mnt_susp_owner == curthread) {
@ -1861,7 +1851,7 @@ void
vfs_write_resume(struct mount *mp, int flags)
{
MPASS(vn_suspendable_mp(mp));
MPASS(vn_suspendable(mp));
MNT_ILOCK(mp);
if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) {
@ -1896,7 +1886,7 @@ vfs_write_suspend_umnt(struct mount *mp)
{
int error;
MPASS(vn_suspendable_mp(mp));
MPASS(vn_suspendable(mp));
KASSERT((curthread->td_pflags & TDP_IGNSUSP) == 0,
("vfs_write_suspend_umnt: recursed"));

View File

@ -362,7 +362,7 @@ void __mnt_vnode_markerfree_active(struct vnode **mvp, struct mount *);
#define MNTK_SUSPEND 0x08000000 /* request write suspension */
#define MNTK_SUSPEND2 0x04000000 /* block secondary writes */
#define MNTK_SUSPENDED 0x10000000 /* write operations are suspended */
#define MNTK_SUSPENDABLE 0x20000000 /* writes can be suspended */
#define MNTK_UNUSED1 0x20000000
#define MNTK_LOOKUP_SHARED 0x40000000 /* FS supports shared lock lookups */
#define MNTK_NOKNOTE 0x80000000 /* Don't send KNOTEs from VOP hooks */

View File

@ -1055,8 +1055,7 @@ ffs_mountfs(devvp, mp, td)
*/
MNT_ILOCK(mp);
mp->mnt_kern_flag |= MNTK_LOOKUP_SHARED | MNTK_EXTENDED_SHARED |
MNTK_NO_IOPF | MNTK_UNMAPPED_BUFS | MNTK_SUSPENDABLE |
MNTK_USES_BCACHE;
MNTK_NO_IOPF | MNTK_UNMAPPED_BUFS | MNTK_USES_BCACHE;
MNT_IUNLOCK(mp);
#ifdef UFS_EXTATTR
#ifdef UFS_EXTATTR_AUTOSTART