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Introduce and use devfs_populate_vp() to unlock a vnode before calling

Browse Source 
devfs_populate(). This is a prerequisite for the automatic removal of
empty directories which will be committed in the future.

Reviewed by:	kib (previous version)
This commit is contained in:
jh 2010-08-22 16:08:12 +00:00
parent bf52da60ea
commit 6471734221
1 changed files with 56 additions and 26 deletions

82
sys/fs/devfs/devfs_vnops.c

@ -185,6 +185,43 @@ devfs_clear_cdevpriv(void)
devfs_fpdrop(fp);
}
/*
* On success devfs_populate_vp() returns with dmp->dm_lock held.
*/
static int
devfs_populate_vp(struct vnode *vp)
{
struct devfs_mount *dmp;
int locked;
ASSERT_VOP_LOCKED(vp, "devfs_populate_vp");
dmp = VFSTODEVFS(vp->v_mount);
locked = VOP_ISLOCKED(vp);
sx_xlock(&dmp->dm_lock);
DEVFS_DMP_HOLD(dmp);
/* Can't call devfs_populate() with the vnode lock held. */
VOP_UNLOCK(vp, 0);
devfs_populate(dmp);
sx_xunlock(&dmp->dm_lock);
vn_lock(vp, locked | LK_RETRY);
sx_xlock(&dmp->dm_lock);
if (DEVFS_DMP_DROP(dmp)) {
sx_xunlock(&dmp->dm_lock);
devfs_unmount_final(dmp);
return (EBADF);
}
if (vp->v_iflag & VI_DOOMED) {
sx_xunlock(&dmp->dm_lock);
return (EBADF);
}
return (0);
}
static int
devfs_vptocnp(struct vop_vptocnp_args *ap)
{
@ -813,14 +850,6 @@ devfs_lookupx(struct vop_lookup_args *ap, int *dm_unlock)
return (error);
}
DEVFS_DMP_HOLD(dmp);
devfs_populate(dmp);
if (DEVFS_DMP_DROP(dmp)) {
*dm_unlock = 0;
sx_xunlock(&dmp->dm_lock);
devfs_unmount_final(dmp);
return (ENOENT);
}
dd = dvp->v_data;
de = devfs_find(dd, cnp->cn_nameptr, cnp->cn_namelen, 0);
while (de == NULL) { /* While(...) so we can use break */
@ -843,7 +872,20 @@ devfs_lookupx(struct vop_lookup_args *ap, int *dm_unlock)
EVENTHANDLER_INVOKE(dev_clone,
td->td_ucred, pname, strlen(pname), &cdev);
sx_sunlock(&clone_drain_lock);
sx_xlock(&dmp->dm_lock);
if (cdev == NULL)
sx_xlock(&dmp->dm_lock);
else if (devfs_populate_vp(dvp) != 0) {
*dm_unlock = 0;
sx_xlock(&dmp->dm_lock);
if (DEVFS_DMP_DROP(dmp)) {
sx_xunlock(&dmp->dm_lock);
devfs_unmount_final(dmp);
} else
sx_xunlock(&dmp->dm_lock);
dev_rel(cdev);
return (ENOENT);
}
if (DEVFS_DMP_DROP(dmp)) {
*dm_unlock = 0;
sx_xunlock(&dmp->dm_lock);
@ -852,19 +894,10 @@ devfs_lookupx(struct vop_lookup_args *ap, int *dm_unlock)
dev_rel(cdev);
return (ENOENT);
}
if (cdev == NULL)
break;
DEVFS_DMP_HOLD(dmp);
devfs_populate(dmp);
if (DEVFS_DMP_DROP(dmp)) {
*dm_unlock = 0;
sx_xunlock(&dmp->dm_lock);
devfs_unmount_final(dmp);
dev_rel(cdev);
return (ENOENT);
}
dev_lock();
dde = &cdev2priv(cdev)->cdp_dirents[dmp->dm_idx];
if (dde != NULL && *dde != NULL)
@ -909,9 +942,11 @@ devfs_lookup(struct vop_lookup_args *ap)
struct devfs_mount *dmp;
int dm_unlock;
if (devfs_populate_vp(ap->a_dvp) != 0)
return (ENOTDIR);
dmp = VFSTODEVFS(ap->a_dvp->v_mount);
dm_unlock = 1;
sx_xlock(&dmp->dm_lock);
j = devfs_lookupx(ap, &dm_unlock);
if (dm_unlock == 1)
sx_xunlock(&dmp->dm_lock);
@ -1139,12 +1174,7 @@ devfs_readdir(struct vop_readdir_args *ap)
}
dmp = VFSTODEVFS(ap->a_vp->v_mount);
sx_xlock(&dmp->dm_lock);
DEVFS_DMP_HOLD(dmp);
devfs_populate(dmp);
if (DEVFS_DMP_DROP(dmp)) {
sx_xunlock(&dmp->dm_lock);
devfs_unmount_final(dmp);
if (devfs_populate_vp(ap->a_vp) != 0) {
if (tmp_ncookies != NULL)
ap->a_ncookies = tmp_ncookies;
return (EIO);