void
lookup_consider_update_cache(vnode_t dvp, vnode_t vp, struct componentname *cnp, int nc_generation)
{
int isdot_or_dotdot;
isdot_or_dotdot = (cnp->cn_namelen == 1 && cnp->cn_nameptr[0] == '.') || (cnp->cn_flags & ISDOTDOT);
if (vp->v_name == NULL || vp->v_parent == NULLVP) {
int update_flags = 0;
if (isdot_or_dotdot == 0) {
if (vp->v_name == NULL)
update_flags |= VNODE_UPDATE_NAME;
if (dvp != NULLVP && vp->v_parent == NULLVP)
update_flags |= VNODE_UPDATE_PARENT;
if (update_flags)
vnode_update_identity(vp, dvp, cnp->cn_nameptr, cnp->cn_namelen, cnp->cn_hash, update_flags);
}
}
if ( (cnp->cn_flags & MAKEENTRY) && (vp->v_flag & VNCACHEABLE) && LIST_FIRST(&vp->v_nclinks) == NULL) {
/*
* missing from name cache, but should
* be in it... this can happen if volfs
* causes the vnode to be created or the
* name cache entry got recycled but the
* vnode didn't...
* check to make sure that ni_dvp is valid
* cache_lookup_path may return a NULL
* do a quick check to see if the generation of the
* directory matches our snapshot... this will get
* rechecked behind the name cache lock, but if it
* already fails to match, no need to go any further
*/
if (dvp != NULLVP && (nc_generation == dvp->v_nc_generation) && (!isdot_or_dotdot))
cache_enter_with_gen(dvp, vp, cnp, nc_generation);
}
}
/*
* Look up a vnode/nfsnode by file handle.
* Callers must check for mount points!!
* In all cases, a pointer to a
* nfsnode structure is returned.
*/
int
nfs_nget(
mount_t mp,
nfsnode_t dnp,
struct componentname *cnp,
u_char *fhp,
int fhsize,
struct nfs_vattr *nvap,
u_int64_t *xidp,
uint32_t auth,
int flags,
nfsnode_t *npp)
{
nfsnode_t np;
struct nfsnodehashhead *nhpp;
vnode_t vp;
int error, nfsvers;
mount_t mp2;
struct vnode_fsparam vfsp;
uint32_t vid;
FSDBG_TOP(263, mp, dnp, flags, npp);
/* Check for unmount in progress */
if (!mp || vfs_isforce(mp)) {
*npp = NULL;
error = ENXIO;
FSDBG_BOT(263, mp, dnp, 0xd1e, error);
return (error);
}
nfsvers = VFSTONFS(mp)->nm_vers;
nhpp = NFSNOHASH(nfs_hash(fhp, fhsize));
loop:
lck_mtx_lock(nfs_node_hash_mutex);
for (np = nhpp->lh_first; np != 0; np = np->n_hash.le_next) {
mp2 = (np->n_hflag & NHINIT) ? np->n_mount : NFSTOMP(np);
if (mp != mp2 || np->n_fhsize != fhsize ||
bcmp(fhp, np->n_fhp, fhsize))
continue;
if (nvap && (nvap->nva_flags & NFS_FFLAG_TRIGGER_REFERRAL) &&
cnp && (cnp->cn_namelen > (fhsize - (int)sizeof(dnp)))) {
/* The name was too long to fit in the file handle. Check it against the node's name. */
int namecmp = 0;
const char *vname = vnode_getname(NFSTOV(np));
if (vname) {
if (cnp->cn_namelen != (int)strlen(vname))
namecmp = 1;
else
namecmp = strncmp(vname, cnp->cn_nameptr, cnp->cn_namelen);
vnode_putname(vname);
}
if (namecmp) /* full name didn't match */
continue;
}
FSDBG(263, dnp, np, np->n_flag, 0xcace0000);
/* if the node is locked, sleep on it */
if ((np->n_hflag & NHLOCKED) && !(flags & NG_NOCREATE)) {
np->n_hflag |= NHLOCKWANT;
FSDBG(263, dnp, np, np->n_flag, 0xcace2222);
msleep(np, nfs_node_hash_mutex, PDROP | PINOD, "nfs_nget", NULL);
FSDBG(263, dnp, np, np->n_flag, 0xcace3333);
goto loop;
}
vp = NFSTOV(np);
vid = vnode_vid(vp);
lck_mtx_unlock(nfs_node_hash_mutex);
if ((error = vnode_getwithvid(vp, vid))) {
/*
* If vnode is being reclaimed or has already
* changed identity, no need to wait.
*/
FSDBG_BOT(263, dnp, *npp, 0xcace0d1e, error);
return (error);
}
if ((error = nfs_node_lock(np))) {
/* this only fails if the node is now unhashed */
/* so let's see if we can find/create it again */
FSDBG(263, dnp, *npp, 0xcaced1e2, error);
vnode_put(vp);
if (flags & NG_NOCREATE) {
*npp = 0;
FSDBG_BOT(263, dnp, *npp, 0xcaced1e0, ENOENT);
return (ENOENT);
}
goto loop;
}
/* update attributes */
if (nvap)
error = nfs_loadattrcache(np, nvap, xidp, 0);
if (error) {
nfs_node_unlock(np);
vnode_put(vp);
} else {
if (dnp && cnp && (flags & NG_MAKEENTRY))
cache_enter(NFSTOV(dnp), vp, cnp);
/*
* Update the vnode if the name/and or the parent has
* changed. We need to do this so that if getattrlist is
* called asking for ATTR_CMN_NAME, that the "most"
* correct name is being returned. In addition for
* monitored vnodes we need to kick the vnode out of the
* name cache. We do this so that if there are hard
* links in the same directory the link will not be
* found and a lookup will get us here to return the
* name of the current link. In addition by removing the
* name from the name cache the old name will not be
* found after a rename done on another client or the
* server. The principle reason to do this is because
* Finder is asking for notifications on a directory.
* The directory changes, Finder gets notified, reads
* the directory (which we have purged) and for each
* entry returned calls getattrlist with the name
* returned from readdir. gettattrlist has to call
* namei/lookup to resolve the name, because its not in
* the cache we end up here. We need to update the name
* so Finder will get the name it called us with.
*
* We had an imperfect solution with respect to case
* sensitivity. There is a test that is run in
* FileBuster that does renames from some name to
* another name differing only in case. It then reads
* the directory looking for the new name, after it
* finds that new name, it ask gettattrlist to verify
* that the name is the new name. Usually that works,
* but renames generate fsevents and fseventsd will do a
* lookup on the name via lstat. Since that test renames
* old name to new name back and forth there is a race
* that an fsevent will be behind and will access the
* file by the old name, on a case insensitive file
* system that will work. Problem is if we do a case
* sensitive compare, we're going to change the name,
* which the test's getattrlist verification step is
* going to fail. So we will check the case sensitivity
* of the file system and do the appropriate compare. In
* a rare instance for non homogeneous file systems
* w.r.t. pathconf we will use case sensitive compares.
* That could break if the file system is actually case
* insensitive.
*
* Note that V2 does not know the case, so we just
* assume case sensitivity.
*
* This is clearly not perfect due to races, but this is
* as good as its going to get. You can defeat the
* handling of hard links simply by doing:
*
* while :; do ls -l > /dev/null; done
*
* in a terminal window. Even a single ls -l can cause a
* race.
*
* <rant>What we really need is for the caller, that
* knows the name being used is valid since it got it
* from a readdir to use that name and not ask for the
* ATTR_CMN_NAME</rant>
*/
if (dnp && cnp && (vp != NFSTOV(dnp))) {
int update_flags = (vnode_ismonitored((NFSTOV(dnp)))) ? VNODE_UPDATE_CACHE : 0;
int (*cmp)(const char *s1, const char *s2, size_t n);
cmp = nfs_case_insensitive(mp) ? strncasecmp : strncmp;
if (vp->v_name && cnp->cn_namelen && (*cmp)(cnp->cn_nameptr, vp->v_name, cnp->cn_namelen))
update_flags |= VNODE_UPDATE_NAME;
if ((vp->v_name == NULL && cnp->cn_namelen != 0) || (vp->v_name != NULL && cnp->cn_namelen == 0))
update_flags |= VNODE_UPDATE_NAME;
if (vnode_parent(vp) != NFSTOV(dnp))
update_flags |= VNODE_UPDATE_PARENT;
if (update_flags) {
NFS_NODE_DBG("vnode_update_identity old name %s new name %.*s update flags = %x\n",
vp->v_name, cnp->cn_namelen, cnp->cn_nameptr ? cnp->cn_nameptr : "", update_flags);
vnode_update_identity(vp, NFSTOV(dnp), cnp->cn_nameptr, cnp->cn_namelen, 0, update_flags);
}
}
*npp = np;
}
FSDBG_BOT(263, dnp, *npp, 0xcace0000, error);
return(error);
}
FSDBG(263, mp, dnp, npp, 0xaaaaaaaa);
if (flags & NG_NOCREATE) {
lck_mtx_unlock(nfs_node_hash_mutex);
*npp = 0;
FSDBG_BOT(263, dnp, *npp, 0x80000001, ENOENT);
return (ENOENT);
}
/*
* allocate and initialize nfsnode and stick it in the hash
* before calling getnewvnode(). Anyone finding it in the
* hash before initialization is complete will wait for it.
*/
MALLOC_ZONE(np, nfsnode_t, sizeof *np, M_NFSNODE, M_WAITOK);
if (!np) {
lck_mtx_unlock(nfs_node_hash_mutex);
*npp = 0;
FSDBG_BOT(263, dnp, *npp, 0x80000001, ENOMEM);
return (ENOMEM);
}
bzero(np, sizeof *np);
np->n_hflag |= (NHINIT | NHLOCKED);
np->n_mount = mp;
np->n_auth = auth;
TAILQ_INIT(&np->n_opens);
TAILQ_INIT(&np->n_lock_owners);
TAILQ_INIT(&np->n_locks);
np->n_dlink.tqe_next = NFSNOLIST;
np->n_dreturn.tqe_next = NFSNOLIST;
np->n_monlink.le_next = NFSNOLIST;
/* ugh... need to keep track of ".zfs" directories to workaround server bugs */
if ((nvap->nva_type == VDIR) && cnp && (cnp->cn_namelen == 4) &&
(cnp->cn_nameptr[0] == '.') && (cnp->cn_nameptr[1] == 'z') &&
(cnp->cn_nameptr[2] == 'f') && (cnp->cn_nameptr[3] == 's'))
np->n_flag |= NISDOTZFS;
if (dnp && (dnp->n_flag & NISDOTZFS))
np->n_flag |= NISDOTZFSCHILD;
if (dnp && cnp && ((cnp->cn_namelen != 2) ||
(cnp->cn_nameptr[0] != '.') || (cnp->cn_nameptr[1] != '.'))) {
vnode_t dvp = NFSTOV(dnp);
if (!vnode_get(dvp)) {
if (!vnode_ref(dvp))
np->n_parent = dvp;
vnode_put(dvp);
}
}
/* setup node's file handle */
if (fhsize > NFS_SMALLFH) {
MALLOC_ZONE(np->n_fhp, u_char *,
fhsize, M_NFSBIGFH, M_WAITOK);
if (!np->n_fhp) {
lck_mtx_unlock(nfs_node_hash_mutex);
FREE_ZONE(np, sizeof *np, M_NFSNODE);
*npp = 0;
FSDBG_BOT(263, dnp, *npp, 0x80000002, ENOMEM);
return (ENOMEM);
}
} else {
/*ARGSUSED*/
static int
zfs_vfs_unmount(struct mount *mp, int mntflags, vfs_context_t context)
{
zfsvfs_t *zfsvfs = vfs_fsprivate(mp);
objset_t *os = zfsvfs->z_os;
znode_t *zp, *nextzp;
int ret, i;
int flags;
/*XXX NOEL: delegation admin stuffs, add back if we use delg. admin */
#if 0
ret = 0; /* UNDEFINED: secpolicy_fs_unmount(cr, vfsp); */
if (ret) {
ret = dsl_deleg_access((char *)refstr_value(vfsp->vfs_resource),
ZFS_DELEG_PERM_MOUNT, cr);
if (ret)
return (ret);
}
/*
* We purge the parent filesystem's vfsp as the parent filesystem
* and all of its snapshots have their vnode's v_vfsp set to the
* parent's filesystem's vfsp. Note, 'z_parent' is self
* referential for non-snapshots.
*/
(void) dnlc_purge_vfsp(zfsvfs->z_parent->z_vfs, 0);
#endif
/*
* Unmount any snapshots mounted under .zfs before unmounting the
* dataset itself.
*/
#if 0
if (zfsvfs->z_ctldir != NULL &&
(ret = zfsctl_umount_snapshots(vfsp, fflag, cr)) != 0) {
return (ret);
#endif
flags = SKIPSYSTEM;
if (mntflags & MNT_FORCE)
flags |= FORCECLOSE;
ret = vflush(mp, NULLVP, flags);
/*
* Mac OS X needs a file system modify time
*
* We use the mtime of the "com.apple.system.mtime"
* extended attribute, which is associated with the
* file system root directory.
*
* Here we need to release the ref we took on z_mtime_vp during mount.
*/
if ((ret == 0) || (mntflags & MNT_FORCE)) {
if (zfsvfs->z_mtime_vp != NULL) {
struct vnode *mvp;
mvp = zfsvfs->z_mtime_vp;
zfsvfs->z_mtime_vp = NULL;
if (vnode_get(mvp) == 0) {
vnode_rele(mvp);
vnode_recycle(mvp);
vnode_put(mvp);
}
}
}
if (!(mntflags & MNT_FORCE)) {
/*
* Check the number of active vnodes in the file system.
* Our count is maintained in the vfs structure, but the
* number is off by 1 to indicate a hold on the vfs
* structure itself.
*
* The '.zfs' directory maintains a reference of its
* own, and any active references underneath are
* reflected in the vnode count.
*/
if (ret)
return (EBUSY);
#if 0
if (zfsvfs->z_ctldir == NULL) {
if (vfsp->vfs_count > 1)
return (EBUSY);
} else {
if (vfsp->vfs_count > 2 ||
zfsvfs->z_ctldir->v_count > 1) {
return (EBUSY);
}
}
#endif
}
rw_enter(&zfsvfs->z_unmount_lock, RW_WRITER);
rw_enter(&zfsvfs->z_unmount_inactive_lock, RW_WRITER);
/*
* At this point there are no vops active, and any new vops will
* fail with EIO since we have z_unmount_lock for writer (only
* relavent for forced unmount).
*
* Release all holds on dbufs.
* Note, the dmu can still callback via znode_pageout_func()
* which can zfs_znode_free() the znode. So we lock
* z_all_znodes; search the list for a held dbuf; drop the lock
* (we know zp can't disappear if we hold a dbuf lock) then
* regrab the lock and restart.
*/
mutex_enter(&zfsvfs->z_znodes_lock);
for (zp = list_head(&zfsvfs->z_all_znodes); zp; zp = nextzp) {
nextzp = list_next(&zfsvfs->z_all_znodes, zp);
if (zp->z_dbuf_held) {
/* dbufs should only be held when force unmounting */
zp->z_dbuf_held = 0;
mutex_exit(&zfsvfs->z_znodes_lock);
dmu_buf_rele(zp->z_dbuf, NULL);
/* Start again */
mutex_enter(&zfsvfs->z_znodes_lock);
nextzp = list_head(&zfsvfs->z_all_znodes);
}
}
mutex_exit(&zfsvfs->z_znodes_lock);
/*
* Set the unmounted flag and let new vops unblock.
* zfs_inactive will have the unmounted behavior, and all other
* vops will fail with EIO.
*/
zfsvfs->z_unmounted = B_TRUE;
rw_exit(&zfsvfs->z_unmount_lock);
rw_exit(&zfsvfs->z_unmount_inactive_lock);
/*
* Unregister properties.
*/
#ifndef __APPLE__
if (!dmu_objset_is_snapshot(os))
zfs_unregister_callbacks(zfsvfs);
#endif
/*
* Close the zil. NB: Can't close the zil while zfs_inactive
* threads are blocked as zil_close can call zfs_inactive.
*/
if (zfsvfs->z_log) {
zil_close(zfsvfs->z_log);
zfsvfs->z_log = NULL;
}
/*
* Evict all dbufs so that cached znodes will be freed
*/
if (dmu_objset_evict_dbufs(os, B_TRUE)) {
txg_wait_synced(dmu_objset_pool(zfsvfs->z_os), 0);
(void) dmu_objset_evict_dbufs(os, B_FALSE);
}
/*
* Finally close the objset
*/
dmu_objset_close(os);
/*
* We can now safely destroy the '.zfs' directory node.
*/
#if 0
if (zfsvfs->z_ctldir != NULL)
zfsctl_destroy(zfsvfs);
#endif
/*
* Note that this work is normally done in zfs_freevfs, but since
* there is no VOP_FREEVFS in OSX, we free VFS items here
*/
OSDecrementAtomic((SInt32 *)&zfs_active_fs_count);
for (i = 0; i != ZFS_OBJ_MTX_SZ; i++)
mutex_destroy(&zfsvfs->z_hold_mtx[i]);
mutex_destroy(&zfsvfs->z_znodes_lock);
list_destroy(&zfsvfs->z_all_znodes);
rw_destroy(&zfsvfs->z_unmount_lock);
rw_destroy(&zfsvfs->z_unmount_inactive_lock);
return (0);
}
struct vnode* vnode_getparent(struct vnode *vp); /* sys/vnode_internal.h */
static int
zfs_vget_internal(zfsvfs_t *zfsvfs, ino64_t ino, struct vnode **vpp)
{
struct vnode *vp;
struct vnode *dvp = NULL;
znode_t *zp;
int error;
*vpp = NULL;
/*
* On Mac OS X we always export the root directory id as 2
* and its parent as 1
*/
if (ino == 2 || ino == 1)
ino = zfsvfs->z_root;
if ((error = zfs_zget(zfsvfs, ino, &zp)))
goto out;
/* Don't expose EA objects! */
if (zp->z_phys->zp_flags & ZFS_XATTR) {
vnode_put(ZTOV(zp));
error = ENOENT;
goto out;
}
*vpp = vp = ZTOV(zp);
if (vnode_isvroot(vp))
goto out;
/*
* If this znode didn't just come from the cache then
* it won't have a valid identity (parent and name).
*
* Manually fix its identity here (normally done by namei lookup).
*/
if ((dvp = vnode_getparent(vp)) == NULL) {
if (zp->z_phys->zp_parent != 0 &&
zfs_vget_internal(zfsvfs, zp->z_phys->zp_parent, &dvp)) {
goto out;
}
if ( vnode_isdir(dvp) ) {
char objname[ZAP_MAXNAMELEN]; /* 256 bytes */
int flags = VNODE_UPDATE_PARENT;
/* Look for znode's name in its parent's zap */
if ( zap_value_search(zfsvfs->z_os,
zp->z_phys->zp_parent,
zp->z_id,
ZFS_DIRENT_OBJ(-1ULL),
objname) == 0 ) {
flags |= VNODE_UPDATE_NAME;
}
/* Update the znode's parent and name */
vnode_update_identity(vp, dvp, objname, 0, 0, flags);
}
}
/* All done with znode's parent */
vnode_put(dvp);
out:
return (error);
}
/*
* Get a vnode from a file id (ignoring the generation)
*
* Use by NFS Server (readdirplus) and VFS (build_path)
*/
static int
zfs_vfs_vget(struct mount *mp, ino64_t ino, struct vnode **vpp, __unused vfs_context_t context)
{
zfsvfs_t *zfsvfs = vfs_fsprivate(mp);
int error;
ZFS_ENTER(zfsvfs);
/*
* On Mac OS X we always export the root directory id as 2.
* So we don't expect to see the real root directory id
* from zfs_vfs_vget KPI (unless of course the real id was
* already 2).
*/
if ((ino == zfsvfs->z_root) && (zfsvfs->z_root != 2)) {
ZFS_EXIT(zfsvfs);
return (ENOENT);
}
error = zfs_vget_internal(zfsvfs, ino, vpp);
ZFS_EXIT(zfsvfs);
return (error);
}
/*
* Search a pathname.
* This is a very central and rather complicated routine.
*
* The pathname is pointed to by ni_ptr and is of length ni_pathlen.
* The starting directory is taken from ni_startdir. The pathname is
* descended until done, or a symbolic link is encountered. The variable
* ni_more is clear if the path is completed; it is set to one if a
* symbolic link needing interpretation is encountered.
*
* The flag argument is LOOKUP, CREATE, RENAME, or DELETE depending on
* whether the name is to be looked up, created, renamed, or deleted.
* When CREATE, RENAME, or DELETE is specified, information usable in
* creating, renaming, or deleting a directory entry may be calculated.
* If flag has LOCKPARENT or'ed into it, the parent directory is returned
* locked. If flag has WANTPARENT or'ed into it, the parent directory is
* returned unlocked. Otherwise the parent directory is not returned. If
* the target of the pathname exists and LOCKLEAF is or'ed into the flag
* the target is returned locked, otherwise it is returned unlocked.
* When creating or renaming and LOCKPARENT is specified, the target may not
* be ".". When deleting and LOCKPARENT is specified, the target may be ".".
*
* Overall outline of lookup:
*
* dirloop:
* identify next component of name at ndp->ni_ptr
* handle degenerate case where name is null string
* if .. and crossing mount points and on mounted filesys, find parent
* call VNOP_LOOKUP routine for next component name
* directory vnode returned in ni_dvp, unlocked unless LOCKPARENT set
* component vnode returned in ni_vp (if it exists), locked.
* if result vnode is mounted on and crossing mount points,
* find mounted on vnode
* if more components of name, do next level at dirloop
* return the answer in ni_vp, locked if LOCKLEAF set
* if LOCKPARENT set, return locked parent in ni_dvp
* if WANTPARENT set, return unlocked parent in ni_dvp
*
* Returns: 0 Success
* ENOENT No such file or directory
* EBADF Bad file descriptor
* ENOTDIR Not a directory
* EROFS Read-only file system [CREATE]
* EISDIR Is a directory [CREATE]
* cache_lookup_path:ERECYCLE (vnode was recycled from underneath us, redrive lookup again)
* vnode_authorize:EROFS
* vnode_authorize:EACCES
* vnode_authorize:EPERM
* vnode_authorize:???
* VNOP_LOOKUP:ENOENT No such file or directory
* VNOP_LOOKUP:EJUSTRETURN Restart system call (INTERNAL)
* VNOP_LOOKUP:???
* VFS_ROOT:ENOTSUP
* VFS_ROOT:ENOENT
* VFS_ROOT:???
*/
int
lookup(struct nameidata *ndp)
{
char *cp; /* pointer into pathname argument */
vnode_t tdp; /* saved dp */
vnode_t dp; /* the directory we are searching */
mount_t mp; /* mount table entry */
int docache = 1; /* == 0 do not cache last component */
int wantparent; /* 1 => wantparent or lockparent flag */
int rdonly; /* lookup read-only flag bit */
int trailing_slash = 0;
int dp_authorized = 0;
int error = 0;
struct componentname *cnp = &ndp->ni_cnd;
vfs_context_t ctx = cnp->cn_context;
int mounted_on_depth = 0;
int dont_cache_mp = 0;
vnode_t mounted_on_dp = NULLVP;
int current_mount_generation = 0;
int vbusyflags = 0;
int nc_generation = 0;
vnode_t last_dp = NULLVP;
/*
* Setup: break out flag bits into variables.
*/
if (cnp->cn_flags & (NOCACHE | DOWHITEOUT)) {
if ((cnp->cn_flags & NOCACHE) || (cnp->cn_nameiop == DELETE))
docache = 0;
}
wantparent = cnp->cn_flags & (LOCKPARENT | WANTPARENT);
rdonly = cnp->cn_flags & RDONLY;
cnp->cn_flags &= ~ISSYMLINK;
cnp->cn_consume = 0;
dp = ndp->ni_startdir;
ndp->ni_startdir = NULLVP;
if ((cnp->cn_flags & CN_NBMOUNTLOOK) != 0)
vbusyflags = LK_NOWAIT;
cp = cnp->cn_nameptr;
if (*cp == '\0') {
if ( (vnode_getwithref(dp)) ) {
dp = NULLVP;
error = ENOENT;
goto bad;
}
goto emptyname;
}
dirloop:
ndp->ni_vp = NULLVP;
if ( (error = cache_lookup_path(ndp, cnp, dp, ctx, &trailing_slash, &dp_authorized, last_dp)) ) {
dp = NULLVP;
goto bad;
}
if ((cnp->cn_flags & ISLASTCN)) {
if (docache)
cnp->cn_flags |= MAKEENTRY;
} else
cnp->cn_flags |= MAKEENTRY;
dp = ndp->ni_dvp;
if (ndp->ni_vp != NULLVP) {
/*
* cache_lookup_path returned a non-NULL ni_vp then,
* we're guaranteed that the dp is a VDIR, it's
* been authorized, and vp is not ".."
*
* make sure we don't try to enter the name back into
* the cache if this vp is purged before we get to that
* check since we won't have serialized behind whatever
* activity is occurring in the FS that caused the purge
*/
if (dp != NULLVP)
nc_generation = dp->v_nc_generation - 1;
goto returned_from_lookup_path;
}
/*
* Handle "..": two special cases.
* 1. If at root directory (e.g. after chroot)
* or at absolute root directory
* then ignore it so can't get out.
* 2. If this vnode is the root of a mounted
* filesystem, then replace it with the
* vnode which was mounted on so we take the
* .. in the other file system.
*/
if ( (cnp->cn_flags & ISDOTDOT) ) {
for (;;) {
if (dp == ndp->ni_rootdir || dp == rootvnode) {
ndp->ni_dvp = dp;
ndp->ni_vp = dp;
/*
* we're pinned at the root
* we've already got one reference on 'dp'
* courtesy of cache_lookup_path... take
* another one for the ".."
* if we fail to get the new reference, we'll
* drop our original down in 'bad'
*/
if ( (vnode_get(dp)) ) {
error = ENOENT;
goto bad;
}
goto nextname;
}
if ((dp->v_flag & VROOT) == 0 ||
(cnp->cn_flags & NOCROSSMOUNT))
break;
if (dp->v_mount == NULL) { /* forced umount */
error = EBADF;
goto bad;
}
tdp = dp;
dp = tdp->v_mount->mnt_vnodecovered;
vnode_put(tdp);
if ( (vnode_getwithref(dp)) ) {
dp = NULLVP;
error = ENOENT;
goto bad;
}
ndp->ni_dvp = dp;
dp_authorized = 0;
}
}
/*
* We now have a segment name to search for, and a directory to search.
*/
unionlookup:
ndp->ni_vp = NULLVP;
if (dp->v_type != VDIR) {
error = ENOTDIR;
goto lookup_error;
}
if ( (cnp->cn_flags & DONOTAUTH) != DONOTAUTH ) {
if (!dp_authorized) {
error = vnode_authorize(dp, NULL, KAUTH_VNODE_SEARCH, ctx);
if (error)
goto lookup_error;
}
#if CONFIG_MACF
error = mac_vnode_check_lookup(ctx, dp, cnp);
if (error)
goto lookup_error;
#endif /* CONFIG_MACF */
}
nc_generation = dp->v_nc_generation;
if ( (error = VNOP_LOOKUP(dp, &ndp->ni_vp, cnp, ctx)) ) {
lookup_error:
if ((error == ENOENT) &&
(dp->v_flag & VROOT) && (dp->v_mount != NULL) &&
(dp->v_mount->mnt_flag & MNT_UNION)) {
if ((cnp->cn_flags & FSNODELOCKHELD)) {
cnp->cn_flags &= ~FSNODELOCKHELD;
unlock_fsnode(dp, NULL);
}
tdp = dp;
dp = tdp->v_mount->mnt_vnodecovered;
vnode_put(tdp);
if ( (vnode_getwithref(dp)) ) {
dp = NULLVP;
error = ENOENT;
goto bad;
}
ndp->ni_dvp = dp;
dp_authorized = 0;
goto unionlookup;
}
if (error != EJUSTRETURN)
goto bad;
if (ndp->ni_vp != NULLVP)
panic("leaf should be empty");
/*
* If creating and at end of pathname, then can consider
* allowing file to be created.
*/
if (rdonly) {
error = EROFS;
goto bad;
}
if ((cnp->cn_flags & ISLASTCN) && trailing_slash && !(cnp->cn_flags & WILLBEDIR)) {
error = ENOENT;
goto bad;
}
/*
* We return with ni_vp NULL to indicate that the entry
* doesn't currently exist, leaving a pointer to the
* referenced directory vnode in ndp->ni_dvp.
*/
if (cnp->cn_flags & SAVESTART) {
if ( (vnode_get(ndp->ni_dvp)) ) {
error = ENOENT;
goto bad;
}
ndp->ni_startdir = ndp->ni_dvp;
}
if (!wantparent)
vnode_put(ndp->ni_dvp);
if (kdebug_enable)
kdebug_lookup(ndp->ni_dvp, cnp);
return (0);
}
returned_from_lookup_path:
dp = ndp->ni_vp;
/*
* Take into account any additional components consumed by
* the underlying filesystem.
*/
if (cnp->cn_consume > 0) {
cnp->cn_nameptr += cnp->cn_consume;
ndp->ni_next += cnp->cn_consume;
ndp->ni_pathlen -= cnp->cn_consume;
cnp->cn_consume = 0;
} else {
if (dp->v_name == NULL || dp->v_parent == NULLVP) {
int isdot_or_dotdot;
int update_flags = 0;
isdot_or_dotdot = (cnp->cn_namelen == 1 && cnp->cn_nameptr[0] == '.') || (cnp->cn_flags & ISDOTDOT);
if (isdot_or_dotdot == 0) {
if (dp->v_name == NULL)
update_flags |= VNODE_UPDATE_NAME;
if (ndp->ni_dvp != NULLVP && dp->v_parent == NULLVP)
update_flags |= VNODE_UPDATE_PARENT;
if (update_flags)
vnode_update_identity(dp, ndp->ni_dvp, cnp->cn_nameptr, cnp->cn_namelen, cnp->cn_hash, update_flags);
}
}
if ( (cnp->cn_flags & MAKEENTRY) && (dp->v_flag & VNCACHEABLE) && LIST_FIRST(&dp->v_nclinks) == NULL) {
/*
* missing from name cache, but should
* be in it... this can happen if volfs
* causes the vnode to be created or the
* name cache entry got recycled but the
* vnode didn't...
* check to make sure that ni_dvp is valid
* cache_lookup_path may return a NULL
* do a quick check to see if the generation of the
* directory matches our snapshot... this will get
* rechecked behind the name cache lock, but if it
* already fails to match, no need to go any further
*/
if (ndp->ni_dvp != NULLVP && (nc_generation == ndp->ni_dvp->v_nc_generation))
cache_enter_with_gen(ndp->ni_dvp, dp, cnp, nc_generation);
}
}
mounted_on_dp = dp;
mounted_on_depth = 0;
dont_cache_mp = 0;
current_mount_generation = mount_generation;
/*
* Check to see if the vnode has been mounted on...
* if so find the root of the mounted file system.
*/
check_mounted_on:
if ((dp->v_type == VDIR) && dp->v_mountedhere &&
((cnp->cn_flags & NOCROSSMOUNT) == 0)) {
vnode_lock(dp);
if ((dp->v_type == VDIR) && (mp = dp->v_mountedhere)) {
struct uthread *uth = (struct uthread *)get_bsdthread_info(current_thread());
mp->mnt_crossref++;
vnode_unlock(dp);
if (vfs_busy(mp, vbusyflags)) {
mount_dropcrossref(mp, dp, 0);
if (vbusyflags == LK_NOWAIT) {
error = ENOENT;
goto bad2;
}
goto check_mounted_on;
}
/*
* XXX - if this is the last component of the
* pathname, and it's either not a lookup operation
* or the NOTRIGGER flag is set for the operation,
* set a uthread flag to let VFS_ROOT() for autofs
* know it shouldn't trigger a mount.
*/
if ((cnp->cn_flags & ISLASTCN) &&
(cnp->cn_nameiop != LOOKUP ||
(cnp->cn_flags & NOTRIGGER))) {
uth->uu_notrigger = 1;
dont_cache_mp = 1;
}
error = VFS_ROOT(mp, &tdp, ctx);
/* XXX - clear the uthread flag */
uth->uu_notrigger = 0;
/*
* mount_dropcrossref does a vnode_put
* on dp if the 3rd arg is non-zero
*/
mount_dropcrossref(mp, dp, 1);
dp = NULL;
vfs_unbusy(mp);
if (error) {
goto bad2;
}
ndp->ni_vp = dp = tdp;
mounted_on_depth++;
goto check_mounted_on;
}
vnode_unlock(dp);
}
#if CONFIG_MACF
if (vfs_flags(vnode_mount(dp)) & MNT_MULTILABEL) {
error = vnode_label(vnode_mount(dp), NULL, dp, NULL,
VNODE_LABEL_NEEDREF, ctx);
if (error)
goto bad2;
}
#endif
if (mounted_on_depth && !dont_cache_mp) {
mp = mounted_on_dp->v_mountedhere;
if (mp) {
mount_lock(mp);
mp->mnt_realrootvp_vid = dp->v_id;
mp->mnt_realrootvp = dp;
mp->mnt_generation = current_mount_generation;
mount_unlock(mp);
}
}
/*
* Check for symbolic link
*/
if ((dp->v_type == VLNK) &&
((cnp->cn_flags & FOLLOW) || trailing_slash || *ndp->ni_next == '/')) {
cnp->cn_flags |= ISSYMLINK;
return (0);
}
/*
* Check for bogus trailing slashes.
*/
if (trailing_slash) {
if (dp->v_type != VDIR) {
error = ENOTDIR;
goto bad2;
}
trailing_slash = 0;
}
nextname:
/*
* Not a symbolic link. If more pathname,
* continue at next component, else return.
*/
if (*ndp->ni_next == '/') {
cnp->cn_nameptr = ndp->ni_next + 1;
ndp->ni_pathlen--;
while (*cnp->cn_nameptr == '/') {
cnp->cn_nameptr++;
ndp->ni_pathlen--;
}
vnode_put(ndp->ni_dvp);
cp = cnp->cn_nameptr;
if (*cp == '\0')
goto emptyname;
/*
* cache_lookup_path is now responsible for dropping io ref on dp
* when it is called again in the dirloop. This ensures we hold
* a ref on dp until we complete the next round of lookup.
*/
last_dp = dp;
goto dirloop;
}
/*
* Disallow directory write attempts on read-only file systems.
*/
if (rdonly &&
(cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME)) {
error = EROFS;
goto bad2;
}
if (cnp->cn_flags & SAVESTART) {
/*
* note that we already hold a reference
* on both dp and ni_dvp, but for some reason
* can't get another one... in this case we
* need to do vnode_put on dp in 'bad2'
*/
if ( (vnode_get(ndp->ni_dvp)) ) {
error = ENOENT;
goto bad2;
}
ndp->ni_startdir = ndp->ni_dvp;
}
if (!wantparent && ndp->ni_dvp) {
vnode_put(ndp->ni_dvp);
ndp->ni_dvp = NULLVP;
}
if (cnp->cn_flags & AUDITVNPATH1)
AUDIT_ARG(vnpath, dp, ARG_VNODE1);
else if (cnp->cn_flags & AUDITVNPATH2)
AUDIT_ARG(vnpath, dp, ARG_VNODE2);
#if NAMEDRSRCFORK
/*
* Caller wants the resource fork.
*/
if ((cnp->cn_flags & CN_WANTSRSRCFORK) && (dp != NULLVP)) {
vnode_t svp = NULLVP;
enum nsoperation nsop;
if (dp->v_type != VREG) {
error = ENOENT;
goto bad2;
}
switch (cnp->cn_nameiop) {
case DELETE:
nsop = NS_DELETE;
break;
case CREATE:
nsop = NS_CREATE;
break;
case LOOKUP:
/* Make sure our lookup of "/..namedfork/rsrc" is allowed. */
if (cnp->cn_flags & CN_ALLOWRSRCFORK) {
nsop = NS_OPEN;
} else {
error = EPERM;
goto bad2;
}
break;
default:
error = EPERM;
goto bad2;
}
/* Ask the file system for the resource fork. */
error = vnode_getnamedstream(dp, &svp, XATTR_RESOURCEFORK_NAME, nsop, 0, ctx);
/* During a create, it OK for stream vnode to be missing. */
if (error == ENOATTR || error == ENOENT) {
error = (nsop == NS_CREATE) ? 0 : ENOENT;
}
if (error) {
goto bad2;
}
/* The "parent" of the stream is the file. */
if (wantparent) {
if (ndp->ni_dvp) {
if (ndp->ni_cnd.cn_flags & FSNODELOCKHELD) {
ndp->ni_cnd.cn_flags &= ~FSNODELOCKHELD;
unlock_fsnode(ndp->ni_dvp, NULL);
}
vnode_put(ndp->ni_dvp);
}
ndp->ni_dvp = dp;
} else {
vnode_put(dp);
}
ndp->ni_vp = dp = svp; /* on create this may be null */
/* Restore the truncated pathname buffer (for audits). */
if (ndp->ni_pathlen == 1 && ndp->ni_next[0] == '\0') {
ndp->ni_next[0] = '/';
}
cnp->cn_flags &= ~MAKEENTRY;
}
#endif
if (kdebug_enable)
kdebug_lookup(dp, cnp);
return (0);
emptyname:
cnp->cn_namelen = 0;
/*
* A degenerate name (e.g. / or "") which is a way of
* talking about a directory, e.g. like "/." or ".".
*/
if (dp->v_type != VDIR) {
error = ENOTDIR;
goto bad;
}
if (cnp->cn_nameiop != LOOKUP) {
error = EISDIR;
goto bad;
}
if (wantparent) {
/*
* note that we already hold a reference
* on dp, but for some reason can't
* get another one... in this case we
* need to do vnode_put on dp in 'bad'
*/
if ( (vnode_get(dp)) ) {
error = ENOENT;
goto bad;
}
ndp->ni_dvp = dp;
}
cnp->cn_flags &= ~ISDOTDOT;
cnp->cn_flags |= ISLASTCN;
ndp->ni_next = cp;
ndp->ni_vp = dp;
if (cnp->cn_flags & AUDITVNPATH1)
AUDIT_ARG(vnpath, dp, ARG_VNODE1);
else if (cnp->cn_flags & AUDITVNPATH2)
AUDIT_ARG(vnpath, dp, ARG_VNODE2);
if (cnp->cn_flags & SAVESTART)
panic("lookup: SAVESTART");
return (0);
bad2:
if ((cnp->cn_flags & FSNODELOCKHELD)) {
cnp->cn_flags &= ~FSNODELOCKHELD;
unlock_fsnode(ndp->ni_dvp, NULL);
}
if (ndp->ni_dvp)
vnode_put(ndp->ni_dvp);
if (dp)
vnode_put(dp);
ndp->ni_vp = NULLVP;
if (kdebug_enable)
kdebug_lookup(dp, cnp);
return (error);
bad:
if ((cnp->cn_flags & FSNODELOCKHELD)) {
cnp->cn_flags &= ~FSNODELOCKHELD;
unlock_fsnode(ndp->ni_dvp, NULL);
}
if (dp)
vnode_put(dp);
ndp->ni_vp = NULLVP;
if (kdebug_enable)
kdebug_lookup(dp, cnp);
return (error);
}
