diff options
author | ru <ru@FreeBSD.org> | 2001-05-23 09:42:29 +0000 |
---|---|---|
committer | ru <ru@FreeBSD.org> | 2001-05-23 09:42:29 +0000 |
commit | 35437d86aa2e89b16dfeb84a5499976559847155 (patch) | |
tree | 2bade94e6086e67f8de015d8c16fd2c15e7f78c3 /sys/miscfs/union/union_subr.c | |
parent | 627a25efaa565e765c3f4d9223bfeef7134724ef (diff) | |
download | FreeBSD-src-35437d86aa2e89b16dfeb84a5499976559847155.zip FreeBSD-src-35437d86aa2e89b16dfeb84a5499976559847155.tar.gz |
- FDESC, FIFO, NULL, PORTAL, PROC, UMAP and UNION file
systems were repo-copied from sys/miscfs to sys/fs.
- Renamed the following file systems and their modules:
fdesc -> fdescfs, portal -> portalfs, union -> unionfs.
- Renamed corresponding kernel options:
FDESC -> FDESCFS, PORTAL -> PORTALFS, UNION -> UNIONFS.
- Install header files for the above file systems.
- Removed bogus -I${.CURDIR}/../../sys CFLAGS from userland
Makefiles.
Diffstat (limited to 'sys/miscfs/union/union_subr.c')
-rw-r--r-- | sys/miscfs/union/union_subr.c | 1360 |
1 files changed, 0 insertions, 1360 deletions
diff --git a/sys/miscfs/union/union_subr.c b/sys/miscfs/union/union_subr.c deleted file mode 100644 index ce38e2d..0000000 --- a/sys/miscfs/union/union_subr.c +++ /dev/null @@ -1,1360 +0,0 @@ -/* - * Copyright (c) 1994 Jan-Simon Pendry - * Copyright (c) 1994 - * The Regents of the University of California. All rights reserved. - * - * This code is derived from software contributed to Berkeley by - * Jan-Simon Pendry. - * - * 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. - * 3. All advertising materials mentioning features or use of this software - * must display the following acknowledgement: - * This product includes software developed by the University of - * California, Berkeley and its contributors. - * 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. - * - * @(#)union_subr.c 8.20 (Berkeley) 5/20/95 - * $FreeBSD$ - */ - -#include <sys/param.h> -#include <sys/systm.h> -#include <sys/fcntl.h> -#include <sys/file.h> -#include <sys/filedesc.h> -#include <sys/kernel.h> -#include <sys/lock.h> -#include <sys/malloc.h> -#include <sys/module.h> -#include <sys/mount.h> -#include <sys/mutex.h> -#include <sys/namei.h> -#include <sys/stat.h> -#include <sys/vnode.h> - -#include <vm/vm.h> -#include <vm/vm_extern.h> /* for vnode_pager_setsize */ -#include <vm/vm_zone.h> -#include <vm/vm_object.h> /* for vm cache coherency */ - -#include <miscfs/union/union.h> - -#include <sys/proc.h> - -extern int union_init __P((void)); - -/* must be power of two, otherwise change UNION_HASH() */ -#define NHASH 32 - -/* unsigned int ... */ -#define UNION_HASH(u, l) \ - (((((uintptr_t) (u)) + ((uintptr_t) l)) >> 8) & (NHASH-1)) - -static LIST_HEAD(unhead, union_node) unhead[NHASH]; -static int unvplock[NHASH]; - -static void union_dircache_r __P((struct vnode *vp, struct vnode ***vppp, - int *cntp)); -static int union_list_lock __P((int ix)); -static void union_list_unlock __P((int ix)); -static int union_relookup __P((struct union_mount *um, struct vnode *dvp, - struct vnode **vpp, - struct componentname *cnp, - struct componentname *cn, char *path, - int pathlen)); -static void union_updatevp __P((struct union_node *un, - struct vnode *uppervp, - struct vnode *lowervp)); -static void union_newlower __P((struct union_node *, struct vnode *)); -static void union_newupper __P((struct union_node *, struct vnode *)); -static int union_copyfile __P((struct vnode *, struct vnode *, - struct ucred *, struct proc *)); -static int union_vn_create __P((struct vnode **, struct union_node *, - struct proc *)); -static int union_vn_close __P((struct vnode *, int, struct ucred *, - struct proc *)); - -int -union_init() -{ - int i; - - for (i = 0; i < NHASH; i++) - LIST_INIT(&unhead[i]); - bzero((caddr_t)unvplock, sizeof(unvplock)); - return (0); -} - -static int -union_list_lock(ix) - int ix; -{ - if (unvplock[ix] & UNVP_LOCKED) { - unvplock[ix] |= UNVP_WANT; - (void) tsleep((caddr_t) &unvplock[ix], PINOD, "unllck", 0); - return (1); - } - unvplock[ix] |= UNVP_LOCKED; - return (0); -} - -static void -union_list_unlock(ix) - int ix; -{ - unvplock[ix] &= ~UNVP_LOCKED; - - if (unvplock[ix] & UNVP_WANT) { - unvplock[ix] &= ~UNVP_WANT; - wakeup((caddr_t) &unvplock[ix]); - } -} - -/* - * union_updatevp: - * - * The uppervp, if not NULL, must be referenced and not locked by us - * The lowervp, if not NULL, must be referenced. - * - * if uppervp and lowervp match pointers already installed, nothing - * happens. The passed vp's (when matching) are not adjusted. This - * routine may only be called by union_newupper() and union_newlower(). - */ - -static void -union_updatevp(un, uppervp, lowervp) - struct union_node *un; - struct vnode *uppervp; - struct vnode *lowervp; -{ - int ohash = UNION_HASH(un->un_uppervp, un->un_lowervp); - int nhash = UNION_HASH(uppervp, lowervp); - int docache = (lowervp != NULLVP || uppervp != NULLVP); - int lhash, uhash; - - /* - * Ensure locking is ordered from lower to higher - * to avoid deadlocks. - */ - if (nhash < ohash) { - lhash = nhash; - uhash = ohash; - } else { - lhash = ohash; - uhash = nhash; - } - - if (lhash != uhash) { - while (union_list_lock(lhash)) - continue; - } - - while (union_list_lock(uhash)) - continue; - - if (ohash != nhash || !docache) { - if (un->un_flags & UN_CACHED) { - un->un_flags &= ~UN_CACHED; - LIST_REMOVE(un, un_cache); - } - } - - if (ohash != nhash) - union_list_unlock(ohash); - - if (un->un_lowervp != lowervp) { - if (un->un_lowervp) { - vrele(un->un_lowervp); - if (un->un_path) { - free(un->un_path, M_TEMP); - un->un_path = 0; - } - } - un->un_lowervp = lowervp; - un->un_lowersz = VNOVAL; - } - - if (un->un_uppervp != uppervp) { - if (un->un_uppervp) - vrele(un->un_uppervp); - un->un_uppervp = uppervp; - un->un_uppersz = VNOVAL; - } - - if (docache && (ohash != nhash)) { - LIST_INSERT_HEAD(&unhead[nhash], un, un_cache); - un->un_flags |= UN_CACHED; - } - - union_list_unlock(nhash); -} - -/* - * Set a new lowervp. The passed lowervp must be referenced and will be - * stored in the vp in a referenced state. - */ - -static void -union_newlower(un, lowervp) - struct union_node *un; - struct vnode *lowervp; -{ - union_updatevp(un, un->un_uppervp, lowervp); -} - -/* - * Set a new uppervp. The passed uppervp must be locked and will be - * stored in the vp in a locked state. The caller should not unlock - * uppervp. - */ - -static void -union_newupper(un, uppervp) - struct union_node *un; - struct vnode *uppervp; -{ - union_updatevp(un, uppervp, un->un_lowervp); -} - -/* - * Keep track of size changes in the underlying vnodes. - * If the size changes, then callback to the vm layer - * giving priority to the upper layer size. - */ -void -union_newsize(vp, uppersz, lowersz) - struct vnode *vp; - off_t uppersz, lowersz; -{ - struct union_node *un; - off_t sz; - - /* only interested in regular files */ - if (vp->v_type != VREG) - return; - - un = VTOUNION(vp); - sz = VNOVAL; - - if ((uppersz != VNOVAL) && (un->un_uppersz != uppersz)) { - un->un_uppersz = uppersz; - if (sz == VNOVAL) - sz = un->un_uppersz; - } - - if ((lowersz != VNOVAL) && (un->un_lowersz != lowersz)) { - un->un_lowersz = lowersz; - if (sz == VNOVAL) - sz = un->un_lowersz; - } - - if (sz != VNOVAL) { - UDEBUG(("union: %s size now %ld\n", - (uppersz != VNOVAL ? "upper" : "lower"), (long)sz)); - /* - * There is no need to change size of non-existent object - */ - /* vnode_pager_setsize(vp, sz); */ - } -} - -/* - * union_allocvp: allocate a union_node and associate it with a - * parent union_node and one or two vnodes. - * - * vpp Holds the returned vnode locked and referenced if no - * error occurs. - * - * mp Holds the mount point. mp may or may not be busied. - * allocvp makes no changes to mp. - * - * dvp Holds the parent union_node to the one we wish to create. - * XXX may only be used to traverse an uncopied lowervp-based - * tree? XXX - * - * dvp may or may not be locked. allocvp makes no changes - * to dvp. - * - * upperdvp Holds the parent vnode to uppervp, generally used along - * with path component information to create a shadow of - * lowervp when uppervp does not exist. - * - * upperdvp is referenced but unlocked on entry, and will be - * dereferenced on return. - * - * uppervp Holds the new uppervp vnode to be stored in the - * union_node we are allocating. uppervp is referenced but - * not locked, and will be dereferenced on return. - * - * lowervp Holds the new lowervp vnode to be stored in the - * union_node we are allocating. lowervp is referenced but - * not locked, and will be dereferenced on return. - * - * cnp Holds path component information to be coupled with - * lowervp and upperdvp to allow unionfs to create an uppervp - * later on. Only used if lowervp is valid. The conents - * of cnp is only valid for the duration of the call. - * - * docache Determine whether this node should be entered in the - * cache or whether it should be destroyed as soon as possible. - * - * all union_nodes are maintained on a singly-linked - * list. new nodes are only allocated when they cannot - * be found on this list. entries on the list are - * removed when the vfs reclaim entry is called. - * - * a single lock is kept for the entire list. this is - * needed because the getnewvnode() function can block - * waiting for a vnode to become free, in which case there - * may be more than one process trying to get the same - * vnode. this lock is only taken if we are going to - * call getnewvnode, since the kernel itself is single-threaded. - * - * if an entry is found on the list, then call vget() to - * take a reference. this is done because there may be - * zero references to it and so it needs to removed from - * the vnode free list. - */ - -int -union_allocvp(vpp, mp, dvp, upperdvp, cnp, uppervp, lowervp, docache) - struct vnode **vpp; - struct mount *mp; - struct vnode *dvp; /* parent union vnode */ - struct vnode *upperdvp; /* parent vnode of uppervp */ - struct componentname *cnp; /* may be null */ - struct vnode *uppervp; /* may be null */ - struct vnode *lowervp; /* may be null */ - int docache; -{ - int error; - struct union_node *un = 0; - struct union_mount *um = MOUNTTOUNIONMOUNT(mp); - struct proc *p = (cnp) ? cnp->cn_proc : curproc; - int hash = 0; - int vflag; - int try; - - if (uppervp == NULLVP && lowervp == NULLVP) - panic("union: unidentifiable allocation"); - - if (uppervp && lowervp && (uppervp->v_type != lowervp->v_type)) { - vrele(lowervp); - lowervp = NULLVP; - } - - /* detect the root vnode (and aliases) */ - vflag = 0; - if ((uppervp == um->um_uppervp) && - ((lowervp == NULLVP) || lowervp == um->um_lowervp)) { - if (lowervp == NULLVP) { - lowervp = um->um_lowervp; - if (lowervp != NULLVP) - VREF(lowervp); - } - vflag = VROOT; - } - -loop: - if (!docache) { - un = 0; - } else for (try = 0; try < 3; try++) { - switch (try) { - case 0: - if (lowervp == NULLVP) - continue; - hash = UNION_HASH(uppervp, lowervp); - break; - - case 1: - if (uppervp == NULLVP) - continue; - hash = UNION_HASH(uppervp, NULLVP); - break; - - case 2: - if (lowervp == NULLVP) - continue; - hash = UNION_HASH(NULLVP, lowervp); - break; - } - - while (union_list_lock(hash)) - continue; - - LIST_FOREACH(un, &unhead[hash], un_cache) { - if ((un->un_lowervp == lowervp || - un->un_lowervp == NULLVP) && - (un->un_uppervp == uppervp || - un->un_uppervp == NULLVP) && - (UNIONTOV(un)->v_mount == mp)) { - if (vget(UNIONTOV(un), 0, - cnp ? cnp->cn_proc : NULL)) { - union_list_unlock(hash); - goto loop; - } - break; - } - } - - union_list_unlock(hash); - - if (un) - break; - } - - if (un) { - /* - * Obtain a lock on the union_node. Everything is unlocked - * except for dvp, so check that case. If they match, our - * new un is already locked. Otherwise we have to lock our - * new un. - * - * A potential deadlock situation occurs when we are holding - * one lock while trying to get another. We must follow - * strict ordering rules to avoid it. We try to locate dvp - * by scanning up from un_vnode, since the most likely - * scenario is un being under dvp. - */ - - if (dvp && un->un_vnode != dvp) { - struct vnode *scan = un->un_vnode; - - do { - scan = VTOUNION(scan)->un_pvp; - } while (scan && scan->v_tag == VT_UNION && scan != dvp); - if (scan != dvp) { - /* - * our new un is above dvp (we never saw dvp - * while moving up the tree). - */ - VREF(dvp); - VOP_UNLOCK(dvp, 0, p); - error = vn_lock(un->un_vnode, LK_EXCLUSIVE, p); - vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY, p); - vrele(dvp); - } else { - /* - * our new un is under dvp - */ - error = vn_lock(un->un_vnode, LK_EXCLUSIVE, p); - } - } else if (dvp == NULLVP) { - /* - * dvp is NULL, we need to lock un. - */ - error = vn_lock(un->un_vnode, LK_EXCLUSIVE, p); - } else { - /* - * dvp == un->un_vnode, we are already locked. - */ - error = 0; - } - - if (error) - goto loop; - - /* - * At this point, the union_node is locked and referenced. - * - * uppervp is locked and referenced or NULL, lowervp is - * referenced or NULL. - */ - UDEBUG(("Modify existing un %p vn %p upper %p(refs %d) -> %p(refs %d)\n", - un, un->un_vnode, un->un_uppervp, - (un->un_uppervp ? un->un_uppervp->v_usecount : -99), - uppervp, - (uppervp ? uppervp->v_usecount : -99) - )); - - if (uppervp != un->un_uppervp) { - KASSERT(uppervp == NULL || uppervp->v_usecount > 0, ("union_allocvp: too few refs %d (at least 1 required) on uppervp", uppervp->v_usecount)); - union_newupper(un, uppervp); - } else if (uppervp) { - KASSERT(uppervp->v_usecount > 1, ("union_allocvp: too few refs %d (at least 2 required) on uppervp", uppervp->v_usecount)); - vrele(uppervp); - } - - /* - * Save information about the lower layer. - * This needs to keep track of pathname - * and directory information which union_vn_create - * might need. - */ - if (lowervp != un->un_lowervp) { - union_newlower(un, lowervp); - if (cnp && (lowervp != NULLVP)) { - un->un_path = malloc(cnp->cn_namelen+1, - M_TEMP, M_WAITOK); - bcopy(cnp->cn_nameptr, un->un_path, - cnp->cn_namelen); - un->un_path[cnp->cn_namelen] = '\0'; - } - } else if (lowervp) { - vrele(lowervp); - } - - /* - * and upperdvp - */ - if (upperdvp != un->un_dirvp) { - if (un->un_dirvp) - vrele(un->un_dirvp); - un->un_dirvp = upperdvp; - } else if (upperdvp) { - vrele(upperdvp); - } - - *vpp = UNIONTOV(un); - return (0); - } - - if (docache) { - /* - * otherwise lock the vp list while we call getnewvnode - * since that can block. - */ - hash = UNION_HASH(uppervp, lowervp); - - if (union_list_lock(hash)) - goto loop; - } - - /* - * Create new node rather then replace old node - */ - - error = getnewvnode(VT_UNION, mp, union_vnodeop_p, vpp); - if (error) { - /* - * If an error occurs clear out vnodes. - */ - if (lowervp) - vrele(lowervp); - if (uppervp) - vrele(uppervp); - if (upperdvp) - vrele(upperdvp); - *vpp = NULL; - goto out; - } - - MALLOC((*vpp)->v_data, void *, sizeof(struct union_node), - M_TEMP, M_WAITOK); - - (*vpp)->v_flag |= vflag; - if (uppervp) - (*vpp)->v_type = uppervp->v_type; - else - (*vpp)->v_type = lowervp->v_type; - - un = VTOUNION(*vpp); - bzero(un, sizeof(*un)); - - lockinit(&un->un_lock, PVFS, "unlock", 0, 0); - vn_lock(*vpp, LK_EXCLUSIVE | LK_RETRY, p); - - un->un_vnode = *vpp; - un->un_uppervp = uppervp; - un->un_uppersz = VNOVAL; - un->un_lowervp = lowervp; - un->un_lowersz = VNOVAL; - un->un_dirvp = upperdvp; - un->un_pvp = dvp; /* only parent dir in new allocation */ - if (dvp != NULLVP) - VREF(dvp); - un->un_dircache = 0; - un->un_openl = 0; - - if (cnp && (lowervp != NULLVP)) { - un->un_path = malloc(cnp->cn_namelen+1, M_TEMP, M_WAITOK); - bcopy(cnp->cn_nameptr, un->un_path, cnp->cn_namelen); - un->un_path[cnp->cn_namelen] = '\0'; - } else { - un->un_path = 0; - un->un_dirvp = NULL; - } - - if (docache) { - LIST_INSERT_HEAD(&unhead[hash], un, un_cache); - un->un_flags |= UN_CACHED; - } - -out: - if (docache) - union_list_unlock(hash); - - return (error); -} - -int -union_freevp(vp) - struct vnode *vp; -{ - struct union_node *un = VTOUNION(vp); - - if (un->un_flags & UN_CACHED) { - un->un_flags &= ~UN_CACHED; - LIST_REMOVE(un, un_cache); - } - - if (un->un_pvp != NULLVP) { - vrele(un->un_pvp); - un->un_pvp = NULL; - } - if (un->un_uppervp != NULLVP) { - vrele(un->un_uppervp); - un->un_uppervp = NULL; - } - if (un->un_lowervp != NULLVP) { - vrele(un->un_lowervp); - un->un_lowervp = NULL; - } - if (un->un_dirvp != NULLVP) { - vrele(un->un_dirvp); - un->un_dirvp = NULL; - } - if (un->un_path) { - free(un->un_path, M_TEMP); - un->un_path = NULL; - } - lockdestroy(&un->un_lock); - - FREE(vp->v_data, M_TEMP); - vp->v_data = 0; - - return (0); -} - -/* - * copyfile. copy the vnode (fvp) to the vnode (tvp) - * using a sequence of reads and writes. both (fvp) - * and (tvp) are locked on entry and exit. - * - * fvp and tvp are both exclusive locked on call, but their refcount's - * haven't been bumped at all. - */ -static int -union_copyfile(fvp, tvp, cred, p) - struct vnode *fvp; - struct vnode *tvp; - struct ucred *cred; - struct proc *p; -{ - char *buf; - struct uio uio; - struct iovec iov; - int error = 0; - - /* - * strategy: - * allocate a buffer of size MAXBSIZE. - * loop doing reads and writes, keeping track - * of the current uio offset. - * give up at the first sign of trouble. - */ - - bzero(&uio, sizeof(uio)); - - uio.uio_procp = p; - uio.uio_segflg = UIO_SYSSPACE; - uio.uio_offset = 0; - - VOP_LEASE(fvp, p, cred, LEASE_READ); - VOP_LEASE(tvp, p, cred, LEASE_WRITE); - - buf = malloc(MAXBSIZE, M_TEMP, M_WAITOK); - - /* ugly loop follows... */ - do { - off_t offset = uio.uio_offset; - int count; - int bufoffset; - - /* - * Setup for big read - */ - uio.uio_iov = &iov; - uio.uio_iovcnt = 1; - iov.iov_base = buf; - iov.iov_len = MAXBSIZE; - uio.uio_resid = iov.iov_len; - uio.uio_rw = UIO_READ; - - if ((error = VOP_READ(fvp, &uio, 0, cred)) != 0) - break; - - /* - * Get bytes read, handle read eof case and setup for - * write loop - */ - if ((count = MAXBSIZE - uio.uio_resid) == 0) - break; - bufoffset = 0; - - /* - * Write until an error occurs or our buffer has been - * exhausted, then update the offset for the next read. - */ - while (bufoffset < count) { - uio.uio_iov = &iov; - uio.uio_iovcnt = 1; - iov.iov_base = buf + bufoffset; - iov.iov_len = count - bufoffset; - uio.uio_offset = offset + bufoffset; - uio.uio_rw = UIO_WRITE; - uio.uio_resid = iov.iov_len; - - if ((error = VOP_WRITE(tvp, &uio, 0, cred)) != 0) - break; - bufoffset += (count - bufoffset) - uio.uio_resid; - } - uio.uio_offset = offset + bufoffset; - } while (error == 0); - - free(buf, M_TEMP); - return (error); -} - -/* - * - * un's vnode is assumed to be locked on entry and remains locked on exit. - */ - -int -union_copyup(un, docopy, cred, p) - struct union_node *un; - int docopy; - struct ucred *cred; - struct proc *p; -{ - int error; - struct mount *mp; - struct vnode *lvp, *uvp; - - /* - * If the user does not have read permission, the vnode should not - * be copied to upper layer. - */ - vn_lock(un->un_lowervp, LK_EXCLUSIVE | LK_RETRY, p); - error = VOP_ACCESS(un->un_lowervp, VREAD, cred, p); - VOP_UNLOCK(un->un_lowervp, 0, p); - if (error) - return (error); - - if ((error = vn_start_write(un->un_dirvp, &mp, V_WAIT | PCATCH)) != 0) - return (error); - if ((error = union_vn_create(&uvp, un, p)) != 0) { - vn_finished_write(mp); - return (error); - } - - lvp = un->un_lowervp; - - KASSERT(uvp->v_usecount > 0, ("copy: uvp refcount 0: %d", uvp->v_usecount)); - if (docopy) { - /* - * XX - should not ignore errors - * from VOP_CLOSE - */ - vn_lock(lvp, LK_EXCLUSIVE | LK_RETRY, p); - error = VOP_OPEN(lvp, FREAD, cred, p); - if (error == 0 && vn_canvmio(lvp) == TRUE) - error = vfs_object_create(lvp, p, cred); - if (error == 0) { - error = union_copyfile(lvp, uvp, cred, p); - VOP_UNLOCK(lvp, 0, p); - (void) VOP_CLOSE(lvp, FREAD, cred, p); - } - if (error == 0) - UDEBUG(("union: copied up %s\n", un->un_path)); - - } - VOP_UNLOCK(uvp, 0, p); - vn_finished_write(mp); - union_newupper(un, uvp); - KASSERT(uvp->v_usecount > 0, ("copy: uvp refcount 0: %d", uvp->v_usecount)); - union_vn_close(uvp, FWRITE, cred, p); - KASSERT(uvp->v_usecount > 0, ("copy: uvp refcount 0: %d", uvp->v_usecount)); - /* - * Subsequent IOs will go to the top layer, so - * call close on the lower vnode and open on the - * upper vnode to ensure that the filesystem keeps - * its references counts right. This doesn't do - * the right thing with (cred) and (FREAD) though. - * Ignoring error returns is not right, either. - */ - if (error == 0) { - int i; - - for (i = 0; i < un->un_openl; i++) { - (void) VOP_CLOSE(lvp, FREAD, cred, p); - (void) VOP_OPEN(uvp, FREAD, cred, p); - } - if (un->un_openl) { - if (vn_canvmio(uvp) == TRUE) - error = vfs_object_create(uvp, p, cred); - } - un->un_openl = 0; - } - - return (error); - -} - -/* - * union_relookup: - * - * dvp should be locked on entry and will be locked on return. No - * net change in the ref count will occur. - * - * If an error is returned, *vpp will be invalid, otherwise it - * will hold a locked, referenced vnode. If *vpp == dvp then - * remember that only one exclusive lock is held. - */ - -static int -union_relookup(um, dvp, vpp, cnp, cn, path, pathlen) - struct union_mount *um; - struct vnode *dvp; - struct vnode **vpp; - struct componentname *cnp; - struct componentname *cn; - char *path; - int pathlen; -{ - int error; - - /* - * A new componentname structure must be faked up because - * there is no way to know where the upper level cnp came - * from or what it is being used for. This must duplicate - * some of the work done by NDINIT, some of the work done - * by namei, some of the work done by lookup and some of - * the work done by VOP_LOOKUP when given a CREATE flag. - * Conclusion: Horrible. - */ - cn->cn_namelen = pathlen; - cn->cn_pnbuf = zalloc(namei_zone); - bcopy(path, cn->cn_pnbuf, cn->cn_namelen); - cn->cn_pnbuf[cn->cn_namelen] = '\0'; - - cn->cn_nameiop = CREATE; - cn->cn_flags = (LOCKPARENT|LOCKLEAF|HASBUF|SAVENAME|ISLASTCN); - cn->cn_proc = cnp->cn_proc; - if (um->um_op == UNMNT_ABOVE) - cn->cn_cred = cnp->cn_cred; - else - cn->cn_cred = um->um_cred; - cn->cn_nameptr = cn->cn_pnbuf; - cn->cn_consume = cnp->cn_consume; - - VREF(dvp); - VOP_UNLOCK(dvp, 0, cnp->cn_proc); - - /* - * Pass dvp unlocked and referenced on call to relookup(). - * - * If an error occurs, dvp will be returned unlocked and dereferenced. - */ - - if ((error = relookup(dvp, vpp, cn)) != 0) { - vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY, cnp->cn_proc); - return(error); - } - - /* - * If no error occurs, dvp will be returned locked with the reference - * left as before, and vpp will be returned referenced and locked. - * - * We want to return with dvp as it was passed to us, so we get - * rid of our reference. - */ - vrele(dvp); - return (0); -} - -/* - * Create a shadow directory in the upper layer. - * The new vnode is returned locked. - * - * (um) points to the union mount structure for access to the - * the mounting process's credentials. - * (dvp) is the directory in which to create the shadow directory, - * it is locked (but not ref'd) on entry and return. - * (cnp) is the componentname to be created. - * (vpp) is the returned newly created shadow directory, which - * is returned locked and ref'd - */ -int -union_mkshadow(um, dvp, cnp, vpp) - struct union_mount *um; - struct vnode *dvp; - struct componentname *cnp; - struct vnode **vpp; -{ - int error; - struct vattr va; - struct proc *p = cnp->cn_proc; - struct componentname cn; - struct mount *mp; - - if ((error = vn_start_write(dvp, &mp, V_WAIT | PCATCH)) != 0) - return (error); - if ((error = union_relookup(um, dvp, vpp, cnp, &cn, - cnp->cn_nameptr, cnp->cn_namelen)) != 0) { - vn_finished_write(mp); - return (error); - } - - if (*vpp) { - if (cn.cn_flags & HASBUF) { - zfree(namei_zone, cn.cn_pnbuf); - cn.cn_flags &= ~HASBUF; - } - if (dvp == *vpp) - vrele(*vpp); - else - vput(*vpp); - vn_finished_write(mp); - *vpp = NULLVP; - return (EEXIST); - } - - /* - * policy: when creating the shadow directory in the - * upper layer, create it owned by the user who did - * the mount, group from parent directory, and mode - * 777 modified by umask (ie mostly identical to the - * mkdir syscall). (jsp, kb) - */ - - VATTR_NULL(&va); - va.va_type = VDIR; - va.va_mode = um->um_cmode; - - /* VOP_LEASE: dvp is locked */ - VOP_LEASE(dvp, p, cn.cn_cred, LEASE_WRITE); - - error = VOP_MKDIR(dvp, vpp, &cn, &va); - if (cn.cn_flags & HASBUF) { - zfree(namei_zone, cn.cn_pnbuf); - cn.cn_flags &= ~HASBUF; - } - /*vput(dvp);*/ - vn_finished_write(mp); - return (error); -} - -/* - * Create a whiteout entry in the upper layer. - * - * (um) points to the union mount structure for access to the - * the mounting process's credentials. - * (dvp) is the directory in which to create the whiteout. - * it is locked on entry and return. - * (cnp) is the componentname to be created. - */ -int -union_mkwhiteout(um, dvp, cnp, path) - struct union_mount *um; - struct vnode *dvp; - struct componentname *cnp; - char *path; -{ - int error; - struct proc *p = cnp->cn_proc; - struct vnode *wvp; - struct componentname cn; - struct mount *mp; - - if ((error = vn_start_write(dvp, &mp, V_WAIT | PCATCH)) != 0) - return (error); - error = union_relookup(um, dvp, &wvp, cnp, &cn, path, strlen(path)); - if (error) { - vn_finished_write(mp); - return (error); - } - - if (wvp) { - if (cn.cn_flags & HASBUF) { - zfree(namei_zone, cn.cn_pnbuf); - cn.cn_flags &= ~HASBUF; - } - if (wvp == dvp) - vrele(wvp); - else - vput(wvp); - vn_finished_write(mp); - return (EEXIST); - } - - /* VOP_LEASE: dvp is locked */ - VOP_LEASE(dvp, p, p->p_ucred, LEASE_WRITE); - - error = VOP_WHITEOUT(dvp, &cn, CREATE); - if (cn.cn_flags & HASBUF) { - zfree(namei_zone, cn.cn_pnbuf); - cn.cn_flags &= ~HASBUF; - } - vn_finished_write(mp); - return (error); -} - -/* - * union_vn_create: creates and opens a new shadow file - * on the upper union layer. this function is similar - * in spirit to calling vn_open but it avoids calling namei(). - * the problem with calling namei is that a) it locks too many - * things, and b) it doesn't start at the "right" directory, - * whereas relookup is told where to start. - * - * On entry, the vnode associated with un is locked. It remains locked - * on return. - * - * If no error occurs, *vpp contains a locked referenced vnode for your - * use. If an error occurs *vpp iis undefined. - */ -static int -union_vn_create(vpp, un, p) - struct vnode **vpp; - struct union_node *un; - struct proc *p; -{ - struct vnode *vp; - struct ucred *cred = p->p_ucred; - struct vattr vat; - struct vattr *vap = &vat; - int fmode = FFLAGS(O_WRONLY|O_CREAT|O_TRUNC|O_EXCL); - int error; - int cmode = UN_FILEMODE & ~p->p_fd->fd_cmask; - struct componentname cn; - - *vpp = NULLVP; - - /* - * Build a new componentname structure (for the same - * reasons outlines in union_mkshadow). - * The difference here is that the file is owned by - * the current user, rather than by the person who - * did the mount, since the current user needs to be - * able to write the file (that's why it is being - * copied in the first place). - */ - cn.cn_namelen = strlen(un->un_path); - cn.cn_pnbuf = zalloc(namei_zone); - bcopy(un->un_path, cn.cn_pnbuf, cn.cn_namelen+1); - cn.cn_nameiop = CREATE; - cn.cn_flags = (LOCKPARENT|LOCKLEAF|HASBUF|SAVENAME|ISLASTCN); - cn.cn_proc = p; - cn.cn_cred = p->p_ucred; - cn.cn_nameptr = cn.cn_pnbuf; - cn.cn_consume = 0; - - /* - * Pass dvp unlocked and referenced on call to relookup(). - * - * If an error occurs, dvp will be returned unlocked and dereferenced. - */ - VREF(un->un_dirvp); - error = relookup(un->un_dirvp, &vp, &cn); - if (error) - return (error); - - /* - * If no error occurs, dvp will be returned locked with the reference - * left as before, and vpp will be returned referenced and locked. - */ - if (vp) { - vput(un->un_dirvp); - if (cn.cn_flags & HASBUF) { - zfree(namei_zone, cn.cn_pnbuf); - cn.cn_flags &= ~HASBUF; - } - if (vp == un->un_dirvp) - vrele(vp); - else - vput(vp); - return (EEXIST); - } - - /* - * Good - there was no race to create the file - * so go ahead and create it. The permissions - * on the file will be 0666 modified by the - * current user's umask. Access to the file, while - * it is unioned, will require access to the top *and* - * bottom files. Access when not unioned will simply - * require access to the top-level file. - * TODO: confirm choice of access permissions. - */ - VATTR_NULL(vap); - vap->va_type = VREG; - vap->va_mode = cmode; - VOP_LEASE(un->un_dirvp, p, cred, LEASE_WRITE); - error = VOP_CREATE(un->un_dirvp, &vp, &cn, vap); - if (cn.cn_flags & HASBUF) { - zfree(namei_zone, cn.cn_pnbuf); - cn.cn_flags &= ~HASBUF; - } - vput(un->un_dirvp); - if (error) - return (error); - - error = VOP_OPEN(vp, fmode, cred, p); - if (error == 0 && vn_canvmio(vp) == TRUE) - error = vfs_object_create(vp, p, cred); - if (error) { - vput(vp); - return (error); - } - vp->v_writecount++; - *vpp = vp; - return (0); -} - -static int -union_vn_close(vp, fmode, cred, p) - struct vnode *vp; - int fmode; - struct ucred *cred; - struct proc *p; -{ - - if (fmode & FWRITE) - --vp->v_writecount; - return (VOP_CLOSE(vp, fmode, cred, p)); -} - -#if 0 - -/* - * union_removed_upper: - * - * called with union_node unlocked. XXX - */ - -void -union_removed_upper(un) - struct union_node *un; -{ - struct proc *p = curproc; /* XXX */ - struct vnode **vpp; - - /* - * Do not set the uppervp to NULLVP. If lowervp is NULLVP, - * union node will have neither uppervp nor lowervp. We remove - * the union node from cache, so that it will not be referrenced. - */ - union_newupper(un, NULLVP); - if (un->un_dircache != 0) { - for (vpp = un->un_dircache; *vpp != NULLVP; vpp++) - vrele(*vpp); - free(un->un_dircache, M_TEMP); - un->un_dircache = 0; - } - - if (un->un_flags & UN_CACHED) { - un->un_flags &= ~UN_CACHED; - LIST_REMOVE(un, un_cache); - } -} - -#endif - -/* - * determine whether a whiteout is needed - * during a remove/rmdir operation. - */ -int -union_dowhiteout(un, cred, p) - struct union_node *un; - struct ucred *cred; - struct proc *p; -{ - struct vattr va; - - if (un->un_lowervp != NULLVP) - return (1); - - if (VOP_GETATTR(un->un_uppervp, &va, cred, p) == 0 && - (va.va_flags & OPAQUE)) - return (1); - - return (0); -} - -static void -union_dircache_r(vp, vppp, cntp) - struct vnode *vp; - struct vnode ***vppp; - int *cntp; -{ - struct union_node *un; - - if (vp->v_op != union_vnodeop_p) { - if (vppp) { - VREF(vp); - *(*vppp)++ = vp; - if (--(*cntp) == 0) - panic("union: dircache table too small"); - } else { - (*cntp)++; - } - - return; - } - - un = VTOUNION(vp); - if (un->un_uppervp != NULLVP) - union_dircache_r(un->un_uppervp, vppp, cntp); - if (un->un_lowervp != NULLVP) - union_dircache_r(un->un_lowervp, vppp, cntp); -} - -struct vnode * -union_dircache(vp, p) - struct vnode *vp; - struct proc *p; -{ - int cnt; - struct vnode *nvp; - struct vnode **vpp; - struct vnode **dircache; - struct union_node *un; - int error; - - vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p); - dircache = VTOUNION(vp)->un_dircache; - - nvp = NULLVP; - - if (dircache == NULL) { - cnt = 0; - union_dircache_r(vp, 0, &cnt); - cnt++; - dircache = malloc(cnt * sizeof(struct vnode *), - M_TEMP, M_WAITOK); - vpp = dircache; - union_dircache_r(vp, &vpp, &cnt); - *vpp = NULLVP; - vpp = dircache + 1; - } else { - vpp = dircache; - do { - if (*vpp++ == VTOUNION(vp)->un_uppervp) - break; - } while (*vpp != NULLVP); - } - - if (*vpp == NULLVP) - goto out; - - /*vn_lock(*vpp, LK_EXCLUSIVE | LK_RETRY, p);*/ - UDEBUG(("ALLOCVP-3 %p ref %d\n", *vpp, (*vpp ? (*vpp)->v_usecount : -99))); - VREF(*vpp); - error = union_allocvp(&nvp, vp->v_mount, NULLVP, NULLVP, NULL, *vpp, NULLVP, 0); - UDEBUG(("ALLOCVP-3B %p ref %d\n", nvp, (*vpp ? (*vpp)->v_usecount : -99))); - if (error) - goto out; - - VTOUNION(vp)->un_dircache = 0; - un = VTOUNION(nvp); - un->un_dircache = dircache; - -out: - VOP_UNLOCK(vp, 0, p); - return (nvp); -} - -/* - * Module glue to remove #ifdef UNION from vfs_syscalls.c - */ -static int -union_dircheck(struct proc *p, struct vnode **vp, struct file *fp) -{ - int error = 0; - - if ((*vp)->v_op == union_vnodeop_p) { - struct vnode *lvp; - - lvp = union_dircache(*vp, p); - if (lvp != NULLVP) { - struct vattr va; - - /* - * If the directory is opaque, - * then don't show lower entries - */ - error = VOP_GETATTR(*vp, &va, fp->f_cred, p); - if (va.va_flags & OPAQUE) { - vput(lvp); - lvp = NULL; - } - } - - if (lvp != NULLVP) { - error = VOP_OPEN(lvp, FREAD, fp->f_cred, p); - if (error == 0 && vn_canvmio(lvp) == TRUE) - error = vfs_object_create(lvp, p, fp->f_cred); - if (error) { - vput(lvp); - return (error); - } - VOP_UNLOCK(lvp, 0, p); - fp->f_data = (caddr_t) lvp; - fp->f_offset = 0; - error = vn_close(*vp, FREAD, fp->f_cred, p); - if (error) - return (error); - *vp = lvp; - return -1; /* goto unionread */ - } - } - return error; -} - -static int -union_modevent(module_t mod, int type, void *data) -{ - switch (type) { - case MOD_LOAD: - union_dircheckp = union_dircheck; - break; - case MOD_UNLOAD: - union_dircheckp = NULL; - break; - default: - break; - } - return 0; -} - -static moduledata_t union_mod = { - "union_dircheck", - union_modevent, - NULL -}; - -DECLARE_MODULE(union_dircheck, union_mod, SI_SUB_VFS, SI_ORDER_ANY); |