xnu-517.tar.gz

[apple/xnu.git] / bsd / hfs / hfs_cnode.c

/*
 * Copyright (c) 2002-2003 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this
 * file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/vnode.h>
#include <sys/mount.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/ubc.h>
#include <sys/quota.h>

#include <miscfs/specfs/specdev.h>
#include <miscfs/fifofs/fifo.h>

#include <hfs/hfs.h>
#include <hfs/hfs_catalog.h>
#include <hfs/hfs_cnode.h>
#include <hfs/hfs_quota.h>

extern int prtactive;


extern void	hfs_relnamehints(struct cnode *dcp);


/*
 * Last reference to an cnode.  If necessary, write or delete it.
 */
__private_extern__
int
hfs_inactive(ap)
	struct vop_inactive_args /* {
		struct vnode *a_vp;
	} */ *ap;
{
	struct vnode *vp = ap->a_vp;
	struct cnode *cp = VTOC(vp);
	struct hfsmount *hfsmp = VTOHFS(vp);
	struct proc *p = ap->a_p;
	struct timeval tv;
	int error = 0;
	int recycle = 0;
	int forkcount = 0;
	int truncated = 0;
	int started_tr = 0, grabbed_lock = 0;
	cat_cookie_t cookie;
	int cat_reserve = 0;

	if (prtactive && vp->v_usecount != 0)
		vprint("hfs_inactive: pushing active", vp);

	/*
	 * Ignore nodes related to stale file handles.
	 */
	if (cp->c_mode == 0)
		goto out;

	if (hfsmp->hfs_flags & HFS_READ_ONLY)
		goto out;

	if (cp->c_datafork)
		++forkcount;
	if (cp->c_rsrcfork)
		++forkcount;

	/* If needed, get rid of any fork's data for a deleted file */
	if ((vp->v_type == VREG) && (cp->c_flag & C_DELETED)) {
		if (VTOF(vp)->ff_blocks != 0) {
			error = VOP_TRUNCATE(vp, (off_t)0, IO_NDELAY, NOCRED, p);
			if (error)
				goto out;
			truncated = 1;
		}
		recycle = 1;
	}

	/*
	 * Check for a postponed deletion.
	 * (only delete cnode when the last fork goes inactive)
	 */
	if ((cp->c_flag & C_DELETED) && (forkcount <= 1)) {			
		/*
		 * Mark cnode in transit so that no one can get this 
		 * cnode from cnode hash.
		 */
		SET(cp->c_flag, C_TRANSIT);
		cp->c_flag &= ~C_DELETED;
		cp->c_rdev = 0;

		// XXXdbg
		hfs_global_shared_lock_acquire(hfsmp);
		grabbed_lock = 1;
		if (hfsmp->jnl) {
		    if (journal_start_transaction(hfsmp->jnl) != 0) {
				error = EINVAL;
				goto out;
		    }
		    started_tr = 1;
		}

		/*
		 * Reserve some space in the Catalog file.
		 */
		if ((error = cat_preflight(hfsmp, CAT_DELETE, &cookie, p))) {
			goto out;
		}
		cat_reserve = 1;


		/* Lock catalog b-tree */
		error = hfs_metafilelocking(hfsmp, kHFSCatalogFileID, LK_EXCLUSIVE, p);
		if (error) goto out;

		if (cp->c_blocks > 0)
			printf("hfs_inactive: attempting to delete a non-empty file!");

		/*
		 * The descriptor name may be zero,
		 * in which case the fileid is used.
		 */
		error = cat_delete(hfsmp, &cp->c_desc, &cp->c_attr);
		
		if (error && truncated && (error != ENXIO))
			printf("hfs_inactive: couldn't delete a truncated file!");

  		/* Update HFS Private Data dir */
		if (error == 0) {
			hfsmp->hfs_privdir_attr.ca_entries--;
			(void)cat_update(hfsmp, &hfsmp->hfs_privdir_desc,
				&hfsmp->hfs_privdir_attr, NULL, NULL);
		}

		/* Unlock catalog b-tree */
		(void) hfs_metafilelocking(hfsmp, kHFSCatalogFileID, LK_RELEASE, p);
		if (error) goto out;

#if QUOTA
		(void)hfs_chkiq(cp, -1, NOCRED, 0);
#endif /* QUOTA */

		cp->c_mode = 0;
		cp->c_flag |= C_NOEXISTS | C_CHANGE | C_UPDATE;

		if (error == 0)
 			hfs_volupdate(hfsmp, VOL_RMFILE, 0);
	}

	if (cp->c_flag & (C_ACCESS | C_CHANGE | C_MODIFIED | C_UPDATE)) {
		tv = time;
		// if the only thing being updated is the access time
		// then set the modified bit too so that update will
		// flush it to disk.  otherwise it'll get dropped.
		if ((cp->c_flag & C_CHANGEMASK) == C_ACCESS) {
		    cp->c_flag |= C_MODIFIED;
		}
		VOP_UPDATE(vp, &tv, &tv, 0);
	}
out:
	if (cat_reserve)
		cat_postflight(hfsmp, &cookie, p);

	// XXXdbg - have to do this because a goto could have come here
	if (started_tr) {
	    journal_end_transaction(hfsmp->jnl);
	    started_tr = 0;
	}
	if (grabbed_lock) {
		hfs_global_shared_lock_release(hfsmp);
	}

	VOP_UNLOCK(vp, 0, p);
	/*
	 * If we are done with the vnode, reclaim it
	 * so that it can be reused immediately.
	 */
	if (cp->c_mode == 0 || recycle)
		vrecycle(vp, (struct slock *)0, p);

	return (error);
}


/*
 * Reclaim a cnode so that it can be used for other purposes.
 */
__private_extern__
int
hfs_reclaim(ap)
	struct vop_reclaim_args /* {
		struct vnode *a_vp;
	} */ *ap;
{
	struct vnode *vp = ap->a_vp;
	struct cnode *cp = VTOC(vp);
	struct vnode *devvp = NULL;
	struct filefork *fp = NULL;
	struct filefork *altfp = NULL;
	int i;

	if (prtactive && vp->v_usecount != 0)
		vprint("hfs_reclaim(): pushing active", vp);

	/*
	 * Keep track of an inactive hot file.
	 */
  	(void) hfs_addhotfile(vp);

 	devvp = cp->c_devvp;		/* For later releasing */

	/*
	 * Find file fork for this vnode (if any)
	 * Also check if another fork is active
	 */
	if ((fp = cp->c_datafork) && (cp->c_vp == vp)) {
		cp->c_datafork = NULL;
		cp->c_vp = NULL;
		altfp = cp->c_rsrcfork;
	} else if ((fp = cp->c_rsrcfork) && (cp->c_rsrc_vp == vp)) {
		cp->c_rsrcfork = NULL;
		cp->c_rsrc_vp = NULL;
		if (VPARENT(vp) == cp->c_vp) {
		    cp->c_flag &= ~C_VPREFHELD;
		}
		altfp = cp->c_datafork;
	} else {
		cp->c_vp = NULL;
		fp = NULL;
		altfp = NULL;
	}

	/*
	 * On the last fork, remove the cnode from its hash chain.
	 */
	if (altfp == NULL)
		hfs_chashremove(cp);

	/* Release the file fork and related data (can block) */
	if (fp) {
		fp->ff_cp = NULL;
		/* Dump cached symlink data */
		if ((vp->v_type == VLNK) && (fp->ff_symlinkptr != NULL)) {
			FREE(fp->ff_symlinkptr, M_TEMP);
			fp->ff_symlinkptr = NULL;
		}
		FREE_ZONE(fp, sizeof(struct filefork), M_HFSFORK);
		fp = NULL;
	}

	/*
	 * Purge old data structures associated with the cnode.
	 */
	cache_purge(vp);
	if (devvp && altfp == NULL) {
		cp->c_devvp = NULL;
		vrele(devvp);
	}

	vp->v_data = NULL;

	/* 
	 * If there was only one active fork then we can release the cnode.
	 */
	if (altfp == NULL) {
#if QUOTA
		for (i = 0; i < MAXQUOTAS; i++) {
			if (cp->c_dquot[i] != NODQUOT) {
				dqreclaim(vp, cp->c_dquot[i]);
				cp->c_dquot[i] = NODQUOT;
			}
		}
#endif /* QUOTA */
		/* 
		 * Free any left over directory indices
		 */
		if (vp->v_type == VDIR)
			hfs_relnamehints(cp);

		/* 
		 * If the descriptor has a name then release it
		 */
		if (cp->c_desc.cd_flags & CD_HASBUF) {
			char *nameptr;

			nameptr = cp->c_desc.cd_nameptr;
			cp->c_desc.cd_nameptr = 0;
			cp->c_desc.cd_flags &= ~CD_HASBUF;
			cp->c_desc.cd_namelen = 0;
			remove_name(nameptr);
		}
		CLR(cp->c_flag, (C_ALLOC | C_TRANSIT));
		if (ISSET(cp->c_flag, C_WALLOC) || ISSET(cp->c_flag, C_WTRANSIT))
			wakeup(cp);
		FREE_ZONE(cp, sizeof(struct cnode), M_HFSNODE);

	}

	return (0);
}


/*
 * get a cnode
 *
 * called by hfs_lookup and hfs_vget (descp == NULL)
 *
 * returns a locked vnode for cnode for given cnid/fileid
 */
__private_extern__
int
hfs_getcnode(struct hfsmount *hfsmp, cnid_t cnid, struct cat_desc *descp, int wantrsrc,
                  struct cat_attr *attrp, struct cat_fork *forkp, struct vnode **vpp)
{
	dev_t dev = hfsmp->hfs_raw_dev;
	struct vnode *vp = NULL;
	struct vnode *rvp = NULL;
	struct vnode *new_vp = NULL;
	struct cnode *cp = NULL;
	struct proc *p = current_proc();
	int retval = E_NONE;

	/* Check if unmount in progress */
	if (HFSTOVFS(hfsmp)->mnt_kern_flag & MNTK_UNMOUNT) {
		*vpp = NULL;
		return (EPERM);
	}

	/*
	 * Check the hash for an active cnode
	 */
	cp = hfs_chashget(dev, cnid, wantrsrc, &vp, &rvp);
	if (cp != NULL) {
		/* hide open files that have been deleted */
		if ((hfsmp->hfs_privdir_desc.cd_cnid != 0)
		&&  (cp->c_parentcnid == hfsmp->hfs_privdir_desc.cd_cnid)
		&&  (cp->c_nlink == 0)) {
			retval = ENOENT;
			goto exit;
		}

		/* Hide private journal files */
		if (hfsmp->jnl &&
			(cp->c_parentcnid == kRootDirID) &&
			((cp->c_cnid == hfsmp->hfs_jnlfileid) ||
			(cp->c_cnid == hfsmp->hfs_jnlinfoblkid))) {
		    retval = ENOENT;
			goto exit;
		}
	 
		if (wantrsrc && rvp != NULL) {
			vp = rvp;
			rvp = NULL;
			goto done;
		}
		if (!wantrsrc && vp != NULL) {
			/* Hardlinks need an updated catalog descriptor */
			if (descp && cp->c_flag & C_HARDLINK) {
				replace_desc(cp, descp);
			}
			/* We have a vnode so we're done. */
			goto done;
		}
	}

	/*
	 * There was no active vnode so get a new one.
	 * Use the existing cnode (if any).
	 */
	if (descp != NULL) {
		/*
		 * hfs_lookup case, use descp, attrp and forkp
		 */
		retval = hfs_getnewvnode(hfsmp, cp, descp, wantrsrc, attrp,
				forkp, &new_vp);
	} else {
		struct cat_desc cndesc = {0};
		struct cat_attr cnattr = {0};
		struct cat_fork cnfork = {0};

		/*
		 * hfs_vget case, need to lookup entry (by file id)
		 */
		if (cnid == kRootParID) {
			static char hfs_rootname[] = "/";

			cndesc.cd_nameptr = &hfs_rootname[0];
			cndesc.cd_namelen = 1;
			cndesc.cd_parentcnid = kRootParID;
			cndesc.cd_cnid = kRootParID;
			cndesc.cd_flags = CD_ISDIR;
	
			cnattr.ca_fileid = kRootParID;
			cnattr.ca_nlink = 2;
			cnattr.ca_entries = 1;
			cnattr.ca_mode = (S_IFDIR | S_IRWXU | S_IRWXG | S_IRWXO);
		} else {
			/* Lock catalog b-tree */
			retval = hfs_metafilelocking(hfsmp, kHFSCatalogFileID, LK_SHARED, p);
			if (retval)
				goto exit;
	
			retval = cat_idlookup(hfsmp, cnid, &cndesc, &cnattr, &cnfork);
	
			/* Unlock catalog b-tree */
			(void) hfs_metafilelocking(hfsmp, kHFSCatalogFileID, LK_RELEASE, p);
			if (retval)
				goto exit;
	
			/* Hide open files that have been deleted */
			if ((hfsmp->hfs_privdir_desc.cd_cnid != 0) &&
			    (cndesc.cd_parentcnid == hfsmp->hfs_privdir_desc.cd_cnid) &&
			    (cnattr.ca_nlink == 0)) {
				cat_releasedesc(&cndesc);
				retval = ENOENT;
				goto exit;
			}
		}
		
		retval = hfs_getnewvnode(hfsmp, cp, &cndesc, 0, &cnattr, &cnfork, &new_vp);

		/* Hardlinks may need an updated catalog descriptor */
		if (retval == 0
		&&  new_vp
		&&  (VTOC(new_vp)->c_flag & C_HARDLINK)
		&&  cndesc.cd_nameptr
		&&  cndesc.cd_namelen > 0) {
			replace_desc(VTOC(new_vp), &cndesc);
		}

		cat_releasedesc(&cndesc);
	}

exit:
	/* Release reference taken on opposite vnode (if any). */
	if (vp)
		vrele(vp);
	else if (rvp)
		vrele(rvp);

	if (retval) {
		*vpp = NULL;
		return (retval);
	}
	vp = new_vp;
done:
	/* The cnode's vnode should be in vp. */
	if (vp == NULL)
		panic("hfs_getcnode: missing vp!");

	if (UBCISVALID(vp))
		UBCINFOCHECK("hfs_getcnode", vp);
	*vpp = vp;
	return (0);
}


/*
 * hfs_getnewvnode - get new default vnode
 *
 * the vnode is returned locked
 */
extern int (**hfs_vnodeop_p) (void *);
extern int (**hfs_specop_p)  (void *);
extern int (**hfs_fifoop_p)  (void *);

__private_extern__
int
hfs_getnewvnode(struct hfsmount *hfsmp, struct cnode *cp,
	struct cat_desc *descp, int wantrsrc,
	struct cat_attr *attrp, struct cat_fork *forkp,
	struct vnode **vpp)
{
	struct mount *mp = HFSTOVFS(hfsmp);
	struct vnode *vp = NULL;
	struct vnode *rvp = NULL;
	struct vnode *new_vp = NULL;
	struct cnode *cp2 = NULL;
	struct filefork *fp = NULL;
	int allocated = 0;
	int i;
	int retval;
	dev_t dev;
	struct proc *p = current_proc();
#if 0
	/* Bail when unmount is in progress */
	if (mp->mnt_kern_flag & MNTK_UNMOUNT) {
		*vpp = NULL;
		return (EPERM);
	}
#endif

#if !FIFO
	if (IFTOVT(attrp->ca_mode) == VFIFO) {
		*vpp = NULL;
		return (EOPNOTSUPP);
	}
#endif
	dev = hfsmp->hfs_raw_dev;

	/* If no cnode was passed in then create one */
	if (cp == NULL) {
		MALLOC_ZONE(cp2, struct cnode *, sizeof(struct cnode),
			M_HFSNODE, M_WAITOK);
		bzero(cp2, sizeof(struct cnode));
		allocated = 1;
		SET(cp2->c_flag, C_ALLOC);
		cp2->c_cnid = descp->cd_cnid;
		cp2->c_fileid = attrp->ca_fileid;
		if (cp2->c_fileid == 0) {
			FREE_ZONE(cp2, sizeof(struct cnode), M_HFSNODE);
			*vpp = NULL;
			return (ENOENT);
		}
		cp2->c_dev = dev;
		lockinit(&cp2->c_lock, PINOD, "cnode", 0, 0);
	    	(void) lockmgr(&cp2->c_lock, LK_EXCLUSIVE, (struct slock *)0, p);
		/*
		 * There were several blocking points since we first
		 * checked the hash. Now that we're through blocking,
		 * check the hash again in case we're racing for the
		 * same cnode.
		 */
		cp = hfs_chashget(dev, attrp->ca_fileid, wantrsrc, &vp, &rvp);
		if (cp != NULL) {
			/* We lost the race - use the winner's cnode */
			FREE_ZONE(cp2, sizeof(struct cnode), M_HFSNODE);
			allocated = 0;
			if (wantrsrc && rvp != NULL) {
				*vpp = rvp;
				return (0);
			}
			if (!wantrsrc && vp != NULL) {
				*vpp = vp;
				return (0);
			}
		} else /* allocated */ {
			cp = cp2;
			hfs_chashinsert(cp);
		}
	}

	/* Allocate a new vnode. If unsuccesful, leave after freeing memory */
	if ((retval = getnewvnode(VT_HFS, mp, hfs_vnodeop_p, &new_vp))) {
		if (allocated) {
			hfs_chashremove(cp);
			if (ISSET(cp->c_flag, C_WALLOC)) {
				CLR(cp->c_flag, C_WALLOC);
				wakeup(cp);
			}
			FREE_ZONE(cp2, sizeof(struct cnode), M_HFSNODE);
			allocated = 0;
		} else if (rvp) {
			vput(rvp);
		} else if (vp) {
			vput(vp);
		}
		*vpp = NULL;
		return (retval);
	}
	if (allocated) {
		bcopy(attrp, &cp->c_attr, sizeof(struct cat_attr));
		bcopy(descp, &cp->c_desc, sizeof(struct cat_desc));
	}
	new_vp->v_data = cp;
	if (wantrsrc && S_ISREG(cp->c_mode))
		cp->c_rsrc_vp = new_vp;
	else
		cp->c_vp = new_vp;

	/* Release reference taken on opposite vnode (if any). */
	if (rvp)
		vrele(rvp);
	if (vp)
		vrele(vp);

	vp = new_vp;
	vp->v_ubcinfo = UBC_NOINFO;

	/*
	 * If this is a new cnode then initialize it using descp and attrp...
	 */
	if (allocated) {
		/* The name was inherited so clear descriptor state... */
		descp->cd_namelen = 0;
		descp->cd_nameptr = NULL;
		descp->cd_flags &= ~CD_HASBUF;

		/* Tag hardlinks */
		if (IFTOVT(cp->c_mode) == VREG &&
		    (descp->cd_cnid != attrp->ca_fileid)) {
			cp->c_flag |= C_HARDLINK;
		}

		/* Take one dev reference for each non-directory cnode */
		if (IFTOVT(cp->c_mode) != VDIR) {
			cp->c_devvp = hfsmp->hfs_devvp;
			VREF(cp->c_devvp);
		}
#if QUOTA
		for (i = 0; i < MAXQUOTAS; i++)
			cp->c_dquot[i] = NODQUOT;
#endif /* QUOTA */
	}

	if (IFTOVT(cp->c_mode) != VDIR) {
		if (forkp && attrp->ca_blocks < forkp->cf_blocks)
			panic("hfs_getnewvnode: bad ca_blocks (too small)");
		/*
		 * Allocate and initialize a file fork...
		 */
		MALLOC_ZONE(fp, struct filefork *, sizeof(struct filefork),
			M_HFSFORK, M_WAITOK);
		bzero(fp, sizeof(struct filefork));
		fp->ff_cp = cp;
		if (forkp)
			bcopy(forkp, &fp->ff_data, sizeof(struct cat_fork));
		rl_init(&fp->ff_invalidranges);
		if (wantrsrc) {
			if (cp->c_rsrcfork != NULL)
				panic("stale rsrc fork");
			cp->c_rsrcfork = fp;
		} else {
			if (cp->c_datafork != NULL)
				panic("stale data fork");
			cp->c_datafork = fp;
		}
	}

	/*
	 * Finish vnode initialization.
	 * Setting the v_type 'stamps' the vnode as 'complete',
	 * so should be done almost last. 
	 * 
	 * At this point the vnode should be locked and fully
	 * allocated. And ready to be used or accessed. (though
	 * having it locked prevents most of this, it can still
	 * be accessed through lists and hashes).
	 */
	vp->v_type = IFTOVT(cp->c_mode);

	/* Tag system files */
	if ((descp->cd_flags & CD_ISMETA) && (vp->v_type == VREG))
		vp->v_flag |= VSYSTEM;
	/* Tag root directory */
	if (cp->c_cnid == kRootDirID)
                vp->v_flag |= VROOT;

	if ((vp->v_type == VREG) && !(vp->v_flag & VSYSTEM)
	    && (UBCINFOMISSING(vp) || UBCINFORECLAIMED(vp))) {
		ubc_info_init(vp);
	} else {
		vp->v_ubcinfo = UBC_NOINFO;
	}

	if (vp->v_type == VCHR || vp->v_type == VBLK) {
		struct vnode *nvp;

		vp->v_op = hfs_specop_p;
		if ((nvp = checkalias(vp, cp->c_rdev, mp))) {
			/*
			 * Discard unneeded vnode, but save its cnode.
			 * Note that the lock is carried over in the
			 * cnode to the replacement vnode.
			 */
			nvp->v_data = vp->v_data;
			vp->v_data = NULL;
			vp->v_op = spec_vnodeop_p;
			vrele(vp);
			vgone(vp);
			/*
			 * Reinitialize aliased cnode.
			 * Assume its not a resource fork.
			 */
			cp->c_vp = nvp;				
			vp = nvp;
		}
	} else if (vp->v_type == VFIFO) {
#if FIFO
		vp->v_op = hfs_fifoop_p;
#endif
	}

	/*
	 * Stop tracking an active hot file.
	 */
	(void) hfs_removehotfile(vp);

	/* Vnode is now initialized - see if anyone was waiting for it. */
	CLR(cp->c_flag, C_ALLOC);
	if (ISSET(cp->c_flag, C_WALLOC)) {
		CLR(cp->c_flag, C_WALLOC);
		wakeup((caddr_t)cp);
	}

	*vpp = vp;
	return (0);
}