예제 #1
0
/*
 * Write a directory entry after a call to namei, using the parameters
 * that it left in nameidata. The argument dirp is the new directory
 * entry contents. Dvp is a pointer to the directory to be written,
 * which was left locked by namei. Remaining parameters (dp->i_offset,
 * dp->i_count) indicate how the space for the new entry is to be obtained.
 * Non-null bp indicates that a directory is being created (for the
 * soft dependency code).
 */
int
ufs_direnter(struct vnode *dvp, struct vnode *tvp, struct direct *dirp,
    struct componentname *cnp, struct buf *newdirbp)
{
  	struct ucred *cr;
  	struct proc *p;
  	int newentrysize;
  	struct inode *dp;
  	struct buf *bp;
  	u_int dsize;
  	struct direct *ep, *nep;
	int error, ret, blkoff, loc, spacefree, flags;
  	char *dirbuf;

	UFS_WAPBL_JLOCK_ASSERT(dvp->v_mount);

 	error = 0;
 	cr = cnp->cn_cred;
 	p = cnp->cn_proc;
  	dp = VTOI(dvp);
  	newentrysize = DIRSIZ(FSFMT(dvp), dirp);

	if (dp->i_count == 0) {
		/*
		 * If dp->i_count is 0, then namei could find no
		 * space in the directory. Here, dp->i_offset will
		 * be on a directory block boundary and we will write the
  		 * new entry into a fresh block.
  		 */
  		if (dp->i_offset & (DIRBLKSIZ - 1))
			panic("ufs_direnter: newblk");
		flags = B_CLRBUF;
		if (!DOINGSOFTDEP(dvp))
			flags |= B_SYNC;
		if ((error = UFS_BUF_ALLOC(dp, (off_t)dp->i_offset, DIRBLKSIZ,
		    cr, flags, &bp)) != 0) {
			if (DOINGSOFTDEP(dvp) && newdirbp != NULL)
				bdwrite(newdirbp);
			return (error);
		}
		DIP_ASSIGN(dp, size, dp->i_offset + DIRBLKSIZ);
		dp->i_flag |= IN_CHANGE | IN_UPDATE;
		uvm_vnp_setsize(dvp, DIP(dp, size));
  		dirp->d_reclen = DIRBLKSIZ;
		blkoff = dp->i_offset &
		    (VFSTOUFS(dvp->v_mount)->um_mountp->mnt_stat.f_iosize - 1);
		memcpy(bp->b_data + blkoff, dirp, newentrysize);

#ifdef UFS_DIRHASH
		if (dp->i_dirhash != NULL) {
			ufsdirhash_newblk(dp, dp->i_offset);
			ufsdirhash_add(dp, dirp, dp->i_offset);
			ufsdirhash_checkblock(dp, (char *)bp->b_data + blkoff,
			dp->i_offset);
		}
#endif

		if (DOINGSOFTDEP(dvp)) {
			/*
			 * Ensure that the entire newly allocated block is a
			 * valid directory so that future growth within the
			 * block does not have to ensure that the block is
			 * written before the inode.
			 */
			blkoff += DIRBLKSIZ;
			while (blkoff < bp->b_bcount) {
				((struct direct *)
				   (bp->b_data + blkoff))->d_reclen = DIRBLKSIZ;
				blkoff += DIRBLKSIZ;
			}
			if (softdep_setup_directory_add(bp, dp, dp->i_offset,
			    dirp->d_ino, newdirbp, 1) == 0) {
				bdwrite(bp);
				return (UFS_UPDATE(dp, 0));
			}
			/* We have just allocated a directory block in an
			 * indirect block. Rather than tracking when it gets
			 * claimed by the inode, we simply do a VOP_FSYNC
			 * now to ensure that it is there (in case the user
			 * does a future fsync). Note that we have to unlock
			 * the inode for the entry that we just entered, as
			 * the VOP_FSYNC may need to lock other inodes which
			 * can lead to deadlock if we also hold a lock on
			 * the newly entered node.
			 */
			if ((error = VOP_BWRITE(bp)))
				return (error);
			if (tvp != NULL)
				VOP_UNLOCK(tvp, 0);
			error = VOP_FSYNC(dvp, p->p_ucred, MNT_WAIT);
			if (tvp != NULL)
				vn_lock(tvp, LK_EXCLUSIVE | LK_RETRY, p);
			return (error);
		}
		error = VOP_BWRITE(bp);
 		ret = UFS_UPDATE(dp, !DOINGSOFTDEP(dvp));
 		if (error == 0)
 			return (ret);
  		return (error);
  	}
  
  	/*
	 * If dp->i_count is non-zero, then namei found space for the new
	 * entry in the range dp->i_offset to dp->i_offset + dp->i_count
	 * in the directory. To use this space, we may have to compact
	 * the entries located there, by copying them together towards the
	 * beginning of the block, leaving the free space in one usable
	 * chunk at the end.
  	 */
  
  	/*
	 * Increase size of directory if entry eats into new space.
	 * This should never push the size past a new multiple of
	 * DIRBLKSIZE.
	 *
	 * N.B. - THIS IS AN ARTIFACT OF 4.2 AND SHOULD NEVER HAPPEN.
	 */
	if (dp->i_offset + dp->i_count > DIP(dp, size)) {
		DIP_ASSIGN(dp, size, dp->i_offset + dp->i_count);
		dp->i_flag |= IN_CHANGE | IN_UPDATE;
		UFS_WAPBL_UPDATE(dp, MNT_WAIT);
	}
	/*
	 * Get the block containing the space for the new directory entry.
	 */
 	if ((error = UFS_BUFATOFF(dp, (off_t)dp->i_offset, &dirbuf, &bp)) 
	    != 0) {
 		if (DOINGSOFTDEP(dvp) && newdirbp != NULL)
 			bdwrite(newdirbp);
  		return (error);
 	}
	/*
	 * Find space for the new entry. In the simple case, the entry at
	 * offset base will have the space. If it does not, then namei
	 * arranged that compacting the region dp->i_offset to
	 * dp->i_offset + dp->i_count would yield the space.
	 */
	ep = (struct direct *)dirbuf;
	dsize = ep->d_ino ? DIRSIZ(FSFMT(dvp), ep) : 0;
	spacefree = ep->d_reclen - dsize;
	for (loc = ep->d_reclen; loc < dp->i_count; ) {
		nep = (struct direct *)(dirbuf + loc);

		/* Trim the existing slot (NB: dsize may be zero). */
		ep->d_reclen = dsize;
		ep = (struct direct *)((char *)ep + dsize);

		/* Read nep->d_reclen now as the memmove() may clobber it. */
		loc += nep->d_reclen;
		if (nep->d_ino == 0) {
			/*
			 * A mid-block unused entry. Such entries are
			 * never created by the kernel, but fsck_ffs
			 * can create them (and it doesn't fix them).
			 *
			 * Add up the free space, and initialise the
			 * relocated entry since we don't memmove it.
			 */
			spacefree += nep->d_reclen;
			ep->d_ino = 0;
			dsize = 0;
			continue;
		}
		dsize = DIRSIZ(FSFMT(dvp), nep);
		spacefree += nep->d_reclen - dsize;
#ifdef UFS_DIRHASH
		if (dp->i_dirhash != NULL)
			ufsdirhash_move(dp, nep,
			    dp->i_offset + ((char *)nep - dirbuf),
			    dp->i_offset + ((char *)ep - dirbuf));
#endif
 		if (DOINGSOFTDEP(dvp))
 			softdep_change_directoryentry_offset(dp, dirbuf,
 			    (caddr_t)nep, (caddr_t)ep, dsize); 
 		else
 			memmove(ep, nep, dsize);
	}
	/*
	 * Here, `ep' points to a directory entry containing `dsize' in-use
	 * bytes followed by `spacefree' unused bytes. If ep->d_ino == 0,
	 * then the entry is completely unused (dsize == 0). The value
	 * of ep->d_reclen is always indeterminate.
	 *
	 * Update the pointer fields in the previous entry (if any),
	 * copy in the new entry, and write out the block.
	 */
	if (ep->d_ino == 0) {
		if (spacefree + dsize < newentrysize)
			panic("ufs_direnter: compact1");
		dirp->d_reclen = spacefree + dsize;
	} else {
		if (spacefree < newentrysize)
			panic("ufs_direnter: compact2");
		dirp->d_reclen = spacefree;
		ep->d_reclen = dsize;
		ep = (struct direct *)((char *)ep + dsize);
	}

#ifdef UFS_DIRHASH
	if (dp->i_dirhash != NULL && (ep->d_ino == 0 ||
	    dirp->d_reclen == spacefree))
		ufsdirhash_add(dp, dirp, dp->i_offset + ((char *)ep - dirbuf));
#endif
	memcpy(ep, dirp, newentrysize);
#ifdef UFS_DIRHASH
	if (dp->i_dirhash != NULL)
		ufsdirhash_checkblock(dp, dirbuf -
		    (dp->i_offset & (DIRBLKSIZ - 1)),
		    dp->i_offset & ~(DIRBLKSIZ - 1));
#endif

  	if (DOINGSOFTDEP(dvp)) {
  		(void)softdep_setup_directory_add(bp, dp,
  		    dp->i_offset + (caddr_t)ep - dirbuf,
		    dirp->d_ino, newdirbp, 0);
  		bdwrite(bp);
  	} else {
  		error = VOP_BWRITE(bp);
  	}
	dp->i_flag |= IN_CHANGE | IN_UPDATE;

 	/*
 	 * If all went well, and the directory can be shortened, proceed
 	 * with the truncation. Note that we have to unlock the inode for
 	 * the entry that we just entered, as the truncation may need to
 	 * lock other inodes which can lead to deadlock if we also hold a
 	 * lock on the newly entered node.
 	 */

	if (error == 0 && dp->i_endoff && dp->i_endoff < DIP(dp, size)) {
		if (tvp != NULL)
			VOP_UNLOCK(tvp, 0);
#ifdef UFS_DIRHASH
		if (dp->i_dirhash != NULL)
			ufsdirhash_dirtrunc(dp, dp->i_endoff);
#endif


		error = UFS_TRUNCATE(dp, (off_t)dp->i_endoff, IO_SYNC, cr);

		if (tvp != NULL)
			vn_lock(tvp, LK_EXCLUSIVE | LK_RETRY, p);
	}
	UFS_WAPBL_UPDATE(dp, MNT_WAIT);
	return (error);
}
예제 #2
0
// ffs文件系统的写入操作
int
ffs_write(void *v)
{
	struct vop_write_args *ap = v;
	struct vnode *vp;
	struct uio *uio;
	struct inode *ip;
	struct fs *fs;
	struct buf *bp;
	daddr_t lbn;
	off_t osize;
	int blkoffset, error, extended, flags, ioflag, size, xfersize;
	ssize_t resid, overrun;

	extended = 0;
	ioflag = ap->a_ioflag;
	uio = ap->a_uio;
	vp = ap->a_vp;
	ip = VTOI(vp);

#ifdef DIAGNOSTIC
	if (uio->uio_rw != UIO_WRITE)
		panic("ffs_write: mode");
#endif

	/*
	 * If writing 0 bytes, succeed and do not change
	 * update time or file offset (standards compliance)
	 */
	if (uio->uio_resid == 0)
		return (0);

	switch (vp->v_type) {
	case VREG:
		if (ioflag & IO_APPEND)
			uio->uio_offset = DIP(ip, size);
		if ((DIP(ip, flags) & APPEND) && uio->uio_offset != DIP(ip, size))
			return (EPERM);
		/* FALLTHROUGH */
	case VLNK:
		break;
	case VDIR:
		if ((ioflag & IO_SYNC) == 0)
			panic("ffs_write: nonsync dir write");
		break;
	default:
		panic("ffs_write: type");
	}

	fs = ip->i_fs;
	if (uio->uio_offset < 0 ||
	    (u_int64_t)uio->uio_offset + uio->uio_resid > fs->fs_maxfilesize)
		return (EFBIG);

	/* do the filesize rlimit check */
	if ((error = vn_fsizechk(vp, uio, ioflag, &overrun)))
		return (error);

	resid = uio->uio_resid;
	osize = DIP(ip, size);
	flags = ioflag & IO_SYNC ? B_SYNC : 0;

	for (error = 0; uio->uio_resid > 0;) {
		lbn = lblkno(fs, uio->uio_offset);
		blkoffset = blkoff(fs, uio->uio_offset);
		xfersize = fs->fs_bsize - blkoffset;
		if (uio->uio_resid < xfersize)
			xfersize = uio->uio_resid;
		if (fs->fs_bsize > xfersize)
			flags |= B_CLRBUF;
		else
			flags &= ~B_CLRBUF;

		if ((error = UFS_BUF_ALLOC(ip, uio->uio_offset, xfersize,
			 ap->a_cred, flags, &bp)) != 0)
			break;
		if (uio->uio_offset + xfersize > DIP(ip, size)) {
			DIP_ASSIGN(ip, size, uio->uio_offset + xfersize);
			uvm_vnp_setsize(vp, DIP(ip, size));
			extended = 1;
		}
		(void)uvm_vnp_uncache(vp);

		size = blksize(fs, ip, lbn) - bp->b_resid;
		if (size < xfersize)
			xfersize = size;

		error =
		    uiomovei(bp->b_data + blkoffset, xfersize, uio);

		if (error != 0)
			memset(bp->b_data + blkoffset, 0, xfersize);

#if 0
		if (ioflag & IO_NOCACHE)
			bp->b_flags |= B_NOCACHE;
#endif
		if (ioflag & IO_SYNC)
			(void)bwrite(bp);
		else if (xfersize + blkoffset == fs->fs_bsize) {
			if (doclusterwrite)
				cluster_write(bp, &ip->i_ci, DIP(ip, size));
			else
				bawrite(bp);
		} else
			bdwrite(bp);

		if (error || xfersize == 0)
			break;
		ip->i_flag |= IN_CHANGE | IN_UPDATE;
	}
	/*
	 * If we successfully wrote any data, and we are not the superuser
	 * we clear the setuid and setgid bits as a precaution against
	 * tampering.
	 */
	if (resid > uio->uio_resid && ap->a_cred && ap->a_cred->cr_uid != 0)
		DIP_ASSIGN(ip, mode, DIP(ip, mode) & ~(ISUID | ISGID));
	if (resid > uio->uio_resid)
		VN_KNOTE(vp, NOTE_WRITE | (extended ? NOTE_EXTEND : 0));
	if (error) {
		if (ioflag & IO_UNIT) {
			(void)UFS_TRUNCATE(ip, osize,
			    ioflag & IO_SYNC, ap->a_cred);
			uio->uio_offset -= resid - uio->uio_resid;
			uio->uio_resid = resid;
		}
	} else if (resid > uio->uio_resid && (ioflag & IO_SYNC)) {
		error = UFS_UPDATE(ip, 1);
	}
	/* correct the result for writes clamped by vn_fsizechk() */
	uio->uio_resid += overrun;
	return (error);
}
예제 #3
0
/*
 * Vnode op for writing.
 */
int
ffs_write(void *v)
{
	struct vop_write_args *ap = v;
	struct vnode *vp;
	struct uio *uio;
	struct inode *ip;
	struct fs *fs;
	struct buf *bp;
	struct proc *p;
	daddr64_t lbn;
	off_t osize;
	int blkoffset, error, extended, flags, ioflag, resid, size, xfersize;

	extended = 0;
	ioflag = ap->a_ioflag;
	uio = ap->a_uio;
	vp = ap->a_vp;
	ip = VTOI(vp);

#ifdef DIAGNOSTIC
	if (uio->uio_rw != UIO_WRITE)
		panic("ffs_write: mode");
#endif

	/*
	 * If writing 0 bytes, succeed and do not change
	 * update time or file offset (standards compliance)
	 */
	if (uio->uio_resid == 0)
		return (0);

	switch (vp->v_type) {
	case VREG:
		if (ioflag & IO_APPEND)
			uio->uio_offset = DIP(ip, size);
		if ((DIP(ip, flags) & APPEND) && uio->uio_offset != DIP(ip, size))
			return (EPERM);
		/* FALLTHROUGH */
	case VLNK:
		break;
	case VDIR:
		if ((ioflag & IO_SYNC) == 0)
			panic("ffs_write: nonsync dir write");
		break;
	default:
		panic("ffs_write: type");
	}

	fs = ip->i_fs;
	if (uio->uio_offset < 0 ||
	    (u_int64_t)uio->uio_offset + uio->uio_resid > fs->fs_maxfilesize)
		return (EFBIG);
	/*
	 * Maybe this should be above the vnode op call, but so long as
	 * file servers have no limits, I don't think it matters.
	 */
	p = uio->uio_procp;
	if (vp->v_type == VREG && p && !(ioflag & IO_NOLIMIT) &&
	    uio->uio_offset + uio->uio_resid >
	    p->p_rlimit[RLIMIT_FSIZE].rlim_cur) {
		psignal(p, SIGXFSZ);
		return (EFBIG);
	}

	resid = uio->uio_resid;
	osize = DIP(ip, size);
	flags = ioflag & IO_SYNC ? B_SYNC : 0;

	for (error = 0; uio->uio_resid > 0;) {
		lbn = lblkno(fs, uio->uio_offset);
		blkoffset = blkoff(fs, uio->uio_offset);
		xfersize = fs->fs_bsize - blkoffset;
		if (uio->uio_resid < xfersize)
			xfersize = uio->uio_resid;
		if (fs->fs_bsize > xfersize)
			flags |= B_CLRBUF;
		else
			flags &= ~B_CLRBUF;

		if ((error = UFS_BUF_ALLOC(ip, uio->uio_offset, xfersize,
			 ap->a_cred, flags, &bp)) != 0)
			break;
		if (uio->uio_offset + xfersize > DIP(ip, size)) {
			DIP_ASSIGN(ip, size, uio->uio_offset + xfersize);
			uvm_vnp_setsize(vp, DIP(ip, size));
			extended = 1;
		}
		(void)uvm_vnp_uncache(vp);

		size = blksize(fs, ip, lbn) - bp->b_resid;
		if (size < xfersize)
			xfersize = size;

		error =
		    uiomove((char *)bp->b_data + blkoffset, xfersize, uio);

		if (error != 0)
			bzero((char *)bp->b_data + blkoffset, xfersize);

		if (ioflag & IO_SYNC)
			(void)bwrite(bp);
		else if (xfersize + blkoffset == fs->fs_bsize) {
			if (doclusterwrite)
				cluster_write(bp, &ip->i_ci, DIP(ip, size));
			else
				bawrite(bp);
		} else
			bdwrite(bp);

		if (error || xfersize == 0)
			break;
		ip->i_flag |= IN_CHANGE | IN_UPDATE;
	}
	/*
	 * If we successfully wrote any data, and we are not the superuser
	 * we clear the setuid and setgid bits as a precaution against
	 * tampering.
	 */
	if (resid > uio->uio_resid && ap->a_cred && ap->a_cred->cr_uid != 0)
		DIP_ASSIGN(ip, mode, DIP(ip, mode) & ~(ISUID | ISGID));
	if (resid > uio->uio_resid)
		VN_KNOTE(vp, NOTE_WRITE | (extended ? NOTE_EXTEND : 0));
	if (error) {
		if (ioflag & IO_UNIT) {
			(void)UFS_TRUNCATE(ip, osize,
			    ioflag & IO_SYNC, ap->a_cred);
			uio->uio_offset -= resid - uio->uio_resid;
			uio->uio_resid = resid;
		}
	} else if (resid > uio->uio_resid && (ioflag & IO_SYNC)) {
		error = UFS_UPDATE(ip, MNT_WAIT);
	}
	return (error);
}
예제 #4
0
/*
 * Truncate the inode oip to at most length size, freeing the
 * disk blocks.
 */
int
ffs_truncate(struct inode *oip, off_t length, int flags, struct ucred *cred)
{
	struct vnode *ovp;
	daddr64_t lastblock;
	daddr64_t bn, lbn, lastiblock[NIADDR], indir_lbn[NIADDR];
	daddr64_t oldblks[NDADDR + NIADDR], newblks[NDADDR + NIADDR];
	struct fs *fs;
	struct buf *bp;
	int offset, size, level;
	long count, nblocks, vflags, blocksreleased = 0;
	int i, aflags, error, allerror, indirect = 0;
	off_t osize;
	extern int num_indirdep;
	extern int max_indirdep;

	if (length < 0)
		return (EINVAL);
	ovp = ITOV(oip);

	if (ovp->v_type != VREG &&
	    ovp->v_type != VDIR &&
	    ovp->v_type != VLNK)
		return (0);

	if (DIP(oip, size) == length)
		return (0);

	if (ovp->v_type == VLNK &&
	    (DIP(oip, size) < ovp->v_mount->mnt_maxsymlinklen ||
	     (ovp->v_mount->mnt_maxsymlinklen == 0 &&
	      oip->i_din1->di_blocks == 0))) {
#ifdef DIAGNOSTIC
		if (length != 0)
			panic("ffs_truncate: partial truncate of symlink");
#endif
		memset(SHORTLINK(oip), 0, (size_t) DIP(oip, size));
		DIP_ASSIGN(oip, size, 0);
		oip->i_flag |= IN_CHANGE | IN_UPDATE;
		return (UFS_UPDATE(oip, MNT_WAIT));
	}

	if ((error = getinoquota(oip)) != 0)
		return (error);

	uvm_vnp_setsize(ovp, length);
	oip->i_ci.ci_lasta = oip->i_ci.ci_clen 
	    = oip->i_ci.ci_cstart = oip->i_ci.ci_lastw = 0;

	if (DOINGSOFTDEP(ovp)) {
		if (length > 0 || softdep_slowdown(ovp)) {
			/*
			 * If a file is only partially truncated, then
			 * we have to clean up the data structures
			 * describing the allocation past the truncation
			 * point. Finding and deallocating those structures
			 * is a lot of work. Since partial truncation occurs
			 * rarely, we solve the problem by syncing the file
			 * so that it will have no data structures left.
			 */
			if ((error = VOP_FSYNC(ovp, cred, MNT_WAIT)) != 0)
				return (error);
		} else {
			(void)ufs_quota_free_blocks(oip, DIP(oip, blocks),
			    NOCRED);
			softdep_setup_freeblocks(oip, length);
			(void) vinvalbuf(ovp, 0, cred, curproc, 0, 0);
			oip->i_flag |= IN_CHANGE | IN_UPDATE;
			return (UFS_UPDATE(oip, 0));
		}
	}

	fs = oip->i_fs;
	osize = DIP(oip, size);
	/*
	 * Lengthen the size of the file. We must ensure that the
	 * last byte of the file is allocated. Since the smallest
	 * value of osize is 0, length will be at least 1.
	 */
	if (osize < length) {
		if (length > fs->fs_maxfilesize)
			return (EFBIG);
		aflags = B_CLRBUF;
		if (flags & IO_SYNC)
			aflags |= B_SYNC;
		error = UFS_BUF_ALLOC(oip, length - 1, 1, 
				   cred, aflags, &bp);
		if (error)
			return (error);
		if (bp->b_lblkno >= NDADDR)
			indirect = 1;
		DIP_ASSIGN(oip, size, length);
		uvm_vnp_setsize(ovp, length);
		(void) uvm_vnp_uncache(ovp);
		if (aflags & B_SYNC)
			bwrite(bp);
		else
			bawrite(bp);
		oip->i_flag |= IN_CHANGE | IN_UPDATE;
		error = UFS_UPDATE(oip, MNT_WAIT);
		if (DOINGSOFTDEP(ovp) && num_indirdep > max_indirdep)
			if (indirect) {
				/*
				 * If the number of pending indirect block
				 * dependencies is sufficiently close to the
				 * maximum number of simultaneously mappable
				 * buffers force a sync on the vnode to prevent
				 * buffer cache exhaustion.
				 */
				VOP_FSYNC(ovp, curproc->p_ucred, MNT_WAIT);
			}
		return (error);
	}
	uvm_vnp_setsize(ovp, length);

	/*
	 * Shorten the size of the file. If the file is not being
	 * truncated to a block boundary, the contents of the
	 * partial block following the end of the file must be
	 * zero'ed in case it ever becomes accessible again because
	 * of subsequent file growth. Directories however are not
	 * zero'ed as they should grow back initialized to empty.
	 */
	offset = blkoff(fs, length);
	if (offset == 0) {
		DIP_ASSIGN(oip, size, length);
	} else {
		lbn = lblkno(fs, length);
		aflags = B_CLRBUF;
		if (flags & IO_SYNC)
			aflags |= B_SYNC;
		error = UFS_BUF_ALLOC(oip, length - 1, 1,
				   cred, aflags, &bp);
		if (error)
			return (error);
		/*
		 * When we are doing soft updates and the UFS_BALLOC
		 * above fills in a direct block hole with a full sized
		 * block that will be truncated down to a fragment below,
		 * we must flush out the block dependency with an FSYNC
		 * so that we do not get a soft updates inconsistency
		 * when we create the fragment below.
		 */
		if (DOINGSOFTDEP(ovp) && lbn < NDADDR &&
		    fragroundup(fs, blkoff(fs, length)) < fs->fs_bsize &&
		    (error = VOP_FSYNC(ovp, cred, MNT_WAIT)) != 0)
			return (error);
		DIP_ASSIGN(oip, size, length);
		size = blksize(fs, oip, lbn);
		(void) uvm_vnp_uncache(ovp);
		if (ovp->v_type != VDIR)
			bzero((char *)bp->b_data + offset,
			      (u_int)(size - offset));
		bp->b_bcount = size;
		if (aflags & B_SYNC)
			bwrite(bp);
		else
			bawrite(bp);
	}
	/*
	 * Calculate index into inode's block list of
	 * last direct and indirect blocks (if any)
	 * which we want to keep.  Lastblock is -1 when
	 * the file is truncated to 0.
	 */
	lastblock = lblkno(fs, length + fs->fs_bsize - 1) - 1;
	lastiblock[SINGLE] = lastblock - NDADDR;
	lastiblock[DOUBLE] = lastiblock[SINGLE] - NINDIR(fs);
	lastiblock[TRIPLE] = lastiblock[DOUBLE] - NINDIR(fs) * NINDIR(fs);
	nblocks = btodb(fs->fs_bsize);

	/*
	 * Update file and block pointers on disk before we start freeing
	 * blocks.  If we crash before free'ing blocks below, the blocks
	 * will be returned to the free list.  lastiblock values are also
	 * normalized to -1 for calls to ffs_indirtrunc below.
	 */
	for (level = TRIPLE; level >= SINGLE; level--) {
		oldblks[NDADDR + level] = DIP(oip, ib[level]);
		if (lastiblock[level] < 0) {
			DIP_ASSIGN(oip, ib[level], 0);
			lastiblock[level] = -1;
		}
	}

	for (i = 0; i < NDADDR; i++) {
		oldblks[i] = DIP(oip, db[i]);
		if (i > lastblock)
			DIP_ASSIGN(oip, db[i], 0);
	}

	oip->i_flag |= IN_CHANGE | IN_UPDATE;
	if ((error = UFS_UPDATE(oip, MNT_WAIT)) != 0)
		allerror = error;

	/*
	 * Having written the new inode to disk, save its new configuration
	 * and put back the old block pointers long enough to process them.
	 * Note that we save the new block configuration so we can check it
	 * when we are done.
	 */
	for (i = 0; i < NDADDR; i++) {
		newblks[i] = DIP(oip, db[i]);
		DIP_ASSIGN(oip, db[i], oldblks[i]);
	}

	for (i = 0; i < NIADDR; i++) {
		newblks[NDADDR + i] = DIP(oip, ib[i]);
		DIP_ASSIGN(oip, ib[i], oldblks[NDADDR + i]);
	}

	DIP_ASSIGN(oip, size, osize);
	vflags = ((length > 0) ? V_SAVE : 0) | V_SAVEMETA;
	allerror = vinvalbuf(ovp, vflags, cred, curproc, 0, 0);

	/*
	 * Indirect blocks first.
	 */
	indir_lbn[SINGLE] = -NDADDR;
	indir_lbn[DOUBLE] = indir_lbn[SINGLE] - NINDIR(fs) - 1;
	indir_lbn[TRIPLE] = indir_lbn[DOUBLE] - NINDIR(fs) * NINDIR(fs) - 1;
	for (level = TRIPLE; level >= SINGLE; level--) {
		bn = DIP(oip, ib[level]);
		if (bn != 0) {
			error = ffs_indirtrunc(oip, indir_lbn[level],
			    fsbtodb(fs, bn), lastiblock[level], level, &count);
			if (error)
				allerror = error;
			blocksreleased += count;
			if (lastiblock[level] < 0) {
				DIP_ASSIGN(oip, ib[level], 0);
				ffs_blkfree(oip, bn, fs->fs_bsize);
				blocksreleased += nblocks;
			}
		}
		if (lastiblock[level] >= 0)
			goto done;
	}

	/*
	 * All whole direct blocks or frags.
	 */
	for (i = NDADDR - 1; i > lastblock; i--) {
		long bsize;

		bn = DIP(oip, db[i]);
		if (bn == 0)
			continue;

		DIP_ASSIGN(oip, db[i], 0);
		bsize = blksize(fs, oip, i);
		ffs_blkfree(oip, bn, bsize);
		blocksreleased += btodb(bsize);
	}
	if (lastblock < 0)
		goto done;

	/*
	 * Finally, look for a change in size of the
	 * last direct block; release any frags.
	 */
	bn = DIP(oip, db[lastblock]);
	if (bn != 0) {
		long oldspace, newspace;

		/*
		 * Calculate amount of space we're giving
		 * back as old block size minus new block size.
		 */
		oldspace = blksize(fs, oip, lastblock);
		DIP_ASSIGN(oip, size, length);
		newspace = blksize(fs, oip, lastblock);
		if (newspace == 0)
			panic("ffs_truncate: newspace");
		if (oldspace - newspace > 0) {
			/*
			 * Block number of space to be free'd is
			 * the old block # plus the number of frags
			 * required for the storage we're keeping.
			 */
			bn += numfrags(fs, newspace);
			ffs_blkfree(oip, bn, oldspace - newspace);
			blocksreleased += btodb(oldspace - newspace);
		}
	}
done:
#ifdef DIAGNOSTIC
	for (level = SINGLE; level <= TRIPLE; level++)
		if (newblks[NDADDR + level] != DIP(oip, ib[level]))
			panic("ffs_truncate1");
	for (i = 0; i < NDADDR; i++)
		if (newblks[i] != DIP(oip, db[i]))
			panic("ffs_truncate2");
#endif /* DIAGNOSTIC */
	/*
	 * Put back the real size.
	 */
	DIP_ASSIGN(oip, size, length);
	DIP_ADD(oip, blocks, -blocksreleased);
	oip->i_flag |= IN_CHANGE;
	(void)ufs_quota_free_blocks(oip, blocksreleased, NOCRED);
	return (allerror);
}
예제 #5
0
파일: ufs_vnops.c 프로젝트: sofuture/bitrig
/*
 * Mkdir system call
 */
int
ufs_mkdir(void *v)
{
	struct vop_mkdir_args *ap = v;
	struct vnode *dvp = ap->a_dvp;
	struct vattr *vap = ap->a_vap;
	struct componentname *cnp = ap->a_cnp;
	struct inode *ip, *dp;
	struct vnode *tvp;
	struct buf *bp;
	struct direct newdir;
	struct dirtemplate dirtemplate, *dtp;
	int error, dmode, blkoff;

#ifdef DIAGNOSTIC
	if ((cnp->cn_flags & HASBUF) == 0)
		panic("ufs_mkdir: no name");
#endif
	dp = VTOI(dvp);
	if ((nlink_t) DIP(dp, nlink) >= LINK_MAX) {
		error = EMLINK;
		goto out;
	}
	dmode = vap->va_mode & 0777;
	dmode |= IFDIR;
	/*
	 * Must simulate part of ufs_makeinode here to acquire the inode,
	 * but not have it entered in the parent directory. The entry is
	 * made later after writing "." and ".." entries.
	 */
	if ((error = UFS_INODE_ALLOC(dp, dmode, cnp->cn_cred, &tvp)) != 0)
		goto out;

	ip = VTOI(tvp);

	DIP_ASSIGN(ip, uid, cnp->cn_cred->cr_uid);
	DIP_ASSIGN(ip, gid, DIP(dp, gid));

	if ((error = getinoquota(ip)) ||
	    (error = ufs_quota_alloc_inode(ip, cnp->cn_cred))) {
		pool_put(&namei_pool, cnp->cn_pnbuf);
		UFS_INODE_FREE(ip, ip->i_number, dmode);
		vput(tvp);
		vput(dvp);
		return (error);
	}

	ip->i_flag |= IN_ACCESS | IN_CHANGE | IN_UPDATE;
	DIP_ASSIGN(ip, mode, dmode);
	tvp->v_type = VDIR;	/* Rest init'd in getnewvnode(). */
	ip->i_effnlink = 2;
	DIP_ASSIGN(ip, nlink, 2);
	if (DOINGSOFTDEP(tvp))
		softdep_change_linkcnt(ip, 0);

	/*
	 * Bump link count in parent directory to reflect work done below.
	 * Should be done before reference is create so cleanup is 
	 * possible if we crash.
	 */
	dp->i_effnlink++;
	DIP_ADD(dp, nlink, 1);
	dp->i_flag |= IN_CHANGE;
	if (DOINGSOFTDEP(dvp))
		softdep_change_linkcnt(dp, 0);
	if ((error = UFS_UPDATE(dp, !DOINGSOFTDEP(dvp))) != 0)
		goto bad;

	/* 
	 * Initialize directory with "." and ".." from static template.
	 */
	if (dvp->v_mount->mnt_maxsymlinklen > 0)
		dtp = &mastertemplate;
	else
		dtp = (struct dirtemplate *)&omastertemplate;
	dirtemplate = *dtp;
	dirtemplate.dot_ino = ip->i_number;
	dirtemplate.dotdot_ino = dp->i_number;

	if ((error = UFS_BUF_ALLOC(ip, (off_t)0, DIRBLKSIZ, cnp->cn_cred,
            B_CLRBUF, &bp)) != 0)
		goto bad;
	DIP_ASSIGN(ip, size, DIRBLKSIZ);
	ip->i_flag |= IN_CHANGE | IN_UPDATE;
	uvm_vnp_setsize(tvp, DIP(ip, size));
	bcopy((caddr_t)&dirtemplate, (caddr_t)bp->b_data, sizeof dirtemplate);
	if (DOINGSOFTDEP(tvp)) {
		/*
		 * Ensure that the entire newly allocated block is a
		 * valid directory so that future growth within the
		 * block does not have to ensure that the block is
		 * written before the inode
		 */
		blkoff = DIRBLKSIZ;
		while (blkoff < bp->b_bcount) {
			((struct direct *)
			 (bp->b_data + blkoff))->d_reclen = DIRBLKSIZ;
			blkoff += DIRBLKSIZ;
		}
	}
	if ((error = UFS_UPDATE(ip, !DOINGSOFTDEP(tvp))) != 0) {
		(void)VOP_BWRITE(bp);
		goto bad;
	}

	/*
         * Directory set up, now install its entry in the parent directory.
         *
         * If we are not doing soft dependencies, then we must write out the
         * buffer containing the new directory body before entering the new
         * name in the parent. If we are doing soft dependencies, then the
         * buffer containing the new directory body will be passed to and
         * released in the soft dependency code after the code has attached
         * an appropriate ordering dependency to the buffer which ensures that
         * the buffer is written before the new name is written in the parent.
	 */
        if (!DOINGSOFTDEP(dvp) && ((error = VOP_BWRITE(bp)) != 0))
                goto bad;
        ufs_makedirentry(ip, cnp, &newdir);
        error = ufs_direnter(dvp, tvp, &newdir, cnp, bp);
  
bad:
        if (error == 0) {
		VN_KNOTE(dvp, NOTE_WRITE | NOTE_LINK);
                *ap->a_vpp = tvp;
        } else {
                dp->i_effnlink--;
                DIP_ADD(dp, nlink, -1);
                dp->i_flag |= IN_CHANGE;
		if (DOINGSOFTDEP(dvp))
			softdep_change_linkcnt(dp, 0);
                /*
                 * No need to do an explicit VOP_TRUNCATE here, vrele will
                 * do this for us because we set the link count to 0.
                 */
                ip->i_effnlink = 0;
                DIP_ASSIGN(ip, nlink, 0);
                ip->i_flag |= IN_CHANGE;
		if (DOINGSOFTDEP(tvp))
			softdep_change_linkcnt(ip, 0);
		vput(tvp);
	}
out:
	pool_put(&namei_pool, cnp->cn_pnbuf);
	vput(dvp);

	return (error);
}
예제 #6
0
/*
 * Extended attribute area writing.
 */
int
ffs_ea_write(struct vnode *vp, struct uio *uio, int ioflag, struct ucred *ucred)
{
	struct inode *ip;
	struct ufs2_dinode *dp;
	struct fs *fs;
	struct buf *bp;
	off_t osize;
	size_t resid;
	int error, flags, xfersize;

	ip = VTOI(vp);
	fs = ip->i_fs;
	dp = ip->i_din2;
	error = 0;

	/* Don't cross the limit for the extended attribute area length. */
	if ((unsigned)uio->uio_offset + uio->uio_resid > NXADDR * fs->fs_bsize)
		return (EFBIG);

	/*
	 * Save the original amount of data to be written ('uio->uio_resid') as
	 * well as the extended attribute area size ('dp->di_extsize') in case
	 * we need to truncate in the end due to an unpredicted error.
	 */

	resid = uio->uio_resid;
	osize = dp->di_extsize;

	/* Prepare flags to be passed to UFS_BUF_ALLOC(). */
	flags = IO_EXT | B_CLRBUF;
	if (!DOINGASYNC(vp))
		flags |= B_SYNC;

	/*
	 * Loop over the amount of data requested by the caller, stopping only
	 * if an error occurs. By default, we always try to write a file system
	 * block worth of bytes per iteration ('xfersize'). Check this value
	 * against what is left to be copied ('uio->uio_resid'). If we are
	 * writing less than a full block, ask the buffer to be cleaned first.
	 */

	while (uio->uio_resid > 0) {

		xfersize = fs->fs_bsize;
		if (uio->uio_resid < xfersize) {
			xfersize = uio->uio_resid;
			flags |= B_CLRBUF;
		}

		/* Ask the ffs_balloc.c code for the block. */
		error = UFS_BUF_ALLOC(ip, uio->uio_offset, xfersize, ucred,
		    flags, &bp);
		if (error)
			break;

		/* Check if we are growing the extended attributes area. */
		if (uio->uio_offset + xfersize > dp->di_extsize)
			dp->di_extsize = uio->uio_offset + xfersize;

		error = uiomove(bp->b_data, xfersize, uio);
		if (error) {
			clrbuf(bp); /* Get rid of stray contents. */
			error = EIO;
			break;
		}

		/*
		 * We use the same criteria for calling bwrite(), bawrite(), or
		 * bdwrite() as the rest of the FFS code does.
		 */

		if (ioflag & IO_SYNC)
			bwrite(bp);
		else if (xfersize == fs->fs_bsize)
			bawrite(bp);
		else
			bdwrite(bp);

		if (error || xfersize == 0)
			break;

		ip->i_flag |= IN_CHANGE | IN_UPDATE;
	}

	/*
	 * If we successfully wrote any data, and we are not the superuser we
	 * clear the setuid and setgid bits as a precaution against tampering.
	 */

	if ((DIP(ip, mode) & (ISUID | ISGID)) && resid > uio->uio_resid)
		if (ucred && suser_ucred(ucred))
			DIP(ip, mode) &= ~(ISUID | ISGID);

	if (error) {
		/* Release blocks if we failed. */
		if (ioflag & IO_UNIT) {
			ffs_truncate(ip, osize, flags, ucred);
			uio->uio_offset -= resid - uio->uio_resid;
			uio->uio_resid = resid;
		}

		return (error);
	}

	/* If needed, sync the inode now. */
	if (resid > uio->uio_resid && (ioflag & IO_SYNC))
		return (ffs_update(ip, NULL, NULL, MNT_WAIT));

	return (0);
}