namei.c

linux 内核源代码

	inode->i_ctime = dir->i_ctime = dir->i_mtime = current_fs_time(dir->i_sb);
	mark_inode_dirty(dir);

end_rmdir:
	if (fibh.sbh != fibh.ebh)
		brelse(fibh.ebh);
	brelse(fibh.sbh);

out:
	unlock_kernel();
	return retval;
}

static int udf_unlink(struct inode *dir, struct dentry *dentry)
{
	int retval;
	struct inode *inode = dentry->d_inode;
	struct udf_fileident_bh fibh;
	struct fileIdentDesc *fi;
	struct fileIdentDesc cfi;
	kernel_lb_addr tloc;

	retval = -ENOENT;
	lock_kernel();
	fi = udf_find_entry(dir, dentry, &fibh, &cfi);
	if (!fi)
		goto out;

	retval = -EIO;
	tloc = lelb_to_cpu(cfi.icb.extLocation);
	if (udf_get_lb_pblock(dir->i_sb, tloc, 0) != inode->i_ino)
		goto end_unlink;

	if (!inode->i_nlink) {
		udf_debug("Deleting nonexistent file (%lu), %d\n",
			  inode->i_ino, inode->i_nlink);
		inode->i_nlink = 1;
	}
	retval = udf_delete_entry(dir, fi, &fibh, &cfi);
	if (retval)
		goto end_unlink;
	dir->i_ctime = dir->i_mtime = current_fs_time(dir->i_sb);
	mark_inode_dirty(dir);
	inode_dec_link_count(inode);
	inode->i_ctime = dir->i_ctime;
	retval = 0;

end_unlink:
	if (fibh.sbh != fibh.ebh)
		brelse(fibh.ebh);
	brelse(fibh.sbh);

out:
	unlock_kernel();
	return retval;
}

static int udf_symlink(struct inode *dir, struct dentry *dentry,
		       const char *symname)
{
	struct inode *inode;
	struct pathComponent *pc;
	char *compstart;
	struct udf_fileident_bh fibh;
	struct extent_position epos = {};
	int eoffset, elen = 0;
	struct fileIdentDesc *fi;
	struct fileIdentDesc cfi;
	char *ea;
	int err;
	int block;
	char name[UDF_NAME_LEN];
	int namelen;

	lock_kernel();
	if (!(inode = udf_new_inode(dir, S_IFLNK, &err)))
		goto out;

	inode->i_mode = S_IFLNK | S_IRWXUGO;
	inode->i_data.a_ops = &udf_symlink_aops;
	inode->i_op = &page_symlink_inode_operations;

	if (UDF_I_ALLOCTYPE(inode) != ICBTAG_FLAG_AD_IN_ICB) {
		kernel_lb_addr eloc;
		uint32_t elen;

		block = udf_new_block(inode->i_sb, inode,
				      UDF_I_LOCATION(inode).partitionReferenceNum,
				      UDF_I_LOCATION(inode).logicalBlockNum, &err);
		if (!block)
			goto out_no_entry;
		epos.block = UDF_I_LOCATION(inode);
		epos.offset = udf_file_entry_alloc_offset(inode);
		epos.bh = NULL;
		eloc.logicalBlockNum = block;
		eloc.partitionReferenceNum = UDF_I_LOCATION(inode).partitionReferenceNum;
		elen = inode->i_sb->s_blocksize;
		UDF_I_LENEXTENTS(inode) = elen;
		udf_add_aext(inode, &epos, eloc, elen, 0);
		brelse(epos.bh);

		block = udf_get_pblock(inode->i_sb, block,
				       UDF_I_LOCATION(inode).partitionReferenceNum, 0);
		epos.bh = udf_tread(inode->i_sb, block);
		lock_buffer(epos.bh);
		memset(epos.bh->b_data, 0x00, inode->i_sb->s_blocksize);
		set_buffer_uptodate(epos.bh);
		unlock_buffer(epos.bh);
		mark_buffer_dirty_inode(epos.bh, inode);
		ea = epos.bh->b_data + udf_ext0_offset(inode);
	} else {
		ea = UDF_I_DATA(inode) + UDF_I_LENEATTR(inode);
	}

	eoffset = inode->i_sb->s_blocksize - udf_ext0_offset(inode);
	pc = (struct pathComponent *)ea;

	if (*symname == '/') {
		do {
			symname++;
		} while (*symname == '/');

		pc->componentType = 1;
		pc->lengthComponentIdent = 0;
		pc->componentFileVersionNum = 0;
		pc += sizeof(struct pathComponent);
		elen += sizeof(struct pathComponent);
	}

	err = -ENAMETOOLONG;

	while (*symname) {
		if (elen + sizeof(struct pathComponent) > eoffset)
			goto out_no_entry;

		pc = (struct pathComponent *)(ea + elen);

		compstart = (char *)symname;

		do {
			symname++;
		} while (*symname && *symname != '/');

		pc->componentType = 5;
		pc->lengthComponentIdent = 0;
		pc->componentFileVersionNum = 0;
		if (compstart[0] == '.') {
			if ((symname - compstart) == 1)
				pc->componentType = 4;
			else if ((symname - compstart) == 2 && compstart[1] == '.')
				pc->componentType = 3;
		}

		if (pc->componentType == 5) {
			namelen = udf_put_filename(inode->i_sb, compstart, name,
						   symname - compstart);
			if (!namelen)
				goto out_no_entry;

			if (elen + sizeof(struct pathComponent) + namelen > eoffset)
				goto out_no_entry;
			else
				pc->lengthComponentIdent = namelen;

			memcpy(pc->componentIdent, name, namelen);
		}

		elen += sizeof(struct pathComponent) + pc->lengthComponentIdent;

		if (*symname) {
			do {
				symname++;
			} while (*symname == '/');
		}
	}

	brelse(epos.bh);
	inode->i_size = elen;
	if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_IN_ICB)
		UDF_I_LENALLOC(inode) = inode->i_size;
	mark_inode_dirty(inode);

	if (!(fi = udf_add_entry(dir, dentry, &fibh, &cfi, &err)))
		goto out_no_entry;
	cfi.icb.extLength = cpu_to_le32(inode->i_sb->s_blocksize);
	cfi.icb.extLocation = cpu_to_lelb(UDF_I_LOCATION(inode));
	if (UDF_SB_LVIDBH(inode->i_sb)) {
		struct logicalVolHeaderDesc *lvhd;
		uint64_t uniqueID;
		lvhd = (struct logicalVolHeaderDesc *)(UDF_SB_LVID(inode->i_sb)->logicalVolContentsUse);
		uniqueID = le64_to_cpu(lvhd->uniqueID);
		*(__le32 *)((struct allocDescImpUse *)cfi.icb.impUse)->impUse =
			cpu_to_le32(uniqueID & 0x00000000FFFFFFFFUL);
		if (!(++uniqueID & 0x00000000FFFFFFFFUL))
			uniqueID += 16;
		lvhd->uniqueID = cpu_to_le64(uniqueID);
		mark_buffer_dirty(UDF_SB_LVIDBH(inode->i_sb));
	}
	udf_write_fi(dir, &cfi, fi, &fibh, NULL, NULL);
	if (UDF_I_ALLOCTYPE(dir) == ICBTAG_FLAG_AD_IN_ICB) {
		mark_inode_dirty(dir);
	}
	if (fibh.sbh != fibh.ebh)
		brelse(fibh.ebh);
	brelse(fibh.sbh);
	d_instantiate(dentry, inode);
	err = 0;

out:
	unlock_kernel();
	return err;

out_no_entry:
	inode_dec_link_count(inode);
	iput(inode);
	goto out;
}

static int udf_link(struct dentry *old_dentry, struct inode *dir,
		    struct dentry *dentry)
{
	struct inode *inode = old_dentry->d_inode;
	struct udf_fileident_bh fibh;
	struct fileIdentDesc cfi, *fi;
	int err;

	lock_kernel();
	if (inode->i_nlink >= (256 << sizeof(inode->i_nlink)) - 1) {
		unlock_kernel();
		return -EMLINK;
	}

	if (!(fi = udf_add_entry(dir, dentry, &fibh, &cfi, &err))) {
		unlock_kernel();
		return err;
	}
	cfi.icb.extLength = cpu_to_le32(inode->i_sb->s_blocksize);
	cfi.icb.extLocation = cpu_to_lelb(UDF_I_LOCATION(inode));
	if (UDF_SB_LVIDBH(inode->i_sb)) {
		struct logicalVolHeaderDesc *lvhd;
		uint64_t uniqueID;
		lvhd = (struct logicalVolHeaderDesc *)(UDF_SB_LVID(inode->i_sb)->logicalVolContentsUse);
		uniqueID = le64_to_cpu(lvhd->uniqueID);
		*(__le32 *)((struct allocDescImpUse *)cfi.icb.impUse)->impUse =
			cpu_to_le32(uniqueID & 0x00000000FFFFFFFFUL);
		if (!(++uniqueID & 0x00000000FFFFFFFFUL))
			uniqueID += 16;
		lvhd->uniqueID = cpu_to_le64(uniqueID);
		mark_buffer_dirty(UDF_SB_LVIDBH(inode->i_sb));
	}
	udf_write_fi(dir, &cfi, fi, &fibh, NULL, NULL);
	if (UDF_I_ALLOCTYPE(dir) == ICBTAG_FLAG_AD_IN_ICB) {
		mark_inode_dirty(dir);
	}

	if (fibh.sbh != fibh.ebh)
		brelse(fibh.ebh);
	brelse(fibh.sbh);
	inc_nlink(inode);
	inode->i_ctime = current_fs_time(inode->i_sb);
	mark_inode_dirty(inode);
	atomic_inc(&inode->i_count);
	d_instantiate(dentry, inode);
	unlock_kernel();

	return 0;
}

/* Anybody can rename anything with this: the permission checks are left to the
 * higher-level routines.
 */
static int udf_rename(struct inode *old_dir, struct dentry *old_dentry,
		      struct inode *new_dir, struct dentry *new_dentry)
{
	struct inode *old_inode = old_dentry->d_inode;
	struct inode *new_inode = new_dentry->d_inode;
	struct udf_fileident_bh ofibh, nfibh;
	struct fileIdentDesc *ofi = NULL, *nfi = NULL, *dir_fi = NULL, ocfi, ncfi;
	struct buffer_head *dir_bh = NULL;
	int retval = -ENOENT;
	kernel_lb_addr tloc;

	lock_kernel();
	if ((ofi = udf_find_entry(old_dir, old_dentry, &ofibh, &ocfi))) {
		if (ofibh.sbh != ofibh.ebh)
			brelse(ofibh.ebh);
		brelse(ofibh.sbh);
	}
	tloc = lelb_to_cpu(ocfi.icb.extLocation);
	if (!ofi || udf_get_lb_pblock(old_dir->i_sb, tloc, 0)
	    != old_inode->i_ino)
		goto end_rename;

	nfi = udf_find_entry(new_dir, new_dentry, &nfibh, &ncfi);
	if (nfi) {
		if (!new_inode) {
			if (nfibh.sbh != nfibh.ebh)
				brelse(nfibh.ebh);
			brelse(nfibh.sbh);
			nfi = NULL;
		}
	}
	if (S_ISDIR(old_inode->i_mode)) {
		uint32_t offset = udf_ext0_offset(old_inode);

		if (new_inode) {
			retval = -ENOTEMPTY;
			if (!empty_dir(new_inode))
				goto end_rename;
		}
		retval = -EIO;
		if (UDF_I_ALLOCTYPE(old_inode) == ICBTAG_FLAG_AD_IN_ICB) {
			dir_fi = udf_get_fileident(UDF_I_DATA(old_inode) -
						   (UDF_I_EFE(old_inode) ?
						    sizeof(struct extendedFileEntry) :
						    sizeof(struct fileEntry)),
						   old_inode->i_sb->s_blocksize, &offset);
		} else {
			dir_bh = udf_bread(old_inode, 0, 0, &retval);
			if (!dir_bh)
				goto end_rename;
			dir_fi = udf_get_fileident(dir_bh->b_data, old_inode->i_sb->s_blocksize, &offset);
		}
		if (!dir_fi)
			goto end_rename;
		tloc = lelb_to_cpu(dir_fi->icb.extLocation);
		if (udf_get_lb_pblock(old_inode->i_sb, tloc, 0) != old_dir->i_ino)
			goto end_rename;

		retval = -EMLINK;
		if (!new_inode && new_dir->i_nlink >= (256 << sizeof(new_dir->i_nlink)) - 1)
			goto end_rename;
	}
	if (!nfi) {
		nfi = udf_add_entry(new_dir, new_dentry, &nfibh, &ncfi, &retval);
		if (!nfi)
			goto end_rename;
	}

	/*
	 * Like most other Unix systems, set the ctime for inodes on a
	 * rename.
	 */
	old_inode->i_ctime = current_fs_time(old_inode->i_sb);
	mark_inode_dirty(old_inode);

	/*
	 * ok, that's it
	 */
	ncfi.fileVersionNum = ocfi.fileVersionNum;
	ncfi.fileCharacteristics = ocfi.fileCharacteristics;
	memcpy(&(ncfi.icb), &(ocfi.icb), sizeof(long_ad));
	udf_write_fi(new_dir, &ncfi, nfi, &nfibh, NULL, NULL);

	/* The old fid may have moved - find it again */
	ofi = udf_find_entry(old_dir, old_dentry, &ofibh, &ocfi);
	udf_delete_entry(old_dir, ofi, &ofibh, &ocfi);

	if (new_inode) {
		new_inode->i_ctime = current_fs_time(new_inode->i_sb);
		inode_dec_link_count(new_inode);
	}
	old_dir->i_ctime = old_dir->i_mtime = current_fs_time(old_dir->i_sb);
	mark_inode_dirty(old_dir);

	if (dir_fi) {
		dir_fi->icb.extLocation = cpu_to_lelb(UDF_I_LOCATION(new_dir));
		udf_update_tag((char *)dir_fi, (sizeof(struct fileIdentDesc) +
						le16_to_cpu(dir_fi->lengthOfImpUse) + 3) & ~3);
		if (UDF_I_ALLOCTYPE(old_inode) == ICBTAG_FLAG_AD_IN_ICB) {
			mark_inode_dirty(old_inode);
		} else {
			mark_buffer_dirty_inode(dir_bh, old_inode);
		}
		inode_dec_link_count(old_dir);
		if (new_inode) {
			inode_dec_link_count(new_inode);
		} else {
			inc_nlink(new_dir);
			mark_inode_dirty(new_dir);
		}
	}

	if (ofi) {
		if (ofibh.sbh != ofibh.ebh)
			brelse(ofibh.ebh);
		brelse(ofibh.sbh);
	}

	retval = 0;

end_rename:
	brelse(dir_bh);
	if (nfi) {
		if (nfibh.sbh != nfibh.ebh)
			brelse(nfibh.ebh);
		brelse(nfibh.sbh);
	}
	unlock_kernel();

	return retval;
}

const struct inode_operations udf_dir_inode_operations = {
	.lookup				= udf_lookup,
	.create				= udf_create,
	.link				= udf_link,
	.unlink				= udf_unlink,
	.symlink			= udf_symlink,
	.mkdir				= udf_mkdir,
	.rmdir				= udf_rmdir,
	.mknod				= udf_mknod,
	.rename				= udf_rename,
};