C++ set_nlink函数代码示例

static int ecryptfs_rmdir(struct inode *dir, struct dentry *dentry)
{
	struct dentry *lower_dentry;
	struct dentry *lower_dir_dentry;
	int rc;

	lower_dentry = ecryptfs_dentry_to_lower(dentry);
	dget(dentry);
	lower_dir_dentry = lock_parent(lower_dentry);
	dget(lower_dentry);
	rc = vfs_rmdir(lower_dir_dentry->d_inode, lower_dentry);
	dput(lower_dentry);
	if (!rc && dentry->d_inode)
		clear_nlink(dentry->d_inode);
	fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
	set_nlink(dir, lower_dir_dentry->d_inode->i_nlink);
	unlock_dir(lower_dir_dentry);
	if (!rc)
		d_drop(dentry);
	dput(dentry);
	return rc;
}

static int wrapfs_rmdir(struct inode *dir, struct dentry *dentry)
{
	struct dentry *lower_dentry;
	struct dentry *lower_dir_dentry;
	int err;
	struct path lower_path;

	if(wrapfs_get_debug(dir->i_sb) & DEBUG_INODE)
		DEBUG_MESG("Enter");

	wrapfs_get_lower_path(dentry, &lower_path);
	lower_dentry = lower_path.dentry;
	lower_dir_dentry = lock_parent(lower_dentry);

	err = mnt_want_write(lower_path.mnt);
	if (err)
		goto out_unlock;
	err = vfs_rmdir(lower_dir_dentry->d_inode, lower_dentry);
	if (err)
		goto out;

	d_drop(dentry);	/* drop our dentry on success (why not VFS's job?) */
	if (dentry->d_inode)
		clear_nlink(dentry->d_inode);
	fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
	fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
	set_nlink(dir, lower_dir_dentry->d_inode->i_nlink);

out:
	mnt_drop_write(lower_path.mnt);
out_unlock:
	unlock_dir(lower_dir_dentry);
	wrapfs_put_lower_path(dentry, &lower_path);

	if(wrapfs_get_debug(dir->i_sb) & DEBUG_INODE)
		DEBUG_RETURN("Exit", err);

	return err;
}

static int diaryfs_unlink(struct inode *dir, struct dentry *dentry) {
	int err;

	struct dentry * lower_dentry;
	struct inode * lower_dir_inode = diaryfs_lower_inode(dir);
	struct dentry * lower_dir_dentry;
	struct path lower_path;

	diaryfs_get_lower_path(dentry, &lower_path);
	lower_dentry = lower_path.dentry;
	dget(lower_dentry);
	lower_dir_dentry = lock_parent(lower_dentry);

	err = vfs_unlink(lower_dir_inode, lower_dentry, NULL);

	/*
	 * Note: unlinking on top of NFS can cause silly-renamed files
	 * Trying to delete such files results in EBUSY from NFS 
	 * below. Silly-renamed files will get deleted by NFS later on, 
	 * so we just need to detect them here and treat EBUSY errors
	 * as if the upper file was successfully deleted.
	 */

	if (err == -EBUSY && lower_dentry->d_flags & DCACHE_NFSFS_RENAMED)
		err = 0;
	if (err)
		goto out;

	fsstack_copy_attr_times(dir, lower_dir_inode);
	fsstack_copy_inode_size(dir, lower_dir_inode);
	set_nlink(dentry->d_inode, diaryfs_lower_inode(dentry->d_inode)->i_nlink);
	dentry->d_inode->i_ctime = dir->i_ctime;
	d_drop(dentry); /* this is needed, else LTP fails */
out:
	unlock_dir(lower_dir_dentry);
	dput(lower_dentry);
	diaryfs_put_lower_path(dentry, &lower_path);
	return err;
}

static int ccfs_link(struct dentry *old_dentry, struct inode *dir,
			 struct dentry *new_dentry)
{
	struct dentry *lower_old_dentry;
	struct dentry *lower_new_dentry;
	struct dentry *lower_dir_dentry;
	u64 file_size_save;
	int rc;
	
// TODO: Update cached link
	file_size_save = i_size_read(old_dentry->d_inode);
	lower_old_dentry = ccfs_get_nested_dentry(old_dentry);
	lower_new_dentry = ccfs_get_nested_dentry(new_dentry);	
	dget(lower_old_dentry);
	dget(lower_new_dentry);
	
	mdbg(INFO3,"Link w/ lower_dentry->d_name.name = [%s] Link = [%s]", lower_old_dentry->d_name.name, lower_new_dentry->d_name.name);
	lower_dir_dentry = lock_parent(lower_new_dentry);
	rc = vfs_link(lower_old_dentry, lower_dir_dentry->d_inode,
		      lower_new_dentry);
	if (rc || !lower_new_dentry->d_inode)
		goto out_lock;
	rc = ccfs_interpose(lower_new_dentry, new_dentry, dir->i_sb, 0);
	if (rc)
		goto out_lock;
	fsstack_copy_attr_times(dir, lower_new_dentry->d_inode);
	fsstack_copy_inode_size(dir, lower_new_dentry->d_inode);
	set_nlink(old_dentry->d_inode, ccfs_get_nested_inode(old_dentry->d_inode)->i_nlink); //Fix for kernel 3.7.1 use function set_nlink by Jiri Rakosnik
	i_size_write(new_dentry->d_inode, file_size_save);
out_lock:
	unlock_dir(lower_dir_dentry);
	dput(lower_new_dentry);
	dput(lower_old_dentry);
	d_drop(lower_old_dentry);
	d_drop(new_dentry);
	d_drop(old_dentry);
	return rc;
}

/*
 * scfs_mkdir
 *
 * Parameters:
 * @*dir: inode of the dir to create
 * @*scfs_dentry: dentry of the dir to create
 * @mode:
 *
 * Return:
 * SCFS_SUCCESS if success, otherwise if error
 *
 * Description:
 * mkdir() for SCFS.
 */
static int scfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
{
	struct dentry *lower_dir_dentry;
	struct dentry *lower_parent_dentry;
	int ret;

	lower_dir_dentry = scfs_lower_dentry(dentry);
	lower_parent_dentry = lock_parent(lower_dir_dentry);
	ret = vfs_mkdir(lower_parent_dentry->d_inode, lower_dir_dentry, mode);
	if (ret || !lower_dir_dentry->d_inode) {
		SCFS_PRINT_ERROR("dir %s vfs_mkdir failed, "
			"lower_dir %s lower_parent %s mode %x\n",
			dentry->d_name.name,
			lower_dir_dentry->d_name.name,
			lower_parent_dentry->d_name.name, mode);
		goto out;
	}
	ret = scfs_interpose(lower_dir_dentry, dentry, dir->i_sb);
	if (ret) {
		SCFS_PRINT_ERROR("dir %s interpose failed, "
			"lower_dir %s lower_parent %s mode %x\n",
			dentry->d_name.name,
			lower_dir_dentry->d_name.name,
			lower_parent_dentry->d_name.name, mode);
		vfs_rmdir(lower_parent_dentry->d_inode, lower_dir_dentry);
		goto out;
	}
	fsstack_copy_attr_times(dir, lower_parent_dentry->d_inode);
	fsstack_copy_inode_size(dir, lower_parent_dentry->d_inode);
	set_nlink(dir, lower_parent_dentry->d_inode->i_nlink);

out:
	unlock_dir(lower_parent_dentry);
	if (!dentry->d_inode)
		d_drop(dentry);

	return ret;
}

void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
				   u64 attr_valid)
{
	struct fuse_conn *fc = get_fuse_conn(inode);
	struct fuse_inode *fi = get_fuse_inode(inode);

	fi->attr_version = ++fc->attr_version;
	fi->i_time = attr_valid;

	inode->i_ino     = fuse_squash_ino(attr->ino);
	inode->i_mode    = (inode->i_mode & S_IFMT) | (attr->mode & 07777);
	set_nlink(inode, attr->nlink);
	inode->i_uid     = make_kuid(&init_user_ns, attr->uid);
	inode->i_gid     = make_kgid(&init_user_ns, attr->gid);
	inode->i_blocks  = attr->blocks;
	inode->i_atime.tv_sec   = attr->atime;
	inode->i_atime.tv_nsec  = attr->atimensec;
	inode->i_mtime.tv_sec   = attr->mtime;
	inode->i_mtime.tv_nsec  = attr->mtimensec;
	inode->i_ctime.tv_sec   = attr->ctime;
	inode->i_ctime.tv_nsec  = attr->ctimensec;

	if (attr->blksize != 0)
		inode->i_blkbits = ilog2(attr->blksize);
	else
		inode->i_blkbits = inode->i_sb->s_blocksize_bits;

	/*
	 * Don't set the sticky bit in i_mode, unless we want the VFS
	 * to check permissions.  This prevents failures due to the
	 * check in may_delete().
	 */
	fi->orig_i_mode = inode->i_mode;
	if (!(fc->flags & FUSE_DEFAULT_PERMISSIONS))
		inode->i_mode &= ~S_ISVTX;

	fi->orig_ino = attr->ino;
}

/*
 * Update the embedded inode given the znode.  We should work toward
 * eliminating this function as soon as possible by removing values
 * which are duplicated between the znode and inode.  If the generic
 * inode has the correct field it should be used, and the ZFS code
 * updated to access the inode.  This can be done incrementally.
 */
void
zfs_inode_update(znode_t *zp)
{
	zfs_sb_t	*zsb;
	struct inode	*ip;
	uint32_t	blksize;
	uint64_t	atime[2], mtime[2], ctime[2];

	ASSERT(zp != NULL);
	zsb = ZTOZSB(zp);
	ip = ZTOI(zp);

	/* Skip .zfs control nodes which do not exist on disk. */
	if (zfsctl_is_node(ip))
		return;

	sa_lookup(zp->z_sa_hdl, SA_ZPL_ATIME(zsb), &atime, 16);
	sa_lookup(zp->z_sa_hdl, SA_ZPL_MTIME(zsb), &mtime, 16);
	sa_lookup(zp->z_sa_hdl, SA_ZPL_CTIME(zsb), &ctime, 16);

	spin_lock(&ip->i_lock);
	ip->i_generation = zp->z_gen;
	ip->i_uid = SUID_TO_KUID(zp->z_uid);
	ip->i_gid = SGID_TO_KGID(zp->z_gid);
	set_nlink(ip, zp->z_links);
	ip->i_mode = zp->z_mode;
	zfs_set_inode_flags(zp, ip);
	ip->i_blkbits = SPA_MINBLOCKSHIFT;
	dmu_object_size_from_db(sa_get_db(zp->z_sa_hdl), &blksize,
	    (u_longlong_t *)&ip->i_blocks);

	ZFS_TIME_DECODE(&ip->i_atime, atime);
	ZFS_TIME_DECODE(&ip->i_mtime, mtime);
	ZFS_TIME_DECODE(&ip->i_ctime, ctime);

	i_size_write(ip, zp->z_size);
	spin_unlock(&ip->i_lock);
}

void au_cpup_attr_nlink(struct inode *inode, int force)
{
	struct inode *h_inode;
	struct super_block *sb;
	aufs_bindex_t bindex, bend;

	sb = inode->i_sb;
	bindex = au_ibstart(inode);
	h_inode = au_h_iptr(inode, bindex);
	if (!force
	    && !S_ISDIR(h_inode->i_mode)
	    && au_opt_test(au_mntflags(sb), PLINK)
	    && au_plink_test(inode))
		return;

	/*
	 * 0 can happen in revalidating.
	 * h_inode->i_mutex may not be held here, but it is harmless since once
	 * i_nlink reaches 0, it will never become positive except O_TMPFILE
	 * case.
	 * todo: O_TMPFILE+linkat(AT_SYMLINK_FOLLOW) bypassing aufs may cause
	 *	 the incorrect link count.
	 */
	set_nlink(inode, h_inode->i_nlink);

	/*
	 * fewer nlink makes find(1) noisy, but larger nlink doesn't.
	 * it may includes whplink directory.
	 */
	if (S_ISDIR(h_inode->i_mode)) {
		bend = au_ibend(inode);
		for (bindex++; bindex <= bend; bindex++) {
			h_inode = au_h_iptr(inode, bindex);
			if (h_inode)
				au_add_nlink(inode, h_inode);
		}
	}
}

static int ecryptfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
{
	int rc;
	struct dentry *lower_dentry;
	struct dentry *lower_dir_dentry;

	lower_dentry = ecryptfs_dentry_to_lower(dentry);
	lower_dir_dentry = lock_parent(lower_dentry);
	rc = vfs_mkdir(lower_dir_dentry->d_inode, lower_dentry, mode);
	if (rc || !lower_dentry->d_inode)
		goto out;
	rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
	if (rc)
		goto out;
	fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
	fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
	set_nlink(dir, lower_dir_dentry->d_inode->i_nlink);
out:
	unlock_dir(lower_dir_dentry);
	if (!dentry->d_inode)
		d_drop(dentry);
	return rc;
}

static int scfs_do_unlink(struct inode *dir, struct dentry *dentry, struct inode *inode)
{
	struct dentry *lower_dentry = scfs_lower_dentry(dentry);
	struct inode *lower_dir_inode = scfs_lower_inode(dir);
	struct dentry *lower_dir_dentry;
	int ret;

	dget(lower_dentry);
	lower_dir_dentry = lock_parent(lower_dentry);
	ret = vfs_unlink(lower_dir_inode, lower_dentry);
	if (ret) {
		SCFS_PRINT_ERROR("error in vfs_unlink, ret : %d\n", ret);
		goto out;
	}
	fsstack_copy_attr_times(dir, lower_dir_inode);
	set_nlink(inode, scfs_lower_inode(inode)->i_nlink);
	inode->i_ctime = dir->i_ctime;
	d_drop(dentry);
out:
	unlock_dir(lower_dir_dentry);
	dput(lower_dentry);
	return ret;
}

struct inode *ovl_get_inode(struct dentry *dentry, struct dentry *upperdentry)
{
	struct dentry *lowerdentry = ovl_dentry_lower(dentry);
	struct inode *realinode = upperdentry ? d_inode(upperdentry) : NULL;
	struct inode *inode;

	if (!realinode)
		realinode = d_inode(lowerdentry);

	if (!S_ISDIR(realinode->i_mode) &&
	    (upperdentry || (lowerdentry && ovl_indexdir(dentry->d_sb)))) {
		struct inode *key = d_inode(lowerdentry ?: upperdentry);
		unsigned int nlink;

		inode = iget5_locked(dentry->d_sb, (unsigned long) key,
				     ovl_inode_test, ovl_inode_set, key);
		if (!inode)
			goto out_nomem;
		if (!(inode->i_state & I_NEW)) {
			/*
			 * Verify that the underlying files stored in the inode
			 * match those in the dentry.
			 */
			if (!ovl_verify_inode(inode, lowerdentry, upperdentry)) {
				iput(inode);
				inode = ERR_PTR(-ESTALE);
				goto out;
			}

			dput(upperdentry);
			goto out;
		}

		nlink = ovl_get_nlink(lowerdentry, upperdentry,
				      realinode->i_nlink);
		set_nlink(inode, nlink);
	} else {

static int ecryptfs_unlink(struct inode *dir, struct dentry *dentry)
{
	int rc = 0;
	struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
	struct inode *lower_dir_inode = ecryptfs_inode_to_lower(dir);
	struct dentry *lower_dir_dentry;

	dget(lower_dentry);
	lower_dir_dentry = lock_parent(lower_dentry);
	rc = vfs_unlink(lower_dir_inode, lower_dentry);
	if (rc) {
		printk(KERN_ERR "Error in vfs_unlink; rc = [%d]\n", rc);
		goto out_unlock;
	}
	fsstack_copy_attr_times(dir, lower_dir_inode);
	set_nlink(dentry->d_inode,
		  ecryptfs_inode_to_lower(dentry->d_inode)->i_nlink);
	dentry->d_inode->i_ctime = dir->i_ctime;
	d_drop(dentry);
out_unlock:
	unlock_dir(lower_dir_dentry);
	dput(lower_dentry);
	return rc;
}

static int
devpts_fill_super(struct super_block *s, void *data, int silent)
{
	struct inode *inode;

	s->s_blocksize = 1024;
	s->s_blocksize_bits = 10;
	s->s_magic = DEVPTS_SUPER_MAGIC;
	s->s_op = &devpts_sops;
	s->s_time_gran = 1;

	s->s_fs_info = new_pts_fs_info();
	if (!s->s_fs_info)
		goto fail;

	inode = new_inode(s);
	if (!inode)
		goto free_fsi;
	inode->i_ino = 1;
	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
	inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO | S_IWUSR;
	inode->i_op = &simple_dir_inode_operations;
	inode->i_fop = &simple_dir_operations;
	set_nlink(inode, 2);

	s->s_root = d_make_root(inode);
	if (s->s_root)
		return 0;

	printk(KERN_ERR "devpts: get root dentry failed\n");

free_fsi:
	kfree(s->s_fs_info);
fail:
	return -ENOMEM;
}

static int wrapfs_link(struct dentry *old_dentry, struct inode *dir,
		       struct dentry *new_dentry)
{
	struct dentry *lower_old_dentry;
	struct dentry *lower_new_dentry;
	struct dentry *lower_dir_dentry;
	u64 file_size_save;
	int err;
	struct path lower_old_path, lower_new_path;

	file_size_save = i_size_read(old_dentry->d_inode);
	wrapfs_get_lower_path(old_dentry, &lower_old_path);
	wrapfs_get_lower_path(new_dentry, &lower_new_path);
	lower_old_dentry = lower_old_path.dentry;
	lower_new_dentry = lower_new_path.dentry;
	lower_dir_dentry = lock_parent(lower_new_dentry);

	err = vfs_link(lower_old_dentry, lower_dir_dentry->d_inode,
		       lower_new_dentry, NULL);
	if (err || !lower_new_dentry->d_inode)
		goto out;

	err = wrapfs_interpose(new_dentry, dir->i_sb, &lower_new_path);
	if (err)
		goto out;
	fsstack_copy_attr_times(dir, lower_new_dentry->d_inode);
	fsstack_copy_inode_size(dir, lower_new_dentry->d_inode);
	set_nlink(old_dentry->d_inode,
		  wrapfs_lower_inode(old_dentry->d_inode)->i_nlink);
	i_size_write(new_dentry->d_inode, file_size_save);
out:
	unlock_dir(lower_dir_dentry);
	wrapfs_put_lower_path(old_dentry, &lower_old_path);
	wrapfs_put_lower_path(new_dentry, &lower_new_path);
	return err;
}

/**
 * vxfs_iinit- helper to fill inode fields
 * @ip:		VFS inode
 * @vip:	VxFS inode
 *
 * Description:
 *  vxfs_instino is a helper function to fill in all relevant
 *  fields in @ip from @vip.
 */
static void
vxfs_iinit(struct inode *ip, struct vxfs_inode_info *vip)
{

	ip->i_mode = vxfs_transmod(vip);
	ip->i_uid = (uid_t)vip->vii_uid;
	ip->i_gid = (gid_t)vip->vii_gid;

	set_nlink(ip, vip->vii_nlink);
	ip->i_size = vip->vii_size;

	ip->i_atime.tv_sec = vip->vii_atime;
	ip->i_ctime.tv_sec = vip->vii_ctime;
	ip->i_mtime.tv_sec = vip->vii_mtime;
	ip->i_atime.tv_nsec = 0;
	ip->i_ctime.tv_nsec = 0;
	ip->i_mtime.tv_nsec = 0;

	ip->i_blocks = vip->vii_blocks;
	ip->i_generation = vip->vii_gen;

	ip->i_private = vip;
	
}