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Commit 146a8595 authored by J. Bruce Fields's avatar J. Bruce Fields Committed by Al Viro
Browse files

locks: break delegations on link 



Cc: Tyler Hicks <tyhicks@canonical.com>
Cc: Dustin Kirkland <dustin.kirkland@gazzang.com>
Acked-by: default avatarJeff Layton <jlayton@redhat.com>
Signed-off-by: default avatarJ. Bruce Fields <bfields@redhat.com>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 8e6d782c

fs/ecryptfs/inode.c

+1 −1
Original line number Diff line number Diff line
@@ -475,7 +475,7 @@ static int ecryptfs_link(struct dentry *old_dentry, struct inode *dir, 
	dget(lower_new_dentry);

	lower_dir_dentry = lock_parent(lower_new_dentry);

	rc = vfs_link(lower_old_dentry, lower_dir_dentry->d_inode,

		      lower_new_dentry);

		      lower_new_dentry, NULL);

	if (rc || !lower_new_dentry->d_inode)

		goto out_lock;

	rc = ecryptfs_interpose(lower_new_dentry, new_dentry, dir->i_sb);

fs/namei.c

+32 −4
Original line number Diff line number Diff line
@@ -3819,7 +3819,26 @@ SYSCALL_DEFINE2(symlink, const char __user *, oldname, const char __user *, newn 
	return sys_symlinkat(oldname, AT_FDCWD, newname);

}



int vfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry)

/**

 * vfs_link - create a new link

 * @old_dentry:	object to be linked

 * @dir:	new parent

 * @new_dentry:	where to create the new link

 * @delegated_inode: returns inode needing a delegation break

 *

 * The caller must hold dir->i_mutex

 *

 * If vfs_link discovers a delegation on the to-be-linked file in need

 * of breaking, it will return -EWOULDBLOCK and return a reference to the

 * inode in delegated_inode.  The caller should then break the delegation

 * and retry.  Because breaking a delegation may take a long time, the

 * caller should drop the i_mutex before doing so.

 *

 * Alternatively, a caller may pass NULL for delegated_inode.  This may

 * be appropriate for callers that expect the underlying filesystem not

 * to be NFS exported.

 */

int vfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry, struct inode **delegated_inode)

{

	struct inode *inode = old_dentry->d_inode;

	unsigned max_links = dir->i_sb->s_max_links;
@@ -3855,8 +3874,11 @@ int vfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_de 
		error =  -ENOENT;

	else if (max_links && inode->i_nlink >= max_links)

		error = -EMLINK;

	else

	else {

		error = try_break_deleg(inode, delegated_inode);

		if (!error)

			error = dir->i_op->link(old_dentry, dir, new_dentry);

	}



	if (!error && (inode->i_state & I_LINKABLE)) {

		spin_lock(&inode->i_lock);
@@ -3883,6 +3905,7 @@ SYSCALL_DEFINE5(linkat, int, olddfd, const char __user *, oldname, 
{

	struct dentry *new_dentry;

	struct path old_path, new_path;

	struct inode *delegated_inode = NULL;

	int how = 0;

	int error;
@@ -3921,9 +3944,14 @@ SYSCALL_DEFINE5(linkat, int, olddfd, const char __user *, oldname, 
	error = security_path_link(old_path.dentry, &new_path, new_dentry);

	if (error)

		goto out_dput;

	error = vfs_link(old_path.dentry, new_path.dentry->d_inode, new_dentry);

	error = vfs_link(old_path.dentry, new_path.dentry->d_inode, new_dentry, &delegated_inode);

out_dput:

	done_path_create(&new_path, new_dentry);

	if (delegated_inode) {

		error = break_deleg_wait(&delegated_inode);

		if (!error)

			goto retry;

	}

	if (retry_estale(error, how)) {

		how |= LOOKUP_REVAL;

		goto retry;

fs/nfsd/vfs.c

+1 −1
Original line number Diff line number Diff line
@@ -1736,7 +1736,7 @@ nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp, 
		err = nfserrno(host_err);

		goto out_dput;

	}

	host_err = vfs_link(dold, dirp, dnew);

	host_err = vfs_link(dold, dirp, dnew, NULL);

	if (!host_err) {

		err = nfserrno(commit_metadata(ffhp));

		if (!err)

include/linux/fs.h

+1 −1
Original line number Diff line number Diff line
@@ -1453,7 +1453,7 @@ extern int vfs_create(struct inode *, struct dentry *, umode_t, bool); 
extern int vfs_mkdir(struct inode *, struct dentry *, umode_t);

extern int vfs_mknod(struct inode *, struct dentry *, umode_t, dev_t);

extern int vfs_symlink(struct inode *, struct dentry *, const char *);

extern int vfs_link(struct dentry *, struct inode *, struct dentry *);

extern int vfs_link(struct dentry *, struct inode *, struct dentry *, struct inode **);

extern int vfs_rmdir(struct inode *, struct dentry *);

extern int vfs_unlink(struct inode *, struct dentry *, struct inode **);

extern int vfs_rename(struct inode *, struct dentry *, struct inode *, struct dentry *, struct inode **);