Commit dda89e2f authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag '9p-for-6.9-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs 

Pull 9p fix from Eric Van Hensbergen:
 "This contains a single mitigation to help deal with an apparent race
  condition between client and server having to deal with inode number
  collisions"

* tag '9p-for-6.9-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs:
  fs/9p: mitigate inode collisions
parents a93289b8 d05dcfdf

fs/9p/v9fs.h

+6 −5
Original line number Diff line number Diff line
@@ -179,13 +179,14 @@ extern int v9fs_vfs_rename(struct mnt_idmap *idmap, 
			   struct inode *old_dir, struct dentry *old_dentry,

			   struct inode *new_dir, struct dentry *new_dentry,

			   unsigned int flags);

extern struct inode *v9fs_fid_iget(struct super_block *sb, struct p9_fid *fid);

extern struct inode *v9fs_fid_iget(struct super_block *sb, struct p9_fid *fid,

						bool new);

extern const struct inode_operations v9fs_dir_inode_operations_dotl;

extern const struct inode_operations v9fs_file_inode_operations_dotl;

extern const struct inode_operations v9fs_symlink_inode_operations_dotl;

extern const struct netfs_request_ops v9fs_req_ops;

extern struct inode *v9fs_fid_iget_dotl(struct super_block *sb,

					struct p9_fid *fid);

						struct p9_fid *fid, bool new);



/* other default globals */

#define V9FS_PORT	564
@@ -224,12 +225,12 @@ static inline int v9fs_proto_dotl(struct v9fs_session_info *v9ses) 
 */

static inline struct inode *

v9fs_get_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,

			struct super_block *sb)

			struct super_block *sb, bool new)

{

	if (v9fs_proto_dotl(v9ses))

		return v9fs_fid_iget_dotl(sb, fid);

		return v9fs_fid_iget_dotl(sb, fid, new);

	else

		return v9fs_fid_iget(sb, fid);

		return v9fs_fid_iget(sb, fid, new);

}



#endif

fs/9p/vfs_inode.c

+29 −8
Original line number Diff line number Diff line
@@ -364,7 +364,8 @@ void v9fs_evict_inode(struct inode *inode) 
		clear_inode(inode);

}



struct inode *v9fs_fid_iget(struct super_block *sb, struct p9_fid *fid)

struct inode *

v9fs_fid_iget(struct super_block *sb, struct p9_fid *fid, bool new)

{

	dev_t rdev;

	int retval;
@@ -376,8 +377,18 @@ struct inode *v9fs_fid_iget(struct super_block *sb, struct p9_fid *fid) 
	inode = iget_locked(sb, QID2INO(&fid->qid));

	if (unlikely(!inode))

		return ERR_PTR(-ENOMEM);

	if (!(inode->i_state & I_NEW))

		return inode;

	if (!(inode->i_state & I_NEW)) {

		if (!new) {

			goto done;

		} else {

			p9_debug(P9_DEBUG_VFS, "WARNING: Inode collision %ld\n",

						inode->i_ino);

			iput(inode);

			remove_inode_hash(inode);

			inode = iget_locked(sb, QID2INO(&fid->qid));

			WARN_ON(!(inode->i_state & I_NEW));

		}

	}



	/*

	 * initialize the inode with the stat info
@@ -401,11 +412,11 @@ struct inode *v9fs_fid_iget(struct super_block *sb, struct p9_fid *fid) 
	v9fs_set_netfs_context(inode);

	v9fs_cache_inode_get_cookie(inode);

	unlock_new_inode(inode);

done:

	return inode;

error:

	iget_failed(inode);

	return ERR_PTR(retval);



}



/**
@@ -437,8 +448,15 @@ static int v9fs_at_to_dotl_flags(int flags) 
 */

static void v9fs_dec_count(struct inode *inode)

{

	if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2)

	if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2) {

		if (inode->i_nlink) {

			drop_nlink(inode);

		} else {

			p9_debug(P9_DEBUG_VFS,

						"WARNING: unexpected i_nlink zero %d inode %ld\n",

						inode->i_nlink, inode->i_ino);

		}

	}

}



/**
@@ -489,6 +507,9 @@ static int v9fs_remove(struct inode *dir, struct dentry *dentry, int flags) 
		} else

			v9fs_dec_count(inode);



		if (inode->i_nlink <= 0)	/* no more refs unhash it */

			remove_inode_hash(inode);



		v9fs_invalidate_inode_attr(inode);

		v9fs_invalidate_inode_attr(dir);
@@ -554,7 +575,7 @@ v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir, 
		/*

		 * instantiate inode and assign the unopened fid to the dentry

		 */

		inode = v9fs_get_inode_from_fid(v9ses, fid, dir->i_sb);

		inode = v9fs_get_inode_from_fid(v9ses, fid, dir->i_sb, true);

		if (IS_ERR(inode)) {

			err = PTR_ERR(inode);

			p9_debug(P9_DEBUG_VFS,
@@ -683,7 +704,7 @@ struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry, 
	else if (IS_ERR(fid))

		inode = ERR_CAST(fid);

	else

		inode = v9fs_get_inode_from_fid(v9ses, fid, dir->i_sb);

		inode = v9fs_get_inode_from_fid(v9ses, fid, dir->i_sb, false);

	/*

	 * If we had a rename on the server and a parallel lookup

	 * for the new name, then make sure we instantiate with

fs/9p/vfs_inode_dotl.c

+20 −8
Original line number Diff line number Diff line
@@ -52,7 +52,10 @@ static kgid_t v9fs_get_fsgid_for_create(struct inode *dir_inode) 
	return current_fsgid();

}



struct inode *v9fs_fid_iget_dotl(struct super_block *sb, struct p9_fid *fid)





struct inode *

v9fs_fid_iget_dotl(struct super_block *sb, struct p9_fid *fid, bool new)

{

	int retval;

	struct inode *inode;
@@ -62,8 +65,18 @@ struct inode *v9fs_fid_iget_dotl(struct super_block *sb, struct p9_fid *fid) 
	inode = iget_locked(sb, QID2INO(&fid->qid));

	if (unlikely(!inode))

		return ERR_PTR(-ENOMEM);

	if (!(inode->i_state & I_NEW))

		return inode;

	if (!(inode->i_state & I_NEW)) {

		if (!new) {

			goto done;

		} else { /* deal with race condition in inode number reuse */

			p9_debug(P9_DEBUG_ERROR, "WARNING: Inode collision %lx\n",

						inode->i_ino);

			iput(inode);

			remove_inode_hash(inode);

			inode = iget_locked(sb, QID2INO(&fid->qid));

			WARN_ON(!(inode->i_state & I_NEW));

		}

	}



	/*

	 * initialize the inode with the stat info
@@ -90,12 +103,11 @@ struct inode *v9fs_fid_iget_dotl(struct super_block *sb, struct p9_fid *fid) 
		goto error;



	unlock_new_inode(inode);



done:

	return inode;

error:

	iget_failed(inode);

	return ERR_PTR(retval);



}



struct dotl_openflag_map {
@@ -247,7 +259,7 @@ v9fs_vfs_atomic_open_dotl(struct inode *dir, struct dentry *dentry, 
		p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);

		goto out;

	}

	inode = v9fs_fid_iget_dotl(dir->i_sb, fid);

	inode = v9fs_fid_iget_dotl(dir->i_sb, fid, true);

	if (IS_ERR(inode)) {

		err = PTR_ERR(inode);

		p9_debug(P9_DEBUG_VFS, "inode creation failed %d\n", err);
@@ -340,7 +352,7 @@ static int v9fs_vfs_mkdir_dotl(struct mnt_idmap *idmap, 
	}



	/* instantiate inode and assign the unopened fid to the dentry */

	inode = v9fs_fid_iget_dotl(dir->i_sb, fid);

	inode = v9fs_fid_iget_dotl(dir->i_sb, fid, true);

	if (IS_ERR(inode)) {

		err = PTR_ERR(inode);

		p9_debug(P9_DEBUG_VFS, "inode creation failed %d\n",
@@ -776,7 +788,7 @@ v9fs_vfs_mknod_dotl(struct mnt_idmap *idmap, struct inode *dir, 
			 err);

		goto error;

	}

	inode = v9fs_fid_iget_dotl(dir->i_sb, fid);

	inode = v9fs_fid_iget_dotl(dir->i_sb, fid, true);

	if (IS_ERR(inode)) {

		err = PTR_ERR(inode);

		p9_debug(P9_DEBUG_VFS, "inode creation failed %d\n",

fs/9p/vfs_super.c

+1 −1
Original line number Diff line number Diff line
@@ -139,7 +139,7 @@ static struct dentry *v9fs_mount(struct file_system_type *fs_type, int flags, 
	else

		sb->s_d_op = &v9fs_dentry_operations;



	inode = v9fs_get_inode_from_fid(v9ses, fid, sb);

	inode = v9fs_get_inode_from_fid(v9ses, fid, sb, true);

	if (IS_ERR(inode)) {

		retval = PTR_ERR(inode);

		goto release_sb;