Commit 102466f3 authored by Paulo Alcantara's avatar Paulo Alcantara Committed by Steve French
Browse files

smb: client: allow creating special files via reparse points 



Add support for creating special files (e.g. char/block devices,
sockets, fifos) via NFS reparse points on SMB2+, which are fully
supported by most SMB servers and documented in MS-FSCC.

smb2_get_reparse_inode() creates the file with a corresponding reparse
point buffer set in @iov through a single roundtrip to the server.

Reported-by: default avatarkernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202311260746.HOJ039BV-lkp@intel.com/


Signed-off-by: default avatarPaulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
parent 3322960c

fs/smb/client/cifsproto.h

+6 −2
Original line number Diff line number Diff line
@@ -211,8 +211,12 @@ int cifs_get_inode_info(struct inode **inode, const char *full_path, 
bool cifs_reparse_point_to_fattr(struct cifs_sb_info *cifs_sb,

				 struct cifs_fattr *fattr,

				 struct cifs_open_info_data *data);

extern int smb311_posix_get_inode_info(struct inode **pinode, const char *search_path,

			struct super_block *sb, unsigned int xid);



extern int smb311_posix_get_inode_info(struct inode **inode,

				       const char *full_path,

				       struct cifs_open_info_data *data,

				       struct super_block *sb,

				       const unsigned int xid);

extern int cifs_get_inode_info_unix(struct inode **pinode,

			const unsigned char *search_path,

			struct super_block *sb, unsigned int xid);

fs/smb/client/dir.c

+4 −3
Original line number Diff line number Diff line
@@ -680,9 +680,10 @@ cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry, 
		 full_path, d_inode(direntry));



again:

	if (pTcon->posix_extensions)

		rc = smb311_posix_get_inode_info(&newInode, full_path, parent_dir_inode->i_sb, xid);

	else if (pTcon->unix_ext) {

	if (pTcon->posix_extensions) {

		rc = smb311_posix_get_inode_info(&newInode, full_path, NULL,

						 parent_dir_inode->i_sb, xid);

	} else if (pTcon->unix_ext) {

		rc = cifs_get_inode_info_unix(&newInode, full_path,

					      parent_dir_inode->i_sb, xid);

	} else {

fs/smb/client/file.c

+6 −4
Original line number Diff line number Diff line
@@ -1020,15 +1020,17 @@ cifs_reopen_file(struct cifsFileInfo *cfile, bool can_flush) 
		if (!is_interrupt_error(rc))

			mapping_set_error(inode->i_mapping, rc);



		if (tcon->posix_extensions)

			rc = smb311_posix_get_inode_info(&inode, full_path, inode->i_sb, xid);

		else if (tcon->unix_ext)

		if (tcon->posix_extensions) {

			rc = smb311_posix_get_inode_info(&inode, full_path,

							 NULL, inode->i_sb, xid);

		} else if (tcon->unix_ext) {

			rc = cifs_get_inode_info_unix(&inode, full_path,

						      inode->i_sb, xid);

		else

		} else {

			rc = cifs_get_inode_info(&inode, full_path, NULL,

						 inode->i_sb, xid, NULL);

		}

	}

	/*

	 * Else we are writing out data to server already and could deadlock if

	 * we tried to flush data, and since we do not know if we have data that

fs/smb/client/inode.c

+50 −26
Original line number Diff line number Diff line
@@ -1061,7 +1061,9 @@ static int reparse_info_to_fattr(struct cifs_open_info_data *data, 
				 const unsigned int xid,

				 struct cifs_tcon *tcon,

				 const char *full_path,

				 struct cifs_fattr *fattr)

				 struct cifs_fattr *fattr,

				 struct cifs_sid *owner,

				 struct cifs_sid *group)

{

	struct TCP_Server_Info *server = tcon->ses->server;

	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
@@ -1092,7 +1094,8 @@ static int reparse_info_to_fattr(struct cifs_open_info_data *data, 
		rc = 0;

		goto out;

	default:

		if (data->symlink_target) {

		/* Check for cached reparse point data */

		if (data->symlink_target || data->reparse.buf) {

			rc = 0;

		} else if (server->ops->parse_reparse_point) {

			rc = server->ops->parse_reparse_point(cifs_sb,
@@ -1101,6 +1104,9 @@ static int reparse_info_to_fattr(struct cifs_open_info_data *data, 
		break;

	}



	if (tcon->posix_extensions)

		smb311_posix_info_to_fattr(fattr, data, owner, group, sb);

	else

		cifs_open_info_to_fattr(fattr, data, sb);

out:

	free_rsp_buf(rsp_buftype, rsp_iov.iov_base);
@@ -1152,7 +1158,8 @@ static int cifs_get_fattr(struct cifs_open_info_data *data, 
		 */

		if (cifs_open_data_reparse(data)) {

			rc = reparse_info_to_fattr(data, sb, xid, tcon,

						   full_path, fattr);

						   full_path, fattr,

						   NULL, NULL);

		} else {

			cifs_open_info_to_fattr(fattr, data, sb);

		}
@@ -1290,18 +1297,19 @@ int cifs_get_inode_info(struct inode **inode, 
	return rc;

}



static int smb311_posix_get_fattr(struct cifs_fattr *fattr,

static int smb311_posix_get_fattr(struct cifs_open_info_data *data,

				  struct cifs_fattr *fattr,

				  const char *full_path,

				  struct super_block *sb,

				  const unsigned int xid)

{

	struct cifs_open_info_data data = {};

	struct cifs_open_info_data tmp_data = {};

	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);

	struct cifs_tcon *tcon;

	struct tcon_link *tlink;

	struct cifs_sid owner, group;

	int tmprc;

	int rc;

	int rc = 0;



	tlink = cifs_sb_tlink(cifs_sb);

	if (IS_ERR(tlink))
@@ -1309,12 +1317,14 @@ static int smb311_posix_get_fattr(struct cifs_fattr *fattr, 
	tcon = tlink_tcon(tlink);



	/*

	 * 1. Fetch file metadata

	 * 1. Fetch file metadata if not provided (data)

	 */



	if (!data) {

		rc = smb311_posix_query_path_info(xid, tcon, cifs_sb,

					  full_path, &data,

						  full_path, &tmp_data,

						  &owner, &group);

		data = &tmp_data;

	}



	/*

	 * 2. Convert it to internal cifs metadata (fattr)
@@ -1322,7 +1332,14 @@ static int smb311_posix_get_fattr(struct cifs_fattr *fattr, 


	switch (rc) {

	case 0:

		smb311_posix_info_to_fattr(fattr, &data, &owner, &group, sb);

		if (cifs_open_data_reparse(data)) {

			rc = reparse_info_to_fattr(data, sb, xid, tcon,

						   full_path, fattr,

						   &owner, &group);

		} else {

			smb311_posix_info_to_fattr(fattr, data,

						   &owner, &group, sb);

		}

		break;

	case -EREMOTE:

		/* DFS link, no metadata available on this server */
@@ -1353,12 +1370,15 @@ static int smb311_posix_get_fattr(struct cifs_fattr *fattr, 


out:

	cifs_put_tlink(tlink);

	cifs_free_open_info(&data);

	cifs_free_open_info(data);

	return rc;

}



int smb311_posix_get_inode_info(struct inode **inode, const char *full_path,

				struct super_block *sb, const unsigned int xid)

int smb311_posix_get_inode_info(struct inode **inode,

				const char *full_path,

				struct cifs_open_info_data *data,

				struct super_block *sb,

				const unsigned int xid)

{

	struct cifs_fattr fattr = {};

	int rc;
@@ -1368,7 +1388,7 @@ int smb311_posix_get_inode_info(struct inode **inode, const char *full_path, 
		return 0;

	}



	rc = smb311_posix_get_fattr(&fattr, full_path, sb, xid);

	rc = smb311_posix_get_fattr(data, &fattr, full_path, sb, xid);

	if (rc)

		goto out;
@@ -1516,7 +1536,7 @@ struct inode *cifs_root_iget(struct super_block *sb) 


	convert_delimiter(path, CIFS_DIR_SEP(cifs_sb));

	if (tcon->posix_extensions)

		rc = smb311_posix_get_fattr(&fattr, path, sb, xid);

		rc = smb311_posix_get_fattr(NULL, &fattr, path, sb, xid);

	else

		rc = cifs_get_fattr(NULL, sb, xid, NULL, &fattr, &inode, path);
@@ -1889,16 +1909,18 @@ cifs_mkdir_qinfo(struct inode *parent, struct dentry *dentry, umode_t mode, 
	int rc = 0;

	struct inode *inode = NULL;



	if (tcon->posix_extensions)

		rc = smb311_posix_get_inode_info(&inode, full_path, parent->i_sb, xid);

	if (tcon->posix_extensions) {

		rc = smb311_posix_get_inode_info(&inode, full_path,

						 NULL, parent->i_sb, xid);

#ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY

	else if (tcon->unix_ext)

	} else if (tcon->unix_ext) {

		rc = cifs_get_inode_info_unix(&inode, full_path, parent->i_sb,

					      xid);

#endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */

	else

	} else {

		rc = cifs_get_inode_info(&inode, full_path, NULL, parent->i_sb,

					 xid, NULL);

	}



	if (rc)

		return rc;
@@ -2579,13 +2601,15 @@ int cifs_revalidate_dentry_attr(struct dentry *dentry) 
		 dentry, cifs_get_time(dentry), jiffies);



again:

	if (cifs_sb_master_tcon(CIFS_SB(sb))->posix_extensions)

		rc = smb311_posix_get_inode_info(&inode, full_path, sb, xid);

	else if (cifs_sb_master_tcon(CIFS_SB(sb))->unix_ext)

	if (cifs_sb_master_tcon(CIFS_SB(sb))->posix_extensions) {

		rc = smb311_posix_get_inode_info(&inode, full_path,

						 NULL, sb, xid);

	} else if (cifs_sb_master_tcon(CIFS_SB(sb))->unix_ext) {

		rc = cifs_get_inode_info_unix(&inode, full_path, sb, xid);

	else

	} else {

		rc = cifs_get_inode_info(&inode, full_path, NULL, sb,

					 xid, NULL);

	}

	if (rc == -EAGAIN && count++ < 10)

		goto again;

out:

fs/smb/client/link.c

+6 −4
Original line number Diff line number Diff line
@@ -614,14 +614,16 @@ cifs_symlink(struct mnt_idmap *idmap, struct inode *inode, 
					cifs_sb_target->local_nls); */



	if (rc == 0) {

		if (pTcon->posix_extensions)

			rc = smb311_posix_get_inode_info(&newinode, full_path, inode->i_sb, xid);

		else if (pTcon->unix_ext)

		if (pTcon->posix_extensions) {

			rc = smb311_posix_get_inode_info(&newinode, full_path,

							 NULL, inode->i_sb, xid);

		} else if (pTcon->unix_ext) {

			rc = cifs_get_inode_info_unix(&newinode, full_path,

						      inode->i_sb, xid);

		else

		} else {

			rc = cifs_get_inode_info(&newinode, full_path, NULL,

						 inode->i_sb, xid, NULL);

		}



		if (rc != 0) {

			cifs_dbg(FYI, "Create symlink ok, getinodeinfo fail rc = %d\n",