Commit 5b432ae5 authored Jul 31, 2025 by Paulo Alcantara Committed by Steve French Aug 04, 2025

smb: client: fix creating symlinks under POSIX mounts

SMB3.1.1 POSIX mounts support native symlinks that are created with
IO_REPARSE_TAG_SYMLINK reparse points, so skip the checking of
FILE_SUPPORTS_REPARSE_POINTS as some servers might not have it set.

Cc: linux-cifs@vger.kernel.org
Cc: Ralph Boehme <slow@samba.org>
Cc: David Howells <dhowells@redhat.com>
Cc: <stable@vger.kernel.org>
Reported-by: Matthew Richardson <m.richardson@ed.ac.uk>
Closes: https://marc.info/?i=1124e7cd-6a46-40a6-9f44-b7664a66654b@ed.ac.uk

Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

parent 6b445309

fs/smb/client/cifsglob.h

+5 −0

Original line number	Diff line number	Diff line
		@@ -2377,4 +2377,9 @@ static inline bool cifs_netbios_name(const char *name, size_t namelen)
		return ret;
		}

		#define CIFS_REPARSE_SUPPORT(tcon) \
		((tcon)->posix_extensions \|\| \
		(le32_to_cpu((tcon)->fsAttrInfo.Attributes) & \
		FILE_SUPPORTS_REPARSE_POINTS))

		#endif /* _CIFS_GLOB_H */

fs/smb/client/cifssmb.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -2751,7 +2751,7 @@ int cifs_query_reparse_point(const unsigned int xid,
		if (cap_unix(tcon->ses))
		return -EOPNOTSUPP;

		if (!(le32_to_cpu(tcon->fsAttrInfo.Attributes) & FILE_SUPPORTS_REPARSE_POINTS))
		if (!CIFS_REPARSE_SUPPORT(tcon))
		return -EOPNOTSUPP;

		oparms = (struct cifs_open_parms) {
		@@ -2879,7 +2879,7 @@ struct inode cifs_create_reparse_inode(struct cifs_open_info_data data,
		* attempt to create reparse point. This will prevent creating unusable
		* empty object on the server.
		*/
		if (!(le32_to_cpu(tcon->fsAttrInfo.Attributes) & FILE_SUPPORTS_REPARSE_POINTS))
		if (!CIFS_REPARSE_SUPPORT(tcon))
		return ERR_PTR(-EOPNOTSUPP);

		#ifndef CONFIG_CIFS_XATTR

fs/smb/client/link.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -635,7 +635,7 @@ cifs_symlink(struct mnt_idmap idmap, struct inode inode,
		case CIFS_SYMLINK_TYPE_NATIVE:
		case CIFS_SYMLINK_TYPE_NFS:
		case CIFS_SYMLINK_TYPE_WSL:
		if (le32_to_cpu(pTcon->fsAttrInfo.Attributes) & FILE_SUPPORTS_REPARSE_POINTS) {
		if (CIFS_REPARSE_SUPPORT(pTcon)) {
		rc = create_reparse_symlink(xid, inode, direntry, pTcon,
		full_path, symname);
		goto symlink_exit;

fs/smb/client/smb1ops.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -1272,7 +1272,7 @@ cifs_make_node(unsigned int xid, struct inode *inode,
		*/
		return cifs_sfu_make_node(xid, inode, dentry, tcon,
		full_path, mode, dev);
		} else if (le32_to_cpu(tcon->fsAttrInfo.Attributes) & FILE_SUPPORTS_REPARSE_POINTS) {
		} else if (CIFS_REPARSE_SUPPORT(tcon)) {
		/*
		* mknod via reparse points requires server support for
		* storing reparse points, which is available since

fs/smb/client/smb2inode.c

+2 −3

Original line number	Diff line number	Diff line
		@@ -1346,8 +1346,7 @@ struct inode smb2_create_reparse_inode(struct cifs_open_info_data data,
		* attempt to create reparse point. This will prevent creating unusable
		* empty object on the server.
		*/
		if (!(le32_to_cpu(tcon->fsAttrInfo.Attributes) & FILE_SUPPORTS_REPARSE_POINTS))
		if (!tcon->posix_extensions)
		if (!CIFS_REPARSE_SUPPORT(tcon))
		return ERR_PTR(-EOPNOTSUPP);

		oparms = CIFS_OPARMS(cifs_sb, tcon, full_path,