Commit cfea70e8 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag '6.12-rc2-cifs-fixes' of git://git.samba.org/sfrench/cifs-2.6 

Pull smb client fixes from Steve French:
 "Two fixes for Windows symlink handling"

* tag '6.12-rc2-cifs-fixes' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: Fix creating native symlinks pointing to current or parent directory
  cifs: Improve creating native symlinks pointing to directory
parents ba01565c 63271b7d

fs/smb/client/cifs_unicode.c

+14 −3
Original line number Diff line number Diff line
@@ -484,10 +484,21 @@ cifsConvertToUTF16(__le16 *target, const char *source, int srclen, 
			/**

			 * Remap spaces and periods found at the end of every

			 * component of the path. The special cases of '.' and

			 * '..' do not need to be dealt with explicitly because

			 * they are addressed in namei.c:link_path_walk().

			 * '..' are need to be handled because of symlinks.

			 * They are treated as non-end-of-string to avoid

			 * remapping and breaking symlinks pointing to . or ..

			 **/

			if ((i == srclen - 1) || (source[i+1] == '\\'))

			if ((i == 0 || source[i-1] == '\\') &&

			    source[i] == '.' &&

			    (i == srclen-1 || source[i+1] == '\\'))

				end_of_string = false; /* "." case */

			else if (i >= 1 &&

				 (i == 1 || source[i-2] == '\\') &&

				 source[i-1] == '.' &&

				 source[i] == '.' &&

				 (i == srclen-1 || source[i+1] == '\\'))

				end_of_string = false; /* ".." case */

			else if ((i == srclen - 1) || (source[i+1] == '\\'))

				end_of_string = true;

			else

				end_of_string = false;

fs/smb/client/reparse.c

+161 −3
Original line number Diff line number Diff line
@@ -14,6 +14,12 @@ 
#include "fs_context.h"

#include "reparse.h"



static int detect_directory_symlink_target(struct cifs_sb_info *cifs_sb,

					   const unsigned int xid,

					   const char *full_path,

					   const char *symname,

					   bool *directory);



int smb2_create_reparse_symlink(const unsigned int xid, struct inode *inode,

				struct dentry *dentry, struct cifs_tcon *tcon,

				const char *full_path, const char *symname)
@@ -24,6 +30,7 @@ int smb2_create_reparse_symlink(const unsigned int xid, struct inode *inode, 
	struct inode *new;

	struct kvec iov;

	__le16 *path;

	bool directory;

	char *sym, sep = CIFS_DIR_SEP(cifs_sb);

	u16 len, plen;

	int rc = 0;
@@ -45,6 +52,18 @@ int smb2_create_reparse_symlink(const unsigned int xid, struct inode *inode, 
		goto out;

	}



	/*

	 * SMB distinguish between symlink to directory and symlink to file.

	 * They cannot be exchanged (symlink of file type which points to

	 * directory cannot be resolved and vice-versa). Try to detect if

	 * the symlink target could be a directory or not. When detection

	 * fails then treat symlink as a file (non-directory) symlink.

	 */

	directory = false;

	rc = detect_directory_symlink_target(cifs_sb, xid, full_path, symname, &directory);

	if (rc < 0)

		goto out;



	plen = 2 * UniStrnlen((wchar_t *)path, PATH_MAX);

	len = sizeof(*buf) + plen * 2;

	buf = kzalloc(len, GFP_KERNEL);
@@ -69,7 +88,8 @@ int smb2_create_reparse_symlink(const unsigned int xid, struct inode *inode, 
	iov.iov_base = buf;

	iov.iov_len = len;

	new = smb2_get_reparse_inode(&data, inode->i_sb, xid,

				     tcon, full_path, &iov, NULL);

				     tcon, full_path, directory,

				     &iov, NULL);

	if (!IS_ERR(new))

		d_instantiate(dentry, new);

	else
@@ -81,6 +101,144 @@ int smb2_create_reparse_symlink(const unsigned int xid, struct inode *inode, 
	return rc;

}



static int detect_directory_symlink_target(struct cifs_sb_info *cifs_sb,

					   const unsigned int xid,

					   const char *full_path,

					   const char *symname,

					   bool *directory)

{

	char sep = CIFS_DIR_SEP(cifs_sb);

	struct cifs_open_parms oparms;

	struct tcon_link *tlink;

	struct cifs_tcon *tcon;

	const char *basename;

	struct cifs_fid fid;

	char *resolved_path;

	int full_path_len;

	int basename_len;

	int symname_len;

	char *path_sep;

	__u32 oplock;

	int open_rc;



	/*

	 * First do some simple check. If the original Linux symlink target ends

	 * with slash, or last path component is dot or dot-dot then it is for

	 * sure symlink to the directory.

	 */

	basename = kbasename(symname);

	basename_len = strlen(basename);

	if (basename_len == 0 || /* symname ends with slash */

	    (basename_len == 1 && basename[0] == '.') || /* last component is "." */

	    (basename_len == 2 && basename[0] == '.' && basename[1] == '.')) { /* or ".." */

		*directory = true;

		return 0;

	}



	/*

	 * For absolute symlinks it is not possible to determinate

	 * if it should point to directory or file.

	 */

	if (symname[0] == '/') {

		cifs_dbg(FYI,

			 "%s: cannot determinate if the symlink target path '%s' "

			 "is directory or not, creating '%s' as file symlink\n",

			 __func__, symname, full_path);

		return 0;

	}



	/*

	 * If it was not detected as directory yet and the symlink is relative

	 * then try to resolve the path on the SMB server, check if the path

	 * exists and determinate if it is a directory or not.

	 */



	full_path_len = strlen(full_path);

	symname_len = strlen(symname);



	tlink = cifs_sb_tlink(cifs_sb);

	if (IS_ERR(tlink))

		return PTR_ERR(tlink);



	resolved_path = kzalloc(full_path_len + symname_len + 1, GFP_KERNEL);

	if (!resolved_path) {

		cifs_put_tlink(tlink);

		return -ENOMEM;

	}



	/*

	 * Compose the resolved SMB symlink path from the SMB full path

	 * and Linux target symlink path.

	 */

	memcpy(resolved_path, full_path, full_path_len+1);

	path_sep = strrchr(resolved_path, sep);

	if (path_sep)

		path_sep++;

	else

		path_sep = resolved_path;

	memcpy(path_sep, symname, symname_len+1);

	if (sep == '\\')

		convert_delimiter(path_sep, sep);



	tcon = tlink_tcon(tlink);

	oparms = CIFS_OPARMS(cifs_sb, tcon, resolved_path,

			     FILE_READ_ATTRIBUTES, FILE_OPEN, 0, ACL_NO_MODE);

	oparms.fid = &fid;



	/* Try to open as a directory (NOT_FILE) */

	oplock = 0;

	oparms.create_options = cifs_create_options(cifs_sb,

						    CREATE_NOT_FILE | OPEN_REPARSE_POINT);

	open_rc = tcon->ses->server->ops->open(xid, &oparms, &oplock, NULL);

	if (open_rc == 0) {

		/* Successful open means that the target path is definitely a directory. */

		*directory = true;

		tcon->ses->server->ops->close(xid, tcon, &fid);

	} else if (open_rc == -ENOTDIR) {

		/* -ENOTDIR means that the target path is definitely a file. */

		*directory = false;

	} else if (open_rc == -ENOENT) {

		/* -ENOENT means that the target path does not exist. */

		cifs_dbg(FYI,

			 "%s: symlink target path '%s' does not exist, "

			 "creating '%s' as file symlink\n",

			 __func__, symname, full_path);

	} else {

		/* Try to open as a file (NOT_DIR) */

		oplock = 0;

		oparms.create_options = cifs_create_options(cifs_sb,

							    CREATE_NOT_DIR | OPEN_REPARSE_POINT);

		open_rc = tcon->ses->server->ops->open(xid, &oparms, &oplock, NULL);

		if (open_rc == 0) {

			/* Successful open means that the target path is definitely a file. */

			*directory = false;

			tcon->ses->server->ops->close(xid, tcon, &fid);

		} else if (open_rc == -EISDIR) {

			/* -EISDIR means that the target path is definitely a directory. */

			*directory = true;

		} else {

			/*

			 * This code branch is called when we do not have a permission to

			 * open the resolved_path or some other client/process denied

			 * opening the resolved_path.

			 *

			 * TODO: Try to use ops->query_dir_first on the parent directory

			 * of resolved_path, search for basename of resolved_path and

			 * check if the ATTR_DIRECTORY is set in fi.Attributes. In some

			 * case this could work also when opening of the path is denied.

			 */

			cifs_dbg(FYI,

				 "%s: cannot determinate if the symlink target path '%s' "

				 "is directory or not, creating '%s' as file symlink\n",

				 __func__, symname, full_path);

		}

	}



	kfree(resolved_path);

	cifs_put_tlink(tlink);

	return 0;

}



static int nfs_set_reparse_buf(struct reparse_posix_data *buf,

			       mode_t mode, dev_t dev,

			       struct kvec *iov)
@@ -137,7 +295,7 @@ static int mknod_nfs(unsigned int xid, struct inode *inode, 
	};



	new = smb2_get_reparse_inode(&data, inode->i_sb, xid,

				     tcon, full_path, &iov, NULL);

				     tcon, full_path, false, &iov, NULL);

	if (!IS_ERR(new))

		d_instantiate(dentry, new);

	else
@@ -283,7 +441,7 @@ static int mknod_wsl(unsigned int xid, struct inode *inode, 
	data.wsl.eas_len = len;



	new = smb2_get_reparse_inode(&data, inode->i_sb,

				     xid, tcon, full_path,

				     xid, tcon, full_path, false,

				     &reparse_iov, &xattr_iov);

	if (!IS_ERR(new))

		d_instantiate(dentry, new);

fs/smb/client/smb2inode.c

+2 −1
Original line number Diff line number Diff line
@@ -1198,6 +1198,7 @@ struct inode *smb2_get_reparse_inode(struct cifs_open_info_data *data, 
				     const unsigned int xid,

				     struct cifs_tcon *tcon,

				     const char *full_path,

				     bool directory,

				     struct kvec *reparse_iov,

				     struct kvec *xattr_iov)

{
@@ -1217,7 +1218,7 @@ struct inode *smb2_get_reparse_inode(struct cifs_open_info_data *data, 
			     FILE_READ_ATTRIBUTES |

			     FILE_WRITE_ATTRIBUTES,

			     FILE_CREATE,

			     CREATE_NOT_DIR | OPEN_REPARSE_POINT,

			     (directory ? CREATE_NOT_FILE : CREATE_NOT_DIR) | OPEN_REPARSE_POINT,

			     ACL_NO_MODE);

	if (xattr_iov)

		oparms.ea_cctx = xattr_iov;

fs/smb/client/smb2proto.h

+1 −0
Original line number Diff line number Diff line
@@ -61,6 +61,7 @@ struct inode *smb2_get_reparse_inode(struct cifs_open_info_data *data, 
				     const unsigned int xid,

				     struct cifs_tcon *tcon,

				     const char *full_path,

				     bool directory,

				     struct kvec *reparse_iov,

				     struct kvec *xattr_iov);

int smb2_query_reparse_point(const unsigned int xid,