diff options
| -rw-r--r-- | fs/smb/client/reparse.c | 164 | ||||
| -rw-r--r-- | fs/smb/client/smb2inode.c | 3 | ||||
| -rw-r--r-- | fs/smb/client/smb2proto.h | 1 |
3 files changed, 164 insertions, 4 deletions
diff --git a/fs/smb/client/reparse.c b/fs/smb/client/reparse.c index c848b5e88d32..74abbdf5026c 100644 --- a/fs/smb/client/reparse.c +++ b/fs/smb/client/reparse.c @@ -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 @@ out: 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); diff --git a/fs/smb/client/smb2inode.c b/fs/smb/client/smb2inode.c index 4e9e225520a6..e49d0c25eb03 100644 --- a/fs/smb/client/smb2inode.c +++ b/fs/smb/client/smb2inode.c @@ -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; diff --git a/fs/smb/client/smb2proto.h b/fs/smb/client/smb2proto.h index c7e1b149877a..6f9885e4f66c 100644 --- a/fs/smb/client/smb2proto.h +++ b/fs/smb/client/smb2proto.h @@ -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, |