From c2f8fde8689272a55b9319b69dfe7e8f0e2e9dfe Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Mon, 14 Oct 2024 11:40:56 +0200 Subject: [PATCH] fs: add helper to use mount option as path or fd Allow filesystems to use a mount option either as a file or path. Link: https://lore.kernel.org/r/20241014-work-overlayfs-v3-1-32b3fed1286e@kernel.org Reviewed-by: Amir Goldstein Signed-off-by: Christian Brauner --- fs/fs_parser.c | 20 ++++++++++++++++++++ include/linux/fs_parser.h | 5 ++++- 2 files changed, 24 insertions(+), 1 deletion(-) diff --git a/fs/fs_parser.c b/fs/fs_parser.c index 24727ec34e5a..8f583b814e6e 100644 --- a/fs/fs_parser.c +++ b/fs/fs_parser.c @@ -308,6 +308,26 @@ int fs_param_is_fd(struct p_log *log, const struct fs_parameter_spec *p, } EXPORT_SYMBOL(fs_param_is_fd); +int fs_param_is_file_or_string(struct p_log *log, + const struct fs_parameter_spec *p, + struct fs_parameter *param, + struct fs_parse_result *result) +{ + switch (param->type) { + case fs_value_is_string: + return fs_param_is_string(log, p, param, result); + case fs_value_is_file: + result->uint_32 = param->dirfd; + if (result->uint_32 <= INT_MAX) + return 0; + break; + default: + break; + } + return fs_param_bad_value(log, param); +} +EXPORT_SYMBOL(fs_param_is_file_or_string); + int fs_param_is_uid(struct p_log *log, const struct fs_parameter_spec *p, struct fs_parameter *param, struct fs_parse_result *result) { diff --git a/include/linux/fs_parser.h b/include/linux/fs_parser.h index 6cf713a7e6c6..3cef566088fc 100644 --- a/include/linux/fs_parser.h +++ b/include/linux/fs_parser.h @@ -28,7 +28,8 @@ typedef int fs_param_type(struct p_log *, */ fs_param_type fs_param_is_bool, fs_param_is_u32, fs_param_is_s32, fs_param_is_u64, fs_param_is_enum, fs_param_is_string, fs_param_is_blob, fs_param_is_blockdev, - fs_param_is_path, fs_param_is_fd, fs_param_is_uid, fs_param_is_gid; + fs_param_is_path, fs_param_is_fd, fs_param_is_uid, fs_param_is_gid, + fs_param_is_file_or_string; /* * Specification of the type of value a parameter wants. @@ -133,6 +134,8 @@ static inline bool fs_validate_description(const char *name, #define fsparam_bdev(NAME, OPT) __fsparam(fs_param_is_blockdev, NAME, OPT, 0, NULL) #define fsparam_path(NAME, OPT) __fsparam(fs_param_is_path, NAME, OPT, 0, NULL) #define fsparam_fd(NAME, OPT) __fsparam(fs_param_is_fd, NAME, OPT, 0, NULL) +#define fsparam_file_or_string(NAME, OPT) \ + __fsparam(fs_param_is_file_or_string, NAME, OPT, 0, NULL) #define fsparam_uid(NAME, OPT) __fsparam(fs_param_is_uid, NAME, OPT, 0, NULL) #define fsparam_gid(NAME, OPT) __fsparam(fs_param_is_gid, NAME, OPT, 0, NULL)