From 0f89589a8c6f1033cb847a606517998efb0da8ee Mon Sep 17 00:00:00 2001 From: Al Viro Date: Tue, 17 Dec 2019 14:15:04 -0500 Subject: [PATCH] Pass consistent param->type to fs_parse() As it is, vfs_parse_fs_string() makes "foo" and "foo=" indistinguishable; both get fs_value_is_string for ->type and NULL for ->string. To make it even more unpleasant, that combination is impossible to produce with fsconfig(). Much saner rules would be "foo" => fs_value_is_flag, NULL "foo=" => fs_value_is_string, "" "foo=bar" => fs_value_is_string, "bar" All cases are distinguishable, all results are expressable by fsconfig(), ->has_value checks are much simpler that way (to the point of the field being useless) and quite a few regressions go away (gfs2 has no business accepting -o nodebug=, for example). Partially based upon patches from Miklos. Signed-off-by: Al Viro --- drivers/block/rbd.c | 7 ++----- fs/fs_context.c | 5 +++-- fs/fs_parser.c | 23 +++++++++++------------ include/linux/fs_parser.h | 1 - 4 files changed, 16 insertions(+), 20 deletions(-) diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index 2b18456..9fc686be 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -6433,7 +6433,7 @@ static int rbd_parse_options(char *options, struct rbd_parse_opts_ctx *pctx) if (*key) { struct fs_parameter param = { .key = key, - .type = fs_value_is_string, + .type = fs_value_is_flag, }; char *value = strchr(key, '='); size_t v_len = 0; @@ -6443,14 +6443,11 @@ static int rbd_parse_options(char *options, struct rbd_parse_opts_ctx *pctx) continue; *value++ = 0; v_len = strlen(value); - } - - - if (v_len > 0) { param.string = kmemdup_nul(value, v_len, GFP_KERNEL); if (!param.string) return -ENOMEM; + param.type = fs_value_is_string; } param.size = v_len; diff --git a/fs/fs_context.c b/fs/fs_context.c index 138b5b4..9097421 100644 --- a/fs/fs_context.c +++ b/fs/fs_context.c @@ -175,14 +175,15 @@ int vfs_parse_fs_string(struct fs_context *fc, const char *key, struct fs_parameter param = { .key = key, - .type = fs_value_is_string, + .type = fs_value_is_flag, .size = v_size, }; - if (v_size > 0) { + if (value) { param.string = kmemdup_nul(value, v_size, GFP_KERNEL); if (!param.string) return -ENOMEM; + param.type = fs_value_is_string; } ret = vfs_parse_fs_param(fc, ¶m); diff --git a/fs/fs_parser.c b/fs/fs_parser.c index d1930ad..07ae041 100644 --- a/fs/fs_parser.c +++ b/fs/fs_parser.c @@ -85,7 +85,6 @@ int fs_parse(struct fs_context *fc, const struct fs_parameter_enum *e; int ret = -ENOPARAM, b; - result->has_value = !!param->string; result->negated = false; result->uint_64 = 0; @@ -95,7 +94,7 @@ int fs_parse(struct fs_context *fc, * "xxx" takes the "no"-form negative - but only if there * wasn't an value. */ - if (result->has_value) + if (param->type != fs_value_is_flag) goto unknown_parameter; if (param->key[0] != 'n' || param->key[1] != 'o' || !param->key[2]) goto unknown_parameter; @@ -127,14 +126,18 @@ int fs_parse(struct fs_context *fc, case fs_param_is_u64: case fs_param_is_enum: case fs_param_is_string: - if (param->type != fs_value_is_string) - goto bad_value; - if (!result->has_value) { + if (param->type == fs_value_is_string) { + if (p->flags & fs_param_v_optional) + break; + if (!*param->string) + goto bad_value; + break; + } + if (param->type == fs_value_is_flag) { if (p->flags & fs_param_v_optional) goto okay; - goto bad_value; } - /* Fall through */ + goto bad_value; default: break; } @@ -144,8 +147,7 @@ int fs_parse(struct fs_context *fc, */ switch (p->type) { case fs_param_is_flag: - if (param->type != fs_value_is_flag && - (param->type != fs_value_is_string || result->has_value)) + if (param->type != fs_value_is_flag) return invalf(fc, "%s: Unexpected value for '%s'", desc->name, param->key); result->boolean = true; @@ -206,9 +208,6 @@ int fs_parse(struct fs_context *fc, case fs_param_is_fd: { switch (param->type) { case fs_value_is_string: - if (!result->has_value) - goto bad_value; - ret = kstrtouint(param->string, 0, &result->uint_32); break; case fs_value_is_file: diff --git a/include/linux/fs_parser.h b/include/linux/fs_parser.h index dee140d..4532320 100644 --- a/include/linux/fs_parser.h +++ b/include/linux/fs_parser.h @@ -72,7 +72,6 @@ struct fs_parameter_description { */ struct fs_parse_result { bool negated; /* T if param was "noxxx" */ - bool has_value; /* T if value supplied to param */ union { bool boolean; /* For spec_bool */ int int_32; /* For spec_s32/spec_enum */ -- 2.7.4