[PATCH v3 4/4] btrfs: migrate to the newer memparse_safe() helper

[Qu Wenruo]

The new helper has better error report and correct overflow detection,
furthermore the old @retptr behavior is also kept, thus there should be
no behavior change.

Signed-off-by: Qu Wenruo <wqu@xxxxxxxx>
Reviewed-by: David Disseldorp <ddiss@xxxxxxx>
---
 fs/btrfs/ioctl.c |  6 +++++-
 fs/btrfs/super.c |  9 ++++++++-
 fs/btrfs/sysfs.c | 14 +++++++++++---
 3 files changed, 24 insertions(+), 5 deletions(-)

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 4e50b62db2a8..cb63f50a2078 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -1175,7 +1175,11 @@ static noinline int btrfs_ioctl_resize(struct file *file,
 			mod = 1;
 			sizestr++;
 		}
-		new_size = memparse(sizestr, &retptr);
+
+		ret = memparse_safe(sizestr, MEMPARSE_SUFFIXES_DEFAULT,
+				    &new_size, &retptr);
+		if (ret < 0)
+			goto out_finish;
 		if (*retptr != '\0' || new_size == 0) {
 			ret = -EINVAL;
 			goto out_finish;
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 3a677b808f0f..0f29fd692e0f 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -263,6 +263,8 @@ static int btrfs_parse_param(struct fs_context *fc, struct fs_parameter *param)
 {
 	struct btrfs_fs_context *ctx = fc->fs_private;
 	struct fs_parse_result result;
+	/* Only for memparse_safe() caller. */
+	int ret;
 	int opt;
 
 	opt = fs_parse(fc, btrfs_fs_parameters, param, &result);
@@ -400,7 +402,12 @@ static int btrfs_parse_param(struct fs_context *fc, struct fs_parameter *param)
 		ctx->thread_pool_size = result.uint_32;
 		break;
 	case Opt_max_inline:
-		ctx->max_inline = memparse(param->string, NULL);
+		ret = memparse_safe(param->string, MEMPARSE_SUFFIXES_DEFAULT,
+				    &ctx->max_inline, NULL);
+		if (ret < 0) {
+			btrfs_err(NULL, "invalid string \"%s\"", param->string);
+			return ret;
+		}
 		break;
 	case Opt_acl:
 		if (result.negated) {
diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
index 84c05246ffd8..6846572496a6 100644
--- a/fs/btrfs/sysfs.c
+++ b/fs/btrfs/sysfs.c
@@ -762,6 +762,7 @@ static ssize_t btrfs_chunk_size_store(struct kobject *kobj,
 	struct btrfs_fs_info *fs_info = to_fs_info(get_btrfs_kobj(kobj));
 	char *retptr;
 	u64 val;
+	int ret;
 
 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
@@ -776,7 +777,10 @@ static ssize_t btrfs_chunk_size_store(struct kobject *kobj,
 	if (space_info->flags & BTRFS_BLOCK_GROUP_SYSTEM)
 		return -EPERM;
 
-	val = memparse(buf, &retptr);
+	ret = memparse_safe(buf, MEMPARSE_SUFFIXES_DEFAULT, &val, &retptr);
+	if (ret < 0)
+		return ret;
+
 	/* There could be trailing '\n', also catch any typos after the value */
 	retptr = skip_spaces(retptr);
 	if (*retptr != 0 || val == 0)
@@ -1779,10 +1783,14 @@ static ssize_t btrfs_devinfo_scrub_speed_max_store(struct kobject *kobj,
 {
 	struct btrfs_device *device = container_of(kobj, struct btrfs_device,
 						   devid_kobj);
-	char *endptr;
 	unsigned long long limit;
+	char *endptr;
+	int ret;
+
+	ret = memparse_safe(buf, MEMPARSE_SUFFIXES_DEFAULT, &limit, &endptr);
+	if (ret < 0)
+		return ret;
 
-	limit = memparse(buf, &endptr);
 	/* There could be trailing '\n', also catch any typos after the value. */
 	endptr = skip_spaces(endptr);
 	if (*endptr != 0)
-- 
2.43.0