[v4,4/9] btrfs: handle value associated with raid1 balancing parameter

Commit Message

Anand Jain Dec. 16, 2024, 6:13 p.m. UTC

This change enables specifying additional configuration values alongside
the raid1 balancing / read policy in a single input string.

Updated btrfs_read_policy_to_enum() to parse and handle a value associated
with the policy in the format `policy:value`, the value part if present is
converted 64-bit integer. Update btrfs_read_policy_store() to accommodate
the new parameter.

Signed-off-by: Anand Jain <[e-mail]>
---
 fs/btrfs/sysfs.c | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

Patch

diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
index 34903e5bf8d0..9c7bedf974d2 100644
--- a/fs/btrfs/sysfs.c
+++ b/fs/btrfs/sysfs.c
@@ -1307,9 +1307,10 @@  BTRFS_ATTR(, temp_fsid, btrfs_temp_fsid_show);
 
 static const char * const btrfs_read_policy_name[] = { "pid" };
 
-static int btrfs_read_policy_to_enum(const char *str)
+static int btrfs_read_policy_to_enum(const char *str, s64 *value)
 {
 	char param[32] = {'\0'};
+	char *__maybe_unused value_str;
 	int index;
 	bool found = false;
 
@@ -1318,6 +1319,16 @@  static int btrfs_read_policy_to_enum(const char *str)
 
 	strcpy(param, str);
 
+#ifdef CONFIG_BTRFS_EXPERIMENTAL
+	/* Separate value from input in policy:value format. */
+	if ((value_str = strchr(param, ':'))) {
+		*value_str = '\0';
+		value_str++;
+		if (value && kstrtou64(value_str, 10, value) != 0)
+			return -EINVAL;
+	}
+#endif
+
 	for (index = 0; index < BTRFS_NR_READ_POLICY; index++) {
 		if (sysfs_streq(param, btrfs_read_policy_name[index])) {
 			found = true;
@@ -1363,8 +1374,9 @@  static ssize_t btrfs_read_policy_store(struct kobject *kobj,
 {
 	struct btrfs_fs_devices *fs_devices = to_fs_devs(kobj);
 	int index;
+	s64 value = -1;
 
-	index = btrfs_read_policy_to_enum(buf);
+	index = btrfs_read_policy_to_enum(buf, &value);
 	if (index == -EINVAL)
 		return -EINVAL;