From 746b90965cfd5d81b91af6d6a63362adf0e08060 Mon Sep 17 00:00:00 2001
From: Christopher Haster <chaster@utexas.edu>
Date: Sun, 8 Apr 2018 22:25:58 -0500
Subject: [PATCH] Added lfs_fs_size for finding a count of used blocks

This has existed for some time in the form of the lfs_traverse
function, through which a user could provide a simple callback that
would just count the number of blocks lfs_traverse finds. However,
this approach is relatively unconventional and has proven to be confusing
for most users.
---
 lfs.c | 16 ++++++++++++++++
 lfs.h |  8 ++++++++
 2 files changed, 24 insertions(+)

diff --git a/lfs.c b/lfs.c
index efc8744..12c903f 100644
--- a/lfs.c
+++ b/lfs.c
@@ -3183,3 +3183,19 @@ int lfs_fs_setattrs(lfs_t *lfs, const struct lfs_attr *attrs, int count) {
 
     return lfs_dir_setattrs(lfs, &dir, &entry, attrs, count);
 }
+
+static int lfs_fs_size_count(void *p, lfs_block_t block) {
+    lfs_size_t *size = p;
+    *size += 1;
+    return 0;
+}
+
+lfs_ssize_t lfs_fs_size(lfs_t *lfs) {
+    lfs_size_t size = 0;
+    int err = lfs_traverse(lfs, lfs_fs_size_count, &size);
+    if (err) {
+        return err;
+    }
+
+    return size;
+}
diff --git a/lfs.h b/lfs.h
index 1e81a38..3fd3ba1 100644
--- a/lfs.h
+++ b/lfs.h
@@ -590,6 +590,14 @@ int lfs_fs_getattrs(lfs_t *lfs, const struct lfs_attr *attrs, int count);
 // Returns a negative error code on failure.
 int lfs_fs_setattrs(lfs_t *lfs, const struct lfs_attr *attrs, int count);
 
+// Finds the current size of the filesystem
+//
+// Note: Result is best effort. If files share COW structures, the returned
+// size may be larger than the filesystem actually is.
+//
+// Returns the number of allocated blocks, or a negative error code on failure.
+lfs_ssize_t lfs_fs_size(lfs_t *lfs);
+
 
 /// Miscellaneous littlefs specific operations ///