From 444d243ae1dfbc00e1ab0109166ebb0138713397 Mon Sep 17 00:00:00 2001
From: ondrap <pilat.ondrej@seznam.cz>
Date: Wed, 2 Aug 2023 11:51:52 +0200
Subject: [PATCH] Update lfs_find_free_blocks to match the latest changes.

---
 lfs.c | 27 +++++++++++++++++----------
 lfs.h |  4 ++++
 2 files changed, 21 insertions(+), 10 deletions(-)

diff --git a/lfs.c b/lfs.c
index 38b825dd..f24002ba 100644
--- a/lfs.c
+++ b/lfs.c
@@ -654,20 +654,27 @@ static int lfs_alloc(lfs_t *lfs, lfs_block_t *block) {
             return LFS_ERR_NOSPC;
         }
 
-        lfs->free.off = (lfs->free.off + lfs->free.size)
-                % lfs->cfg->block_count;
-        lfs->free.size = lfs_min(8*lfs->cfg->lookahead_size, lfs->free.ack);
-        lfs->free.i = 0;
-
-        // find mask of free blocks from tree
-        memset(lfs->free.buffer, 0, lfs->cfg->lookahead_size);
-        int err = lfs_fs_rawtraverse(lfs, lfs_alloc_lookahead, lfs, true);
-        if (err) {
-            lfs_alloc_drop(lfs);
+        int err = lfs_find_free_blocks(lfs);
+        if(err) {
             return err;
         }
     }
 }
+
+int lfs_find_free_blocks(lfs_t *lfs){
+    lfs->free.off = (lfs->free.off + lfs->free.size)
+        % lfs->cfg->block_count;
+    lfs->free.size = lfs_min(8*lfs->cfg->lookahead_size, lfs->free.ack);
+    lfs->free.i = 0;
+
+    // find mask of free blocks from tree
+    memset(lfs->free.buffer, 0, lfs->cfg->lookahead_size);
+    int const err = lfs_fs_rawtraverse(lfs, lfs_alloc_lookahead, lfs, true);
+    if (err) {
+        lfs_alloc_drop(lfs);
+    }
+    return err;
+}
 #endif
 
 /// Metadata pair and directory operations ///
diff --git a/lfs.h b/lfs.h
index 1081735f..004e1465 100644
--- a/lfs.h
+++ b/lfs.h
@@ -705,6 +705,10 @@ lfs_ssize_t lfs_fs_size(lfs_t *lfs);
 // Returns a negative error code on failure.
 int lfs_fs_traverse(lfs_t *lfs, int (*cb)(void*, lfs_block_t), void *data);
 
+// Use Traverse function and try to find free blocks. LittleFS free blocks search is unpredictable.
+// Search is costly operation which may delay write. In realtime write scenarios can be better to find them before a write.
+int lfs_find_free_blocks(lfs_t *lfs);
+
 #ifndef LFS_READONLY
 // Attempt to make the filesystem consistent and ready for writing
 //