[fs][spifs] Add truncate functionality to spifs.

lib/fs/spifs/spifs.c

@@ -1032,6 +1032,34 @@ err:
     return len == 0 ? (ssize_t)size : err;
 }
 
+static status_t spifs_truncate(filecookie *fcookie, uint64_t len)
+{
+    LTRACEF("filecookie %p, len %llu\n", fcookie, len);
+
+    status_t rc = NO_ERROR;
+
+    spifs_file_t *file = (spifs_file_t *)fcookie;
+
+    mutex_acquire(&file->fs_handle->lock);
+
+    spifs_t *spifs = (spifs_t *)(file->fs_handle);
+
+    // Can't use truncate to grow a file.
+    if (len > file->metadata.length) {
+        rc = ERR_INVALID_ARGS;
+        goto finish;
+    }
+
+    file->metadata.length = len;
+
+    rc = spifs_commit_toc(spifs);
+
+finish:
+    mutex_release(&file->fs_handle->lock);
+
+    return rc;
+}
+
 static status_t spifs_stat(filecookie *fcookie, struct file_stat *stat)
 {
     LTRACEF("filecookie %p stat %p\n", fcookie, stat);
@@ -1194,6 +1222,7 @@ static const struct fs_api spifs_api = {
 
     .read = spifs_read,
     .write = spifs_write,
+    .truncate = spifs_truncate,
 
     .stat = spifs_stat,
 

lib/fs/spifs/test/spifstest.c

@@ -58,6 +58,7 @@ static bool test_corrupt_toc(const char *);
 static bool test_write_with_offset(const char *);
 static bool test_read_write_big(const char *);
 static bool test_rm_active_dirent(const char *);
+static bool test_truncate_file(const char *);
 
 static test tests[] = {
     {&test_empty_after_format, "Test no files in ToC after format.", 1},
@@ -72,6 +73,7 @@ static test tests[] = {
     {&test_write_with_offset, "Test that files can be written to at an offset.", 1},
     {&test_read_write_big, "Test that an unaligned ~10kb buffer can be written and read.", 1},
     {&test_rm_active_dirent, "Test that we can remove a file with an open dirent.", 1},
+    {&test_truncate_file, "Test that we can truncate a file.", 1},
 };
 
 bool test_setup(const char *dev_name, uint32_t toc_pages)
@@ -627,6 +629,35 @@ static bool test_rm_active_dirent(const char *dev_name)
     return success;
 }
 
+static bool test_truncate_file(const char *dev_name)
+{
+    filehandle *handle;
+    status_t status =
+        fs_create_file(TEST_FILE_PATH, &handle, 1024);
+    if (status != NO_ERROR) {
+        return false;
+    }
+
+    // File size is 1024?
+    struct file_stat stat;
+    fs_stat_file(handle, &stat);
+    if (stat.size != 1024) {
+        return false;
+    }
+
+    status = fs_truncate_file(handle, 512);
+    if (status != NO_ERROR) {
+        return false;
+    }
+
+    fs_stat_file(handle, &stat);
+    if (stat.size != 512) {
+        return false;
+    }
+
+    return fs_close_file(handle) == NO_ERROR;
+}
+
 // Run the SPIFS test suite.
 static int spifs_test(int argc, const cmd_args *argv)
 {