lfs:Added lfs_file_getattr interface

1. Added a new interface lfs_file_getattr to get the corresponding
   file attributes through lfs_file. This interface is similar to lfs_getattr,
   but lfs_file_getattr replaces path with lfs_file.
2. Implemented the corresponding test case in test_attrs.toml.

Signed-off-by: chenrun1 <[email protected]>

Author: crafcat7

lfs.c

@@ -6235,6 +6235,38 @@ lfs_soff_t lfs_file_size(lfs_t *lfs, lfs_file_t *file) {
     return res;
 }
 
+lfs_ssize_t lfs_file_getattr(lfs_t *lfs, lfs_file_t *file,
+        uint8_t type, void *buffer, lfs_size_t size)
+{
+    int err = LFS_LOCK(lfs->cfg);
+    if (err) {
+        return err;
+    }
+    LFS_TRACE("lfs_file_setattr(%p, %p)", (void*)lfs, (void*)file);
+    LFS_TRACE("lfs_file_setattr(%"PRIu8", %p, %"PRIu32")",
+            type, buffer, size);
+    LFS_ASSERT(lfs_mlist_isopen(lfs->mlist, (struct lfs_mlist*)file));
+
+    if (file->cfg && file->cfg->attrs) {
+        for (unsigned i = 0; i < file->cfg->attr_count; i++) {
+            const struct lfs_attr *attr = &file->cfg->attrs[i];
+            if (attr->type == LFS_TYPE_USERATTR + type) {
+                lfs_size_t attr_size = lfs_min(size, attr->size);
+                memcpy(buffer, attr->buffer, attr_size);
+                LFS_UNLOCK(lfs->cfg);
+                return 0;
+            }
+        }
+    }
+
+    int res = lfs_dir_get(lfs, &file->m,
+            LFS_MKTAG(0x7ff, 0x3ff, 0),
+            LFS_MKTAG(LFS_TYPE_USERATTR + type,
+                      file->id, lfs_min(size, lfs->attr_max)), buffer);
+    LFS_UNLOCK(lfs->cfg);
+    return (res < 0) ? LFS_ERR_NOATTR : 0;
+}
+
 #ifndef LFS_READONLY
 int lfs_mkdir(lfs_t *lfs, const char *path) {
     int err = LFS_LOCK(lfs->cfg);

lfs.h

@@ -656,6 +656,13 @@ int lfs_file_rewind(lfs_t *lfs, lfs_file_t *file);
 // Returns the size of the file, or a negative error code on failure.
 lfs_soff_t lfs_file_size(lfs_t *lfs, lfs_file_t *file);
 
+// Get the attribute of a file
+//
+// Retrieves the value of the attribute specified by `type` for the given `file`.
+// Copies up to `size` bytes into `buffer`. Returns 0 on success, or a negative
+// error code (e.g., LFS_ERR_NOATTR if not found).
+lfs_ssize_t lfs_file_getattr(lfs_t *lfs, lfs_file_t *file,
+        uint8_t type, void *buffer, lfs_size_t size);
 
 /// Directory operations ///
 

tests/test_attrs.toml

@@ -314,3 +314,51 @@ code = '''
     lfs_file_close(&lfs, &file) => 0;
     lfs_unmount(&lfs) => 0;
 '''
+
+[cases.test_file_getattr]
+code = '''
+    struct lfs_attr_s {
+        uint32_t at_ver;
+        uint32_t at_mode;
+        uint32_t at_uid;
+        uint32_t at_gid;
+        uint64_t at_atim;
+        uint64_t at_mtim;
+        uint64_t at_ctim;
+    };
+
+    lfs_t lfs;
+    lfs_format(&lfs, cfg) => 0;
+    lfs_mount(&lfs, cfg) => 0;
+
+    lfs_file_t file;
+    struct lfs_attr_s attr_get[1024];
+    memset(attr_get, 0, sizeof(attr_get));
+    lfs_file_open(&lfs, &file, "hello", LFS_O_WRONLY | LFS_O_CREAT) => 0;
+    lfs_file_write(&lfs, &file, "world", strlen("world")) => strlen("world");
+    lfs_file_getattr(&lfs, &file, 0, attr_get, sizeof(struct lfs_attr_s)) => -61;
+
+    struct lfs_attr_s attr_set = {
+        .at_ver = 1,
+        .at_mode = 0644,
+        .at_uid = 1000,
+        .at_gid = 1000,
+        .at_atim = 1693123456,
+        .at_mtim = 1693123456,
+        .at_ctim = 1693123456,
+    };
+    lfs_setattr(&lfs, "hello", 0, &attr_set, sizeof(attr_set)) => 0;
+    memset(attr_get, 0, sizeof(attr_get));
+    lfs_file_getattr(&lfs, &file, 0, attr_get, sizeof(struct lfs_attr_s)) => 0;
+    attr_get->at_ver => attr_set.at_ver;
+    attr_get->at_mode => attr_set.at_mode;
+    attr_get->at_uid => attr_set.at_uid;
+    attr_get->at_gid => attr_set.at_gid;
+    attr_get->at_atim => attr_set.at_atim;
+    attr_get->at_mtim => attr_set.at_mtim;
+    attr_get->at_ctim => attr_set.at_ctim;
+
+    lfs_file_sync(&lfs, &file) => 0;
+    lfs_file_close(&lfs, &file) => 0;
+    lfs_unmount(&lfs) => 0;
+'''