Merge branch 'bugfix/fatfs_stat' into 'master'

Fix stat behavior for FATFS mount point

See merge request !1652

components/fatfs/src/vfs_fat.c

@@ -43,6 +43,25 @@ typedef struct {
     struct dirent cur_dirent;
 } vfs_fat_dir_t;
 
+/* Date and time storage formats in FAT */
+typedef union {
+    struct {
+        uint16_t mday : 5;  /* Day of month, 1 - 31 */
+        uint16_t mon : 4;   /* Month, 1 - 12 */
+        uint16_t year : 7;  /* Year, counting from 1980. E.g. 37 for 2017 */
+    };
+    uint16_t as_int;
+} fat_date_t;
+
+typedef union {
+    struct {
+        uint16_t sec : 5;   /* Seconds divided by 2. E.g. 21 for 42 seconds */
+        uint16_t min : 6;   /* Minutes, 0 - 59 */
+        uint16_t hour : 5;  /* Hour, 0 - 23 */
+    };
+    uint16_t as_int;
+} fat_time_t;
+
 static const char* TAG = "vfs_fat";
 
 static ssize_t vfs_fat_write(void* p, int fd, const void * data, size_t size);
@@ -395,8 +414,23 @@ static int vfs_fat_fstat(void* ctx, int fd, struct stat * st)
     return 0;
 }
 
+static inline mode_t get_stat_mode(bool is_dir)
+{
+    return S_IRWXU | S_IRWXG | S_IRWXO |
+            ((is_dir) ? S_IFDIR : S_IFREG);
+}
+
 static int vfs_fat_stat(void* ctx, const char * path, struct stat * st)
 {
+    if (strcmp(path, "/") == 0) {
+        /* FatFS f_stat function does not work for the drive root.
+         * Just pretend that this is a directory.
+         */
+        memset(st, 0, sizeof(*st));
+        st->st_mode = get_stat_mode(true);
+        return 0;
+    }
+
     vfs_fat_ctx_t* fat_ctx = (vfs_fat_ctx_t*) ctx;
     _lock_acquire(&fat_ctx->lock);
     prepend_drive_to_path(fat_ctx, &path, NULL);
@@ -408,22 +442,20 @@ static int vfs_fat_stat(void* ctx, const char * path, struct stat * st)
         errno = fresult_to_errno(res);
         return -1;
     }
+
+    memset(st, 0, sizeof(*st));
     st->st_size = info.fsize;
-    st->st_mode = S_IRWXU | S_IRWXG | S_IRWXO |
-            ((info.fattrib & AM_DIR) ? S_IFDIR : S_IFREG);
-    struct tm tm;
-    uint16_t fdate = info.fdate;
-    tm.tm_mday = fdate & 0x1f;
-    fdate >>= 5;
-    tm.tm_mon = (fdate & 0xf) - 1;
-    fdate >>=4;
-    tm.tm_year = fdate + 80;
-    uint16_t ftime = info.ftime;
-    tm.tm_sec = (ftime & 0x1f) * 2;
-    ftime >>= 5;
-    tm.tm_min = (ftime & 0x3f);
-    ftime >>= 6;
-    tm.tm_hour = (ftime & 0x1f);
+    st->st_mode = get_stat_mode((info.fattrib & AM_DIR) != 0);
+    fat_date_t fdate = { .as_int = info.fdate };
+    fat_time_t ftime = { .as_int = info.ftime };
+    struct tm tm = {
+        .tm_mday = fdate.mday,
+        .tm_mon = fdate.mon - 1,    /* unlike tm_mday, tm_mon is zero-based */
+        .tm_year = fdate.year + 80,
+        .tm_sec = ftime.sec * 2,
+        .tm_min = ftime.min,
+        .tm_hour = ftime.hour
+    };
     st->st_mtime = mktime(&tm);
     st->st_atime = 0;
     st->st_ctime = 0;

components/fatfs/test/test_fatfs_common.c

@@ -125,15 +125,15 @@ void test_fatfs_lseek(const char* filename)
     TEST_ASSERT_EQUAL(0, fclose(f));
 }
 
-void test_fatfs_stat(const char* filename)
+void test_fatfs_stat(const char* filename, const char* root_dir)
 {
     struct tm tm;
-    tm.tm_year = 2016 - 1900;
-    tm.tm_mon = 0;
-    tm.tm_mday = 10;
-    tm.tm_hour = 16;
-    tm.tm_min = 30;
-    tm.tm_sec = 0;
+    tm.tm_year = 2017 - 1900;
+    tm.tm_mon = 11;
+    tm.tm_mday = 8;
+    tm.tm_hour = 19;
+    tm.tm_min = 51;
+    tm.tm_sec = 10;
     time_t t = mktime(&tm);
     printf("Setting time: %s", asctime(&tm));
     struct timeval now = { .tv_sec = t };
@@ -151,6 +151,11 @@ void test_fatfs_stat(const char* filename)
 
     TEST_ASSERT(st.st_mode & S_IFREG);
     TEST_ASSERT_FALSE(st.st_mode & S_IFDIR);
+
+    memset(&st, 0, sizeof(st));
+    TEST_ASSERT_EQUAL(0, stat(root_dir, &st));
+    TEST_ASSERT(st.st_mode & S_IFDIR);
+    TEST_ASSERT_FALSE(st.st_mode & S_IFREG);
 }
 
 void test_fatfs_unlink(const char* filename)

components/fatfs/test/test_fatfs_common.h

@@ -43,7 +43,7 @@ void test_fatfs_open_max_files(const char* filename_prefix, size_t files_count);
 
 void test_fatfs_lseek(const char* filename);
 
-void test_fatfs_stat(const char* filename);
+void test_fatfs_stat(const char* filename, const char* root_dir);
 
 void test_fatfs_unlink(const char* filename);
 

components/fatfs/test/test_fatfs_sdmmc.c

@@ -105,7 +105,7 @@ TEST_CASE("(SD) can lseek", "[fatfs][sdcard][ignore]")
 TEST_CASE("(SD) stat returns correct values", "[fatfs][ignore]")
 {
     test_setup();
-    test_fatfs_stat("/sdcard/stat.txt");
+    test_fatfs_stat("/sdcard/stat.txt", "/sdcard");
     test_teardown();
 }
 

components/fatfs/test/test_fatfs_spiflash.c

@@ -100,7 +100,7 @@ TEST_CASE("(WL) can lseek", "[fatfs][wear_levelling]")
 TEST_CASE("(WL) stat returns correct values", "[fatfs][wear_levelling]")
 {
     test_setup();
-    test_fatfs_stat("/spiflash/stat.txt");
+    test_fatfs_stat("/spiflash/stat.txt", "/spiflash");
     test_teardown();
 }