Implement storedevs, prepare to port littlefs

kernel/fs/littlefs/bd/lfs_emubd.h

@@ -0,0 +1,244 @@
+/*
+ * Emulating block device, wraps filebd and rambd while providing a bunch
+ * of hooks for testing littlefs in various conditions.
+ *
+ * Copyright (c) 2022, The littlefs authors.
+ * Copyright (c) 2017, Arm Limited. All rights reserved.
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+#ifndef LFS_EMUBD_H
+#define LFS_EMUBD_H
+
+#include "lfs.h"
+#include "lfs_util.h"
+#include "bd/lfs_rambd.h"
+#include "bd/lfs_filebd.h"
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+
+// Block device specific tracing
+#ifndef LFS_EMUBD_TRACE
+#ifdef LFS_EMUBD_YES_TRACE
+#define LFS_EMUBD_TRACE(...) LFS_TRACE(__VA_ARGS__)
+#else
+#define LFS_EMUBD_TRACE(...)
+#endif
+#endif
+
+// Mode determining how "bad-blocks" behave during testing. This simulates
+// some real-world circumstances such as progs not sticking (prog-noop),
+// a readonly disk (erase-noop), and ECC failures (read-error).
+//
+// Not that read-noop is not allowed. Read _must_ return a consistent (but
+// may be arbitrary) value on every read.
+typedef enum lfs_emubd_badblock_behavior {
+    LFS_EMUBD_BADBLOCK_PROGERROR  = 0, // Error on prog
+    LFS_EMUBD_BADBLOCK_ERASEERROR = 1, // Error on erase
+    LFS_EMUBD_BADBLOCK_READERROR  = 2, // Error on read
+    LFS_EMUBD_BADBLOCK_PROGNOOP   = 3, // Prog does nothing silently
+    LFS_EMUBD_BADBLOCK_ERASENOOP  = 4, // Erase does nothing silently
+} lfs_emubd_badblock_behavior_t;
+
+// Mode determining how power-loss behaves during testing. For now this
+// only supports a noop behavior, leaving the data on-disk untouched.
+typedef enum lfs_emubd_powerloss_behavior {
+    LFS_EMUBD_POWERLOSS_NOOP = 0, // Progs are atomic
+    LFS_EMUBD_POWERLOSS_OOO  = 1, // Blocks are written out-of-order
+} lfs_emubd_powerloss_behavior_t;
+
+// Type for measuring read/program/erase operations
+typedef uint64_t lfs_emubd_io_t;
+typedef int64_t lfs_emubd_sio_t;
+
+// Type for measuring wear
+typedef uint32_t lfs_emubd_wear_t;
+typedef int32_t lfs_emubd_swear_t;
+
+// Type for tracking power-cycles
+typedef uint32_t lfs_emubd_powercycles_t;
+typedef int32_t lfs_emubd_spowercycles_t;
+
+// Type for delays in nanoseconds
+typedef uint64_t lfs_emubd_sleep_t;
+typedef int64_t lfs_emubd_ssleep_t;
+
+// emubd config, this is required for testing
+struct lfs_emubd_config {
+    // Minimum size of a read operation in bytes.
+    lfs_size_t read_size;
+
+    // Minimum size of a program operation in bytes.
+    lfs_size_t prog_size;
+
+    // Size of an erase operation in bytes.
+    lfs_size_t erase_size;
+
+    // Number of erase blocks on the device.
+    lfs_size_t erase_count;
+
+    // 8-bit erase value to use for simulating erases. -1 does not simulate
+    // erases, which can speed up testing by avoiding the extra block-device
+    // operations to store the erase value.
+    int32_t erase_value;
+
+    // Number of erase cycles before a block becomes "bad". The exact behavior
+    // of bad blocks is controlled by badblock_behavior.
+    uint32_t erase_cycles;
+
+    // The mode determining how bad-blocks fail
+    lfs_emubd_badblock_behavior_t badblock_behavior;
+
+    // Number of write operations (erase/prog) before triggering a power-loss.
+    // power_cycles=0 disables this. The exact behavior of power-loss is
+    // controlled by a combination of powerloss_behavior and powerloss_cb.
+    lfs_emubd_powercycles_t power_cycles;
+
+    // The mode determining how power-loss affects disk
+    lfs_emubd_powerloss_behavior_t powerloss_behavior;
+
+    // Function to call to emulate power-loss. The exact behavior of power-loss
+    // is up to the runner to provide.
+    void (*powerloss_cb)(void*);
+
+    // Data for power-loss callback
+    void *powerloss_data;
+
+    // True to track when power-loss could have occured. Note this involves 
+    // heavy memory usage!
+    bool track_branches;
+
+    // Path to file to use as a mirror of the disk. This provides a way to view
+    // the current state of the block device.
+    const char *disk_path;
+
+    // Artificial delay in nanoseconds, there is no purpose for this other
+    // than slowing down the simulation.
+    lfs_emubd_sleep_t read_sleep;
+
+    // Artificial delay in nanoseconds, there is no purpose for this other
+    // than slowing down the simulation.
+    lfs_emubd_sleep_t prog_sleep;
+
+    // Artificial delay in nanoseconds, there is no purpose for this other
+    // than slowing down the simulation.
+    lfs_emubd_sleep_t erase_sleep;
+};
+
+// A reference counted block
+typedef struct lfs_emubd_block {
+    uint32_t rc;
+    lfs_emubd_wear_t wear;
+
+    uint8_t data[];
+} lfs_emubd_block_t;
+
+// Disk mirror
+typedef struct lfs_emubd_disk {
+    uint32_t rc;
+    int fd;
+    uint8_t *scratch;
+} lfs_emubd_disk_t;
+
+// emubd state
+typedef struct lfs_emubd {
+    // array of copy-on-write blocks
+    lfs_emubd_block_t **blocks;
+
+    // some other test state
+    lfs_emubd_io_t readed;
+    lfs_emubd_io_t proged;
+    lfs_emubd_io_t erased;
+    lfs_emubd_powercycles_t power_cycles;
+    lfs_ssize_t ooo_block;
+    lfs_emubd_block_t *ooo_data;
+    lfs_emubd_disk_t *disk;
+
+    const struct lfs_emubd_config *cfg;
+} lfs_emubd_t;
+
+
+/// Block device API ///
+
+// Create an emulating block device using the geometry in lfs_config
+int lfs_emubd_create(const struct lfs_config *cfg,
+        const struct lfs_emubd_config *bdcfg);
+
+// Clean up memory associated with block device
+int lfs_emubd_destroy(const struct lfs_config *cfg);
+
+// Read a block
+int lfs_emubd_read(const struct lfs_config *cfg, lfs_block_t block,
+        lfs_off_t off, void *buffer, lfs_size_t size);
+
+// Program a block
+//
+// The block must have previously been erased.
+int lfs_emubd_prog(const struct lfs_config *cfg, lfs_block_t block,
+        lfs_off_t off, const void *buffer, lfs_size_t size);
+
+// Erase a block
+//
+// A block must be erased before being programmed. The
+// state of an erased block is undefined.
+int lfs_emubd_erase(const struct lfs_config *cfg, lfs_block_t block);
+
+// Sync the block device
+int lfs_emubd_sync(const struct lfs_config *cfg);
+
+
+/// Additional extended API for driving test features ///
+
+// A CRC of a block for debugging purposes
+int lfs_emubd_crc(const struct lfs_config *cfg,
+        lfs_block_t block, uint32_t *crc);
+
+// A CRC of the entire block device for debugging purposes
+int lfs_emubd_bdcrc(const struct lfs_config *cfg, uint32_t *crc);
+
+// Get total amount of bytes read
+lfs_emubd_sio_t lfs_emubd_readed(const struct lfs_config *cfg);
+
+// Get total amount of bytes programmed
+lfs_emubd_sio_t lfs_emubd_proged(const struct lfs_config *cfg);
+
+// Get total amount of bytes erased
+lfs_emubd_sio_t lfs_emubd_erased(const struct lfs_config *cfg);
+
+// Manually set amount of bytes read
+int lfs_emubd_setreaded(const struct lfs_config *cfg, lfs_emubd_io_t readed);
+
+// Manually set amount of bytes programmed
+int lfs_emubd_setproged(const struct lfs_config *cfg, lfs_emubd_io_t proged);
+
+// Manually set amount of bytes erased
+int lfs_emubd_seterased(const struct lfs_config *cfg, lfs_emubd_io_t erased);
+
+// Get simulated wear on a given block
+lfs_emubd_swear_t lfs_emubd_wear(const struct lfs_config *cfg,
+        lfs_block_t block);
+
+// Manually set simulated wear on a given block
+int lfs_emubd_setwear(const struct lfs_config *cfg,
+        lfs_block_t block, lfs_emubd_wear_t wear);
+
+// Get the remaining power-cycles
+lfs_emubd_spowercycles_t lfs_emubd_powercycles(
+        const struct lfs_config *cfg);
+
+// Manually set the remaining power-cycles
+int lfs_emubd_setpowercycles(const struct lfs_config *cfg,
+        lfs_emubd_powercycles_t power_cycles);
+
+// Create a copy-on-write copy of the state of this block device
+int lfs_emubd_copy(const struct lfs_config *cfg, lfs_emubd_t *copy);
+
+
+#ifdef __cplusplus
+} /* extern "C" */
+#endif
+
+#endif