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https://github.com/eledio-devices/thirdparty-littlefs.git
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fb65057a3c
Also finished migrating tests with test_relocations and test_exhaustion. The issue I was running into when migrating these tests was a lack of flexibility with what you could do with the block devices. It was possible to hack in some hooks for things like bad blocks and power loss, but it wasn't clean or easily extendable. The solution here was to just put all of these test extensions into a third block device, testbd, that uses the other two example block devices internally. testbd has several useful features for testing. Note this makes it a pretty terrible block device _example_ since these hooks look more complicated than a block device needs to be. - testbd can simulate different erase values, supporting 1s, 0s, other byte patterns, or no erases at all (which can cause surprising bugs). This actually depends on the simulated erase values in ramdb and filebd. I did try to move this out of rambd/filebd, but it's not possible to simulate erases in testbd without buffering entire blocks and creating an excessive amount of extra write operations. - testbd also helps simulate power-loss by containing a "power cycles" counter that is decremented every write operation until it calls exit. This is notably faster than the previous gdb approach, which is valuable since the reentrant tests tend to take a while to resolve. - testbd also tracks wear, which can be manually set and read. This is very useful for testing things like bad block handling, wear leveling, or even changing the effective size of the block device at runtime.
66 lines
1.6 KiB
C
66 lines
1.6 KiB
C
/*
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* Block device emulated in a file
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*
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* Copyright (c) 2017, Arm Limited. All rights reserved.
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* SPDX-License-Identifier: BSD-3-Clause
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*/
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#ifndef LFS_FILEBD_H
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#define LFS_FILEBD_H
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#include "lfs.h"
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#include "lfs_util.h"
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#ifdef __cplusplus
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extern "C"
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{
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#endif
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// filebd config (optional)
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struct lfs_filebd_config {
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// 8-bit erase value to use for simulating erases. -1 does not simulate
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// erases, which can speed up testing by avoiding all the extra block-device
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// operations to store the erase value.
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int32_t erase_value;
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};
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// filebd state
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typedef struct lfs_filebd {
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int fd;
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const struct lfs_filebd_config *cfg;
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} lfs_filebd_t;
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// Create a file block device using the geometry in lfs_config
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int lfs_filebd_create(const struct lfs_config *cfg, const char *path);
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int lfs_filebd_createcfg(const struct lfs_config *cfg, const char *path,
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const struct lfs_filebd_config *bdcfg);
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// Clean up memory associated with block device
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int lfs_filebd_destroy(const struct lfs_config *cfg);
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// Read a block
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int lfs_filebd_read(const struct lfs_config *cfg, lfs_block_t block,
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lfs_off_t off, void *buffer, lfs_size_t size);
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// Program a block
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//
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// The block must have previously been erased.
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int lfs_filebd_prog(const struct lfs_config *cfg, lfs_block_t block,
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lfs_off_t off, const void *buffer, lfs_size_t size);
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// Erase a block
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//
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// A block must be erased before being programmed. The
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// state of an erased block is undefined.
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int lfs_filebd_erase(const struct lfs_config *cfg, lfs_block_t block);
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// Sync the block device
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int lfs_filebd_sync(const struct lfs_config *cfg);
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#ifdef __cplusplus
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} /* extern "C" */
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#endif
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#endif
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