71ea438561
The superblock for littlefs is in block 0 and 1, but block 0 may be erased or partially written, so block 1 must be checked if block 0 does not have a valid littlefs superblock in it. Prior to this commit, the mount of a block device which auto-detected the filysystem type would fail for littlefs if block 0 did not contain a valid superblock. That is now fixed. Signed-off-by: Damien George <damien@micropython.org>
48 lines
2.2 KiB
Python
48 lines
2.2 KiB
Python
# Test for VfsLfs using a RAM device, when the first superblock does not exist
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try:
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import uos
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uos.VfsLfs2
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except (ImportError, AttributeError):
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print("SKIP")
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raise SystemExit
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class RAMBlockDevice:
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def __init__(self, block_size, data):
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self.block_size = block_size
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self.data = data
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def readblocks(self, block, buf, off):
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addr = block * self.block_size + off
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for i in range(len(buf)):
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buf[i] = self.data[addr + i]
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def ioctl(self, op, arg):
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if op == 4: # block count
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return len(self.data) // self.block_size
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if op == 5: # block size
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return self.block_size
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if op == 6: # erase block
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return 0
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# This is a valid littlefs2 filesystem with a block size of 64 bytes.
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# The first block (where the first superblock is stored) is fully erased.
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lfs2_data = b"\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\x02\x00\x00\x00\xf0\x0f\xff\xf7littlefs/\xe0\x00\x10\x00\x00\x02\x00@\x00\x00\x00\x04\x00\x00\x00\xff\x00\x00\x00\xff\xff\xff\x7f\xfe\x03\x00\x00p\x1f\xfc\x08\x1b\xb4\x14\xa7\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\x01\x00\x00\x00\xff\xef\xff\xf7test.txt \x00\x00\x08p\x1f\xfc\x08\x83\xf1u\xba\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
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# Create the block device from the static data (it will be read-only).
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bdev = RAMBlockDevice(64, lfs2_data)
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# Create the VFS explicitly, no auto-detection is needed for this.
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vfs = uos.VfsLfs2(bdev)
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print(list(vfs.ilistdir()))
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# Mount the block device directly; this relies on auto-detection.
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uos.mount(bdev, "/userfs")
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print(uos.listdir("/userfs"))
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# Clean up.
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uos.umount("/userfs")
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