forked from Imagelibrary/littlefs
635e1fe8d4
This sort of turned into a complete refactor of lfs_alloc in order to
move/reuse the lookahead buffer filling logic into lfsr_fs_traverse.
lfs_alloc now calls lfsr_fs_traverse to fill the lookahead buffer when
no more blocks are available, but also you can too with lfsr_traversal_t
+ LFS_T_LOOKAHEAD.
The one big caveat being if any mutation happens to the filesystem, any
incomplete lookahead needs to be tossed out. To help with this,
lfsr_traversal_read now returns LFS_ERR_BUSY (-16) instead of
LFS_ERR_NOENT (-2) if the filesystem has been modified since the
traversal was opened.
Note that by default lfsr_traversal_t will still try to keep traversing
blocks, but can be told to terminate immediately with LFS_T_EXCL.
Continuing the traversal is probably desired for checking checksums,
debugging, etc, as otherwise you could end up looping over only the
first couple blocks in a write-heavy system, but if you are trying to
populate the lookahead buffer you probably want to just abort and start
over.
I considered adding a flags field to lfs_tinfo for this, but decided
against it since it would be the only place in the current API where we
don't use error codes to convey behavior-changing information. Though
this may be worth reconsidering at some point...
---
In reworking lfs_alloc, a lot of the internal logic was broken up into
specific functions:
- lfs_alloc_ckpoint - checkpoint the allocator
- lfs_alloc_discard - discard any lookahead
- lfs_alloc_shift - discard/shift lookahead if progress can be made
- lfs_alloc_markinuse - mark a block as in-use
- lfs_alloc_markfree - mark any remaining blocks as free
- lfs_alloc_findnext - find the next free block in lookahead
If anything this probably makes lfs_alloc more readable, though the
original motivation was to allow lfsr_traversal_t to only shift/zero the
lookahead buffer if there's a chance we can make progress.
This was based on upstream work by opilat and myself.
Code changes:
code stack
before: 34226 2560
after: 34474 (+0.7%) 2552 (-0.3%)
98 lines
3.3 KiB
Python
Executable File
98 lines
3.3 KiB
Python
Executable File
#!/usr/bin/env python3
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ERRS = [
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('OK', 0, "No error" ),
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('UNKNOWN', -1, "Unknown error" ),
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('INVAL', -22, "Invalid parameter" ),
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('NOTSUP', -95, "Operation not supported" ),
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('BUSY', -16, "Device or resource busy" ),
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('IO', -5, "Error during device operation" ),
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('CORRUPT', -84, "Corrupted" ),
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('NOENT', -2, "No directory entry" ),
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('EXIST', -17, "Entry already exists" ),
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('NOTDIR', -20, "Entry is not a dir" ),
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('ISDIR', -21, "Entry is a dir" ),
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('NOTEMPTY', -39, "Dir is not empty" ),
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('FBIG', -27, "File too large" ),
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('NOSPC', -28, "No space left on device" ),
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('NOMEM', -12, "No more memory available" ),
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('NOATTR', -61, "No data/attr available" ),
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('NAMETOOLONG', -36, "File name too long" ),
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('RANGE', -34, "Result out of range" ),
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]
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def main(errs, *,
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list=False):
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list_, list = list, __builtins__.list
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# list all known error codes
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if list_:
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# first find the widths
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w = [0, 0]
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for n, e, h in ERRS:
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w[0] = max(w[0], len('LFS_ERR_')+len(n))
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w[1] = max(w[1], len(str(e)))
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# print
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for n, e, h in ERRS:
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print('%-*s %-*s %s' % (
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w[0], 'LFS_ERR_'+n,
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w[1], e,
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h))
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# find these errors
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else:
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def find_err(err):
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# find by LFS_ERR_+name
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for n, e, h in ERRS:
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if 'LFS_ERR_'+n == err:
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return n, e, h
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# find by name
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for n, e, h in ERRS:
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if n == err:
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return n, e, h
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# find by E+name
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for n, e, h in ERRS:
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if 'E'+n == err:
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return n, e, h
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try:
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# find by err code
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for n, e, h in ERRS:
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if e == int(err, 0):
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return n, e, h
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# find by negated err code
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for n, e, h in ERRS:
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if e == -int(err, 0):
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return n, e, h
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except ValueError:
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pass
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# not found
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raise KeyError(err)
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for err in errs:
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try:
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n, e, h = find_err(err)
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print('%s %s %s' % ('LFS_ERR_'+n, e, h))
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except KeyError:
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print('%s ?' % err)
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if __name__ == "__main__":
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import argparse
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import sys
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parser = argparse.ArgumentParser(
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description="Decode littlefs error codes.",
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allow_abbrev=False)
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parser.add_argument(
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'errs',
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nargs='*',
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help="Error codes or error names to decode.")
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parser.add_argument(
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'-l', '--list',
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action='store_true',
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help="List all known error codes.")
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sys.exit(main(**{k: v
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for k, v in vars(parser.parse_intermixed_args()).items()
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if v is not None}))
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