Files
littlefs/scripts/dbgflags.py
Christopher Haster f967cad907 kv: Adopted LFS3_o_WRSET for better key-value API integration
This adds LFS3_o_WRSET as an internal-only 3rd file open mode (I knew
that missing open mode would come in handy) that has some _very_
interesting behavior:

- Do _not_ clear the configured file cache. The file cache is prefilled
  with the file's data.

- If the file does _not_ exist and is small, create it immediately in
  lfs3_file_open using the provided file cache.

- If the file _does_ exist or is not small, do nothing and open the file
  normally. lfs3_file_close/sync can do the rest of the work in one
  commit.

This makes it possible to implement one-commit lfs3_set on top of the
file APIs with minimal code impact:

- All of the metadata commit logic can be handled by lfs3_file_sync_, we
  just call lfs3_file_sync_ with the found did+name in lfs3_file_opencfg
  when WRSET.

- The invariant that lfs3_file_opencfg always reserves an mid remains
  intact, since we go ahead and write the full file if necessary,
  minimizing the impact on lfs3_file_opencfg's internals.

This claws back most of the code cost of the one-commit key-value API:

              code          stack          ctx
  before:    38232           2400          636
  after:     37856 (-1.0%)   2416 (+0.7%)  636 (+0.0%)

  before kv: 37352           2280          636
  after kv:  37856 (+1.3%)   2416 (+6.0%)  636 (+0.0%)

---

I'm quite happy how this turned out. I was worried there for a bit the
key-value API was going to end up an ugly wart for the internals, but
with LFS3_o_WRSET this integrates quite nicely.

It also raises a really interesting question, should LFS3_o_WRSET be
exposed to users?

For now I'm going to play it safe and say no. While potentially useful,
it's still a pretty unintuitive API.

Another thing worth mentioning is that this does have a negative impact
on compile-time gc. Duplication adds code cost when viewing the system
as a whole, but tighter integration can backfire if the user never calls
half the APIs.

Oh well, compile-time opt-out is always an option in the future, and
users seem to care more about pre-linked measurements, probably because
it's an easier thing to find. Still, it's funny how measuring code can
have a negative impact on code. Something something Goodhart's law.
2025-06-22 15:37:07 -05:00

364 lines
17 KiB
Python
Executable File

#!/usr/bin/env python3
# prevent local imports
if __name__ == "__main__":
__import__('sys').path.pop(0)
import collections as co
ALIASES = [
{'O', 'OPEN'},
{'A', 'ATTR'},
{'F', 'FORMAT'},
{'M', 'MOUNT'},
{'GC'},
{'I', 'INFO'},
{'T', 'TRAVERSAL'},
{'RC', 'RCOMPAT'},
{'WC', 'WCOMPAT'},
{'OC', 'OCOMPAT'}
]
FLAGS = [
# File open flags
('O', 'MODE', 3, "The file's access mode" ),
('^', 'RDONLY', 0, "Open a file as read only" ),
('^', 'WRONLY', 1, "Open a file as write only" ),
('^', 'RDWR', 2, "Open a file as read and write" ),
('O', 'CREAT', 0x00000004, "Create a file if it does not exist" ),
('O', 'EXCL', 0x00000008, "Fail if a file already exists" ),
('O', 'TRUNC', 0x00000010, "Truncate the existing file to zero size" ),
('O', 'APPEND', 0x00000020, "Move to end of file on every write" ),
('O', 'FLUSH', 0x00000040, "Flush data on every write" ),
('O', 'SYNC', 0x00000080, "Sync metadata on every write" ),
('O', 'DESYNC', 0x04000000, "Do not sync or recieve file updates" ),
('O', 'CKMETA', 0x00001000, "Check metadata checksums" ),
('O', 'CKDATA', 0x00002000, "Check metadata + data checksums" ),
('o', 'WRSET', 3, "Open a file as an atomic write" ),
('o', 'TYPE', 0xf0000000, "The file's type" ),
('^', 'REG', 0x10000000, "Type = regular-file" ),
('^', 'DIR', 0x20000000, "Type = directory" ),
('^', 'STICKYNOTE',0x30000000, "Type = stickynote" ),
('^', 'BOOKMARK', 0x40000000, "Type = bookmark" ),
('^', 'ORPHAN', 0x50000000, "Type = orphan" ),
('^', 'TRAVERSAL', 0x60000000, "Type = traversal" ),
('^', 'UNKNOWN', 0x70000000, "Type = unknown" ),
('o', 'ZOMBIE', 0x08000000, "File has been removed" ),
('o', 'UNCREAT', 0x02000000, "File does not exist yet" ),
('o', 'UNSYNC', 0x01000000, "File's metadata does not match disk" ),
('o', 'UNCRYST', 0x00800000, "File's leaf not fully crystallized" ),
('o', 'UNGRAFT', 0x00400000, "File's leaf does not match bshrub/btree" ),
('o', 'UNFLUSH', 0x00200000, "File's data does not match disk" ),
# Custom attribute flags
('A', 'MODE', 3, "The attr's access mode" ),
('^', 'RDONLY', 0, "Open an attr as read only" ),
('^', 'WRONLY', 1, "Open an attr as write only" ),
('^', 'RDWR', 2, "Open an attr as read and write" ),
('A', 'LAZY', 0x04, "Only write attr if file changed" ),
# Filesystem format flags
('F', 'MODE', 1, "Format's access mode" ),
('^', 'RDWR', 0, "Format the filesystem as read and write" ),
('F', 'REVDBG', 0x00000010, "Add debug info to revision counts" ),
('F', 'REVNOISE', 0x00000020, "Add noise to revision counts" ),
('F', 'CKPROGS', 0x00080000, "Check progs by reading back progged data" ),
('F', 'CKFETCHES', 0x00100000, "Check block checksums before first use" ),
('F', 'CKMETAPARITY',
0x00200000, "Check metadata tag parity bits" ),
('F', 'CKDATACKSUMREADS',
0x00800000, "Check data checksums on reads" ),
('F', 'CKMETA', 0x00001000, "Check metadata checksums" ),
('F', 'CKDATA', 0x00002000, "Check metadata + data checksums" ),
# Filesystem mount flags
('M', 'MODE', 1, "Mount's access mode" ),
('^', 'RDWR', 0, "Mount the filesystem as read and write" ),
('^', 'RDONLY', 1, "Mount the filesystem as read only" ),
('M', 'FLUSH', 0x00000040, "Open all files with LFS3_O_FLUSH" ),
('M', 'SYNC', 0x00000080, "Open all files with LFS3_O_SYNC" ),
('M', 'REVDBG', 0x00000010, "Add debug info to revision counts" ),
('M', 'REVNOISE', 0x00000020, "Add noise to revision counts" ),
('M', 'CKPROGS', 0x00080000, "Check progs by reading back progged data" ),
('M', 'CKFETCHES', 0x00100000, "Check block checksums before first use" ),
('M', 'CKMETAPARITY',
0x00200000, "Check metadata tag parity bits" ),
('M', 'CKDATACKSUMREADS',
0x00800000, "Check data checksums on reads" ),
('M', 'MKCONSISTENT',
0x00000100, "Make the filesystem consistent" ),
('M', 'LOOKAHEAD', 0x00000200, "Populate lookahead buffer" ),
('M', 'COMPACT', 0x00000800, "Compact metadata logs" ),
('M', 'CKMETA', 0x00001000, "Check metadata checksums" ),
('M', 'CKDATA', 0x00002000, "Check metadata + data checksums" ),
# GC flags
('GC', 'MKCONSISTENT',
0x00000100, "Make the filesystem consistent" ),
('GC', 'LOOKAHEAD',0x00000200, "Populate lookahead buffer" ),
('GC', 'COMPACT', 0x00000800, "Compact metadata logs" ),
('GC', 'CKMETA', 0x00001000, "Check metadata checksums" ),
('GC', 'CKDATA', 0x00002000, "Check metadata + data checksums" ),
# Filesystem info flags
('I', 'RDONLY', 0x00000001, "Mounted read only" ),
('I', 'FLUSH', 0x00000040, "Mounted with LFS3_M_FLUSH" ),
('I', 'SYNC', 0x00000080, "Mounted with LFS3_M_SYNC" ),
('I', 'REVDBG', 0x00000010, "Mounted with LFS3_M_REVDBG" ),
('I', 'REVNOISE', 0x00000020, "Mounted with LFS3_M_REVNOISE" ),
('I', 'CKPROGS', 0x00080000, "Mounted with LFS3_M_CKPROGS" ),
('I', 'CKFETCHES', 0x00100000, "Mounted with LFS3_M_CKFETCHES" ),
('I', 'CKMETAPARITY',
0x00200000, "Mounted with LFS3_M_CKMETAPARITY" ),
('I', 'CKDATACKSUMREADS',
0x00800000, "Mounted with LFS3_M_CKDATACKSUMREADS" ),
('I', 'MKCONSISTENT',
0x00000100, "Filesystem needs mkconsistent to write" ),
('I', 'LOOKAHEAD', 0x00000200, "Lookahead buffer is not full" ),
('I', 'COMPACT', 0x00000800, "Filesystem may have uncompacted metadata" ),
('I', 'CKMETA', 0x00001000, "Metadata checksums not checked recently" ),
('I', 'CKDATA', 0x00002000, "Data checksums not checked recently" ),
('i', 'INMTREE', 0x08000000, "Committing to mtree" ),
# Traversal flags
('T', 'MODE', 1, "The traversal's access mode" ),
('^', 'RDWR', 0, "Open traversal as read and write" ),
('^', 'RDONLY', 1, "Open traversal as read only" ),
('T', 'MTREEONLY', 0x00000002, "Only traverse the mtree" ),
('T', 'MKCONSISTENT',
0x00000100, "Make the filesystem consistent" ),
('T', 'LOOKAHEAD', 0x00000200, "Populate lookahead buffer" ),
('T', 'COMPACT', 0x00000800, "Compact metadata logs" ),
('T', 'CKMETA', 0x00001000, "Check metadata checksums" ),
('T', 'CKDATA', 0x00002000, "Check metadata + data checksums" ),
('t', 'TYPE', 0xf0000000, "The traversal's type" ),
('^', 'REG', 0x10000000, "Type = regular-file" ),
('^', 'DIR', 0x20000000, "Type = directory" ),
('^', 'STICKYNOTE',0x30000000, "Type = stickynote" ),
('^', 'BOOKMARK', 0x40000000, "Type = bookmark" ),
('^', 'ORPHAN', 0x50000000, "Type = orphan" ),
('^', 'TRAVERSAL', 0x60000000, "Type = traversal" ),
('^', 'UNKNOWN', 0x70000000, "Type = unknown" ),
('t', 'TSTATE', 0x000f0000, "The current traversal state" ),
('^', 'MROOTANCHOR',
0x00000000, "Tstate = mroot-anchor" ),
('^', 'MROOTCHAIN',0x00010000, "Tstate = mroot-chain" ),
('^', 'MTREE', 0x00020000, "Tstate = mtree" ),
('^', 'MDIRS', 0x00030000, "Tstate = mtree-mdirs" ),
('^', 'MDIR', 0x00040000, "Tstate = mdir" ),
('^', 'BTREE', 0x00050000, "Tstate = btree" ),
('^', 'OMDIRS', 0x00060000, "Tstate = open-mdirs" ),
('^', 'OBTREE', 0x00070000, "Tstate = open-btree" ),
('^', 'DONE', 0x00080000, "Tstate = done" ),
('t', 'BTYPE', 0x00f00000, "The current block type" ),
('^', 'MDIR', 0x00100000, "Btype = mdir" ),
('^', 'BTREE', 0x00200000, "Btype = btree" ),
('^', 'DATA', 0x00300000, "Btype = data" ),
('t', 'ZOMBIE', 0x08000000, "File has been removed" ),
('t', 'DIRTY', 0x02000000, "Filesystem modified during traversal" ),
('t', 'MUTATED', 0x01000000, "Filesystem modified by traversal" ),
# Read-compat flags
('RCOMPAT', 'NONSTANDARD',
0x00000001, "Non-standard filesystem format" ),
('RCOMPAT', 'WRONLY',
0x00000002, "Reading is disallowed" ),
('RCOMPAT', 'BMOSS',
0x00000010, "Files may use inlined data" ),
('RCOMPAT', 'BSPROUT',
0x00000020, "Files may use block pointers" ),
('RCOMPAT', 'BSHRUB',
0x00000040, "Files may use inlined btrees" ),
('RCOMPAT', 'BTREE',
0x00000080, "Files may use btrees" ),
('RCOMPAT', 'MMOSS',
0x00000100, "May use an inlined mdir" ),
('RCOMPAT', 'MSPROUT',
0x00000200, "May use an mdir pointer" ),
('RCOMPAT', 'MSHRUB',
0x00000400, "May use an inlined mtree" ),
('RCOMPAT', 'MTREE',
0x00000800, "May use an mdir btree" ),
('RCOMPAT', 'GRM',
0x00001000, "Global-remove in use" ),
('rcompat', 'OVERFLOW',
0x80000000, "Can't represent all flags" ),
# Write-compat flags
('WCOMPAT', 'NONSTANDARD',
0x00000001, "Non-standard filesystem format" ),
('WCOMPAT', 'RDONLY',
0x00000002, "Writing is disallowed" ),
('WCOMPAT', 'DIR',
0x00000010, "Directory file types in use" ),
('WCOMPAT', 'GCKSUM',
0x00001000, "Global-checksum in use" ),
('wcompat', 'OVERFLOW',
0x80000000, "Can't represent all flags" ),
# Optional-compat flags
('OCOMPAT', 'NONSTANDARD',
0x00000001, "Non-standard filesystem format" ),
('ocompat', 'OVERFLOW',
0x80000000, "Can't represent all flags" ),
]
def main(flags, *,
list=False,
all=False):
import builtins
list_, list = list, builtins.list
all_, all = all, builtins.all
# first compile prefixes
prefixes = {}
for a in ALIASES:
for k in a:
prefixes[k] = a
for p, n, f, h in FLAGS:
if p not in prefixes:
prefixes[p] = {p}
# only look at specific prefix?
flags_ = []
prefix = set()
for f in flags:
# accept prefix prefix
if f.upper() in prefixes:
prefix.update(prefixes[f.upper()])
# accept LFS3_+prefix prefix
elif (f.upper().startswith('LFS3_')
and f.upper()[len('LFS3_'):] in prefixes):
prefix.update(prefixes[f.upper()[len('LFS3_'):]])
else:
flags_.append(f)
# filter by prefix
flags__ = []
types__ = co.defaultdict(lambda: set())
for p, n, f, h in FLAGS:
if p == '^':
p = last_p
t = last_t
types__[p].add(t)
else:
t = None
last_p = p
last_t = f
if not prefix or p.upper() in prefix:
flags__.append((p, t, n, f, h))
lines = []
# list all known flags
if list_:
for p, t, n, f, h in flags__:
if not all_ and (t is not None or p[0].islower()):
continue
lines.append(('LFS3_%s_%s' % (p, n), '0x%08x' % f, h))
# find flags by name or value
else:
for f_ in flags_:
found = False
# find by LFS3_+prefix+_+name
for p, t, n, f, h in flags__:
if 'LFS3_%s_%s' % (p, n) == f_.upper():
lines.append(('LFS3_%s_%s' % (p, n), '0x%08x' % f, h))
found = True
if found:
continue
# find by prefix+_+name
for p, t, n, f, h in flags__:
if '%s_%s' % (p, n) == f_.upper():
lines.append(('LFS3_%s_%s' % (p, n), '0x%08x' % f, h))
found = True
if found:
continue
# find by name
for p, t, n, f, h in flags__:
if n == f_.upper():
lines.append(('LFS3_%s_%s' % (p, n), '0x%08x' % f, h))
found = True
if found:
continue
# find by value
try:
f__ = int(f_, 0)
f___ = f__
for p, t, n, f, h in flags__:
# ignore type masks here
if t is None and f in types__[p]:
continue
# matches flag?
if t is None and (f__ & f) == f:
lines.append(('LFS3_%s_%s' % (p, n), '0x%08x' % f, h))
f___ &= ~f
# matches type?
elif t is not None and (f__ & t) == f:
lines.append(('LFS3_%s_%s' % (p, n), '0x%08x' % f, h))
f___ &= ~t
if f___:
lines.append(('?', '0x%08x' % f___, 'Unknown flags'))
except ValueError:
lines.append(('?', f_, 'Unknown flag'))
# first find widths
w = [0, 0]
for l in lines:
w[0] = max(w[0], len(l[0]))
w[1] = max(w[1], len(l[1]))
# then print results
for l in lines:
print('%-*s %-*s %s' % (
w[0], l[0],
w[1], l[1],
l[2]))
if __name__ == "__main__":
import argparse
import sys
parser = argparse.ArgumentParser(
description="Decode littlefs flags.",
allow_abbrev=False)
class AppendFlags(argparse.Action):
def __call__(self, parser, namespace, value, option):
if getattr(namespace, 'flags', None) is None:
namespace.flags = []
if value is None:
pass
elif isinstance(value, str):
namespace.flags.append(value)
else:
namespace.flags.extend(value)
parser.add_argument(
'prefix',
nargs='?',
action=AppendFlags,
help="Flag prefix to consider, defaults to all flags.")
parser.add_argument(
'flags',
nargs='*',
action=AppendFlags,
help="Flags or names of flags to decode.")
parser.add_argument(
'-l', '--list',
action='store_true',
help="List all known flags.")
parser.add_argument(
'-a', '--all',
action='store_true',
help="Also show internal flags and types.")
sys.exit(main(**{k: v
for k, v in vars(parser.parse_intermixed_args()).items()
if v is not None}))