forked from Imagelibrary/littlefs
09c3749d7a
This changes how we approach unknown file types.
Before:
> Unknown file types are allowed and may leak resources if modified,
> so attempted modification (rename/remove) will error with
> LFS_ERR_NOTSUP.
Now:
> Unknown file types are only allowed in RDONLY mode. This avoids the
> whole leaking resources headache.
Additionally, unknown types are now mapped to LFS_TYPE_UNKNOWN, instead
of just being forwarded to the user. This allows us to add internal
types/tags to the LFSR_TAG_NAME type space without worrying about
conflicts with future types:
- reg -> LFS_TYPE_REG
- dir -> LFS_TYPE_DIR
- stickynote -> LFS_TYPE_STICKYNOTE
- everything else -> LFS_TYPE_UNKNOWN
Thinking about potential future types, it seems most (symlinks,
compressed files, etc) can be better implemented via custom attributes.
Using custom attributes doesn't mean the filesystem _can't_ inject
special behavior, and custom attributes allow for perfect backwards
compatibility.
So with future types less likely, forwarding type info to users is less
important (and potentially error prone). Instead, allowing on-disk +
internal types to be represented densely is much more useful.
And it avoids setting an upper bound on future types prematurely.
---
This also includes a minor rcompat/wcompat rework. Since we're probably
going to end up with 32-bit rcompat flags anyways, might as well make
them more human-readable (nibble-aligned):
LFS_RCOMPAT_NONSTANDARD 0x00000001 Non-standard filesystem format
LFS_RCOMPAT_WRONLY 0x00000002 Reading is disallowed
LFS_RCOMPAT_BMOSS 0x00000010 Files may use inlined data
LFS_RCOMPAT_BSPROUT 0x00000020 Files may use block pointers
LFS_RCOMPAT_BSHRUB 0x00000040 Files may use inlined btrees
LFS_RCOMPAT_BTREE 0x00000080 Files may use btrees
LFS_RCOMPAT_MMOSS 0x00000100 May use an inlined mdir
LFS_RCOMPAT_MSPROUT 0x00000200 May use an mdir pointer
LFS_RCOMPAT_MSHRUB 0x00000400 May use an inlined mtree
LFS_RCOMPAT_MTREE 0x00000800 May use an mdir btree
LFS_RCOMPAT_GRM 0x00001000 Global-remove in use
LFS_WCOMPAT_NONSTANDARD 0x00000001 Non-standard filesystem format
LFS_WCOMPAT_RDONLY 0x00000002 Writing is disallowed
LFS_WCOMPAT_REG 0x00000010 Regular file types in use
LFS_WCOMPAT_DIR 0x00000020 Directory file types in use
LFS_WCOMPAT_STICKYNOTE 0x00000040 Stickynote file types in use
LFS_WCOMPAT_GCKSUM 0x00001000 Global-checksum in use
---
Code changes:
code stack ctx
before: 35928 2440 640
after: 35924 (-0.0%) 2440 (+0.0%) 640 (+0.0%)
356 lines
16 KiB
Python
Executable File
356 lines
16 KiB
Python
Executable File
#!/usr/bin/env python3
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# prevent local imports
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if __name__ == "__main__":
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__import__('sys').path.pop(0)
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import collections as co
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ALIASES = [
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{'O', 'OPEN'},
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{'A', 'ATTR'},
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{'F', 'FORMAT'},
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{'M', 'MOUNT'},
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{'GC'},
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{'I', 'INFO'},
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{'T', 'TRAVERSAL'},
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{'RC', 'RCOMPAT'},
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{'WC', 'WCOMPAT'},
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{'OC', 'OCOMPAT'}
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]
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FLAGS = [
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# File open flags
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('O', 'MODE', 3, "The file's access mode" ),
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('^', 'RDONLY', 0, "Open a file as read only" ),
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('^', 'WRONLY', 1, "Open a file as write only" ),
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('^', 'RDWR', 2, "Open a file as read and write" ),
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('O', 'CREAT', 0x00000004, "Create a file if it does not exist" ),
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('O', 'EXCL', 0x00000008, "Fail if a file already exists" ),
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('O', 'TRUNC', 0x00000010, "Truncate the existing file to zero size" ),
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('O', 'APPEND', 0x00000020, "Move to end of file on every write" ),
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('O', 'FLUSH', 0x00000040, "Flush data on every write" ),
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('O', 'SYNC', 0x00000080, "Sync metadata on every write" ),
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('O', 'DESYNC', 0x00000100, "Do not sync or recieve file updates" ),
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('O', 'CKMETA', 0x00100000, "Check metadata checksums" ),
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('O', 'CKDATA', 0x00200000, "Check metadata + data checksums" ),
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('o', 'TYPE', 0xf0000000, "The file's type" ),
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('^', 'REG', 0x10000000, "Type = regular-file" ),
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('^', 'DIR', 0x20000000, "Type = directory" ),
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('^', 'STICKYNOTE',0x30000000, "Type = stickynote" ),
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('^', 'BOOKMARK', 0x40000000, "Type = bookmark" ),
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('^', 'TRAVERSAL', 0x50000000, "Type = traversal" ),
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('^', 'UNKNOWN', 0x60000000, "Type = unknown" ),
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('o', 'UNFLUSH', 0x01000000, "File's data does not match disk" ),
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('o', 'UNSYNC', 0x02000000, "File's metadata does not match disk" ),
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('o', 'UNCREAT', 0x04000000, "File does not exist yet" ),
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('o', 'ZOMBIE', 0x08000000, "File has been removed" ),
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# Custom attribute flags
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('A', 'MODE', 3, "The attr's access mode" ),
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('^', 'RDONLY', 0, "Open an attr as read only" ),
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('^', 'WRONLY', 1, "Open an attr as write only" ),
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('^', 'RDWR', 2, "Open an attr as read and write" ),
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('A', 'LAZY', 0x04, "Only write attr if file changed" ),
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# Filesystem format flags
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('F', 'MODE', 1, "Format's access mode" ),
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('^', 'RDWR', 0, "Format the filesystem as read and write" ),
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('F', 'REVDBG', 0x00000010, "Add debug info to revision counts" ),
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('F', 'REVNOISE', 0x00000020, "Add noise to revision counts" ),
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('F', 'CKPROGS', 0x00000800, "Check progs by reading back progged data" ),
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('F', 'CKFETCHES', 0x00001000, "Check block checksums before first use" ),
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('F', 'CKPARITY', 0x00002000, "Check metadata tag parity bits" ),
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('F', 'CKDATACKSUMS',
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0x00008000, "Check data checksums on reads" ),
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('F', 'CKMETA', 0x00100000, "Check metadata checksums" ),
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('F', 'CKDATA', 0x00200000, "Check metadata + data checksums" ),
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# Filesystem mount flags
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('M', 'MODE', 1, "Mount's access mode" ),
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('^', 'RDWR', 0, "Mount the filesystem as read and write" ),
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('^', 'RDONLY', 1, "Mount the filesystem as read only" ),
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('M', 'FLUSH', 0x00000040, "Open all files with LFS_O_FLUSH" ),
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('M', 'SYNC', 0x00000080, "Open all files with LFS_O_SYNC" ),
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('M', 'REVDBG', 0x00000010, "Add debug info to revision counts" ),
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('M', 'REVNOISE', 0x00000020, "Add noise to revision counts" ),
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('M', 'CKPROGS', 0x00000800, "Check progs by reading back progged data" ),
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('M', 'CKFETCHES', 0x00001000, "Check block checksums before first use" ),
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('M', 'CKPARITY', 0x00002000, "Check metadata tag parity bits" ),
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('M', 'CKDATACKSUMS',
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0x00008000, "Check data checksums on reads" ),
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('M', 'MKCONSISTENT',
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0x00010000, "Make the filesystem consistent" ),
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('M', 'LOOKAHEAD', 0x00020000, "Populate lookahead buffer" ),
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('M', 'COMPACT', 0x00080000, "Compact metadata logs" ),
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('M', 'CKMETA', 0x00100000, "Check metadata checksums" ),
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('M', 'CKDATA', 0x00200000, "Check metadata + data checksums" ),
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# GC flags
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('GC', 'MKCONSISTENT',
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0x00010000, "Make the filesystem consistent" ),
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('GC', 'LOOKAHEAD',0x00020000, "Populate lookahead buffer" ),
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('GC', 'COMPACT', 0x00080000, "Compact metadata logs" ),
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('GC', 'CKMETA', 0x00100000, "Check metadata checksums" ),
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('GC', 'CKDATA', 0x00200000, "Check metadata + data checksums" ),
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# Filesystem info flags
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('I', 'RDONLY', 0x00000001, "Mounted read only" ),
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('I', 'FLUSH', 0x00000040, "Mounted with LFS_M_FLUSH" ),
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('I', 'SYNC', 0x00000080, "Mounted with LFS_M_SYNC" ),
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('I', 'REVDBG', 0x00000010, "Mounted with LFS_M_REVDBG" ),
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('I', 'REVNOISE', 0x00000020, "Mounted with LFS_M_REVNOISE" ),
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('I', 'CKPROGS', 0x00000800, "Mounted with LFS_M_CKPROGS" ),
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('I', 'CKFETCHES', 0x00001000, "Mounted with LFS_M_CKFETCHES" ),
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('I', 'CKPARITY', 0x00002000, "Mounted with LFS_M_CKPARITY" ),
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('I', 'CKDATACKSUMS',
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0x00008000, "Mounted with LFS_M_CKDATACKSUMS" ),
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('I', 'MKCONSISTENT',
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0x00010000, "Filesystem needs mkconsistent to write" ),
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('I', 'LOOKAHEAD', 0x00020000, "Lookahead buffer is not full" ),
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('I', 'COMPACT', 0x00080000, "Filesystem may have uncompacted metadata" ),
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('I', 'CKMETA', 0x00100000, "Metadata checksums not checked recently" ),
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('I', 'CKDATA', 0x00200000, "Data checksums not checked recently" ),
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('i', 'INMTREE', 0x01000000, "Committing to mtree" ),
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# Traversal flags
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('T', 'MTREEONLY', 0x00000010, "Only traverse the mtree" ),
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('T', 'MKCONSISTENT',
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0x00010000, "Make the filesystem consistent" ),
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('T', 'LOOKAHEAD', 0x00020000, "Populate lookahead buffer" ),
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('T', 'COMPACT', 0x00080000, "Compact metadata logs" ),
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('T', 'CKMETA', 0x00100000, "Check metadata checksums" ),
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('T', 'CKDATA', 0x00200000, "Check metadata + data checksums" ),
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('t', 'TYPE', 0xf0000000, "The file's type" ),
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('^', 'REG', 0x10000000, "Type = regular-file" ),
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('^', 'DIR', 0x20000000, "Type = directory" ),
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('^', 'STICKYNOTE',0x30000000, "Type = stickynote" ),
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('^', 'BOOKMARK', 0x40000000, "Type = bookmark" ),
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('^', 'TRAVERSAL', 0x50000000, "Type = traversal" ),
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('^', 'UNKNOWN', 0x60000000, "Type = unknown" ),
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('t', 'TSTATE', 0x0000000f, "The traversal's current tstate" ),
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('^', 'MROOTANCHOR',
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0x00000000, "Tstate = mroot-anchor" ),
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('^', 'MROOTCHAIN',0x00000001, "Tstate = mroot-chain" ),
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('^', 'MTREE', 0x00000002, "Tstate = mtree" ),
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('^', 'MDIRS', 0x00000003, "Tstate = mtree-mdirs" ),
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('^', 'MDIR', 0x00000004, "Tstate = mdir" ),
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('^', 'BTREE', 0x00000005, "Tstate = btree" ),
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('^', 'OMDIRS', 0x00000006, "Tstate = open-mdirs" ),
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('^', 'OBTREE', 0x00000007, "Tstate = open-btree" ),
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('^', 'DONE', 0x00000008, "Tstate = done" ),
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('t', 'BTYPE', 0x00000f00, "The traversal's current btype" ),
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('^', 'MDIR', 0x00000100, "Btype = mdir" ),
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('^', 'BTREE', 0x00000200, "Btype = btree" ),
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('^', 'DATA', 0x00000300, "Btype = data" ),
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('t', 'DIRTY', 0x01000000, "Filesystem modified during traversal" ),
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('t', 'MUTATED', 0x02000000, "Filesystem modified by traversal" ),
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('t', 'ZOMBIE', 0x08000000, "File has been removed" ),
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# Read-compat flags
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('RCOMPAT', 'NONSTANDARD',
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0x00000001, "Non-standard filesystem format" ),
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('RCOMPAT', 'WRONLY',
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0x00000002, "Reading is disallowed" ),
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('RCOMPAT', 'BMOSS',
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0x00000010, "Files may use inlined data" ),
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('RCOMPAT', 'BSPROUT',
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0x00000020, "Files may use block pointers" ),
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('RCOMPAT', 'BSHRUB',
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0x00000040, "Files may use inlined btrees" ),
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('RCOMPAT', 'BTREE',
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0x00000080, "Files may use btrees" ),
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('RCOMPAT', 'MMOSS',
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0x00000100, "May use an inlined mdir" ),
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('RCOMPAT', 'MSPROUT',
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0x00000200, "May use an mdir pointer" ),
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('RCOMPAT', 'MSHRUB',
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0x00000400, "May use an inlined mtree" ),
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('RCOMPAT', 'MTREE',
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0x00000800, "May use an mdir btree" ),
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('RCOMPAT', 'GRM',
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0x00001000, "Global-remove in use" ),
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('rcompat', 'OVERFLOW',
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0x80000000, "Can't represent all flags" ),
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# Write-compat flags
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('WCOMPAT', 'NONSTANDARD',
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0x00000001, "Non-standard filesystem format" ),
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('WCOMPAT', 'RDONLY',
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0x00000002, "Writing is disallowed" ),
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('WCOMPAT', 'REG',
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0x00000010, "Regular file types in use" ),
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('WCOMPAT', 'DIR',
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0x00000020, "Directory file types in use" ),
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('WCOMPAT', 'STICKYNOTE',
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0x00000040, "Stickynote file types in use" ),
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('WCOMPAT', 'GCKSUM',
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0x00001000, "Global-checksum in use" ),
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('wcompat', 'OVERFLOW',
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0x80000000, "Can't represent all flags" ),
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# Optional-compat flags
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('OCOMPAT', 'NONSTANDARD',
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0x00000001, "Non-standard filesystem format" ),
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('ocompat', 'OVERFLOW',
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0x80000000, "Can't represent all flags" ),
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]
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def main(flags, *,
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list=False,
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all=False):
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list_ = list; del list
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all_ = all; del all
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# first compile prefixes
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prefixes = {}
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for a in ALIASES:
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for k in a:
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prefixes[k] = a
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for p, n, f, h in FLAGS:
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if p not in prefixes:
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prefixes[p] = {p}
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# only look at specific prefix?
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flags_ = []
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prefix = set()
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for f in flags:
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# accept prefix prefix
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if f.upper() in prefixes:
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prefix.update(prefixes[f.upper()])
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# accept LFS_+prefix prefix
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elif (f.upper().startswith('LFS_')
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and f.upper()[len('LFS_'):] in prefixes):
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prefix.update(prefixes[f.upper()[len('LFS_'):]])
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else:
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flags_.append(f)
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# filter by prefix
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flags__ = []
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types__ = co.defaultdict(lambda: set())
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for p, n, f, h in FLAGS:
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if p == '^':
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p = last_p
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t = last_t
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types__[p].add(t)
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else:
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t = None
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last_p = p
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last_t = f
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if not prefix or p.upper() in prefix:
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flags__.append((p, t, n, f, h))
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lines = []
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# list all known flags
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if list_:
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for p, t, n, f, h in flags__:
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if not all_ and (t is not None or p[0].islower()):
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continue
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lines.append(('LFS_%s_%s' % (p, n), '0x%08x' % f, h))
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# find flags by name or value
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else:
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for f_ in flags_:
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found = False
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# find by LFS_+prefix+_+name
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for p, t, n, f, h in flags__:
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if 'LFS_%s_%s' % (p, n) == f_.upper():
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lines.append(('LFS_%s_%s' % (p, n), '0x%08x' % f, h))
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found = True
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if found:
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continue
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# find by prefix+_+name
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for p, t, n, f, h in flags__:
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if '%s_%s' % (p, n) == f_.upper():
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lines.append(('LFS_%s_%s' % (p, n), '0x%08x' % f, h))
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found = True
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if found:
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continue
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# find by name
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for p, t, n, f, h in flags__:
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if n == f_.upper():
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lines.append(('LFS_%s_%s' % (p, n), '0x%08x' % f, h))
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found = True
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if found:
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continue
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# find by value
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try:
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f__ = int(f_, 0)
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f___ = f__
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for p, t, n, f, h in flags__:
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# ignore type masks here
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if t is None and f in types__[p]:
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continue
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# matches flag?
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if t is None and (f__ & f) == f:
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lines.append(('LFS_%s_%s' % (p, n), '0x%08x' % f, h))
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f___ &= ~f
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# matches type?
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elif t is not None and (f__ & t) == f:
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lines.append(('LFS_%s_%s' % (p, n), '0x%08x' % f, h))
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f___ &= ~t
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if f___:
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lines.append(('?', '0x%08x' % f___, 'Unknown flags'))
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except ValueError:
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lines.append(('?', f_, 'Unknown flag'))
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# first find widths
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w = [0, 0]
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for l in lines:
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w[0] = max(w[0], len(l[0]))
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w[1] = max(w[1], len(l[1]))
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# then print results
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for l in lines:
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print('%-*s %-*s %s' % (
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w[0], l[0],
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w[1], l[1],
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l[2]))
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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 flags.",
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allow_abbrev=False)
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class AppendFlags(argparse.Action):
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def __call__(self, parser, namespace, value, option):
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if getattr(namespace, 'flags', None) is None:
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namespace.flags = []
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if value is None:
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pass
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elif isinstance(value, str):
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namespace.flags.append(value)
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else:
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namespace.flags.extend(value)
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parser.add_argument(
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'prefix',
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nargs='?',
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action=AppendFlags,
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help="Flag prefix to consider, defaults to all flags.")
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parser.add_argument(
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'flags',
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nargs='*',
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action=AppendFlags,
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help="Flags or names of flags 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 flags.")
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parser.add_argument(
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'-a', '--all',
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action='store_true',
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help="Also show internal flags and types.")
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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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