This has been a long-time coming, mount flags are just too useful for
configuring a filesystem at runtime.
Currently this is limited to LFS_M_RDONLY and LFS_M_CKPROGS, but there
are a few more planned in the future:
LFS_M_RDWR = 0x0000, // Mount the filesystem as read and write
LFS_M_RDONLY = 0x0001, // Mount the filesystem as readonly
LFS_M_STRICT* = 0x0002, // Error if on-disk config does not match
LFS_M_FORCE* = 0x0004, // Ignore compat flags, mount readonly
LFS_M_FORCEWITHRECKLESSABANDON*
= 0x0008, // Ignore compat flags, mount read write
LFS_M_CKPROGS = 0x0010, // Check progs by reading back progged data
LFS_M_CKREADS* = 0x0020, // Check reads via checksums
* Hypothetical
As a convenience, we also return mount flags in the struct lfs_fsinfo's
flags field as their relevant LFS_I_* variants. Though only to match
statvfs, and only because it's cheap, littlefs's API is low-level and we
should expect users to know what flags they passed to lfsr_mount.
As for the new mount flags:
- LFS_M_RDONLY - For consistency with existing APIs, this just asserts
on write operations, which makes it a bit useless... But the info flag
LFS_I_RDONLY may be useful for falling back to a readonly mode if
we encounter on-disk compat issues.
At least if implement the theoretical LFS_UNTRUSTED_USER mode
LFS_M_RDONLY could become a runtime error.
- LFS_M_RDWR - This really just exists to compliment LFS_M_RDONLY and to
match LFS_O_RDONLY/LFS_O_RDWR. It's just an alias for 0, and I don't
think there will ever be a reason to make it non-0 (but I can always
be wrong!).
- LFS_M_CKPROGS - This replaces the check_progs config option and avoids
using a full byte to store a bool.
We should probably also have a compile-time option to compile this out
(LFS_NO_CKPROGS?), but that's a future thing to do.
This ended up adding a surprising bit of code, considering we're just
moving flags around, and noise in lfs_alloc added a bit of stack again:
code stack
before: 35880 2672
after: 35932 (+0.1%) 2680 (+0.3%)
Changed:
- lfsr_mkdir(&lfs, "/") => LFS_ERR_EXIST
- lfsr_file_open(&lfs, &file, "/", *) => LFS_ERR_ISDIR
Unchanged:
- lfsr_remove(&lfs, "/") => LFS_ERR_INVAL
- lfsr_rename(&lfs, "/", *) => LFS_ERR_INVAL
- lfsr_rename(&lfs, *, "/") => LFS_ERR_INVAL
This better matches what Linux, etc, does: prefering a normal
dir-related error unless the only issue is that the dir in question is
the root.
Though Linux, etc, usually return EBUSY, which seems to also be used for
special device files. We could add LFS_ERR_BUSY, but I'm not sure it's
really worth it for such a rare error. It's not like the name would help
anything...
Internally, lfsr_mtree_pathlookup always returns LFS_ERR_INVAL for root,
so this unfortunately requires a bit more code to map to the correct
errors:
code stack
before: 33598 2592
after 33634 (+0.1%) 2592 (+0.0%)
This makes it easier to evaluate the code/stack/etc sizes and run tests
without bringing in all of the outdated code.
I guess this officially makes this branch more-or-less a full rewrite,
though the benefit of commenting vs deleting this code is that it can be
easily pulled back in when useful.
The main benefit is small test ids everywhere, though this is with the
downside of needing longer names to properly prefix and avoid
collisions. But this fits into the rest of the scripts with globally
unique names a bit better. This is a C project after all.
The other small benefit is test generators may have an easier time since
per-case symbols can expect to be unique.
This mostly required names for each test case, declarations of
previously-implicit variables since the new test framework is more
conservative with what it declares (the small extra effort to add
declarations is well worth the simplicity and improved readability),
and tweaks to work with not-really-constant defines.
Also renamed test_ -> test, replacing the old ./scripts/test.py,
unfortunately git seems to have had a hard time with this.
- Added caching to Travis install dirs, because otherwise
pip3 install fails randomly
- Increased size of littlefs-fuse disk because test script has
a larger footprint now
- Skip a couple of reentrant tests under byte-level writes because
the tests just take too long and cause Travis to bail due to no
output for 10m
- Fixed various Valgrind errors
- Suppressed uninit checks for tests where LFS_BLOCK_ERASE_VALUE == -1.
In this case rambd goes uninitialized, which is fine for rambd's
purposes. Note I couldn't figure out how to limit this suppression
to only the malloc in rambd, this doesn't seem possible with Valgrind.
- Fixed memory leaks in exhaustion tests
- Fixed off-by-1 string null-terminator issue in paths tests
- Fixed lfs_file_sync issue caused by revealed by fixing memory leaks
in exhaustion tests. Getting ENOSPC during a file write puts the file
in a bad state where littlefs doesn't know how to write it out safely.
In this case, lfs_file_sync and lfs_file_close return 0 without
writing out state so that device-side resources can still be cleaned
up. To recover from ENOSPC, the file needs to be reopened and the
writes recreated. Not sure if there is a better way to handle this.
- Added some quality-of-life improvements to Valgrind testing
- Fit Valgrind messages into truncated output when not in verbose mode
- Turned on origin tracking
- Removed old tests and test scripts
- Reorganize the block devices to live under one directory
- Plugged new test framework into Makefile
renamed:
- scripts/test_.py -> scripts/test.py
- tests_ -> tests
- {file,ram,test}bd/* -> bd/*
It took a surprising amount of effort to make the Makefile behave since
it turns out the "test_%" rule could override "tests/test_%.toml.test"
which is generated as part of test.py.
Christopher Haster