MAVFTP defines @MAV_LOG as the flight-stack-independent location for log
files, so that a GCS can find them without being told where a particular
board keeps them. QGroundControl asks for it before anything else, and
falls back to guessing per-firmware paths when it is not there.
It is an alias rather than a filesystem of its own: the backend table
gains a root, and where a row carries one the resolver rewrites a path
under that prefix to sit under that directory before handing it to the
filesystem which serves it. @MAV_LOG points at the local filesystem, under
whatever directory this board logs to, following a custom log directory
the same way AP_Logger_File does.
The rewritten path has to hold the root as well as the path, so the buffer
is sized for the longest path an FTP listing stats - the longest path a
request can carry, a separator and a 255 byte name - underneath the longest
log directory a board has, and a static_assert holds boards to that. A
path too long to rewrite is refused with ENAMETOOLONG before any filesystem
sees it, rather than being truncated into the name of some other file.
That buffer is not on the stack, where every path-based call would pay for
it. It is allocated the first time an alias is used and kept, and a
semaphore is held around each backend call which uses it. rename, the one
call with two paths alive at once, allocates a second buffer for its new
path and frees it afterwards. Paths which are not aliases take neither the
semaphore nor a buffer.
An alias can't sit on LittleFS for now, and @MAV_LOG is not built where
LittleFS is the local filesystem; forcing it on is a build error. LittleFS
holds its lock from opendir() to closedir(), so the semaphore, held across
each call, would be released before that lock, which ChibiOS mutexes do not
allow, and a thread listing an alias directory would wait for the semaphore
while holding the lock another thread holding the semaphore could be
waiting for.
rename now compares the filesystems which serve its two paths rather than
their table rows, since an alias shares its filesystem with other paths,
and sets EXDEV when they differ.
A prefix now has to be the whole of a path's first component, so that
"@MAV_LOG_backup" is not served as "_backup" under the log directory. This
is not particular to the alias: "@SYSfoo" used to be served by @SYS as
"foo", and is now the local file of that name. Nothing in the tree relied
on the old behaviour.
@MAV_LOG, and the alias support with it, is only built where the logs go
to a filesystem at all.
buflen now includes the space required for the null terminator, so up
to buflen-1 characters are returned. Previously fgets could write
buf[buflen], one byte beyond the caller-nominated length. All
in-tree callers passed sizeof(buf)-1 to compensate, but
posix_compat's apfs_fgets forwards its C-style size argument
directly, so a caller supplying a size-byte buffer could have that
buffer overrun by one byte on an over-long line.
Update callers to pass the full buffer size; usable capacity is
unchanged.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
use correct read status for nor flash
implement format on littlefs
optimize device calls in littlefs flash usage
check for fileops allowed in littlefs
littlefs optimization and support for mtime
normally fgets is on a buffered FILE handle. For AP_Filesystem we use
an unbuffered file descriptor. This means we were reading one byte at
a time from the file
this uses lseek to make fgets() much more efficient by reading the max
buffer size at a time in the file
Improves safety of use and clarity of users. Termination is not
included in the reported size to avoid changing user behavior or
misrepresenting the file contents.
Adds virtual directory entries for these virtual filesystems in /
RTL> ftp list
RTL> Listing /
D @MISSION
D @PARAM
D @ROMFS
D @SYS
D APM
D log
V5_BT.dfu 10541
bootlog.txt 297
dataman 350216
message-intervals-chan0.txt 7
Total size 352.60 kByte
ftp list @MISSION
RTL> Listing @MISSION
LIST: OP seq:7 sess:2 opcode:129 req_opcode:3 size:2 bc:0 ofs:0 plen=2 [2]
ftp list @ROMFS
RTL> Listing @ROMFS
bootloader.bin 16448
hwdef.dat 5743
io_firmware.bin 40880
Total size 61.59 kByte
This PR also makes us *much* more lenient in what we accept for looking at virtual filesystems, so
ftp list @SYS
ftp list /@SYS
ftp list @SYS/
ftp list /@SYS/
should all work
these are causing some boards to crash on startup. Tested with a
QiotekZealotH743 which doesn't get out of setup_usb_strings()
once we have debugged this we can re-add the functionality
Peter Barker
Thomas Watson
Andy Piper
Iampete1
Andrew Tridgell
bugobliterator
Willian Galvani
Buzz