Squashed commit of the following:
Author: Gregory Nutt <gnutt@nuttx.org>
fs/littlefs: Fix some compilation errors.
fs/littlefs: Brings code a little closer to NuttX coding standard. Not 100%, but closer.
fs/littlefs: Convert all C++ style comments to C comments.
Author: lihaichen <li8303@163.com>
fs/littlefs: Adds port of the mbed littlefs.
depends on !DISABLE_MOUNTPOINT && MTD_BYTE_WRITE
register_mtddriver("/dev/w25", mtd, 0755, NULL);
mount("/dev/w25", "/w25", "littlefs", 0, NULL);
fs/procfs/fs_procfsproc: Extended the process ID ProcFS output to show per-thread maximum time for pre-emption disabled and maximum time within a critical section.
sched/sched/sched_critmonitor.c: Adds data collection logic in support of monitoring critical sections and pre-emption state.
I see the following behaviour on NuttX 7.26, where I have SD card mounted on /flash and a directory called "frm" on it:
opendir("/flash") returns (DIR *) 0x1000c580
opendir("/flash/") returns (DIR *) 0x1000c5d0
opendir("/flash/frm") returns (DIR *) 0x1000c620
opendir("/flash/frm/") returns (DIR *) 0x0
From POSIX specs for opendir(): "A pathname ... that ends with one or more trailing slashes shall be resolved as if a single dot character ( '.' ) were appended to the pathname."
So for mount points, opendir() works correctly, but for FAT32 filesystem it fails to open directory if the path has a trailing slash. I'm not quite sure how to cleanly fix this. Stripping the trailing slash in opendir() would require allocating a separate buffer, while fixing it in the FAT32 code seems somewhat complex due to the short/long filename logic.
It is not a big issue for me, I'm just going to fix it on the application side. But still a small portability and standards compliance issue.
NOTE: You would not see this problem if you call opendir() indirectly in NSH (like 'ls -R /') because NSH contains logic to remove trailing '/' characters from paths.
Pullreq FAT improvements
* NuttX: Add CONFIG_FAT_LFN_ALIAS_HASH to speed up creating long filenames.
Long filenames on FAT filesystems have associated 8.3 character alias
short filenames. The traditional form of these is FILENA~1.EXT with
a running count of the number of similar names. However creating this
unique count can take several seconds if there are many similarly named
files in the directory. Enabling FAT_LFN_ALIAS_HASH uses an alternative
format of FI0123~1.TXT where the four digits are a hash of the original
filename. This method is similar to what is used by Windows 2000 and
later.
* NuttX: Add CONFIG_FAT_LFN_ALIAS_TRAILCHARS alternative format for 8.3 filenames.
Traditional format for long filename 8.3 aliases takes first 6
characters of long filename. If this option is set to N > 0,
NuttX will instead take first 6-N and last N characters to form
the short name. This is useful for filenames like "datafile12.txt"
where the first characters would always remain the same.
* NuttX: FAT32: Fix file date corruption in fat_truncate().
* NuttX: if SD card wait seems to be a long one, give time for other threads to run.
Approved-by: GregoryN <gnutt@nuttx.org>
