* Simplify EINTR/ECANCEL error handling
1. Add semaphore uninterruptible wait function
2 .Replace semaphore wait loop with a single uninterruptible wait
3. Replace all sem_xxx to nxsem_xxx
* Unify the void cast usage
1. Remove void cast for function because many place ignore the returned value witout cast
2. Replace void cast for variable with UNUSED macro
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.
FAT. Effectively handles the situation when a new file position is within the current sector.
* Find begin of the next token
* EOL
* revert
* Accelerates the work of the FS with a multitude of operations to write small pieces of data within the current sector.
Approved-by: Gregory Nutt <gnutt@nuttx.org>
Squashed commit of the following:
fs/fat: Resolves issues with truncating the cluster chain when shrinking files via ftruncate().
fs/fat: First cut at implementation file shrinkage logic needed to support ftruncate(). Certainly shrinks the file size but it does not appear to correctly disconnect the cluster chains.
fs/fat: Restructure some functions in files to better support forthcoming file shrinkage logic. Put framework for file shrinkage in place. That logic is incomplete on initial commit.
fs/nxffs: Add partial implementation of the truncate method: It extend files, but cannot yet shrink them.
fs/smartfs: Add partial implementation of the truncate method: It extend files, but cannot yet shrink them.
fs/fat: Add partial implementation of the truncate method: It extend files, but no yet shrink them.
fs/nfs: Add support for the truncate method to the NFS file system.
fs: Add truncate() support for userfs
fs/unionfs: Add truncate() support to the unionfs
fs/tmpfs: Add ftruncate() support to tmpfs
syscall/: Add system call support for ftruncate()
net/route: Adding ftruncate() support eliminates an issue in file-based routing table management.
fs: Add basic framework to support truncate() and ftruncate(). The infrastructure is complete. Now, however, the actual implementation of ftruncate() will have to be done for each file system.
sched/semaphore: Add nxsem_post() which is identical to sem_post() except that it never modifies the errno variable. Changed all references to sem_post in the OS to nxsem_post().
sched/semaphore: Add nxsem_destroy() which is identical to sem_destroy() except that it never modifies the errno variable. Changed all references to sem_destroy() in the OS to nxsem_destroy().
libc/semaphore and sched/semaphore: Add nxsem_getprotocol() and nxsem_setprotocola which are identical to sem_getprotocol() and set_setprotocol() except that they never modifies the errno variable. Changed all references to sem_setprotocol in the OS to nxsem_setprotocol(). sem_getprotocol() was not used in the OS
libc/semaphore: Add nxsem_getvalue() which is identical to sem_getvalue() except that it never modifies the errno variable. Changed all references to sem_getvalue in the OS to nxsem_getvalue().
sched/semaphore: Rename all internal private functions from sem_xyz to nxsem_xyz. The sem_ prefix is (will be) reserved only for the application semaphore interfaces.
libc/semaphore: Add nxsem_init() which is identical to sem_init() except that it never modifies the errno variable. Changed all references to sem_init in the OS to nxsem_init().
sched/semaphore: Rename sem_tickwait() to nxsem_tickwait() so that it is clear this is an internal OS function.
sched/semaphoate: Rename sem_reset() to nxsem_reset() so that it is clear this is an internal OS function.
