This patch is a newer version of the test presented on
http://www.rtems.org/pipermail/rtems-devel/2014-February/005318.html
Unchecked error cases:
- EIO (physical error)
- ENOSPC (no space left in the new filepath)
- EROFS (already covered on testsuites/fstests/fsrofs01)
Untested functionality:
- File system lock during rename() operation
- If after rename() the link count of a file becomes 0 it should be
removed and the space ocupied by the file shall be freed and no longer
accessible (the function statvfs() gives "not implemented" on the imfs
file system, so this is postponed for now)
Test handling of file names and directory names according to Microsofts
specification for the FAT file system. So far tested only for the
default character set (code page 850).
Script does what is expected and tries to do it as
smartly as possible.
+ remove occurrences of two blank comment lines
next to each other after Id string line removed.
+ remove entire comment blocks which only exited to
contain CVS Ids
+ If the processing left a blank line at the top of
a file, it was removed.
The fat_file_datasync() read every cluster of the file into the cache
and then synchronized it step-by-step. For unmodified buffers this is a
non-operation. For modified buffers this will wake-up the swapout task
which performs then a single buffer write operation. This is usually
quite inefficient. Firstly we do single buffer writes, secondly we
may perform a lot of unnecessary read operations (for huge files this is
really bad), and thirdly this leads likely to cache evictions.
The synchronization procedure is replaced by a simple
rtems_bdbuf_sync_dev(). This has the side-effect that also buffers not
related to the file are synchronized, but since the modified list is
normally short this should be acceptable.
Generic nodes are an alternative to standard drivers in RTEMS. The
handlers of a generic node are called with less overhead compared to the
standard driver operations. The usage of file system node handlers
enable more features like support for fsync() and fdatasync(). The
generic nodes use the reference counting of the IMFS. This provides
automatic node destruction when the last reference vanishes.
Extend type IMFS_types_union by new type IMFS_generic_t.
Extend enum IMFS_jnode_types_t by IMFS_GENERIC.
Add functions
o IMFS_make_generic_node(),
o IMFS_is_imfs_instance(),
o IMFS_generic_get_context_by_node(),
o IMFS_generic_get_context_by_location(), and
o IMFS_generic_get_context_by_iop().
New test fstests/fsimfsgeneric01.
o A new data structure rtems_filesystem_global_location_t was
introduced to be used for
o the mount point location in the mount table entry,
o the file system root location in the mount table entry,
o the root directory location in the user environment, and
o the current directory location in the user environment.
During the path evaluation global start locations are obtained to
ensure that the current file system instance will be not unmounted in
the meantime.
o The user environment uses now reference counting and is protected
from concurrent access.
o The path evaluation process was completely rewritten and simplified.
The IMFS, RFS, NFS, and DOSFS use now a generic path evaluation
method. Recursive calls in the path evaluation have been replaced
with iteration to avoid stack overflows. Only the evaluation of
symbolic links is recursive. No dynamic memory allocations and
intermediate buffers are used in the high level path evaluation. No
global locks are held during the file system instance specific path
evaluation process.
o Recursive symbolic link evaluation is now limited by
RTEMS_FILESYSTEM_SYMLOOP_MAX. Applications can retrieve this value
via sysconf().
o The device file system (devFS) uses now no global variables and
allocation from the workspace. Node names are allocated from the
heap.
o The upper layer lseek() performs now some parameter checks.
o The upper layer ftruncate() performs now some parameter checks.
o unmask() is now restricted to the RWX flags and protected from
concurrent access.
o The fchmod_h and rmnod_h file system node handlers are now a file
system operation.
o The unlink_h operation has been removed. All nodes are now destroyed
with the rmnod_h operation.
o New lock_h, unlock_h, clonenod_h, and are_nodes_equal_h file system
operations.
o The path evaluation and file system operations are now protected by
per file system instance lock and unlock operations.
o Fix and test file descriptor duplicate in fcntl().
o New test fstests/fsnofs01.
