Add and use rtems_blkdev_request_done(). Block device transfer requests
must signal the completion status now with rtems_blkdev_request_done().
The return value of the block device IO control will be ignored for
transfer requests.
The first parameter of rtems_blkdev_request_cb is now the transfer
request structure.
Renamed rtems_blkdev_request::req_done to rtems_blkdev_request::done to
break third party drivers at compile time, otherwise this API change
would result in runtime errors.
The set block size must synchronize and purge the disk to avoid an
inconsistent cache state and data corruption. The synchronization is
optional depending on the new sync parameter. In some contexts a
synchronization must not be performed, e.g. during disk creation.
In case the read-ahead task is not configured we must not send a wake-up
event. This would send the wake-up event to the executing task.
We must send the wake-up event only in case the request list changes
from empty to non-empty. Since otherwise we may send a false transfer
event.
In case the read-ahead task has a higher priority than the reading task,
this ensures that the read-ahead request is issued after the read miss
is serviced.
Read-ahead requests were previously executed in the context of the
reading task. This blocks the reading task until the complete read
with read-ahead transfer is finished. A read-ahead task is introduced
to off-load the read-ahead transfer. This allows the reading task to
work with the requested block more quickly. The read-ahead is triggered
after two misses of ascending consecutive blocks or a read hit of a
block read by the most-recent read-ahead transfer. The read-ahead
feature is configurable and can be disabled.
It is now the responsibility of the read() and write() handler to update
the offset field of the IO descriptor (rtems_libio_t). This change
makes it possible to protect the IO descriptor from concurrent access by
per file locks.
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.
According to POSIX the lseek() function shall not, by itself, extend the
size of a file.
Remove the size field of rtems_libio_t. A file has only one size but
may have multiple open file descriptors. Thus a file size field in the
file descriptor may lead to inconsistencies.
New default handlers rtems_filesystem_default_lseek_file() and
rtems_filesystem_default_lseek_directory().
Do not use the unavailable block count as the erased blocks starvation
threshold. Use instead the block count of the largest segment. This
improves the starvation resolution gain of available blocks.
The new function rtems_bdbuf_set_block_size() must be used to set the
block size of a disk device. It will check if the block size is valid
and set the new fields block_to_media_block_shift and bds_per_group of
the rtems_disk_device structure. This helps to avoid complex arithmetic
operations in the block device buffer get and read path.
The compaction process needs erased blocks. It is only possible to
erase an entire segment. Thus in order to make a progress we always
need enough erased blocks to empty a used or available segment which can
be erased in turn. A (possibly the worst case) lower bound of erased
blocks is the block count of the largest segment. The number of
unavailable blocks specified by the configuration will be used to
determine the erase blocks starvation situation. The number of
unavailable blocks must be greater than or equal to the number of blocks
in the largest segment.
The functions
o rtems_bdbuf_get(),
o rtems_bdbuf_read(),
o rtems_bdbuf_syncdev(), and
o rtems_bdbuf_purge_dev(),
use now the disk device instead of the device identifier. This makes
bdbuf independent of rtems_disk_obtain() and rtems_disk_release(). It
is the responsiblity of the file system to obtain the disk device. This
also reduces the overhead to get a buffer.
The key for the AVL tree uses now the disk device instead of the device
identifier. The pointer is interpreted as an unsigned integer. This
reduces the memory overhead and makes the comparison operation a bit
faster.
Removed function rtems_bdbuf_purge_major(). This function was too
destructive and could have unpredictable side effects.
