The readv() and writev() support was implemented in terms of multiple
calls to the read and write handlers. This imposes a problem on device
files which use an IO vector as single request entity. For example a
low-level network device (e.g. BPF(4)) may use an IO vector to create
one frame from multiple protocol layers each with its own IO vector
entry.
Show the correct index of partition's last block (partition end).
The documentation of struct rtems_bdpart_partition (P) says that the member
'end' is the "Block index for partition end (this block is not a part of the
partition)". Then, the fdisk's partition table dump should print ((P)->end -
1).
Currently, one can think that the last block of a partition P is superposing
the beginning of the partition (P + 1). Example:
----------------------------------------
PARTITION TABLE
------------+------------+--------------
BEGIN | END | TYPE
------------+------------+--------------
2048 | 133120 | FAT 32
133120 | 15628032 | FAT 32
------------+------------+--------------
With be proposed patch, it would be:
----------------------------------------
PARTITION TABLE
------------+------------+--------------
BEGIN | END | TYPE
------------+------------+--------------
2048 | 133119 | FAT 32
133120 | 15628031 | FAT 32
------------+------------+--------------
All resource allocations take place in rtems_bdbuf_init() now. After
rtems_bdbuf_init() no fatal errors can happen due to configuration
errors or resource limits. This makes it easier to detect
configuration errors for users.
Add rtems_bdbuf_fatal_code as a replacement for the previous fatal error
codes. Remove unused error codes. Add new error codes. Use
rtems_fatal() with RTEMS_FATAL_SOURCE_BDBUF as source.
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.
