There are some console messages printed by the early loading code, but these happen before the regular kernel printf code is initialized, so you can only see them if you enable "options EARLY_PRINTF" in your kernel config and also use "options UART_NS8250_EARLY_PORT=0x3f8" to set which serial port the early printf output should go to. (eg. the 0x3f8 in this example is com1). you also need to boot with "-v" to enable "bootverbose" messages for the ucode early load activity to be printed.

Updated diff for latest review comments.

move the code copied from cpucontrol to a new file so that we can share it between the kernel and cpucontrol.

I added the handling you requested for the loader blob containing all of the amd ucode files concatenated together.

updated patch with requested changes

I agree, this msgbuftrigger thing is rather loosey-goosey. I'm just trying to have all the msgbuf paths achieve a consistent level of loosey-gooseyness.

In D39246#894657, @mckusick wrote:

You have a very valid point. I addressed this by having just a single message come out when running with -p (preen mode). When encountering a filesystem with no depths it prints `UPDATING FILESYSTEM TO TRACK DIRECTORY DEPTH'' then updates all the directory depths. When running in interactive mode and -y mode it asks once `UPDATE FILESYSTEM TO TRACK DIRECTORY DEPTH?'' then just does it. No further reporting happens in either case.

The concern I have with this change is about user interface. With this patch, if someone renames a directory that is the root of a subtree containing other directories and then unmounts the file system cleanly, fsck will report that the file system is now corrupted because all of the dirdepth values for directories in that subtree are wrong. In fact, every existing file system will immediately be reported as corrupted the first time that the new fsck is run. There are millions of people in the world who know what the fsck output for a clean and uncorrupted UFS file system looks like, and that clean fsck output is very easy to recognize because it's very short and always the same (modulo the line with the last-mounted-on path and the line at the end with the block/inode usage and fragmentation summary). After this patch, fsck can produce millions of lines of output for file systems that aren't really corrupted but rather are merely not optimal, and it will no longer be so simple to tell if a file system is corrupted or not by looking at the fsck output.

I was waiting for the UFS fixes to land.

Updated the diff based on review comments.
The suggestion was to only enable vn_read_from_obj() if the fs fragment size is larger than the page size, but it's actually fine to use vn_read_from_obj() as long as the fs block size is greater than or equal to the page size, so I made the check that way.

This makes sense to me.

No, in this example of 16k pages and 4k blocks, the first page would contain the first 4 blocks, the second page would contain the next 4 blocks, etc, so mmap'ing the file works as you would expect.

made requested changes.

It would be good to go ahead and resolve the XXX comments that are currently being added by the patch.

I would characterize this change as: redefine "read_bias==0" from the current meaning of "prefer writes" to instead mean "no read-vs-write bias".
This patch looks correct in implementing that new meaning, though it would be nice if it didn't involve essentially duplicating the code of cam_iosched_get_write() in cam_iosched_next_bio().

I agree with kib that there is no need to serialize read requests (that need to choose whether to read from lower or upper) with write requests (that change the target of future reads from lower to upper)... allowing a pending read from the lower layer to complete after a write changes the target of future reads of that sector to be the upper layer is fine. The application must be prepared for the read to return either the old data or the new data in this case because the order of processing of these parallel async operations is not guaranteed.

Yea, I couldn't see any reason for the linker to leave the gap in libcrypto.so's memory layout either, but it doesn't seem like an invalid thing to do either, and it's easy enough to handle it.

update for review comments.

there's one more unsafe use of g_io_request() in UFS, in softdep_synchronize(), but that can be fixed separately from this one.

I'm told that these day using "bool" and true/false is preferred over using "int" and 1/0, but otherwise this is good.

overall I agree with mjg and kirk that it would be simpler and better in the long term for the bufobj to be part of the fs-specific "inode" structure for file systems that need it, rather than having the fs-independent code need to know about multiple flavors of vnodes.

what is the "issue reported by jhb" that you mention?