Various disk controllers require their buffers to be aligned to a
cache-line size (128 bytes). For buffers allocated in structures,
ensure that they are 128-byte aligned. Use aligned_malloc to allocate
memory to ensure that the returned memory is 128-byte aligned.
While we are here, we replace the dynamically allocated inode buffer
with a buffer allocated in the uufsd structure just as the superblock
and cylinder group buffers do.
This can be removed if/when the kernel is fixed. Because this problem
has existed on one I/O subsystem or another since the 1990's, we
are probably stuck with dealing with it forever.
The problem most recent showed up in Azure, see:
https://reviews.freebsd.org/D41728https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=267654
Before these fixes were applied, it was confirmed that the changes
in this commit also fixed the issue in Azure.
Reviewed-by: Warner Losh, kib
Tested-by: Souradeep Chakrabarti of Microsoft (earlier version)
PR: 267654
Differential Revision: https://reviews.freebsd.org/D41724
use almost anything that uses libufs(3) against a file as an unprivileged user, e.g.
tunefs(8) and dumpfs(8) against a makefs(8)-created image.
Prodded by: kensmith
getino(3)/putino(3), inode.c has been reworked in Perforce to the point
where a manual page may not be accurate. Certainly putino(3) has not
even been merged back yet.
These will need a lot of improvement for most applications, but they
document the API enough to get someone on their feet, most likely. The
best documentation still exists in the form of libufs(3) consumers in the
base system.
