completely different file system, we still might re-enter the same
puffs fs in case we execute something on the other file system,
which wants to get a new vnode and ends up recycling a puffs vnode
for the purpose. In this case the fs server will sleep in the
kernel until it itself handles the operation .... which of course
is a slightly unlikely event.
After analyzing the path from getcleanvnode() to the vnode cemetary,
identify that fsync and putpages (strategy) are the ones in danger
of striking a deadlock deal. Abuse the vnode flag VXLOCK to tell
them "this vnode is irreversably going to meet its maker, don't
care about user server return values" (failure is not acceptable
down the vgonel() path) and issue the respective operations as
Fire-And-Forget (FAF) operations. no wait -> no deadlock.
This of course is a "fix" skating on thin ice. A better, more
generic solution is already in sight, but will take more effort to
implement.
The suspension helpers are now put into file system specific operations.
This means every file system not supporting these helpers cannot be suspended
and therefore snapshots are no longer possible.
Implemented for file systems of type ffs.
The new API is enabled on a kernel option NEWVNGATE. This option is
not enabled by default in any kernel config.
Presented and discussed on tech-kern with much input from
Bill Studenmund <wrstuden@netbsd.org> and YAMAMOTO Takashi <yamt@netbsd.org>.
Welcome to 4.99.9 (new vfs op vfs_suspendctl).
Be consistant with the spaces around * and +
Use data32io[th] for 32bit access
Use stream bus_space access unless we have DRIVE_NOSTREAM
all pointed out by enami tsugutomo, thanks !
extract the register state from this for the live kernel case. If there
is no switchframe then use the frame pointer to get enough state for crash
dump case.
More information needs to be saved by savectx to avoid this mess.
Should fix PR/35118
* Check for non-ASCII characters in getch() because the rest of the code
doesn't expect such.
* Removed use of -traditional and constructs which relied on this.
* Use raise(SIGFPE) in dump() instead of attempting a division-by-zero.
* Fixed compiler warnings regarding missing prototypes or unused
parameters.
fixes the case where a directory lookup is done in a directory has never
been visted/listed; the search optimalisation that searches the directory
from where it left behind the last time would never reach the initial
offset of zero since it would always have at least processed one entry.
