also to a place less panicy, namely fifo_fsync (because currently the
metadata information is update when the node is changed. This will
probably change soon, though).
servers. This is still pretty much on the level "if it breaks ...".
It should work for single-threaded servers which handle one operation
from start to finish in one go. Also, it does not yet totally
correctly synchronize metadata and data in some cases. So needless
to say, it needs improvement, but it is possible that will have to
wait for some lock revampage.
since DIOCGPART is going to fail. Unfortunately there is no way to get the
geometry information we need from the wedge; it would be nice for wedges
to support a geometry ioctl. The values we cannot retrieve are marked with
XXX.
- Add a lot more debugging.
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).
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.
of rolling around VOP_FSYNC(). The user server will be given the
VFS_SYNC instruction and it can do its own equivalent of VOP_FSYNC()
if it pleases, no need for the kernel to explicitly issue #{vnodes}
FSYNCs.
kernel caching. Currently supported are only flushing the name
cache for a directory or flushing the name cache for the entire fs.
Also, get rid of PNODE_INACTIVE status, since it was racy and
essentially didn't work. All this on top of being useless in the
first place ....
kernel->server calls at that time and it allows a window where
operations use an incorrect root node cookie.
XXX: there's still a (very much smaller and biglock safe) race, but
that's going to be solved by some more thorough restructuring
cbiere