need to understand the locking around that field. Instead of setting
B_ERROR, set b_error instead. b_error is 'owned' by whoever completes
the I/O request.
function that does the work, genfs_do_putpages(), now takes as an argument
a pointer to the page that would be waited on, if PGO_BUSYWAIT were not set.
This allows a consumer, e.g. lfs_putpages(), to perform an action outside
the scope of UVM before sleeping on the page in question.
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).
unlocked instead of locked. chuq agrees
* use slock set to &uobj->vmobjlock also for the last simple lock
operation to be consistent with the rest of the function
vnodes were synced and processed backwards. This meant that the last
accessed node was processed first and the earlierst last.
An extra benefit is the removal of the ugly hack from the Berkly days on
LFS.
In the proces, i've also replaced the various variations hand written loops
by the TAILQ_FOREACH() macro's.
intervened by truncation.
it also fixes a deadlock. (g_glock vs pages locking order)
- uvm_vnp_setsize: modify v_size while holding v_interlock.
reviewed by Chuck Silvers.
- remove GOP_SIZE_READ/GOP_SIZE_WRITE flags.
they have not been used since the change.
- ufs_balloc_range: remove code which has been no-op since the change.
thanks Konrad Schroder for explaining the original intention of the code.
- ffs_gop_size: don't extend past eof, in the case of GOP_SIZE_MEM.
otherwise genfs_getpages end up to allocate pages past eof unnecessarily.
- use vmspace rather than proc or lwp where appropriate.
the latter is more natural to specify an address space.
(and less likely to be abused for random purposes.)
- fix a swdmover race.
