the mapping is:
VM_PAGER_OK 0
VM_PAGER_BAD <unused>
VM_PAGER_FAIL <unused>
VM_PAGER_PEND 0 (see below)
VM_PAGER_ERROR EIO
VM_PAGER_AGAIN EAGAIN
VM_PAGER_UNLOCK EBUSY
VM_PAGER_REFAULT ERESTART
for async i/o requests, it used to be possible for the request to
be convert to sync, and the pager would return VM_PAGER_OK or VM_PAGER_PEND
to indicate whether the caller should perform post-i/o cleanup.
this is no longer allowed; pagers must now return 0 to indicate that
the async i/o was successfully started, and the caller never needs to
worry about doing the post-i/o cleanup.
devices will actually be notified if this is the last close.
this allows raidframe swap devices to be marked clean.
also, move the corresponding vref() into swap_on() for symmetry
and improve some comments.
default, as the copyright on the main file (ffs_softdep.c) is such
that is has been put into gnusrc. options SOFTDEP will pull this
in. This code also contains the trickle syncer.
Bump version number to 1.4O
not set, unlock the vnode before calling the device's close routine and
relock it after it returns. tty close routines will sleep waiting for
buffers to drain, which won't happen often times as the other side needs
to grab the vnode lock first.
Make all unmount routines lock the device vnode before calling VOP_CLOSE().
thing would be to allocate the block, but I don't know how to do this.
The panic is preferable to the random memory corruption the old code
was causing.
the pathname of the swap device is saved into. add a char *swd_path
member to struct swapdev, that contains a copy of the pathname
(using malloc(9)). rename swapctl(2)'s SWAP_STATS to SWAP_OSTATS,
and add a new SWAP_STATS command (number). make swapctl(SWAP_STATS,
...) [new version] copy the path out. if COMPAT_13, also include
support for SWAP_OSTATS. also fix a minor bug in swapctl(2).
the point of this is that swapfiles are now shown in `swapctl -l'.
later incremented correctedly, causing the wrong data to be paged out, which
then caused general lossage later when the data was paged in and the process
tried to use it. found by pk.
the history buffers are "struct uvm_history_ent" to ensure proper
alignment (eg, alpha). this fixes a boottime panic when the pdhist was
used before it had been initialised.
UVM was written by chuck cranor <chuck@maria.wustl.edu>, with some
minor portions derived from the old Mach code. i provided some help
getting swap and paging working, and other bug fixes/ideas. chuck
silvers <chuq@chuq.com> also provided some other fixes.
this is the UVM kernel code portion.
this will be KNF'd shortly. :-)
thorpej