- Suspend filesystem for unmount. This prevents new tmpfs nodes from
instantiating, and also ensures that only unmount thread can destroy
nodes.
- Do not start tmpfs node deletion until all vnodes are reclaimed,
which guarantees that no thread can access tmpfs data. For this,
call vflush() in the loop, until the mnt_nvnodelistsize is non-zero.
Note that after mnt_nvnodelistsize becomes 0, insmntque() blocks
insertion of a vnode germ into the mount list of vnodes.
- Fail node allocation when the filesystem is being unmounted. This
is race-free due to the vflush() call in loop. This is mostly
cosmetic, avoiding some more work which might be done until
suspension in unmount is started.
Note that there is currently no way to prevent new vnode instantiation
from readers during the unmount. Due to this, forced unmount might
live-lock if vflush() loop cannot get to the zero vnode count due to
races with readers. The unmount would proceed after the load is
lifted.
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
vnode for the tmpfs node owning this object. The flag is currently
used for two purposes. First, it allows to correctly handle VV_TEXT
for tmpfs vnode when the ref count on the object is decremented to 1,
similar to vnode_pager_dealloc() for regular filesystems. Second, it
prevents some operations, which are done on OBJT_SWAP vm objects
backing user anonymous memory, but are incorrect for the object owned
by tmpfs node.
The second kind of use of the OBJ_TMPFS flag is incorrect, since the
vnode might be reclaimed, which clears the flag, but vm object
operations must still be disallowed.
Introduce one more flag, OBJ_TMPFS_NODE, which is permanently set on
the object for VREG tmpfs node, and used instead of OBJ_TMPFS to test
whether vm object collapse and similar actions should be disabled.
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
unmount time) in the helper vfs_write_suspend_umnt(). Use it instead
of two inline copies in FFS.
Fix the bug in the FFS unmount, when suspension failed, the ufs
extattrs were not reinitialized.
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
In particular, vnode must be exclusively locked when the tmpfs vnode
and object are divorced. When the vnode is opened, the object must be
still alive, since only live vnode can be opened, and the tmpfs node
owns a reference on the object.
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
a vnode until it is verified that the vnode indeed belongs to tmpfs
mount. Otherwise, it might access random memory, at least in the
debug kernel.
Reported and tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
producer, instead of hard-coding VFS_VGET(). New function, which
takes callback, is called vn_get_ino_gen(), standard callback for
vn_get_ino() is provided.
Convert inline copies of vn_get_ino() in msdosfs and cd9660 into the
uses of vn_get_ino_gen().
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
the upstream implementation and helps ensure that a trap induced by tracing
fbt::trap:entry is handled without recursively generating another trap.
This makes it possible to run most (but not all) of the DTrace tests under
common/safety/ without triggering a kernel panic.
Submitted by: Anton Rang <anton.rang@isilon.com> (original version)
Phabric: D95
- Remove 4 extra bytes from the ethernet payload.
- The maximum RX buffer was incorrectly set. Increase it to 64K for
now, until the exact limit is understood.
- Enable hardware checksumming again.
- Make hardware data structure packed.
MFC after: 3 days
o Do not use UMA refcount zone. The problem with this zone is that
several refcounting words (16 on amd64) share the same cache line,
and issueing atomic(9) updates on them creates cache line contention.
Also, allocating and freeing them is extra CPU cycles.
Instead, refcount the page directly via vm_page_wire() and the sfbuf
via sf_buf_alloc(sf_buf_page(sf)) [1].
o Call refcounting/freeing function for EXT_SFBUF via direct function
call, instead of function pointer. This removes barrier for CPU
branch predictor.
o Do not cleanup the mbuf to be freed in mb_free_ext(), merely to
satisfy assertion in mb_dtor_mbuf(). Remove the assertion from
mb_dtor_mbuf(). Use bcopy() instead of manual assignments to
copy m_ext in mb_dupcl().
[1] This has some problems for now. Using sf_buf_alloc() merely to
increase refcount is expensive, and is broken on sparc64. To be
fixed.
Sponsored by: Netflix
Sponsored by: Nginx, Inc.
a source address was selected and cached, but it was not
stored that is was cached. This resulted in selecting
different source addresses for the INIT-ACK and COOKIE-ACK
when possible.
Thanks to Niu Zhixiong for reporting the issue.
MFC after: 1 week
Code trying to take a look has to check fd_refcnt and it is 0 by that time.
This is a follow up to r268505, without this the code would leak memory for
tables bigger than the default.
MFC after: 1 week
entry was being tested. We were incrementing and decrementing the pmap's
wired mapping count based on whether the physical page being mapped or
unmapped was cache coherent, not whether it was a wired mapping.
Reviewed by: nwhitehorn
