writers that want to extend the file. It was also used to serialize
readers that might want to read the last block of the file (with a
writer extending the file). Now that we support vnode locking for
NFS, the rslock is unnecessary. Writers grab the exclusive vnode
lock before writing and readers grab the shared (or in some cases
the exclusive) lock.
Submitted by: Mohan Srinivasan
- Fix nfsm_disct() so that after pulling up data, the remaining data
is aligned if necessary.
- Fix nfs_clnt_tcp_soupcall() to bcopy() the rpc length out of the
mbuf (instead of casting m_data to a uint32).
Submitted by: Pyun YongHyeon
Reviewed by: Mohan Srinivasan
pending discussion of how implementation would proceed. Applications
like -lc_r expect select(3) to match the EAGAIN-status of IO
functions.
Approved by: re
atomic write request, it can fill the buffer cache with the entirety
of that write in order to handle retries. However, it never drops
the vnode lock, or else it wouldn't be atomic, so it ends up waiting
indefinitely for more buf memory that cannot be gotten as it has it
all, and it waits in an uncancellable state.
To fix this, hibufspace is exported and scaled to a reasonable
fraction. This is used as the limit of how much of an atomic write
request by the NFS client will be handled asynchronously. If the
request is larger than this, it will be turned into a synchronous
request which won't deadlock the system. It's possible this value is
far off from what is required by some, so it shall be tunable as soon
as mount_nfs(8) learns of the new field.
The slowdown between an asynchronous and a synchronous write on NFS
appears to be on the order of 2x-4x.
General nod by: gad
MFC after: 2 weeks
More testing: wes
PR: kern/79208
re-sent instead of timing out.
don't log an error message on reconnection, which is not an error.
remove unused nfs_mrep_before_tsleep.
Reviewed by: Mohan Srinivasan
Approved by: alfred
as they have no connection with the expected MNT_* flags. This bug
was exposed 18 months ago when the assignments to f_flags in
vfs_syscalls.c were moved to before the VFS_STATFS() call. It was
fixed in the CSRG source 10 years ago, but we never picked up that
change.
PR: kern/80390
MFC after: 1 week
the MNT_RDONLY flag if the "ro" option was passed in from userland, and
clears it otherwise. In the diskless case, the MNT_RDONLY flag is already
set when this code is reached, but there are no mount options, so it was
incorrectly cleared. Change the logic so the MNT_RDONLY flag is set if the
"ro" option was specified, and left alone otherwise.
Note that the NFS code will still happily let you mount a filesystem RW
even if the server exports it RO. I'm not sure how to fix that.
- Network filesystems are written with a special idiom that checks the
cache first, and may even unlock dvp before discovering that a network
round-trip is required to resolve the name. I believe dvp is prevented
from being recycled even in the forced unmount case by the shared lock
on the mount point. If not, this code should grow checks for VI_DOOMED
after it relocks dvp or it will access NULL v_data fields.
Sponsored by: Isilon Systems, Inc.
these filesystems will support shared locks until they are explicitly
modified to do so. Careful review must be done to ensure that this
is safe for each individual filesystem.
Sponsored by: Isilon Systems, Inc.
non-maskable).
- The NFS client needs to guard against spurious wakeups
while waiting for the response. ltrace causes the process
under question to wakeup (possibly from ptrace()), which
causes NFS to wakeup from tsleep without the response being
delivered.
Submitted by: Mohan Srinivasan
that NFS ever started using it. Long time ago I added the necessary
vhold()/vdrop() calls to replace it, but forgot to remove the v_id code.
Do it now.
patch from kan@).
Pull bufobj_invalbuf() out of vinvalbuf() and make g_vfs call it on
close. This is not yet a generally safe function, but for this very
specific use it is safe. This solves the problem with buffers not
being flushed by unmount or after failed mount attempts.
and tweaks. The code was actually quite broken because it discarded the
upper bits of the 64 bit division. We only had a 50% chance of scaling up
the blocksize for large NFS client mounts when it was needed. For 5.x and
beyond, this was harmless because we could represent the result in either
case. For 4.x this was a big problem though. (4.x also has a df(1) bug to
compound the problem)
I'm not sure why a credential was added to these in the first place, it is
not used anywhere and it doesn't make much sense:
The credentials for syncing a file (ability to write to the
file) should be checked at the system call level.
Credentials for syncing one or more filesystems ("none")
should be checked at the system call level as well.
If the filesystem implementation needs a particular credential
to carry out the syncing it would logically have to the
cached mount credential, or a credential cached along with
any delayed write data.
Discussed with: rwatson
and if the client (erroneously) reads the RPC length as 0 bytes, the
client can loop around in the socket callback. Explicitly check for
the length being 0 case and teardown/re-connect.
Submitted by: Mohan Srinivasan
of sillyrenames (which were limited to 58 per pid per directory,
for no good reason). The new format of sillyrenames looks like
.nfs.0000b31a.00d24.4
^^^^^^^^ ^^^^^
ticks pid
Submitted by: Mohan Srinivasan mohans at yahoo-inc dot com
Obtained from: Yahoo!
- NFS direct IO completely bypasses the buffer and page caches.
If a file is open for direct IO all caching is disabled.
- Direct IO for Directories will be addressed later.
- 2 new NFS directio related sysctls are added. One is a knob to
disable NFS direct IO completely (direct IO is enabled by default).
The other is to disallow mmaped IO on a file that has at least one
O_DIRECT open (see the comment in nfs_vnops.c for more details).
The default is to allow mmaps on a file that has O_DIRECT opens.
Submitted by: Mohan Srinivasan mohans at yahoo-inc dot com
Obtained from: Yahoo!
ia64) was not the result of a change in the vector operations. It
was caused by the NFS locking code using a FIFO and those bypassing
the vnode. This indirectly caused the panic. The NFS locking code has
been changed.
Requested by: phk
either src or dst) fails. This closes a potential data loss case
(where the fsync failed with ENOSPC, for example).
Submitted by: Mohan Srinivasan mohans at yahoo-inc dot com
Obtained from: Yahoo!
Kick off a readahead only when sequential access is detected. This
eliminates wasteful readaheads in random file access.
Submitted by: Mohan Srinivasan mohans at yahoo-inc dot com
Obtained from: Yahoo!
split the conversion of the remaining three filesystems out from the root
mounting changes, so in one go:
cd9660:
Convert to nmount.
Add omount compat shims.
Remove dedicated rootfs mounting code.
Use vfs_mountedfrom()
Rely on vfs_mount.c calling VFS_STATFS()
nfs(client):
Convert to nmount (the simple way, mount_nfs(8) is still necessary).
Add omount compat shims.
Drop COMPAT_PRELITE2 mount arg compatibility.
ffs:
Convert to nmount.
Add omount compat shims.
Remove dedicated rootfs mounting code.
Use vfs_mountedfrom()
Rely on vfs_mount.c calling VFS_STATFS()
Remove vfs_omount() method, all filesystems are now converted.
Remove MNTK_WANTRDWR, handling RO/RW conversions is a filesystem
task, and they all do it now.
Change rootmounting to use DEVFS trampoline:
vfs_mount.c:
Mount devfs on /. Devfs needs no 'from' so this is clean.
symlink /dev to /. This makes it possible to lookup /dev/foo.
Mount "real" root filesystem on /.
Surgically move the devfs mountpoint from under the real root
filesystem onto /dev in the real root filesystem.
Remove now unnecessary getdiskbyname().
kern_init.c:
Don't do devfs mounting and rootvnode assignment here, it was
already handled by vfs_mount.c.
Remove now unused bdevvp(), addaliasu() and addalias(). Put the
few necessary lines in devfs where they belong. This eliminates the
second-last source of bogo vnodes, leaving only the lemming-syncer.
Remove rootdev variable, it doesn't give meaning in a global context and
was not trustworth anyway. Correct information is provided by
statfs(/).
upcalls which do RPC header parsing and match up the reply with the
request. NFS calls now sleep on the nfsreq structure. This enables
us to eliminate the NFS recvlock.
Submitted by: Mohan Srinivasan mohans at yahoo-inc dot com
- Change the cached mtime to a 'struct timespec' from a
time_t. Improving the precision of the cached mtime tightens up
NFS' "close-to-open" consistency considerably.
- Always force an over-the-wire consistency check from nfs_open()
(unless the file is marked modified). This further improves
NFS' "close-to-open" consistency.
Submitted by: Mohan Srinivasan mohans at yahoo-inc dot com
vnode EXCLUSIVE lock. This prevents threads from adding pages to
the vnode while an invalidation is in progress, closing potential
races. In the bioread() path, callers acquire the SHARED vnode lock
- so while an invalidate was in progress, it was possible to fault
in new pages onto the vnode causing the invalidation to take a while
or fail. We saw these races at Yahoo! with very large files+heavy
concurrent access. Forcing an upgrade to EXCLUSIVE lock before doing
the invalidation closes all these races.
Submitted by: Mohan Srinivasan mohans at yahoo-inc dot com
socket callbacks or similar callers, from both the NFS client and the
server.
Instituted nfsm_dissect_nonblock(), nfsm_dissect_xx_nonblock(). And
nfsm_disct() now takes an extra M_TRYWAIT/M_DONTWAIT argument.
Submitted by: Mohan Srinivasan mohans at yahoo-inc dot com
is safe to turn off the nfsnode's NMODIFIED flag.
- Move the check for signals to the top of the loop where we loop
around the dirty buffers on the vnode, scheduling writes. This
ensures that we'll break ouf of the flush operation on reception of
a signal.
Submitted by: Mohan Srinivasan mohans at yahoo-inc dot com
userland and a dedicated system call to get replies.
The vnode-bypass of fifos broke this into a panic.
Ditch all the magic and create a device /dev/nfslock instead, and
use that for both directions apart from the shorter path, this is
also faster because the device driver runs Giant free using the
vnode bypass.
Noticed by: marcel
and annotate that nfs_mountroot assumes it is OK to step on the
values in the global NFSv3 diskless structure as the mountroot
function is called during a serialized part of the boot, before
any other NFS client activity occurs.
MFC after: 2 weeks
doesn't. Most of the implementations have grown weeds for this so they
copy some fields from mnt_stat if the passed argument isn't that.
Fix this the cleaner way: Always call the implementation on mnt_stat
and copy that in toto to the VFS_STATFS argument if different.
commit. In the new world order, the transitive closure on the vector
operations is not precomputed. As such, it's unsafe to actually use
any of the function pointers in an indirect function call. They can
be null, and we need to use the default vector in that case.
This is mostly a quick fix for the four function pointers that are
ed explicitly. A more generic or scalable solution is likely to see
the light of day.
No pathos on: current@
initializations but we did have lofty goals and big ideals.
Adjust to more contemporary circumstances and gain type checking.
Replace the entire vop_t frobbing thing with properly typed
structures. The only casualty is that we can not add a new
VOP_ method with a loadable module. History has not given
us reason to belive this would ever be feasible in the the
first place.
Eliminate in toto VOCALL(), vop_t, VNODEOP_SET() etc.
Give coda correct prototypes and function definitions for
all vop_()s.
Generate a bit more data from the vnode_if.src file: a
struct vop_vector and protype typedefs for all vop methods.
Add a new vop_bypass() and make vop_default be a pointer
to another struct vop_vector.
Remove a lot of vfs_init since vop_vector is ready to use
from the compiler.
Cast various vop_mumble() to void * with uppercase name,
for instance VOP_PANIC, VOP_NULL etc.
Implement VCALL() by making vdesc_offset the offsetof() the
relevant function pointer in vop_vector. This is disgusting
but since the code is generated by a script comparatively
safe. The alternative for nullfs etc. would be much worse.
Fix up all vnode method vectors to remove casts so they
become typesafe. (The bulk of this is generated by scripts)
a deadlock (with NFS exclusive vnode locks enabled). Lookup
grabs the parent's lock and wants to lock child. Readdirplus
locks the child and wants to lock parent (for loading the attrs
for ".."). The fix is to not load the attrs for ".." in
readdirplus.
Submitted by: Mohan Srinivasan mohans at yahoo-inc dot com
Reviewed by: rwatson
This closes a major hole in close-to-open consistency support.
Added a new sysctl so that this can be disabled for single NFS
client applications with very large amounts of mmap'ed IO (for
performance).
Submitted by: Mohan Srinivasan mohans at yahoo-inc dot com
Reviewed by: rwatson
returned back to df from a statfs call. Causing df to print negative
values.
Submitted by: Mohan Srinivasan mohans at yahoo-inc dot com
Reviewed by: rwatson
setting the B_REMFREE flag in the buf. This is done to prevent lock order
reversals with code that must call bremfree() with a local lock held.
This also reduces overhead by removing two lock operations per buf for
fsync() and similar.
- Check for the B_REMFREE flag in brelse() and bqrelse() after the bqlock
has been acquired so that we may remove ourself from the free-list.
- Provide a bremfreef() function to immediately remove a buf from a
free-list for use only by NFS. This is done because the nfsclient code
overloads the b_freelist queue for its own async. io queue.
- Simplify the numfreebuffers accounting by removing a switch statement
that executed the same code in every possible case.
- getnewbuf() can encounter locked bufs on free-lists once Giant is removed.
Remove a panic associated with this condition and delay asserts that
inspect the buf until after it is locked.
Reviewed by: phk
Sponsored by: Isilon Systems, Inc.
Extend it with a strategy method.
Add bufstrategy() which do the usual VOP_SPECSTRATEGY/VOP_STRATEGY
song and dance.
Rename ibwrite to bufwrite().
Move the two NFS buf_ops to more sensible places, add bufstrategy
to them.
Add inlines for bwrite() and bstrategy() which calls through
buf->b_bufobj->b_ops->b_{write,strategy}().
Replace almost all VOP_STRATEGY()/VOP_SPECSTRATEGY() calls with bstrategy().
Initialize b_bufobj for all buffers.
Make incore() and gbincore() take a bufobj instead of a vnode.
Make inmem() local to vfs_bio.c
Change a lot of VI_[UN]LOCK(bp->b_vp) to BO_[UN]LOCK(bp->b_bufobj)
also VI_MTX() to BO_MTX(),
Make buf_vlist_add() take a bufobj instead of a vnode.
Eliminate other uses of bp->b_vp where bp->b_bufobj will do.
Various minor polishing: remove "register", turn panic into KASSERT,
use new function declarations, TAILQ_FOREACH_SAFE() etc.
Add bufobj_wref(), bufobj_wdrop() and bufobj_wwait() to handle the write
count on a bufobj. Bufobj_wdrop() replaces vwakeup().
Use these functions all relevant places except in ffs_softdep.c where
the use if interlocked_sleep() makes this impossible.
Rename b_vnbufs to b_bobufs now that we touch all the relevant files anyway.
on anything but DEVFS and in this case it was not even used (see below).
Put the NFS4 vop method for fifo's behind "#if 0" because it is unused.
Add a XXX comment to say that I think the unusedness is a bug.
send routine. In IPv6 UDP, the thread will be passed to suser(), which
asserts that if a thread is used for a super user check, it be
curthread. Many of these protocol entry points probably need to
accept credentials instead of threads.
MT5 candidate.
Noticed/tested by: kuriyama
and refuse initializing filesystems with a wrong version. This will
aid maintenance activites on the 5-stable branch.
s/vfs_mount/vfs_omount/
s/vfs_nmount/vfs_mount/
Name our filesystems mount function consistently.
Eliminate the namiedata argument to both vfs_mount and vfs_omount.
It was originally there to save stack space. A few places abused
it to get hold of some credentials to pass around. Effectively
it is unused.
Reorganize the root filesystem selection code.
Add local rootvp variables as needed.
Remove checks for miniroot's in the swappartition. We never did that
and most of the filesystems could never be used for that, but it had
still been copy&pasted all over the place.
a better name. I have a kern_[sg]etsockopt which I plan to commit
shortly, but the arguments to these function will be quite different
from so_setsockopt.
Approved by: alfred
This is to allow filesystems to decide based on the passed thread
which vnode to return.
Several filesystems used curthread, they now use the passed thread.
bootp -> BOOTP
bootp.nfsroot -> BOOTP_NFSROOT
bootp.nfsv3 -> BOOTP_NFSV3
bootp.compat -> BOOTP_COMPAT
bootp.wired_to -> BOOTP_WIRED_TO
- i.e. back out the previous commit. It's already possible to
pxeboot(8) with a GENERIC kernel.
Pointed out by: dwmalone
BOOTP -> bootp
BOOTP_NFSROOT -> bootp.nfsroot
BOOTP_NFSV3 -> bootp.nfsv3
BOOTP_COMPAT -> bootp.compat
BOOTP_WIRED_TO -> bootp.wired_to
This lets you PXE boot with a GENERIC kernel by putting this sort of thing
in loader.conf:
bootp="YES"
bootp.nfsroot="YES"
bootp.nfsv3="YES"
bootp.wired_to="bge1"
or even setting the variables manually from the OK prompt.
