In today's Linux NFS server implementation, the NFS dispatcher
initializes each XDR result stream, and the NFSv4 .pc_func and
.pc_encode methods all use xdr_stream-based encoding. This keeps
rq_res.len automatically updated. There is no longer a need for
the WARN_ON_ONCE() check in nfs4svc_encode_compoundres().
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Have SunRPC clear everything except for the iops array. Then have
each NFSv4 XDR decoder clear it's own argument before decoding.
Now individual operations may have a large argument struct while not
penalizing the vast majority of operations with a small struct.
And, clearing the argument structure occurs as the argument fields
are initialized, enabling the CPU to do write combining on that
memory. In some cases, clearing is not even necessary because all
of the fields in the argument structure are initialized by the
decoder.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
This was discussed with Chuck as part of this patch set. Returning
nfserr_resource was decided to not be the best error message here, and
he suggested changing to nfserr_serverfault instead.
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Link: https://lore.kernel.org/linux-nfs/20220907195259.926736-1-anna@kernel.org/T/#t
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
We only need the inode number for this, not a full rack of attributes.
Rename this function make it take a pointer to a u64 instead of
struct kstat, and change it to just request STATX_INO.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
[ cel: renamed get_mounted_on_ino() ]
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
If an NFS server returns NFS4ERR_RESOURCE on the first operation in
an NFSv4 COMPOUND, there's no way for a client to know where the
problem is and then simplify the compound to make forward progress.
So instead, make NFSD process as many operations in an oversized
COMPOUND as it can and then return NFS4ERR_RESOURCE on the first
operation it did not process.
pynfs NFSv4.0 COMP6 exercises this case, but checks only for the
COMPOUND status code, not whether the server has processed any
of the operations.
pynfs NFSv4.1 SEQ6 and SEQ7 exercise the NFSv4.1 case, which detects
too many operations per COMPOUND by checking against the limits
negotiated when the session was created.
Suggested-by: Bruce Fields <bfields@fieldses.org>
Fixes: 0078117c6d ("nfsd: return RESOURCE not GARBAGE_ARGS on too many ops")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
When attempting an NFSv4 mount, a Solaris NFSv4 client builds a
single large COMPOUND that chains a series of LOOKUPs to get to the
pseudo filesystem root directory that is to be mounted. The Linux
NFS server's current maximum of 16 operations per NFSv4 COMPOUND is
not large enough to ensure that this works for paths that are more
than a few components deep.
Since NFSD_MAX_OPS_PER_COMPOUND is mostly a sanity check, and most
NFSv4 COMPOUNDS are between 3 and 6 operations (thus they do not
trigger any re-allocation of the operation array on the server),
increasing this maximum should result in little to no impact.
The ops array can get large now, so allocate it via vmalloc() to
help ensure memory fragmentation won't cause an allocation failure.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216383
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Similar changes to nfsd4_encode_readv(), all bundled into a single
patch.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Clean up: Use a helper instead of open-coding the calculation of
the XDR pad size.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Clean-up: Now that nfsd4_encode_readv() does not have to encode the
EOF or rd_length values, it no longer needs to subtract 8 from
@starting_len.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
write_bytes_to_xdr_buf() is pretty expensive to use for inserting
an XDR data item that is always 1 XDR_UNIT at an address that is
always XDR word-aligned.
Since both the readv and splice read paths encode EOF and maxcount
values, move both to a common code path.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Refactor: Make the EOF result available in the entire NFSv4 READ
path.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Do the test_bit() once -- this reduces the number of locked-bus
operations and makes the function a little easier to read.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
write_bytes_to_xdr_buf() is a generic way to place a variable-length
data item in an already-reserved spot in the encoding buffer.
However, it is costly. In nfsd4_encode_fattr(), it is unnecessary
because the data item is fixed in size and the buffer destination
address is always word-aligned.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
write_bytes_to_xdr_buf() is a generic way to place a variable-length
data item in an already-reserved spot in the encoding buffer.
However, it is costly, and here, it is unnecessary because the
data item is fixed in size, the buffer destination address is
always word-aligned, and the destination location is already in
@p.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
NFSD has advertised support for the NFSv4 time_create attribute
since commit e377a3e698 ("nfsd: Add support for the birth time
attribute").
Igor Mammedov reports that Mac OS clients attempt to set the NFSv4
birth time attribute via OPEN(CREATE) and SETATTR if the server
indicates that it supports it, but since the above commit was
merged, those attempts now fail.
Table 5 in RFC 8881 lists the time_create attribute as one that can
be both set and retrieved, but the above commit did not add server
support for clients to provide a time_create attribute. IMO that's
a bug in our implementation of the NFSv4 protocol, which this commit
addresses.
Whether NFSD silently ignores the new birth time or actually sets it
is another matter. I haven't found another filesystem service in the
Linux kernel that enables users or clients to modify a file's birth
time attribute.
This commit reflects my (perhaps incorrect) understanding of whether
Linux users can set a file's birth time. NFSD will now recognize a
time_create attribute but it ignores its value. It clears the
time_create bit in the returned attribute bitmask to indicate that
the value was not used.
Reported-by: Igor Mammedov <imammedo@redhat.com>
Fixes: e377a3e698 ("nfsd: Add support for the birth time attribute")
Tested-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
I noticed CPU pipeline stalls while using perf.
Once an svc thread is scheduled and executing an RPC, no other
processes will touch svc_rqst::rq_flags. Thus bus-locked atomics are
not needed outside the svc thread scheduler.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
For filesystems that supports "btime" timestamp (i.e. most modern
filesystems do) we share it via kernel nfsd. Btime support for NFS
client has already been added by Trond recently.
Suggested-by: Bruce Fields <bfields@fieldses.org>
Signed-off-by: Ondrej Valousek <ondrej.valousek.xm@renesas.com>
[ cel: addressed some whitespace/checkpatch nits ]
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
NFS_OFFSET_MAX was introduced way back in Linux v2.3.y before there
was a kernel-wide OFFSET_MAX value. As a clean up, replace the last
few uses of it with its generic equivalent, and get rid of it.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Dan Aloni reports:
> Due to commit 8cfb901528 ("NFS: Always provide aligned buffers to
> the RPC read layers") on the client, a read of 0xfff is aligned up
> to server rsize of 0x1000.
>
> As a result, in a test where the server has a file of size
> 0x7fffffffffffffff, and the client tries to read from the offset
> 0x7ffffffffffff000, the read causes loff_t overflow in the server
> and it returns an NFS code of EINVAL to the client. The client as
> a result indefinitely retries the request.
The Linux NFS client does not handle NFS?ERR_INVAL, even though all
NFS specifications permit servers to return that status code for a
READ.
Instead of NFS?ERR_INVAL, have out-of-range READ requests succeed
and return a short result. Set the EOF flag in the result to prevent
the client from retrying the READ request. This behavior appears to
be consistent with Solaris NFS servers.
Note that NFSv3 and NFSv4 use u64 offset values on the wire. These
must be converted to loff_t internally before use -- an implicit
type cast is not adequate for this purpose. Otherwise VFS checks
against sb->s_maxbytes do not work properly.
Reported-by: Dan Aloni <dan.aloni@vastdata.com>
Cc: stable@vger.kernel.org
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Clean up. Trond points out that xdr_stream_decode_uint32_array()
does the same thing as nfsd4_decode_bitmap4().
Suggested-by: Trond Myklebust <trondmy@hammerspace.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
-----BEGIN PGP SIGNATURE-----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=beJ8
-----END PGP SIGNATURE-----
Merge tag 'nfsd-5.16-1' of git://linux-nfs.org/~bfields/linux
Pull nfsd bugfix from Bruce Fields:
"This is just one bugfix for a buffer overflow in knfsd's xdr decoding"
* tag 'nfsd-5.16-1' of git://linux-nfs.org/~bfields/linux:
NFSD: Fix exposure in nfsd4_decode_bitmap()
rtm@csail.mit.edu reports:
> nfsd4_decode_bitmap4() will write beyond bmval[bmlen-1] if the RPC
> directs it to do so. This can cause nfsd4_decode_state_protect4_a()
> to write client-supplied data beyond the end of
> nfsd4_exchange_id.spo_must_allow[] when called by
> nfsd4_decode_exchange_id().
Rewrite the loops so nfsd4_decode_bitmap() cannot iterate beyond
@bmlen.
Reported by: rtm@csail.mit.edu
Fixes: d1c263a031 ("NFSD: Replace READ* macros in nfsd4_decode_fattr()")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
support for a filehandle format deprecated 20 years ago, and further
xdr-related cleanup from Chuck.
-----BEGIN PGP SIGNATURE-----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=yKBl
-----END PGP SIGNATURE-----
Merge tag 'nfsd-5.16' of git://linux-nfs.org/~bfields/linux
Pull nfsd updates from Bruce Fields:
"A slow cycle for nfsd: mainly cleanup, including Neil's patch dropping
support for a filehandle format deprecated 20 years ago, and further
xdr-related cleanup from Chuck"
* tag 'nfsd-5.16' of git://linux-nfs.org/~bfields/linux: (26 commits)
nfsd4: remove obselete comment
nfsd: document server-to-server-copy parameters
NFSD:fix boolreturn.cocci warning
nfsd: update create verifier comment
SUNRPC: Change return value type of .pc_encode
SUNRPC: Replace the "__be32 *p" parameter to .pc_encode
NFSD: Save location of NFSv4 COMPOUND status
SUNRPC: Change return value type of .pc_decode
SUNRPC: Replace the "__be32 *p" parameter to .pc_decode
SUNRPC: De-duplicate .pc_release() call sites
SUNRPC: Simplify the SVC dispatch code path
SUNRPC: Capture value of xdr_buf::page_base
SUNRPC: Add trace event when alloc_pages_bulk() makes no progress
svcrdma: Split svcrmda_wc_{read,write} tracepoints
svcrdma: Split the svcrdma_wc_send() tracepoint
svcrdma: Split the svcrdma_wc_receive() tracepoint
NFSD: Have legacy NFSD WRITE decoders use xdr_stream_subsegment()
SUNRPC: xdr_stream_subsegment() must handle non-zero page_bases
NFSD: Initialize pointer ni with NULL and not plain integer 0
NFSD: simplify struct nfsfh
...
Returning an undecorated integer is an age-old trope, but it's
not clear (even to previous experts in this code) that the only
valid return values are 1 and 0. These functions do not return
a negative errno, rpc_stat value, or a positive length.
Document there are only two valid return values by having
.pc_encode return only true or false.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
The passed-in value of the "__be32 *p" parameter is now unused in
every server-side XDR encoder, and can be removed.
Note also that there is a line in each encoder that sets up a local
pointer to a struct xdr_stream. Passing that pointer from the
dispatcher instead saves one line per encoder function.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Refactor: Currently nfs4svc_encode_compoundres() relies on the NFS
dispatcher to pass in the buffer location of the COMPOUND status.
Instead, save that buffer location in struct nfsd4_compoundres.
The compound tag follows immediately after.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Returning an undecorated integer is an age-old trope, but it's
not clear (even to previous experts in this code) that the only
valid return values are 1 and 0. These functions do not return
a negative errno, rpc_stat value, or a positive length.
Document there are only two valid return values by having
.pc_decode return only true or false.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
The passed-in value of the "__be32 *p" parameter is now unused in
every server-side XDR decoder, and can be removed.
Note also that there is a line in each decoder that sets up a local
pointer to a struct xdr_stream. Passing that pointer from the
dispatcher instead saves one line per decoder function.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Most of the fields in 'struct knfsd_fh' are 2 levels deep (a union and a
struct) and are accessed using macros like:
#define fh_FOO fh_base.fh_new.fb_FOO
This patch makes the union and struct anonymous, so that "fh_FOO" can be
a name directly within 'struct knfsd_fh' and the #defines aren't needed.
The file handle as a whole is sometimes accessed as "fh_base" or
"fh_base.fh_pad", neither of which are particularly helpful names.
As the struct holding the filehandle is now anonymous, we
cannot use the name of that, so we union it with 'fh_raw' and use that
where the raw filehandle is needed. fh_raw also ensure the structure is
large enough for the largest possible filehandle.
fh_raw is a 'char' array, removing any need to cast it for memcpy etc.
SVCFH_fmt() is simplified using the "%ph" printk format. This
changes the appearance of filehandles in dprintk() debugging, making
them a little more precise.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
RFC3530 notes that the 'dircount' field may be zero, in which case the
recommendation is to ignore it, and only enforce the 'maxcount' field.
In RFC5661, this recommendation to ignore a zero valued field becomes a
requirement.
Fixes: aee3776441 ("nfsd4: fix rd_dircount enforcement")
Cc: <stable@vger.kernel.org>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
The section "19) Editor modelines and other cruft" in
Documentation/process/coding-style.rst clearly says, "Do not include any
of these in source files."
I recently receive a patch to explicitly add a new one.
Let's do treewide cleanups, otherwise some people follow the existing code
and attempt to upstream their favoriate editor setups.
It is even nicer if scripts/checkpatch.pl can check it.
If we like to impose coding style in an editor-independent manner, I think
editorconfig (patch [1]) is a saner solution.
[1] https://lore.kernel.org/lkml/20200703073143.423557-1-danny@kdrag0n.dev/
Link: https://lkml.kernel.org/r/20210324054457.1477489-1-masahiroy@kernel.org
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Miguel Ojeda <ojeda@kernel.org> [auxdisplay]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
NFSD initializes an encode xdr_stream only after the RPC layer has
already inserted the RPC Reply header. Thus it behaves differently
than xdr_init_encode does, which assumes the passed-in xdr_buf is
entirely devoid of content.
nfs4proc.c has this server-side stream initialization helper, but
it is visible only to the NFSv4 code. Move this helper to a place
that can be accessed by NFSv2 and NFSv3 server XDR functions.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
While converting the NFSv4 decoder to use xdr_stream-based XDR
processing, I removed the old SAVEMEM() macro. This macro wrapped
a bit of logic that avoided a memory allocation by recognizing when
the decoded item resides in a linear section of the Receive buffer.
In that case, it returned a pointer into that buffer instead of
allocating a bounce buffer.
The bounce buffer is necessary only when xdr_inline_decode() has
placed the decoded item in the xdr_stream's scratch buffer, which
disappears the next time xdr_inline_decode() is called with that
xdr_stream. That happens only if the data item crosses a page
boundary in the receive buffer, an exceedingly rare occurrence.
Allocating a bounce buffer every time results in a minor performance
regression that was introduced by the recent NFSv4 decoder overhaul.
Let's restore the previous behavior. On average, it saves about 1.5
kmalloc() calls per COMPOUND.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
If the READ_PLUS operation was truncated due to an error, then ensure we
clear the 'eof' flag.
Fixes: 9f0b5792f0 ("NFSD: Encode a full READ_PLUS reply")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Ensure that we encode the data payload + padding, and that we truncate
the preallocated buffer to the actual read size.
Fixes: 528b84934e ("NFSD: Add READ_PLUS data support")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
This reverts commit a85857633b.
We're still factoring ctime into our change attribute even in the
IS_I_VERSION case. If someone sets the system time backwards, a client
could see the change attribute go backwards. Maybe we can just say
"well, don't do that", but there's some question whether that's good
enough, or whether we need a better guarantee.
Also, the client still isn't actually using the attribute.
While we're still figuring this out, let's just stop returning this
attribute.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
It doesn't make sense to carry all these extra fields around. Just
make everything into change attribute from the start.
This is just cleanup, there should be no change in behavior.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
inode_query_iversion() can modify i_version. Depending on the exported
filesystem, that may not be safe. For example, if you're re-exporting
NFS, NFS stores the server's change attribute in i_version and does not
expect it to be modified locally. This has been observed causing
unnecessary cache invalidations.
The way a filesystem indicates that it's OK to call
inode_query_iverson() is by setting SB_I_VERSION.
So, move the I_VERSION check out of encode_change(), where it's used
only in GETATTR responses, to nfsd4_change_attribute(), which is
also called for pre- and post- operation attributes.
(Note we could also pull the NFSEXP_V4ROOT case into
nfsd4_change_attribute() as well. That would actually be a no-op,
since pre/post attrs are only used for metadata-modifying operations,
and V4ROOT exports are read-only. But we might make the change in
the future just for simplicity.)
Reported-by: Daire Byrne <daire@dneg.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Now that all the NFSv4 decoder functions have been converted to
make direct calls to the xdr helpers, remove the unused C macros.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
And clean-up: Now that we have removed the DECODE_TAIL macro from
nfsd4_decode_compound(), we observe that there's no benefit for
nfsd4_decode_compound() to return nfs_ok or nfserr_bad_xdr only to
have its sole caller convert those values to one or zero,
respectively. Have nfsd4_decode_compound() return 1/0 instead.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
