Nothing appears to limit the number of concurrent async COPY
operations that clients can start. In addition, AFAICT each async
COPY can copy an unlimited number of 4MB chunks, so can run for a
long time. Thus IMO async COPY can become a DoS vector.
Add a restriction mechanism that bounds the number of concurrent
background COPY operations. Start simple and try to be fair -- this
patch implements a per-namespace limit.
An async COPY request that occurs while this limit is exceeded gets
NFS4ERR_DELAY. The requesting client can choose to send the request
again after a delay or fall back to a traditional read/write style
copy.
If there is need to make the mechanism more sophisticated, we can
visit that in future patches.
Cc: stable@vger.kernel.org
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Clients that send an OFFLOAD_STATUS might want to distinguish
between an async COPY operation that is still running, has
completed successfully, or that has failed.
The intention of this patch is to make NFSD behave like this:
* Copy still running:
OFFLOAD_STATUS returns NFS4_OK, the number of bytes copied
so far, and an empty osr_status array
* Copy completed successfully:
OFFLOAD_STATUS returns NFS4_OK, the number of bytes copied,
and an osr_status of NFS4_OK
* Copy failed:
OFFLOAD_STATUS returns NFS4_OK, the number of bytes copied,
and an osr_status other than NFS4_OK
* Copy operation lost, canceled, or otherwise unrecognized:
OFFLOAD_STATUS returns NFS4ERR_BAD_STATEID
NB: Though RFC 7862 Section 11.2 lists a small set of NFS status
codes that are valid for OFFLOAD_STATUS, there do not seem to be any
explicit spec limits on the status codes that may be returned in the
osr_status field.
At this time we have no unit tests for COPY and its brethren, as
pynfs does not yet implement support for NFSv4.2.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
After a client has started an asynchronous COPY operation, a
subsequent OFFLOAD_STATUS operation will need to report the status
code once that COPY operation has completed. The recorded status
record will be used by a subsequent patch.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
This adds basic infrastructure for handing GET_DIR_DELEGATION calls from
clients, including the decoders and encoders. For now, it always just
returns NFS4_OK + GDD4_UNAVAIL.
Eventually clients may start sending this operation, and it's better if
we can return GDD4_UNAVAIL instead of having to abort the whole compound.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Avoid the use of an atomic bitop, and prepare for adding a run-time
switch for using splice reads.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Replace open-coded encoding logic with the use of conventional XDR
utility functions.
Note that if we replace the cpn_sec and cpn_nsec fields with a
single struct timespec64 field, the encoder can use
nfsd4_encode_nfstime4(), as that is the data type specified by the
XDR spec.
NFS4ERR_INVAL seems inappropriate if the encoder doesn't support
encoding the response. Instead use NFS4ERR_SERVERFAULT, since this
condition is a software bug on the server.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Refactor nfsd4_encode_secinfo() so it is more clear what XDR data
item is being encoded by which piece of code.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reshape nfsd4_encode_entry4() to be more like the legacy dirent
encoders, which were recently rewritten to use xdr_stream.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
De-duplicate open-coded encoding of the sessionid, and convert the
rest of the function to use conventional XDR utility functions.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Convert nfsd4_encode_create_session() to use the conventional XDR
encoding utilities.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Refactor nfsd4_encode_open() so the open_read_delegation4 type is
encoded in a separate function. This makes it more straightforward
to later add support for returning an nfsace4 in OPEN responses that
offer a delegation.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
An XDR encoder is responsible for marshaling results, not releasing
memory that was allocated by the upper layer. We have .op_release
for that purpose.
Move the release of the ld_owner.data string to op_release functions
for LOCK and LOCKT.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Adopt the use of conventional XDR utility functions. Restructure
the encoder to better align with the XDR definition of the result.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Adopt the use of conventional XDR utility functions. Restructure
the encoder to better align with the XDR definition of the result.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
De-duplicate the open-coded stateid4 encoder. Adopt the use of the
conventional current XDR encoding helpers. Refactor the encoder to
align with the XDR specification.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
This is a synonym for nfsd4_encode_uint32_t() that matches the
name of the XDR type. It will get at least one more use in a
subsequent patch.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Refactor the encoder for FATTR4_MODE into a helper. In a subsequent
patch, this helper will be called from a bitmask loop.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Refactor the ACE encoding helper so that it can eventually be reused
for encoding OPEN results that contain delegation ACEs.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Refactor the encoder for FATTR4_LEASE_TIME into a helper. In a
subsequent patch, this helper will be called from a bitmask loop.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Refactor the encoder for FATTR4_CHANGE into a helper. In a
subsequent patch, this helper will be called from a bitmask loop.
The code is restructured a bit to use the modern xdr_stream flow,
and the encoded cinfo value is made const so that callers of the
encoders can be passed a const cinfo.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
The generic XDR encoders return a length or a negative errno. NFSv4
encoders want to know simply whether the encode ran out of stream
buffer space. The return values for server-side encoding are either
nfs_ok or nfserr_resource.
So far I've found it adds a lot of duplicate code to try to use the
generic XDR encoder utilities when encoding the simple data types in
the NFSv4 operation encoders.
Add a set of NFSv4-specific utilities that handle the basic XDR data
types. These are added in xdr4.h so they might eventually be used by
the callback server and pNFS driver encoders too.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
At one time, nfsd would scrape inode information directly out of struct
inode in order to populate the change_info4. At that time, the BUG_ON in
set_change_info made some sense, since having it unset meant a coding
error.
More recently, it calls vfs_getattr to get this information, which can
fail. If that fails, fh_pre_saved can end up not being set. While this
situation is unfortunate, we don't need to crash the box.
Move set_change_info to nfs4proc.c since all of the callers are there.
Revise the condition for setting "atomic" to also check for
fh_pre_saved. Drop the BUG_ON and just have it zero out both
change_attr4s when this occurs.
Reported-by: Boyang Xue <bxue@redhat.com>
Closes: https://bugzilla.redhat.com/show_bug.cgi?id=2223560
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Currently nfsd4_setup_inter_ssc returns the vfsmount of the source
server's export when the mount completes. After the copy is done
nfsd4_cleanup_inter_ssc is called with the vfsmount of the source
server and it searches nfsd_ssc_mount_list for a matching entry
to do the clean up.
The problems with this approach are (1) the need to search the
nfsd_ssc_mount_list and (2) the code has to handle the case where
the matching entry is not found which looks ugly.
The enhancement is instead of nfsd4_setup_inter_ssc returning the
vfsmount, it returns the nfsd4_ssc_umount_item which has the
vfsmount embedded in it. When nfsd4_cleanup_inter_ssc is called
it's passed with the nfsd4_ssc_umount_item directly to do the
clean up so no searching is needed and there is no need to handle
the 'not found' case.
Signed-off-by: Dai Ngo <dai.ngo@oracle.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
[ cel: adjusted whitespace and variable/function names ]
Reviewed-by: Olga Kornievskaia <kolga@netapp.com>
This field was added by commit 1091006c5e ("nfsd: turn on reply
cache for NFSv4") but was never put to use.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
These helpers are always invoked indirectly, so the compiler can't
inline these anyway. While we're updating the synopses of these
helpers, defensively convert their parameters to const pointers.
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>
Between opening a file and setting a delegation on it, someone could
rename or unlink the dentry. If this happens, we do not want to grant a
delegation on the open.
On a CLAIM_NULL open, we're opening by filename, and we may (in the
non-create case) or may not (in the create case) be holding i_rwsem
when attempting to set a delegation. The latter case allows a
race.
After getting a lease, redo the lookup of the file being opened and
validate that the resulting dentry matches the one in the open file
description.
To properly redo the lookup we need an rqst pointer to pass to
nfsd_lookup_dentry(), so make sure that is available.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Refactor so that CB_OFFLOAD arguments can be passed without
allocating a whole struct nfsd4_copy object. On my system (x86_64)
this removes another 96 bytes from struct nfsd4_copy.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Pack the fields to reduce the size of struct nfsd4_op, which is used
an array in struct nfsd4_compoundargs.
sizeof(struct nfsd4_op):
Before: /* size: 672, cachelines: 11, members: 5 */
After: /* size: 640, cachelines: 10, members: 5 */
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>
There have been reports of races that cause NFSv4 OPEN(CREATE) to
return an error even though the requested file was created. NFSv4
does not provide a status code for this case.
To mitigate some of these problems, reorganize the NFSv4
OPEN(CREATE) logic to allocate resources before the file is actually
created, and open the new file while the parent directory is still
locked.
Two new APIs are added:
+ Add an API that works like nfsd_file_acquire() but does not open
the underlying file. The OPEN(CREATE) path can use this API when it
already has an open file.
+ Add an API that is kin to dentry_open(). NFSD needs to create a
file and grab an open "struct file *" atomically. The
alloc_empty_file() has to be done before the inode create. If it
fails (for example, because the NFS server has exceeded its
max_files limit), we avoid creating the file and can still return
an error to the NFS client.
BugLink: https://bugzilla.linux-nfs.org/show_bug.cgi?id=382
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: JianHong Yin <jiyin@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_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>
Currently, the server does all copies as NFS_UNSTABLE. For synchronous
copies linux client will append a COMMIT to the COPY compound but for
async copies it does not (because COMMIT needs to be done after all
bytes are copied and not as a reply to the COPY operation).
However, in order to save the client doing a COMMIT as a separate
rpc, the server can reply back with NFS_FILE_SYNC copy. This patch
proposed to add vfs_fsync() call at the end of the async copy.
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.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>
fs/nfsd/nfssvc.c:36:6: warning: symbol 'inter_copy_offload_enable' was not declared. Should it be static?
The parameter was added by commit ce0887ac96 ("NFSD add nfs4 inter
ssc to nfsd4_copy"). Relocate it into the source file that uses it,
and make it static. This approach is similar to the
nfs4_disable_idmapping, cltrack_prog, and cltrack_legacy_disable
module parameters.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
For the case of NFSv4, specify to the client that the pre/post-op
attributes were not recorded atomically with the main operation.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.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>
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>
