658 Commits

Author SHA1 Message Date
Chuck Lever
993474e8a6 NFSD: Add nfsd4_encode_fattr4_time_delta()
Refactor the encoder for FATTR4_TIME_DELTA into a helper. In a
subsequent patch, this helper will be called from a bitmask loop.

fattr4_time_delta is specified as an nfstime4, so de-duplicate this
encoder.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-10-16 12:44:23 -04:00
Chuck Lever
2e38722d4a NFSD: Add nfsd4_encode_fattr4_time_create()
Refactor the encoder for FATTR4_TIME_CREATE 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>
2023-10-16 12:44:23 -04:00
Chuck Lever
eed4d1adbb NFSD: Add nfsd4_encode_fattr4_time_access()
Refactor the encoder for FATTR4_TIME_ACCESS 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>
2023-10-16 12:44:23 -04:00
Chuck Lever
6d37ac3adb NFSD: Add nfsd4_encode_fattr4_space_used()
Refactor the encoder for FATTR4_SPACE_USED 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>
2023-10-16 12:44:22 -04:00
Chuck Lever
d0cde979e9 NFSD: Add nfsd4_encode_fattr4_space_total()
Refactor the encoder for FATTR4_SPACE_TOTAL 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>
2023-10-16 12:44:22 -04:00
Chuck Lever
74ebc69705 NFSD: Add nfsd4_encode_fattr4_space_free()
Refactor the encoder for FATTR4_SPACE_FREE 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>
2023-10-16 12:44:22 -04:00
Chuck Lever
83afa09179 NFSD: Add nfsd4_encode_fattr4_space_avail()
Refactor the encoder for FATTR4_SPACE_AVAIL 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>
2023-10-16 12:44:21 -04:00
Chuck Lever
a460cda28e NFSD: Add nfsd4_encode_fattr4_rawdev()
Refactor the encoder for FATTR4_RAWDEV 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>
2023-10-16 12:44:21 -04:00
Chuck Lever
62f31e56d5 NFSD: Add nfsd4_encode_fattr4_owner_group()
Refactor the encoder for FATTR4_OWNER_GROUP 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>
2023-10-16 12:44:21 -04:00
Chuck Lever
fa51a5201b NFSD: Add nfsd4_encode_fattr4_owner()
Refactor the encoder for FATTR4_OWNER 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>
2023-10-16 12:44:20 -04:00
Chuck Lever
9f329fea25 NFSD: Add nfsd4_encode_fattr4_numlinks()
Refactor the encoder for FATTR4_NUMLINKS 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>
2023-10-16 12:44:20 -04:00
Chuck Lever
f4cf504201 NFSD: Add nfsd4_encode_fattr4_mode()
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>
2023-10-16 12:44:20 -04:00
Chuck Lever
951378dc96 NFSD: Add nfsd4_encode_fattr4_maxwrite()
Refactor the encoder for FATTR4_MAXWRITE 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>
2023-10-16 12:44:19 -04:00
Chuck Lever
c17195c397 NFSD: Add nfsd4_encode_fattr4_maxread()
Refactor the encoder for FATTR4_MAXREAD 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>
2023-10-16 12:44:19 -04:00
Chuck Lever
9c1adaccd1 NFSD: Add nfsd4_encode_fattr4_maxname()
Refactor the encoder for FATTR4_MAXNAME 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>
2023-10-16 12:44:19 -04:00
Chuck Lever
b066aa5ca3 NFSD: Add nfsd4_encode_fattr4_maxlink()
Refactor the encoder for FATTR4_MAXLINK 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>
2023-10-16 12:44:18 -04:00
Chuck Lever
7c605dccc5 NFSD: Add nfsd4_encode_fattr4_maxfilesize()
Refactor the encoder for FATTR4_MAXFILESIZE 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>
2023-10-16 12:44:18 -04:00
Chuck Lever
a1469a3704 NFSD: Add nfsd4_encode_fattr4_fs_locations()
Refactor the encoder for FATTR4_FS_LOCATIONS 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>
2023-10-16 12:44:18 -04:00
Chuck Lever
b56b752663 NFSD: Add nfsd4_encode_fattr4_files_total()
Refactor the encoder for FATTR4_FILES_TOTAL 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>
2023-10-16 12:44:17 -04:00
Chuck Lever
74361e2b5d NFSD: Add nfsd4_encode_fattr4_files_free()
Refactor the encoder for FATTR4_FILES_FREE 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>
2023-10-16 12:44:17 -04:00
Chuck Lever
b0c3a5f8c8 NFSD: Add nfsd4_encode_fattr4_files_avail()
Refactor the encoder for FATTR4_FILES_AVAIL 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>
2023-10-16 12:44:17 -04:00
Chuck Lever
eb7ece81d5 NFSD: Add nfsd4_encode_fattr4_fileid()
Refactor the encoder for FATTR4_FILEID 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>
2023-10-16 12:44:17 -04:00
Chuck Lever
3283bf64ef NFSD: Add nfsd4_encode_fattr4_filehandle()
Refactor the encoder for FATTR4_FILEHANDLE into a helper. In a
subsequent patch, this helper will be called from a bitmask loop.

We can de-duplicate the other filehandle encoder (in GETFH) using
our new helper.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-10-16 12:44:16 -04:00
Chuck Lever
07455dc45d NFSD: Add nfsd4_encode_fattr4_acl()
Refactor the encoder for FATTR4_ACL 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>
2023-10-16 12:44:16 -04:00
Chuck Lever
0207ee0818 NFSD: Add nfsd4_encode_nfsace4()
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>
2023-10-16 12:44:16 -04:00
Chuck Lever
6515b7d71d NFSD: Add nfsd4_encode_fattr4_aclsupport()
Refactor the encoder for FATTR4_ACLSUPPORT 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>
2023-10-16 12:44:15 -04:00
Chuck Lever
782448e1ec NFSD: Add nfsd4_encode_fattr4_rdattr_error()
Refactor the encoder for FATTR4_RDATTR_ERROR 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>
2023-10-16 12:44:15 -04:00
Chuck Lever
1252b283aa NFSD: Add nfsd4_encode_fattr4_lease_time()
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>
2023-10-16 12:44:15 -04:00
Chuck Lever
b6b6259590 NFSD: Add nfsd4_encode_fattr4_fsid()
Refactor the encoder for FATTR4_FSID 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>
2023-10-16 12:44:14 -04:00
Chuck Lever
d0b28aadfd NFSD: Add nfsd4_encode_fattr4_size()
Refactor the encoder for FATTR4_SIZE 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>
2023-10-16 12:44:14 -04:00
Chuck Lever
263453d9bb NFSD: Add nfsd4_encode_fattr4_change()
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>
2023-10-16 12:44:14 -04:00
Chuck Lever
36ed7e6494 NFSD: Add nfsd4_encode_fattr4_fh_expire_type()
Refactor the encoder for FATTR4_FH_EXPIRE_TYPE 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>
2023-10-16 12:44:13 -04:00
Chuck Lever
b06cf37545 NFSD: Add nfsd4_encode_fattr4_type()
Refactor the encoder for FATTR4_TYPE into a helper. In a subsequent
patch, this helper will be called from a bitmask loop.

In addition, restructure the code so that byte-swapping is done on
constant values rather than at run time. Run-time swapping can be
costly on some platforms, and "type" is a frequently-requested
attribute.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-10-16 12:44:13 -04:00
Chuck Lever
c9090e2733 NFSD: Add nfsd4_encode_fattr4_supported_attrs()
Refactor the encoder for FATTR4_SUPPORTED_ATTRS 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>
2023-10-16 12:44:13 -04:00
Chuck Lever
8c4422881f NFSD: Add nfsd4_encode_fattr4__false()
Add an encoding helper that encodes a single boolean "false" value.
Attributes that always return "false" can use this helper.

In a subsequent patch, this helper will be called from a bitmask
loop, so it is given a standardized synopsis.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-10-16 12:44:12 -04:00
Chuck Lever
c88cb4727a NFSD: Add nfsd4_encode_fattr4__true()
Add an encoding helper that encodes a single boolean "true" value.
Attributes that always return "true" can use this helper.

In a subsequent patch, this helper will be called from a bitmask
loop, so it is given a standardized synopsis.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-10-16 12:44:12 -04:00
Chuck Lever
83ab8678ad NFSD: Add struct nfsd4_fattr_args
I'm about to split nfsd4_encode_fattr() into a number of smaller
functions. Instead of passing a large number of arguments to each of
the smaller functions, create a struct that can gather the common
argument variables into something with a convenient handle on it.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-10-16 12:44:12 -04:00
Chuck Lever
c3dcb45bcd NFSD: Clean up nfsd4_encode_setattr()
De-duplicate the encoding of bitmap4 results in
nfsd4_encode_setattr().

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-10-16 12:44:11 -04:00
Chuck Lever
e64301f51b NFSD: Rename nfsd4_encode_bitmap()
For alignment with the specification, the name of NFSD's encoder
function should match the name of the XDR type.

I've also replaced a few "naked integers" with symbolic constants
that better reflect the usage of these values.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-10-16 12:44:11 -04:00
Dai Ngo
6c41d9a9bd NFSD: handle GETATTR conflict with write delegation
If the GETATTR request on a file that has write delegation in effect
and the request attributes include the change info and size attribute
then the request is handled as below:

Server sends CB_GETATTR to client to get the latest change info and file
size. If these values are the same as the server's cached values then
the GETATTR proceeds as normal.

If either the change info or file size is different from the server's
cached values, or the file was already marked as modified, then:

    . update time_modify and time_metadata into file's metadata
      with current time

    . encode GETATTR as normal except the file size is encoded with
      the value returned from CB_GETATTR

    . mark the file as modified

If the CB_GETATTR fails for any reasons, the delegation is recalled
and NFS4ERR_DELAY is returned for the GETATTR.

Signed-off-by: Dai Ngo <dai.ngo@oracle.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-10-16 12:44:09 -04:00
Chuck Lever
0d32a6bbb8 NFSD: Fix zero NFSv4 READ results when RQ_SPLICE_OK is not set
nfsd4_encode_readv() uses xdr->buf->page_len as a starting point for
the nfsd_iter_read() sink buffer -- page_len is going to be offset
by the parts of the COMPOUND that have already been encoded into
xdr->buf->pages.

However, that value must be captured /before/
xdr_reserve_space_vec() advances page_len by the expected size of
the read payload. Otherwise, the whole front part of the first
page of the payload in the reply will be uninitialized.

Mantas hit this because sec=krb5i forces RQ_SPLICE_OK off, which
invokes the readv part of the nfsd4_encode_read() path. Also,
older Linux NFS clients appear to send shorter READ requests
for files smaller than a page, whereas newer clients just send
page-sized requests and let the server send as many bytes as
are in the file.

Reported-by: Mantas Mikulėnas <grawity@gmail.com>
Closes: https://lore.kernel.org/linux-nfs/f1d0b234-e650-0f6e-0f5d-126b3d51d1eb@gmail.com/
Fixes: 703d75215555 ("NFSD: Hoist rq_vec preparation into nfsd_read() [step two]")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-09-28 10:34:28 -04:00
Chuck Lever
6372e2ee62 NFSD: da_addr_body field missing in some GETDEVICEINFO replies
The XDR specification in RFC 8881 looks like this:

struct device_addr4 {
	layouttype4	da_layout_type;
	opaque		da_addr_body<>;
};

struct GETDEVICEINFO4resok {
	device_addr4	gdir_device_addr;
	bitmap4		gdir_notification;
};

union GETDEVICEINFO4res switch (nfsstat4 gdir_status) {
case NFS4_OK:
	GETDEVICEINFO4resok gdir_resok4;
case NFS4ERR_TOOSMALL:
	count4		gdir_mincount;
default:
	void;
};

Looking at nfsd4_encode_getdeviceinfo() ....

When the client provides a zero gd_maxcount, then the Linux NFS
server implementation encodes the da_layout_type field and then
skips the da_addr_body field completely, proceeding directly to
encode gdir_notification field.

There does not appear to be an option in the specification to skip
encoding da_addr_body. Moreover, Section 18.40.3 says:

> If the client wants to just update or turn off notifications, it
> MAY send a GETDEVICEINFO operation with gdia_maxcount set to zero.
> In that event, if the device ID is valid, the reply's da_addr_body
> field of the gdir_device_addr field will be of zero length.

Since the layout drivers are responsible for encoding the
da_addr_body field, put this fix inside the ->encode_getdeviceinfo
methods.

Fixes: 9cf514ccfacb ("nfsd: implement pNFS operations")
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Tom Haynes <loghyr@gmail.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-08-29 17:45:22 -04:00
Chuck Lever
50bce06f0e NFSD: Report zero space limit for write delegations
Replace the -1 (no limit) with a zero (no reserved space).

This prevents certain non-determinant client behavior, such as
silly-renaming a file when the only open reference is a write
delegation. Such a rename can leave unexpected .nfs files in a
directory that is otherwise supposed to be empty.

Note that other server implementations that support write delegation
also set this field to zero.

Suggested-by: Dai Ngo <dai.ngo@oracle.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-08-29 17:45:22 -04:00
Dai Ngo
fd19ca36fd NFSD: handle GETATTR conflict with write delegation
If the GETATTR request on a file that has write delegation in effect and
the request attributes include the change info and size attribute then
the write delegation is recalled. If the delegation is returned within
30ms then the GETATTR is serviced as normal otherwise the NFS4ERR_DELAY
error is returned for the GETATTR.

Add counter for write delegation recall due to conflict GETATTR. This is
used to evaluate the need to implement CB_GETATTR to adoid recalling the
delegation with conflit GETATTR.

Signed-off-by: Dai Ngo <dai.ngo@oracle.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-08-29 17:45:22 -04:00
Tavian Barnes
d7dbed457c nfsd: Fix creation time serialization order
In nfsd4_encode_fattr(), TIME_CREATE was being written out after all
other times.  However, they should be written out in an order that
matches the bit flags in bmval1, which in this case are

    #define FATTR4_WORD1_TIME_ACCESS        (1UL << 15)
    #define FATTR4_WORD1_TIME_CREATE        (1UL << 18)
    #define FATTR4_WORD1_TIME_DELTA         (1UL << 19)
    #define FATTR4_WORD1_TIME_METADATA      (1UL << 20)
    #define FATTR4_WORD1_TIME_MODIFY        (1UL << 21)

so TIME_CREATE should come second.

I noticed this on a FreeBSD NFSv4.2 client, which supports creation
times.  On this client, file times were weirdly permuted.  With this
patch applied on the server, times looked normal on the client.

Fixes: e377a3e698fb ("nfsd: Add support for the birth time attribute")
Link: https://unix.stackexchange.com/q/749605/56202
Signed-off-by: Tavian Barnes <tavianator@tavianator.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-06-27 12:10:47 -04:00
Chuck Lever
262176798b NFSD: Add an nfsd4_encode_nfstime4() helper
Clean up: de-duplicate some common code.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Acked-by: Tom Talpey <tom@talpey.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-06-17 13:18:06 -04:00
Dai Ngo
58f5d89400 NFSD: add encoding of op_recall flag for write delegation
Modified nfsd4_encode_open to encode the op_recall flag properly
for OPEN result with write delegation granted.

Signed-off-by: Dai Ngo <dai.ngo@oracle.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: stable@vger.kernel.org
2023-06-12 12:16:35 -04:00
Chuck Lever
703d752155 NFSD: Hoist rq_vec preparation into nfsd_read() [step two]
Now that the preparation of an rq_vec has been removed from the
generic read path, nfsd_splice_read() no longer needs to reset
rq_next_page.

nfsd4_encode_read() calls nfsd_splice_read() directly. As far as I
can ascertain, resetting rq_next_page for NFSv4 splice reads is
unnecessary because rq_next_page is already set correctly.

Moreover, resetting it might even be incorrect if previous
operations in the COMPOUND have already consumed at least a page of
the send buffer. I would expect that the result would be encoding
the READ payload over previously-encoded results.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-06-11 16:37:46 -04:00
Chuck Lever
ed4a567a17 NFSD: Update rq_next_page between COMPOUND operations
A GETATTR with a large result can advance xdr->page_ptr without
updating rq_next_page. If a splice READ follows that GETATTR in the
COMPOUND, nfsd_splice_actor can start splicing at the wrong page.

I've also seen READLINK and READDIR leave rq_next_page in an
unmodified state.

There are potentially a myriad of combinations like this, so play it
safe: move the rq_next_page update to nfsd4_encode_operation.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-06-11 16:37:45 -04:00
Chuck Lever
ba21e20b30 NFSD: Use svcxdr_encode_opaque_pages() in nfsd4_encode_splice_read()
Commit 15b23ef5d348 ("nfsd4: fix corruption of NFSv4 read data")
encountered exactly the same issue: after a splice read, a
filesystem-owned page is left in rq_pages[]; the symptoms are the
same as described there.

If the computed number of pages in nfsd4_encode_splice_read() is not
exactly the same as the actual number of pages that were consumed by
nfsd_splice_actor() (say, because of a bug) then hilarity ensues.

Instead of recomputing the page offset based on the size of the
payload, use rq_next_page, which is already properly updated by
nfsd_splice_actor(), to cause svc_rqst_release_pages() to operate
correctly in every instance.

This is a defensive change since we believe that after commit
27c934dd8832 ("nfsd: don't replace page in rq_pages if it's a
continuation of last page") has been applied, there are no known
opportunities for nfsd_splice_actor() to screw up. So I'm not
marking it for stable backport.

Reported-by: Andy Zlotek <andy.zlotek@oracle.com>
Suggested-by: Calum Mackay <calum.mackay@oracle.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-06-11 16:37:40 -04:00