Looks like there are still cases when "space_left - frag1bytes" can
legitimately exceed PAGE_SIZE. Ensure that xdr->end always remains
within the current encode buffer.
Reported-by: Bruce Fields <bfields@fieldses.org>
Reported-by: Zorro Lang <zlang@redhat.com>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216151
Fixes: 6c254bf3b6 ("SUNRPC: Fix the calculation of xdr->end in xdr_get_next_encode_buffer()")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
To make the code easier to read, remove visual clutter by changing
the declared type of @p.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: NeilBrown <neilb@suse.de>
Reviewed-by: J. Bruce Fields <bfields@fieldses.org>
The value of @p is not used until the "location of the next item" is
computed. Help human readers by moving its initial assignment to the
paragraph where that value is used and by clarifying the antecedents
in the documenting comment.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: NeilBrown <neilb@suse.com>
Reviewed-by: J. Bruce Fields <bfields@fieldses.org>
Both the kvec::iov_len field and the third parameter of memcpy() and
memmove() are size_t. There's no reason for the implicit conversion
from size_t to int and back. Change the type of @shift to make the
code easier to read and understand.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: NeilBrown <neilb@suse.de>
Reviewed-by: J. Bruce Fields <bfields@fieldses.org>
Transitioning between encode buffers is quite infrequent. It happens
about 1 time in 400 calls to xdr_reserve_space(), measured on NFSD
with a typical build/test workload.
Force the compiler to remove that code from xdr_reserve_space(),
which is a hot path on both the server and the client. This change
reduces the size of xdr_reserve_space() from 10 cache lines to 2
when compiled with -Os.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: J. Bruce Fields <bfields@fieldses.org>
I found that NFSD's new NFSv3 READDIRPLUS XDR encoder was screwing up
right at the end of the page array. xdr_get_next_encode_buffer() does
not compute the value of xdr->end correctly:
* The check to see if we're on the final available page in xdr->buf
needs to account for the space consumed by @nbytes.
* The new xdr->end value needs to account for the portion of @nbytes
that is to be encoded into the previous buffer.
Fixes: 2825a7f907 ("nfsd4: allow encoding across page boundaries")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: NeilBrown <neilb@suse.de>
Reviewed-by: J. Bruce Fields <bfields@fieldses.org>
xdr_stream_subsegment() was introduced in commit c1346a1216
("NFSD: Replace the internals of the READ_BUF() macro").
There are two call sites for xdr_stream_subsegment(). One is
nfsd4_decode_write(), and the other is nfsd4_decode_setxattr().
Currently neither of these call sites calls this API when
xdr_buf::page_base is a non-zero value.
However, I'm about to add a case where page_base will sometimes not
be zero when nfsd4_decode_write() invokes this API. Replace the
logic in xdr_stream_subsegment() that advances to the next data item
in the xdr_stream with something more generic in order to handle
this new use case.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
This seems to happen fairly easily during READ_PLUS testing on NFS v4.2.
I found that we could end up accessing xdr->buf->pages[pgnr] with a pgnr
greater than the number of pages in the array. So let's just return
early if we're setting base to a point at the end of the page data and
let xdr_set_tail_base() handle setting up the buffer pointers instead.
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Fixes: 8d86e373b0 ("SUNRPC: Clean up helpers xdr_set_iov() and xdr_set_page_base()")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Highlights include:
Features:
- NFSv3: Add emulation of lookupp() to improve open_by_filehandle()
support.
- A series of patches to improve readdir performance, particularly with
large directories.
- Basic support for using NFS/RDMA with the pNFS files and flexfiles
drivers.
- Micro-optimisations for RDMA.
- RDMA tracing improvements.
Bugfixes:
- Fix a long standing bug with xs_read_xdr_buf() when receiving partial
pages (Dan Aloni).
- Various fixes for getxattr and listxattr, when used over non-TCP
transports.
- Fixes for containerised NFS from Sargun Dhillon.
- switch nfsiod to be an UNBOUND workqueue (Neil Brown).
- READDIR should not ask for security label information if there is no
LSM policy. (Olga Kornievskaia)
- Avoid using interval-based rebinding with TCP in lockd (Calum Mackay).
- A series of RPC and NFS layer fixes to support the NFSv4.2 READ_PLUS code.
- A couple of fixes for pnfs/flexfiles read failover
Cleanups:
- Various cleanups for the SUNRPC xdr code in conjunction with the
READ_PLUS fixes.
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Merge tag 'nfs-for-5.11-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs
Pull NFS client updates from Trond Myklebust:
"Highlights include:
Features:
- NFSv3: Add emulation of lookupp() to improve open_by_filehandle()
support
- A series of patches to improve readdir performance, particularly
with large directories
- Basic support for using NFS/RDMA with the pNFS files and flexfiles
drivers
- Micro-optimisations for RDMA
- RDMA tracing improvements
Bugfixes:
- Fix a long standing bug with xs_read_xdr_buf() when receiving
partial pages (Dan Aloni)
- Various fixes for getxattr and listxattr, when used over non-TCP
transports
- Fixes for containerised NFS from Sargun Dhillon
- switch nfsiod to be an UNBOUND workqueue (Neil Brown)
- READDIR should not ask for security label information if there is
no LSM policy (Olga Kornievskaia)
- Avoid using interval-based rebinding with TCP in lockd (Calum
Mackay)
- A series of RPC and NFS layer fixes to support the NFSv4.2
READ_PLUS code
- A couple of fixes for pnfs/flexfiles read failover
Cleanups:
- Various cleanups for the SUNRPC xdr code in conjunction with the
READ_PLUS fixes"
* tag 'nfs-for-5.11-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (90 commits)
NFS/pNFS: Fix a typo in ff_layout_resend_pnfs_read()
pNFS/flexfiles: Avoid spurious layout returns in ff_layout_choose_ds_for_read
NFSv4/pnfs: Add tracing for the deviceid cache
fs/lockd: convert comma to semicolon
NFSv4.2: fix error return on memory allocation failure
NFSv4.2/pnfs: Don't use READ_PLUS with pNFS yet
NFSv4.2: Deal with potential READ_PLUS data extent buffer overflow
NFSv4.2: Don't error when exiting early on a READ_PLUS buffer overflow
NFSv4.2: Handle hole lengths that exceed the READ_PLUS read buffer
NFSv4.2: decode_read_plus_hole() needs to check the extent offset
NFSv4.2: decode_read_plus_data() must skip padding after data segment
NFSv4.2: Ensure we always reset the result->count in decode_read_plus()
SUNRPC: When expanding the buffer, we may need grow the sparse pages
SUNRPC: Cleanup - constify a number of xdr_buf helpers
SUNRPC: Clean up open coded setting of the xdr_stream 'nwords' field
SUNRPC: _copy_to/from_pages() now check for zero length
SUNRPC: Cleanup xdr_shrink_bufhead()
SUNRPC: Fix xdr_expand_hole()
SUNRPC: Fixes for xdr_align_data()
SUNRPC: _shift_data_left/right_pages should check the shift length
...
If we're shifting the page data to the right, and this happens to be a
sparse page array, then we may need to allocate new pages in order to
receive the data.
Reported-by: "Mkrtchyan, Tigran" <tigran.mkrtchyan@desy.de>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
There are a number of xdr helpers for struct xdr_buf that do not change
the structure itself. Mark those as taking const pointers for
documentation purposes.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Move the setting of the xdr_stream 'nwords' field into the helpers that
reset the xdr_stream cursor.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
We do want to try to grow the buffer if possible, but if that attempt
fails, we still want to move the data and truncate the XDR message.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
The main use case right now for xdr_align_data() is to shift the page
data to the left, and in practice shrink the total XDR data buffer.
This patch ensures that we fix up the accounting for the buffer length
as we shift that data around.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
While we always want to align to the next page and/or the beginning of
the tail buffer when we call xdr_set_next_page(), the functions
xdr_align_data() and xdr_expand_hole() really want to align to the next
object in that next page or tail.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
rpc_prepare_reply_pages() currently expects the 'hdrsize' argument to
contain the length of the data that we expect to want placed in the head
kvec plus a count of 1 word of padding that is placed after the page data.
This is very confusing when trying to read the code, and sometimes leads
to callers adding an arbitrary value of '1' just in order to satisfy the
requirement (whether or not the page data actually needs such padding).
This patch aims to clarify the code by changing the 'hdrsize' argument
to remove that 1 word of padding. This means we need to subtract the
padding from all the existing callers.
Fixes: 02ef04e432 ("NFS: Account for XDR pad of buf->pages")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Fix up xdr_read_pages() so that it can handle object lengths that are
larger than the page length, by simply aligning to the next object in
the buffer tail.
The function will continue to return the length of the truncate object
data that actually fit into the pages.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Allow xdr_set_iov() to set a base so that we can use it to set the
cursor to a specific position in the kvec buffer.
If the new base overflows the kvec/pages buffer in either xdr_set_iov()
or xdr_set_page_base(), then truncate it so that we point to the end of
the buffer.
Finally, change both function to return the number of bytes remaining to
read in their buffers.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
We already know that the head buffer and page are empty, so if there is
any data, it is in the tail.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Convert the READ_BUF macro in nfs4xdr.c from open code to instead
use the new xdr_stream-style decoders already in use by the encode
side (and by the in-kernel NFS client implementation). Once this
conversion is done, each individual NFSv4 argument decoder can be
independently cleaned up to replace these macros with C code.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
has the same arguments as READ but allows the server to return an array
of data and hole extents.
Otherwise it's a lot of cleanup and bugfixes.
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Merge tag 'nfsd-5.10' of git://linux-nfs.org/~bfields/linux
Pull nfsd updates from Bruce Fields:
"The one new feature this time, from Anna Schumaker, is READ_PLUS,
which has the same arguments as READ but allows the server to return
an array of data and hole extents.
Otherwise it's a lot of cleanup and bugfixes"
* tag 'nfsd-5.10' of git://linux-nfs.org/~bfields/linux: (43 commits)
NFSv4.2: Fix NFS4ERR_STALE error when doing inter server copy
SUNRPC: fix copying of multiple pages in gss_read_proxy_verf()
sunrpc: raise kernel RPC channel buffer size
svcrdma: fix bounce buffers for unaligned offsets and multiple pages
nfsd: remove unneeded break
net/sunrpc: Fix return value for sysctl sunrpc.transports
NFSD: Encode a full READ_PLUS reply
NFSD: Return both a hole and a data segment
NFSD: Add READ_PLUS hole segment encoding
NFSD: Add READ_PLUS data support
NFSD: Hoist status code encoding into XDR encoder functions
NFSD: Map nfserr_wrongsec outside of nfsd_dispatch
NFSD: Remove the RETURN_STATUS() macro
NFSD: Call NFSv2 encoders on error returns
NFSD: Fix .pc_release method for NFSv2
NFSD: Remove vestigial typedefs
NFSD: Refactor nfsd_dispatch() error paths
NFSD: Clean up nfsd_dispatch() variables
NFSD: Clean up stale comments in nfsd_dispatch()
NFSD: Clean up switch statement in nfsd_dispatch()
...
For now, this function simply aligns the data at the beginning of the
pages. This can eventually be expanded to shift data to the correct
offsets when we're ready.
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
This patch adds the ability to "read a hole" into a set of XDR data
pages by taking the following steps:
1) Shift all data after the current xdr->p to the right, possibly into
the tail,
2) Zero the specified range, and
3) Update xdr->p to point beyond the hole.
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
xdr_shrink_pagelen() is very similar to what we need for hole expansion,
so split out the common code into its own function that can be used by
both functions.
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
I don't need the entire align pages code for READ_PLUS, so split out the
part I do need so I don't need to reimplement anything.
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
I'll need this for READ_PLUS to help figure out the offset where page
data is stored at, but it might also be useful for other things.
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
I'm going to need this bit of code in a few places for READ_PLUS
decoding, so let's make it a helper function.
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Reserving space for a large READ payload requires special handling when
reserving space in the xdr buffer pages. One problem we can have is use
of the scratch buffer, which is used to get a pointer to a contiguous
region of data up to PAGE_SIZE. When using the scratch buffer, calls to
xdr_commit_encode() shift the data to it's proper alignment in the xdr
buffer. If we've reserved several pages in a vector, then this could
potentially invalidate earlier pointers and result in incorrect READ
data being sent to the client.
I get around this by looking at the amount of space left in the current
page, and never reserve more than that for each entry in the read
vector. This lets us place data directly where it needs to go in the
buffer pages.
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Drop duplicate words in net/sunrpc/.
Also fix "Anyone" to be "Any one".
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: linux-nfs@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
@subbuf is an output parameter of xdr_buf_subsegment(). A survey of
call sites shows that @subbuf is always uninitialized before
xdr_buf_segment() is invoked by callers.
There are some execution paths through xdr_buf_subsegment() that do
not set all of the fields in @subbuf, leaving some pointer fields
containing garbage addresses. Subsequent processing of that buffer
then results in a page fault.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
I've noticed that when krb5i or krb5p security is in use,
retransmitted requests are missing the server's duplicate reply
cache. The computed checksum on the retransmitted request does not
match the cached checksum, resulting in the server performing the
retransmitted request again instead of returning the cached reply.
The assumptions made when removing xdr_buf_trim() were not correct.
In the send paths, the upper layer has already set the segment
lengths correctly, and shorting the buffer's content is simply a
matter of reducing buf->len.
xdr_buf_trim() is the right answer in the receive/unwrap path on
both the client and the server. The buffer segment lengths have to
be shortened one-by-one.
On the server side in particular, head.iov_len needs to be updated
correctly to enable nfsd_cache_csum() to work correctly. The simple
buf->len computation doesn't do that, and that results in
checksumming stale data in the buffer.
The problem isn't noticed until there's significant instability of
the RPC transport. At that point, the reliability of retransmit
detection on the server becomes crucial.
Fixes: 241b1f419f ("SUNRPC: Remove xdr_buf_trim()")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Clean up: this function is no longer used.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
The empty_iov structure is only copied into another structure,
so make it const.
The opportunity for this change was found using Coccinelle.
Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
xdr_shrink_pagelen() BUG's when @len is larger than buf->page_len.
This can happen when xdr_buf_read_mic() is given an xdr_buf with
a small page array (like, only a few bytes).
Instead, just cap the number of bytes that xdr_shrink_pagelen()
will move.
Fixes: 5f1bc39979 ("SUNRPC: Fix buffer handling of GSS MIC ... ")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Let the name reflect the single use. The function now assumes the GSS MIC
is the last object in the buffer.
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
The GSS Message Integrity Check data for krb5i may lie partially in the XDR
reply buffer's pages and tail. If so, we try to copy the entire MIC into
free space in the tail. But as the estimations of the slack space required
for authentication and verification have improved there may be less free
space in the tail to complete this copy -- see commit 2c94b8eca1
("SUNRPC: Use au_rslack when computing reply buffer size"). In fact, there
may only be room in the tail for a single copy of the MIC, and not part of
the MIC and then another complete copy.
The real world failure reported is that `ls` of a directory on NFS may
sometimes return -EIO, which can be traced back to xdr_buf_read_netobj()
failing to find available free space in the tail to copy the MIC.
Fix this by checking for the case of the MIC crossing the boundaries of
head, pages, and tail. If so, shift the buffer until the MIC is contained
completely within the pages or tail. This allows the remainder of the
function to create a sub buffer that directly address the complete MIC.
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Cc: stable@vger.kernel.org # v5.1
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Micro-optimization: For xdr_commit_encode call sites in
net/sunrpc/xdr.c, eliminate the extra calling sequence. On my
client, this change saves about a microsecond for every 30 calls
to xdr_reserve_space().
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Add SPDX license identifiers to all files which:
- Have no license information of any form
- Have EXPORT_.*_SYMBOL_GPL inside which was used in the
initial scan/conversion to ignore the file
These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:
GPL-2.0-only
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Certain NFS results (eg. READLINK) might expect a data payload that
is not an exact multiple of 4 bytes. In this case, XDR encoding
is required to pad that payload so its length on the wire is a
multiple of 4 bytes. The constants that define the maximum size of
each NFS result do not appear to account for this extra word.
In each case where the data payload is to be received into pages:
- 1 word is added to the size of the receive buffer allocated by
call_allocate
- rpc_inline_rcv_pages subtracts 1 word from @hdrsize so that the
extra buffer space falls into the rcv_buf's tail iovec
- If buf->pagelen is word-aligned, an XDR pad is not needed and
is thus removed from the tail
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
prepare_reply_buffer() and its NFSv4 equivalents expose the details
of the RPC header and the auth slack values to upper layer
consumers, creating a layering violation, and duplicating code.
Remedy these issues by adding a new RPC client API that hides those
details from upper layers in a common helper function.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
The key action of xdr_buf_trim() is that it shortens buf->len, the
length of the xdr_buf's content. The other actions -- shortening the
head, pages, and tail components -- are actually not necessary. In
particular, changing the size of those components can corrupt the
RPC message contained in the buffer. This is an accident waiting to
happen rather than a current bug, as far as we know.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Acked-by: Bruce Fields <bfields@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
We don't want READ payloads that are partially in the head iovec and
in the page buffer because this requires pull-up, which can be
expensive.
The NFS/RPC client tries hard to predict the size of the head iovec
so that the incoming READ data payload lands only in the page
vector, but it doesn't always get it right. To help diagnose such
problems, add a trace point in the logic that decodes READ-like
operations that reports whether pull-up is being done.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
This can help field troubleshooting without needing the overhead of
a full network capture (ie, tcpdump).
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
