libceph: init the cursor when preparing sparse read in msgr2

The cursor is no longer initialized in the OSD client, causing the
sparse read state machine to fall into an infinite loop. The cursor
should be initialized in IN_S_PREPARE_SPARSE_DATA state.

[ idryomov: use msg instead of con->in_msg, changelog ]

Link: https://tracker.ceph.com/issues/64607
Fixes: 8e46a2d068c9 ("libceph: just wait for more data to be available on the socket")
Signed-off-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Tested-by: Luis Henriques <lhenriques@suse.de>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

libceph: just wait for more data to be available on the socket

A short read may occur while reading the message footer from the
socket. Later, when the socket is ready for another read, the
messenger invokes all read_partial_*() handlers, including
read_partial_sparse_msg_data(). The expectation is that
read_partial_sparse_msg_data() would bail, allowing the messenger to
invoke read_partial() for the footer and pick up where it left off.

However read_partial_sparse_msg_data() violates that and ends up
calling into the state machine in the OSD client. The sparse-read
state machine assumes that it's a new op and interprets some piece of
the footer as the sparse-read header and returns bogus extents/data
length, etc.

To determine whether read_partial_sparse_msg_data() should bail, let's
reuse cursor->total_resid. Because once it reaches to zero that means
all the extents and data have been successfully received in last read,
else it could break out when partially reading any of the extents and
data. And then osd_sparse_read() could continue where it left off.

[ idryomov: changelog ]

Link: https://tracker.ceph.com/issues/63586
Fixes: d396f89db39a ("libceph: add sparse read support to msgr1")
Signed-off-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

libceph: stop checking crypto_shash_alignmask

Now that the shash algorithm type does not support nonzero alignmasks,
crypto_shash_alignmask() always returns 0 and will be removed. In
preparation for this, stop checking crypto_shash_alignmask() in
net/ceph/messenger_v2.c.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

libceph: do not include crypto/algapi.h

The header file crypto/algapi.h is for internal use only. Use the
header file crypto/utils.h instead.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

libceph: support sparse reads on msgr2 secure codepath

Add a new init_sgs_pages helper that populates the scatterlist from
an arbitrary point in an array of pages.

Change setup_message_sgs to take an optional pointer to an array of
pages. If that's set, then the scatterlist will be set using that
array instead of the cursor.

When given a sparse read on a secure connection, decrypt the data
in-place rather than into the final destination, by passing it the
in_enc_pages array.

After decrypting, run the sparse_read state machine in a loop, copying
data from the decrypted pages until it's complete.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Xiubo Li <xiubli@redhat.com>
Reviewed-and-tested-by: Luís Henriques <lhenriques@suse.de>
Reviewed-by: Milind Changire <mchangir@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

libceph: new sparse_read op, support sparse reads on msgr2 crc codepath

Add support for a new sparse_read ceph_connection operation. The idea is
that the client driver can define this operation use it to do special
handling for incoming reads.

The alloc_msg routine will look at the request and determine whether the
reply is expected to be sparse. If it is, then we'll dispatch to a
different set of state machine states that will repeatedly call the
driver's sparse_read op to get length and placement info for reading the
extent map, and the extents themselves.

This necessitates adding some new field to some other structs:

- The msg gets a new bool to track whether it's a sparse_read request.

- A new field is added to the cursor to track the amount remaining in the
current extent. This is used to cap the read from the socket into the
msg_data

- Handing a revoke with all of this is particularly difficult, so I've
added a new data_len_remain field to the v2 connection info, and then
use that to skip that much on a revoke. We may want to expand the use of
that to the normal read path as well, just for consistency's sake.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Xiubo Li <xiubli@redhat.com>
Reviewed-and-tested-by: Luís Henriques <lhenriques@suse.de>
Reviewed-by: Milind Changire <mchangir@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

libceph: harden msgr2.1 frame segment length checks

ceph_frame_desc::fd_lens is an int array. decode_preamble() thus
effectively casts u32 -> int but the checks for segment lengths are
written as if on unsigned values. While reading in HELLO or one of the
AUTH frames (before authentication is completed), arithmetic in
head_onwire_len() can get duped by negative ctrl_len and produce
head_len which is less than CEPH_PREAMBLE_LEN but still positive.
This would lead to a buffer overrun in prepare_read_control() as the
preamble gets copied to the newly allocated buffer of size head_len.

Cc: stable@vger.kernel.org
Fixes: cd1a677cad99 ("libceph, ceph: implement msgr2.1 protocol (crc and secure modes)")
Reported-by: Thelford Williams <thelford@google.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Xiubo Li <xiubli@redhat.com>

libceph: Partially revert changes to support MSG_SPLICE_PAGES

Fix the mishandling of MSG_DONTWAIT and also reinstates the per-page
checking of the source pages (which might have come from a DIO write by
userspace) by partially reverting the changes to support MSG_SPLICE_PAGES
and doing things a little differently. In messenger_v1:

(1) The ceph_tcp_sendpage() is resurrected and the callers reverted to use
that.

(2) The callers now pass MSG_MORE unconditionally. Previously, they were
passing in MSG_MORE|MSG_SENDPAGE_NOTLAST and then degrading that to
just MSG_MORE on the last call to ->sendpage().

(3) Make ceph_tcp_sendpage() a wrapper around sendmsg() rather than
sendpage(), setting MSG_SPLICE_PAGES if sendpage_ok() returns true on
the page.

In messenger_v2:

(4) Bring back do_try_sendpage() and make the callers use that.

(5) Make do_try_sendpage() use sendmsg() for both cases and set
MSG_SPLICE_PAGES if sendpage_ok() is set.

Fixes: 40a8c17aa770 ("ceph: Use sendmsg(MSG_SPLICE_PAGES) rather than sendpage")
Fixes: fa094ccae1e7 ("ceph: Use sendmsg(MSG_SPLICE_PAGES) rather than sendpage()")
Reported-by: Ilya Dryomov <idryomov@gmail.com>
Link: https://lore.kernel.org/r/CAOi1vP9vjLfk3W+AJFeexC93jqPaPUn2dD_4NrzxwoZTbYfOnw@mail.gmail.com/
Link: https://lore.kernel.org/r/CAOi1vP_Bn918j24S94MuGyn+Gxk212btw7yWeDrRcW1U8pc_BA@mail.gmail.com/
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Xiubo Li <xiubli@redhat.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: Jens Axboe <axboe@kernel.dk>
cc: Matthew Wilcox <willy@infradead.org>
Link: https://lore.kernel.org/r/3101881.1687801973@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/3111635.1687813501@warthog.procyon.org.uk/ # v2
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Link: https://lore.kernel.org/r/3199652.1687873788@warthog.procyon.org.uk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

ceph: Use sendmsg(MSG_SPLICE_PAGES) rather than sendpage()

Use sendmsg() and MSG_SPLICE_PAGES rather than sendpage in ceph when
transmitting data. For the moment, this can only transmit one page at a
time because of the architecture of net/ceph/, but if
write_partial_message_data() can be given a bvec[] at a time by the
iteration code, this would allow pages to be sent in a batch.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Ilya Dryomov <idryomov@gmail.com>
cc: Xiubo Li <xiubli@redhat.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: Jens Axboe <axboe@kernel.dk>
cc: Matthew Wilcox <willy@infradead.org>
Link: https://lore.kernel.org/r/20230623225513.2732256-5-dhowells@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

libceph: use bvec_set_page to initialize bvecs

Use the bvec_set_page helper to initialize bvecs.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Link: https://lore.kernel.org/r/20230203150634.3199647-24-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

use less confusing names for iov_iter direction initializers

READ/WRITE proved to be actively confusing - the meanings are
"data destination, as used with read(2)" and "data source, as
used with write(2)", but people keep interpreting those as
"we read data from it" and "we write data to it", i.e. exactly
the wrong way.

Call them ITER_DEST and ITER_SOURCE - at least that is harder
to misinterpret...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

libceph: drop last_piece flag from ceph_msg_data_cursor

ceph_msg_data_next is always passed a NULL pointer for this field. Some
of the "next" operations look at it in order to determine the length,
but we can just take the min of the data on the page or cursor->resid.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

libceph: drop else branches in prepare_read_data{,_cont}

Just call set_in_bvec in the non-conditional part.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

libceph: optionally use bounce buffer on recv path in crc mode

Both msgr1 and msgr2 in crc mode are zero copy in the sense that
message data is read from the socket directly into the destination
buffer. We assume that the destination buffer is stable (i.e. remains
unchanged while it is being read to) though. Otherwise, CRC errors
ensue:

libceph: read_partial_message 0000000048edf8ad data crc 1063286393 != exp. 228122706
libceph: osd1 (1)192.168.122.1:6843 bad crc/signature

libceph: bad data crc, calculated 57958023, expected 1805382778
libceph: osd2 (2)192.168.122.1:6876 integrity error, bad crc

Introduce rxbounce option to enable use of a bounce buffer when
receiving message data. In particular this is needed if a mapped
image is a Windows VM disk, passed to QEMU. Windows has a system-wide
"dummy" page that may be mapped into the destination buffer (potentially
more than once into the same buffer) by the Windows Memory Manager in
an effort to generate a single large I/O [1][2]. QEMU makes a point of
preserving overlap relationships when cloning I/O vectors, so krbd gets
exposed to this behaviour.

[1] "What Is Really in That MDL?"
https://docs.microsoft.com/en-us/previous-versions/windows/hardware/design/dn614012(v=vs.85)
[2] https://blogs.msmvps.com/kernelmustard/2005/05/04/dummy-pages/

URL: https://bugzilla.redhat.com/show_bug.cgi?id=1973317
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>

libceph: make recv path in secure mode work the same as send path

The recv path of secure mode is intertwined with that of crc mode.
While it's slightly more efficient that way (the ciphertext is read
into the destination buffer and decrypted in place, thus avoiding
two potentially heavy memory allocations for the bounce buffer and
the corresponding sg array), it isn't really amenable to changes.
Sacrifice that edge and align with the send path which always uses
a full-sized bounce buffer (currently there is no other way -- if
the kernel crypto API ever grows support for streaming (piecewise)
en/decryption for GCM [1], we would be able to easily take advantage
of that on both sides).

[1] https://lore.kernel.org/all/20141225202830.GA18794@gondor.apana.org.au/

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>

mm: allow !GFP_KERNEL allocations for kvmalloc

Support for GFP_NO{FS,IO} and __GFP_NOFAIL has been implemented by
previous patches so we can allow the support for kvmalloc. This will
allow some external users to simplify or completely remove their
helpers.

GFP_NOWAIT semantic hasn't been supported so far but it hasn't been
explicitly documented so let's add a note about that.

ceph_kvmalloc is the first helper to be dropped and changed to kvmalloc.

Link: https://lkml.kernel.org/r/20211122153233.9924-5-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Ilya Dryomov <idryomov@gmail.com>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Neil Brown <neilb@suse.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

libceph: zero out session key and connection secret

Try and avoid leaving bits and pieces of session key and connection
secret (gets split into GCM key and a pair of GCM IVs) around.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>

libceph: align session_key and con_secret to 16 bytes

crypto_shash_setkey() and crypto_aead_setkey() will do a (small)
GFP_ATOMIC allocation to align the key if it isn't suitably aligned.
It's not a big deal, but at the same time easy to avoid.

The actual alignment requirement is dynamic, queryable with
crypto_shash_alignmask() and crypto_aead_alignmask(), but shouldn't
be stricter than 16 bytes for our algorithms.

Fixes: cd1a677cad99 ("libceph, ceph: implement msgr2.1 protocol (crc and secure modes)")
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

libceph: fix auth_signature buffer allocation in secure mode

auth_signature frame is 68 bytes in plain mode and 96 bytes in
secure mode but we are requesting 68 bytes in both modes. By luck,
this doesn't actually result in any invalid memory accesses because
the allocation is satisfied out of kmalloc-96 slab and so exactly
96 bytes are allocated, but KASAN rightfully complains.

Fixes: cd1a677cad99 ("libceph, ceph: implement msgr2.1 protocol (crc and secure modes)")
Reported-by: Luis Henriques <lhenriques@suse.de>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

libceph, ceph: implement msgr2.1 protocol (crc and secure modes)

Implement msgr2.1 wire protocol, available since nautilus 14.2.11
and octopus 15.2.5. msgr2.0 wire protocol is not implemented -- it
has several security, integrity and robustness issues and therefore
considered deprecated.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>