<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/fs/afs, branch v4.9</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>afs: call-&gt;operation_ID sometimes used as __be32 sometimes as u32</title>
<updated>2016-10-13T16:03:52+00:00</updated>
<author>
<name>David Howells</name>
<email>dhowells@redhat.com</email>
</author>
<published>2016-10-13T07:27:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=50a2c95381a7d0e453d7bdfde81d0c5f8351ba54'/>
<id>50a2c95381a7d0e453d7bdfde81d0c5f8351ba54</id>
<content type='text'>
call-&gt;operation_ID is sometimes being used as __be32 sometimes is being
used as u32.  Be consistent and settle on using as u32.

Signed-off-by: David Howells &lt;dhowells@redhat.com.
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
call-&gt;operation_ID is sometimes being used as __be32 sometimes is being
used as u32.  Be consistent and settle on using as u32.

Signed-off-by: David Howells &lt;dhowells@redhat.com.
</pre>
</div>
</content>
</entry>
<entry>
<title>afs: unmapping the wrong buffer</title>
<updated>2016-10-13T07:33:28+00:00</updated>
<author>
<name>Dan Carpenter</name>
<email>dan.carpenter@oracle.com</email>
</author>
<published>2016-10-12T06:09:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=233c9edcca0136f2b9b304fd4f32e9bb6ce88ea9'/>
<id>233c9edcca0136f2b9b304fd4f32e9bb6ce88ea9</id>
<content type='text'>
We switched from kmap_atomic() to kmap() so the kunmap() calls need to
be updated to match.

Fixes: d001648ec7cf ('rxrpc: Don't expose skbs to in-kernel users [ver #2]')
Signed-off-by: Dan Carpenter &lt;dan.carpenter@oracle.com&gt;
Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
We switched from kmap_atomic() to kmap() so the kunmap() calls need to
be updated to match.

Fixes: d001648ec7cf ('rxrpc: Don't expose skbs to in-kernel users [ver #2]')
Signed-off-by: Dan Carpenter &lt;dan.carpenter@oracle.com&gt;
Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>fs: use mapping_set_error instead of opencoded set_bit</title>
<updated>2016-10-11T22:06:33+00:00</updated>
<author>
<name>Michal Hocko</name>
<email>mhocko@suse.com</email>
</author>
<published>2016-10-11T20:56:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=5114a97a8bce7f4ead29a32b67dee85438699b9e'/>
<id>5114a97a8bce7f4ead29a32b67dee85438699b9e</id>
<content type='text'>
The mapping_set_error() helper sets the correct AS_ flag for the mapping
so there is no reason to open code it.  Use the helper directly.

[akpm@linux-foundation.org: be honest about conversion from -ENXIO to -EIO]
Link: http://lkml.kernel.org/r/20160912111608.2588-2-mhocko@kernel.org
Signed-off-by: Michal Hocko &lt;mhocko@suse.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The mapping_set_error() helper sets the correct AS_ flag for the mapping
so there is no reason to open code it.  Use the helper directly.

[akpm@linux-foundation.org: be honest about conversion from -ENXIO to -EIO]
Link: http://lkml.kernel.org/r/20160912111608.2588-2-mhocko@kernel.org
Signed-off-by: Michal Hocko &lt;mhocko@suse.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net</title>
<updated>2016-10-11T15:10:19+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2016-10-11T15:10:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=6b5e09a748ad0a0b198d0e268c7e689044bfe48a'/>
<id>6b5e09a748ad0a0b198d0e268c7e689044bfe48a</id>
<content type='text'>
Pull networking fixes from David Miller:

 1) Netfilter list handling fix, from Linus.

 2) RXRPC/AFS bug fixes from David Howells (oops on call to serviceless
    endpoints, build warnings, missing notifications, etc.) From David
    Howells.

 3) Kernel log message missing newlines, from Colin Ian King.

 4) Don't enter direct reclaim in netlink dumps, the idea is to use a
    high order allocation first and fallback quickly to a 0-order
    allocation if such a high-order one cannot be done cheaply and
    without reclaim. From Eric Dumazet.

 5) Fix firmware download errors in btusb bluetooth driver, from Ethan
    Hsieh.

 6) Missing Kconfig deps for QCOM_EMAC, from Geert Uytterhoeven.

 7) Fix MDIO_XGENE dup Kconfig entry. From Laura Abbott.

 8) Constrain ipv6 rtr_solicits sysctl values properly, from Maciej
    Żenczykowski.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (65 commits)
  netfilter: Fix slab corruption.
  be2net: Enable VF link state setting for BE3
  be2net: Fix TX stats for TSO packets
  be2net: Update Copyright string in be_hw.h
  be2net: NCSI FW section should be properly updated with ethtool for BE3
  be2net: Provide an alternate way to read pf_num for BEx chips
  wan/fsl_ucc_hdlc: Fix size used in dma_free_coherent()
  net: macb: NULL out phydev after removing mdio bus
  xen-netback: make sure that hashes are not send to unaware frontends
  Fixing a bug in team driver due to incorrect 'unsigned int' to 'int' conversion
  MAINTAINERS: add myself as a maintainer of xen-netback
  ipv6 addrconf: disallow rtr_solicits &lt; -1
  Bluetooth: btusb: Fix atheros firmware download error
  drivers: net: phy: Correct duplicate MDIO_XGENE entry
  ethernet: qualcomm: QCOM_EMAC should depend on HAS_DMA and HAS_IOMEM
  net: ethernet: mediatek: remove hwlro property in the device tree
  net: ethernet: mediatek: get hw lro capability by the chip id instead of by the dtsi
  net: ethernet: mediatek: get the chip id by ETHDMASYS registers
  net: bgmac: Fix errant feature flag check
  netlink: do not enter direct reclaim from netlink_dump()
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull networking fixes from David Miller:

 1) Netfilter list handling fix, from Linus.

 2) RXRPC/AFS bug fixes from David Howells (oops on call to serviceless
    endpoints, build warnings, missing notifications, etc.) From David
    Howells.

 3) Kernel log message missing newlines, from Colin Ian King.

 4) Don't enter direct reclaim in netlink dumps, the idea is to use a
    high order allocation first and fallback quickly to a 0-order
    allocation if such a high-order one cannot be done cheaply and
    without reclaim. From Eric Dumazet.

 5) Fix firmware download errors in btusb bluetooth driver, from Ethan
    Hsieh.

 6) Missing Kconfig deps for QCOM_EMAC, from Geert Uytterhoeven.

 7) Fix MDIO_XGENE dup Kconfig entry. From Laura Abbott.

 8) Constrain ipv6 rtr_solicits sysctl values properly, from Maciej
    Żenczykowski.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (65 commits)
  netfilter: Fix slab corruption.
  be2net: Enable VF link state setting for BE3
  be2net: Fix TX stats for TSO packets
  be2net: Update Copyright string in be_hw.h
  be2net: NCSI FW section should be properly updated with ethtool for BE3
  be2net: Provide an alternate way to read pf_num for BEx chips
  wan/fsl_ucc_hdlc: Fix size used in dma_free_coherent()
  net: macb: NULL out phydev after removing mdio bus
  xen-netback: make sure that hashes are not send to unaware frontends
  Fixing a bug in team driver due to incorrect 'unsigned int' to 'int' conversion
  MAINTAINERS: add myself as a maintainer of xen-netback
  ipv6 addrconf: disallow rtr_solicits &lt; -1
  Bluetooth: btusb: Fix atheros firmware download error
  drivers: net: phy: Correct duplicate MDIO_XGENE entry
  ethernet: qualcomm: QCOM_EMAC should depend on HAS_DMA and HAS_IOMEM
  net: ethernet: mediatek: remove hwlro property in the device tree
  net: ethernet: mediatek: get hw lro capability by the chip id instead of by the dtsi
  net: ethernet: mediatek: get the chip id by ETHDMASYS registers
  net: bgmac: Fix errant feature flag check
  netlink: do not enter direct reclaim from netlink_dump()
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs</title>
<updated>2016-10-11T03:16:43+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2016-10-11T03:16:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=101105b1717f536ca741f940033996302d4ef191'/>
<id>101105b1717f536ca741f940033996302d4ef191</id>
<content type='text'>
Pull more vfs updates from Al Viro:
 "&gt;rename2() work from Miklos + current_time() from Deepa"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fs: Replace current_fs_time() with current_time()
  fs: Replace CURRENT_TIME_SEC with current_time() for inode timestamps
  fs: Replace CURRENT_TIME with current_time() for inode timestamps
  fs: proc: Delete inode time initializations in proc_alloc_inode()
  vfs: Add current_time() api
  vfs: add note about i_op-&gt;rename changes to porting
  fs: rename "rename2" i_op to "rename"
  vfs: remove unused i_op-&gt;rename
  fs: make remaining filesystems use .rename2
  libfs: support RENAME_NOREPLACE in simple_rename()
  fs: support RENAME_NOREPLACE for local filesystems
  ncpfs: fix unused variable warning
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull more vfs updates from Al Viro:
 "&gt;rename2() work from Miklos + current_time() from Deepa"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fs: Replace current_fs_time() with current_time()
  fs: Replace CURRENT_TIME_SEC with current_time() for inode timestamps
  fs: Replace CURRENT_TIME with current_time() for inode timestamps
  fs: proc: Delete inode time initializations in proc_alloc_inode()
  vfs: Add current_time() api
  vfs: add note about i_op-&gt;rename changes to porting
  fs: rename "rename2" i_op to "rename"
  vfs: remove unused i_op-&gt;rename
  fs: make remaining filesystems use .rename2
  libfs: support RENAME_NOREPLACE in simple_rename()
  fs: support RENAME_NOREPLACE for local filesystems
  ncpfs: fix unused variable warning
</pre>
</div>
</content>
</entry>
<entry>
<title>afs: Check for fatal error when in waiting for ack state</title>
<updated>2016-10-06T07:11:50+00:00</updated>
<author>
<name>David Howells</name>
<email>dhowells@redhat.com</email>
</author>
<published>2016-10-06T07:11:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=9008f998a2e992991a5d60656d4573ba4c516c58'/>
<id>9008f998a2e992991a5d60656d4573ba4c516c58</id>
<content type='text'>
When it's in the waiting-for-ACK state, the AFS filesystem needs to check
the result of rxrpc_kernel_recv_data() any time it is notified to see if it
is indicating a fatal error.  If this is the case, it needs to mark the
call completed otherwise the call just sits there and never goes away.

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When it's in the waiting-for-ACK state, the AFS filesystem needs to check
the result of rxrpc_kernel_recv_data() any time it is notified to see if it
is indicating a fatal error.  If this is the case, it needs to mark the
call completed otherwise the call just sits there and never goes away.

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>fs: rename "rename2" i_op to "rename"</title>
<updated>2016-09-27T09:03:58+00:00</updated>
<author>
<name>Miklos Szeredi</name>
<email>mszeredi@redhat.com</email>
</author>
<published>2016-09-27T09:03:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=2773bf00aeb9bf39e022463272a61dd0ec9f55f4'/>
<id>2773bf00aeb9bf39e022463272a61dd0ec9f55f4</id>
<content type='text'>
Generated patch:

sed -i "s/\.rename2\t/\.rename\t\t/" `git grep -wl rename2`
sed -i "s/\brename2\b/rename/g" `git grep -wl rename2`

Signed-off-by: Miklos Szeredi &lt;mszeredi@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Generated patch:

sed -i "s/\.rename2\t/\.rename\t\t/" `git grep -wl rename2`
sed -i "s/\brename2\b/rename/g" `git grep -wl rename2`

Signed-off-by: Miklos Szeredi &lt;mszeredi@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>fs: make remaining filesystems use .rename2</title>
<updated>2016-09-27T09:03:58+00:00</updated>
<author>
<name>Miklos Szeredi</name>
<email>mszeredi@redhat.com</email>
</author>
<published>2016-09-27T09:03:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=1cd66c93ba8cdb873258f58ae6a817b28a02bcc3'/>
<id>1cd66c93ba8cdb873258f58ae6a817b28a02bcc3</id>
<content type='text'>
This is trivial to do:

 - add flags argument to foo_rename()
 - check if flags is zero
 - assign foo_rename() to .rename2 instead of .rename

This doesn't mean it's impossible to support RENAME_NOREPLACE for these
filesystems, but it is not trivial, like for local filesystems.
RENAME_NOREPLACE must guarantee atomicity (i.e. it shouldn't be possible
for a file to be created on one host while it is overwritten by rename on
another host).

Filesystems converted:

9p, afs, ceph, coda, ecryptfs, kernfs, lustre, ncpfs, nfs, ocfs2, orangefs.

After this, we can get rid of the duplicate interfaces for rename.

Signed-off-by: Miklos Szeredi &lt;mszeredi@redhat.com&gt;
Acked-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Acked-by: David Howells &lt;dhowells@redhat.com&gt; [AFS]
Acked-by: Mike Marshall &lt;hubcap@omnibond.com&gt;
Cc: Eric Van Hensbergen &lt;ericvh@gmail.com&gt;
Cc: Ilya Dryomov &lt;idryomov@gmail.com&gt;
Cc: Jan Harkes &lt;jaharkes@cs.cmu.edu&gt;
Cc: Tyler Hicks &lt;tyhicks@canonical.com&gt;
Cc: Oleg Drokin &lt;oleg.drokin@intel.com&gt;
Cc: Trond Myklebust &lt;trond.myklebust@primarydata.com&gt;
Cc: Mark Fasheh &lt;mfasheh@suse.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This is trivial to do:

 - add flags argument to foo_rename()
 - check if flags is zero
 - assign foo_rename() to .rename2 instead of .rename

This doesn't mean it's impossible to support RENAME_NOREPLACE for these
filesystems, but it is not trivial, like for local filesystems.
RENAME_NOREPLACE must guarantee atomicity (i.e. it shouldn't be possible
for a file to be created on one host while it is overwritten by rename on
another host).

Filesystems converted:

9p, afs, ceph, coda, ecryptfs, kernfs, lustre, ncpfs, nfs, ocfs2, orangefs.

After this, we can get rid of the duplicate interfaces for rename.

Signed-off-by: Miklos Szeredi &lt;mszeredi@redhat.com&gt;
Acked-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Acked-by: David Howells &lt;dhowells@redhat.com&gt; [AFS]
Acked-by: Mike Marshall &lt;hubcap@omnibond.com&gt;
Cc: Eric Van Hensbergen &lt;ericvh@gmail.com&gt;
Cc: Ilya Dryomov &lt;idryomov@gmail.com&gt;
Cc: Jan Harkes &lt;jaharkes@cs.cmu.edu&gt;
Cc: Tyler Hicks &lt;tyhicks@canonical.com&gt;
Cc: Oleg Drokin &lt;oleg.drokin@intel.com&gt;
Cc: Trond Myklebust &lt;trond.myklebust@primarydata.com&gt;
Cc: Mark Fasheh &lt;mfasheh@suse.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>rxrpc: Rewrite the data and ack handling code</title>
<updated>2016-09-08T10:10:12+00:00</updated>
<author>
<name>David Howells</name>
<email>dhowells@redhat.com</email>
</author>
<published>2016-09-08T10:10:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=248f219cb8bcbfbd7f132752d44afa2df7c241d1'/>
<id>248f219cb8bcbfbd7f132752d44afa2df7c241d1</id>
<content type='text'>
Rewrite the data and ack handling code such that:

 (1) Parsing of received ACK and ABORT packets and the distribution and the
     filing of DATA packets happens entirely within the data_ready context
     called from the UDP socket.  This allows us to process and discard ACK
     and ABORT packets much more quickly (they're no longer stashed on a
     queue for a background thread to process).

 (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim().  We instead
     keep track of the offset and length of the content of each packet in
     the sk_buff metadata.  This means we don't do any allocation in the
     receive path.

 (3) Jumbo DATA packet parsing is now done in data_ready context.  Rather
     than cloning the packet once for each subpacket and pulling/trimming
     it, we file the packet multiple times with an annotation for each
     indicating which subpacket is there.  From that we can directly
     calculate the offset and length.

 (4) A call's receive queue can be accessed without taking locks (memory
     barriers do have to be used, though).

 (5) Incoming calls are set up from preallocated resources and immediately
     made live.  They can than have packets queued upon them and ACKs
     generated.  If insufficient resources exist, DATA packet #1 is given a
     BUSY reply and other DATA packets are discarded).

 (6) sk_buffs no longer take a ref on their parent call.

To make this work, the following changes are made:

 (1) Each call's receive buffer is now a circular buffer of sk_buff
     pointers (rxtx_buffer) rather than a number of sk_buff_heads spread
     between the call and the socket.  This permits each sk_buff to be in
     the buffer multiple times.  The receive buffer is reused for the
     transmit buffer.

 (2) A circular buffer of annotations (rxtx_annotations) is kept parallel
     to the data buffer.  Transmission phase annotations indicate whether a
     buffered packet has been ACK'd or not and whether it needs
     retransmission.

     Receive phase annotations indicate whether a slot holds a whole packet
     or a jumbo subpacket and, if the latter, which subpacket.  They also
     note whether the packet has been decrypted in place.

 (3) DATA packet window tracking is much simplified.  Each phase has just
     two numbers representing the window (rx_hard_ack/rx_top and
     tx_hard_ack/tx_top).

     The hard_ack number is the sequence number before base of the window,
     representing the last packet the other side says it has consumed.
     hard_ack starts from 0 and the first packet is sequence number 1.

     The top number is the sequence number of the highest-numbered packet
     residing in the buffer.  Packets between hard_ack+1 and top are
     soft-ACK'd to indicate they've been received, but not yet consumed.

     Four macros, before(), before_eq(), after() and after_eq() are added
     to compare sequence numbers within the window.  This allows for the
     top of the window to wrap when the hard-ack sequence number gets close
     to the limit.

     Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also
     to indicate when rx_top and tx_top point at the packets with the
     LAST_PACKET bit set, indicating the end of the phase.

 (4) Calls are queued on the socket 'receive queue' rather than packets.
     This means that we don't need have to invent dummy packets to queue to
     indicate abnormal/terminal states and we don't have to keep metadata
     packets (such as ABORTs) around

 (5) The offset and length of a (sub)packet's content are now passed to
     the verify_packet security op.  This is currently expected to decrypt
     the packet in place and validate it.

     However, there's now nowhere to store the revised offset and length of
     the actual data within the decrypted blob (there may be a header and
     padding to skip) because an sk_buff may represent multiple packets, so
     a locate_data security op is added to retrieve these details from the
     sk_buff content when needed.

 (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is
     individually secured and needs to be individually decrypted.  The code
     to do this is broken out into rxrpc_recvmsg_data() and shared with the
     kernel API.  It now iterates over the call's receive buffer rather
     than walking the socket receive queue.

Additional changes:

 (1) The timers are condensed to a single timer that is set for the soonest
     of three timeouts (delayed ACK generation, DATA retransmission and
     call lifespan).

 (2) Transmission of ACK and ABORT packets is effected immediately from
     process-context socket ops/kernel API calls that cause them instead of
     them being punted off to a background work item.  The data_ready
     handler still has to defer to the background, though.

 (3) A shutdown op is added to the AF_RXRPC socket so that the AFS
     filesystem can shut down the socket and flush its own work items
     before closing the socket to deal with any in-progress service calls.

Future additional changes that will need to be considered:

 (1) Make sure that a call doesn't hog the front of the queue by receiving
     data from the network as fast as userspace is consuming it to the
     exclusion of other calls.

 (2) Transmit delayed ACKs from within recvmsg() when we've consumed
     sufficiently more packets to avoid the background work item needing to
     run.

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Rewrite the data and ack handling code such that:

 (1) Parsing of received ACK and ABORT packets and the distribution and the
     filing of DATA packets happens entirely within the data_ready context
     called from the UDP socket.  This allows us to process and discard ACK
     and ABORT packets much more quickly (they're no longer stashed on a
     queue for a background thread to process).

 (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim().  We instead
     keep track of the offset and length of the content of each packet in
     the sk_buff metadata.  This means we don't do any allocation in the
     receive path.

 (3) Jumbo DATA packet parsing is now done in data_ready context.  Rather
     than cloning the packet once for each subpacket and pulling/trimming
     it, we file the packet multiple times with an annotation for each
     indicating which subpacket is there.  From that we can directly
     calculate the offset and length.

 (4) A call's receive queue can be accessed without taking locks (memory
     barriers do have to be used, though).

 (5) Incoming calls are set up from preallocated resources and immediately
     made live.  They can than have packets queued upon them and ACKs
     generated.  If insufficient resources exist, DATA packet #1 is given a
     BUSY reply and other DATA packets are discarded).

 (6) sk_buffs no longer take a ref on their parent call.

To make this work, the following changes are made:

 (1) Each call's receive buffer is now a circular buffer of sk_buff
     pointers (rxtx_buffer) rather than a number of sk_buff_heads spread
     between the call and the socket.  This permits each sk_buff to be in
     the buffer multiple times.  The receive buffer is reused for the
     transmit buffer.

 (2) A circular buffer of annotations (rxtx_annotations) is kept parallel
     to the data buffer.  Transmission phase annotations indicate whether a
     buffered packet has been ACK'd or not and whether it needs
     retransmission.

     Receive phase annotations indicate whether a slot holds a whole packet
     or a jumbo subpacket and, if the latter, which subpacket.  They also
     note whether the packet has been decrypted in place.

 (3) DATA packet window tracking is much simplified.  Each phase has just
     two numbers representing the window (rx_hard_ack/rx_top and
     tx_hard_ack/tx_top).

     The hard_ack number is the sequence number before base of the window,
     representing the last packet the other side says it has consumed.
     hard_ack starts from 0 and the first packet is sequence number 1.

     The top number is the sequence number of the highest-numbered packet
     residing in the buffer.  Packets between hard_ack+1 and top are
     soft-ACK'd to indicate they've been received, but not yet consumed.

     Four macros, before(), before_eq(), after() and after_eq() are added
     to compare sequence numbers within the window.  This allows for the
     top of the window to wrap when the hard-ack sequence number gets close
     to the limit.

     Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also
     to indicate when rx_top and tx_top point at the packets with the
     LAST_PACKET bit set, indicating the end of the phase.

 (4) Calls are queued on the socket 'receive queue' rather than packets.
     This means that we don't need have to invent dummy packets to queue to
     indicate abnormal/terminal states and we don't have to keep metadata
     packets (such as ABORTs) around

 (5) The offset and length of a (sub)packet's content are now passed to
     the verify_packet security op.  This is currently expected to decrypt
     the packet in place and validate it.

     However, there's now nowhere to store the revised offset and length of
     the actual data within the decrypted blob (there may be a header and
     padding to skip) because an sk_buff may represent multiple packets, so
     a locate_data security op is added to retrieve these details from the
     sk_buff content when needed.

 (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is
     individually secured and needs to be individually decrypted.  The code
     to do this is broken out into rxrpc_recvmsg_data() and shared with the
     kernel API.  It now iterates over the call's receive buffer rather
     than walking the socket receive queue.

Additional changes:

 (1) The timers are condensed to a single timer that is set for the soonest
     of three timeouts (delayed ACK generation, DATA retransmission and
     call lifespan).

 (2) Transmission of ACK and ABORT packets is effected immediately from
     process-context socket ops/kernel API calls that cause them instead of
     them being punted off to a background work item.  The data_ready
     handler still has to defer to the background, though.

 (3) A shutdown op is added to the AF_RXRPC socket so that the AFS
     filesystem can shut down the socket and flush its own work items
     before closing the socket to deal with any in-progress service calls.

Future additional changes that will need to be considered:

 (1) Make sure that a call doesn't hog the front of the queue by receiving
     data from the network as fast as userspace is consuming it to the
     exclusion of other calls.

 (2) Transmit delayed ACKs from within recvmsg() when we've consumed
     sufficiently more packets to avoid the background work item needing to
     run.

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>rxrpc: Preallocate peers, conns and calls for incoming service requests</title>
<updated>2016-09-08T10:10:12+00:00</updated>
<author>
<name>David Howells</name>
<email>dhowells@redhat.com</email>
</author>
<published>2016-09-08T10:10:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=00e907127e6f86d0f9b122d9b4347a8aa09a8b61'/>
<id>00e907127e6f86d0f9b122d9b4347a8aa09a8b61</id>
<content type='text'>
Make it possible for the data_ready handler called from the UDP transport
socket to completely instantiate an rxrpc_call structure and make it
immediately live by preallocating all the memory it might need.  The idea
is to cut out the background thread usage as much as possible.

[Note that the preallocated structs are not actually used in this patch -
 that will be done in a future patch.]

If insufficient resources are available in the preallocation buffers, it
will be possible to discard the DATA packet in the data_ready handler or
schedule a BUSY packet without the need to schedule an attempt at
allocation in a background thread.

To this end:

 (1) Preallocate rxrpc_peer, rxrpc_connection and rxrpc_call structs to a
     maximum number each of the listen backlog size.  The backlog size is
     limited to a maxmimum of 32.  Only this many of each can be in the
     preallocation buffer.

 (2) For userspace sockets, the preallocation is charged initially by
     listen() and will be recharged by accepting or rejecting pending
     new incoming calls.

 (3) For kernel services {,re,dis}charging of the preallocation buffers is
     handled manually.  Two notifier callbacks have to be provided before
     kernel_listen() is invoked:

     (a) An indication that a new call has been instantiated.  This can be
     	 used to trigger background recharging.

     (b) An indication that a call is being discarded.  This is used when
     	 the socket is being released.

     A function, rxrpc_kernel_charge_accept() is called by the kernel
     service to preallocate a single call.  It should be passed the user ID
     to be used for that call and a callback to associate the rxrpc call
     with the kernel service's side of the ID.

 (4) Discard the preallocation when the socket is closed.

 (5) Temporarily bump the refcount on the call allocated in
     rxrpc_incoming_call() so that rxrpc_release_call() can ditch the
     preallocation ref on service calls unconditionally.  This will no
     longer be necessary once the preallocation is used.

Note that this does not yet control the number of active service calls on a
client - that will come in a later patch.

A future development would be to provide a setsockopt() call that allows a
userspace server to manually charge the preallocation buffer.  This would
allow user call IDs to be provided in advance and the awkward manual accept
stage to be bypassed.

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Make it possible for the data_ready handler called from the UDP transport
socket to completely instantiate an rxrpc_call structure and make it
immediately live by preallocating all the memory it might need.  The idea
is to cut out the background thread usage as much as possible.

[Note that the preallocated structs are not actually used in this patch -
 that will be done in a future patch.]

If insufficient resources are available in the preallocation buffers, it
will be possible to discard the DATA packet in the data_ready handler or
schedule a BUSY packet without the need to schedule an attempt at
allocation in a background thread.

To this end:

 (1) Preallocate rxrpc_peer, rxrpc_connection and rxrpc_call structs to a
     maximum number each of the listen backlog size.  The backlog size is
     limited to a maxmimum of 32.  Only this many of each can be in the
     preallocation buffer.

 (2) For userspace sockets, the preallocation is charged initially by
     listen() and will be recharged by accepting or rejecting pending
     new incoming calls.

 (3) For kernel services {,re,dis}charging of the preallocation buffers is
     handled manually.  Two notifier callbacks have to be provided before
     kernel_listen() is invoked:

     (a) An indication that a new call has been instantiated.  This can be
     	 used to trigger background recharging.

     (b) An indication that a call is being discarded.  This is used when
     	 the socket is being released.

     A function, rxrpc_kernel_charge_accept() is called by the kernel
     service to preallocate a single call.  It should be passed the user ID
     to be used for that call and a callback to associate the rxrpc call
     with the kernel service's side of the ID.

 (4) Discard the preallocation when the socket is closed.

 (5) Temporarily bump the refcount on the call allocated in
     rxrpc_incoming_call() so that rxrpc_release_call() can ditch the
     preallocation ref on service calls unconditionally.  This will no
     longer be necessary once the preallocation is used.

Note that this does not yet control the number of active service calls on a
client - that will come in a later patch.

A future development would be to provide a setsockopt() call that allows a
userspace server to manually charge the preallocation buffer.  This would
allow user call IDs to be provided in advance and the awkward manual accept
stage to be bypassed.

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
</pre>
</div>
</content>
</entry>
</feed>
