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2014-04-30net: socket: error on a negative msg_namelenMatthew Leach
[ Upstream commit dbb490b96584d4e958533fb637f08b557f505657 ] When copying in a struct msghdr from the user, if the user has set the msg_namelen parameter to a negative value it gets clamped to a valid size due to a comparison between signed and unsigned values. Ensure the syscall errors when the user passes in a negative value. Signed-off-by: Matthew Leach <matthew.leach@arm.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2014-01-03net: clamp ->msg_namelen instead of returning an errorDan Carpenter
[ Upstream commit db31c55a6fb245fdbb752a2ca4aefec89afabb06 ] If kmsg->msg_namelen > sizeof(struct sockaddr_storage) then in the original code that would lead to memory corruption in the kernel if you had audit configured. If you didn't have audit configured it was harmless. There are some programs such as beta versions of Ruby which use too large of a buffer and returning an error code breaks them. We should clamp the ->msg_namelen value instead. Fixes: 1661bf364ae9 ("net: heap overflow in __audit_sockaddr()") Reported-by: Eric Wong <normalperson@yhbt.net> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Tested-by: Eric Wong <normalperson@yhbt.net> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2014-01-03net: add BUG_ON if kernel advertises msg_namelen > sizeof(struct ↵Hannes Frederic Sowa
sockaddr_storage) [ Upstream commit 68c6beb373955da0886d8f4f5995b3922ceda4be ] In that case it is probable that kernel code overwrote part of the stack. So we should bail out loudly here. The BUG_ON may be removed in future if we are sure all protocols are conformant. Suggested-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2014-01-03net: rework recvmsg handler msg_name and msg_namelen logicHannes Frederic Sowa
[ Upstream commit f3d3342602f8bcbf37d7c46641cb9bca7618eb1c ] This patch now always passes msg->msg_namelen as 0. recvmsg handlers must set msg_namelen to the proper size <= sizeof(struct sockaddr_storage) to return msg_name to the user. This prevents numerous uninitialized memory leaks we had in the recvmsg handlers and makes it harder for new code to accidentally leak uninitialized memory. Optimize for the case recvfrom is called with NULL as address. We don't need to copy the address at all, so set it to NULL before invoking the recvmsg handler. We can do so, because all the recvmsg handlers must cope with the case a plain read() is called on them. read() also sets msg_name to NULL. Also document these changes in include/linux/net.h as suggested by David Miller. Changes since RFC: Set msg->msg_name = NULL if user specified a NULL in msg_name but had a non-null msg_namelen in verify_iovec/verify_compat_iovec. This doesn't affect sendto as it would bail out earlier while trying to copy-in the address. It also more naturally reflects the logic by the callers of verify_iovec. With this change in place I could remove " if (!uaddr || msg_sys->msg_namelen == 0) msg->msg_name = NULL ". This change does not alter the user visible error logic as we ignore msg_namelen as long as msg_name is NULL. Also remove two unnecessary curly brackets in ___sys_recvmsg and change comments to netdev style. Cc: David Miller <davem@davemloft.net> Suggested-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2013-11-28net: heap overflow in __audit_sockaddr()Dan Carpenter
[ Upstream commit 1661bf364ae9c506bc8795fef70d1532931be1e8 ] We need to cap ->msg_namelen or it leads to a buffer overflow when we to the memcpy() in __audit_sockaddr(). It requires CAP_AUDIT_CONTROL to exploit this bug. The call tree is: ___sys_recvmsg() move_addr_to_user() audit_sockaddr() __audit_sockaddr() Reported-by: Jüri Aedla <juri.aedla@gmail.com> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2013-06-29net: Block MSG_CMSG_COMPAT in send(m)msg and recv(m)msgAndy Lutomirski
[ Upstream commits 1be374a0518a288147c6a7398792583200a67261 and a7526eb5d06b0084ef12d7b168d008fcf516caab ] MSG_CMSG_COMPAT is (AFAIK) not intended to be part of the API -- it's a hack that steals a bit to indicate to other networking code that a compat entry was used. So don't allow it from a non-compat syscall. This prevents an oops when running this code: int main() { int s; struct sockaddr_in addr; struct msghdr *hdr; char *highpage = mmap((void*)(TASK_SIZE_MAX - 4096), 4096, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, -1, 0); if (highpage == MAP_FAILED) err(1, "mmap"); s = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP); if (s == -1) err(1, "socket"); addr.sin_family = AF_INET; addr.sin_port = htons(1); addr.sin_addr.s_addr = htonl(INADDR_LOOPBACK); if (connect(s, (struct sockaddr*)&addr, sizeof(addr)) != 0) err(1, "connect"); void *evil = highpage + 4096 - COMPAT_MSGHDR_SIZE; printf("Evil address is %p\n", evil); if (syscall(__NR_sendmmsg, s, evil, 1, MSG_CMSG_COMPAT) < 0) err(1, "sendmmsg"); return 0; } Cc: David S. Miller <davem@davemloft.net> Signed-off-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-09-19net: fix info leak in compat dev_ifconf()Mathias Krause
[ Upstream commit 43da5f2e0d0c69ded3d51907d9552310a6b545e8 ] The implementation of dev_ifconf() for the compat ioctl interface uses an intermediate ifc structure allocated in userland for the duration of the syscall. Though, it fails to initialize the padding bytes inserted for alignment and that for leaks four bytes of kernel stack. Add an explicit memset(0) before filling the structure to avoid the info leak. Signed-off-by: Mathias Krause <minipli@googlemail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-05-11tcp: allow splice() to build full TSO packetsEric Dumazet
[ This combines upstream commit 2f53384424251c06038ae612e56231b96ab610ee and the follow-on bug fix commit 35f9c09fe9c72eb8ca2b8e89a593e1c151f28fc2 ] vmsplice()/splice(pipe, socket) call do_tcp_sendpages() one page at a time, adding at most 4096 bytes to an skb. (assuming PAGE_SIZE=4096) The call to tcp_push() at the end of do_tcp_sendpages() forces an immediate xmit when pipe is not already filled, and tso_fragment() try to split these skb to MSS multiples. 4096 bytes are usually split in a skb with 2 MSS, and a remaining sub-mss skb (assuming MTU=1500) This makes slow start suboptimal because many small frames are sent to qdisc/driver layers instead of big ones (constrained by cwnd and packets in flight of course) In fact, applications using sendmsg() (adding an additional memory copy) instead of vmsplice()/splice()/sendfile() are a bit faster because of this anomaly, especially if serving small files in environments with large initial [c]wnd. Call tcp_push() only if MSG_MORE is not set in the flags parameter. This bit is automatically provided by splice() internals but for the last page, or on all pages if user specified SPLICE_F_MORE splice() flag. In some workloads, this can reduce number of sent logical packets by an order of magnitude, making zero-copy TCP actually faster than one-copy :) Reported-by: Tom Herbert <therbert@google.com> Cc: Nandita Dukkipati <nanditad@google.com> Cc: Neal Cardwell <ncardwell@google.com> Cc: Tom Herbert <therbert@google.com> Cc: Yuchung Cheng <ycheng@google.com> Cc: H.K. Jerry Chu <hkchu@google.com> Cc: Maciej Żenczykowski <maze@google.com> Cc: Mahesh Bandewar <maheshb@google.com> Cc: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-02-03net: reintroduce missing rcu_assign_pointer() callsEric Dumazet
[ Upstream commit cf778b00e96df6d64f8e21b8395d1f8a859ecdc7 ] commit a9b3cd7f32 (rcu: convert uses of rcu_assign_pointer(x, NULL) to RCU_INIT_POINTER) did a lot of incorrect changes, since it did a complete conversion of rcu_assign_pointer(x, y) to RCU_INIT_POINTER(x, y). We miss needed barriers, even on x86, when y is not NULL. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> CC: Stephen Hemminger <shemminger@vyatta.com> CC: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2011-09-22Merge branch 'master' of github.com:davem330/netDavid S. Miller
Conflicts: MAINTAINERS drivers/net/Kconfig drivers/net/ethernet/broadcom/bnx2x/bnx2x_link.c drivers/net/ethernet/broadcom/tg3.c drivers/net/wireless/iwlwifi/iwl-pci.c drivers/net/wireless/iwlwifi/iwl-trans-tx-pcie.c drivers/net/wireless/rt2x00/rt2800usb.c drivers/net/wireless/wl12xx/main.c
2011-08-24sendmmsg/sendmsg: fix unsafe user pointer accessMathieu Desnoyers
Dereferencing a user pointer directly from kernel-space without going through the copy_from_user family of functions is a bad idea. Two of such usages can be found in the sendmsg code path called from sendmmsg, added by commit c71d8ebe7a4496fb7231151cb70a6baa0cb56f9a upstream. commit 5b47b8038f183b44d2d8ff1c7d11a5c1be706b34 in the 3.0-stable tree. Usages are performed through memcmp() and memcpy() directly. Fix those by using the already copied msg_sys structure instead of the __user *msg structure. Note that msg_sys can be set to NULL by verify_compat_iovec() or verify_iovec(), which requires additional NULL pointer checks. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: David Goulet <dgoulet@ev0ke.net> CC: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> CC: Anton Blanchard <anton@samba.org> CC: David S. Miller <davem@davemloft.net> CC: stable <stable@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-08-07Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/netDavid S. Miller
2011-08-05net: Fix security_socket_sendmsg() bypass problem.Tetsuo Handa
The sendmmsg() introduced by commit 228e548e "net: Add sendmmsg socket system call" is capable of sending to multiple different destination addresses. SMACK is using destination's address for checking sendmsg() permission. However, security_socket_sendmsg() is called for only once even if multiple different destination addresses are passed to sendmmsg(). Therefore, we need to call security_socket_sendmsg() for each destination address rather than only the first destination address. Since calling security_socket_sendmsg() every time when only single destination address was passed to sendmmsg() is a waste of time, omit calling security_socket_sendmsg() unless destination address of previous datagram and that of current datagram differs. Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Acked-by: Anton Blanchard <anton@samba.org> Cc: stable <stable@kernel.org> [3.0+] Signed-off-by: David S. Miller <davem@davemloft.net>
2011-08-05net: Cap number of elements for sendmmsgAnton Blanchard
To limit the amount of time we can spend in sendmmsg, cap the number of elements to UIO_MAXIOV (currently 1024). For error handling an application using sendmmsg needs to retry at the first unsent message, so capping is simpler and requires less application logic than returning EINVAL. Signed-off-by: Anton Blanchard <anton@samba.org> Cc: stable <stable@kernel.org> [3.0+] Signed-off-by: David S. Miller <davem@davemloft.net>
2011-08-05net: sendmmsg should only return an error if no messages were sentAnton Blanchard
sendmmsg uses a similar error return strategy as recvmmsg but it turns out to be a confusing way to communicate errors. The current code stores the error code away and returns it on the next sendmmsg call. This means a call with completely valid arguments could get an error from a previous call. Change things so we only return an error if no datagrams could be sent. If less than the requested number of messages were sent, the application must retry starting at the first failed one and if the problem is persistent the error will be returned. This matches the behaviour of other syscalls like read/write - it is not an error if less than the requested number of elements are sent. Signed-off-by: Anton Blanchard <anton@samba.org> Cc: stable <stable@kernel.org> [3.0+] Signed-off-by: David S. Miller <davem@davemloft.net>
2011-08-02rcu: convert uses of rcu_assign_pointer(x, NULL) to RCU_INIT_POINTERStephen Hemminger
When assigning a NULL value to an RCU protected pointer, no barrier is needed. The rcu_assign_pointer, used to handle that but will soon change to not handle the special case. Convert all rcu_assign_pointer of NULL value. //smpl @@ expression P; @@ - rcu_assign_pointer(P, NULL) + RCU_INIT_POINTER(P, NULL) // </smpl> Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-07-28Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (32 commits) tg3: Remove 5719 jumbo frames and TSO blocks tg3: Break larger frags into 4k chunks for 5719 tg3: Add tx BD budgeting code tg3: Consolidate code that calls tg3_tx_set_bd() tg3: Add partial fragment unmapping code tg3: Generalize tg3_skb_error_unmap() tg3: Remove short DMA check for 1st fragment tg3: Simplify tx bd assignments tg3: Reintroduce tg3_tx_ring_info ASIX: Use only 11 bits of header for data size ASIX: Simplify condition in rx_fixup() Fix cdc-phonet build bonding: reduce noise during init bonding: fix string comparison errors net: Audit drivers to identify those needing IFF_TX_SKB_SHARING cleared net: add IFF_SKB_TX_SHARED flag to priv_flags net: sock_sendmsg_nosec() is static forcedeth: fix vlans gianfar: fix bug caused by 87c288c6e9aa31720b72e2bc2d665e24e1653c3e gro: Only reset frag0 when skb can be pulled ...
2011-07-27net: sock_sendmsg_nosec() is staticEric Dumazet
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> CC: Anton Blanchard <anton@samba.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-07-26vfs: dont chain pipe/anon/socket on superblock s_inodes listEric Dumazet
Workloads using pipes and sockets hit inode_sb_list_lock contention. superblock s_inodes list is needed for quota, dirty, pagecache and fsnotify management. pipe/anon/socket fs are clearly not candidates for these. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-05-20Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6: (1446 commits) macvlan: fix panic if lowerdev in a bond tg3: Add braces around 5906 workaround. tg3: Fix NETIF_F_LOOPBACK error macvlan: remove one synchronize_rcu() call networking: NET_CLS_ROUTE4 depends on INET irda: Fix error propagation in ircomm_lmp_connect_response() irda: Kill set but unused variable 'bytes' in irlan_check_command_param() irda: Kill set but unused variable 'clen' in ircomm_connect_indication() rxrpc: Fix set but unused variable 'usage' in rxrpc_get_transport() be2net: Kill set but unused variable 'req' in lancer_fw_download() irda: Kill set but unused vars 'saddr' and 'daddr' in irlan_provider_connect_indication() atl1c: atl1c_resume() is only used when CONFIG_PM_SLEEP is defined. rxrpc: Fix set but unused variable 'usage' in rxrpc_get_peer(). rxrpc: Kill set but unused variable 'local' in rxrpc_UDP_error_handler() rxrpc: Kill set but unused variable 'sp' in rxrpc_process_connection() rxrpc: Kill set but unused variable 'sp' in rxrpc_rotate_tx_window() pkt_sched: Kill set but unused variable 'protocol' in tc_classify() isdn: capi: Use pr_debug() instead of ifdefs. tg3: Update version to 3.119 tg3: Apply rx_discards fix to 5719/5720 ... Fix up trivial conflicts in arch/x86/Kconfig and net/mac80211/agg-tx.c as per Davem.
2011-05-17Merge branch 'master' of ↵David S. Miller
master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 Conflicts: drivers/net/vmxnet3/vmxnet3_ethtool.c net/core/dev.c
2011-05-17net: recvmmsg: Strip MSG_WAITFORONE when calling recvmsgAnton Blanchard
recvmmsg fails on a raw socket with EINVAL. The reason for this is packet_recvmsg checks the incoming flags: err = -EINVAL; if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE)) goto out; This patch strips out MSG_WAITFORONE when calling recvmmsg which fixes the issue. Signed-off-by: Anton Blanchard <anton@samba.org> Cc: stable@kernel.org [2.6.34+] Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-07net,rcu: convert call_rcu(wq_free_rcu) to kfree_rcu()Lai Jiangshan
The rcu callback wq_free_rcu() just calls a kfree(), so we use kfree_rcu() instead of the call_rcu(wq_free_rcu). Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2011-05-05net: Add sendmmsg socket system callAnton Blanchard
This patch adds a multiple message send syscall and is the send version of the existing recvmmsg syscall. This is heavily based on the patch by Arnaldo that added recvmmsg. I wrote a microbenchmark to test the performance gains of using this new syscall: http://ozlabs.org/~anton/junkcode/sendmmsg_test.c The test was run on a ppc64 box with a 10 Gbit network card. The benchmark can send both UDP and RAW ethernet packets. 64B UDP batch pkts/sec 1 804570 2 872800 (+ 8 %) 4 916556 (+14 %) 8 939712 (+17 %) 16 952688 (+18 %) 32 956448 (+19 %) 64 964800 (+20 %) 64B raw socket batch pkts/sec 1 1201449 2 1350028 (+12 %) 4 1461416 (+22 %) 8 1513080 (+26 %) 16 1541216 (+28 %) 32 1553440 (+29 %) 64 1557888 (+30 %) We see a 20% improvement in throughput on UDP send and 30% on raw socket send. [ Add sparc syscall entries. -DaveM ] Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-11Merge branch 'master' of ↵David S. Miller
master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 Conflicts: drivers/net/smsc911x.c
2011-04-11v3 ethtool: add ntuple flow specifier data to network flow classifierAlexander Duyck
This change is meant to add an ntuple data extensions to the rx network flow classification specifiers. The idea is to allow ntuple to be displayed via the network flow classification interface. The first patch had some left over stuff from the original flow extension flags I had added. That bit is removed in this patch. The second had some left over comments that stated we ignored bits in the masks when we actually match them. This work is based on input from Ben Hutchings. Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com> Reviewed-by: Ben Hutchings <bhutchings@solarflare.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-31Fix common misspellingsLucas De Marchi
Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-18ethtool: Compat handling for struct ethtool_rxnfcBen Hutchings
This structure was accidentally defined such that its layout can differ between 32-bit and 64-bit processes. Add compat structure definitions and an ioctl wrapper function. Signed-off-by: Ben Hutchings <bhutchings@solarflare.com> Acked-by: Alexander Duyck <alexander.h.duyck@intel.com> Cc: stable@kernel.org [2.6.30+] Signed-off-by: David S. Miller <davem@davemloft.net>
2011-02-23socket: suppress sparse warningsstephen hemminger
Use __force to quiet sparse warnings for cases where the code is simulating user space pointers. Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-02-22net: add __rcu annotations to sk_wq and wqEric Dumazet
Add proper RCU annotations/verbs to sk_wq and wq members Fix __sctp_write_space() sk_sleep() abuse (and sock->wq access) Fix sunrpc sk_sleep() abuse too Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-12pass default dentry_operations to mount_pseudo()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-07Merge branch 'vfs-scale-working' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/npiggin/linux-npiggin * 'vfs-scale-working' of git://git.kernel.org/pub/scm/linux/kernel/git/npiggin/linux-npiggin: (57 commits) fs: scale mntget/mntput fs: rename vfsmount counter helpers fs: implement faster dentry memcmp fs: prefetch inode data in dcache lookup fs: improve scalability of pseudo filesystems fs: dcache per-inode inode alias locking fs: dcache per-bucket dcache hash locking bit_spinlock: add required includes kernel: add bl_list xfs: provide simple rcu-walk ACL implementation btrfs: provide simple rcu-walk ACL implementation ext2,3,4: provide simple rcu-walk ACL implementation fs: provide simple rcu-walk generic_check_acl implementation fs: provide rcu-walk aware permission i_ops fs: rcu-walk aware d_revalidate method fs: cache optimise dentry and inode for rcu-walk fs: dcache reduce branches in lookup path fs: dcache remove d_mounted fs: fs_struct use seqlock fs: rcu-walk for path lookup ...
2011-01-07fs: scale mntget/mntputNick Piggin
The problem that this patch aims to fix is vfsmount refcounting scalability. We need to take a reference on the vfsmount for every successful path lookup, which often go to the same mount point. The fundamental difficulty is that a "simple" reference count can never be made scalable, because any time a reference is dropped, we must check whether that was the last reference. To do that requires communication with all other CPUs that may have taken a reference count. We can make refcounts more scalable in a couple of ways, involving keeping distributed counters, and checking for the global-zero condition less frequently. - check the global sum once every interval (this will delay zero detection for some interval, so it's probably a showstopper for vfsmounts). - keep a local count and only taking the global sum when local reaches 0 (this is difficult for vfsmounts, because we can't hold preempt off for the life of a reference, so a counter would need to be per-thread or tied strongly to a particular CPU which requires more locking). - keep a local difference of increments and decrements, which allows us to sum the total difference and hence find the refcount when summing all CPUs. Then, keep a single integer "long" refcount for slow and long lasting references, and only take the global sum of local counters when the long refcount is 0. This last scheme is what I implemented here. Attached mounts and process root and working directory references are "long" references, and everything else is a short reference. This allows scalable vfsmount references during path walking over mounted subtrees and unattached (lazy umounted) mounts with processes still running in them. This results in one fewer atomic op in the fastpath: mntget is now just a per-CPU inc, rather than an atomic inc; and mntput just requires a spinlock and non-atomic decrement in the common case. However code is otherwise bigger and heavier, so single threaded performance is basically a wash. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07fs: improve scalability of pseudo filesystemsNick Piggin
Regardless of how much we possibly try to scale dcache, there is likely always going to be some fundamental contention when adding or removing children under the same parent. Pseudo filesystems do not seem need to have connected dentries because by definition they are disconnected. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07fs: dcache reduce branches in lookup pathNick Piggin
Reduce some branches and memory accesses in dcache lookup by adding dentry flags to indicate common d_ops are set, rather than having to check them. This saves a pointer memory access (dentry->d_op) in common path lookup situations, and saves another pointer load and branch in cases where we have d_op but not the particular operation. Patched with: git grep -E '[.>]([[:space:]])*d_op([[:space:]])*=' | xargs sed -e 's/\([^\t ]*\)->d_op = \(.*\);/d_set_d_op(\1, \2);/' -e 's/\([^\t ]*\)\.d_op = \(.*\);/d_set_d_op(\&\1, \2);/' -i Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07fs: avoid inode RCU freeing for pseudo fsNick Piggin
Pseudo filesystems that don't put inode on RCU list or reachable by rcu-walk dentries do not need to RCU free their inodes. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07fs: icache RCU free inodesNick Piggin
RCU free the struct inode. This will allow: - Subsequent store-free path walking patch. The inode must be consulted for permissions when walking, so an RCU inode reference is a must. - sb_inode_list_lock to be moved inside i_lock because sb list walkers who want to take i_lock no longer need to take sb_inode_list_lock to walk the list in the first place. This will simplify and optimize locking. - Could remove some nested trylock loops in dcache code - Could potentially simplify things a bit in VM land. Do not need to take the page lock to follow page->mapping. The downsides of this is the performance cost of using RCU. In a simple creat/unlink microbenchmark, performance drops by about 10% due to inability to reuse cache-hot slab objects. As iterations increase and RCU freeing starts kicking over, this increases to about 20%. In cases where inode lifetimes are longer (ie. many inodes may be allocated during the average life span of a single inode), a lot of this cache reuse is not applicable, so the regression caused by this patch is smaller. The cache-hot regression could largely be avoided by using SLAB_DESTROY_BY_RCU, however this adds some complexity to list walking and store-free path walking, so I prefer to implement this at a later date, if it is shown to be a win in real situations. I haven't found a regression in any non-micro benchmark so I doubt it will be a problem. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2010-12-17Merge branch 'master' of ↵David S. Miller
master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 Conflicts: drivers/net/bnx2x/bnx2x.h drivers/net/wireless/iwlwifi/iwl-1000.c drivers/net/wireless/iwlwifi/iwl-6000.c drivers/net/wireless/iwlwifi/iwl-core.h drivers/vhost/vhost.c
2010-12-10net: Document the kernel_recvmsg() functionMartin Lucina
Signed-off-by: Martin Lucina <mato@kotelna.sk> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-12net: net_families __rcu annotationsEric Dumazet
Use modern RCU API / annotations for net_families array. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-30Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: isdn: mISDN: socket: fix information leak to userland netdev: can: Change mail address of Hans J. Koch pcnet_cs: add new_id net: Truncate recvfrom and sendto length to INT_MAX. RDS: Let rds_message_alloc_sgs() return NULL RDS: Copy rds_iovecs into kernel memory instead of rereading from userspace RDS: Clean up error handling in rds_cmsg_rdma_args RDS: Return -EINVAL if rds_rdma_pages returns an error net: fix rds_iovec page count overflow can: pch_can: fix section mismatch warning by using a whitelisted name can: pch_can: fix sparse warning netxen_nic: Fix the tx queue manipulation bug in netxen_nic_probe ip_gre: fix fallback tunnel setup vmxnet: trivial annotation of protocol constant vmxnet3: remove unnecessary byteswapping in BAR writing macros ipv6/udp: report SndbufErrors and RcvbufErrors phy/marvell: rename 88ec048 to 88e1318s and fix mscr1 addr
2010-10-30net: Truncate recvfrom and sendto length to INT_MAX.Linus Torvalds
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-29convert get_sb_pseudo() usersAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-26Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (52 commits) split invalidate_inodes() fs: skip I_FREEING inodes in writeback_sb_inodes fs: fold invalidate_list into invalidate_inodes fs: do not drop inode_lock in dispose_list fs: inode split IO and LRU lists fs: switch bdev inode bdi's correctly fs: fix buffer invalidation in invalidate_list fsnotify: use dget_parent smbfs: use dget_parent exportfs: use dget_parent fs: use RCU read side protection in d_validate fs: clean up dentry lru modification fs: split __shrink_dcache_sb fs: improve DCACHE_REFERENCED usage fs: use percpu counter for nr_dentry and nr_dentry_unused fs: simplify __d_free fs: take dcache_lock inside __d_path fs: do not assign default i_ino in new_inode fs: introduce a per-cpu last_ino allocator new helper: ihold() ...
2010-10-26Merge branch 'for-2.6.37' of git://linux-nfs.org/~bfields/linuxLinus Torvalds
* 'for-2.6.37' of git://linux-nfs.org/~bfields/linux: (99 commits) svcrpc: svc_tcp_sendto XPT_DEAD check is redundant svcrpc: no need for XPT_DEAD check in svc_xprt_enqueue svcrpc: assume svc_delete_xprt() called only once svcrpc: never clear XPT_BUSY on dead xprt nfsd4: fix connection allocation in sequence() nfsd4: only require krb5 principal for NFSv4.0 callbacks nfsd4: move minorversion to client nfsd4: delay session removal till free_client nfsd4: separate callback change and callback probe nfsd4: callback program number is per-session nfsd4: track backchannel connections nfsd4: confirm only on succesful create_session nfsd4: make backchannel sequence number per-session nfsd4: use client pointer to backchannel session nfsd4: move callback setup into session init code nfsd4: don't cache seq_misordered replies SUNRPC: Properly initialize sock_xprt.srcaddr in all cases SUNRPC: Use conventional switch statement when reclassifying sockets sunrpc/xprtrdma: clean up workqueue usage sunrpc: Turn list_for_each-s into the ..._entry-s ... Fix up trivial conflicts (two different deprecation notices added in separate branches) in Documentation/feature-removal-schedule.txt
2010-10-25fs: do not assign default i_ino in new_inodeChristoph Hellwig
Instead of always assigning an increasing inode number in new_inode move the call to assign it into those callers that actually need it. For now callers that need it is estimated conservatively, that is the call is added to all filesystems that do not assign an i_ino by themselves. For a few more filesystems we can avoid assigning any inode number given that they aren't user visible, and for others it could be done lazily when an inode number is actually needed, but that's left for later patches. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-25new helper: ihold()Al Viro
Clones an existing reference to inode; caller must already hold one. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-23Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6: (1699 commits) bnx2/bnx2x: Unsupported Ethtool operations should return -EINVAL. vlan: Calling vlan_hwaccel_do_receive() is always valid. tproxy: use the interface primary IP address as a default value for --on-ip tproxy: added IPv6 support to the socket match cxgb3: function namespace cleanup tproxy: added IPv6 support to the TPROXY target tproxy: added IPv6 socket lookup function to nf_tproxy_core be2net: Changes to use only priority codes allowed by f/w tproxy: allow non-local binds of IPv6 sockets if IP_TRANSPARENT is enabled tproxy: added tproxy sockopt interface in the IPV6 layer tproxy: added udp6_lib_lookup function tproxy: added const specifiers to udp lookup functions tproxy: split off ipv6 defragmentation to a separate module l2tp: small cleanup nf_nat: restrict ICMP translation for embedded header can: mcp251x: fix generation of error frames can: mcp251x: fix endless loop in interrupt handler if CANINTF_MERRF is set can-raw: add msg_flags to distinguish local traffic 9p: client code cleanup rds: make local functions/variables static ... Fix up conflicts in net/core/dev.c, drivers/net/pcmcia/smc91c92_cs.c and drivers/net/wireless/ath/ath9k/debug.c as per David
2010-10-21socket: localize functionsstephen hemminger
A couple of functions in socket.c are only used there and should be localized. Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-15llseek: automatically add .llseek fopArnd Bergmann
All file_operations should get a .llseek operation so we can make nonseekable_open the default for future file operations without a .llseek pointer. The three cases that we can automatically detect are no_llseek, seq_lseek and default_llseek. For cases where we can we can automatically prove that the file offset is always ignored, we use noop_llseek, which maintains the current behavior of not returning an error from a seek. New drivers should normally not use noop_llseek but instead use no_llseek and call nonseekable_open at open time. Existing drivers can be converted to do the same when the maintainer knows for certain that no user code relies on calling seek on the device file. The generated code is often incorrectly indented and right now contains comments that clarify for each added line why a specific variant was chosen. In the version that gets submitted upstream, the comments will be gone and I will manually fix the indentation, because there does not seem to be a way to do that using coccinelle. Some amount of new code is currently sitting in linux-next that should get the same modifications, which I will do at the end of the merge window. Many thanks to Julia Lawall for helping me learn to write a semantic patch that does all this. ===== begin semantic patch ===== // This adds an llseek= method to all file operations, // as a preparation for making no_llseek the default. // // The rules are // - use no_llseek explicitly if we do nonseekable_open // - use seq_lseek for sequential files // - use default_llseek if we know we access f_pos // - use noop_llseek if we know we don't access f_pos, // but we still want to allow users to call lseek // @ open1 exists @ identifier nested_open; @@ nested_open(...) { <+... nonseekable_open(...) ...+> } @ open exists@ identifier open_f; identifier i, f; identifier open1.nested_open; @@ int open_f(struct inode *i, struct file *f) { <+... ( nonseekable_open(...) | nested_open(...) ) ...+> } @ read disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ read_no_fpos disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { ... when != off } @ write @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ write_no_fpos @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { ... when != off } @ fops0 @ identifier fops; @@ struct file_operations fops = { ... }; @ has_llseek depends on fops0 @ identifier fops0.fops; identifier llseek_f; @@ struct file_operations fops = { ... .llseek = llseek_f, ... }; @ has_read depends on fops0 @ identifier fops0.fops; identifier read_f; @@ struct file_operations fops = { ... .read = read_f, ... }; @ has_write depends on fops0 @ identifier fops0.fops; identifier write_f; @@ struct file_operations fops = { ... .write = write_f, ... }; @ has_open depends on fops0 @ identifier fops0.fops; identifier open_f; @@ struct file_operations fops = { ... .open = open_f, ... }; // use no_llseek if we call nonseekable_open //////////////////////////////////////////// @ nonseekable1 depends on !has_llseek && has_open @ identifier fops0.fops; identifier nso ~= "nonseekable_open"; @@ struct file_operations fops = { ... .open = nso, ... +.llseek = no_llseek, /* nonseekable */ }; @ nonseekable2 depends on !has_llseek @ identifier fops0.fops; identifier open.open_f; @@ struct file_operations fops = { ... .open = open_f, ... +.llseek = no_llseek, /* open uses nonseekable */ }; // use seq_lseek for sequential files ///////////////////////////////////// @ seq depends on !has_llseek @ identifier fops0.fops; identifier sr ~= "seq_read"; @@ struct file_operations fops = { ... .read = sr, ... +.llseek = seq_lseek, /* we have seq_read */ }; // use default_llseek if there is a readdir /////////////////////////////////////////// @ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier readdir_e; @@ // any other fop is used that changes pos struct file_operations fops = { ... .readdir = readdir_e, ... +.llseek = default_llseek, /* readdir is present */ }; // use default_llseek if at least one of read/write touches f_pos ///////////////////////////////////////////////////////////////// @ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read.read_f; @@ // read fops use offset struct file_operations fops = { ... .read = read_f, ... +.llseek = default_llseek, /* read accesses f_pos */ }; @ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, ... + .llseek = default_llseek, /* write accesses f_pos */ }; // Use noop_llseek if neither read nor write accesses f_pos /////////////////////////////////////////////////////////// @ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; identifier write_no_fpos.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, .read = read_f, ... +.llseek = noop_llseek, /* read and write both use no f_pos */ }; @ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write_no_fpos.write_f; @@ struct file_operations fops = { ... .write = write_f, ... +.llseek = noop_llseek, /* write uses no f_pos */ }; @ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; @@ struct file_operations fops = { ... .read = read_f, ... +.llseek = noop_llseek, /* read uses no f_pos */ }; @ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; @@ struct file_operations fops = { ... +.llseek = noop_llseek, /* no read or write fn */ }; ===== End semantic patch ===== Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Julia Lawall <julia@diku.dk> Cc: Christoph Hellwig <hch@infradead.org>