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path: root/net/9p/trans_virtio.c
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2011-04-159p: Fix sparse errorAneesh Kumar K.V
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2011-03-22[net/9p]: Introduce basic flow-control for VirtIO transport.Venkateswararao Jujjuri (JV)
Recent zerocopy work in the 9P VirtIO transport maps and pins user buffers into kernel memory for the server to work on them. Since the user process can initiate this kind of pinning with a simple read/write call, thousands of IO threads initiated by the user process can hog the system resources and could result into denial of service. This patch introduces flow control to avoid that extreme scenario. The ceiling limit to avoid denial of service attacks is set to relatively high (nr_free_pagecache_pages()/4) so that it won't interfere with regular usage, but can step in extreme cases to limit the total system hang. Since we don't have a global structure to accommodate this variable, I choose the virtio_chan as the home for this. Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com> Reviewed-by: Badari Pulavarty <pbadari@us.ibm.com> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2011-03-22[net/9p] Don't re-pin pages on retrying virtqueue_add_buf().Venkateswararao Jujjuri (JV)
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2011-03-22[net/9p] Set the condition just before waking up.Venkateswararao Jujjuri (JV)
Given that the sprious wake-ups are common, we need to move the condition setting right next to the wake_up(). After setting the condition to req->status = REQ_STATUS_RCVD, sprious wakeups may cause the virtqueue back on the free list for someone else to use. This may result in kernel panic while relasing the pinned pages in p9_release_req_pages(). Also rearranged the while loop in req_done() for better redability. Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2011-03-22[net/9p] unconditional wake_up to proc waiting for space on VirtIO ringVenkateswararao Jujjuri (JV)
Process may wait to get space on VirtIO ring to send a transaction to VirtFS server. Current code just does a conditional wake_up() which means only one process will be woken up even if multiple processes are waiting. This fix makes the wake_up unconditional. Hence we won't have any processes waiting for-ever. Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2011-03-15[net/9p] Add preferences to transport layer.Venkateswararao Jujjuri (JV)
This patch adds preferences field to the p9_trans_module. Through this, now transport layer can express its preference about the payload. i.e if payload neds to be part of the PDU or it prefers it to be sent sepearetly so that the transport layer can handle it in a better way. Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2011-03-15[net/9p] Add gup/zero_copy support to VirtIO transport layer.Venkateswararao Jujjuri (JV)
Modify p9_virtio_request() and req_done() functions to support additional payload sent down to the transport layer through tc->pubuf and tc->pkbuf. Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2010-10-28net/9p: Add waitq to VirtIO transport.Venkateswararao Jujjuri (JV)
If there is not enough space for the PDU on the VirtIO ring, current code returns -EIO propagating the error to user. This patch introduced a wqit_queue on the channel, and lets the process wait on this queue until VirtIO ring frees up. Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2010-10-28[net/9p]Serialize virtqueue operations to make VirtIO transport SMP safe.Venkateswararao Jujjuri (JV)
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2010-09-27net/9p: Mount only matching virtio channelsSven Eckelmann
p9_virtio_create will only compare the the channel's tag characters against the device name till the end of the channel's tag but not till the end of the device name. This means that if a user defines channels with the tags foo and foobar then he would mount foo when he requested foonot and may mount foo when he requested foobar. Thus it is necessary to check both string lengths against each other in case of a successful partial string match. Signed-off-by: Sven Eckelmann <sven.eckelmann@gmx.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-19trans_virtio: use virtqueue_xxx wrappersMichael S. Tsirkin
Switch trans_virtio to new virtqueue_xxx wrappers. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2010-03-30include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo
implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-13net/9p: Add sysfs mount_tag file for virtio 9P deviceAneesh Kumar K.V
This adds a new file for virtio 9P device. The file contain details of the mount device name that should be used to mount the 9P file system. Ex: /sys/devices/virtio-pci/virtio1/mount_tag file now contian the tag name to be used to mount the 9P file system. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2010-03-13net/9p: Use the tag name in the config space for identifying mount pointAneesh Kumar K.V
This patch use the tag name in the config space to identify the mount device. The the virtio device name depend on the enumeration order of the device and may not remain the same across multiple boots So we use the tag name which is set via qemu option to uniquely identify the mount device Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2010-03-05net/9p: Handle mount errors correctly.Aneesh Kumar K.V
With this patch we have # mount -t 9p -o trans=virtio virtio2 /mnt/ # mount -t 9p -o trans=virtio virtio2 /mnt/ mount: virtio2 already mounted or /mnt/ busy mount: according to mtab, virtio2 is already mounted on /mnt # mount -t 9p -o trans=virtio virtio3 /mnt/ -o debug=0xfff mount: special device virtio3 does not exist Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2010-03-05net/9p: Remove MAX_9P_CHAN limitAneesh Kumar K.V
Use a list to track the channel instead of statically allocated array Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2010-03-05net/9p: Add multi channel support.Aneesh Kumar K.V
This is needed for supporting multiple mount points. We can find out the device names to be used with mount by checking /sys/devices/virtio-pci/virtio*/device file if the device file have value 9 then the specific virtio device can be used for mounting. ex: #cat /sys/devices/virtio-pci/virtio1/device 9 now we can mount using # mount -t 9p -o trans=virtio virtio1 /mnt/ Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2010-02-089p: Fix the kernel crash on a failed mountAneesh Kumar K.V
The patch fix the crash repoted below [ 15.149907] BUG: unable to handle kernel NULL pointer dereference at 00000001 [ 15.150806] IP: [<c140b886>] p9_virtio_close+0x18/0x24 ..... .... [ 15.150806] Call Trace: [ 15.150806] [<c1408e78>] ? p9_client_destroy+0x3f/0x163 [ 15.150806] [<c1409342>] ? p9_client_create+0x25f/0x270 [ 15.150806] [<c1063b72>] ? trace_hardirqs_on+0xb/0xd [ 15.150806] [<c11ed4e8>] ? match_token+0x64/0x164 [ 15.150806] [<c1175e8d>] ? v9fs_session_init+0x2f1/0x3c8 [ 15.150806] [<c109cfc9>] ? kmem_cache_alloc+0x98/0xb8 [ 15.150806] [<c1063b72>] ? trace_hardirqs_on+0xb/0xd [ 15.150806] [<c1173dd1>] ? v9fs_get_sb+0x47/0x1e8 [ 15.150806] [<c1173dea>] ? v9fs_get_sb+0x60/0x1e8 [ 15.150806] [<c10a2e77>] ? vfs_kern_mount+0x81/0x11a [ 15.150806] [<c10a2f55>] ? do_kern_mount+0x33/0xbe [ 15.150806] [<c10b40b9>] ? do_mount+0x654/0x6b3 [ 15.150806] [<c1038949>] ? do_page_fault+0x0/0x284 [ 15.150806] [<c10b28ec>] ? copy_mount_options+0x73/0xd2 [ 15.150806] [<c10b4179>] ? sys_mount+0x61/0x94 [ 15.150806] [<c14284e9>] ? syscall_call+0x7/0xb .... [ 15.203562] ---[ end trace 1dd159357709eb4b ]--- [ Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2010-02-08net/9p: fix virtio transport to correctly update status on connectEric Van Hensbergen
The 9p virtio transport was not updating its connection status correctly preventing it from being able to mount the server. Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2009-10-22virtio: let header files include virtio_ids.hChristian Borntraeger
Rusty, commit 3ca4f5ca73057a617f9444a91022d7127041970a virtio: add virtio IDs file moved all device IDs into a single file. While the change itself is a very good one, it can break userspace applications. For example if a userspace tool wanted to get the ID of virtio_net it used to include virtio_net.h. This does no longer work, since virtio_net.h does not include virtio_ids.h. This patch moves all "#include <linux/virtio_ids.h>" from the C files into the header files, making the header files compatible with the old ones. In addition, this patch exports virtio_ids.h to userspace. CC: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-09-23virtio: add virtio IDs fileFernando Luis Vazquez Cao
Virtio IDs are spread all over the tree which makes assigning new IDs bothersome. Putting them together should make the process less error-prone. Signed-off-by: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-09-23virtio: get rid of redundant VIRTIO_ID_9P definitionFernando Luis Vazquez Cao
VIRTIO_ID_9P is already defined in include/linux/virtio_9p.h so use that definition instead. Signed-off-by: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Eric Van Hensbergen <ericvh@gmail.com>
2009-09-23virtio: make add_buf return capacity remainingRusty Russell
This API change means that virtio_net can tell how much capacity remains for buffers. It's necessarily fuzzy, since VIRTIO_RING_F_INDIRECT_DESC means we can fit any number of descriptors in one, *if* we can kmalloc. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Dinesh Subhraveti <dineshs@us.ibm.com>
2009-08-179p: minor comment fixesAbhishek Kulkarni
Fix the comments -- mostly the improper and/or missing descriptions of function parameters. Signed-off-by: Abhishek Kulkarni <adkulkar@umail.iu.edu> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2009-06-12virtio: find_vqs/del_vqs virtio operationsMichael S. Tsirkin
This replaces find_vq/del_vq with find_vqs/del_vqs virtio operations, and updates all drivers. This is needed for MSI support, because MSI needs to know the total number of vectors upfront. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (+ lguest/9p compile fixes)
2009-06-12virtio: add names to virtqueue struct, mapping from devices to queues.Rusty Russell
Add a linked list of all virtqueues for a virtio device: this helps for debugging and is also needed for upcoming interface change. Also, add a "name" field for clearer debug messages. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-04-05net/9p: handle correctly interrupted 9P requestsLatchesar Ionkov
Currently the 9p code crashes when a operation is interrupted, i.e. for example when the user presses ^C while reading from a file. This patch fixes the code that is responsible for interruption and flushing of 9P operations. Signed-off-by: Latchesar Ionkov <lucho@ionkov.net>
2008-10-179p: make rpc code common and rework flush codeEric Van Hensbergen
This code moves the rpc function to the common client base, reorganizes the flush code to be more simple and stable, and makes the necessary adjustments to the underlying transports to adapt to the new structure. This reduces the overall amount of code duplication between the transports and should make adding new transports more straightforward. Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2008-10-179p: apply common request code to trans_fdEric Van Hensbergen
Apply the now common p9_req_t structure to the fd transport. Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2008-10-179p: move request management to client codeEric Van Hensbergen
The virtio transport uses a simplified request management system that I want to use for all transports. This patch adapts and moves the exisiting code for managing requests to the client common code. Later patches will apply these mechanisms to the other transports. Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2008-10-179p: consolidate transport structureEric Van Hensbergen
Right now there is a transport module structure which provides per-transport type functions and data and a transport structure which contains per-instance public data as well as function pointers to instance specific functions. This patch moves public transport visible instance data to the client structure (which in some cases had duplicate data) and consolidates the functions into the transport module structure. Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2008-09-249p: implement proper trans module refcounting and unregistrationTejun Heo
9p trans modules aren't refcounted nor were they unregistered properly. Fix it. * Add 9p_trans_module->owner and reference the module on each trans instance creation and put it on destruction. * Protect v9fs_trans_list with a spinlock. This isn't strictly necessary as the list is manipulated only during module loading / unloading but it's a good idea to make the API safe. * Unregister trans modules when the corresponding module is being unloaded. * While at it, kill unnecessary EXPORT_SYMBOL on p9_trans_fd_init(). Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2008-05-149p: fix flags length in netSteven Rostedt
Some files in the net/9p directory uses "int" for flags. This can cause hard to find bugs on some architectures. This patch converts the flags to use "long" instead. This bug was discovered by doing an allyesconfig make on the -rt kernel where checks are done to ensure all flags are of size sizeof(long). Signed-off-by: Steven Rostedt <srostedt@redhat.com> Acked-by: Eric Van Hensbergen <ericvh@gmail.com>
2008-05-149p: use struct mutex instead of struct semaphoreJosef 'Jeff' Sipek
Replace semaphores protecting use flags with a mutex. Signed-off-by: Josef 'Jeff' Sipek <jeffpc@josefsipek.net> Acked-by: Eric Van Hensbergen <ericvh@gmail.com>
2008-05-149p: Documentation updatesEric Van Hensbergen
The kernel-doc comments of much of the 9p system have been in disarray since reorganization. This patch fixes those problems, adds additional documentation and a template book which collects the 9p information. Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2008-02-19net/9p/trans_virtio.c: kmalloc() enough memoryAdrian Bunk
The Coverity checker spotted that less memory than required was allocated. Signed-off-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-02-17net/9p/trans_virtio.c: Use BUG_ONJulia Lawall
if (...) BUG(); should be replaced with BUG_ON(...) when the test has no side-effects to allow a definition of BUG_ON that drops the code completely. The semantic patch that makes this change is as follows: (http://www.emn.fr/x-info/coccinelle/) // <smpl> @ disable unlikely @ expression E,f; @@ ( if (<... f(...) ...>) { BUG(); } | - if (unlikely(E)) { BUG(); } + BUG_ON(E); ) @@ expression E,f; @@ ( if (<... f(...) ...>) { BUG(); } | - if (E) { BUG(); } + BUG_ON(E); ) // </smpl> Signed-off-by: Julia Lawall <julia@diku.dk> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-02-069p: transport API reorganizationEric Van Hensbergen
This merges the mux.c (including the connection interface) with trans_fd in preparation for transport API changes. Ultimately, trans_fd will need to be rewritten to clean it up and simplify the implementation, but this reorganization is viewed as the first step. Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2008-02-069p: add remove function to trans_virtioEric Van Hensbergen
Request from rusty: Just cleaning up patches for 2.6.25 merge, and noticed that net/9p/trans_virtio.c doesn't have a remove function. This will crash when removing the module (console doesn't have one because it can't really be removed). Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2008-02-069p: Fix soft lockup in virtio transportEric Van Hensbergen
This fixes a poorly placed spinlock which could result in a soft lockup condition. Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2008-02-069p: block-based virtio clientEric Van Hensbergen
This replaces the console-based virto client with a block-based client using a single request queue. Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2008-02-04virtio: explicit enable_cb/disable_cb rather than callback return.Rusty Russell
It seems that virtio_net wants to disable callbacks (interrupts) before calling netif_rx_schedule(), so we can't use the return value to do so. Rename "restart" to "cb_enable" and introduce "cb_disable" hook: callback now returns void, rather than a boolean. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-02-04virtio: simplify config mechanism.Rusty Russell
Previously we used a type/len pair within the config space, but this seems overkill. We now simply define a structure which represents the layout in the config space: the config space can now only be extended at the end. The main driver-visible changes: 1) We indicate what fields are present with an explicit feature bit. 2) Virtqueues are explicitly numbered, and not in the config space. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2007-10-239p: add virtio transportEric Van Hensbergen
This adds a transport to 9p for communicating between guests and a host using a virtio based transport. Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>