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| * 9p: Drop kref usageKent Overstreet2022-07-091-11/+8
| | | | | | | | | | | | | | | | | | | | | | | | An upcoming patch is going to require passing the client through p9_req_put() -> p9_req_free(), but that's awkward with the kref indirection - so this patch switches to using refcount_t directly. Link: https://lkml.kernel.org/r/20220704014243.153050-1-kent.overstreet@gmail.com Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com> Cc: Eric Van Hensbergen <ericvh@gmail.com> Cc: Latchesar Ionkov <lucho@ionkov.net> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
| * 9p fid refcount: add a 9p_fid_ref tracepointDominique Martinet2022-07-021-1/+19
| | | | | | | | | | | | | | | | | | | | This adds a tracepoint event for 9p fid lifecycle tracing: when a fid is created, its reference count increased/decreased, and freed. The new 9p_fid_ref tracepoint should help anyone wishing to debug any fid problem such as missing clunk (destroy) or use-after-free. Link: https://lkml.kernel.org/r/20220612085330.1451496-6-asmadeus@codewreck.org Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
| * 9p fid refcount: add p9_fid_get/put wrappersDominique Martinet2022-07-021-12/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | I was recently reminded that it is not clear that p9_client_clunk() was actually just decrementing refcount and clunking only when that reaches zero: make it clear through a set of helpers. This will also allow instrumenting refcounting better for debugging next patch Link: https://lkml.kernel.org/r/20220612085330.1451496-5-asmadeus@codewreck.org Reviewed-by: Tyler Hicks <tyhicks@linux.microsoft.com> Reviewed-by: Christian Schoenebeck <linux_oss@crudebyte.com> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
* | 9p: handling Rerror without copy_from_iter_full()Al Viro2022-06-092-85/+35
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | p9_client_zc_rpc()/p9_check_zc_errors() are playing fast and loose with copy_from_iter_full(). Reading from file is done by sending Tread request. Response consists of fixed-sized header (including the amount of data actually read) followed by the data itself. For zero-copy case we arrange the things so that the first 11 bytes of reply go into the fixed-sized buffer, with the rest going straight into the pages we want to read into. What makes the things inconvenient is that sglist describing what should go where has to be set *before* the reply arrives. As the result, if reply is an error, the things get interesting. On success we get size[4] Rread tag[2] count[4] data[count] For error layout varies depending upon the protocol variant - in original 9P and 9P2000 it's size[4] Rerror tag[2] len[2] error[len] in 9P2000.U size[4] Rerror tag[2] len[2] error[len] errno[4] in 9P2000.L size[4] Rlerror tag[2] errno[4] The last case is nice and simple - we have an 11-byte response that fits into the fixed-sized buffer we hoped to get an Rread into. In other two, though, we get a variable-length string spill into the pages we'd prepared for the data to be read. Had that been in fixed-sized buffer (which is actually 4K), we would've dealt with that the same way we handle non-zerocopy case. However, for zerocopy it doesn't end up there, so we need to copy it from those pages. The trouble is, by the time we get around to that, the references to pages in question are already dropped. As the result, p9_zc_check_errors() tries to get the data using copy_from_iter_full(). Unfortunately, the iov_iter it's trying to read from might *NOT* be capable of that. It is, after all, a data destination, not data source. In particular, if it's an ITER_PIPE one, copy_from_iter_full() will simply fail. In ->zc_request() itself we do have those pages and dealing with the problem in there would be a simple matter of memcpy_from_page() into the fixed-sized buffer. Moreover, it isn't hard to recognize the (rare) case when such copying is needed. That way we get rid of p9_zc_check_errors() entirely - p9_check_errors() can be used instead both for zero-copy and non-zero-copy cases. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* xen: switch gnttab_end_foreign_access() to take a struct page pointerJuergen Gross2022-05-271-4/+4
| | | | | | | | | | | | | | | | | Instead of a virtual kernel address use a pointer of the associated struct page as second parameter of gnttab_end_foreign_access(). Most users have that pointer available already and are creating the virtual address from it, risking problems in case the memory is located in highmem. gnttab_end_foreign_access() itself won't need to get the struct page from the address again. Suggested-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com>
* xen/grant-table: remove readonly parameter from functionsJuergen Gross2022-03-151-4/+4
| | | | | | | | | | | | The gnttab_end_foreign_access() family of functions is taking a "readonly" parameter, which isn't used. Remove it from the function parameters. Signed-off-by: Juergen Gross <jgross@suse.com> Link: https://lore.kernel.org/r/20220311103429.12845-3-jgross@suse.com Reviewed-by: Jan Beulich <jbeulich@suse.com> Acked-by: Christian Schoenebeck <qemu_oss@crudebyte.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
* xen/9p: use alloc/free_pages_exact()Juergen Gross2022-03-071-8/+6
| | | | | | | | | | | | | | | | | | | | | | | | | Instead of __get_free_pages() and free_pages() use alloc_pages_exact() and free_pages_exact(). This is in preparation of a change of gnttab_end_foreign_access() which will prohibit use of high-order pages. By using the local variable "order" instead of ring->intf->ring_order in the error path of xen_9pfs_front_alloc_dataring() another bug is fixed, as the error path can be entered before ring->intf->ring_order is being set. By using alloc_pages_exact() the size in bytes is specified for the allocation, which fixes another bug for the case of order < (PAGE_SHIFT - XEN_PAGE_SHIFT). This is part of CVE-2022-23041 / XSA-396. Reported-by: Simon Gaiser <simon@invisiblethingslab.com> Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Jan Beulich <jbeulich@suse.com> --- V4: - new patch
* Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhostLinus Torvalds2022-01-181-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull virtio updates from Michael Tsirkin: "virtio,vdpa,qemu_fw_cfg: features, cleanups, and fixes. - partial support for < MAX_ORDER - 1 granularity for virtio-mem - driver_override for vdpa - sysfs ABI documentation for vdpa - multiqueue config support for mlx5 vdpa - and misc fixes, cleanups" * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (42 commits) vdpa/mlx5: Fix tracking of current number of VQs vdpa/mlx5: Fix is_index_valid() to refer to features vdpa: Protect vdpa reset with cf_mutex vdpa: Avoid taking cf_mutex lock on get status vdpa/vdpa_sim_net: Report max device capabilities vdpa: Use BIT_ULL for bit operations vdpa/vdpa_sim: Configure max supported virtqueues vdpa/mlx5: Report max device capabilities vdpa: Support reporting max device capabilities vdpa/mlx5: Restore cur_num_vqs in case of failure in change_num_qps() vdpa: Add support for returning device configuration information vdpa/mlx5: Support configuring max data virtqueue vdpa/mlx5: Fix config_attr_mask assignment vdpa: Allow to configure max data virtqueues vdpa: Read device configuration only if FEATURES_OK vdpa: Sync calls set/get config/status with cf_mutex vdpa/mlx5: Distribute RX virtqueues in RQT object vdpa: Provide interface to read driver features vdpa: clean up get_config_size ret value handling virtio_ring: mark ring unused on error ...
| * virtio: wrap config->reset callsMichael S. Tsirkin2022-01-141-1/+1
| | | | | | | | | | | | | | | | | | | | | | This will enable cleanups down the road. The idea is to disable cbs, then add "flush_queued_cbs" callback as a parameter, this way drivers can flush any work queued after callbacks have been disabled. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Link: https://lore.kernel.org/r/20211013105226.20225-1-mst@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* | net/9p: show error message if user 'msize' cannot be satisfiedChristian Schoenebeck2022-01-101-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | If user supplied a large value with the 'msize' option, then client would silently limit that 'msize' value to the maximum value supported by transport. That's a bit confusing for users of not having any indication why the preferred 'msize' value could not be satisfied. Link: https://lkml.kernel.org/r/783ba37c1566dd715b9a67d437efa3b77e3cd1a7.1640870037.git.linux_oss@crudebyte.com Reported-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Christian Schoenebeck <linux_oss@crudebyte.com> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
* | net/p9: load default transportsThomas Weißschuh2022-01-101-2/+11
| | | | | | | | | | | | | | | | | | | | | | Now that all transports are split into modules it may happen that no transports are registered when v9fs_get_default_trans() is called. When that is the case try to load more transports from modules. Link: https://lkml.kernel.org/r/20211103193823.111007-5-linux@weissschuh.net Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> [Dominique: constify v9fs_get_trans_by_name argument as per patch1v2] Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
* | 9p/xen: autoload when xenbus service is availableThomas Weißschuh2022-01-101-0/+1
| | | | | | | | | | | | Link: https://lkml.kernel.org/r/20211103193823.111007-4-linux@weissschuh.net Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
* | 9p/trans_fd: split into dedicated moduleThomas Weißschuh2022-01-104-5/+23
| | | | | | | | | | | | | | | | | | This allows these transports only to be used when needed. Link: https://lkml.kernel.org/r/20211103193823.111007-3-linux@weissschuh.net Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> [Dominique: Kconfig NET_9P_FD: -depends VIRTIO, +default NET_9P] Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
* | 9p/trans_virtio: Fix typo in the comment for p9_virtio_create()zhuxinran2021-12-181-1/+1
|/ | | | | | | | couldlook ==> could look Link: https://lkml.kernel.org/r/20211216061439.4186-1-zhuran@mail.ustc.edu.cn Signed-off-by: zhuxinran <zhuran@mail.ustc.edu.cn> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
* 9p: fix a bunch of checkpatch warningsDominique Martinet2021-11-046-246/+237
| | | | | | | | | | Sohaib Mohamed started a serie of tiny and incomplete checkpatch fixes but seemingly stopped halfway -- take over and do most of it. This is still missing net/9p/trans* and net/9p/protocol.c for a later time... Link: http://lkml.kernel.org/r/20211102134608.1588018-3-dominique.martinet@atmark-techno.com Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
* 9p: fix file headersDominique Martinet2021-11-0310-56/+3
| | | | | | | | - add missing SPDX-License-Identifier - remove (sometimes incorrect) file name from file header Link: http://lkml.kernel.org/r/20211102134608.1588018-2-dominique.martinet@atmark-techno.com Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
* net/9p: autoload transport modulesThomas Weißschuh2021-11-034-6/+27
| | | | | | | | | | Automatically load transport modules based on the trans= parameter passed to mount. This removes the requirement for the user to know which module to use. Link: http://lkml.kernel.org/r/20211017134611.4330-1-linux@weissschuh.net Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
* 9p/net: fix missing error check in p9_check_errorsDominique Martinet2021-11-031-0/+2
| | | | | | | Link: https://lkml.kernel.org/r/99338965-d36c-886e-cd0e-1d8fff2b4746@gmail.com Reported-by: syzbot+06472778c97ed94af66d@syzkaller.appspotmail.com Cc: stable@vger.kernel.org Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
* net/9p: increase default msize to 128kChristian Schoenebeck2021-09-051-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | Let's raise the default msize value to 128k. The 'msize' option defines the maximum message size allowed for any message being transmitted (in both directions) between 9p server and 9p client during a 9p session. Currently the default 'msize' is just 8k, which is way too conservative. Such a small 'msize' value has quite a negative performance impact, because individual 9p messages have to be split up far too often into numerous smaller messages to fit into this message size limitation. A default value of just 8k also has a much higher probablity of hitting short-read issues like: https://gitlab.com/qemu-project/qemu/-/issues/409 Unfortunately user feedback showed that many 9p users are not aware that this option even exists, nor the negative impact it might have if it is too low. Link: http://lkml.kernel.org/r/61ea0f0faaaaf26dd3c762eabe4420306ced21b9.1630770829.git.linux_oss@crudebyte.com Link: https://lists.gnu.org/archive/html/qemu-devel/2021-03/msg01003.html Signed-off-by: Christian Schoenebeck <linux_oss@crudebyte.com> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
* net/9p: use macro to define default msizeChristian Schoenebeck2021-09-051-2/+4
| | | | | | | | | Use a macro to define the default value for the 'msize' option at one place instead of using two separate integer literals. Link: http://lkml.kernel.org/r/28bb651ae0349a7d57e8ddc92c1bd5e62924a912.1630770829.git.linux_oss@crudebyte.com Signed-off-by: Christian Schoenebeck <linux_oss@crudebyte.com> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
* net/9p: increase tcp max msize to 1MBDominique Martinet2021-09-051-1/+1
| | | | | | | | | | | | | | | | Historically TCP has been limited to 64K buffers, but increasing msize provides huge performance benefits especially as latency increase so allow for bigger buffers. Ideally further improvements could change the allocation from the current contiguous chunk in slab (kmem_cache) to some scatter-gather compatible API... Note this only increases the max possible setting, not the default value. Link: http://lkml.kernel.org/r/YTQB5jCbvhmCWzNd@codewreck.org Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
* 9p/xen: Fix end of loop tests for list_for_each_entryHarshvardhan Jha2021-07-271-2/+2
| | | | | | | | | | | | | | | This patch addresses the following problems: - priv can never be NULL, so this part of the check is useless - if the loop ran through the whole list, priv->client is invalid and it is more appropriate and sufficient to check for the end of list_for_each_entry loop condition. Link: http://lkml.kernel.org/r/20210727000709.225032-1-harshvardhan.jha@oracle.com Signed-off-by: Harshvardhan Jha <harshvardhan.jha@oracle.com> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> Tested-by: Stefano Stabellini <sstabellini@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
* 9p/trans_virtio: Remove sysfs file on probe failureXie Yongji2021-07-271-1/+3
| | | | | | | | | | This ensures we don't leak the sysfs file if we failed to allocate chan->vc_wq during probe. Link: http://lkml.kernel.org/r/20210517083557.172-1-xieyongji@bytedance.com Fixes: 86c8437383ac ("net/9p: Add sysfs mount_tag file for virtio 9P device") Signed-off-by: Xie Yongji <xieyongji@bytedance.com> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
* 9p/trans_virtio: Fix spelling mistakesZheng Yongjun2021-06-021-3/+3
| | | | | | | | | reseting ==> resetting alloced ==> allocated accomodate ==> accommodate Signed-off-by: Zheng Yongjun <zhengyongjun3@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: 9p: Correct function names in the kerneldoc commentsXiongfeng Wang2021-03-281-2/+2
| | | | | | | | | | | Fix the following W=1 kernel build warning(s): net/9p/client.c:133: warning: expecting prototype for parse_options(). Prototype was for parse_opts() instead net/9p/client.c:269: warning: expecting prototype for p9_req_alloc(). Prototype was for p9_tag_alloc() instead Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* 9p/trans_fd: Correct function name p9_mux_destroy() in the kerneldocXiongfeng Wang2021-03-281-1/+1
| | | | | | | | | | Fix the following W=1 kernel build warning(s): net/9p/trans_fd.c:881: warning: expecting prototype for p9_mux_destroy(). Prototype was for p9_conn_destroy() instead Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: 9p: Correct function name errstr2errno() in the kerneldoc commentsXiongfeng Wang2021-03-281-1/+1
| | | | | | | | | | Fix the following W=1 kernel build warning(s): net/9p/error.c:207: warning: expecting prototype for errstr2errno(). Prototype was for p9_errstr2errno() instead Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: 9p: advance iov on empty readJisheng Zhang2021-03-031-4/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I met below warning when cating a small size(about 80bytes) txt file on 9pfs(msize=2097152 is passed to 9p mount option), the reason is we miss iov_iter_advance() if the read count is 0 for zerocopy case, so we didn't truncate the pipe, then iov_iter_pipe() thinks the pipe is full. Fix it by removing the exception for 0 to ensure to call iov_iter_advance() even on empty read for zerocopy case. [ 8.279568] WARNING: CPU: 0 PID: 39 at lib/iov_iter.c:1203 iov_iter_pipe+0x31/0x40 [ 8.280028] Modules linked in: [ 8.280561] CPU: 0 PID: 39 Comm: cat Not tainted 5.11.0+ #6 [ 8.281260] RIP: 0010:iov_iter_pipe+0x31/0x40 [ 8.281974] Code: 2b 42 54 39 42 5c 76 22 c7 07 20 00 00 00 48 89 57 18 8b 42 50 48 c7 47 08 b [ 8.283169] RSP: 0018:ffff888000cbbd80 EFLAGS: 00000246 [ 8.283512] RAX: 0000000000000010 RBX: ffff888000117d00 RCX: 0000000000000000 [ 8.283876] RDX: ffff88800031d600 RSI: 0000000000000000 RDI: ffff888000cbbd90 [ 8.284244] RBP: ffff888000cbbe38 R08: 0000000000000000 R09: ffff8880008d2058 [ 8.284605] R10: 0000000000000002 R11: ffff888000375510 R12: 0000000000000050 [ 8.284964] R13: ffff888000cbbe80 R14: 0000000000000050 R15: ffff88800031d600 [ 8.285439] FS: 00007f24fd8af600(0000) GS:ffff88803ec00000(0000) knlGS:0000000000000000 [ 8.285844] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 8.286150] CR2: 00007f24fd7d7b90 CR3: 0000000000c97000 CR4: 00000000000406b0 [ 8.286710] Call Trace: [ 8.288279] generic_file_splice_read+0x31/0x1a0 [ 8.289273] ? do_splice_to+0x2f/0x90 [ 8.289511] splice_direct_to_actor+0xcc/0x220 [ 8.289788] ? pipe_to_sendpage+0xa0/0xa0 [ 8.290052] do_splice_direct+0x8b/0xd0 [ 8.290314] do_sendfile+0x1ad/0x470 [ 8.290576] do_syscall_64+0x2d/0x40 [ 8.290818] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 8.291409] RIP: 0033:0x7f24fd7dca0a [ 8.292511] Code: c3 0f 1f 80 00 00 00 00 4c 89 d2 4c 89 c6 e9 bd fd ff ff 0f 1f 44 00 00 31 8 [ 8.293360] RSP: 002b:00007ffc20932818 EFLAGS: 00000206 ORIG_RAX: 0000000000000028 [ 8.293800] RAX: ffffffffffffffda RBX: 0000000001000000 RCX: 00007f24fd7dca0a [ 8.294153] RDX: 0000000000000000 RSI: 0000000000000003 RDI: 0000000000000001 [ 8.294504] RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000000 [ 8.294867] R10: 0000000001000000 R11: 0000000000000206 R12: 0000000000000003 [ 8.295217] R13: 0000000000000001 R14: 0000000000000001 R15: 0000000000000000 [ 8.295782] ---[ end trace 63317af81b3ca24b ]--- Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: remove redundant 'depends on NET'Masahiro Yamada2021-01-271-1/+0
| | | | | | | | | | | These Kconfig files are included from net/Kconfig, inside the if NET ... endif. Remove 'depends on NET', which we know it is already met. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Link: https://lore.kernel.org/r/20210125232026.106855-1-masahiroy@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* Merge tag '9p-for-5.11-rc1' of git://github.com/martinetd/linuxLinus Torvalds2020-12-211-5/+9
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull 9p update from Dominique Martinet: - fix long-standing limitation on open-unlink-fop pattern - add refcount to p9_fid (fixes the above and will allow for more cleanups and simplifications in the future) * tag '9p-for-5.11-rc1' of git://github.com/martinetd/linux: 9p: Remove unnecessary IS_ERR() check 9p: Uninitialized variable in v9fs_writeback_fid() 9p: Fix writeback fid incorrectly being attached to dentry 9p: apply review requests for fid refcounting 9p: add refcount to p9_fid struct fs/9p: search open fids first fs/9p: track open fids fs/9p: fix create-unlink-getattr idiom
| * 9p: apply review requests for fid refcountingDominique Martinet2020-11-191-2/+2
| | | | | | | | | | | | | | | | | | Fix style issues in parent commit ("apply review requests for fid refcounting"), no functional change. Link: http://lkml.kernel.org/r/1605802012-31133-2-git-send-email-asmadeus@codewreck.org Fixes: 6636b6dcc3db ("9p: add refcount to p9_fid struct") Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
| * 9p: add refcount to p9_fid structJianyong Wu2020-11-191-4/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix race issue in fid contention. Eric's and Greg's patch offer a mechanism to fix open-unlink-f*syscall bug in 9p. But there is race issue in fid parallel accesses. As Greg's patch stores all of fids from opened files into according inode, so all the lookup fid ops can retrieve fid from inode preferentially. But there is no mechanism to handle the fid contention issue. For example, there are two threads get the same fid in the same time and one of them clunk the fid before the other thread ready to discard the fid. In this scenario, it will lead to some fatal problems, even kernel core dump. I introduce a mechanism to fix this race issue. A counter field introduced into p9_fid struct to store the reference counter to the fid. When a fid is allocated from the inode or dentry, the counter will increase, and will decrease at the end of its occupation. It is guaranteed that the fid won't be clunked before the reference counter go down to 0, then we can avoid the clunked fid to be used. tests: race issue test from the old test case: for file in {01..50}; do touch f.${file}; done seq 1 1000 | xargs -n 1 -P 50 -I{} cat f.* > /dev/null open-unlink-f*syscall test: I have tested for f*syscall include: ftruncate fstat fchown fchmod faccessat. Link: http://lkml.kernel.org/r/20200923141146.90046-5-jianyong.wu@arm.com Fixes: 478ba09edc1f ("fs/9p: search open fids first") Signed-off-by: Jianyong Wu <jianyong.wu@arm.com> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
| * fs/9p: fix create-unlink-getattr idiomEric Van Hensbergen2020-11-031-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fixes several outstanding bug reports of not being able to getattr from an open file after an unlink. This patch cleans up transient fids on an unlink and will search open fids on a client if it detects a dentry that appears to have been unlinked. This search is necessary because fstat does not pass fd information through the VFS API to the filesystem, only the dentry which for 9p has an imperfect match to fids. Inherent in this patch is also a fix for the qid handling on create/open which apparently wasn't being set correctly and was necessary for the search to succeed. A possible optimization over this fix is to include accounting of open fids with the inode in the private data (in a similar fashion to the way we track transient fids with dentries). This would allow a much quicker search for a matching open fid. (changed v9fs_fid_find_global to v9fs_fid_find_inode in comment) Link: http://lkml.kernel.org/r/20200923141146.90046-2-jianyong.wu@arm.com Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com> Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com> Signed-off-by: Jianyong Wu <jianyong.wu@arm.com> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
* | net: 9p: Fix kerneldoc warnings of missing parameters etcAndrew Lunn2020-11-025-6/+19
|/ | | | | | | | | | | | | | | | | | | | | | | | | net/9p/client.c:420: warning: Function parameter or member 'c' not described in 'p9_client_cb' net/9p/client.c:420: warning: Function parameter or member 'req' not described in 'p9_client_cb' net/9p/client.c:420: warning: Function parameter or member 'status' not described in 'p9_client_cb' net/9p/client.c:568: warning: Function parameter or member 'uidata' not described in 'p9_check_zc_errors' net/9p/trans_common.c:23: warning: Function parameter or member 'nr_pages' not described in 'p9_release_pages' net/9p/trans_common.c:23: warning: Function parameter or member 'pages' not described in 'p9_release_pages' net/9p/trans_fd.c:132: warning: Function parameter or member 'rreq' not described in 'p9_conn' net/9p/trans_fd.c:132: warning: Function parameter or member 'wreq' not described in 'p9_conn' net/9p/trans_fd.c:56: warning: Function parameter or member 'privport' not described in 'p9_fd_opts' net/9p/trans_rdma.c:113: warning: Function parameter or member 'cqe' not described in 'p9_rdma_context' net/9p/trans_rdma.c:129: warning: Function parameter or member 'privport' not described in 'p9_rdma_opts' net/9p/trans_virtio.c:215: warning: Function parameter or member 'limit' not described in 'pack_sg_list_p' net/9p/trans_virtio.c:83: warning: Function parameter or member 'chan_list' not described in 'virtio_chan' net/9p/trans_virtio.c:83: warning: Function parameter or member 'p9_max_pages' not described in 'virtio_chan' net/9p/trans_virtio.c:83: warning: Function parameter or member 'ring_bufs_avail' not described in 'virtio_chan' net/9p/trans_virtio.c:83: warning: Function parameter or member 'tag' not described in 'virtio_chan' net/9p/trans_virtio.c:83: warning: Function parameter or member 'vc_wq' not described in 'virtio_chan' Signed-off-by: Andrew Lunn <andrew@lunn.ch> Acked-by: Dominique Martinet <asmadeus@codewreck.org> Link: https://lore.kernel.org/r/20201031182655.1082065-1-andrew@lunn.ch Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* net: 9p: initialize sun_server.sun_path to have addr's value only when addr ↵Anant Thazhemadam2020-10-121-1/+1
| | | | | | | | | | | | | | | | | | | is valid In p9_fd_create_unix, checking is performed to see if the addr (passed as an argument) is NULL or not. However, no check is performed to see if addr is a valid address, i.e., it doesn't entirely consist of only 0's. The initialization of sun_server.sun_path to be equal to this faulty addr value leads to an uninitialized variable, as detected by KMSAN. Checking for this (faulty addr) and returning a negative error number appropriately, resolves this issue. Link: http://lkml.kernel.org/r/20201012042404.2508-1-anant.thazhemadam@gmail.com Reported-by: syzbot+75d51fe5bf4ebe988518@syzkaller.appspotmail.com Tested-by: syzbot+75d51fe5bf4ebe988518@syzkaller.appspotmail.com Signed-off-by: Anant Thazhemadam <anant.thazhemadam@gmail.com> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
* 9p/xen: Fix format argument warningYe Bin2020-10-091-2/+2
| | | | | | | | | | | | | Fix follow warnings: [net/9p/trans_xen.c:454]: (warning) %u in format string (no. 1) requires 'unsigned int' but the argument type is 'int'. [net/9p/trans_xen.c:460]: (warning) %u in format string (no. 1) requires 'unsigned int' but the argument type is 'int'. Link: http://lkml.kernel.org/r/20201009080552.89918-1-yebin10@huawei.com Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Ye Bin <yebin10@huawei.com> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
* treewide: Use fallthrough pseudo-keywordGustavo A. R. Silva2020-08-231-1/+1
| | | | | | | | | | Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
* Merge tag '9p-for-5.9-rc1' of git://github.com/martinetd/linuxLinus Torvalds2020-08-151-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull 9p updates from Dominique Martinet: - some code cleanup - a couple of static analysis fixes - setattr: try to pick a fid associated with the file rather than the dentry, which might sometimes matter * tag '9p-for-5.9-rc1' of git://github.com/martinetd/linux: 9p: Remove unneeded cast from memory allocation 9p: remove unused code in 9p net/9p: Fix sparse endian warning in trans_fd.c 9p: Fix memory leak in v9fs_mount 9p: retrieve fid from file when file instance exist.
| * net/9p: Fix sparse endian warning in trans_fd.cAlexander Kapshuk2020-07-191-1/+1
| | | | | | | | | | | | | | | | | | | | | | Address sparse endian warning: net/9p/trans_fd.c:932:28: warning: incorrect type in assignment (different base types) net/9p/trans_fd.c:932:28: expected restricted __be32 [addressable] [assigned] [usertype] s_addr net/9p/trans_fd.c:932:28: got unsigned long Link: http://lkml.kernel.org/r/20200618183417.5423-1-alexander.kapshuk@gmail.com Signed-off-by: Alexander Kapshuk <alexander.kapshuk@gmail.com> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
* | Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller2020-08-021-9/+30
|\| | | | | | | | | | | | | Resolved kernel/bpf/btf.c using instructions from merge commit 69138b34a7248d2396ab85c8652e20c0c39beaba Signed-off-by: David S. Miller <davem@davemloft.net>
| * 9p/trans_fd: Fix concurrency del of req_list in p9_fd_cancelled/p9_read_workWang Hai2020-07-191-1/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | p9_read_work and p9_fd_cancelled may be called concurrently. In some cases, req->req_list may be deleted by both p9_read_work and p9_fd_cancelled. We can fix it by ignoring replies associated with a cancelled request and ignoring cancelled request if message has been received before lock. Link: http://lkml.kernel.org/r/20200612090833.36149-1-wanghai38@huawei.com Fixes: 60ff779c4abb ("9p: client: remove unused code and any reference to "cancelled" function") Cc: <stable@vger.kernel.org> # v3.12+ Reported-by: syzbot+77a25acfa0382e06ab23@syzkaller.appspotmail.com Signed-off-by: Wang Hai <wanghai38@huawei.com> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
| * net/9p: validate fds in p9_fd_openChristoph Hellwig2020-07-191-8/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | p9_fd_open just fgets file descriptors passed in from userspace, but doesn't verify that they are valid for read or writing. This gets cought down in the VFS when actually attempting a read or write, but a new warning added in linux-next upsets syzcaller. Fix this by just verifying the fds early on. Link: http://lkml.kernel.org/r/20200710085722.435850-1-hch@lst.de Reported-by: syzbot+e6f77e16ff68b2434a2c@syzkaller.appspotmail.com Signed-off-by: Christoph Hellwig <hch@lst.de> [Dominique: amend goto as per Doug Nazar's review] Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
* | net: 9p: kerneldoc fixesAndrew Lunn2020-07-132-4/+5
|/ | | | | | | | | | Simple fixes which require no deep knowledge of the code. Cc: Eric Van Hensbergen <ericvh@gmail.com> Cc: Latchesar Ionkov <lucho@ionkov.net> Cc: Dominique Martinet <asmadeus@codewreck.org> Signed-off-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: Add MODULE_DESCRIPTION entries to network modulesRob Gill2020-06-201-0/+1
| | | | | | | | | | | | | | | | | | | | | The user tool modinfo is used to get information on kernel modules, including a description where it is available. This patch adds a brief MODULE_DESCRIPTION to the following modules: 9p drop_monitor esp4_offload esp6_offload fou fou6 ila sch_fq sch_fq_codel sch_hhf Signed-off-by: Rob Gill <rrobgill@protonmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* 9p/xen: increase XEN_9PFS_RING_ORDERStefano Stabellini2020-06-021-27/+34
| | | | | | | | | | | | | | | | | | | | | | | | | | | Increase XEN_9PFS_RING_ORDER to 9 for performance reason. Order 9 is the max allowed by the protocol. We can't assume that all backends will support order 9. The xenstore property max-ring-page-order specifies the max order supported by the backend. We'll use max-ring-page-order for the size of the ring. This means that the size of the ring is not static (XEN_FLEX_RING_SIZE(9)) anymore. Change XEN_9PFS_RING_SIZE to take an argument and base the calculation on the order chosen at setup time. Finally, modify p9_xen_trans.maxsize to be divided by 4 compared to the original value. We need to divide it by 2 because we have two rings coming off the same order allocation: the in and out rings. This was a mistake in the original code. Also divide it further by 2 because we don't want a single request/reply to fill up the entire ring. There can be multiple requests/replies outstanding at any given time and if we use the full ring with one, we risk forcing the backend to wait for the client to read back more replies before continuing, which is not performant. Link: http://lkml.kernel.org/r/20200521193242.15953-1-sstabellini@kernel.org Signed-off-by: Stefano Stabellini <stefano.stabellini@xilinx.com> Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
* 9pnet: allow making incomplete read requestsSergey Alirzaev2020-03-271-61/+73
| | | | | | | | | | | | | A user doesn't necessarily want to wait for all the requested data to be available, since the waiting time for each request is unbounded. The new method permits sending one read request at a time and getting the response ASAP, allowing to use 9pnet with synthetic file systems representing arbitrary data streams. Link: http://lkml.kernel.org/r/20200205204053.12751-1-l29ah@cock.li Signed-off-by: Sergey Alirzaev <l29ah@cock.li> Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
* Merge tag '9p-for-5.4' of git://github.com/martinetd/linuxLinus Torvalds2019-09-271-0/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull 9p updates from Dominique Martinet: "Some of the usual small fixes and cleanup. Small fixes all around: - avoid overlayfs copy-up for PRIVATE mmaps - KUMSAN uninitialized warning for transport error - one syzbot memory leak fix in 9p cache - internal API cleanup for v9fs_fill_super" * tag '9p-for-5.4' of git://github.com/martinetd/linux: 9p/vfs_super.c: Remove unused parameter data in v9fs_fill_super 9p/cache.c: Fix memory leak in v9fs_cache_session_get_cookie 9p: Transport error uninitialized 9p: avoid attaching writeback_fid on mmap with type PRIVATE
| * 9p: Transport error uninitializedLu Shuaibing2019-09-031-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The p9_tag_alloc() does not initialize the transport error t_err field. The struct p9_req_t *req is allocated and stored in a struct p9_client variable. The field t_err is never initialized before p9_conn_cancel() checks its value. KUMSAN(KernelUninitializedMemorySantizer, a new error detection tool) reports this bug. ================================================================== BUG: KUMSAN: use of uninitialized memory in p9_conn_cancel+0x2d9/0x3b0 Read of size 4 at addr ffff88805f9b600c by task kworker/1:2/1216 CPU: 1 PID: 1216 Comm: kworker/1:2 Not tainted 5.2.0-rc4+ #28 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 Workqueue: events p9_write_work Call Trace: dump_stack+0x75/0xae __kumsan_report+0x17c/0x3e6 kumsan_report+0xe/0x20 p9_conn_cancel+0x2d9/0x3b0 p9_write_work+0x183/0x4a0 process_one_work+0x4d1/0x8c0 worker_thread+0x6e/0x780 kthread+0x1ca/0x1f0 ret_from_fork+0x35/0x40 Allocated by task 1979: save_stack+0x19/0x80 __kumsan_kmalloc.constprop.3+0xbc/0x120 kmem_cache_alloc+0xa7/0x170 p9_client_prepare_req.part.9+0x3b/0x380 p9_client_rpc+0x15e/0x880 p9_client_create+0x3d0/0xac0 v9fs_session_init+0x192/0xc80 v9fs_mount+0x67/0x470 legacy_get_tree+0x70/0xd0 vfs_get_tree+0x4a/0x1c0 do_mount+0xba9/0xf90 ksys_mount+0xa8/0x120 __x64_sys_mount+0x62/0x70 do_syscall_64+0x6d/0x1e0 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Freed by task 0: (stack is not available) The buggy address belongs to the object at ffff88805f9b6008 which belongs to the cache p9_req_t of size 144 The buggy address is located 4 bytes inside of 144-byte region [ffff88805f9b6008, ffff88805f9b6098) The buggy address belongs to the page: page:ffffea00017e6d80 refcount:1 mapcount:0 mapping:ffff888068b63740 index:0xffff88805f9b7d90 compound_mapcount: 0 flags: 0x100000000010200(slab|head) raw: 0100000000010200 ffff888068b66450 ffff888068b66450 ffff888068b63740 raw: ffff88805f9b7d90 0000000000100001 00000001ffffffff 0000000000000000 page dumped because: kumsan: bad access detected ================================================================== Link: http://lkml.kernel.org/r/20190613070854.10434-1-shuaibinglu@126.com Signed-off-by: Lu Shuaibing <shuaibinglu@126.com> [dominique.martinet@cea.fr: grouped the added init with the others] Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
* | rdma: Enable ib_alloc_cq to spread work over a device's comp_vectorsChuck Lever2019-08-051-3/+3
|/ | | | | | | | | | | | | | | | | | | | | | | | Send and Receive completion is handled on a single CPU selected at the time each Completion Queue is allocated. Typically this is when an initiator instantiates an RDMA transport, or when a target accepts an RDMA connection. Some ULPs cannot open a connection per CPU to spread completion workload across available CPUs and MSI vectors. For such ULPs, provide an API that allows the RDMA core to select a completion vector based on the device's complement of available comp_vecs. ULPs that invoke ib_alloc_cq() with only comp_vector 0 are converted to use the new API so that their completion workloads interfere less with each other. Suggested-by: Håkon Bugge <haakon.bugge@oracle.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Leon Romanovsky <leonro@mellanox.com> Cc: <linux-cifs@vger.kernel.org> Cc: <v9fs-developer@lists.sourceforge.net> Link: https://lore.kernel.org/r/20190729171923.13428.52555.stgit@manet.1015granger.net Signed-off-by: Doug Ledford <dledford@redhat.com>
* Merge tag '9p-for-5.3' of git://github.com/martinetd/linuxLinus Torvalds2019-07-122-2/+14
|\ | | | | | | | | | | | | | | | | | | | | | | | | Pull 9p updates from Dominique Martinet: "Two small fixes to properly cleanup the 9p transports list if virtio/xen module initialization fail. 9p might otherwise try to access memory from a module that failed to register got freed" * tag '9p-for-5.3' of git://github.com/martinetd/linux: 9p/xen: Add cleanup path in p9_trans_xen_init 9p/virtio: Add cleanup path in p9_virtio_init