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2017-07-15Merge branch 'work.mount' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull ->s_options removal from Al Viro: "Preparations for fsmount/fsopen stuff (coming next cycle). Everything gets moved to explicit ->show_options(), killing ->s_options off + some cosmetic bits around fs/namespace.c and friends. Basically, the stuff needed to work with fsmount series with minimum of conflicts with other work. It's not strictly required for this merge window, but it would reduce the PITA during the coming cycle, so it would be nice to have those bits and pieces out of the way" * 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: isofs: Fix isofs_show_options() VFS: Kill off s_options and helpers orangefs: Implement show_options 9p: Implement show_options isofs: Implement show_options afs: Implement show_options affs: Implement show_options befs: Implement show_options spufs: Implement show_options bpf: Implement show_options ramfs: Implement show_options pstore: Implement show_options omfs: Implement show_options hugetlbfs: Implement show_options VFS: Don't use save/replace_mount_options if not using generic_show_options VFS: Provide empty name qstr VFS: Make get_filesystem() return the affected filesystem VFS: Clean up whitespace in fs/namespace.c and fs/super.c Provide a function to create a NUL-terminated string from unterminated data
2017-07-11afs: Implement show_optionsDavid Howells
Implement the show_options superblock op for afs as part of a bid to get rid of s_options and generic_show_options() to make it easier to implement a context-based mount where the mount options can be passed individually over a file descriptor. Also implement the show_devname op to display the correct device name and thus avoid the need to display the cell= and volume= options. Signed-off-by: David Howells <dhowells@redhat.com> cc: linux-afs@lists.infradead.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-07-09afs: Add metadata xattrsDavid Howells
Add xattrs to allow the user to get/set metadata in lieu of having pioctl() available. The following xattrs are now available: - "afs.cell" The name of the cell in which the vnode's volume resides. - "afs.fid" The volume ID, vnode ID and vnode uniquifier of the file as three hex numbers separated by colons. - "afs.volume" The name of the volume in which the vnode resides. For example: # getfattr -d -m ".*" /mnt/scratch getfattr: Removing leading '/' from absolute path names # file: mnt/scratch afs.cell="mycell.myorg.org" afs.fid="10000b:1:1" afs.volume="scratch" Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-09afs: Ignore AFS_ACE_READ and AFS_ACE_WRITE for directoriesMarc Dionne
The AFS_ACE_READ and AFS_ACE_WRITE permission bits should not be used to make access decisions for the directory itself. They are meant to control access for the objects contained in that directory. Reading a directory is allowed if the AFS_ACE_LOOKUP bit is set. This would cause an incorrect access denied error for a directory with AFS_ACE_LOOKUP but not AFS_ACE_READ. The AFS_ACE_WRITE bit does not allow operations that modify the directory. For a directory with AFS_ACE_WRITE but neither AFS_ACE_INSERT nor AFS_ACE_DELETE, this would result in trying operations that would ultimately be denied by the server. Signed-off-by: Marc Dionne <marc.dionne@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-05Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-nextLinus Torvalds
Pull networking updates from David Miller: "Reasonably busy this cycle, but perhaps not as busy as in the 4.12 merge window: 1) Several optimizations for UDP processing under high load from Paolo Abeni. 2) Support pacing internally in TCP when using the sch_fq packet scheduler for this is not practical. From Eric Dumazet. 3) Support mutliple filter chains per qdisc, from Jiri Pirko. 4) Move to 1ms TCP timestamp clock, from Eric Dumazet. 5) Add batch dequeueing to vhost_net, from Jason Wang. 6) Flesh out more completely SCTP checksum offload support, from Davide Caratti. 7) More plumbing of extended netlink ACKs, from David Ahern, Pablo Neira Ayuso, and Matthias Schiffer. 8) Add devlink support to nfp driver, from Simon Horman. 9) Add RTM_F_FIB_MATCH flag to RTM_GETROUTE queries, from Roopa Prabhu. 10) Add stack depth tracking to BPF verifier and use this information in the various eBPF JITs. From Alexei Starovoitov. 11) Support XDP on qed device VFs, from Yuval Mintz. 12) Introduce BPF PROG ID for better introspection of installed BPF programs. From Martin KaFai Lau. 13) Add bpf_set_hash helper for TC bpf programs, from Daniel Borkmann. 14) For loads, allow narrower accesses in bpf verifier checking, from Yonghong Song. 15) Support MIPS in the BPF selftests and samples infrastructure, the MIPS eBPF JIT will be merged in via the MIPS GIT tree. From David Daney. 16) Support kernel based TLS, from Dave Watson and others. 17) Remove completely DST garbage collection, from Wei Wang. 18) Allow installing TCP MD5 rules using prefixes, from Ivan Delalande. 19) Add XDP support to Intel i40e driver, from Björn Töpel 20) Add support for TC flower offload in nfp driver, from Simon Horman, Pieter Jansen van Vuuren, Benjamin LaHaise, Jakub Kicinski, and Bert van Leeuwen. 21) IPSEC offloading support in mlx5, from Ilan Tayari. 22) Add HW PTP support to macb driver, from Rafal Ozieblo. 23) Networking refcount_t conversions, From Elena Reshetova. 24) Add sock_ops support to BPF, from Lawrence Brako. This is useful for tuning the TCP sockopt settings of a group of applications, currently via CGROUPs" * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1899 commits) net: phy: dp83867: add workaround for incorrect RX_CTRL pin strap dt-bindings: phy: dp83867: provide a workaround for incorrect RX_CTRL pin strap cxgb4: Support for get_ts_info ethtool method cxgb4: Add PTP Hardware Clock (PHC) support cxgb4: time stamping interface for PTP nfp: default to chained metadata prepend format nfp: remove legacy MAC address lookup nfp: improve order of interfaces in breakout mode net: macb: remove extraneous return when MACB_EXT_DESC is defined bpf: add missing break in for the TCP_BPF_SNDCWND_CLAMP case bpf: fix return in load_bpf_file mpls: fix rtm policy in mpls_getroute net, ax25: convert ax25_cb.refcount from atomic_t to refcount_t net, ax25: convert ax25_route.refcount from atomic_t to refcount_t net, ax25: convert ax25_uid_assoc.refcount from atomic_t to refcount_t net, sctp: convert sctp_ep_common.refcnt from atomic_t to refcount_t net, sctp: convert sctp_transport.refcnt from atomic_t to refcount_t net, sctp: convert sctp_chunk.refcnt from atomic_t to refcount_t net, sctp: convert sctp_datamsg.refcnt from atomic_t to refcount_t net, sctp: convert sctp_auth_bytes.refcnt from atomic_t to refcount_t ...
2017-06-07rxrpc: Provide a cmsg to specify the amount of Tx data for a callDavid Howells
Provide a control message that can be specified on the first sendmsg() of a client call or the first sendmsg() of a service response to indicate the total length of the data to be transmitted for that call. Currently, because the length of the payload of an encrypted DATA packet is encrypted in front of the data, the packet cannot be encrypted until we know how much data it will hold. By specifying the length at the beginning of the transmit phase, each DATA packet length can be set before we start loading data from userspace (where several sendmsg() calls may contribute to a particular packet). An error will be returned if too little or too much data is presented in the Tx phase. Signed-off-by: David Howells <dhowells@redhat.com>
2017-06-05uuid,afs: move struct uuid_v1 back into afsChristoph Hellwig
This essentially is a partial revert of commit ff548773 ("afs: Move UUID struct to linux/uuid.h") and moves struct uuid_v1 back into fs/afs as struct afs_uuid. It however keeps it as big endian structure so that we can use the normal uuid generation helpers when casting to/from struct afs_uuid. The V1 uuid intrepretation in struct form isn't really useful to the rest of the kernel, and not really compatible to it either, so move it back to AFS instead of polluting the global uuid.h. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: David Howells <dhowells@redhat.com>
2017-05-02Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-nextLinus Torvalds
Pull networking updates from David Millar: "Here are some highlights from the 2065 networking commits that happened this development cycle: 1) XDP support for IXGBE (John Fastabend) and thunderx (Sunil Kowuri) 2) Add a generic XDP driver, so that anyone can test XDP even if they lack a networking device whose driver has explicit XDP support (me). 3) Sparc64 now has an eBPF JIT too (me) 4) Add a BPF program testing framework via BPF_PROG_TEST_RUN (Alexei Starovoitov) 5) Make netfitler network namespace teardown less expensive (Florian Westphal) 6) Add symmetric hashing support to nft_hash (Laura Garcia Liebana) 7) Implement NAPI and GRO in netvsc driver (Stephen Hemminger) 8) Support TC flower offload statistics in mlxsw (Arkadi Sharshevsky) 9) Multiqueue support in stmmac driver (Joao Pinto) 10) Remove TCP timewait recycling, it never really could possibly work well in the real world and timestamp randomization really zaps any hint of usability this feature had (Soheil Hassas Yeganeh) 11) Support level3 vs level4 ECMP route hashing in ipv4 (Nikolay Aleksandrov) 12) Add socket busy poll support to epoll (Sridhar Samudrala) 13) Netlink extended ACK support (Johannes Berg, Pablo Neira Ayuso, and several others) 14) IPSEC hw offload infrastructure (Steffen Klassert)" * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (2065 commits) tipc: refactor function tipc_sk_recv_stream() tipc: refactor function tipc_sk_recvmsg() net: thunderx: Optimize page recycling for XDP net: thunderx: Support for XDP header adjustment net: thunderx: Add support for XDP_TX net: thunderx: Add support for XDP_DROP net: thunderx: Add basic XDP support net: thunderx: Cleanup receive buffer allocation net: thunderx: Optimize CQE_TX handling net: thunderx: Optimize RBDR descriptor handling net: thunderx: Support for page recycling ipx: call ipxitf_put() in ioctl error path net: sched: add helpers to handle extended actions qed*: Fix issues in the ptp filter config implementation. qede: Fix concurrency issue in PTP Tx path processing. stmmac: Add support for SIMATIC IOT2000 platform net: hns: fix ethtool_get_strings overflow in hns driver tcp: fix wraparound issue in tcp_lp bpf, arm64: fix jit branch offset related to ldimm64 bpf, arm64: implement jiting of BPF_XADD ...
2017-04-20afs: Convert to separately allocated bdiJan Kara
Allocate struct backing_dev_info separately instead of embedding it inside the superblock. This unifies handling of bdi among users. CC: David Howells <dhowells@redhat.com> CC: linux-afs@lists.infradead.org Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@fb.com>
2017-04-06rxrpc: Use negative error codes in rxrpc_call structDavid Howells
Use negative error codes in struct rxrpc_call::error because that's what the kernel normally deals with and to make the code consistent. We only turn them positive when transcribing into a cmsg for userspace recvmsg. Signed-off-by: David Howells <dhowells@redhat.com>
2017-03-16afs: Don't wait for page writeback with the page lock heldDavid Howells
Drop the page lock before waiting for page writeback. Signed-off-by: David Howells <dhowells@redhat.com>
2017-03-16afs: ->writepage() shouldn't call clear_page_dirty_for_io()David Howells
The ->writepage() op shouldn't call clear_page_dirty_for_io() as that has already been called by the caller. Fix afs_writepage() by moving the call out of afs_write_back_from_locked_page() to afs_writepages_region() where it is needed. Signed-off-by: David Howells <dhowells@redhat.com>
2017-03-16afs: Fix abort on signal while waiting for call completionDavid Howells
Fix the way in which a call that's in progress and being waited for is aborted in the case that EINTR is detected. We should be sending RX_USER_ABORT rather than RX_CALL_DEAD as the abort code. Note that since the only two ways out of the loop are if the call completes or if a signal happens, the kill-the-call clause after the loop has finished can only happen in the case of EINTR. This means that we only have one abort case to deal with, not two, and the "KWC" case can never happen and so can be deleted. Note further that simply aborting the call isn't necessarily the best thing here since at this point: the request has been entirely sent and it's likely the server will do the operation anyway - whether we abort it or not. In future, we should punt the handling of the remainder of the call off to a background thread. Reported-by: Marc Dionne <marc.c.dionne@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com>
2017-03-16afs: Fix an off-by-one error in afs_send_pages()David Howells
afs_send_pages() should only put the call into the AFS_CALL_AWAIT_REPLY state if it has sent all the pages - but the check it makes is incorrect and sometimes it will finish the loop early. Signed-off-by: David Howells <dhowells@redhat.com>
2017-03-16afs: Fix afs_kill_pages()David Howells
Fix afs_kill_pages() in two ways: (1) If a writeback has been partially flushed, then if we try and kill the pages it contains, some of them may no longer be undergoing writeback and end_page_writeback() will assert. Fix this by checking to see whether the page in question is actually undergoing writeback before ending that writeback. (2) The loop that scans for pages to kill doesn't increase the first page index, and so the loop may not terminate, but it will try to process the same pages over and over again. Fix this by increasing the first page index to one after the last page we processed. Signed-off-by: David Howells <dhowells@redhat.com>
2017-03-16afs: Fix page leak in afs_write_begin()David Howells
afs_write_begin() leaks a ref and a lock on a page if afs_fill_page() fails. Fix the leak by unlocking and releasing the page in the error path. Signed-off-by: David Howells <dhowells@redhat.com>
2017-03-16afs: Don't set PG_error on local EINTR or ENOMEM when filling a pageDavid Howells
Don't set PG_error on a page if we get local EINTR or ENOMEM when filling a page for writing. Signed-off-by: David Howells <dhowells@redhat.com>
2017-03-16afs: Populate and use client modification timeMarc Dionne
The inode timestamps should be set from the client time in the status received from the server, rather than the server time which is meant for internal server use. Set AFS_SET_MTIME and populate the mtime for operations that take an input status, such as file/dir creation and StoreData. If an input time is not provided the server will set the vnode times based on the current server time. In a situation where the server has some skew with the client, this could lead to the client seeing a timestamp in the future for a file that it just created or wrote. Signed-off-by: Marc Dionne <marc.dionne@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com>
2017-03-16afs: Better abort and net error handlingDavid Howells
If we receive a network error, a remote abort or a protocol error whilst we're still transmitting data, make sure we return an appropriate error to the caller rather than ESHUTDOWN or ECONNABORTED. Signed-off-by: David Howells <dhowells@redhat.com>
2017-03-16afs: Invalid op ID should abort with RXGEN_OPCODEDavid Howells
When we are given an invalid operation ID, we should abort that with RXGEN_OPCODE rather than RX_INVALID_OPERATION. Also map RXGEN_OPCODE to -ENOTSUPP. Signed-off-by: David Howells <dhowells@redhat.com>
2017-03-16afs: Fix the maths in afs_fs_store_data()David Howells
afs_fs_store_data() works out of the size of the write it's going to make, but it uses 32-bit unsigned subtraction in one place that gets automatically cast to loff_t. However, if to < offset, then the number goes negative, but as the result isn't signed, this doesn't get sign-extended to 64-bits when placed in a loff_t. Fix by casting the operands to loff_t. Signed-off-by: David Howells <dhowells@redhat.com>
2017-03-16afs: Use a bvec rather than a kvec in afs_send_pages()David Howells
Use a bvec rather than a kvec in afs_send_pages() as we don't then have to call kmap() in advance. This allows us to pass the array of contiguous pages that we extracted through to rxrpc in one go rather than passing a single page at a time. Signed-off-by: David Howells <dhowells@redhat.com>
2017-03-16afs: Make struct afs_read::remain 64-bitDavid Howells
Make struct afs_read::remain 64-bit so that it can handle huge transfers if we ever request them or the server decides to give us a bit extra data (the other fields there are already 64-bit). Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Marc Dionne <marc.dionne@auristor.com>
2017-03-16afs: Fix AFS read bugDavid Howells
Fix a bug in AFS read whereby the request page afs_read::index isn't incremented after calling ->page_done() if ->remain reaches 0, indicating that the data read is complete. Without this a NULL pointer exception happens when ->page_done() is called twice for the last page because the page clearing loop will call it also and afs_readpages_page_done() clears the current entry in the page list. BUG: unable to handle kernel NULL pointer dereference at (null) IP: afs_readpages_page_done+0x21/0xa4 [kafs] PGD 0 Oops: 0002 [#1] SMP Modules linked in: kafs(E) CPU: 2 PID: 3002 Comm: md5sum Tainted: G E 4.10.0-fscache #485 Hardware name: ASUS All Series/H97-PLUS, BIOS 2306 10/09/2014 task: ffff8804017d86c0 task.stack: ffff8803fc1d8000 RIP: 0010:afs_readpages_page_done+0x21/0xa4 [kafs] RSP: 0018:ffff8803fc1db978 EFLAGS: 00010282 RAX: ffff880405d39af8 RBX: 0000000000000000 RCX: ffff880407d83ed4 RDX: 0000000000000000 RSI: ffff880405d39a00 RDI: ffff880405c6f400 RBP: ffff8803fc1db988 R08: 0000000000000000 R09: 0000000000000001 R10: ffff8803fc1db820 R11: ffff88040cf56000 R12: ffff8804088f1780 R13: ffff8804017d86c0 R14: ffff8804088f1780 R15: 0000000000003840 FS: 00007f8154469700(0000) GS:ffff88041fb00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 00000004016ec000 CR4: 00000000001406e0 Call Trace: afs_deliver_fs_fetch_data+0x5b9/0x60e [kafs] ? afs_make_call+0x316/0x4e8 [kafs] ? afs_make_call+0x359/0x4e8 [kafs] afs_deliver_to_call+0x173/0x2e8 [kafs] ? afs_make_call+0x316/0x4e8 [kafs] afs_make_call+0x37a/0x4e8 [kafs] ? wake_up_q+0x4f/0x4f ? __init_waitqueue_head+0x36/0x49 afs_fs_fetch_data+0x21c/0x227 [kafs] ? afs_fs_fetch_data+0x21c/0x227 [kafs] afs_vnode_fetch_data+0xf3/0x1d2 [kafs] afs_readpages+0x314/0x3fd [kafs] __do_page_cache_readahead+0x208/0x2c5 ondemand_readahead+0x3a2/0x3b7 ? ondemand_readahead+0x3a2/0x3b7 page_cache_async_readahead+0x5e/0x67 generic_file_read_iter+0x23b/0x70c ? __inode_security_revalidate+0x2f/0x62 __vfs_read+0xc4/0xe8 vfs_read+0xd1/0x15a SyS_read+0x4c/0x89 do_syscall_64+0x80/0x191 entry_SYSCALL64_slow_path+0x25/0x25 Reported-by: Marc Dionne <marc.dionne@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Marc Dionne <marc.dionne@auristor.com>
2017-03-16afs: Prevent callback expiry timer overflowTina Ruchandani
get_seconds() returns real wall-clock seconds. On 32-bit systems this value will overflow in year 2038 and beyond. This patch changes afs_vnode record to use ktime_get_real_seconds() instead, for the fields cb_expires and cb_expires_at. Signed-off-by: Tina Ruchandani <ruchandani.tina@gmail.com> Signed-off-by: David Howells <dhowells@redhat.com>
2017-03-16afs: Migrate vlocation fields to 64-bitTina Ruchandani
get_seconds() returns real wall-clock seconds. On 32-bit systems this value will overflow in year 2038 and beyond. This patch changes afs's vlocation record to use ktime_get_real_seconds() instead, for the fields time_of_death and update_at. Signed-off-by: Tina Ruchandani <ruchandani.tina@gmail.com> Signed-off-by: David Howells <dhowells@redhat.com>
2017-03-16afs: security: Replace rcu_assign_pointer() with RCU_INIT_POINTER()Andreea-Cristina Bernat
The use of "rcu_assign_pointer()" is NULLing out the pointer. According to RCU_INIT_POINTER()'s block comment: "1. This use of RCU_INIT_POINTER() is NULLing out the pointer" it is better to use it instead of rcu_assign_pointer() because it has a smaller overhead. The following Coccinelle semantic patch was used: @@ @@ - rcu_assign_pointer + RCU_INIT_POINTER (..., NULL) Signed-off-by: Andreea-Cristina Bernat <bernat.ada@gmail.com> Signed-off-by: David Howells <dhowells@redhat.com>
2017-03-16afs: inode: Replace rcu_assign_pointer() with RCU_INIT_POINTER()Andreea-Cristina Bernat
The use of "rcu_assign_pointer()" is NULLing out the pointer. According to RCU_INIT_POINTER()'s block comment: "1. This use of RCU_INIT_POINTER() is NULLing out the pointer" it is better to use it instead of rcu_assign_pointer() because it has a smaller overhead. The following Coccinelle semantic patch was used: @@ @@ - rcu_assign_pointer + RCU_INIT_POINTER (..., NULL) Signed-off-by: Andreea-Cristina Bernat <bernat.ada@gmail.com> Signed-off-by: David Howells <dhowells@redhat.com>
2017-03-16afs: Distinguish mountpoints from symlinks by file mode aloneDavid Howells
In AFS, mountpoints appear as symlinks with mode 0644 and normal symlinks have mode 0777, so use this to distinguish them rather than reading the content and parsing it. In the case of a mountpoint, the symlink body is a formatted string indicating the location of the target volume. Note that with this, kAFS no longer 'pre-fetches' the contents of symlinks, so afs_readpage() may fail with an access-denial because when the VFS calls d_automount(), it wraps the call in an credentials override that sets the initial creds - thereby preventing access to the caller's keyrings and the authentication keys held therein. To this end, a patch reverting that change to the VFS is required also. Reported-by: Jeffrey Altman <jaltman@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com>
2017-03-16afs: Flush outstanding writes when an fd is closedDavid Howells
Flush outstanding writes in afs when an fd is closed. This is what NFS and CIFS do. Reported-by: Marc Dionne <marc.c.dionne@gmail.com> Signed-off-by: David Howells <dhowells@redhat.com>
2017-03-16afs: Handle a short write to an AFS pageDavid Howells
Handle the situation where afs_write_begin() is told to expect that a full-page write will be made, but this doesn't happen (EFAULT, CTRL-C, etc.), and so afs_write_end() sees a partial write took place. Currently, no attempt is to deal with the discrepency. Fix this by loading the gap from the server. Reported-by: Al Viro <viro@ZenIV.linux.org.uk> Signed-off-by: David Howells <dhowells@redhat.com>
2017-03-16afs: Kill struct afs_read::pg_offsetDavid Howells
Kill struct afs_read::pg_offset as nothing uses it. It's unnecessary as pos can be masked off. Signed-off-by: David Howells <dhowells@redhat.com>
2017-03-16afs: Handle better the server returning excess or short dataDavid Howells
When an AFS server is given an FS.FetchData{,64} request to read data from a file, it is permitted by the protocol to return more or less than was requested. kafs currently relies on the latter behaviour in readpage{,s} to handle a partial page at the end of the file (we just ask for a whole page and clear space beyond the short read). However, we don't handle all cases. Add: (1) Handle excess data by discarding it rather than aborting. Note that we use a common static buffer to discard into so that the decryption algorithm advances the PCBC state. (2) Handle a short read that affects more than just the last page. Note that if a read comes up unexpectedly short of long, it's possible that the server's copy of the file changed - in which case the data version number will have been incremented and the callback will have been broken - in which case all the pages currently attached to the inode will be zapped anyway at some point. Signed-off-by: David Howells <dhowells@redhat.com>
2017-03-16afs: Deal with an empty callback arrayMarc Dionne
Servers may send a callback array that is the same size as the FID array, or an empty array. If the callback count is 0, the code would attempt to read (fid_count * 12) bytes of data, which would fail and result in an unmarshalling error. This would lead to stale data for remotely modified files or directories. Store the callback array size in the internal afs_call structure and use that to determine the amount of data to read. Signed-off-by: Marc Dionne <marc.dionne@auristor.com>
2017-03-16afs: Adjust mode bits processingMarc Dionne
Mode bits for an afs file should not be enforced in the usual way. For files, the absence of user bits can restrict file access with respect to what is granted by the server. These bits apply regardless of the owner or the current uid; the rest of the mode bits (group, other) are ignored. Signed-off-by: Marc Dionne <marc.dionne@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com>
2017-03-16afs: Populate group ID from vnode statusMarc Dionne
The group was hard coded to GLOBAL_ROOT_GID; use the group ID that was received from the server. Signed-off-by: Marc Dionne <marc.dionne@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com>
2017-03-16afs: Fix page overput in afs_fill_page()David Howells
afs_fill_page() loads the page it wants to fill into the afs_read request without incrementing its refcount - but then calls afs_put_read() to clean up afterwards, which then releases a ref on the page. Fix this by getting a ref on the page before calling afs_vnode_fetch_data(). This causes sync after a write to hang in afs_writepages_region() because find_get_pages_tag() gets confused and doesn't return. Fixes: 196ee9cd2d04 ("afs: Make afs_fs_fetch_data() take a list of pages") Reported-by: Marc Dionne <marc.dionne@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Marc Dionne <marc.dionne@auristor.com>
2017-03-16afs: Fix missing put_page()David Howells
In afs_writepages_region(), inside the loop where we find dirty pages to deal with, one of the if-statements is missing a put_page(). Signed-off-by: David Howells <dhowells@redhat.com>
2017-03-03Merge branch 'rebased-statx' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs 'statx()' update from Al Viro. This adds the new extended stat() interface that internally subsumes our previous stat interfaces, and allows user mode to specify in more detail what kind of information it wants. It also allows for some explicit synchronization information to be passed to the filesystem, which can be relevant for network filesystems: is the cached value ok, or do you need open/close consistency, or what? From David Howells. Andreas Dilger points out that the first version of the extended statx interface was posted June 29, 2010: https://www.spinics.net/lists/linux-fsdevel/msg33831.html * 'rebased-statx' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: statx: Add a system call to make enhanced file info available
2017-03-03Merge branch 'WIP.sched-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull sched.h split-up from Ingo Molnar: "The point of these changes is to significantly reduce the <linux/sched.h> header footprint, to speed up the kernel build and to have a cleaner header structure. After these changes the new <linux/sched.h>'s typical preprocessed size goes down from a previous ~0.68 MB (~22K lines) to ~0.45 MB (~15K lines), which is around 40% faster to build on typical configs. Not much changed from the last version (-v2) posted three weeks ago: I eliminated quirks, backmerged fixes plus I rebased it to an upstream SHA1 from yesterday that includes most changes queued up in -next plus all sched.h changes that were pending from Andrew. I've re-tested the series both on x86 and on cross-arch defconfigs, and did a bisectability test at a number of random points. I tried to test as many build configurations as possible, but some build breakage is probably still left - but it should be mostly limited to architectures that have no cross-compiler binaries available on kernel.org, and non-default configurations" * 'WIP.sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (146 commits) sched/headers: Clean up <linux/sched.h> sched/headers: Remove #ifdefs from <linux/sched.h> sched/headers: Remove the <linux/topology.h> include from <linux/sched.h> sched/headers, hrtimer: Remove the <linux/wait.h> include from <linux/hrtimer.h> sched/headers, x86/apic: Remove the <linux/pm.h> header inclusion from <asm/apic.h> sched/headers, timers: Remove the <linux/sysctl.h> include from <linux/timer.h> sched/headers: Remove <linux/magic.h> from <linux/sched/task_stack.h> sched/headers: Remove <linux/sched.h> from <linux/sched/init.h> sched/core: Remove unused prefetch_stack() sched/headers: Remove <linux/rculist.h> from <linux/sched.h> sched/headers: Remove the 'init_pid_ns' prototype from <linux/sched.h> sched/headers: Remove <linux/signal.h> from <linux/sched.h> sched/headers: Remove <linux/rwsem.h> from <linux/sched.h> sched/headers: Remove the runqueue_is_locked() prototype sched/headers: Remove <linux/sched.h> from <linux/sched/hotplug.h> sched/headers: Remove <linux/sched.h> from <linux/sched/debug.h> sched/headers: Remove <linux/sched.h> from <linux/sched/nohz.h> sched/headers: Remove <linux/sched.h> from <linux/sched/stat.h> sched/headers: Remove the <linux/gfp.h> include from <linux/sched.h> sched/headers: Remove <linux/rtmutex.h> from <linux/sched.h> ...
2017-03-02statx: Add a system call to make enhanced file info availableDavid Howells
Add a system call to make extended file information available, including file creation and some attribute flags where available through the underlying filesystem. The getattr inode operation is altered to take two additional arguments: a u32 request_mask and an unsigned int flags that indicate the synchronisation mode. This change is propagated to the vfs_getattr*() function. Functions like vfs_stat() are now inline wrappers around new functions vfs_statx() and vfs_statx_fd() to reduce stack usage. ======== OVERVIEW ======== The idea was initially proposed as a set of xattrs that could be retrieved with getxattr(), but the general preference proved to be for a new syscall with an extended stat structure. A number of requests were gathered for features to be included. The following have been included: (1) Make the fields a consistent size on all arches and make them large. (2) Spare space, request flags and information flags are provided for future expansion. (3) Better support for the y2038 problem [Arnd Bergmann] (tv_sec is an __s64). (4) Creation time: The SMB protocol carries the creation time, which could be exported by Samba, which will in turn help CIFS make use of FS-Cache as that can be used for coherency data (stx_btime). This is also specified in NFSv4 as a recommended attribute and could be exported by NFSD [Steve French]. (5) Lightweight stat: Ask for just those details of interest, and allow a netfs (such as NFS) to approximate anything not of interest, possibly without going to the server [Trond Myklebust, Ulrich Drepper, Andreas Dilger] (AT_STATX_DONT_SYNC). (6) Heavyweight stat: Force a netfs to go to the server, even if it thinks its cached attributes are up to date [Trond Myklebust] (AT_STATX_FORCE_SYNC). And the following have been left out for future extension: (7) Data version number: Could be used by userspace NFS servers [Aneesh Kumar]. Can also be used to modify fill_post_wcc() in NFSD which retrieves i_version directly, but has just called vfs_getattr(). It could get it from the kstat struct if it used vfs_xgetattr() instead. (There's disagreement on the exact semantics of a single field, since not all filesystems do this the same way). (8) BSD stat compatibility: Including more fields from the BSD stat such as creation time (st_btime) and inode generation number (st_gen) [Jeremy Allison, Bernd Schubert]. (9) Inode generation number: Useful for FUSE and userspace NFS servers [Bernd Schubert]. (This was asked for but later deemed unnecessary with the open-by-handle capability available and caused disagreement as to whether it's a security hole or not). (10) Extra coherency data may be useful in making backups [Andreas Dilger]. (No particular data were offered, but things like last backup timestamp, the data version number and the DOS archive bit would come into this category). (11) Allow the filesystem to indicate what it can/cannot provide: A filesystem can now say it doesn't support a standard stat feature if that isn't available, so if, for instance, inode numbers or UIDs don't exist or are fabricated locally... (This requires a separate system call - I have an fsinfo() call idea for this). (12) Store a 16-byte volume ID in the superblock that can be returned in struct xstat [Steve French]. (Deferred to fsinfo). (13) Include granularity fields in the time data to indicate the granularity of each of the times (NFSv4 time_delta) [Steve French]. (Deferred to fsinfo). (14) FS_IOC_GETFLAGS value. These could be translated to BSD's st_flags. Note that the Linux IOC flags are a mess and filesystems such as Ext4 define flags that aren't in linux/fs.h, so translation in the kernel may be a necessity (or, possibly, we provide the filesystem type too). (Some attributes are made available in stx_attributes, but the general feeling was that the IOC flags were to ext[234]-specific and shouldn't be exposed through statx this way). (15) Mask of features available on file (eg: ACLs, seclabel) [Brad Boyer, Michael Kerrisk]. (Deferred, probably to fsinfo. Finding out if there's an ACL or seclabal might require extra filesystem operations). (16) Femtosecond-resolution timestamps [Dave Chinner]. (A __reserved field has been left in the statx_timestamp struct for this - if there proves to be a need). (17) A set multiple attributes syscall to go with this. =============== NEW SYSTEM CALL =============== The new system call is: int ret = statx(int dfd, const char *filename, unsigned int flags, unsigned int mask, struct statx *buffer); The dfd, filename and flags parameters indicate the file to query, in a similar way to fstatat(). There is no equivalent of lstat() as that can be emulated with statx() by passing AT_SYMLINK_NOFOLLOW in flags. There is also no equivalent of fstat() as that can be emulated by passing a NULL filename to statx() with the fd of interest in dfd. Whether or not statx() synchronises the attributes with the backing store can be controlled by OR'ing a value into the flags argument (this typically only affects network filesystems): (1) AT_STATX_SYNC_AS_STAT tells statx() to behave as stat() does in this respect. (2) AT_STATX_FORCE_SYNC will require a network filesystem to synchronise its attributes with the server - which might require data writeback to occur to get the timestamps correct. (3) AT_STATX_DONT_SYNC will suppress synchronisation with the server in a network filesystem. The resulting values should be considered approximate. mask is a bitmask indicating the fields in struct statx that are of interest to the caller. The user should set this to STATX_BASIC_STATS to get the basic set returned by stat(). It should be noted that asking for more information may entail extra I/O operations. buffer points to the destination for the data. This must be 256 bytes in size. ====================== MAIN ATTRIBUTES RECORD ====================== The following structures are defined in which to return the main attribute set: struct statx_timestamp { __s64 tv_sec; __s32 tv_nsec; __s32 __reserved; }; struct statx { __u32 stx_mask; __u32 stx_blksize; __u64 stx_attributes; __u32 stx_nlink; __u32 stx_uid; __u32 stx_gid; __u16 stx_mode; __u16 __spare0[1]; __u64 stx_ino; __u64 stx_size; __u64 stx_blocks; __u64 __spare1[1]; struct statx_timestamp stx_atime; struct statx_timestamp stx_btime; struct statx_timestamp stx_ctime; struct statx_timestamp stx_mtime; __u32 stx_rdev_major; __u32 stx_rdev_minor; __u32 stx_dev_major; __u32 stx_dev_minor; __u64 __spare2[14]; }; The defined bits in request_mask and stx_mask are: STATX_TYPE Want/got stx_mode & S_IFMT STATX_MODE Want/got stx_mode & ~S_IFMT STATX_NLINK Want/got stx_nlink STATX_UID Want/got stx_uid STATX_GID Want/got stx_gid STATX_ATIME Want/got stx_atime{,_ns} STATX_MTIME Want/got stx_mtime{,_ns} STATX_CTIME Want/got stx_ctime{,_ns} STATX_INO Want/got stx_ino STATX_SIZE Want/got stx_size STATX_BLOCKS Want/got stx_blocks STATX_BASIC_STATS [The stuff in the normal stat struct] STATX_BTIME Want/got stx_btime{,_ns} STATX_ALL [All currently available stuff] stx_btime is the file creation time, stx_mask is a bitmask indicating the data provided and __spares*[] are where as-yet undefined fields can be placed. Time fields are structures with separate seconds and nanoseconds fields plus a reserved field in case we want to add even finer resolution. Note that times will be negative if before 1970; in such a case, the nanosecond fields will also be negative if not zero. The bits defined in the stx_attributes field convey information about a file, how it is accessed, where it is and what it does. The following attributes map to FS_*_FL flags and are the same numerical value: STATX_ATTR_COMPRESSED File is compressed by the fs STATX_ATTR_IMMUTABLE File is marked immutable STATX_ATTR_APPEND File is append-only STATX_ATTR_NODUMP File is not to be dumped STATX_ATTR_ENCRYPTED File requires key to decrypt in fs Within the kernel, the supported flags are listed by: KSTAT_ATTR_FS_IOC_FLAGS [Are any other IOC flags of sufficient general interest to be exposed through this interface?] New flags include: STATX_ATTR_AUTOMOUNT Object is an automount trigger These are for the use of GUI tools that might want to mark files specially, depending on what they are. Fields in struct statx come in a number of classes: (0) stx_dev_*, stx_blksize. These are local system information and are always available. (1) stx_mode, stx_nlinks, stx_uid, stx_gid, stx_[amc]time, stx_ino, stx_size, stx_blocks. These will be returned whether the caller asks for them or not. The corresponding bits in stx_mask will be set to indicate whether they actually have valid values. If the caller didn't ask for them, then they may be approximated. For example, NFS won't waste any time updating them from the server, unless as a byproduct of updating something requested. If the values don't actually exist for the underlying object (such as UID or GID on a DOS file), then the bit won't be set in the stx_mask, even if the caller asked for the value. In such a case, the returned value will be a fabrication. Note that there are instances where the type might not be valid, for instance Windows reparse points. (2) stx_rdev_*. This will be set only if stx_mode indicates we're looking at a blockdev or a chardev, otherwise will be 0. (3) stx_btime. Similar to (1), except this will be set to 0 if it doesn't exist. ======= TESTING ======= The following test program can be used to test the statx system call: samples/statx/test-statx.c Just compile and run, passing it paths to the files you want to examine. The file is built automatically if CONFIG_SAMPLES is enabled. Here's some example output. Firstly, an NFS directory that crosses to another FSID. Note that the AUTOMOUNT attribute is set because transiting this directory will cause d_automount to be invoked by the VFS. [root@andromeda ~]# /tmp/test-statx -A /warthog/data statx(/warthog/data) = 0 results=7ff Size: 4096 Blocks: 8 IO Block: 1048576 directory Device: 00:26 Inode: 1703937 Links: 125 Access: (3777/drwxrwxrwx) Uid: 0 Gid: 4041 Access: 2016-11-24 09:02:12.219699527+0000 Modify: 2016-11-17 10:44:36.225653653+0000 Change: 2016-11-17 10:44:36.225653653+0000 Attributes: 0000000000001000 (-------- -------- -------- -------- -------- -------- ---m---- --------) Secondly, the result of automounting on that directory. [root@andromeda ~]# /tmp/test-statx /warthog/data statx(/warthog/data) = 0 results=7ff Size: 4096 Blocks: 8 IO Block: 1048576 directory Device: 00:27 Inode: 2 Links: 125 Access: (3777/drwxrwxrwx) Uid: 0 Gid: 4041 Access: 2016-11-24 09:02:12.219699527+0000 Modify: 2016-11-17 10:44:36.225653653+0000 Change: 2016-11-17 10:44:36.225653653+0000 Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-03-02Merge branch 'work.sendmsg' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs sendmsg updates from Al Viro: "More sendmsg work. This is a fairly separate isolated stuff (there's a continuation around lustre, but that one was too late to soak in -next), thus the separate pull request" * 'work.sendmsg' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: ncpfs: switch to sock_sendmsg() ncpfs: don't mess with manually advancing iovec on send ncpfs: sendmsg does *not* bugger iovec these days ceph_tcp_sendpage(): use ITER_BVEC sendmsg afs_send_pages(): use ITER_BVEC rds: remove dead code ceph: switch to sock_recvmsg() usbip_recv(): switch to sock_recvmsg() iscsi_target: deal with short writes on the tx side [nbd] pass iov_iter to nbd_xmit() [nbd] switch sock_xmit() to sock_{send,recv}msg() [drbd] use sock_sendmsg()
2017-03-02sched/headers: Prepare to move signal wakeup & sigpending methods from ↵Ingo Molnar
<linux/sched.h> into <linux/sched/signal.h> Fix up affected files that include this signal functionality via sched.h. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-02-27lib/vsprintf.c: remove %Z supportAlexey Dobriyan
Now that %z is standartised in C99 there is no reason to support %Z. Unlike %L it doesn't even make format strings smaller. Use BUILD_BUG_ON in a couple ATM drivers. In case anyone didn't notice lib/vsprintf.o is about half of SLUB which is in my opinion is quite an achievement. Hopefully this patch inspires someone else to trim vsprintf.c more. Link: http://lkml.kernel.org/r/20170103230126.GA30170@avx2 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Andy Shevchenko <andy.shevchenko@gmail.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-23Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull namespace updates from Eric Biederman: "There is a lot here. A lot of these changes result in subtle user visible differences in kernel behavior. I don't expect anything will care but I will revert/fix things immediately if any regressions show up. From Seth Forshee there is a continuation of the work to make the vfs ready for unpriviled mounts. We had thought the previous changes prevented the creation of files outside of s_user_ns of a filesystem, but it turns we missed the O_CREAT path. Ooops. Pavel Tikhomirov and Oleg Nesterov worked together to fix a long standing bug in the implemenation of PR_SET_CHILD_SUBREAPER where only children that are forked after the prctl are considered and not children forked before the prctl. The only known user of this prctl systemd forks all children after the prctl. So no userspace regressions will occur. Holding earlier forked children to the same rules as later forked children creates a semantic that is sane enough to allow checkpoing of processes that use this feature. There is a long delayed change by Nikolay Borisov to limit inotify instances inside a user namespace. Michael Kerrisk extends the API for files used to maniuplate namespaces with two new trivial ioctls to allow discovery of the hierachy and properties of namespaces. Konstantin Khlebnikov with the help of Al Viro adds code that when a network namespace exits purges it's sysctl entries from the dcache. As in some circumstances this could use a lot of memory. Vivek Goyal fixed a bug with stacked filesystems where the permissions on the wrong inode were being checked. I continue previous work on ptracing across exec. Allowing a file to be setuid across exec while being ptraced if the tracer has enough credentials in the user namespace, and if the process has CAP_SETUID in it's own namespace. Proc files for setuid or otherwise undumpable executables are now owned by the root in the user namespace of their mm. Allowing debugging of setuid applications in containers to work better. A bug I introduced with permission checking and automount is now fixed. The big change is to mark the mounts that the kernel initiates as a result of an automount. This allows the permission checks in sget to be safely suppressed for this kind of mount. As the permission check happened when the original filesystem was mounted. Finally a special case in the mount namespace is removed preventing unbounded chains in the mount hash table, and making the semantics simpler which benefits CRIU. The vfs fix along with related work in ima and evm I believe makes us ready to finish developing and merge fully unprivileged mounts of the fuse filesystem. The cleanups of the mount namespace makes discussing how to fix the worst case complexity of umount. The stacked filesystem fixes pave the way for adding multiple mappings for the filesystem uids so that efficient and safer containers can be implemented" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: proc/sysctl: Don't grab i_lock under sysctl_lock. vfs: Use upper filesystem inode in bprm_fill_uid() proc/sysctl: prune stale dentries during unregistering mnt: Tuck mounts under others instead of creating shadow/side mounts. prctl: propagate has_child_subreaper flag to every descendant introduce the walk_process_tree() helper nsfs: Add an ioctl() to return owner UID of a userns fs: Better permission checking for submounts exit: fix the setns() && PR_SET_CHILD_SUBREAPER interaction vfs: open() with O_CREAT should not create inodes with unknown ids nsfs: Add an ioctl() to return the namespace type proc: Better ownership of files for non-dumpable tasks in user namespaces exec: Remove LSM_UNSAFE_PTRACE_CAP exec: Test the ptracer's saved cred to see if the tracee can gain caps exec: Don't reset euid and egid when the tracee has CAP_SETUID inotify: Convert to using per-namespace limits
2017-02-10afs: Use core kernel UUID generationArnd Bergmann
AFS uses a time based UUID to identify the host itself. This requires getting a timestamp which is currently done through the getnstimeofday() interface that we want to eventually get rid of. Instead of replacing it with a ktime-based interface, simply remove the entire function and use generate_random_uuid() instead, which has a v4 ("completely random") UUID instead of the time-based one. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: David Howells <dhowells@redhat.com>
2017-02-10afs: Move UUID struct to linux/uuid.hDavid Howells
Move the afs_uuid struct to linux/uuid.h, rename it to uuid_v1 and change the u16/u32 fields to __be16/__be32 instead so that the structure can be cast to a 16-octet network-order buffer. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de
2017-02-02fs: Better permission checking for submountsEric W. Biederman
To support unprivileged users mounting filesystems two permission checks have to be performed: a test to see if the user allowed to create a mount in the mount namespace, and a test to see if the user is allowed to access the specified filesystem. The automount case is special in that mounting the original filesystem grants permission to mount the sub-filesystems, to any user who happens to stumble across the their mountpoint and satisfies the ordinary filesystem permission checks. Attempting to handle the automount case by using override_creds almost works. It preserves the idea that permission to mount the original filesystem is permission to mount the sub-filesystem. Unfortunately using override_creds messes up the filesystems ordinary permission checks. Solve this by being explicit that a mount is a submount by introducing vfs_submount, and using it where appropriate. vfs_submount uses a new mount internal mount flags MS_SUBMOUNT, to let sget and friends know that a mount is a submount so they can take appropriate action. sget and sget_userns are modified to not perform any permission checks on submounts. follow_automount is modified to stop using override_creds as that has proven problemantic. do_mount is modified to always remove the new MS_SUBMOUNT flag so that we know userspace will never by able to specify it. autofs4 is modified to stop using current_real_cred that was put in there to handle the previous version of submount permission checking. cifs is modified to pass the mountpoint all of the way down to vfs_submount. debugfs is modified to pass the mountpoint all of the way down to trace_automount by adding a new parameter. To make this change easier a new typedef debugfs_automount_t is introduced to capture the type of the debugfs automount function. Cc: stable@vger.kernel.org Fixes: 069d5ac9ae0d ("autofs: Fix automounts by using current_real_cred()->uid") Fixes: aeaa4a79ff6a ("fs: Call d_automount with the filesystems creds") Reviewed-by: Trond Myklebust <trond.myklebust@primarydata.com> Reviewed-by: Seth Forshee <seth.forshee@canonical.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2017-01-16afs: Conditionalise a new unused variableArnd Bergmann
The bulk readpages support introduced a harmless warning: fs/afs/file.c: In function 'afs_readpages_page_done': fs/afs/file.c:270:20: error: unused variable 'vnode' [-Werror=unused-variable] This adds an #ifdef to match the user of that variable. The user of the variable has to be conditional because it accesses a member of a struct that is also conditional. Fixes: 91b467e0a3f5 ("afs: Make afs_readpages() fetch data in bulk") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-09afs: Refcount the afs_call structDavid Howells
A static checker warning occurs in the AFS filesystem: fs/afs/cmservice.c:155 SRXAFSCB_CallBack() error: dereferencing freed memory 'call' due to the reply being sent before we access the server it points to. The act of sending the reply causes the call to be freed if an error occurs (but not if it doesn't). On top of this, the lifetime handling of afs_call structs is fragile because they get passed around through workqueues without any sort of refcounting. Deal with the issues by: (1) Fix the maybe/maybe not nature of the reply sending functions with regards to whether they release the call struct. (2) Refcount the afs_call struct and sort out places that need to get/put references. (3) Pass a ref through the work queue and release (or pass on) that ref in the work function. Care has to be taken because a work queue may already own a ref to the call. (4) Do the cleaning up in the put function only. (5) Simplify module cleanup by always incrementing afs_outstanding_calls whenever a call is allocated. (6) Set the backlog to 0 with kernel_listen() at the beginning of the process of closing the socket to prevent new incoming calls from occurring and to remove the contribution of preallocated calls from afs_outstanding_calls before we wait on it. A tracepoint is also added to monitor the afs_call refcount and lifetime. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: David Howells <dhowells@redhat.com> Fixes: 08e0e7c82eea: "[AF_RXRPC]: Make the in-kernel AFS filesystem use AF_RXRPC."