summaryrefslogtreecommitdiff
path: root/fs/nfs/localio.c
AgeCommit message (Collapse)Author
2025-01-21nfs: fix incorrect error handling in LOCALIOMike Snitzer
nfs4_stat_to_errno() expects a NFSv4 error code as an argument and returns a POSIX errno. The problem is LOCALIO is passing nfs4_stat_to_errno() the POSIX errno return values from filp->f_op->read_iter(), filp->f_op->write_iter() and vfs_fsync_range(). So the POSIX errno that nfs_local_pgio_done() and nfs_local_commit_done() are passing to nfs4_stat_to_errno() are failing to match any NFSv4 error code, which results in nfs4_stat_to_errno() defaulting to returning -EREMOTEIO. This causes assertions in upper layers due to -EREMOTEIO not being a valid NFSv4 error code. Fix this by updating nfs_local_pgio_done() and nfs_local_commit_done() to use the new nfs_localio_errno_to_nfs4_stat() to map a POSIX errno to an NFSv4 error code. Care was taken to factor out nfs4_errtbl_common[] to avoid duplicating the same NFS error to errno table. nfs4_errtbl_common[] is checked first by both nfs4_stat_to_errno and nfs_localio_errno_to_nfs4_stat before they check their own more specialized tables (nfs4_errtbl[] and nfs4_errtbl_localio[] respectively). While auditing the associated error mapping tables, the (ab)use of -1 for the last table entry was removed in favor of using ARRAY_SIZE to iterate the nfs_errtbl[] and nfs4_errtbl[]. And 'errno_NFSERR_IO' was removed because it caused needless obfuscation. Fixes: 70ba381e1a431 ("nfs: add LOCALIO support") Reported-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
2025-01-14nfs: probe for LOCALIO when v4 client reconnects to serverMike Snitzer
Introduce nfs_local_probe_async() for the NFS client to initiate if/when it reconnects with server. For NFSv4 it is a simple matter to call nfs_local_probe_async() from nfs4_do_reclaim (during NFSv4 grace). Signed-off-by: Mike Snitzer <snitzer@kernel.org> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
2025-01-14nfs/localio: remove redundant code and simplify LOCALIO enablementMike Snitzer
Remove nfs_local_enable and nfs_local_disable, instead use nfs_localio_enable_client and nfs_localio_disable_client. Discontinue use of the NFS_CS_LOCAL_IO bit in the nfs_client struct's cl_flags to reflect that LOCALIO is enabled; instead just test if the net member of the nfs_uuid_t struct is set. Also remove NFS_CS_LOCAL_IO. Lastly, remove trace_nfs_local_enable and trace_nfs_local_disable because comparable traces are available from nfs_localio.ko. Suggested-by: NeilBrown <neilb@suse.de> Signed-off-by: Mike Snitzer <snitzer@kernel.org> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
2025-01-14nfs: cache all open LOCALIO nfsd_file(s) in clientMike Snitzer
This commit switches from leaning heavily on NFSD's filecache (in terms of GC'd nfsd_files) back to caching nfsd_files in the client. A later commit will add the callback mechanism needed to allow NFSD to force the NFS client to cleanup all cached nfsd_files. Add nfs_fh_localio_init() and 'struct nfs_fh_localio' to cache opened nfsd_file(s) (both a RO and RW nfsd_file is able to be opened and cached for a given nfs_fh). Update nfs_local_open_fh() to cache the nfsd_file once it is opened using __nfs_local_open_fh(). Introduce nfs_close_local_fh() to clear the cached open nfsd_files and call nfs_to_nfsd_file_put_local(). Refcounting is such that: - nfs_local_open_fh() is paired with nfs_close_local_fh(). - __nfs_local_open_fh() is paired with nfs_to_nfsd_file_put_local(). - nfs_local_file_get() is paired with nfs_local_file_put(). Signed-off-by: Mike Snitzer <snitzer@kernel.org> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
2025-01-14nfs_common: move localio_lock to new lock member of nfs_uuid_tMike Snitzer
Remove cl_localio_lock from 'struct nfs_client' in favor of adding a lock to the nfs_uuid_t struct (which is embedded in each nfs_client). Push nfs_local_{enable,disable} implementation down to nfs_common. Those methods now call nfs_localio_{enable,disable}_client. This allows implementing nfs_localio_invalidate_clients in terms of nfs_localio_disable_client. Signed-off-by: Mike Snitzer <snitzer@kernel.org> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
2025-01-14nfs_common: rename functions that invalidate LOCALIO nfs_clientsMike Snitzer
Rename nfs_uuid_invalidate_one_client to nfs_localio_disable_client. Rename nfs_uuid_invalidate_clients to nfs_localio_invalidate_clients. Signed-off-by: Mike Snitzer <snitzer@kernel.org> Reviewed-by: NeilBrown <neilb@suse.de> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
2025-01-14nfs/localio: add direct IO enablement with sync and async IO supportMike Snitzer
This commit simply adds the required O_DIRECT plumbing. It doesn't address the fact that NFS doesn't ensure all writes are page aligned (nor device logical block size aligned as required by O_DIRECT). Because NFS will read-modify-write for IO that isn't aligned, LOCALIO will not use O_DIRECT semantics by default if/when an application requests the use of O_DIRECT. Allow the use of O_DIRECT semantics by: 1: Adding a flag to the nfs_pgio_header struct to allow the NFS O_DIRECT layer to signal that O_DIRECT was used by the application 2: Adding a 'localio_O_DIRECT_semantics' NFS module parameter that when enabled will cause LOCALIO to use O_DIRECT semantics (this may cause IO to fail if applications do not properly align their IO). This commit is derived from code developed by Weston Andros Adamson. Signed-off-by: Mike Snitzer <snitzer@kernel.org> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
2024-11-09nfs/localio: must clear res.replen in nfs_local_read_doneNeilBrown
Otherwise memory corruption can occur due to NFSv3 LOCALIO reads leaving garbage in res.replen: - nfs3_read_done() copies that into server->read_hdrsize; from there nfs3_proc_read_setup() copies it to args.replen in new requests. - nfs3_xdr_enc_read3args() passes that to rpc_prepare_reply_pages() which includes it in hdrsize for xdr_init_pages, so that rq_rcv_buf contains a ridiculous len. - This is copied to rq_private_buf and xs_read_stream_request() eventually passes the kvec to sock_recvmsg() which receives incoming data into entirely the wrong place. This is easily reproduced with NFSv3 LOCALIO that is servicing reads when it is made to pivot back to using normal RPC. This switch back to using normal NFSv3 with RPC can occur for a few reasons but this issue was exposed with a test that stops and then restarts the NFSv3 server while LOCALIO is performing heavy read IO. Fixes: 70ba381e1a43 ("nfs: add LOCALIO support") Reported-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: NeilBrown <neilb@suse.de> Co-developed-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2024-11-08nfs/localio: eliminate need for nfs_local_fsync_work forward declarationMike Snitzer
Move nfs_local_fsync_ctx_alloc() after nfs_local_fsync_work(). Signed-off-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2024-11-08nfs/localio: remove extra indirect nfs_to call to check {read,write}_iterMike Snitzer
Push the read_iter and write_iter availability checks down to nfs_do_local_read and nfs_do_local_write respectively. This eliminates a redundant nfs_to->nfsd_file_file() call. Signed-off-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2024-11-08nfs/localio: eliminate unnecessary kref in nfs_local_fsync_ctxMike Snitzer
nfs_local_commit() doesn't need async cleanup of nfs_local_fsync_ctx, so there is no need to use a kref. Signed-off-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2024-11-08nfs/localio: remove redundant suid/sgid handlingMike Snitzer
nfs_writeback_done() will take care of suid/sgid corner case. Signed-off-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2024-11-04nfs_common: fix localio to cope with racing nfs_local_probe()Mike Snitzer
Fix the possibility of racing nfs_local_probe() resulting in: list_add double add: new=ffff8b99707f9f58, prev=ffff8b99707f9f58, next=ffffffffc0f30000. ------------[ cut here ]------------ kernel BUG at lib/list_debug.c:35! Add nfs_uuid_init() to properly initialize all nfs_uuid_t members (particularly its list_head). Switch to returning bool from nfs_uuid_begin(), returns false if nfs_uuid_t is already in-use (its list_head is on a list). Update nfs_local_probe() to return early if the nfs_client's cl_uuid (nfs_uuid_t) is in-use. Also, switch nfs_uuid_begin() from using list_add_tail_rcu() to list_add_tail() -- rculist was used in an earlier version of the localio code that had a lockless nfs_uuid_lookup interface. Signed-off-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
2024-10-03nfs_common: fix race in NFS calls to nfsd_file_put_local() and nfsd_serv_put()Mike Snitzer
Add nfs_to_nfsd_file_put_local() interface to fix race with nfsd module unload. Similarly, use RCU around nfs_open_local_fh()'s error path call to nfs_to->nfsd_serv_put(). Holding RCU ensures that NFS will safely _call and return_ from its nfs_to calls into the NFSD functions nfsd_file_put_local() and nfsd_serv_put(). Otherwise, if RCU isn't used then there is a narrow window when NFS's reference for the nfsd_file and nfsd_serv are dropped and the NFSD module could be unloaded, which could result in a crash from the return instruction for either nfs_to->nfsd_file_put_local() or nfs_to->nfsd_serv_put(). Reported-by: NeilBrown <neilb@suse.de> Signed-off-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
2024-09-30nfs: Remove duplicated include in localio.cYang Li
The header files linux/module.h is included twice in localio.c, so one inclusion of each can be removed. Reported-by: Abaci Robot <abaci@linux.alibaba.com> Closes: https://bugzilla.openanolis.cn/show_bug.cgi?id=11073 Signed-off-by: Yang Li <yang.lee@linux.alibaba.com> Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
2024-09-23nfs: implement client support for NFS_LOCALIO_PROGRAMMike Snitzer
The LOCALIO auxiliary RPC protocol consists of a single "UUID_IS_LOCAL" RPC method that allows the Linux NFS client to verify the local Linux NFS server can see the nonce (single-use UUID) the client generated and made available in nfs_common for subsequent lookup and verification by the NFS server. If matched, the NFS server populates members in the nfs_uuid_t struct. The NFS client then transfers these nfs_uuid_t struct member pointers to the nfs_client struct and cleans up the nfs_uuid_t struct. See: fs/nfs/localio.c:nfs_local_probe() This protocol isn't part of an IETF standard, nor does it need to be considering it is Linux-to-Linux auxiliary RPC protocol that amounts to an implementation detail. Localio is only supported when UNIX-style authentication (AUTH_UNIX, aka AUTH_SYS) is used (enforced by fs/nfs/localio.c:nfs_local_probe()). The UUID_IS_LOCAL method encodes the client generated uuid_t in terms of the fixed UUID_SIZE (16 bytes). The fixed size opaque encode and decode XDR methods are used instead of the less efficient variable sized methods. Having a nonce (single-use uuid) is better than using the same uuid for the life of the server, and sending it proactively by client rather than reactively by the server is also safer. Signed-off-by: Mike Snitzer <snitzer@kernel.org> Co-developed-by: NeilBrown <neilb@suse.de> Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
2024-09-23nfs/localio: use dedicated workqueues for filesystem read and writeTrond Myklebust
For localio access, don't call filesystem read() and write() routines directly. This solves two problems: 1) localio writes need to use a normal (non-memreclaim) unbound workqueue. This avoids imposing new requirements on how underlying filesystems process frontend IO, which would cause a large amount of work to update all filesystems. Without this change, when XFS starts getting low on space, XFS flushes work on a non-memreclaim work queue, which causes a priority inversion problem: 00573 workqueue: WQ_MEM_RECLAIM writeback:wb_workfn is flushing !WQ_MEM_RECLAIM xfs-sync/vdc:xfs_flush_inodes_worker 00573 WARNING: CPU: 6 PID: 8525 at kernel/workqueue.c:3706 check_flush_dependency+0x2a4/0x328 00573 Modules linked in: 00573 CPU: 6 PID: 8525 Comm: kworker/u71:5 Not tainted 6.10.0-rc3-ktest-00032-g2b0a133403ab #18502 00573 Hardware name: linux,dummy-virt (DT) 00573 Workqueue: writeback wb_workfn (flush-0:33) 00573 pstate: 400010c5 (nZcv daIF -PAN -UAO -TCO -DIT +SSBS BTYPE=--) 00573 pc : check_flush_dependency+0x2a4/0x328 00573 lr : check_flush_dependency+0x2a4/0x328 00573 sp : ffff0000c5f06bb0 00573 x29: ffff0000c5f06bb0 x28: ffff0000c998a908 x27: 1fffe00019331521 00573 x26: ffff0000d0620900 x25: ffff0000c5f06ca0 x24: ffff8000828848c0 00573 x23: 1fffe00018be0d8e x22: ffff0000c1210000 x21: ffff0000c75fde00 00573 x20: ffff800080bfd258 x19: ffff0000cad63400 x18: ffff0000cd3a4810 00573 x17: 0000000000000000 x16: 0000000000000000 x15: ffff800080508d98 00573 x14: 0000000000000000 x13: 204d49414c434552 x12: 1fffe0001b6eeab2 00573 x11: ffff60001b6eeab2 x10: dfff800000000000 x9 : ffff60001b6eeab3 00573 x8 : 0000000000000001 x7 : 00009fffe491154e x6 : ffff0000db775593 00573 x5 : ffff0000db775590 x4 : ffff0000db775590 x3 : 0000000000000000 00573 x2 : 0000000000000027 x1 : ffff600018be0d62 x0 : dfff800000000000 00573 Call trace: 00573 check_flush_dependency+0x2a4/0x328 00573 __flush_work+0x184/0x5c8 00573 flush_work+0x18/0x28 00573 xfs_flush_inodes+0x68/0x88 00573 xfs_file_buffered_write+0x128/0x6f0 00573 xfs_file_write_iter+0x358/0x448 00573 nfs_local_doio+0x854/0x1568 00573 nfs_initiate_pgio+0x214/0x418 00573 nfs_generic_pg_pgios+0x304/0x480 00573 nfs_pageio_doio+0xe8/0x240 00573 nfs_pageio_complete+0x160/0x480 00573 nfs_writepages+0x300/0x4f0 00573 do_writepages+0x12c/0x4a0 00573 __writeback_single_inode+0xd4/0xa68 00573 writeback_sb_inodes+0x470/0xcb0 00573 __writeback_inodes_wb+0xb0/0x1d0 00573 wb_writeback+0x594/0x808 00573 wb_workfn+0x5e8/0x9e0 00573 process_scheduled_works+0x53c/0xd90 00573 worker_thread+0x370/0x8c8 00573 kthread+0x258/0x2e8 00573 ret_from_fork+0x10/0x20 2) Some filesystem writeback routines can end up taking up a lot of stack space (particularly XFS). Instead of risking running over due to the extra overhead from the NFS stack, we should just call these routines from a workqueue job. Since we need to do this to address 1) above we're able to avoid possibly blowing the stack "for free". Use of dedicated workqueues improves performance over using the system_unbound_wq. Also, the creds used to open the file are used to override_creds() in both nfs_local_call_read() and nfs_local_call_write() -- otherwise the workqueue could have elevated capabilities (which the caller may not). Lastly, care is taken to set PF_LOCAL_THROTTLE | PF_MEMALLOC_NOIO in nfs_do_local_write() to avoid writeback deadlocks. The PF_LOCAL_THROTTLE flag prevents deadlocks in balance_dirty_pages() by causing writes to only be throttled against other writes to the same bdi (it keeps the throttling local). Normally all writes to bdi(s) are throttled equally (after throughput factors are allowed for). The PF_MEMALLOC_NOIO flag prevents the lower filesystem IO from causing memory reclaim to re-enter filesystems or IO devices and so prevents deadlocks from occuring where IO that cleans pages is waiting on IO to complete. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Co-developed-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Mike Snitzer <snitzer@kernel.org> Co-developed-by: NeilBrown <neilb@suse.de> Signed-off-by: NeilBrown <neilb@suse.de> # eliminated wait_for_completion Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
2024-09-23nfs: add LOCALIO supportWeston Andros Adamson
Add client support for bypassing NFS for localhost reads, writes, and commits. This is only useful when the client and the server are running on the same host. nfs_local_probe() is stubbed out, later commits will enable client and server handshake via a Linux-only LOCALIO auxiliary RPC protocol. This has dynamic binding with the nfsd module (via nfs_localio module which is part of nfs_common). LOCALIO will only work if nfsd is already loaded. The "localio_enabled" nfs kernel module parameter can be used to disable and enable the ability to use LOCALIO support. CONFIG_NFS_LOCALIO enables NFS client support for LOCALIO. Lastly, LOCALIO uses an nfsd_file to initiate all IO. To make proper use of nfsd_file (and nfsd's filecache) its lifetime (duration before nfsd_file_put is called) must extend until after commit, read and write operations. So rather than immediately drop the nfsd_file reference in nfs_local_open_fh(), that doesn't happen until nfs_local_pgio_release() for read/write and not until nfs_local_release_commit_data() for commit. The same applies to the reference held on nfsd's nn->nfsd_serv. Both objects' lifetimes and associated references are managed through calls to nfs_to->nfsd_file_put_local(). Signed-off-by: Weston Andros Adamson <dros@primarydata.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Co-developed-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: NeilBrown <neilb@suse.de> # nfs_open_local_fh Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>