kernel/linux.git/fs/nfs_common, branch v6.12.80

NFSD: Remove NFSERR_EAGAIN

2026-01-17T15:31:15+00:00

commit c6c209ceb87f64a6ceebe61761951dcbbf4a0baa upstream. I haven't found an NFSERR_EAGAIN in RFCs 1094, 1813, 7530, or 8881. None of these RFCs have an NFS status code that match the numeric value "11". Based on the meaning of the EAGAIN errno, I presume the use of this status in NFSD means NFS4ERR_DELAY. So replace the one usage of nfserr_eagain, and remove it from NFSD's NFS status conversion tables. As far as I can tell, NFSERR_EAGAIN has existed since the pre-git era, but was not actually used by any code until commit f4e44b393389 ("NFSD: delay unmount source's export after inter-server copy completed."), at which time it become possible for NFSD to return a status code of 11 (which is not valid NFS protocol). Fixes: f4e44b393389 ("NFSD: delay unmount source's export after inter-server copy completed.") Cc: stable@vger.kernel.org Reviewed-by: NeilBrown Reviewed-by: Jeff Layton Signed-off-by: Chuck Lever Signed-off-by: Greg Kroah-Hartman

nfsd: rename nfsd_serv_ prefixed methods and variables with nfsd_net_

2026-01-08T09:14:09+00:00

[ Upstream commit b33f7dec3a67216123312c7bb752b8f6faa1c465 ] Also update Documentation/filesystems/nfs/localio.rst accordingly and reduce the technical documentation debt that was previously captured in that document. Signed-off-by: Mike Snitzer Reviewed-by: Jeff Layton Acked-by: Chuck Lever Signed-off-by: Anna Schumaker Stable-dep-of: df8d829bba3a ("nfsd: fix memory leak in nfsd_create_serv error paths") Signed-off-by: Sasha Levin

nfs: fix incorrect error handling in LOCALIO

2025-02-08T08:57:59+00:00

[ Upstream commit ead11ac50ad4b8ef1b64806e962ea984862d96ad ] 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 Signed-off-by: Mike Snitzer Signed-off-by: Anna Schumaker Signed-off-by: Sasha Levin

nfs_common: must not hold RCU while calling nfsd_file_put_local

2024-12-05T13:02:27+00:00

[ Upstream commit c840b8e1f039e90f97ca55525667eb961422f86c ] Move holding the RCU from nfs_to_nfsd_file_put_local to nfs_to_nfsd_net_put. It is the call to nfs_to->nfsd_serv_put that requires the RCU anyway (the puts for nfsd_file and netns were combined to avoid an extra indirect reference but that micro-optimization isn't possible now). This fixes xfstests generic/013 and it triggering: "Voluntary context switch within RCU read-side critical section!" [ 143.545738] Call Trace: [ 143.546206] [ 143.546625] ? show_regs+0x6d/0x80 [ 143.547267] ? __warn+0x91/0x140 [ 143.547951] ? rcu_note_context_switch+0x496/0x5d0 [ 143.548856] ? report_bug+0x193/0x1a0 [ 143.549557] ? handle_bug+0x63/0xa0 [ 143.550214] ? exc_invalid_op+0x1d/0x80 [ 143.550938] ? asm_exc_invalid_op+0x1f/0x30 [ 143.551736] ? rcu_note_context_switch+0x496/0x5d0 [ 143.552634] ? wakeup_preempt+0x62/0x70 [ 143.553358] __schedule+0xaa/0x1380 [ 143.554025] ? _raw_spin_unlock_irqrestore+0x12/0x40 [ 143.554958] ? try_to_wake_up+0x1fe/0x6b0 [ 143.555715] ? wake_up_process+0x19/0x20 [ 143.556452] schedule+0x2e/0x120 [ 143.557066] schedule_preempt_disabled+0x19/0x30 [ 143.557933] rwsem_down_read_slowpath+0x24d/0x4a0 [ 143.558818] ? xfs_efi_item_format+0x50/0xc0 [xfs] [ 143.559894] down_read+0x4e/0xb0 [ 143.560519] xlog_cil_commit+0x1b2/0xbc0 [xfs] [ 143.561460] ? _raw_spin_unlock+0x12/0x30 [ 143.562212] ? xfs_inode_item_precommit+0xc7/0x220 [xfs] [ 143.563309] ? xfs_trans_run_precommits+0x69/0xd0 [xfs] [ 143.564394] __xfs_trans_commit+0xb5/0x330 [xfs] [ 143.565367] xfs_trans_roll+0x48/0xc0 [xfs] [ 143.566262] xfs_defer_trans_roll+0x57/0x100 [xfs] [ 143.567278] xfs_defer_finish_noroll+0x27a/0x490 [xfs] [ 143.568342] xfs_defer_finish+0x1a/0x80 [xfs] [ 143.569267] xfs_bunmapi_range+0x4d/0xb0 [xfs] [ 143.570208] xfs_itruncate_extents_flags+0x13d/0x230 [xfs] [ 143.571353] xfs_free_eofblocks+0x12e/0x190 [xfs] [ 143.572359] xfs_file_release+0x12d/0x140 [xfs] [ 143.573324] __fput+0xe8/0x2d0 [ 143.573922] __fput_sync+0x1d/0x30 [ 143.574574] nfsd_filp_close+0x33/0x60 [nfsd] [ 143.575430] nfsd_file_free+0x96/0x150 [nfsd] [ 143.576274] nfsd_file_put+0xf7/0x1a0 [nfsd] [ 143.577104] nfsd_file_put_local+0x18/0x30 [nfsd] [ 143.578070] nfs_close_local_fh+0x101/0x110 [nfs_localio] [ 143.579079] __put_nfs_open_context+0xc9/0x180 [nfs] [ 143.580031] nfs_file_clear_open_context+0x4a/0x60 [nfs] [ 143.581038] nfs_file_release+0x3e/0x60 [nfs] [ 143.581879] __fput+0xe8/0x2d0 [ 143.582464] __fput_sync+0x1d/0x30 [ 143.583108] __x64_sys_close+0x41/0x80 [ 143.583823] x64_sys_call+0x189a/0x20d0 [ 143.584552] do_syscall_64+0x64/0x170 [ 143.585240] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 143.586185] RIP: 0033:0x7f3c5153efd7 Fixes: 65f2a5c36635 ("nfs_common: fix race in NFS calls to nfsd_file_put_local() and nfsd_serv_put()") Signed-off-by: Mike Snitzer Reviewed-by: NeilBrown Reviewed-by: Jeff Layton Signed-off-by: Chuck Lever Signed-off-by: Sasha Levin

nfs_common: fix localio to cope with racing nfs_local_probe()

2024-11-04T15:24:19+00:00

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 Signed-off-by: Anna Schumaker

nfs_common: fix race in NFS calls to nfsd_file_put_local() and nfsd_serv_put()

2024-10-03T20:19:43+00:00

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 Signed-off-by: Mike Snitzer Signed-off-by: Anna Schumaker

nfs: add LOCALIO support

2024-09-23T19:03:30+00:00

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 Signed-off-by: Trond Myklebust Co-developed-by: Mike Snitzer Signed-off-by: Mike Snitzer Signed-off-by: NeilBrown # nfs_open_local_fh Reviewed-by: Jeff Layton Signed-off-by: Anna Schumaker

nfs_common: prepare for the NFS client to use nfsd_file for LOCALIO

2024-09-23T19:03:30+00:00

The next commit will introduce nfsd_open_local_fh() which returns an nfsd_file structure. This commit exposes LOCALIO's required NFSD symbols to the NFS client: - Make nfsd_open_local_fh() symbol and other required NFSD symbols available to NFS in a global 'nfs_to' nfsd_localio_operations struct (global access suggested by Trond, nfsd_localio_operations suggested by NeilBrown). The next commit will also introduce nfsd_localio_ops_init() that init_nfsd() will call to initialize 'nfs_to'. - Introduce nfsd_file_file() that provides access to nfsd_file's backing file. Keeps nfsd_file structure opaque to NFS client (as suggested by Jeff Layton). - Introduce nfsd_file_put_local() that will put the reference to the nfsd_file's associated nn->nfsd_serv and then put the reference to the nfsd_file (as suggested by NeilBrown). Suggested-by: Trond Myklebust # nfs_to Suggested-by: NeilBrown # nfsd_localio_operations Suggested-by: Jeff Layton # nfsd_file_file Signed-off-by: Mike Snitzer Reviewed-by: NeilBrown Reviewed-by: Jeff Layton Signed-off-by: Anna Schumaker

nfs_common: add NFS LOCALIO auxiliary protocol enablement

2024-09-23T19:03:30+00:00

fs/nfs_common/nfslocalio.c provides interfaces that enable an NFS client to generate a nonce (single-use UUID) and associated nfs_uuid_t struct, register it with nfs_common for subsequent lookup and verification by the NFS server and if matched the NFS server populates members in the nfs_uuid_t struct. nfs_common's nfs_uuids list is the basis for localio enablement, as such it has members that point to nfsd memory for direct use by the client (e.g. 'net' is the server's network namespace, through it the client can access nn->nfsd_serv). This commit also provides the base nfs_uuid_t interfaces to allow proper net namespace refcounting for the LOCALIO use case. CONFIG_NFS_LOCALIO controls the nfs_common, NFS server and NFS client enablement for LOCALIO. If both NFS_FS=m and NFSD=m then NFS_COMMON_LOCALIO_SUPPORT=m and nfs_localio.ko is built (and provides nfs_common's LOCALIO support). # lsmod | grep nfs_localio nfs_localio 12288 2 nfsd,nfs sunrpc 745472 35 nfs_localio,nfsd,auth_rpcgss,lockd,nfsv3,nfs Signed-off-by: Mike Snitzer Co-developed-by: NeilBrown Signed-off-by: NeilBrown Reviewed-by: Jeff Layton Signed-off-by: Anna Schumaker

nfs_common: factor out nfs4_errtbl and nfs4_stat_to_errno

2024-09-23T19:03:29+00:00

Common nfs4_stat_to_errno() is used by fs/nfs/nfs4xdr.c and will be used by fs/nfs/localio.c Signed-off-by: Mike Snitzer Reviewed-by: Jeff Layton Reviewed-by: NeilBrown Signed-off-by: Anna Schumaker