- 24 Sep, 2024 1 commit
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Anna Schumaker authored
Reported-by:
Stephen Rothwell <sfr@canb.auug.org.au> Fixes: 92945bd8 ("nfs: add Documentation/filesystems/nfs/localio.rst") Signed-off-by:
Anna Schumaker <anna.schumaker@oracle.com>
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- 23 Sep, 2024 39 commits
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Mike Snitzer authored
This section answers a new FAQ entry: 9. How does LOCALIO make certain that object lifetimes are managed properly given NFSD and NFS operate in different contexts? See the detailed "NFS Client and Server Interlock" section below. The first half of the section details NeilBrown's elegant design for LOCALIO's nfs_uuid_t based interlock and is heavily based on Neil's "net namespace refcounting" description here: https://marc.info/?l=linux-nfs&m=172498546024767&w=2 The second half of the section details the per-cpu-refcount introduced to ensure NFSD's nfsd_serv isn't destroyed while in use by a LOCALIO client. Signed-off-by:
Mike Snitzer <snitzer@kernel.org> Reviewed-by:
NeilBrown <neilb@suse.de> Reviewed-by:
Jeff Layton <jlayton@kernel.org> Signed-off-by:
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Trond Myklebust authored
Add a FAQ section to give answers to questions that have been raised during review of the localio feature. Signed-off-by:
Trond Myklebust <trond.myklebust@hammerspace.com> Co-developed-by:
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Mike Snitzer authored
This document gives an overview of the LOCALIO auxiliary RPC protocol added to the Linux NFS client and server to allow them to reliably handshake to determine if they are on the same host. Once an NFS client and server handshake as "local", the client will bypass the network RPC protocol for read, write and commit operations. Due to this XDR and RPC bypass, these operations will operate faster. Signed-off-by:
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Mike Snitzer authored
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:
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Trond Myklebust authored
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:
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Trond Myklebust authored
If the DS is local to this client use localio to write the data. Signed-off-by:
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Trond Myklebust authored
Try a local open of the file being written to, and if it succeeds, then use localio to issue IO. Signed-off-by:
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Weston Andros Adamson authored
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:
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Mike Snitzer authored
The nfsd_file will be passed, in future commits, by callers that enable LOCALIO support (for both regular NFS and pNFS IO). [Derived from patch authored by Weston Andros Adamson, but switched from passing struct file to struct nfsd_file] Signed-off-by:
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Mike Snitzer authored
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. The server expects this protocol to use the same transport as NFS and NFSACL for its RPCs. 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. 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. The RPC program number for the NFS_LOCALIO_PROGRAM is 400122 (as assigned by IANA, see https://www.iana.org/assignments/rpc-program-numbers/ ): Linux Kernel Organization 400122 nfslocalio Signed-off-by:
Chuck Lever <chuck.lever@oracle.com> Reviewed-by:
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Weston Andros Adamson authored
Add server support for bypassing NFS for localhost reads, writes, and commits. This is only useful when both the client and server are running on the same host. If nfsd_open_local_fh() fails then the NFS client will both retry and fallback to normal network-based read, write and commit operations if localio is no longer supported. Care is taken to ensure the same NFS security mechanisms are used (authentication, etc) regardless of whether localio or regular NFS access is used. The auth_domain established as part of the traditional NFS client access to the NFS server is also used for localio. Store auth_domain for localio in nfsd_uuid_t and transfer it to the client if it is local to the server. Relative to containers, localio gives the client access to the network namespace the server has. This is required to allow the client to access the server's per-namespace nfsd_net struct. This commit also introduces the use of NFSD's percpu_ref to interlock nfsd_destroy_serv and nfsd_open_local_fh, to ensure nn->nfsd_serv is not destroyed while in use by nfsd_open_local_fh and other LOCALIO client code. CONFIG_NFS_LOCALIO enables NFS server support for LOCALIO. Signed-off-by:
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Mike Snitzer authored
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 <trond.myklebust@hammerspace.com> # nfs_to Suggested-by: NeilBrown <neilb@suse.de> # nfsd_localio_operations Suggested-by: Jeff Layton <jlayton@kernel.org> # nfsd_file_file Signed-off-by:
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Mike Snitzer authored
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:
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NeilBrown authored
A service created with svc_create_pooled() can be given a linked list of programs and all of these will be served. Using a linked list makes it cumbersome when there are several programs that can be optionally selected with CONFIG settings. After this patch is applied, API consumers must use only svc_create_pooled() when creating an RPC service that listens for more than one RPC program. Signed-off-by:
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Weston Andros Adamson authored
Add new funtion svcauth_map_clnt_to_svc_cred_local which maps a generic cred to a svc_cred suitable for use in nfsd. This is needed by the localio code to map nfs client creds to nfs server credentials. Following from net/sunrpc/auth_unix.c:unx_marshal() it is clear that ->fsuid and ->fsgid must be used (rather than ->uid and ->gid). In addition, these uid and gid must be translated with from_kuid_munged() so local client uses correct uid and gid when acting as local server. Jeff Layton noted: This is where the magic happens. Since we're working in kuid_t/kgid_t, we don't need to worry about further idmapping. Suggested-by: NeilBrown <neilb@suse.de> # to approximate unx_marshal() Signed-off-by:
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Mike Snitzer authored
Remove BUG_ON if p_arglen=0 to allow RPC with void arg. Remove BUG_ON if p_replen=0 to allow RPC with void return. The former was needed for the first revision of the LOCALIO protocol which had an RPC that took a void arg: /* raw RFC 9562 UUID */ typedef u8 uuid_t<UUID_SIZE>; program NFS_LOCALIO_PROGRAM { version LOCALIO_V1 { void NULL(void) = 0; uuid_t GETUUID(void) = 1; } = 1; } = 400122; The latter is needed for the final revision of the LOCALIO protocol which has a UUID_IS_LOCAL RPC which returns a void: /* raw RFC 9562 UUID */ typedef u8 uuid_t<UUID_SIZE>; program NFS_LOCALIO_PROGRAM { version LOCALIO_V1 { void NULL(void) = 0; void UUID_IS_LOCAL(uuid_t) = 1; } = 1; } = 400122; There is really no value in triggering a BUG_ON in response to either of these previously unsupported conditions. NeilBrown would like the entire 'if (proc->p_proc != 0)' branch removed (not just the one BUG_ON that must be removed for LOCALIO's immediate needs of returning void). Signed-off-by: -
Mike Snitzer authored
Introduce nfsd_serv_try_get and nfsd_serv_put and update the nfsd code to prevent nfsd_destroy_serv from destroying nn->nfsd_serv until any caller of nfsd_serv_try_get releases their reference using nfsd_serv_put. A percpu_ref is used to implement the interlock between nfsd_destroy_serv and any caller of nfsd_serv_try_get. This interlock is needed to properly wait for the completion of client initiated localio calls to nfsd (that are _not_ in the context of nfsd). Signed-off-by:
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NeilBrown authored
nfsd_file_acquire_local() can be used to look up a file by filehandle without having a struct svc_rqst. This can be used by NFS LOCALIO to allow the NFS client to bypass the NFS protocol to directly access a file provided by the NFS server which is running in the same kernel. In nfsd_file_do_acquire() care is taken to always use fh_verify() if rqstp is not NULL (as is the case for non-LOCALIO callers). Otherwise the non-LOCALIO callers will not supply the correct and required arguments to __fh_verify (e.g. gssclient isn't passed). Introduce fh_verify_local() wrapper around __fh_verify to make it clear that LOCALIO is intended caller. Also, use GC for nfsd_file returned by nfsd_file_acquire_local. GC offers performance improvements if/when a file is reopened before launderette cleans it from the filecache's LRU. Suggested-by: Jeff Layton <jlayton@kernel.org> # use filecache's GC Signed-off-by:
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NeilBrown authored
__fh_verify() offers an interface like fh_verify() but doesn't require a struct svc_rqst *, instead it also takes the specific parts as explicit required arguments. So it is safe to call __fh_verify() with a NULL rqstp, but the net, cred, and client args must not be NULL. __fh_verify() does not use SVC_NET(), nor does the functions it calls. Rather than using rqstp->rq_client pass the client and gssclient explicitly to __fh_verify and then to nfsd_set_fh_dentry(). Lastly, it should be noted that the previous commit prepared for 4 associated tracepoints to only be used if rqstp is not NULL (this is a stop-gap that should be properly fixed so localio also benefits from the utility these tracepoints provide when debugging fh_verify issues). Signed-off-by:
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Chuck Lever authored
LOCALIO will be able to call fh_verify() with a NULL rqstp. In this case, the existing trace points need to be skipped because they want to dereference the address fields in the passed-in rqstp. Temporarily make these trace points conditional to avoid a seg fault in this case. Putting the "rqstp != NULL" check in the trace points themselves makes the check more efficient. Signed-off-by:
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Chuck Lever authored
Currently, fh_verify() makes some daring assumptions about which version of file handle the caller wants, based on the things it can find in the passed-in rqstp. The about-to-be-introduced LOCALIO use case sometimes has no svc_rqst context, so this logic won't work in that case. Instead, examine the passed-in file handle. It's .max_size field should carry information to allow nfsd_set_fh_dentry() to initialize the file handle appropriately. The file handle used by lockd and the one created by write_filehandle never need any of the version-specific fields (which affect things like write and getattr requests and pre/post attributes). Signed-off-by:
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NeilBrown authored
There are several places where __fh_verify unconditionally dereferences rqstp to check that the connection is suitably secure. They look at rqstp->rq_xprt which is not meaningful in the target use case of "localio" NFS in which the client talks directly to the local server. Prepare these to always succeed when rqstp is NULL. Signed-off-by:
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NeilBrown authored
LOCALIO-initiated open operations are not running in an nfsd thread and thus do not have an associated svc_rqst context. Signed-off-by:
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Mike Snitzer authored
Eliminates duplicate functions in various files to allow for additional callers. Signed-off-by:
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Mike Snitzer authored
Common nfs4_stat_to_errno() is used by fs/nfs/nfs4xdr.c and will be used by fs/nfs/localio.c Signed-off-by:
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Mike Snitzer authored
Common nfs_stat_to_errno() is used by both fs/nfs/nfs2xdr.c and fs/nfs/nfs3xdr.c Will also be used by fs/nfsd/localio.c Signed-off-by:
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Dan Aloni authored
There are some applications that write to predefined non-overlapping file offsets from multiple clients and therefore don't need to rely on file locking. However, if these applications want non-aligned offsets and sizes they need to either use locks or risk data corruption, as the NFS client defaults to extending writes to whole pages. This commit adds a new mount option `noalignwrite`, which allows to turn that off and avoid the need of locking, as long as these applications don't overlap on offsets. Signed-off-by:
Dan Aloni <dan.aloni@vastdata.com> Reviewed-by:
Sagi Grimberg <sagi@grimberg.me> Reviewed-by:
Christoph Hellwig <hch@lst.de> Signed-off-by:
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Li Lingfeng authored
The comment for nfs_get_root() needs to be updated as it would also be used by NFS4 as follows: @x[ nfs_get_root+1 nfs_get_tree_common+1819 nfs_get_tree+2594 vfs_get_tree+73 fc_mount+23 do_nfs4_mount+498 nfs4_try_get_tree+134 nfs_get_tree+2562 vfs_get_tree+73 path_mount+2776 do_mount+226 __se_sys_mount+343 __x64_sys_mount+106 do_syscall_64+69 entry_SYSCALL_64_after_hwframe+97 , mount.nfs4]: 1 Signed-off-by:Li Lingfeng <lilingfeng3@huawei.com> Acked-by:
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Roi Azarzar authored
According to draft-ietf-nfsv4-delstid-07: If a server informs the client via the fattr4_open_arguments attribute that it supports OPEN_ARGS_SHARE_ACCESS_WANT_DELEG_TIMESTAMPS and it returns a valid delegation stateid for an OPEN operation which sets the OPEN4_SHARE_ACCESS_WANT_DELEG_TIMESTAMPS flag, then it MUST query the client via a CB_GETATTR for the fattr4_time_deleg_access (see Section 5.2) attribute and fattr4_time_deleg_modify attribute (see Section 5.2). Thus, we should look that the server supports proxying of times via OPEN4_SHARE_ACCESS_WANT_DELEG_TIMESTAMPS. We want to be extra pedantic and continue to check that FATTR4_TIME_DELEG_ACCESS and FATTR4_TIME_DELEG_MODIFY are set. The server needs to expose both for the client to correctly detect "Proxying of Times" support. Signed-off-by:
Roi Azarzar <roi.azarzar@vastdata.com> Reviewed-by:
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Trond Myklebust authored
If the server is down when the client is trying to mount, so that the calls to exchange_id or create_session fail, then we should allow the mount system call to fail rather than hang and block other mount/umount calls. Reported-by:
Oleksandr Tymoshenko <ovt@google.com> Signed-off-by:
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Zhaoyang Huang authored
This patch is inspired by a code review of fs codes which aims at folio's extra refcnt that could introduce unwanted behavious when judging refcnt, such as[1].That is, the folio passed to mapping_evict_folio carries the refcnts from find_lock_entries, page_cache, corresponding to PTEs and folio's private if has. However, current code doesn't take the refcnt for folio's private which could have mapping_evict_folio miss the one to only PTE and lead to call filemap_release_folio wrongly. [1] long mapping_evict_folio(struct address_space *mapping, struct folio *folio) { ... //current code will misjudge here if there is one pte on the folio which is be deemed as the one as folio's private if (folio_ref_count(folio) > folio_nr_pages(folio) + folio_has_private(folio) + 1) return 0; if (!filemap_release_folio(folio, 0)) return 0; return remove_mapping(mapping, folio); } Signed-off-by:Zhaoyang Huang <zhaoyang.huang@unisoc.com> Signed-off-by:
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Gaosheng Cui authored
The nfs_read_prepare() have been removed since commit a4cdda59 ("NFS: Create a common pgio_rpc_prepare function"), and now it is useless, so remove it. Signed-off-by:
Gaosheng Cui <cuigaosheng1@huawei.com> Signed-off-by:
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Hongbo Li authored
list_head can be initialized automatically with LIST_HEAD() instead of calling INIT_LIST_HEAD(). Here we can simplify the code. Signed-off-by:
Hongbo Li <lihongbo22@huawei.com> Signed-off-by:
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Siddh Raman Pant authored
destroy_wait doesn't store all RPC clients. There was a list named "all_clients" above it, which got moved to struct sunrpc_net in 2012, but the comment was never removed. Fixes: 70abc49b ("SUNRPC: make SUNPRC clients list per network namespace context") Signed-off-by:
Siddh Raman Pant <siddh.raman.pant@oracle.com> Signed-off-by:
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Stephen Brennan authored
The RPC_TASK_* constants are defined as macros, which means that most kernel builds will not contain their definitions in the debuginfo. However, it's quite useful for debuggers to be able to view the task state constant and interpret it correctly. Conversion to an enum will ensure the constants are present in debuginfo and can be interpreted by debuggers without needing to hard-code them and track their changes. Signed-off-by:
Stephen Brennan <stephen.s.brennan@oracle.com> Signed-off-by:
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Kunwu Chan authored
Increase size of the servername array to avoid truncated output warning. net/sunrpc/clnt.c:582:75: error：‘%s’ directive output may be truncated writing up to 107 bytes into a region of size 48 [-Werror=format-truncation=] 582 | snprintf(servername, sizeof(servername), "%s", | ^~ net/sunrpc/clnt.c:582:33: note:‘snprintf’ output between 1 and 108 bytes into a destination of size 48 582 | snprintf(servername, sizeof(servername), "%s", | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 583 | sun->sun_path); Signed-off-by:Kunwu Chan <chentao@kylinos.cn> Suggested-by:
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Thorsten Blum authored
Since kfree() already checks if its argument is NULL, an additional check before calling kfree() is unnecessary and can be removed. Remove it and thus also the following Coccinelle/coccicheck warning reported by ifnullfree.cocci: WARNING: NULL check before some freeing functions is not needed Reviewed-by:
Benjamin Coddington <bcodding@redhat.com> Signed-off-by:
Thorsten Blum <thorsten.blum@toblux.com> Reviewed-by:
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Thorsten Blum authored
Add the __counted_by compiler attribute to the flexible array member array to improve access bounds-checking via CONFIG_UBSAN_BOUNDS and CONFIG_FORTIFY_SOURCE. Increment size before adding a new struct to the array. Signed-off-by:
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NeilBrown authored
I have evidence of an Linux NFS client getting NFS4ERR_BAD_SEQID to a v4.0 LOCK request to a Linux server (which had fixed the problem with RELEASE_LOCKOWNER bug fixed). The LOCK request presented a "new" lock owner so there are two seq ids in the request: that for the open file, and that for the new lock. Given the context I am confident that the new lock owner was reported to have the wrong seqid. As lock owner identifiers are reused, the server must still have a lock owner active which the client thinks is no longer active. I wasn't able to determine a root-cause but the simplest fix seems to be to ensure lock owners are always unique much as open owners are (thanks to a time stamp). The easiest way to ensure uniqueness is with a 64bit counter for each server. That will never cycle (if updated once a nanosecond the last 584 years. A single NFS server would not handle open/lock requests nearly that fast, and a Linux node is unlikely to have an uptime approaching that). This patch removes the 2 ida and instead uses a per-server atomic64_t to provide uniqueness. Note that the lock owner already encodes the id as 64 bits even though it is a 32bit value. So changing to a 64bit value does not change the encoding of the lock owner. The open owner encoding is now 4 bytes larger. Signed-off-by:
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