kernel/linux.git/fs/nfs/proc.c, branch v5.15.213

NFS: NFSv2/v3 clients should never be setting NFS_CAP_XATTR

2022-04-08T12:22:52+00:00

commit b622ffe1d9ecbac71f0cddb52ff0831efdf8fb83 upstream. Ensure that we always initialise the 'xattr_support' field in struct nfs_fsinfo, so that nfs_server_set_fsinfo() doesn't declare our NFSv2/v3 client to be capable of supporting the NFSv4.2 xattr protocol by setting the NFS_CAP_XATTR capability. This configuration can cause nfs_do_access() to set access mode bits that are unsupported by the NFSv3 ACCESS call, which may confuse spec-compliant servers. Reported-by: Olga Kornievskaia Fixes: b78ef845c35d ("NFSv4.2: query the server for extended attribute support") Cc: stable@vger.kernel.org Signed-off-by: Trond Myklebust Signed-off-by: Greg Kroah-Hartman

NFS: Default change_attr_type to NFS4_CHANGE_TYPE_IS_UNDEFINED

2021-11-18T18:16:59+00:00

[ Upstream commit eea413308f2e6deb00f061f18081a53f3ecc8cc6 ] Both NFSv3 and NFSv2 generate their change attribute from the ctime value that was supplied by the server. However the problem is that there are plenty of servers out there with ctime resolutions of 1ms or worse. In a modern performance system, this is insufficient when trying to decide which is the most recent set of attributes when, for instance, a READ or GETATTR call races with a WRITE or SETATTR. For this reason, let's revert to labelling the NFSv2/v3 change attributes as NFS4_CHANGE_TYPE_IS_UNDEFINED. This will ensure we protect against such races. Fixes: 7b24dacf0840 ("NFS: Another inode revalidation improvement") Signed-off-by: Trond Myklebust Tested-by: Chuck Lever Signed-off-by: Sasha Levin

NFSv4: Add support for the NFSv4.2 "change_attr_type" attribute

2021-04-13T14:04:05+00:00

The change_attr_type allows the server to provide a description of how the change attribute will behave. This again will allow the client to optimise its behaviour w.r.t. attribute revalidation. Signed-off-by: Trond Myklebust

NFS: Allow the NFS generic code to pass in a verifier to readdir

2020-12-02T19:05:52+00:00

If we're ever going to allow support for servers that use the readdir verifier, then that use needs to be managed by the middle layers as those need to be able to reject cookies from other verifiers. Signed-off-by: Trond Myklebust Reviewed-by: Benjamin Coddington Tested-by: Benjamin Coddington Tested-by: Dave Wysochanski

NFS: Add softreval behaviour to nfs_lookup_revalidate()

2020-01-24T21:51:13+00:00

If the server is unavaliable, we want to allow the revalidating lookup to time out, and to default to validating the cached dentry if the 'softreval' mount option is set. Signed-off-by: Trond Myklebust Signed-off-by: Anna Schumaker

NFS: Add mount option 'softreval'

2020-01-15T15:54:33+00:00

Add a mount option 'softreval' that allows attribute revalidation 'getattr' calls to time out, and causes them to fall back to using the cached attributes. The use case for this option is for ensuring that we can still (slowly) traverse paths and use cached information even when the server is down. Once the server comes back up again, the getattr calls start succeeding, and the caches will revalidate as usual. The 'softreval' mount option is automatically enabled if you have specified 'softerr'. It can be turned off using the options 'nosoftreval', or 'hard'. Signed-off-by: Trond Myklebust Signed-off-by: Anna Schumaker

NFS: Add fs_context support.

2020-01-15T15:15:17+00:00

Add filesystem context support to NFS, parsing the options in advance and attaching the information to struct nfs_fs_context. The highlights are: (*) Merge nfs_mount_info and nfs_clone_mount into nfs_fs_context. This structure represents NFS's superblock config. (*) Make use of the VFS's parsing support to split comma-separated lists (*) Pin the NFS protocol module in the nfs_fs_context. (*) Attach supplementary error information to fs_context. This has the downside that these strings must be static and can't be formatted. (*) Remove the auxiliary file_system_type structs since the information necessary can be conveyed in the nfs_fs_context struct instead. (*) Root mounts are made by duplicating the config for the requested mount so as to have the same parameters. Submounts pick up their parameters from the parent superblock. [AV -- retrans is u32, not string] [SM -- Renamed cfg to ctx in a few functions in an earlier patch] [SM -- Moved fs_context mount option parsing to an earlier patch] [SM -- Moved fs_context error logging to a later patch] [SM -- Fixed printks in nfs4_try_get_tree() and nfs4_get_referral_tree()] [SM -- Added is_remount_fc() helper] [SM -- Deferred some refactoring to a later patch] [SM -- Fixed referral mounts, which were broken in the original patch] [SM -- Fixed leak of nfs_fattr when fs_context is freed] Signed-off-by: David Howells Signed-off-by: Al Viro Signed-off-by: Scott Mayhew Signed-off-by: Anna Schumaker

NFSv2: Fix write regression

2019-08-27T14:24:56+00:00

Ensure we update the write result count on success, since the RPC call itself does not do so. Reported-by: Jan Stancek Reported-by: Naresh Kamboju Signed-off-by: Trond Myklebust Tested-by: Jan Stancek

NFSv2: Fix eof handling

2019-08-27T14:24:56+00:00

If we received a reply from the server with a zero length read and no error, then that implies we are at eof. Signed-off-by: Trond Myklebust

NFS/NFSD/SUNRPC: replace generic creds with 'struct cred'.

2018-12-19T18:52:46+00:00

SUNRPC has two sorts of credentials, both of which appear as "struct rpc_cred". There are "generic credentials" which are supplied by clients such as NFS and passed in 'struct rpc_message' to indicate which user should be used to authorize the request, and there are low-level credentials such as AUTH_NULL, AUTH_UNIX, AUTH_GSS which describe the credential to be sent over the wires. This patch replaces all the generic credentials by 'struct cred' pointers - the credential structure used throughout Linux. For machine credentials, there is a special 'struct cred *' pointer which is statically allocated and recognized where needed as having a special meaning. A look-up of a low-level cred will map this to a machine credential. Signed-off-by: NeilBrown Acked-by: J. Bruce Fields Signed-off-by: Anna Schumaker