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authorLinus Torvalds <torvalds@linux-foundation.org>2023-08-31 15:32:18 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2023-08-31 15:32:18 -0700
commitf35d1706159e015848ec7421e91b44b614c02dc2 (patch)
tree8a6604d318f604cddf8b84fd809cb1e43dd4553b /Documentation/filesystems
parent8ae5d298ef2005da5454fc1680f983e85d3e1622 (diff)
parentb38a6023da6a12b561f0421c6a5a1f7624a1529c (diff)
downloadlinux-f35d1706159e015848ec7421e91b44b614c02dc2.tar.gz
Merge tag 'nfsd-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux
Pull nfsd updates from Chuck Lever: "I'm thrilled to announce that the Linux in-kernel NFS server now offers NFSv4 write delegations. A write delegation enables a client to cache data and metadata for a single file more aggressively, reducing network round trips and server workload. Many thanks to Dai Ngo for contributing this facility, and to Jeff Layton and Neil Brown for reviewing and testing it. This release also sees the removal of all support for DES- and triple-DES-based Kerberos encryption types in the kernel's SunRPC implementation. These encryption types have been deprecated by the Internet community for years and are considered insecure. This change affects both the in-kernel NFS client and server. The server's UDP and TCP socket transports have now fully adopted David Howells' new bio_vec iterator so that no more than one sendmsg() call is needed to transmit each RPC message. In particular, this helps kTLS optimize record boundaries when sending RPC-with-TLS replies, and it takes the server a baby step closer to handling file I/O via folios. We've begun work on overhauling the SunRPC thread scheduler to remove a costly linked-list walk when looking for an idle RPC service thread to wake. The pre-requisites are included in this release. Thanks to Neil Brown for his ongoing work on this improvement" * tag 'nfsd-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux: (56 commits) Documentation: Add missing documentation for EXPORT_OP flags SUNRPC: Remove unused declaration rpc_modcount() SUNRPC: Remove unused declarations NFSD: da_addr_body field missing in some GETDEVICEINFO replies SUNRPC: Remove return value of svc_pool_wake_idle_thread() SUNRPC: make rqst_should_sleep() idempotent() SUNRPC: Clean up svc_set_num_threads SUNRPC: Count ingress RPC messages per svc_pool SUNRPC: Deduplicate thread wake-up code SUNRPC: Move trace_svc_xprt_enqueue SUNRPC: Add enum svc_auth_status SUNRPC: change svc_xprt::xpt_flags bits to enum SUNRPC: change svc_rqst::rq_flags bits to enum SUNRPC: change svc_pool::sp_flags bits to enum SUNRPC: change cache_head.flags bits to enum SUNRPC: remove timeout arg from svc_recv() SUNRPC: change svc_recv() to return void. SUNRPC: call svc_process() from svc_recv(). nfsd: separate nfsd_last_thread() from nfsd_put() nfsd: Simplify code around svc_exit_thread() call in nfsd() ...
Diffstat (limited to 'Documentation/filesystems')
-rw-r--r--Documentation/filesystems/nfs/exporting.rst26
1 files changed, 26 insertions, 0 deletions
diff --git a/Documentation/filesystems/nfs/exporting.rst b/Documentation/filesystems/nfs/exporting.rst
index 3d97b8d8f7354..4b30daee399af 100644
--- a/Documentation/filesystems/nfs/exporting.rst
+++ b/Documentation/filesystems/nfs/exporting.rst
@@ -215,3 +215,29 @@ following flags are defined:
This flag causes nfsd to close any open files for this inode _before_
calling into the vfs to do an unlink or a rename that would replace
an existing file.
+
+ EXPORT_OP_REMOTE_FS - Backing storage for this filesystem is remote
+ PF_LOCAL_THROTTLE exists for loopback NFSD, where a thread needs to
+ write to one bdi (the final bdi) in order to free up writes queued
+ to another bdi (the client bdi). Such threads get a private balance
+ of dirty pages so that dirty pages for the client bdi do not imact
+ the daemon writing to the final bdi. For filesystems whose durable
+ storage is not local (such as exported NFS filesystems), this
+ constraint has negative consequences. EXPORT_OP_REMOTE_FS enables
+ an export to disable writeback throttling.
+
+ EXPORT_OP_NOATOMIC_ATTR - Filesystem does not update attributes atomically
+ EXPORT_OP_NOATOMIC_ATTR indicates that the exported filesystem
+ cannot provide the semantics required by the "atomic" boolean in
+ NFSv4's change_info4. This boolean indicates to a client whether the
+ returned before and after change attributes were obtained atomically
+ with the respect to the requested metadata operation (UNLINK,
+ OPEN/CREATE, MKDIR, etc).
+
+ EXPORT_OP_FLUSH_ON_CLOSE - Filesystem flushes file data on close(2)
+ On most filesystems, inodes can remain under writeback after the
+ file is closed. NFSD relies on client activity or local flusher
+ threads to handle writeback. Certain filesystems, such as NFS, flush
+ all of an inode's dirty data on last close. Exports that behave this
+ way should set EXPORT_OP_FLUSH_ON_CLOSE so that NFSD knows to skip
+ waiting for writeback when closing such files.