- 11 Dec, 2022 1 commit
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Jeff Layton authored
The filecache refcounting is a bit non-standard for something searchable by RCU, in that we maintain a sentinel reference while it's hashed. This in turn requires that we have to do things differently in the "put" depending on whether its hashed, which we believe to have led to races. There are other problems in here too. nfsd_file_close_inode_sync can end up freeing an nfsd_file while there are still outstanding references to it, and there are a number of subtle ToC/ToU races. Rework the code so that the refcount is what drives the lifecycle. When the refcount goes to zero, then unhash and rcu free the object. A task searching for a nfsd_file is allowed to bump its refcount, but only if it's not already 0. Ensure that we don't make any other changes to it until a reference is held. With this change, the LRU carries a reference. Take special care to deal with it when removing an entry from the list, and ensure that we only repurpose the nf_lru list_head when the refcount is 0 to ensure exclusive access to it. Signed-off-by:
Jeff Layton <jlayton@kernel.org> Signed-off-by:
Chuck Lever <chuck.lever@oracle.com>
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- 10 Dec, 2022 21 commits
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Kees Cook authored
When built with Control Flow Integrity, function prototypes between caller and function declaration must match. These mismatches are visible at compile time with the new -Wcast-function-type-strict in Clang[1]. There were 97 warnings produced by NFS. For example: fs/nfsd/nfs4xdr.c:2228:17: warning: cast from '__be32 (*)(struct nfsd4_compoundargs *, struct nfsd4_access *)' (aka 'unsigned int (*)(struct nfsd4_compoundargs *, struct nfsd4_access *)') to 'nfsd4_dec' (aka 'unsigned int (*)(struct nfsd4_compoundargs *, void *)') converts to incompatible function type [-Wcast-function-type-strict] [OP_ACCESS] = (nfsd4_dec)nfsd4_decode_access, ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The enc/dec callbacks were defined as passing "void *" as the second argument, but were being implicitly cast to a new type. Replace the argument with union nfsd4_op_u, and perform explicit member selection in the function body. There are no resulting binary differences. Changes were made mechanically using the following Coccinelle script, with minor by-hand fixes for members that didn't already match their existing argument name: @find@ identifier func; type T, opsT; identifier ops, N; @@ opsT ops[] = { [N] = (T) func, }; @already_void@ identifier find.func; identifier name; @@ func(..., -void +union nfsd4_op_u *name) { ... } @proto depends on !already_void@ identifier find.func; type T; identifier name; position p; @@ func@p(..., T name ) { ... } @script:python get_member@ type_name << proto.T; member; @@ coccinelle.member = cocci.make_ident(type_name.split("_", 1)[1].split(' ',1)[0]) @convert@ identifier find.func; type proto.T; identifier proto.name; position proto.p; identifier get_member.member; @@ func@p(..., - T name + union nfsd4_op_u *u ) { + T name = &u->member; ... } @cast@ identifier find.func; type T, opsT; identifier ops, N; @@ opsT ops[] = { [N] = - (T) func, }; Cc: Chuck Lever <chuck.lever@oracle.com> Cc: Jeff Layton <jlayton@kernel.org> Cc: Gustavo A. R. Silva <gustavoars@kernel.org> Cc: linux-nfs@vger.kernel.org Signed-off-by:Kees Cook <keescook@chromium.org> Signed-off-by:
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Chuck Lever authored
If a zero length is passed to kmalloc() it returns 0x10, which is not a valid address. gss_verify_mic() subsequently crashes when it attempts to dereference that pointer. Instead of allocating this memory on every call based on an untrusted size value, use a piece of dynamically-allocated scratch memory that is always available. Signed-off-by:
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Chuck Lever authored
Clean up: Simplify the tracepoint's only call site. Also, I noticed that when svc_authenticate() returns SVC_COMPLETE, it leaves rq_auth_stat set to an error value. That doesn't need to be recorded in the trace log. Signed-off-by:
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Chuck Lever authored
Clean up: NFSv2 has the only two usages of rpc_drop_reply in the NFSD code base. Since NFSv2 is going away at some point, replace these in order to simplify the "drop this reply?" check in nfsd_dispatch(). Signed-off-by:
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Chuck Lever authored
Make it more evident how xdr_write_pages() updates the tail buffer by using the convention of naming the iov pointer variable "tail". I spent more than a couple of hours chasing through code to understand this, so someone is likely to find this useful later. Signed-off-by:
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Chuck Lever authored
Fixes: 030d794b ("SUNRPC: Use gssproxy upcall for server RPCGSS authentication.") Signed-off-by:
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Dai Ngo authored
Add tracepoints to trace start and end of CB_RECALL_ANY operation. Signed-off-by:
Dai Ngo <dai.ngo@oracle.com> [ cel: added show_rca_mask() macro ] Signed-off-by:
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Dai Ngo authored
The delegation reaper is called by nfsd memory shrinker's on the 'count' callback. It scans the client list and sends the courtesy CB_RECALL_ANY to the clients that hold delegations. To avoid flooding the clients with CB_RECALL_ANY requests, the delegation reaper sends only one CB_RECALL_ANY request to each client per 5 seconds. Signed-off-by:
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Dai Ngo authored
Add XDR encode and decode function for CB_RECALL_ANY. Signed-off-by:
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Dai Ngo authored
Refactoring courtesy_client_reaper to generic low memory shrinker so it can be used for other purposes. Signed-off-by:
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Chuck Lever authored
Steven Rostedt says: > The include/trace/events/ directory should only hold files that > are to create events, not headers that hold helper functions. > > Can you please move them out of include/trace/events/ as that > directory is "special" in the creation of events. Signed-off-by:
Leon Romanovsky <leonro@nvidia.com> Acked-by:
Steven Rostedt (Google) <rostedt@goodmis.org> Acked-by:
Anna Schumaker <Anna.Schumaker@Netapp.com>
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Brian Foster authored
_nfsd_copy_file_range() calls vfs_fsync_range() with an offset and count (bytes written), but the former wants the start and end bytes of the range to sync. Fix it up. Fixes: eac0b17a ("NFSD add vfs_fsync after async copy is done") Signed-off-by:
Brian Foster <bfoster@redhat.com> Tested-by:
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Jeff Layton authored
We currently do a lock_to_openmode call based on the arguments from the NLM_UNLOCK call, but that will always set the fl_type of the lock to F_UNLCK, and the O_RDONLY descriptor is always chosen. Fix it to use the file_lock from the block instead. Signed-off-by:
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Jeff Layton authored
Shared locks are set on O_RDONLY descriptors and exclusive locks are set on O_WRONLY ones. nlmsvc_unlock however calls vfs_lock_file twice, once for each descriptor, but it doesn't reset fl_file. Ensure that it does. Signed-off-by:
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Jeff Layton authored
Signed-off-by:
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Xiu Jianfeng authored
Use struct_size() helper to simplify the code, no functional changes. Signed-off-by:
Xiu Jianfeng <xiujianfeng@huawei.com> Reviewed-by:
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Jeff Layton authored
With the addition of POSIX ACLs to struct nfsd_attrs, we no longer return an error if setting the ACL fails. Ensure we return the na_aclerr error on SETATTR if there is one. Fixes: c0cbe707 ("NFSD: add posix ACLs to struct nfsd_attrs") Cc: Neil Brown <neilb@suse.de> Reported-by:
Yongcheng Yang <yoyang@redhat.com> Signed-off-by:
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Trond Myklebust authored
vfs_lock_file() expects the struct file_lock to be fully initialised by the caller. Re-exported NFSv3 has been seen to Oops if the fl_file field is NULL. Fixes: aec15824 ("lockd: set fl_owner when unlocking files") Signed-off-by:
Trond Myklebust <trond.myklebust@hammerspace.com> Reviewed-by:
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Chuck Lever authored
Add a tracepoint to capture the number of filecache-triggered fsync calls and which files needed it. Also, record when an fsync triggers a write verifier reset. Examples: <...>-97 [007] 262.505611: nfsd_file_free: inode=0xffff888171e08140 ref=0 flags=GC may=WRITE nf_file=0xffff8881373d2400 <...>-97 [007] 262.505612: nfsd_file_fsync: inode=0xffff888171e08140 ref=0 flags=GC may=WRITE nf_file=0xffff8881373d2400 ret=0 <...>-97 [007] 262.505623: nfsd_file_free: inode=0xffff888171e08dc0 ref=0 flags=GC may=WRITE nf_file=0xffff8881373d1e00 <...>-97 [007] 262.505624: nfsd_file_fsync: inode=0xffff888171e08dc0 ref=0 flags=GC may=WRITE nf_file=0xffff8881373d1e00 ret=0 Signed-off-by:
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Li zeming authored
The svc_ungetu32 function is not used, you could remove it. Signed-off-by:
Li zeming <zeming@nfschina.com> Signed-off-by:
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Jeff Layton authored
We don't really care whether there are hashed entries when it comes to scheduling the laundrette. They might all be non-gc entries, after all. We only want to schedule it if there are entries on the LRU. Switch to using list_lru_count, and move the check into nfsd_file_gc_worker. The other callsite in nfsd_file_put doesn't need to count entries, since it only schedules the laundrette after adding an entry to the LRU. Signed-off-by:
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- 28 Nov, 2022 18 commits
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Jeff Layton authored
In a coming patch, we're going to rework how the filecache refcounting works. Move some code around in the function to reduce the churn in the later patches, and rename some of the functions with (hopefully) clearer names: nfsd_file_flush becomes nfsd_file_fsync, and nfsd_file_unhash_and_dispose is renamed to nfsd_file_unhash_and_queue. Also, the nfsd_file_put_final tracepoint is renamed to nfsd_file_free, to better match the name of the function from which it's called. Signed-off-by:
NeilBrown <neilb@suse.de> Signed-off-by:
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Jeff Layton authored
We're counting mapping->nrpages, but not all of those are necessarily dirty. We don't really have a simple way to count just the dirty pages, so just remove this stat since it's not accurate. Signed-off-by:
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Chuck Lever authored
We recently received a patch for fs/exportfs/expfs.c, but there isn't a subsystem maintainer listed for fs/exportfs: Christian Brauner <brauner@kernel.org> (commit_signer:2/2=100%,authored:1/2=50%,added_lines:3/6=50%,removed_lines:2/6=33%) Al Viro <viro@zeniv.linux.org.uk> (commit_signer:1/2=50%,authored:1/2=50%,added_lines:3/6=50%,removed_lines:4/6=67%) Miklos Szeredi <mszeredi@redhat.com> (commit_signer:1/2=50%) Amir Goldstein <amir73il@gmail.com> (commit_signer:1/2=50%) linux-kernel@vger.kernel.org (open list) Neil says: > Looking at recent commits, patches come in through multiple > different trees. > nfsd certainly has an interest in expfs.c. The only other user is > name_to_handle/open_by_handle API. > I see it as primarily nfsd functionality which is useful enough to > be exported directly to user-space. > (It was created by me when I was nfsd maintainer - does that > count?) Suggested-by:
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Chuck Lever authored
Add a missing SPDX header. Signed-off-by:
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Chuck Lever authored
fh_match() is costly, especially when filehandles are large (as is the case for NFSv4). It needs to be used sparingly when searching data structures. Unfortunately, with common workloads, I see multiple thousands of objects stored in file_hashtbl[], which has just 256 buckets, making its bucket hash chains quite lengthy. Walking long hash chains with the state_lock held blocks other activity that needs that lock. Sizable hash chains are a common occurrance once the server has handed out some delegations, for example -- IIUC, each delegated file is held open on the server by an nfs4_file object. To help mitigate the cost of searching with fh_match(), replace the nfs4_file hash table with an rhashtable, which can dynamically resize its bucket array to minimize hash chain length. The result of this modification is an improvement in the latency of NFSv4 operations, and the reduction of nfsd CPU utilization due to eliminating the cost of multiple calls to fh_match() and reducing the CPU cache misses incurred while walking long hash chains in the nfs4_file hash table. Signed-off-by:
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Chuck Lever authored
find_file() is now the only caller of find_file_locked(), so just fold these two together. Signed-off-by:
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Chuck Lever authored
Remove the call to find_file_locked() in insert_nfs4_file(). Tracing shows that over 99% of these calls return NULL. Thus it is not worth the expense of the extra bucket list traversal. insert_file() already deals correctly with the case where the item is already in the hash bucket. Since nfsd4_file_hash_insert() is now just a wrapper around insert_file(), move the meat of insert_file() into nfsd4_file_hash_insert() and get rid of it. Signed-off-by:
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Chuck Lever authored
Refactor to relocate hash deletion operation to a helper function that is close to most other nfs4_file data structure operations. The "noinline" annotation will become useful in a moment when the hlist_del_rcu() is replaced with a more complex rhash remove operation. It also guarantees that hash remove operations can be traced with "-p function -l remove_nfs4_file_locked". This also simplifies the organization of forward declarations: the to-be-added rhashtable and its param structure will be defined /after/ put_nfs4_file(). Signed-off-by:
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Chuck Lever authored
Name this function more consistently. I'm going to use nfsd4_file_ and nfsd4_file_hash_ for these helpers. Change the @fh parameter to be const pointer for better type safety. Finally, move the hash insertion operation to the caller. This is typical for most other "init_object" type helpers, and it is where most of the other nfs4_file hash table operations are located. Signed-off-by:
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Chuck Lever authored
Enable callers to use const pointers for type safety. Signed-off-by:
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Chuck Lever authored
Enable callers to use const pointers where they are able to. Signed-off-by:
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Chuck Lever authored
Delegation revocation is an exceptional event that is not otherwise visible externally (eg, no network traffic is emitted). Generate a trace record when it occurs so that revocation can be observed or other activity can be triggered. Example: nfsd-1104 [005] 1912.002544: nfsd_stid_revoke: client 633c9343:4e82788d stateid 00000003:00000001 ref=2 type=DELEG Trace infrastructure is provided for subsequent additional tracing related to nfs4_stid activity. Signed-off-by:
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Chuck Lever authored
Handing out a delegation stateid is recorded with the nfsd_deleg_read tracepoint, but there isn't a matching tracepoint for recording when the stateid is returned. Signed-off-by:
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Chuck Lever authored
Remove the lame-duck dprintk()s around nfs4_preprocess_stateid_op() call sites. Signed-off-by:
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Chuck Lever authored
Record what we've learned recently about the NFSD filecache in a documenting comment so our future selves don't forget what all this is for. Signed-off-by:
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Chuck Lever authored
NFSv4 operations manage the lifetime of nfsd_file items they use by means of NFSv4 OPEN and CLOSE. Hence there's no need for them to be garbage collected. Introduce a mechanism to enable garbage collection for nfsd_file items used only by NFSv2/3 callers. Note that the change in nfsd_file_put() ensures that both CLOSE and DELEGRETURN will actually close out and free an nfsd_file on last reference of a non-garbage-collected file. Link: https://bugzilla.linux-nfs.org/show_bug.cgi?id=394Suggested-by:
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Chuck Lever authored
This reverts commit 5e138c4a. That commit attempted to make files available to other users as soon as all NFSv4 clients were done with them, rather than waiting until the filecache LRU had garbage collected them. It gets the reference counting wrong, for one thing. But it also misses that DELEGRETURN should release a file in the same fashion. In fact, any nfsd_file_put() on an file held open by an NFSv4 client needs potentially to release the file immediately... Clear the way for implementing that idea. Signed-off-by:
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Chuck Lever authored
In a moment I'm going to introduce separate nfsd_file types, one of which is garbage-collected; the other, not. The garbage-collected variety is to be used by NFSv2 and v3, and the non-garbage-collected variety is to be used by NFSv4. nfsd_commit() is invoked by both NFSv3 and NFSv4 consumers. We want nfsd_commit() to find and use the correct variety of cached nfsd_file object for the NFS version that is in use. Signed-off-by:
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