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path: root/fs/nfsd/nfs4state.c
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2022-10-11treewide: use get_random_u32() when possibleJason A. Donenfeld
The prandom_u32() function has been a deprecated inline wrapper around get_random_u32() for several releases now, and compiles down to the exact same code. Replace the deprecated wrapper with a direct call to the real function. The same also applies to get_random_int(), which is just a wrapper around get_random_u32(). This was done as a basic find and replace. Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Yury Norov <yury.norov@gmail.com> Reviewed-by: Jan Kara <jack@suse.cz> # for ext4 Acked-by: Toke Høiland-Jørgensen <toke@toke.dk> # for sch_cake Acked-by: Chuck Lever <chuck.lever@oracle.com> # for nfsd Acked-by: Jakub Kicinski <kuba@kernel.org> Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com> # for thunderbolt Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs Acked-by: Helge Deller <deller@gmx.de> # for parisc Acked-by: Heiko Carstens <hca@linux.ibm.com> # for s390 Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-09-26nfsd: extra checks when freeing delegation stateidsJeff Layton
We've had some reports of problems in the refcounting for delegation stateids that we've yet to track down. Add some extra checks to ensure that we've removed the object from various lists before freeing it. Link: https://bugzilla.redhat.com/show_bug.cgi?id=2127067 Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-09-26nfsd: make nfsd4_run_cb a bool return functionJeff Layton
queue_work can return false and not queue anything, if the work is already queued. If that happens in the case of a CB_RECALL, we'll have taken an extra reference to the stid that will never be put. Ensure we throw a warning in that case. Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-09-26nfsd: fix comments about spinlock handling with delegationsJeff Layton
Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-09-26nfsd: only fill out return pointer on success in nfsd4_lookup_stateidJeff Layton
In the case of a revoked delegation, we still fill out the pointer even when returning an error, which is bad form. Only overwrite the pointer on success. Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-09-26NFSD: fix use-after-free on source server when doing inter-server copyDai Ngo
Use-after-free occurred when the laundromat tried to free expired cpntf_state entry on the s2s_cp_stateids list after inter-server copy completed. The sc_cp_list that the expired copy state was inserted on was already freed. When COPY completes, the Linux client normally sends LOCKU(lock_state x), FREE_STATEID(lock_state x) and CLOSE(open_state y) to the source server. The nfs4_put_stid call from nfsd4_free_stateid cleans up the copy state from the s2s_cp_stateids list before freeing the lock state's stid. However, sometimes the CLOSE was sent before the FREE_STATEID request. When this happens, the nfsd4_close_open_stateid call from nfsd4_close frees all lock states on its st_locks list without cleaning up the copy state on the sc_cp_list list. When the time the FREE_STATEID arrives the server returns BAD_STATEID since the lock state was freed. This causes the use-after-free error to occur when the laundromat tries to free the expired cpntf_state. This patch adds a call to nfs4_free_cpntf_statelist in nfsd4_close_open_stateid to clean up the copy state before calling free_ol_stateid_reaplist to free the lock state's stid on the reaplist. Signed-off-by: Dai Ngo <dai.ngo@oracle.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-09-26NFSD: Rename the fields in copy_stateid_tChuck Lever
Code maintenance: The name of the copy_stateid_t::sc_count field collides with the sc_count field in struct nfs4_stid, making the latter difficult to grep for when auditing stateid reference counting. No behavior change expected. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-09-26nfsd: use DEFINE_SHOW_ATTRIBUTE to define client_info_fopsChenXiaoSong
Use DEFINE_SHOW_ATTRIBUTE helper macro to simplify the code. inode is converted from seq_file->file instead of seq_file->private in client_info_show(). Signed-off-by: ChenXiaoSong <chenxiaosong2@huawei.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-09-26NFSD: add shrinker to reap courtesy clients on low memory conditionDai Ngo
Add courtesy_client_reaper to react to low memory condition triggered by the system memory shrinker. The delayed_work for the courtesy_client_reaper is scheduled on the shrinker's count callback using the laundry_wq. The shrinker's scan callback is not used for expiring the courtesy clients due to potential deadlocks. Signed-off-by: Dai Ngo <dai.ngo@oracle.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-09-26NFSD: keep track of the number of courtesy clients in the systemDai Ngo
Add counter nfs4_courtesy_client_count to nfsd_net to keep track of the number of courtesy clients in the system. Signed-off-by: Dai Ngo <dai.ngo@oracle.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-09-26NFSD: Add a mechanism to wait for a DELEGRETURNChuck Lever
Subsequent patches will use this mechanism to wake up an operation that is waiting for a client to return a delegation. The new tracepoint records whether the wait timed out or was properly awoken by the expected DELEGRETURN: nfsd-1155 [002] 83799.493199: nfsd_delegret_wakeup: xid=0x14b7d6ef fh_hash=0xf6826792 (timed out) Suggested-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Jeff Layton <jlayton@kernel.org>
2022-09-26NFSD: Add tracepoints to report NFSv4 callback completionsChuck Lever
Wireshark has always been lousy about dissecting NFSv4 callbacks, especially NFSv4.0 backchannel requests. Add tracepoints so we can surgically capture these events in the trace log. Tracepoints are time-stamped and ordered so that we can now observe the timing relationship between a CB_RECALL Reply and the client's DELEGRETURN Call. Example: nfsd-1153 [002] 211.986391: nfsd_cb_recall: addr=192.168.1.67:45767 client 62ea82e4:fee7492a stateid 00000003:00000001 nfsd-1153 [002] 212.095634: nfsd_compound: xid=0x0000002c opcnt=2 nfsd-1153 [002] 212.095647: nfsd_compound_status: op=1/2 OP_PUTFH status=0 nfsd-1153 [002] 212.095658: nfsd_file_put: hash=0xf72 inode=0xffff9291148c7410 ref=3 flags=HASHED|REFERENCED may=READ file=0xffff929103b3ea00 nfsd-1153 [002] 212.095661: nfsd_compound_status: op=2/2 OP_DELEGRETURN status=0 kworker/u25:8-148 [002] 212.096713: nfsd_cb_recall_done: client 62ea82e4:fee7492a stateid 00000003:00000001 status=0 Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Jeff Layton <jlayton@kernel.org>
2022-08-04NFSD: use (un)lock_inode instead of fh_(un)lock for file operationsNeilBrown
When locking a file to access ACLs and xattrs etc, use explicit locking with inode_lock() instead of fh_lock(). This means that the calls to fh_fill_pre/post_attr() are also explicit which improves readability and allows us to place them only where they are needed. Only the xattr calls need pre/post information. When locking a file we don't need I_MUTEX_PARENT as the file is not a parent of anything, so we can use inode_lock() directly rather than the inode_lock_nested() call that fh_lock() uses. Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-08-04NFSD: reduce locking in nfsd_lookup()NeilBrown
nfsd_lookup() takes an exclusive lock on the parent inode, but no callers want the lock and it may not be needed at all if the result is in the dcache. Change nfsd_lookup_dentry() to not take the lock, and call lookup_one_len_locked() which takes lock only if needed. nfsd4_open() currently expects the lock to still be held, but that isn't necessary as nfsd_validate_delegated_dentry() provides required guarantees without the lock. NOTE: NFSv4 requires directory changeinfo for OPEN even when a create wasn't requested and no change happened. Now that nfsd_lookup() doesn't use fh_lock(), we need to explicitly fill the attributes when no create happens. A new fh_fill_both_attrs() is provided for that task. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-07-29NFSD: introduce struct nfsd_attrsNeilBrown
The attributes that nfsd might want to set on a file include 'struct iattr' as well as an ACL and security label. The latter two are passed around quite separately from the first, in part because they are only needed for NFSv4. This leads to some clumsiness in the code, such as the attributes NOT being set in nfsd_create_setattr(). We need to keep the directory locked until all attributes are set to ensure the file is never visibile without all its attributes. This need combined with the inconsistent handling of attributes leads to more clumsiness. As a first step towards tidying this up, introduce 'struct nfsd_attrs'. This is passed (by reference) to vfs.c functions that work with attributes, and is assembled by the various nfs*proc functions which call them. As yet only iattr is included, but future patches will expand this. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-07-29NFSD: verify the opened dentry after setting a delegationJeff Layton
Between opening a file and setting a delegation on it, someone could rename or unlink the dentry. If this happens, we do not want to grant a delegation on the open. On a CLAIM_NULL open, we're opening by filename, and we may (in the non-create case) or may not (in the create case) be holding i_rwsem when attempting to set a delegation. The latter case allows a race. After getting a lease, redo the lookup of the file being opened and validate that the resulting dentry matches the one in the open file description. To properly redo the lookup we need an rqst pointer to pass to nfsd_lookup_dentry(), so make sure that is available. Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-07-29NFSD: drop fh argument from alloc_init_delegJeff Layton
Currently, we pass the fh of the opened file down through several functions so that alloc_init_deleg can pass it to delegation_blocked. The filehandle of the open file is available in the nfs4_file however, so there's no need to pass it in a separate argument. Drop the argument from alloc_init_deleg, nfs4_open_delegation and nfs4_set_delegation. Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-07-29NFSD: limit the number of v4 clients to 1024 per 1GB of system memoryDai Ngo
Currently there is no limit on how many v4 clients are supported by the system. This can be a problem in systems with small memory configuration to function properly when a very large number of clients exist that creates memory shortage conditions. This patch enforces a limit of 1024 NFSv4 clients, including courtesy clients, per 1GB of system memory. When the number of the clients reaches the limit, requests that create new clients are returned with NFS4ERR_DELAY and the laundromat is kicked start to trim old clients. Due to the overhead of the upcall to remove the client record, the maximun number of clients the laundromat removes on each run is limited to 128. This is done to ensure the laundromat can still process the other tasks in a timely manner. Since there is now a limit of the number of clients, the 24-hr idle time limit of courtesy client is no longer needed and was removed. Signed-off-by: Dai Ngo <dai.ngo@oracle.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-07-29NFSD: keep track of the number of v4 clients in the systemDai Ngo
Add counter nfs4_client_count to keep track of the total number of v4 clients, including courtesy clients, in the system. Signed-off-by: Dai Ngo <dai.ngo@oracle.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-07-29NFSD: refactoring v4 specific code to a helper in nfs4state.cDai Ngo
This patch moves the v4 specific code from nfsd_init_net() to nfsd4_init_leases_net() helper in nfs4state.c Signed-off-by: Dai Ngo <dai.ngo@oracle.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-07-29NFSD: Ensure nf_inode is never dereferencedChuck Lever
The documenting comment for struct nf_file states: /* * A representation of a file that has been opened by knfsd. These are hashed * in the hashtable by inode pointer value. Note that this object doesn't * hold a reference to the inode by itself, so the nf_inode pointer should * never be dereferenced, only used for comparison. */ Replace the two existing dereferences to make the comment always true. Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-07-29NFSD: NFSv4 CLOSE should release an nfsd_file immediatelyChuck Lever
The last close of a file should enable other accessors to open and use that file immediately. Leaving the file open in the filecache prevents other users from accessing that file until the filecache garbage-collects the file -- sometimes that takes several seconds. Reported-by: Wang Yugui <wangyugui@e16-tech.com> Link: https://bugzilla.linux-nfs.org/show_bug.cgi?387 Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-07-29NFSD: Separate tracepoints for acquire and createChuck Lever
These tracepoints collect different information: the create case does not open a file, so there's no nf_file available. Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-05-26NFSD: Add documenting comment for nfsd4_release_lockowner()Chuck Lever
And return explicit nfserr values that match what is documented in the new comment / API contract. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-05-26NFSD: Modernize nfsd4_release_lockowner()Chuck Lever
Refactor: Use existing helpers that other lock operations use. This change removes several automatic variables, so re-organize the variable declarations for readability. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-05-26NFSD: Fix possible sleep during nfsd4_release_lockowner()Chuck Lever
nfsd4_release_lockowner() holds clp->cl_lock when it calls check_for_locks(). However, check_for_locks() calls nfsd_file_get() / nfsd_file_put() to access the backing inode's flc_posix list, and nfsd_file_put() can sleep if the inode was recently removed. Let's instead rely on the stateowner's reference count to gate whether the release is permitted. This should be a reliable indication of locks-in-use since file lock operations and ->lm_get_owner take appropriate references, which are released appropriately when file locks are removed. Reported-by: Dai Ngo <dai.ngo@oracle.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Cc: stable@vger.kernel.org
2022-05-23NFSD: Move documenting comment for nfsd4_process_open2()Chuck Lever
Clean up nfsd4_open() by converting a large comment at the only call site for nfsd4_process_open2() to a kerneldoc comment in front of that function. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-05-23NFSD: Instantiate a struct file when creating a regular NFSv4 fileChuck Lever
There have been reports of races that cause NFSv4 OPEN(CREATE) to return an error even though the requested file was created. NFSv4 does not provide a status code for this case. To mitigate some of these problems, reorganize the NFSv4 OPEN(CREATE) logic to allocate resources before the file is actually created, and open the new file while the parent directory is still locked. Two new APIs are added: + Add an API that works like nfsd_file_acquire() but does not open the underlying file. The OPEN(CREATE) path can use this API when it already has an open file. + Add an API that is kin to dentry_open(). NFSD needs to create a file and grab an open "struct file *" atomically. The alloc_empty_file() has to be done before the inode create. If it fails (for example, because the NFS server has exceeded its max_files limit), we avoid creating the file and can still return an error to the NFS client. BugLink: https://bugzilla.linux-nfs.org/show_bug.cgi?id=382 Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Tested-by: JianHong Yin <jiyin@redhat.com>
2022-05-19NFSD: Show state of courtesy client in client infoDai Ngo
Update client_info_show to show state of courtesy client and seconds since last renew. Reviewed-by: J. Bruce Fields <bfields@fieldses.org> Signed-off-by: Dai Ngo <dai.ngo@oracle.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-05-19NFSD: add support for lock conflict to courteous serverDai Ngo
This patch allows expired client with lock state to be in COURTESY state. Lock conflict with COURTESY client is resolved by the fs/lock code using the lm_lock_expirable and lm_expire_lock callback in the struct lock_manager_operations. If conflict client is in COURTESY state, set it to EXPIRABLE and schedule the laundromat to run immediately to expire the client. The callback lm_expire_lock waits for the laundromat to flush its work queue before returning to caller. Reviewed-by: J. Bruce Fields <bfields@fieldses.org> Signed-off-by: Dai Ngo <dai.ngo@oracle.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-05-19NFSD: move create/destroy of laundry_wq to init_nfsd and exit_nfsdDai Ngo
This patch moves create/destroy of laundry_wq from nfs4_state_start and nfs4_state_shutdown_net to init_nfsd and exit_nfsd to prevent the laundromat from being freed while a thread is processing a conflicting lock. Reviewed-by: J. Bruce Fields <bfields@fieldses.org> Signed-off-by: Dai Ngo <dai.ngo@oracle.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-05-19NFSD: add support for share reservation conflict to courteous serverDai Ngo
This patch allows expired client with open state to be in COURTESY state. Share/access conflict with COURTESY client is resolved by setting COURTESY client to EXPIRABLE state, schedule laundromat to run and returning nfserr_jukebox to the request client. Reviewed-by: J. Bruce Fields <bfields@fieldses.org> Signed-off-by: Dai Ngo <dai.ngo@oracle.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-05-19NFSD: add courteous server support for thread with only delegationDai Ngo
This patch provides courteous server support for delegation only. Only expired client with delegation but no conflict and no open or lock state is allowed to be in COURTESY state. Delegation conflict with COURTESY/EXPIRABLE client is resolved by setting it to EXPIRABLE, queue work for the laundromat and return delay to the caller. Conflict is resolved when the laudromat runs and expires the EXIRABLE client while the NFS client retries the OPEN request. Local thread request that gets conflict is doing the retry in _break_lease. Client in COURTESY or EXPIRABLE state is allowed to reconnect and continues to have access to its state. Access to the nfs4_client by the reconnecting thread and the laundromat is serialized via the client_lock. Reviewed-by: J. Bruce Fields <bfields@fieldses.org> Signed-off-by: Dai Ngo <dai.ngo@oracle.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-03-11NFSD: Fix nfsd_breaker_owns_lease() return valuesChuck Lever
These have been incorrect since the function was introduced. A proper kerneldoc comment is added since this function, though static, is part of an external interface. Reported-by: Dai Ngo <dai.ngo@oracle.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-03-11NFSD: Clean up _lm_ operation namesChuck Lever
The common practice is to name function instances the same as the method names, but with a uniquifying prefix. Commit aef9583b234a ("NFSD: Get reference of lockowner when coping file_lock") missed this -- the new function names should both have been of the form "nfsd4_lm_*". Before more lock manager operations are added in NFSD, rename these two functions for consistency. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-01-28nfsd: nfsd4_setclientid_confirm mistakenly expires confirmed client.Dai Ngo
From RFC 7530 Section 16.34.5: o The server has not recorded an unconfirmed { v, x, c, *, * } and has recorded a confirmed { v, x, c, *, s }. If the principals of the record and of SETCLIENTID_CONFIRM do not match, the server returns NFS4ERR_CLID_INUSE without removing any relevant leased client state, and without changing recorded callback and callback_ident values for client { x }. The current code intends to do what the spec describes above but it forgot to set 'old' to NULL resulting to the confirmed client to be expired. Fixes: 2b63482185e6 ("nfsd: fix clid_inuse on mount with security change") Signed-off-by: Dai Ngo <dai.ngo@oracle.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Bruce Fields <bfields@fieldses.org>
2022-01-08nfsd: fix crash on COPY_NOTIFY with special stateidJ. Bruce Fields
RTM says "If the special ONE stateid is passed to nfs4_preprocess_stateid_op(), it returns status=0 but does not set *cstid. nfsd4_copy_notify() depends on stid being set if status=0, and thus can crash if the client sends the right COPY_NOTIFY RPC." RFC 7862 says "The cna_src_stateid MUST refer to either open or locking states provided earlier by the server. If it is invalid, then the operation MUST fail." The RFC doesn't specify an error, and the choice doesn't matter much as this is clearly illegal client behavior, but bad_stateid seems reasonable. Simplest is just to guarantee that nfs4_preprocess_stateid_op, called with non-NULL cstid, errors out if it can't return a stateid. Reported-by: rtm@csail.mit.edu Fixes: 624322f1adc5 ("NFSD add COPY_NOTIFY operation") Signed-off-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Olga Kornievskaia <kolga@netapp.com> Tested-by: Olga Kornievskaia <kolga@netapp.com>
2022-01-08nfsd4: add refcount for nfsd4_blocked_lockVasily Averin
nbl allocated in nfsd4_lock can be released by a several ways: directly in nfsd4_lock(), via nfs4_laundromat(), via another nfs command RELEASE_LOCKOWNER or via nfsd4_callback. This structure should be refcounted to be used and released correctly in all these cases. Refcount is initialized to 1 during allocation and is incremented when nbl is added into nbl_list/nbl_lru lists. Usually nbl is linked into both lists together, so only one refcount is used for both lists. However nfsd4_lock() should keep in mind that nbl can be present in one of lists only. This can happen if nbl was handled already by nfs4_laundromat/nfsd4_callback/etc. Refcount is decremented if vfs_lock_file() returns FILE_LOCK_DEFERRED, because nbl can be handled already by nfs4_laundromat/nfsd4_callback/etc. Refcount is not changed in find_blocked_lock() because of it reuses counter released after removing nbl from lists. Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-01-08nfs: block notification on fs with its own ->lockJ. Bruce Fields
NFSv4.1 supports an optional lock notification feature which notifies the client when a lock comes available. (Normally NFSv4 clients just poll for locks if necessary.) To make that work, we need to request a blocking lock from the filesystem. We turned that off for NFS in commit f657f8eef3ff ("nfs: don't atempt blocking locks on nfs reexports") [sic] because it actually blocks the nfsd thread while waiting for the lock. Thanks to Vasily Averin for pointing out that NFS isn't the only filesystem with that problem. Any filesystem that leaves ->lock NULL will use posix_lock_file(), which does the right thing. Simplest is just to assume that any filesystem that defines its own ->lock is not safe to request a blocking lock from. So, this patch mostly reverts commit f657f8eef3ff ("nfs: don't atempt blocking locks on nfs reexports") [sic] and commit b840be2f00c0 ("lockd: don't attempt blocking locks on nfs reexports"), and instead uses a check of ->lock (Vasily's suggestion) to decide whether to support blocking lock notifications on a given filesystem. Also add a little documentation. Perhaps someday we could add back an export flag later to allow filesystems with "good" ->lock methods to support blocking lock notifications. Reported-by: Vasily Averin <vvs@virtuozzo.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com> [ cel: Description rewritten to address checkpatch nits ] [ cel: Fixed warning when SUNRPC debugging is disabled ] [ cel: Fixed NULL check ] Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Vasily Averin <vvs@virtuozzo.com>
2022-01-08nfsd: improve stateid access bitmask documentationJ. Bruce Fields
The use of the bitmaps is confusing. Add a cross-reference to make it easier to find the existing comment. Add an updated reference with URL to make it quicker to look up. And a bit more editorializing about the value of this. Signed-off-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-10nfsd: fix use-after-free due to delegation raceJ. Bruce Fields
A delegation break could arrive as soon as we've called vfs_setlease. A delegation break runs a callback which immediately (in nfsd4_cb_recall_prepare) adds the delegation to del_recall_lru. If we then exit nfs4_set_delegation without hashing the delegation, it will be freed as soon as the callback is done with it, without ever being removed from del_recall_lru. Symptoms show up later as use-after-free or list corruption warnings, usually in the laundromat thread. I suspect aba2072f4523 "nfsd: grant read delegations to clients holding writes" made this bug easier to hit, but I looked as far back as v3.0 and it looks to me it already had the same problem. So I'm not sure where the bug was introduced; it may have been there from the beginning. Cc: stable@vger.kernel.org Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2021-11-10Merge tag 'nfsd-5.16' of git://linux-nfs.org/~bfields/linuxLinus Torvalds
Pull nfsd updates from Bruce Fields: "A slow cycle for nfsd: mainly cleanup, including Neil's patch dropping support for a filehandle format deprecated 20 years ago, and further xdr-related cleanup from Chuck" * tag 'nfsd-5.16' of git://linux-nfs.org/~bfields/linux: (26 commits) nfsd4: remove obselete comment nfsd: document server-to-server-copy parameters NFSD:fix boolreturn.cocci warning nfsd: update create verifier comment SUNRPC: Change return value type of .pc_encode SUNRPC: Replace the "__be32 *p" parameter to .pc_encode NFSD: Save location of NFSv4 COMPOUND status SUNRPC: Change return value type of .pc_decode SUNRPC: Replace the "__be32 *p" parameter to .pc_decode SUNRPC: De-duplicate .pc_release() call sites SUNRPC: Simplify the SVC dispatch code path SUNRPC: Capture value of xdr_buf::page_base SUNRPC: Add trace event when alloc_pages_bulk() makes no progress svcrdma: Split svcrmda_wc_{read,write} tracepoints svcrdma: Split the svcrdma_wc_send() tracepoint svcrdma: Split the svcrdma_wc_receive() tracepoint NFSD: Have legacy NFSD WRITE decoders use xdr_stream_subsegment() SUNRPC: xdr_stream_subsegment() must handle non-zero page_bases NFSD: Initialize pointer ni with NULL and not plain integer 0 NFSD: simplify struct nfsfh ...
2021-10-02NFSD: Initialize pointer ni with NULL and not plain integer 0Colin Ian King
Pointer ni is being initialized with plain integer zero. Fix this by initializing with NULL. Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2021-10-02NFSD: simplify struct nfsfhNeilBrown
Most of the fields in 'struct knfsd_fh' are 2 levels deep (a union and a struct) and are accessed using macros like: #define fh_FOO fh_base.fh_new.fb_FOO This patch makes the union and struct anonymous, so that "fh_FOO" can be a name directly within 'struct knfsd_fh' and the #defines aren't needed. The file handle as a whole is sometimes accessed as "fh_base" or "fh_base.fh_pad", neither of which are particularly helpful names. As the struct holding the filehandle is now anonymous, we cannot use the name of that, so we union it with 'fh_raw' and use that where the raw filehandle is needed. fh_raw also ensure the structure is large enough for the largest possible filehandle. fh_raw is a 'char' array, removing any need to cast it for memcpy etc. SVCFH_fmt() is simplified using the "%ph" printk format. This changes the appearance of filehandles in dprintk() debugging, making them a little more precise. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2021-09-22Merge tag 'nfsd-5.15-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux Pull nfsd fixes from Chuck Lever: "Critical bug fixes: - Fix crash in NLM TEST procedure - NFSv4.1+ backchannel not restored after PATH_DOWN" * tag 'nfsd-5.15-2' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux: nfsd: back channel stuck in SEQ4_STATUS_CB_PATH_DOWN NLM: Fix svcxdr_encode_owner()
2021-09-17nfsd: back channel stuck in SEQ4_STATUS_CB_PATH_DOWNDai Ngo
When the back channel enters SEQ4_STATUS_CB_PATH_DOWN state, the client recovers by sending BIND_CONN_TO_SESSION but the server fails to recover the back channel and leaves it as NFSD4_CB_DOWN. Fix by enhancing nfsd4_bind_conn_to_session to probe the back channel by calling nfsd4_probe_callback. Signed-off-by: Dai Ngo <dai.ngo@oracle.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-08-31Merge tag 'nfsd-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linuxLinus Torvalds
Pull nfsd updates from Chuck Lever: "New features: - Support for server-side disconnect injection via debugfs - Protocol definitions for new RPC_AUTH_TLS authentication flavor Performance improvements: - Reduce page allocator traffic in the NFSD splice read actor - Reduce CPU utilization in svcrdma's Send completion handler Notable bug fixes: - Stabilize lockd operation when re-exporting NFS mounts - Fix the use of %.*s in NFSD tracepoints - Fix /proc/sys/fs/nfs/nsm_use_hostnames" * tag 'nfsd-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux: (31 commits) nfsd: fix crash on LOCKT on reexported NFSv3 nfs: don't allow reexport reclaims lockd: don't attempt blocking locks on nfs reexports nfs: don't atempt blocking locks on nfs reexports Keep read and write fds with each nlm_file lockd: update nlm_lookup_file reexport comment nlm: minor refactoring nlm: minor nlm_lookup_file argument change lockd: lockd server-side shouldn't set fl_ops SUNRPC: Add documentation for the fail_sunrpc/ directory SUNRPC: Server-side disconnect injection SUNRPC: Move client-side disconnect injection SUNRPC: Add a /sys/kernel/debug/fail_sunrpc/ directory svcrdma: xpt_bc_xprt is already clear in __svc_rdma_free() nfsd4: Fix forced-expiry locking rpc: fix gss_svc_init cleanup on failure SUNRPC: Add RPC_AUTH_TLS protocol numbers lockd: change the proc_handler for nsm_use_hostnames sysctl: introduce new proc handler proc_dobool SUNRPC: Fix a NULL pointer deref in trace_svc_stats_latency() ...
2021-08-26nfsd: fix crash on LOCKT on reexported NFSv3J. Bruce Fields
Unlike other filesystems, NFSv3 tries to use fl_file in the GETLK case. Signed-off-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-08-26nfs: don't allow reexport reclaimsJ. Bruce Fields
In the reexport case, nfsd is currently passing along locks with the reclaim bit set. The client sends a new lock request, which is granted if there's currently no conflict--even if it's possible a conflicting lock could have been briefly held in the interim. We don't currently have any way to safely grant reclaim, so for now let's just deny them all. I'm doing this by passing the reclaim bit to nfs and letting it fail the call, with the idea that eventually the client might be able to do something more forgiving here. Signed-off-by: J. Bruce Fields <bfields@redhat.com> Acked-by: Anna Schumaker <Anna.Schumaker@Netapp.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-08-26nfs: don't atempt blocking locks on nfs reexportsJ. Bruce Fields
NFS implements blocking locks by blocking inside its lock method. In the reexport case, this blocks the nfs server thread, which could lead to deadlocks since an nfs server thread might be required to unlock the conflicting lock. It also causes a crash, since the nfs server thread assumes it can free the lock when its lm_notify lock callback is called. Ideal would be to make the nfs lock method return without blocking in this case, but for now it works just not to attempt blocking locks. The difference is just that the original client will have to poll (as it does in the v4.0 case) instead of getting a callback when the lock's available. Signed-off-by: J. Bruce Fields <bfields@redhat.com> Acked-by: Anna Schumaker <Anna.Schumaker@Netapp.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>