kernel.git/fs/nfsd/filecache.c, branch linux-5.19.y

nfsd: eliminate the NFSD_FILE_BREAK_* flags

2022-08-17T13:13:40Z

commit 23ba98de6dcec665e15c0ca19244379bb0d30932 upstream. We had a report from the spring Bake-a-thon of data corruption in some nfstest_interop tests. Looking at the traces showed the NFS server allowing a v3 WRITE to proceed while a read delegation was still outstanding. Currently, we only set NFSD_FILE_BREAK_* flags if NFSD_MAY_NOT_BREAK_LEASE was set when we call nfsd_file_alloc. NFSD_MAY_NOT_BREAK_LEASE was intended to be set when finding files for COMMIT ops, where we need a writeable filehandle but don't need to break read leases. It doesn't make any sense to consult that flag when allocating a file since the file may be used on subsequent calls where we do want to break the lease (and the usage of it here seems to be reverse from what it should be anyway). Also, after calling nfsd_open_break_lease, we don't want to clear the BREAK_* bits. A lease could end up being set on it later (more than once) and we need to be able to break those leases as well. This means that the NFSD_FILE_BREAK_* flags now just mirror NFSD_MAY_{READ,WRITE} flags, so there's no need for them at all. Just drop those flags and unconditionally call nfsd_open_break_lease every time. Reported-by: Olga Kornieskaia Link: https://bugzilla.redhat.com/show_bug.cgi?id=2107360 Fixes: 65294c1f2c5e (nfsd: add a new struct file caching facility to nfsd) Cc: # 5.4.x : bb283ca18d1e NFSD: Clean up the show_nf_flags() macro Cc: # 5.4.x Signed-off-by: Jeff Layton Signed-off-by: Chuck Lever Signed-off-by: Greg Kroah-Hartman

Merge tag 'nfsd-5.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux

2022-06-11T00:28:43Z

Pull nfsd fixes from Chuck Lever: "Notable changes: - There is now a backup maintainer for NFSD Notable fixes: - Prevent array overruns in svc_rdma_build_writes() - Prevent buffer overruns when encoding NFSv3 READDIR results - Fix a potential UAF in nfsd_file_put()" * tag 'nfsd-5.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux: SUNRPC: Remove pointer type casts from xdr_get_next_encode_buffer() SUNRPC: Clean up xdr_get_next_encode_buffer() SUNRPC: Clean up xdr_commit_encode() SUNRPC: Optimize xdr_reserve_space() SUNRPC: Fix the calculation of xdr->end in xdr_get_next_encode_buffer() SUNRPC: Trap RDMA segment overflows NFSD: Fix potential use-after-free in nfsd_file_put() MAINTAINERS: reciprocal co-maintainership for file locking and nfsd

NFSD: Fix potential use-after-free in nfsd_file_put()

2022-06-02T17:05:58Z

nfsd_file_put_noref() can free @nf, so don't dereference @nf immediately upon return from nfsd_file_put_noref(). Suggested-by: Trond Myklebust Fixes: 999397926ab3 ("nfsd: Clean up nfsd_file_put()") Signed-off-by: Chuck Lever

Merge tag 'nfsd-5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux

2022-05-27T03:52:24Z

Pull nfsd updates from Chuck Lever: "We introduce 'courteous server' in this release. Previously NFSD would purge open and lock state for an unresponsive client after one lease period (typically 90 seconds). Now, after one lease period, another client can open and lock those files and the unresponsive client's lease is purged; otherwise if the unresponsive client's open and lock state is uncontended, the server retains that open and lock state for up to 24 hours, allowing the client's workload to resume after a lengthy network partition. A longstanding issue with NFSv4 file creation is also addressed. Previously a file creation can fail internally, returning an error to the client, but leave the newly created file in place as an artifact. The file creation code path has been reorganized so that internal failures and race conditions are less likely to result in an unwanted file creation. A fault injector has been added to help exercise paths that are run during kernel metadata cache invalidation. These caches contain information maintained by user space about exported filesystems. Many of our test workloads do not trigger cache invalidation. There is one patch that is needed to support PREEMPT_RT and a fix for an ancient 'sleep while spin-locked' splat that seems to have become easier to hit since v5.18-rc3" * tag 'nfsd-5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux: (36 commits) NFSD: nfsd_file_put() can sleep NFSD: Add documenting comment for nfsd4_release_lockowner() NFSD: Modernize nfsd4_release_lockowner() NFSD: Fix possible sleep during nfsd4_release_lockowner() nfsd: destroy percpu stats counters after reply cache shutdown nfsd: Fix null-ptr-deref in nfsd_fill_super() nfsd: Unregister the cld notifier when laundry_wq create failed SUNRPC: Use RMW bitops in single-threaded hot paths NFSD: Clean up the show_nf_flags() macro NFSD: Trace filecache opens NFSD: Move documenting comment for nfsd4_process_open2() NFSD: Fix whitespace NFSD: Remove dprintk call sites from tail of nfsd4_open() NFSD: Instantiate a struct file when creating a regular NFSv4 file NFSD: Clean up nfsd_open_verified() NFSD: Remove do_nfsd_create() NFSD: Refactor NFSv4 OPEN(CREATE) NFSD: Refactor NFSv3 CREATE NFSD: Refactor nfsd_create_setattr() NFSD: Avoid calling fh_drop_write() twice in do_nfsd_create() ...

NFSD: nfsd_file_put() can sleep

2022-05-26T14:50:51Z

Now that there are no more callers of nfsd_file_put() that might hold a spin lock, ensure the lockdep infrastructure can catch newly introduced calls to nfsd_file_put() made while a spinlock is held. Link: https://lore.kernel.org/linux-nfs/ece7fd1d-5fb3-5155-54ba-347cfc19bd9a@oracle.com/T/#mf1855552570cf9a9c80d1e49d91438cd9085aada Signed-off-by: Chuck Lever Reviewed-by: Jeff Layton

NFSD: Trace filecache opens

2022-05-23T15:06:29Z

Instrument calls to nfsd_open_verified() to get a sense of the filecache hit rate. Signed-off-by: Chuck Lever

NFSD: Instantiate a struct file when creating a regular NFSv4 file

2022-05-23T15:06:29Z

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 Tested-by: JianHong Yin

NFSD: Clean up nfsd_open_verified()

2022-05-20T17:18:25Z

Its only caller always passes S_IFREG as the @type parameter. As an additional clean-up, add a kerneldoc comment. Signed-off-by: Chuck Lever

nfsd: use fsnotify group lock helpers

2022-04-25T12:37:31Z

Before commit 9542e6a643fc6 ("nfsd: Containerise filecache laundrette") nfsd would close open files in direct reclaim context and that could cause a deadlock when fsnotify mark allocation went into direct reclaim and nfsd shrinker tried to free existing fsnotify marks. To avoid issues like this in future code, set the FSNOTIFY_GROUP_NOFS flag on nfsd fsnotify group to prevent going into direct reclaim from fsnotify_add_inode_mark(). Link: https://lore.kernel.org/r/20220422120327.3459282-10-amir73il@gmail.com Suggested-by: Jan Kara Link: https://lore.kernel.org/r/20220321112310.vpr7oxro2xkz5llh@quack3.lan/ Signed-off-by: Amir Goldstein Signed-off-by: Jan Kara

fsnotify: pass flags argument to fsnotify_alloc_group()

2022-04-25T12:37:12Z

Add flags argument to fsnotify_alloc_group(), define and use the flag FSNOTIFY_GROUP_USER in inotify and fanotify instead of the helper fsnotify_alloc_user_group() to indicate user allocation. Although the flag FSNOTIFY_GROUP_USER is currently not used after group allocation, we store the flags argument in the group struct for future use of other group flags. Link: https://lore.kernel.org/r/20220422120327.3459282-5-amir73il@gmail.com Signed-off-by: Amir Goldstein Signed-off-by: Jan Kara