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2022-01-17Merge branch 'signal-for-v5.17' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull signal/exit/ptrace updates from Eric Biederman: "This set of changes deletes some dead code, makes a lot of cleanups which hopefully make the code easier to follow, and fixes bugs found along the way. The end-game which I have not yet reached yet is for fatal signals that generate coredumps to be short-circuit deliverable from complete_signal, for force_siginfo_to_task not to require changing userspace configured signal delivery state, and for the ptrace stops to always happen in locations where we can guarantee on all architectures that the all of the registers are saved and available on the stack. Removal of profile_task_ext, profile_munmap, and profile_handoff_task are the big successes for dead code removal this round. A bunch of small bug fixes are included, as most of the issues reported were small enough that they would not affect bisection so I simply added the fixes and did not fold the fixes into the changes they were fixing. There was a bug that broke coredumps piped to systemd-coredump. I dropped the change that caused that bug and replaced it entirely with something much more restrained. Unfortunately that required some rebasing. Some successes after this set of changes: There are few enough calls to do_exit to audit in a reasonable amount of time. The lifetime of struct kthread now matches the lifetime of struct task, and the pointer to struct kthread is no longer stored in set_child_tid. The flag SIGNAL_GROUP_COREDUMP is removed. The field group_exit_task is removed. Issues where task->exit_code was examined with signal->group_exit_code should been examined were fixed. There are several loosely related changes included because I am cleaning up and if I don't include them they will probably get lost. The original postings of these changes can be found at: https://lkml.kernel.org/r/87a6ha4zsd.fsf@email.froward.int.ebiederm.org https://lkml.kernel.org/r/87bl1kunjj.fsf@email.froward.int.ebiederm.org https://lkml.kernel.org/r/87r19opkx1.fsf_-_@email.froward.int.ebiederm.org I trimmed back the last set of changes to only the obviously correct once. Simply because there was less time for review than I had hoped" * 'signal-for-v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (44 commits) ptrace/m68k: Stop open coding ptrace_report_syscall ptrace: Remove unused regs argument from ptrace_report_syscall ptrace: Remove second setting of PT_SEIZED in ptrace_attach taskstats: Cleanup the use of task->exit_code exit: Use the correct exit_code in /proc/<pid>/stat exit: Fix the exit_code for wait_task_zombie exit: Coredumps reach do_group_exit exit: Remove profile_handoff_task exit: Remove profile_task_exit & profile_munmap signal: clean up kernel-doc comments signal: Remove the helper signal_group_exit signal: Rename group_exit_task group_exec_task coredump: Stop setting signal->group_exit_task signal: Remove SIGNAL_GROUP_COREDUMP signal: During coredumps set SIGNAL_GROUP_EXIT in zap_process signal: Make coredump handling explicit in complete_signal signal: Have prepare_signal detect coredumps using signal->core_state signal: Have the oom killer detect coredumps using signal->core_state exit: Move force_uaccess back into do_exit exit: Guarantee make_task_dead leaks the tsk when calling do_task_exit ...
2022-01-16Merge tag 'nfsd-5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linuxLinus Torvalds21-400/+493
Pull nfsd updates from Chuck Lever: "Bruce has announced he is leaving Red Hat at the end of the month and is stepping back from his role as NFSD co-maintainer. As a result, this includes a patch removing him from the MAINTAINERS file. There is one patch in here that Jeff Layton was carrying in the locks tree. Since he had only one for this cycle, he asked us to send it to you via the nfsd tree. There continues to be 0-day reports from Robert Morris @MIT. This time we include a fix for a crash in the COPY_NOTIFY operation. Highlights: - Bruce steps down as NFSD maintainer - Prepare for dynamic nfsd thread management - More work on supporting re-exporting NFS mounts - One fs/locks patch on behalf of Jeff Layton Notable bug fixes: - Fix zero-length NFSv3 WRITEs - Fix directory cinfo on FS's that do not support iversion - Fix WRITE verifiers for stable writes - Fix crash on COPY_NOTIFY with a special state ID" * tag 'nfsd-5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux: (51 commits) SUNRPC: Fix sockaddr handling in svcsock_accept_class trace points SUNRPC: Fix sockaddr handling in the svc_xprt_create_error trace point fs/locks: fix fcntl_getlk64/fcntl_setlk64 stub prototypes nfsd: fix crash on COPY_NOTIFY with special stateid MAINTAINERS: remove bfields NFSD: Move fill_pre_wcc() and fill_post_wcc() Revert "nfsd: skip some unnecessary stats in the v4 case" NFSD: Trace boot verifier resets NFSD: Rename boot verifier functions NFSD: Clean up the nfsd_net::nfssvc_boot field NFSD: Write verifier might go backwards nfsd: Add a tracepoint for errors in nfsd4_clone_file_range() NFSD: De-duplicate net_generic(nf->nf_net, nfsd_net_id) NFSD: De-duplicate net_generic(SVC_NET(rqstp), nfsd_net_id) NFSD: Clean up nfsd_vfs_write() nfsd: Replace use of rwsem with errseq_t NFSD: Fix verifier returned in stable WRITEs nfsd: Retry once in nfsd_open on an -EOPENSTALE return nfsd: Add errno mapping for EREMOTEIO nfsd: map EBADF ...
2022-01-12Merge tag 'fs.idmapped.v5.17' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux Pull fs idmapping updates from Christian Brauner: "This contains the work to enable the idmapping infrastructure to support idmapped mounts of filesystems mounted with an idmapping. In addition this contains various cleanups that avoid repeated open-coding of the same functionality and simplify the code in quite a few places. We also finish the renaming of the mapping helpers we started a few kernel releases back and move them to a dedicated header to not continue polluting the fs header needlessly with low-level idmapping helpers. With this series the fs header only contains idmapping helpers that interact with fs objects. Currently we only support idmapped mounts for filesystems mounted without an idmapping themselves. This was a conscious decision mentioned in multiple places (cf. [1]). As explained at length in [3] it is perfectly fine to extend support for idmapped mounts to filesystem's mounted with an idmapping should the need arise. The need has been there for some time now (cf. [2]). Before we can port any filesystem that is mountable with an idmapping to support idmapped mounts in the coming cycles, we need to first extend the mapping helpers to account for the filesystem's idmapping. This again, is explained at length in our documentation at [3] and also in the individual commit messages so here's an overview. Currently, the low-level mapping helpers implement the remapping algorithms described in [3] in a simplified manner as we could rely on the fact that all filesystems supporting idmapped mounts are mounted without an idmapping. In contrast, filesystems mounted with an idmapping are very likely to not use an identity mapping and will instead use a non-identity mapping. So the translation step from or into the filesystem's idmapping in the remapping algorithm cannot be skipped for such filesystems. Non-idmapped filesystems and filesystems not supporting idmapped mounts are unaffected by this change as the remapping algorithms can take the same shortcut as before. If the low-level helpers detect that they are dealing with an idmapped mount but the underlying filesystem is mounted without an idmapping we can rely on the previous shortcut and can continue to skip the translation step from or into the filesystem's idmapping. And of course, if the low-level helpers detect that they are not dealing with an idmapped mount they can simply return the relevant id unchanged; no remapping needs to be performed at all. These checks guarantee that only the minimal amount of work is performed. As before, if idmapped mounts aren't used the low-level helpers are idempotent and no work is performed at all" Link: 2ca4dcc4909d ("fs/mount_setattr: tighten permission checks") [1] Link: https://github.com/containers/podman/issues/10374 [2] Link: Documentations/filesystems/idmappings.rst [3] Link: a65e58e791a1 ("fs: document and rename fsid helpers") [4] * tag 'fs.idmapped.v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux: fs: support mapped mounts of mapped filesystems fs: add i_user_ns() helper fs: port higher-level mapping helpers fs: remove unused low-level mapping helpers fs: use low-level mapping helpers docs: update mapping documentation fs: account for filesystem mappings fs: tweak fsuidgid_has_mapping() fs: move mapping helpers fs: add is_idmapped_mnt() helper
2022-01-08nfsd: fix crash on COPY_NOTIFY with special stateidJ. Bruce Fields1-1/+5
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>
2022-01-08NFSD: Move fill_pre_wcc() and fill_post_wcc()Chuck Lever5-75/+96
These functions are related to file handle processing and have nothing to do with XDR encoding or decoding. Also they are no longer NFSv3-specific. As a clean-up, move their definitions to a more appropriate location. WCC is also an NFSv3-specific term, so rename them as general-purpose helpers. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-01-08Revert "nfsd: skip some unnecessary stats in the v4 case"Chuck Lever1-27/+17
On the wire, I observed NFSv4 OPEN(CREATE) operations sometimes returning a reasonable-looking value in the cinfo.before field and zero in the cinfo.after field. RFC 8881 Section 10.8.1 says: > When a client is making changes to a given directory, it needs to > determine whether there have been changes made to the directory by > other clients. It does this by using the change attribute as > reported before and after the directory operation in the associated > change_info4 value returned for the operation. and > ... The post-operation change > value needs to be saved as the basis for future change_info4 > comparisons. A good quality client implementation therefore saves the zero cinfo.after value. During a subsequent OPEN operation, it will receive a different non-zero value in the cinfo.before field for that directory, and it will incorrectly believe the directory has changed, triggering an undesirable directory cache invalidation. There are filesystem types where fs_supports_change_attribute() returns false, tmpfs being one. On NFSv4 mounts, this means the fh_getattr() call site in fill_pre_wcc() and fill_post_wcc() is never invoked. Subsequently, nfsd4_change_attribute() is invoked with an uninitialized @stat argument. In fill_pre_wcc(), @stat contains stale stack garbage, which is then placed on the wire. In fill_post_wcc(), ->fh_post_wc is all zeroes, so zero is placed on the wire. Both of these values are meaningless. This fix can be applied immediately to stable kernels. Once there are more regression tests in this area, this optimization can be attempted again. Fixes: 428a23d2bf0c ("nfsd: skip some unnecessary stats in the v4 case") Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-01-08NFSD: Trace boot verifier resetsChuck Lever2-3/+38
According to commit bbf2f098838a ("nfsd: Reset the boot verifier on all write I/O errors"), the Linux NFS server forces all clients to resend pending unstable writes if any server-side write or commit operation encounters an error (say, ENOSPC). This is a rare and quite exceptional event that could require administrative recovery action, so it should be made trace-able. Example trace event: nfsd-938 [002] 7174.945558: nfsd_writeverf_reset: boot_time= 61cc920d xid=0xdcd62036 error=-28 new verifier=0x08aecc6142515904 Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-01-08NFSD: Rename boot verifier functionsChuck Lever5-20/+20
Clean up: These functions handle what the specs call a write verifier, which in the Linux NFS server implementation is now divorced from the server's boot instance Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-01-08NFSD: Clean up the nfsd_net::nfssvc_boot fieldChuck Lever3-17/+45
There are two boot-time fields in struct nfsd_net: one called boot_time and one called nfssvc_boot. The latter is used only to form write verifiers, but its documenting comment declares: /* Time of server startup */ Since commit 27c438f53e79 ("nfsd: Support the server resetting the boot verifier"), this field can be reset at any time; it's no longer tied to server restart. So that comment is stale. Also, according to pahole, struct timespec64 is 16 bytes long on x86_64. The nfssvc_boot field is used only to form a write verifier, which is 8 bytes long. Let's clarify this situation by manufacturing an 8-byte verifier in nfs_reset_boot_verifier() and storing only that in struct nfsd_net. We're grabbing 128 bits of time, so compress all of those into a 64-bit verifier instead of throwing out the high-order bits. In the future, the siphash_key can be re-used for other hashed objects per-nfsd_net. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-01-08NFSD: Write verifier might go backwardsChuck Lever1-1/+1
When vfs_iter_write() starts to fail because a file system is full, a bunch of writes can fail at once with ENOSPC. These writes repeatedly invoke nfsd_reset_boot_verifier() in quick succession. Ensure that the time it grabs doesn't go backwards due to an ntp adjustment going on at the same time. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-01-08nfsd: Add a tracepoint for errors in nfsd4_clone_file_range()Trond Myklebust4-4/+69
Since a clone error commit can cause the boot verifier to change, we should trace those errors. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> [ cel: Addressed a checkpatch.pl splat in fs/nfsd/vfs.h ]
2022-01-08NFSD: De-duplicate net_generic(nf->nf_net, nfsd_net_id)Chuck Lever1-6/+5
Since this pointer is used repeatedly, move it to a stack variable. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-01-08NFSD: De-duplicate net_generic(SVC_NET(rqstp), nfsd_net_id)Chuck Lever1-7/+4
Since this pointer is used repeatedly, move it to a stack variable. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-01-08NFSD: Clean up nfsd_vfs_write()Chuck Lever1-16/+5
The RWF_SYNC and !RWF_SYNC arms are now exactly alike except that the RWF_SYNC arm resets the boot verifier twice in a row. Fix that redundancy and de-duplicate the code. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-01-08nfsd: Replace use of rwsem with errseq_tTrond Myklebust4-34/+24
The nfsd_file nf_rwsem is currently being used to separate file write and commit instances to ensure that we catch errors and apply them to the correct write/commit. We can improve scalability at the expense of a little accuracy (some extra false positives) by replacing the nf_rwsem with more careful use of the errseq_t mechanism to track errors across the different operations. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> [ cel: rebased on zero-verifier fix ]
2022-01-08NFSD: Fix verifier returned in stable WRITEsChuck Lever1-0/+4
RFC 8881 explains the purpose of the write verifier this way: > The final portion of the result is the field writeverf. This field > is the write verifier and is a cookie that the client can use to > determine whether a server has changed instance state (e.g., server > restart) between a call to WRITE and a subsequent call to either > WRITE or COMMIT. But then it says: > This cookie MUST be unchanged during a single instance of the > NFSv4.1 server and MUST be unique between instances of the NFSv4.1 > server. If the cookie changes, then the client MUST assume that > any data written with an UNSTABLE4 value for committed and an old > writeverf in the reply has been lost and will need to be > recovered. RFC 1813 has similar language for NFSv3. NFSv2 does not have a write verifier since it doesn't implement the COMMIT procedure. Since commit 19e0663ff9bc ("nfsd: Ensure sampling of the write verifier is atomic with the write"), the Linux NFS server has returned a boot-time-based verifier for UNSTABLE WRITEs, but a zero verifier for FILE_SYNC and DATA_SYNC WRITEs. FILE_SYNC and DATA_SYNC WRITEs are not followed up with a COMMIT, so there's no need for clients to compare verifiers for stable writes. However, by returning a different verifier for stable and unstable writes, the above commit puts the Linux NFS server a step farther out of compliance with the first MUST above. At least one NFS client (FreeBSD) noticed the difference, making this a potential regression. Reported-by: Rick Macklem <rmacklem@uoguelph.ca> Link: https://lore.kernel.org/linux-nfs/YQXPR0101MB096857EEACF04A6DF1FC6D9BDD749@YQXPR0101MB0968.CANPRD01.PROD.OUTLOOK.COM/T/ Fixes: 19e0663ff9bc ("nfsd: Ensure sampling of the write verifier is atomic with the write") Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-01-08nfsd: Retry once in nfsd_open on an -EOPENSTALE returnJeff Layton2-1/+10
If we get back -EOPENSTALE from an NFSv4 open, then we either got some unhandled error or the inode we got back was not the same as the one associated with the dentry. We really have no recourse in that situation other than to retry the open, and if it fails to just return nfserr_stale back to the client. Signed-off-by: Jeff Layton <jeff.layton@primarydata.com> Signed-off-by: Lance Shelton <lance.shelton@hammerspace.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-01-08nfsd: Add errno mapping for EREMOTEIOJeff Layton1-0/+1
The NFS client can occasionally return EREMOTEIO when signalling issues with the server. ...map to NFSERR_IO. Signed-off-by: Jeff Layton <jeff.layton@primarydata.com> Signed-off-by: Lance Shelton <lance.shelton@hammerspace.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-01-08nfsd: map EBADFPeng Tao1-0/+1
Now that we have open file cache, it is possible that another client deletes the file and DP will not know about it. Then IO to MDS would fail with BADSTATEID and knfsd would start state recovery, which should fail as well and then nfs read/write will fail with EBADF. And it triggers a WARN() in nfserrno(). -----------[ cut here ]------------ WARNING: CPU: 0 PID: 13529 at fs/nfsd/nfsproc.c:758 nfserrno+0x58/0x70 [nfsd]() nfsd: non-standard errno: -9 modules linked in: nfsv3 nfs_layout_flexfiles rpcsec_gss_krb5 nfsv4 dns_resolver nfs fscache ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 xt_connt pata_acpi floppy CPU: 0 PID: 13529 Comm: nfsd Tainted: G W 4.1.5-00307-g6e6579b #7 Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 09/30/2014 0000000000000000 00000000464e6c9c ffff88079085fba8 ffffffff81789936 0000000000000000 ffff88079085fc00 ffff88079085fbe8 ffffffff810a08ea ffff88079085fbe8 ffff88080f45c900 ffff88080f627d50 ffff880790c46a48 all Trace: [<ffffffff81789936>] dump_stack+0x45/0x57 [<ffffffff810a08ea>] warn_slowpath_common+0x8a/0xc0 [<ffffffff810a0975>] warn_slowpath_fmt+0x55/0x70 [<ffffffff81252908>] ? splice_direct_to_actor+0x148/0x230 [<ffffffffa02fb8c0>] ? fsid_source+0x60/0x60 [nfsd] [<ffffffffa02f9918>] nfserrno+0x58/0x70 [nfsd] [<ffffffffa02fba57>] nfsd_finish_read+0x97/0xb0 [nfsd] [<ffffffffa02fc7a6>] nfsd_splice_read+0x76/0xa0 [nfsd] [<ffffffffa02fcca1>] nfsd_read+0xc1/0xd0 [nfsd] [<ffffffffa0233af2>] ? svc_tcp_adjust_wspace+0x12/0x30 [sunrpc] [<ffffffffa03073da>] nfsd3_proc_read+0xba/0x150 [nfsd] [<ffffffffa02f7a03>] nfsd_dispatch+0xc3/0x210 [nfsd] [<ffffffffa0233af2>] ? svc_tcp_adjust_wspace+0x12/0x30 [sunrpc] [<ffffffffa0232913>] svc_process_common+0x453/0x6f0 [sunrpc] [<ffffffffa0232cc3>] svc_process+0x113/0x1b0 [sunrpc] [<ffffffffa02f740f>] nfsd+0xff/0x170 [nfsd] [<ffffffffa02f7310>] ? nfsd_destroy+0x80/0x80 [nfsd] [<ffffffff810bf3a8>] kthread+0xd8/0xf0 [<ffffffff810bf2d0>] ? kthread_create_on_node+0x1b0/0x1b0 [<ffffffff817912a2>] ret_from_fork+0x42/0x70 [<ffffffff810bf2d0>] ? kthread_create_on_node+0x1b0/0x1b0 Signed-off-by: Peng Tao <tao.peng@primarydata.com> Signed-off-by: Lance Shelton <lance.shelton@hammerspace.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-01-08NFSD: Fix zero-length NFSv3 WRITEsChuck Lever2-10/+1
The Linux NFS server currently responds to a zero-length NFSv3 WRITE request with NFS3ERR_IO. It responds to a zero-length NFSv4 WRITE with NFS4_OK and count of zero. RFC 1813 says of the WRITE procedure's @count argument: count The number of bytes of data to be written. If count is 0, the WRITE will succeed and return a count of 0, barring errors due to permissions checking. RFC 8881 has similar language for NFSv4, though NFSv4 removed the explicit @count argument because that value is already contained in the opaque payload array. The synthetic client pynfs's WRT4 and WRT15 tests do emit zero- length WRITEs to exercise this spec requirement. Commit fdec6114ee1f ("nfsd4: zero-length WRITE should succeed") addressed the same problem there with the same fix. But interestingly the Linux NFS client does not appear to emit zero- length WRITEs, instead squelching them. I'm not aware of a test that can generate such WRITEs for NFSv3, so I wrote a naive C program to generate a zero-length WRITE and test this fix. Fixes: 8154ef2776aa ("NFSD: Clean up legacy NFS WRITE argument XDR decoders") Reported-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Cc: stable@vger.kernel.org Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-01-08nfsd4: add refcount for nfsd4_blocked_lockVasily Averin2-3/+23
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 Fields1-6/+12
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: De-duplicate nfsd4_decode_bitmap4()Chuck Lever1-14/+3
Clean up. Trond points out that xdr_stream_decode_uint32_array() does the same thing as nfsd4_decode_bitmap4(). Suggested-by: Trond Myklebust <trondmy@hammerspace.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-01-08nfsd: improve stateid access bitmask documentationJ. Bruce Fields2-4/+14
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>
2022-01-08NFSD: Combine XDR error tracepointsChuck Lever1-21/+7
Clean up: The garbage_args and cant_encode tracepoints report the same information as each other, so combine them into a single tracepoint class to reduce code duplication and slightly reduce the size of trace.o. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-19NFSD: Fix READDIR buffer overflowChuck Lever2-11/+8
If a client sends a READDIR count argument that is too small (say, zero), then the buffer size calculation in the new init_dirlist helper functions results in an underflow, allowing the XDR stream functions to write beyond the actual buffer. This calculation has always been suspect. NFSD has never sanity- checked the READDIR count argument, but the old entry encoders managed the problem correctly. With the commits below, entry encoding changed, exposing the underflow to the pointer arithmetic in xdr_reserve_space(). Modern NFS clients attempt to retrieve as much data as possible for each READDIR request. Also, we have no unit tests that exercise the behavior of READDIR at the lower bound of @count values. Thus this case was missed during testing. Reported-by: Anatoly Trosinenko <anatoly.trosinenko@gmail.com> Fixes: f5dcccd647da ("NFSD: Update the NFSv2 READDIR entry encoder to use struct xdr_stream") Fixes: 7f87fc2d34d4 ("NFSD: Update NFSv3 READDIR entry encoders to use struct xdr_stream") Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13NFSD: simplify per-net file cache managementNeilBrown2-61/+17
We currently have a 'laundrette' for closing cached files - a different work-item for each network-namespace. These 'laundrettes' (aka struct nfsd_fcache_disposal) are currently on a list, and are freed using rcu. The list is not necessary as we have a per-namespace structure (struct nfsd_net) which can hold a link to the nfsd_fcache_disposal. The use of kfree_rcu is also unnecessary as the cache is cleaned of all files associated with a given namespace, and no new files can be added, before the nfsd_fcache_disposal is freed. So add a '->fcache_disposal' link to nfsd_net, and discard the list management and rcu usage. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13NFSD: Fix inconsistent indentingJiapeng Chong1-2/+2
Eliminate the follow smatch warning: fs/nfsd/nfs4xdr.c:4766 nfsd4_encode_read_plus_hole() warn: inconsistent indenting. Reported-by: Abaci Robot <abaci@linux.alibaba.com> Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13NFSD: Remove be32_to_cpu() from DRC hash functionChuck Lever1-1/+1
Commit 7142b98d9fd7 ("nfsd: Clean up drc cache in preparation for global spinlock elimination"), billed as a clean-up, added be32_to_cpu() to the DRC hash function without explanation. That commit removed two comments that state that byte-swapping in the hash function is unnecessary without explaining whether there was a need for that change. On some Intel CPUs, the swab32 instruction is known to cause a CPU pipeline stall. be32_to_cpu() does not add extra randomness, since the hash multiplication is done /before/ shifting to the high-order bits of the result. As a micro-optimization, remove the unnecessary transform from the DRC hash function. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13NFSD: simplify locking for network notifier.NeilBrown3-23/+20
nfsd currently maintains an open-coded read/write semaphore (refcount and wait queue) for each network namespace to ensure the nfs service isn't shut down while the notifier is running. This is excessive. As there is unlikely to be contention between notifiers and they run without sleeping, a single spinlock is sufficient to avoid problems. Signed-off-by: NeilBrown <neilb@suse.de> [ cel: ensure nfsd_notifier_lock is static ] Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13SUNRPC: discard svo_setup and rename svc_set_num_threads_sync()NeilBrown1-6/+5
The ->svo_setup callback serves no purpose. It is always called from within the same module that chooses which callback is needed. So discard it and call the relevant function directly. Now that svc_set_num_threads() is no longer used remove it and rename svc_set_num_threads_sync() to remove the "_sync" suffix. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13NFSD: Make it possible to use svc_set_num_threads_syncNeilBrown2-24/+20
nfsd cannot currently use svc_set_num_threads_sync. It instead uses svc_set_num_threads which does *not* wait for threads to all exit, and has a separate mechanism (nfsd_shutdown_complete) to wait for completion. The reason that nfsd is unlike other services is that nfsd threads can exit separately from svc_set_num_threads being called - they die on receipt of SIGKILL. Also, when the last thread exits, the service must be shut down (sockets closed). For this, the nfsd_mutex needs to be taken, and as that mutex needs to be held while svc_set_num_threads is called, the one cannot wait for the other. This patch changes the nfsd thread so that it can drop the ref on the service without blocking on nfsd_mutex, so that svc_set_num_threads_sync can be used: - if it can drop a non-last reference, it does that. This does not trigger shutdown and does not require a mutex. This will likely happen for all but the last thread signalled, and for all threads being shut down by nfsd_shutdown_threads() - if it can get the mutex without blocking (trylock), it does that and then drops the reference. This will likely happen for the last thread killed by SIGKILL - Otherwise there might be an unrelated task holding the mutex, possibly in another network namespace, or nfsd_shutdown_threads() might be just about to get a reference on the service, after which we can drop ours safely. We cannot conveniently get wakeup notifications on these events, and we are unlikely to need to, so we sleep briefly and check again. With this we can discard nfsd_shutdown_complete and nfsd_complete_shutdown(), and switch to svc_set_num_threads_sync. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13NFSD: narrow nfsd_mutex protection in nfsd threadNeilBrown1-6/+2
There is nothing happening in the start of nfsd() that requires protection by the mutex, so don't take it until shutting down the thread - which does still require protection - but only for nfsd_put(). Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13SUNRPC: use sv_lock to protect updates to sv_nrthreads.NeilBrown1-3/+2
Using sv_lock means we don't need to hold the service mutex over these updates. In particular, svc_exit_thread() no longer requires synchronisation, so threads can exit asynchronously. Note that we could use an atomic_t, but as there are many more read sites than writes, that would add unnecessary noise to the code. Some reads are already racy, and there is no need for them to not be. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13nfsd: make nfsd_stats.th_cnt atomic_tNeilBrown3-7/+5
This allows us to move the updates for th_cnt out of the mutex. This is a step towards reducing mutex coverage in nfsd(). Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13SUNRPC: stop using ->sv_nrthreads as a refcountNeilBrown3-28/+43
The use of sv_nrthreads as a general refcount results in clumsy code, as is seen by various comments needed to explain the situation. This patch introduces a 'struct kref' and uses that for reference counting, leaving sv_nrthreads to be a pure count of threads. The kref is managed particularly in svc_get() and svc_put(), and also nfsd_put(); svc_destroy() now takes a pointer to the embedded kref, rather than to the serv. nfsd allows the svc_serv to exist with ->sv_nrhtreads being zero. This happens when a transport is created before the first thread is started. To support this, a 'keep_active' flag is introduced which holds a ref on the svc_serv. This is set when any listening socket is successfully added (unless there are running threads), and cleared when the number of threads is set. So when the last thread exits, the nfs_serv will be destroyed. The use of 'keep_active' replaces previous code which checked if there were any permanent sockets. We no longer clear ->rq_server when nfsd() exits. This was done to prevent svc_exit_thread() from calling svc_destroy(). Instead we take an extra reference to the svc_serv to prevent svc_destroy() from being called. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13SUNRPC/NFSD: clean up get/put functions.NeilBrown3-17/+19
svc_destroy() is poorly named - it doesn't necessarily destroy the svc, it might just reduce the ref count. nfsd_destroy() is poorly named for the same reason. This patch: - removes the refcount functionality from svc_destroy(), moving it to a new svc_put(). Almost all previous callers of svc_destroy() now call svc_put(). - renames nfsd_destroy() to nfsd_put() and improves the code, using the new svc_destroy() rather than svc_put() - removes a few comments that explain the important for balanced get/put calls. This should be obvious. The only non-trivial part of this is that svc_destroy() would call svc_sock_update() on a non-final decrement. It can no longer do that, and svc_put() isn't really a good place of it. This call is now made from svc_exit_thread() which seems like a good place. This makes the call *before* sv_nrthreads is decremented rather than after. This is not particularly important as the call just sets a flag which causes sv_nrthreads set be checked later. A subsequent patch will improve the ordering. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13NFSD: handle errors better in write_ports_addfd()NeilBrown1-1/+1
If write_ports_add() fails, we shouldn't destroy the serv, unless we had only just created it. So if there are any permanent sockets already attached, leave the serv in place. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13NFSD: Fix sparse warningChuck Lever1-1/+1
/home/cel/src/linux/linux/fs/nfsd/nfs4proc.c:1539:24: warning: incorrect type in assignment (different base types) /home/cel/src/linux/linux/fs/nfsd/nfs4proc.c:1539:24: expected restricted __be32 [usertype] status /home/cel/src/linux/linux/fs/nfsd/nfs4proc.c:1539:24: got int Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13exit: Rename module_put_and_exit to module_put_and_kthread_exitEric W. Biederman1-1/+1
Update module_put_and_exit to call kthread_exit instead of do_exit. Change the name to reflect this change in functionality. All of the users of module_put_and_exit are causing the current kthread to exit so this change makes it clear what is happening. There is no functional change. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2021-12-10nfsd: fix use-after-free due to delegation raceJ. Bruce Fields1-2/+7
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>
2021-12-10nfsd: Fix nsfd startup race (again)Alexander Sverdlin2-7/+8
Commit bd5ae9288d64 ("nfsd: register pernet ops last, unregister first") has re-opened rpc_pipefs_event() race against nfsd_net_id registration (register_pernet_subsys()) which has been fixed by commit bb7ffbf29e76 ("nfsd: fix nsfd startup race triggering BUG_ON"). Restore the order of register_pernet_subsys() vs register_cld_notifier(). Add WARN_ON() to prevent a future regression. Crash info: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000012 CPU: 8 PID: 345 Comm: mount Not tainted 5.4.144-... #1 pc : rpc_pipefs_event+0x54/0x120 [nfsd] lr : rpc_pipefs_event+0x48/0x120 [nfsd] Call trace: rpc_pipefs_event+0x54/0x120 [nfsd] blocking_notifier_call_chain rpc_fill_super get_tree_keyed rpc_fs_get_tree vfs_get_tree do_mount ksys_mount __arm64_sys_mount el0_svc_handler el0_svc Fixes: bd5ae9288d64 ("nfsd: register pernet ops last, unregister first") Cc: stable@vger.kernel.org Signed-off-by: Alexander Sverdlin <alexander.sverdlin@nokia.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2021-12-03fs: add is_idmapped_mnt() helperChristian Brauner1-1/+1
Multiple places open-code the same check to determine whether a given mount is idmapped. Introduce a simple helper function that can be used instead. This allows us to get rid of the fragile open-coding. We will later change the check that is used to determine whether a given mount is idmapped. Introducing a helper allows us to do this in a single place instead of doing it for multiple places. Link: https://lore.kernel.org/r/20211123114227.3124056-2-brauner@kernel.org (v1) Link: https://lore.kernel.org/r/20211130121032.3753852-2-brauner@kernel.org (v2) Link: https://lore.kernel.org/r/20211203111707.3901969-2-brauner@kernel.org Cc: Seth Forshee <sforshee@digitalocean.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Al Viro <viro@zeniv.linux.org.uk> CC: linux-fsdevel@vger.kernel.org Reviewed-by: Amir Goldstein <amir73il@gmail.com> Reviewed-by: Seth Forshee <sforshee@digitalocean.com> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2021-11-17Merge tag 'nfsd-5.16-1' of git://linux-nfs.org/~bfields/linuxLinus Torvalds1-5/+2
Pull nfsd bugfix from Bruce Fields: "This is just one bugfix for a buffer overflow in knfsd's xdr decoding" * tag 'nfsd-5.16-1' of git://linux-nfs.org/~bfields/linux: NFSD: Fix exposure in nfsd4_decode_bitmap()
2021-11-15NFSD: Fix exposure in nfsd4_decode_bitmap()Chuck Lever1-5/+2
rtm@csail.mit.edu reports: > nfsd4_decode_bitmap4() will write beyond bmval[bmlen-1] if the RPC > directs it to do so. This can cause nfsd4_decode_state_protect4_a() > to write client-supplied data beyond the end of > nfsd4_exchange_id.spo_must_allow[] when called by > nfsd4_decode_exchange_id(). Rewrite the loops so nfsd4_decode_bitmap() cannot iterate beyond @bmlen. Reported by: rtm@csail.mit.edu Fixes: d1c263a031e8 ("NFSD: Replace READ* macros in nfsd4_decode_fattr()") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2021-11-11Merge tag 'nfsd-5.16' of git://linux-nfs.org/~bfields/linuxLinus Torvalds22-607/+539
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 ...
2021-11-11Merge tag 'nfs-for-5.16-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfsLinus Torvalds1-0/+1
Pull NFS client updates from Trond Myklebust: "Highlights include: Features: - NFSv4.1 can always retrieve and cache the ACCESS mode on OPEN - Optimisations for READDIR and the 'ls -l' style workload - Further replacements of dprintk() with tracepoints and other tracing improvements - Ensure we re-probe NFSv4 server capabilities when the user does a "mount -o remount" Bugfixes: - Fix an Oops in pnfs_mark_request_commit() - Fix up deadlocks in the commit code - Fix regressions in NFSv2/v3 attribute revalidation due to the change_attr_type optimisations - Fix some dentry verifier races - Fix some missing dentry verifier settings - Fix a performance regression in nfs_set_open_stateid_locked() - SUNRPC was sending multiple SYN calls when re-establishing a TCP connection. - Fix multiple NFSv4 issues due to missing sanity checking of server return values - Fix a potential Oops when FREE_STATEID races with an unmount Cleanups: - Clean up the labelled NFS code - Remove unused header <linux/pnfs_osd_xdr.h>" * tag 'nfs-for-5.16-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (84 commits) NFSv4: Sanity check the parameters in nfs41_update_target_slotid() NFS: Remove the nfs4_label argument from decode_getattr_*() functions NFS: Remove the nfs4_label argument from nfs_setsecurity NFS: Remove the nfs4_label argument from nfs_fhget() NFS: Remove the nfs4_label argument from nfs_add_or_obtain() NFS: Remove the nfs4_label argument from nfs_instantiate() NFS: Remove the nfs4_label from the nfs_setattrres NFS: Remove the nfs4_label from the nfs4_getattr_res NFS: Remove the f_label from the nfs4_opendata and nfs_openres NFS: Remove the nfs4_label from the nfs4_lookupp_res struct NFS: Remove the label from the nfs4_lookup_res struct NFS: Remove the nfs4_label from the nfs4_link_res struct NFS: Remove the nfs4_label from the nfs4_create_res struct NFS: Remove the nfs4_label from the nfs_entry struct NFS: Create a new nfs_alloc_fattr_with_label() function NFS: Always initialise fattr->label in nfs_fattr_alloc() NFSv4.2: alloc_file_pseudo() takes an open flag, not an f_mode NFS: Don't allocate nfs_fattr on the stack in __nfs42_ssc_open() NFSv4: Remove unnecessary 'minor version' check NFSv4: Fix potential Oops in decode_op_map() ...
2021-11-07Merge tag 'fsnotify_for_v5.16-rc1' of ↵Linus Torvalds1-0/+3
git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs Pull fsnotify updates from Jan Kara: "Support for reporting filesystem errors through fanotify so that system health monitoring daemons can watch for these and act instead of scraping system logs" * tag 'fsnotify_for_v5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs: (34 commits) samples: remove duplicate include in fs-monitor.c samples: Fix warning in fsnotify sample docs: Fix formatting of literal sections in fanotify docs samples: Make fs-monitor depend on libc and headers docs: Document the FAN_FS_ERROR event samples: Add fs error monitoring example ext4: Send notifications on error fanotify: Allow users to request FAN_FS_ERROR events fanotify: Emit generic error info for error event fanotify: Report fid info for file related file system errors fanotify: WARN_ON against too large file handles fanotify: Add helpers to decide whether to report FID/DFID fanotify: Wrap object_fh inline space in a creator macro fanotify: Support merging of error events fanotify: Support enqueueing of error events fanotify: Pre-allocate pool of error events fanotify: Reserve UAPI bits for FAN_FS_ERROR fsnotify: Support FS_ERROR event type fanotify: Require fid_mode for any non-fd event fanotify: Encode empty file handle when no inode is provided ...
2021-11-02NFS: Move NFS protocol display macros to global headerChuck Lever1-0/+1
Refactor: surface useful show_ macros so they can be shared between the client and server trace code. Additional clean up: - Housekeeping: ensure the correct #include files are pulled in and add proper TRACE_DEFINE_ENUM where they are missing - Use a consistent naming scheme for the helpers - Store values to be displayed symbolically as unsigned long, as that is the type that the __print_yada() functions take Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2021-11-02nfsd4: remove obselete commentJ. Bruce Fields1-3/+0
Mandatory locking has been removed. And the rest of this comment is redundant with the code. Reported-by: Jeff layton <jlayton@kernel.org> Signed-off-by: J. Bruce Fields <bfields@redhat.com>