Pull vfs atomic_open updates from Christian Brauner:
"Allow knfsd to use atomic_open()
While knfsd offers combined exclusive create and open results to
clients, on some filesystems those results are not atomic. The
separate vfs_create() + vfs_open() sequence in dentry_create() can
produce races and unexpected errors. For example, open O_CREAT with
mode 0 will succeed in creating the file but return -EACCES from
vfs_open(). Additionally, network filesystems benefit from reducing
remote round-trip operations by using a single atomic_open() call.
Teach dentry_create() -- whose sole caller is knfsd -- to use
atomic_open() for filesystems that support it"
* tag 'vfs-7.0-rc1.atomic_open' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
fs/namei: fix kernel-doc markup for dentry_create
VFS/knfsd: Teach dentry_create() to use atomic_open()
VFS: Prepare atomic_open() for dentry_create()
VFS: move dentry_create() from fs/open.c to fs/namei.c
Pull nfsd fixes from Chuck Lever:
"A set of NFSD fixes for stable that arrived after the merge window:
- Remove an invalid NFS status code
- Fix an fstests failure when using pNFS
- Fix a UAF in v4_end_grace()
- Fix the administrative interface used to revoke NFSv4 state
- Fix a memory leak reported by syzbot"
* tag 'nfsd-6.19-3' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux:
NFSD: net ref data still needs to be freed even if net hasn't startup
nfsd: check that server is running in unlock_filesystem
nfsd: use correct loop termination in nfsd4_revoke_states()
nfsd: provide locking for v4_end_grace
NFSD: Fix permission check for read access to executable-only files
NFSD: Remove NFSERR_EAGAIN
I haven't found an NFSERR_EAGAIN in RFCs 1094, 1813, 7530, or 8881.
None of these RFCs have an NFS status code that match the numeric
value "11".
Based on the meaning of the EAGAIN errno, I presume the use of this
status in NFSD means NFS4ERR_DELAY. So replace the one usage of
nfserr_eagain, and remove it from NFSD's NFS status conversion
tables.
As far as I can tell, NFSERR_EAGAIN has existed since the pre-git
era, but was not actually used by any code until commit f4e44b3933
("NFSD: delay unmount source's export after inter-server copy
completed."), at which time it become possible for NFSD to return
a status code of 11 (which is not valid NFS protocol).
Fixes: f4e44b3933 ("NFSD: delay unmount source's export after inter-server copy completed.")
Cc: stable@vger.kernel.org
Reviewed-by: NeilBrown <neil@brown.name>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
While knfsd offers combined exclusive create and open results to clients,
on some filesystems those results may not be atomic. This behavior can be
observed. For example, an open O_CREAT with mode 0 will succeed in creating
the file but unexpectedly return -EACCES from vfs_open().
Additionally reducing the number of remote RPC calls required for O_CREAT
on network filesystem provides a performance benefit in the open path.
Teach knfsd's helper dentry_create() to use atomic_open() for filesystems
that support it. The previously const @path is passed up to atomic_open()
and may be modified depending on whether an existing entry was found or if
the atomic_open() returned an error and consumed the passed-in dentry.
Signed-off-by: Benjamin Coddington <bcodding@hammerspace.com>
Link: https://patch.msgid.link/8e449bfb64ab055abb9fd82641a171531415a88c.1764259052.git.bcodding@hammerspace.com
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Pull directory locking updates from Christian Brauner:
"This contains the work to add centralized APIs for directory locking
operations.
This series is part of a larger effort to change directory operation
locking to allow multiple concurrent operations in a directory. The
ultimate goal is to lock the target dentry(s) rather than the whole
parent directory.
To help with changing the locking protocol, this series centralizes
locking and lookup in new helper functions. The helpers establish a
pattern where it is the dentry that is being locked and unlocked
(currently the lock is held on dentry->d_parent->d_inode, but that can
change in the future).
This also changes vfs_mkdir() to unlock the parent on failure, as well
as dput()ing the dentry. This allows end_creating() to only require
the target dentry (which may be IS_ERR() after vfs_mkdir()), not the
parent"
* tag 'vfs-6.19-rc1.directory.locking' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
nfsd: fix end_creating() conversion
VFS: introduce end_creating_keep()
VFS: change vfs_mkdir() to unlock on failure.
ecryptfs: use new start_creating/start_removing APIs
Add start_renaming_two_dentries()
VFS/ovl/smb: introduce start_renaming_dentry()
VFS/nfsd/ovl: introduce start_renaming() and end_renaming()
VFS: add start_creating_killable() and start_removing_killable()
VFS: introduce start_removing_dentry()
smb/server: use end_removing_noperm for for target of smb2_create_link()
VFS: introduce start_creating_noperm() and start_removing_noperm()
VFS/nfsd/cachefiles/ovl: introduce start_removing() and end_removing()
VFS/nfsd/cachefiles/ovl: add start_creating() and end_creating()
VFS: tidy up do_unlinkat()
VFS: introduce start_dirop() and end_dirop()
debugfs: rename end_creating() to debugfs_end_creating()
Pull directory delegations update from Christian Brauner:
"This contains the work for recall-only directory delegations for
knfsd.
Add support for simple, recallable-only directory delegations. This
was decided at the fall NFS Bakeathon where the NFS client and server
maintainers discussed how to merge directory delegation support.
The approach starts with recallable-only delegations for several reasons:
1. RFC8881 has gaps that are being addressed in RFC8881bis. In
particular, it requires directory position information for
CB_NOTIFY callbacks, which is difficult to implement properly
under Linux. The spec is being extended to allow that information
to be omitted.
2. Client-side support for CB_NOTIFY still lags. The client side
involves heuristics about when to request a delegation.
3. Early indication shows simple, recallable-only delegations can
help performance. Anna Schumaker mentioned seeing a multi-minute
speedup in xfstests runs with them enabled.
With these changes, userspace can also request a read lease on a
directory that will be recalled on conflicting accesses. This may be
useful for applications like Samba. Users can disable leases
altogether via the fs.leases-enable sysctl if needed.
VFS changes:
- Dedicated Type for Delegations
Introduce struct delegated_inode to track inodes that may have
delegations that need to be broken. This replaces the previous
approach of passing raw inode pointers through the delegation
breaking code paths, providing better type safety and clearer
semantics for the delegation machinery.
- Break parent directory delegations in open(..., O_CREAT) codepath
- Allow mkdir to wait for delegation break on parent
- Allow rmdir to wait for delegation break on parent
- Add try_break_deleg calls for parents to vfs_link(), vfs_rename(),
and vfs_unlink()
- Make vfs_create(), vfs_mknod(), and vfs_symlink() break delegations
on parent directory
- Clean up argument list for vfs_create()
- Expose delegation support to userland
Filelock changes:
- Make lease_alloc() take a flags argument
- Rework the __break_lease API to use flags
- Add struct delegated_inode
- Push the S_ISREG check down to ->setlease handlers
- Lift the ban on directory leases in generic_setlease
NFSD changes:
- Allow filecache to hold S_IFDIR files
- Allow DELEGRETURN on directories
- Wire up GET_DIR_DELEGATION handling
Fixes:
- Fix kernel-doc warnings in __fcntl_getlease
- Add needed headers for new struct delegation definition"
* tag 'vfs-6.19-rc1.directory.delegations' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
vfs: add needed headers for new struct delegation definition
filelock: __fcntl_getlease: fix kernel-doc warnings
vfs: expose delegation support to userland
nfsd: wire up GET_DIR_DELEGATION handling
nfsd: allow DELEGRETURN on directories
nfsd: allow filecache to hold S_IFDIR files
filelock: lift the ban on directory leases in generic_setlease
vfs: make vfs_symlink break delegations on parent dir
vfs: make vfs_mknod break delegations on parent directory
vfs: make vfs_create break delegations on parent directory
vfs: clean up argument list for vfs_create()
vfs: break parent dir delegations in open(..., O_CREAT) codepath
vfs: allow rmdir to wait for delegation break on parent
vfs: allow mkdir to wait for delegation break on parent
vfs: add try_break_deleg calls for parents to vfs_{link,rename,unlink}
filelock: push the S_ISREG check down to ->setlease handlers
filelock: add struct delegated_inode
filelock: rework the __break_lease API to use flags
filelock: make lease_alloc() take a flags argument
vfs_mkdir() already drops the reference to the dentry on failure but it
leaves the parent locked.
This complicates end_creating() which needs to unlock the parent even
though the dentry is no longer available.
If we change vfs_mkdir() to unlock on failure as well as releasing the
dentry, we can remove the "parent" arg from end_creating() and simplify
the rules for calling it.
Note that cachefiles_get_directory() can choose to substitute an error
instead of actually calling vfs_mkdir(), for fault injection. In that
case it needs to call end_creating(), just as vfs_mkdir() now does on
error.
ovl_create_real() will now unlock on error. So the conditional
end_creating() after the call is removed, and end_creating() is called
internally on error.
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Tested-by: syzbot@syzkaller.appspotmail.com
Signed-off-by: NeilBrown <neil@brown.name>
Link: https://patch.msgid.link/20251113002050.676694-15-neilb@ownmail.net
Signed-off-by: Christian Brauner <brauner@kernel.org>
start_creating() is similar to simple_start_creating() but is not so
simple.
It takes a qstr for the name, includes permission checking, and does NOT
report an error if the name already exists, returning a positive dentry
instead.
This is currently used by nfsd, cachefiles, and overlayfs.
end_creating() is called after the dentry has been used.
end_creating() drops the reference to the dentry as it is generally no
longer needed. This is exactly the first section of end_creating_path()
so that function is changed to call the new end_creating()
These calls help encapsulate locking rules so that directory locking can
be changed.
Occasionally this change means that the parent lock is held for a
shorter period of time, for example in cachefiles_commit_tmpfile().
As this function now unlocks after an unlink and before the following
lookup, it is possible that the lookup could again find a positive
dentry, so a while loop is introduced there.
In overlayfs the ovl_lookup_temp() function has ovl_tempname()
split out to be used in ovl_start_creating_temp(). The other use
of ovl_lookup_temp() is preparing for a rename. When rename handling
is updated, ovl_lookup_temp() will be removed.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: NeilBrown <neil@brown.name>
Link: https://patch.msgid.link/20251113002050.676694-5-neilb@ownmail.net
Tested-by: syzbot@syzkaller.appspotmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
Add a new routine for acquiring a read delegation on a directory. These
are recallable-only delegations with no support for CB_NOTIFY. That will
be added in a later phase.
Since the same CB_RECALL/DELEGRETURN infrastructure is used for regular
and directory delegations, a normal nfs4_delegation is used to represent
a directory delegation.
Reviewed-by: NeilBrown <neil@brown.name>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://patch.msgid.link/20251111-dir-deleg-ro-v6-16-52f3feebb2f2@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
I've found that pynfs COMP6 now leaves the connection or lease in a
strange state, which causes CLOSE9 to hang indefinitely. I've dug
into it a little, but I haven't been able to root-cause it yet.
However, I bisected to commit 48aab1606f ("NFSD: Remove the cap on
number of operations per NFSv4 COMPOUND").
Tianshuo Han also reports a potential vulnerability when decoding
an NFSv4 COMPOUND. An attacker can place an arbitrarily large op
count in the COMPOUND header, which results in:
[ 51.410584] nfsd: vmalloc error: size 1209533382144, exceeds total
pages, mode:0xdc0(GFP_KERNEL|__GFP_ZERO),
nodemask=(null),cpuset=/,mems_allowed=0
when NFSD attempts to allocate the COMPOUND op array.
Let's restore the operation-per-COMPOUND limit, but increased to 200
for now.
Reported-by: tianshuo han <hantianshuo233@gmail.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Cc: stable@vger.kernel.org
Tested-by: Tianshuo Han <hantianshuo233@gmail.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
When tracing is enabled, the trace_nfsd_read_done trace point
crashes during the pynfs read.testNoFh test.
Fixes: 15a8b55dbb ("nfsd: call op_release, even when op_func returns an error")
Cc: stable@vger.kernel.org
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
RFC 8881 Section 18.43.3 states:
> If the metadata server is in a grace period, and does not persist
> layouts and device ID to device address mappings, then it MUST
> return NFS4ERR_GRACE (see Section 8.4.2.1).
Jeff observed that this suggests the grace period check is better
done by the individual layout type implementations, because checking
for the server grace period is unnecessary for some layout types.
Suggested-by: Jeff Layton <jlayton@kernel.org>
Link: https://lore.kernel.org/linux-nfs/7h5p5ktyptyt37u6jhpbjfd5u6tg44lriqkdc7iz7czeeabrvo@ijgxz27dw4sg/T/#t
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
If the loca_reclaim field is set to TRUE, this indicates that the client
is attempting to commit changes to a layout after the restart of the
metadata server during the metadata server's recovery grace period. This
type of request may be necessary when the client has uncommitted writes
to provisionally allocated byte-ranges of a file that were sent to the
storage devices before the restart of the metadata server. See RFC 8881,
section 18.42.3.
Without this, the client is not able to increase the file size and commit
preallocated extents when the block/scsi layout server is restarted
during a write and is in a grace period. And when the grace period ends,
the client also cannot perform layoutcommit because the old layout state
becomes invalid, resulting in file corruption.
Co-developed-by: Konstantin Evtushenko <koevtushenko@yandex.com>
Signed-off-by: Konstantin Evtushenko <koevtushenko@yandex.com>
Signed-off-by: Sergey Bashirov <sergeybashirov@gmail.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
When the server is recovering from a reboot and is in a grace period,
any operation that may result in deletion or reallocation of block
extents should not be allowed. See RFC 8881, section 18.43.3.
If multiple clients write data to the same file, rebooting the server
during writing may result in file corruption. In the worst case, the
exported XFS may also become corrupted. Observed this behavior while
testing pNFS block volume setup.
Co-developed-by: Konstantin Evtushenko <koevtushenko@yandex.com>
Signed-off-by: Konstantin Evtushenko <koevtushenko@yandex.com>
Signed-off-by: Sergey Bashirov <sergeybashirov@gmail.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Commit 5304877936 ("NFSD: Fix strncpy() fortify warning") replaced
strncpy(,, sizeof(..)) with strlcpy(,, sizeof(..) - 1), but strlcpy()
already guaranteed NUL-termination of the destination buffer and
subtracting one byte potentially truncated the source string.
The incorrect size was then carried over in commit 72f78ae00a ("NFSD:
move from strlcpy with unused retval to strscpy") when switching from
strlcpy() to strscpy().
Fix this off-by-one error by using the full size of the destination
buffer again.
Cc: stable@vger.kernel.org
Fixes: 5304877936 ("NFSD: Fix strncpy() fortify warning")
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Instead of allowing the ctime to roll backward with a WRITE_ATTRS
delegation, set FMODE_NOCMTIME on the file and have it skip mtime and
ctime updates.
It is possible that the client will never send a SETATTR to set the
times before returning the delegation. Add two new bools to struct
nfs4_delegation:
dl_written: tracks whether the file has been written since the
delegation was granted. This is set in the WRITE and LAYOUTCOMMIT
handlers.
dl_setattr: tracks whether the client has sent at least one valid
mtime that can also update the ctime in a SETATTR.
When unlocking the lease for the delegation, clear FMODE_NOCMTIME. If
the file has been written, but no setattr for the delegated mtime and
ctime has been done, update the timestamps to current_time().
Suggested-by: NeilBrown <neil@brown.name>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
SETATTRs containing delegated timestamp updates are currently not being
vetted properly. Since we no longer need to compare the timestamps vs.
the current timestamps, move the vetting of delegated timestamps wholly
into nfsd.
Rename the set_cb_time() helper to nfsd4_vet_deleg_time(), and make it
non-static. Add a new vet_deleg_attrs() helper that is called from
nfsd4_setattr that uses nfsd4_vet_deleg_time() to properly validate the
all the timestamps. If the validation indicates that the update should
be skipped, unset the appropriate flags in ia_valid.
Fixes: 7e13f4f8d2 ("nfsd: handle delegated timestamps in SETATTR")
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
The data type of loca_last_write_offset is newoffset4 and is switched
on a boolean value, no_newoffset, that indicates if a previous write
occurred or not. If no_newoffset is FALSE, an offset is not given.
This means that client does not try to update the file size. Thus,
server should not try to calculate new file size and check if it fits
into the segment range. See RFC 8881, section 12.5.4.2.
Sometimes the current incorrect logic may cause clients to hang when
trying to sync an inode. If layoutcommit fails, the client marks the
inode as dirty again.
Fixes: 9cf514ccfa ("nfsd: implement pNFS operations")
Cc: stable@vger.kernel.org
Co-developed-by: Konstantin Evtushenko <koevtushenko@yandex.com>
Signed-off-by: Konstantin Evtushenko <koevtushenko@yandex.com>
Signed-off-by: Sergey Bashirov <sergeybashirov@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
When pNFS client in the block or scsi layout mode sends layoutcommit
to MDS, a variable length array of modified extents is supplied within
the request. This patch allows the server to accept such extent arrays
if they do not fit within single memory page.
The issue can be reproduced when writing to a 1GB file using FIO with
O_DIRECT, 4K block and large I/O depth without preallocation of the
file. In this case, the server returns NFSERR_BADXDR to the client.
Co-developed-by: Konstantin Evtushenko <koevtushenko@yandex.com>
Signed-off-by: Konstantin Evtushenko <koevtushenko@yandex.com>
Signed-off-by: Sergey Bashirov <sergeybashirov@gmail.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Remove dprintk in nfsd4_layoutcommit. These are not needed
in day to day usage, and the information is also available
in Wireshark when capturing NFS traffic.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sergey Bashirov <sergeybashirov@gmail.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
In the past several kernel releases, we've made NFSv4.2 async copy
reliable:
- The Linux NFS client and server now both implement and use the
NFSv4.2 OFFLOAD_STATUS operation
- The Linux NFS server keeps copy stateids around longer
- The Linux NFS client and server now both implement referring call
lists
And resilient against DoS:
- The Linux NFS server limits the number of concurrent async copy
operations
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
This limit has always been a sanity check; in nearly all cases a
large COMPOUND is a sign of a malfunctioning client. The only real
limit on COMPOUND size and complexity is the size of NFSD's send
and receive buffers.
However, there are a few cases where a large COMPOUND is sane. For
example, when a client implementation wants to walk down a long file
pathname in a single round trip.
A small risk is that now a client can construct a COMPOUND request
that can keep a single nfsd thread busy for quite some time.
Suggested-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Pull nfsd updates from Chuck Lever:
"The marquee feature for this release is that the limit on the maximum
rsize and wsize has been raised to 4MB. The default remains at 1MB,
but risk-seeking administrators now have the ability to try larger I/O
sizes with NFS clients that support them. Eventually the default
setting will be increased when we have confidence that this change
will not have negative impact.
With v6.16, NFSD now has its own debugfs file system where we can add
experimental features and make them available outside of our
development community without impacting production deployments. The
first experimental setting added is one that makes all NFS READ
operations use vfs_iter_read() instead of the NFSD splice actor. The
plan is to eventually retire the splice actor, as that will enable a
number of new capabilities such as the use of struct bio_vec from the
top to the bottom of the NFSD stack.
Jeff Layton contributed a number of observability improvements. The
use of dprintk() in a number of high-traffic code paths has been
replaced with static trace points.
This release sees the continuation of efforts to harden the NFSv4.2
COPY operation. Soon, the restriction on async COPY operations can be
lifted.
Many thanks to the contributors, reviewers, testers, and bug reporters
who participated during the v6.16 development cycle"
* tag 'nfsd-6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux: (60 commits)
xdrgen: Fix code generated for counted arrays
SUNRPC: Bump the maximum payload size for the server
NFSD: Add a "default" block size
NFSD: Remove NFSSVC_MAXBLKSIZE_V2 macro
NFSD: Remove NFSD_BUFSIZE
sunrpc: Remove the RPCSVC_MAXPAGES macro
svcrdma: Adjust the number of entries in svc_rdma_send_ctxt::sc_pages
svcrdma: Adjust the number of entries in svc_rdma_recv_ctxt::rc_pages
sunrpc: Adjust size of socket's receive page array dynamically
SUNRPC: Remove svc_rqst :: rq_vec
SUNRPC: Remove svc_fill_write_vector()
NFSD: Use rqstp->rq_bvec in nfsd_iter_write()
SUNRPC: Export xdr_buf_to_bvec()
NFSD: De-duplicate the svc_fill_write_vector() call sites
NFSD: Use rqstp->rq_bvec in nfsd_iter_read()
sunrpc: Replace the rq_bvec array with dynamically-allocated memory
sunrpc: Replace the rq_pages array with dynamically-allocated memory
sunrpc: Remove backchannel check in svc_init_buffer()
sunrpc: Add a helper to derive maxpages from sv_max_mesg
svcrdma: Reduce the number of rdma_rw contexts per-QP
...
Clean up: The documenting comment for NFSD_BUFSIZE is quite stale.
NFSD_BUFSIZE is used only for NFSv4 Reply these days; never for
NFSv2 or v3, and never for RPC Calls. Even so, the byte count
estimate does not include the size of the NFSv4 COMPOUND Reply
HEADER or the RPC auth flavor.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: NeilBrown <neil@brown.name>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
All three call sites do the same thing.
I'm struggling with this a bit, however. struct xdr_buf is an XDR
layer object and unmarshaling a WRITE payload is clearly a task
intended to be done by the proc and xdr functions, not by VFS. This
feels vaguely like a layering violation.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
There isn't a common helper for getattrs, so add these into the
protocol-specific helpers.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Observe the start of NFS READDIR operations.
The NFS READDIR's count argument can be interesting when tuning a
client's readdir behavior.
However, the count argument is not passed to nfsd_readdir(). To
properly capture the count argument, this tracepoint must appear in
each proc function before the nfsd_readdir() call.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
If the request being processed is not a v4 compound request, then
examining the cstate can have undefined results.
This patch adds a check that the rpc procedure being executed
(rq_procinfo) is the NFSPROC4_COMPOUND procedure.
Reported-by: Olga Kornievskaia <okorniev@redhat.com>
Cc: stable@vger.kernel.org
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: NeilBrown <neil@brown.name>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
It can be removed since svc_fill_write_vector already has the
same WARN_ON_ONCE.
Signed-off-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Help the client resolve the race between the reply to an
asynchronous COPY reply and the associated CB_OFFLOAD callback by
planting the session, slot, and sequence number of the COPY in the
CB_SEQUENCE contained in the CB_OFFLOAD COMPOUND.
Suggested-by: Trond Myklebust <trondmy@hammerspace.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Try not to prolong the wait for completion of a COPY or COPY_NOTIFY
operation.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Update the status of an async COPY operation when it has been
stopped. OFFLOAD_STATUS needs to indicate that the COPY is no longer
running.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
nfsd uses some VFS interfaces (such as vfs_mkdir) which take an explicit
mnt_idmap, and it passes &nop_mnt_idmap as nfsd doesn't yet support
idmapped mounts.
It also uses the lookup_one_len() family of functions which implicitly
use &nop_mnt_idmap. This mixture of implicit and explicit could be
confusing. When we eventually update nfsd to support idmap mounts it
would be best if all places which need an idmap determined from the
mount point were similar and easily found.
So this patch changes nfsd to use lookup_one(), lookup_one_unlocked(),
and lookup_one_positive_unlocked(), passing &nop_mnt_idmap.
This has the benefit of removing some uses of the lookup_one_len
functions where permission checking is actually needed. Many callers
don't care about permission checking and using these function only where
permission checking is needed is a valuable simplification.
This change requires passing the name in a qstr. Currently this is a
little clumsy, but if nfsd is changed to use qstr more broadly it will
result in a net improvement.
Signed-off-by: NeilBrown <neil@brown.name>
Link: https://lore.kernel.org/r/20250319031545.2999807-3-neil@brown.name
Signed-off-by: Christian Brauner <brauner@kernel.org>
The nfsd4_callback workqueue jobs exist to queue backchannel RPCs to
rpciod. Because they run in different workqueue contexts, the rpc_task
can run concurrently with the workqueue job itself, should it become
requeued. This is problematic as there is no locking when accessing the
fields in the nfsd4_callback.
Add a new unsigned long to nfsd4_callback and declare a new
NFSD4_CALLBACK_RUNNING flag to be set in it. When attempting to run a
workqueue job, do a test_and_set_bit() on that flag first, and don't
queue the workqueue job if it returns true. Clear NFSD4_CALLBACK_RUNNING
in nfsd41_destroy_cb().
This also gives us a more reliable mechanism for handling queueing
failures in codepaths where we have to take references under spinlocks.
We can now do the test_and_set_bit on NFSD4_CALLBACK_RUNNING first, and
only take references to the objects if that returns false.
Most of the nfsd4_run_cb() callers are converted to use this new flag or
the nfsd4_try_run_cb() wrapper. The main exception is the callback
channel probe, which has its own synchronization.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Allow SETATTR to handle delegated timestamps. This patch assumes that
only the delegation holder has the ability to set the timestamps in this
way, so we allow this only if the SETATTR stateid refers to a
*_ATTRS_DELEG delegation.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Currently the pending_async_copies count is decremented just
before a struct nfsd4_copy is destroyed. After commit aa0ebd21df
("NFSD: Add nfsd4_copy time-to-live") nfsd4_copy structures sticks
around for 10 lease periods after the COPY itself has completed,
the pending_async_copies count stays high for a long time. This
causes NFSD to avoid the use of background copy even though the
actual background copy workload might no longer be running.
In this patch, decrement pending_async_copies once async copy thread
is done processing the copy work.
Fixes: aa0ebd21df ("NFSD: Add nfsd4_copy time-to-live")
Signed-off-by: Olga Kornievskaia <okorniev@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Keep async copy state alive for a few lease cycles after the copy
completes so that OFFLOAD_STATUS returns something meaningful.
This means that NFSD's client shutdown processing needs to purge
any of this state that happens to be waiting to die.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
RFC 7862 Section 4.8 states:
> A copy offload stateid will be valid until either (A) the client
> or server restarts or (B) the client returns the resource by
> issuing an OFFLOAD_CANCEL operation or the client replies to a
> CB_OFFLOAD operation.
Instead of releasing async copy state when the CB_OFFLOAD callback
completes, now let it live until the next laundromat run after the
callback completes.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Currently __destroy_client() consults the nfs4_client's async_copies
list to determine whether there are ongoing async COPY operations.
However, NFSD now keeps copy state in that list even when the
async copy has completed, to enable OFFLOAD_STATUS to find the
COPY results for a while after the COPY has completed.
DESTROY_CLIENTID should not be blocked if the client's async_copies
list contains state for only completed copy operations.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
RFC 7862 permits callback services to respond to CB_OFFLOAD with
NFS4ERR_DELAY. Currently NFSD drops the CB_OFFLOAD in that case.
To improve the reliability of COPY offload, NFSD should rather send
another CB_OFFLOAD completion notification.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
RFC 7862 Section 4.8 states:
> A copy offload stateid will be valid until either (A) the client
> or server restarts or (B) the client returns the resource by
> issuing an OFFLOAD_CANCEL operation or the client replies to a
> CB_OFFLOAD operation.
Currently, NFSD purges the metadata for an async COPY operation as
soon as the CB_OFFLOAD callback has been sent. It does not wait even
for the client's CB_OFFLOAD response, as the paragraph above
suggests that it should.
This makes the OFFLOAD_STATUS operation ineffective during the
window between the completion of an asynchronous COPY and the
server's receipt of the corresponding CB_OFFLOAD response. This is
important if, for example, the client responds with NFS4ERR_DELAY,
or the transport is lost before the server receives the response. A
client might use OFFLOAD_STATUS to query the server about the still
pending asynchronous COPY, but NFSD will respond to OFFLOAD_STATUS
as if it had never heard of the presented copy stateid.
This patch starts to address this issue by extending the lifetime of
struct nfsd4_copy at least until the server has seen the client's
CB_OFFLOAD response, or the CB_OFFLOAD has timed out.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
nfsd4_shutdown_copy() is just this:
while ((copy = nfsd4_get_copy(clp)) != NULL)
nfsd4_stop_copy(copy);
nfsd4_get_copy() bumps @copy's reference count, preventing
nfsd4_stop_copy() from releasing @copy.
A while loop like this usually works by removing the first element
of the list, but neither nfsd4_get_copy() nor nfsd4_stop_copy()
alters the async_copies list.
Best I can tell, then, is that nfsd4_shutdown_copy() continues to
loop until other threads manage to remove all the items from this
list. The spinning loop blocks shutdown until these items are gone.
Possibly the reason we haven't seen this issue in the field is
because client_has_state() prevents __destroy_client() from calling
nfsd4_shutdown_copy() if there are any items on this list. In a
subsequent patch I plan to remove that restriction.
Fixes: e0639dc580 ("NFSD introduce async copy feature")
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Currently NFSD_MAY_BYPASS_GSS and NFSD_MAY_BYPASS_GSS_ON_ROOT do not bypass
only GSS, but bypass any method. This is a problem specially for NFS3
AUTH_NULL-only exports.
The purpose of NFSD_MAY_BYPASS_GSS_ON_ROOT is described in RFC 2623,
section 2.3.2, to allow mounting NFS2/3 GSS-only export without
authentication. So few procedures which do not expose security risk used
during mount time can be called also with AUTH_NONE or AUTH_SYS, to allow
client mount operation to finish successfully.
The problem with current implementation is that for AUTH_NULL-only exports,
the NFSD_MAY_BYPASS_GSS_ON_ROOT is active also for NFS3 AUTH_UNIX mount
attempts which confuse NFS3 clients, and make them think that AUTH_UNIX is
enabled and is working. Linux NFS3 client never switches from AUTH_UNIX to
AUTH_NONE on active mount, which makes the mount inaccessible.
Fix the NFSD_MAY_BYPASS_GSS and NFSD_MAY_BYPASS_GSS_ON_ROOT implementation
and really allow to bypass only exports which have enabled some real
authentication (GSS, TLS, or any other).
The result would be: For AUTH_NULL-only export if client attempts to do
mount with AUTH_UNIX flavor then it will receive access errors, which
instruct client that AUTH_UNIX flavor is not usable and will either try
other auth flavor (AUTH_NULL if enabled) or fails mount procedure.
Similarly if client attempt to do mount with AUTH_NULL flavor and only
AUTH_UNIX flavor is enabled then the client will receive access error.
This should fix problems with AUTH_NULL-only or AUTH_UNIX-only exports if
client attempts to mount it with other auth flavor (e.g. with AUTH_NULL for
AUTH_UNIX-only export, or with AUTH_UNIX for AUTH_NULL-only export).
Signed-off-by: Pali Rohár <pali@kernel.org>
Reviewed-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
NFSv4.1 OP_EXCHANGE_ID response from server may contain server
implementation details (domain, name and build time) in optional
nfs_impl_id4 field. Currently nfsd does not fill this field.
Send these information in NFSv4.1 OP_EXCHANGE_ID response. Fill them with
the same values as what is Linux NFSv4.1 client doing. Domain is hardcoded
to "kernel.org", name is composed in the same way as "uname -srvm" output
and build time is hardcoded to zeros.
NFSv4.1 client and server implementation fields are useful for statistic
purposes or for identifying type of clients and servers.
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Turn nfsd_compound_encode_err tracepoint into a class and add a new
nfsd_compound_op_err tracepoint.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
The error flow in nfsd4_copy() calls cleanup_async_copy(), which
already decrements nn->pending_async_copies.
Reported-by: Olga Kornievskaia <okorniev@redhat.com>
Fixes: aadc3bbea1 ("NFSD: Limit the number of concurrent async COPY operations")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Ensure the refcount and async_copies fields are initialized early.
cleanup_async_copy() will reference these fields if an error occurs
in nfsd4_copy(). If they are not correctly initialized, at the very
least, a refcount underflow occurs.
Reported-by: Olga Kornievskaia <okorniev@redhat.com>
Fixes: aadc3bbea1 ("NFSD: Limit the number of concurrent async COPY operations")
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Tested-by: Olga Kornievskaia <okorniev@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Add an nfsd_copy_async_done to record the timestamp, the final
status code, and the callback stateid of an async copy.
Rename the nfsd_copy_do_async tracepoint to match that naming
convention to make it easier to enable both of these with a
single glob.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Nothing appears to limit the number of concurrent async COPY
operations that clients can start. In addition, AFAICT each async
COPY can copy an unlimited number of 4MB chunks, so can run for a
long time. Thus IMO async COPY can become a DoS vector.
Add a restriction mechanism that bounds the number of concurrent
background COPY operations. Start simple and try to be fair -- this
patch implements a per-namespace limit.
An async COPY request that occurs while this limit is exceeded gets
NFS4ERR_DELAY. The requesting client can choose to send the request
again after a delay or fall back to a traditional read/write style
copy.
If there is need to make the mechanism more sophisticated, we can
visit that in future patches.
Cc: stable@vger.kernel.org
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
