- Fix a crash during NFS READs from certain client implementations
- Address a minor kbuild regression in v6.3
-----BEGIN PGP SIGNATURE-----
iQIzBAABCAAdFiEEKLLlsBKG3yQ88j7+M2qzM29mf5cFAmQaEJgACgkQM2qzM29m
f5ceYBAAiGHz+ISIIirg2+B5DttDL5ssPoqbgfZ16JZfBgaDduOg8oK7pbILv1nf
4ufZQRcLpJDSnzhqNXxQE/L4Vsei8+tqkbwILSqFsCBZk5ei2AYSsZMu7Ptf8X8X
Y+KZ55Bko0uTYAsglnPiEaDEGeq0ZYwfUc5/bnw7ZzXdAHhlwgjoAads6Q25A9f1
6ZuKQ6nIis/ok9q88GdLf7x51IdKrXTrkC1iYAeVTXCgR3qXPezqmPOzW44rZs0t
TMzUgDuyPgvB5eT/N+pwXoI9Bli9v1PFoXZjm2NchhJ/Iy6Gt1eEEB93J/qRSU/x
ziJLkk0jnJEPWJ0Ht5li4+60b58t2OoWCTJTr3FzHCcF5Iqr7YjenSi2U8IT84ct
EeFdqR2nZpJ4Y1wbAhTjQ2w6rw5WpaXDLHCRRdE7OF/D121n3FkSNo8DtSn+fbR8
sFDpOruZn4tjgpf3AjCR1zbyKw9baC6clhnLrW6AE6T4ht9XwfE6eCUSy48FSMzg
4IZKLcofQh2UEvlVtCvGOjtcK151eFKocsq+p6/yhYE6BM20Z3dBqhw9iBzqOAPg
0qZk60AWl9W5h7M+ovkGAZpwXv4djsdWf7LbFuYOQ0kodzXOQ/5sFQm4zC5F3I1Z
8WPPA9SkYyNiNSBUt65tca4JNw5h6x9A3scPWtuHB7Lz3fuGTnE=
=frHb
-----END PGP SIGNATURE-----
Merge tag 'nfsd-6.3-3' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux
Pull nfsd fixes from Chuck Lever:
- Fix a crash during NFS READs from certain client implementations
- Address a minor kbuild regression in v6.3
* tag 'nfsd-6.3-3' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux:
nfsd: don't replace page in rq_pages if it's a continuation of last page
NFS & NFSD: Update GSS dependencies
The splice read calls nfsd_splice_actor to put the pages containing file
data into the svc_rqst->rq_pages array. It's possible however to get a
splice result that only has a partial page at the end, if (e.g.) the
filesystem hands back a short read that doesn't cover the whole page.
nfsd_splice_actor will plop the partial page into its rq_pages array and
return. Then later, when nfsd_splice_actor is called again, the
remainder of the page may end up being filled out. At this point,
nfsd_splice_actor will put the page into the array _again_ corrupting
the reply. If this is done enough times, rq_next_page will overrun the
array and corrupt the trailing fields -- the rq_respages and
rq_next_page pointers themselves.
If we've already added the page to the array in the last pass, don't add
it to the array a second time when dealing with a splice continuation.
This was originally handled properly in nfsd_splice_actor, but commit
91e23b1c39 ("NFSD: Clean up nfsd_splice_actor()") removed the check
for it.
Fixes: 91e23b1c39 ("NFSD: Clean up nfsd_splice_actor()")
Cc: Al Viro <viro@zeniv.linux.org.uk>
Reported-by: Dario Lesca <d.lesca@solinos.it>
Tested-by: David Critch <dcritch@redhat.com>
Link: https://bugzilla.redhat.com/show_bug.cgi?id=2150630
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
- Protect NFSD writes against filesystem freezing
- Fix a potential memory leak during server shutdown
-----BEGIN PGP SIGNATURE-----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=z6NN
-----END PGP SIGNATURE-----
Merge tag 'nfsd-6.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux
Pull nfsd fixes from Chuck Lever:
- Protect NFSD writes against filesystem freezing
- Fix a potential memory leak during server shutdown
* tag 'nfsd-6.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux:
SUNRPC: Fix a server shutdown leak
NFSD: Protect against filesystem freezing
Flole observes this WARNING on occasion:
[1210423.486503] WARNING: CPU: 8 PID: 1524732 at fs/ext4/ext4_jbd2.c:75 ext4_journal_check_start+0x68/0xb0
Reported-by: <flole@flole.de>
Suggested-by: Jan Kara <jack@suse.cz>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=217123
Fixes: 73da852e38 ("nfsd: use vfs_iter_read/write")
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Two significant security enhancements are part of this release:
* NFSD's RPC header encoding and decoding, including RPCSEC GSS
and gssproxy header parsing, has been overhauled to make it
more memory-safe.
* Support for Kerberos AES-SHA2-based encryption types has been
added for both the NFS client and server. This provides a clean
path for deprecating and removing insecure encryption types
based on DES and SHA-1. AES-SHA2 is also FIPS-140 compliant, so
that NFS with Kerberos may now be used on systems with fips
enabled.
In addition to these, NFSD is now able to handle crossing into an
auto-mounted mount point on an exported NFS mount. A number of
fixes have been made to NFSD's server-side copy implementation.
RPC metrics have been converted to per-CPU variables. This helps
reduce unnecessary cross-CPU and cross-node memory bus traffic,
and significantly reduces noise when KCSAN is enabled.
-----BEGIN PGP SIGNATURE-----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=ZG/7
-----END PGP SIGNATURE-----
Merge tag 'nfsd-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux
Pull nfsd updates from Chuck Lever:
"Two significant security enhancements are part of this release:
- NFSD's RPC header encoding and decoding, including RPCSEC GSS and
gssproxy header parsing, has been overhauled to make it more
memory-safe.
- Support for Kerberos AES-SHA2-based encryption types has been added
for both the NFS client and server. This provides a clean path for
deprecating and removing insecure encryption types based on DES and
SHA-1. AES-SHA2 is also FIPS-140 compliant, so that NFS with
Kerberos may now be used on systems with fips enabled.
In addition to these, NFSD is now able to handle crossing into an
auto-mounted mount point on an exported NFS mount. A number of fixes
have been made to NFSD's server-side copy implementation.
RPC metrics have been converted to per-CPU variables. This helps
reduce unnecessary cross-CPU and cross-node memory bus traffic, and
significantly reduces noise when KCSAN is enabled"
* tag 'nfsd-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux: (121 commits)
NFSD: Clean up nfsd_symlink()
NFSD: copy the whole verifier in nfsd_copy_write_verifier
nfsd: don't fsync nfsd_files on last close
SUNRPC: Fix occasional warning when destroying gss_krb5_enctypes
nfsd: fix courtesy client with deny mode handling in nfs4_upgrade_open
NFSD: fix problems with cleanup on errors in nfsd4_copy
nfsd: fix race to check ls_layouts
nfsd: don't hand out delegation on setuid files being opened for write
SUNRPC: Remove ->xpo_secure_port()
SUNRPC: Clean up the svc_xprt_flags() macro
nfsd: remove fs/nfsd/fault_inject.c
NFSD: fix leaked reference count of nfsd4_ssc_umount_item
nfsd: clean up potential nfsd_file refcount leaks in COPY codepath
nfsd: zero out pointers after putting nfsd_files on COPY setup error
SUNRPC: Fix whitespace damage in svcauth_unix.c
nfsd: eliminate __nfs4_get_fd
nfsd: add some kerneldoc comments for stateid preprocessing functions
nfsd: eliminate find_deleg_file_locked
nfsd: don't take nfsd4_copy ref for OP_OFFLOAD_STATUS
SUNRPC: Add encryption self-tests
...
This function is only used by NFSD to cross mount points.
If a mount point is of type auto mount, follow_down() will
not uncover it. Add LOOKUP_AUTOMOUNT to the lookup flags
to have ->d_automount() called when NFSD walks down the
mount tree.
Signed-off-by: Richard Weinberger <richard@nod.at>
Reviewed-by: Ian Kent <raven@themaw.net>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Currently nfsd_mountpoint() tests for mount points using d_mountpoint(),
this works only when a mount point is already uncovered.
In our case the mount point is of type auto mount and can be coverted.
i.e. ->d_automount() was not called.
Using d_managed() nfsd_mountpoint() can test whether a mount point is
either already uncovered or can be uncovered later.
Signed-off-by: Richard Weinberger <richard@nod.at>
Reviewed-by: Ian Kent <raven@themaw.net>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Convert to struct mnt_idmap.
Last cycle we merged the necessary infrastructure in
256c8aed2b ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.
Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.
Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.
Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Convert to struct mnt_idmap.
Last cycle we merged the necessary infrastructure in
256c8aed2b ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.
Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.
Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.
Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Convert to struct mnt_idmap.
Last cycle we merged the necessary infrastructure in
256c8aed2b ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.
Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.
Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.
Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
This release introduces support for the CB_RECALL_ANY operation.
NFSD can send this operation to request that clients return any
delegations they choose. The server uses this operation to handle
low memory scenarios or indicate to a client when that client has
reached the maximum number of delegations the server supports.
The NFSv4.2 READ_PLUS operation has been simplified temporarily
whilst support for sparse files in local filesystems and the VFS is
improved.
Two major data structure fixes appear in this release:
* The nfs4_file hash table is replaced with a resizable hash table
to reduce the latency of NFSv4 OPEN operations.
* Reference counting in the NFSD filecache has been hardened against
races.
In furtherance of removing support for NFSv2 in a subsequent kernel
release, a new Kconfig option enables server-side support for NFSv2
to be left out of a kernel build.
MAINTAINERS has been updated to indicate that changes to fs/exportfs
should go through the NFSD tree.
-----BEGIN PGP SIGNATURE-----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=jNlu
-----END PGP SIGNATURE-----
Merge tag 'nfsd-6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux
Pull nfsd updates from Chuck Lever:
"This release introduces support for the CB_RECALL_ANY operation. NFSD
can send this operation to request that clients return any delegations
they choose. The server uses this operation to handle low memory
scenarios or indicate to a client when that client has reached the
maximum number of delegations the server supports.
The NFSv4.2 READ_PLUS operation has been simplified temporarily whilst
support for sparse files in local filesystems and the VFS is improved.
Two major data structure fixes appear in this release:
- The nfs4_file hash table is replaced with a resizable hash table to
reduce the latency of NFSv4 OPEN operations.
- Reference counting in the NFSD filecache has been hardened against
races.
In furtherance of removing support for NFSv2 in a subsequent kernel
release, a new Kconfig option enables server-side support for NFSv2 to
be left out of a kernel build.
MAINTAINERS has been updated to indicate that changes to fs/exportfs
should go through the NFSD tree"
* tag 'nfsd-6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux: (49 commits)
NFSD: Avoid clashing function prototypes
SUNRPC: Fix crasher in unwrap_integ_data()
SUNRPC: Make the svc_authenticate tracepoint conditional
NFSD: Use only RQ_DROPME to signal the need to drop a reply
SUNRPC: Clean up xdr_write_pages()
SUNRPC: Don't leak netobj memory when gss_read_proxy_verf() fails
NFSD: add CB_RECALL_ANY tracepoints
NFSD: add delegation reaper to react to low memory condition
NFSD: add support for sending CB_RECALL_ANY
NFSD: refactoring courtesy_client_reaper to a generic low memory shrinker
trace: Relocate event helper files
NFSD: pass range end to vfs_fsync_range() instead of count
lockd: fix file selection in nlmsvc_cancel_blocked
lockd: ensure we use the correct file descriptor when unlocking
lockd: set missing fl_flags field when retrieving args
NFSD: Use struct_size() helper in alloc_session()
nfsd: return error if nfs4_setacl fails
lockd: set other missing fields when unlocking files
NFSD: Add an nfsd_file_fsync tracepoint
sunrpc: svc: Remove an unused static function svc_ungetu32()
...
-----BEGIN PGP SIGNATURE-----
iHUEABYKAB0WIQRAhzRXHqcMeLMyaSiRxhvAZXjcogUCY5bwTgAKCRCRxhvAZXjc
ovd2AQCK00NAtGjQCjQPQGyTa4GAPqvWgq1ef0lnhv+TL5US5gD9FncQ8UofeMXt
pBfjtAD6ettTPCTxUQfnTwWEU4rc7Qg=
=27Wm
-----END PGP SIGNATURE-----
Merge tag 'fs.acl.rework.v6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/idmapping
Pull VFS acl updates from Christian Brauner:
"This contains the work that builds a dedicated vfs posix acl api.
The origins of this work trace back to v5.19 but it took quite a while
to understand the various filesystem specific implementations in
sufficient detail and also come up with an acceptable solution.
As we discussed and seen multiple times the current state of how posix
acls are handled isn't nice and comes with a lot of problems: The
current way of handling posix acls via the generic xattr api is error
prone, hard to maintain, and type unsafe for the vfs until we call
into the filesystem's dedicated get and set inode operations.
It is already the case that posix acls are special-cased to death all
the way through the vfs. There are an uncounted number of hacks that
operate on the uapi posix acl struct instead of the dedicated vfs
struct posix_acl. And the vfs must be involved in order to interpret
and fixup posix acls before storing them to the backing store, caching
them, reporting them to userspace, or for permission checking.
Currently a range of hacks and duct tape exist to make this work. As
with most things this is really no ones fault it's just something that
happened over time. But the code is hard to understand and difficult
to maintain and one is constantly at risk of introducing bugs and
regressions when having to touch it.
Instead of continuing to hack posix acls through the xattr handlers
this series builds a dedicated posix acl api solely around the get and
set inode operations.
Going forward, the vfs_get_acl(), vfs_remove_acl(), and vfs_set_acl()
helpers must be used in order to interact with posix acls. They
operate directly on the vfs internal struct posix_acl instead of
abusing the uapi posix acl struct as we currently do. In the end this
removes all of the hackiness, makes the codepaths easier to maintain,
and gets us type safety.
This series passes the LTP and xfstests suites without any
regressions. For xfstests the following combinations were tested:
- xfs
- ext4
- btrfs
- overlayfs
- overlayfs on top of idmapped mounts
- orangefs
- (limited) cifs
There's more simplifications for posix acls that we can make in the
future if the basic api has made it.
A few implementation details:
- The series makes sure to retain exactly the same security and
integrity module permission checks. Especially for the integrity
modules this api is a win because right now they convert the uapi
posix acl struct passed to them via a void pointer into the vfs
struct posix_acl format to perform permission checking on the mode.
There's a new dedicated security hook for setting posix acls which
passes the vfs struct posix_acl not a void pointer. Basing checking
on the posix acl stored in the uapi format is really unreliable.
The vfs currently hacks around directly in the uapi struct storing
values that frankly the security and integrity modules can't
correctly interpret as evidenced by bugs we reported and fixed in
this area. It's not necessarily even their fault it's just that the
format we provide to them is sub optimal.
- Some filesystems like 9p and cifs need access to the dentry in
order to get and set posix acls which is why they either only
partially or not even at all implement get and set inode
operations. For example, cifs allows setxattr() and getxattr()
operations but doesn't allow permission checking based on posix
acls because it can't implement a get acl inode operation.
Thus, this patch series updates the set acl inode operation to take
a dentry instead of an inode argument. However, for the get acl
inode operation we can't do this as the old get acl method is
called in e.g., generic_permission() and inode_permission(). These
helpers in turn are called in various filesystem's permission inode
operation. So passing a dentry argument to the old get acl inode
operation would amount to passing a dentry to the permission inode
operation which we shouldn't and probably can't do.
So instead of extending the existing inode operation Christoph
suggested to add a new one. He also requested to ensure that the
get and set acl inode operation taking a dentry are consistently
named. So for this version the old get acl operation is renamed to
->get_inode_acl() and a new ->get_acl() inode operation taking a
dentry is added. With this we can give both 9p and cifs get and set
acl inode operations and in turn remove their complex custom posix
xattr handlers.
In the future I hope to get rid of the inode method duplication but
it isn't like we have never had this situation. Readdir is just one
example. And frankly, the overall gain in type safety and the more
pleasant api wise are simply too big of a benefit to not accept
this duplication for a while.
- We've done a full audit of every codepaths using variant of the
current generic xattr api to get and set posix acls and
surprisingly it isn't that many places. There's of course always a
chance that we might have missed some and if so I'm sure we'll find
them soon enough.
The crucial codepaths to be converted are obviously stacking
filesystems such as ecryptfs and overlayfs.
For a list of all callers currently using generic xattr api helpers
see [2] including comments whether they support posix acls or not.
- The old vfs generic posix acl infrastructure doesn't obey the
create and replace semantics promised on the setxattr(2) manpage.
This patch series doesn't address this. It really is something we
should revisit later though.
The patches are roughly organized as follows:
(1) Change existing set acl inode operation to take a dentry
argument (Intended to be a non-functional change)
(2) Rename existing get acl method (Intended to be a non-functional
change)
(3) Implement get and set acl inode operations for filesystems that
couldn't implement one before because of the missing dentry.
That's mostly 9p and cifs (Intended to be a non-functional
change)
(4) Build posix acl api, i.e., add vfs_get_acl(), vfs_remove_acl(),
and vfs_set_acl() including security and integrity hooks
(Intended to be a non-functional change)
(5) Implement get and set acl inode operations for stacking
filesystems (Intended to be a non-functional change)
(6) Switch posix acl handling in stacking filesystems to new posix
acl api now that all filesystems it can stack upon support it.
(7) Switch vfs to new posix acl api (semantical change)
(8) Remove all now unused helpers
(9) Additional regression fixes reported after we merged this into
linux-next
Thanks to Seth for a lot of good discussion around this and
encouragement and input from Christoph"
* tag 'fs.acl.rework.v6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/idmapping: (36 commits)
posix_acl: Fix the type of sentinel in get_acl
orangefs: fix mode handling
ovl: call posix_acl_release() after error checking
evm: remove dead code in evm_inode_set_acl()
cifs: check whether acl is valid early
acl: make vfs_posix_acl_to_xattr() static
acl: remove a slew of now unused helpers
9p: use stub posix acl handlers
cifs: use stub posix acl handlers
ovl: use stub posix acl handlers
ecryptfs: use stub posix acl handlers
evm: remove evm_xattr_acl_change()
xattr: use posix acl api
ovl: use posix acl api
ovl: implement set acl method
ovl: implement get acl method
ecryptfs: implement set acl method
ecryptfs: implement get acl method
ksmbd: use vfs_remove_acl()
acl: add vfs_remove_acl()
...
direction misannotations and (hopefully) preventing
more of the same for the future.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
-----BEGIN PGP SIGNATURE-----
iHQEABYIAB0WIQQqUNBr3gm4hGXdBJlZ7Krx/gZQ6wUCY5ZzQAAKCRBZ7Krx/gZQ
65RZAP4nTkvOn0NZLVFkuGOx8pgJelXAvrteyAuecVL8V6CR4AD40qCVY51PJp8N
MzwiRTeqnGDxTTF7mgd//IB6hoatAA==
=bcvF
-----END PGP SIGNATURE-----
Merge tag 'pull-iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull iov_iter updates from Al Viro:
"iov_iter work; most of that is about getting rid of direction
misannotations and (hopefully) preventing more of the same for the
future"
* tag 'pull-iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
use less confusing names for iov_iter direction initializers
iov_iter: saner checks for attempt to copy to/from iterator
[xen] fix "direction" argument of iov_iter_kvec()
[vhost] fix 'direction' argument of iov_iter_{init,bvec}()
[target] fix iov_iter_bvec() "direction" argument
[s390] memcpy_real(): WRITE is "data source", not destination...
[s390] zcore: WRITE is "data source", not destination...
[infiniband] READ is "data destination", not source...
[fsi] WRITE is "data source", not destination...
[s390] copy_oldmem_kernel() - WRITE is "data source", not destination
csum_and_copy_to_iter(): handle ITER_DISCARD
get rid of unlikely() on page_copy_sane() calls
NFSv4 operations manage the lifetime of nfsd_file items they use by
means of NFSv4 OPEN and CLOSE. Hence there's no need for them to be
garbage collected.
Introduce a mechanism to enable garbage collection for nfsd_file
items used only by NFSv2/3 callers.
Note that the change in nfsd_file_put() ensures that both CLOSE and
DELEGRETURN will actually close out and free an nfsd_file on last
reference of a non-garbage-collected file.
Link: https://bugzilla.linux-nfs.org/show_bug.cgi?id=394
Suggested-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: NeilBrown <neilb@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
In a moment I'm going to introduce separate nfsd_file types, one of
which is garbage-collected; the other, not. The garbage-collected
variety is to be used by NFSv2 and v3, and the non-garbage-collected
variety is to be used by NFSv4.
nfsd_commit() is invoked by both NFSv3 and NFSv4 consumers. We want
nfsd_commit() to find and use the correct variety of cached
nfsd_file object for the NFS version that is in use.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: NeilBrown <neilb@suse.de>
nfserrno() is common to all nfs versions, but nfsproc.c is specifically
for NFSv2. Move it to vfs.c, and the prototype to vfs.h.
While we're in here, remove the #ifdef EDQUOT check in this function.
It's apparently a holdover from the initial merge of the nfsd code in
1997. No other place in the kernel checks that that symbol is defined
before using it, so I think we can dispense with it here.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Variable host_err is assigned a value that is never read, it is being
re-assigned a value in every different execution path in the following
switch statement. The assignment is redundant and can be removed.
Cleans up clang-scan warning:
warning: Value stored to 'host_err' is never read [deadcode.DeadStores]
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
- Fix rare data corruption on READ operations
-----BEGIN PGP SIGNATURE-----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=zxjk
-----END PGP SIGNATURE-----
Merge tag 'nfsd-6.1-6' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux
Pull nfsd fix from Chuck Lever:
- Fix rare data corruption on READ operations
* tag 'nfsd-6.1-6' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux:
NFSD: Fix reads with a non-zero offset that don't end on a page boundary
READ/WRITE proved to be actively confusing - the meanings are
"data destination, as used with read(2)" and "data source, as
used with write(2)", but people keep interpreting those as
"we read data from it" and "we write data to it", i.e. exactly
the wrong way.
Call them ITER_DEST and ITER_SOURCE - at least that is harder
to misinterpret...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Commit 868f9f2f8e ("vfs: fix copy_file_range() regression in cross-fs
copies") removed fallback to generic_copy_file_range() for cross-fs
cases inside vfs_copy_file_range().
To preserve behavior of nfsd and ksmbd server-side-copy, the fallback to
generic_copy_file_range() was added in nfsd and ksmbd code, but that
call is missing sb_start_write(), fsnotify hooks and more.
Ideally, nfsd and ksmbd would pass a flag to vfs_copy_file_range() that
will take care of the fallback, but that code would be subtle and we got
vfs_copy_file_range() logic wrong too many times already.
Instead, add a flag to explicitly request vfs_copy_file_range() to
perform only generic_copy_file_range() and let nfsd and ksmbd use this
flag only in the fallback path.
This choise keeps the logic changes to minimum in the non-nfsd/ksmbd code
paths to reduce the risk of further regressions.
Fixes: 868f9f2f8e ("vfs: fix copy_file_range() regression in cross-fs copies")
Tested-by: Namjae Jeon <linkinjeon@kernel.org>
Tested-by: Luis Henriques <lhenriques@suse.de>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This was found when virtual machines with nfs-mounted qcow2 disks
failed to boot properly.
Reported-by: Anders Blomdell <anders.blomdell@control.lth.se>
Suggested-by: Al Viro <viro@zeniv.linux.org.uk>
Link: https://bugzilla.redhat.com/show_bug.cgi?id=2142132
Fixes: bfbfb6182a ("nfsd_splice_actor(): handle compound pages")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
The current way of setting and getting posix acls through the generic
xattr interface is error prone and type unsafe. The vfs needs to
interpret and fixup posix acls before storing or reporting it to
userspace. Various hacks exist to make this work. The code is hard to
understand and difficult to maintain in it's current form. Instead of
making this work by hacking posix acls through xattr handlers we are
building a dedicated posix acl api around the get and set inode
operations. This removes a lot of hackiness and makes the codepaths
easier to maintain. A lot of background can be found in [1].
Since some filesystem rely on the dentry being available to them when
setting posix acls (e.g., 9p and cifs) they cannot rely on set acl inode
operation. But since ->set_acl() is required in order to use the generic
posix acl xattr handlers filesystems that do not implement this inode
operation cannot use the handler and need to implement their own
dedicated posix acl handlers.
Update the ->set_acl() inode method to take a dentry argument. This
allows all filesystems to rely on ->set_acl().
As far as I can tell all codepaths can be switched to rely on the dentry
instead of just the inode. Note that the original motivation for passing
the dentry separate from the inode instead of just the dentry in the
xattr handlers was because of security modules that call
security_d_instantiate(). This hook is called during
d_instantiate_new(), d_add(), __d_instantiate_anon(), and
d_splice_alias() to initialize the inode's security context and possibly
to set security.* xattrs. Since this only affects security.* xattrs this
is completely irrelevant for posix acls.
Link: https://lore.kernel.org/all/20220801145520.1532837-1-brauner@kernel.org [1]
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
nfsd_unlink() can kick off a CB_RECALL (via
vfs_unlink() -> leases_conflict()) if a delegation is present.
Before returning NFS4ERR_DELAY, give the client holding that
delegation a chance to return it and then retry the nfsd_unlink()
again, once.
Link: https://bugzilla.linux-nfs.org/show_bug.cgi?id=354
Tested-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
nfsd_rename() can kick off a CB_RECALL (via
vfs_rename() -> leases_conflict()) if a delegation is present.
Before returning NFS4ERR_DELAY, give the client holding that
delegation a chance to return it and then retry the nfsd_rename()
again, once.
This version of the patch handles renaming an existing file,
but does not deal with renaming onto an existing file. That
case will still always trigger an NFS4ERR_DELAY.
Link: https://bugzilla.linux-nfs.org/show_bug.cgi?id=354
Tested-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
nfsd_setattr() can kick off a CB_RECALL (via
notify_change() -> break_lease()) if a delegation is present. Before
returning NFS4ERR_DELAY, give the client holding that delegation a
chance to return it and then retry the nfsd_setattr() again, once.
Link: https://bugzilla.linux-nfs.org/show_bug.cgi?id=354
Tested-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Move code that will be retried (in a subsequent patch) into a helper
function.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
nfsd_create_locked() does not use the "fname" and "flen" arguments, so
drop them from declaration and all callers.
Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
-----BEGIN PGP SIGNATURE-----
iHUEABYIAB0WIQQqUNBr3gm4hGXdBJlZ7Krx/gZQ6wUCYx/tpQAKCRBZ7Krx/gZQ
6wuPAQCrJ18XdncE/VnpRfcpQ+UQJXryURXwijaVBswv3LpM/gEAgQcmFff7pR0P
ZXzS56F/D0faE2evltbAMQCWUoeapQA=
=mTrE
-----END PGP SIGNATURE-----
Merge tag 'pull-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull iov_iter fix from Al Viro:
"Fix for a nfsd regression caused by the iov_iter stuff this window"
* tag 'pull-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
nfsd_splice_actor(): handle compound pages
pipe_buffer might refer to a compound page (and contain more than a PAGE_SIZE
worth of data). Theoretically it had been possible since way back, but
nfsd_splice_actor() hadn't run into that until copy_page_to_iter() change.
Fortunately, the only thing that changes for compound pages is that we
need to stuff each relevant subpage in and convert the offset into offset
in the first subpage.
Acked-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Benjamin Coddington <bcodding@redhat.com>
Fixes: f0f6b614f8 "copy_page_to_iter(): don't split high-order page in case of ITER_PIPE"
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
A recent patch moved ACL setting into nfsd_setattr().
Unfortunately it didn't work as nfsd_setattr() aborts early if
iap->ia_valid is 0.
Remove this test, and instead avoid calling notify_change() when
ia_valid is 0.
This means that nfsd_setattr() will now *always* lock the inode.
Previously it didn't if only a ATTR_MODE change was requested on a
symlink (see Commit 15b7a1b86d ("[PATCH] knfsd: fix setattr-on-symlink
error return")). I don't think this change really matters.
Fixes: c0cbe70742 ("NFSD: add posix ACLs to struct nfsd_attrs")
Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
filldir_t instances (directory iterators callbacks) used to return 0 for
"OK, keep going" or -E... for "stop". Note that it's *NOT* how the
error values are reported - the rules for those are callback-dependent
and ->iterate{,_shared}() instances only care about zero vs. non-zero
(look at emit_dir() and friends).
So let's just return bool ("should we keep going?") - it's less confusing
that way. The choice between "true means keep going" and "true means
stop" is bikesheddable; we have two groups of callbacks -
do something for everything in directory, until we run into problem
and
find an entry in directory and do something to it.
The former tended to use 0/-E... conventions - -E<something> on failure.
The latter tended to use 0/1, 1 being "stop, we are done".
The callers treated anything non-zero as "stop", ignoring which
non-zero value did they get.
"true means stop" would be more natural for the second group; "true
means keep going" - for the first one. I tried both variants and
the things like
if allocation failed
something = -ENOMEM;
return true;
just looked unnatural and asking for trouble.
[folded suggestion from Matthew Wilcox <willy@infradead.org>]
Acked-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
As all inode locking is now fully balanced, fh_put() does not need to
call fh_unlock().
fh_lock() and fh_unlock() are no longer used, so discard them.
These are the only real users of ->fh_locked, so discard that too.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
When locking a file to access ACLs and xattrs etc, use explicit locking
with inode_lock() instead of fh_lock(). This means that the calls to
fh_fill_pre/post_attr() are also explicit which improves readability and
allows us to place them only where they are needed. Only the xattr
calls need pre/post information.
When locking a file we don't need I_MUTEX_PARENT as the file is not a
parent of anything, so we can use inode_lock() directly rather than the
inode_lock_nested() call that fh_lock() uses.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
When creating or unlinking a name in a directory use explicit
inode_lock_nested() instead of fh_lock(), and explicit calls to
fh_fill_pre_attrs() and fh_fill_post_attrs(). This is already done
for renames, with lock_rename() as the explicit locking.
Also move the 'fill' calls closer to the operation that might change the
attributes. This way they are avoided on some error paths.
For the v2-only code in nfsproc.c, the fill calls are not replaced as
they aren't needed.
Making the locking explicit will simplify proposed future changes to
locking for directories. It also makes it easily visible exactly where
pre/post attributes are used - not all callers of fh_lock() actually
need the pre/post attributes.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
nfsd_lookup() takes an exclusive lock on the parent inode, but no
callers want the lock and it may not be needed at all if the
result is in the dcache.
Change nfsd_lookup_dentry() to not take the lock, and call
lookup_one_len_locked() which takes lock only if needed.
nfsd4_open() currently expects the lock to still be held, but that isn't
necessary as nfsd_validate_delegated_dentry() provides required
guarantees without the lock.
NOTE: NFSv4 requires directory changeinfo for OPEN even when a create
wasn't requested and no change happened. Now that nfsd_lookup()
doesn't use fh_lock(), we need to explicitly fill the attributes
when no create happens. A new fh_fill_both_attrs() is provided
for that task.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
On non-error paths, nfsd_link() calls fh_unlock() twice. This is safe
because fh_unlock() records that the unlock has been done and doesn't
repeat it.
However it makes the code a little confusing and interferes with changes
that are planned for directory locking.
So rearrange the code to ensure fh_unlock() is called exactly once if
fh_lock() was called.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Some error paths in nfsd_unlink() allow it to exit without unlocking the
directory. This is not a problem in practice as the directory will be
locked with an fh_put(), but it is untidy and potentially confusing.
This allows us to remove all the fh_unlock() calls that are immediately
after nfsd_unlink() calls.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
nfsd_create() usually returns with the directory still locked.
nfsd_symlink() usually returns with it unlocked. This is clumsy.
Until recently nfsd_create() needed to keep the directory locked until
ACLs and security label had been set. These are now set inside
nfsd_create() (in nfsd_setattr()) so this need is gone.
So change nfsd_create() and nfsd_symlink() to always unlock, and remove
any fh_unlock() calls that follow calls to these functions.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
pacl and dpacl pointers are added to struct nfsd_attrs, which requires
that we have an nfsd_attrs_free() function to free them.
Those nfsv4 functions that can set ACLs now set up these pointers
based on the passed in NFSv4 ACL.
nfsd_setattr() sets the acls as appropriate.
Errors are handled as with security labels.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
nfsd_setattr() now sets a security label if provided, and nfsv4 provides
it in the 'open' and 'create' paths and the 'setattr' path.
If setting the label failed (including because the kernel doesn't
support labels), an error field in 'struct nfsd_attrs' is set, and the
caller can respond. The open/create callers clear
FATTR4_WORD2_SECURITY_LABEL in the returned attr set in this case.
The setattr caller returns the error.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
The NFS protocol includes attributes when creating symlinks.
Linux does store attributes for symlinks and allows them to be set,
though they are not used for permission checking.
NFSD currently doesn't set standard (struct iattr) attributes when
creating symlinks, but for NFSv4 it does set ACLs and security labels.
This is inconsistent.
To improve consistency, pass the provided attributes into nfsd_symlink()
and call nfsd_create_setattr() to set them.
NOTE: this results in a behaviour change for all NFS versions when the
client sends non-default attributes with a SYMLINK request. With the
Linux client, the only attributes are:
attr.ia_mode = S_IFLNK | S_IRWXUGO;
attr.ia_valid = ATTR_MODE;
so the final outcome will be unchanged. Other clients might sent
different attributes, and if they did they probably expect them to be
honoured.
We ignore any error from nfsd_create_setattr(). It isn't really clear
what should be done if a file is successfully created, but the
attributes cannot be set. NFS doesn't allow partial success to be
reported. Reporting failure is probably more misleading than reporting
success, so the status is ignored.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
The attributes that nfsd might want to set on a file include 'struct
iattr' as well as an ACL and security label.
The latter two are passed around quite separately from the first, in
part because they are only needed for NFSv4. This leads to some
clumsiness in the code, such as the attributes NOT being set in
nfsd_create_setattr().
We need to keep the directory locked until all attributes are set to
ensure the file is never visibile without all its attributes. This need
combined with the inconsistent handling of attributes leads to more
clumsiness.
As a first step towards tidying this up, introduce 'struct nfsd_attrs'.
This is passed (by reference) to vfs.c functions that work with
attributes, and is assembled by the various nfs*proc functions which
call them. As yet only iattr is included, but future patches will
expand this.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
A regression has been reported by Nicolas Boichat, found while using the
copy_file_range syscall to copy a tracefs file.
Before commit 5dae222a5f ("vfs: allow copy_file_range to copy across
devices") the kernel would return -EXDEV to userspace when trying to
copy a file across different filesystems. After this commit, the
syscall doesn't fail anymore and instead returns zero (zero bytes
copied), as this file's content is generated on-the-fly and thus reports
a size of zero.
Another regression has been reported by He Zhe - the assertion of
WARN_ON_ONCE(ret == -EOPNOTSUPP) can be triggered from userspace when
copying from a sysfs file whose read operation may return -EOPNOTSUPP.
Since we do not have test coverage for copy_file_range() between any two
types of filesystems, the best way to avoid these sort of issues in the
future is for the kernel to be more picky about filesystems that are
allowed to do copy_file_range().
This patch restores some cross-filesystem copy restrictions that existed
prior to commit 5dae222a5f ("vfs: allow copy_file_range to copy across
devices"), namely, cross-sb copy is not allowed for filesystems that do
not implement ->copy_file_range().
Filesystems that do implement ->copy_file_range() have full control of
the result - if this method returns an error, the error is returned to
the user. Before this change this was only true for fs that did not
implement the ->remap_file_range() operation (i.e. nfsv3).
Filesystems that do not implement ->copy_file_range() still fall-back to
the generic_copy_file_range() implementation when the copy is within the
same sb. This helps the kernel can maintain a more consistent story
about which filesystems support copy_file_range().
nfsd and ksmbd servers are modified to fall-back to the
generic_copy_file_range() implementation in case vfs_copy_file_range()
fails with -EOPNOTSUPP or -EXDEV, which preserves behavior of
server-side-copy.
fall-back to generic_copy_file_range() is not implemented for the smb
operation FSCTL_DUPLICATE_EXTENTS_TO_FILE, which is arguably a correct
change of behavior.
Fixes: 5dae222a5f ("vfs: allow copy_file_range to copy across devices")
Link: https://lore.kernel.org/linux-fsdevel/20210212044405.4120619-1-drinkcat@chromium.org/
Link: https://lore.kernel.org/linux-fsdevel/CANMq1KDZuxir2LM5jOTm0xx+BnvW=ZmpsG47CyHFJwnw7zSX6Q@mail.gmail.com/
Link: https://lore.kernel.org/linux-fsdevel/20210126135012.1.If45b7cdc3ff707bc1efa17f5366057d60603c45f@changeid/
Link: https://lore.kernel.org/linux-fsdevel/20210630161320.29006-1-lhenriques@suse.de/
Reported-by: Nicolas Boichat <drinkcat@chromium.org>
Reported-by: kernel test robot <oliver.sang@intel.com>
Signed-off-by: Luis Henriques <lhenriques@suse.de>
Fixes: 64bf5ff58d ("vfs: no fallback for ->copy_file_range")
Link: https://lore.kernel.org/linux-fsdevel/20f17f64-88cb-4e80-07c1-85cb96c83619@windriver.com/
Reported-by: He Zhe <zhe.he@windriver.com>
Tested-by: Namjae Jeon <linkinjeon@kernel.org>
Tested-by: Luis Henriques <lhenriques@suse.de>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
commit 555dbf1a9a ("nfsd: Replace use of rwsem with errseq_t")
incidentally broke translation of -EINVAL to nfserr_notsupp.
The patch restores that.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Fixes: 555dbf1a9a ("nfsd: Replace use of rwsem with errseq_t")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
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 <chuck.lever@oracle.com>
Now that its two callers have their own version-specific instance of
this function, do_nfsd_create() is no longer used.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
I'd like to move do_nfsd_create() out of vfs.c. Therefore
nfsd_create_setattr() needs to be made publicly visible.
Note that both call sites in vfs.c commit both the new object and
its parent directory, so just combine those common metadata commits
into nfsd_create_setattr().
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Clean up: The "out" label already invokes fh_drop_write().
Note that fh_drop_write() is already careful not to invoke
mnt_drop_write() if either it has already been done or there is
nothing to drop. Therefore no change in behavior is expected.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
nfsd_splice_actor() checks that the page being spliced does not
match the previous element in the svc_rqst::rq_pages array. We
believe this is to prevent a double put_page() in cases where the
READ payload is partially contained in the xdr_buf's head buffer.
However, the NFSD READ proc functions no longer place any part of
the READ payload in the head buffer, in order to properly support
NFS/RDMA READ with Write chunks. Therefore, simplify the logic in
nfsd_splice_actor() to remove this unnecessary check.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
- Rewrite how munlock works to massively reduce the contention
on i_mmap_rwsem (Hugh Dickins):
https://lore.kernel.org/linux-mm/8e4356d-9622-a7f0-b2c-f116b5f2efea@google.com/
- Sort out the page refcount mess for ZONE_DEVICE pages (Christoph Hellwig):
https://lore.kernel.org/linux-mm/20220210072828.2930359-1-hch@lst.de/
- Convert GUP to use folios and make pincount available for order-1
pages. (Matthew Wilcox)
- Convert a few more truncation functions to use folios (Matthew Wilcox)
- Convert page_vma_mapped_walk to use PFNs instead of pages (Matthew Wilcox)
- Convert rmap_walk to use folios (Matthew Wilcox)
- Convert most of shrink_page_list() to use a folio (Matthew Wilcox)
- Add support for creating large folios in readahead (Matthew Wilcox)
-----BEGIN PGP SIGNATURE-----
iQEzBAABCgAdFiEEejHryeLBw/spnjHrDpNsjXcpgj4FAmI4ucgACgkQDpNsjXcp
gj69Wgf6AwqwmO5Tmy+fLScDPqWxmXJofbocae1kyoGHf7Ui91OK4U2j6IpvAr+g
P/vLIK+JAAcTQcrSCjymuEkf4HkGZOR03QQn7maPIEe4eLrZRQDEsmHC1L9gpeJp
s/GMvDWiGE0Tnxu0EOzfVi/yT+qjIl/S8VvqtCoJv1HdzxitZ7+1RDuqImaMC5MM
Qi3uHag78vLmCltLXpIOdpgZhdZexCdL2Y/1npf+b6FVkAJRRNUnA0gRbS7YpoVp
CbxEJcmAl9cpJLuj5i5kIfS9trr+/QcvbUlzRxh4ggC58iqnmF2V09l2MJ7YU3XL
v1O/Elq4lRhXninZFQEm9zjrri7LDQ==
=n9Ad
-----END PGP SIGNATURE-----
Merge tag 'folio-5.18c' of git://git.infradead.org/users/willy/pagecache
Pull folio updates from Matthew Wilcox:
- Rewrite how munlock works to massively reduce the contention on
i_mmap_rwsem (Hugh Dickins):
https://lore.kernel.org/linux-mm/8e4356d-9622-a7f0-b2c-f116b5f2efea@google.com/
- Sort out the page refcount mess for ZONE_DEVICE pages (Christoph
Hellwig):
https://lore.kernel.org/linux-mm/20220210072828.2930359-1-hch@lst.de/
- Convert GUP to use folios and make pincount available for order-1
pages. (Matthew Wilcox)
- Convert a few more truncation functions to use folios (Matthew
Wilcox)
- Convert page_vma_mapped_walk to use PFNs instead of pages (Matthew
Wilcox)
- Convert rmap_walk to use folios (Matthew Wilcox)
- Convert most of shrink_page_list() to use a folio (Matthew Wilcox)
- Add support for creating large folios in readahead (Matthew Wilcox)
* tag 'folio-5.18c' of git://git.infradead.org/users/willy/pagecache: (114 commits)
mm/damon: minor cleanup for damon_pa_young
selftests/vm/transhuge-stress: Support file-backed PMD folios
mm/filemap: Support VM_HUGEPAGE for file mappings
mm/readahead: Switch to page_cache_ra_order
mm/readahead: Align file mappings for non-DAX
mm/readahead: Add large folio readahead
mm: Support arbitrary THP sizes
mm: Make large folios depend on THP
mm: Fix READ_ONLY_THP warning
mm/filemap: Allow large folios to be added to the page cache
mm: Turn can_split_huge_page() into can_split_folio()
mm/vmscan: Convert pageout() to take a folio
mm/vmscan: Turn page_check_references() into folio_check_references()
mm/vmscan: Account large folios correctly
mm/vmscan: Optimise shrink_page_list for non-PMD-sized folios
mm/vmscan: Free non-shmem folios without splitting them
mm/rmap: Constify the rmap_walk_control argument
mm/rmap: Convert rmap_walk() to take a folio
mm: Turn page_anon_vma() into folio_anon_vma()
mm/rmap: Turn page_lock_anon_vma_read() into folio_lock_anon_vma_read()
...
These functions are page cache functionality and don't need to be
declared in fs.h.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Eventually support for NFSv2 in the Linux NFS server is to be
deprecated and then removed.
However, NFSv2 is the "always supported" version that is available
as soon as CONFIG_NFSD is set. Before NFSv2 support can be removed,
we need to choose a different "always supported" version.
This patch removes CONFIG_NFSD_V3 so that NFSv3 is always supported,
as NFSv2 is today. When NFSv2 support is removed, NFSv3 will become
the only "always supported" NFS version.
The defconfigs still need to be updated to remove CONFIG_NFSD_V3=y.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Since, well, forever, the Linux NFS server's nfsd_commit() function
has returned nfserr_inval when the passed-in byte range arguments
were non-sensical.
However, according to RFC 1813 section 3.3.21, NFSv3 COMMIT requests
are permitted to return only the following non-zero status codes:
NFS3ERR_IO
NFS3ERR_STALE
NFS3ERR_BADHANDLE
NFS3ERR_SERVERFAULT
NFS3ERR_INVAL is not included in that list. Likewise, NFS4ERR_INVAL
is not listed in the COMMIT row of Table 6 in RFC 8881.
RFC 7530 does permit COMMIT to return NFS4ERR_INVAL, but does not
specify when it can or should be used.
Instead of dropping or failing a COMMIT request in a byte range that
is not supported, turn it into a valid request by treating one or
both arguments as zero. Offset zero means start-of-file, count zero
means until-end-of-file, so we only ever extend the commit range.
NFS servers are always allowed to commit more and sooner than
requested.
The range check is no longer bounded by NFS_OFFSET_MAX, but rather
by the value that is returned in the maxfilesize field of the NFSv3
FSINFO procedure or the NFSv4 maxfilesize file attribute.
Note that this change results in a new pynfs failure:
CMT4 st_commit.testCommitOverflow : RUNNING
CMT4 st_commit.testCommitOverflow : FAILURE
COMMIT with offset + count overflow should return
NFS4ERR_INVAL, instead got NFS4_OK
IMO the test is not correct as written: RFC 8881 does not allow the
COMMIT operation to return NFS4ERR_INVAL.
Reported-by: Dan Aloni <dan.aloni@vastdata.com>
Cc: stable@vger.kernel.org
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Bruce Fields <bfields@fieldses.org>
iattr::ia_size is a loff_t, which is a signed 64-bit type. NFSv3 and
NFSv4 both define file size as an unsigned 64-bit type. Thus there
is a range of valid file size values an NFS client can send that is
already larger than Linux can handle.
Currently decode_fattr4() dumps a full u64 value into ia_size. If
that value happens to be larger than S64_MAX, then ia_size
underflows. I'm about to fix up the NFSv3 behavior as well, so let's
catch the underflow in the common code path: nfsd_setattr().
Cc: stable@vger.kernel.org
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
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>
According to commit bbf2f09883 ("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>
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>
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 ]
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>
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 ]
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 19e0663ff9 ("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: 19e0663ff9 ("nfsd: Ensure sampling of the write verifier is atomic with the write")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
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>
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>
I don't know if that Solaris behavior matters any more or if it's still
possible to look up that bug ID any more. The XFS behavior's definitely
still relevant, though; any but the most recent XFS filesystems will
lose the top bits.
Reported-by: Frank S. Filz <ffilzlnx@mindspring.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
A small part of the declaration concerning filehandle format are
currently in the "uapi" include directory:
include/uapi/linux/nfsd/nfsfh.h
There is a lot more to the filehandle format, including "enum fid_type"
and "enum nfsd_fsid" which are not exported via "uapi".
This small part of the filehandle definition is of minimal use outside
of the kernel, and I can find no evidence that an other code is using
it. Certainly nfs-utils and wireshark (The most likely candidates) do not
use these declarations.
So move it out of "uapi" by copying the content from
include/uapi/linux/nfsd/nfsfh.h
into
fs/nfsd/nfsfh.h
A few unnecessary "#include" directives are not copied, and neither is
the #define of fh_auth, which is annotated as being for userspace only.
The copyright claims in the uapi file are identical to those in the nfsd
file, so there is no need to copy those.
The "__u32" style integer types are only needed in "uapi". In
kernel-only code we can use the more familiar "u32" style.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
- Support for server-side disconnect injection via debugfs
- Protocol definitions for new RPC_AUTH_TLS authentication flavor
Performance improvements:
- Reduce page allocator traffic in the NFSD splice read actor
- Reduce CPU utilization in svcrdma's Send completion handler
Notable bug fixes:
- Stabilize lockd operation when re-exporting NFS mounts
- Fix the use of %.*s in NFSD tracepoints
- Fix /proc/sys/fs/nfs/nsm_use_hostnames
-----BEGIN PGP SIGNATURE-----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=TGkK
-----END PGP SIGNATURE-----
Merge tag 'nfsd-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux
Pull nfsd updates from Chuck Lever:
"New features:
- Support for server-side disconnect injection via debugfs
- Protocol definitions for new RPC_AUTH_TLS authentication flavor
Performance improvements:
- Reduce page allocator traffic in the NFSD splice read actor
- Reduce CPU utilization in svcrdma's Send completion handler
Notable bug fixes:
- Stabilize lockd operation when re-exporting NFS mounts
- Fix the use of %.*s in NFSD tracepoints
- Fix /proc/sys/fs/nfs/nsm_use_hostnames"
* tag 'nfsd-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux: (31 commits)
nfsd: fix crash on LOCKT on reexported NFSv3
nfs: don't allow reexport reclaims
lockd: don't attempt blocking locks on nfs reexports
nfs: don't atempt blocking locks on nfs reexports
Keep read and write fds with each nlm_file
lockd: update nlm_lookup_file reexport comment
nlm: minor refactoring
nlm: minor nlm_lookup_file argument change
lockd: lockd server-side shouldn't set fl_ops
SUNRPC: Add documentation for the fail_sunrpc/ directory
SUNRPC: Server-side disconnect injection
SUNRPC: Move client-side disconnect injection
SUNRPC: Add a /sys/kernel/debug/fail_sunrpc/ directory
svcrdma: xpt_bc_xprt is already clear in __svc_rdma_free()
nfsd4: Fix forced-expiry locking
rpc: fix gss_svc_init cleanup on failure
SUNRPC: Add RPC_AUTH_TLS protocol numbers
lockd: change the proc_handler for nsm_use_hostnames
sysctl: introduce new proc handler proc_dobool
SUNRPC: Fix a NULL pointer deref in trace_svc_stats_latency()
...
We added CONFIG_MANDATORY_FILE_LOCKING in 2015, and soon after turned it
off in Fedora and RHEL8. Several other distros have followed suit.
I've heard of one problem in all that time: Someone migrated from an
older distro that supported "-o mand" to one that didn't, and the host
had a fstab entry with "mand" in it which broke on reboot. They didn't
actually _use_ mandatory locking so they just removed the mount option
and moved on.
This patch rips out mandatory locking support wholesale from the kernel,
along with the Kconfig option and the Documentation file. It also
changes the mount code to ignore the "mand" mount option instead of
erroring out, and to throw a big, ugly warning.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Including one's name in copyright claims is appropriate. Including it
in random comments is just vanity. After 2 decades, it is time for
these to be gone.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Large splice reads call put_page() repeatedly. put_page() is
relatively expensive to call, so replace it with the new
svc_rqst_replace_page() helper to help amortize that cost.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: NeilBrown <neilb@suse.de>
A few useful observations:
- The value in @size is never modified.
- splice_desc.len is an unsigned int, and so is xdr_buf.page_len.
An implicit cast to size_t is unnecessary.
- The computation of .page_len is the same in all three arms
of the "if" statement, so hoist it out to make it clear that
the operation is an unconditional invariant.
The resulting function is 18 bytes shorter on my system (-Os).
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: NeilBrown <neilb@suse.de>
When flushing out the unstable file writes as part of a COMMIT call, try
to perform most of of the data writes and waits outside the semaphore.
This means that if the client is sending the COMMIT as part of a memory
reclaim operation, then it can continue performing I/O, with contention
for the lock occurring only once the data sync is finished.
Fixes: 5011af4c69 ("nfsd: Fix stable writes")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Tested-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
The commit may be time-consuming and there's no need to hold the lock
for it.
More of these are possible, these were just some easy ones.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Truncation of an unlinked inode may take a long time for I/O waiting, and
it doesn't have to prevent access to the directory. Thus, let truncation
occur outside the directory's mutex, just like do_unlinkat() does.
Signed-off-by: Yu Hsiang Huang <nickhuang@synology.com>
Signed-off-by: Bing Jing Chang <bingjingc@synology.com>
Signed-off-by: Robbie Ko <robbieko@synology.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Enable watching the progress of directory encoding to capture the
timing of any issues with reading or encoding a directory. The
new tracepoint captures dirent encoding for all NFS versions.
For example, here's what a few NFSv4 directory entries might look
like:
nfsd-989 [002] 468.596265: nfsd_dirent: fh_hash=0x5d162594 ino=2 name=.
nfsd-989 [002] 468.596267: nfsd_dirent: fh_hash=0x5d162594 ino=1 name=..
nfsd-989 [002] 468.596299: nfsd_dirent: fh_hash=0x5d162594 ino=3827 name=zlib.c
nfsd-989 [002] 468.596325: nfsd_dirent: fh_hash=0x5d162594 ino=3811 name=xdiff
nfsd-989 [002] 468.596351: nfsd_dirent: fh_hash=0x5d162594 ino=3810 name=xdiff-interface.h
nfsd-989 [002] 468.596377: nfsd_dirent: fh_hash=0x5d162594 ino=3809 name=xdiff-interface.c
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
-----BEGIN PGP SIGNATURE-----
iHUEABYKAB0WIQRAhzRXHqcMeLMyaSiRxhvAZXjcogUCYCegywAKCRCRxhvAZXjc
ouJ6AQDlf+7jCQlQdeKKoN9QDFfMzG1ooemat36EpRRTONaGuAD8D9A4sUsG4+5f
4IU5Lj9oY4DEmF8HenbWK2ZHsesL2Qg=
=yPaw
-----END PGP SIGNATURE-----
Merge tag 'idmapped-mounts-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux
Pull idmapped mounts from Christian Brauner:
"This introduces idmapped mounts which has been in the making for some
time. Simply put, different mounts can expose the same file or
directory with different ownership. This initial implementation comes
with ports for fat, ext4 and with Christoph's port for xfs with more
filesystems being actively worked on by independent people and
maintainers.
Idmapping mounts handle a wide range of long standing use-cases. Here
are just a few:
- Idmapped mounts make it possible to easily share files between
multiple users or multiple machines especially in complex
scenarios. For example, idmapped mounts will be used in the
implementation of portable home directories in
systemd-homed.service(8) where they allow users to move their home
directory to an external storage device and use it on multiple
computers where they are assigned different uids and gids. This
effectively makes it possible to assign random uids and gids at
login time.
- It is possible to share files from the host with unprivileged
containers without having to change ownership permanently through
chown(2).
- It is possible to idmap a container's rootfs and without having to
mangle every file. For example, Chromebooks use it to share the
user's Download folder with their unprivileged containers in their
Linux subsystem.
- It is possible to share files between containers with
non-overlapping idmappings.
- Filesystem that lack a proper concept of ownership such as fat can
use idmapped mounts to implement discretionary access (DAC)
permission checking.
- They allow users to efficiently changing ownership on a per-mount
basis without having to (recursively) chown(2) all files. In
contrast to chown (2) changing ownership of large sets of files is
instantenous with idmapped mounts. This is especially useful when
ownership of a whole root filesystem of a virtual machine or
container is changed. With idmapped mounts a single syscall
mount_setattr syscall will be sufficient to change the ownership of
all files.
- Idmapped mounts always take the current ownership into account as
idmappings specify what a given uid or gid is supposed to be mapped
to. This contrasts with the chown(2) syscall which cannot by itself
take the current ownership of the files it changes into account. It
simply changes the ownership to the specified uid and gid. This is
especially problematic when recursively chown(2)ing a large set of
files which is commong with the aforementioned portable home
directory and container and vm scenario.
- Idmapped mounts allow to change ownership locally, restricting it
to specific mounts, and temporarily as the ownership changes only
apply as long as the mount exists.
Several userspace projects have either already put up patches and
pull-requests for this feature or will do so should you decide to pull
this:
- systemd: In a wide variety of scenarios but especially right away
in their implementation of portable home directories.
https://systemd.io/HOME_DIRECTORY/
- container runtimes: containerd, runC, LXD:To share data between
host and unprivileged containers, unprivileged and privileged
containers, etc. The pull request for idmapped mounts support in
containerd, the default Kubernetes runtime is already up for quite
a while now: https://github.com/containerd/containerd/pull/4734
- The virtio-fs developers and several users have expressed interest
in using this feature with virtual machines once virtio-fs is
ported.
- ChromeOS: Sharing host-directories with unprivileged containers.
I've tightly synced with all those projects and all of those listed
here have also expressed their need/desire for this feature on the
mailing list. For more info on how people use this there's a bunch of
talks about this too. Here's just two recent ones:
https://www.cncf.io/wp-content/uploads/2020/12/Rootless-Containers-in-Gitpod.pdfhttps://fosdem.org/2021/schedule/event/containers_idmap/
This comes with an extensive xfstests suite covering both ext4 and
xfs:
https://git.kernel.org/brauner/xfstests-dev/h/idmapped_mounts
It covers truncation, creation, opening, xattrs, vfscaps, setid
execution, setgid inheritance and more both with idmapped and
non-idmapped mounts. It already helped to discover an unrelated xfs
setgid inheritance bug which has since been fixed in mainline. It will
be sent for inclusion with the xfstests project should you decide to
merge this.
In order to support per-mount idmappings vfsmounts are marked with
user namespaces. The idmapping of the user namespace will be used to
map the ids of vfs objects when they are accessed through that mount.
By default all vfsmounts are marked with the initial user namespace.
The initial user namespace is used to indicate that a mount is not
idmapped. All operations behave as before and this is verified in the
testsuite.
Based on prior discussions we want to attach the whole user namespace
and not just a dedicated idmapping struct. This allows us to reuse all
the helpers that already exist for dealing with idmappings instead of
introducing a whole new range of helpers. In addition, if we decide in
the future that we are confident enough to enable unprivileged users
to setup idmapped mounts the permission checking can take into account
whether the caller is privileged in the user namespace the mount is
currently marked with.
The user namespace the mount will be marked with can be specified by
passing a file descriptor refering to the user namespace as an
argument to the new mount_setattr() syscall together with the new
MOUNT_ATTR_IDMAP flag. The system call follows the openat2() pattern
of extensibility.
The following conditions must be met in order to create an idmapped
mount:
- The caller must currently have the CAP_SYS_ADMIN capability in the
user namespace the underlying filesystem has been mounted in.
- The underlying filesystem must support idmapped mounts.
- The mount must not already be idmapped. This also implies that the
idmapping of a mount cannot be altered once it has been idmapped.
- The mount must be a detached/anonymous mount, i.e. it must have
been created by calling open_tree() with the OPEN_TREE_CLONE flag
and it must not already have been visible in the filesystem.
The last two points guarantee easier semantics for userspace and the
kernel and make the implementation significantly simpler.
By default vfsmounts are marked with the initial user namespace and no
behavioral or performance changes are observed.
The manpage with a detailed description can be found here:
1d7b902e28
In order to support idmapped mounts, filesystems need to be changed
and mark themselves with the FS_ALLOW_IDMAP flag in fs_flags. The
patches to convert individual filesystem are not very large or
complicated overall as can be seen from the included fat, ext4, and
xfs ports. Patches for other filesystems are actively worked on and
will be sent out separately. The xfstestsuite can be used to verify
that port has been done correctly.
The mount_setattr() syscall is motivated independent of the idmapped
mounts patches and it's been around since July 2019. One of the most
valuable features of the new mount api is the ability to perform
mounts based on file descriptors only.
Together with the lookup restrictions available in the openat2()
RESOLVE_* flag namespace which we added in v5.6 this is the first time
we are close to hardened and race-free (e.g. symlinks) mounting and
path resolution.
While userspace has started porting to the new mount api to mount
proper filesystems and create new bind-mounts it is currently not
possible to change mount options of an already existing bind mount in
the new mount api since the mount_setattr() syscall is missing.
With the addition of the mount_setattr() syscall we remove this last
restriction and userspace can now fully port to the new mount api,
covering every use-case the old mount api could. We also add the
crucial ability to recursively change mount options for a whole mount
tree, both removing and adding mount options at the same time. This
syscall has been requested multiple times by various people and
projects.
There is a simple tool available at
https://github.com/brauner/mount-idmapped
that allows to create idmapped mounts so people can play with this
patch series. I'll add support for the regular mount binary should you
decide to pull this in the following weeks:
Here's an example to a simple idmapped mount of another user's home
directory:
u1001@f2-vm:/$ sudo ./mount --idmap both:1000:1001:1 /home/ubuntu/ /mnt
u1001@f2-vm:/$ ls -al /home/ubuntu/
total 28
drwxr-xr-x 2 ubuntu ubuntu 4096 Oct 28 22:07 .
drwxr-xr-x 4 root root 4096 Oct 28 04:00 ..
-rw------- 1 ubuntu ubuntu 3154 Oct 28 22:12 .bash_history
-rw-r--r-- 1 ubuntu ubuntu 220 Feb 25 2020 .bash_logout
-rw-r--r-- 1 ubuntu ubuntu 3771 Feb 25 2020 .bashrc
-rw-r--r-- 1 ubuntu ubuntu 807 Feb 25 2020 .profile
-rw-r--r-- 1 ubuntu ubuntu 0 Oct 16 16:11 .sudo_as_admin_successful
-rw------- 1 ubuntu ubuntu 1144 Oct 28 00:43 .viminfo
u1001@f2-vm:/$ ls -al /mnt/
total 28
drwxr-xr-x 2 u1001 u1001 4096 Oct 28 22:07 .
drwxr-xr-x 29 root root 4096 Oct 28 22:01 ..
-rw------- 1 u1001 u1001 3154 Oct 28 22:12 .bash_history
-rw-r--r-- 1 u1001 u1001 220 Feb 25 2020 .bash_logout
-rw-r--r-- 1 u1001 u1001 3771 Feb 25 2020 .bashrc
-rw-r--r-- 1 u1001 u1001 807 Feb 25 2020 .profile
-rw-r--r-- 1 u1001 u1001 0 Oct 16 16:11 .sudo_as_admin_successful
-rw------- 1 u1001 u1001 1144 Oct 28 00:43 .viminfo
u1001@f2-vm:/$ touch /mnt/my-file
u1001@f2-vm:/$ setfacl -m u:1001:rwx /mnt/my-file
u1001@f2-vm:/$ sudo setcap -n 1001 cap_net_raw+ep /mnt/my-file
u1001@f2-vm:/$ ls -al /mnt/my-file
-rw-rwxr--+ 1 u1001 u1001 0 Oct 28 22:14 /mnt/my-file
u1001@f2-vm:/$ ls -al /home/ubuntu/my-file
-rw-rwxr--+ 1 ubuntu ubuntu 0 Oct 28 22:14 /home/ubuntu/my-file
u1001@f2-vm:/$ getfacl /mnt/my-file
getfacl: Removing leading '/' from absolute path names
# file: mnt/my-file
# owner: u1001
# group: u1001
user::rw-
user:u1001:rwx
group::rw-
mask::rwx
other::r--
u1001@f2-vm:/$ getfacl /home/ubuntu/my-file
getfacl: Removing leading '/' from absolute path names
# file: home/ubuntu/my-file
# owner: ubuntu
# group: ubuntu
user::rw-
user:ubuntu:rwx
group::rw-
mask::rwx
other::r--"
* tag 'idmapped-mounts-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux: (41 commits)
xfs: remove the possibly unused mp variable in xfs_file_compat_ioctl
xfs: support idmapped mounts
ext4: support idmapped mounts
fat: handle idmapped mounts
tests: add mount_setattr() selftests
fs: introduce MOUNT_ATTR_IDMAP
fs: add mount_setattr()
fs: add attr_flags_to_mnt_flags helper
fs: split out functions to hold writers
namespace: only take read lock in do_reconfigure_mnt()
mount: make {lock,unlock}_mount_hash() static
namespace: take lock_mount_hash() directly when changing flags
nfs: do not export idmapped mounts
overlayfs: do not mount on top of idmapped mounts
ecryptfs: do not mount on top of idmapped mounts
ima: handle idmapped mounts
apparmor: handle idmapped mounts
fs: make helpers idmap mount aware
exec: handle idmapped mounts
would_dump: handle idmapped mounts
...
Collect some nfsd stats per export in addition to the global stats.
A new nfsdfs export_stats file is created. It uses the same ops as the
exports file to iterate the export entries and we use the file's name to
determine the reported info per export. For example:
$ cat /proc/fs/nfsd/export_stats
# Version 1.1
# Path Client Start-time
# Stats
/test localhost 92
fh_stale: 0
io_read: 9
io_write: 1
Every export entry reports the start time when stats collection
started, so stats collecting scripts can know if stats where reset
between samples.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
nfsd stats counters can be updated by concurrent nfsd threads without any
protection.
Convert some nfsd_stats and nfsd_net struct members to use percpu counters.
The longest_chain* members of struct nfsd_net remain unprotected.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
The various vfs_*() helpers are called by filesystems or by the vfs
itself to perform core operations such as create, link, mkdir, mknod, rename,
rmdir, tmpfile and unlink. Enable them to handle idmapped mounts. If the
inode is accessed through an idmapped mount map it into the
mount's user namespace and pass it down. Afterwards the checks and
operations are identical to non-idmapped mounts. If the initial user
namespace is passed nothing changes so non-idmapped mounts will see
identical behavior as before.
Link: https://lore.kernel.org/r/20210121131959.646623-15-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
In order to handle idmapped mounts we will extend the vfs rename helper
to take two new arguments in follow up patches. Since this operations
already takes a bunch of arguments add a simple struct renamedata and
make the current helper use it before we extend it.
Link: https://lore.kernel.org/r/20210121131959.646623-14-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
When interacting with extended attributes the vfs verifies that the
caller is privileged over the inode with which the extended attribute is
associated. For posix access and posix default extended attributes a uid
or gid can be stored on-disk. Let the functions handle posix extended
attributes on idmapped mounts. If the inode is accessed through an
idmapped mount we need to map it according to the mount's user
namespace. Afterwards the checks are identical to non-idmapped mounts.
This has no effect for e.g. security xattrs since they don't store uids
or gids and don't perform permission checks on them like posix acls do.
Link: https://lore.kernel.org/r/20210121131959.646623-10-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
Signed-off-by: Tycho Andersen <tycho@tycho.pizza>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
When file attributes are changed most filesystems rely on the
setattr_prepare(), setattr_copy(), and notify_change() helpers for
initialization and permission checking. Let them handle idmapped mounts.
If the inode is accessed through an idmapped mount map it into the
mount's user namespace. Afterwards the checks are identical to
non-idmapped mounts. If the initial user namespace is passed nothing
changes so non-idmapped mounts will see identical behavior as before.
Helpers that perform checks on the ia_uid and ia_gid fields in struct
iattr assume that ia_uid and ia_gid are intended values and have already
been mapped correctly at the userspace-kernelspace boundary as we
already do today. If the initial user namespace is passed nothing
changes so non-idmapped mounts will see identical behavior as before.
Link: https://lore.kernel.org/r/20210121131959.646623-8-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
The two helpers inode_permission() and generic_permission() are used by
the vfs to perform basic permission checking by verifying that the
caller is privileged over an inode. In order to handle idmapped mounts
we extend the two helpers with an additional user namespace argument.
On idmapped mounts the two helpers will make sure to map the inode
according to the mount's user namespace and then peform identical
permission checks to inode_permission() and generic_permission(). If the
initial user namespace is passed nothing changes so non-idmapped mounts
will see identical behavior as before.
Link: https://lore.kernel.org/r/20210121131959.646623-6-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
Acked-by: Serge Hallyn <serge@hallyn.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Don't set PF_LOCAL_THROTTLE on remote filesystems like NFS, since they
aren't expected to ever be subject to double buffering.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
It's not uncommon for some workloads to do a bunch of I/O to a file and
delete it just afterward. If knfsd has a cached open file however, then
the file may still be open when the dentry is unlinked. If the
underlying filesystem is nfs, then that could trigger it to do a
sillyrename.
On a REMOVE or RENAME scan the nfsd_file cache for open files that
correspond to the inode, and proactively unhash and put their
references. This should prevent any delete-on-last-close activity from
occurring, solely due to knfsd's open file cache.
This must be done synchronously though so we use the variants that call
flush_delayed_fput. There are deadlock possibilities if you call
flush_delayed_fput while holding locks, however. In the case of
nfsd_rename, we don't even do the lookups of the dentries to be renamed
until we've locked for rename.
Once we've figured out what the target dentry is for a rename, check to
see whether there are cached open files associated with it. If there
are, then unwind all of the locking, close them all, and then reattempt
the rename.
None of this is really necessary for "typical" filesystems though. It's
mostly of use for NFS, so declare a new export op flag and use that to
determine whether to close the files beforehand.
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>
Squelch some sparse warnings:
/home/cel/src/linux/linux/fs/nfsd/vfs.c:2264:13: warning: incorrect type in assignment (different base types)
/home/cel/src/linux/linux/fs/nfsd/vfs.c:2264:13: expected int err
/home/cel/src/linux/linux/fs/nfsd/vfs.c:2264:13: got restricted __be32
/home/cel/src/linux/linux/fs/nfsd/vfs.c:2266:24: warning: incorrect type in return expression (different base types)
/home/cel/src/linux/linux/fs/nfsd/vfs.c:2266:24: expected restricted __be32
/home/cel/src/linux/linux/fs/nfsd/vfs.c:2266:24: got int err
/home/cel/src/linux/linux/fs/nfsd/vfs.c:2288:13: warning: incorrect type in assignment (different base types)
/home/cel/src/linux/linux/fs/nfsd/vfs.c:2288:13: expected int err
/home/cel/src/linux/linux/fs/nfsd/vfs.c:2288:13: got restricted __be32
/home/cel/src/linux/linux/fs/nfsd/vfs.c:2290:24: warning: incorrect type in return expression (different base types)
/home/cel/src/linux/linux/fs/nfsd/vfs.c:2290:24: expected restricted __be32
/home/cel/src/linux/linux/fs/nfsd/vfs.c:2290:24: got int err
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Since the NFSv4.2 extended attributes extension defines 3 new access
bits for xattr operations, take them in to account when validating
what the client is asking for, and when checking permissions.
Signed-off-by: Frank van der Linden <fllinden@amazon.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
This adds the filehandle based functions for the xattr operations
that call in to the vfs layer to do the actual work.
Signed-off-by: Frank van der Linden <fllinden@amazon.com>
[ cel: address checkpatch.pl complaint ]
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
The server is failing to apply the umask when creating new objects on
filesystems without ACL support.
To reproduce this, you need to use NFSv4.2 and a client and server
recent enough to support umask, and you need to export a filesystem that
lacks ACL support (for example, ext4 with the "noacl" mount option).
Filesystems with ACL support are expected to take care of the umask
themselves (usually by calling posix_acl_create).
For filesystems without ACL support, this is up to the caller of
vfs_create(), vfs_mknod(), or vfs_mkdir().
Reported-by: Elliott Mitchell <ehem+debian@m5p.com>
Reported-by: Salvatore Bonaccorso <carnil@debian.org>
Tested-by: Salvatore Bonaccorso <carnil@debian.org>
Fixes: 47057abde5 ("nfsd: add support for the umask attribute")
Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
PF_LESS_THROTTLE exists for loop-back nfsd (and a similar need in the
loop block driver and callers of prctl(PR_SET_IO_FLUSHER)), where a
daemon needs to write to one bdi (the final bdi) in order to free up
writes queued to another bdi (the client bdi).
The daemon sets PF_LESS_THROTTLE and gets a larger allowance of dirty
pages, so that it can still dirty pages after other processses have been
throttled. The purpose of this is to avoid deadlock that happen when
the PF_LESS_THROTTLE process must write for any dirty pages to be freed,
but it is being thottled and cannot write.
This approach was designed when all threads were blocked equally,
independently on which device they were writing to, or how fast it was.
Since that time the writeback algorithm has changed substantially with
different threads getting different allowances based on non-trivial
heuristics. This means the simple "add 25%" heuristic is no longer
reliable.
The important issue is not that the daemon needs a *larger* dirty page
allowance, but that it needs a *private* dirty page allowance, so that
dirty pages for the "client" bdi that it is helping to clear (the bdi
for an NFS filesystem or loop block device etc) do not affect the
throttling of the daemon writing to the "final" bdi.
This patch changes the heuristic so that the task is not throttled when
the bdi it is writing to has a dirty page count below below (or equal
to) the free-run threshold for that bdi. This ensures it will always be
able to have some pages in flight, and so will not deadlock.
In a steady-state, it is expected that PF_LOCAL_THROTTLE tasks might
still be throttled by global threshold, but that is acceptable as it is
only the deadlock state that is interesting for this flag.
This approach of "only throttle when target bdi is busy" is consistent
with the other use of PF_LESS_THROTTLE in current_may_throttle(), were
it causes attention to be focussed only on the target bdi.
So this patch
- renames PF_LESS_THROTTLE to PF_LOCAL_THROTTLE,
- removes the 25% bonus that that flag gives, and
- If PF_LOCAL_THROTTLE is set, don't delay at all unless the
global and the local free-run thresholds are exceeded.
Note that previously realtime threads were treated the same as
PF_LESS_THROTTLE threads. This patch does *not* change the behvaiour
for real-time threads, so it is now different from the behaviour of nfsd
and loop tasks. I don't know what is wanted for realtime.
[akpm@linux-foundation.org: coding style fixes]
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Chuck Lever <chuck.lever@oracle.com> [nfsd]
Cc: Christoph Hellwig <hch@lst.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Link: http://lkml.kernel.org/r/87ftbf7gs3.fsf@notabene.neil.brown.name
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When doing an unstable write, we need to ensure that we sample the
write verifier before releasing the lock, and allowing a commit to
the same file to proceed.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
When we have a successful commit, ensure we sample the commit verifier
before releasing the lock.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Ensure that we can distinguish between synchronous CLONE and
WRITE errors, and that we can assign them correctly.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Needed in order to fix exclusion w.r.t. writes.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
We don't know if the error returned by the fsync() call is
exclusive to the data written by the stable write, so play it
safe.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
