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2022-02-09NFSD: COMMIT operations must not return NFS?ERR_INVALChuck Lever1-17/+36
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>
2022-02-09NFSD: Fix ia_size underflowChuck Lever1-0/+4
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>
2022-01-08NFSD: Move fill_pre_wcc() and fill_post_wcc()Chuck Lever1-4/+4
These functions are related to file handle processing and have nothing to do with XDR encoding or decoding. Also they are no longer NFSv3-specific. As a clean-up, move their definitions to a more appropriate location. WCC is also an NFSv3-specific term, so rename them as general-purpose helpers. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-01-08NFSD: Trace boot verifier resetsChuck Lever1-3/+10
According to commit bbf2f098838a ("nfsd: Reset the boot verifier on all write I/O errors"), the Linux NFS server forces all clients to resend pending unstable writes if any server-side write or commit operation encounters an error (say, ENOSPC). This is a rare and quite exceptional event that could require administrative recovery action, so it should be made trace-able. Example trace event: nfsd-938 [002] 7174.945558: nfsd_writeverf_reset: boot_time= 61cc920d xid=0xdcd62036 error=-28 new verifier=0x08aecc6142515904 Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-01-08NFSD: Rename boot verifier functionsChuck Lever1-8/+8
Clean up: These functions handle what the specs call a write verifier, which in the Linux NFS server implementation is now divorced from the server's boot instance Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-01-08nfsd: Add a tracepoint for errors in nfsd4_clone_file_range()Trond Myklebust1-2/+16
Since a clone error commit can cause the boot verifier to change, we should trace those errors. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> [ cel: Addressed a checkpatch.pl splat in fs/nfsd/vfs.h ]
2022-01-08NFSD: De-duplicate net_generic(nf->nf_net, nfsd_net_id)Chuck Lever1-6/+5
Since this pointer is used repeatedly, move it to a stack variable. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-01-08NFSD: De-duplicate net_generic(SVC_NET(rqstp), nfsd_net_id)Chuck Lever1-7/+4
Since this pointer is used repeatedly, move it to a stack variable. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-01-08NFSD: Clean up nfsd_vfs_write()Chuck Lever1-16/+5
The RWF_SYNC and !RWF_SYNC arms are now exactly alike except that the RWF_SYNC arm resets the boot verifier twice in a row. Fix that redundancy and de-duplicate the code. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-01-08nfsd: Replace use of rwsem with errseq_tTrond Myklebust1-25/+15
The nfsd_file nf_rwsem is currently being used to separate file write and commit instances to ensure that we catch errors and apply them to the correct write/commit. We can improve scalability at the expense of a little accuracy (some extra false positives) by replacing the nf_rwsem with more careful use of the errseq_t mechanism to track errors across the different operations. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> [ cel: rebased on zero-verifier fix ]
2022-01-08NFSD: Fix verifier returned in stable WRITEsChuck Lever1-0/+4
RFC 8881 explains the purpose of the write verifier this way: > The final portion of the result is the field writeverf. This field > is the write verifier and is a cookie that the client can use to > determine whether a server has changed instance state (e.g., server > restart) between a call to WRITE and a subsequent call to either > WRITE or COMMIT. But then it says: > This cookie MUST be unchanged during a single instance of the > NFSv4.1 server and MUST be unique between instances of the NFSv4.1 > server. If the cookie changes, then the client MUST assume that > any data written with an UNSTABLE4 value for committed and an old > writeverf in the reply has been lost and will need to be > recovered. RFC 1813 has similar language for NFSv3. NFSv2 does not have a write verifier since it doesn't implement the COMMIT procedure. Since commit 19e0663ff9bc ("nfsd: Ensure sampling of the write verifier is atomic with the write"), the Linux NFS server has returned a boot-time-based verifier for UNSTABLE WRITEs, but a zero verifier for FILE_SYNC and DATA_SYNC WRITEs. FILE_SYNC and DATA_SYNC WRITEs are not followed up with a COMMIT, so there's no need for clients to compare verifiers for stable writes. However, by returning a different verifier for stable and unstable writes, the above commit puts the Linux NFS server a step farther out of compliance with the first MUST above. At least one NFS client (FreeBSD) noticed the difference, making this a potential regression. Reported-by: Rick Macklem <rmacklem@uoguelph.ca> Link: https://lore.kernel.org/linux-nfs/YQXPR0101MB096857EEACF04A6DF1FC6D9BDD749@YQXPR0101MB0968.CANPRD01.PROD.OUTLOOK.COM/T/ Fixes: 19e0663ff9bc ("nfsd: Ensure sampling of the write verifier is atomic with the write") Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-01-08nfsd: Retry once in nfsd_open on an -EOPENSTALE returnJeff Layton1-1/+9
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>
2021-11-02nfsd4: remove obselete commentJ. Bruce Fields1-3/+0
Mandatory locking has been removed. And the rest of this comment is redundant with the code. Reported-by: Jeff layton <jlayton@kernel.org> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2021-10-15nfsd: update create verifier commentJ. Bruce Fields1-1/+2
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>
2021-10-02NFSD: move filehandle format declarations out of "uapi".NeilBrown1-0/+1
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>
2021-08-31Merge tag 'nfsd-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linuxLinus Torvalds1-16/+5
Pull nfsd updates from Chuck Lever: "New features: - Support for server-side disconnect injection via debugfs - Protocol definitions for new RPC_AUTH_TLS authentication flavor Performance improvements: - Reduce page allocator traffic in the NFSD splice read actor - Reduce CPU utilization in svcrdma's Send completion handler Notable bug fixes: - Stabilize lockd operation when re-exporting NFS mounts - Fix the use of %.*s in NFSD tracepoints - Fix /proc/sys/fs/nfs/nsm_use_hostnames" * tag 'nfsd-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux: (31 commits) nfsd: fix crash on LOCKT on reexported NFSv3 nfs: don't allow reexport reclaims lockd: don't attempt blocking locks on nfs reexports nfs: don't atempt blocking locks on nfs reexports Keep read and write fds with each nlm_file lockd: update nlm_lookup_file reexport comment nlm: minor refactoring nlm: minor nlm_lookup_file argument change lockd: lockd server-side shouldn't set fl_ops SUNRPC: Add documentation for the fail_sunrpc/ directory SUNRPC: Server-side disconnect injection SUNRPC: Move client-side disconnect injection SUNRPC: Add a /sys/kernel/debug/fail_sunrpc/ directory svcrdma: xpt_bc_xprt is already clear in __svc_rdma_free() nfsd4: Fix forced-expiry locking rpc: fix gss_svc_init cleanup on failure SUNRPC: Add RPC_AUTH_TLS protocol numbers lockd: change the proc_handler for nsm_use_hostnames sysctl: introduce new proc handler proc_dobool SUNRPC: Fix a NULL pointer deref in trace_svc_stats_latency() ...
2021-08-23fs: remove mandatory file locking supportJeff Layton1-22/+1
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>
2021-08-17NFSD: remove vanity commentsNeilBrown1-1/+0
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>
2021-08-17NFSD: Batch release pages during splice readChuck Lever1-7/+2
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>
2021-08-17NFSD: Clean up splice actorChuck Lever1-8/+3
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>
2021-07-07nfsd: Reduce contention for the nfsd_file nf_rwsemTrond Myklebust1-2/+16
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: 5011af4c698a ("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>
2021-05-26nfsd: move some commit_metadata()s outside the inode lockJ. Bruce Fields1-2/+3
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>
2021-05-26nfsd: Prevent truncation of an unlinked inode from blocking access to its ↵Yu Hsiang Huang1-0/+5
directory 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>
2021-03-22NFSD: Add a tracepoint to record directory entry encodingChuck Lever1-3/+6
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>
2021-02-24Merge tag 'idmapped-mounts-v5.12' of ↵Linus Torvalds1-19/+31
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.pdf https://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: https://git.kernel.org/brauner/man-pages/c/1d7b902e2875a1ff342e036a9f866a995640aea8 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 ...
2021-01-25nfsd: report per-export statsAmir Goldstein1-2/+2
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>
2021-01-25nfsd: protect concurrent access to nfsd stats countersAmir Goldstein1-2/+2
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>
2021-01-24namei: prepare for idmapped mountsChristian Brauner1-8/+11
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>
2021-01-24namei: introduce struct renamedataChristian Brauner1-1/+7
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>
2021-01-24xattr: handle idmapped mountsTycho Andersen1-6/+8
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>
2021-01-24attr: handle idmapped mountsChristian Brauner1-2/+2
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>
2021-01-24namei: make permission helpers idmapped mount awareChristian Brauner1-2/+3
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>
2020-12-09nfsd: Set PF_LOCAL_THROTTLE on local filesystems onlyTrond Myklebust1-2/+11
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>
2020-12-09nfsd: close cached files prior to a REMOVE or RENAME that would replace targetJeff Layton1-7/+9
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>
2020-09-26NFSD: Correct type annotations in user xattr helpersChuck Lever1-2/+4
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>
2020-08-24treewide: Use fallthrough pseudo-keywordGustavo A. R. Silva1-2/+2
Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-07-14nfsd: take xattr bits into account for permission checksFrank van der Linden1-0/+12
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>
2020-07-14nfsd: define xattr functions to call into their vfs counterpartsFrank van der Linden1-0/+227
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>
2020-06-17nfsd: apply umask on fs without ACL supportJ. Bruce Fields1-0/+6
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: 47057abde515 ("nfsd: add support for the umask attribute") Cc: stable@vger.kernel.org Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2020-06-02mm/writeback: replace PF_LESS_THROTTLE with PF_LOCAL_THROTTLENeilBrown1-4/+5
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>
2020-01-23nfsd: Ensure sampling of the write verifier is atomic with the writeTrond Myklebust1-3/+9
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>
2020-01-23nfsd: Ensure sampling of the commit verifier is atomic with the commitTrond Myklebust1-2/+6
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>
2020-01-23nfsd: Ensure exclusion between CLONE and WRITE errorsTrond Myklebust1-7/+18
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>
2020-01-23nfsd: Pass the nfsd_file as arguments to nfsd4_clone_file_range()Trond Myklebust1-2/+4
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>
2020-01-23nfsd: Update the boot verifier on stable writes too.Trond Myklebust1-1/+4
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>
2020-01-23nfsd: Fix stable writesTrond Myklebust1-2/+16
Strictly speaking, a stable write error needs to reflect the write + the commit of that write (and only that write). To ensure that we don't pick up the write errors from other writebacks, add a rw_semaphore to provide exclusion. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2020-01-23nfsd: Allow nfsd_vfs_write() to take the nfsd_file as an argumentTrond Myklebust1-2/+3
Needed in order to fix stable writes. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2020-01-03nfsd: use true,false for bool variable in vfs.czhengbin1-3/+3
Fixes coccicheck warning: fs/nfsd/vfs.c:1389:5-13: WARNING: Assignment of 0/1 to bool variable fs/nfsd/vfs.c:1398:5-13: WARNING: Assignment of 0/1 to bool variable fs/nfsd/vfs.c:1415:2-10: WARNING: Assignment of 0/1 to bool variable Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: zhengbin <zhengbin13@huawei.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2019-12-20nfsd: pass a 64-bit guardtime to nfsd_setattr()Arnd Bergmann1-2/+2
Guardtime handling in nfs3 differs between 32-bit and 64-bit architectures, and uses the deprecated time_t type. Change it to using time64_t, which behaves the same way on 64-bit and 32-bit architectures, treating the number as an unsigned 32-bit entity with a range of year 1970 to 2106 consistently, and avoiding the y2038 overflow. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2019-12-20nfsd: Clone should commit src file metadata tooTrond Myklebust1-5/+14
vfs_clone_file_range() can modify the metadata on the source file too, so we need to commit that to stable storage as well. Reported-by: Dave Chinner <david@fromorbit.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Acked-by: Dave Chinner <david@fromorbit.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>