linux-stable.git/fs/nfsd, branch linux-4.1.y

nfsd4: permit layoutget of executable-only files

2018-05-23T01:33:52+00:00

[ Upstream commit 66282ec1cf004c09083c29cb5e49019037937bbd ]

Clients must be able to read a file in order to execute it, and for pNFS
that means the client needs to be able to perform a LAYOUTGET on the file.

This behavior for executable-only files was added for OPEN in commit
a043226bc140 "nfsd4: permit read opens of executable-only files".

This fixes up xfstests generic/126 on block/scsi layouts.

Signed-off-by: Benjamin Coddington 
Signed-off-by: J. Bruce Fields 
Signed-off-by: Sasha Levin

NFS: don't try to cross a mountpount when there isn't one there.

2018-05-23T01:33:50+00:00

[ Upstream commit 99bbf6ecc694dfe0b026e15359c5aa2a60b97a93 ]

consider the sequence of commands:
 mkdir -p /import/nfs /import/bind /import/etc
 mount --bind / /import/bind
 mount --make-private /import/bind
 mount --bind /import/etc /import/bind/etc

 exportfs -o rw,no_root_squash,crossmnt,async,no_subtree_check localhost:/
 mount -o vers=4 localhost:/ /import/nfs
 ls -l /import/nfs/etc

You would not expect this to report a stale file handle.
Yet it does.

The manipulations under /import/bind cause the dentry for
/etc to get the DCACHE_MOUNTED flag set, even though nothing
is mounted on /etc.  This causes nfsd to call
nfsd_cross_mnt() even though there is no mountpoint.  So an
upcall to mountd for "/etc" is performed.

The 'crossmnt' flag on the export of / causes mountd to
report that /etc is exported as it is a descendant of /.  It
assumes the kernel wouldn't ask about something that wasn't
a mountpoint.  The filehandle returned identifies the
filesystem and the inode number of /etc.

When this filehandle is presented to rpc.mountd, via
"nfsd.fh", the inode cannot be found associated with any
name in /etc/exports, or with any mountpoint listed by
getmntent().  So rpc.mountd says the filehandle doesn't
exist. Hence ESTALE.

This is fixed by teaching nfsd not to trust DCACHE_MOUNTED
too much.  It is just a hint, not a guarantee.
Change nfsd_mountpoint() to return '1' for a certain mountpoint,
'2' for a possible mountpoint, and 0 otherwise.

Then change nfsd_crossmnt() to check if follow_down()
actually found a mountpount and, if not, to avoid performing
a lookup if the location is not known to certainly require
an export-point.

Signed-off-by: NeilBrown 
Signed-off-by: J. Bruce Fields 
Signed-off-by: Sasha Levin

nfsd: check for use of the closed special stateid

2018-03-01T03:09:46+00:00

[ Upstream commit ae254dac721d44c0bfebe2795df87459e2e88219 ]

Prevent the use of the closed (invalid) special stateid by clients.

Signed-off-by: Andrew Elble 
Signed-off-by: J. Bruce Fields 
Signed-off-by: Sasha Levin

nfsd: CLOSE SHOULD return the invalid special stateid for NFSv4.x (x>0)

2018-03-01T03:09:46+00:00

[ Upstream commit fb500a7cfee7f2f447d2bbf30cb59629feab6ac1 ]

Signed-off-by: Trond Myklebust 
Signed-off-by: J. Bruce Fields 
Signed-off-by: Sasha Levin

nfsd: auth: Fix gid sorting when rootsquash enabled

2018-03-01T03:09:45+00:00

[ Upstream commit 1995266727fa8143897e89b55f5d3c79aa828420 ]

Commit bdcf0a423ea1 ("kernel: make groups_sort calling a responsibility
group_info allocators") appears to break nfsd rootsquash in a pretty
major way.

It adds a call to groups_sort() inside the loop that copies/squashes
gids, which means the valid gids are sorted along with the following
garbage.  The net result is that the highest numbered valid gids are
replaced with any lower-valued garbage gids, possibly including 0.

We should sort only once, after filling in all the gids.

Fixes: bdcf0a423ea1 ("kernel: make groups_sort calling a responsibility ...")
Signed-off-by: Ben Hutchings 
Acked-by: J. Bruce Fields 
Signed-off-by: Linus Torvalds 
Signed-off-by: Sasha Levin

kernel: make groups_sort calling a responsibility group_info allocators

2018-03-01T00:32:19+00:00

[ Upstream commit bdcf0a423ea1c40bbb40e7ee483b50fc8aa3d758 ]

In testing, we found that nfsd threads may call set_groups in parallel
for the same entry cached in auth.unix.gid, racing in the call of
groups_sort, corrupting the groups for that entry and leading to
permission denials for the client.

This patch:
 - Make groups_sort globally visible.
 - Move the call to groups_sort to the modifiers of group_info
 - Remove the call to groups_sort from set_groups

Link: http://lkml.kernel.org/r/20171211151420.18655-1-thiago.becker@gmail.com
Signed-off-by: Thiago Rafael Becker 
Reviewed-by: Matthew Wilcox 
Reviewed-by: NeilBrown 
Acked-by: "J. Bruce Fields" 
Cc: Al Viro 
Cc: Martin Schwidefsky 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Sasha Levin

NFSD: fix nfsd_reset_versions for NFSv4.

2018-01-17T17:55:33+00:00

[ Upstream commit 800a938f0bf9130c8256116649c0cc5806bfb2fd ]

If you write "-2 -3 -4" to the "versions" file, it will
notice that no versions are enabled, and nfsd_reset_versions()
is called.
This enables all major versions, not no minor versions.
So we lose the invariant that NFSv4 is only advertised when
at least one minor is enabled.

Fix the code to explicitly enable minor versions for v4,
change it to use nfsd_vers() to test and set, and simplify
the code.

Signed-off-by: NeilBrown 
Signed-off-by: J. Bruce Fields 
Signed-off-by: Sasha Levin

NFSD: fix nfsd_minorversion(.., NFSD_AVAIL)

2018-01-17T17:55:33+00:00

[ Upstream commit 928c6fb3a9bfd6c5b287aa3465226add551c13c0 ]

Current code will return 1 if the version is supported,
and -1 if it isn't.
This is confusing and inconsistent with the one place where this
is used.
So change to return 1 if it is supported, and zero if not.
i.e. an error is never returned.

Signed-off-by: NeilBrown 
Signed-off-by: J. Bruce Fields 
Signed-off-by: Sasha Levin

nfsd: special case truncates some more

2018-01-17T17:25:43+00:00

[ Upstream commit 41f53350a0f36a7b8e31bec0d0ca907e028ab4cd ]

Both the NFS protocols and the Linux VFS use a setattr operation with a
bitmap of attributs to set to set various file attributes including the
file size and the uid/gid.

The Linux syscalls never mixes size updates with unrelated updates like
the uid/gid, and some file systems like XFS and GFS2 rely on the fact
that truncates might not update random other attributes, and many other
file systems handle the case but do not update the different attributes
in the same transaction.  NFSD on the other hand passes the attributes
it gets on the wire more or less directly through to the VFS, leading to
updates the file systems don't expect.  XFS at least has an assert on
the allowed attributes, which caught an unusual NFS client setting the
size and group at the same time.

To handle this issue properly this switches nfsd to call vfs_truncate
for size changes, and then handle all other attributes through
notify_change.  As a side effect this also means less boilerplace code
around the size change as we can now reuse the VFS code.

Signed-off-by: Christoph Hellwig 
Signed-off-by: J. Bruce Fields 
Signed-off-by: Sasha Levin

nfsd: minor nfsd_setattr cleanup

2018-01-17T17:25:38+00:00

[ Upstream commit 758e99fefe1d9230111296956335cd35995c0eaf ]

Simplify exit paths, size_change use.

Signed-off-by: Christoph Hellwig 
Cc: stable@kernel.org
Signed-off-by: J. Bruce Fields 
Signed-off-by: Sasha Levin