NFS: Fix dentry verifier races

[ Upstream commit cec08f452a687fce9dfdf47946d00a1d12a8bec5 ]

If the directory changed while we were revalidating the dentry, then
don't update the dentry verifier. Th

NFS: Fix dentry verifier races

[ Upstream commit cec08f452a687fce9dfdf47946d00a1d12a8bec5 ]

If the directory changed while we were revalidating the dentry, then
don't update the dentry verifier. There is no value in setting the
verifier to an older value, and we could end up overwriting a more up to
date verifier from a parallel revalidation.

Fixes: efeda80da38d ("NFSv4: Fix revalidation of dentries with delegations")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Tested-by: Benjamin Coddington <bcodding@redhat.com>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

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NFS: Ignore the directory size when marking for revalidation

[ Upstream commit a6a361c4ca3cc3e6f3b39d1b6bca1de90f5f4b11 ]

If we want to revalidate the directory, then just mark the change
attribute

NFS: Ignore the directory size when marking for revalidation

[ Upstream commit a6a361c4ca3cc3e6f3b39d1b6bca1de90f5f4b11 ]

If we want to revalidate the directory, then just mark the change
attribute as invalid.

Fixes: 13c0b082b6a9 ("NFS: Replace use of NFS_INO_REVAL_PAGECACHE when checking cache validity")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Tested-by: Benjamin Coddington <bcodding@redhat.com>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

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treewide: remove editor modelines and cruft

The section "19) Editor modelines and other cruft" in
Documentation/process/coding-style.rst clearly says, "Do not include any
of these in source files."

treewide: remove editor modelines and cruft

The section "19) Editor modelines and other cruft" in
Documentation/process/coding-style.rst clearly says, "Do not include any
of these in source files."

I recently receive a patch to explicitly add a new one.

Let's do treewide cleanups, otherwise some people follow the existing code
and attempt to upstream their favoriate editor setups.

It is even nicer if scripts/checkpatch.pl can check it.

If we like to impose coding style in an editor-independent manner, I think
editorconfig (patch [1]) is a saner solution.

[1] https://lore.kernel.org/lkml/20200703073143.423557-1-danny@kdrag0n.dev/

Link: https://lkml.kernel.org/r/20210324054457.1477489-1-masahiroy@kernel.org
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Miguel Ojeda <ojeda@kernel.org> [auxdisplay]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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NFSv4: link must update the inode nlink.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: Separate tracking of file mode cache validity from the uid/gid

chown()/chgrp() and chmod() are separate operations, and in addition,
there are mode operations that are performed automatically b

NFS: Separate tracking of file mode cache validity from the uid/gid

chown()/chgrp() and chmod() are separate operations, and in addition,
there are mode operations that are performed automatically by the
server. So let's track mode validity separately from the file ownership
validity.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

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NFS: Separate tracking of file nlinks cache validity from the mode/uid/gid

Rename can cause us to revalidate the access cache, so lets track the
nlinks separately from the mode/uid/gid.

Signed-off-

NFS: Separate tracking of file nlinks cache validity from the mode/uid/gid

Rename can cause us to revalidate the access cache, so lets track the
nlinks separately from the mode/uid/gid.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

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NFS: Add a cache validity flag argument to nfs_revalidate_inode()

Add an argument to nfs_revalidate_inode() to allow callers to specify
which attributes they need to check for validity.

Signed-off-

NFS: Add a cache validity flag argument to nfs_revalidate_inode()

Add an argument to nfs_revalidate_inode() to allow callers to specify
which attributes they need to check for validity.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

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NFS: Only change the cookie verifier if the directory page cache is empty

The cached NFSv3/v4 readdir cookies are associated with a verifier,
which is checked by the server on subsequent calls to re

NFS: Only change the cookie verifier if the directory page cache is empty

The cached NFSv3/v4 readdir cookies are associated with a verifier,
which is checked by the server on subsequent calls to readdir, and is
only expected to change when the cookies (and hence also the page cache
contents) are considered invalid.
We therefore do have to store the verifier, but only when the page cache
is empty.

Fixes: b593c09f83a2 ("NFS: Improve handling of directory verifiers")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

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NFS: Fix handling of cookie verifier in uncached_readdir()

If we're doing uncached readdir(), then the readdir cookie could be
different from the one cached in the nfs_inode. We should therefore
ens

NFS: Fix handling of cookie verifier in uncached_readdir()

If we're doing uncached readdir(), then the readdir cookie could be
different from the one cached in the nfs_inode. We should therefore
ensure that we save that one in the struct nfs_open_dir_context.

Fixes: 35df59d3ef69 ("NFS: Reduce number of RPC calls when doing uncached readdir")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

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nfs: Subsequent READDIR calls should carry non-zero cookieverifier

If the loop in nfs_readdir_xdr_to_array() runs more than once, subsequent
READDIR RPCs may wrongly carry a zero cookie verifier and

nfs: Subsequent READDIR calls should carry non-zero cookieverifier

If the loop in nfs_readdir_xdr_to_array() runs more than once, subsequent
READDIR RPCs may wrongly carry a zero cookie verifier and non-zero cookie.
Make sure subsequent calls to READDIR carry the cookie verifier returned
by the first call.

Signed-off-by: Nagendra S Tomar <natomar@microsoft.com>
Fixes: b593c09f83a2 ("NFS: Improve handling of directory verifiers")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

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NFS: Fix open coded versions of nfs_set_cache_invalid()

nfs_set_cache_invalid() has code to handle delegations, and other
optimisations, so let's use it when appropriate.

Signed-off-by: Trond Mykle

NFS: Fix open coded versions of nfs_set_cache_invalid()

nfs_set_cache_invalid() has code to handle delegations, and other
optimisations, so let's use it when appropriate.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

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NFS: Clean up function nfs_mark_dir_for_revalidate()

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFS: Don't gratuitously clear the inode cache when lookup failed

The fact that the lookup revalidation failed, does not mean that the
inode contents have changed.

Fixes: 5ceb9d7fdaaf ("NFS: Refacto

NFS: Don't gratuitously clear the inode cache when lookup failed

The fact that the lookup revalidation failed, does not mean that the
inode contents have changed.

Fixes: 5ceb9d7fdaaf ("NFS: Refactor nfs_lookup_revalidate()")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

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NFS: Don't revalidate the directory permissions on a lookup failure

There should be no reason to expect the directory permissions to change
just because the directory contents changed or a negative

NFS: Don't revalidate the directory permissions on a lookup failure

There should be no reason to expect the directory permissions to change
just because the directory contents changed or a negative lookup timed
out. So let's avoid doing a full call to nfs_mark_for_revalidate() in
that case.
Furthermore, if this is a negative dentry, and we haven't actually done
a new lookup, then we have no reason yet to believe the directory has
changed at all. So let's remove the gratuitous directory inode
invalidation altogether when called from
nfs_lookup_revalidate_negative().

Reported-by: Geert Jansen <gerardu@amazon.com>
Fixes: 5ceb9d7fdaaf ("NFS: Refactor nfs_lookup_revalidate()")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

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fs: make helpers idmap mount aware

Extend some inode methods with an additional user namespace argument. A
filesystem that is aware of idmapped mounts will receive the user
namespace the mount has b

fs: make helpers idmap mount aware

Extend some inode methods with an additional user namespace argument. A
filesystem that is aware of idmapped mounts will receive the user
namespace the mount has been marked with. This can be used for
additional permission checking and also to enable filesystems to
translate between uids and gids if they need to. We have implemented all
relevant helpers in earlier patches.

As requested we simply extend the exisiting inode method instead of
introducing new ones. This is a little more code churn but it's mostly
mechanical and doesnt't leave us with additional inode methods.

Link: https://lore.kernel.org/r/20210121131959.646623-25-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>

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namei: make permission helpers idmapped mount aware

The two helpers inode_permission() and generic_permission() are used by
the vfs to perform basic permission checking by verifying that the
caller

namei: make permission helpers idmapped mount aware

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>

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NFS: Do uncached readdir when we're seeking a cookie in an empty page cache

If the directory is changing, causing the page cache to get invalidated
while we are listing the contents, then the NFS cl

NFS: Do uncached readdir when we're seeking a cookie in an empty page cache

If the directory is changing, causing the page cache to get invalidated
while we are listing the contents, then the NFS client is currently forced
to read in the entire directory contents from scratch, because it needs
to perform a linear search for the readdir cookie. While this is not
an issue for small directories, it does not scale to directories with
millions of entries.
In order to be able to deal with large directories that are changing,
add a heuristic to ensure that if the page cache is empty, and we are
searching for a cookie that is not the zero cookie, we just default to
performing uncached readdir.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Tested-by: Benjamin Coddington <bcodding@redhat.com>
Tested-by: Dave Wysochanski <dwysocha@redhat.com>

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NFS: Reduce number of RPC calls when doing uncached readdir

If we're doing uncached readdir, allocate multiple pages in order to
try to avoid duplicate RPC calls for the same getdents() call.

Signe

NFS: Reduce number of RPC calls when doing uncached readdir

If we're doing uncached readdir, allocate multiple pages in order to
try to avoid duplicate RPC calls for the same getdents() call.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Tested-by: Benjamin Coddington <bcodding@redhat.com>
Tested-by: Dave Wysochanski <dwysocha@redhat.com>

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NFS: Optimisations for monotonically increasing readdir cookies

If the server is handing out monotonically increasing readdir cookie values,
then we can optimise away searches through pages that con

NFS: Optimisations for monotonically increasing readdir cookies

If the server is handing out monotonically increasing readdir cookie values,
then we can optimise away searches through pages that contain cookies that
lie outside our search range.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Tested-by: Benjamin Coddington <bcodding@redhat.com>
Tested-by: Dave Wysochanski <dwysocha@redhat.com>

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NFS: Improve handling of directory verifiers

If the server insists on using the readdir verifiers in order to allow
cookies to expire, then we should ensure that we cache the verifier
with the cooki

NFS: Improve handling of directory verifiers

If the server insists on using the readdir verifiers in order to allow
cookies to expire, then we should ensure that we cache the verifier
with the cookie, so that we can return an error if the application
tries to use the expired cookie.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Tested-by: Benjamin Coddington <bcodding@redhat.com>
Tested-by: Dave Wysochanski <dwysocha@redhat.com>

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NFS: Handle NFS4ERR_NOT_SAME and NFSERR_BADCOOKIE from readdir calls

If the server returns NFS4ERR_NOT_SAME or tells us that the cookie is
bad in response to a READDIR call, then we should empty the

NFS: Handle NFS4ERR_NOT_SAME and NFSERR_BADCOOKIE from readdir calls

If the server returns NFS4ERR_NOT_SAME or tells us that the cookie is
bad in response to a READDIR call, then we should empty the page cache
so that we can fill it from scratch again.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Tested-by: Benjamin Coddington <bcodding@redhat.com>
Tested-by: Dave Wysochanski <dwysocha@redhat.com>

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NFS: Allow the NFS generic code to pass in a verifier to readdir

If we're ever going to allow support for servers that use the readdir
verifier, then that use needs to be managed by the middle layer

NFS: Allow the NFS generic code to pass in a verifier to readdir

If we're ever going to allow support for servers that use the readdir
verifier, then that use needs to be managed by the middle layers as
those need to be able to reject cookies from other verifiers.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Tested-by: Benjamin Coddington <bcodding@redhat.com>
Tested-by: Dave Wysochanski <dwysocha@redhat.com>

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NFS: Cleanup to remove nfs_readdir_descriptor_t typedef

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Tested-by: Benjamin Co

NFS: Cleanup to remove nfs_readdir_descriptor_t typedef

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Tested-by: Benjamin Coddington <bcodding@redhat.com>
Tested-by: Dave Wysochanski <dwysocha@redhat.com>

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NFS: Reduce readdir stack usage

The descriptor and the struct nfs_entry are both large structures,
so don't allocate them from the stack.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace

NFS: Reduce readdir stack usage

The descriptor and the struct nfs_entry are both large structures,
so don't allocate them from the stack.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Tested-by: Benjamin Coddington <bcodding@redhat.com>
Tested-by: Dave Wysochanski <dwysocha@redhat.com>

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NFS: nfs_do_filldir() does not return a value

Clean up nfs_do_filldir().

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Test

NFS: nfs_do_filldir() does not return a value

Clean up nfs_do_filldir().

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Tested-by: Benjamin Coddington <bcodding@redhat.com>
Tested-by: Dave Wysochanski <dwysocha@redhat.com>

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