FAILED: patch "[PATCH] NFS: revalidate "." etc correctly on "open"." failed to apply to 3.18-stable tree

FAILED: patch "[PATCH] NFS: revalidate "." etc correctly on "open"." failed to apply to 3.18-stable tree

[gregkh]

The patch below does not apply to the 3.18-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

>From b688741cb06695312f18b730653d6611e1bad28d Mon Sep 17 00:00:00 2001
From: NeilBrown <neilb@suse.com>
Date: Fri, 25 Aug 2017 17:34:41 +1000
Subject: [PATCH] NFS: revalidate "." etc correctly on "open".

For correct close-to-open semantics, NFS must validate
the change attribute of a directory (or file) on open.

Since commit ecf3d1f1aa74 ("vfs: kill FS_REVAL_DOT by adding a
d_weak_revalidate dentry op"), open() of "." or a path ending ".." is
not revalidated reliably (except when that direct is a mount point).

Prior to that commit, "." was revalidated using nfs_lookup_revalidate()
which checks the LOOKUP_OPEN flag and forces revalidation if the flag is
set.
Since that commit, nfs_weak_revalidate() is used for NFSv3 (which
ignores the flags) and nothing is used for NFSv4.

This is fixed by using nfs_lookup_verify_inode() in
nfs_weak_revalidate().  This does the revalidation exactly when needed.
Also, add a definition of .d_weak_revalidate for NFSv4.

The incorrect behavior is easily demonstrated by running "echo *" in
some non-mountpoint NFS directory while watching network traffic.
Without this patch, "echo *" sometimes doesn't produce any traffic.
With the patch it always does.

Fixes: ecf3d1f1aa74 ("vfs: kill FS_REVAL_DOT by adding a d_weak_revalidate dentry op")
cc: stable@vger.kernel.org (3.9+)
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index db482d4c15d5..c583093a066b 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -1241,8 +1241,7 @@ static int nfs_weak_revalidate(struct dentry *dentry, unsigned int flags)
 		return 0;
 	}
 
-	if (nfs_mapping_need_revalidate_inode(inode))
-		error = __nfs_revalidate_inode(NFS_SERVER(inode), inode);
+	error = nfs_lookup_verify_inode(inode, flags);
 	dfprintk(LOOKUPCACHE, "NFS: %s: inode %lu is %s\n",
 			__func__, inode->i_ino, error ? "invalid" : "valid");
 	return !error;
@@ -1393,6 +1392,7 @@ static int nfs4_lookup_revalidate(struct dentry *, unsigned int);
 
 const struct dentry_operations nfs4_dentry_operations = {
 	.d_revalidate	= nfs4_lookup_revalidate,
+	.d_weak_revalidate	= nfs_weak_revalidate,
 	.d_delete	= nfs_dentry_delete,
 	.d_iput		= nfs_dentry_iput,
 	.d_automount	= nfs_d_automount,

Re: FAILED: patch "[PATCH] NFS: revalidate "." etc correctly on "open"." failed to apply to 3.18-stable tree

[NeilBrown]

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Subject: [PATCH] NFS: revalidate "." etc correctly on "open".

commit b688741cb06695312f18b730653d6611e1bad28d upstream.

For correct close-to-open semantics, NFS must validate
the change attribute of a directory (or file) on open.

Since commit ecf3d1f1aa74 ("vfs: kill FS_REVAL_DOT by adding a
d_weak_revalidate dentry op"), open() of "." or a path ending ".." is
not revalidated reliably (except when that direct is a mount point).

Prior to that commit, "." was revalidated using nfs_lookup_revalidate()
which checks the LOOKUP_OPEN flag and forces revalidation if the flag is
set.
Since that commit, nfs_weak_revalidate() is used for NFSv3 (which
ignores the flags) and nothing is used for NFSv4.

This is fixed by using nfs_lookup_verify_inode() in
nfs_weak_revalidate().  This does the revalidation exactly when needed.
Also, add a definition of .d_weak_revalidate for NFSv4.

The incorrect behavior is easily demonstrated by running "echo *" in
some non-mountpoint NFS directory while watching network traffic.
Without this patch, "echo *" sometimes doesn't produce any traffic.
With the patch it always does.

Fixes: ecf3d1f1aa74 ("vfs: kill FS_REVAL_DOT by adding a d_weak_revalidate dentry op")
cc: stable@vger.kernel.org (3.9+)
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
---
 fs/nfs/dir.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

This version applies to 3.18.y 4.4.y and 4.9.y

Thanks,
NeilBrown



diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index d04ec3814779..65566d5fcf39 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -1292,7 +1292,7 @@ static int nfs_weak_revalidate(struct dentry *dentry, unsigned int flags)
 		return 0;
 	}
 
-	error = nfs_revalidate_inode(NFS_SERVER(inode), inode);
+	error = nfs_lookup_verify_inode(inode, flags);
 	dfprintk(LOOKUPCACHE, "NFS: %s: inode %lu is %s\n",
 			__func__, inode->i_ino, error ? "invalid" : "valid");
 	return !error;
@@ -1443,6 +1443,7 @@ static int nfs4_lookup_revalidate(struct dentry *, unsigned int);
 
 const struct dentry_operations nfs4_dentry_operations = {
 	.d_revalidate	= nfs4_lookup_revalidate,
+	.d_weak_revalidate	= nfs_weak_revalidate,
 	.d_delete	= nfs_dentry_delete,
 	.d_iput		= nfs_dentry_iput,
 	.d_automount	= nfs_d_automount,
-- 
2.14.0.rc0.dirty


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Re: FAILED: patch "[PATCH] NFS: revalidate "." etc correctly on "open"." failed to apply to 3.18-stable tree

[Greg KH]

On Wed, Nov 29, 2017 at 01:06:35PM +1100, NeilBrown wrote:
> 
> Subject: [PATCH] NFS: revalidate "." etc correctly on "open".
> 
> commit b688741cb06695312f18b730653d6611e1bad28d upstream.
> 
> For correct close-to-open semantics, NFS must validate
> the change attribute of a directory (or file) on open.
> 
> Since commit ecf3d1f1aa74 ("vfs: kill FS_REVAL_DOT by adding a
> d_weak_revalidate dentry op"), open() of "." or a path ending ".." is
> not revalidated reliably (except when that direct is a mount point).
> 
> Prior to that commit, "." was revalidated using nfs_lookup_revalidate()
> which checks the LOOKUP_OPEN flag and forces revalidation if the flag is
> set.
> Since that commit, nfs_weak_revalidate() is used for NFSv3 (which
> ignores the flags) and nothing is used for NFSv4.
> 
> This is fixed by using nfs_lookup_verify_inode() in
> nfs_weak_revalidate().  This does the revalidation exactly when needed.
> Also, add a definition of .d_weak_revalidate for NFSv4.
> 
> The incorrect behavior is easily demonstrated by running "echo *" in
> some non-mountpoint NFS directory while watching network traffic.
> Without this patch, "echo *" sometimes doesn't produce any traffic.
> With the patch it always does.
> 
> Fixes: ecf3d1f1aa74 ("vfs: kill FS_REVAL_DOT by adding a d_weak_revalidate dentry op")
> cc: stable@vger.kernel.org (3.9+)
> Signed-off-by: NeilBrown <neilb@suse.com>
> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
> ---
>  fs/nfs/dir.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> This version applies to 3.18.y 4.4.y and 4.9.y

Thanks for the backport, now applied.

greg k-h