linux-toradex.git/fs/nfs/inode.c, branch v4.9.84

NFS: only invalidate dentrys that are clearly invalid.

2017-07-27T22:08:06+00:00

commit cc89684c9a265828ce061037f1f79f4a68ccd3f7 upstream.

Since commit bafc9b754f75 ("vfs: More precise tests in d_invalidate")
in v3.18, a return of '0' from ->d_revalidate() will cause the dentry
to be invalidated even if it has filesystems mounted on or it or on a
descendant.  The mounted filesystem is unmounted.

This means we need to be careful not to return 0 unless the directory
referred to truly is invalid.  So -ESTALE or -ENOENT should invalidate
the directory.  Other errors such a -EPERM or -ERESTARTSYS should be
returned from ->d_revalidate() so they are propagated to the caller.

A particular problem can be demonstrated by:

1/ mount an NFS filesystem using NFSv3 on /mnt
2/ mount any other filesystem on /mnt/foo
3/ ls /mnt/foo
4/ turn off network, or otherwise make the server unable to respond
5/ ls /mnt/foo &
6/ cat /proc/$!/stack # note that nfs_lookup_revalidate is in the call stack
7/ kill -9 $! # this results in -ERESTARTSYS being returned
8/ observe that /mnt/foo has been unmounted.

This patch changes nfs_lookup_revalidate() to only treat
  -ESTALE from nfs_lookup_verify_inode() and
  -ESTALE or -ENOENT from ->lookup()
as indicating an invalid inode.  Other errors are returned.

Also nfs_check_inode_attributes() is changed to return -ESTALE rather
than -EIO.  This is consistent with the error returned in similar
circumstances from nfs_update_inode().

As this bug allows any user to unmount a filesystem mounted on an NFS
filesystem, this fix is suitable for stable kernels.

Fixes: bafc9b754f75 ("vfs: More precise tests in d_invalidate")
Signed-off-by: NeilBrown 
Signed-off-by: Anna Schumaker 
Signed-off-by: Greg Kroah-Hartman

pNFS: Actively set attributes as invalid if LAYOUTCOMMIT is outstanding

2016-07-28T18:49:08+00:00

A LAYOUTCOMMIT then subsequent GETATTR may both return the same attributes,
and in that case NFS_INO_INVALID_ATTR is never set on the second pass
through nfs_update_inode().  The existing check to skip the clearing of
NFS_INO_INVALID_ATTR if a LAYOUTCOMMIT is outstanding does not help in this
case (see commit 10b7e9ad4488: "pNFS: Don't mark the inode as revalidated
if a LAYOUTCOMMIT is outstanding").  We know that if a LAYOUTCOMMIT is
outstanding then attributes will need upating, so always set
NFS_INO_INVALID_ATTR.

Signed-off-by: Benjamin Coddington 
Signed-off-by: Trond Myklebust

Merge branch 'writeback'

2016-07-24T21:08:31+00:00

pNFS: Don't mark the inode as revalidated if a LAYOUTCOMMIT is outstanding

2016-07-18T04:51:01+00:00

We know that the attributes will need updating if there is still a
LAYOUTCOMMIT outstanding.

Reported-by: Christoph Hellwig 
Signed-off-by: Trond Myklebust

NFS: Getattr doesn't require data sync semantics

2016-07-05T23:11:06+00:00

When retrieving stat() information, NFS unfortunately does require us to
sync writes to disk in order to ensure that mtime and ctime are up to
date. However we shouldn't have to ensure that those writes are persisted.

Relaxing that requirement does mean that we may see an mtime/ctime change
if the server reboots and forces us to replay all writes.

The exception to this rule are pNFS clients that are required to send
layoutcommit, however that is dealt with by the call to pnfs_sync_inode()
in _nfs_revalidate_inode().

Signed-off-by: Trond Myklebust

NFS: Do not aggressively cache file attributes in the case of O_DIRECT

2016-07-05T23:11:06+00:00

A file that is open for O_DIRECT is by definition not obeying
close-to-open cache consistency semantics, so let's not cache
the attributes too aggressively either.

Signed-off-by: Trond Myklebust

NFS: Remove unused function nfs_revalidate_mapping_protected()

2016-07-05T23:11:05+00:00

Clean up...

Signed-off-by: Trond Myklebust

pNFS: Ensure we layoutcommit before revalidating attributes

2016-07-05T23:08:27+00:00

If we need to update the cached attributes, then we'd better make
sure that we also layoutcommit first. Otherwise, the server may have stale
attributes.

Prior to this patch, the revalidation code tried to "fix" this problem by
simply disabling attributes that would be affected by the layoutcommit.
That approach breaks nfs_writeback_check_extend(), leading to a file size
corruption.

Signed-off-by: Trond Myklebust

NFS: Fix potential race in nfs_fhget()

2016-06-24T16:01:00+00:00

If we don't set the mode correctly in nfs_init_locked(), then there is
potential for a race with a second call to nfs_fhget that will cause
inode aliasing.

Signed-off-by: Trond Myklebust 
Reviewed-by: Jeff Layton 
Signed-off-by: Anna Schumaker

NFS: Cache aggressively when file is open for writing

2016-06-22T13:59:42+00:00

Unless the user is using file locking, we must assume close-to-open
cache consistency when the file is open for writing. Adjust the
caching algorithm so that it does not clear the cache on out-of-order
writes and/or attribute revalidations.

Signed-off-by: Trond Myklebust