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authorTrond Myklebust <trond.myklebust@primarydata.com>2016-09-22 13:38:52 -0400
committerAnna Schumaker <Anna.Schumaker@Netapp.com>2016-09-27 14:31:52 -0400
commit7dc72d5f7a0ec97a53e126c46e2cbd2560757955 (patch)
tree156b815db4fd3d78958bb3754a57855e02984c11
parent0a014a44a50839a8064618e959fae5bbc44c2fd5 (diff)
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NFS: Fix inode corruption in nfs_prime_dcache()
Due to inode number reuse in filesystems, we can end up corrupting the inode on our client if we apply the file attributes without ensuring that the filehandle matches. Typical symptoms include spurious "mode changed" reports in the syslog. We still do want to ensure that we don't invalidate the dentry if the inode number matches, but we don't have a filehandle. Fixes: fa9233699cc1 ("NFS: Don't require a filehandle to refresh...") Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com> Cc: stable@vger.kernel.org # v4.0+ Tested-by: Oleg Drokin <green@linuxhacker.ru> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
-rw-r--r--fs/nfs/dir.c16
1 files changed, 11 insertions, 5 deletions
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index eb095f77c39d..2bade7909dec 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -435,11 +435,11 @@ int nfs_same_file(struct dentry *dentry, struct nfs_entry *entry)
return 0;
nfsi = NFS_I(inode);
- if (entry->fattr->fileid == nfsi->fileid)
- return 1;
- if (nfs_compare_fh(entry->fh, &nfsi->fh) == 0)
- return 1;
- return 0;
+ if (entry->fattr->fileid != nfsi->fileid)
+ return 0;
+ if (entry->fh->size && nfs_compare_fh(entry->fh, &nfsi->fh) != 0)
+ return 0;
+ return 1;
}
static
@@ -525,6 +525,8 @@ again:
&entry->fattr->fsid))
goto out;
if (nfs_same_file(dentry, entry)) {
+ if (!entry->fh->size)
+ goto out;
nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
status = nfs_refresh_inode(d_inode(dentry), entry->fattr);
if (!status)
@@ -537,6 +539,10 @@ again:
goto again;
}
}
+ if (!entry->fh->size) {
+ d_lookup_done(dentry);
+ goto out;
+ }
inode = nfs_fhget(dentry->d_sb, entry->fh, entry->fattr, entry->label);
alias = d_splice_alias(inode, dentry);