3.19-stable review patch. If anyone has any objections, please let me know.
------------------ From: Trond Myklebust <[email protected]> commit 6c441c254eea2354d686be7f5544bcd79fb6a61f upstream. If we're traversing a directory which contains a submounted filesystem, or one that has a referral, the NFS server that is processing the READDIR request will often return information for the underlying (mounted-on) directory. It may, or may not, also return filehandle information. If this happens, and the lookup in nfs_prime_dcache() returns the dentry for the submounted directory, the filehandle comparison will fail, and we call d_invalidate(). Post-commit 8ed936b5671bf ("vfs: Lazily remove mounts on unlinked files and directories."), this means the entire subtree is unmounted. The following minimal patch addresses this problem by punting on the invalidation if there is a submount. Kudos to Neil Brown <[email protected]> for having tracked down this issue (see link). Reported-by: Nix <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Trond Myklebust <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- fs/nfs/dir.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/fs/nfs/dir.c +++ b/fs/nfs/dir.c @@ -469,6 +469,8 @@ void nfs_prime_dcache(struct dentry *par struct inode *inode; int status; + if (!(entry->fattr->valid & NFS_ATTR_FATTR_FSID)) + return; if (filename.name[0] == '.') { if (filename.len == 1) return; @@ -479,6 +481,10 @@ void nfs_prime_dcache(struct dentry *par dentry = d_lookup(parent, &filename); if (dentry != NULL) { + /* Is there a mountpoint here? If so, just exit */ + if (!nfs_fsid_equal(&NFS_SB(dentry->d_sb)->fsid, + &entry->fattr->fsid)) + goto out; if (nfs_same_file(dentry, entry)) { nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); status = nfs_refresh_inode(dentry->d_inode, entry->fattr); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
