This is a note to let you know that I've just added the patch titled
ovl: take mnt_want_write() for removing impure xattr
to the 4.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: ovl-take-mnt_want_write-for-removing-impure-xattr.patch and it can be found in the queue-4.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From a5a927a7c82e28ea76599dee4019c41e372c911f Mon Sep 17 00:00:00 2001
From: Amir Goldstein amir73il@gmail.com Date: Wed, 3 Jan 2018 18:54:42 +0200 Subject: ovl: take mnt_want_write() for removing impure xattr
From: Amir Goldstein amir73il@gmail.com
commit a5a927a7c82e28ea76599dee4019c41e372c911f upstream.
The optimization in ovl_cache_get_impure() that tries to remove an unneeded "impure" xattr needs to take mnt_want_write() on upper fs.
Fixes: 4edb83bb1041 ("ovl: constant d_ino for non-merge dirs") Signed-off-by: Amir Goldstein amir73il@gmail.com Signed-off-by: Miklos Szeredi mszeredi@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- fs/overlayfs/readdir.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-)
--- a/fs/overlayfs/readdir.c +++ b/fs/overlayfs/readdir.c @@ -593,8 +593,15 @@ static struct ovl_dir_cache *ovl_cache_g return ERR_PTR(res); } if (list_empty(&cache->entries)) { - /* Good oportunity to get rid of an unnecessary "impure" flag */ - ovl_do_removexattr(ovl_dentry_upper(dentry), OVL_XATTR_IMPURE); + /* + * A good opportunity to get rid of an unneeded "impure" flag. + * Removing the "impure" xattr is best effort. + */ + if (!ovl_want_write(dentry)) { + ovl_do_removexattr(ovl_dentry_upper(dentry), + OVL_XATTR_IMPURE); + ovl_drop_write(dentry); + } ovl_clear_flag(OVL_IMPURE, d_inode(dentry)); kfree(cache); return NULL;
Patches currently in stable-queue which might be from amir73il@gmail.com are
queue-4.15/ovl-take-mnt_want_write-for-removing-impure-xattr.patch queue-4.15/ovl-take-mnt_want_write-for-work-index-dir-setup.patch queue-4.15/ovl-hash-directory-inodes-for-fsnotify.patch queue-4.15/ovl-force-r-o-mount-when-index-dir-creation-fails.patch queue-4.15/ovl-fix-failure-to-fsync-lower-dir.patch