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MAdnPcDVFzaXJdlAAJdjfg/lyJtAyxifflG8NnXJ3elwGqoBso84XBNWWzbc5VKmatzhYLOvXtfzDhu4mNPv/z7S1HTtRguI0NlH5RVBzSvfzybin9hysE3/+r3C0HJ2xiOHzucNAmG03aztzZYDMTbKQW4bQqeD5MJxT68vBYu8MtzfIe41lSLpb/qlwq1qg0iQElBBgBAgAPBQJUdhaZAhsMBQkA7U4AAAoJEIFK5HwhSFTW3YgH/AyJL2rlCvGrkLcas94ND9Pmn0cUlVrPl7wVGcIV+6I4nrw6u49TyqNMmsYam2YpjervJGgbvIbMzoHFCREi6R9XyUsw5w7GCRoWegw2blZYi5A52xe500+/RruG//MKfOtVUotu3N+u7FcXaYAg9gbYeGNZCV70vI+cnFgq0AEJRdjidzfCWVKPjafTo7jHeFxX7Q22kUfWOkMzzhoDbFg0jPhVYNiEXpNyXCwirzvKA7bvFwZPlRkbfihaiXDE7QKIUtQ10i5kw4C9rqDKwx8F0PaWDRF9gGaKd7/IJGHJaac/OcSJ36zxgkNgLsVX5GUroJ2GaZcR7W9Vppj5H+C4UgRkuRyTEwgqhkjOPQMBBwIDBOySomnsW2SkApXv1zUBaD38dFEj0LQeDEMdSE7bm1fnrdjAYt0f/CtbUUiDaPodQk2qeHzOP6wA/2K6rrjwNIWJAT0EGAEIACcDGyAEFiEE1WBuc8i0YnG+rZrfgUrkfCFIVNYFAmWoM/gFCQSxfmUACgkQgUrkfCFIVNZhTgf/VQxtQ5rgu2aoXh2KOH6naGzPKDkYDJ/K7XCJAq3nJYEpYN8G+F8mL/ql0hrihAsHfjmoDOlt+INa3AcG3v0jDZIMEzmcjAlu7g5NcXS3kntcMHgw3dCgE9eYDaKGipUCubdXvBaZWU6AUlTldaB8FE6u7It7+UO+IW4/L+KpLYKs8V5POInu2rqahlm7vgxY5iv4Txz4EvCW2e4dAlG 8mT2Eh9SkH+YVOmaKsajgZgrBxA7fWmGoxXswEVxJIFj3vW7yNc0C5HaUdYa5iGOMs4kg2ht4s7yy7NRQuh7BifWjo6BQ6k4S1H+6axZucxhSV1L6zN9d+lr3Xo/vy1unzA== Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.50.3 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 On Mon, 2025-03-31 at 14:42 +0200, Christian Brauner wrote: > Allow efivarfs to partake to resync variable state during system > hibernation and suspend. Add freeze/thaw support. >=20 > This is a pretty straightforward implementation. We simply add > regular freeze/thaw support for both userspace and the kernel. This > works without any big issues and congrats afaict efivars is the first > pseudofilesystem that adds support for filesystem freezing and > thawing. >=20 > The simplicity comes from the fact that we simply always resync > variable state after efivarfs has been frozen. It doesn't matter > whether that's because of suspend, userspace initiated freeze or > hibernation. Efivars is simple enough that it doesn't matter that we > walk all dentries. There are no directories and there aren't insane > amounts of entries and both freeze/thaw are already heavy-handed > operations. We really really don't need to care. Just as a point of order: this can't actually work until freeze/thaw is actually plumbed into suspend/resume. >=20 > Signed-off-by: Christian Brauner > --- > =C2=A0fs/efivarfs/internal.h |=C2=A0=C2=A0 1 - > =C2=A0fs/efivarfs/super.c=C2=A0=C2=A0=C2=A0 | 196 +++++++++++++----------= ---------------- > ---------- > =C2=A02 files changed, 51 insertions(+), 146 deletions(-) >=20 > diff --git a/fs/efivarfs/internal.h b/fs/efivarfs/internal.h > index ac6a1dd0a6a5..f913b6824289 100644 > --- a/fs/efivarfs/internal.h > +++ b/fs/efivarfs/internal.h > @@ -17,7 +17,6 @@ struct efivarfs_fs_info { > =C2=A0 struct efivarfs_mount_opts mount_opts; > =C2=A0 struct super_block *sb; > =C2=A0 struct notifier_block nb; > - struct notifier_block pm_nb; > =C2=A0}; > =C2=A0 > =C2=A0struct efi_variable { > diff --git a/fs/efivarfs/super.c b/fs/efivarfs/super.c > index 0486e9b68bc6..567e849a03fe 100644 > --- a/fs/efivarfs/super.c > +++ b/fs/efivarfs/super.c > @@ -20,6 +20,7 @@ > =C2=A0#include > =C2=A0 > =C2=A0#include "internal.h" > +#include "../internal.h" > =C2=A0 > =C2=A0static int efivarfs_ops_notifier(struct notifier_block *nb, unsigne= d > long event, > =C2=A0 void *data) > @@ -119,12 +120,18 @@ static int efivarfs_statfs(struct dentry > *dentry, struct kstatfs *buf) > =C2=A0 > =C2=A0 return 0; > =C2=A0} > + > +static int efivarfs_freeze_fs(struct super_block *sb); > +static int efivarfs_unfreeze_fs(struct super_block *sb); > + > =C2=A0static const struct super_operations efivarfs_ops =3D { > =C2=A0 .statfs =3D efivarfs_statfs, > =C2=A0 .drop_inode =3D generic_delete_inode, > =C2=A0 .alloc_inode =3D efivarfs_alloc_inode, > =C2=A0 .free_inode =3D efivarfs_free_inode, > =C2=A0 .show_options =3D efivarfs_show_options, > + .freeze_fs =3D efivarfs_freeze_fs, Why is it necessary to have a freeze_fs operation? The current code in super.c:freeze_super() reads: if (sb->s_op->freeze_fs) { ret =3D sb->s_op->freeze_fs(sb); So it would seem that setting this to NULL has exactly the same effect as providing a null method. > + .unfreeze_fs =3D efivarfs_unfreeze_fs, > =C2=A0}; > =C2=A0 > =C2=A0/* >=20 [...] > @@ -608,9 +516,7 @@ static void efivarfs_kill_sb(struct super_block > *sb) > =C2=A0{ > =C2=A0 struct efivarfs_fs_info *sfi =3D sb->s_fs_info; > =C2=A0 > - blocking_notifier_chain_unregister(&efivar_ops_nh, &sfi- > >nb); This is an extraneous deletion of an unrelated notifier which efivarfs still needs to listen for ops updates from the efi subsystem. Regards, James