| Message ID | 1493283574-1497-2-git-send-email-amir73il@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, Apr 27, 2017 at 11:59:30AM +0300, Amir Goldstein wrote: > Overlayfs would like to make use of underlying filesystem's > sb->s_uuid, but not all filesytems fill this field. > > Define a flag to be set by filesystems that do fill the s_uuid > field, so let consumers like overlayfs know that the content > of this field is valid. > > Signed-off-by: Amir Goldstein <amir73il@gmail.com> > --- > include/linux/fs.h | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/include/linux/fs.h b/include/linux/fs.h > index 80daadf..de913b4 100644 > --- a/include/linux/fs.h > +++ b/include/linux/fs.h > @@ -1272,6 +1272,9 @@ struct mm_struct; > /* sb->s_iflags to limit user namespace mounts */ > #define SB_I_USERNS_VISIBLE 0x00000010 /* fstype already mounted */ > > +/* sb->s_iflags for optional information available in super_block struct */ > +#define SB_I_HAVE_UUID 0x00000100 /* s_uuid */ SB_I_CAN_HAZ_UUID, heh. :) There seems to be demand for a "Yes I really filled this out" flag, so for the vfs and xfs parts, Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> (I wonder why we can't just leave s_uuid as nil and to heck with anyone who deliberately sets their fs to have a nil uuid (like we do now), but whatever... :)) --D > + > /* Possible states of 'frozen' field */ > enum { > SB_UNFROZEN = 0, /* FS is unfrozen */ > -- > 2.7.4 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-xfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/include/linux/fs.h b/include/linux/fs.h index 80daadf..de913b4 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1272,6 +1272,9 @@ struct mm_struct; /* sb->s_iflags to limit user namespace mounts */ #define SB_I_USERNS_VISIBLE 0x00000010 /* fstype already mounted */ +/* sb->s_iflags for optional information available in super_block struct */ +#define SB_I_HAVE_UUID 0x00000100 /* s_uuid */ + /* Possible states of 'frozen' field */ enum { SB_UNFROZEN = 0, /* FS is unfrozen */
Overlayfs would like to make use of underlying filesystem's sb->s_uuid, but not all filesytems fill this field. Define a flag to be set by filesystems that do fill the s_uuid field, so let consumers like overlayfs know that the content of this field is valid. Signed-off-by: Amir Goldstein <amir73il@gmail.com> --- include/linux/fs.h | 3 +++ 1 file changed, 3 insertions(+)