From c6f589303d8e87238b8592af96e9126849006cc7 Mon Sep 17 00:00:00 2001 From: pfg Date: Thu, 27 Feb 2014 16:05:52 +0000 Subject: [PATCH] MFC r262346: ext2fs: fully enable ext4 read-only support. The ext4 developers tend to tag Ext4-specific flags as "incompatible" even when such features are not relevant for read-only support. This is a consequence of the process though which this filesystem is implemented without design and the fact that some new features are not extensible to ext2/3. Organize the features according to what we support and sort them so that we can now read-only mount filesystems with some features that may be found in newly formatted ext4 fs. Submitted by: Zheng Liu git-svn-id: svn://svn.freebsd.org/base/stable/10@262563 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f --- sys/fs/ext2fs/ext2_vfsops.c | 3 ++- sys/fs/ext2fs/ext2fs.h | 17 ++++++++++++----- 2 files changed, 14 insertions(+), 6 deletions(-) diff --git a/sys/fs/ext2fs/ext2_vfsops.c b/sys/fs/ext2fs/ext2_vfsops.c index a18d5cc1d..77e08ce09 100644 --- a/sys/fs/ext2fs/ext2_vfsops.c +++ b/sys/fs/ext2fs/ext2_vfsops.c @@ -290,7 +290,8 @@ ext2_check_sb_compat(struct ext2fs *es, struct cdev *dev, int ronly) return (1); } if (es->e2fs_rev > E2FS_REV0) { - if (es->e2fs_features_incompat & ~EXT2F_INCOMPAT_SUPP) { + if (es->e2fs_features_incompat & ~(EXT2F_INCOMPAT_SUPP | + EXT4F_RO_INCOMPAT_SUPP)) { printf( "WARNING: mount of %s denied due to unsupported optional features\n", devtoname(dev)); diff --git a/sys/fs/ext2fs/ext2fs.h b/sys/fs/ext2fs/ext2fs.h index b562287ca..fcb2cde7b 100644 --- a/sys/fs/ext2fs/ext2fs.h +++ b/sys/fs/ext2fs/ext2fs.h @@ -200,19 +200,26 @@ struct csum { * We support the following REV1 features: * - EXT2F_ROCOMPAT_SPARSESUPER * - EXT2F_ROCOMPAT_LARGEFILE + * - EXT2F_ROCOMPAT_EXTRA_ISIZE * - EXT2F_INCOMPAT_FTYPE * - * We partially (read-only) support the following EXT4 features: + * We partially support (read-only) the following EXT4 features: * - EXT2F_ROCOMPAT_HUGE_FILE - * - EXT2F_ROCOMPAT_EXTRA_ISIZE * - EXT2F_INCOMPAT_EXTENTS + * + * We do not support these EXT4 features but they are irrelevant + * for read-only support: + * - EXT2F_INCOMPAT_FLEX_BG + * - EXT2F_INCOMPAT_META_BG */ -#define EXT2F_COMPAT_SUPP 0x0000 +#define EXT2F_COMPAT_SUPP EXT2F_COMPAT_DIRHASHINDEX #define EXT2F_ROCOMPAT_SUPP (EXT2F_ROCOMPAT_SPARSESUPER | \ EXT2F_ROCOMPAT_LARGEFILE | \ EXT2F_ROCOMPAT_EXTRA_ISIZE) -#define EXT2F_INCOMPAT_SUPP (EXT2F_INCOMPAT_FTYPE | \ - EXT2F_INCOMPAT_EXTENTS) +#define EXT2F_INCOMPAT_SUPP EXT2F_INCOMPAT_FTYPE +#define EXT4F_RO_INCOMPAT_SUPP (EXT2F_INCOMPAT_EXTENTS | \ + EXT2F_INCOMPAT_FLEX_BG | \ + EXT2F_INCOMPAT_META_BG ) /* Assume that user mode programs are passing in an ext2fs superblock, not * a kernel struct super_block. This will allow us to call the feature-test -- 2.45.0