diff options
author | pfg <pfg@FreeBSD.org> | 2014-02-22 22:07:16 +0000 |
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committer | pfg <pfg@FreeBSD.org> | 2014-02-22 22:07:16 +0000 |
commit | 9e48499196550691019d14fa0694357a14039db4 (patch) | |
tree | b5559eca5ecc321cd7df531dca0a5206e5363544 | |
parent | f462797a7d2b0afc9492194e33457e4887fcee49 (diff) | |
download | FreeBSD-src-9e48499196550691019d14fa0694357a14039db4.zip FreeBSD-src-9e48499196550691019d14fa0694357a14039db4.tar.gz |
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
Reviewed by: pfg
MFC after: 5 days
-rw-r--r-- | sys/fs/ext2fs/ext2_vfsops.c | 3 | ||||
-rw-r--r-- | sys/fs/ext2fs/ext2fs.h | 15 |
2 files changed, 13 insertions, 5 deletions
diff --git a/sys/fs/ext2fs/ext2_vfsops.c b/sys/fs/ext2fs/ext2_vfsops.c index a18d5cc1..77e08ce 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 b562287..d6d045b 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: * - 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 |