From: Dave Chinner dchinner@redhat.com
[ Upstream commit f0f5f658065a5af09126ec892e4c383540a1c77f ]
We don't check that the v4 feature flags taht v5 requires to be set are actually set anywhere. Do this check when we see that the filesystem is a v5 filesystem.
Signed-off-by: Dave Chinner dchinner@redhat.com Reviewed-by: Christoph Hellwig hch@lst.de Reviewed-by: Darrick J. Wong djwong@kernel.org Signed-off-by: Dave Chinner david@fromorbit.com Signed-off-by: Leah Rumancik leah.rumancik@gmail.com Acked-by: Darrick J. Wong djwong@kernel.org --- fs/xfs/libxfs/xfs_sb.c | 68 +++++++++++++++++++++++++++++++++++------- 1 file changed, 58 insertions(+), 10 deletions(-)
diff --git a/fs/xfs/libxfs/xfs_sb.c b/fs/xfs/libxfs/xfs_sb.c index 72c05485c870..04e2a57313fa 100644 --- a/fs/xfs/libxfs/xfs_sb.c +++ b/fs/xfs/libxfs/xfs_sb.c @@ -30,6 +30,47 @@ * Physical superblock buffer manipulations. Shared with libxfs in userspace. */
+/* + * Check that all the V4 feature bits that the V5 filesystem format requires are + * correctly set. + */ +static bool +xfs_sb_validate_v5_features( + struct xfs_sb *sbp) +{ + /* We must not have any unknown V4 feature bits set */ + if (sbp->sb_versionnum & ~XFS_SB_VERSION_OKBITS) + return false; + + /* + * The CRC bit is considered an invalid V4 flag, so we have to add it + * manually to the OKBITS mask. + */ + if (sbp->sb_features2 & ~(XFS_SB_VERSION2_OKBITS | + XFS_SB_VERSION2_CRCBIT)) + return false; + + /* Now check all the required V4 feature flags are set. */ + +#define V5_VERS_FLAGS (XFS_SB_VERSION_NLINKBIT | \ + XFS_SB_VERSION_ALIGNBIT | \ + XFS_SB_VERSION_LOGV2BIT | \ + XFS_SB_VERSION_EXTFLGBIT | \ + XFS_SB_VERSION_DIRV2BIT | \ + XFS_SB_VERSION_MOREBITSBIT) + +#define V5_FEAT_FLAGS (XFS_SB_VERSION2_LAZYSBCOUNTBIT | \ + XFS_SB_VERSION2_ATTR2BIT | \ + XFS_SB_VERSION2_PROJID32BIT | \ + XFS_SB_VERSION2_CRCBIT) + + if ((sbp->sb_versionnum & V5_VERS_FLAGS) != V5_VERS_FLAGS) + return false; + if ((sbp->sb_features2 & V5_FEAT_FLAGS) != V5_FEAT_FLAGS) + return false; + return true; +} + /* * We support all XFS versions newer than a v4 superblock with V2 directories. */ @@ -37,9 +78,19 @@ bool xfs_sb_good_version( struct xfs_sb *sbp) { - /* all v5 filesystems are supported */ + /* + * All v5 filesystems are supported, but we must check that all the + * required v4 feature flags are enabled correctly as the code checks + * those flags and not for v5 support. + */ if (xfs_sb_is_v5(sbp)) - return true; + return xfs_sb_validate_v5_features(sbp); + + /* We must not have any unknown v4 feature bits set */ + if ((sbp->sb_versionnum & ~XFS_SB_VERSION_OKBITS) || + ((sbp->sb_versionnum & XFS_SB_VERSION_MOREBITSBIT) && + (sbp->sb_features2 & ~XFS_SB_VERSION2_OKBITS))) + return false;
/* versions prior to v4 are not supported */ if (XFS_SB_VERSION_NUM(sbp) < XFS_SB_VERSION_4) @@ -51,12 +102,6 @@ xfs_sb_good_version( if (!(sbp->sb_versionnum & XFS_SB_VERSION_EXTFLGBIT)) return false;
- /* And must not have any unknown v4 feature bits set */ - if ((sbp->sb_versionnum & ~XFS_SB_VERSION_OKBITS) || - ((sbp->sb_versionnum & XFS_SB_VERSION_MOREBITSBIT) && - (sbp->sb_features2 & ~XFS_SB_VERSION2_OKBITS))) - return false; - /* It's a supported v4 filesystem */ return true; } @@ -264,12 +309,15 @@ xfs_validate_sb_common( bool has_dalign;
if (!xfs_verify_magic(bp, dsb->sb_magicnum)) { - xfs_warn(mp, "bad magic number"); + xfs_warn(mp, +"Superblock has bad magic number 0x%x. Not an XFS filesystem?", + be32_to_cpu(dsb->sb_magicnum)); return -EWRONGFS; }
if (!xfs_sb_good_version(sbp)) { - xfs_warn(mp, "bad version"); + xfs_warn(mp, +"Superblock has unknown features enabled or corrupted feature masks."); return -EWRONGFS; }