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| author | Brian Foster | 2014-04-24 08:00:52 +0200 |
|---|---|---|
| committer | Dave Chinner | 2014-04-24 08:00:52 +0200 |
| commit | 8e2c84df20aa66ae9a6ee32831a9c622f4823118 (patch) | |
| tree | 8bd22beb613b809dbf75531b56fbb6c9ad0f6d6a | |
| parent | xfs: refactor xfs_ialloc_btree.c to support multiple inobt numbers (diff) | |
| download | kernel-qcow2-linux-8e2c84df20aa66ae9a6ee32831a9c622f4823118.tar.gz kernel-qcow2-linux-8e2c84df20aa66ae9a6ee32831a9c622f4823118.tar.xz kernel-qcow2-linux-8e2c84df20aa66ae9a6ee32831a9c622f4823118.zip | |
xfs: reserve v5 superblock read-only compat. feature bit for finobt
Reserve a v5 read-only compatibility feature bit for the finobt and
create the xfs_sb_version_hasfinobt() helper to determine whether
an fs has the feature enabled.
The finobt does not change existing on-disk structures, but must
remain consistent with the ialloc btree. Modifications from older
kernels would violate that constrant. Therefore, we restrict older
kernels to read-only mounts of finobt-enabled filesystems.
Note that this does not yet enable the ability to rw mount a finobt
fs (by setting the feature bit in the XFS_SB_FEAT_RO_COMPAT_ALL
mask).
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
| -rw-r--r-- | fs/xfs/xfs_sb.h | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/fs/xfs/xfs_sb.h b/fs/xfs/xfs_sb.h index f7b2fe77c5a5..7f53a858e85b 100644 --- a/fs/xfs/xfs_sb.h +++ b/fs/xfs/xfs_sb.h @@ -587,6 +587,7 @@ xfs_sb_has_compat_feature( return (sbp->sb_features_compat & feature) != 0; } +#define XFS_SB_FEAT_RO_COMPAT_FINOBT (1 << 0) /* free inode btree */ #define XFS_SB_FEAT_RO_COMPAT_ALL 0 #define XFS_SB_FEAT_RO_COMPAT_UNKNOWN ~XFS_SB_FEAT_RO_COMPAT_ALL static inline bool @@ -641,6 +642,12 @@ static inline int xfs_sb_version_hasftype(struct xfs_sb *sbp) (sbp->sb_features2 & XFS_SB_VERSION2_FTYPE)); } +static inline int xfs_sb_version_hasfinobt(xfs_sb_t *sbp) +{ + return (XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_5) && + (sbp->sb_features_ro_compat & XFS_SB_FEAT_RO_COMPAT_FINOBT); +} + /* * end of superblock version macros */ |