Re: [PATCH 023/119] xfs: introduce rmap btree definitions

Brian Foster
2016-06-30T17:32:46Z

On Thu, Jun 16, 2016 at 06:20:19PM -0700, Darrick J. Wong wrote:
> From: Dave Chinner <dchinner@redhat.com>
>
> Add new per-ag rmap btree definitions to the per-ag structures. The
> rmap btree will sit in the empty slots on disk after the free space
> btrees, and hence form a part of the array of space management
> btrees. This requires the definition of the btree to be contiguous
> with the free space btrees.
>
> Signed-off-by: Dave Chinner <dchinner@redhat.com>
> Signed-off-by: Dave Chinner <david@fromorbit.com>
> ---

Reviewed-by: Brian Foster <bfoster@redhat.com>

> fs/xfs/libxfs/xfs_alloc.c | 6 ++++++
> fs/xfs/libxfs/xfs_btree.c | 4 ++--
> fs/xfs/libxfs/xfs_btree.h | 3 +++
> fs/xfs/libxfs/xfs_format.h | 22 +++++++++++++++++-----
> fs/xfs/libxfs/xfs_types.h | 4 ++--
> 5 files changed, 30 insertions(+), 9 deletions(-)
>
>
> diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c
> index 56c8690..b61e9c6 100644
> --- a/fs/xfs/libxfs/xfs_alloc.c
> +++ b/fs/xfs/libxfs/xfs_alloc.c
> @@ -2272,6 +2272,10 @@ xfs_agf_verify(
> be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNT]) > XFS_BTREE_MAXLEVELS)
> return false;
>
> + if (xfs_sb_version_hasrmapbt(&mp->m_sb) &&
> + be32_to_cpu(agf->agf_levels[XFS_BTNUM_RMAP]) > XFS_BTREE_MAXLEVELS)
> + return false;
> +
> /*
> * during growfs operations, the perag is not fully initialised,
> * so we can't use it for any useful checking. growfs ensures we can't
> @@ -2403,6 +2407,8 @@ xfs_alloc_read_agf(
> be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNOi]);
> pag->pagf_levels[XFS_BTNUM_CNTi] =
> be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNTi]);
> + pag->pagf_levels[XFS_BTNUM_RMAPi] =
> + be32_to_cpu(agf->agf_levels[XFS_BTNUM_RMAPi]);
> spin_lock_init(&pag->pagb_lock);
> pag->pagb_count = 0;
> #ifdef __KERNEL__
> diff --git a/fs/xfs/libxfs/xfs_btree.c b/fs/xfs/libxfs/xfs_btree.c
> index 5b3743a..624b572 100644
> --- a/fs/xfs/libxfs/xfs_btree.c
> +++ b/fs/xfs/libxfs/xfs_btree.c
> @@ -44,9 +44,9 @@ kmem_zone_t *xfs_btree_cur_zone;
> * Btree magic numbers.
> */
> static const __uint32_t xfs_magics[2][XFS_BTNUM_MAX] = {
> - { XFS_ABTB_MAGIC, XFS_ABTC_MAGIC, XFS_BMAP_MAGIC, XFS_IBT_MAGIC,
> + { XFS_ABTB_MAGIC, XFS_ABTC_MAGIC, 0, XFS_BMAP_MAGIC, XFS_IBT_MAGIC,
> XFS_FIBT_MAGIC },
> - { XFS_ABTB_CRC_MAGIC, XFS_ABTC_CRC_MAGIC,
> + { XFS_ABTB_CRC_MAGIC, XFS_ABTC_CRC_MAGIC, XFS_RMAP_CRC_MAGIC,
> XFS_BMAP_CRC_MAGIC, XFS_IBT_CRC_MAGIC, XFS_FIBT_CRC_MAGIC }
> };
> #define xfs_btree_magic(cur) \
> diff --git a/fs/xfs/libxfs/xfs_btree.h b/fs/xfs/libxfs/xfs_btree.h
> index 7483cac..202fdd3 100644
> --- a/fs/xfs/libxfs/xfs_btree.h
> +++ b/fs/xfs/libxfs/xfs_btree.h
> @@ -63,6 +63,7 @@ union xfs_btree_rec {
> #define XFS_BTNUM_BMAP ((xfs_btnum_t)XFS_BTNUM_BMAPi)
> #define XFS_BTNUM_INO ((xfs_btnum_t)XFS_BTNUM_INOi)
> #define XFS_BTNUM_FINO ((xfs_btnum_t)XFS_BTNUM_FINOi)
> +#define XFS_BTNUM_RMAP ((xfs_btnum_t)XFS_BTNUM_RMAPi)
>
> /*
> * For logging record fields.
> @@ -95,6 +96,7 @@ do { \
> case XFS_BTNUM_BMAP: __XFS_BTREE_STATS_INC(__mp, bmbt, stat); break; \
> case XFS_BTNUM_INO: __XFS_BTREE_STATS_INC(__mp, ibt, stat); break; \
> case XFS_BTNUM_FINO: __XFS_BTREE_STATS_INC(__mp, fibt, stat); break; \
> + case XFS_BTNUM_RMAP: break; \
> case XFS_BTNUM_MAX: ASSERT(0); __mp = __mp /* fucking gcc */ ; break; \
> } \
> } while (0)
> @@ -115,6 +117,7 @@ do { \
> __XFS_BTREE_STATS_ADD(__mp, ibt, stat, val); break; \
> case XFS_BTNUM_FINO: \
> __XFS_BTREE_STATS_ADD(__mp, fibt, stat, val); break; \
> + case XFS_BTNUM_RMAP: break; \
> case XFS_BTNUM_MAX: ASSERT(0); __mp = __mp /* fucking gcc */ ; break; \
> } \
> } while (0)
> diff --git a/fs/xfs/libxfs/xfs_format.h b/fs/xfs/libxfs/xfs_format.h
> index ba528b3..8ca4a3d 100644
> --- a/fs/xfs/libxfs/xfs_format.h
> +++ b/fs/xfs/libxfs/xfs_format.h
> @@ -455,6 +455,7 @@ xfs_sb_has_compat_feature(
> }
>
> #define XFS_SB_FEAT_RO_COMPAT_FINOBT (1 << 0) /* free inode btree */
> +#define XFS_SB_FEAT_RO_COMPAT_RMAPBT (1 << 1) /* reverse map btree */
> #define XFS_SB_FEAT_RO_COMPAT_ALL \
> (XFS_SB_FEAT_RO_COMPAT_FINOBT)
> #define XFS_SB_FEAT_RO_COMPAT_UNKNOWN ~XFS_SB_FEAT_RO_COMPAT_ALL
> @@ -538,6 +539,12 @@ static inline bool xfs_sb_version_hasmetauuid(struct xfs_sb *sbp)
> (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_META_UUID);
> }
>
> +static inline bool xfs_sb_version_hasrmapbt(struct xfs_sb *sbp)
> +{
> + return (XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_5) &&
> + (sbp->sb_features_ro_compat & XFS_SB_FEAT_RO_COMPAT_RMAPBT);
> +}
> +
> /*
> * end of superblock version macros
> */
> @@ -598,10 +605,10 @@ xfs_is_quota_inode(struct xfs_sb *sbp, xfs_ino_t ino)
> #define XFS_AGI_GOOD_VERSION(v) ((v) == XFS_AGI_VERSION)
>
> /*
> - * Btree number 0 is bno, 1 is cnt. This value gives the size of the
> + * Btree number 0 is bno, 1 is cnt, 2 is rmap. This value gives the size of the
> * arrays below.
> */
> -#define XFS_BTNUM_AGF ((int)XFS_BTNUM_CNTi + 1)
> +#define XFS_BTNUM_AGF ((int)XFS_BTNUM_RMAPi + 1)
>
> /*
> * The second word of agf_levels in the first a.g. overlaps the EFS
> @@ -618,12 +625,10 @@ typedef struct xfs_agf {
> __be32 agf_seqno; /* sequence # starting from 0 */
> __be32 agf_length; /* size in blocks of a.g. */
> /*
> - * Freespace information
> + * Freespace and rmap information
> */
> __be32 agf_roots[XFS_BTNUM_AGF]; /* root blocks */
> - __be32 agf_spare0; /* spare field */
> __be32 agf_levels[XFS_BTNUM_AGF]; /* btree levels */
> - __be32 agf_spare1; /* spare field */
>
> __be32 agf_flfirst; /* first freelist block's index */
> __be32 agf_fllast; /* last freelist block's index */
> @@ -1307,6 +1312,13 @@ typedef __be32 xfs_inobt_ptr_t;
> #define XFS_FIBT_BLOCK(mp) ((xfs_agblock_t)(XFS_IBT_BLOCK(mp) + 1))
>
> /*
> + * Reverse mapping btree format definitions
> + *
> + * There is a btree for the reverse map per allocation group
> + */
> +#define XFS_RMAP_CRC_MAGIC 0x524d4233 /* 'RMB3' */
> +
> +/*
> * The first data block of an AG depends on whether the filesystem was formatted
> * with the finobt feature. If so, account for the finobt reserved root btree
> * block.
> diff --git a/fs/xfs/libxfs/xfs_types.h b/fs/xfs/libxfs/xfs_types.h
> index f0d145a..da87796 100644
> --- a/fs/xfs/libxfs/xfs_types.h
> +++ b/fs/xfs/libxfs/xfs_types.h
> @@ -111,8 +111,8 @@ typedef enum {
> } xfs_lookup_t;
>
> typedef enum {
> - XFS_BTNUM_BNOi, XFS_BTNUM_CNTi, XFS_BTNUM_BMAPi, XFS_BTNUM_INOi,
> - XFS_BTNUM_FINOi, XFS_BTNUM_MAX
> + XFS_BTNUM_BNOi, XFS_BTNUM_CNTi, XFS_BTNUM_RMAPi, XFS_BTNUM_BMAPi,
> + XFS_BTNUM_INOi, XFS_BTNUM_FINOi, XFS_BTNUM_MAX
> } xfs_btnum_t;
>
> struct xfs_name {
>
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