Re: [PATCH 05/24] xfs: define the on-disk refcount btree format

Darrick J. Wong
2015-07-30T22:14:21Z

On Thu, Jul 30, 2015 at 10:42:15AM +1000, Dave Chinner wrote:
> On Wed, Jul 29, 2015 at 03:33:30PM -0700, Darrick J. Wong wrote:
> > Start constructing the refcount btree implementation by establishing
> > the on-disk format and everything needed to read, write, and
> > manipulate the refcount btree blocks.
> >
> > Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
> ....
> > +STATIC bool
> > +xfs_refcountbt_verify(
> > + struct xfs_buf *bp)
>
> feel free to shorten that prefix to xfs_refcbt_.....

Ok, will do for next release.

>
> > +{
> > + struct xfs_mount *mp = bp->b_target->bt_mount;
> > + struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
> > + struct xfs_perag *pag = bp->b_pag;
> > + unsigned int level;
> > +
> > + if (block->bb_magic != cpu_to_be32(XFS_REFC_CRC_MAGIC))
> > + return false;
> > +
> > + if (!xfs_sb_version_hasreflink(&mp->m_sb))
> > + return false;
> > + if (!uuid_equal(&block->bb_u.s.bb_uuid, &mp->m_sb.sb_uuid))
> > + return false;
> > + if (block->bb_u.s.bb_blkno != cpu_to_be64(bp->b_bn))
> > + return false;
> > + if (pag &&
> > + be32_to_cpu(block->bb_u.s.bb_owner) != pag->pag_agno)
> > + return false;
> > +
> > + level = be16_to_cpu(block->bb_level);
> > + if (pag && pag->pagf_init) {
> > + if (level >= pag->pagf_refcount_level)
> > + return false;
> > + } else if (level >= mp->m_ag_maxlevels)
> > + return false;
> > +
> > + /* numrecs verification */
> > + if (be16_to_cpu(block->bb_numrecs) > mp->m_refc_mxr[level != 0])
> > + return false;
> > +
> > + /* sibling pointer verification */
> > + if (!block->bb_u.s.bb_leftsib ||
> > + (be32_to_cpu(block->bb_u.s.bb_leftsib) >= mp->m_sb.sb_agblocks &&
> > + block->bb_u.s.bb_leftsib != cpu_to_be32(NULLAGBLOCK)))
> > + return false;
> > + if (!block->bb_u.s.bb_rightsib ||
> > + (be32_to_cpu(block->bb_u.s.bb_rightsib) >= mp->m_sb.sb_agblocks &&
> > + block->bb_u.s.bb_rightsib != cpu_to_be32(NULLAGBLOCK)))
> > + return false;
>
> I'm starting to think there's a xfs_btree_sblock_verify() function
> we need to factor out of all these btree verification functions...

Something like this?

--D

From: Darrick J. Wong <darrick.wong@oracle.com>
Subject: [PATCH] libxfs: refactor short btree block verification

Create xfs_btree_sblock_verify() to verify short-format btree blocks
(i.e. the per-AG btrees with 32-bit block pointers) instead of
open-coding them.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
fs/xfs/libxfs/xfs_alloc_btree.c | 34 ++--------------------
fs/xfs/libxfs/xfs_btree.c | 58 ++++++++++++++++++++++++++++++++++++++
fs/xfs/libxfs/xfs_btree.h | 3 ++
fs/xfs/libxfs/xfs_ialloc_btree.c | 30 +++-----------------
fs/xfs/libxfs/xfs_rmap_btree.c | 25 +++-------------
5 files changed, 73 insertions(+), 77 deletions(-)

diff --git a/fs/xfs/libxfs/xfs_alloc_btree.c b/fs/xfs/libxfs/xfs_alloc_btree.c
index 59d521c..1352322 100644
--- a/fs/xfs/libxfs/xfs_alloc_btree.c
+++ b/fs/xfs/libxfs/xfs_alloc_btree.c
@@ -293,14 +293,7 @@ xfs_allocbt_verify(
level = be16_to_cpu(block->bb_level);
switch (block->bb_magic) {
case cpu_to_be32(XFS_ABTB_CRC_MAGIC):
- if (!xfs_sb_version_hascrc(&mp->m_sb))
- return false;
- if (!uuid_equal(&block->bb_u.s.bb_uuid, &mp->m_sb.sb_uuid))
- return false;
- if (block->bb_u.s.bb_blkno != cpu_to_be64(bp->b_bn))
- return false;
- if (pag &&
- be32_to_cpu(block->bb_u.s.bb_owner) != pag->pag_agno)
+ if (!xfs_btree_sblock_v5hdr_verify(bp))
return false;
/* fall through */
case cpu_to_be32(XFS_ABTB_MAGIC):
@@ -311,14 +304,7 @@ xfs_allocbt_verify(
return false;
break;
case cpu_to_be32(XFS_ABTC_CRC_MAGIC):
- if (!xfs_sb_version_hascrc(&mp->m_sb))
- return false;
- if (!uuid_equal(&block->bb_u.s.bb_uuid, &mp->m_sb.sb_uuid))
- return false;
- if (block->bb_u.s.bb_blkno != cpu_to_be64(bp->b_bn))
- return false;
- if (pag &&
- be32_to_cpu(block->bb_u.s.bb_owner) != pag->pag_agno)
+ if (!xfs_btree_sblock_v5hdr_verify(bp))
return false;
/* fall through */
case cpu_to_be32(XFS_ABTC_MAGIC):
@@ -332,21 +318,7 @@ xfs_allocbt_verify(
return false;
}

- /* numrecs verification */
- if (be16_to_cpu(block->bb_numrecs) > mp->m_alloc_mxr[level != 0])
- return false;
-
- /* sibling pointer verification */
- if (!block->bb_u.s.bb_leftsib ||
- (be32_to_cpu(block->bb_u.s.bb_leftsib) >= mp->m_sb.sb_agblocks &&
- block->bb_u.s.bb_leftsib != cpu_to_be32(NULLAGBLOCK)))
- return false;
- if (!block->bb_u.s.bb_rightsib ||
- (be32_to_cpu(block->bb_u.s.bb_rightsib) >= mp->m_sb.sb_agblocks &&
- block->bb_u.s.bb_rightsib != cpu_to_be32(NULLAGBLOCK)))
- return false;
-
- return true;
+ return xfs_btree_sblock_verify(bp, mp->m_alloc_mxr[level != 0]);
}

static void
diff --git a/fs/xfs/libxfs/xfs_btree.c b/fs/xfs/libxfs/xfs_btree.c
index 4c9b9b3..d0ca2ca 100644
--- a/fs/xfs/libxfs/xfs_btree.c
+++ b/fs/xfs/libxfs/xfs_btree.c
@@ -4068,3 +4068,61 @@ xfs_btree_change_owner(

return 0;
}
+
+/**
+ * xfs_btree_sblock_v5hdr_verify() -- verify the v5 fields of a short-format
+ * btree block
+ *
+ * @bp: buffer containing the btree block
+ * @max_recs: pointer to the m_*_mxr max records field in the xfs mount
+ * @pag_max_level: pointer to the per-ag max level field
+ */
+bool
+xfs_btree_sblock_v5hdr_verify(
+ struct xfs_buf *bp)
+{
+ struct xfs_mount *mp = bp->b_target->bt_mount;
+ struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
+ struct xfs_perag *pag = bp->b_pag;
+
+ if (!xfs_sb_version_hascrc(&mp->m_sb))
+ return false;
+ if (!uuid_equal(&block->bb_u.s.bb_uuid, &mp->m_sb.sb_uuid))
+ return false;
+ if (block->bb_u.s.bb_blkno != cpu_to_be64(bp->b_bn))
+ return false;
+ if (pag && be32_to_cpu(block->bb_u.s.bb_owner) != pag->pag_agno)
+ return false;
+ return true;
+}
+
+/**
+ * xfs_btree_sblock_verify() -- verify a short-format btree block
+ *
+ * @bp: buffer containing the btree block
+ * @max_recs: maximum records allowed in this btree node
+ */
+bool
+xfs_btree_sblock_verify(
+ struct xfs_buf *bp,
+ unsigned int max_recs)
+{
+ struct xfs_mount *mp = bp->b_target->bt_mount;
+ struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
+
+ /* numrecs verification */
+ if (be16_to_cpu(block->bb_numrecs) > max_recs)
+ return false;
+
+ /* sibling pointer verification */
+ if (!block->bb_u.s.bb_leftsib ||
+ (be32_to_cpu(block->bb_u.s.bb_leftsib) >= mp->m_sb.sb_agblocks &&
+ block->bb_u.s.bb_leftsib != cpu_to_be32(NULLAGBLOCK)))
+ return false;
+ if (!block->bb_u.s.bb_rightsib ||
+ (be32_to_cpu(block->bb_u.s.bb_rightsib) >= mp->m_sb.sb_agblocks &&
+ block->bb_u.s.bb_rightsib != cpu_to_be32(NULLAGBLOCK)))
+ return false;
+
+ return true;
+}
diff --git a/fs/xfs/libxfs/xfs_btree.h b/fs/xfs/libxfs/xfs_btree.h
index 48ab2b1..dd29d15 100644
--- a/fs/xfs/libxfs/xfs_btree.h
+++ b/fs/xfs/libxfs/xfs_btree.h
@@ -471,4 +471,7 @@ static inline int xfs_btree_get_level(struct xfs_btree_block *block)
#define XFS_BTREE_TRACE_ARGR(c, r)
#define XFS_BTREE_TRACE_CURSOR(c, t)

+bool xfs_btree_sblock_v5hdr_verify(struct xfs_buf *bp);
+bool xfs_btree_sblock_verify(struct xfs_buf *bp, unsigned int max_recs);
+
#endif /* __XFS_BTREE_H__ */
diff --git a/fs/xfs/libxfs/xfs_ialloc_btree.c b/fs/xfs/libxfs/xfs_ialloc_btree.c
index b96db1c..2d692fb 100644
--- a/fs/xfs/libxfs/xfs_ialloc_btree.c
+++ b/fs/xfs/libxfs/xfs_ialloc_btree.c
@@ -222,7 +222,6 @@ xfs_inobt_verify(
{
struct xfs_mount *mp = bp->b_target->bt_mount;
struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
- struct xfs_perag *pag = bp->b_pag;
unsigned int level;

/*
@@ -238,14 +237,7 @@ xfs_inobt_verify(
switch (block->bb_magic) {
case cpu_to_be32(XFS_IBT_CRC_MAGIC):
case cpu_to_be32(XFS_FIBT_CRC_MAGIC):
- if (!xfs_sb_version_hascrc(&mp->m_sb))
- return false;
- if (!uuid_equal(&block->bb_u.s.bb_uuid, &mp->m_sb.sb_uuid))
- return false;
- if (block->bb_u.s.bb_blkno != cpu_to_be64(bp->b_bn))
- return false;
- if (pag &&
- be32_to_cpu(block->bb_u.s.bb_owner) != pag->pag_agno)
+ if (!xfs_btree_sblock_v5hdr_verify(bp))
return false;
/* fall through */
case cpu_to_be32(XFS_IBT_MAGIC):
@@ -255,24 +247,12 @@ xfs_inobt_verify(
return 0;
}

- /* numrecs and level verification */
+ /* level verification */
level = be16_to_cpu(block->bb_level);
if (level >= mp->m_in_maxlevels)
- return false;
- if (be16_to_cpu(block->bb_numrecs) > mp->m_inobt_mxr[level != 0])
- return false;
-
- /* sibling pointer verification */
- if (!block->bb_u.s.bb_leftsib ||
- (be32_to_cpu(block->bb_u.s.bb_leftsib) >= mp->m_sb.sb_agblocks &&
- block->bb_u.s.bb_leftsib != cpu_to_be32(NULLAGBLOCK)))
- return false;
- if (!block->bb_u.s.bb_rightsib ||
- (be32_to_cpu(block->bb_u.s.bb_rightsib) >= mp->m_sb.sb_agblocks &&
- block->bb_u.s.bb_rightsib != cpu_to_be32(NULLAGBLOCK)))
- return false;
-
- return true;
+ return false;
+
+ return xfs_btree_sblock_verify(bp, mp->m_inobt_mxr[level != 0]);
}

static void
diff --git a/fs/xfs/libxfs/xfs_rmap_btree.c b/fs/xfs/libxfs/xfs_rmap_btree.c
index 0b396e6..208435e 100644
--- a/fs/xfs/libxfs/xfs_rmap_btree.c
+++ b/fs/xfs/libxfs/xfs_rmap_btree.c
@@ -235,35 +235,18 @@ xfs_rmapbt_verify(

if (!xfs_sb_version_hasrmapbt(&mp->m_sb))
return false;
- if (!uuid_equal(&block->bb_u.s.bb_uuid, &mp->m_sb.sb_uuid))
- return false;
- if (block->bb_u.s.bb_blkno != cpu_to_be64(bp->b_bn))
- return false;
- if (pag && be32_to_cpu(block->bb_u.s.bb_owner) != pag->pag_agno)
+ if (!xfs_btree_sblock_v5hdr_verify(bp))
return false;

+ /* level verification */
level = be16_to_cpu(block->bb_level);
if (pag && pag->pagf_init) {
if (level >= pag->pagf_levels[XFS_BTNUM_RMAPi])
return false;
} else if (level >= mp->m_ag_maxlevels)
- return false;
-
- /* numrecs verification */
- if (be16_to_cpu(block->bb_numrecs) > mp->m_rmap_mxr[level != 0])
- return false;
-
- /* sibling pointer verification */
- if (!block->bb_u.s.bb_leftsib ||
- (be32_to_cpu(block->bb_u.s.bb_leftsib) >= mp->m_sb.sb_agblocks &&
- block->bb_u.s.bb_leftsib != cpu_to_be32(NULLAGBLOCK)))
- return false;
- if (!block->bb_u.s.bb_rightsib ||
- (be32_to_cpu(block->bb_u.s.bb_rightsib) >= mp->m_sb.sb_agblocks &&
- block->bb_u.s.bb_rightsib != cpu_to_be32(NULLAGBLOCK)))
- return false;
+ return false;

- return true;
+ return xfs_btree_sblock_verify(bp, mp->m_rmap_mxr[level != 0]);
}

static void