From: Darrick J. Wong Date: Thu, 28 Apr 2022 19:39:03 +0000 (-0400) Subject: xfs: compute absolute maximum nlevels for each btree type X-Git-Tag: v5.16.0-rc0~12 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=441815c7820d51207d2567a15dd1d3686aa79685;p=thirdparty%2Fxfsprogs-dev.git xfs: compute absolute maximum nlevels for each btree type Source kernel commit: 0ed5f7356daee74244b02e100b3cc043e886e686 Add code for all five btree types so that we can compute the absolute maximum possible btree height for each btree type. This is a setup for the next patch, which makes every btree type have its own cursor cache. The functions are exported so that we can have xfs_db report the absolute maximum btree heights for each btree type, rather than making everyone run their own ad-hoc computations. Signed-off-by: Darrick J. Wong Reviewed-by: Dave Chinner Signed-off-by: Eric Sandeen --- diff --git a/libxfs/xfs_alloc.c b/libxfs/xfs_alloc.c index e20d8fb74..7d304160d 100644 --- a/libxfs/xfs_alloc.c +++ b/libxfs/xfs_alloc.c @@ -2194,6 +2194,7 @@ xfs_alloc_compute_maxlevels( { mp->m_alloc_maxlevels = xfs_btree_compute_maxlevels(mp->m_alloc_mnr, (mp->m_sb.sb_agblocks + 1) / 2); + ASSERT(mp->m_alloc_maxlevels <= xfs_allocbt_maxlevels_ondisk()); } /* diff --git a/libxfs/xfs_alloc_btree.c b/libxfs/xfs_alloc_btree.c index d752500be..6de3af371 100644 --- a/libxfs/xfs_alloc_btree.c +++ b/libxfs/xfs_alloc_btree.c @@ -564,6 +564,17 @@ xfs_allocbt_commit_staged_btree( } } +/* Calculate number of records in an alloc btree block. */ +static inline unsigned int +xfs_allocbt_block_maxrecs( + unsigned int blocklen, + bool leaf) +{ + if (leaf) + return blocklen / sizeof(xfs_alloc_rec_t); + return blocklen / (sizeof(xfs_alloc_key_t) + sizeof(xfs_alloc_ptr_t)); +} + /* * Calculate number of records in an alloc btree block. */ @@ -574,10 +585,26 @@ xfs_allocbt_maxrecs( int leaf) { blocklen -= XFS_ALLOC_BLOCK_LEN(mp); + return xfs_allocbt_block_maxrecs(blocklen, leaf); +} - if (leaf) - return blocklen / sizeof(xfs_alloc_rec_t); - return blocklen / (sizeof(xfs_alloc_key_t) + sizeof(xfs_alloc_ptr_t)); +/* Free space btrees are at their largest when every other block is free. */ +#define XFS_MAX_FREESP_RECORDS ((XFS_MAX_AG_BLOCKS + 1) / 2) + +/* Compute the max possible height for free space btrees. */ +unsigned int +xfs_allocbt_maxlevels_ondisk(void) +{ + unsigned int minrecs[2]; + unsigned int blocklen; + + blocklen = min(XFS_MIN_BLOCKSIZE - XFS_BTREE_SBLOCK_LEN, + XFS_MIN_CRC_BLOCKSIZE - XFS_BTREE_SBLOCK_CRC_LEN); + + minrecs[0] = xfs_allocbt_block_maxrecs(blocklen, true) / 2; + minrecs[1] = xfs_allocbt_block_maxrecs(blocklen, false) / 2; + + return xfs_btree_compute_maxlevels(minrecs, XFS_MAX_FREESP_RECORDS); } /* Calculate the freespace btree size for some records. */ diff --git a/libxfs/xfs_alloc_btree.h b/libxfs/xfs_alloc_btree.h index 2f6b816aa..c715bee5a 100644 --- a/libxfs/xfs_alloc_btree.h +++ b/libxfs/xfs_alloc_btree.h @@ -60,4 +60,6 @@ extern xfs_extlen_t xfs_allocbt_calc_size(struct xfs_mount *mp, void xfs_allocbt_commit_staged_btree(struct xfs_btree_cur *cur, struct xfs_trans *tp, struct xfs_buf *agbp); +unsigned int xfs_allocbt_maxlevels_ondisk(void); + #endif /* __XFS_ALLOC_BTREE_H__ */ diff --git a/libxfs/xfs_bmap.c b/libxfs/xfs_bmap.c index 3b8b1b617..bc8a2033d 100644 --- a/libxfs/xfs_bmap.c +++ b/libxfs/xfs_bmap.c @@ -86,6 +86,7 @@ xfs_bmap_compute_maxlevels( maxblocks = (maxblocks + minnoderecs - 1) / minnoderecs; } mp->m_bm_maxlevels[whichfork] = level; + ASSERT(mp->m_bm_maxlevels[whichfork] <= xfs_bmbt_maxlevels_ondisk()); } unsigned int diff --git a/libxfs/xfs_bmap_btree.c b/libxfs/xfs_bmap_btree.c index 9e2263ed5..85faea1dd 100644 --- a/libxfs/xfs_bmap_btree.c +++ b/libxfs/xfs_bmap_btree.c @@ -569,6 +569,17 @@ xfs_bmbt_init_cursor( return cur; } +/* Calculate number of records in a block mapping btree block. */ +static inline unsigned int +xfs_bmbt_block_maxrecs( + unsigned int blocklen, + bool leaf) +{ + if (leaf) + return blocklen / sizeof(xfs_bmbt_rec_t); + return blocklen / (sizeof(xfs_bmbt_key_t) + sizeof(xfs_bmbt_ptr_t)); +} + /* * Calculate number of records in a bmap btree block. */ @@ -579,10 +590,24 @@ xfs_bmbt_maxrecs( int leaf) { blocklen -= XFS_BMBT_BLOCK_LEN(mp); + return xfs_bmbt_block_maxrecs(blocklen, leaf); +} - if (leaf) - return blocklen / sizeof(xfs_bmbt_rec_t); - return blocklen / (sizeof(xfs_bmbt_key_t) + sizeof(xfs_bmbt_ptr_t)); +/* Compute the max possible height for block mapping btrees. */ +unsigned int +xfs_bmbt_maxlevels_ondisk(void) +{ + unsigned int minrecs[2]; + unsigned int blocklen; + + blocklen = min(XFS_MIN_BLOCKSIZE - XFS_BTREE_SBLOCK_LEN, + XFS_MIN_CRC_BLOCKSIZE - XFS_BTREE_SBLOCK_CRC_LEN); + + minrecs[0] = xfs_bmbt_block_maxrecs(blocklen, true) / 2; + minrecs[1] = xfs_bmbt_block_maxrecs(blocklen, false) / 2; + + /* One extra level for the inode root. */ + return xfs_btree_compute_maxlevels(minrecs, MAXEXTNUM) + 1; } /* diff --git a/libxfs/xfs_bmap_btree.h b/libxfs/xfs_bmap_btree.h index 729e3bc56..2a1c9e607 100644 --- a/libxfs/xfs_bmap_btree.h +++ b/libxfs/xfs_bmap_btree.h @@ -110,4 +110,6 @@ extern struct xfs_btree_cur *xfs_bmbt_init_cursor(struct xfs_mount *, extern unsigned long long xfs_bmbt_calc_size(struct xfs_mount *mp, unsigned long long len); +unsigned int xfs_bmbt_maxlevels_ondisk(void); + #endif /* __XFS_BMAP_BTREE_H__ */ diff --git a/libxfs/xfs_fs.h b/libxfs/xfs_fs.h index bde2b4c64..c43877c8a 100644 --- a/libxfs/xfs_fs.h +++ b/libxfs/xfs_fs.h @@ -268,6 +268,8 @@ typedef struct xfs_fsop_resblks { */ #define XFS_MIN_AG_BYTES (1ULL << 24) /* 16 MB */ #define XFS_MAX_AG_BYTES (1ULL << 40) /* 1 TB */ +#define XFS_MAX_AG_BLOCKS (XFS_MAX_AG_BYTES / XFS_MIN_BLOCKSIZE) +#define XFS_MAX_CRC_AG_BLOCKS (XFS_MAX_AG_BYTES / XFS_MIN_CRC_BLOCKSIZE) /* keep the maximum size under 2^31 by a small amount */ #define XFS_MAX_LOG_BYTES \ diff --git a/libxfs/xfs_ialloc.c b/libxfs/xfs_ialloc.c index 3b96e828c..b18ddc4ef 100644 --- a/libxfs/xfs_ialloc.c +++ b/libxfs/xfs_ialloc.c @@ -2788,6 +2788,7 @@ xfs_ialloc_setup_geometry( inodes = (1LL << XFS_INO_AGINO_BITS(mp)) >> XFS_INODES_PER_CHUNK_LOG; igeo->inobt_maxlevels = xfs_btree_compute_maxlevels(igeo->inobt_mnr, inodes); + ASSERT(igeo->inobt_maxlevels <= xfs_iallocbt_maxlevels_ondisk()); /* * Set the maximum inode count for this filesystem, being careful not diff --git a/libxfs/xfs_ialloc_btree.c b/libxfs/xfs_ialloc_btree.c index be0918b7a..30b1abe91 100644 --- a/libxfs/xfs_ialloc_btree.c +++ b/libxfs/xfs_ialloc_btree.c @@ -525,6 +525,17 @@ xfs_inobt_commit_staged_btree( } } +/* Calculate number of records in an inode btree block. */ +static inline unsigned int +xfs_inobt_block_maxrecs( + unsigned int blocklen, + bool leaf) +{ + if (leaf) + return blocklen / sizeof(xfs_inobt_rec_t); + return blocklen / (sizeof(xfs_inobt_key_t) + sizeof(xfs_inobt_ptr_t)); +} + /* * Calculate number of records in an inobt btree block. */ @@ -535,10 +546,54 @@ xfs_inobt_maxrecs( int leaf) { blocklen -= XFS_INOBT_BLOCK_LEN(mp); + return xfs_inobt_block_maxrecs(blocklen, leaf); +} - if (leaf) - return blocklen / sizeof(xfs_inobt_rec_t); - return blocklen / (sizeof(xfs_inobt_key_t) + sizeof(xfs_inobt_ptr_t)); +/* + * Maximum number of inode btree records per AG. Pretend that we can fill an + * entire AG completely full of inodes except for the AG headers. + */ +#define XFS_MAX_INODE_RECORDS \ + ((XFS_MAX_AG_BYTES - (4 * BBSIZE)) / XFS_DINODE_MIN_SIZE) / \ + XFS_INODES_PER_CHUNK + +/* Compute the max possible height for the inode btree. */ +static inline unsigned int +xfs_inobt_maxlevels_ondisk(void) +{ + unsigned int minrecs[2]; + unsigned int blocklen; + + blocklen = min(XFS_MIN_BLOCKSIZE - XFS_BTREE_SBLOCK_LEN, + XFS_MIN_CRC_BLOCKSIZE - XFS_BTREE_SBLOCK_CRC_LEN); + + minrecs[0] = xfs_inobt_block_maxrecs(blocklen, true) / 2; + minrecs[1] = xfs_inobt_block_maxrecs(blocklen, false) / 2; + + return xfs_btree_compute_maxlevels(minrecs, XFS_MAX_INODE_RECORDS); +} + +/* Compute the max possible height for the free inode btree. */ +static inline unsigned int +xfs_finobt_maxlevels_ondisk(void) +{ + unsigned int minrecs[2]; + unsigned int blocklen; + + blocklen = XFS_MIN_CRC_BLOCKSIZE - XFS_BTREE_SBLOCK_CRC_LEN; + + minrecs[0] = xfs_inobt_block_maxrecs(blocklen, true) / 2; + minrecs[1] = xfs_inobt_block_maxrecs(blocklen, false) / 2; + + return xfs_btree_compute_maxlevels(minrecs, XFS_MAX_INODE_RECORDS); +} + +/* Compute the max possible height for either inode btree. */ +unsigned int +xfs_iallocbt_maxlevels_ondisk(void) +{ + return max(xfs_inobt_maxlevels_ondisk(), + xfs_finobt_maxlevels_ondisk()); } /* diff --git a/libxfs/xfs_ialloc_btree.h b/libxfs/xfs_ialloc_btree.h index 8a322d402..6d3e4a331 100644 --- a/libxfs/xfs_ialloc_btree.h +++ b/libxfs/xfs_ialloc_btree.h @@ -75,4 +75,6 @@ int xfs_inobt_cur(struct xfs_mount *mp, struct xfs_trans *tp, void xfs_inobt_commit_staged_btree(struct xfs_btree_cur *cur, struct xfs_trans *tp, struct xfs_buf *agbp); +unsigned int xfs_iallocbt_maxlevels_ondisk(void); + #endif /* __XFS_IALLOC_BTREE_H__ */ diff --git a/libxfs/xfs_refcount_btree.c b/libxfs/xfs_refcount_btree.c index 6a7169244..1d7b2d7c0 100644 --- a/libxfs/xfs_refcount_btree.c +++ b/libxfs/xfs_refcount_btree.c @@ -392,6 +392,18 @@ xfs_refcountbt_commit_staged_btree( xfs_btree_commit_afakeroot(cur, tp, agbp, &xfs_refcountbt_ops); } +/* Calculate number of records in a refcount btree block. */ +static inline unsigned int +xfs_refcountbt_block_maxrecs( + unsigned int blocklen, + bool leaf) +{ + if (leaf) + return blocklen / sizeof(struct xfs_refcount_rec); + return blocklen / (sizeof(struct xfs_refcount_key) + + sizeof(xfs_refcount_ptr_t)); +} + /* * Calculate the number of records in a refcount btree block. */ @@ -401,11 +413,22 @@ xfs_refcountbt_maxrecs( bool leaf) { blocklen -= XFS_REFCOUNT_BLOCK_LEN; + return xfs_refcountbt_block_maxrecs(blocklen, leaf); +} - if (leaf) - return blocklen / sizeof(struct xfs_refcount_rec); - return blocklen / (sizeof(struct xfs_refcount_key) + - sizeof(xfs_refcount_ptr_t)); +/* Compute the max possible height of the maximally sized refcount btree. */ +unsigned int +xfs_refcountbt_maxlevels_ondisk(void) +{ + unsigned int minrecs[2]; + unsigned int blocklen; + + blocklen = XFS_MIN_CRC_BLOCKSIZE - XFS_BTREE_SBLOCK_CRC_LEN; + + minrecs[0] = xfs_refcountbt_block_maxrecs(blocklen, true) / 2; + minrecs[1] = xfs_refcountbt_block_maxrecs(blocklen, false) / 2; + + return xfs_btree_compute_maxlevels(minrecs, XFS_MAX_CRC_AG_BLOCKS); } /* Compute the maximum height of a refcount btree. */ @@ -413,8 +436,14 @@ void xfs_refcountbt_compute_maxlevels( struct xfs_mount *mp) { + if (!xfs_has_reflink(mp)) { + mp->m_refc_maxlevels = 0; + return; + } + mp->m_refc_maxlevels = xfs_btree_compute_maxlevels( mp->m_refc_mnr, mp->m_sb.sb_agblocks); + ASSERT(mp->m_refc_maxlevels <= xfs_refcountbt_maxlevels_ondisk()); } /* Calculate the refcount btree size for some records. */ diff --git a/libxfs/xfs_refcount_btree.h b/libxfs/xfs_refcount_btree.h index bd9ed9e1e..d7f7c89cb 100644 --- a/libxfs/xfs_refcount_btree.h +++ b/libxfs/xfs_refcount_btree.h @@ -65,4 +65,6 @@ extern int xfs_refcountbt_calc_reserves(struct xfs_mount *mp, void xfs_refcountbt_commit_staged_btree(struct xfs_btree_cur *cur, struct xfs_trans *tp, struct xfs_buf *agbp); +unsigned int xfs_refcountbt_maxlevels_ondisk(void); + #endif /* __XFS_REFCOUNT_BTREE_H__ */ diff --git a/libxfs/xfs_rmap_btree.c b/libxfs/xfs_rmap_btree.c index eeaa1e283..eb3ef4090 100644 --- a/libxfs/xfs_rmap_btree.c +++ b/libxfs/xfs_rmap_btree.c @@ -517,6 +517,18 @@ xfs_rmapbt_commit_staged_btree( xfs_btree_commit_afakeroot(cur, tp, agbp, &xfs_rmapbt_ops); } +/* Calculate number of records in a reverse mapping btree block. */ +static inline unsigned int +xfs_rmapbt_block_maxrecs( + unsigned int blocklen, + bool leaf) +{ + if (leaf) + return blocklen / sizeof(struct xfs_rmap_rec); + return blocklen / + (2 * sizeof(struct xfs_rmap_key) + sizeof(xfs_rmap_ptr_t)); +} + /* * Calculate number of records in an rmap btree block. */ @@ -526,11 +538,33 @@ xfs_rmapbt_maxrecs( int leaf) { blocklen -= XFS_RMAP_BLOCK_LEN; + return xfs_rmapbt_block_maxrecs(blocklen, leaf); +} - if (leaf) - return blocklen / sizeof(struct xfs_rmap_rec); - return blocklen / - (2 * sizeof(struct xfs_rmap_key) + sizeof(xfs_rmap_ptr_t)); +/* Compute the max possible height for reverse mapping btrees. */ +unsigned int +xfs_rmapbt_maxlevels_ondisk(void) +{ + unsigned int minrecs[2]; + unsigned int blocklen; + + blocklen = XFS_MIN_CRC_BLOCKSIZE - XFS_BTREE_SBLOCK_CRC_LEN; + + minrecs[0] = xfs_rmapbt_block_maxrecs(blocklen, true) / 2; + minrecs[1] = xfs_rmapbt_block_maxrecs(blocklen, false) / 2; + + /* + * Compute the asymptotic maxlevels for an rmapbt on any reflink fs. + * + * On a reflink filesystem, each AG block can have up to 2^32 (per the + * refcount record format) owners, which means that theoretically we + * could face up to 2^64 rmap records. However, we're likely to run + * out of blocks in the AG long before that happens, which means that + * we must compute the max height based on what the btree will look + * like if it consumes almost all the blocks in the AG due to maximal + * sharing factor. + */ + return xfs_btree_space_to_height(minrecs, XFS_MAX_CRC_AG_BLOCKS); } /* Compute the maximum height of an rmap btree. */ @@ -567,6 +601,7 @@ xfs_rmapbt_compute_maxlevels( mp->m_rmap_maxlevels = xfs_btree_compute_maxlevels( mp->m_rmap_mnr, mp->m_sb.sb_agblocks); } + ASSERT(mp->m_rmap_maxlevels <= xfs_rmapbt_maxlevels_ondisk()); } /* Calculate the refcount btree size for some records. */ diff --git a/libxfs/xfs_rmap_btree.h b/libxfs/xfs_rmap_btree.h index f2eee6572..e9778b62a 100644 --- a/libxfs/xfs_rmap_btree.h +++ b/libxfs/xfs_rmap_btree.h @@ -59,4 +59,6 @@ extern xfs_extlen_t xfs_rmapbt_max_size(struct xfs_mount *mp, extern int xfs_rmapbt_calc_reserves(struct xfs_mount *mp, struct xfs_trans *tp, struct xfs_perag *pag, xfs_extlen_t *ask, xfs_extlen_t *used); +unsigned int xfs_rmapbt_maxlevels_ondisk(void); + #endif /* __XFS_RMAP_BTREE_H__ */