[PATCH 2/4] xfs: define an in-memory btree for storing refcount bag info during repairs

Darrick J. Wong
2023-12-31T20:19:49Z

Create a new in-memory btree type so that we can store refcount bag info
in a much more memory-efficient format.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
---
fs/xfs/Makefile | 1
fs/xfs/libxfs/xfs_btree.h | 1
fs/xfs/libxfs/xfs_types.h | 6 +
fs/xfs/scrub/rcbag_btree.c | 314 ++++++++++++++++++++++++++++++++++++++++++++
fs/xfs/scrub/rcbag_btree.h | 76 +++++++++++
fs/xfs/scrub/trace.h | 1
fs/xfs/xfs_trace.h | 1
7 files changed, 398 insertions(+), 2 deletions(-)
create mode 100644 fs/xfs/scrub/rcbag_btree.c
create mode 100644 fs/xfs/scrub/rcbag_btree.h

diff --git a/fs/xfs/Makefile b/fs/xfs/Makefile
index dfa142eb16f46..f927a43cc16a5 100644
--- a/fs/xfs/Makefile
+++ b/fs/xfs/Makefile
@@ -198,6 +198,7 @@ xfs-y += $(addprefix scrub/, \
inode_repair.o \
newbt.o \
nlinks_repair.o \
+ rcbag_btree.o \
reap.o \
refcount_repair.o \
repair.o \
diff --git a/fs/xfs/libxfs/xfs_btree.h b/fs/xfs/libxfs/xfs_btree.h
index edbcd4f0e9888..339b5561e5b04 100644
--- a/fs/xfs/libxfs/xfs_btree.h
+++ b/fs/xfs/libxfs/xfs_btree.h
@@ -62,6 +62,7 @@ union xfs_btree_rec {
#define XFS_BTNUM_FINO ((xfs_btnum_t)XFS_BTNUM_FINOi)
#define XFS_BTNUM_RMAP ((xfs_btnum_t)XFS_BTNUM_RMAPi)
#define XFS_BTNUM_REFC ((xfs_btnum_t)XFS_BTNUM_REFCi)
+#define XFS_BTNUM_RCBAG ((xfs_btnum_t)XFS_BTNUM_RCBAGi)

struct xfs_btree_ops;
uint32_t xfs_btree_magic(struct xfs_mount *mp, const struct xfs_btree_ops *ops);
diff --git a/fs/xfs/libxfs/xfs_types.h b/fs/xfs/libxfs/xfs_types.h
index 035bf703d719a..5556615a2ff9c 100644
--- a/fs/xfs/libxfs/xfs_types.h
+++ b/fs/xfs/libxfs/xfs_types.h
@@ -121,7 +121,8 @@ typedef enum {
*/
typedef enum {
XFS_BTNUM_BNOi, XFS_BTNUM_CNTi, XFS_BTNUM_RMAPi, XFS_BTNUM_BMAPi,
- XFS_BTNUM_INOi, XFS_BTNUM_FINOi, XFS_BTNUM_REFCi, XFS_BTNUM_MAX
+ XFS_BTNUM_INOi, XFS_BTNUM_FINOi, XFS_BTNUM_REFCi, XFS_BTNUM_RCBAGi,
+ XFS_BTNUM_MAX
} xfs_btnum_t;

#define XFS_BTNUM_STRINGS \
@@ -131,7 +132,8 @@ typedef enum {
{ XFS_BTNUM_BMAPi, "bmbt" }, \
{ XFS_BTNUM_INOi, "inobt" }, \
{ XFS_BTNUM_FINOi, "finobt" }, \
- { XFS_BTNUM_REFCi, "refcbt" }
+ { XFS_BTNUM_REFCi, "refcbt" }, \
+ { XFS_BTNUM_RCBAGi, "rcbagbt" }

struct xfs_name {
const unsigned char *name;
diff --git a/fs/xfs/scrub/rcbag_btree.c b/fs/xfs/scrub/rcbag_btree.c
new file mode 100644
index 0000000000000..4b0c849321b25
--- /dev/null
+++ b/fs/xfs/scrub/rcbag_btree.c
@@ -0,0 +1,314 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2022-2024 Oracle. All Rights Reserved.
+ * Author: Darrick J. Wong <djwong@kernel.org>
+ */
+#include "xfs.h"
+#include "xfs_fs.h"
+#include "xfs_shared.h"
+#include "xfs_format.h"
+#include "xfs_trans_resv.h"
+#include "xfs_mount.h"
+#include "xfs_defer.h"
+#include "xfs_btree.h"
+#include "xfs_btree_mem.h"
+#include "xfs_error.h"
+#include "scrub/xfile.h"
+#include "scrub/xfbtree.h"
+#include "scrub/rcbag_btree.h"
+#include "scrub/trace.h"
+
+static struct kmem_cache *rcbagbt_cur_cache;
+
+STATIC void
+rcbagbt_init_key_from_rec(
+ union xfs_btree_key *key,
+ const union xfs_btree_rec *rec)
+{
+ struct rcbag_key *bag_key = (struct rcbag_key *)key;
+ const struct rcbag_rec *bag_rec = (const struct rcbag_rec *)rec;
+
+ BUILD_BUG_ON(sizeof(struct rcbag_key) > sizeof(union xfs_btree_key));
+ BUILD_BUG_ON(sizeof(struct rcbag_rec) > sizeof(union xfs_btree_rec));
+
+ bag_key->rbg_startblock = bag_rec->rbg_startblock;
+ bag_key->rbg_blockcount = bag_rec->rbg_blockcount;
+}
+
+STATIC void
+rcbagbt_init_rec_from_cur(
+ struct xfs_btree_cur *cur,
+ union xfs_btree_rec *rec)
+{
+ struct rcbag_rec *bag_rec = (struct rcbag_rec *)rec;
+ struct rcbag_rec *bag_irec = (struct rcbag_rec *)&cur->bc_rec;
+
+ bag_rec->rbg_startblock = bag_irec->rbg_startblock;
+ bag_rec->rbg_blockcount = bag_irec->rbg_blockcount;
+ bag_rec->rbg_refcount = bag_irec->rbg_refcount;
+}
+
+STATIC int64_t
+rcbagbt_key_diff(
+ struct xfs_btree_cur *cur,
+ const union xfs_btree_key *key)
+{
+ struct rcbag_rec *rec = (struct rcbag_rec *)&cur->bc_rec;
+ const struct rcbag_key *kp = (const struct rcbag_key *)key;
+
+ if (kp->rbg_startblock > rec->rbg_startblock)
+ return 1;
+ if (kp->rbg_startblock < rec->rbg_startblock)
+ return -1;
+
+ if (kp->rbg_blockcount > rec->rbg_blockcount)
+ return 1;
+ if (kp->rbg_blockcount < rec->rbg_blockcount)
+ return -1;
+
+ return 0;
+}
+
+STATIC int64_t
+rcbagbt_diff_two_keys(
+ struct xfs_btree_cur *cur,
+ const union xfs_btree_key *k1,
+ const union xfs_btree_key *k2,
+ const union xfs_btree_key *mask)
+{
+ const struct rcbag_key *kp1 = (const struct rcbag_key *)k1;
+ const struct rcbag_key *kp2 = (const struct rcbag_key *)k2;
+
+ ASSERT(mask == NULL);
+
+ if (kp1->rbg_startblock > kp2->rbg_startblock)
+ return 1;
+ if (kp1->rbg_startblock < kp2->rbg_startblock)
+ return -1;
+
+ if (kp1->rbg_blockcount > kp2->rbg_blockcount)
+ return 1;
+ if (kp1->rbg_blockcount < kp2->rbg_blockcount)
+ return -1;
+
+ return 0;
+}
+
+STATIC int
+rcbagbt_keys_inorder(
+ struct xfs_btree_cur *cur,
+ const union xfs_btree_key *k1,
+ const union xfs_btree_key *k2)
+{
+ const struct rcbag_key *kp1 = (const struct rcbag_key *)k1;
+ const struct rcbag_key *kp2 = (const struct rcbag_key *)k2;
+
+ if (kp1->rbg_startblock > kp2->rbg_startblock)
+ return 0;
+ if (kp1->rbg_startblock < kp2->rbg_startblock)
+ return 1;
+
+ if (kp1->rbg_blockcount > kp2->rbg_blockcount)
+ return 0;
+ if (kp1->rbg_blockcount < kp2->rbg_blockcount)
+ return 1;
+
+ return 0;
+}
+
+STATIC int
+rcbagbt_recs_inorder(
+ struct xfs_btree_cur *cur,
+ const union xfs_btree_rec *r1,
+ const union xfs_btree_rec *r2)
+{
+ const struct rcbag_rec *rp1 = (const struct rcbag_rec *)r1;
+ const struct rcbag_rec *rp2 = (const struct rcbag_rec *)r2;
+
+ if (rp1->rbg_startblock > rp2->rbg_startblock)
+ return 0;
+ if (rp1->rbg_startblock < rp2->rbg_startblock)
+ return 1;
+
+ if (rp1->rbg_blockcount > rp2->rbg_blockcount)
+ return 0;
+ if (rp1->rbg_blockcount < rp2->rbg_blockcount)
+ return 1;
+
+ return 0;
+}
+
+static xfs_failaddr_t
+rcbagbt_verify(
+ struct xfs_buf *bp)
+{
+ struct xfs_mount *mp = bp->b_mount;
+ struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
+ xfs_failaddr_t fa;
+ unsigned int level;
+
+ if (!xfs_verify_magic(bp, block->bb_magic))
+ return __this_address;
+
+ fa = xfs_btree_lblock_v5hdr_verify(bp, XFS_RMAP_OWN_UNKNOWN);
+ if (fa)
+ return fa;
+
+ level = be16_to_cpu(block->bb_level);
+ if (level >= rcbagbt_maxlevels_possible())
+ return __this_address;
+
+ return xfbtree_lblock_verify(bp,
+ rcbagbt_maxrecs(mp, xfo_to_b(1), level == 0));
+}
+
+static void
+rcbagbt_rw_verify(
+ struct xfs_buf *bp)
+{
+ xfs_failaddr_t fa = rcbagbt_verify(bp);
+
+ if (fa)
+ xfs_verifier_error(bp, -EFSCORRUPTED, fa);
+}
+
+/* skip crc checks on in-memory btrees to save time */
+static const struct xfs_buf_ops rcbagbt_mem_buf_ops = {
+ .name = "rcbagbt_mem",
+ .magic = { 0, cpu_to_be32(RCBAG_MAGIC) },
+ .verify_read = rcbagbt_rw_verify,
+ .verify_write = rcbagbt_rw_verify,
+ .verify_struct = rcbagbt_verify,
+};
+
+static const struct xfs_btree_ops rcbagbt_mem_ops = {
+ .rec_len = sizeof(struct rcbag_rec),
+ .key_len = sizeof(struct rcbag_key),
+ .lru_refs = 1,
+ .geom_flags = XFS_BTREE_CRC_BLOCKS | XFS_BTREE_LONG_PTRS |
+ XFS_BTREE_IN_XFILE,
+
+ .dup_cursor = xfbtree_dup_cursor,
+ .set_root = xfbtree_set_root,
+ .alloc_block = xfbtree_alloc_block,
+ .free_block = xfbtree_free_block,
+ .get_minrecs = xfbtree_get_minrecs,
+ .get_maxrecs = xfbtree_get_maxrecs,
+ .init_key_from_rec = rcbagbt_init_key_from_rec,
+ .init_rec_from_cur = rcbagbt_init_rec_from_cur,
+ .init_ptr_from_cur = xfbtree_init_ptr_from_cur,
+ .key_diff = rcbagbt_key_diff,
+ .buf_ops = &rcbagbt_mem_buf_ops,
+ .diff_two_keys = rcbagbt_diff_two_keys,
+ .keys_inorder = rcbagbt_keys_inorder,
+ .recs_inorder = rcbagbt_recs_inorder,
+};
+
+/* Create a cursor for an in-memory btree. */
+struct xfs_btree_cur *
+rcbagbt_mem_cursor(
+ struct xfs_mount *mp,
+ struct xfs_trans *tp,
+ struct xfs_buf *head_bp,
+ struct xfbtree *xfbtree)
+{
+ struct xfs_btree_cur *cur;
+
+ cur = xfs_btree_alloc_cursor(mp, tp, XFS_BTNUM_RCBAG, &rcbagbt_mem_ops,
+ rcbagbt_maxlevels_possible(), rcbagbt_cur_cache);
+
+ cur->bc_mem.xfbtree = xfbtree;
+ cur->bc_mem.head_bp = head_bp;
+ cur->bc_nlevels = xfs_btree_mem_head_nlevels(head_bp);
+ return cur;
+}
+
+/* Create an in-memory refcount bag btree. */
+int
+rcbagbt_mem_create(
+ struct xfs_mount *mp,
+ struct xfs_buftarg *target,
+ struct xfbtree **xfbtreep)
+{
+ struct xfbtree_config cfg = {
+ .btree_ops = &rcbagbt_mem_ops,
+ .target = target,
+ };
+
+ return xfbtree_create(mp, &cfg, xfbtreep);
+}
+
+/* Calculate number of records in a refcount bag btree block. */
+static inline unsigned int
+rcbagbt_block_maxrecs(
+ unsigned int blocklen,
+ bool leaf)
+{
+ if (leaf)
+ return blocklen / sizeof(struct rcbag_rec);
+ return blocklen /
+ (sizeof(struct rcbag_key) + sizeof(rcbag_ptr_t));
+}
+
+/*
+ * Calculate number of records in an refcount bag btree block.
+ */
+unsigned int
+rcbagbt_maxrecs(
+ struct xfs_mount *mp,
+ unsigned int blocklen,
+ bool leaf)
+{
+ blocklen -= RCBAG_BLOCK_LEN;
+ return rcbagbt_block_maxrecs(blocklen, leaf);
+}
+
+#define RCBAGBT_INIT_MINRECS(minrecs) \
+ do { \
+ unsigned int blocklen; \
+\
+ blocklen = PAGE_SIZE - XFS_BTREE_LBLOCK_CRC_LEN; \
+\
+ minrecs[0] = rcbagbt_block_maxrecs(blocklen, true) / 2; \
+ minrecs[1] = rcbagbt_block_maxrecs(blocklen, false) / 2; \
+ } while (0)
+
+/* Compute the max possible height for refcount bag btrees. */
+unsigned int
+rcbagbt_maxlevels_possible(void)
+{
+ unsigned int minrecs[2];
+
+ RCBAGBT_INIT_MINRECS(minrecs);
+ return xfs_btree_space_to_height(minrecs, ULLONG_MAX);
+}
+
+/* Calculate the refcount bag btree size for some records. */
+unsigned long long
+rcbagbt_calc_size(
+ unsigned long long nr_records)
+{
+ unsigned int minrecs[2];
+
+ RCBAGBT_INIT_MINRECS(minrecs);
+ return xfs_btree_calc_size(minrecs, nr_records);
+}
+
+int __init
+rcbagbt_init_cur_cache(void)
+{
+ rcbagbt_cur_cache = kmem_cache_create("xfs_rcbagbt_cur",
+ xfs_btree_cur_sizeof(rcbagbt_maxlevels_possible()),
+ 0, 0, NULL);
+
+ if (!rcbagbt_cur_cache)
+ return -ENOMEM;
+ return 0;
+}
+
+void
+rcbagbt_destroy_cur_cache(void)
+{
+ kmem_cache_destroy(rcbagbt_cur_cache);
+ rcbagbt_cur_cache = NULL;
+}
diff --git a/fs/xfs/scrub/rcbag_btree.h b/fs/xfs/scrub/rcbag_btree.h
new file mode 100644
index 0000000000000..dfe276cfd96c1
--- /dev/null
+++ b/fs/xfs/scrub/rcbag_btree.h
@@ -0,0 +1,76 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2022-2024 Oracle. All Rights Reserved.
+ * Author: Darrick J. Wong <djwong@kernel.org>
+ */
+#ifndef __XFS_SCRUB_RCBAG_BTREE_H__
+#define __XFS_SCRUB_RCBAG_BTREE_H__
+
+#ifdef CONFIG_XFS_BTREE_IN_XFILE
+
+struct xfs_buf;
+struct xfs_btree_cur;
+struct xfs_mount;
+
+#define RCBAG_MAGIC 0x74826671 /* 'JRBG' */
+
+struct rcbag_key {
+ uint32_t rbg_startblock;
+ uint32_t rbg_blockcount;
+};
+
+struct rcbag_rec {
+ uint32_t rbg_startblock;
+ uint32_t rbg_blockcount;
+ uint64_t rbg_refcount;
+};
+
+typedef __be64 rcbag_ptr_t;
+
+/* reflinks only exist on crc enabled filesystems */
+#define RCBAG_BLOCK_LEN XFS_BTREE_LBLOCK_CRC_LEN
+
+/*
+ * Record, key, and pointer address macros for btree blocks.
+ *
+ * (note that some of these may appear unused, but they are used in userspace)
+ */
+#define RCBAG_REC_ADDR(block, index) \
+ ((struct rcbag_rec *) \
+ ((char *)(block) + RCBAG_BLOCK_LEN + \
+ (((index) - 1) * sizeof(struct rcbag_rec))))
+
+#define RCBAG_KEY_ADDR(block, index) \
+ ((struct rcbag_key *) \
+ ((char *)(block) + RCBAG_BLOCK_LEN + \
+ ((index) - 1) * sizeof(struct rcbag_key)))
+
+#define RCBAG_PTR_ADDR(block, index, maxrecs) \
+ ((rcbag_ptr_t *) \
+ ((char *)(block) + RCBAG_BLOCK_LEN + \
+ (maxrecs) * sizeof(struct rcbag_key) + \
+ ((index) - 1) * sizeof(rcbag_ptr_t)))
+
+unsigned int rcbagbt_maxrecs(struct xfs_mount *mp, unsigned int blocklen,
+ bool leaf);
+
+unsigned long long rcbagbt_calc_size(unsigned long long nr_records);
+
+unsigned int rcbagbt_maxlevels_possible(void);
+
+int __init rcbagbt_init_cur_cache(void);
+void rcbagbt_destroy_cur_cache(void);
+
+struct xfbtree;
+struct xfs_btree_cur *rcbagbt_mem_cursor(struct xfs_mount *mp,
+ struct xfs_trans *tp, struct xfs_buf *head_bp,
+ struct xfbtree *xfbtree);
+int rcbagbt_mem_create(struct xfs_mount *mp, struct xfs_buftarg *target,
+ struct xfbtree **xfbtreep);
+
+#else
+# define rcbagbt_init_cur_cache() 0
+# define rcbagbt_destroy_cur_cache() ((void)0)
+#endif /* CONFIG_XFS_BTREE_IN_XFILE */
+
+#endif /* __XFS_SCRUB_RCBAG_BTREE_H__ */
diff --git a/fs/xfs/scrub/trace.h b/fs/xfs/scrub/trace.h
index 14bbefdd7ab81..e8f71179e1eab 100644
--- a/fs/xfs/scrub/trace.h
+++ b/fs/xfs/scrub/trace.h
@@ -42,6 +42,7 @@ TRACE_DEFINE_ENUM(XFS_BTNUM_INOi);
TRACE_DEFINE_ENUM(XFS_BTNUM_FINOi);
TRACE_DEFINE_ENUM(XFS_BTNUM_RMAPi);
TRACE_DEFINE_ENUM(XFS_BTNUM_REFCi);
+TRACE_DEFINE_ENUM(XFS_BTNUM_RCBAGi);

TRACE_DEFINE_ENUM(XFS_REFC_DOMAIN_SHARED);
TRACE_DEFINE_ENUM(XFS_REFC_DOMAIN_COW);
diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h
index ba3eed23533f0..1690f518ae74b 100644
--- a/fs/xfs/xfs_trace.h
+++ b/fs/xfs/xfs_trace.h
@@ -2458,6 +2458,7 @@ TRACE_DEFINE_ENUM(XFS_BTNUM_INOi);
TRACE_DEFINE_ENUM(XFS_BTNUM_FINOi);
TRACE_DEFINE_ENUM(XFS_BTNUM_RMAPi);
TRACE_DEFINE_ENUM(XFS_BTNUM_REFCi);
+TRACE_DEFINE_ENUM(XFS_BTNUM_RCBAGi);

DECLARE_EVENT_CLASS(xfs_btree_cur_class,
TP_PROTO(struct xfs_btree_cur *cur, int level, struct xfs_buf *bp),