OpenCloudOS-Kernel/fs/xfs/scrub/bitmap.c

454 lines
11 KiB
C
Raw Normal View History

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) 2018-2023 Oracle. All Rights Reserved.
* Author: Darrick J. Wong <djwong@kernel.org>
*/
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_shared.h"
#include "xfs_bit.h"
#include "xfs_format.h"
#include "xfs_trans_resv.h"
#include "xfs_mount.h"
#include "xfs_btree.h"
#include "scrub/scrub.h"
#include "scrub/bitmap.h"
#include <linux/interval_tree_generic.h>
struct xbitmap_node {
struct rb_node bn_rbnode;
/* First set bit of this interval and subtree. */
uint64_t bn_start;
/* Last set bit of this interval. */
uint64_t bn_last;
/* Last set bit of this subtree. Do not touch this. */
uint64_t __bn_subtree_last;
};
/* Define our own interval tree type with uint64_t parameters. */
#define START(node) ((node)->bn_start)
#define LAST(node) ((node)->bn_last)
/*
* These functions are defined by the INTERVAL_TREE_DEFINE macro, but we'll
* forward-declare them anyway for clarity.
*/
static inline void
xbitmap_tree_insert(struct xbitmap_node *node, struct rb_root_cached *root);
static inline void
xbitmap_tree_remove(struct xbitmap_node *node, struct rb_root_cached *root);
static inline struct xbitmap_node *
xbitmap_tree_iter_first(struct rb_root_cached *root, uint64_t start,
uint64_t last);
static inline struct xbitmap_node *
xbitmap_tree_iter_next(struct xbitmap_node *node, uint64_t start,
uint64_t last);
INTERVAL_TREE_DEFINE(struct xbitmap_node, bn_rbnode, uint64_t,
__bn_subtree_last, START, LAST, static inline, xbitmap_tree)
/* Iterate each interval of a bitmap. Do not change the bitmap. */
#define for_each_xbitmap_extent(bn, bitmap) \
for ((bn) = rb_entry_safe(rb_first(&(bitmap)->xb_root.rb_root), \
struct xbitmap_node, bn_rbnode); \
(bn) != NULL; \
(bn) = rb_entry_safe(rb_next(&(bn)->bn_rbnode), \
struct xbitmap_node, bn_rbnode))
/* Clear a range of this bitmap. */
int
xbitmap_clear(
struct xbitmap *bitmap,
uint64_t start,
uint64_t len)
{
struct xbitmap_node *bn;
struct xbitmap_node *new_bn;
uint64_t last = start + len - 1;
while ((bn = xbitmap_tree_iter_first(&bitmap->xb_root, start, last))) {
if (bn->bn_start < start && bn->bn_last > last) {
uint64_t old_last = bn->bn_last;
/* overlaps with the entire clearing range */
xbitmap_tree_remove(bn, &bitmap->xb_root);
bn->bn_last = start - 1;
xbitmap_tree_insert(bn, &bitmap->xb_root);
/* add an extent */
new_bn = kmalloc(sizeof(struct xbitmap_node),
XCHK_GFP_FLAGS);
if (!new_bn)
return -ENOMEM;
new_bn->bn_start = last + 1;
new_bn->bn_last = old_last;
xbitmap_tree_insert(new_bn, &bitmap->xb_root);
} else if (bn->bn_start < start) {
/* overlaps with the left side of the clearing range */
xbitmap_tree_remove(bn, &bitmap->xb_root);
bn->bn_last = start - 1;
xbitmap_tree_insert(bn, &bitmap->xb_root);
} else if (bn->bn_last > last) {
/* overlaps with the right side of the clearing range */
xbitmap_tree_remove(bn, &bitmap->xb_root);
bn->bn_start = last + 1;
xbitmap_tree_insert(bn, &bitmap->xb_root);
break;
} else {
/* in the middle of the clearing range */
xbitmap_tree_remove(bn, &bitmap->xb_root);
kfree(bn);
}
}
return 0;
}
/* Set a range of this bitmap. */
int
xbitmap_set(
struct xbitmap *bitmap,
uint64_t start,
uint64_t len)
{
struct xbitmap_node *left;
struct xbitmap_node *right;
uint64_t last = start + len - 1;
int error;
/* Is this whole range already set? */
left = xbitmap_tree_iter_first(&bitmap->xb_root, start, last);
if (left && left->bn_start <= start && left->bn_last >= last)
return 0;
/* Clear out everything in the range we want to set. */
error = xbitmap_clear(bitmap, start, len);
if (error)
return error;
/* Do we have a left-adjacent extent? */
left = xbitmap_tree_iter_first(&bitmap->xb_root, start - 1, start - 1);
ASSERT(!left || left->bn_last + 1 == start);
/* Do we have a right-adjacent extent? */
right = xbitmap_tree_iter_first(&bitmap->xb_root, last + 1, last + 1);
ASSERT(!right || right->bn_start == last + 1);
if (left && right) {
/* combine left and right adjacent extent */
xbitmap_tree_remove(left, &bitmap->xb_root);
xbitmap_tree_remove(right, &bitmap->xb_root);
left->bn_last = right->bn_last;
xbitmap_tree_insert(left, &bitmap->xb_root);
kfree(right);
} else if (left) {
/* combine with left extent */
xbitmap_tree_remove(left, &bitmap->xb_root);
left->bn_last = last;
xbitmap_tree_insert(left, &bitmap->xb_root);
} else if (right) {
/* combine with right extent */
xbitmap_tree_remove(right, &bitmap->xb_root);
right->bn_start = start;
xbitmap_tree_insert(right, &bitmap->xb_root);
} else {
/* add an extent */
left = kmalloc(sizeof(struct xbitmap_node), XCHK_GFP_FLAGS);
if (!left)
return -ENOMEM;
left->bn_start = start;
left->bn_last = last;
xbitmap_tree_insert(left, &bitmap->xb_root);
}
return 0;
}
/* Free everything related to this bitmap. */
void
xbitmap_destroy(
struct xbitmap *bitmap)
{
struct xbitmap_node *bn;
while ((bn = xbitmap_tree_iter_first(&bitmap->xb_root, 0, -1ULL))) {
xbitmap_tree_remove(bn, &bitmap->xb_root);
kfree(bn);
}
}
/* Set up a per-AG block bitmap. */
void
xbitmap_init(
struct xbitmap *bitmap)
{
bitmap->xb_root = RB_ROOT_CACHED;
}
/*
* Remove all the blocks mentioned in @sub from the extents in @bitmap.
*
* The intent is that callers will iterate the rmapbt for all of its records
* for a given owner to generate @bitmap; and iterate all the blocks of the
* metadata structures that are not being rebuilt and have the same rmapbt
* owner to generate @sub. This routine subtracts all the extents
* mentioned in sub from all the extents linked in @bitmap, which leaves
* @bitmap as the list of blocks that are not accounted for, which we assume
* are the dead blocks of the old metadata structure. The blocks mentioned in
* @bitmap can be reaped.
*
* This is the logical equivalent of bitmap &= ~sub.
*/
int
xbitmap_disunion(
struct xbitmap *bitmap,
struct xbitmap *sub)
{
struct xbitmap_node *bn;
int error;
if (xbitmap_empty(bitmap) || xbitmap_empty(sub))
return 0;
for_each_xbitmap_extent(bn, sub) {
error = xbitmap_clear(bitmap, bn->bn_start,
bn->bn_last - bn->bn_start + 1);
if (error)
return error;
}
return 0;
}
/*
* Record all btree blocks seen while iterating all records of a btree.
*
* We know that the btree query_all function starts at the left edge and walks
* towards the right edge of the tree. Therefore, we know that we can walk up
* the btree cursor towards the root; if the pointer for a given level points
* to the first record/key in that block, we haven't seen this block before;
* and therefore we need to remember that we saw this block in the btree.
*
* So if our btree is:
*
* 4
* / | \
* 1 2 3
*
* Pretend for this example that each leaf block has 100 btree records. For
* the first btree record, we'll observe that bc_levels[0].ptr == 1, so we
* record that we saw block 1. Then we observe that bc_levels[1].ptr == 1, so
* we record block 4. The list is [1, 4].
*
* For the second btree record, we see that bc_levels[0].ptr == 2, so we exit
* the loop. The list remains [1, 4].
*
* For the 101st btree record, we've moved onto leaf block 2. Now
* bc_levels[0].ptr == 1 again, so we record that we saw block 2. We see that
* bc_levels[1].ptr == 2, so we exit the loop. The list is now [1, 4, 2].
*
* For the 102nd record, bc_levels[0].ptr == 2, so we continue.
*
* For the 201st record, we've moved on to leaf block 3.
* bc_levels[0].ptr == 1, so we add 3 to the list. Now it is [1, 4, 2, 3].
*
* For the 300th record we just exit, with the list being [1, 4, 2, 3].
*/
/* Mark a btree block to the agblock bitmap. */
STATIC int
xagb_bitmap_visit_btblock(
struct xfs_btree_cur *cur,
int level,
void *priv)
{
struct xagb_bitmap *bitmap = priv;
struct xfs_buf *bp;
xfs_fsblock_t fsbno;
xfs_agblock_t agbno;
xfs_btree_get_block(cur, level, &bp);
if (!bp)
return 0;
fsbno = XFS_DADDR_TO_FSB(cur->bc_mp, xfs_buf_daddr(bp));
agbno = XFS_FSB_TO_AGBNO(cur->bc_mp, fsbno);
return xagb_bitmap_set(bitmap, agbno, 1);
}
/* Mark all (per-AG) btree blocks in the agblock bitmap. */
int
xagb_bitmap_set_btblocks(
struct xagb_bitmap *bitmap,
struct xfs_btree_cur *cur)
{
return xfs_btree_visit_blocks(cur, xagb_bitmap_visit_btblock,
XFS_BTREE_VISIT_ALL, bitmap);
}
/*
* Record all the buffers pointed to by the btree cursor. Callers already
* engaged in a btree walk should call this function to capture the list of
* blocks going from the leaf towards the root.
*/
int
xbitmap_set_btcur_path(
struct xbitmap *bitmap,
struct xfs_btree_cur *cur)
{
struct xfs_buf *bp;
xfs_fsblock_t fsb;
int i;
int error;
for (i = 0; i < cur->bc_nlevels && cur->bc_levels[i].ptr == 1; i++) {
xfs_btree_get_block(cur, i, &bp);
if (!bp)
continue;
fsb = XFS_DADDR_TO_FSB(cur->bc_mp, xfs_buf_daddr(bp));
error = xbitmap_set(bitmap, fsb, 1);
if (error)
return error;
}
return 0;
}
/* Collect a btree's block in the bitmap. */
STATIC int
xbitmap_collect_btblock(
struct xfs_btree_cur *cur,
int level,
void *priv)
{
struct xbitmap *bitmap = priv;
struct xfs_buf *bp;
xfs_fsblock_t fsbno;
xfs_btree_get_block(cur, level, &bp);
if (!bp)
return 0;
fsbno = XFS_DADDR_TO_FSB(cur->bc_mp, xfs_buf_daddr(bp));
return xbitmap_set(bitmap, fsbno, 1);
}
/* Walk the btree and mark the bitmap wherever a btree block is found. */
int
xbitmap_set_btblocks(
struct xbitmap *bitmap,
struct xfs_btree_cur *cur)
{
return xfs_btree_visit_blocks(cur, xbitmap_collect_btblock,
XFS_BTREE_VISIT_ALL, bitmap);
}
/* How many bits are set in this bitmap? */
uint64_t
xbitmap_hweight(
struct xbitmap *bitmap)
{
struct xbitmap_node *bn;
uint64_t ret = 0;
for_each_xbitmap_extent(bn, bitmap)
ret += bn->bn_last - bn->bn_start + 1;
return ret;
}
/* Call a function for every run of set bits in this bitmap. */
int
xbitmap_walk(
struct xbitmap *bitmap,
xbitmap_walk_fn fn,
void *priv)
{
struct xbitmap_node *bn;
int error = 0;
for_each_xbitmap_extent(bn, bitmap) {
error = fn(bn->bn_start, bn->bn_last - bn->bn_start + 1, priv);
if (error)
break;
}
return error;
}
struct xbitmap_walk_bits {
xbitmap_walk_bits_fn fn;
void *priv;
};
/* Walk all the bits in a run. */
static int
xbitmap_walk_bits_in_run(
uint64_t start,
uint64_t len,
void *priv)
{
struct xbitmap_walk_bits *wb = priv;
uint64_t i;
int error = 0;
for (i = start; i < start + len; i++) {
error = wb->fn(i, wb->priv);
if (error)
break;
}
return error;
}
/* Call a function for every set bit in this bitmap. */
int
xbitmap_walk_bits(
struct xbitmap *bitmap,
xbitmap_walk_bits_fn fn,
void *priv)
{
struct xbitmap_walk_bits wb = {.fn = fn, .priv = priv};
return xbitmap_walk(bitmap, xbitmap_walk_bits_in_run, &wb);
}
/* Does this bitmap have no bits set at all? */
bool
xbitmap_empty(
struct xbitmap *bitmap)
{
return bitmap->xb_root.rb_root.rb_node == NULL;
}
/* Is the start of the range set or clear? And for how long? */
bool
xbitmap_test(
struct xbitmap *bitmap,
uint64_t start,
uint64_t *len)
{
struct xbitmap_node *bn;
uint64_t last = start + *len - 1;
bn = xbitmap_tree_iter_first(&bitmap->xb_root, start, last);
if (!bn)
return false;
if (bn->bn_start <= start) {
if (bn->bn_last < last)
*len = bn->bn_last - start + 1;
return true;
}
*len = bn->bn_start - start;
return false;
}