// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2014 Red Hat, Inc.
* All Rights Reserved.
*/
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_shared.h"
#include "xfs_format.h"
#include "xfs_log_format.h"
#include "xfs_trans_resv.h"
#include "xfs_mount.h"
#include "xfs_trans.h"
#include "xfs_alloc.h"
#include "xfs_btree.h"
#include "xfs_btree_staging.h"
#include "xfs_rmap.h"
#include "xfs_rmap_btree.h"
#include "xfs_health.h"
#include "xfs_trace.h"
#include "xfs_error.h"
#include "xfs_extent_busy.h"
#include "xfs_ag.h"
#include "xfs_ag_resv.h"
#include "xfs_buf_mem.h"
#include "xfs_btree_mem.h"
static struct kmem_cache *xfs_rmapbt_cur_cache;
/*
* Reverse map btree.
*
* This is a per-ag tree used to track the owner(s) of a given extent. With
* reflink it is possible for there to be multiple owners, which is a departure
* from classic XFS. Owner records for data extents are inserted when the
* extent is mapped and removed when an extent is unmapped. Owner records for
* all other block types (i.e. metadata) are inserted when an extent is
* allocated and removed when an extent is freed. There can only be one owner
* of a metadata extent, usually an inode or some other metadata structure like
* an AG btree.
*
* The rmap btree is part of the free space management, so blocks for the tree
* are sourced from the agfl. Hence we need transaction reservation support for
* this tree so that the freelist is always large enough. This also impacts on
* the minimum space we need to leave free in the AG.
*
* The tree is ordered by [ag block, owner, offset]. This is a large key size,
* but it is the only way to enforce unique keys when a block can be owned by
* multiple files at any offset. There's no need to order/search by extent
* size for online updating/management of the tree. It is intended that most
* reverse lookups will be to find the owner(s) of a particular block, or to
* try to recover tree and file data from corrupt primary metadata.
*/
static struct xfs_btree_cur *
xfs_rmapbt_dup_cursor(
struct xfs_btree_cur *cur)
{
return xfs_rmapbt_init_cursor(cur->bc_mp, cur->bc_tp,
cur->bc_ag.agbp, cur->bc_ag.pag);
}
STATIC void
xfs_rmapbt_set_root(
struct xfs_btree_cur *cur,
const union xfs_btree_ptr *ptr,
int inc)
{
struct xfs_buf *agbp = cur->bc_ag.agbp;
struct xfs_agf *agf = agbp->b_addr;
ASSERT(ptr->s != 0);
agf->agf_rmap_root = ptr->s;
be32_add_cpu(&agf->agf_rmap_level, inc);
cur->bc_ag.pag->pagf_rmap_level += inc;
xfs_alloc_log_agf(cur->bc_tp, agbp, XFS_AGF_ROOTS | XFS_AGF_LEVELS);
}
STATIC int
xfs_rmapbt_alloc_block(
struct xfs_btree_cur *cur,
const union xfs_btree_ptr *start,
union xfs_btree_ptr *new,
int *stat)
{
struct xfs_buf *agbp = cur->bc_ag.agbp;
struct xfs_agf *agf = agbp->b_addr;
struct xfs_perag *pag = cur->bc_ag.pag;
int error;
xfs_agblock_t bno;
/* Allocate the new block from the freelist. If we can't, give up. */
error = xfs_alloc_get_freelist(pag, cur->bc_tp, cur->bc_ag.agbp,
&bno, 1);
if (error)
return error;
if (bno == NULLAGBLOCK) {
*stat = 0;
return 0;
}
xfs_extent_busy_reuse(cur->bc_mp, pag, bno, 1, false);
new->s = cpu_to_be32(bno);
be32_add_cpu(&agf->agf_rmap_blocks, 1);
xfs_alloc_log_agf(cur->bc_tp, agbp, XFS_AGF_RMAP_BLOCKS);
xfs_ag_resv_rmapbt_alloc(cur->bc_mp, pag->pag_agno);
*stat = 1;
return 0;
}
STATIC int
xfs_rmapbt_free_block(
struct xfs_btree_cur *cur,
struct xfs_buf *bp)
{
struct xfs_buf *agbp = cur->bc_ag.agbp;
struct xfs_agf *agf = agbp->b_addr;
struct xfs_perag *pag = cur->bc_ag.pag;
xfs_agblock_t bno;
int error;
bno = xfs_daddr_to_agbno(cur->bc_mp, xfs_buf_daddr(bp));
be32_add_cpu(&agf->agf_rmap_blocks, -1);
xfs_alloc_log_agf(cur->bc_tp, agbp, XFS_AGF_RMAP_BLOCKS);
error = xfs_alloc_put_freelist(pag, cur->bc_tp, agbp, NULL, bno, 1);
if (error)
return error;
xfs_extent_busy_insert(cur->bc_tp, pag, bno, 1,
XFS_EXTENT_BUSY_SKIP_DISCARD);
xfs_ag_resv_free_extent(pag, XFS_AG_RESV_RMAPBT, NULL, 1);
return 0;
}
STATIC int
xfs_rmapbt_get_minrecs(
struct xfs_btree_cur *cur,
int level)
{
return cur->bc_mp->m_rmap_mnr[level != 0];
}
STATIC int
xfs_rmapbt_get_maxrecs(
struct xfs_btree_cur *cur,
int level)
{
return cur->bc_mp->m_rmap_mxr[level != 0];
}
/*
* Convert the ondisk record's offset field into the ondisk key's offset field.
* Fork and bmbt are significant parts of the rmap record key, but written
* status is merely a record attribute.
*/
static inline __be64 ondisk_rec_offset_to_key(const union xfs_btree_rec *rec)
{
return rec->rmap.rm_offset & ~cpu_to_be64(XFS_RMAP_OFF_UNWRITTEN);
}
STATIC void
xfs_rmapbt_init_key_from_rec(
union xfs_btree_key *key,
const union xfs_btree_rec *rec)
{
key->rmap.rm_startblock = rec->rmap.rm_startblock;
key->rmap.rm_owner = rec->rmap.rm_owner;
key->rmap.rm_offset = ondisk_rec_offset_to_key(rec);
}
/*
* The high key for a reverse mapping record can be computed by shifting
* the startblock and offset to the highest value that would still map
* to that record. In practice this means that we add blockcount-1 to
* the startblock for all records, and if the record is for a data/attr
* fork mapping, we add blockcount-1 to the offset too.
*/
STATIC void
xfs_rmapbt_init_high_key_from_rec(
union xfs_btree_key *key,
const union xfs_btree_rec *rec)
{
uint64_t off;
int adj;
adj = be32_to_cpu(rec->rmap.rm_blockcount) - 1;
key->rmap.rm_startblock = rec->rmap.rm_startblock;
be32_add_cpu(&key->rmap.rm_startblock, adj);
key->rmap.rm_owner = rec->rmap.rm_owner;
key->rmap.rm_offset = ondisk_rec_offset_to_key(rec);
if (XFS_RMAP_NON_INODE_OWNER(be64_to_cpu(rec->rmap.rm_owner)) ||
XFS_RMAP_IS_BMBT_BLOCK(be64_to_cpu(rec->rmap.rm_offset)))
return;
off = be64_to_cpu(key->rmap.rm_offset);
off = (XFS_RMAP_OFF(off) + adj) | (off & ~XFS_RMAP_OFF_MASK);
key->rmap.rm_offset = cpu_to_be64(off);
}
STATIC void
xfs_rmapbt_init_rec_from_cur(
struct xfs_btree_cur *cur,
union xfs_btree_rec *rec)
{
rec->rmap.rm_startblock = cpu_to_be32(cur->bc_rec.r.rm_startblock);
rec->rmap.rm_blockcount = cpu_to_be32(cur->bc_rec.r.rm_blockcount);
rec->rmap.rm_owner = cpu_to_be64(cur->bc_rec.r.rm_owner);
rec->rmap.rm_offset = cpu_to_be64(
xfs_rmap_irec_offset_pack(&cur->bc_rec.r));
}
STATIC void
xfs_rmapbt_init_ptr_from_cur(
struct xfs_btree_cur *cur,
union xfs_btree_ptr *ptr)
{
struct xfs_agf *agf = cur->bc_ag.agbp->b_addr;
ASSERT(cur->bc_ag.pag->pag_agno == be32_to_cpu(agf->agf_seqno));
ptr->s = agf->agf_rmap_root;
}
/*
* Mask the appropriate parts of the ondisk key field for a key comparison.
* Fork and bmbt are significant parts of the rmap record key, but written
* status is merely a record attribute.
*/
static inline uint64_t offset_keymask(uint64_t offset)
{
return offset & ~XFS_RMAP_OFF_UNWRITTEN;
}
STATIC int64_t
xfs_rmapbt_key_diff(
struct xfs_btree_cur *cur,
const union xfs_btree_key *key)
{
struct xfs_rmap_irec *rec = &cur->bc_rec.r;
const struct xfs_rmap_key *kp = &key->rmap;
__u64 x, y;
int64_t d;
d = (int64_t)be32_to_cpu(kp->rm_startblock) - rec->rm_startblock;
if (d)
return d;
x = be64_to_cpu(kp->rm_owner);
y = rec->rm_owner;
if (x > y)
return 1;
else if (y > x)
return -1;
x = offset_keymask(be64_to_cpu(kp->rm_offset));
y = offset_keymask(xfs_rmap_irec_offset_pack(rec));
if (x > y)
return 1;
else if (y > x)
return -1;
return 0;
}
STATIC int64_t
xfs_rmapbt_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 xfs_rmap_key *kp1 = &k1->rmap;
const struct xfs_rmap_key *kp2 = &k2->rmap;
int64_t d;
__u64 x, y;
/* Doesn't make sense to mask off the physical space part */
ASSERT(!mask || mask->rmap.rm_startblock);
d = (int64_t)be32_to_cpu(kp1->rm_startblock) -
be32_to_cpu(kp2->rm_startblock);
if (d)
return d;
if (!mask || mask->rmap.rm_owner) {
x = be64_to_cpu(kp1->rm_owner);
y = be64_to_cpu(kp2->rm_owner);
if (x > y)
return 1;
else if (y > x)
return -1;
}
if (!mask || mask->rmap.rm_offset) {
/* Doesn't make sense to allow offset but not owner */
ASSERT(!mask || mask->rmap.rm_owner);
x = offset_keymask(be64_to_cpu(kp1->rm_offset));
y = offset_keymask(be64_to_cpu(kp2->rm_offset));
if (x > y)
return 1;
else if (y > x)
return -1;
}
return 0;
}
static xfs_failaddr_t
xfs_rmapbt_verify(
struct xfs_buf *bp)
{
struct xfs_mount *mp = bp->b_mount;
struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
struct xfs_perag *pag = bp->b_pag;
xfs_failaddr_t fa;
unsigned int level;
/*
* magic number and level verification
*
* During growfs operations, we can't verify the exact level or owner as
* the perag is not fully initialised and hence not attached to the
* buffer. In this case, check against the maximum tree depth.
*
* Similarly, during log recovery we will have a perag structure
* attached, but the agf information will not yet have been initialised
* from the on disk AGF. Again, we can only check against maximum limits
* in this case.
*/
if (!xfs_verify_magic(bp, block->bb_magic))
return __this_address;
if (!xfs_has_rmapbt(mp))
return __this_address;
fa = xfs_btree_agblock_v5hdr_verify(bp);
if (fa)
return fa;
level = be16_to_cpu(block->bb_level);
if (pag && xfs_perag_initialised_agf(pag)) {
unsigned int maxlevel = pag->pagf_rmap_level;
#ifdef CONFIG_XFS_ONLINE_REPAIR
/*
* Online repair could be rewriting the free space btrees, so
* we'll validate against the larger of either tree while this
* is going on.
*/
maxlevel = max_t(unsigned int, maxlevel,
pag->pagf_repair_rmap_level);
#endif
if (level >= maxlevel)
return __this_address;
} else if (level >= mp->m_rmap_maxlevels)
return __this_address;
return xfs_btree_agblock_verify(bp, mp->m_rmap_mxr[level != 0]);
}
static void
xfs_rmapbt_read_verify(
struct xfs_buf *bp)
{
xfs_failaddr_t fa;
if (!xfs_btree_agblock_verify_crc(bp))
xfs_verifier_error(bp, -EFSBADCRC, __this_address);
else {
fa = xfs_rmapbt_verify(bp);
if (fa)
xfs_verifier_error(bp, -EFSCORRUPTED, fa);
}
if (bp->b_error)
trace_xfs_btree_corrupt(bp, _RET_IP_);
}
static void
xfs_rmapbt_write_verify(
struct xfs_buf *bp)
{
xfs_failaddr_t fa;
fa = xfs_rmapbt_verify(bp);
if (fa) {
trace_xfs_btree_corrupt(bp, _RET_IP_);
xfs_verifier_error(bp, -EFSCORRUPTED, fa);
return;
}
xfs_btree_agblock_calc_crc(bp);
}
const struct xfs_buf_ops xfs_rmapbt_buf_ops = {
.name = "xfs_rmapbt",
.magic = { 0, cpu_to_be32(XFS_RMAP_CRC_MAGIC) },
.verify_read = xfs_rmapbt_read_verify,
.verify_write = xfs_rmapbt_write_verify,
.verify_struct = xfs_rmapbt_verify,
};
STATIC int
xfs_rmapbt_keys_inorder(
struct xfs_btree_cur *cur,
const union xfs_btree_key *k1,
const union xfs_btree_key *k2)
{
uint32_t x;
uint32_t y;
uint64_t a;
uint64_t b;
x = be32_to_cpu(k1->rmap.rm_startblock);
y = be32_to_cpu(k2->rmap.rm_startblock);
if (x < y)
return 1;
else if (x > y)
return 0;
a = be64_to_cpu(k1->rmap.rm_owner);
b = be64_to_cpu(k2->rmap.rm_owner);
if (a < b)
return 1;
else if (a > b)
return 0;
a = offset_keymask(be64_to_cpu(k1->rmap.rm_offset));
b = offset_keymask(be64_to_cpu(k2->rmap.rm_offset));
if (a <= b)
return 1;
return 0;
}
STATIC int
xfs_rmapbt_recs_inorder(
struct xfs_btree_cur *cur,
const union xfs_btree_rec *r1,
const union xfs_btree_rec *r2)
{
uint32_t x;
uint32_t y;
uint64_t a;
uint64_t b;
x = be32_to_cpu(r1->rmap.rm_startblock);
y = be32_to_cpu(r2->rmap.rm_startblock);
if (x < y)
return 1;
else if (x > y)
return 0;
a = be64_to_cpu(r1->rmap.rm_owner);
b = be64_to_cpu(r2->rmap.rm_owner);
if (a < b)
return 1;
else if (a > b)
return 0;
a = offset_keymask(be64_to_cpu(r1->rmap.rm_offset));
b = offset_keymask(be64_to_cpu(r2->rmap.rm_offset));
if (a <= b)
return 1;
return 0;
}
STATIC enum xbtree_key_contig
xfs_rmapbt_keys_contiguous(
struct xfs_btree_cur *cur,
const union xfs_btree_key *key1,
const union xfs_btree_key *key2,
const union xfs_btree_key *mask)
{
ASSERT(!mask || mask->rmap.rm_startblock);
/*
* We only support checking contiguity of the physical space component.
* If any callers ever need more specificity than that, they'll have to
* implement it here.
*/
ASSERT(!mask || (!mask->rmap.rm_owner && !mask->rmap.rm_offset));
return xbtree_key_contig(be32_to_cpu(key1->rmap.rm_startblock),
be32_to_cpu(key2->rmap.rm_startblock));
}
const struct xfs_btree_ops xfs_rmapbt_ops = {
.name = "rmap",
.type = XFS_BTREE_TYPE_AG,
.geom_flags = XFS_BTGEO_OVERLAPPING,
.rec_len = sizeof(struct xfs_rmap_rec),
/* Overlapping btree; 2 keys per pointer. */
.key_len = 2 * sizeof(struct xfs_rmap_key),
.ptr_len = XFS_BTREE_SHORT_PTR_LEN,
.lru_refs = XFS_RMAP_BTREE_REF,
.statoff = XFS_STATS_CALC_INDEX(xs_rmap_2),
.sick_mask = XFS_SICK_AG_RMAPBT,
.dup_cursor = xfs_rmapbt_dup_cursor,
.set_root = xfs_rmapbt_set_root,
.alloc_block = xfs_rmapbt_alloc_block,
.free_block = xfs_rmapbt_free_block,
.get_minrecs = xfs_rmapbt_get_minrecs,
.get_maxrecs = xfs_rmapbt_get_maxrecs,
.init_key_from_rec = xfs_rmapbt_init_key_from_rec,
.init_high_key_from_rec = xfs_rmapbt_init_high_key_from_rec,
.init_rec_from_cur = xfs_rmapbt_init_rec_from_cur,
.init_ptr_from_cur = xfs_rmapbt_init_ptr_from_cur,
.key_diff = xfs_rmapbt_key_diff,
.buf_ops = &xfs_rmapbt_buf_ops,
.diff_two_keys = xfs_rmapbt_diff_two_keys,
.keys_inorder = xfs_rmapbt_keys_inorder,
.recs_inorder = xfs_rmapbt_recs_inorder,
.keys_contiguous = xfs_rmapbt_keys_contiguous,
};
/*
* Create a new reverse mapping btree cursor.
*
* For staging cursors tp and agbp are NULL.
*/
struct xfs_btree_cur *
xfs_rmapbt_init_cursor(
struct xfs_mount *mp,
struct xfs_trans *tp,
struct xfs_buf *agbp,
struct xfs_perag *pag)
{
struct xfs_btree_cur *cur;
cur = xfs_btree_alloc_cursor(mp, tp, &xfs_rmapbt_ops,
mp->m_rmap_maxlevels, xfs_rmapbt_cur_cache);
cur->bc_ag.pag = xfs_perag_hold(pag);
cur->bc_ag.agbp = agbp;
if (agbp) {
struct xfs_agf *agf = agbp->b_addr;
cur->bc_nlevels = be32_to_cpu(agf->agf_rmap_level);
}
return cur;
}
#ifdef CONFIG_XFS_BTREE_IN_MEM
static inline unsigned int
xfs_rmapbt_mem_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(__be64));
}
/*
* Validate an in-memory rmap btree block. Callers are allowed to generate an
* in-memory btree even if the ondisk feature is not enabled.
*/
static xfs_failaddr_t
xfs_rmapbt_mem_verify(
struct xfs_buf *bp)
{
struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
xfs_failaddr_t fa;
unsigned int level;
unsigned int maxrecs;
if (!xfs_verify_magic(bp, block->bb_magic))
return __this_address;
fa = xfs_btree_fsblock_v5hdr_verify(bp, XFS_RMAP_OWN_UNKNOWN);
if (fa)
return fa;
level = be16_to_cpu(block->bb_level);
if (level >= xfs_rmapbt_maxlevels_ondisk())
return __this_address;
maxrecs = xfs_rmapbt_mem_block_maxrecs(
XFBNO_BLOCKSIZE - XFS_BTREE_LBLOCK_CRC_LEN, level == 0);
return xfs_btree_memblock_verify(bp, maxrecs);
}
static void
xfs_rmapbt_mem_rw_verify(
struct xfs_buf *bp)
{
xfs_failaddr_t fa = xfs_rmapbt_mem_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 xfs_rmapbt_mem_buf_ops = {
.name = "xfs_rmapbt_mem",
.magic = { 0, cpu_to_be32(XFS_RMAP_CRC_MAGIC) },
.verify_read = xfs_rmapbt_mem_rw_verify,
.verify_write = xfs_rmapbt_mem_rw_verify,
.verify_struct = xfs_rmapbt_mem_verify,
};
const struct xfs_btree_ops xfs_rmapbt_mem_ops = {
.name = "mem_rmap",
.type = XFS_BTREE_TYPE_MEM,
.geom_flags = XFS_BTGEO_OVERLAPPING,
.rec_len = sizeof(struct xfs_rmap_rec),
/* Overlapping btree; 2 keys per pointer. */
.key_len = 2 * sizeof(struct xfs_rmap_key),
.ptr_len = XFS_BTREE_LONG_PTR_LEN,
.lru_refs = XFS_RMAP_BTREE_REF,
.statoff = XFS_STATS_CALC_INDEX(xs_rmap_mem_2),
.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 = xfs_rmapbt_init_key_from_rec,
.init_high_key_from_rec = xfs_rmapbt_init_high_key_from_rec,
.init_rec_from_cur = xfs_rmapbt_init_rec_from_cur,
.init_ptr_from_cur = xfbtree_init_ptr_from_cur,
.key_diff = xfs_rmapbt_key_diff,
.buf_ops = &xfs_rmapbt_mem_buf_ops,
.diff_two_keys = xfs_rmapbt_diff_two_keys,
.keys_inorder = xfs_rmapbt_keys_inorder,
.recs_inorder = xfs_rmapbt_recs_inorder,
.keys_contiguous = xfs_rmapbt_keys_contiguous,
};
/* Create a cursor for an in-memory btree. */
struct xfs_btree_cur *
xfs_rmapbt_mem_cursor(
struct xfs_perag *pag,
struct xfs_trans *tp,
struct xfbtree *xfbt)
{
struct xfs_btree_cur *cur;
struct xfs_mount *mp = pag->pag_mount;
cur = xfs_btree_alloc_cursor(mp, tp, &xfs_rmapbt_mem_ops,
xfs_rmapbt_maxlevels_ondisk(), xfs_rmapbt_cur_cache);
cur->bc_mem.xfbtree = xfbt;
cur->bc_nlevels = xfbt->nlevels;
cur->bc_mem.pag = xfs_perag_hold(pag);
return cur;
}
/* Create an in-memory rmap btree. */
int
xfs_rmapbt_mem_init(
struct xfs_mount *mp,
struct xfbtree *xfbt,
struct xfs_buftarg *btp,
xfs_agnumber_t agno)
{
xfbt->owner = agno;
return xfbtree_init(mp, xfbt, btp, &xfs_rmapbt_mem_ops);
}
/* Compute the max possible height for reverse mapping btrees in memory. */
static unsigned int
xfs_rmapbt_mem_maxlevels(void)
{
unsigned int minrecs[2];
unsigned int blocklen;
blocklen = XFBNO_BLOCKSIZE - XFS_BTREE_LBLOCK_CRC_LEN;
minrecs[0] = xfs_rmapbt_mem_block_maxrecs(blocklen, true) / 2;
minrecs[1] = xfs_rmapbt_mem_block_maxrecs(blocklen, false) / 2;
/*
* How tall can an in-memory rmap btree become if we filled the entire
* AG with rmap records?
*/
return xfs_btree_compute_maxlevels(minrecs,
XFS_MAX_AG_BYTES / sizeof(struct xfs_rmap_rec));
}
#else
# define xfs_rmapbt_mem_maxlevels() (0)
#endif /* CONFIG_XFS_BTREE_IN_MEM */
/*
* Install a new reverse mapping btree root. Caller is responsible for
* invalidating and freeing the old btree blocks.
*/
void
xfs_rmapbt_commit_staged_btree(
struct xfs_btree_cur *cur,
struct xfs_trans *tp,
struct xfs_buf *agbp)
{
struct xfs_agf *agf = agbp->b_addr;
struct xbtree_afakeroot *afake = cur->bc_ag.afake;
ASSERT(cur->bc_flags & XFS_BTREE_STAGING);
agf->agf_rmap_root = cpu_to_be32(afake->af_root);
agf->agf_rmap_level = cpu_to_be32(afake->af_levels);
agf->agf_rmap_blocks = cpu_to_be32(afake->af_blocks);
xfs_alloc_log_agf(tp, agbp, XFS_AGF_ROOTS | XFS_AGF_LEVELS |
XFS_AGF_RMAP_BLOCKS);
xfs_btree_commit_afakeroot(cur, tp, agbp);
}
/* 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.
*/
int
xfs_rmapbt_maxrecs(
int blocklen,
int leaf)
{
blocklen -= XFS_RMAP_BLOCK_LEN;
return xfs_rmapbt_block_maxrecs(blocklen, leaf);
}
/* 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 max(xfs_btree_space_to_height(minrecs, XFS_MAX_CRC_AG_BLOCKS),
xfs_rmapbt_mem_maxlevels());
}
/* Compute the maximum height of an rmap btree. */
void
xfs_rmapbt_compute_maxlevels(
struct xfs_mount *mp)
{
if (!xfs_has_rmapbt(mp)) {
mp->m_rmap_maxlevels = 0;
return;
}
if (xfs_has_reflink(mp)) {
/*
* Compute the asymptotic maxlevels for an rmap btree on a
* filesystem that supports reflink.
*
* 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.
*/
mp->m_rmap_maxlevels = xfs_btree_space_to_height(mp->m_rmap_mnr,
mp->m_sb.sb_agblocks);
} else {
/*
* If there's no block sharing, compute the maximum rmapbt
* height assuming one rmap record per AG block.
*/
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. */
xfs_extlen_t
xfs_rmapbt_calc_size(
struct xfs_mount *mp,
unsigned long long len)
{
return xfs_btree_calc_size(mp->m_rmap_mnr, len);
}
/*
* Calculate the maximum refcount btree size.
*/
xfs_extlen_t
xfs_rmapbt_max_size(
struct xfs_mount *mp,
xfs_agblock_t agblocks)
{
/* Bail out if we're uninitialized, which can happen in mkfs. */
if (mp->m_rmap_mxr[0] == 0)
return 0;
return xfs_rmapbt_calc_size(mp, agblocks);
}
/*
* Figure out how many blocks to reserve and how many are used by this btree.
*/
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)
{
struct xfs_buf *agbp;
struct xfs_agf *agf;
xfs_agblock_t agblocks;
xfs_extlen_t tree_len;
int error;
if (!xfs_has_rmapbt(mp))
return 0;
error = xfs_alloc_read_agf(pag, tp, 0, &agbp);
if (error)
return error;
agf = agbp->b_addr;
agblocks = be32_to_cpu(agf->agf_length);
tree_len = be32_to_cpu(agf->agf_rmap_blocks);
xfs_trans_brelse(tp, agbp);
/*
* The log is permanently allocated, so the space it occupies will
* never be available for the kinds of things that would require btree
* expansion. We therefore can pretend the space isn't there.
*/
if (xfs_ag_contains_log(mp, pag->pag_agno))
agblocks -= mp->m_sb.sb_logblocks;
/* Reserve 1% of the AG or enough for 1 block per record. */
*ask += max(agblocks / 100, xfs_rmapbt_max_size(mp, agblocks));
*used += tree_len;
return error;
}
int __init
xfs_rmapbt_init_cur_cache(void)
{
xfs_rmapbt_cur_cache = kmem_cache_create("xfs_rmapbt_cur",
xfs_btree_cur_sizeof(xfs_rmapbt_maxlevels_ondisk()),
0, 0, NULL);
if (!xfs_rmapbt_cur_cache)
return -ENOMEM;
return 0;
}
void
xfs_rmapbt_destroy_cur_cache(void)
{
kmem_cache_destroy(xfs_rmapbt_cur_cache);
xfs_rmapbt_cur_cache = NULL;
}
