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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /fs/xfs/libxfs/xfs_bmap_btree.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'fs/xfs/libxfs/xfs_bmap_btree.c')
-rw-r--r--fs/xfs/libxfs/xfs_bmap_btree.c703
1 files changed, 703 insertions, 0 deletions
diff --git a/fs/xfs/libxfs/xfs_bmap_btree.c b/fs/xfs/libxfs/xfs_bmap_btree.c
new file mode 100644
index 000000000..cfa052d40
--- /dev/null
+++ b/fs/xfs/libxfs/xfs_bmap_btree.c
@@ -0,0 +1,703 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2000-2003,2005 Silicon Graphics, 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_bit.h"
+#include "xfs_mount.h"
+#include "xfs_inode.h"
+#include "xfs_trans.h"
+#include "xfs_alloc.h"
+#include "xfs_btree.h"
+#include "xfs_bmap_btree.h"
+#include "xfs_bmap.h"
+#include "xfs_error.h"
+#include "xfs_quota.h"
+#include "xfs_trace.h"
+#include "xfs_rmap.h"
+
+static struct kmem_cache *xfs_bmbt_cur_cache;
+
+/*
+ * Convert on-disk form of btree root to in-memory form.
+ */
+void
+xfs_bmdr_to_bmbt(
+ struct xfs_inode *ip,
+ xfs_bmdr_block_t *dblock,
+ int dblocklen,
+ struct xfs_btree_block *rblock,
+ int rblocklen)
+{
+ struct xfs_mount *mp = ip->i_mount;
+ int dmxr;
+ xfs_bmbt_key_t *fkp;
+ __be64 *fpp;
+ xfs_bmbt_key_t *tkp;
+ __be64 *tpp;
+
+ xfs_btree_init_block_int(mp, rblock, XFS_BUF_DADDR_NULL,
+ XFS_BTNUM_BMAP, 0, 0, ip->i_ino,
+ XFS_BTREE_LONG_PTRS);
+ rblock->bb_level = dblock->bb_level;
+ ASSERT(be16_to_cpu(rblock->bb_level) > 0);
+ rblock->bb_numrecs = dblock->bb_numrecs;
+ dmxr = xfs_bmdr_maxrecs(dblocklen, 0);
+ fkp = XFS_BMDR_KEY_ADDR(dblock, 1);
+ tkp = XFS_BMBT_KEY_ADDR(mp, rblock, 1);
+ fpp = XFS_BMDR_PTR_ADDR(dblock, 1, dmxr);
+ tpp = XFS_BMAP_BROOT_PTR_ADDR(mp, rblock, 1, rblocklen);
+ dmxr = be16_to_cpu(dblock->bb_numrecs);
+ memcpy(tkp, fkp, sizeof(*fkp) * dmxr);
+ memcpy(tpp, fpp, sizeof(*fpp) * dmxr);
+}
+
+void
+xfs_bmbt_disk_get_all(
+ const struct xfs_bmbt_rec *rec,
+ struct xfs_bmbt_irec *irec)
+{
+ uint64_t l0 = get_unaligned_be64(&rec->l0);
+ uint64_t l1 = get_unaligned_be64(&rec->l1);
+
+ irec->br_startoff = (l0 & xfs_mask64lo(64 - BMBT_EXNTFLAG_BITLEN)) >> 9;
+ irec->br_startblock = ((l0 & xfs_mask64lo(9)) << 43) | (l1 >> 21);
+ irec->br_blockcount = l1 & xfs_mask64lo(21);
+ if (l0 >> (64 - BMBT_EXNTFLAG_BITLEN))
+ irec->br_state = XFS_EXT_UNWRITTEN;
+ else
+ irec->br_state = XFS_EXT_NORM;
+}
+
+/*
+ * Extract the blockcount field from an on disk bmap extent record.
+ */
+xfs_filblks_t
+xfs_bmbt_disk_get_blockcount(
+ const struct xfs_bmbt_rec *r)
+{
+ return (xfs_filblks_t)(be64_to_cpu(r->l1) & xfs_mask64lo(21));
+}
+
+/*
+ * Extract the startoff field from a disk format bmap extent record.
+ */
+xfs_fileoff_t
+xfs_bmbt_disk_get_startoff(
+ const struct xfs_bmbt_rec *r)
+{
+ return ((xfs_fileoff_t)be64_to_cpu(r->l0) &
+ xfs_mask64lo(64 - BMBT_EXNTFLAG_BITLEN)) >> 9;
+}
+
+/*
+ * Set all the fields in a bmap extent record from the uncompressed form.
+ */
+void
+xfs_bmbt_disk_set_all(
+ struct xfs_bmbt_rec *r,
+ struct xfs_bmbt_irec *s)
+{
+ int extent_flag = (s->br_state != XFS_EXT_NORM);
+
+ ASSERT(s->br_state == XFS_EXT_NORM || s->br_state == XFS_EXT_UNWRITTEN);
+ ASSERT(!(s->br_startoff & xfs_mask64hi(64-BMBT_STARTOFF_BITLEN)));
+ ASSERT(!(s->br_blockcount & xfs_mask64hi(64-BMBT_BLOCKCOUNT_BITLEN)));
+ ASSERT(!(s->br_startblock & xfs_mask64hi(64-BMBT_STARTBLOCK_BITLEN)));
+
+ put_unaligned_be64(
+ ((xfs_bmbt_rec_base_t)extent_flag << 63) |
+ ((xfs_bmbt_rec_base_t)s->br_startoff << 9) |
+ ((xfs_bmbt_rec_base_t)s->br_startblock >> 43), &r->l0);
+ put_unaligned_be64(
+ ((xfs_bmbt_rec_base_t)s->br_startblock << 21) |
+ ((xfs_bmbt_rec_base_t)s->br_blockcount &
+ (xfs_bmbt_rec_base_t)xfs_mask64lo(21)), &r->l1);
+}
+
+/*
+ * Convert in-memory form of btree root to on-disk form.
+ */
+void
+xfs_bmbt_to_bmdr(
+ struct xfs_mount *mp,
+ struct xfs_btree_block *rblock,
+ int rblocklen,
+ xfs_bmdr_block_t *dblock,
+ int dblocklen)
+{
+ int dmxr;
+ xfs_bmbt_key_t *fkp;
+ __be64 *fpp;
+ xfs_bmbt_key_t *tkp;
+ __be64 *tpp;
+
+ if (xfs_has_crc(mp)) {
+ ASSERT(rblock->bb_magic == cpu_to_be32(XFS_BMAP_CRC_MAGIC));
+ ASSERT(uuid_equal(&rblock->bb_u.l.bb_uuid,
+ &mp->m_sb.sb_meta_uuid));
+ ASSERT(rblock->bb_u.l.bb_blkno ==
+ cpu_to_be64(XFS_BUF_DADDR_NULL));
+ } else
+ ASSERT(rblock->bb_magic == cpu_to_be32(XFS_BMAP_MAGIC));
+ ASSERT(rblock->bb_u.l.bb_leftsib == cpu_to_be64(NULLFSBLOCK));
+ ASSERT(rblock->bb_u.l.bb_rightsib == cpu_to_be64(NULLFSBLOCK));
+ ASSERT(rblock->bb_level != 0);
+ dblock->bb_level = rblock->bb_level;
+ dblock->bb_numrecs = rblock->bb_numrecs;
+ dmxr = xfs_bmdr_maxrecs(dblocklen, 0);
+ fkp = XFS_BMBT_KEY_ADDR(mp, rblock, 1);
+ tkp = XFS_BMDR_KEY_ADDR(dblock, 1);
+ fpp = XFS_BMAP_BROOT_PTR_ADDR(mp, rblock, 1, rblocklen);
+ tpp = XFS_BMDR_PTR_ADDR(dblock, 1, dmxr);
+ dmxr = be16_to_cpu(dblock->bb_numrecs);
+ memcpy(tkp, fkp, sizeof(*fkp) * dmxr);
+ memcpy(tpp, fpp, sizeof(*fpp) * dmxr);
+}
+
+STATIC struct xfs_btree_cur *
+xfs_bmbt_dup_cursor(
+ struct xfs_btree_cur *cur)
+{
+ struct xfs_btree_cur *new;
+
+ new = xfs_bmbt_init_cursor(cur->bc_mp, cur->bc_tp,
+ cur->bc_ino.ip, cur->bc_ino.whichfork);
+
+ /*
+ * Copy the firstblock, dfops, and flags values,
+ * since init cursor doesn't get them.
+ */
+ new->bc_ino.flags = cur->bc_ino.flags;
+
+ return new;
+}
+
+STATIC void
+xfs_bmbt_update_cursor(
+ struct xfs_btree_cur *src,
+ struct xfs_btree_cur *dst)
+{
+ ASSERT((dst->bc_tp->t_firstblock != NULLFSBLOCK) ||
+ (dst->bc_ino.ip->i_diflags & XFS_DIFLAG_REALTIME));
+
+ dst->bc_ino.allocated += src->bc_ino.allocated;
+ dst->bc_tp->t_firstblock = src->bc_tp->t_firstblock;
+
+ src->bc_ino.allocated = 0;
+}
+
+STATIC int
+xfs_bmbt_alloc_block(
+ struct xfs_btree_cur *cur,
+ const union xfs_btree_ptr *start,
+ union xfs_btree_ptr *new,
+ int *stat)
+{
+ xfs_alloc_arg_t args; /* block allocation args */
+ int error; /* error return value */
+
+ memset(&args, 0, sizeof(args));
+ args.tp = cur->bc_tp;
+ args.mp = cur->bc_mp;
+ args.fsbno = cur->bc_tp->t_firstblock;
+ xfs_rmap_ino_bmbt_owner(&args.oinfo, cur->bc_ino.ip->i_ino,
+ cur->bc_ino.whichfork);
+
+ if (args.fsbno == NULLFSBLOCK) {
+ args.fsbno = be64_to_cpu(start->l);
+ args.type = XFS_ALLOCTYPE_START_BNO;
+ /*
+ * Make sure there is sufficient room left in the AG to
+ * complete a full tree split for an extent insert. If
+ * we are converting the middle part of an extent then
+ * we may need space for two tree splits.
+ *
+ * We are relying on the caller to make the correct block
+ * reservation for this operation to succeed. If the
+ * reservation amount is insufficient then we may fail a
+ * block allocation here and corrupt the filesystem.
+ */
+ args.minleft = args.tp->t_blk_res;
+ } else if (cur->bc_tp->t_flags & XFS_TRANS_LOWMODE) {
+ args.type = XFS_ALLOCTYPE_START_BNO;
+ } else {
+ args.type = XFS_ALLOCTYPE_NEAR_BNO;
+ }
+
+ args.minlen = args.maxlen = args.prod = 1;
+ args.wasdel = cur->bc_ino.flags & XFS_BTCUR_BMBT_WASDEL;
+ if (!args.wasdel && args.tp->t_blk_res == 0) {
+ error = -ENOSPC;
+ goto error0;
+ }
+ error = xfs_alloc_vextent(&args);
+ if (error)
+ goto error0;
+
+ if (args.fsbno == NULLFSBLOCK && args.minleft) {
+ /*
+ * Could not find an AG with enough free space to satisfy
+ * a full btree split. Try again and if
+ * successful activate the lowspace algorithm.
+ */
+ args.fsbno = 0;
+ args.type = XFS_ALLOCTYPE_FIRST_AG;
+ error = xfs_alloc_vextent(&args);
+ if (error)
+ goto error0;
+ cur->bc_tp->t_flags |= XFS_TRANS_LOWMODE;
+ }
+ if (WARN_ON_ONCE(args.fsbno == NULLFSBLOCK)) {
+ *stat = 0;
+ return 0;
+ }
+
+ ASSERT(args.len == 1);
+ cur->bc_tp->t_firstblock = args.fsbno;
+ cur->bc_ino.allocated++;
+ cur->bc_ino.ip->i_nblocks++;
+ xfs_trans_log_inode(args.tp, cur->bc_ino.ip, XFS_ILOG_CORE);
+ xfs_trans_mod_dquot_byino(args.tp, cur->bc_ino.ip,
+ XFS_TRANS_DQ_BCOUNT, 1L);
+
+ new->l = cpu_to_be64(args.fsbno);
+
+ *stat = 1;
+ return 0;
+
+ error0:
+ return error;
+}
+
+STATIC int
+xfs_bmbt_free_block(
+ struct xfs_btree_cur *cur,
+ struct xfs_buf *bp)
+{
+ struct xfs_mount *mp = cur->bc_mp;
+ struct xfs_inode *ip = cur->bc_ino.ip;
+ struct xfs_trans *tp = cur->bc_tp;
+ xfs_fsblock_t fsbno = XFS_DADDR_TO_FSB(mp, xfs_buf_daddr(bp));
+ struct xfs_owner_info oinfo;
+
+ xfs_rmap_ino_bmbt_owner(&oinfo, ip->i_ino, cur->bc_ino.whichfork);
+ xfs_free_extent_later(cur->bc_tp, fsbno, 1, &oinfo);
+ ip->i_nblocks--;
+
+ xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
+ xfs_trans_mod_dquot_byino(tp, ip, XFS_TRANS_DQ_BCOUNT, -1L);
+ return 0;
+}
+
+STATIC int
+xfs_bmbt_get_minrecs(
+ struct xfs_btree_cur *cur,
+ int level)
+{
+ if (level == cur->bc_nlevels - 1) {
+ struct xfs_ifork *ifp;
+
+ ifp = xfs_ifork_ptr(cur->bc_ino.ip,
+ cur->bc_ino.whichfork);
+
+ return xfs_bmbt_maxrecs(cur->bc_mp,
+ ifp->if_broot_bytes, level == 0) / 2;
+ }
+
+ return cur->bc_mp->m_bmap_dmnr[level != 0];
+}
+
+int
+xfs_bmbt_get_maxrecs(
+ struct xfs_btree_cur *cur,
+ int level)
+{
+ if (level == cur->bc_nlevels - 1) {
+ struct xfs_ifork *ifp;
+
+ ifp = xfs_ifork_ptr(cur->bc_ino.ip,
+ cur->bc_ino.whichfork);
+
+ return xfs_bmbt_maxrecs(cur->bc_mp,
+ ifp->if_broot_bytes, level == 0);
+ }
+
+ return cur->bc_mp->m_bmap_dmxr[level != 0];
+
+}
+
+/*
+ * Get the maximum records we could store in the on-disk format.
+ *
+ * For non-root nodes this is equivalent to xfs_bmbt_get_maxrecs, but
+ * for the root node this checks the available space in the dinode fork
+ * so that we can resize the in-memory buffer to match it. After a
+ * resize to the maximum size this function returns the same value
+ * as xfs_bmbt_get_maxrecs for the root node, too.
+ */
+STATIC int
+xfs_bmbt_get_dmaxrecs(
+ struct xfs_btree_cur *cur,
+ int level)
+{
+ if (level != cur->bc_nlevels - 1)
+ return cur->bc_mp->m_bmap_dmxr[level != 0];
+ return xfs_bmdr_maxrecs(cur->bc_ino.forksize, level == 0);
+}
+
+STATIC void
+xfs_bmbt_init_key_from_rec(
+ union xfs_btree_key *key,
+ const union xfs_btree_rec *rec)
+{
+ key->bmbt.br_startoff =
+ cpu_to_be64(xfs_bmbt_disk_get_startoff(&rec->bmbt));
+}
+
+STATIC void
+xfs_bmbt_init_high_key_from_rec(
+ union xfs_btree_key *key,
+ const union xfs_btree_rec *rec)
+{
+ key->bmbt.br_startoff = cpu_to_be64(
+ xfs_bmbt_disk_get_startoff(&rec->bmbt) +
+ xfs_bmbt_disk_get_blockcount(&rec->bmbt) - 1);
+}
+
+STATIC void
+xfs_bmbt_init_rec_from_cur(
+ struct xfs_btree_cur *cur,
+ union xfs_btree_rec *rec)
+{
+ xfs_bmbt_disk_set_all(&rec->bmbt, &cur->bc_rec.b);
+}
+
+STATIC void
+xfs_bmbt_init_ptr_from_cur(
+ struct xfs_btree_cur *cur,
+ union xfs_btree_ptr *ptr)
+{
+ ptr->l = 0;
+}
+
+STATIC int64_t
+xfs_bmbt_key_diff(
+ struct xfs_btree_cur *cur,
+ const union xfs_btree_key *key)
+{
+ return (int64_t)be64_to_cpu(key->bmbt.br_startoff) -
+ cur->bc_rec.b.br_startoff;
+}
+
+STATIC int64_t
+xfs_bmbt_diff_two_keys(
+ struct xfs_btree_cur *cur,
+ const union xfs_btree_key *k1,
+ const union xfs_btree_key *k2)
+{
+ uint64_t a = be64_to_cpu(k1->bmbt.br_startoff);
+ uint64_t b = be64_to_cpu(k2->bmbt.br_startoff);
+
+ /*
+ * Note: This routine previously casted a and b to int64 and subtracted
+ * them to generate a result. This lead to problems if b was the
+ * "maximum" key value (all ones) being signed incorrectly, hence this
+ * somewhat less efficient version.
+ */
+ if (a > b)
+ return 1;
+ if (b > a)
+ return -1;
+ return 0;
+}
+
+static xfs_failaddr_t
+xfs_bmbt_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;
+
+ if (xfs_has_crc(mp)) {
+ /*
+ * XXX: need a better way of verifying the owner here. Right now
+ * just make sure there has been one set.
+ */
+ fa = xfs_btree_lblock_v5hdr_verify(bp, XFS_RMAP_OWN_UNKNOWN);
+ if (fa)
+ return fa;
+ }
+
+ /*
+ * numrecs and level verification.
+ *
+ * We don't know what fork we belong to, so just verify that the level
+ * is less than the maximum of the two. Later checks will be more
+ * precise.
+ */
+ level = be16_to_cpu(block->bb_level);
+ if (level > max(mp->m_bm_maxlevels[0], mp->m_bm_maxlevels[1]))
+ return __this_address;
+
+ return xfs_btree_lblock_verify(bp, mp->m_bmap_dmxr[level != 0]);
+}
+
+static void
+xfs_bmbt_read_verify(
+ struct xfs_buf *bp)
+{
+ xfs_failaddr_t fa;
+
+ if (!xfs_btree_lblock_verify_crc(bp))
+ xfs_verifier_error(bp, -EFSBADCRC, __this_address);
+ else {
+ fa = xfs_bmbt_verify(bp);
+ if (fa)
+ xfs_verifier_error(bp, -EFSCORRUPTED, fa);
+ }
+
+ if (bp->b_error)
+ trace_xfs_btree_corrupt(bp, _RET_IP_);
+}
+
+static void
+xfs_bmbt_write_verify(
+ struct xfs_buf *bp)
+{
+ xfs_failaddr_t fa;
+
+ fa = xfs_bmbt_verify(bp);
+ if (fa) {
+ trace_xfs_btree_corrupt(bp, _RET_IP_);
+ xfs_verifier_error(bp, -EFSCORRUPTED, fa);
+ return;
+ }
+ xfs_btree_lblock_calc_crc(bp);
+}
+
+const struct xfs_buf_ops xfs_bmbt_buf_ops = {
+ .name = "xfs_bmbt",
+ .magic = { cpu_to_be32(XFS_BMAP_MAGIC),
+ cpu_to_be32(XFS_BMAP_CRC_MAGIC) },
+ .verify_read = xfs_bmbt_read_verify,
+ .verify_write = xfs_bmbt_write_verify,
+ .verify_struct = xfs_bmbt_verify,
+};
+
+
+STATIC int
+xfs_bmbt_keys_inorder(
+ struct xfs_btree_cur *cur,
+ const union xfs_btree_key *k1,
+ const union xfs_btree_key *k2)
+{
+ return be64_to_cpu(k1->bmbt.br_startoff) <
+ be64_to_cpu(k2->bmbt.br_startoff);
+}
+
+STATIC int
+xfs_bmbt_recs_inorder(
+ struct xfs_btree_cur *cur,
+ const union xfs_btree_rec *r1,
+ const union xfs_btree_rec *r2)
+{
+ return xfs_bmbt_disk_get_startoff(&r1->bmbt) +
+ xfs_bmbt_disk_get_blockcount(&r1->bmbt) <=
+ xfs_bmbt_disk_get_startoff(&r2->bmbt);
+}
+
+static const struct xfs_btree_ops xfs_bmbt_ops = {
+ .rec_len = sizeof(xfs_bmbt_rec_t),
+ .key_len = sizeof(xfs_bmbt_key_t),
+
+ .dup_cursor = xfs_bmbt_dup_cursor,
+ .update_cursor = xfs_bmbt_update_cursor,
+ .alloc_block = xfs_bmbt_alloc_block,
+ .free_block = xfs_bmbt_free_block,
+ .get_maxrecs = xfs_bmbt_get_maxrecs,
+ .get_minrecs = xfs_bmbt_get_minrecs,
+ .get_dmaxrecs = xfs_bmbt_get_dmaxrecs,
+ .init_key_from_rec = xfs_bmbt_init_key_from_rec,
+ .init_high_key_from_rec = xfs_bmbt_init_high_key_from_rec,
+ .init_rec_from_cur = xfs_bmbt_init_rec_from_cur,
+ .init_ptr_from_cur = xfs_bmbt_init_ptr_from_cur,
+ .key_diff = xfs_bmbt_key_diff,
+ .diff_two_keys = xfs_bmbt_diff_two_keys,
+ .buf_ops = &xfs_bmbt_buf_ops,
+ .keys_inorder = xfs_bmbt_keys_inorder,
+ .recs_inorder = xfs_bmbt_recs_inorder,
+};
+
+/*
+ * Allocate a new bmap btree cursor.
+ */
+struct xfs_btree_cur * /* new bmap btree cursor */
+xfs_bmbt_init_cursor(
+ struct xfs_mount *mp, /* file system mount point */
+ struct xfs_trans *tp, /* transaction pointer */
+ struct xfs_inode *ip, /* inode owning the btree */
+ int whichfork) /* data or attr fork */
+{
+ struct xfs_ifork *ifp = xfs_ifork_ptr(ip, whichfork);
+ struct xfs_btree_cur *cur;
+ ASSERT(whichfork != XFS_COW_FORK);
+
+ cur = xfs_btree_alloc_cursor(mp, tp, XFS_BTNUM_BMAP,
+ mp->m_bm_maxlevels[whichfork], xfs_bmbt_cur_cache);
+ cur->bc_nlevels = be16_to_cpu(ifp->if_broot->bb_level) + 1;
+ cur->bc_statoff = XFS_STATS_CALC_INDEX(xs_bmbt_2);
+
+ cur->bc_ops = &xfs_bmbt_ops;
+ cur->bc_flags = XFS_BTREE_LONG_PTRS | XFS_BTREE_ROOT_IN_INODE;
+ if (xfs_has_crc(mp))
+ cur->bc_flags |= XFS_BTREE_CRC_BLOCKS;
+
+ cur->bc_ino.forksize = xfs_inode_fork_size(ip, whichfork);
+ cur->bc_ino.ip = ip;
+ cur->bc_ino.allocated = 0;
+ cur->bc_ino.flags = 0;
+ cur->bc_ino.whichfork = whichfork;
+
+ 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.
+ */
+int
+xfs_bmbt_maxrecs(
+ struct xfs_mount *mp,
+ int blocklen,
+ int leaf)
+{
+ blocklen -= XFS_BMBT_BLOCK_LEN(mp);
+ return xfs_bmbt_block_maxrecs(blocklen, leaf);
+}
+
+/*
+ * Calculate the maximum possible height of the btree that the on-disk format
+ * supports. This is used for sizing structures large enough to support every
+ * possible configuration of a filesystem that might get mounted.
+ */
+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,
+ XFS_MAX_EXTCNT_DATA_FORK_LARGE) + 1;
+}
+
+/*
+ * Calculate number of records in a bmap btree inode root.
+ */
+int
+xfs_bmdr_maxrecs(
+ int blocklen,
+ int leaf)
+{
+ blocklen -= sizeof(xfs_bmdr_block_t);
+
+ if (leaf)
+ return blocklen / sizeof(xfs_bmdr_rec_t);
+ return blocklen / (sizeof(xfs_bmdr_key_t) + sizeof(xfs_bmdr_ptr_t));
+}
+
+/*
+ * Change the owner of a btree format fork fo the inode passed in. Change it to
+ * the owner of that is passed in so that we can change owners before or after
+ * we switch forks between inodes. The operation that the caller is doing will
+ * determine whether is needs to change owner before or after the switch.
+ *
+ * For demand paged transactional modification, the fork switch should be done
+ * after reading in all the blocks, modifying them and pinning them in the
+ * transaction. For modification when the buffers are already pinned in memory,
+ * the fork switch can be done before changing the owner as we won't need to
+ * validate the owner until the btree buffers are unpinned and writes can occur
+ * again.
+ *
+ * For recovery based ownership change, there is no transactional context and
+ * so a buffer list must be supplied so that we can record the buffers that we
+ * modified for the caller to issue IO on.
+ */
+int
+xfs_bmbt_change_owner(
+ struct xfs_trans *tp,
+ struct xfs_inode *ip,
+ int whichfork,
+ xfs_ino_t new_owner,
+ struct list_head *buffer_list)
+{
+ struct xfs_btree_cur *cur;
+ int error;
+
+ ASSERT(tp || buffer_list);
+ ASSERT(!(tp && buffer_list));
+ ASSERT(xfs_ifork_ptr(ip, whichfork)->if_format == XFS_DINODE_FMT_BTREE);
+
+ cur = xfs_bmbt_init_cursor(ip->i_mount, tp, ip, whichfork);
+ cur->bc_ino.flags |= XFS_BTCUR_BMBT_INVALID_OWNER;
+
+ error = xfs_btree_change_owner(cur, new_owner, buffer_list);
+ xfs_btree_del_cursor(cur, error);
+ return error;
+}
+
+/* Calculate the bmap btree size for some records. */
+unsigned long long
+xfs_bmbt_calc_size(
+ struct xfs_mount *mp,
+ unsigned long long len)
+{
+ return xfs_btree_calc_size(mp->m_bmap_dmnr, len);
+}
+
+int __init
+xfs_bmbt_init_cur_cache(void)
+{
+ xfs_bmbt_cur_cache = kmem_cache_create("xfs_bmbt_cur",
+ xfs_btree_cur_sizeof(xfs_bmbt_maxlevels_ondisk()),
+ 0, 0, NULL);
+
+ if (!xfs_bmbt_cur_cache)
+ return -ENOMEM;
+ return 0;
+}
+
+void
+xfs_bmbt_destroy_cur_cache(void)
+{
+ kmem_cache_destroy(xfs_bmbt_cur_cache);
+ xfs_bmbt_cur_cache = NULL;
+}