/* Ensure we asked for crc for crc-only magics. */
ASSERT(magic != 0); return be32_to_cpu(magic);
}
/* * These sibling pointer checks are optimised for null sibling pointers. This * happens a lot, and we don't need to byte swap at runtime if the sibling * pointer is NULL. * * These are explicitly marked at inline because the cost of calling them as * functions instead of inlining them is about 36 bytes extra code per call site * on x86-64. Yes, gcc-11 fails to inline them, and explicit inlining of these * two sibling check functions reduces the compiled code size by over 300 * bytes.
*/ staticinline xfs_failaddr_t
xfs_btree_check_fsblock_siblings( struct xfs_mount *mp,
xfs_fsblock_t fsb,
__be64 dsibling)
{
xfs_fsblock_t sibling;
if (dsibling == cpu_to_be64(NULLFSBLOCK)) return NULL;
sibling = be64_to_cpu(dsibling); if (sibling == fsb) return __this_address; if (!xfs_verify_fsbno(mp, sibling)) return __this_address; return NULL;
}
if (xfs_has_crc(mp)) { if (!uuid_equal(&block->bb_u.l.bb_uuid, &mp->m_sb.sb_meta_uuid)) return __this_address; if (block->bb_u.l.bb_blkno !=
cpu_to_be64(bp ? xfs_buf_daddr(bp) : XFS_BUF_DADDR_NULL)) return __this_address; if (block->bb_u.l.bb_pad != cpu_to_be32(0)) return __this_address;
}
if (be32_to_cpu(block->bb_magic) != xfs_btree_magic(mp, cur->bc_ops)) return __this_address; if (be16_to_cpu(block->bb_level) != level) return __this_address; if (be16_to_cpu(block->bb_numrecs) >
cur->bc_ops->get_maxrecs(cur, level)) return __this_address;
return NULL;
}
/* * Check a long btree block header. Return the address of the failing check, * or NULL if everything is ok.
*/ static xfs_failaddr_t
__xfs_btree_check_fsblock( struct xfs_btree_cur *cur, struct xfs_btree_block *block, int level, struct xfs_buf *bp)
{ struct xfs_mount *mp = cur->bc_mp;
xfs_failaddr_t fa;
xfs_fsblock_t fsb;
fa = __xfs_btree_check_lblock_hdr(cur, block, level, bp); if (fa) return fa;
/* * For inode-rooted btrees, the root block sits in the inode fork. In * that case bp is NULL, and the block must not have any siblings.
*/ if (!bp) { if (block->bb_u.l.bb_leftsib != cpu_to_be64(NULLFSBLOCK)) return __this_address; if (block->bb_u.l.bb_rightsib != cpu_to_be64(NULLFSBLOCK)) return __this_address; return NULL;
}
fsb = XFS_DADDR_TO_FSB(mp, xfs_buf_daddr(bp));
fa = xfs_btree_check_fsblock_siblings(mp, fsb,
block->bb_u.l.bb_leftsib); if (!fa)
fa = xfs_btree_check_fsblock_siblings(mp, fsb,
block->bb_u.l.bb_rightsib); return fa;
}
/* * Check an in-memory btree block header. Return the address of the failing * check, or NULL if everything is ok.
*/ static xfs_failaddr_t
__xfs_btree_check_memblock( struct xfs_btree_cur *cur, struct xfs_btree_block *block, int level, struct xfs_buf *bp)
{ struct xfs_buftarg *btp = cur->bc_mem.xfbtree->target;
xfs_failaddr_t fa;
xfbno_t bno;
fa = __xfs_btree_check_lblock_hdr(cur, block, level, bp); if (fa) return fa;
bno = xfs_daddr_to_xfbno(xfs_buf_daddr(bp));
fa = xfs_btree_check_memblock_siblings(btp, bno,
block->bb_u.l.bb_leftsib); if (!fa)
fa = xfs_btree_check_memblock_siblings(btp, bno,
block->bb_u.l.bb_rightsib); return fa;
}
/* * Check a short btree block header. Return the address of the failing check, * or NULL if everything is ok.
*/ static xfs_failaddr_t
__xfs_btree_check_agblock( struct xfs_btree_cur *cur, struct xfs_btree_block *block, int level, struct xfs_buf *bp)
{ struct xfs_mount *mp = cur->bc_mp; struct xfs_perag *pag = to_perag(cur->bc_group);
xfs_failaddr_t fa;
xfs_agblock_t agbno;
if (xfs_has_crc(mp)) { if (!uuid_equal(&block->bb_u.s.bb_uuid, &mp->m_sb.sb_meta_uuid)) return __this_address; if (block->bb_u.s.bb_blkno != cpu_to_be64(xfs_buf_daddr(bp))) return __this_address;
}
if (be32_to_cpu(block->bb_magic) != xfs_btree_magic(mp, cur->bc_ops)) return __this_address; if (be16_to_cpu(block->bb_level) != level) return __this_address; if (be16_to_cpu(block->bb_numrecs) >
cur->bc_ops->get_maxrecs(cur, level)) return __this_address;
agbno = xfs_daddr_to_agbno(mp, xfs_buf_daddr(bp));
fa = xfs_btree_check_agblock_siblings(pag, agbno,
block->bb_u.s.bb_leftsib); if (!fa)
fa = xfs_btree_check_agblock_siblings(pag, agbno,
block->bb_u.s.bb_rightsib); return fa;
}
/* * Internal btree block check. * * Return NULL if the block is ok or the address of the failed check otherwise.
*/
xfs_failaddr_t
__xfs_btree_check_block( struct xfs_btree_cur *cur, struct xfs_btree_block *block, int level, struct xfs_buf *bp)
{ switch (cur->bc_ops->type) { case XFS_BTREE_TYPE_MEM: return __xfs_btree_check_memblock(cur, block, level, bp); case XFS_BTREE_TYPE_AG: return __xfs_btree_check_agblock(cur, block, level, bp); case XFS_BTREE_TYPE_INODE: return __xfs_btree_check_fsblock(cur, block, level, bp); default:
ASSERT(0); return __this_address;
}
}
/* * Debug routine: check that block header is ok.
*/ int
xfs_btree_check_block( struct xfs_btree_cur *cur, /* btree cursor */ struct xfs_btree_block *block, /* generic btree block pointer */ int level, /* level of the btree block */ struct xfs_buf *bp) /* buffer containing block, if any */
{ struct xfs_mount *mp = cur->bc_mp;
xfs_failaddr_t fa;
fa = __xfs_btree_check_block(cur, block, level, bp); if (XFS_IS_CORRUPT(mp, fa != NULL) ||
XFS_TEST_ERROR(false, mp, xfs_btree_block_errtag(cur))) { if (bp)
trace_xfs_btree_corrupt(bp, _RET_IP_);
xfs_btree_mark_sick(cur); return -EFSCORRUPTED;
} return 0;
}
int
__xfs_btree_check_ptr( struct xfs_btree_cur *cur, constunion xfs_btree_ptr *ptr, int index, int level)
{ if (level <= 0) return -EFSCORRUPTED;
switch (cur->bc_ops->type) { case XFS_BTREE_TYPE_MEM: if (!xfbtree_verify_bno(cur->bc_mem.xfbtree,
be64_to_cpu((&ptr->l)[index]))) return -EFSCORRUPTED; break; case XFS_BTREE_TYPE_INODE: if (!xfs_verify_fsbno(cur->bc_mp,
be64_to_cpu((&ptr->l)[index]))) return -EFSCORRUPTED; break; case XFS_BTREE_TYPE_AG: if (!xfs_verify_agbno(to_perag(cur->bc_group),
be32_to_cpu((&ptr->s)[index]))) return -EFSCORRUPTED; break;
}
return 0;
}
/* * Check that a given (indexed) btree pointer at a certain level of a * btree is valid and doesn't point past where it should.
*/ staticint
xfs_btree_check_ptr( struct xfs_btree_cur *cur, constunion xfs_btree_ptr *ptr, int index, int level)
{ int error;
error = __xfs_btree_check_ptr(cur, ptr, index, level); if (error) { switch (cur->bc_ops->type) { case XFS_BTREE_TYPE_MEM:
xfs_err(cur->bc_mp, "In-memory: Corrupt %sbt flags 0x%x pointer at level %d index %d fa %pS.",
cur->bc_ops->name, cur->bc_flags, level, index,
__this_address); break; case XFS_BTREE_TYPE_INODE:
xfs_err(cur->bc_mp, "Inode %llu fork %d: Corrupt %sbt pointer at level %d index %d.",
cur->bc_ino.ip->i_ino,
cur->bc_ino.whichfork, cur->bc_ops->name,
level, index); break; case XFS_BTREE_TYPE_AG:
xfs_err(cur->bc_mp, "AG %u: Corrupt %sbt pointer at level %d index %d.",
cur->bc_group->xg_gno, cur->bc_ops->name,
level, index); break;
}
xfs_btree_mark_sick(cur);
}
/* * Calculate CRC on the whole btree block and stuff it into the * long-form btree header. * * Prior to calculting the CRC, pull the LSN out of the buffer log item and put * it into the buffer so recovery knows what the last modification was that made * it to disk.
*/ void
xfs_btree_fsblock_calc_crc( struct xfs_buf *bp)
{ struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp); struct xfs_buf_log_item *bip = bp->b_log_item;
if (!xfs_has_crc(bp->b_mount)) return; if (bip)
block->bb_u.l.bb_lsn = cpu_to_be64(bip->bli_item.li_lsn);
xfs_buf_update_cksum(bp, XFS_BTREE_LBLOCK_CRC_OFF);
}
if (xfs_has_crc(mp)) { if (!xfs_log_check_lsn(mp, be64_to_cpu(block->bb_u.l.bb_lsn))) returnfalse; return xfs_buf_verify_cksum(bp, XFS_BTREE_LBLOCK_CRC_OFF);
}
returntrue;
}
/* * Calculate CRC on the whole btree block and stuff it into the * short-form btree header. * * Prior to calculting the CRC, pull the LSN out of the buffer log item and put * it into the buffer so recovery knows what the last modification was that made * it to disk.
*/ void
xfs_btree_agblock_calc_crc( struct xfs_buf *bp)
{ struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp); struct xfs_buf_log_item *bip = bp->b_log_item;
if (!xfs_has_crc(bp->b_mount)) return; if (bip)
block->bb_u.s.bb_lsn = cpu_to_be64(bip->bli_item.li_lsn);
xfs_buf_update_cksum(bp, XFS_BTREE_SBLOCK_CRC_OFF);
}
/* * Don't allow block freeing for a staging cursor, because staging * cursors do not support regular btree modifications.
*/ if (unlikely(cur->bc_flags & XFS_BTREE_STAGING)) {
ASSERT(0); return -EFSCORRUPTED;
}
/* * Delete the btree cursor.
*/ void
xfs_btree_del_cursor( struct xfs_btree_cur *cur, /* btree cursor */ int error) /* del because of error */
{ int i; /* btree level */
/* * Clear the buffer pointers and release the buffers. If we're doing * this because of an error, inspect all of the entries in the bc_bufs * array for buffers to be unlocked. This is because some of the btree * code works from level n down to 0, and if we get an error along the * way we won't have initialized all the entries down to 0.
*/ for (i = 0; i < cur->bc_nlevels; i++) { if (cur->bc_levels[i].bp)
xfs_trans_brelse(cur->bc_tp, cur->bc_levels[i].bp); elseif (!error) break;
}
/* * If we are doing a BMBT update, the number of unaccounted blocks * allocated during this cursor life time should be zero. If it's not * zero, then we should be shut down or on our way to shutdown due to * cancelling a dirty transaction on error.
*/
ASSERT(!xfs_btree_is_bmap(cur->bc_ops) || cur->bc_bmap.allocated == 0 ||
xfs_is_shutdown(cur->bc_mp) || error != 0);
if (cur->bc_group)
xfs_group_put(cur->bc_group);
kmem_cache_free(cur->bc_cache, cur);
}
/* Return the buffer target for this btree's buffer. */ staticinlinestruct xfs_buftarg *
xfs_btree_buftarg( struct xfs_btree_cur *cur)
{ if (cur->bc_ops->type == XFS_BTREE_TYPE_MEM) return cur->bc_mem.xfbtree->target; return cur->bc_mp->m_ddev_targp;
}
/* Return the block size (in units of 512b sectors) for this btree. */ staticinlineunsignedint
xfs_btree_bbsize( struct xfs_btree_cur *cur)
{ if (cur->bc_ops->type == XFS_BTREE_TYPE_MEM) return XFBNO_BBSIZE; return cur->bc_mp->m_bsize;
}
/* * Duplicate the btree cursor. * Allocate a new one, copy the record, re-get the buffers.
*/ int/* error */
xfs_btree_dup_cursor( struct xfs_btree_cur *cur, /* input cursor */ struct xfs_btree_cur **ncur) /* output cursor */
{ struct xfs_mount *mp = cur->bc_mp; struct xfs_trans *tp = cur->bc_tp; struct xfs_buf *bp; struct xfs_btree_cur *new; int error; int i;
/* * Don't allow staging cursors to be duplicated because they're supposed * to be kept private to a single thread.
*/ if (unlikely(cur->bc_flags & XFS_BTREE_STAGING)) {
ASSERT(0); return -EFSCORRUPTED;
}
/* * Allocate a new cursor like the old one.
*/ new = cur->bc_ops->dup_cursor(cur);
/* * Copy the record currently in the cursor.
*/
new->bc_rec = cur->bc_rec;
/* * For each level current, re-get the buffer and copy the ptr value.
*/ for (i = 0; i < new->bc_nlevels; i++) {
new->bc_levels[i].ptr = cur->bc_levels[i].ptr;
new->bc_levels[i].ra = cur->bc_levels[i].ra;
bp = cur->bc_levels[i].bp; if (bp) {
error = xfs_trans_read_buf(mp, tp,
xfs_btree_buftarg(cur),
xfs_buf_daddr(bp),
xfs_btree_bbsize(cur), 0, &bp,
cur->bc_ops->buf_ops); if (xfs_metadata_is_sick(error))
xfs_btree_mark_sick(new); if (error) {
xfs_btree_del_cursor(new, error);
*ncur = NULL; return error;
}
}
new->bc_levels[i].bp = bp;
}
*ncur = new; return 0;
}
/* * XFS btree block layout and addressing: * * There are two types of blocks in the btree: leaf and non-leaf blocks. * * The leaf record start with a header then followed by records containing * the values. A non-leaf block also starts with the same header, and * then first contains lookup keys followed by an equal number of pointers * to the btree blocks at the previous level. * * +--------+-------+-------+-------+-------+-------+-------+ * Leaf: | header | rec 1 | rec 2 | rec 3 | rec 4 | rec 5 | rec N | * +--------+-------+-------+-------+-------+-------+-------+ * * +--------+-------+-------+-------+-------+-------+-------+ * Non-Leaf: | header | key 1 | key 2 | key N | ptr 1 | ptr 2 | ptr N | * +--------+-------+-------+-------+-------+-------+-------+ * * The header is called struct xfs_btree_block for reasons better left unknown * and comes in different versions for short (32bit) and long (64bit) block * pointers. The record and key structures are defined by the btree instances * and opaque to the btree core. The block pointers are simple disk endian * integers, available in a short (32bit) and long (64bit) variant. * * The helpers below calculate the offset of a given record, key or pointer * into a btree block (xfs_btree_*_offset) or return a pointer to the given * record, key or pointer (xfs_btree_*_addr). Note that all addressing * inside the btree block is done using indices starting at one, not zero! * * If XFS_BTGEO_OVERLAPPING is set, then this btree supports keys containing * overlapping intervals. In such a tree, records are still sorted lowest to * highest and indexed by the smallest key value that refers to the record. * However, nodes are different: each pointer has two associated keys -- one * indexing the lowest key available in the block(s) below (the same behavior * as the key in a regular btree) and another indexing the highest key * available in the block(s) below. Because records are /not/ sorted by the * highest key, all leaf block updates require us to compute the highest key * that matches any record in the leaf and to recursively update the high keys * in the nodes going further up in the tree, if necessary. Nodes look like * this: * * +--------+-----+-----+-----+-----+-----+-------+-------+-----+ * Non-Leaf: | header | lo1 | hi1 | lo2 | hi2 | ... | ptr 1 | ptr 2 | ... | * +--------+-----+-----+-----+-----+-----+-------+-------+-----+ * * To perform an interval query on an overlapped tree, perform the usual * depth-first search and use the low and high keys to decide if we can skip * that particular node. If a leaf node is reached, return the records that * intersect the interval. Note that an interval query may return numerous * entries. For a non-overlapped tree, simply search for the record associated * with the lowest key and iterate forward until a non-matching record is * found. Section 14.3 ("Interval Trees") of _Introduction to Algorithms_ by * Cormen, Leiserson, Rivest, and Stein (2nd or 3rd ed. only) discuss this in * more detail. * * Why do we care about overlapping intervals? Let's say you have a bunch of * reverse mapping records on a reflink filesystem: * * 1: +- file A startblock B offset C length D -----------+ * 2: +- file E startblock F offset G length H --------------+ * 3: +- file I startblock F offset J length K --+ * 4: +- file L... --+ * * Now say we want to map block (B+D) into file A at offset (C+D). Ideally, * we'd simply increment the length of record 1. But how do we find the record * that ends at (B+D-1) (i.e. record 1)? A LE lookup of (B+D-1) would return * record 3 because the keys are ordered first by startblock. An interval * query would return records 1 and 2 because they both overlap (B+D-1), and * from that we can pick out record 1 as the appropriate left neighbor. * * In the non-overlapped case you can do a LE lookup and decrement the cursor * because a record's interval must end before the next record.
*/
/* * Return size of the btree block header for this btree instance.
*/ staticinline size_t xfs_btree_block_len(struct xfs_btree_cur *cur)
{ if (cur->bc_ops->ptr_len == XFS_BTREE_LONG_PTR_LEN) { if (xfs_has_crc(cur->bc_mp)) return XFS_BTREE_LBLOCK_CRC_LEN; return XFS_BTREE_LBLOCK_LEN;
} if (xfs_has_crc(cur->bc_mp)) return XFS_BTREE_SBLOCK_CRC_LEN; return XFS_BTREE_SBLOCK_LEN;
}
/* * Calculate offset of the n-th record in a btree block.
*/ STATIC size_t
xfs_btree_rec_offset( struct xfs_btree_cur *cur, int n)
{ return xfs_btree_block_len(cur) +
(n - 1) * cur->bc_ops->rec_len;
}
/* * Calculate offset of the n-th key in a btree block.
*/ STATIC size_t
xfs_btree_key_offset( struct xfs_btree_cur *cur, int n)
{ return xfs_btree_block_len(cur) +
(n - 1) * cur->bc_ops->key_len;
}
/* * Calculate offset of the n-th high key in a btree block.
*/ STATIC size_t
xfs_btree_high_key_offset( struct xfs_btree_cur *cur, int n)
{ return xfs_btree_block_len(cur) +
(n - 1) * cur->bc_ops->key_len + (cur->bc_ops->key_len / 2);
}
/* * Calculate offset of the n-th block pointer in a btree block.
*/ STATIC size_t
xfs_btree_ptr_offset( struct xfs_btree_cur *cur, int n, int level)
{ return xfs_btree_block_len(cur) +
cur->bc_ops->get_maxrecs(cur, level) * cur->bc_ops->key_len +
(n - 1) * cur->bc_ops->ptr_len;
}
/* * Return a pointer to the n-th record in the btree block.
*/ union xfs_btree_rec *
xfs_btree_rec_addr( struct xfs_btree_cur *cur, int n, struct xfs_btree_block *block)
{ return (union xfs_btree_rec *)
((char *)block + xfs_btree_rec_offset(cur, n));
}
/* * Return a pointer to the n-th key in the btree block.
*/ union xfs_btree_key *
xfs_btree_key_addr( struct xfs_btree_cur *cur, int n, struct xfs_btree_block *block)
{ return (union xfs_btree_key *)
((char *)block + xfs_btree_key_offset(cur, n));
}
/* * Return a pointer to the n-th high key in the btree block.
*/ union xfs_btree_key *
xfs_btree_high_key_addr( struct xfs_btree_cur *cur, int n, struct xfs_btree_block *block)
{ return (union xfs_btree_key *)
((char *)block + xfs_btree_high_key_offset(cur, n));
}
/* * Return a pointer to the n-th block pointer in the btree block.
*/ union xfs_btree_ptr *
xfs_btree_ptr_addr( struct xfs_btree_cur *cur, int n, struct xfs_btree_block *block)
{ int level = xfs_btree_get_level(block);
if (cur->bc_flags & XFS_BTREE_STAGING) return cur->bc_ino.ifake->if_fork; return xfs_ifork_ptr(cur->bc_ino.ip, cur->bc_ino.whichfork);
}
/* * Get the root block which is stored in the inode. * * For now this btree implementation assumes the btree root is always * stored in the if_broot field of an inode fork.
*/ STATICstruct xfs_btree_block *
xfs_btree_get_iroot( struct xfs_btree_cur *cur)
{ struct xfs_ifork *ifp = xfs_btree_ifork_ptr(cur);
return (struct xfs_btree_block *)ifp->if_broot;
}
/* * Retrieve the block pointer from the cursor at the given level. * This may be an inode btree root or from a buffer.
*/ struct xfs_btree_block * /* generic btree block pointer */
xfs_btree_get_block( struct xfs_btree_cur *cur, /* btree cursor */ int level, /* level in btree */ struct xfs_buf **bpp) /* buffer containing the block */
{ if (xfs_btree_at_iroot(cur, level)) {
*bpp = NULL; return xfs_btree_get_iroot(cur);
}
/* * Change the cursor to point to the first record at the given level. * Other levels are unaffected.
*/ STATICint/* success=1, failure=0 */
xfs_btree_firstrec( struct xfs_btree_cur *cur, /* btree cursor */ int level) /* level to change */
{ struct xfs_btree_block *block; /* generic btree block pointer */ struct xfs_buf *bp; /* buffer containing block */
/* * Get the block pointer for this level.
*/
block = xfs_btree_get_block(cur, level, &bp); if (xfs_btree_check_block(cur, block, level, bp)) return 0; /* * It's empty, there is no such record.
*/ if (!block->bb_numrecs) return 0; /* * Set the ptr value to 1, that's the first record/key.
*/
cur->bc_levels[level].ptr = 1; return 1;
}
/* * Change the cursor to point to the last record in the current block * at the given level. Other levels are unaffected.
*/ STATICint/* success=1, failure=0 */
xfs_btree_lastrec( struct xfs_btree_cur *cur, /* btree cursor */ int level) /* level to change */
{ struct xfs_btree_block *block; /* generic btree block pointer */ struct xfs_buf *bp; /* buffer containing block */
/* * Get the block pointer for this level.
*/
block = xfs_btree_get_block(cur, level, &bp); if (xfs_btree_check_block(cur, block, level, bp)) return 0; /* * It's empty, there is no such record.
*/ if (!block->bb_numrecs) return 0; /* * Set the ptr value to numrecs, that's the last record/key.
*/
cur->bc_levels[level].ptr = be16_to_cpu(block->bb_numrecs); return 1;
}
/* * Compute first and last byte offsets for the fields given. * Interprets the offsets table, which contains struct field offsets.
*/ void
xfs_btree_offsets(
uint32_t fields, /* bitmask of fields */ constshort *offsets, /* table of field offsets */ int nbits, /* number of bits to inspect */ int *first, /* output: first byte offset */ int *last) /* output: last byte offset */
{ int i; /* current bit number */
uint32_t imask; /* mask for current bit number */
ASSERT(fields != 0); /* * Find the lowest bit, so the first byte offset.
*/ for (i = 0, imask = 1u; ; i++, imask <<= 1) { if (imask & fields) {
*first = offsets[i]; break;
}
} /* * Find the highest bit, so the last byte offset.
*/ for (i = nbits - 1, imask = 1u << i; ; i--, imask >>= 1) { if (imask & fields) {
*last = offsets[i + 1] - 1; break;
}
}
}
STATICint
xfs_btree_readahead_fsblock( struct xfs_btree_cur *cur, int lr, struct xfs_btree_block *block)
{ struct xfs_mount *mp = cur->bc_mp;
xfs_fsblock_t left = be64_to_cpu(block->bb_u.l.bb_leftsib);
xfs_fsblock_t right = be64_to_cpu(block->bb_u.l.bb_rightsib); int rval = 0;
if ((lr & XFS_BTCUR_LEFTRA) && left != NULLFSBLOCK) {
xfs_buf_readahead(mp->m_ddev_targp, XFS_FSB_TO_DADDR(mp, left),
mp->m_bsize, cur->bc_ops->buf_ops);
rval++;
}
if ((lr & XFS_BTCUR_RIGHTRA) && right != NULLFSBLOCK) {
xfs_buf_readahead(mp->m_ddev_targp, XFS_FSB_TO_DADDR(mp, right),
mp->m_bsize, cur->bc_ops->buf_ops);
rval++;
}
return rval;
}
STATICint
xfs_btree_readahead_memblock( struct xfs_btree_cur *cur, int lr, struct xfs_btree_block *block)
{ struct xfs_buftarg *btp = cur->bc_mem.xfbtree->target;
xfbno_t left = be64_to_cpu(block->bb_u.l.bb_leftsib);
xfbno_t right = be64_to_cpu(block->bb_u.l.bb_rightsib); int rval = 0;
if ((lr & XFS_BTCUR_LEFTRA) && left != NULLFSBLOCK) {
xfs_buf_readahead(btp, xfbno_to_daddr(left), XFBNO_BBSIZE,
cur->bc_ops->buf_ops);
rval++;
}
if ((lr & XFS_BTCUR_RIGHTRA) && right != NULLFSBLOCK) {
xfs_buf_readahead(btp, xfbno_to_daddr(right), XFBNO_BBSIZE,
cur->bc_ops->buf_ops);
rval++;
}
return rval;
}
STATICint
xfs_btree_readahead_agblock( struct xfs_btree_cur *cur, int lr, struct xfs_btree_block *block)
{ struct xfs_mount *mp = cur->bc_mp; struct xfs_perag *pag = to_perag(cur->bc_group);
xfs_agblock_t left = be32_to_cpu(block->bb_u.s.bb_leftsib);
xfs_agblock_t right = be32_to_cpu(block->bb_u.s.bb_rightsib); int rval = 0;
if ((lr & XFS_BTCUR_LEFTRA) && left != NULLAGBLOCK) {
xfs_buf_readahead(mp->m_ddev_targp,
xfs_agbno_to_daddr(pag, left), mp->m_bsize,
cur->bc_ops->buf_ops);
rval++;
}
if ((lr & XFS_BTCUR_RIGHTRA) && right != NULLAGBLOCK) {
xfs_buf_readahead(mp->m_ddev_targp,
xfs_agbno_to_daddr(pag, right), mp->m_bsize,
cur->bc_ops->buf_ops);
rval++;
}
return rval;
}
/* * Read-ahead btree blocks, at the given level. * Bits in lr are set from XFS_BTCUR_{LEFT,RIGHT}RA.
*/ STATICint
xfs_btree_readahead( struct xfs_btree_cur *cur, /* btree cursor */ int lev, /* level in btree */ int lr) /* left/right bits */
{ struct xfs_btree_block *block;
/* * No readahead needed if we are at the root level and the * btree root is stored in the inode.
*/ if (xfs_btree_at_iroot(cur, lev)) return 0;
if ((cur->bc_levels[lev].ra | lr) == cur->bc_levels[lev].ra) return 0;
error = xfs_btree_check_ptr(cur, ptr, 0, 1); if (error) return error;
switch (cur->bc_ops->type) { case XFS_BTREE_TYPE_AG:
*daddr = xfs_agbno_to_daddr(to_perag(cur->bc_group),
be32_to_cpu(ptr->s)); break; case XFS_BTREE_TYPE_INODE:
*daddr = XFS_FSB_TO_DADDR(cur->bc_mp, be64_to_cpu(ptr->l)); break; case XFS_BTREE_TYPE_MEM:
*daddr = xfbno_to_daddr(be64_to_cpu(ptr->l)); break;
} return 0;
}
/* * Readahead @count btree blocks at the given @ptr location. * * We don't need to care about long or short form btrees here as we have a * method of converting the ptr directly to a daddr available to us.
*/ STATICvoid
xfs_btree_readahead_ptr( struct xfs_btree_cur *cur, union xfs_btree_ptr *ptr,
xfs_extlen_t count)
{
xfs_daddr_t daddr;
/* * Set the buffer for level "lev" in the cursor to bp, releasing * any previous buffer.
*/ STATICvoid
xfs_btree_setbuf( struct xfs_btree_cur *cur, /* btree cursor */ int lev, /* level in btree */ struct xfs_buf *bp) /* new buffer to set */
{ struct xfs_btree_block *b; /* btree block */
if (cur->bc_levels[lev].bp)
xfs_trans_brelse(cur->bc_tp, cur->bc_levels[lev].bp);
cur->bc_levels[lev].bp = bp;
cur->bc_levels[lev].ra = 0;
b = XFS_BUF_TO_BLOCK(bp); if (cur->bc_ops->ptr_len == XFS_BTREE_LONG_PTR_LEN) { if (b->bb_u.l.bb_leftsib == cpu_to_be64(NULLFSBLOCK))
cur->bc_levels[lev].ra |= XFS_BTCUR_LEFTRA; if (b->bb_u.l.bb_rightsib == cpu_to_be64(NULLFSBLOCK))
cur->bc_levels[lev].ra |= XFS_BTCUR_RIGHTRA;
} else { if (b->bb_u.s.bb_leftsib == cpu_to_be32(NULLAGBLOCK))
cur->bc_levels[lev].ra |= XFS_BTCUR_LEFTRA; if (b->bb_u.s.bb_rightsib == cpu_to_be32(NULLAGBLOCK))
cur->bc_levels[lev].ra |= XFS_BTCUR_RIGHTRA;
}
}
/* * Read in the buffer at the given ptr and return the buffer and * the block pointer within the buffer.
*/ int
xfs_btree_read_buf_block( struct xfs_btree_cur *cur, constunion xfs_btree_ptr *ptr, int flags, struct xfs_btree_block **block, struct xfs_buf **bpp)
{ struct xfs_mount *mp = cur->bc_mp;
xfs_daddr_t d; int error;
/* need to sort out how callers deal with failures first */
ASSERT(!(flags & XBF_TRYLOCK));
error = xfs_btree_ptr_to_daddr(cur, ptr, &d); if (error) return error;
error = xfs_trans_read_buf(mp, cur->bc_tp, xfs_btree_buftarg(cur), d,
xfs_btree_bbsize(cur), flags, bpp,
cur->bc_ops->buf_ops); if (xfs_metadata_is_sick(error))
xfs_btree_mark_sick(cur); if (error) return error;
/* * Copy keys from one btree block to another.
*/ void
xfs_btree_copy_keys( struct xfs_btree_cur *cur, union xfs_btree_key *dst_key, constunion xfs_btree_key *src_key, int numkeys)
{
ASSERT(numkeys >= 0);
memcpy(dst_key, src_key, numkeys * cur->bc_ops->key_len);
}
/* * Copy records from one btree block to another.
*/ STATICvoid
xfs_btree_copy_recs( struct xfs_btree_cur *cur, union xfs_btree_rec *dst_rec, union xfs_btree_rec *src_rec, int numrecs)
{
ASSERT(numrecs >= 0);
memcpy(dst_rec, src_rec, numrecs * cur->bc_ops->rec_len);
}
/* * Copy block pointers from one btree block to another.
*/ void
xfs_btree_copy_ptrs( struct xfs_btree_cur *cur, union xfs_btree_ptr *dst_ptr, constunion xfs_btree_ptr *src_ptr, int numptrs)
{
ASSERT(numptrs >= 0);
memcpy(dst_ptr, src_ptr, numptrs * cur->bc_ops->ptr_len);
}
/* * Shift keys one index left/right inside a single btree block.
*/ STATICvoid
xfs_btree_shift_keys( struct xfs_btree_cur *cur, union xfs_btree_key *key, int dir, int numkeys)
{ char *dst_key;
ASSERT(numkeys >= 0);
ASSERT(dir == 1 || dir == -1);
/* * Shift records one index left/right inside a single btree block.
*/ STATICvoid
xfs_btree_shift_recs( struct xfs_btree_cur *cur, union xfs_btree_rec *rec, int dir, int numrecs)
{ char *dst_rec;
ASSERT(numrecs >= 0);
ASSERT(dir == 1 || dir == -1);
/* * Shift block pointers one index left/right inside a single btree block.
*/ STATICvoid
xfs_btree_shift_ptrs( struct xfs_btree_cur *cur, union xfs_btree_ptr *ptr, int dir, int numptrs)
{ char *dst_ptr;
ASSERT(numptrs >= 0);
ASSERT(dir == 1 || dir == -1);
/* * Log block pointer fields from a btree block (nonleaf).
*/ STATICvoid
xfs_btree_log_ptrs( struct xfs_btree_cur *cur, /* btree cursor */ struct xfs_buf *bp, /* buffer containing btree block */ int first, /* index of first pointer to log */ int last) /* index of last pointer to log */
{
if (bp) { struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp); int level = xfs_btree_get_level(block);
if (xfs_has_crc(cur->bc_mp)) { /* * We don't log the CRC when updating a btree * block but instead recreate it during log * recovery. As the log buffers have checksums * of their own this is safe and avoids logging a crc * update in a lot of places.
*/ if (fields == XFS_BB_ALL_BITS)
fields = XFS_BB_ALL_BITS_CRC;
nbits = XFS_BB_NUM_BITS_CRC;
} else {
nbits = XFS_BB_NUM_BITS;
}
xfs_btree_offsets(fields,
(cur->bc_ops->ptr_len == XFS_BTREE_LONG_PTR_LEN) ?
loffsets : soffsets,
nbits, &first, &last);
xfs_trans_buf_set_type(cur->bc_tp, bp, XFS_BLFT_BTREE_BUF);
xfs_trans_log_buf(cur->bc_tp, bp, first, last);
} else {
xfs_trans_log_inode(cur->bc_tp, cur->bc_ino.ip,
xfs_ilog_fbroot(cur->bc_ino.whichfork));
}
}
/* * Increment cursor by one record at the level. * For nonzero levels the leaf-ward information is untouched.
*/ int/* error */
xfs_btree_increment( struct xfs_btree_cur *cur, int level, int *stat) /* success/failure */
{ struct xfs_btree_block *block; union xfs_btree_ptr ptr; struct xfs_buf *bp; int error; /* error return value */ int lev;
ASSERT(level < cur->bc_nlevels);
/* Read-ahead to the right at this level. */
xfs_btree_readahead(cur, level, XFS_BTCUR_RIGHTRA);
/* Get a pointer to the btree block. */
block = xfs_btree_get_block(cur, level, &bp);
/* We're done if we remain in the block after the increment. */ if (++cur->bc_levels[level].ptr <= xfs_btree_get_numrecs(block)) goto out1;
/* Fail if we just went off the right edge of the tree. */
xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB); if (xfs_btree_ptr_is_null(cur, &ptr)) goto out0;
XFS_BTREE_STATS_INC(cur, increment);
/* * March up the tree incrementing pointers. * Stop when we don't go off the right edge of a block.
*/ for (lev = level + 1; lev < cur->bc_nlevels; lev++) {
block = xfs_btree_get_block(cur, lev, &bp);
#ifdef DEBUG
error = xfs_btree_check_block(cur, block, lev, bp); if (error) goto error0; #endif
if (++cur->bc_levels[lev].ptr <= xfs_btree_get_numrecs(block)) break;
/* Read-ahead the right block for the next loop. */
xfs_btree_readahead(cur, lev, XFS_BTCUR_RIGHTRA);
}
/* * If we went off the root then we are either seriously * confused or have the tree root in an inode.
*/ if (lev == cur->bc_nlevels) { if (cur->bc_ops->type == XFS_BTREE_TYPE_INODE) goto out0;
ASSERT(0);
xfs_btree_mark_sick(cur);
error = -EFSCORRUPTED; goto error0;
}
ASSERT(lev < cur->bc_nlevels);
/* * Now walk back down the tree, fixing up the cursor's buffer * pointers and key numbers.
*/ for (block = xfs_btree_get_block(cur, lev, &bp); lev > level; ) { union xfs_btree_ptr *ptrp;
/* * Decrement cursor by one record at the level. * For nonzero levels the leaf-ward information is untouched.
*/ int/* error */
xfs_btree_decrement( struct xfs_btree_cur *cur, int level, int *stat) /* success/failure */
{ struct xfs_btree_block *block; struct xfs_buf *bp; int error; /* error return value */ int lev; union xfs_btree_ptr ptr;
ASSERT(level < cur->bc_nlevels);
/* Read-ahead to the left at this level. */
xfs_btree_readahead(cur, level, XFS_BTCUR_LEFTRA);
/* We're done if we remain in the block after the decrement. */ if (--cur->bc_levels[level].ptr > 0) goto out1;
/* Get a pointer to the btree block. */
block = xfs_btree_get_block(cur, level, &bp);
/* Fail if we just went off the left edge of the tree. */
xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_LEFTSIB); if (xfs_btree_ptr_is_null(cur, &ptr)) goto out0;
XFS_BTREE_STATS_INC(cur, decrement);
/* * March up the tree decrementing pointers. * Stop when we don't go off the left edge of a block.
*/ for (lev = level + 1; lev < cur->bc_nlevels; lev++) { if (--cur->bc_levels[lev].ptr > 0) break; /* Read-ahead the left block for the next loop. */
xfs_btree_readahead(cur, lev, XFS_BTCUR_LEFTRA);
}
/* * If we went off the root then we are seriously confused. * or the root of the tree is in an inode.
*/ if (lev == cur->bc_nlevels) { if (cur->bc_ops->type == XFS_BTREE_TYPE_INODE) goto out0;
ASSERT(0);
xfs_btree_mark_sick(cur);
error = -EFSCORRUPTED; goto error0;
}
ASSERT(lev < cur->bc_nlevels);
/* * Now walk back down the tree, fixing up the cursor's buffer * pointers and key numbers.
*/ for (block = xfs_btree_get_block(cur, lev, &bp); lev > level; ) { union xfs_btree_ptr *ptrp;
/* * Check the btree block owner now that we have the context to know who the * real owner is.
*/ staticinline xfs_failaddr_t
xfs_btree_check_block_owner( struct xfs_btree_cur *cur, struct xfs_btree_block *block)
{
__u64 owner;
if (!xfs_has_crc(cur->bc_mp) ||
(cur->bc_flags & XFS_BTREE_BMBT_INVALID_OWNER)) return NULL;
owner = xfs_btree_owner(cur); if (cur->bc_ops->ptr_len == XFS_BTREE_LONG_PTR_LEN) { if (be64_to_cpu(block->bb_u.l.bb_owner) != owner) return __this_address;
} else { if (be32_to_cpu(block->bb_u.s.bb_owner) != owner) return __this_address;
}
return NULL;
}
int
xfs_btree_lookup_get_block( struct xfs_btree_cur *cur, /* btree cursor */ int level, /* level in the btree */ constunion xfs_btree_ptr *pp, /* ptr to btree block */ struct xfs_btree_block **blkp) /* return btree block */
{ struct xfs_buf *bp; /* buffer pointer for btree block */
xfs_daddr_t daddr; int error = 0;
/* special case the root block if in an inode */ if (xfs_btree_at_iroot(cur, level)) {
*blkp = xfs_btree_get_iroot(cur); return 0;
}
/* * If the old buffer at this level for the disk address we are * looking for re-use it. * * Otherwise throw it away and get a new one.
*/
bp = cur->bc_levels[level].bp;
error = xfs_btree_ptr_to_daddr(cur, pp, &daddr); if (error) return error; if (bp && xfs_buf_daddr(bp) == daddr) {
*blkp = XFS_BUF_TO_BLOCK(bp); return 0;
}
/* * Get current search key. For level 0 we don't actually have a key * structure so we make one up from the record. For all other levels * we just return the right key.
*/ STATICunion xfs_btree_key *
xfs_lookup_get_search_key( struct xfs_btree_cur *cur, int level, int keyno, struct xfs_btree_block *block, union xfs_btree_key *kp)
{ if (level == 0) {
cur->bc_ops->init_key_from_rec(kp,
xfs_btree_rec_addr(cur, keyno, block)); return kp;
}
return xfs_btree_key_addr(cur, keyno, block);
}
/* * Initialize a pointer to the root block.
*/ void
xfs_btree_init_ptr_from_cur( struct xfs_btree_cur *cur, union xfs_btree_ptr *ptr)
{ if (cur->bc_ops->type == XFS_BTREE_TYPE_INODE) { /* * Inode-rooted btrees call xfs_btree_get_iroot to find the root * in xfs_btree_lookup_get_block and don't need a pointer here.
*/
ptr->l = 0;
} elseif (cur->bc_flags & XFS_BTREE_STAGING) {
ptr->s = cpu_to_be32(cur->bc_ag.afake->af_root);
} else {
cur->bc_ops->init_ptr_from_cur(cur, ptr);
}
}
/* * Lookup the record. The cursor is made to point to it, based on dir. * stat is set to 0 if can't find any such record, 1 for success.
*/ int/* error */
xfs_btree_lookup( struct xfs_btree_cur *cur, /* btree cursor */
xfs_lookup_t dir, /* <=, ==, or >= */ int *stat) /* success/failure */
{ struct xfs_btree_block *block; /* current btree block */ int cmp_r; /* current key comparison result */ int error; /* error return value */ int keyno; /* current key number */ int level; /* level in the btree */ union xfs_btree_ptr *pp; /* ptr to btree block */ union xfs_btree_ptr ptr; /* ptr to btree block */
XFS_BTREE_STATS_INC(cur, lookup);
/* No such thing as a zero-level tree. */ if (XFS_IS_CORRUPT(cur->bc_mp, cur->bc_nlevels == 0)) {
xfs_btree_mark_sick(cur); return -EFSCORRUPTED;
}
/* * Iterate over each level in the btree, starting at the root. * For each level above the leaves, find the key we need, based * on the lookup record, then follow the corresponding block * pointer down to the next level.
*/ for (level = cur->bc_nlevels - 1, cmp_r = 1; level >= 0; level--) { /* Get the block we need to do the lookup on. */
error = xfs_btree_lookup_get_block(cur, level, pp, &block); if (error) goto error0;
if (cmp_r == 0) { /* * If we already had a key match at a higher level, we * know we need to use the first entry in this block.
*/
keyno = 1;
} else { /* Otherwise search this block. Do a binary search. */
int high; /* high entry number */ int low; /* low entry number */
/* Set low and high entry numbers, 1-based. */
low = 1;
high = xfs_btree_get_numrecs(block); if (!high) { /* Block is empty, must be an empty leaf. */ if (level != 0 || cur->bc_nlevels != 1) {
XFS_CORRUPTION_ERROR(__func__,
XFS_ERRLEVEL_LOW,
cur->bc_mp, block, sizeof(*block));
xfs_btree_mark_sick(cur); return -EFSCORRUPTED;
}
/* Binary search the block. */ while (low <= high) { union xfs_btree_key key; union xfs_btree_key *kp;
XFS_BTREE_STATS_INC(cur, compare);
/* keyno is average of low and high. */
keyno = (low + high) >> 1;
/* Get current search key */
kp = xfs_lookup_get_search_key(cur, level,
keyno, block, &key);
/* * Compute comparison result to get next * direction: * - less than, move right * - greater than, move left * - equal, we're done
*/
cmp_r = cur->bc_ops->cmp_key_with_cur(cur, kp); if (cmp_r < 0)
low = keyno + 1; elseif (cmp_r > 0)
high = keyno - 1; else break;
}
}
/* * If there are more levels, set up for the next level * by getting the block number and filling in the cursor.
*/ if (level > 0) { /* * If we moved left, need the previous key number, * unless there isn't one.
*/ if (cmp_r > 0 && --keyno < 1)
keyno = 1;
pp = xfs_btree_ptr_addr(cur, keyno, block);
error = xfs_btree_debug_check_ptr(cur, pp, 0, level); if (error) goto error0;
cur->bc_levels[level].ptr = keyno;
}
}
/* Done with the search. See if we need to adjust the results. */ if (dir != XFS_LOOKUP_LE && cmp_r < 0) {
keyno++; /* * If ge search and we went off the end of the block, but it's * not the last block, we're in the wrong block.
*/
xfs_btree_get_sibling(cur, block, &ptr, XFS_BB_RIGHTSIB); if (dir == XFS_LOOKUP_GE &&
keyno > xfs_btree_get_numrecs(block) &&
!xfs_btree_ptr_is_null(cur, &ptr)) { int i;
/* Return if we succeeded or not. */ if (keyno == 0 || keyno > xfs_btree_get_numrecs(block))
*stat = 0; elseif (dir != XFS_LOOKUP_EQ || cmp_r == 0)
*stat = 1; else
*stat = 0; return 0;
error0: return error;
}
/* Find the high key storage area from a regular key. */ union xfs_btree_key *
xfs_btree_high_key_from_key( struct xfs_btree_cur *cur, union xfs_btree_key *key)
{
ASSERT(cur->bc_ops->geom_flags & XFS_BTGEO_OVERLAPPING); return (union xfs_btree_key *)((char *)key +
(cur->bc_ops->key_len / 2));
}
/* Determine the low (and high if overlapped) keys of a leaf block */ STATICvoid
xfs_btree_get_leaf_keys( struct xfs_btree_cur *cur, struct xfs_btree_block *block, union xfs_btree_key *key)
{ union xfs_btree_key max_hkey; union xfs_btree_key hkey; union xfs_btree_rec *rec; union xfs_btree_key *high; int n;
/* Determine the low (and high if overlapped) keys of a node block */ STATICvoid
xfs_btree_get_node_keys( struct xfs_btree_cur *cur, struct xfs_btree_block *block, union xfs_btree_key *key)
{ union xfs_btree_key *hkey; union xfs_btree_key *max_hkey; union xfs_btree_key *high; int n;
/* Derive the keys for any btree block. */ void
xfs_btree_get_keys( struct xfs_btree_cur *cur, struct xfs_btree_block *block, union xfs_btree_key *key)
{ if (be16_to_cpu(block->bb_level) == 0)
xfs_btree_get_leaf_keys(cur, block, key); else
xfs_btree_get_node_keys(cur, block, key);
}
/* * Decide if we need to update the parent keys of a btree block. For * a standard btree this is only necessary if we're updating the first * record/key. For an overlapping btree, we must always update the * keys because the highest key can be in any of the records or keys * in the block.
*/ staticinlinebool
xfs_btree_needs_key_update( struct xfs_btree_cur *cur, int ptr)
{ return (cur->bc_ops->geom_flags & XFS_BTGEO_OVERLAPPING) || ptr == 1;
}
/* * Update the low and high parent keys of the given level, progressing * towards the root. If force_all is false, stop if the keys for a given * level do not need updating.
*/ STATICint
__xfs_btree_updkeys( struct xfs_btree_cur *cur, int level, struct xfs_btree_block *block, struct xfs_buf *bp0, bool force_all)
{ union xfs_btree_key key; /* keys from current level */ union xfs_btree_key *lkey; /* keys from the next level up */ union xfs_btree_key *hkey; union xfs_btree_key *nlkey; /* keys from the next level up */ union xfs_btree_key *nhkey; struct xfs_buf *bp; int ptr;
/* Update all the keys from some level in cursor back to the root. */ STATICint
xfs_btree_updkeys_force( struct xfs_btree_cur *cur, int level)
{ struct xfs_buf *bp; struct xfs_btree_block *block;
/* * Update the parent keys of the given level, progressing towards the root.
*/ STATICint
xfs_btree_update_keys( struct xfs_btree_cur *cur, int level)
{ struct xfs_btree_block *block; struct xfs_buf *bp; union xfs_btree_key *kp; union xfs_btree_key key; int ptr;
/* * Go up the tree from this level toward the root. * At each level, update the key value to the value input. * Stop when we reach a level where the cursor isn't pointing * at the first entry in the block.
*/
xfs_btree_get_keys(cur, block, &key); for (level++, ptr = 1; ptr == 1 && level < cur->bc_nlevels; level++) { #ifdef DEBUG int error; #endif
block = xfs_btree_get_block(cur, level, &bp); #ifdef DEBUG
error = xfs_btree_check_block(cur, block, level, bp); if (error) return error; #endif
ptr = cur->bc_levels[level].ptr;
kp = xfs_btree_key_addr(cur, ptr, block);
xfs_btree_copy_keys(cur, kp, &key, 1);
xfs_btree_log_keys(cur, bp, ptr, ptr);
}
return 0;
}
/* * Update the record referred to by cur to the value in the * given record. This either works (return 0) or gets an * EFSCORRUPTED error.
*/ int
xfs_btree_update( struct xfs_btree_cur *cur, union xfs_btree_rec *rec)
{ struct xfs_btree_block *block; struct xfs_buf *bp; int error; int ptr; union xfs_btree_rec *rp;
/* Pick up the current block. */
block = xfs_btree_get_block(cur, 0, &bp);
#ifdef DEBUG
error = xfs_btree_check_block(cur, block, 0, bp); if (error) goto error0; #endif /* Get the address of the rec to be updated. */
ptr = cur->bc_levels[0].ptr;
rp = xfs_btree_rec_addr(cur, ptr, block);
/* Fill in the new contents and log them. */
xfs_btree_copy_recs(cur, rp, rec, 1);
xfs_btree_log_recs(cur, bp, ptr, ptr);
/* Pass new key value up to our parent. */ if (xfs_btree_needs_key_update(cur, ptr)) {
error = xfs_btree_update_keys(cur, 0); if (error) goto error0;
}
return 0;
error0: return error;
}
/* * Move 1 record left from cur/level if possible. * Update cur to reflect the new path.
*/ STATICint/* error */
xfs_btree_lshift( struct xfs_btree_cur *cur, int level, int *stat) /* success/failure */
{ struct xfs_buf *lbp; /* left buffer pointer */ struct xfs_btree_block *left; /* left btree block */ int lrecs; /* left record count */ struct xfs_buf *rbp; /* right buffer pointer */ struct xfs_btree_block *right; /* right btree block */ struct xfs_btree_cur *tcur; /* temporary btree cursor */ int rrecs; /* right record count */ union xfs_btree_ptr lptr; /* left btree pointer */ union xfs_btree_key *rkp = NULL; /* right btree key */ union xfs_btree_ptr *rpp = NULL; /* right address pointer */ union xfs_btree_rec *rrp = NULL; /* right record pointer */ int error; /* error return value */ int i;
if (xfs_btree_at_iroot(cur, level)) goto out0;
/* Set up variables for this block as "right". */
right = xfs_btree_get_block(cur, level, &rbp);
/* If we've got no left sibling then we can't shift an entry left. */
xfs_btree_get_sibling(cur, right, &lptr, XFS_BB_LEFTSIB); if (xfs_btree_ptr_is_null(cur, &lptr)) goto out0;
/* * If the cursor entry is the one that would be moved, don't * do it... it's too complicated.
*/ if (cur->bc_levels[level].ptr <= 1) goto out0;
/* Set up the left neighbor as "left". */
error = xfs_btree_read_buf_block(cur, &lptr, 0, &left, &lbp); if (error) goto error0;
/* If it's full, it can't take another entry. */
lrecs = xfs_btree_get_numrecs(left); if (lrecs == cur->bc_ops->get_maxrecs(cur, level)) goto out0;
rrecs = xfs_btree_get_numrecs(right);
/* * We add one entry to the left side and remove one for the right side. * Account for it here, the changes will be updated on disk and logged * later.
*/
lrecs++;
rrecs--;
/* * If non-leaf, copy a key and a ptr to the left block. * Log the changes to the left block.
*/ if (level > 0) { /* It's a non-leaf. Move keys and pointers. */ union xfs_btree_key *lkp; /* left btree key */ union xfs_btree_ptr *lpp; /* left address pointer */
lkp = xfs_btree_key_addr(cur, lrecs, left);
rkp = xfs_btree_key_addr(cur, 1, right);
ASSERT(cur->bc_ops->keys_inorder(cur,
xfs_btree_key_addr(cur, lrecs - 1, left), lkp));
} else { /* It's a leaf. Move records. */ union xfs_btree_rec *lrp; /* left record pointer */
/* * Slide the contents of right down one entry.
*/
XFS_BTREE_STATS_ADD(cur, moves, rrecs - 1); if (level > 0) { /* It's a nonleaf. operate on keys and ptrs */ for (i = 0; i < rrecs; i++) {
error = xfs_btree_debug_check_ptr(cur, rpp, i + 1, level); if (error) goto error0;
}
xfs_btree_log_keys(cur, rbp, 1, rrecs);
xfs_btree_log_ptrs(cur, rbp, 1, rrecs);
} else { /* It's a leaf. operate on records */
xfs_btree_shift_recs(cur,
xfs_btree_rec_addr(cur, 2, right),
-1, rrecs);
xfs_btree_log_recs(cur, rbp, 1, rrecs);
}
/* * Using a temporary cursor, update the parent key values of the * block on the left.
*/ if (cur->bc_ops->geom_flags & XFS_BTGEO_OVERLAPPING) {
error = xfs_btree_dup_cursor(cur, &tcur); if (error) goto error0;
i = xfs_btree_firstrec(tcur, level); if (XFS_IS_CORRUPT(tcur->bc_mp, i != 1)) {
xfs_btree_mark_sick(cur);
error = -EFSCORRUPTED; goto error0;
}
error = xfs_btree_decrement(tcur, level, &i); if (error) goto error1;
/* Update the parent high keys of the left block, if needed. */
error = xfs_btree_update_keys(tcur, level); if (error) goto error1;
xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
}
/* Update the parent keys of the right block. */
error = xfs_btree_update_keys(cur, level); if (error) goto error0;
/* Slide the cursor value left one. */
cur->bc_levels[level].ptr--;
/* * Move 1 record right from cur/level if possible. * Update cur to reflect the new path.
*/ STATICint/* error */
xfs_btree_rshift( struct xfs_btree_cur *cur, int level, int *stat) /* success/failure */
{ struct xfs_buf *lbp; /* left buffer pointer */ struct xfs_btree_block *left; /* left btree block */ struct xfs_buf *rbp; /* right buffer pointer */ struct xfs_btree_block *right; /* right btree block */ struct xfs_btree_cur *tcur; /* temporary btree cursor */ union xfs_btree_ptr rptr; /* right block pointer */ union xfs_btree_key *rkp; /* right btree key */ int rrecs; /* right record count */ int lrecs; /* left record count */ int error; /* error return value */ int i; /* loop counter */
if (xfs_btree_at_iroot(cur, level)) goto out0;
/* Set up variables for this block as "left". */
left = xfs_btree_get_block(cur, level, &lbp);
/* If we've got no right sibling then we can't shift an entry right. */
xfs_btree_get_sibling(cur, left, &rptr, XFS_BB_RIGHTSIB); if (xfs_btree_ptr_is_null(cur, &rptr)) goto out0;
/* * If the cursor entry is the one that would be moved, don't * do it... it's too complicated.
*/
lrecs = xfs_btree_get_numrecs(left); if (cur->bc_levels[level].ptr >= lrecs) goto out0;
/* Set up the right neighbor as "right". */
error = xfs_btree_read_buf_block(cur, &rptr, 0, &right, &rbp); if (error) goto error0;
/* If it's full, it can't take another entry. */
rrecs = xfs_btree_get_numrecs(right); if (rrecs == cur->bc_ops->get_maxrecs(cur, level)) goto out0;
/* * Make a hole at the start of the right neighbor block, then * copy the last left block entry to the hole.
*/ if (level > 0) { /* It's a nonleaf. make a hole in the keys and ptrs */ union xfs_btree_key *lkp; union xfs_btree_ptr *lpp; union xfs_btree_ptr *rpp;
ASSERT(cur->bc_ops->keys_inorder(cur, rkp,
xfs_btree_key_addr(cur, 2, right)));
} else { /* It's a leaf. make a hole in the records */ union xfs_btree_rec *lrp; union xfs_btree_rec *rrp;
/* * Using a temporary cursor, update the parent key values of the * block on the right.
*/
error = xfs_btree_dup_cursor(cur, &tcur); if (error) goto error0;
i = xfs_btree_lastrec(tcur, level); if (XFS_IS_CORRUPT(tcur->bc_mp, i != 1)) {
xfs_btree_mark_sick(cur);
error = -EFSCORRUPTED; goto error0;
}
error = xfs_btree_increment(tcur, level, &i); if (error) goto error1;
/* Update the parent high keys of the left block, if needed. */ if (cur->bc_ops->geom_flags & XFS_BTGEO_OVERLAPPING) {
error = xfs_btree_update_keys(cur, level); if (error) goto error1;
}
/* Update the parent keys of the right block. */
error = xfs_btree_update_keys(tcur, level); if (error) goto error1;
staticinlineint
xfs_btree_alloc_block( struct xfs_btree_cur *cur, constunion xfs_btree_ptr *hint_block, union xfs_btree_ptr *new_block, int *stat)
{ int error;
/* * Don't allow block allocation for a staging cursor, because staging * cursors do not support regular btree modifications. * * Bulk loading uses a separate callback to obtain new blocks from a * preallocated list, which prevents ENOSPC failures during loading.
*/ if (unlikely(cur->bc_flags & XFS_BTREE_STAGING)) {
ASSERT(0); return -EFSCORRUPTED;
}
/* * Split cur/level block in half. * Return new block number and the key to its first * record (to be inserted into parent).
*/ STATICint/* error */
__xfs_btree_split( struct xfs_btree_cur *cur, int level, union xfs_btree_ptr *ptrp, union xfs_btree_key *key, struct xfs_btree_cur **curp, int *stat) /* success/failure */
{ union xfs_btree_ptr lptr; /* left sibling block ptr */ struct xfs_buf *lbp; /* left buffer pointer */ struct xfs_btree_block *left; /* left btree block */ union xfs_btree_ptr rptr; /* right sibling block ptr */ struct xfs_buf *rbp; /* right buffer pointer */ struct xfs_btree_block *right; /* right btree block */ union xfs_btree_ptr rrptr; /* right-right sibling ptr */ struct xfs_buf *rrbp; /* right-right buffer pointer */ struct xfs_btree_block *rrblock; /* right-right btree block */ int lrecs; int rrecs; int src_index; int error; /* error return value */ int i;
XFS_BTREE_STATS_INC(cur, split);
/* Set up left block (current one). */
left = xfs_btree_get_block(cur, level, &lbp);
/* Allocate the new block. If we can't do it, we're toast. Give up. */
error = xfs_btree_alloc_block(cur, &lptr, &rptr, stat); if (error) goto error0; if (*stat == 0) goto out0;
XFS_BTREE_STATS_INC(cur, alloc);
/* Set up the new block as "right". */
error = xfs_btree_get_buf_block(cur, &rptr, &right, &rbp); if (error) goto error0;
/* Fill in the btree header for the new right block. */
xfs_btree_init_block_cur(cur, rbp, xfs_btree_get_level(left), 0);
/* * Split the entries between the old and the new block evenly. * Make sure that if there's an odd number of entries now, that * each new block will have the same number of entries.
*/
lrecs = xfs_btree_get_numrecs(left);
rrecs = lrecs / 2; if ((lrecs & 1) && cur->bc_levels[level].ptr <= rrecs + 1)
rrecs++;
src_index = (lrecs - rrecs + 1);
XFS_BTREE_STATS_ADD(cur, moves, rrecs);
/* Adjust numrecs for the later get_*_keys() calls. */
lrecs -= rrecs;
xfs_btree_set_numrecs(left, lrecs);
xfs_btree_set_numrecs(right, xfs_btree_get_numrecs(right) + rrecs);
/* * Copy btree block entries from the left block over to the * new block, the right. Update the right block and log the * changes.
*/ if (level > 0) { /* It's a non-leaf. Move keys and pointers. */ union xfs_btree_key *lkp; /* left btree key */ union xfs_btree_ptr *lpp; /* left address pointer */ union xfs_btree_key *rkp; /* right btree key */ union xfs_btree_ptr *rpp; /* right address pointer */
/* Stash the keys of the new block for later insertion. */
xfs_btree_get_node_keys(cur, right, key);
} else { /* It's a leaf. Move records. */ union xfs_btree_rec *lrp; /* left record pointer */ union xfs_btree_rec *rrp; /* right record pointer */
/* * If there's a block to the new block's right, make that block * point back to right instead of to left.
*/ if (!xfs_btree_ptr_is_null(cur, &rrptr)) {
error = xfs_btree_read_buf_block(cur, &rrptr,
0, &rrblock, &rrbp); if (error) goto error0;
xfs_btree_set_sibling(cur, rrblock, &rptr, XFS_BB_LEFTSIB);
xfs_btree_log_block(cur, rrbp, XFS_BB_LEFTSIB);
}
/* Update the parent high keys of the left block, if needed. */ if (cur->bc_ops->geom_flags & XFS_BTGEO_OVERLAPPING) {
error = xfs_btree_update_keys(cur, level); if (error) goto error0;
}
/* * If the cursor is really in the right block, move it there. * If it's just pointing past the last entry in left, then we'll * insert there, so don't change anything in that case.
*/ if (cur->bc_levels[level].ptr > lrecs + 1) {
xfs_btree_setbuf(cur, level, rbp);
cur->bc_levels[level].ptr -= lrecs;
} /* * If there are more levels, we'll need another cursor which refers * the right block, no matter where this cursor was.
*/ if (level + 1 < cur->bc_nlevels) {
error = xfs_btree_dup_cursor(cur, curp); if (error) goto error0;
(*curp)->bc_levels[level + 1].ptr++;
}
*ptrp = rptr;
*stat = 1; return 0;
out0:
*stat = 0; return 0;
error0: return error;
}
#ifdef __KERNEL__ struct xfs_btree_split_args { struct xfs_btree_cur *cur; int level; union xfs_btree_ptr *ptrp; union xfs_btree_key *key; struct xfs_btree_cur **curp; int *stat; /* success/failure */ int result; bool kswapd; /* allocation in kswapd context */ struct completion *done; struct work_struct work;
};
/* * we are in a transaction context here, but may also be doing work * in kswapd context, and hence we may need to inherit that state * temporarily to ensure that we don't block waiting for memory reclaim * in any way.
*/ if (args->kswapd)
new_pflags |= PF_MEMALLOC | PF_KSWAPD;
/* * Do not access args after complete() has run here. We don't own args * and the owner may run and free args before we return here.
*/
complete(args->done);
}
/* * BMBT split requests often come in with little stack to work on so we push * them off to a worker thread so there is lots of stack to use. For the other * btree types, just call directly to avoid the context switch overhead here. * * Care must be taken here - the work queue rescuer thread introduces potential * AGF <> worker queue deadlocks if the BMBT block allocation has to lock new * AGFs to allocate blocks. A task being run by the rescuer could attempt to * lock an AGF that is already locked by a task queued to run by the rescuer, * resulting in an ABBA deadlock as the rescuer cannot run the lock holder to * release it until the current thread it is running gains the lock. * * To avoid this issue, we only ever queue BMBT splits that don't have an AGF * already locked to allocate from. The only place that doesn't hold an AGF * locked is unwritten extent conversion at IO completion, but that has already * been offloaded to a worker thread and hence has no stack consumption issues * we have to worry about.
*/ STATICint/* error */
xfs_btree_split( struct xfs_btree_cur *cur, int level, union xfs_btree_ptr *ptrp, union xfs_btree_key *key, struct xfs_btree_cur **curp, int *stat) /* success/failure */
{ struct xfs_btree_split_args args;
DECLARE_COMPLETION_ONSTACK(done);
/* Move the records from a root leaf block to a separate block. */ STATICvoid
xfs_btree_promote_leaf_iroot( struct xfs_btree_cur *cur, struct xfs_btree_block *block, struct xfs_buf *cbp, union xfs_btree_ptr *cptr, struct xfs_btree_block *cblock)
{ union xfs_btree_rec *rp; union xfs_btree_rec *crp; union xfs_btree_key *kp; union xfs_btree_ptr *pp; struct xfs_btree_block *broot; int numrecs = xfs_btree_get_numrecs(block);
/* Copy the records from the leaf broot into the new child block. */
rp = xfs_btree_rec_addr(cur, 1, block);
crp = xfs_btree_rec_addr(cur, 1, cblock);
xfs_btree_copy_recs(cur, crp, rp, numrecs);
/* * Increment the tree height. * * Trickery here: The amount of memory that we need per record for the * ifork's btree root block may change when we convert the broot from a * leaf to a node block. Free the existing leaf broot so that nobody * thinks we need to migrate node pointers when we realloc the broot * buffer after bumping nlevels.
*/
cur->bc_ops->broot_realloc(cur, 0);
cur->bc_nlevels++;
cur->bc_levels[1].ptr = 1;
/* * Allocate a new node broot and initialize it to point to the new * child block.
*/
broot = cur->bc_ops->broot_realloc(cur, 1);
xfs_btree_init_block(cur->bc_mp, broot, cur->bc_ops,
cur->bc_nlevels - 1, 1, cur->bc_ino.ip->i_ino);
/* Attach the new block to the cursor and log it. */
xfs_btree_setbuf(cur, 0, cbp);
xfs_btree_log_block(cur, cbp, XFS_BB_ALL_BITS);
xfs_btree_log_recs(cur, cbp, 1, numrecs);
}
/* * Move the keys and pointers from a root block to a separate block. * * Since the keyptr size does not change, all we have to do is increase the * tree height, copy the keyptrs to the new internal node (cblock), shrink * the root, and copy the pointers there.
*/ STATICint
xfs_btree_promote_node_iroot( struct xfs_btree_cur *cur, struct xfs_btree_block *block, int level, struct xfs_buf *cbp, union xfs_btree_ptr *cptr, struct xfs_btree_block *cblock)
{ union xfs_btree_key *ckp; union xfs_btree_key *kp; union xfs_btree_ptr *cpp; union xfs_btree_ptr *pp; int i; int error; int numrecs = xfs_btree_get_numrecs(block);
/* * Increase tree height, adjusting the root block level to match. * We cannot change the root btree node size until we've copied the * block contents to the new child block.
*/
be16_add_cpu(&block->bb_level, 1);
cur->bc_nlevels++;
cur->bc_levels[level + 1].ptr = 1;
/* * Adjust the root btree record count, then copy the keys from the old * root to the new child block.
*/
xfs_btree_set_numrecs(block, 1);
kp = xfs_btree_key_addr(cur, 1, block);
ckp = xfs_btree_key_addr(cur, 1, cblock);
xfs_btree_copy_keys(cur, ckp, kp, numrecs);
/* Check the pointers and copy them to the new child block. */
pp = xfs_btree_ptr_addr(cur, 1, block);
cpp = xfs_btree_ptr_addr(cur, 1, cblock); for (i = 0; i < numrecs; i++) {
error = xfs_btree_debug_check_ptr(cur, pp, i, level); if (error) return error;
}
xfs_btree_copy_ptrs(cur, cpp, pp, numrecs);
/* * Set the first keyptr to point to the new child block, then shrink * the memory buffer for the root block.
*/
error = xfs_btree_debug_check_ptr(cur, cptr, 0, level); if (error) return error;
xfs_btree_copy_ptrs(cur, pp, cptr, 1);
xfs_btree_get_keys(cur, cblock, kp);
cur->bc_ops->broot_realloc(cur, 1);
/* Attach the new block to the cursor and log it. */
xfs_btree_setbuf(cur, level, cbp);
xfs_btree_log_block(cur, cbp, XFS_BB_ALL_BITS);
xfs_btree_log_keys(cur, cbp, 1, numrecs);
xfs_btree_log_ptrs(cur, cbp, 1, numrecs); return 0;
}
/* * Copy the old inode root contents into a real block and make the * broot point to it.
*/ int/* error */
xfs_btree_new_iroot( struct xfs_btree_cur *cur, /* btree cursor */ int *logflags, /* logging flags for inode */ int *stat) /* return status - 0 fail */
{ struct xfs_buf *cbp; /* buffer for cblock */ struct xfs_btree_block *block; /* btree block */ struct xfs_btree_block *cblock; /* child btree block */ union xfs_btree_ptr aptr; union xfs_btree_ptr nptr; /* new block addr */ int level; /* btree level */ int error; /* error return code */
/* Allocate the new block. If we can't do it, we're toast. Give up. */
error = xfs_btree_alloc_block(cur, &aptr, &nptr, stat); if (error) goto error0; if (*stat == 0) return 0;
XFS_BTREE_STATS_INC(cur, alloc);
/* Copy the root into a real block. */
error = xfs_btree_get_buf_block(cur, &nptr, &cblock, &cbp); if (error) goto error0;
/* * we can't just memcpy() the root in for CRC enabled btree blocks. * In that case have to also ensure the blkno remains correct
*/
memcpy(cblock, block, xfs_btree_block_len(cur)); if (xfs_has_crc(cur->bc_mp)) {
__be64 bno = cpu_to_be64(xfs_buf_daddr(cbp)); if (cur->bc_ops->ptr_len == XFS_BTREE_LONG_PTR_LEN)
cblock->bb_u.l.bb_blkno = bno; else
cblock->bb_u.s.bb_blkno = bno;
}
staticvoid
xfs_btree_set_root( struct xfs_btree_cur *cur, constunion xfs_btree_ptr *ptr, int inc)
{ if (cur->bc_flags & XFS_BTREE_STAGING) { /* Update the btree root information for a per-AG fake root. */
cur->bc_ag.afake->af_root = be32_to_cpu(ptr->s);
cur->bc_ag.afake->af_levels += inc;
} else {
cur->bc_ops->set_root(cur, ptr, inc);
}
}
/* * Allocate a new root block, fill it in.
*/ STATICint/* error */
xfs_btree_new_root( struct xfs_btree_cur *cur, /* btree cursor */ int *stat) /* success/failure */
{ struct xfs_btree_block *block; /* one half of the old root block */ struct xfs_buf *bp; /* buffer containing block */ int error; /* error return value */ struct xfs_buf *lbp; /* left buffer pointer */ struct xfs_btree_block *left; /* left btree block */ struct xfs_buf *nbp; /* new (root) buffer */ struct xfs_btree_block *new; /* new (root) btree block */ int nptr; /* new value for key index, 1 or 2 */ struct xfs_buf *rbp; /* right buffer pointer */ struct xfs_btree_block *right; /* right btree block */ union xfs_btree_ptr rptr; union xfs_btree_ptr lptr;
XFS_BTREE_STATS_INC(cur, newroot);
/* initialise our start point from the cursor */
xfs_btree_init_ptr_from_cur(cur, &rptr);
/* Allocate the new block. If we can't do it, we're toast. Give up. */
error = xfs_btree_alloc_block(cur, &rptr, &lptr, stat); if (error) goto error0; if (*stat == 0) goto out0;
XFS_BTREE_STATS_INC(cur, alloc);
/* Set up the new block. */
error = xfs_btree_get_buf_block(cur, &lptr, &new, &nbp); if (error) goto error0;
/* Set the root in the holding structure increasing the level by 1. */
xfs_btree_set_root(cur, &lptr, 1);
/* * At the previous root level there are now two blocks: the old root, * and the new block generated when it was split. We don't know which * one the cursor is pointing at, so we set up variables "left" and * "right" for each case.
*/
block = xfs_btree_get_block(cur, cur->bc_nlevels - 1, &bp);
xfs_btree_get_sibling(cur, block, &rptr, XFS_BB_RIGHTSIB); if (!xfs_btree_ptr_is_null(cur, &rptr)) { /* Our block is left, pick up the right block. */
lbp = bp;
xfs_btree_buf_to_ptr(cur, lbp, &lptr);
left = block;
error = xfs_btree_read_buf_block(cur, &rptr, 0, &right, &rbp); if (error) goto error0;
bp = rbp;
nptr = 1;
} else { /* Our block is right, pick up the left block. */
rbp = bp;
xfs_btree_buf_to_ptr(cur, rbp, &rptr);
right = block;
xfs_btree_get_sibling(cur, right, &lptr, XFS_BB_LEFTSIB);
error = xfs_btree_read_buf_block(cur, &lptr, 0, &left, &lbp); if (error) goto error0;
bp = lbp;
nptr = 2;
}
/* Fill in the new block's btree header and log it. */
xfs_btree_init_block_cur(cur, nbp, cur->bc_nlevels, 2);
xfs_btree_log_block(cur, nbp, XFS_BB_ALL_BITS);
ASSERT(!xfs_btree_ptr_is_null(cur, &lptr) &&
!xfs_btree_ptr_is_null(cur, &rptr));
/* Fill in the key data in the new root. */ if (xfs_btree_get_level(left) > 0) { /* * Get the keys for the left block's keys and put them directly * in the parent block. Do the same for the right block.
*/
xfs_btree_get_node_keys(cur, left,
xfs_btree_key_addr(cur, 1, new));
xfs_btree_get_node_keys(cur, right,
xfs_btree_key_addr(cur, 2, new));
} else { /* * Get the keys for the left block's records and put them * directly in the parent block. Do the same for the right * block.
*/
xfs_btree_get_leaf_keys(cur, left,
xfs_btree_key_addr(cur, 1, new));
xfs_btree_get_leaf_keys(cur, right,
xfs_btree_key_addr(cur, 2, new));
}
xfs_btree_log_keys(cur, nbp, 1, 2);
/* Fill in the pointer data in the new root. */
xfs_btree_copy_ptrs(cur,
xfs_btree_ptr_addr(cur, 1, new), &lptr, 1);
xfs_btree_copy_ptrs(cur,
xfs_btree_ptr_addr(cur, 2, new), &rptr, 1);
xfs_btree_log_ptrs(cur, nbp, 1, 2);
STATICint
xfs_btree_make_block_unfull( struct xfs_btree_cur *cur, /* btree cursor */ int level, /* btree level */ int numrecs,/* # of recs in block */ int *oindex,/* old tree index */ int *index, /* new tree index */ union xfs_btree_ptr *nptr, /* new btree ptr */ struct xfs_btree_cur **ncur, /* new btree cursor */ union xfs_btree_key *key, /* key of new block */ int *stat)
{ int error = 0;
if (xfs_btree_at_iroot(cur, level)) { struct xfs_inode *ip = cur->bc_ino.ip;
if (numrecs < cur->bc_ops->get_dmaxrecs(cur, level)) { /* A root block that can be made bigger. */
cur->bc_ops->broot_realloc(cur, numrecs + 1);
*stat = 1;
} else { /* A root block that needs replacing */ int logflags = 0;
/* * Next, try splitting the current block in half. * * If this works we have to re-set our variables because we * could be in a different block now.
*/
error = xfs_btree_split(cur, level, nptr, key, ncur, stat); if (error || *stat == 0) return error;
*index = cur->bc_levels[level].ptr; return 0;
}
/* * Insert one record/level. Return information to the caller * allowing the next level up to proceed if necessary.
*/ STATICint
xfs_btree_insrec( struct xfs_btree_cur *cur, /* btree cursor */ int level, /* level to insert record at */ union xfs_btree_ptr *ptrp, /* i/o: block number inserted */ union xfs_btree_rec *rec, /* record to insert */ union xfs_btree_key *key, /* i/o: block key for ptrp */ struct xfs_btree_cur **curp, /* output: new cursor replacing cur */ int *stat) /* success/failure */
{ struct xfs_btree_block *block; /* btree block */ struct xfs_buf *bp; /* buffer for block */ union xfs_btree_ptr nptr; /* new block ptr */ struct xfs_btree_cur *ncur = NULL; /* new btree cursor */ union xfs_btree_key nkey; /* new block key */ union xfs_btree_key *lkey; int optr; /* old key/record index */ int ptr; /* key/record index */ int numrecs;/* number of records */ int error; /* error return value */ int i;
xfs_daddr_t old_bn;
ncur = NULL;
lkey = &nkey;
/* * If we have an external root pointer, and we've made it to the * root level, allocate a new root block and we're done.
*/ if (cur->bc_ops->type != XFS_BTREE_TYPE_INODE &&
level >= cur->bc_nlevels) {
error = xfs_btree_new_root(cur, stat);
xfs_btree_set_ptr_null(cur, ptrp);
return error;
}
/* If we're off the left edge, return failure. */
ptr = cur->bc_levels[level].ptr; if (ptr == 0) {
*stat = 0; return 0;
}
optr = ptr;
XFS_BTREE_STATS_INC(cur, insrec);
/* Get pointers to the btree buffer and block. */
block = xfs_btree_get_block(cur, level, &bp);
old_bn = bp ? xfs_buf_daddr(bp) : XFS_BUF_DADDR_NULL;
numrecs = xfs_btree_get_numrecs(block);
/* Check that the new entry is being inserted in the right place. */ if (ptr <= numrecs) { if (level == 0) {
ASSERT(cur->bc_ops->recs_inorder(cur, rec,
xfs_btree_rec_addr(cur, ptr, block)));
} else {
ASSERT(cur->bc_ops->keys_inorder(cur, key,
xfs_btree_key_addr(cur, ptr, block)));
}
} #endif
/* * If the block is full, we can't insert the new entry until we * make the block un-full.
*/
xfs_btree_set_ptr_null(cur, &nptr); if (numrecs == cur->bc_ops->get_maxrecs(cur, level)) {
error = xfs_btree_make_block_unfull(cur, level, numrecs,
&optr, &ptr, &nptr, &ncur, lkey, stat); if (error || *stat == 0) goto error0;
}
/* * The current block may have changed if the block was * previously full and we have just made space in it.
*/
block = xfs_btree_get_block(cur, level, &bp);
numrecs = xfs_btree_get_numrecs(block);
error = xfs_btree_debug_check_ptr(cur, ptrp, 0, level); if (error) goto error0;
/* Now put the new data in, bump numrecs and log it. */
xfs_btree_copy_keys(cur, kp, key, 1);
xfs_btree_copy_ptrs(cur, pp, ptrp, 1);
numrecs++;
xfs_btree_set_numrecs(block, numrecs);
xfs_btree_log_ptrs(cur, bp, ptr, numrecs);
xfs_btree_log_keys(cur, bp, ptr, numrecs); #ifdef DEBUG if (ptr < numrecs) {
ASSERT(cur->bc_ops->keys_inorder(cur, kp,
xfs_btree_key_addr(cur, ptr + 1, block)));
} #endif
} else { /* It's a leaf. make a hole in the records */ union xfs_btree_rec *rp;
/* Now put the new data in, bump numrecs and log it. */
xfs_btree_copy_recs(cur, rp, rec, 1);
xfs_btree_set_numrecs(block, ++numrecs);
xfs_btree_log_recs(cur, bp, ptr, numrecs); #ifdef DEBUG if (ptr < numrecs) {
ASSERT(cur->bc_ops->recs_inorder(cur, rp,
xfs_btree_rec_addr(cur, ptr + 1, block)));
} #endif
}
/* Log the new number of records in the btree header. */
xfs_btree_log_block(cur, bp, XFS_BB_NUMRECS);
/* * Update btree keys to reflect the newly added record or keyptr. * There are three cases here to be aware of. Normally, all we have to * do is walk towards the root, updating keys as necessary. * * If the caller had us target a full block for the insertion, we dealt * with that by calling the _make_block_unfull function. If the * "make unfull" function splits the block, it'll hand us back the key * and pointer of the new block. We haven't yet added the new block to * the next level up, so if we decide to add the new record to the new * block (bp->b_bn != old_bn), we have to update the caller's pointer * so that the caller adds the new block with the correct key. * * However, there is a third possibility-- if the selected block is the * root block of an inode-rooted btree and cannot be expanded further, * the "make unfull" function moves the root block contents to a new * block and updates the root block to point to the new block. In this * case, no block pointer is passed back because the block has already * been added to the btree. In this case, we need to use the regular * key update function, just like the first case. This is critical for * overlapping btrees, because the high key must be updated to reflect * the entire tree, not just the subtree accessible through the first * child of the root (which is now two levels down from the root).
*/ if (!xfs_btree_ptr_is_null(cur, &nptr) &&
bp && xfs_buf_daddr(bp) != old_bn) {
xfs_btree_get_keys(cur, block, lkey);
} elseif (xfs_btree_needs_key_update(cur, optr)) {
error = xfs_btree_update_keys(cur, level); if (error) goto error0;
}
/* * Return the new block number, if any. * If there is one, give back a record value and a cursor too.
*/
*ptrp = nptr; if (!xfs_btree_ptr_is_null(cur, &nptr)) {
xfs_btree_copy_keys(cur, key, lkey, 1);
*curp = ncur;
}
*stat = 1; return 0;
error0: if (ncur)
xfs_btree_del_cursor(ncur, error); return error;
}
/* * Insert the record at the point referenced by cur. * * A multi-level split of the tree on insert will invalidate the original * cursor. All callers of this function should assume that the cursor is * no longer valid and revalidate it.
*/ int
xfs_btree_insert( struct xfs_btree_cur *cur, int *stat)
{ int error; /* error return value */ int i; /* result value, 0 for failure */ int level; /* current level number in btree */ union xfs_btree_ptr nptr; /* new block number (split result) */ struct xfs_btree_cur *ncur; /* new cursor (split result) */ struct xfs_btree_cur *pcur; /* previous level's cursor */ union xfs_btree_key bkey; /* key of block to insert */ union xfs_btree_key *key; union xfs_btree_rec rec; /* record to insert */
level = 0;
ncur = NULL;
pcur = cur;
key = &bkey;
xfs_btree_set_ptr_null(cur, &nptr);
/* Make a key out of the record data to be inserted, and save it. */
cur->bc_ops->init_rec_from_cur(cur, &rec);
cur->bc_ops->init_key_from_rec(key, &rec);
/* * Loop going up the tree, starting at the leaf level. * Stop when we don't get a split block, that must mean that * the insert is finished with this level.
*/ do { /* * Insert nrec/nptr into this level of the tree. * Note if we fail, nptr will be null.
*/
error = xfs_btree_insrec(pcur, level, &nptr, &rec, key,
&ncur, &i); if (error) { if (pcur != cur)
xfs_btree_del_cursor(pcur, XFS_BTREE_ERROR); goto error0;
}
if (XFS_IS_CORRUPT(cur->bc_mp, i != 1)) {
xfs_btree_mark_sick(cur);
error = -EFSCORRUPTED; goto error0;
}
level++;
/* * See if the cursor we just used is trash. * Can't trash the caller's cursor, but otherwise we should * if ncur is a new cursor or we're about to be done.
*/ if (pcur != cur &&
(ncur || xfs_btree_ptr_is_null(cur, &nptr))) { /* Save the state from the cursor before we trash it */ if (cur->bc_ops->update_cursor &&
!(cur->bc_flags & XFS_BTREE_STAGING))
cur->bc_ops->update_cursor(pcur, cur);
cur->bc_nlevels = pcur->bc_nlevels;
xfs_btree_del_cursor(pcur, XFS_BTREE_NOERROR);
} /* If we got a new cursor, switch to it. */ if (ncur) {
pcur = ncur;
ncur = NULL;
}
} while (!xfs_btree_ptr_is_null(cur, &nptr));
*stat = i; return 0;
error0: return error;
}
/* Move the records from a child leaf block to the root block. */ STATICvoid
xfs_btree_demote_leaf_child( struct xfs_btree_cur *cur, struct xfs_btree_block *cblock, int numrecs)
{ union xfs_btree_rec *rp; union xfs_btree_rec *crp; struct xfs_btree_block *broot;
/* * Decrease the tree height. * * Trickery here: The amount of memory that we need per record for the * ifork's btree root block may change when we convert the broot from a * node to a leaf. Free the old node broot so that we can get a fresh * leaf broot.
*/
cur->bc_ops->broot_realloc(cur, 0);
cur->bc_nlevels--;
/* * Allocate a new leaf broot and copy the records from the old child. * Detach the old child from the cursor.
*/
broot = cur->bc_ops->broot_realloc(cur, numrecs);
xfs_btree_init_block(cur->bc_mp, broot, cur->bc_ops, 0, numrecs,
cur->bc_ino.ip->i_ino);
/* * Move the keyptrs from a child node block to the root block. * * Since the keyptr size does not change, all we have to do is increase the * tree height, copy the keyptrs to the new internal node (cblock), shrink * the root, and copy the pointers there.
*/ STATICint
xfs_btree_demote_node_child( struct xfs_btree_cur *cur, struct xfs_btree_block *cblock, int level, int numrecs)
{ struct xfs_btree_block *block; union xfs_btree_key *ckp; union xfs_btree_key *kp; union xfs_btree_ptr *cpp; union xfs_btree_ptr *pp; int i; int error;
/* * Adjust the root btree node size and the record count to match the * doomed child so that we can copy the keyptrs ahead of changing the * tree shape.
*/
block = cur->bc_ops->broot_realloc(cur, numrecs);
/* Copy pointers from the doomed block. */
pp = xfs_btree_ptr_addr(cur, 1, block);
cpp = xfs_btree_ptr_addr(cur, 1, cblock); for (i = 0; i < numrecs; i++) {
error = xfs_btree_debug_check_ptr(cur, cpp, i, level - 1); if (error) return error;
}
xfs_btree_copy_ptrs(cur, pp, cpp, numrecs);
/* Decrease tree height, adjusting the root block level to match. */
cur->bc_levels[level - 1].bp = NULL;
be16_add_cpu(&block->bb_level, -1);
cur->bc_nlevels--; return 0;
}
/* * Try to merge a non-leaf block back into the inode root. * * Note: the killroot names comes from the fact that we're effectively * killing the old root block. But because we can't just delete the * inode we have to copy the single block it was pointing to into the * inode.
*/ STATICint
xfs_btree_kill_iroot( struct xfs_btree_cur *cur)
{ struct xfs_inode *ip = cur->bc_ino.ip; struct xfs_btree_block *block; struct xfs_btree_block *cblock; struct xfs_buf *cbp; int level; int numrecs; int error; #ifdef DEBUG union xfs_btree_ptr ptr; #endif
/* * Don't deal with the root block needs to be a leaf case. * We're just going to turn the thing back into extents anyway.
*/
level = cur->bc_nlevels - 1; if (level == 1 && !(cur->bc_ops->geom_flags & XFS_BTGEO_IROOT_RECORDS)) goto out0;
/* If we're already a leaf, jump out. */ if (level == 0) goto out0;
/* * Give up if the root has multiple children.
*/
block = xfs_btree_get_iroot(cur); if (xfs_btree_get_numrecs(block) != 1) goto out0;
/* * Only do this if the next level will fit. * Then the data must be copied up to the inode, * instead of freeing the root you free the next level.
*/ if (numrecs > cur->bc_ops->get_dmaxrecs(cur, level)) goto out0;
/* * Kill the current root node, and replace it with it's only child node.
*/ STATICint
xfs_btree_kill_root( struct xfs_btree_cur *cur, struct xfs_buf *bp, int level, union xfs_btree_ptr *newroot)
{ int error;
XFS_BTREE_STATS_INC(cur, killroot);
/* * Update the root pointer, decreasing the level by 1 and then * free the old root.
*/
xfs_btree_set_root(cur, newroot, -1);
error = xfs_btree_free_block(cur, bp); if (error) return error;
STATICint
xfs_btree_dec_cursor( struct xfs_btree_cur *cur, int level, int *stat)
{ int error; int i;
if (level > 0) {
error = xfs_btree_decrement(cur, level, &i); if (error) return error;
}
*stat = 1; return 0;
}
/* * Single level of the btree record deletion routine. * Delete record pointed to by cur/level. * Remove the record from its block then rebalance the tree. * Return 0 for error, 1 for done, 2 to go on to the next level.
*/ STATICint/* error */
xfs_btree_delrec( struct xfs_btree_cur *cur, /* btree cursor */ int level, /* level removing record from */ int *stat) /* fail/done/go-on */
{ struct xfs_btree_block *block; /* btree block */ union xfs_btree_ptr cptr; /* current block ptr */ struct xfs_buf *bp; /* buffer for block */ int error; /* error return value */ int i; /* loop counter */ union xfs_btree_ptr lptr; /* left sibling block ptr */ struct xfs_buf *lbp; /* left buffer pointer */ struct xfs_btree_block *left; /* left btree block */ int lrecs = 0; /* left record count */ int ptr; /* key/record index */ union xfs_btree_ptr rptr; /* right sibling block ptr */ struct xfs_buf *rbp; /* right buffer pointer */ struct xfs_btree_block *right; /* right btree block */ struct xfs_btree_block *rrblock; /* right-right btree block */ struct xfs_buf *rrbp; /* right-right buffer pointer */ int rrecs = 0; /* right record count */ struct xfs_btree_cur *tcur; /* temporary btree cursor */ int numrecs; /* temporary numrec count */
tcur = NULL;
/* Get the index of the entry being deleted, check for nothing there. */
ptr = cur->bc_levels[level].ptr; if (ptr == 0) {
*stat = 0; return 0;
}
/* Get the buffer & block containing the record or key/ptr. */
block = xfs_btree_get_block(cur, level, &bp);
numrecs = xfs_btree_get_numrecs(block);
/* Excise the entries being deleted. */ if (level > 0) { /* It's a nonleaf. operate on keys and ptrs */ union xfs_btree_key *lkp; union xfs_btree_ptr *lpp;
/* * Decrement and log the number of entries in the block.
*/
xfs_btree_set_numrecs(block, --numrecs);
xfs_btree_log_block(cur, bp, XFS_BB_NUMRECS);
/* * We're at the root level. First, shrink the root block in-memory. * Try to get rid of the next level down. If we can't then there's * nothing left to do. numrecs was decremented above.
*/ if (xfs_btree_at_iroot(cur, level)) {
cur->bc_ops->broot_realloc(cur, numrecs);
error = xfs_btree_kill_iroot(cur); if (error) goto error0;
/* * If this is the root level, and there's only one entry left, and it's * NOT the leaf level, then we can get rid of this level.
*/ if (level == cur->bc_nlevels - 1) { if (numrecs == 1 && level > 0) { union xfs_btree_ptr *pp; /* * pp is still set to the first pointer in the block. * Make it the new root of the btree.
*/
pp = xfs_btree_ptr_addr(cur, 1, block);
error = xfs_btree_kill_root(cur, bp, level, pp); if (error) goto error0;
} elseif (level > 0) {
error = xfs_btree_dec_cursor(cur, level, stat); if (error) goto error0;
}
*stat = 1; return 0;
}
/* * If we deleted the leftmost entry in the block, update the * key values above us in the tree.
*/ if (xfs_btree_needs_key_update(cur, ptr)) {
error = xfs_btree_update_keys(cur, level); if (error) goto error0;
}
/* * If the number of records remaining in the block is at least * the minimum, we're done.
*/ if (numrecs >= cur->bc_ops->get_minrecs(cur, level)) {
error = xfs_btree_dec_cursor(cur, level, stat); if (error) goto error0; return 0;
}
/* * Otherwise, we have to move some records around to keep the * tree balanced. Look at the left and right sibling blocks to * see if we can re-balance by moving only one record.
*/
xfs_btree_get_sibling(cur, block, &rptr, XFS_BB_RIGHTSIB);
xfs_btree_get_sibling(cur, block, &lptr, XFS_BB_LEFTSIB);
if (cur->bc_ops->type == XFS_BTREE_TYPE_INODE) { /* * One child of root, need to get a chance to copy its contents * into the root and delete it. Can't go up to next level, * there's nothing to delete there.
*/ if (xfs_btree_ptr_is_null(cur, &rptr) &&
xfs_btree_ptr_is_null(cur, &lptr) &&
level == cur->bc_nlevels - 2) {
error = xfs_btree_kill_iroot(cur); if (!error)
error = xfs_btree_dec_cursor(cur, level, stat); if (error) goto error0; return 0;
}
}
/* * Duplicate the cursor so our btree manipulations here won't * disrupt the next level up.
*/
error = xfs_btree_dup_cursor(cur, &tcur); if (error) goto error0;
/* * If there's a right sibling, see if it's ok to shift an entry * out of it.
*/ if (!xfs_btree_ptr_is_null(cur, &rptr)) { /* * Move the temp cursor to the last entry in the next block. * Actually any entry but the first would suffice.
*/
i = xfs_btree_lastrec(tcur, level); if (XFS_IS_CORRUPT(cur->bc_mp, i != 1)) {
xfs_btree_mark_sick(cur);
error = -EFSCORRUPTED; goto error0;
}
error = xfs_btree_increment(tcur, level, &i); if (error) goto error0; if (XFS_IS_CORRUPT(cur->bc_mp, i != 1)) {
xfs_btree_mark_sick(cur);
error = -EFSCORRUPTED; goto error0;
}
i = xfs_btree_lastrec(tcur, level); if (XFS_IS_CORRUPT(cur->bc_mp, i != 1)) {
xfs_btree_mark_sick(cur);
error = -EFSCORRUPTED; goto error0;
}
/* Grab a pointer to the block. */
right = xfs_btree_get_block(tcur, level, &rbp); #ifdef DEBUG
error = xfs_btree_check_block(tcur, right, level, rbp); if (error) goto error0; #endif /* Grab the current block number, for future use. */
xfs_btree_get_sibling(tcur, right, &cptr, XFS_BB_LEFTSIB);
/* * If right block is full enough so that removing one entry * won't make it too empty, and left-shifting an entry out * of right to us works, we're done.
*/ if (xfs_btree_get_numrecs(right) - 1 >=
cur->bc_ops->get_minrecs(tcur, level)) {
error = xfs_btree_lshift(tcur, level, &i); if (error) goto error0; if (i) {
ASSERT(xfs_btree_get_numrecs(block) >=
cur->bc_ops->get_minrecs(tcur, level));
/* * Otherwise, grab the number of records in right for * future reference, and fix up the temp cursor to point * to our block again (last record).
*/
rrecs = xfs_btree_get_numrecs(right); if (!xfs_btree_ptr_is_null(cur, &lptr)) {
i = xfs_btree_firstrec(tcur, level); if (XFS_IS_CORRUPT(cur->bc_mp, i != 1)) {
xfs_btree_mark_sick(cur);
error = -EFSCORRUPTED; goto error0;
}
error = xfs_btree_decrement(tcur, level, &i); if (error) goto error0; if (XFS_IS_CORRUPT(cur->bc_mp, i != 1)) {
xfs_btree_mark_sick(cur);
error = -EFSCORRUPTED; goto error0;
}
}
}
/* * If there's a left sibling, see if it's ok to shift an entry * out of it.
*/ if (!xfs_btree_ptr_is_null(cur, &lptr)) { /* * Move the temp cursor to the first entry in the * previous block.
*/
i = xfs_btree_firstrec(tcur, level); if (XFS_IS_CORRUPT(cur->bc_mp, i != 1)) {
xfs_btree_mark_sick(cur);
error = -EFSCORRUPTED; goto error0;
}
error = xfs_btree_decrement(tcur, level, &i); if (error) goto error0;
i = xfs_btree_firstrec(tcur, level); if (XFS_IS_CORRUPT(cur->bc_mp, i != 1)) {
xfs_btree_mark_sick(cur);
error = -EFSCORRUPTED; goto error0;
}
/* Grab a pointer to the block. */
left = xfs_btree_get_block(tcur, level, &lbp); #ifdef DEBUG
error = xfs_btree_check_block(cur, left, level, lbp); if (error) goto error0; #endif /* Grab the current block number, for future use. */
xfs_btree_get_sibling(tcur, left, &cptr, XFS_BB_RIGHTSIB);
/* * If left block is full enough so that removing one entry * won't make it too empty, and right-shifting an entry out * of left to us works, we're done.
*/ if (xfs_btree_get_numrecs(left) - 1 >=
cur->bc_ops->get_minrecs(tcur, level)) {
error = xfs_btree_rshift(tcur, level, &i); if (error) goto error0; if (i) {
ASSERT(xfs_btree_get_numrecs(block) >=
cur->bc_ops->get_minrecs(tcur, level));
xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
tcur = NULL; if (level == 0)
cur->bc_levels[0].ptr++;
*stat = 1; return 0;
}
}
/* * Otherwise, grab the number of records in right for * future reference.
*/
lrecs = xfs_btree_get_numrecs(left);
}
/* Delete the temp cursor, we're done with it. */
xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
tcur = NULL;
/* If here, we need to do a join to keep the tree balanced. */
ASSERT(!xfs_btree_ptr_is_null(cur, &cptr));
if (!xfs_btree_ptr_is_null(cur, &lptr) &&
lrecs + xfs_btree_get_numrecs(block) <=
cur->bc_ops->get_maxrecs(cur, level)) { /* * Set "right" to be the starting block, * "left" to be the left neighbor.
*/
rptr = cptr;
right = block;
rbp = bp;
error = xfs_btree_read_buf_block(cur, &lptr, 0, &left, &lbp); if (error) goto error0;
/* * If that won't work, see if we can join with the right neighbor block.
*/
} elseif (!xfs_btree_ptr_is_null(cur, &rptr) &&
rrecs + xfs_btree_get_numrecs(block) <=
cur->bc_ops->get_maxrecs(cur, level)) { /* * Set "left" to be the starting block, * "right" to be the right neighbor.
*/
lptr = cptr;
left = block;
lbp = bp;
error = xfs_btree_read_buf_block(cur, &rptr, 0, &right, &rbp); if (error) goto error0;
/* * Otherwise, we can't fix the imbalance. * Just return. This is probably a logic error, but it's not fatal.
*/
} else {
error = xfs_btree_dec_cursor(cur, level, stat); if (error) goto error0; return 0;
}
/* * We're now going to join "left" and "right" by moving all the stuff * in "right" to "left" and deleting "right".
*/
XFS_BTREE_STATS_ADD(cur, moves, rrecs); if (level > 0) { /* It's a non-leaf. Move keys and pointers. */ union xfs_btree_key *lkp; /* left btree key */ union xfs_btree_ptr *lpp; /* left address pointer */ union xfs_btree_key *rkp; /* right btree key */ union xfs_btree_ptr *rpp; /* right address pointer */
/* * Fix up the number of records and right block pointer in the * surviving block, and log it.
*/
xfs_btree_set_numrecs(left, lrecs + rrecs);
xfs_btree_get_sibling(cur, right, &cptr, XFS_BB_RIGHTSIB);
xfs_btree_set_sibling(cur, left, &cptr, XFS_BB_RIGHTSIB);
xfs_btree_log_block(cur, lbp, XFS_BB_NUMRECS | XFS_BB_RIGHTSIB);
/* If there is a right sibling, point it to the remaining block. */
xfs_btree_get_sibling(cur, left, &cptr, XFS_BB_RIGHTSIB); if (!xfs_btree_ptr_is_null(cur, &cptr)) {
error = xfs_btree_read_buf_block(cur, &cptr, 0, &rrblock, &rrbp); if (error) goto error0;
xfs_btree_set_sibling(cur, rrblock, &lptr, XFS_BB_LEFTSIB);
xfs_btree_log_block(cur, rrbp, XFS_BB_LEFTSIB);
}
/* Free the deleted block. */
error = xfs_btree_free_block(cur, rbp); if (error) goto error0;
/* * If we joined with the left neighbor, set the buffer in the * cursor to the left block, and fix up the index.
*/ if (bp != lbp) {
cur->bc_levels[level].bp = lbp;
cur->bc_levels[level].ptr += lrecs;
cur->bc_levels[level].ra = 0;
} /* * If we joined with the right neighbor and there's a level above * us, increment the cursor at that level.
*/ elseif (cur->bc_ops->type == XFS_BTREE_TYPE_INODE ||
level + 1 < cur->bc_nlevels) {
error = xfs_btree_increment(cur, level + 1, &i); if (error) goto error0;
}
/* * Readjust the ptr at this level if it's not a leaf, since it's * still pointing at the deletion point, which makes the cursor * inconsistent. If this makes the ptr 0, the caller fixes it up. * We can't use decrement because it would change the next level up.
*/ if (level > 0)
cur->bc_levels[level].ptr--;
/* * We combined blocks, so we have to update the parent keys if the * btree supports overlapped intervals. However, * bc_levels[level + 1].ptr points to the old block so that the caller * knows which record to delete. Therefore, the caller must be savvy * enough to call updkeys for us if we return stat == 2. The other * exit points from this function don't require deletions further up * the tree, so they can call updkeys directly.
*/
/* Return value means the next level up has something to do. */
*stat = 2; return 0;
error0: if (tcur)
xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR); return error;
}
/* * Delete the record pointed to by cur. * The cursor refers to the place where the record was (could be inserted) * when the operation returns.
*/ int/* error */
xfs_btree_delete( struct xfs_btree_cur *cur, int *stat) /* success/failure */
{ int error; /* error return value */ int level; int i; bool joined = false;
/* * Go up the tree, starting at leaf level. * * If 2 is returned then a join was done; go to the next level. * Otherwise we are done.
*/ for (level = 0, i = 2; i == 2; level++) {
error = xfs_btree_delrec(cur, level, &i); if (error) goto error0; if (i == 2)
joined = true;
}
/* * If we combined blocks as part of deleting the record, delrec won't * have updated the parent high keys so we have to do that here.
*/ if (joined && (cur->bc_ops->geom_flags & XFS_BTGEO_OVERLAPPING)) {
error = xfs_btree_updkeys_force(cur, 0); if (error) goto error0;
}
if (i == 0) { for (level = 1; level < cur->bc_nlevels; level++) { if (cur->bc_levels[level].ptr == 0) {
error = xfs_btree_decrement(cur, level, &i); if (error) goto error0; break;
}
}
}
*stat = i; return 0;
error0: return error;
}
/* * Get the data from the pointed-to record.
*/ int/* error */
xfs_btree_get_rec( struct xfs_btree_cur *cur, /* btree cursor */ union xfs_btree_rec **recp, /* output: btree record */ int *stat) /* output: success/failure */
{ struct xfs_btree_block *block; /* btree block */ struct xfs_buf *bp; /* buffer pointer */ int ptr; /* record number */ #ifdef DEBUG int error; /* error return value */ #endif
/* * Off the right end or left end, return failure.
*/ if (ptr > xfs_btree_get_numrecs(block) || ptr <= 0) {
*stat = 0; return 0;
}
/* * Point to the record and extract its data.
*/
*recp = xfs_btree_rec_addr(cur, ptr, block);
*stat = 1; return 0;
}
/* Visit a block in a btree. */ STATICint
xfs_btree_visit_block( struct xfs_btree_cur *cur, int level,
xfs_btree_visit_blocks_fn fn, void *data)
{ struct xfs_btree_block *block; struct xfs_buf *bp; union xfs_btree_ptr rptr, bufptr; int error;
/* do right sibling readahead */
xfs_btree_readahead(cur, level, XFS_BTCUR_RIGHTRA);
block = xfs_btree_get_block(cur, level, &bp);
/* process the block */
error = fn(cur, level, data); if (error) return error;
/* now read rh sibling block for next iteration */
xfs_btree_get_sibling(cur, block, &rptr, XFS_BB_RIGHTSIB); if (xfs_btree_ptr_is_null(cur, &rptr)) return -ENOENT;
/* * We only visit blocks once in this walk, so we have to avoid the * internal xfs_btree_lookup_get_block() optimisation where it will * return the same block without checking if the right sibling points * back to us and creates a cyclic reference in the btree.
*/
xfs_btree_buf_to_ptr(cur, bp, &bufptr); if (xfs_btree_ptrs_equal(cur, &rptr, &bufptr)) {
xfs_btree_mark_sick(cur); return -EFSCORRUPTED;
}
/* Visit every block in a btree. */ int
xfs_btree_visit_blocks( struct xfs_btree_cur *cur,
xfs_btree_visit_blocks_fn fn, unsignedint flags, void *data)
{ union xfs_btree_ptr lptr; int level; struct xfs_btree_block *block = NULL; int error = 0;
xfs_btree_init_ptr_from_cur(cur, &lptr);
/* for each level */ for (level = cur->bc_nlevels - 1; level >= 0; level--) { /* grab the left hand block */
error = xfs_btree_lookup_get_block(cur, level, &lptr, &block); if (error) return error;
/* readahead the left most block for the next level down */ if (level > 0) { union xfs_btree_ptr *ptr;
/* for each buffer in the level */ do {
error = xfs_btree_visit_block(cur, level, fn, data);
} while (!error);
if (error != -ENOENT) return error;
}
return 0;
}
/* * Change the owner of a btree. * * The mechanism we use here is ordered buffer logging. Because we don't know * how many buffers were are going to need to modify, we don't really want to * have to make transaction reservations for the worst case of every buffer in a * full size btree as that may be more space that we can fit in the log.... * * We do the btree walk in the most optimal manner possible - we have sibling * pointers so we can just walk all the blocks on each level from left to right * in a single pass, and then move to the next level and do the same. We can * also do readahead on the sibling pointers to get IO moving more quickly, * though for slow disks this is unlikely to make much difference to performance * as the amount of CPU work we have to do before moving to the next block is * relatively small. * * For each btree block that we load, modify the owner appropriately, set the * buffer as an ordered buffer and log it appropriately. We need to ensure that * we mark the region we change dirty so that if the buffer is relogged in * a subsequent transaction the changes we make here as an ordered buffer are * correctly relogged in that transaction. If we are in recovery context, then * just queue the modified buffer as delayed write buffer so the transaction * recovery completion writes the changes to disk.
*/ struct xfs_btree_block_change_owner_info {
uint64_t new_owner; struct list_head *buffer_list;
};
/* modify the owner */
block = xfs_btree_get_block(cur, level, &bp); if (cur->bc_ops->ptr_len == XFS_BTREE_LONG_PTR_LEN) { if (block->bb_u.l.bb_owner == cpu_to_be64(bbcoi->new_owner)) return 0;
block->bb_u.l.bb_owner = cpu_to_be64(bbcoi->new_owner);
} else { if (block->bb_u.s.bb_owner == cpu_to_be32(bbcoi->new_owner)) return 0;
block->bb_u.s.bb_owner = cpu_to_be32(bbcoi->new_owner);
}
/* * If the block is a root block hosted in an inode, we might not have a * buffer pointer here and we shouldn't attempt to log the change as the * information is already held in the inode and discarded when the root * block is formatted into the on-disk inode fork. We still change it, * though, so everything is consistent in memory.
*/ if (!bp) {
ASSERT(cur->bc_ops->type == XFS_BTREE_TYPE_INODE);
ASSERT(level == cur->bc_nlevels - 1); return 0;
}
if (cur->bc_tp) { if (!xfs_trans_ordered_buf(cur->bc_tp, bp)) {
xfs_btree_log_block(cur, bp, XFS_BB_OWNER); return -EAGAIN;
}
} else {
xfs_buf_delwri_queue(bp, bbcoi->buffer_list);
}
if (!xfs_has_crc(mp)) return __this_address; if (!uuid_equal(&block->bb_u.s.bb_uuid, &mp->m_sb.sb_meta_uuid)) return __this_address; if (block->bb_u.s.bb_blkno != cpu_to_be64(xfs_buf_daddr(bp))) return __this_address; if (pag && be32_to_cpu(block->bb_u.s.bb_owner) != pag_agno(pag)) return __this_address; return NULL;
}
/** * xfs_btree_agblock_verify() -- verify a short-format btree block * * @bp: buffer containing the btree block * @max_recs: maximum records allowed in this btree node
*/
xfs_failaddr_t
xfs_btree_agblock_verify( struct xfs_buf *bp, unsignedint max_recs)
{ struct xfs_mount *mp = bp->b_mount; struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
xfs_agblock_t agbno;
xfs_failaddr_t fa;
ASSERT(!xfs_buftarg_is_mem(bp->b_target));
/* numrecs verification */ if (be16_to_cpu(block->bb_numrecs) > max_recs) return __this_address;
/* sibling pointer verification */
agbno = xfs_daddr_to_agbno(mp, xfs_buf_daddr(bp));
fa = xfs_btree_check_agblock_siblings(bp->b_pag, agbno,
block->bb_u.s.bb_leftsib); if (!fa)
fa = xfs_btree_check_agblock_siblings(bp->b_pag, agbno,
block->bb_u.s.bb_rightsib); return fa;
}
/* * For the given limits on leaf and keyptr records per block, calculate the * height of the tree needed to index the number of leaf records.
*/ unsignedint
xfs_btree_compute_maxlevels( constunsignedint *limits, unsignedlonglong records)
{ unsignedlonglong level_blocks = howmany_64(records, limits[0]); unsignedint height = 1;
/* * For the given limits on leaf and keyptr records per block, calculate the * number of blocks needed to index the given number of leaf records.
*/ unsignedlonglong
xfs_btree_calc_size( constunsignedint *limits, unsignedlonglong records)
{ unsignedlonglong level_blocks = howmany_64(records, limits[0]); unsignedlonglong blocks = level_blocks;
/* * Given a number of available blocks for the btree to consume with records and * pointers, calculate the height of the tree needed to index all the records * that space can hold based on the number of pointers each interior node * holds. * * We start by assuming a single level tree consumes a single block, then track * the number of blocks each node level consumes until we no longer have space * to store the next node level. At this point, we are indexing all the leaf * blocks in the space, and there's no more free space to split the tree any * further. That's our maximum btree height.
*/ unsignedint
xfs_btree_space_to_height( constunsignedint *limits, unsignedlonglong leaf_blocks)
{ /* * The root btree block can have fewer than minrecs pointers in it * because the tree might not be big enough to require that amount of * fanout. Hence it has a minimum size of 2 pointers, not limits[1].
*/ unsignedlonglong node_blocks = 2; unsignedlonglong blocks_left = leaf_blocks - 1; unsignedint height = 1;
/* * Query a regular btree for all records overlapping a given interval. * Start with a LE lookup of the key of low_rec and return all records * until we find a record with a key greater than the key of high_rec.
*/ STATICint
xfs_btree_simple_query_range( struct xfs_btree_cur *cur, constunion xfs_btree_key *low_key, constunion xfs_btree_key *high_key,
xfs_btree_query_range_fn fn, void *priv)
{ union xfs_btree_rec *recp; union xfs_btree_key rec_key; int stat; bool firstrec = true; int error;
/* * Find the leftmost record. The btree cursor must be set * to the low record used to generate low_key.
*/
stat = 0;
error = xfs_btree_lookup(cur, XFS_LOOKUP_LE, &stat); if (error) goto out;
/* Nothing? See if there's anything to the right. */ if (!stat) {
error = xfs_btree_increment(cur, 0, &stat); if (error) goto out;
}
while (stat) { /* Find the record. */
error = xfs_btree_get_rec(cur, &recp, &stat); if (error || !stat) break;
/* Skip if low_key > high_key(rec). */ if (firstrec) {
cur->bc_ops->init_high_key_from_rec(&rec_key, recp);
firstrec = false; if (xfs_btree_keycmp_gt(cur, low_key, &rec_key)) goto advloop;
}
/* Stop if low_key(rec) > high_key. */
cur->bc_ops->init_key_from_rec(&rec_key, recp); if (xfs_btree_keycmp_gt(cur, &rec_key, high_key)) break;
advloop: /* Move on to the next record. */
error = xfs_btree_increment(cur, 0, &stat); if (error) break;
}
out: return error;
}
/* * Query an overlapped interval btree for all records overlapping a given * interval. This function roughly follows the algorithm given in * "Interval Trees" of _Introduction to Algorithms_, which is section * 14.3 in the 2nd and 3rd editions. * * First, generate keys for the low and high records passed in. * * For any leaf node, generate the high and low keys for the record. * If the record keys overlap with the query low/high keys, pass the * record to the function iterator. * * For any internal node, compare the low and high keys of each * pointer against the query low/high keys. If there's an overlap, * follow the pointer. * * As an optimization, we stop scanning a block when we find a low key * that is greater than the query's high key.
*/ STATICint
xfs_btree_overlapped_query_range( struct xfs_btree_cur *cur, constunion xfs_btree_key *low_key, constunion xfs_btree_key *high_key,
xfs_btree_query_range_fn fn, void *priv)
{ union xfs_btree_ptr ptr; union xfs_btree_ptr *pp; union xfs_btree_key rec_key; union xfs_btree_key rec_hkey; union xfs_btree_key *lkp; union xfs_btree_key *hkp; union xfs_btree_rec *recp; struct xfs_btree_block *block; int level; struct xfs_buf *bp; int i; int error;
/* Load the root of the btree. */
level = cur->bc_nlevels - 1;
xfs_btree_init_ptr_from_cur(cur, &ptr);
error = xfs_btree_lookup_get_block(cur, level, &ptr, &block); if (error) return error;
xfs_btree_get_block(cur, level, &bp);
trace_xfs_btree_overlapped_query_range(cur, level, bp); #ifdef DEBUG
error = xfs_btree_check_block(cur, block, level, bp); if (error) goto out; #endif
cur->bc_levels[level].ptr = 1;
while (level < cur->bc_nlevels) {
block = xfs_btree_get_block(cur, level, &bp);
/* End of node, pop back towards the root. */ if (cur->bc_levels[level].ptr >
be16_to_cpu(block->bb_numrecs)) {
pop_up: if (level < cur->bc_nlevels - 1)
cur->bc_levels[level + 1].ptr++;
level++; continue;
}
if (level == 0) { /* Handle a leaf node. */
recp = xfs_btree_rec_addr(cur, cur->bc_levels[0].ptr,
block);
/* * If (query's high key < record's low key), then there * are no more interesting records in this block. Pop * up to the leaf level to find more record blocks. * * If (record's high key >= query's low key) and * (query's high key >= record's low key), then * this record overlaps the query range; callback.
*/ if (xfs_btree_keycmp_lt(cur, high_key, &rec_key)) goto pop_up; if (xfs_btree_keycmp_ge(cur, &rec_hkey, low_key)) {
error = fn(cur, recp, priv); if (error) break;
}
cur->bc_levels[level].ptr++; continue;
}
/* * If (query's high key < pointer's low key), then there are no * more interesting keys in this block. Pop up one leaf level * to continue looking for records. * * If (pointer's high key >= query's low key) and * (query's high key >= pointer's low key), then * this record overlaps the query range; follow pointer.
*/ if (xfs_btree_keycmp_lt(cur, high_key, lkp)) goto pop_up; if (xfs_btree_keycmp_ge(cur, hkp, low_key)) {
level--;
error = xfs_btree_lookup_get_block(cur, level, pp,
&block); if (error) goto out;
xfs_btree_get_block(cur, level, &bp);
trace_xfs_btree_overlapped_query_range(cur, level, bp); #ifdef DEBUG
error = xfs_btree_check_block(cur, block, level, bp); if (error) goto out; #endif
cur->bc_levels[level].ptr = 1; continue;
}
cur->bc_levels[level].ptr++;
}
out: /* * If we don't end this function with the cursor pointing at a record * block, a subsequent non-error cursor deletion will not release * node-level buffers, causing a buffer leak. This is quite possible * with a zero-results range query, so release the buffers if we * failed to return any results.
*/ if (cur->bc_levels[0].bp == NULL) { for (i = 0; i < cur->bc_nlevels; i++) { if (cur->bc_levels[i].bp) {
xfs_trans_brelse(cur->bc_tp,
cur->bc_levels[i].bp);
cur->bc_levels[i].bp = NULL;
cur->bc_levels[i].ptr = 0;
cur->bc_levels[i].ra = 0;
}
}
}
return error;
}
staticinlinevoid
xfs_btree_key_from_irec( struct xfs_btree_cur *cur, union xfs_btree_key *key, constunion xfs_btree_irec *irec)
{ union xfs_btree_rec rec;
/* * Query a btree for all records overlapping a given interval of keys. The * supplied function will be called with each record found; return one of the * XFS_BTREE_QUERY_RANGE_{CONTINUE,ABORT} values or the usual negative error * code. This function returns -ECANCELED, zero, or a negative error code.
*/ int
xfs_btree_query_range( struct xfs_btree_cur *cur, constunion xfs_btree_irec *low_rec, constunion xfs_btree_irec *high_rec,
xfs_btree_query_range_fn fn, void *priv)
{ union xfs_btree_key low_key; union xfs_btree_key high_key;
/* Find the keys of both ends of the interval. */
xfs_btree_key_from_irec(cur, &high_key, high_rec);
xfs_btree_key_from_irec(cur, &low_key, low_rec);
/* Enforce low key <= high key. */ if (!xfs_btree_keycmp_le(cur, &low_key, &high_key)) return -EINVAL;
/* Query a btree for all records. */ int
xfs_btree_query_all( struct xfs_btree_cur *cur,
xfs_btree_query_range_fn fn, void *priv)
{ union xfs_btree_key low_key; union xfs_btree_key high_key;
/* Count the blocks in a btree and return the result in *blocks. */ int
xfs_btree_count_blocks( struct xfs_btree_cur *cur,
xfs_filblks_t *blocks)
{
*blocks = 0; return xfs_btree_visit_blocks(cur, xfs_btree_count_blocks_helper,
XFS_BTREE_VISIT_ALL, blocks);
}
/* Compare two btree pointers. */ int
xfs_btree_cmp_two_ptrs( struct xfs_btree_cur *cur, constunion xfs_btree_ptr *a, constunion xfs_btree_ptr *b)
{ if (cur->bc_ops->ptr_len == XFS_BTREE_LONG_PTR_LEN) return cmp_int(be64_to_cpu(a->l), be64_to_cpu(b->l)); return cmp_int(be32_to_cpu(a->s), be32_to_cpu(b->s));
}
struct xfs_btree_has_records { /* Keys for the start and end of the range we want to know about. */ union xfs_btree_key start_key; union xfs_btree_key end_key;
/* Mask for key comparisons, if desired. */ constunion xfs_btree_key *key_mask;
/* Highest record key we've seen so far. */ union xfs_btree_key high_key;
if (info->outcome == XBTREE_RECPACKING_EMPTY) {
info->outcome = XBTREE_RECPACKING_SPARSE;
/* * If the first record we find does not overlap the start key, * then there is a hole at the start of the search range. * Classify this as sparse and stop immediately.
*/ if (xfs_btree_masked_keycmp_lt(cur, &info->start_key, &rec_key,
info->key_mask)) return -ECANCELED;
} else { /* * If a subsequent record does not overlap with the any record * we've seen so far, there is a hole in the middle of the * search range. Classify this as sparse and stop. * If the keys overlap and this btree does not allow overlap, * signal corruption.
*/
key_contig = cur->bc_ops->keys_contiguous(cur, &info->high_key,
&rec_key, info->key_mask); if (key_contig == XBTREE_KEY_OVERLAP &&
!(cur->bc_ops->geom_flags & XFS_BTGEO_OVERLAPPING)) return -EFSCORRUPTED; if (key_contig == XBTREE_KEY_GAP) return -ECANCELED;
}
/* * If high_key(rec) is larger than any other high key we've seen, * remember it for later.
*/
cur->bc_ops->init_high_key_from_rec(&rec_high_key, rec); if (xfs_btree_masked_keycmp_gt(cur, &rec_high_key, &info->high_key,
info->key_mask))
info->high_key = rec_high_key; /* struct copy */
return 0;
}
/* * Scan part of the keyspace of a btree and tell us if that keyspace does not * map to any records; is fully mapped to records; or is partially mapped to * records. This is the btree record equivalent to determining if a file is * sparse. * * For most btree types, the record scan should use all available btree key * fields to compare the keys encountered. These callers should pass NULL for * @mask. However, some callers (e.g. scanning physical space in the rmapbt) * want to ignore some part of the btree record keyspace when performing the * comparison. These callers should pass in a union xfs_btree_key object with * the fields that *should* be a part of the comparison set to any nonzero * value, and the rest zeroed.
*/ int
xfs_btree_has_records( struct xfs_btree_cur *cur, constunion xfs_btree_irec *low, constunion xfs_btree_irec *high, constunion xfs_btree_key *mask, enum xbtree_recpacking *outcome)
{ struct xfs_btree_has_records info = {
.outcome = XBTREE_RECPACKING_EMPTY,
.key_mask = mask,
}; int error;
/* Not all btrees support this operation. */ if (!cur->bc_ops->keys_contiguous) {
ASSERT(0); return -EOPNOTSUPP;
}
error = xfs_btree_query_range(cur, low, high,
xfs_btree_has_records_helper, &info); if (error == -ECANCELED) goto out; if (error) return error;
if (info.outcome == XBTREE_RECPACKING_EMPTY) goto out;
/* * If the largest high_key(rec) we saw during the walk is greater than * the end of the search range, classify this as full. Otherwise, * there is a hole at the end of the search range.
*/ if (xfs_btree_masked_keycmp_ge(cur, &info.high_key, &info.end_key,
mask))
info.outcome = XBTREE_RECPACKING_FULL;
out:
*outcome = info.outcome; return 0;
}
/* Are there more records in this btree? */ bool
xfs_btree_has_more_records( struct xfs_btree_cur *cur)
{ struct xfs_btree_block *block; struct xfs_buf *bp;
block = xfs_btree_get_block(cur, 0, &bp);
/* There are still records in this block. */ if (cur->bc_levels[0].ptr < xfs_btree_get_numrecs(block)) returntrue;
/* There are more record blocks. */ if (cur->bc_ops->ptr_len == XFS_BTREE_LONG_PTR_LEN) return block->bb_u.l.bb_rightsib != cpu_to_be64(NULLFSBLOCK); else return block->bb_u.s.bb_rightsib != cpu_to_be32(NULLAGBLOCK);
}
/* Set up all the btree cursor caches. */ int __init
xfs_btree_init_cur_caches(void)
{ int error;
error = xfs_allocbt_init_cur_cache(); if (error) return error;
error = xfs_inobt_init_cur_cache(); if (error) goto err;
error = xfs_bmbt_init_cur_cache(); if (error) goto err;
error = xfs_rmapbt_init_cur_cache(); if (error) goto err;
error = xfs_refcountbt_init_cur_cache(); if (error) goto err;
error = xfs_rtrmapbt_init_cur_cache(); if (error) goto err;
error = xfs_rtrefcountbt_init_cur_cache(); if (error) goto err;
Die Informationen auf dieser Webseite wurden
nach bestem Wissen sorgfältig zusammengestellt. Es wird jedoch weder Vollständigkeit, noch Richtigkeit,
noch Qualität der bereit gestellten Informationen zugesichert.
Bemerkung:
Die farbliche Syntaxdarstellung und die Messung sind noch experimentell.
