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linux/fs/xfs/xfs_alloc_btree.c
David Chinner 92821e2ba4 [XFS] Lazy Superblock Counters 
When we have a couple of hundred transactions on the fly at once, they all
typically modify the on disk superblock in some way.
create/unclink/mkdir/rmdir modify inode counts, allocation/freeing modify
free block counts.

When these counts are modified in a transaction, they must eventually lock
the superblock buffer and apply the mods. The buffer then remains locked
until the transaction is committed into the incore log buffer. The result
of this is that with enough transactions on the fly the incore superblock
buffer becomes a bottleneck.

The result of contention on the incore superblock buffer is that
transaction rates fall - the more pressure that is put on the superblock
buffer, the slower things go.

The key to removing the contention is to not require the superblock fields
in question to be locked. We do that by not marking the superblock dirty
in the transaction. IOWs, we modify the incore superblock but do not
modify the cached superblock buffer. In short, we do not log superblock
modifications to critical fields in the superblock on every transaction.
In fact we only do it just before we write the superblock to disk every
sync period or just before unmount.

This creates an interesting problem - if we don't log or write out the
fields in every transaction, then how do the values get recovered after a
crash? the answer is simple - we keep enough duplicate, logged information
in other structures that we can reconstruct the correct count after log
recovery has been performed.

It is the AGF and AGI structures that contain the duplicate information;
after recovery, we walk every AGI and AGF and sum their individual
counters to get the correct value, and we do a transaction into the log to
correct them. An optimisation of this is that if we have a clean unmount
record, we know the value in the superblock is correct, so we can avoid
the summation walk under normal conditions and so mount/recovery times do
not change under normal operation.

One wrinkle that was discovered during development was that the blocks
used in the freespace btrees are never accounted for in the AGF counters.
This was once a valid optimisation to make; when the filesystem is full,
the free space btrees are empty and consume no space. Hence when it
matters, the "accounting" is correct. But that means the when we do the
AGF summations, we would not have a correct count and xfs_check would
complain. Hence a new counter was added to track the number of blocks used
by the free space btrees. This is an *on-disk format change*.

As a result of this, lazy superblock counters are a mkfs option and at the
moment on linux there is no way to convert an old filesystem. This is
possible - xfs_db can be used to twiddle the right bits and then
xfs_repair will do the format conversion for you. Similarly, you can
convert backwards as well. At some point we'll add functionality to
xfs_admin to do the bit twiddling easily....

SGI-PV: 964999
SGI-Modid: xfs-linux-melb:xfs-kern:28652a

Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Tim Shimmin <tes@sgi.com>
2007-07-14 15:28:50 +10:00

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/*
* Copyright (c) 2000-2001,2005 Silicon Graphics, Inc.
* All Rights Reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it would be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_types.h"
#include "xfs_bit.h"
#include "xfs_log.h"
#include "xfs_inum.h"
#include "xfs_trans.h"
#include "xfs_sb.h"
#include "xfs_ag.h"
#include "xfs_dir2.h"
#include "xfs_dmapi.h"
#include "xfs_mount.h"
#include "xfs_bmap_btree.h"
#include "xfs_alloc_btree.h"
#include "xfs_ialloc_btree.h"
#include "xfs_dir2_sf.h"
#include "xfs_attr_sf.h"
#include "xfs_dinode.h"
#include "xfs_inode.h"
#include "xfs_btree.h"
#include "xfs_ialloc.h"
#include "xfs_alloc.h"
#include "xfs_error.h"
/*
* Prototypes for internal functions.
*/
STATIC void xfs_alloc_log_block(xfs_trans_t *, xfs_buf_t *, int);
STATIC void xfs_alloc_log_keys(xfs_btree_cur_t *, xfs_buf_t *, int, int);
STATIC void xfs_alloc_log_ptrs(xfs_btree_cur_t *, xfs_buf_t *, int, int);
STATIC void xfs_alloc_log_recs(xfs_btree_cur_t *, xfs_buf_t *, int, int);
STATIC int xfs_alloc_lshift(xfs_btree_cur_t *, int, int *);
STATIC int xfs_alloc_newroot(xfs_btree_cur_t *, int *);
STATIC int xfs_alloc_rshift(xfs_btree_cur_t *, int, int *);
STATIC int xfs_alloc_split(xfs_btree_cur_t *, int, xfs_agblock_t *,
xfs_alloc_key_t *, xfs_btree_cur_t **, int *);
STATIC int xfs_alloc_updkey(xfs_btree_cur_t *, xfs_alloc_key_t *, int);
/*
* Internal functions.
*/
/*
* Single level of the xfs_alloc_delete 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.
*/
STATIC int /* error */
xfs_alloc_delrec(
xfs_btree_cur_t *cur, /* btree cursor */
int level, /* level removing record from */
int *stat) /* fail/done/go-on */
{
xfs_agf_t *agf; /* allocation group freelist header */
xfs_alloc_block_t *block; /* btree block record/key lives in */
xfs_agblock_t bno; /* btree block number */
xfs_buf_t *bp; /* buffer for block */
int error; /* error return value */
int i; /* loop index */
xfs_alloc_key_t key; /* kp points here if block is level 0 */
xfs_agblock_t lbno; /* left block's block number */
xfs_buf_t *lbp; /* left block's buffer pointer */
xfs_alloc_block_t *left; /* left btree block */
xfs_alloc_key_t *lkp=NULL; /* left block key pointer */
xfs_alloc_ptr_t *lpp=NULL; /* left block address pointer */
int lrecs=0; /* number of records in left block */
xfs_alloc_rec_t *lrp; /* left block record pointer */
xfs_mount_t *mp; /* mount structure */
int ptr; /* index in btree block for this rec */
xfs_agblock_t rbno; /* right block's block number */
xfs_buf_t *rbp; /* right block's buffer pointer */
xfs_alloc_block_t *right; /* right btree block */
xfs_alloc_key_t *rkp; /* right block key pointer */
xfs_alloc_ptr_t *rpp; /* right block address pointer */
int rrecs=0; /* number of records in right block */
int numrecs;
xfs_alloc_rec_t *rrp; /* right block record pointer */
xfs_btree_cur_t *tcur; /* temporary btree cursor */
/*
* Get the index of the entry being deleted, check for nothing there.
*/
ptr = cur->bc_ptrs[level];
if (ptr == 0) {
*stat = 0;
return 0;
}
/*
* Get the buffer & block containing the record or key/ptr.
*/
bp = cur->bc_bufs[level];
block = XFS_BUF_TO_ALLOC_BLOCK(bp);
#ifdef DEBUG
if ((error = xfs_btree_check_sblock(cur, block, level, bp)))
return error;
#endif
/*
* Fail if we're off the end of the block.
*/
numrecs = be16_to_cpu(block->bb_numrecs);
if (ptr > numrecs) {
*stat = 0;
return 0;
}
XFS_STATS_INC(xs_abt_delrec);
/*
* It's a nonleaf. Excise the key and ptr being deleted, by
* sliding the entries past them down one.
* Log the changed areas of the block.
*/
if (level > 0) {
lkp = XFS_ALLOC_KEY_ADDR(block, 1, cur);
lpp = XFS_ALLOC_PTR_ADDR(block, 1, cur);
#ifdef DEBUG
for (i = ptr; i < numrecs; i++) {
if ((error = xfs_btree_check_sptr(cur, be32_to_cpu(lpp[i]), level)))
return error;
}
#endif
if (ptr < numrecs) {
memmove(&lkp[ptr - 1], &lkp[ptr],
(numrecs - ptr) * sizeof(*lkp));
memmove(&lpp[ptr - 1], &lpp[ptr],
(numrecs - ptr) * sizeof(*lpp));
xfs_alloc_log_ptrs(cur, bp, ptr, numrecs - 1);
xfs_alloc_log_keys(cur, bp, ptr, numrecs - 1);
}
}
/*
* It's a leaf. Excise the record being deleted, by sliding the
* entries past it down one. Log the changed areas of the block.
*/
else {
lrp = XFS_ALLOC_REC_ADDR(block, 1, cur);
if (ptr < numrecs) {
memmove(&lrp[ptr - 1], &lrp[ptr],
(numrecs - ptr) * sizeof(*lrp));
xfs_alloc_log_recs(cur, bp, ptr, numrecs - 1);
}
/*
* If it's the first record in the block, we'll need a key
* structure to pass up to the next level (updkey).
*/
if (ptr == 1) {
key.ar_startblock = lrp->ar_startblock;
key.ar_blockcount = lrp->ar_blockcount;
lkp = &key;
}
}
/*
* Decrement and log the number of entries in the block.
*/
numrecs--;
block->bb_numrecs = cpu_to_be16(numrecs);
xfs_alloc_log_block(cur->bc_tp, bp, XFS_BB_NUMRECS);
/*
* See if the longest free extent in the allocation group was
* changed by this operation. True if it's the by-size btree, and
* this is the leaf level, and there is no right sibling block,
* and this was the last record.
*/
agf = XFS_BUF_TO_AGF(cur->bc_private.a.agbp);
mp = cur->bc_mp;
if (level == 0 &&
cur->bc_btnum == XFS_BTNUM_CNT &&
be32_to_cpu(block->bb_rightsib) == NULLAGBLOCK &&
ptr > numrecs) {
ASSERT(ptr == numrecs + 1);
/*
* There are still records in the block. Grab the size
* from the last one.
*/
if (numrecs) {
rrp = XFS_ALLOC_REC_ADDR(block, numrecs, cur);
agf->agf_longest = rrp->ar_blockcount;
}
/*
* No free extents left.
*/
else
agf->agf_longest = 0;
mp->m_perag[be32_to_cpu(agf->agf_seqno)].pagf_longest =
be32_to_cpu(agf->agf_longest);
xfs_alloc_log_agf(cur->bc_tp, cur->bc_private.a.agbp,
XFS_AGF_LONGEST);
}
/*
* Is this the root level? If so, we're almost done.
*/
if (level == cur->bc_nlevels - 1) {
/*
* 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 (numrecs == 1 && level > 0) {
/*
* lpp is still set to the first pointer in the block.
* Make it the new root of the btree.
*/
bno = be32_to_cpu(agf->agf_roots[cur->bc_btnum]);
agf->agf_roots[cur->bc_btnum] = *lpp;
be32_add(&agf->agf_levels[cur->bc_btnum], -1);
mp->m_perag[be32_to_cpu(agf->agf_seqno)].pagf_levels[cur->bc_btnum]--;
/*
* Put this buffer/block on the ag's freelist.
*/
error = xfs_alloc_put_freelist(cur->bc_tp,
cur->bc_private.a.agbp, NULL, bno, 1);
if (error)
return error;
/*
* Since blocks move to the free list without the
* coordination used in xfs_bmap_finish, we can't allow
* block to be available for reallocation and
* non-transaction writing (user data) until we know
* that the transaction that moved it to the free list
* is permanently on disk. We track the blocks by
* declaring these blocks as "busy"; the busy list is
* maintained on a per-ag basis and each transaction
* records which entries should be removed when the
* iclog commits to disk. If a busy block is
* allocated, the iclog is pushed up to the LSN
* that freed the block.
*/
xfs_alloc_mark_busy(cur->bc_tp,
be32_to_cpu(agf->agf_seqno), bno, 1);
xfs_trans_agbtree_delta(cur->bc_tp, -1);
xfs_alloc_log_agf(cur->bc_tp, cur->bc_private.a.agbp,
XFS_AGF_ROOTS | XFS_AGF_LEVELS);
/*
* Update the cursor so there's one fewer level.
*/
xfs_btree_setbuf(cur, level, NULL);
cur->bc_nlevels--;
} else if (level > 0 &&
(error = xfs_alloc_decrement(cur, level, &i)))
return error;
*stat = 1;
return 0;
}
/*
* If we deleted the leftmost entry in the block, update the
* key values above us in the tree.
*/
if (ptr == 1 && (error = xfs_alloc_updkey(cur, lkp, level + 1)))
return error;
/*
* If the number of records remaining in the block is at least
* the minimum, we're done.
*/
if (numrecs >= XFS_ALLOC_BLOCK_MINRECS(level, cur)) {
if (level > 0 && (error = xfs_alloc_decrement(cur, level, &i)))
return error;
*stat = 1;
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.
*/
rbno = be32_to_cpu(block->bb_rightsib);
lbno = be32_to_cpu(block->bb_leftsib);
bno = NULLAGBLOCK;
ASSERT(rbno != NULLAGBLOCK || lbno != NULLAGBLOCK);
/*
* Duplicate the cursor so our btree manipulations here won't
* disrupt the next level up.
*/
if ((error = xfs_btree_dup_cursor(cur, &tcur)))
return error;
/*
* If there's a right sibling, see if it's ok to shift an entry
* out of it.
*/
if (rbno != NULLAGBLOCK) {
/*
* 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);
XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
if ((error = xfs_alloc_increment(tcur, level, &i)))
goto error0;
XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
i = xfs_btree_lastrec(tcur, level);
XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
/*
* Grab a pointer to the block.
*/
rbp = tcur->bc_bufs[level];
right = XFS_BUF_TO_ALLOC_BLOCK(rbp);
#ifdef DEBUG
if ((error = xfs_btree_check_sblock(cur, right, level, rbp)))
goto error0;
#endif
/*
* Grab the current block number, for future use.
*/
bno = be32_to_cpu(right->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 (be16_to_cpu(right->bb_numrecs) - 1 >=
XFS_ALLOC_BLOCK_MINRECS(level, cur)) {
if ((error = xfs_alloc_lshift(tcur, level, &i)))
goto error0;
if (i) {
ASSERT(be16_to_cpu(block->bb_numrecs) >=
XFS_ALLOC_BLOCK_MINRECS(level, cur));
xfs_btree_del_cursor(tcur,
XFS_BTREE_NOERROR);
if (level > 0 &&
(error = xfs_alloc_decrement(cur, level,
&i)))
return error;
*stat = 1;
return 0;
}
}
/*
* 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 = be16_to_cpu(right->bb_numrecs);
if (lbno != NULLAGBLOCK) {
i = xfs_btree_firstrec(tcur, level);
XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
if ((error = xfs_alloc_decrement(tcur, level, &i)))
goto error0;
XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
}
}
/*
* If there's a left sibling, see if it's ok to shift an entry
* out of it.
*/
if (lbno != NULLAGBLOCK) {
/*
* Move the temp cursor to the first entry in the
* previous block.
*/
i = xfs_btree_firstrec(tcur, level);
XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
if ((error = xfs_alloc_decrement(tcur, level, &i)))
goto error0;
XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
xfs_btree_firstrec(tcur, level);
/*
* Grab a pointer to the block.
*/
lbp = tcur->bc_bufs[level];
left = XFS_BUF_TO_ALLOC_BLOCK(lbp);
#ifdef DEBUG
if ((error = xfs_btree_check_sblock(cur, left, level, lbp)))
goto error0;
#endif
/*
* Grab the current block number, for future use.
*/
bno = be32_to_cpu(left->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 (be16_to_cpu(left->bb_numrecs) - 1 >=
XFS_ALLOC_BLOCK_MINRECS(level, cur)) {
if ((error = xfs_alloc_rshift(tcur, level, &i)))
goto error0;
if (i) {
ASSERT(be16_to_cpu(block->bb_numrecs) >=
XFS_ALLOC_BLOCK_MINRECS(level, cur));
xfs_btree_del_cursor(tcur,
XFS_BTREE_NOERROR);
if (level == 0)
cur->bc_ptrs[0]++;
*stat = 1;
return 0;
}
}
/*
* Otherwise, grab the number of records in right for
* future reference.
*/
lrecs = be16_to_cpu(left->bb_numrecs);
}
/*
* Delete the temp cursor, we're done with it.
*/
xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
/*
* If here, we need to do a join to keep the tree balanced.
*/
ASSERT(bno != NULLAGBLOCK);
/*
* See if we can join with the left neighbor block.
*/
if (lbno != NULLAGBLOCK &&
lrecs + numrecs <= XFS_ALLOC_BLOCK_MAXRECS(level, cur)) {
/*
* Set "right" to be the starting block,
* "left" to be the left neighbor.
*/
rbno = bno;
right = block;
rrecs = be16_to_cpu(right->bb_numrecs);
rbp = bp;
if ((error = xfs_btree_read_bufs(mp, cur->bc_tp,
cur->bc_private.a.agno, lbno, 0, &lbp,
XFS_ALLOC_BTREE_REF)))
return error;
left = XFS_BUF_TO_ALLOC_BLOCK(lbp);
lrecs = be16_to_cpu(left->bb_numrecs);
if ((error = xfs_btree_check_sblock(cur, left, level, lbp)))
return error;
}
/*
* If that won't work, see if we can join with the right neighbor block.
*/
else if (rbno != NULLAGBLOCK &&
rrecs + numrecs <= XFS_ALLOC_BLOCK_MAXRECS(level, cur)) {
/*
* Set "left" to be the starting block,
* "right" to be the right neighbor.
*/
lbno = bno;
left = block;
lrecs = be16_to_cpu(left->bb_numrecs);
lbp = bp;
if ((error = xfs_btree_read_bufs(mp, cur->bc_tp,
cur->bc_private.a.agno, rbno, 0, &rbp,
XFS_ALLOC_BTREE_REF)))
return error;
right = XFS_BUF_TO_ALLOC_BLOCK(rbp);
rrecs = be16_to_cpu(right->bb_numrecs);
if ((error = xfs_btree_check_sblock(cur, right, level, rbp)))
return error;
}
/*
* Otherwise, we can't fix the imbalance.
* Just return. This is probably a logic error, but it's not fatal.
*/
else {
if (level > 0 && (error = xfs_alloc_decrement(cur, level, &i)))
return error;
*stat = 1;
return 0;
}
/*
* We're now going to join "left" and "right" by moving all the stuff
* in "right" to "left" and deleting "right".
*/
if (level > 0) {
/*
* It's a non-leaf. Move keys and pointers.
*/
lkp = XFS_ALLOC_KEY_ADDR(left, lrecs + 1, cur);
lpp = XFS_ALLOC_PTR_ADDR(left, lrecs + 1, cur);
rkp = XFS_ALLOC_KEY_ADDR(right, 1, cur);
rpp = XFS_ALLOC_PTR_ADDR(right, 1, cur);
#ifdef DEBUG
for (i = 0; i < rrecs; i++) {
if ((error = xfs_btree_check_sptr(cur, be32_to_cpu(rpp[i]), level)))
return error;
}
#endif
memcpy(lkp, rkp, rrecs * sizeof(*lkp));
memcpy(lpp, rpp, rrecs * sizeof(*lpp));
xfs_alloc_log_keys(cur, lbp, lrecs + 1, lrecs + rrecs);
xfs_alloc_log_ptrs(cur, lbp, lrecs + 1, lrecs + rrecs);
} else {
/*
* It's a leaf. Move records.
*/
lrp = XFS_ALLOC_REC_ADDR(left, lrecs + 1, cur);
rrp = XFS_ALLOC_REC_ADDR(right, 1, cur);
memcpy(lrp, rrp, rrecs * sizeof(*lrp));
xfs_alloc_log_recs(cur, lbp, lrecs + 1, lrecs + rrecs);
}
/*
* 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) {
xfs_btree_setbuf(cur, level, lbp);
cur->bc_ptrs[level] += lrecs;
}
/*
* If we joined with the right neighbor and there's a level above
* us, increment the cursor at that level.
*/
else if (level + 1 < cur->bc_nlevels &&
(error = xfs_alloc_increment(cur, level + 1, &i)))
return error;
/*
* Fix up the number of records in the surviving block.
*/
lrecs += rrecs;
left->bb_numrecs = cpu_to_be16(lrecs);
/*
* Fix up the right block pointer in the surviving block, and log it.
*/
left->bb_rightsib = right->bb_rightsib;
xfs_alloc_log_block(cur->bc_tp, lbp, XFS_BB_NUMRECS | XFS_BB_RIGHTSIB);
/*
* If there is a right sibling now, make it point to the
* remaining block.
*/
if (be32_to_cpu(left->bb_rightsib) != NULLAGBLOCK) {
xfs_alloc_block_t *rrblock;
xfs_buf_t *rrbp;
if ((error = xfs_btree_read_bufs(mp, cur->bc_tp,
cur->bc_private.a.agno, be32_to_cpu(left->bb_rightsib), 0,
&rrbp, XFS_ALLOC_BTREE_REF)))
return error;
rrblock = XFS_BUF_TO_ALLOC_BLOCK(rrbp);
if ((error = xfs_btree_check_sblock(cur, rrblock, level, rrbp)))
return error;
rrblock->bb_leftsib = cpu_to_be32(lbno);
xfs_alloc_log_block(cur->bc_tp, rrbp, XFS_BB_LEFTSIB);
}
/*
* Free the deleting block by putting it on the freelist.
*/
error = xfs_alloc_put_freelist(cur->bc_tp,
cur->bc_private.a.agbp, NULL, rbno, 1);
if (error)
return error;
/*
* Since blocks move to the free list without the coordination
* used in xfs_bmap_finish, we can't allow block to be available
* for reallocation and non-transaction writing (user data)
* until we know that the transaction that moved it to the free
* list is permanently on disk. We track the blocks by declaring
* these blocks as "busy"; the busy list is maintained on a
* per-ag basis and each transaction records which entries
* should be removed when the iclog commits to disk. If a
* busy block is allocated, the iclog is pushed up to the
* LSN that freed the block.
*/
xfs_alloc_mark_busy(cur->bc_tp, be32_to_cpu(agf->agf_seqno), bno, 1);
xfs_trans_agbtree_delta(cur->bc_tp, -1);
/*
* Adjust the current level's cursor so that we're left referring
* to the right node, after we're done.
* If this leaves the ptr value 0 our caller will fix it up.
*/
if (level > 0)
cur->bc_ptrs[level]--;
/*
* Return value means the next level up has something to do.
*/
*stat = 2;
return 0;
error0:
xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR);
return error;
}
/*
* Insert one record/level. Return information to the caller
* allowing the next level up to proceed if necessary.
*/
STATIC int /* error */
xfs_alloc_insrec(
xfs_btree_cur_t *cur, /* btree cursor */
int level, /* level to insert record at */
xfs_agblock_t *bnop, /* i/o: block number inserted */
xfs_alloc_rec_t *recp, /* i/o: record data inserted */
xfs_btree_cur_t **curp, /* output: new cursor replacing cur */
int *stat) /* output: success/failure */
{
xfs_agf_t *agf; /* allocation group freelist header */
xfs_alloc_block_t *block; /* btree block record/key lives in */
xfs_buf_t *bp; /* buffer for block */
int error; /* error return value */
int i; /* loop index */
xfs_alloc_key_t key; /* key value being inserted */
xfs_alloc_key_t *kp; /* pointer to btree keys */
xfs_agblock_t nbno; /* block number of allocated block */
xfs_btree_cur_t *ncur; /* new cursor to be used at next lvl */
xfs_alloc_key_t nkey; /* new key value, from split */
xfs_alloc_rec_t nrec; /* new record value, for caller */
int numrecs;
int optr; /* old ptr value */
xfs_alloc_ptr_t *pp; /* pointer to btree addresses */
int ptr; /* index in btree block for this rec */
xfs_alloc_rec_t *rp; /* pointer to btree records */
ASSERT(be32_to_cpu(recp->ar_blockcount) > 0);
/*
* GCC doesn't understand the (arguably complex) control flow in
* this function and complains about uninitialized structure fields
* without this.
*/
memset(&nrec, 0, sizeof(nrec));
/*
* If we made it to the root level, allocate a new root block
* and we're done.
*/
if (level >= cur->bc_nlevels) {
XFS_STATS_INC(xs_abt_insrec);
if ((error = xfs_alloc_newroot(cur, &i)))
return error;
*bnop = NULLAGBLOCK;
*stat = i;
return 0;
}
/*
* Make a key out of the record data to be inserted, and save it.
*/
key.ar_startblock = recp->ar_startblock;
key.ar_blockcount = recp->ar_blockcount;
optr = ptr = cur->bc_ptrs[level];
/*
* If we're off the left edge, return failure.
*/
if (ptr == 0) {
*stat = 0;
return 0;
}
XFS_STATS_INC(xs_abt_insrec);
/*
* Get pointers to the btree buffer and block.
*/
bp = cur->bc_bufs[level];
block = XFS_BUF_TO_ALLOC_BLOCK(bp);
numrecs = be16_to_cpu(block->bb_numrecs);
#ifdef DEBUG
if ((error = xfs_btree_check_sblock(cur, block, level, bp)))
return error;
/*
* Check that the new entry is being inserted in the right place.
*/
if (ptr <= numrecs) {
if (level == 0) {
rp = XFS_ALLOC_REC_ADDR(block, ptr, cur);
xfs_btree_check_rec(cur->bc_btnum, recp, rp);
} else {
kp = XFS_ALLOC_KEY_ADDR(block, ptr, cur);
xfs_btree_check_key(cur->bc_btnum, &key, kp);
}
}
#endif
nbno = NULLAGBLOCK;
ncur = NULL;
/*
* If the block is full, we can't insert the new entry until we
* make the block un-full.
*/
if (numrecs == XFS_ALLOC_BLOCK_MAXRECS(level, cur)) {
/*
* First, try shifting an entry to the right neighbor.
*/
if ((error = xfs_alloc_rshift(cur, level, &i)))
return error;
if (i) {
/* nothing */
}
/*
* Next, try shifting an entry to the left neighbor.
*/
else {
if ((error = xfs_alloc_lshift(cur, level, &i)))
return error;
if (i)
optr = ptr = cur->bc_ptrs[level];
else {
/*
* 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.
*/
if ((error = xfs_alloc_split(cur, level, &nbno,
&nkey, &ncur, &i)))
return error;
if (i) {
bp = cur->bc_bufs[level];
block = XFS_BUF_TO_ALLOC_BLOCK(bp);
#ifdef DEBUG
if ((error =
xfs_btree_check_sblock(cur,
block, level, bp)))
return error;
#endif
ptr = cur->bc_ptrs[level];
nrec.ar_startblock = nkey.ar_startblock;
nrec.ar_blockcount = nkey.ar_blockcount;
}
/*
* Otherwise the insert fails.
*/
else {
*stat = 0;
return 0;
}
}
}
}
/*
* At this point we know there's room for our new entry in the block
* we're pointing at.
*/
numrecs = be16_to_cpu(block->bb_numrecs);
if (level > 0) {
/*
* It's a non-leaf entry. Make a hole for the new data
* in the key and ptr regions of the block.
*/
kp = XFS_ALLOC_KEY_ADDR(block, 1, cur);
pp = XFS_ALLOC_PTR_ADDR(block, 1, cur);
#ifdef DEBUG
for (i = numrecs; i >= ptr; i--) {
if ((error = xfs_btree_check_sptr(cur, be32_to_cpu(pp[i - 1]), level)))
return error;
}
#endif
memmove(&kp[ptr], &kp[ptr - 1],
(numrecs - ptr + 1) * sizeof(*kp));
memmove(&pp[ptr], &pp[ptr - 1],
(numrecs - ptr + 1) * sizeof(*pp));
#ifdef DEBUG
if ((error = xfs_btree_check_sptr(cur, *bnop, level)))
return error;
#endif
/*
* Now stuff the new data in, bump numrecs and log the new data.
*/
kp[ptr - 1] = key;
pp[ptr - 1] = cpu_to_be32(*bnop);
numrecs++;
block->bb_numrecs = cpu_to_be16(numrecs);
xfs_alloc_log_keys(cur, bp, ptr, numrecs);
xfs_alloc_log_ptrs(cur, bp, ptr, numrecs);
#ifdef DEBUG
if (ptr < numrecs)
xfs_btree_check_key(cur->bc_btnum, kp + ptr - 1,
kp + ptr);
#endif
} else {
/*
* It's a leaf entry. Make a hole for the new record.
*/
rp = XFS_ALLOC_REC_ADDR(block, 1, cur);
memmove(&rp[ptr], &rp[ptr - 1],
(numrecs - ptr + 1) * sizeof(*rp));
/*
* Now stuff the new record in, bump numrecs
* and log the new data.
*/
rp[ptr - 1] = *recp;
numrecs++;
block->bb_numrecs = cpu_to_be16(numrecs);
xfs_alloc_log_recs(cur, bp, ptr, numrecs);
#ifdef DEBUG
if (ptr < numrecs)
xfs_btree_check_rec(cur->bc_btnum, rp + ptr - 1,
rp + ptr);
#endif
}
/*
* Log the new number of records in the btree header.
*/
xfs_alloc_log_block(cur->bc_tp, bp, XFS_BB_NUMRECS);
/*
* If we inserted at the start of a block, update the parents' keys.
*/
if (optr == 1 && (error = xfs_alloc_updkey(cur, &key, level + 1)))
return error;
/*
* Look to see if the longest extent in the allocation group
* needs to be updated.
*/
agf = XFS_BUF_TO_AGF(cur->bc_private.a.agbp);
if (level == 0 &&
cur->bc_btnum == XFS_BTNUM_CNT &&
be32_to_cpu(block->bb_rightsib) == NULLAGBLOCK &&
be32_to_cpu(recp->ar_blockcount) > be32_to_cpu(agf->agf_longest)) {
/*
* If this is a leaf in the by-size btree and there
* is no right sibling block and this block is bigger
* than the previous longest block, update it.
*/
agf->agf_longest = recp->ar_blockcount;
cur->bc_mp->m_perag[be32_to_cpu(agf->agf_seqno)].pagf_longest
= be32_to_cpu(recp->ar_blockcount);
xfs_alloc_log_agf(cur->bc_tp, cur->bc_private.a.agbp,
XFS_AGF_LONGEST);
}
/*
* Return the new block number, if any.
* If there is one, give back a record value and a cursor too.
*/
*bnop = nbno;
if (nbno != NULLAGBLOCK) {
*recp = nrec;
*curp = ncur;
}
*stat = 1;
return 0;
}
/*
* Log header fields from a btree block.
*/
STATIC void
xfs_alloc_log_block(
xfs_trans_t *tp, /* transaction pointer */
xfs_buf_t *bp, /* buffer containing btree block */
int fields) /* mask of fields: XFS_BB_... */
{
int first; /* first byte offset logged */
int last; /* last byte offset logged */
static const short offsets[] = { /* table of offsets */
offsetof(xfs_alloc_block_t, bb_magic),
offsetof(xfs_alloc_block_t, bb_level),
offsetof(xfs_alloc_block_t, bb_numrecs),
offsetof(xfs_alloc_block_t, bb_leftsib),
offsetof(xfs_alloc_block_t, bb_rightsib),
sizeof(xfs_alloc_block_t)
};
xfs_btree_offsets(fields, offsets, XFS_BB_NUM_BITS, &first, &last);
xfs_trans_log_buf(tp, bp, first, last);
}
/*
* Log keys from a btree block (nonleaf).
*/
STATIC void
xfs_alloc_log_keys(
xfs_btree_cur_t *cur, /* btree cursor */
xfs_buf_t *bp, /* buffer containing btree block */
int kfirst, /* index of first key to log */
int klast) /* index of last key to log */
{
xfs_alloc_block_t *block; /* btree block to log from */
int first; /* first byte offset logged */
xfs_alloc_key_t *kp; /* key pointer in btree block */
int last; /* last byte offset logged */
block = XFS_BUF_TO_ALLOC_BLOCK(bp);
kp = XFS_ALLOC_KEY_ADDR(block, 1, cur);
first = (int)((xfs_caddr_t)&kp[kfirst - 1] - (xfs_caddr_t)block);
last = (int)(((xfs_caddr_t)&kp[klast] - 1) - (xfs_caddr_t)block);
xfs_trans_log_buf(cur->bc_tp, bp, first, last);
}
/*
* Log block pointer fields from a btree block (nonleaf).
*/
STATIC void
xfs_alloc_log_ptrs(
xfs_btree_cur_t *cur, /* btree cursor */
xfs_buf_t *bp, /* buffer containing btree block */
int pfirst, /* index of first pointer to log */
int plast) /* index of last pointer to log */
{
xfs_alloc_block_t *block; /* btree block to log from */
int first; /* first byte offset logged */
int last; /* last byte offset logged */
xfs_alloc_ptr_t *pp; /* block-pointer pointer in btree blk */
block = XFS_BUF_TO_ALLOC_BLOCK(bp);
pp = XFS_ALLOC_PTR_ADDR(block, 1, cur);
first = (int)((xfs_caddr_t)&pp[pfirst - 1] - (xfs_caddr_t)block);
last = (int)(((xfs_caddr_t)&pp[plast] - 1) - (xfs_caddr_t)block);
xfs_trans_log_buf(cur->bc_tp, bp, first, last);
}
/*
* Log records from a btree block (leaf).
*/
STATIC void
xfs_alloc_log_recs(
xfs_btree_cur_t *cur, /* btree cursor */
xfs_buf_t *bp, /* buffer containing btree block */
int rfirst, /* index of first record to log */
int rlast) /* index of last record to log */
{
xfs_alloc_block_t *block; /* btree block to log from */
int first; /* first byte offset logged */
int last; /* last byte offset logged */
xfs_alloc_rec_t *rp; /* record pointer for btree block */
block = XFS_BUF_TO_ALLOC_BLOCK(bp);
rp = XFS_ALLOC_REC_ADDR(block, 1, cur);
#ifdef DEBUG
{
xfs_agf_t *agf;
xfs_alloc_rec_t *p;
agf = XFS_BUF_TO_AGF(cur->bc_private.a.agbp);
for (p = &rp[rfirst - 1]; p <= &rp[rlast - 1]; p++)
ASSERT(be32_to_cpu(p->ar_startblock) +
be32_to_cpu(p->ar_blockcount) <=
be32_to_cpu(agf->agf_length));
}
#endif
first = (int)((xfs_caddr_t)&rp[rfirst - 1] - (xfs_caddr_t)block);
last = (int)(((xfs_caddr_t)&rp[rlast] - 1) - (xfs_caddr_t)block);
xfs_trans_log_buf(cur->bc_tp, bp, first, last);
}
/*
* Lookup the record. The cursor is made to point to it, based on dir.
* Return 0 if can't find any such record, 1 for success.
*/
STATIC int /* error */
xfs_alloc_lookup(
xfs_btree_cur_t *cur, /* btree cursor */
xfs_lookup_t dir, /* <=, ==, or >= */
int *stat) /* success/failure */
{
xfs_agblock_t agbno; /* a.g. relative btree block number */
xfs_agnumber_t agno; /* allocation group number */
xfs_alloc_block_t *block=NULL; /* current btree block */
int diff; /* difference for the current key */
int error; /* error return value */
int keyno=0; /* current key number */
int level; /* level in the btree */
xfs_mount_t *mp; /* file system mount point */
XFS_STATS_INC(xs_abt_lookup);
/*
* Get the allocation group header, and the root block number.
*/
mp = cur->bc_mp;
{
xfs_agf_t *agf; /* a.g. freespace header */
agf = XFS_BUF_TO_AGF(cur->bc_private.a.agbp);
agno = be32_to_cpu(agf->agf_seqno);
agbno = be32_to_cpu(agf->agf_roots[cur->bc_btnum]);
}
/*
* 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, diff = 1; level >= 0; level--) {
xfs_buf_t *bp; /* buffer pointer for btree block */
xfs_daddr_t d; /* disk address of btree block */
/*
* Get the disk address we're looking for.
*/
d = XFS_AGB_TO_DADDR(mp, agno, agbno);
/*
* If the old buffer at this level is for a different block,
* throw it away, otherwise just use it.
*/
bp = cur->bc_bufs[level];
if (bp && XFS_BUF_ADDR(bp) != d)
bp = NULL;
if (!bp) {
/*
* Need to get a new buffer. Read it, then
* set it in the cursor, releasing the old one.
*/
if ((error = xfs_btree_read_bufs(mp, cur->bc_tp, agno,
agbno, 0, &bp, XFS_ALLOC_BTREE_REF)))
return error;
xfs_btree_setbuf(cur, level, bp);
/*
* Point to the btree block, now that we have the buffer
*/
block = XFS_BUF_TO_ALLOC_BLOCK(bp);
if ((error = xfs_btree_check_sblock(cur, block, level,
bp)))
return error;
} else
block = XFS_BUF_TO_ALLOC_BLOCK(bp);
/*
* If we already had a key match at a higher level, we know
* we need to use the first entry in this block.
*/
if (diff == 0)
keyno = 1;
/*
* Otherwise we need to search this block. Do a binary search.
*/
else {
int high; /* high entry number */
xfs_alloc_key_t *kkbase=NULL;/* base of keys in block */
xfs_alloc_rec_t *krbase=NULL;/* base of records in block */
int low; /* low entry number */
/*
* Get a pointer to keys or records.
*/
if (level > 0)
kkbase = XFS_ALLOC_KEY_ADDR(block, 1, cur);
else
krbase = XFS_ALLOC_REC_ADDR(block, 1, cur);
/*
* Set low and high entry numbers, 1-based.
*/
low = 1;
if (!(high = be16_to_cpu(block->bb_numrecs))) {
/*
* If the block is empty, the tree must
* be an empty leaf.
*/
ASSERT(level == 0 && cur->bc_nlevels == 1);
cur->bc_ptrs[0] = dir != XFS_LOOKUP_LE;
*stat = 0;
return 0;
}
/*
* Binary search the block.
*/
while (low <= high) {
xfs_extlen_t blockcount; /* key value */
xfs_agblock_t startblock; /* key value */
XFS_STATS_INC(xs_abt_compare);
/*
* keyno is average of low and high.
*/
keyno = (low + high) >> 1;
/*
* Get startblock & blockcount.
*/
if (level > 0) {
xfs_alloc_key_t *kkp;
kkp = kkbase + keyno - 1;
startblock = be32_to_cpu(kkp->ar_startblock);
blockcount = be32_to_cpu(kkp->ar_blockcount);
} else {
xfs_alloc_rec_t *krp;
krp = krbase + keyno - 1;
startblock = be32_to_cpu(krp->ar_startblock);
blockcount = be32_to_cpu(krp->ar_blockcount);
}
/*
* Compute difference to get next direction.
*/
if (cur->bc_btnum == XFS_BTNUM_BNO)
diff = (int)startblock -
(int)cur->bc_rec.a.ar_startblock;
else if (!(diff = (int)blockcount -
(int)cur->bc_rec.a.ar_blockcount))
diff = (int)startblock -
(int)cur->bc_rec.a.ar_startblock;
/*
* Less than, move right.
*/
if (diff < 0)
low = keyno + 1;
/*
* Greater than, move left.
*/
else if (diff > 0)
high = keyno - 1;
/*
* Equal, we're done.
*/
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 (diff > 0 && --keyno < 1)
keyno = 1;
agbno = be32_to_cpu(*XFS_ALLOC_PTR_ADDR(block, keyno, cur));
#ifdef DEBUG
if ((error = xfs_btree_check_sptr(cur, agbno, level)))
return error;
#endif
cur->bc_ptrs[level] = keyno;
}
}
/*
* Done with the search.
* See if we need to adjust the results.
*/
if (dir != XFS_LOOKUP_LE && diff < 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.
*/
if (dir == XFS_LOOKUP_GE &&
keyno > be16_to_cpu(block->bb_numrecs) &&
be32_to_cpu(block->bb_rightsib) != NULLAGBLOCK) {
int i;
cur->bc_ptrs[0] = keyno;
if ((error = xfs_alloc_increment(cur, 0, &i)))
return error;
XFS_WANT_CORRUPTED_RETURN(i == 1);
*stat = 1;
return 0;
}
}
else if (dir == XFS_LOOKUP_LE && diff > 0)
keyno--;
cur->bc_ptrs[0] = keyno;
/*
* Return if we succeeded or not.
*/
if (keyno == 0 || keyno > be16_to_cpu(block->bb_numrecs))
*stat = 0;
else
*stat = ((dir != XFS_LOOKUP_EQ) || (diff == 0));
return 0;
}
/*
* Move 1 record left from cur/level if possible.
* Update cur to reflect the new path.
*/
STATIC int /* error */
xfs_alloc_lshift(
xfs_btree_cur_t *cur, /* btree cursor */
int level, /* level to shift record on */
int *stat) /* success/failure */
{
int error; /* error return value */
#ifdef DEBUG
int i; /* loop index */
#endif
xfs_alloc_key_t key; /* key value for leaf level upward */
xfs_buf_t *lbp; /* buffer for left neighbor block */
xfs_alloc_block_t *left; /* left neighbor btree block */
int nrec; /* new number of left block entries */
xfs_buf_t *rbp; /* buffer for right (current) block */
xfs_alloc_block_t *right; /* right (current) btree block */
xfs_alloc_key_t *rkp=NULL; /* key pointer for right block */
xfs_alloc_ptr_t *rpp=NULL; /* address pointer for right block */
xfs_alloc_rec_t *rrp=NULL; /* record pointer for right block */
/*
* Set up variables for this block as "right".
*/
rbp = cur->bc_bufs[level];
right = XFS_BUF_TO_ALLOC_BLOCK(rbp);
#ifdef DEBUG
if ((error = xfs_btree_check_sblock(cur, right, level, rbp)))
return error;
#endif
/*
* If we've got no left sibling then we can't shift an entry left.
*/
if (be32_to_cpu(right->bb_leftsib) == NULLAGBLOCK) {
*stat = 0;
return 0;
}
/*
* If the cursor entry is the one that would be moved, don't
* do it... it's too complicated.
*/
if (cur->bc_ptrs[level] <= 1) {
*stat = 0;
return 0;
}
/*
* Set up the left neighbor as "left".
*/
if ((error = xfs_btree_read_bufs(cur->bc_mp, cur->bc_tp,
cur->bc_private.a.agno, be32_to_cpu(right->bb_leftsib),
0, &lbp, XFS_ALLOC_BTREE_REF)))
return error;
left = XFS_BUF_TO_ALLOC_BLOCK(lbp);
if ((error = xfs_btree_check_sblock(cur, left, level, lbp)))
return error;
/*
* If it's full, it can't take another entry.
*/
if (be16_to_cpu(left->bb_numrecs) == XFS_ALLOC_BLOCK_MAXRECS(level, cur)) {
*stat = 0;
return 0;
}
nrec = be16_to_cpu(left->bb_numrecs) + 1;
/*
* If non-leaf, copy a key and a ptr to the left block.
*/
if (level > 0) {
xfs_alloc_key_t *lkp; /* key pointer for left block */
xfs_alloc_ptr_t *lpp; /* address pointer for left block */
lkp = XFS_ALLOC_KEY_ADDR(left, nrec, cur);
rkp = XFS_ALLOC_KEY_ADDR(right, 1, cur);
*lkp = *rkp;
xfs_alloc_log_keys(cur, lbp, nrec, nrec);
lpp = XFS_ALLOC_PTR_ADDR(left, nrec, cur);
rpp = XFS_ALLOC_PTR_ADDR(right, 1, cur);
#ifdef DEBUG
if ((error = xfs_btree_check_sptr(cur, be32_to_cpu(*rpp), level)))
return error;
#endif
*lpp = *rpp;
xfs_alloc_log_ptrs(cur, lbp, nrec, nrec);
xfs_btree_check_key(cur->bc_btnum, lkp - 1, lkp);
}
/*
* If leaf, copy a record to the left block.
*/
else {
xfs_alloc_rec_t *lrp; /* record pointer for left block */
lrp = XFS_ALLOC_REC_ADDR(left, nrec, cur);
rrp = XFS_ALLOC_REC_ADDR(right, 1, cur);
*lrp = *rrp;
xfs_alloc_log_recs(cur, lbp, nrec, nrec);
xfs_btree_check_rec(cur->bc_btnum, lrp - 1, lrp);
}
/*
* Bump and log left's numrecs, decrement and log right's numrecs.
*/
be16_add(&left->bb_numrecs, 1);
xfs_alloc_log_block(cur->bc_tp, lbp, XFS_BB_NUMRECS);
be16_add(&right->bb_numrecs, -1);
xfs_alloc_log_block(cur->bc_tp, rbp, XFS_BB_NUMRECS);
/*
* Slide the contents of right down one entry.
*/
if (level > 0) {
#ifdef DEBUG
for (i = 0; i < be16_to_cpu(right->bb_numrecs); i++) {
if ((error = xfs_btree_check_sptr(cur, be32_to_cpu(rpp[i + 1]),
level)))
return error;
}
#endif
memmove(rkp, rkp + 1, be16_to_cpu(right->bb_numrecs) * sizeof(*rkp));
memmove(rpp, rpp + 1, be16_to_cpu(right->bb_numrecs) * sizeof(*rpp));
xfs_alloc_log_keys(cur, rbp, 1, be16_to_cpu(right->bb_numrecs));
xfs_alloc_log_ptrs(cur, rbp, 1, be16_to_cpu(right->bb_numrecs));
} else {
memmove(rrp, rrp + 1, be16_to_cpu(right->bb_numrecs) * sizeof(*rrp));
xfs_alloc_log_recs(cur, rbp, 1, be16_to_cpu(right->bb_numrecs));
key.ar_startblock = rrp->ar_startblock;
key.ar_blockcount = rrp->ar_blockcount;
rkp = &key;
}
/*
* Update the parent key values of right.
*/
if ((error = xfs_alloc_updkey(cur, rkp, level + 1)))
return error;
/*
* Slide the cursor value left one.
*/
cur->bc_ptrs[level]--;
*stat = 1;
return 0;
}
/*
* Allocate a new root block, fill it in.
*/
STATIC int /* error */
xfs_alloc_newroot(
xfs_btree_cur_t *cur, /* btree cursor */
int *stat) /* success/failure */
{
int error; /* error return value */
xfs_agblock_t lbno; /* left block number */
xfs_buf_t *lbp; /* left btree buffer */
xfs_alloc_block_t *left; /* left btree block */
xfs_mount_t *mp; /* mount structure */
xfs_agblock_t nbno; /* new block number */
xfs_buf_t *nbp; /* new (root) buffer */
xfs_alloc_block_t *new; /* new (root) btree block */
int nptr; /* new value for key index, 1 or 2 */
xfs_agblock_t rbno; /* right block number */
xfs_buf_t *rbp; /* right btree buffer */
xfs_alloc_block_t *right; /* right btree block */
mp = cur->bc_mp;
ASSERT(cur->bc_nlevels < XFS_AG_MAXLEVELS(mp));
/*
* Get a buffer from the freelist blocks, for the new root.
*/
error = xfs_alloc_get_freelist(cur->bc_tp,
cur->bc_private.a.agbp, &nbno, 1);
if (error)
return error;
/*
* None available, we fail.
*/
if (nbno == NULLAGBLOCK) {
*stat = 0;
return 0;
}
xfs_trans_agbtree_delta(cur->bc_tp, 1);
nbp = xfs_btree_get_bufs(mp, cur->bc_tp, cur->bc_private.a.agno, nbno,
0);
new = XFS_BUF_TO_ALLOC_BLOCK(nbp);
/*
* Set the root data in the a.g. freespace structure.
*/
{
xfs_agf_t *agf; /* a.g. freespace header */
xfs_agnumber_t seqno;
agf = XFS_BUF_TO_AGF(cur->bc_private.a.agbp);
agf->agf_roots[cur->bc_btnum] = cpu_to_be32(nbno);
be32_add(&agf->agf_levels[cur->bc_btnum], 1);
seqno = be32_to_cpu(agf->agf_seqno);
mp->m_perag[seqno].pagf_levels[cur->bc_btnum]++;
xfs_alloc_log_agf(cur->bc_tp, cur->bc_private.a.agbp,
XFS_AGF_ROOTS | XFS_AGF_LEVELS);
}
/*
* 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.
*/
lbp = cur->bc_bufs[cur->bc_nlevels - 1];
left = XFS_BUF_TO_ALLOC_BLOCK(lbp);
#ifdef DEBUG
if ((error = xfs_btree_check_sblock(cur, left, cur->bc_nlevels - 1, lbp)))
return error;
#endif
if (be32_to_cpu(left->bb_rightsib) != NULLAGBLOCK) {
/*
* Our block is left, pick up the right block.
*/
lbno = XFS_DADDR_TO_AGBNO(mp, XFS_BUF_ADDR(lbp));
rbno = be32_to_cpu(left->bb_rightsib);
if ((error = xfs_btree_read_bufs(mp, cur->bc_tp,
cur->bc_private.a.agno, rbno, 0, &rbp,
XFS_ALLOC_BTREE_REF)))
return error;
right = XFS_BUF_TO_ALLOC_BLOCK(rbp);
if ((error = xfs_btree_check_sblock(cur, right,
cur->bc_nlevels - 1, rbp)))
return error;
nptr = 1;
} else {
/*
* Our block is right, pick up the left block.
*/
rbp = lbp;
right = left;
rbno = XFS_DADDR_TO_AGBNO(mp, XFS_BUF_ADDR(rbp));
lbno = be32_to_cpu(right->bb_leftsib);
if ((error = xfs_btree_read_bufs(mp, cur->bc_tp,
cur->bc_private.a.agno, lbno, 0, &lbp,
XFS_ALLOC_BTREE_REF)))
return error;
left = XFS_BUF_TO_ALLOC_BLOCK(lbp);
if ((error = xfs_btree_check_sblock(cur, left,
cur->bc_nlevels - 1, lbp)))
return error;
nptr = 2;
}
/*
* Fill in the new block's btree header and log it.
*/
new->bb_magic = cpu_to_be32(xfs_magics[cur->bc_btnum]);
new->bb_level = cpu_to_be16(cur->bc_nlevels);
new->bb_numrecs = cpu_to_be16(2);
new->bb_leftsib = cpu_to_be32(NULLAGBLOCK);
new->bb_rightsib = cpu_to_be32(NULLAGBLOCK);
xfs_alloc_log_block(cur->bc_tp, nbp, XFS_BB_ALL_BITS);
ASSERT(lbno != NULLAGBLOCK && rbno != NULLAGBLOCK);
/*
* Fill in the key data in the new root.
*/
{
xfs_alloc_key_t *kp; /* btree key pointer */
kp = XFS_ALLOC_KEY_ADDR(new, 1, cur);
if (be16_to_cpu(left->bb_level) > 0) {
kp[0] = *XFS_ALLOC_KEY_ADDR(left, 1, cur);
kp[1] = *XFS_ALLOC_KEY_ADDR(right, 1, cur);
} else {
xfs_alloc_rec_t *rp; /* btree record pointer */
rp = XFS_ALLOC_REC_ADDR(left, 1, cur);
kp[0].ar_startblock = rp->ar_startblock;
kp[0].ar_blockcount = rp->ar_blockcount;
rp = XFS_ALLOC_REC_ADDR(right, 1, cur);
kp[1].ar_startblock = rp->ar_startblock;
kp[1].ar_blockcount = rp->ar_blockcount;
}
}
xfs_alloc_log_keys(cur, nbp, 1, 2);
/*
* Fill in the pointer data in the new root.
*/
{
xfs_alloc_ptr_t *pp; /* btree address pointer */
pp = XFS_ALLOC_PTR_ADDR(new, 1, cur);
pp[0] = cpu_to_be32(lbno);
pp[1] = cpu_to_be32(rbno);
}
xfs_alloc_log_ptrs(cur, nbp, 1, 2);
/*
* Fix up the cursor.
*/
xfs_btree_setbuf(cur, cur->bc_nlevels, nbp);
cur->bc_ptrs[cur->bc_nlevels] = nptr;
cur->bc_nlevels++;
*stat = 1;
return 0;
}
/*
* Move 1 record right from cur/level if possible.
* Update cur to reflect the new path.
*/
STATIC int /* error */
xfs_alloc_rshift(
xfs_btree_cur_t *cur, /* btree cursor */
int level, /* level to shift record on */
int *stat) /* success/failure */
{
int error; /* error return value */
int i; /* loop index */
xfs_alloc_key_t key; /* key value for leaf level upward */
xfs_buf_t *lbp; /* buffer for left (current) block */
xfs_alloc_block_t *left; /* left (current) btree block */
xfs_buf_t *rbp; /* buffer for right neighbor block */
xfs_alloc_block_t *right; /* right neighbor btree block */
xfs_alloc_key_t *rkp; /* key pointer for right block */
xfs_btree_cur_t *tcur; /* temporary cursor */
/*
* Set up variables for this block as "left".
*/
lbp = cur->bc_bufs[level];
left = XFS_BUF_TO_ALLOC_BLOCK(lbp);
#ifdef DEBUG
if ((error = xfs_btree_check_sblock(cur, left, level, lbp)))
return error;
#endif
/*
* If we've got no right sibling then we can't shift an entry right.
*/
if (be32_to_cpu(left->bb_rightsib) == NULLAGBLOCK) {
*stat = 0;
return 0;
}
/*
* If the cursor entry is the one that would be moved, don't
* do it... it's too complicated.
*/
if (cur->bc_ptrs[level] >= be16_to_cpu(left->bb_numrecs)) {
*stat = 0;
return 0;
}
/*
* Set up the right neighbor as "right".
*/
if ((error = xfs_btree_read_bufs(cur->bc_mp, cur->bc_tp,
cur->bc_private.a.agno, be32_to_cpu(left->bb_rightsib),
0, &rbp, XFS_ALLOC_BTREE_REF)))
return error;
right = XFS_BUF_TO_ALLOC_BLOCK(rbp);
if ((error = xfs_btree_check_sblock(cur, right, level, rbp)))
return error;
/*
* If it's full, it can't take another entry.
*/
if (be16_to_cpu(right->bb_numrecs) == XFS_ALLOC_BLOCK_MAXRECS(level, cur)) {
*stat = 0;
return 0;
}
/*
* Make a hole at the start of the right neighbor block, then
* copy the last left block entry to the hole.
*/
if (level > 0) {
xfs_alloc_key_t *lkp; /* key pointer for left block */
xfs_alloc_ptr_t *lpp; /* address pointer for left block */
xfs_alloc_ptr_t *rpp; /* address pointer for right block */
lkp = XFS_ALLOC_KEY_ADDR(left, be16_to_cpu(left->bb_numrecs), cur);
lpp = XFS_ALLOC_PTR_ADDR(left, be16_to_cpu(left->bb_numrecs), cur);
rkp = XFS_ALLOC_KEY_ADDR(right, 1, cur);
rpp = XFS_ALLOC_PTR_ADDR(right, 1, cur);
#ifdef DEBUG
for (i = be16_to_cpu(right->bb_numrecs) - 1; i >= 0; i--) {
if ((error = xfs_btree_check_sptr(cur, be32_to_cpu(rpp[i]), level)))
return error;
}
#endif
memmove(rkp + 1, rkp, be16_to_cpu(right->bb_numrecs) * sizeof(*rkp));
memmove(rpp + 1, rpp, be16_to_cpu(right->bb_numrecs) * sizeof(*rpp));
#ifdef DEBUG
if ((error = xfs_btree_check_sptr(cur, be32_to_cpu(*lpp), level)))
return error;
#endif
*rkp = *lkp;
*rpp = *lpp;
xfs_alloc_log_keys(cur, rbp, 1, be16_to_cpu(right->bb_numrecs) + 1);
xfs_alloc_log_ptrs(cur, rbp, 1, be16_to_cpu(right->bb_numrecs) + 1);
xfs_btree_check_key(cur->bc_btnum, rkp, rkp + 1);
} else {
xfs_alloc_rec_t *lrp; /* record pointer for left block */
xfs_alloc_rec_t *rrp; /* record pointer for right block */
lrp = XFS_ALLOC_REC_ADDR(left, be16_to_cpu(left->bb_numrecs), cur);
rrp = XFS_ALLOC_REC_ADDR(right, 1, cur);
memmove(rrp + 1, rrp, be16_to_cpu(right->bb_numrecs) * sizeof(*rrp));
*rrp = *lrp;
xfs_alloc_log_recs(cur, rbp, 1, be16_to_cpu(right->bb_numrecs) + 1);
key.ar_startblock = rrp->ar_startblock;
key.ar_blockcount = rrp->ar_blockcount;
rkp = &key;
xfs_btree_check_rec(cur->bc_btnum, rrp, rrp + 1);
}
/*
* Decrement and log left's numrecs, bump and log right's numrecs.
*/
be16_add(&left->bb_numrecs, -1);
xfs_alloc_log_block(cur->bc_tp, lbp, XFS_BB_NUMRECS);
be16_add(&right->bb_numrecs, 1);
xfs_alloc_log_block(cur->bc_tp, rbp, XFS_BB_NUMRECS);
/*
* Using a temporary cursor, update the parent key values of the
* block on the right.
*/
if ((error = xfs_btree_dup_cursor(cur, &tcur)))
return error;
i = xfs_btree_lastrec(tcur, level);
XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
if ((error = xfs_alloc_increment(tcur, level, &i)) ||
(error = xfs_alloc_updkey(tcur, rkp, level + 1)))
goto error0;
xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
*stat = 1;
return 0;
error0:
xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR);
return error;
}
/*
* Split cur/level block in half.
* Return new block number and its first record (to be inserted into parent).
*/
STATIC int /* error */
xfs_alloc_split(
xfs_btree_cur_t *cur, /* btree cursor */
int level, /* level to split */
xfs_agblock_t *bnop, /* output: block number allocated */
xfs_alloc_key_t *keyp, /* output: first key of new block */
xfs_btree_cur_t **curp, /* output: new cursor */
int *stat) /* success/failure */
{
int error; /* error return value */
int i; /* loop index/record number */
xfs_agblock_t lbno; /* left (current) block number */
xfs_buf_t *lbp; /* buffer for left block */
xfs_alloc_block_t *left; /* left (current) btree block */
xfs_agblock_t rbno; /* right (new) block number */
xfs_buf_t *rbp; /* buffer for right block */
xfs_alloc_block_t *right; /* right (new) btree block */
/*
* Allocate the new block from the freelist.
* If we can't do it, we're toast. Give up.
*/
error = xfs_alloc_get_freelist(cur->bc_tp,
cur->bc_private.a.agbp, &rbno, 1);
if (error)
return error;
if (rbno == NULLAGBLOCK) {
*stat = 0;
return 0;
}
xfs_trans_agbtree_delta(cur->bc_tp, 1);
rbp = xfs_btree_get_bufs(cur->bc_mp, cur->bc_tp, cur->bc_private.a.agno,
rbno, 0);
/*
* Set up the new block as "right".
*/
right = XFS_BUF_TO_ALLOC_BLOCK(rbp);
/*
* "Left" is the current (according to the cursor) block.
*/
lbp = cur->bc_bufs[level];
left = XFS_BUF_TO_ALLOC_BLOCK(lbp);
#ifdef DEBUG
if ((error = xfs_btree_check_sblock(cur, left, level, lbp)))
return error;
#endif
/*
* Fill in the btree header for the new block.
*/
right->bb_magic = cpu_to_be32(xfs_magics[cur->bc_btnum]);
right->bb_level = left->bb_level;
right->bb_numrecs = cpu_to_be16(be16_to_cpu(left->bb_numrecs) / 2);
/*
* Make sure that if there's an odd number of entries now, that
* each new block will have the same number of entries.
*/
if ((be16_to_cpu(left->bb_numrecs) & 1) &&
cur->bc_ptrs[level] <= be16_to_cpu(right->bb_numrecs) + 1)
be16_add(&right->bb_numrecs, 1);
i = be16_to_cpu(left->bb_numrecs) - be16_to_cpu(right->bb_numrecs) + 1;
/*
* For non-leaf blocks, copy keys and addresses over to the new block.
*/
if (level > 0) {
xfs_alloc_key_t *lkp; /* left btree key pointer */
xfs_alloc_ptr_t *lpp; /* left btree address pointer */
xfs_alloc_key_t *rkp; /* right btree key pointer */
xfs_alloc_ptr_t *rpp; /* right btree address pointer */
lkp = XFS_ALLOC_KEY_ADDR(left, i, cur);
lpp = XFS_ALLOC_PTR_ADDR(left, i, cur);
rkp = XFS_ALLOC_KEY_ADDR(right, 1, cur);
rpp = XFS_ALLOC_PTR_ADDR(right, 1, cur);
#ifdef DEBUG
for (i = 0; i < be16_to_cpu(right->bb_numrecs); i++) {
if ((error = xfs_btree_check_sptr(cur, be32_to_cpu(lpp[i]), level)))
return error;
}
#endif
memcpy(rkp, lkp, be16_to_cpu(right->bb_numrecs) * sizeof(*rkp));
memcpy(rpp, lpp, be16_to_cpu(right->bb_numrecs) * sizeof(*rpp));
xfs_alloc_log_keys(cur, rbp, 1, be16_to_cpu(right->bb_numrecs));
xfs_alloc_log_ptrs(cur, rbp, 1, be16_to_cpu(right->bb_numrecs));
*keyp = *rkp;
}
/*
* For leaf blocks, copy records over to the new block.
*/
else {
xfs_alloc_rec_t *lrp; /* left btree record pointer */
xfs_alloc_rec_t *rrp; /* right btree record pointer */
lrp = XFS_ALLOC_REC_ADDR(left, i, cur);
rrp = XFS_ALLOC_REC_ADDR(right, 1, cur);
memcpy(rrp, lrp, be16_to_cpu(right->bb_numrecs) * sizeof(*rrp));
xfs_alloc_log_recs(cur, rbp, 1, be16_to_cpu(right->bb_numrecs));
keyp->ar_startblock = rrp->ar_startblock;
keyp->ar_blockcount = rrp->ar_blockcount;
}
/*
* Find the left block number by looking in the buffer.
* Adjust numrecs, sibling pointers.
*/
lbno = XFS_DADDR_TO_AGBNO(cur->bc_mp, XFS_BUF_ADDR(lbp));
be16_add(&left->bb_numrecs, -(be16_to_cpu(right->bb_numrecs)));
right->bb_rightsib = left->bb_rightsib;
left->bb_rightsib = cpu_to_be32(rbno);
right->bb_leftsib = cpu_to_be32(lbno);
xfs_alloc_log_block(cur->bc_tp, rbp, XFS_BB_ALL_BITS);
xfs_alloc_log_block(cur->bc_tp, lbp, XFS_BB_NUMRECS | XFS_BB_RIGHTSIB);
/*
* If there's a block to the new block's right, make that block
* point back to right instead of to left.
*/
if (be32_to_cpu(right->bb_rightsib) != NULLAGBLOCK) {
xfs_alloc_block_t *rrblock; /* rr btree block */
xfs_buf_t *rrbp; /* buffer for rrblock */
if ((error = xfs_btree_read_bufs(cur->bc_mp, cur->bc_tp,
cur->bc_private.a.agno, be32_to_cpu(right->bb_rightsib), 0,
&rrbp, XFS_ALLOC_BTREE_REF)))
return error;
rrblock = XFS_BUF_TO_ALLOC_BLOCK(rrbp);
if ((error = xfs_btree_check_sblock(cur, rrblock, level, rrbp)))
return error;
rrblock->bb_leftsib = cpu_to_be32(rbno);
xfs_alloc_log_block(cur->bc_tp, rrbp, XFS_BB_LEFTSIB);
}
/*
* 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_ptrs[level] > be16_to_cpu(left->bb_numrecs) + 1) {
xfs_btree_setbuf(cur, level, rbp);
cur->bc_ptrs[level] -= be16_to_cpu(left->bb_numrecs);
}
/*
* If there are more levels, we'll need another cursor which refers to
* the right block, no matter where this cursor was.
*/
if (level + 1 < cur->bc_nlevels) {
if ((error = xfs_btree_dup_cursor(cur, curp)))
return error;
(*curp)->bc_ptrs[level + 1]++;
}
*bnop = rbno;
*stat = 1;
return 0;
}
/*
* Update keys at all levels from here to the root along the cursor's path.
*/
STATIC int /* error */
xfs_alloc_updkey(
xfs_btree_cur_t *cur, /* btree cursor */
xfs_alloc_key_t *keyp, /* new key value to update to */
int level) /* starting level for update */
{
int ptr; /* index of key in block */
/*
* 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.
*/
for (ptr = 1; ptr == 1 && level < cur->bc_nlevels; level++) {
xfs_alloc_block_t *block; /* btree block */
xfs_buf_t *bp; /* buffer for block */
#ifdef DEBUG
int error; /* error return value */
#endif
xfs_alloc_key_t *kp; /* ptr to btree block keys */
bp = cur->bc_bufs[level];
block = XFS_BUF_TO_ALLOC_BLOCK(bp);
#ifdef DEBUG
if ((error = xfs_btree_check_sblock(cur, block, level, bp)))
return error;
#endif
ptr = cur->bc_ptrs[level];
kp = XFS_ALLOC_KEY_ADDR(block, ptr, cur);
*kp = *keyp;
xfs_alloc_log_keys(cur, bp, ptr, ptr);
}
return 0;
}
/*
* Externally visible routines.
*/
/*
* Decrement cursor by one record at the level.
* For nonzero levels the leaf-ward information is untouched.
*/
int /* error */
xfs_alloc_decrement(
xfs_btree_cur_t *cur, /* btree cursor */
int level, /* level in btree, 0 is leaf */
int *stat) /* success/failure */
{
xfs_alloc_block_t *block; /* btree block */
int error; /* error return value */
int lev; /* btree level */
ASSERT(level < cur->bc_nlevels);
/*
* Read-ahead to the left at this level.
*/
xfs_btree_readahead(cur, level, XFS_BTCUR_LEFTRA);
/*
* Decrement the ptr at this level. If we're still in the block
* then we're done.
*/
if (--cur->bc_ptrs[level] > 0) {
*stat = 1;
return 0;
}
/*
* Get a pointer to the btree block.
*/
block = XFS_BUF_TO_ALLOC_BLOCK(cur->bc_bufs[level]);
#ifdef DEBUG
if ((error = xfs_btree_check_sblock(cur, block, level,
cur->bc_bufs[level])))
return error;
#endif
/*
* If we just went off the left edge of the tree, return failure.
*/
if (be32_to_cpu(block->bb_leftsib) == NULLAGBLOCK) {
*stat = 0;
return 0;
}
/*
* 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_ptrs[lev] > 0)
break;
/*
* Read-ahead the left block, we're going to read it
* in the next loop.
*/
xfs_btree_readahead(cur, lev, XFS_BTCUR_LEFTRA);
}
/*
* If we went off the root then we are seriously confused.
*/
ASSERT(lev < cur->bc_nlevels);
/*
* Now walk back down the tree, fixing up the cursor's buffer
* pointers and key numbers.
*/
for (block = XFS_BUF_TO_ALLOC_BLOCK(cur->bc_bufs[lev]); lev > level; ) {
xfs_agblock_t agbno; /* block number of btree block */
xfs_buf_t *bp; /* buffer pointer for block */
agbno = be32_to_cpu(*XFS_ALLOC_PTR_ADDR(block, cur->bc_ptrs[lev], cur));
if ((error = xfs_btree_read_bufs(cur->bc_mp, cur->bc_tp,
cur->bc_private.a.agno, agbno, 0, &bp,
XFS_ALLOC_BTREE_REF)))
return error;
lev--;
xfs_btree_setbuf(cur, lev, bp);
block = XFS_BUF_TO_ALLOC_BLOCK(bp);
if ((error = xfs_btree_check_sblock(cur, block, lev, bp)))
return error;
cur->bc_ptrs[lev] = be16_to_cpu(block->bb_numrecs);
}
*stat = 1;
return 0;
}
/*
* 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_alloc_delete(
xfs_btree_cur_t *cur, /* btree cursor */
int *stat) /* success/failure */
{
int error; /* error return value */
int i; /* result code */
int level; /* btree level */
/*
* 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++) {
if ((error = xfs_alloc_delrec(cur, level, &i)))
return error;
}
if (i == 0) {
for (level = 1; level < cur->bc_nlevels; level++) {
if (cur->bc_ptrs[level] == 0) {
if ((error = xfs_alloc_decrement(cur, level, &i)))
return error;
break;
}
}
}
*stat = i;
return 0;
}
/*
* Get the data from the pointed-to record.
*/
int /* error */
xfs_alloc_get_rec(
xfs_btree_cur_t *cur, /* btree cursor */
xfs_agblock_t *bno, /* output: starting block of extent */
xfs_extlen_t *len, /* output: length of extent */
int *stat) /* output: success/failure */
{
xfs_alloc_block_t *block; /* btree block */
#ifdef DEBUG
int error; /* error return value */
#endif
int ptr; /* record number */
ptr = cur->bc_ptrs[0];
block = XFS_BUF_TO_ALLOC_BLOCK(cur->bc_bufs[0]);
#ifdef DEBUG
if ((error = xfs_btree_check_sblock(cur, block, 0, cur->bc_bufs[0])))
return error;
#endif
/*
* Off the right end or left end, return failure.
*/
if (ptr > be16_to_cpu(block->bb_numrecs) || ptr <= 0) {
*stat = 0;
return 0;
}
/*
* Point to the record and extract its data.
*/
{
xfs_alloc_rec_t *rec; /* record data */
rec = XFS_ALLOC_REC_ADDR(block, ptr, cur);
*bno = be32_to_cpu(rec->ar_startblock);
*len = be32_to_cpu(rec->ar_blockcount);
}
*stat = 1;
return 0;
}
/*
* Increment cursor by one record at the level.
* For nonzero levels the leaf-ward information is untouched.
*/
int /* error */
xfs_alloc_increment(
xfs_btree_cur_t *cur, /* btree cursor */
int level, /* level in btree, 0 is leaf */
int *stat) /* success/failure */
{
xfs_alloc_block_t *block; /* btree block */
xfs_buf_t *bp; /* tree block buffer */
int error; /* error return value */
int lev; /* btree level */
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.
*/
bp = cur->bc_bufs[level];
block = XFS_BUF_TO_ALLOC_BLOCK(bp);
#ifdef DEBUG
if ((error = xfs_btree_check_sblock(cur, block, level, bp)))
return error;
#endif
/*
* Increment the ptr at this level. If we're still in the block
* then we're done.
*/
if (++cur->bc_ptrs[level] <= be16_to_cpu(block->bb_numrecs)) {
*stat = 1;
return 0;
}
/*
* If we just went off the right edge of the tree, return failure.
*/
if (be32_to_cpu(block->bb_rightsib) == NULLAGBLOCK) {
*stat = 0;
return 0;
}
/*
* 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++) {
bp = cur->bc_bufs[lev];
block = XFS_BUF_TO_ALLOC_BLOCK(bp);
#ifdef DEBUG
if ((error = xfs_btree_check_sblock(cur, block, lev, bp)))
return error;
#endif
if (++cur->bc_ptrs[lev] <= be16_to_cpu(block->bb_numrecs))
break;
/*
* Read-ahead the right block, we're going to read it
* in the next loop.
*/
xfs_btree_readahead(cur, lev, XFS_BTCUR_RIGHTRA);
}
/*
* If we went off the root then we are seriously confused.
*/
ASSERT(lev < cur->bc_nlevels);
/*
* Now walk back down the tree, fixing up the cursor's buffer
* pointers and key numbers.
*/
for (bp = cur->bc_bufs[lev], block = XFS_BUF_TO_ALLOC_BLOCK(bp);
lev > level; ) {
xfs_agblock_t agbno; /* block number of btree block */
agbno = be32_to_cpu(*XFS_ALLOC_PTR_ADDR(block, cur->bc_ptrs[lev], cur));
if ((error = xfs_btree_read_bufs(cur->bc_mp, cur->bc_tp,
cur->bc_private.a.agno, agbno, 0, &bp,
XFS_ALLOC_BTREE_REF)))
return error;
lev--;
xfs_btree_setbuf(cur, lev, bp);
block = XFS_BUF_TO_ALLOC_BLOCK(bp);
if ((error = xfs_btree_check_sblock(cur, block, lev, bp)))
return error;
cur->bc_ptrs[lev] = 1;
}
*stat = 1;
return 0;
}
/*
* Insert the current record at the point referenced by cur.
* The cursor may be inconsistent on return if splits have been done.
*/
int /* error */
xfs_alloc_insert(
xfs_btree_cur_t *cur, /* btree cursor */
int *stat) /* success/failure */
{
int error; /* error return value */
int i; /* result value, 0 for failure */
int level; /* current level number in btree */
xfs_agblock_t nbno; /* new block number (split result) */
xfs_btree_cur_t *ncur; /* new cursor (split result) */
xfs_alloc_rec_t nrec; /* record being inserted this level */
xfs_btree_cur_t *pcur; /* previous level's cursor */
level = 0;
nbno = NULLAGBLOCK;
nrec.ar_startblock = cpu_to_be32(cur->bc_rec.a.ar_startblock);
nrec.ar_blockcount = cpu_to_be32(cur->bc_rec.a.ar_blockcount);
ncur = NULL;
pcur = cur;
/*
* 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/nbno into this level of the tree.
* Note if we fail, nbno will be null.
*/
if ((error = xfs_alloc_insrec(pcur, level++, &nbno, &nrec, &ncur,
&i))) {
if (pcur != cur)
xfs_btree_del_cursor(pcur, XFS_BTREE_ERROR);
return error;
}
/*
* 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 || nbno == NULLAGBLOCK)) {
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 (nbno != NULLAGBLOCK);
*stat = i;
return 0;
}
/*
* Lookup the record equal to [bno, len] in the btree given by cur.
*/
int /* error */
xfs_alloc_lookup_eq(
xfs_btree_cur_t *cur, /* btree cursor */
xfs_agblock_t bno, /* starting block of extent */
xfs_extlen_t len, /* length of extent */
int *stat) /* success/failure */
{
cur->bc_rec.a.ar_startblock = bno;
cur->bc_rec.a.ar_blockcount = len;
return xfs_alloc_lookup(cur, XFS_LOOKUP_EQ, stat);
}
/*
* Lookup the first record greater than or equal to [bno, len]
* in the btree given by cur.
*/
int /* error */
xfs_alloc_lookup_ge(
xfs_btree_cur_t *cur, /* btree cursor */
xfs_agblock_t bno, /* starting block of extent */
xfs_extlen_t len, /* length of extent */
int *stat) /* success/failure */
{
cur->bc_rec.a.ar_startblock = bno;
cur->bc_rec.a.ar_blockcount = len;
return xfs_alloc_lookup(cur, XFS_LOOKUP_GE, stat);
}
/*
* Lookup the first record less than or equal to [bno, len]
* in the btree given by cur.
*/
int /* error */
xfs_alloc_lookup_le(
xfs_btree_cur_t *cur, /* btree cursor */
xfs_agblock_t bno, /* starting block of extent */
xfs_extlen_t len, /* length of extent */
int *stat) /* success/failure */
{
cur->bc_rec.a.ar_startblock = bno;
cur->bc_rec.a.ar_blockcount = len;
return xfs_alloc_lookup(cur, XFS_LOOKUP_LE, stat);
}
/*
* Update the record referred to by cur, to the value given by [bno, len].
* This either works (return 0) or gets an EFSCORRUPTED error.
*/
int /* error */
xfs_alloc_update(
xfs_btree_cur_t *cur, /* btree cursor */
xfs_agblock_t bno, /* starting block of extent */
xfs_extlen_t len) /* length of extent */
{
xfs_alloc_block_t *block; /* btree block to update */
int error; /* error return value */
int ptr; /* current record number (updating) */
ASSERT(len > 0);
/*
* Pick up the a.g. freelist struct and the current block.
*/
block = XFS_BUF_TO_ALLOC_BLOCK(cur->bc_bufs[0]);
#ifdef DEBUG
if ((error = xfs_btree_check_sblock(cur, block, 0, cur->bc_bufs[0])))
return error;
#endif
/*
* Get the address of the rec to be updated.
*/
ptr = cur->bc_ptrs[0];
{
xfs_alloc_rec_t *rp; /* pointer to updated record */
rp = XFS_ALLOC_REC_ADDR(block, ptr, cur);
/*
* Fill in the new contents and log them.
*/
rp->ar_startblock = cpu_to_be32(bno);
rp->ar_blockcount = cpu_to_be32(len);
xfs_alloc_log_recs(cur, cur->bc_bufs[0], ptr, ptr);
}
/*
* If it's the by-size btree and it's the last leaf block and
* it's the last record... then update the size of the longest
* extent in the a.g., which we cache in the a.g. freelist header.
*/
if (cur->bc_btnum == XFS_BTNUM_CNT &&
be32_to_cpu(block->bb_rightsib) == NULLAGBLOCK &&
ptr == be16_to_cpu(block->bb_numrecs)) {
xfs_agf_t *agf; /* a.g. freespace header */
xfs_agnumber_t seqno;
agf = XFS_BUF_TO_AGF(cur->bc_private.a.agbp);
seqno = be32_to_cpu(agf->agf_seqno);
cur->bc_mp->m_perag[seqno].pagf_longest = len;
agf->agf_longest = cpu_to_be32(len);
xfs_alloc_log_agf(cur->bc_tp, cur->bc_private.a.agbp,
XFS_AGF_LONGEST);
}
/*
* Updating first record in leaf. Pass new key value up to our parent.
*/
if (ptr == 1) {
xfs_alloc_key_t key; /* key containing [bno, len] */
key.ar_startblock = cpu_to_be32(bno);
key.ar_blockcount = cpu_to_be32(len);
if ((error = xfs_alloc_updkey(cur, &key, 1)))
return error;
}
return 0;
}
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