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xfs_alloc_btree.c
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xfs_alloc_btree.c
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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;