Commit 1e7eeed2 authored by Hallvard Furuseth's avatar Hallvard Furuseth
Browse files

Fix loose pages in mdb_freelist_save().

Leaving them in dirty_list caused breakage.  Instead merge them
into me_pghead at the end, when no more pages will be allocated.
parent 983f896a
......@@ -745,7 +745,7 @@ typedef struct MDB_page {
/** The number of overflow pages needed to store the given size. */
#define OVPAGES(size, psize) ((PAGEHDRSZ-1 + (size)) / (psize) + 1)
/** Link in #MDB_txn.%mt_loose_pages list */
/** Link in #MDB_txn.%mt_loose_pgs list */
#define NEXT_LOOSE_PAGE(p) (*(MDB_page **)((p) + 2))
/** Header for a single key/data pair within a page.
......@@ -950,6 +950,8 @@ struct MDB_txn {
* in this transaction, linked through #NEXT_LOOSE_PAGE(page).
*/
MDB_page *mt_loose_pgs;
/* #Number of loose pages (#mt_loose_pgs) */
int mt_loose_count;
/** The sorted list of dirty pages we temporarily wrote to disk
* because the dirty list was full. page numbers in here are
* shifted left by 1, deleted slots have the LSB set.
......@@ -1661,6 +1663,7 @@ mdb_page_loose(MDB_cursor *mc, MDB_page *mp)
mp->mp_pgno));
NEXT_LOOSE_PAGE(mp) = mc->mc_txn->mt_loose_pgs;
mc->mc_txn->mt_loose_pgs = mp;
mc->mc_txn->mt_loose_count++;
mp->mp_flags |= P_LOOSE;
} else {
int rc = mdb_midl_append(&mc->mc_txn->mt_free_pgs, pgno);
......@@ -1950,6 +1953,7 @@ mdb_page_alloc(MDB_cursor *mc, int num, MDB_page **mp)
if (num == 1 && txn->mt_loose_pgs) {
np = txn->mt_loose_pgs;
txn->mt_loose_pgs = NEXT_LOOSE_PAGE(np);
txn->mt_loose_count--;
DPRINTF(("db %d use loose page %"Z"u", DDBI(mc),
np->mp_pgno));
*mp = np;
......@@ -2823,30 +2827,17 @@ mdb_freelist_save(MDB_txn *txn)
return rc;
}
/* Dispose of loose pages. Usually they will have all
* been used up by the time we get here.
*/
if (txn->mt_loose_pgs) {
if (!env->me_pghead) {
/* Put loose page numbers in mt_free_pgs, since
* we may be unable to return them to me_pghead.
*/
MDB_page *mp = txn->mt_loose_pgs;
/* Just return them to freeDB */
if (env->me_pghead) {
int i, j;
mop = env->me_pghead;
for (; mp; mp = NEXT_LOOSE_PAGE(mp)) {
pgno_t pg = mp->mp_pgno;
j = mop[0] + 1;
for (i = mop[0]; i && mop[i] < pg; i--)
mop[j--] = mop[i];
mop[j] = pg;
mop[0] += 1;
}
} else {
/* Oh well, they were wasted. Put on freelist */
for (; mp; mp = NEXT_LOOSE_PAGE(mp)) {
mdb_midl_append(&txn->mt_free_pgs, mp->mp_pgno);
}
}
if ((rc = mdb_midl_need(&txn->mt_free_pgs, txn->mt_loose_count)) != 0)
return rc;
for (; mp; mp = NEXT_LOOSE_PAGE(mp))
mdb_midl_xappend(txn->mt_free_pgs, mp->mp_pgno);
txn->mt_loose_pgs = NULL;
txn->mt_loose_count = 0;
}
/* MDB_RESERVE cancels meminit in ovpage malloc (when no WRITEMAP) */
......@@ -2910,7 +2901,7 @@ mdb_freelist_save(MDB_txn *txn)
}
mop = env->me_pghead;
mop_len = mop ? mop[0] : 0;
mop_len = (mop ? mop[0] : 0) + txn->mt_loose_count;
/* Reserve records for me_pghead[]. Split it if multi-page,
* to avoid searching freeDB for a page range. Use keys in
......@@ -2950,6 +2941,28 @@ mdb_freelist_save(MDB_txn *txn)
total_room += head_room;
}
/* Return loose page numbers to me_pghead, though usually none are
* left at this point. The pages themselves remain in dirty_list.
*/
if (txn->mt_loose_pgs) {
MDB_page *mp = txn->mt_loose_pgs;
unsigned count = txn->mt_loose_count;
MDB_IDL loose;
/* Room for loose pages + temp IDL with same */
if ((rc = mdb_midl_need(&env->me_pghead, 2*count+1)) != 0)
return rc;
mop = env->me_pghead;
loose = mop + MDB_IDL_ALLOCLEN(mop) - count;
for (count = 0; mp; mp = NEXT_LOOSE_PAGE(mp))
loose[ ++count ] = mp->mp_pgno;
loose[0] = count;
mdb_midl_sort(loose);
mdb_midl_xmerge(mop, loose);
txn->mt_loose_pgs = NULL;
txn->mt_loose_count = 0;
mop_len = mop[0];
}
/* Fill in the reserved me_pghead records */
rc = MDB_SUCCESS;
if (mop_len) {
......@@ -3264,6 +3277,7 @@ mdb_txn_commit(MDB_txn *txn)
for (lp = &parent->mt_loose_pgs; *lp; lp = &NEXT_LOOSE_PAGE(lp))
;
*lp = txn->mt_loose_pgs;
parent->mt_loose_count += txn->mt_loose_count;
parent->mt_child = NULL;
mdb_midl_free(((MDB_ntxn *)txn)->mnt_pgstate.mf_pghead);
......@@ -3326,6 +3340,10 @@ mdb_txn_commit(MDB_txn *txn)
(rc = mdb_env_write_meta(txn)))
goto fail;
/* Free P_LOOSE pages left behind in dirty_list */
if (!(env->me_flags & MDB_WRITEMAP))
mdb_dlist_free(txn);
done:
env->me_pglast = 0;
env->me_txn = NULL;
......
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