}
/*
- * Allocation group level functions.
+ * Block allocation algorithm and data structures.
*/
+struct xfs_alloc_cur {
+ struct xfs_btree_cur *cnt; /* btree cursors */
+ struct xfs_btree_cur *bnolt;
+ struct xfs_btree_cur *bnogt;
+};
+
+/*
+ * Set up cursors, etc. in the extent allocation cursor. This function can be
+ * called multiple times to reset an initialized structure without having to
+ * reallocate cursors.
+ */
+static int
+xfs_alloc_cur_setup(
+ struct xfs_alloc_arg *args,
+ struct xfs_alloc_cur *acur)
+{
+ int error;
+ int i;
+
+ ASSERT(args->alignment == 1 || args->type != XFS_ALLOCTYPE_THIS_BNO);
+
+ /*
+ * Perform an initial cntbt lookup to check for availability of maxlen
+ * extents. If this fails, we'll return -ENOSPC to signal the caller to
+ * attempt a small allocation.
+ */
+ if (!acur->cnt)
+ acur->cnt = xfs_allocbt_init_cursor(args->mp, args->tp,
+ args->agbp, args->agno, XFS_BTNUM_CNT);
+ error = xfs_alloc_lookup_ge(acur->cnt, 0, args->maxlen, &i);
+ if (error)
+ return error;
+
+ /*
+ * Allocate the bnobt left and right search cursors.
+ */
+ if (!acur->bnolt)
+ acur->bnolt = xfs_allocbt_init_cursor(args->mp, args->tp,
+ args->agbp, args->agno, XFS_BTNUM_BNO);
+ if (!acur->bnogt)
+ acur->bnogt = xfs_allocbt_init_cursor(args->mp, args->tp,
+ args->agbp, args->agno, XFS_BTNUM_BNO);
+ return i == 1 ? 0 : -ENOSPC;
+}
+
+static void
+xfs_alloc_cur_close(
+ struct xfs_alloc_cur *acur,
+ bool error)
+{
+ int cur_error = XFS_BTREE_NOERROR;
+
+ if (error)
+ cur_error = XFS_BTREE_ERROR;
+
+ if (acur->cnt)
+ xfs_btree_del_cursor(acur->cnt, cur_error);
+ if (acur->bnolt)
+ xfs_btree_del_cursor(acur->bnolt, cur_error);
+ if (acur->bnogt)
+ xfs_btree_del_cursor(acur->bnogt, cur_error);
+ acur->cnt = acur->bnolt = acur->bnogt = NULL;
+}
/*
* Deal with the case where only small freespaces remain. Either return the
STATIC int
xfs_alloc_find_best_extent(
struct xfs_alloc_arg *args, /* allocation argument structure */
- struct xfs_btree_cur **gcur, /* good cursor */
- struct xfs_btree_cur **scur, /* searching cursor */
+ struct xfs_btree_cur *gcur, /* good cursor */
+ struct xfs_btree_cur *scur, /* searching cursor */
xfs_agblock_t gdiff, /* difference for search comparison */
xfs_agblock_t *sbno, /* extent found by search */
xfs_extlen_t *slen, /* extent length */
* Look until we find a better one, run out of space or run off the end.
*/
do {
- error = xfs_alloc_get_rec(*scur, sbno, slen, &i);
+ error = xfs_alloc_get_rec(scur, sbno, slen, &i);
if (error)
goto error0;
XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0);
}
if (!dir)
- error = xfs_btree_increment(*scur, 0, &i);
+ error = xfs_btree_increment(scur, 0, &i);
else
- error = xfs_btree_decrement(*scur, 0, &i);
+ error = xfs_btree_decrement(scur, 0, &i);
if (error)
goto error0;
} while (i);
out_use_good:
- xfs_btree_del_cursor(*scur, XFS_BTREE_NOERROR);
- *scur = NULL;
+ scur->bc_private.a.priv.abt.active = false;
return 0;
out_use_search:
- xfs_btree_del_cursor(*gcur, XFS_BTREE_NOERROR);
- *gcur = NULL;
+ gcur->bc_private.a.priv.abt.active = false;
return 0;
error0:
* and of the form k * prod + mod unless there's nothing that large.
* Return the starting a.g. block, or NULLAGBLOCK if we can't do it.
*/
-STATIC int /* error */
+STATIC int
xfs_alloc_ag_vextent_near(
- xfs_alloc_arg_t *args) /* allocation argument structure */
+ struct xfs_alloc_arg *args)
{
- xfs_btree_cur_t *bno_cur_gt; /* cursor for bno btree, right side */
- xfs_btree_cur_t *bno_cur_lt; /* cursor for bno btree, left side */
- xfs_btree_cur_t *cnt_cur; /* cursor for count btree */
+ struct xfs_alloc_cur acur = {};
+ struct xfs_btree_cur *bno_cur;
xfs_agblock_t gtbno; /* start bno of right side entry */
xfs_agblock_t gtbnoa; /* aligned ... */
xfs_extlen_t gtdiff; /* difference to right side entry */
args->agbno = args->max_agbno;
restart:
- bno_cur_lt = NULL;
- bno_cur_gt = NULL;
ltlen = 0;
gtlena = 0;
ltlena = 0;
busy = false;
/*
- * Get a cursor for the by-size btree.
+ * Set up cursors and see if there are any free extents as big as
+ * maxlen. If not, pick the last entry in the tree unless the tree is
+ * empty.
*/
- cnt_cur = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp,
- args->agno, XFS_BTNUM_CNT);
-
- /*
- * See if there are any free extents as big as maxlen.
- */
- if ((error = xfs_alloc_lookup_ge(cnt_cur, 0, args->maxlen, &i)))
- goto error0;
- /*
- * If none, then pick up the last entry in the tree unless the
- * tree is empty.
- */
- if (!i) {
- if ((error = xfs_alloc_ag_vextent_small(args, cnt_cur, <bno,
- <len, &i)))
- goto error0;
+ error = xfs_alloc_cur_setup(args, &acur);
+ if (error == -ENOSPC) {
+ error = xfs_alloc_ag_vextent_small(args, acur.cnt, <bno,
+ <len, &i);
+ if (error)
+ goto out;
if (i == 0 || ltlen == 0) {
- xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
trace_xfs_alloc_near_noentry(args);
- return 0;
+ goto out;
}
ASSERT(i == 1);
+ } else if (error) {
+ goto out;
}
args->wasfromfl = 0;
* This is written as a while loop so we can break out of it,
* but we never loop back to the top.
*/
- while (xfs_btree_islastblock(cnt_cur, 0)) {
+ while (xfs_btree_islastblock(acur.cnt, 0)) {
xfs_extlen_t bdiff;
int besti=0;
xfs_extlen_t blen=0;
* and skip all those smaller than minlen.
*/
if (ltlen || args->alignment > 1) {
- cnt_cur->bc_ptrs[0] = 1;
+ acur.cnt->bc_ptrs[0] = 1;
do {
- if ((error = xfs_alloc_get_rec(cnt_cur, <bno,
- <len, &i)))
- goto error0;
- XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0);
+ error = xfs_alloc_get_rec(acur.cnt, <bno,
+ <len, &i);
+ if (error)
+ goto out;
+ XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, out);
if (ltlen >= args->minlen)
break;
- if ((error = xfs_btree_increment(cnt_cur, 0, &i)))
- goto error0;
+ error = xfs_btree_increment(acur.cnt, 0, &i);
+ if (error)
+ goto out;
} while (i);
ASSERT(ltlen >= args->minlen);
if (!i)
break;
}
- i = cnt_cur->bc_ptrs[0];
+ i = acur.cnt->bc_ptrs[0];
for (j = 1, blen = 0, bdiff = 0;
!error && j && (blen < args->maxlen || bdiff > 0);
- error = xfs_btree_increment(cnt_cur, 0, &j)) {
+ error = xfs_btree_increment(acur.cnt, 0, &j)) {
/*
* For each entry, decide if it's better than
* the previous best entry.
*/
- if ((error = xfs_alloc_get_rec(cnt_cur, <bno, <len, &i)))
- goto error0;
- XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0);
+ error = xfs_alloc_get_rec(acur.cnt, <bno, <len, &i);
+ if (error)
+ goto out;
+ XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, out);
busy = xfs_alloc_compute_aligned(args, ltbno, ltlen,
<bnoa, <lena, &busy_gen);
if (ltlena < args->minlen)
bdiff = ltdiff;
bnew = ltnew;
blen = args->len;
- besti = cnt_cur->bc_ptrs[0];
+ besti = acur.cnt->bc_ptrs[0];
}
}
/*
/*
* Point at the best entry, and retrieve it again.
*/
- cnt_cur->bc_ptrs[0] = besti;
- if ((error = xfs_alloc_get_rec(cnt_cur, <bno, <len, &i)))
- goto error0;
- XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0);
+ acur.cnt->bc_ptrs[0] = besti;
+ error = xfs_alloc_get_rec(acur.cnt, <bno, <len, &i);
+ if (error)
+ goto out;
+ XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, out);
ASSERT(ltbno + ltlen <= be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length));
args->len = blen;
args->agbno = bnew;
ASSERT(bnew >= ltbno);
ASSERT(bnew + blen <= ltbno + ltlen);
- /*
- * Set up a cursor for the by-bno tree.
- */
- bno_cur_lt = xfs_allocbt_init_cursor(args->mp, args->tp,
- args->agbp, args->agno, XFS_BTNUM_BNO);
- /*
- * Fix up the btree entries.
- */
- if ((error = xfs_alloc_fixup_trees(cnt_cur, bno_cur_lt, ltbno,
- ltlen, bnew, blen, XFSA_FIXUP_CNT_OK)))
- goto error0;
- xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
- xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_NOERROR);
-
+ error = xfs_alloc_fixup_trees(acur.cnt, acur.bnolt, ltbno,
+ ltlen, bnew, blen, XFSA_FIXUP_CNT_OK);
+ if (error)
+ goto out;
trace_xfs_alloc_near_first(args);
- return 0;
+ goto out;
}
+
/*
* Second algorithm.
* Search in the by-bno tree to the left and to the right
* level algorithm that picks allocation groups for allocations
* is not supposed to do this.
*/
- /*
- * Allocate and initialize the cursor for the leftward search.
- */
- bno_cur_lt = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp,
- args->agno, XFS_BTNUM_BNO);
- /*
- * Lookup <= bno to find the leftward search's starting point.
- */
- if ((error = xfs_alloc_lookup_le(bno_cur_lt, args->agbno, args->maxlen, &i)))
- goto error0;
- if (!i) {
- /*
- * Didn't find anything; use this cursor for the rightward
- * search.
- */
- bno_cur_gt = bno_cur_lt;
- bno_cur_lt = NULL;
- }
- /*
- * Found something. Duplicate the cursor for the rightward search.
- */
- else if ((error = xfs_btree_dup_cursor(bno_cur_lt, &bno_cur_gt)))
- goto error0;
- /*
- * Increment the cursor, so we will point at the entry just right
- * of the leftward entry if any, or to the leftmost entry.
- */
- if ((error = xfs_btree_increment(bno_cur_gt, 0, &i)))
- goto error0;
- if (!i) {
- /*
- * It failed, there are no rightward entries.
- */
- xfs_btree_del_cursor(bno_cur_gt, XFS_BTREE_NOERROR);
- bno_cur_gt = NULL;
- }
+ error = xfs_alloc_lookup_le(acur.bnolt, args->agbno, 0, &i);
+ if (error)
+ goto out;
+ error = xfs_alloc_lookup_ge(acur.bnogt, args->agbno, 0, &i);
+ if (error)
+ goto out;
+
/*
* Loop going left with the leftward cursor, right with the
* rightward cursor, until either both directions give up or
* we find an entry at least as big as minlen.
*/
do {
- if (bno_cur_lt) {
- if ((error = xfs_alloc_get_rec(bno_cur_lt, <bno, <len, &i)))
- goto error0;
- XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0);
+ if (xfs_alloc_cur_active(acur.bnolt)) {
+ error = xfs_alloc_get_rec(acur.bnolt, <bno, <len, &i);
+ if (error)
+ goto out;
+ XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, out);
busy |= xfs_alloc_compute_aligned(args, ltbno, ltlen,
<bnoa, <lena, &busy_gen);
if (ltlena >= args->minlen && ltbnoa >= args->min_agbno)
break;
- if ((error = xfs_btree_decrement(bno_cur_lt, 0, &i)))
- goto error0;
- if (!i || ltbnoa < args->min_agbno) {
- xfs_btree_del_cursor(bno_cur_lt,
- XFS_BTREE_NOERROR);
- bno_cur_lt = NULL;
- }
+ error = xfs_btree_decrement(acur.bnolt, 0, &i);
+ if (error)
+ goto out;
+ if (!i || ltbnoa < args->min_agbno)
+ acur.bnolt->bc_private.a.priv.abt.active = false;
}
- if (bno_cur_gt) {
- if ((error = xfs_alloc_get_rec(bno_cur_gt, >bno, >len, &i)))
- goto error0;
- XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0);
+ if (xfs_alloc_cur_active(acur.bnogt)) {
+ error = xfs_alloc_get_rec(acur.bnogt, >bno, >len, &i);
+ if (error)
+ goto out;
+ XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, out);
busy |= xfs_alloc_compute_aligned(args, gtbno, gtlen,
>bnoa, >lena, &busy_gen);
if (gtlena >= args->minlen && gtbnoa <= args->max_agbno)
break;
- if ((error = xfs_btree_increment(bno_cur_gt, 0, &i)))
- goto error0;
- if (!i || gtbnoa > args->max_agbno) {
- xfs_btree_del_cursor(bno_cur_gt,
- XFS_BTREE_NOERROR);
- bno_cur_gt = NULL;
- }
+ error = xfs_btree_increment(acur.bnogt, 0, &i);
+ if (error)
+ goto out;
+ if (!i || gtbnoa > args->max_agbno)
+ acur.bnogt->bc_private.a.priv.abt.active = false;
}
- } while (bno_cur_lt || bno_cur_gt);
+ } while (xfs_alloc_cur_active(acur.bnolt) ||
+ xfs_alloc_cur_active(acur.bnogt));
/*
* Got both cursors still active, need to find better entry.
*/
- if (bno_cur_lt && bno_cur_gt) {
+ if (xfs_alloc_cur_active(acur.bnolt) &&
+ xfs_alloc_cur_active(acur.bnogt)) {
if (ltlena >= args->minlen) {
/*
* Left side is good, look for a right side entry.
ltlena, <new);
error = xfs_alloc_find_best_extent(args,
- &bno_cur_lt, &bno_cur_gt,
+ acur.bnolt, acur.bnogt,
ltdiff, >bno, >len,
>bnoa, >lena,
0 /* search right */);
gtlena, >new);
error = xfs_alloc_find_best_extent(args,
- &bno_cur_gt, &bno_cur_lt,
+ acur.bnogt, acur.bnolt,
gtdiff, <bno, <len,
<bnoa, <lena,
1 /* search left */);
}
if (error)
- goto error0;
+ goto out;
}
/*
* If we couldn't get anything, give up.
*/
- if (bno_cur_lt == NULL && bno_cur_gt == NULL) {
- xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
-
+ if (!xfs_alloc_cur_active(acur.bnolt) &&
+ !xfs_alloc_cur_active(acur.bnogt)) {
if (busy) {
trace_xfs_alloc_near_busy(args);
xfs_extent_busy_flush(args->mp, args->pag, busy_gen);
}
trace_xfs_alloc_size_neither(args);
args->agbno = NULLAGBLOCK;
- return 0;
+ goto out;
}
/*
* useful variables to the "left" set so we only have one
* copy of this code.
*/
- if (bno_cur_gt) {
- bno_cur_lt = bno_cur_gt;
- bno_cur_gt = NULL;
+ if (xfs_alloc_cur_active(acur.bnogt)) {
+ bno_cur = acur.bnogt;
ltbno = gtbno;
ltbnoa = gtbnoa;
ltlen = gtlen;
ltlena = gtlena;
j = 1;
- } else
+ } else {
+ bno_cur = acur.bnolt;
j = 0;
+ }
/*
* Fix up the length and compute the useful address.
ASSERT(ltnew >= args->min_agbno && ltnew <= args->max_agbno);
args->agbno = ltnew;
- if ((error = xfs_alloc_fixup_trees(cnt_cur, bno_cur_lt, ltbno, ltlen,
- ltnew, rlen, XFSA_FIXUP_BNO_OK)))
- goto error0;
+ error = xfs_alloc_fixup_trees(acur.cnt, bno_cur, ltbno, ltlen, ltnew,
+ rlen, XFSA_FIXUP_BNO_OK);
+ if (error)
+ goto out;
if (j)
trace_xfs_alloc_near_greater(args);
else
trace_xfs_alloc_near_lesser(args);
- xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
- xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_NOERROR);
- return 0;
-
- error0:
- trace_xfs_alloc_near_error(args);
- if (cnt_cur != NULL)
- xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
- if (bno_cur_lt != NULL)
- xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_ERROR);
- if (bno_cur_gt != NULL)
- xfs_btree_del_cursor(bno_cur_gt, XFS_BTREE_ERROR);
+out:
+ xfs_alloc_cur_close(&acur, error);
return error;
}
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