diff options
Diffstat (limited to 'fs/xfs/xfs_alloc.c')
| -rw-r--r-- | fs/xfs/xfs_alloc.c | 361 |
1 files changed, 148 insertions, 213 deletions
diff --git a/fs/xfs/xfs_alloc.c b/fs/xfs/xfs_alloc.c index 112abc439ca..f3227984a9b 100644 --- a/fs/xfs/xfs_alloc.c +++ b/fs/xfs/xfs_alloc.c @@ -41,10 +41,6 @@ #define XFSA_FIXUP_BNO_OK 1 #define XFSA_FIXUP_CNT_OK 2 -static int -xfs_alloc_busy_search(struct xfs_mount *mp, xfs_agnumber_t agno, - xfs_agblock_t bno, xfs_extlen_t len); - /* * Prototypes for per-ag allocation routines */ @@ -94,7 +90,7 @@ xfs_alloc_lookup_ge( * Lookup the first record less than or equal to [bno, len] * in the btree given by cur. */ -STATIC int /* error */ +int /* error */ xfs_alloc_lookup_le( struct xfs_btree_cur *cur, /* btree cursor */ xfs_agblock_t bno, /* starting block of extent */ @@ -127,7 +123,7 @@ xfs_alloc_update( /* * Get the data from the pointed-to record. */ -STATIC int /* error */ +int /* error */ xfs_alloc_get_rec( struct xfs_btree_cur *cur, /* btree cursor */ xfs_agblock_t *bno, /* output: starting block of extent */ @@ -577,61 +573,58 @@ xfs_alloc_ag_vextent_exact( xfs_extlen_t rlen; /* length of returned extent */ ASSERT(args->alignment == 1); + /* * Allocate/initialize a cursor for the by-number freespace btree. */ bno_cur = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp, - args->agno, XFS_BTNUM_BNO); + args->agno, XFS_BTNUM_BNO); + /* * Lookup bno and minlen in the btree (minlen is irrelevant, really). * Look for the closest free block <= bno, it must contain bno * if any free block does. */ - if ((error = xfs_alloc_lookup_le(bno_cur, args->agbno, args->minlen, &i))) + error = xfs_alloc_lookup_le(bno_cur, args->agbno, args->minlen, &i); + if (error) goto error0; - if (!i) { - /* - * Didn't find it, return null. - */ - xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR); - args->agbno = NULLAGBLOCK; - return 0; - } + if (!i) + goto not_found; + /* * Grab the freespace record. */ - if ((error = xfs_alloc_get_rec(bno_cur, &fbno, &flen, &i))) + error = xfs_alloc_get_rec(bno_cur, &fbno, &flen, &i); + if (error) goto error0; XFS_WANT_CORRUPTED_GOTO(i == 1, error0); ASSERT(fbno <= args->agbno); minend = args->agbno + args->minlen; maxend = args->agbno + args->maxlen; fend = fbno + flen; + /* * Give up if the freespace isn't long enough for the minimum request. */ - if (fend < minend) { - xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR); - args->agbno = NULLAGBLOCK; - return 0; - } + if (fend < minend) + goto not_found; + /* * End of extent will be smaller of the freespace end and the * maximal requested end. - */ - end = XFS_AGBLOCK_MIN(fend, maxend); - /* + * * Fix the length according to mod and prod if given. */ + end = XFS_AGBLOCK_MIN(fend, maxend); args->len = end - args->agbno; xfs_alloc_fix_len(args); - if (!xfs_alloc_fix_minleft(args)) { - xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR); - return 0; - } + if (!xfs_alloc_fix_minleft(args)) + goto not_found; + rlen = args->len; ASSERT(args->agbno + rlen <= fend); end = args->agbno + rlen; + /* * We are allocating agbno for rlen [agbno .. end] * Allocate/initialize a cursor for the by-size btree. @@ -640,16 +633,25 @@ xfs_alloc_ag_vextent_exact( args->agno, XFS_BTNUM_CNT); ASSERT(args->agbno + args->len <= be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length)); - if ((error = xfs_alloc_fixup_trees(cnt_cur, bno_cur, fbno, flen, - args->agbno, args->len, XFSA_FIXUP_BNO_OK))) { + error = xfs_alloc_fixup_trees(cnt_cur, bno_cur, fbno, flen, args->agbno, + args->len, XFSA_FIXUP_BNO_OK); + if (error) { xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR); goto error0; } + xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR); xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR); - trace_xfs_alloc_exact_done(args); args->wasfromfl = 0; + trace_xfs_alloc_exact_done(args); + return 0; + +not_found: + /* Didn't find it, return null. */ + xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR); + args->agbno = NULLAGBLOCK; + trace_xfs_alloc_exact_notfound(args); return 0; error0: @@ -659,6 +661,95 @@ error0: } /* + * Search the btree in a given direction via the search cursor and compare + * the records found against the good extent we've already found. + */ +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 */ + xfs_agblock_t gdiff, /* difference for search comparison */ + xfs_agblock_t *sbno, /* extent found by search */ + xfs_extlen_t *slen, + xfs_extlen_t *slena, /* aligned length */ + int dir) /* 0 = search right, 1 = search left */ +{ + xfs_agblock_t bno; + xfs_agblock_t new; + xfs_agblock_t sdiff; + int error; + int i; + + /* The good extent is perfect, no need to search. */ + if (!gdiff) + goto out_use_good; + + /* + * 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); + if (error) + goto error0; + XFS_WANT_CORRUPTED_GOTO(i == 1, error0); + xfs_alloc_compute_aligned(*sbno, *slen, args->alignment, + args->minlen, &bno, slena); + + /* + * The good extent is closer than this one. + */ + if (!dir) { + if (bno >= args->agbno + gdiff) + goto out_use_good; + } else { + if (bno <= args->agbno - gdiff) + goto out_use_good; + } + + /* + * Same distance, compare length and pick the best. + */ + if (*slena >= args->minlen) { + args->len = XFS_EXTLEN_MIN(*slena, args->maxlen); + xfs_alloc_fix_len(args); + + sdiff = xfs_alloc_compute_diff(args->agbno, args->len, + args->alignment, *sbno, + *slen, &new); + + /* + * Choose closer size and invalidate other cursor. + */ + if (sdiff < gdiff) + goto out_use_search; + goto out_use_good; + } + + if (!dir) + error = xfs_btree_increment(*scur, 0, &i); + else + 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; + return 0; + +out_use_search: + xfs_btree_del_cursor(*gcur, XFS_BTREE_NOERROR); + *gcur = NULL; + return 0; + +error0: + /* caller invalidates cursors */ + return error; +} + +/* * Allocate a variable extent near bno in the allocation group agno. * Extent's length (returned in len) will be between minlen and maxlen, * and of the form k * prod + mod unless there's nothing that large. @@ -925,203 +1016,45 @@ xfs_alloc_ag_vextent_near( } } } while (bno_cur_lt || bno_cur_gt); + /* * Got both cursors still active, need to find better entry. */ if (bno_cur_lt && bno_cur_gt) { - /* - * Left side is long enough, look for a right side entry. - */ if (ltlena >= args->minlen) { /* - * Fix up the length. + * Left side is good, look for a right side entry. */ args->len = XFS_EXTLEN_MIN(ltlena, args->maxlen); xfs_alloc_fix_len(args); - rlen = args->len; - ltdiff = xfs_alloc_compute_diff(args->agbno, rlen, + ltdiff = xfs_alloc_compute_diff(args->agbno, args->len, args->alignment, ltbno, ltlen, <new); + + error = xfs_alloc_find_best_extent(args, + &bno_cur_lt, &bno_cur_gt, + ltdiff, >bno, >len, >lena, + 0 /* search right */); + } else { + ASSERT(gtlena >= args->minlen); + /* - * Not perfect. - */ - if (ltdiff) { - /* - * Look until we find a better one, run out of - * space, or run off the end. - */ - while (bno_cur_lt && bno_cur_gt) { - if ((error = xfs_alloc_get_rec( - bno_cur_gt, >bno, - >len, &i))) - goto error0; - XFS_WANT_CORRUPTED_GOTO(i == 1, error0); - xfs_alloc_compute_aligned(gtbno, gtlen, - args->alignment, args->minlen, - >bnoa, >lena); - /* - * The left one is clearly better. - */ - if (gtbnoa >= args->agbno + ltdiff) { - xfs_btree_del_cursor( - bno_cur_gt, - XFS_BTREE_NOERROR); - bno_cur_gt = NULL; - break; - } - /* - * If we reach a big enough entry, - * compare the two and pick the best. - */ - if (gtlena >= args->minlen) { - args->len = - XFS_EXTLEN_MIN(gtlena, - args->maxlen); - xfs_alloc_fix_len(args); - rlen = args->len; - gtdiff = xfs_alloc_compute_diff( - args->agbno, rlen, - args->alignment, - gtbno, gtlen, >new); - /* - * Right side is better. - */ - if (gtdiff < ltdiff) { - xfs_btree_del_cursor( - bno_cur_lt, - XFS_BTREE_NOERROR); - bno_cur_lt = NULL; - } - /* - * Left side is better. - */ - else { - xfs_btree_del_cursor( - bno_cur_gt, - XFS_BTREE_NOERROR); - bno_cur_gt = NULL; - } - break; - } - /* - * Fell off the right end. - */ - if ((error = xfs_btree_increment( - bno_cur_gt, 0, &i))) - goto error0; - if (!i) { - xfs_btree_del_cursor( - bno_cur_gt, - XFS_BTREE_NOERROR); - bno_cur_gt = NULL; - break; - } - } - } - /* - * The left side is perfect, trash the right side. - */ - else { - xfs_btree_del_cursor(bno_cur_gt, - XFS_BTREE_NOERROR); - bno_cur_gt = NULL; - } - } - /* - * It's the right side that was found first, look left. - */ - else { - /* - * Fix up the length. + * Right side is good, look for a left side entry. */ args->len = XFS_EXTLEN_MIN(gtlena, args->maxlen); xfs_alloc_fix_len(args); - rlen = args->len; - gtdiff = xfs_alloc_compute_diff(args->agbno, rlen, + gtdiff = xfs_alloc_compute_diff(args->agbno, args->len, args->alignment, gtbno, gtlen, >new); - /* - * Right side entry isn't perfect. - */ - if (gtdiff) { - /* - * Look until we find a better one, run out of - * space, or run off the end. - */ - while (bno_cur_lt && bno_cur_gt) { - if ((error = xfs_alloc_get_rec( - bno_cur_lt, <bno, - <len, &i))) - goto error0; - XFS_WANT_CORRUPTED_GOTO(i == 1, error0); - xfs_alloc_compute_aligned(ltbno, ltlen, - args->alignment, args->minlen, - <bnoa, <lena); - /* - * The right one is clearly better. - */ - if (ltbnoa <= args->agbno - gtdiff) { - xfs_btree_del_cursor( - bno_cur_lt, - XFS_BTREE_NOERROR); - bno_cur_lt = NULL; - break; - } - /* - * If we reach a big enough entry, - * compare the two and pick the best. - */ - if (ltlena >= args->minlen) { - args->len = XFS_EXTLEN_MIN( - ltlena, args->maxlen); - xfs_alloc_fix_len(args); - rlen = args->len; - ltdiff = xfs_alloc_compute_diff( - args->agbno, rlen, - args->alignment, - ltbno, ltlen, <new); - /* - * Left side is better. - */ - if (ltdiff < gtdiff) { - xfs_btree_del_cursor( - bno_cur_gt, - XFS_BTREE_NOERROR); - bno_cur_gt = NULL; - } - /* - * Right side is better. - */ - else { - xfs_btree_del_cursor( - bno_cur_lt, - XFS_BTREE_NOERROR); - bno_cur_lt = NULL; - } - break; - } - /* - * Fell off the left end. - */ - if ((error = xfs_btree_decrement( - bno_cur_lt, 0, &i))) - goto error0; - if (!i) { - xfs_btree_del_cursor(bno_cur_lt, - XFS_BTREE_NOERROR); - bno_cur_lt = NULL; - break; - } - } - } - /* - * The right side is perfect, trash the left side. - */ - else { - xfs_btree_del_cursor(bno_cur_lt, - XFS_BTREE_NOERROR); - bno_cur_lt = NULL; - } + + error = xfs_alloc_find_best_extent(args, + &bno_cur_gt, &bno_cur_lt, + gtdiff, <bno, <len, <lena, + 1 /* search left */); } + + if (error) + goto error0; } + /* * If we couldn't get anything, give up. */ @@ -1130,6 +1063,7 @@ xfs_alloc_ag_vextent_near( args->agbno = NULLAGBLOCK; return 0; } + /* * At this point we have selected a freespace entry, either to the * left or to the right. If it's on the right, copy all the @@ -1146,6 +1080,7 @@ xfs_alloc_ag_vextent_near( j = 1; } else j = 0; + /* * Fix up the length and compute the useful address. */ @@ -2676,7 +2611,7 @@ restart: * will require a synchronous transaction, but it can still be * used to distinguish between a partial or exact match. */ -static int +int xfs_alloc_busy_search( struct xfs_mount *mp, xfs_agnumber_t agno, |