From: Darrick J. Wong <darrick.wong@xxxxxxxxxx> Refactor the weird while loop out of existence. Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx> --- fs/xfs/libxfs/xfs_alloc.c | 119 +++++++++++++++++++++++++-------------------- 1 file changed, 66 insertions(+), 53 deletions(-) diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c index 60ca09bedc23..3a724d80783a 100644 --- a/fs/xfs/libxfs/xfs_alloc.c +++ b/fs/xfs/libxfs/xfs_alloc.c @@ -1486,6 +1486,65 @@ xfs_alloc_ag_vextent_locality( return 0; } +/* Check the last block of the cnt btree for allocations. */ +static int +xfs_alloc_ag_vextent_lastblock( + struct xfs_alloc_arg *args, + struct xfs_alloc_cur *acur, + xfs_agblock_t *bno, + xfs_extlen_t *len, + bool *allocated) +{ + int error; + int i; + +#ifdef DEBUG + /* Randomly don't execute the first algorithm. */ + if (prandom_u32() & 1) + return 0; +#endif + + /* + * Start from the entry that lookup found, sequence through all larger + * free blocks. If we're actually pointing at a record smaller than + * maxlen, go to the start of this block, and skip all those smaller + * than minlen. + */ + if (len || args->alignment > 1) { + acur->cnt->bc_ptrs[0] = 1; + do { + error = xfs_alloc_get_rec(acur->cnt, bno, len, &i); + if (error) + return error; + if (XFS_IS_CORRUPT(args->mp, i != 1)) + return -EFSCORRUPTED; + if (*len >= args->minlen) + break; + error = xfs_btree_increment(acur->cnt, 0, &i); + if (error) + return error; + } while (i); + ASSERT(*len >= args->minlen); + if (!i) + return 0; + } + + error = xfs_alloc_walk_iter(args, acur, acur->cnt, true, false, -1, &i); + if (error) + return error; + + /* + * It didn't work. We COULD be in a case where there's a good record + * somewhere, so try again. + */ + if (acur->len == 0) + return 0; + + trace_xfs_alloc_near_first(args); + *allocated = true; + return 0; +} + /* * Allocate a variable extent near bno in the allocation group agno. * Extent's length (returned in len) will be between minlen and maxlen, @@ -1501,14 +1560,6 @@ xfs_alloc_ag_vextent_near( int i; /* result code, temporary */ xfs_agblock_t bno; xfs_extlen_t len; -#ifdef DEBUG - /* - * Randomly don't execute the first algorithm. - */ - int dofirst; /* set to do first algorithm */ - - dofirst = prandom_u32() & 1; -#endif /* handle uninitialized agbno range so caller doesn't have to */ if (!args->min_agbno && !args->max_agbno) @@ -1551,54 +1602,16 @@ xfs_alloc_ag_vextent_near( * near the right edge of the tree. If it's in the last btree leaf * block, then we just examine all the entries in that block * that are big enough, and pick the best one. - * 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(acur.cnt, 0)) { -#ifdef DEBUG - if (dofirst) - break; -#endif - /* - * Start from the entry that lookup found, sequence through - * all larger free blocks. If we're actually pointing at a - * record smaller than maxlen, go to the start of this block, - * and skip all those smaller than minlen. - */ - if (len || args->alignment > 1) { - acur.cnt->bc_ptrs[0] = 1; - do { - error = xfs_alloc_get_rec(acur.cnt, &bno, &len, - &i); - if (error) - goto out; - if (XFS_IS_CORRUPT(args->mp, i != 1)) - goto out; - if (len >= args->minlen) - break; - error = xfs_btree_increment(acur.cnt, 0, &i); - if (error) - goto out; - } while (i); - ASSERT(len >= args->minlen); - if (!i) - break; - } + if (xfs_btree_islastblock(acur.cnt, 0)) { + bool allocated = false; - error = xfs_alloc_walk_iter(args, &acur, acur.cnt, true, false, - -1, &i); + error = xfs_alloc_ag_vextent_lastblock(args, &acur, &bno, &len, + &allocated); if (error) goto out; - - /* - * It didn't work. We COULD be in a case where - * there's a good record somewhere, so try again. - */ - if (acur.len == 0) - break; - - trace_xfs_alloc_near_first(args); - goto alloc; + if (allocated) + goto alloc_finish; } /* @@ -1624,7 +1637,7 @@ xfs_alloc_ag_vextent_near( goto out; } -alloc: +alloc_finish: /* fix up btrees on a successful allocation */ error = xfs_alloc_cur_finish(args, &acur);