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author | Darrick J. Wong <darrick.wong@oracle.com> | 2019-11-07 12:29:00 -0800 |
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committer | Darrick J. Wong <darrick.wong@oracle.com> | 2019-11-10 10:21:58 -0800 |
commit | 5113f8ec3753ed4d68a5d54d3345fee33a914bfe (patch) | |
tree | eefc2a2d66b0db25d70e2bde5252285533904d08 /fs/xfs/libxfs/xfs_alloc.c | |
parent | f755979355d46ef088f9c9fdb5d11c4a425e738e (diff) | |
download | linux-5113f8ec3753ed4d68a5d54d3345fee33a914bfe.tar.gz linux-5113f8ec3753ed4d68a5d54d3345fee33a914bfe.tar.bz2 linux-5113f8ec3753ed4d68a5d54d3345fee33a914bfe.zip |
xfs: clean up weird while loop in xfs_alloc_ag_vextent_near
Refactor the weird while loop out of existence.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'fs/xfs/libxfs/xfs_alloc.c')
-rw-r--r-- | fs/xfs/libxfs/xfs_alloc.c | 117 |
1 files changed, 65 insertions, 52 deletions
diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c index b39bd81d78bd..675613c7bacb 100644 --- a/fs/xfs/libxfs/xfs_alloc.c +++ b/fs/xfs/libxfs/xfs_alloc.c @@ -1464,6 +1464,64 @@ 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; + XFS_WANT_CORRUPTED_RETURN(args->mp, i == 1); + 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, @@ -1479,14 +1537,6 @@ 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) @@ -1529,53 +1579,16 @@ restart: * 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; - XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, 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; } /* @@ -1601,7 +1614,7 @@ restart: goto out; } -alloc: +alloc_finish: /* fix up btrees on a successful allocation */ error = xfs_alloc_cur_finish(args, &acur); |