With -o mincluster, we save the location of the last successful allocation, so as to emulate some of the cluster allocation logic (though not non-bitmap preference) without actually going through the exercise of allocating clusters.
Signed-off-by: Alexandre Oliva <ol...@lsd.ic.unicamp.br> --- fs/btrfs/extent-tree.c | 16 +++++++++++++--- fs/btrfs/free-space-cache.c | 1 + fs/btrfs/super.c | 17 +++++++++++++---- 3 files changed, 27 insertions(+), 7 deletions(-) diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 7ddbf9b..3c649fe 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -5172,7 +5172,7 @@ static noinline int find_free_extent(struct btrfs_trans_handle *trans, { int ret = 0; struct btrfs_root *root = orig_root->fs_info->extent_root; - struct btrfs_free_cluster *last_ptr = NULL; + struct btrfs_free_cluster *last_ptr = NULL, *save_ptr = NULL; struct btrfs_block_group_cache *block_group = NULL; struct btrfs_block_group_cache *used_block_group; int empty_cluster = 2 * 1024 * 1024; @@ -5219,8 +5219,16 @@ static noinline int find_free_extent(struct btrfs_trans_handle *trans, debug = 1; debugid = atomic_inc_return(&debugcnt); last_ptr = &root->fs_info->meta_alloc_cluster; - if (!btrfs_test_opt(root, SSD)) - empty_cluster = 64 * 1024; + if (!btrfs_test_opt(root, SSD)) { + /* !SSD && SSD_SPREAD == -o mincluster. */ + if (btrfs_test_opt(root, SSD_SPREAD)) { + save_ptr = last_ptr; + hint_byte = save_ptr->window_start; + last_ptr = NULL; + use_cluster = false; + } else + empty_cluster = 64 * 1024; + } } if ((data & BTRFS_BLOCK_GROUP_DATA) && use_cluster && @@ -5556,6 +5564,8 @@ checks: btrfs_add_free_space(used_block_group, offset, search_start - offset); BUG_ON(offset > search_start); + if (save_ptr) + save_ptr->window_start = search_start + num_bytes; if (used_block_group != block_group) btrfs_put_block_group(used_block_group); btrfs_put_block_group(block_group); diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c index 3aa56e4..953f7dd 100644 --- a/fs/btrfs/free-space-cache.c +++ b/fs/btrfs/free-space-cache.c @@ -2579,6 +2579,7 @@ void btrfs_init_free_cluster(struct btrfs_free_cluster *cluster) cluster->max_size = 0; INIT_LIST_HEAD(&cluster->block_group_list); cluster->block_group = NULL; + cluster->window_start = 0; } int btrfs_trim_block_group(struct btrfs_block_group_cache *block_group, diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index 26b13d7..32fe064 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -165,7 +165,7 @@ enum { Opt_space_cache, Opt_clear_cache, Opt_user_subvol_rm_allowed, Opt_enospc_debug, Opt_subvolrootid, Opt_defrag, Opt_inode_cache, Opt_no_space_cache, Opt_recovery, - Opt_nocluster, Opt_cluster, Opt_err, + Opt_nocluster, Opt_cluster, Opt_mincluster, Opt_err, }; static match_table_t tokens = { @@ -202,6 +202,7 @@ static match_table_t tokens = { {Opt_recovery, "recovery"}, {Opt_nocluster, "nocluster"}, {Opt_cluster, "cluster"}, + {Opt_mincluster, "mincluster"}, {Opt_err, NULL}, }; @@ -407,6 +408,11 @@ int btrfs_parse_options(struct btrfs_root *root, char *options) printk(KERN_INFO "btrfs: enabling alloc clustering\n"); btrfs_clear_opt(info->mount_opt, NO_ALLOC_CLUSTER); break; + case Opt_mincluster: + printk(KERN_INFO "btrfs: enabling minimal alloc clustering\n"); + btrfs_clear_opt(info->mount_opt, NO_ALLOC_CLUSTER); + btrfs_set_opt(info->mount_opt, SSD_SPREAD); + break; case Opt_err: printk(KERN_INFO "btrfs: unrecognized mount option " "'%s'\n", p); @@ -706,9 +712,12 @@ static int btrfs_show_options(struct seq_file *seq, struct vfsmount *vfs) } if (btrfs_test_opt(root, NOSSD)) seq_puts(seq, ",nossd"); - if (btrfs_test_opt(root, SSD_SPREAD)) - seq_puts(seq, ",ssd_spread"); - else if (btrfs_test_opt(root, SSD)) + if (btrfs_test_opt(root, SSD_SPREAD)) { + if (btrfs_test_opt(root, SSD)) + seq_puts(seq, ",ssd_spread"); + else + seq_puts(seq, ",mincluster"); + } else if (btrfs_test_opt(root, SSD)) seq_puts(seq, ",ssd"); if (btrfs_test_opt(root, NOTREELOG)) seq_puts(seq, ",notreelog"); -- 1.7.4.4 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html