From d0bd456074dca089579818312da7cbe726ad2ff9 Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Wed, 23 Sep 2015 14:54:14 -0400 Subject: Btrfs: add fragment=* debug mount option In tracking down these weird bitmap problems it was helpful to artificially create an extremely fragmented file system. These mount options let us either fragment data or metadata or both. With these options I could reproduce all sorts of weird latencies and hangs that occur under extreme fragmentation and get them fixed. Thanks, Signed-off-by: Josef Bacik Signed-off-by: Chris Mason --- fs/btrfs/super.c | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) (limited to 'fs/btrfs/super.c') diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index b23d49daa1a2..24154e422945 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -303,6 +303,9 @@ enum { Opt_commit_interval, Opt_barrier, Opt_nodefrag, Opt_nodiscard, Opt_noenospc_debug, Opt_noflushoncommit, Opt_acl, Opt_datacow, Opt_datasum, Opt_treelog, Opt_noinode_cache, +#ifdef CONFIG_BTRFS_DEBUG + Opt_fragment_data, Opt_fragment_metadata, Opt_fragment_all, +#endif Opt_err, }; @@ -355,6 +358,11 @@ static match_table_t tokens = { {Opt_rescan_uuid_tree, "rescan_uuid_tree"}, {Opt_fatal_errors, "fatal_errors=%s"}, {Opt_commit_interval, "commit=%d"}, +#ifdef CONFIG_BTRFS_DEBUG + {Opt_fragment_data, "fragment=data"}, + {Opt_fragment_metadata, "fragment=metadata"}, + {Opt_fragment_all, "fragment=all"}, +#endif {Opt_err, NULL}, }; @@ -721,6 +729,22 @@ int btrfs_parse_options(struct btrfs_root *root, char *options) info->commit_interval = BTRFS_DEFAULT_COMMIT_INTERVAL; } break; +#ifdef CONFIG_BTRFS_DEBUG + case Opt_fragment_all: + btrfs_info(root->fs_info, "fragmenting all space"); + btrfs_set_opt(info->mount_opt, FRAGMENT_DATA); + btrfs_set_opt(info->mount_opt, FRAGMENT_METADATA); + break; + case Opt_fragment_metadata: + btrfs_info(root->fs_info, "fragmenting metadata"); + btrfs_set_opt(info->mount_opt, + FRAGMENT_METADATA); + break; + case Opt_fragment_data: + btrfs_info(root->fs_info, "fragmenting data"); + btrfs_set_opt(info->mount_opt, FRAGMENT_DATA); + break; +#endif case Opt_err: btrfs_info(root->fs_info, "unrecognized mount option '%s'", p); ret = -EINVAL; @@ -1172,6 +1196,12 @@ static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry) seq_puts(seq, ",fatal_errors=panic"); if (info->commit_interval != BTRFS_DEFAULT_COMMIT_INTERVAL) seq_printf(seq, ",commit=%d", info->commit_interval); +#ifdef CONFIG_BTRFS_DEBUG + if (btrfs_test_opt(root, FRAGMENT_DATA)) + seq_puts(seq, ",fragment=data"); + if (btrfs_test_opt(root, FRAGMENT_METADATA)) + seq_puts(seq, ",fragment=metadata"); +#endif seq_printf(seq, ",subvolid=%llu", BTRFS_I(d_inode(dentry))->root->root_key.objectid); seq_puts(seq, ",subvol="); -- cgit v1.2.3