On Oct 29, 2011, Chris Mason <chris.mason@xxxxxxxxxx> wrote:
> The last one isn't a bad idea, but please do make a real mount option
> for it ;)
Like this?
>From af086e7b88637be5c9806181a1d70db9c645cb50 Mon Sep 17 00:00:00 2001
From: Alexandre Oliva <lxoliva@xxxxxxxxx>
Date: Sat, 29 Oct 2011 02:20:55 -0200
Subject: [PATCH 4/4] Disable clustered allocation with -o nocluster
Introduce -o nocluster to disable the use of clusters for extent
allocation.
Signed-off-by: Alexandre Oliva <oliva@xxxxxxxxxxxxxxxxx>
---
fs/btrfs/ctree.h | 1 +
fs/btrfs/extent-tree.c | 2 +-
fs/btrfs/super.c | 11 +++++++++--
3 files changed, 11 insertions(+), 3 deletions(-)
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 03912c5..b1138fb 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -1363,6 +1363,7 @@ struct btrfs_ioctl_defrag_range_args {
#define BTRFS_MOUNT_ENOSPC_DEBUG (1 << 15)
#define BTRFS_MOUNT_AUTO_DEFRAG (1 << 16)
#define BTRFS_MOUNT_INODE_MAP_CACHE (1 << 17)
+#define BTRFS_MOUNT_NO_ALLOC_CLUSTER (1 << 18)
#define btrfs_clear_opt(o, opt) ((o) &= ~BTRFS_MOUNT_##opt)
#define btrfs_set_opt(o, opt) ((o) |= BTRFS_MOUNT_##opt)
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index f5be06a..5d7c9a7 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -4886,7 +4886,7 @@ static noinline int find_free_extent(struct btrfs_trans_handle *trans,
bool found_uncached_bg = false;
bool failed_cluster_refill = false;
bool failed_alloc = false;
- bool use_cluster = true;
+ bool use_cluster = !btrfs_test_opt(root, NO_ALLOC_CLUSTER);
u64 ideal_cache_percent = 0;
u64 ideal_cache_offset = 0;
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 15634d4..57c7bb1 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -162,7 +162,7 @@ enum {
Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_discard,
Opt_space_cache, Opt_clear_cache, Opt_user_subvol_rm_allowed,
Opt_enospc_debug, Opt_subvolrootid, Opt_defrag,
- Opt_inode_cache, Opt_err,
+ Opt_inode_cache, Opt_nocluster, Opt_err,
};
static match_table_t tokens = {
@@ -195,6 +195,7 @@ static match_table_t tokens = {
{Opt_subvolrootid, "subvolrootid=%d"},
{Opt_defrag, "autodefrag"},
{Opt_inode_cache, "inode_cache"},
+ {Opt_nocluster, "nocluster"},
{Opt_err, NULL},
};
@@ -378,9 +379,13 @@ int btrfs_parse_options(struct btrfs_root *root, char *options)
btrfs_set_opt(info->mount_opt, ENOSPC_DEBUG);
break;
case Opt_defrag:
- printk(KERN_INFO "btrfs: enabling auto defrag");
+ printk(KERN_INFO "btrfs: enabling auto defrag\n");
btrfs_set_opt(info->mount_opt, AUTO_DEFRAG);
break;
+ case Opt_nocluster:
+ printk(KERN_INFO "btrfs: disabling alloc clustering\n");
+ btrfs_set_opt(info->mount_opt, NO_ALLOC_CLUSTER);
+ break;
case Opt_err:
printk(KERN_INFO "btrfs: unrecognized mount option "
"'%s'\n", p);
@@ -729,6 +734,8 @@ static int btrfs_show_options(struct seq_file *seq, struct vfsmount *vfs)
seq_puts(seq, ",autodefrag");
if (btrfs_test_opt(root, INODE_MAP_CACHE))
seq_puts(seq, ",inode_cache");
+ if (btrfs_test_opt(root, NO_ALLOC_CLUSTER))
+ seq_puts(seq, ",nocluster");
return 0;
}
--
1.7.4.4
--
Alexandre Oliva, freedom fighter http://FSFLA.org/~lxoliva/
You must be the change you wish to see in the world. -- Gandhi
Be Free! -- http://FSFLA.org/ FSF Latin America board member
Free Software Evangelist Red Hat Brazil Compiler Engineer
