[PATCH v6 09/11] VFS hot tracking, btrfs: Add hot tracking support

Zhi Yong Wu
2013-11-06T13:48:47Z

From: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>

Introduce one new mount option '-o hot_track',
and add its parsing support.

Its usage looks like:
mount -o hot_track
mount -o nouser,hot_track
mount -o nouser,hot_track,loop
mount -o hot_track,nouser

Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
---
fs/btrfs/ctree.h | 1 +
fs/btrfs/super.c | 22 +++++++++++++++++++++-
2 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 0506f40..b8d8982 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -1990,6 +1990,7 @@ struct btrfs_ioctl_defrag_range_args {
#define BTRFS_MOUNT_CHECK_INTEGRITY_INCLUDING_EXTENT_DATA (1 << 21)
#define BTRFS_MOUNT_PANIC_ON_FATAL_ERROR (1 << 22)
#define BTRFS_MOUNT_RESCAN_UUID_TREE (1 << 23)
+#define BTRFS_MOUNT_HOT_TRACK (1 << 24)

#define BTRFS_DEFAULT_COMMIT_INTERVAL (30)

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index e913328..69fe31d 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -42,6 +42,7 @@
#include <linux/cleancache.h>
#include <linux/ratelimit.h>
#include <linux/btrfs.h>
+#include <linux/hot_tracking.h>
#include "compat.h"
#include "delayed-inode.h"
#include "ctree.h"
@@ -310,6 +311,10 @@ static void btrfs_put_super(struct super_block *sb)
* last process that kept it busy. Or segfault in the aforementioned
* process... Whom would you report that to?
*/
+
+ /* Hot data tracking */
+ if (btrfs_test_opt(btrfs_sb(sb)->tree_root, HOT_TRACK))
+ hot_track_exit(sb);
}

enum {
@@ -323,7 +328,7 @@ enum {
Opt_no_space_cache, Opt_recovery, Opt_skip_balance,
Opt_check_integrity, Opt_check_integrity_including_extent_data,
Opt_check_integrity_print_mask, Opt_fatal_errors, Opt_rescan_uuid_tree,
- Opt_commit_interval,
+ Opt_commit_interval, Opt_hot_track,
Opt_err,
};

@@ -366,6 +371,7 @@ static match_table_t tokens = {
{Opt_rescan_uuid_tree, "rescan_uuid_tree"},
{Opt_fatal_errors, "fatal_errors=%s"},
{Opt_commit_interval, "commit=%d"},
+ {Opt_hot_track, "hot_track"},
{Opt_err, NULL},
};

@@ -676,6 +682,9 @@ int btrfs_parse_options(struct btrfs_root *root, char *options)
info->commit_interval = BTRFS_DEFAULT_COMMIT_INTERVAL;
}
break;
+ case Opt_hot_track:
+ btrfs_set_opt(info->mount_opt, HOT_TRACK);
+ break;
case Opt_err:
printk(KERN_INFO "btrfs: unrecognized mount option "
"'%s'\n", p);
@@ -898,11 +907,20 @@ static int btrfs_fill_super(struct super_block *sb,
goto fail_close;
}

+ if (btrfs_test_opt(fs_info->tree_root, HOT_TRACK)) {
+ err = hot_track_init(sb);
+ if (err)
+ goto fail_hot;
+ }
+
save_mount_options(sb, data);
cleancache_init_fs(sb);
sb->s_flags |= MS_ACTIVE;
return 0;

+fail_hot:
+ dput(sb->s_root);
+ sb->s_root = NULL;
fail_close:
close_ctree(fs_info->tree_root);
return err;
@@ -1014,6 +1032,8 @@ 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);
+ if (btrfs_test_opt(root, HOT_TRACK))
+ seq_puts(seq, ",hot_track");
return 0;
}

--
1.7.11.7