Commit dccae999 authored by Sage Weil's avatar Sage Weil Committed by Chris Mason
Browse files

Btrfs: add flushoncommit mount option



The 'flushoncommit' mount option forces any data dirtied by a write in a
prior transaction to commit as part of the current commit.  This makes
the committed state a fully consistent view of the file system from the
application's perspective (i.e., it includes all completed file system
operations).  This was previously the behavior only when a snapshot is
created.

This is used by Ceph to ensure that completed writes make it to the
platter along with the metadata operations they are bound to (by
BTRFS_IOC_TRANS_{START,END}).
Signed-off-by: default avatarSage Weil <sage@newdream.net>
Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
parent 3a5e1404
......@@ -1037,6 +1037,7 @@ struct btrfs_root {
#define BTRFS_MOUNT_DEGRADED (1 << 4)
#define BTRFS_MOUNT_COMPRESS (1 << 5)
#define BTRFS_MOUNT_NOTREELOG (1 << 6)
#define BTRFS_MOUNT_FLUSHONCOMMIT (1 << 7)
#define btrfs_clear_opt(o, opt) ((o) &= ~BTRFS_MOUNT_##opt)
#define btrfs_set_opt(o, opt) ((o) |= BTRFS_MOUNT_##opt)
......
......@@ -68,7 +68,7 @@ enum {
Opt_degraded, Opt_subvol, Opt_device, Opt_nodatasum, Opt_nodatacow,
Opt_max_extent, Opt_max_inline, Opt_alloc_start, Opt_nobarrier,
Opt_ssd, Opt_thread_pool, Opt_noacl, Opt_compress, Opt_notreelog,
Opt_err,
Opt_flushoncommit, Opt_err,
};
static match_table_t tokens = {
......@@ -86,6 +86,7 @@ static match_table_t tokens = {
{Opt_ssd, "ssd"},
{Opt_noacl, "noacl"},
{Opt_notreelog, "notreelog"},
{Opt_flushoncommit, "flushoncommit"},
{Opt_err, NULL},
};
......@@ -229,6 +230,10 @@ int btrfs_parse_options(struct btrfs_root *root, char *options)
printk(KERN_INFO "btrfs: disabling tree log\n");
btrfs_set_opt(info->mount_opt, NOTREELOG);
break;
case Opt_flushoncommit:
printk(KERN_INFO "btrfs: turning on flush-on-commit\n");
btrfs_set_opt(info->mount_opt, FLUSHONCOMMIT);
break;
default:
break;
}
......@@ -370,9 +375,8 @@ fail_close:
int btrfs_sync_fs(struct super_block *sb, int wait)
{
struct btrfs_trans_handle *trans;
struct btrfs_root *root;
struct btrfs_root *root = btrfs_sb(sb);
int ret;
root = btrfs_sb(sb);
if (sb->s_flags & MS_RDONLY)
return 0;
......@@ -419,7 +423,9 @@ static int btrfs_show_options(struct seq_file *seq, struct vfsmount *vfs)
if (btrfs_test_opt(root, SSD))
seq_puts(seq, ",ssd");
if (btrfs_test_opt(root, NOTREELOG))
seq_puts(seq, ",notreelog");
seq_puts(seq, ",no-treelog");
if (btrfs_test_opt(root, FLUSHONCOMMIT))
seq_puts(seq, ",flush-on-commit");
if (!(root->fs_info->sb->s_flags & MS_POSIXACL))
seq_puts(seq, ",noacl");
return 0;
......
......@@ -972,6 +972,7 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
int ret;
int should_grow = 0;
unsigned long now = get_seconds();
int flush_on_commit = btrfs_test_opt(root, FLUSHONCOMMIT);
btrfs_run_ordered_operations(root, 0);
......@@ -1051,7 +1052,9 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
mutex_unlock(&root->fs_info->trans_mutex);
if (snap_pending) {
if (flush_on_commit || snap_pending) {
if (flush_on_commit)
btrfs_start_delalloc_inodes(root);
ret = btrfs_wait_ordered_extents(root, 1);
BUG_ON(ret);
}
......
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