From dccae99995089641fbac452ebc7f0cab18751ddb Mon Sep 17 00:00:00 2001 From: Sage Weil Date: Thu, 2 Apr 2009 16:59:01 -0400 Subject: [PATCH] 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: Sage Weil Signed-off-by: Chris Mason --- fs/btrfs/ctree.h | 1 + fs/btrfs/super.c | 14 ++++++++++---- fs/btrfs/transaction.c | 5 ++++- 3 files changed, 15 insertions(+), 5 deletions(-) diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 1e99a9948637..bb6ac5b87652 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -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) diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index 3baa2c109e55..9744af9d71e9 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -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; diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index 3e8225de4e9d..2869b3361eb6 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -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); } -- 2.20.1