liubo
2010-Dec-03 08:17 UTC
[RFC PATCH 4/5 v3] Btrfs: deal with filesystem state at mount, umount
Since there is a filesystem state, we should deal with it carefully at mount,
umount and remount.
- At mount, the FS state should be checked if there is error on these FS.
If it does have, btrfsck is recommended.
- At umount, the FS state should be saved into disk for consistency.
v2->v3:
do write super stuff at umount time.
Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
---
fs/btrfs/disk-io.c | 47 ++++++++++++++++++++++++++++++++++++++++++++++-
1 files changed, 46 insertions(+), 1 deletions(-)
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index b40dfe4..15d795a 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -43,6 +43,8 @@
static struct extent_io_ops btree_extent_io_ops;
static void end_workqueue_fn(struct btrfs_work *work);
static void free_fs_root(struct btrfs_root *root);
+static void btrfs_check_super_valid(struct btrfs_fs_info *fs_info,
+ int read_only);
/*
* end_io_wq structs are used to do processing in task context when an IO is
@@ -1700,6 +1702,11 @@ struct btrfs_root *open_ctree(struct super_block *sb,
if (!btrfs_super_root(disk_super))
goto fail_iput;
+ /* check filesystem state */
+ fs_info->fs_state |= btrfs_super_flags(disk_super);
+
+ btrfs_check_super_valid(fs_info, sb->s_flags & MS_RDONLY);
+
ret = btrfs_parse_options(tree_root, options);
if (ret) {
err = ret;
@@ -2405,10 +2412,17 @@ int btrfs_commit_super(struct btrfs_root *root)
up_write(&root->fs_info->cleanup_work_sem);
trans = btrfs_join_transaction(root, 1);
+ if (IS_ERR(trans))
+ return PTR_ERR(trans);
+
ret = btrfs_commit_transaction(trans, root);
BUG_ON(ret);
+
/* run commit again to drop the original snapshot */
trans = btrfs_join_transaction(root, 1);
+ if (IS_ERR(trans))
+ return PTR_ERR(trans);
+
btrfs_commit_transaction(trans, root);
ret = btrfs_write_and_wait_transaction(NULL, root);
BUG_ON(ret);
@@ -2426,8 +2440,28 @@ int close_ctree(struct btrfs_root *root)
smp_mb();
btrfs_put_block_group_cache(fs_info);
+
+ /*
+ * Here come 2 situations when btrfs flips readonly:
+ *
+ * 1. when btrfs flips readonly somewhere else before
+ * btrfs_commit_super, sb->s_flags has MS_RDONLY flag,
+ * and btrfs will skip to write sb directly to keep
+ * ERROR state on disk.
+ *
+ * 2. when btrfs flips readonly just in btrfs_commit_super,
+ * and in such case, btrfs cannnot write sb via btrfs_commit_super,
+ * and since fs_state has been set BTRFS_SUPER_FLAG_ERROR flag,
+ * btrfs will directly write sb.
+ */
if (!(fs_info->sb->s_flags & MS_RDONLY)) {
- ret = btrfs_commit_super(root);
+ ret = btrfs_commit_super(root);
+ if (ret)
+ printk(KERN_ERR "btrfs: commit super ret %d\n", ret);
+ }
+
+ if (fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) {
+ ret = write_ctree_super(NULL, root, 0);
if (ret)
printk(KERN_ERR "btrfs: commit super ret %d\n", ret);
}
@@ -2603,6 +2637,17 @@ out:
return 0;
}
+static void btrfs_check_super_valid(struct btrfs_fs_info *fs_info,
+ int read_only)
+{
+ if (read_only)
+ return;
+
+ if (fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR)
+ printk(KERN_WARNING "warning: mount fs with errors, "
+ "running btrfsck is recommended\n");
+}
+
static struct extent_io_ops btree_extent_io_ops = {
.write_cache_pages_lock_hook = btree_lock_page_hook,
.readpage_end_io_hook = btree_readpage_end_io_hook,
--
1.7.1
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