btrfs: Introduce new mount option to disable tree log replay
Introduce a new mount option "nologreplay" to co-operate with "ro" mount
option to get real readonly mount, like "norecovery" in ext* and xfs.
Since the new parse_options() need to check new flags at remount time,
so add a new parameter for parse_options().
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Reviewed-by: Chandan Rajendra <chandan@linux.vnet.ibm.com>
Tested-by: Austin S. Hemmelgarn <ahferroin7@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index e39eeb9..a79bb73 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -2250,6 +2250,7 @@
#define BTRFS_MOUNT_FRAGMENT_DATA (1 << 24)
#define BTRFS_MOUNT_FRAGMENT_METADATA (1 << 25)
#define BTRFS_MOUNT_FREE_SPACE_TREE (1 << 26)
+#define BTRFS_MOUNT_NOLOGREPLAY (1 << 27)
#define BTRFS_DEFAULT_COMMIT_INTERVAL (30)
#define BTRFS_DEFAULT_MAX_INLINE (8192)
@@ -4151,7 +4152,8 @@
ssize_t btrfs_listxattr(struct dentry *dentry, char *buffer, size_t size);
/* super.c */
-int btrfs_parse_options(struct btrfs_root *root, char *options);
+int btrfs_parse_options(struct btrfs_root *root, char *options,
+ unsigned long new_flags);
int btrfs_sync_fs(struct super_block *sb, int wait);
#ifdef CONFIG_PRINTK
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index c036362..18541dc 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -2750,7 +2750,7 @@
*/
fs_info->compress_type = BTRFS_COMPRESS_ZLIB;
- ret = btrfs_parse_options(tree_root, options);
+ ret = btrfs_parse_options(tree_root, options, sb->s_flags);
if (ret) {
err = ret;
goto fail_alloc;
@@ -3029,8 +3029,9 @@
if (ret)
goto fail_trans_kthread;
- /* do not make disk changes in broken FS */
- if (btrfs_super_log_root(disk_super) != 0) {
+ /* do not make disk changes in broken FS or nologreplay is given */
+ if (btrfs_super_log_root(disk_super) != 0 &&
+ !btrfs_test_opt(tree_root, NOLOGREPLAY)) {
ret = btrfs_replay_log(fs_info, fs_devices);
if (ret) {
err = ret;
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 7ed3863..e8a7a9f 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -304,6 +304,7 @@
Opt_commit_interval, Opt_barrier, Opt_nodefrag, Opt_nodiscard,
Opt_noenospc_debug, Opt_noflushoncommit, Opt_acl, Opt_datacow,
Opt_datasum, Opt_treelog, Opt_noinode_cache, Opt_usebackuproot,
+ Opt_nologreplay,
#ifdef CONFIG_BTRFS_DEBUG
Opt_fragment_data, Opt_fragment_metadata, Opt_fragment_all,
#endif
@@ -335,6 +336,7 @@
{Opt_noacl, "noacl"},
{Opt_notreelog, "notreelog"},
{Opt_treelog, "treelog"},
+ {Opt_nologreplay, "nologreplay"},
{Opt_flushoncommit, "flushoncommit"},
{Opt_noflushoncommit, "noflushoncommit"},
{Opt_ratio, "metadata_ratio=%d"},
@@ -374,7 +376,8 @@
* reading in a new superblock is parsed here.
* XXX JDM: This needs to be cleaned up for remount.
*/
-int btrfs_parse_options(struct btrfs_root *root, char *options)
+int btrfs_parse_options(struct btrfs_root *root, char *options,
+ unsigned long new_flags)
{
struct btrfs_fs_info *info = root->fs_info;
substring_t args[MAX_OPT_ARGS];
@@ -394,8 +397,12 @@
else if (cache_gen)
btrfs_set_opt(info->mount_opt, SPACE_CACHE);
+ /*
+ * Even the options are empty, we still need to do extra check
+ * against new flags
+ */
if (!options)
- goto out;
+ goto check;
/*
* strsep changes the string, duplicate it because parse_options
@@ -607,6 +614,10 @@
btrfs_clear_and_info(root, NOTREELOG,
"enabling tree log");
break;
+ case Opt_nologreplay:
+ btrfs_set_and_info(root, NOLOGREPLAY,
+ "disabling log replay at mount time");
+ break;
case Opt_flushoncommit:
btrfs_set_and_info(root, FLUSHONCOMMIT,
"turning on flush-on-commit");
@@ -797,6 +808,15 @@
break;
}
}
+check:
+ /*
+ * Extra check for current option against current flag
+ */
+ if (btrfs_test_opt(root, NOLOGREPLAY) && !(new_flags & MS_RDONLY)) {
+ btrfs_err(root->fs_info,
+ "nologreplay must be used with ro mount option");
+ ret = -EINVAL;
+ }
out:
if (btrfs_fs_compat_ro(root->fs_info, FREE_SPACE_TREE) &&
!btrfs_test_opt(root, FREE_SPACE_TREE) &&
@@ -1207,6 +1227,8 @@
seq_puts(seq, ",ssd");
if (btrfs_test_opt(root, NOTREELOG))
seq_puts(seq, ",notreelog");
+ if (btrfs_test_opt(root, NOLOGREPLAY))
+ seq_puts(seq, ",nologreplay");
if (btrfs_test_opt(root, FLUSHONCOMMIT))
seq_puts(seq, ",flushoncommit");
if (btrfs_test_opt(root, DISCARD))
@@ -1688,7 +1710,7 @@
}
}
- ret = btrfs_parse_options(root, data);
+ ret = btrfs_parse_options(root, data, *flags);
if (ret) {
ret = -EINVAL;
goto restore;