Add a debug mount option to simulate errors while replaying. If
fc_debug_max_replay is set, ext4 will replay only as many fast
commit blocks as passed as an argument.
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@xxxxxxxxx>
---
fs/ext4/ext4.h | 3 +++
fs/ext4/ext4_jbd2.c | 6 ++++++
fs/ext4/super.c | 12 +++++++++++-
3 files changed, 20 insertions(+), 1 deletion(-)
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index e12900d77673..62d72e7005ad 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1652,6 +1652,9 @@ struct ext4_sb_info {
struct list_head s_fc_dentry_q;
struct ext4_fc_replay_state s_fc_replay_state;
spinlock_t s_fc_lock;
+#ifdef EXT4_FC_DEBUG
+ int s_fc_debug_max_replay;
+#endif
struct ext4_fc_stats s_fc_stats;
};
diff --git a/fs/ext4/ext4_jbd2.c b/fs/ext4/ext4_jbd2.c
index ef36a973ed8b..1f8ba23912ba 100644
--- a/fs/ext4/ext4_jbd2.c
+++ b/fs/ext4/ext4_jbd2.c
@@ -1520,6 +1520,12 @@ static int ext4_journal_fc_replay_cb(journal_t *journal, struct buffer_head *bh,
return sbi->s_fc_replay_state.fc_replay_error;
}
+#ifdef EXT4_FC_DEBUG
+ if (sbi->s_fc_debug_max_replay && off >= sbi->s_fc_debug_max_replay) {
+ pr_warn("Dropping fc block %d because max_replay set\n", off);
+ return -EINVAL;
+ }
+#endif
sbi->s_mount_state |= EXT4_FC_REPLAY;
fc_hdr = (struct ext4_fc_commit_hdr *)
((__u8 *)bh->b_data + sizeof(journal_header_t));
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index bfd19a127188..117ccde1a7c1 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1475,7 +1475,7 @@ enum {
Opt_dioread_nolock, Opt_dioread_lock,
Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
- Opt_no_fc, Opt_fc_soft_consistency
+ Opt_no_fc, Opt_fc_soft_consistency, Opt_fc_debug_max_replay
};
static const match_table_t tokens = {
@@ -1560,6 +1560,9 @@ static const match_table_t tokens = {
{Opt_noinit_itable, "noinit_itable"},
{Opt_no_fc, "no_fc"},
{Opt_fc_soft_consistency, "fc_soft_consistency"},
+#ifdef EXT4_FC_DEBUG
+ {Opt_fc_debug_max_replay, "fc_debug_max_replay=%u"},
+#endif
{Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
{Opt_test_dummy_encryption, "test_dummy_encryption"},
{Opt_nombcache, "nombcache"},
@@ -1779,6 +1782,9 @@ static const struct mount_opts {
MOPT_CLEAR | MOPT_2 | MOPT_EXT4_ONLY},
{Opt_fc_soft_consistency, EXT4_MOUNT2_JOURNAL_FC_SOFT_CONSISTENCY,
MOPT_SET | MOPT_2 | MOPT_EXT4_ONLY},
+#ifdef EXT4_FC_DEBUG
+ {Opt_fc_debug_max_replay, 0, MOPT_GTE0},
+#endif
{Opt_err, 0, 0}
};
@@ -1931,6 +1937,10 @@ static int handle_mount_opt(struct super_block *sb, char *opt, int token,
sbi->s_li_wait_mult = arg;
} else if (token == Opt_max_dir_size_kb) {
sbi->s_max_dir_size_kb = arg;
+#ifdef EXT4_FC_DEBUG
+ } else if (token == Opt_fc_debug_max_replay) {
+ sbi->s_fc_debug_max_replay = arg;
+#endif
} else if (token == Opt_stripe) {
sbi->s_stripe = arg;
} else if (token == Opt_resuid) {
--
2.24.1.735.g03f4e72817-goog
