[PATCH v5 20/20] ext4: add debug mount option to test fast commit replay
From: Harshad Shirwadkar <hidden>
Date: 2020-03-09 07:06:15
Subsystem:
ext4 file system, filesystems (vfs and infrastructure), the rest · Maintainers:
"Theodore Ts'o", Alexander Viro, Christian Brauner, Linus Torvalds
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 <redacted> --- 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 cc92a333bc68..5fea64ca8b5b 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h@@ -1661,6 +1661,9 @@ 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 9e4b6bcbd76c..602eb3392a5d 100644
--- a/fs/ext4/ext4_jbd2.c
+++ b/fs/ext4/ext4_jbd2.c@@ -1561,6 +1561,12 @@ 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 ffa91815dacf..a7bc3a4e75d0 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c@@ -1542,7 +1542,7 @@ 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 = {
@@ -1628,6 +1628,9 @@ 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"},
@@ -1847,6 +1850,9 @@ 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} };
@@ -2006,6 +2012,10 @@ 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) {
--
2.25.1.481.gfbce0eb801-goog