1 files changed, 86 insertions, 121 deletions

diff --git a/fs/ext4/fast_commit.c b/fs/ext4/fast_commit.c
index 0f32b445582a..5ae8026a0c56 100644
--- a/fs/ext4/fast_commit.c
+++ b/fs/ext4/fast_commit.c
@@ -65,21 +65,11 @@
  *
  * Fast Commit Ineligibility
  * -------------------------
- * Not all operations are supported by fast commits today (e.g extended
- * attributes). Fast commit ineligibility is marked by calling one of the
- * two following functions:
- *
- * - ext4_fc_mark_ineligible(): This makes next fast commit operation to fall
- *   back to full commit. This is useful in case of transient errors.
  *
- * - ext4_fc_start_ineligible() and ext4_fc_stop_ineligible() - This makes all
- *   the fast commits happening between ext4_fc_start_ineligible() and
- *   ext4_fc_stop_ineligible() and one fast commit after the call to
- *   ext4_fc_stop_ineligible() to fall back to full commits. It is important to
- *   make one more fast commit to fall back to full commit after stop call so
- *   that it guaranteed that the fast commit ineligible operation contained
- *   within ext4_fc_start_ineligible() and ext4_fc_stop_ineligible() is
- *   followed by at least 1 full commit.
+ * Not all operations are supported by fast commits today (e.g extended
+ * attributes). Fast commit ineligibility is marked by calling
+ * ext4_fc_mark_ineligible(): This makes next fast commit operation to fall back
+ * to full commit.
  *
  * Atomicity of commits
  * --------------------
@@ -166,15 +156,13 @@
  *    fast commit recovery even if that area is invalidated by later full
  *    commits.
  *
- * 1) Make fast commit atomic updates more fine grained. Today, a fast commit
- *    eligible update must be protected within ext4_fc_start_update() and
- *    ext4_fc_stop_update(). These routines are called at much higher
- *    routines. This can be made more fine grained by combining with
- *    ext4_journal_start().
+ * 1) Fast commit's commit path locks the entire file system during fast
+ *    commit. This has significant performance penalty. Instead of that, we
+ *    should use ext4_fc_start/stop_update functions to start inode level
+ *    updates from ext4_journal_start/stop. Once we do that we can drop file
+ *    system locking during commit path.
  *
- * 2) Same above for ext4_fc_start_ineligible() and ext4_fc_stop_ineligible()
- *
- * 3) Handle more ineligible cases.
+ * 2) Handle more ineligible cases.
  */
 
 #include <trace/events/ext4.h>
@@ -329,44 +317,6 @@ void ext4_fc_mark_ineligible(struct super_block *sb, int reason)
 }
 
 /*
- * Start a fast commit ineligible update. Any commits that happen while
- * such an operation is in progress fall back to full commits.
- */
-void ext4_fc_start_ineligible(struct super_block *sb, int reason)
-{
-	struct ext4_sb_info *sbi = EXT4_SB(sb);
-
-	if (!test_opt2(sb, JOURNAL_FAST_COMMIT) ||
-	    (EXT4_SB(sb)->s_mount_state & EXT4_FC_REPLAY))
-		return;
-
-	WARN_ON(reason >= EXT4_FC_REASON_MAX);
-	sbi->s_fc_stats.fc_ineligible_reason_count[reason]++;
-	atomic_inc(&sbi->s_fc_ineligible_updates);
-}
-
-/*
- * Stop a fast commit ineligible update. We set EXT4_MF_FC_INELIGIBLE flag here
- * to ensure that after stopping the ineligible update, at least one full
- * commit takes place.
- */
-void ext4_fc_stop_ineligible(struct super_block *sb)
-{
-	if (!test_opt2(sb, JOURNAL_FAST_COMMIT) ||
-	    (EXT4_SB(sb)->s_mount_state & EXT4_FC_REPLAY))
-		return;
-
-	ext4_set_mount_flag(sb, EXT4_MF_FC_INELIGIBLE);
-	atomic_dec(&EXT4_SB(sb)->s_fc_ineligible_updates);
-}
-
-static inline int ext4_fc_is_ineligible(struct super_block *sb)
-{
-	return (ext4_test_mount_flag(sb, EXT4_MF_FC_INELIGIBLE) ||
-		atomic_read(&EXT4_SB(sb)->s_fc_ineligible_updates));
-}
-
-/*
  * Generic fast commit tracking function. If this is the first time this we are
  * called after a full commit, we initialize fast commit fields and then call
  * __fc_track_fn() with update = 0. If we have already been called after a full
@@ -391,7 +341,7 @@ static int ext4_fc_track_template(
 	    (sbi->s_mount_state & EXT4_FC_REPLAY))
 		return -EOPNOTSUPP;
 
-	if (ext4_fc_is_ineligible(inode->i_sb))
+	if (ext4_test_mount_flag(inode->i_sb, EXT4_MF_FC_INELIGIBLE))
 		return -EINVAL;
 
 	tid = handle->h_transaction->t_tid;
@@ -796,7 +746,6 @@ static bool ext4_fc_add_dentry_tlv(struct super_block *sb, u32 *crc,
 	ext4_fc_memcpy(sb, dst, &fcd, sizeof(fcd), crc);
 	dst += sizeof(fcd);
 	ext4_fc_memcpy(sb, dst, fc_dentry->fcd_name.name, dlen, crc);
-	dst += dlen;
 
 	return true;
 }
@@ -1123,6 +1072,32 @@ out:
 	return ret;
 }
 
+static void ext4_fc_update_stats(struct super_block *sb, int status,
+				 u64 commit_time, int nblks)
+{
+	struct ext4_fc_stats *stats = &EXT4_SB(sb)->s_fc_stats;
+
+	jbd_debug(1, "Fast commit ended with status = %d", status);
+	if (status == EXT4_FC_STATUS_OK) {
+		stats->fc_num_commits++;
+		stats->fc_numblks += nblks;
+		if (likely(stats->s_fc_avg_commit_time))
+			stats->s_fc_avg_commit_time =
+				(commit_time +
+				 stats->s_fc_avg_commit_time * 3) / 4;
+		else
+			stats->s_fc_avg_commit_time = commit_time;
+	} else if (status == EXT4_FC_STATUS_FAILED ||
+		   status == EXT4_FC_STATUS_INELIGIBLE) {
+		if (status == EXT4_FC_STATUS_FAILED)
+			stats->fc_failed_commits++;
+		stats->fc_ineligible_commits++;
+	} else {
+		stats->fc_skipped_commits++;
+	}
+	trace_ext4_fc_commit_stop(sb, nblks, status);
+}
+
 /*
  * The main commit entry point. Performs a fast commit for transaction
  * commit_tid if needed. If it's not possible to perform a fast commit
@@ -1135,18 +1110,15 @@ int ext4_fc_commit(journal_t *journal, tid_t commit_tid)
 	struct ext4_sb_info *sbi = EXT4_SB(sb);
 	int nblks = 0, ret, bsize = journal->j_blocksize;
 	int subtid = atomic_read(&sbi->s_fc_subtid);
-	int reason = EXT4_FC_REASON_OK, fc_bufs_before = 0;
+	int status = EXT4_FC_STATUS_OK, fc_bufs_before = 0;
 	ktime_t start_time, commit_time;
 
 	trace_ext4_fc_commit_start(sb);
 
 	start_time = ktime_get();
 
-	if (!test_opt2(sb, JOURNAL_FAST_COMMIT) ||
-		(ext4_fc_is_ineligible(sb))) {
-		reason = EXT4_FC_REASON_INELIGIBLE;
-		goto out;
-	}
+	if (!test_opt2(sb, JOURNAL_FAST_COMMIT))
+		return jbd2_complete_transaction(journal, commit_tid);
 
 restart_fc:
 	ret = jbd2_fc_begin_commit(journal, commit_tid);
@@ -1155,67 +1127,52 @@ restart_fc:
 		if (atomic_read(&sbi->s_fc_subtid) <= subtid &&
 			commit_tid > journal->j_commit_sequence)
 			goto restart_fc;
-		reason = EXT4_FC_REASON_ALREADY_COMMITTED;
-		goto out;
+		ext4_fc_update_stats(sb, EXT4_FC_STATUS_SKIPPED, 0, 0);
+		return 0;
 	} else if (ret) {
-		sbi->s_fc_stats.fc_ineligible_reason_count[EXT4_FC_COMMIT_FAILED]++;
-		reason = EXT4_FC_REASON_FC_START_FAILED;
-		goto out;
+		/*
+		 * Commit couldn't start. Just update stats and perform a
+		 * full commit.
+		 */
+		ext4_fc_update_stats(sb, EXT4_FC_STATUS_FAILED, 0, 0);
+		return jbd2_complete_transaction(journal, commit_tid);
+	}
+
+	/*
+	 * After establishing journal barrier via jbd2_fc_begin_commit(), check
+	 * if we are fast commit ineligible.
+	 */
+	if (ext4_test_mount_flag(sb, EXT4_MF_FC_INELIGIBLE)) {
+		status = EXT4_FC_STATUS_INELIGIBLE;
+		goto fallback;
 	}
 
 	fc_bufs_before = (sbi->s_fc_bytes + bsize - 1) / bsize;
 	ret = ext4_fc_perform_commit(journal);
 	if (ret < 0) {
-		sbi->s_fc_stats.fc_ineligible_reason_count[EXT4_FC_COMMIT_FAILED]++;
-		reason = EXT4_FC_REASON_FC_FAILED;
-		goto out;
+		status = EXT4_FC_STATUS_FAILED;
+		goto fallback;
 	}
 	nblks = (sbi->s_fc_bytes + bsize - 1) / bsize - fc_bufs_before;
 	ret = jbd2_fc_wait_bufs(journal, nblks);
 	if (ret < 0) {
-		sbi->s_fc_stats.fc_ineligible_reason_count[EXT4_FC_COMMIT_FAILED]++;
-		reason = EXT4_FC_REASON_FC_FAILED;
-		goto out;
+		status = EXT4_FC_STATUS_FAILED;
+		goto fallback;
 	}
 	atomic_inc(&sbi->s_fc_subtid);
-	jbd2_fc_end_commit(journal);
-out:
-	/* Has any ineligible update happened since we started? */
-	if (reason == EXT4_FC_REASON_OK && ext4_fc_is_ineligible(sb)) {
-		sbi->s_fc_stats.fc_ineligible_reason_count[EXT4_FC_COMMIT_FAILED]++;
-		reason = EXT4_FC_REASON_INELIGIBLE;
-	}
-
-	spin_lock(&sbi->s_fc_lock);
-	if (reason != EXT4_FC_REASON_OK &&
-		reason != EXT4_FC_REASON_ALREADY_COMMITTED) {
-		sbi->s_fc_stats.fc_ineligible_commits++;
-	} else {
-		sbi->s_fc_stats.fc_num_commits++;
-		sbi->s_fc_stats.fc_numblks += nblks;
-	}
-	spin_unlock(&sbi->s_fc_lock);
-	nblks = (reason == EXT4_FC_REASON_OK) ? nblks : 0;
-	trace_ext4_fc_commit_stop(sb, nblks, reason);
-	commit_time = ktime_to_ns(ktime_sub(ktime_get(), start_time));
+	ret = jbd2_fc_end_commit(journal);
 	/*
-	 * weight the commit time higher than the average time so we don't
-	 * react too strongly to vast changes in the commit time
+	 * weight the commit time higher than the average time so we
+	 * don't react too strongly to vast changes in the commit time
 	 */
-	if (likely(sbi->s_fc_avg_commit_time))
-		sbi->s_fc_avg_commit_time = (commit_time +
-				sbi->s_fc_avg_commit_time * 3) / 4;
-	else
-		sbi->s_fc_avg_commit_time = commit_time;
-	jbd_debug(1,
-		"Fast commit ended with blks = %d, reason = %d, subtid - %d",
-		nblks, reason, subtid);
-	if (reason == EXT4_FC_REASON_FC_FAILED)
-		return jbd2_fc_end_commit_fallback(journal);
-	if (reason == EXT4_FC_REASON_FC_START_FAILED ||
-		reason == EXT4_FC_REASON_INELIGIBLE)
-		return jbd2_complete_transaction(journal, commit_tid);
-	return 0;
+	commit_time = ktime_to_ns(ktime_sub(ktime_get(), start_time));
+	ext4_fc_update_stats(sb, status, commit_time, nblks);
+	return ret;
+
+fallback:
+	ret = jbd2_fc_end_commit_fallback(journal);
+	ext4_fc_update_stats(sb, status, 0, 0);
+	return ret;
 }
 
 /*
@@ -1812,11 +1769,14 @@ ext4_fc_replay_del_range(struct super_block *sb, struct ext4_fc_tl *tl,
 		}
 	}
 
-	ret = ext4_punch_hole(inode,
-		le32_to_cpu(lrange.fc_lblk) << sb->s_blocksize_bits,
-		le32_to_cpu(lrange.fc_len) <<  sb->s_blocksize_bits);
-	if (ret)
-		jbd_debug(1, "ext4_punch_hole returned %d", ret);
+	down_write(&EXT4_I(inode)->i_data_sem);
+	ret = ext4_ext_remove_space(inode, lrange.fc_lblk,
+				lrange.fc_lblk + lrange.fc_len - 1);
+	up_write(&EXT4_I(inode)->i_data_sem);
+	if (ret) {
+		iput(inode);
+		return 0;
+	}
 	ext4_ext_replay_shrink_inode(inode,
 		i_size_read(inode) >> sb->s_blocksize_bits);
 	ext4_mark_inode_dirty(NULL, inode);
@@ -2173,7 +2133,7 @@ int ext4_fc_info_show(struct seq_file *seq, void *v)
 		"fc stats:\n%ld commits\n%ld ineligible\n%ld numblks\n%lluus avg_commit_time\n",
 		   stats->fc_num_commits, stats->fc_ineligible_commits,
 		   stats->fc_numblks,
-		   div_u64(sbi->s_fc_avg_commit_time, 1000));
+		   div_u64(stats->s_fc_avg_commit_time, 1000));
 	seq_puts(seq, "Ineligible reasons:\n");
 	for (i = 0; i < EXT4_FC_REASON_MAX; i++)
 		seq_printf(seq, "\"%s\":\t%d\n", fc_ineligible_reasons[i],
@@ -2192,3 +2152,8 @@ int __init ext4_fc_init_dentry_cache(void)
 
 	return 0;
 }
+
+void ext4_fc_destroy_dentry_cache(void)
+{
+	kmem_cache_destroy(ext4_fc_dentry_cachep);
+}