[PATCH v7 8/9] ext4: make fast commit ineligible on ext4_reserve_inode_write failure

[Harshad Shirwadkar <harshadshirwadkar@gmail.com>]

Fast commit by default makes every inode on which
ext4_reserve_inode_write() is called. Thus, if that function
fails for some reason, make the next fast commit ineligible.

Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
---
 fs/ext4/fast_commit.c       |  1 +
 fs/ext4/fast_commit.h       |  1 +
 fs/ext4/inode.c             | 29 ++++++++++++++++++-----------
 include/trace/events/ext4.h |  7 +++++--
 4 files changed, 25 insertions(+), 13 deletions(-)

diff --git a/fs/ext4/fast_commit.c b/fs/ext4/fast_commit.c
index 2fc43b1e2..7525450f1 100644
--- a/fs/ext4/fast_commit.c
+++ b/fs/ext4/fast_commit.c
@@ -2282,6 +2282,7 @@ static const char * const fc_ineligible_reasons[] = {
 	[EXT4_FC_REASON_FALLOC_RANGE] = "Falloc range op",
 	[EXT4_FC_REASON_INODE_JOURNAL_DATA] = "Data journalling",
 	[EXT4_FC_REASON_ENCRYPTED_FILENAME] = "Encrypted filename",
+	[EXT4_FC_REASON_INODE_RSV_WRITE_FAIL] = "Inode reserve write failure"
 };
 
 int ext4_fc_info_show(struct seq_file *seq, void *v)
diff --git a/fs/ext4/fast_commit.h b/fs/ext4/fast_commit.h
index 2fadb2c47..f7f85c3dd 100644
--- a/fs/ext4/fast_commit.h
+++ b/fs/ext4/fast_commit.h
@@ -97,6 +97,7 @@ enum {
 	EXT4_FC_REASON_FALLOC_RANGE,
 	EXT4_FC_REASON_INODE_JOURNAL_DATA,
 	EXT4_FC_REASON_ENCRYPTED_FILENAME,
+	EXT4_FC_REASON_INODE_RSV_WRITE_FAIL,
 	EXT4_FC_REASON_MAX
 };
 
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index c82eba178..5a187902b 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -5798,20 +5798,27 @@ ext4_reserve_inode_write(handle_t *handle, struct inode *inode,
 {
 	int err;
 
-	if (unlikely(ext4_forced_shutdown(inode->i_sb)))
-		return -EIO;
+	if (unlikely(ext4_forced_shutdown(inode->i_sb))) {
+		err = -EIO;
+		goto out;
+	}
 
 	err = ext4_get_inode_loc(inode, iloc);
-	if (!err) {
-		BUFFER_TRACE(iloc->bh, "get_write_access");
-		err = ext4_journal_get_write_access(handle, inode->i_sb,
-						    iloc->bh, EXT4_JTR_NONE);
-		if (err) {
-			brelse(iloc->bh);
-			iloc->bh = NULL;
-		}
-		ext4_fc_track_inode(handle, inode);
+	if (err)
+		goto out;
+
+	BUFFER_TRACE(iloc->bh, "get_write_access");
+	err = ext4_journal_get_write_access(handle, inode->i_sb,
+						iloc->bh, EXT4_JTR_NONE);
+	if (err) {
+		brelse(iloc->bh);
+		iloc->bh = NULL;
 	}
+	ext4_fc_track_inode(handle, inode);
+out:
+	if (err)
+		ext4_fc_mark_ineligible(inode->i_sb,
+			EXT4_FC_REASON_INODE_RSV_WRITE_FAIL, handle);
 	ext4_std_error(inode->i_sb, err);
 	return err;
 }
diff --git a/include/trace/events/ext4.h b/include/trace/events/ext4.h
index cc5e9b7b2..8bab4febd 100644
--- a/include/trace/events/ext4.h
+++ b/include/trace/events/ext4.h
@@ -105,6 +105,7 @@ TRACE_DEFINE_ENUM(EXT4_FC_REASON_RENAME_DIR);
 TRACE_DEFINE_ENUM(EXT4_FC_REASON_FALLOC_RANGE);
 TRACE_DEFINE_ENUM(EXT4_FC_REASON_INODE_JOURNAL_DATA);
 TRACE_DEFINE_ENUM(EXT4_FC_REASON_ENCRYPTED_FILENAME);
+TRACE_DEFINE_ENUM(EXT4_FC_REASON_INODE_RSV_WRITE_FAIL);
 TRACE_DEFINE_ENUM(EXT4_FC_REASON_MAX);
 
 #define show_fc_reason(reason)						\
@@ -118,7 +119,8 @@ TRACE_DEFINE_ENUM(EXT4_FC_REASON_MAX);
 		{ EXT4_FC_REASON_RENAME_DIR,	"RENAME_DIR"},		\
 		{ EXT4_FC_REASON_FALLOC_RANGE,	"FALLOC_RANGE"},	\
 		{ EXT4_FC_REASON_INODE_JOURNAL_DATA,	"INODE_JOURNAL_DATA"}, \
-		{ EXT4_FC_REASON_ENCRYPTED_FILENAME,	"ENCRYPTED_FILENAME"})
+		{ EXT4_FC_REASON_ENCRYPTED_FILENAME,	"ENCRYPTED_FILENAME"}, \
+		{ EXT4_FC_REASON_INODE_RSV_WRITE_FAIL,	"INODE_RSV_WRITE_FAIL"})
 
 TRACE_DEFINE_ENUM(CR_POWER2_ALIGNED);
 TRACE_DEFINE_ENUM(CR_GOAL_LEN_FAST);
@@ -2809,7 +2811,7 @@ TRACE_EVENT(ext4_fc_stats,
 	),
 
 	TP_printk("dev %d,%d fc ineligible reasons:\n"
-		  "%s:%u, %s:%u, %s:%u, %s:%u, %s:%u, %s:%u, %s:%u, %s:%u, %s:%u, %s:%u"
+		  "%s:%u, %s:%u, %s:%u, %s:%u, %s:%u, %s:%u, %s:%u, %s:%u, %s:%u, %s:%u, %s:%u"
 		  "num_commits:%lu, ineligible: %lu, numblks: %lu",
 		  MAJOR(__entry->dev), MINOR(__entry->dev),
 		  FC_REASON_NAME_STAT(EXT4_FC_REASON_XATTR),
@@ -2822,6 +2824,7 @@ TRACE_EVENT(ext4_fc_stats,
 		  FC_REASON_NAME_STAT(EXT4_FC_REASON_FALLOC_RANGE),
 		  FC_REASON_NAME_STAT(EXT4_FC_REASON_INODE_JOURNAL_DATA),
 		  FC_REASON_NAME_STAT(EXT4_FC_REASON_ENCRYPTED_FILENAME),
+		  FC_REASON_NAME_STAT(EXT4_FC_REASON_INODE_RSV_WRITE_FAIL),
 		  __entry->fc_commits, __entry->fc_ineligible_commits,
 		  __entry->fc_numblks)
 );
-- 
2.46.0.184.g6999bdac58-goog