[PATCH v3 2/2] ext4: remove unused locked_ei parameter from __es_shrink()

[Qiliang Yuan]

__es_shrink()'s locked_ei parameter exists to let a caller pass in an
inode it already holds i_es_lock on, so the shrinker walk can skip
that inode instead of deadlocking on write_trylock(), and fall back
to reclaiming from it directly if nothing else could be freed. Its
only caller, ext4_es_scan(), always passes NULL.

Drop the parameter along with the two code paths that exist solely to
support it: the ei == locked_ei skip check, and the trailing
es_reclaim_extents(locked_ei, ...) fallback, neither of which can ever
run while locked_ei is always NULL.

Signed-off-by: Qiliang Yuan <odys.yuan@xxxxxxxxx>
---
 fs/ext4/extents_status.c | 13 ++++---------
 1 file changed, 4 insertions(+), 9 deletions(-)

diff --git a/fs/ext4/extents_status.c b/fs/ext4/extents_status.c
index d88af807d36e7..efbccb29d5fd1 100644
--- a/fs/ext4/extents_status.c
+++ b/fs/ext4/extents_status.c
@@ -183,8 +183,7 @@ static int __es_remove_extent(struct inode *inode, ext4_lblk_t lblk,
 			      int *reserved, struct extent_status *res,
 			      struct extent_status *prealloc);
 static int es_reclaim_extents(struct ext4_inode_info *ei, int *nr_to_scan);
-static int __es_shrink(struct ext4_sb_info *sbi, int nr_to_scan,
-		       struct ext4_inode_info *locked_ei);
+static int __es_shrink(struct ext4_sb_info *sbi, int nr_to_scan);
 static int __revise_pending(struct inode *inode, ext4_lblk_t lblk,
 			    ext4_lblk_t len,
 			    struct pending_reservation **prealloc);
@@ -1669,8 +1668,7 @@ void ext4_es_remove_extent(struct inode *inode, ext4_lblk_t lblk,
 	ext4_da_release_space(inode, reserved);
 }
 
-static int __es_shrink(struct ext4_sb_info *sbi, int nr_to_scan,
-		       struct ext4_inode_info *locked_ei)
+static int __es_shrink(struct ext4_sb_info *sbi, int nr_to_scan)
 {
 	struct ext4_inode_info *ei;
 	struct ext4_es_stats *es_stats;
@@ -1706,7 +1704,7 @@ static int __es_shrink(struct ext4_sb_info *sbi, int nr_to_scan,
 			continue;
 		}
 
-		if (ei == locked_ei || !write_trylock(&ei->i_es_lock)) {
+		if (!write_trylock(&ei->i_es_lock)) {
 			nr_skipped++;
 			continue;
 		}
@@ -1734,9 +1732,6 @@ static int __es_shrink(struct ext4_sb_info *sbi, int nr_to_scan,
 		goto retry;
 	}
 
-	if (locked_ei && nr_shrunk == 0)
-		nr_shrunk = es_reclaim_extents(locked_ei, &nr_to_scan);
-
 out:
 	scan_time = ktime_to_ns(ktime_sub(ktime_get(), start_time));
 	if (likely(es_stats->es_stats_scan_time))
@@ -1779,7 +1774,7 @@ static unsigned long ext4_es_scan(struct shrinker *shrink,
 	ret = percpu_counter_read_positive(&sbi->s_es_stats.es_stats_shk_cnt);
 	trace_ext4_es_shrink_scan_enter(sbi->s_sb, nr_to_scan, ret);
 
-	nr_shrunk = __es_shrink(sbi, nr_to_scan, NULL);
+	nr_shrunk = __es_shrink(sbi, nr_to_scan);
 
 	ret = percpu_counter_read_positive(&sbi->s_es_stats.es_stats_shk_cnt);
 	trace_ext4_es_shrink_scan_exit(sbi->s_sb, nr_shrunk, ret);

-- 
2.43.0