Merge branch 'writeback-plugging'
Fix up the writeback plugging introduced in commit d353d7587d02
("writeback: plug writeback at a high level") that then caused problems
due to the unplug happening with a spinlock held.
* writeback-plugging:
writeback: plug writeback in wb_writeback() and writeback_inodes_wb()
Revert "writeback: plug writeback at a high level"
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index 2448912..587ac08 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -1380,6 +1380,10 @@
* Write a portion of b_io inodes which belong to @sb.
*
* Return the number of pages and/or inodes written.
+ *
+ * NOTE! This is called with wb->list_lock held, and will
+ * unlock and relock that for each inode it ends up doing
+ * IO for.
*/
static long writeback_sb_inodes(struct super_block *sb,
struct bdi_writeback *wb,
@@ -1398,9 +1402,7 @@
unsigned long start_time = jiffies;
long write_chunk;
long wrote = 0; /* count both pages and inodes */
- struct blk_plug plug;
- blk_start_plug(&plug);
while (!list_empty(&wb->b_io)) {
struct inode *inode = wb_inode(wb->b_io.prev);
@@ -1498,7 +1500,6 @@
break;
}
}
- blk_finish_plug(&plug);
return wrote;
}
@@ -1545,12 +1546,15 @@
.range_cyclic = 1,
.reason = reason,
};
+ struct blk_plug plug;
+ blk_start_plug(&plug);
spin_lock(&wb->list_lock);
if (list_empty(&wb->b_io))
queue_io(wb, &work);
__writeback_inodes_wb(wb, &work);
spin_unlock(&wb->list_lock);
+ blk_finish_plug(&plug);
return nr_pages - work.nr_pages;
}
@@ -1578,10 +1582,12 @@
unsigned long oldest_jif;
struct inode *inode;
long progress;
+ struct blk_plug plug;
oldest_jif = jiffies;
work->older_than_this = &oldest_jif;
+ blk_start_plug(&plug);
spin_lock(&wb->list_lock);
for (;;) {
/*
@@ -1661,6 +1667,7 @@
}
}
spin_unlock(&wb->list_lock);
+ blk_finish_plug(&plug);
return nr_pages - work->nr_pages;
}