[PATCH 4/6] Add stream ID support for buffered writeback

[Jens Axboe <axboe@fb.com>]

Add a streamid field to the writeback_control structure, and use
it for the various parts of buffered writeback.

Signed-off-by: Jens Axboe <axboe@fb.com>
---
 fs/buffer.c               | 4 ++--
 fs/fs-writeback.c         | 1 +
 fs/mpage.c                | 1 +
 include/linux/writeback.h | 2 ++
 mm/filemap.c              | 1 +
 mm/migrate.c              | 1 +
 mm/page-writeback.c       | 1 +
 mm/vmscan.c               | 1 +
 8 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/fs/buffer.c b/fs/buffer.c
index 20805db2c987..1ae99868f6fb 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -1774,7 +1774,7 @@ static int __block_write_full_page(struct inode *inode, struct page *page,
 	do {
 		struct buffer_head *next = bh->b_this_page;
 		if (buffer_async_write(bh)) {
-			submit_bh(write_op, bh);
+			_submit_bh(write_op, bh, streamid_to_flags(wbc->streamid));
 			nr_underway++;
 		}
 		bh = next;
@@ -1828,7 +1828,7 @@ recover:
 		struct buffer_head *next = bh->b_this_page;
 		if (buffer_async_write(bh)) {
 			clear_buffer_dirty(bh);
-			submit_bh(write_op, bh);
+			_submit_bh(write_op, bh, streamid_to_flags(wbc->streamid));
 			nr_underway++;
 		}
 		bh = next;
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index e907052eeadb..0d0a9f6268f5 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -733,6 +733,7 @@ static long writeback_sb_inodes(struct super_block *sb,
 		 * We use I_SYNC to pin the inode in memory. While it is set
 		 * evict_inode() will wait so the inode cannot be freed.
 		 */
+		wbc.streamid = inode->i_streamid;
 		__writeback_single_inode(inode, &wbc);
 
 		work->nr_pages -= write_chunk - wbc.nr_to_write;
diff --git a/fs/mpage.c b/fs/mpage.c
index 3e79220babac..ae19d35bdd96 100644
--- a/fs/mpage.c
+++ b/fs/mpage.c
@@ -605,6 +605,7 @@ alloc_new:
 				bio_get_nr_vecs(bdev), GFP_NOFS|__GFP_HIGH);
 		if (bio == NULL)
 			goto confused;
+		bio_set_streamid(bio, wbc->streamid);
 	}
 
 	/*
diff --git a/include/linux/writeback.h b/include/linux/writeback.h
index 00048339c23e..3ac2ce545dac 100644
--- a/include/linux/writeback.h
+++ b/include/linux/writeback.h
@@ -78,6 +78,8 @@ struct writeback_control {
 
 	enum writeback_sync_modes sync_mode;
 
+	unsigned int streamid;
+
 	unsigned for_kupdate:1;		/* A kupdate writeback */
 	unsigned for_background:1;	/* A background writeback */
 	unsigned tagged_writepages:1;	/* tag-and-write to avoid livelock */
diff --git a/mm/filemap.c b/mm/filemap.c
index ad7242043bdb..85aa2cc77d67 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -276,6 +276,7 @@ int __filemap_fdatawrite_range(struct address_space *mapping, loff_t start,
 	struct writeback_control wbc = {
 		.sync_mode = sync_mode,
 		.nr_to_write = LONG_MAX,
+		.streamid = inode_streamid(mapping->host),
 		.range_start = start,
 		.range_end = end,
 	};
diff --git a/mm/migrate.c b/mm/migrate.c
index 85e042686031..614407dceb55 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -645,6 +645,7 @@ static int writeout(struct address_space *mapping, struct page *page)
 	struct writeback_control wbc = {
 		.sync_mode = WB_SYNC_NONE,
 		.nr_to_write = 1,
+		.streamid = inode_streamid(mapping->host),
 		.range_start = 0,
 		.range_end = LLONG_MAX,
 		.for_reclaim = 1
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 45e187b2d971..47120abe8afb 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -2051,6 +2051,7 @@ int write_one_page(struct page *page, int wait)
 	int ret = 0;
 	struct writeback_control wbc = {
 		.sync_mode = WB_SYNC_ALL,
+		.streamid = inode_streamid(mapping->host),
 		.nr_to_write = 1,
 	};
 
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 5e8eadd71bac..67fcdd082c17 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -546,6 +546,7 @@ static pageout_t pageout(struct page *page, struct address_space *mapping,
 		struct writeback_control wbc = {
 			.sync_mode = WB_SYNC_NONE,
 			.nr_to_write = SWAP_CLUSTER_MAX,
+			.streamid = inode_streamid(mapping->host),
 			.range_start = 0,
 			.range_end = LLONG_MAX,
 			.for_reclaim = 1,
-- 
1.9.1