diff mbox

Btrfs: add write_flags for compression bio

Message ID 20171013211035.26765-1-bo.li.liu@oracle.com (mailing list archive)
State New, archived
Headers show

Commit Message

Liu Bo Oct. 13, 2017, 9:10 p.m. UTC 
Compression code path has only flaged bios with REQ_OP_WRITE no matter
where the bios come from.  This breaks the rule that sync writes and
writeback writes need to be differentiated from each other.

This passes writeback_control to compression write path so that it can
send bios with proper flags to block layer.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
---
 fs/btrfs/compression.c |  7 ++++---
 fs/btrfs/compression.h |  3 ++-
 fs/btrfs/extent_io.c   |  2 +-
 fs/btrfs/extent_io.h   |  3 ++-
 fs/btrfs/inode.c       | 15 +++++++++++----
 5 files changed, 20 insertions(+), 10 deletions(-)

Comments

David Sterba Oct. 16, 2017, 1:33 p.m. UTC | #1 
On Fri, Oct 13, 2017 at 03:10:35PM -0600, Liu Bo wrote:
> Compression code path has only flaged bios with REQ_OP_WRITE no matter
> where the bios come from.  This breaks the rule that sync writes and
> writeback writes need to be differentiated from each other.

What are the implications of the change?
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Liu Bo Oct. 16, 2017, 5:34 p.m. UTC | #2 
On Mon, Oct 16, 2017 at 03:33:10PM +0200, David Sterba wrote:
> On Fri, Oct 13, 2017 at 03:10:35PM -0600, Liu Bo wrote:
> > Compression code path has only flaged bios with REQ_OP_WRITE no matter
> > where the bios come from.  This breaks the rule that sync writes and
> > writeback writes need to be differentiated from each other.
> 
> What are the implications of the change?

All writes need to have the correct bio flag so that block layer can
recognize them to do throttle or other stuff.  Compression writes are
no exception, but currently we don't attach the correct bio flag to
either compressed writeback writes or compressed sync writes.

Does it make sense?

Thanks,

-liubo
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diff mbox

Patch

diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index 280384b..3dae2f5 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -292,7 +292,8 @@  blk_status_t btrfs_submit_compressed_write(struct inode *inode, u64 start,
 				 unsigned long len, u64 disk_start,
 				 unsigned long compressed_len,
 				 struct page **compressed_pages,
-				 unsigned long nr_pages)
+				 unsigned long nr_pages,
+				 unsigned int write_flags)
 {
 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 	struct bio *bio = NULL;
@@ -324,7 +325,7 @@  blk_status_t btrfs_submit_compressed_write(struct inode *inode, u64 start,
 	bdev = fs_info->fs_devices->latest_bdev;
 
 	bio = btrfs_bio_alloc(bdev, first_byte);
-	bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
+	bio->bi_opf = REQ_OP_WRITE | write_flags;
 	bio->bi_private = cb;
 	bio->bi_end_io = end_compressed_bio_write;
 	refcount_set(&cb->pending_bios, 1);
@@ -371,7 +372,7 @@  blk_status_t btrfs_submit_compressed_write(struct inode *inode, u64 start,
 			bio_put(bio);
 
 			bio = btrfs_bio_alloc(bdev, first_byte);
-			bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
+			bio->bi_opf = REQ_OP_WRITE | write_flags;
 			bio->bi_private = cb;
 			bio->bi_end_io = end_compressed_bio_write;
 			bio_add_page(bio, page, PAGE_SIZE, 0);
diff --git a/fs/btrfs/compression.h b/fs/btrfs/compression.h
index d2781ff..dc45b94 100644
--- a/fs/btrfs/compression.h
+++ b/fs/btrfs/compression.h
@@ -91,7 +91,8 @@  blk_status_t btrfs_submit_compressed_write(struct inode *inode, u64 start,
 				  unsigned long len, u64 disk_start,
 				  unsigned long compressed_len,
 				  struct page **compressed_pages,
-				  unsigned long nr_pages);
+				  unsigned long nr_pages,
+				  unsigned int write_flags);
 blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
 				 int mirror_num, unsigned long bio_flags);
 
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 3e5bb0c..ea64ad0 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -3252,7 +3252,7 @@  static noinline_for_stack int writepage_delalloc(struct inode *inode,
 					       delalloc_start,
 					       delalloc_end,
 					       &page_started,
-					       nr_written);
+					       nr_written, wbc);
 		/* File system has been set read-only */
 		if (ret) {
 			SetPageError(page);
diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
index faffa28..a92fd98 100644
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -116,7 +116,8 @@  struct extent_io_ops {
 	 */
 	int (*fill_delalloc)(void *private_data, struct page *locked_page,
 			     u64 start, u64 end, int *page_started,
-			     unsigned long *nr_written);
+			     unsigned long *nr_written,
+			     struct writeback_control *wbc);
 
 	int (*writepage_start_hook)(struct page *page, u64 start, u64 end);
 	void (*writepage_end_io_hook)(struct page *page, u64 start, u64 end,
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 128f3e5..ee67773 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -367,6 +367,7 @@  struct async_cow {
 	struct page *locked_page;
 	u64 start;
 	u64 end;
+	unsigned int write_flags;
 	struct list_head extents;
 	struct btrfs_work work;
 };
@@ -846,7 +847,8 @@  static noinline void submit_compressed_extents(struct inode *inode,
 				    async_extent->ram_size,
 				    ins.objectid,
 				    ins.offset, async_extent->pages,
-				    async_extent->nr_pages)) {
+				    async_extent->nr_pages,
+				    async_cow->write_flags)) {
 			struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
 			struct page *p = async_extent->pages[0];
 			const u64 start = async_extent->start;
@@ -1176,7 +1178,8 @@  static noinline void async_cow_free(struct btrfs_work *work)
 
 static int cow_file_range_async(struct inode *inode, struct page *locked_page,
 				u64 start, u64 end, int *page_started,
-				unsigned long *nr_written)
+				unsigned long *nr_written,
+				unsigned int write_flags)
 {
 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 	struct async_cow *async_cow;
@@ -1193,6 +1196,7 @@  static int cow_file_range_async(struct inode *inode, struct page *locked_page,
 		async_cow->root = root;
 		async_cow->locked_page = locked_page;
 		async_cow->start = start;
+		async_cow->write_flags = write_flags;
 
 		if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS &&
 		    !btrfs_test_opt(fs_info, FORCE_COMPRESS))
@@ -1569,11 +1573,13 @@  static inline int need_force_cow(struct inode *inode, u64 start, u64 end)
  */
 static int run_delalloc_range(void *private_data, struct page *locked_page,
 			      u64 start, u64 end, int *page_started,
-			      unsigned long *nr_written)
+			      unsigned long *nr_written,
+			      struct writeback_control *wbc)
 {
 	struct inode *inode = private_data;
 	int ret;
 	int force_cow = need_force_cow(inode, start, end);
+	unsigned int write_flags = wbc_to_write_flags(wbc);
 
 	if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW && !force_cow) {
 		ret = run_delalloc_nocow(inode, locked_page, start, end,
@@ -1588,7 +1594,8 @@  static int run_delalloc_range(void *private_data, struct page *locked_page,
 		set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
 			&BTRFS_I(inode)->runtime_flags);
 		ret = cow_file_range_async(inode, locked_page, start, end,
-					   page_started, nr_written);
+					   page_started, nr_written,
+					   write_flags);
 	}
 	if (ret)
 		btrfs_cleanup_ordered_extents(inode, start, end - start + 1);