diff mbox series

[03/11] btrfs: stash ordered extent in dio_data during iomap dio

Message ID 20230324023207.544800-4-hch@lst.de (mailing list archive)
State New, archived
Headers show
Series [01/11] btrfs: add function to create and return an ordered extent | expand

Commit Message

Christoph Hellwig March 24, 2023, 2:31 a.m. UTC 
From: Boris Burkov <boris@bur.io>

While it is not feasible for an ordered extent to survive across the
calls btrfs_direct_write makes into __iomap_dio_rw, it is still helpful
to stash it on the dio_data in between creating it in iomap_begin and
finishing it in either end_io or iomap_end.

The specific use I have in mind is that we can check if a partcular bio
is partial in submit_io without unconditionally looking up the ordered
extent. This is a preparatory patch for a later patch which does just
that.

Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 fs/btrfs/inode.c | 37 ++++++++++++++++++++++++-------------
 1 file changed, 24 insertions(+), 13 deletions(-)

Comments

Naohiro Aota March 24, 2023, 7:41 a.m. UTC | #1 
On Fri, Mar 24, 2023 at 10:31:59AM +0800, Christoph Hellwig wrote:
> From: Boris Burkov <boris@bur.io>
> 
> While it is not feasible for an ordered extent to survive across the
> calls btrfs_direct_write makes into __iomap_dio_rw, it is still helpful
> to stash it on the dio_data in between creating it in iomap_begin and
> finishing it in either end_io or iomap_end.
> 
> The specific use I have in mind is that we can check if a partcular bio
> is partial in submit_io without unconditionally looking up the ordered
> extent. This is a preparatory patch for a later patch which does just
> that.
> 
> Signed-off-by: Boris Burkov <boris@bur.io>
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  fs/btrfs/inode.c | 37 ++++++++++++++++++++++++-------------
>  1 file changed, 24 insertions(+), 13 deletions(-)
> 
> diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
> index 865d56ff2ce150..a92f482e898950 100644
> --- a/fs/btrfs/inode.c
> +++ b/fs/btrfs/inode.c
> @@ -81,6 +81,7 @@ struct btrfs_dio_data {
>  	struct extent_changeset *data_reserved;
>  	bool data_space_reserved;
>  	bool nocow_done;
> +	struct btrfs_ordered_extent *ordered;
>  };
>  
>  struct btrfs_dio_private {
> @@ -6965,6 +6966,7 @@ struct extent_map *btrfs_get_extent(struct btrfs_inode *inode,
>  }
>  
>  static struct extent_map *btrfs_create_dio_extent(struct btrfs_inode *inode,
> +						  struct btrfs_dio_data *dio_data,
>  						  const u64 start,
>  						  const u64 len,
>  						  const u64 orig_start,
> @@ -6975,7 +6977,7 @@ static struct extent_map *btrfs_create_dio_extent(struct btrfs_inode *inode,
>  						  const int type)
>  {
>  	struct extent_map *em = NULL;
> -	int ret;
> +	struct btrfs_ordered_extent *ordered;
>  
>  	if (type != BTRFS_ORDERED_NOCOW) {
>  		em = create_io_em(inode, start, len, orig_start, block_start,
> @@ -6985,18 +6987,21 @@ static struct extent_map *btrfs_create_dio_extent(struct btrfs_inode *inode,
>  		if (IS_ERR(em))
>  			goto out;
>  	}
> -	ret = btrfs_add_ordered_extent(inode, start, len, len, block_start,
> -				       block_len, 0,
> -				       (1 << type) |
> -				       (1 << BTRFS_ORDERED_DIRECT),
> -				       BTRFS_COMPRESS_NONE);
> -	if (ret) {
> +	ordered = btrfs_alloc_ordered_extent(inode, start, len, len,
> +					     block_start, block_len, 0,
> +					     (1 << type) |
> +					     (1 << BTRFS_ORDERED_DIRECT),
> +					     BTRFS_COMPRESS_NONE);
> +	if (IS_ERR(ordered)) {
>  		if (em) {
>  			free_extent_map(em);
>  			btrfs_drop_extent_map_range(inode, start,
>  						    start + len - 1, false);
>  		}
> -		em = ERR_PTR(ret);
> +		em = ERR_PTR(PTR_ERR(ordered));

We can use "em = ERR_CAST(ordered);" here ?

> +	} else {
> +		ASSERT(!dio_data->ordered);
> +		dio_data->ordered = ordered;
>  	}
>   out:
>  

Other than that,

Reviewed-by: Naohiro Aota <naohiro.aota@wdc.com>
diff mbox series

Patch

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 865d56ff2ce150..a92f482e898950 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -81,6 +81,7 @@  struct btrfs_dio_data {
 	struct extent_changeset *data_reserved;
 	bool data_space_reserved;
 	bool nocow_done;
+	struct btrfs_ordered_extent *ordered;
 };
 
 struct btrfs_dio_private {
@@ -6965,6 +6966,7 @@  struct extent_map *btrfs_get_extent(struct btrfs_inode *inode,
 }
 
 static struct extent_map *btrfs_create_dio_extent(struct btrfs_inode *inode,
+						  struct btrfs_dio_data *dio_data,
 						  const u64 start,
 						  const u64 len,
 						  const u64 orig_start,
@@ -6975,7 +6977,7 @@  static struct extent_map *btrfs_create_dio_extent(struct btrfs_inode *inode,
 						  const int type)
 {
 	struct extent_map *em = NULL;
-	int ret;
+	struct btrfs_ordered_extent *ordered;
 
 	if (type != BTRFS_ORDERED_NOCOW) {
 		em = create_io_em(inode, start, len, orig_start, block_start,
@@ -6985,18 +6987,21 @@  static struct extent_map *btrfs_create_dio_extent(struct btrfs_inode *inode,
 		if (IS_ERR(em))
 			goto out;
 	}
-	ret = btrfs_add_ordered_extent(inode, start, len, len, block_start,
-				       block_len, 0,
-				       (1 << type) |
-				       (1 << BTRFS_ORDERED_DIRECT),
-				       BTRFS_COMPRESS_NONE);
-	if (ret) {
+	ordered = btrfs_alloc_ordered_extent(inode, start, len, len,
+					     block_start, block_len, 0,
+					     (1 << type) |
+					     (1 << BTRFS_ORDERED_DIRECT),
+					     BTRFS_COMPRESS_NONE);
+	if (IS_ERR(ordered)) {
 		if (em) {
 			free_extent_map(em);
 			btrfs_drop_extent_map_range(inode, start,
 						    start + len - 1, false);
 		}
-		em = ERR_PTR(ret);
+		em = ERR_PTR(PTR_ERR(ordered));
+	} else {
+		ASSERT(!dio_data->ordered);
+		dio_data->ordered = ordered;
 	}
  out:
 
@@ -7004,6 +7009,7 @@  static struct extent_map *btrfs_create_dio_extent(struct btrfs_inode *inode,
 }
 
 static struct extent_map *btrfs_new_extent_direct(struct btrfs_inode *inode,
+						  struct btrfs_dio_data *dio_data,
 						  u64 start, u64 len)
 {
 	struct btrfs_root *root = inode->root;
@@ -7019,7 +7025,8 @@  static struct extent_map *btrfs_new_extent_direct(struct btrfs_inode *inode,
 	if (ret)
 		return ERR_PTR(ret);
 
-	em = btrfs_create_dio_extent(inode, start, ins.offset, start,
+	em = btrfs_create_dio_extent(inode, dio_data,
+				     start, ins.offset, start,
 				     ins.objectid, ins.offset, ins.offset,
 				     ins.offset, BTRFS_ORDERED_REGULAR);
 	btrfs_dec_block_group_reservations(fs_info, ins.objectid);
@@ -7364,7 +7371,7 @@  static int btrfs_get_blocks_direct_write(struct extent_map **map,
 		}
 		space_reserved = true;
 
-		em2 = btrfs_create_dio_extent(BTRFS_I(inode), start, len,
+		em2 = btrfs_create_dio_extent(BTRFS_I(inode), dio_data, start, len,
 					      orig_start, block_start,
 					      len, orig_block_len,
 					      ram_bytes, type);
@@ -7406,7 +7413,7 @@  static int btrfs_get_blocks_direct_write(struct extent_map **map,
 			goto out;
 		space_reserved = true;
 
-		em = btrfs_new_extent_direct(BTRFS_I(inode), start, len);
+		em = btrfs_new_extent_direct(BTRFS_I(inode), dio_data, start, len);
 		if (IS_ERR(em)) {
 			ret = PTR_ERR(em);
 			goto out;
@@ -7712,6 +7719,10 @@  static int btrfs_dio_iomap_end(struct inode *inode, loff_t pos, loff_t length,
 				      pos + length - 1, NULL);
 		ret = -ENOTBLK;
 	}
+	if (write) {
+		btrfs_put_ordered_extent(dio_data->ordered);
+		dio_data->ordered = NULL;
+	}
 
 	if (write)
 		extent_changeset_free(dio_data->data_reserved);
@@ -7773,7 +7784,7 @@  static const struct iomap_dio_ops btrfs_dio_ops = {
 
 ssize_t btrfs_dio_read(struct kiocb *iocb, struct iov_iter *iter, size_t done_before)
 {
-	struct btrfs_dio_data data;
+	struct btrfs_dio_data data = { 0 };
 
 	return iomap_dio_rw(iocb, iter, &btrfs_dio_iomap_ops, &btrfs_dio_ops,
 			    IOMAP_DIO_PARTIAL, &data, done_before);
@@ -7782,7 +7793,7 @@  ssize_t btrfs_dio_read(struct kiocb *iocb, struct iov_iter *iter, size_t done_be
 struct iomap_dio *btrfs_dio_write(struct kiocb *iocb, struct iov_iter *iter,
 				  size_t done_before)
 {
-	struct btrfs_dio_data data;
+	struct btrfs_dio_data data = { 0 };
 
 	return __iomap_dio_rw(iocb, iter, &btrfs_dio_iomap_ops, &btrfs_dio_ops,
 			    IOMAP_DIO_PARTIAL, &data, done_before);