[RFC,v3,04/12] btrfs: get rid of trivial __btrfs_lookup_bio_sums() wrappers
diff mbox series

Message ID bca47beb2f4eef766accebef683137e94313f7d3.1574273658.git.osandov@fb.com
State New
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Series
  • fs: interface for directly reading/writing compressed data
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Commit Message

Omar Sandoval Nov. 20, 2019, 6:24 p.m. UTC
From: Omar Sandoval <osandov@fb.com>

Currently, we have two wrappers for __btrfs_lookup_bio_sums():
btrfs_lookup_bio_sums_dio(), which is used for direct I/O, and
btrfs_lookup_bio_sums(), which is used everywhere else. The only
difference is that the _dio variant looks up csums starting at the given
offset instead of using the page index, which isn't actually direct
I/O-specific. Let's clean up the signature and return value of
__btrfs_lookup_bio_sums(), rename it to btrfs_lookup_bio_sums(), and get
rid of the trivial helpers.

Signed-off-by: Omar Sandoval <osandov@fb.com>
---
 fs/btrfs/compression.c |  4 ++--
 fs/btrfs/ctree.h       |  4 +---
 fs/btrfs/file-item.c   | 35 +++++++++++++++++------------------
 fs/btrfs/inode.c       |  6 +++---
 4 files changed, 23 insertions(+), 26 deletions(-)

Comments

Nikolay Borisov Nov. 26, 2019, 1:56 p.m. UTC | #1
On 20.11.19 г. 20:24 ч., Omar Sandoval wrote:
> From: Omar Sandoval <osandov@fb.com>
> 
> Currently, we have two wrappers for __btrfs_lookup_bio_sums():
> btrfs_lookup_bio_sums_dio(), which is used for direct I/O, and
> btrfs_lookup_bio_sums(), which is used everywhere else. The only
> difference is that the _dio variant looks up csums starting at the given
> offset instead of using the page index, which isn't actually direct
> I/O-specific. Let's clean up the signature and return value of
> __btrfs_lookup_bio_sums(), rename it to btrfs_lookup_bio_sums(), and get
> rid of the trivial helpers.
> 
> Signed-off-by: Omar Sandoval <osandov@fb.com>

Overall looks good but 2 nits, see below.

In any case:

Reviewed-by: Nikolay Borisov <nborisov@suse.com>

> ---
>  fs/btrfs/compression.c |  4 ++--
>  fs/btrfs/ctree.h       |  4 +---
>  fs/btrfs/file-item.c   | 35 +++++++++++++++++------------------
>  fs/btrfs/inode.c       |  6 +++---
>  4 files changed, 23 insertions(+), 26 deletions(-)
> 
> diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
> index b05b361e2062..4df6f0c58dc9 100644
> --- a/fs/btrfs/compression.c
> +++ b/fs/btrfs/compression.c
> @@ -660,7 +660,7 @@ blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
>  
>  			if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) {
>  				ret = btrfs_lookup_bio_sums(inode, comp_bio,
> -							    sums);
> +							    false, 0, sums);
>  				BUG_ON(ret); /* -ENOMEM */
>  			}
>  
> @@ -689,7 +689,7 @@ blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
>  	BUG_ON(ret); /* -ENOMEM */
>  
>  	if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) {
> -		ret = btrfs_lookup_bio_sums(inode, comp_bio, sums);
> +		ret = btrfs_lookup_bio_sums(inode, comp_bio, false, 0, sums);
>  		BUG_ON(ret); /* -ENOMEM */
>  	}
>  
> diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
> index fe2b8765d9e6..4bc40bf49b0e 100644
> --- a/fs/btrfs/ctree.h
> +++ b/fs/btrfs/ctree.h
> @@ -2787,9 +2787,7 @@ struct btrfs_dio_private;
>  int btrfs_del_csums(struct btrfs_trans_handle *trans,
>  		    struct btrfs_fs_info *fs_info, u64 bytenr, u64 len);
>  blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio,
> -				   u8 *dst);
> -blk_status_t btrfs_lookup_bio_sums_dio(struct inode *inode, struct bio *bio,
> -			      u64 logical_offset);
> +				   bool at_offset, u64 offset, u8 *dst);
>  int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
>  			     struct btrfs_root *root,
>  			     u64 objectid, u64 pos,
> diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
> index 1a599f50837b..a87c40502267 100644
> --- a/fs/btrfs/file-item.c
> +++ b/fs/btrfs/file-item.c
> @@ -148,8 +148,21 @@ int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
>  	return ret;
>  }
>  
> -static blk_status_t __btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio,
> -				   u64 logical_offset, u8 *dst, int dio)
> +/**
> + * btrfs_lookup_bio_sums - Look up checksums for a bio.
> + * @inode: inode that the bio is for.
> + * @bio: bio embedded in btrfs_io_bio.
> + * @at_offset: If true, look up checksums for the extent at @c offset.

nit: that @c is an editing artifact? On the other hand rather than
having an explicit bool signifying whether we want a specific offset
can't we simply check if offset is != 0 ?

<snip>
Omar Sandoval Nov. 26, 2019, 5:42 p.m. UTC | #2
On Tue, Nov 26, 2019 at 03:56:31PM +0200, Nikolay Borisov wrote:
> 
> 
> On 20.11.19 г. 20:24 ч., Omar Sandoval wrote:
> > From: Omar Sandoval <osandov@fb.com>
> > 
> > Currently, we have two wrappers for __btrfs_lookup_bio_sums():
> > btrfs_lookup_bio_sums_dio(), which is used for direct I/O, and
> > btrfs_lookup_bio_sums(), which is used everywhere else. The only
> > difference is that the _dio variant looks up csums starting at the given
> > offset instead of using the page index, which isn't actually direct
> > I/O-specific. Let's clean up the signature and return value of
> > __btrfs_lookup_bio_sums(), rename it to btrfs_lookup_bio_sums(), and get
> > rid of the trivial helpers.
> > 
> > Signed-off-by: Omar Sandoval <osandov@fb.com>
> 
> Overall looks good but 2 nits, see below.
> 
> In any case:
> 
> Reviewed-by: Nikolay Borisov <nborisov@suse.com>

Thanks!

> > ---
> >  fs/btrfs/compression.c |  4 ++--
> >  fs/btrfs/ctree.h       |  4 +---
> >  fs/btrfs/file-item.c   | 35 +++++++++++++++++------------------
> >  fs/btrfs/inode.c       |  6 +++---
> >  4 files changed, 23 insertions(+), 26 deletions(-)
> > 
> > diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
> > index b05b361e2062..4df6f0c58dc9 100644
> > --- a/fs/btrfs/compression.c
> > +++ b/fs/btrfs/compression.c
> > @@ -660,7 +660,7 @@ blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
> >  
> >  			if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) {
> >  				ret = btrfs_lookup_bio_sums(inode, comp_bio,
> > -							    sums);
> > +							    false, 0, sums);
> >  				BUG_ON(ret); /* -ENOMEM */
> >  			}
> >  
> > @@ -689,7 +689,7 @@ blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
> >  	BUG_ON(ret); /* -ENOMEM */
> >  
> >  	if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) {
> > -		ret = btrfs_lookup_bio_sums(inode, comp_bio, sums);
> > +		ret = btrfs_lookup_bio_sums(inode, comp_bio, false, 0, sums);
> >  		BUG_ON(ret); /* -ENOMEM */
> >  	}
> >  
> > diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
> > index fe2b8765d9e6..4bc40bf49b0e 100644
> > --- a/fs/btrfs/ctree.h
> > +++ b/fs/btrfs/ctree.h
> > @@ -2787,9 +2787,7 @@ struct btrfs_dio_private;
> >  int btrfs_del_csums(struct btrfs_trans_handle *trans,
> >  		    struct btrfs_fs_info *fs_info, u64 bytenr, u64 len);
> >  blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio,
> > -				   u8 *dst);
> > -blk_status_t btrfs_lookup_bio_sums_dio(struct inode *inode, struct bio *bio,
> > -			      u64 logical_offset);
> > +				   bool at_offset, u64 offset, u8 *dst);
> >  int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
> >  			     struct btrfs_root *root,
> >  			     u64 objectid, u64 pos,
> > diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
> > index 1a599f50837b..a87c40502267 100644
> > --- a/fs/btrfs/file-item.c
> > +++ b/fs/btrfs/file-item.c
> > @@ -148,8 +148,21 @@ int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
> >  	return ret;
> >  }
> >  
> > -static blk_status_t __btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio,
> > -				   u64 logical_offset, u8 *dst, int dio)
> > +/**
> > + * btrfs_lookup_bio_sums - Look up checksums for a bio.
> > + * @inode: inode that the bio is for.
> > + * @bio: bio embedded in btrfs_io_bio.
> > + * @at_offset: If true, look up checksums for the extent at @c offset.
> 
> nit: that @c is an editing artifact?

Oops, I mixed up kernel-doc with Doxygen. Fixed, thanks.

> On the other hand rather than
> having an explicit bool signifying whether we want a specific offset
> can't we simply check if offset is != 0 ?

Zero is a perfectly valid offset to have an extent at, but we could do
(u64)-1 instead. I'm not sure what's cleaner.

Patch
diff mbox series

diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index b05b361e2062..4df6f0c58dc9 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -660,7 +660,7 @@  blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
 
 			if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) {
 				ret = btrfs_lookup_bio_sums(inode, comp_bio,
-							    sums);
+							    false, 0, sums);
 				BUG_ON(ret); /* -ENOMEM */
 			}
 
@@ -689,7 +689,7 @@  blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
 	BUG_ON(ret); /* -ENOMEM */
 
 	if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) {
-		ret = btrfs_lookup_bio_sums(inode, comp_bio, sums);
+		ret = btrfs_lookup_bio_sums(inode, comp_bio, false, 0, sums);
 		BUG_ON(ret); /* -ENOMEM */
 	}
 
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index fe2b8765d9e6..4bc40bf49b0e 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -2787,9 +2787,7 @@  struct btrfs_dio_private;
 int btrfs_del_csums(struct btrfs_trans_handle *trans,
 		    struct btrfs_fs_info *fs_info, u64 bytenr, u64 len);
 blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio,
-				   u8 *dst);
-blk_status_t btrfs_lookup_bio_sums_dio(struct inode *inode, struct bio *bio,
-			      u64 logical_offset);
+				   bool at_offset, u64 offset, u8 *dst);
 int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
 			     struct btrfs_root *root,
 			     u64 objectid, u64 pos,
diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index 1a599f50837b..a87c40502267 100644
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -148,8 +148,21 @@  int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
 	return ret;
 }
 
-static blk_status_t __btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio,
-				   u64 logical_offset, u8 *dst, int dio)
+/**
+ * btrfs_lookup_bio_sums - Look up checksums for a bio.
+ * @inode: inode that the bio is for.
+ * @bio: bio embedded in btrfs_io_bio.
+ * @at_offset: If true, look up checksums for the extent at @c offset.
+ *             If false, use the page offsets from the bio.
+ * @offset: If @at_offset is true, offset in file to look up checksums for.
+ *          Ignored otherwise.
+ * @dst: Buffer of size btrfs_super_csum_size() used to return checksum. If
+ *       NULL, the checksum is returned in btrfs_io_bio(bio)->csum instead.
+ *
+ * Return: BLK_STS_RESOURCE if allocating memory fails, BLK_STS_OK otherwise.
+ */
+blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio,
+				   bool at_offset, u64 offset, u8 *dst)
 {
 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 	struct bio_vec bvec;
@@ -159,7 +172,6 @@  static blk_status_t __btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio
 	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
 	struct btrfs_path *path;
 	u8 *csum;
-	u64 offset = 0;
 	u64 item_start_offset = 0;
 	u64 item_last_offset = 0;
 	u64 disk_bytenr;
@@ -205,15 +217,13 @@  static blk_status_t __btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio
 	}
 
 	disk_bytenr = (u64)bio->bi_iter.bi_sector << 9;
-	if (dio)
-		offset = logical_offset;
 
 	bio_for_each_segment(bvec, bio, iter) {
 		page_bytes_left = bvec.bv_len;
 		if (count)
 			goto next;
 
-		if (!dio)
+		if (!at_offset)
 			offset = page_offset(bvec.bv_page) + bvec.bv_offset;
 		count = btrfs_find_ordered_sum(inode, offset, disk_bytenr,
 					       csum, nblocks);
@@ -285,18 +295,7 @@  static blk_status_t __btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio
 
 	WARN_ON_ONCE(count);
 	btrfs_free_path(path);
-	return 0;
-}
-
-blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio,
-				   u8 *dst)
-{
-	return __btrfs_lookup_bio_sums(inode, bio, 0, dst, 0);
-}
-
-blk_status_t btrfs_lookup_bio_sums_dio(struct inode *inode, struct bio *bio, u64 offset)
-{
-	return __btrfs_lookup_bio_sums(inode, bio, offset, NULL, 1);
+	return BLK_STS_OK;
 }
 
 int btrfs_lookup_csums_range(struct btrfs_root *root, u64 start, u64 end,
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 015910079e73..ad5bffb24199 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -2090,7 +2090,7 @@  static blk_status_t btrfs_submit_bio_hook(struct inode *inode, struct bio *bio,
 							   bio_flags);
 			goto out;
 		} else if (!skip_sum) {
-			ret = btrfs_lookup_bio_sums(inode, bio, NULL);
+			ret = btrfs_lookup_bio_sums(inode, bio, false, 0, NULL);
 			if (ret)
 				goto out;
 		}
@@ -8332,8 +8332,8 @@  static inline blk_status_t btrfs_lookup_and_bind_dio_csum(struct inode *inode,
 	 * contention.
 	 */
 	if (dip->logical_offset == file_offset) {
-		ret = btrfs_lookup_bio_sums_dio(inode, dip->orig_bio,
-						file_offset);
+		ret = btrfs_lookup_bio_sums(inode, dip->orig_bio, true,
+					    file_offset, NULL);
 		if (ret)
 			return ret;
 	}