diff mbox series

[3/5] btrfs: add helpers to get fs_info from page/folio pointers

Message ID b93ed05e42a65c5bb11a8c5a3bdad9facb3ed43a.1706553080.git.dsterba@suse.com (mailing list archive)
State New, archived
Headers show
Series Struct to fs_info helpers | expand

Commit Message

David Sterba Jan. 29, 2024, 6:33 p.m. UTC 
Add convenience helpers to get a fs_info from a page or folio pointer
instead of open coding the chain or using btrfs_sb() that in some cases
does one more pointer hop.  This is implemented as a macro so we don't
need full definitions of struct page or address_space.

Signed-off-by: David Sterba <dsterba@suse.com>
---
 fs/btrfs/compression.c |  2 +-
 fs/btrfs/disk-io.c     |  2 +-
 fs/btrfs/extent_io.c   | 18 +++++++++---------
 fs/btrfs/inode.c       |  2 +-
 fs/btrfs/lzo.c         |  2 +-
 fs/btrfs/misc.h        |  2 ++
 6 files changed, 15 insertions(+), 13 deletions(-)

Comments

Johannes Thumshirn Jan. 30, 2024, 11:58 a.m. UTC | #1 
On 29.01.24 19:34, David Sterba wrote:
> @@ -1929,7 +1929,7 @@ int btree_write_cache_pages(struct address_space *mapping,
>   				   struct writeback_control *wbc)
>   {
>   	struct btrfs_eb_write_context ctx = { .wbc = wbc };
> -	struct btrfs_fs_info *fs_info = BTRFS_I(mapping->host)->root->fs_info;
> +	struct btrfs_fs_info *fs_info = page_to_fs_info(mapping->host);

This is wrong, page_to_fs_info() expects a struct page, but 
mapping->host gives you a struct inode.
David Sterba Jan. 30, 2024, 7:32 p.m. UTC | #2 
On Tue, Jan 30, 2024 at 11:58:40AM +0000, Johannes Thumshirn wrote:
> On 29.01.24 19:34, David Sterba wrote:
> > @@ -1929,7 +1929,7 @@ int btree_write_cache_pages(struct address_space *mapping,
> >   				   struct writeback_control *wbc)
> >   {
> >   	struct btrfs_eb_write_context ctx = { .wbc = wbc };
> > -	struct btrfs_fs_info *fs_info = BTRFS_I(mapping->host)->root->fs_info;
> > +	struct btrfs_fs_info *fs_info = page_to_fs_info(mapping->host);
> 
> This is wrong, page_to_fs_info() expects a struct page, but 
> mapping->host gives you a struct inode.

Right, strange that it did not crash. We need the type checking for such
errors.
diff mbox series

Patch

diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index 488089acd49f..9cae8542c7e0 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -1036,7 +1036,7 @@  static int btrfs_decompress_bio(struct compressed_bio *cb)
 int btrfs_decompress(int type, const u8 *data_in, struct page *dest_page,
 		     unsigned long dest_pgoff, size_t srclen, size_t destlen)
 {
-	struct btrfs_fs_info *fs_info = btrfs_sb(dest_page->mapping->host->i_sb);
+	struct btrfs_fs_info *fs_info = page_to_fs_info(dest_page);
 	struct list_head *workspace;
 	const u32 sectorsize = fs_info->sectorsize;
 	int ret;
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index e711bfe4d221..ebefc69ddcfa 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -533,7 +533,7 @@  static void btree_invalidate_folio(struct folio *folio, size_t offset,
 	extent_invalidate_folio(tree, folio, offset);
 	btree_release_folio(folio, GFP_NOFS);
 	if (folio_get_private(folio)) {
-		btrfs_warn(BTRFS_I(folio->mapping->host)->root->fs_info,
+		btrfs_warn(folio_to_fs_info(folio),
 			   "folio private not zero on folio %llu",
 			   (unsigned long long)folio_pos(folio));
 		folio_detach_private(folio);
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 46667c9d61a6..7327b276cd07 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -432,7 +432,7 @@  static bool btrfs_verify_page(struct page *page, u64 start)
 
 static void end_page_read(struct page *page, bool uptodate, u64 start, u32 len)
 {
-	struct btrfs_fs_info *fs_info = btrfs_sb(page->mapping->host->i_sb);
+	struct btrfs_fs_info *fs_info = page_to_fs_info(page);
 	struct folio *folio = page_folio(page);
 
 	ASSERT(page_offset(page) <= start &&
@@ -960,7 +960,7 @@  int set_folio_extent_mapped(struct folio *folio)
 	if (folio_test_private(folio))
 		return 0;
 
-	fs_info = btrfs_sb(folio->mapping->host->i_sb);
+	fs_info = folio_to_fs_info(page);
 
 	if (btrfs_is_subpage(fs_info, folio->mapping))
 		return btrfs_attach_subpage(fs_info, folio, BTRFS_SUBPAGE_DATA);
@@ -979,7 +979,7 @@  void clear_page_extent_mapped(struct page *page)
 	if (!folio_test_private(folio))
 		return;
 
-	fs_info = btrfs_sb(page->mapping->host->i_sb);
+	fs_info = page_to_fs_info(page);
 	if (btrfs_is_subpage(fs_info, page->mapping))
 		return btrfs_detach_subpage(fs_info, folio);
 
@@ -1780,7 +1780,7 @@  static noinline_for_stack void write_one_eb(struct extent_buffer *eb,
  */
 static int submit_eb_subpage(struct page *page, struct writeback_control *wbc)
 {
-	struct btrfs_fs_info *fs_info = btrfs_sb(page->mapping->host->i_sb);
+	struct btrfs_fs_info *fs_info = page_to_fs_info(page);
 	struct folio *folio = page_folio(page);
 	int submitted = 0;
 	u64 page_start = page_offset(page);
@@ -1871,7 +1871,7 @@  static int submit_eb_page(struct page *page, struct btrfs_eb_write_context *ctx)
 	if (!folio_test_private(folio))
 		return 0;
 
-	if (btrfs_sb(page->mapping->host->i_sb)->nodesize < PAGE_SIZE)
+	if (page_to_fs_info(page)->nodesize < PAGE_SIZE)
 		return submit_eb_subpage(page, wbc);
 
 	spin_lock(&mapping->i_private_lock);
@@ -1929,7 +1929,7 @@  int btree_write_cache_pages(struct address_space *mapping,
 				   struct writeback_control *wbc)
 {
 	struct btrfs_eb_write_context ctx = { .wbc = wbc };
-	struct btrfs_fs_info *fs_info = BTRFS_I(mapping->host)->root->fs_info;
+	struct btrfs_fs_info *fs_info = page_to_fs_info(mapping->host);
 	int ret = 0;
 	int done = 0;
 	int nr_to_write_done = 0;
@@ -2323,7 +2323,7 @@  int extent_invalidate_folio(struct extent_io_tree *tree,
 	struct extent_state *cached_state = NULL;
 	u64 start = folio_pos(folio);
 	u64 end = start + folio_size(folio) - 1;
-	size_t blocksize = btrfs_sb(folio->mapping->host->i_sb)->sectorsize;
+	size_t blocksize = folio_to_fs_info(folio)->sectorsize;
 
 	/* This function is only called for the btree inode */
 	ASSERT(tree->owner == IO_TREE_BTREE_INODE_IO);
@@ -4783,7 +4783,7 @@  static struct extent_buffer *get_next_extent_buffer(
 
 static int try_release_subpage_extent_buffer(struct page *page)
 {
-	struct btrfs_fs_info *fs_info = btrfs_sb(page->mapping->host->i_sb);
+	struct btrfs_fs_info *fs_info = page_to_fs_info(page);
 	u64 cur = page_offset(page);
 	const u64 end = page_offset(page) + PAGE_SIZE;
 	int ret;
@@ -4856,7 +4856,7 @@  int try_release_extent_buffer(struct page *page)
 	struct folio *folio = page_folio(page);
 	struct extent_buffer *eb;
 
-	if (btrfs_sb(page->mapping->host->i_sb)->nodesize < PAGE_SIZE)
+	if (page_to_fs_info(page)->nodesize < PAGE_SIZE)
 		return try_release_subpage_extent_buffer(page);
 
 	/*
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 2d3e5359d067..27d67c4580bc 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -7869,7 +7869,7 @@  static void btrfs_readahead(struct readahead_control *rac)
  */
 static void wait_subpage_spinlock(struct page *page)
 {
-	struct btrfs_fs_info *fs_info = btrfs_sb(page->mapping->host->i_sb);
+	struct btrfs_fs_info *fs_info = page_to_fs_info(page);
 	struct folio *folio = page_folio(page);
 	struct btrfs_subpage *subpage;
 
diff --git a/fs/btrfs/lzo.c b/fs/btrfs/lzo.c
index e43bc0fdc74e..110a2c304bdc 100644
--- a/fs/btrfs/lzo.c
+++ b/fs/btrfs/lzo.c
@@ -429,7 +429,7 @@  int lzo_decompress(struct list_head *ws, const u8 *data_in,
 		size_t destlen)
 {
 	struct workspace *workspace = list_entry(ws, struct workspace, list);
-	struct btrfs_fs_info *fs_info = btrfs_sb(dest_page->mapping->host->i_sb);
+	struct btrfs_fs_info *fs_info = page_to_fs_info(dest_page);
 	const u32 sectorsize = fs_info->sectorsize;
 	size_t in_len;
 	size_t out_len;
diff --git a/fs/btrfs/misc.h b/fs/btrfs/misc.h
index 8be09234c575..9cb671ef136c 100644
--- a/fs/btrfs/misc.h
+++ b/fs/btrfs/misc.h
@@ -10,6 +10,8 @@ 
 
 #define page_to_inode(page)	BTRFS_I((page)->mapping->host)
 #define folio_to_inode(folio)	BTRFS_I((folio)->mapping->host)
+#define page_to_fs_info(page)	BTRFS_I((page)->mapping->host)->root->fs_info
+#define folio_to_fs_info(page)	BTRFS_I((folio)->mapping->host)->root->fs_info
 
 /*
  * Enumerate bits using enum autoincrement. Define the @name as the n-th bit.