[PATCH v2 01/10] btrfs: introduce struct to consolidate extent buffer write context

Naohiro Aota
2023-07-31T17:20:05Z

Introduce btrfs_eb_write_context to consolidate writeback_control and the
exntent buffer context.

This will help adding a block group context as well.

While at it, move the eb context setting before
btrfs_check_meta_write_pointer(). We can set it here because we anyway need
to skip pages in the same eb if that eb is rejected by
btrfs_check_meta_write_pointer().

Suggested-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
---
fs/btrfs/extent_io.c | 17 ++++++++++-------
fs/btrfs/extent_io.h | 5 +++++
2 files changed, 15 insertions(+), 7 deletions(-)

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 177d65d51447..40633bc15c97 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -1784,9 +1784,9 @@ static int submit_eb_subpage(struct page *page, struct writeback_control *wbc)
* previous call.
* Return <0 for fatal error.
*/
-static int submit_eb_page(struct page *page, struct writeback_control *wbc,
- struct extent_buffer **eb_context)
+static int submit_eb_page(struct page *page, struct btrfs_eb_write_context *ctx)
{
+ struct writeback_control *wbc = ctx->wbc;
struct address_space *mapping = page->mapping;
struct btrfs_block_group *cache = NULL;
struct extent_buffer *eb;
@@ -1815,7 +1815,7 @@ static int submit_eb_page(struct page *page, struct writeback_control *wbc,
return 0;
}

- if (eb == *eb_context) {
+ if (eb == ctx->eb) {
spin_unlock(&mapping->private_lock);
return 0;
}
@@ -1824,6 +1824,8 @@ static int submit_eb_page(struct page *page, struct writeback_control *wbc,
if (!ret)
return 0;

+ ctx->eb = eb;
+
if (!btrfs_check_meta_write_pointer(eb->fs_info, eb, &cache)) {
/*
* If for_sync, this hole will be filled with
@@ -1837,8 +1839,6 @@ static int submit_eb_page(struct page *page, struct writeback_control *wbc,
return ret;
}

- *eb_context = eb;
-
if (!lock_extent_buffer_for_io(eb, wbc)) {
btrfs_revert_meta_write_pointer(cache, eb);
if (cache)
@@ -1861,7 +1861,10 @@ static int submit_eb_page(struct page *page, struct writeback_control *wbc,
int btree_write_cache_pages(struct address_space *mapping,
struct writeback_control *wbc)
{
- struct extent_buffer *eb_context = NULL;
+ struct btrfs_eb_write_context ctx = {
+ .wbc = wbc,
+ .eb = NULL,
+ };
struct btrfs_fs_info *fs_info = BTRFS_I(mapping->host)->root->fs_info;
int ret = 0;
int done = 0;
@@ -1903,7 +1906,7 @@ int btree_write_cache_pages(struct address_space *mapping,
for (i = 0; i < nr_folios; i++) {
struct folio *folio = fbatch.folios[i];

- ret = submit_eb_page(&folio->page, wbc, &eb_context);
+ ret = submit_eb_page(&folio->page, &ctx);
if (ret == 0)
continue;
if (ret < 0) {
diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
index adda14c1b763..e243a8eac910 100644
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -93,6 +93,11 @@ struct extent_buffer {
#endif
};

+struct btrfs_eb_write_context {
+ struct writeback_control *wbc;
+ struct extent_buffer *eb;
+};
+
/*
* Get the correct offset inside the page of extent buffer.
*
--
2.41.0