6.6-stable review patch. If anyone has any objections, please let me know.
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From: Matthew Wilcox (Oracle) willy@infradead.org
[ Upstream commit 3decb8564eff88a2533f83b01cec2cf9259c3eaf ]
Patch series "Finish the create_empty_buffers() transition", v2.
Pankaj recently added folio_create_empty_buffers() as the folio equivalent to create_empty_buffers(). This patch set finishes the conversion by first converting all remaining filesystems to call folio_create_empty_buffers(), then renaming it back to create_empty_buffers(). I took the opportunity to make a few simplifications like making folio_create_empty_buffers() return the head buffer and extracting get_nth_bh() from nilfs2.
A few of the patches in this series aren't directly related to create_empty_buffers(), but I saw them while I was working on this and thought they'd be easy enough to add to this series. Compile-tested only, other than ext4.
This patch (of 26):
Almost all callers want to know the first BH that was allocated for this folio. We already have that handy, so return it.
Link: https://lkml.kernel.org/r/20231016201114.1928083-1-willy@infradead.org Link: https://lkml.kernel.org/r/20231016201114.1928083-3-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) willy@infradead.org Reviewed-by: Pankaj Raghav p.raghav@samsung.com Cc: Andreas Gruenbacher agruenba@redhat.com Cc: Ryusuke Konishi konishi.ryusuke@gmail.com Signed-off-by: Andrew Morton akpm@linux-foundation.org Stable-dep-of: 367a9bffabe0 ("nilfs2: protect access to buffers with no active references") Signed-off-by: Sasha Levin sashal@kernel.org --- fs/buffer.c | 24 +++++++++++++----------- include/linux/buffer_head.h | 4 ++-- 2 files changed, 15 insertions(+), 13 deletions(-)
diff --git a/fs/buffer.c b/fs/buffer.c index ecd8b47507ff8..4b86e971efd8a 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -1640,8 +1640,8 @@ EXPORT_SYMBOL(block_invalidate_folio); * block_dirty_folio() via private_lock. try_to_free_buffers * is already excluded via the folio lock. */ -void folio_create_empty_buffers(struct folio *folio, unsigned long blocksize, - unsigned long b_state) +struct buffer_head *folio_create_empty_buffers(struct folio *folio, + unsigned long blocksize, unsigned long b_state) { struct buffer_head *bh, *head, *tail;
@@ -1667,6 +1667,8 @@ void folio_create_empty_buffers(struct folio *folio, unsigned long blocksize, } folio_attach_private(folio, head); spin_unlock(&folio->mapping->private_lock); + + return head; } EXPORT_SYMBOL(folio_create_empty_buffers);
@@ -1768,13 +1770,15 @@ static struct buffer_head *folio_create_buffers(struct folio *folio, struct inode *inode, unsigned int b_state) { + struct buffer_head *bh; + BUG_ON(!folio_test_locked(folio));
- if (!folio_buffers(folio)) - folio_create_empty_buffers(folio, - 1 << READ_ONCE(inode->i_blkbits), - b_state); - return folio_buffers(folio); + bh = folio_buffers(folio); + if (!bh) + bh = folio_create_empty_buffers(folio, + 1 << READ_ONCE(inode->i_blkbits), b_state); + return bh; }
/* @@ -2678,10 +2682,8 @@ int block_truncate_page(struct address_space *mapping, return PTR_ERR(folio);
bh = folio_buffers(folio); - if (!bh) { - folio_create_empty_buffers(folio, blocksize, 0); - bh = folio_buffers(folio); - } + if (!bh) + bh = folio_create_empty_buffers(folio, blocksize, 0);
/* Find the buffer that contains "offset" */ offset = offset_in_folio(folio, from); diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h index 44e9de51eedfb..572030db2f061 100644 --- a/include/linux/buffer_head.h +++ b/include/linux/buffer_head.h @@ -203,8 +203,8 @@ struct buffer_head *alloc_page_buffers(struct page *page, unsigned long size, bool retry); void create_empty_buffers(struct page *, unsigned long, unsigned long b_state); -void folio_create_empty_buffers(struct folio *folio, unsigned long blocksize, - unsigned long b_state); +struct buffer_head *folio_create_empty_buffers(struct folio *folio, + unsigned long blocksize, unsigned long b_state); void end_buffer_read_sync(struct buffer_head *bh, int uptodate); void end_buffer_write_sync(struct buffer_head *bh, int uptodate); void end_buffer_async_write(struct buffer_head *bh, int uptodate);