fs: factor out a __generic_write_end helper (a6d639da) · Commits · 戴 / test

fs/buffer.c

+35 −32

Original line number	Diff line number	Diff line
		@@ -2076,6 +2076,40 @@ int block_write_begin(struct address_space *mapping, loff_t pos, unsigned len,
		}
		EXPORT_SYMBOL(block_write_begin);

		int __generic_write_end(struct inode *inode, loff_t pos, unsigned copied,
		struct page *page)
		{
		loff_t old_size = inode->i_size;
		bool i_size_changed = false;

		/*
		* No need to use i_size_read() here, the i_size cannot change under us
		* because we hold i_rwsem.
		*
		* But it's important to update i_size while still holding page lock:
		* page writeout could otherwise come in and zero beyond i_size.
		*/
		if (pos + copied > inode->i_size) {
		i_size_write(inode, pos + copied);
		i_size_changed = true;
		}

		unlock_page(page);
		put_page(page);

		if (old_size < pos)
		pagecache_isize_extended(inode, old_size, pos);
		/*
		* Don't mark the inode dirty under page lock. First, it unnecessarily
		* makes the holding time of page lock longer. Second, it forces lock
		* ordering of page lock and transaction start for journaling
		* filesystems.
		*/
		if (i_size_changed)
		mark_inode_dirty(inode);
		return copied;
		}

		int block_write_end(struct file file, struct address_space mapping,
		loff_t pos, unsigned len, unsigned copied,
		struct page page, void fsdata)
		@@ -2116,39 +2150,8 @@ int generic_write_end(struct file file, struct address_space mapping,
		loff_t pos, unsigned len, unsigned copied,
		struct page page, void fsdata)
		{
		struct inode *inode = mapping->host;
		loff_t old_size = inode->i_size;
		int i_size_changed = 0;

		copied = block_write_end(file, mapping, pos, len, copied, page, fsdata);

		/*
		* No need to use i_size_read() here, the i_size
		* cannot change under us because we hold i_mutex.
		*
		* But it's important to update i_size while still holding page lock:
		* page writeout could otherwise come in and zero beyond i_size.
		*/
		if (pos+copied > inode->i_size) {
		i_size_write(inode, pos+copied);
		i_size_changed = 1;
		}

		unlock_page(page);
		put_page(page);

		if (old_size < pos)
		pagecache_isize_extended(inode, old_size, pos);
		/*
		* Don't mark the inode dirty under page lock. First, it unnecessarily
		* makes the holding time of page lock longer. Second, it forces lock
		* ordering of page lock and transaction start for journaling
		* filesystems.
		*/
		if (i_size_changed)
		mark_inode_dirty(inode);

		return copied;
		return __generic_write_end(mapping->host, pos, copied, page);
		}
		EXPORT_SYMBOL(generic_write_end);

fs/internal.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -43,6 +43,8 @@ static inline int __sync_blockdev(struct block_device *bdev, int wait)
		extern void guard_bio_eod(int rw, struct bio *bio);
		extern int __block_write_begin_int(struct page *page, loff_t pos, unsigned len,
		get_block_t get_block, struct iomap iomap);
		int __generic_write_end(struct inode *inode, loff_t pos, unsigned copied,
		struct page *page);

		/*
		* char_dev.c

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