f2fs: flush symlink path to avoid broken symlink after POR (d0cae97c) · Commits · 戴 / test

This patch tries to avoid broken symlink case after POR in best effort. This results in performance regression. But, if f2fs has inline_data and the target path is under 3KB-sized long, the page would be stored in its inode_block, so that there would be no performance regression. Note that, if user wants to keep this file atomically, it needs to trigger dir->fsync. And, there is still a hole to produce broken symlink. Signed-off-by:

Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/namei.c

+11 −0

Original line number	Diff line number	Diff line
		@@ -324,6 +324,17 @@ static int f2fs_symlink(struct inode dir, struct dentry dentry,
		d_instantiate(dentry, inode);
		unlock_new_inode(inode);

		/*
		* Let's flush symlink data in order to avoid broken symlink as much as
		* possible. Nevertheless, fsyncing is the best way, but there is no
		* way to get a file descriptor in order to flush that.
		*
		* Note that, it needs to do dir->fsync to make this recoverable.
		* If the symlink path is stored into inline_data, there is no
		* performance regression.
		*/
		filemap_write_and_wait_range(inode->i_mapping, 0, symlen - 1);

		if (IS_DIRSYNC(dir))
		f2fs_sync_fs(sbi->sb, 1);
		return err;

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