ext4: Automatically allocate delay allocated blocks on rename (8750c6d5) · Commits · 戴 / test

When renaming a file such that a link to another inode is overwritten, force any delay allocated blocks that to be allocated so that if the filesystem is mounted with data=ordered, the data blocks will be pushed out to disk along with the journal commit. Many application programs expect this, so we do this to avoid zero length files if the system crashes unexpectedly. Signed-off-by:

"Theodore Ts'o" <tytso@mit.edu>

fs/ext4/namei.c

+4 −1

Original line number	Diff line number	Diff line
		@@ -2357,7 +2357,7 @@ static int ext4_rename(struct inode old_dir, struct dentry old_dentry,
		struct inode old_inode, new_inode;
		struct buffer_head old_bh, new_bh, *dir_bh;
		struct ext4_dir_entry_2 old_de, new_de;
		int retval;
		int retval, force_da_alloc = 0;

		old_bh = new_bh = dir_bh = NULL;

		@@ -2497,6 +2497,7 @@ static int ext4_rename(struct inode old_dir, struct dentry old_dentry,
		ext4_mark_inode_dirty(handle, new_inode);
		if (!new_inode->i_nlink)
		ext4_orphan_add(handle, new_inode);
		force_da_alloc = 1;
		}
		retval = 0;

		@@ -2505,6 +2506,8 @@ end_rename:
		brelse(old_bh);
		brelse(new_bh);
		ext4_journal_stop(handle);
		if (retval == 0 && force_da_alloc)
		ext4_alloc_da_blocks(old_inode);
		return retval;
		}

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