ext4: refactor truncate code
Move common code in ext4_ind_truncate() and ext4_ext_truncate() into
ext4_truncate(). This saves over 60 lines of code.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 9bda50a..49c80e4 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -3738,9 +3738,9 @@
stop_block);
ext4_discard_preallocations(inode);
+ up_write(&EXT4_I(inode)->i_data_sem);
if (IS_SYNC(inode))
ext4_handle_sync(handle);
- up_write(&EXT4_I(inode)->i_data_sem);
inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
ext4_mark_inode_dirty(handle, inode);
out_stop:
@@ -3782,6 +3782,12 @@
*/
void ext4_truncate(struct inode *inode)
{
+ struct ext4_inode_info *ei = EXT4_I(inode);
+ unsigned int credits;
+ handle_t *handle;
+ struct address_space *mapping = inode->i_mapping;
+ loff_t page_len;
+
trace_ext4_truncate_enter(inode);
if (!ext4_can_truncate(inode))
@@ -3800,10 +3806,72 @@
return;
}
+ /*
+ * finish any pending end_io work so we won't run the risk of
+ * converting any truncated blocks to initialized later
+ */
+ ext4_flush_unwritten_io(inode);
+
if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
- ext4_ext_truncate(inode);
+ credits = ext4_writepage_trans_blocks(inode);
else
- ext4_ind_truncate(inode);
+ credits = ext4_blocks_for_truncate(inode);
+
+ handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits);
+ if (IS_ERR(handle)) {
+ ext4_std_error(inode->i_sb, PTR_ERR(handle));
+ return;
+ }
+
+ if (inode->i_size % PAGE_CACHE_SIZE != 0) {
+ page_len = PAGE_CACHE_SIZE -
+ (inode->i_size & (PAGE_CACHE_SIZE - 1));
+
+ if (ext4_discard_partial_page_buffers(handle,
+ mapping, inode->i_size, page_len, 0))
+ goto out_stop;
+ }
+
+ /*
+ * We add the inode to the orphan list, so that if this
+ * truncate spans multiple transactions, and we crash, we will
+ * resume the truncate when the filesystem recovers. It also
+ * marks the inode dirty, to catch the new size.
+ *
+ * Implication: the file must always be in a sane, consistent
+ * truncatable state while each transaction commits.
+ */
+ if (ext4_orphan_add(handle, inode))
+ goto out_stop;
+
+ down_write(&EXT4_I(inode)->i_data_sem);
+
+ ext4_discard_preallocations(inode);
+
+ if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
+ ext4_ext_truncate(handle, inode);
+ else
+ ext4_ind_truncate(handle, inode);
+
+ up_write(&ei->i_data_sem);
+
+ if (IS_SYNC(inode))
+ ext4_handle_sync(handle);
+
+out_stop:
+ /*
+ * If this was a simple ftruncate() and the file will remain alive,
+ * then we need to clear up the orphan record which we created above.
+ * However, if this was a real unlink then we were called by
+ * ext4_delete_inode(), and we allow that function to clean up the
+ * orphan info for us.
+ */
+ if (inode->i_nlink)
+ ext4_orphan_del(handle, inode);
+
+ inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
+ ext4_mark_inode_dirty(handle, inode);
+ ext4_journal_stop(handle);
trace_ext4_truncate_exit(inode);
}