ext4: fix hole punch failure when depth is greater than 0 (968dee77) · Commits · 戴 / test

Whether to continue removing extents or not is decided by the return value of function ext4_ext_more_to_rm() which checks 2 conditions: a) if there are no more indexes to process. b) if the number of entries are decreased in the header of "depth -1". In case of hole punch, if the last block to be removed is not part of the last extent index than this index will not be deleted, hence the number of valid entries in the extent header of "depth - 1" will remain as it is and ext4_ext_more_to_rm will return 0 although the required blocks are not yet removed. This patch fixes the above mentioned problem as instead of removing the extents from the end of file, it starts removing the blocks from the particular extent from which removing blocks is actually required and continue backward until done. Signed-off-by:

Ashish Sangwan <ashish.sangwan2@gmail.com> Signed-off-by:

Namjae Jeon <linkinjeon@gmail.com> Reviewed-by:

Lukas Czerner <lczerner@redhat.com> Cc: stable@vger.kernel.org

fs/ext4/extents.c

+29 −17

Original line number	Diff line number	Diff line
		@@ -2569,10 +2569,10 @@ static int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start,
		{
		struct super_block *sb = inode->i_sb;
		int depth = ext_depth(inode);
		struct ext4_ext_path *path;
		struct ext4_ext_path *path = NULL;
		ext4_fsblk_t partial_cluster = 0;
		handle_t *handle;
		int i, err;
		int i = 0, err;

		ext_debug("truncate since %u to %u\n", start, end);

		@@ -2605,8 +2605,12 @@ again:
		}
		depth = ext_depth(inode);
		ex = path[depth].p_ext;
		if (!ex)
		if (!ex) {
		ext4_ext_drop_refs(path);
		kfree(path);
		path = NULL;
		goto cont;
		}

		ee_block = le32_to_cpu(ex->ee_block);

		@@ -2636,8 +2640,6 @@ again:
		if (err < 0)
		goto out;
		}
		ext4_ext_drop_refs(path);
		kfree(path);
		}
		cont:

		@@ -2646,7 +2648,14 @@ cont:
		* after i_size and walking into the tree depth-wise.
		*/
		depth = ext_depth(inode);
		path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 1), GFP_NOFS);
		if (path) {
		int k = i = depth;
		while (--k > 0)
		path[k].p_block =
		le16_to_cpu(path[k].p_hdr->eh_entries)+1;
		} else {
		path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 1),
		GFP_NOFS);
		if (path == NULL) {
		ext4_journal_stop(handle);
		return -ENOMEM;
		@@ -2658,7 +2667,8 @@ cont:
		err = -EIO;
		goto out;
		}
		i = err = 0;
		}
		err = 0;

		while (i >= 0 && err == 0) {
		if (i == depth) {
		@@ -2772,8 +2782,10 @@ cont:
		out:
		ext4_ext_drop_refs(path);
		kfree(path);
		if (err == -EAGAIN)
		if (err == -EAGAIN) {
		path = NULL;
		goto again;
		}
		ext4_journal_stop(handle);

		return err;

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