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Commit 04da11bf authored by Artem Bityutskiy's avatar Artem Bityutskiy
Browse files

UBIFS: fix zero-length truncations 



Always allow truncations to zero, even if budgeting thinks there
is no space. UBIFS reserves some space for deletions anyway.

Otherwise, the following happans:
1. create a file, and write as much as possible there, until ENOSPC
2. truncate the file, which fails with ENOSPC, which is not good.

Signed-off-by: default avatarArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
parent 6a55617e

fs/ubifs/dir.c

+0 −1
Original line number Diff line number Diff line
@@ -587,7 +587,6 @@ static int ubifs_unlink(struct inode *dir, struct dentry *dentry) 
	if (err) {

		if (err != -ENOSPC)

			return err;

		err = 0;

		budgeted = 0;

	}

fs/ubifs/file.c

+16 −4
Original line number Diff line number Diff line
@@ -793,7 +793,7 @@ static int do_truncation(struct ubifs_info *c, struct inode *inode, 
	int err;

	struct ubifs_budget_req req;

	loff_t old_size = inode->i_size, new_size = attr->ia_size;

	int offset = new_size & (UBIFS_BLOCK_SIZE - 1);

	int offset = new_size & (UBIFS_BLOCK_SIZE - 1), budgeted = 1;

	struct ubifs_inode *ui = ubifs_inode(inode);



	dbg_gen("ino %lu, size %lld -> %lld", inode->i_ino, old_size, new_size);
@@ -811,8 +811,15 @@ static int do_truncation(struct ubifs_info *c, struct inode *inode, 
	/* A funny way to budget for truncation node */

	req.dirtied_ino_d = UBIFS_TRUN_NODE_SZ;

	err = ubifs_budget_space(c, &req);

	if (err)

	if (err) {

		/*

		 * Treat truncations to zero as deletion and always allow them,

		 * just like we do for '->unlink()'.

		 */

		if (new_size || err != -ENOSPC)

			return err;

		budgeted = 0;

	}



	err = vmtruncate(inode, new_size);

	if (err)
@@ -869,7 +876,12 @@ static int do_truncation(struct ubifs_info *c, struct inode *inode, 
	err = ubifs_jnl_truncate(c, inode, old_size, new_size);

	mutex_unlock(&ui->ui_mutex);

out_budg:

	if (budgeted)

		ubifs_release_budget(c, &req);

	else {

		c->nospace = c->nospace_rp = 0;

		smp_wmb();

	}

	return err;

}