hpfs: don't truncate the file when delete fails (b6853f78) · Commits · 戴 / test

The delete opration can allocate additional space on the HPFS filesystem due to btree split. The HPFS driver checks in advance if there is available space, so that it won't corrupt the btree if we run out of space during splitting. If there is not enough available space, the HPFS driver attempted to truncate the file, but this results in a deadlock since the commit ("HPFS: Introduce a global mutex and lock it on every callback from VFS"). This patch removes the code that tries to truncate the file and -ENOSPC is returned instead. If the user hits -ENOSPC on delete, he should try to delete other files (that are stored in a leaf btree node), so that the delete operation will make some space for deleting the file stored in non-leaf btree node. Reported-by:

Al Viro <viro@ZenIV.linux.org.uk> Signed-off-by:

Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz> Cc: stable@vger.kernel.org # 2.6.39+ Signed-off-by:

Al Viro <viro@zeniv.linux.org.uk>

fs/hpfs/namei.c

+3 −28

Original line number	Diff line number	Diff line
		@@ -376,12 +376,11 @@ static int hpfs_unlink(struct inode dir, struct dentry dentry)
		struct inode *inode = d_inode(dentry);
		dnode_secno dno;
		int r;
		int rep = 0;
		int err;

		hpfs_lock(dir->i_sb);
		hpfs_adjust_length(name, &len);
		again:

		err = -ENOENT;
		de = map_dirent(dir, hpfs_i(dir)->i_dno, name, len, &dno, &qbh);
		if (!de)
		@@ -401,33 +400,9 @@ again:
		hpfs_error(dir->i_sb, "there was error when removing dirent");
		err = -EFSERROR;
		break;
		case 2: /* no space for deleting, try to truncate file */

		case 2: /* no space for deleting */
		err = -ENOSPC;
		if (rep++)
		break;

		dentry_unhash(dentry);
		if (!d_unhashed(dentry)) {
		hpfs_unlock(dir->i_sb);
		return -ENOSPC;
		}
		if (generic_permission(inode, MAY_WRITE) \|\|
		!S_ISREG(inode->i_mode) \|\|
		get_write_access(inode)) {
		d_rehash(dentry);
		} else {
		struct iattr newattrs;
		/pr_info("truncating file before delete.\n");/
		newattrs.ia_size = 0;
		newattrs.ia_valid = ATTR_SIZE \| ATTR_CTIME;
		err = notify_change(dentry, &newattrs, NULL);
		put_write_access(inode);
		if (!err)
		goto again;
		}
		hpfs_unlock(dir->i_sb);
		return -ENOSPC;
		default:
		drop_nlink(inode);
		err = 0;

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