Revert "Revert "ovl: get_write_access() in truncate""

This reverts commit 31c3a70695.

Re-add functionality dealing with i_writecount on truncate to overlayfs.
This patch shouldn't have any observable effects, since we just re-assert
the writecout that vfs_truncate() already got for us.

This is in preparation for moving overlay functionality out of the VFS.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
This commit is contained in:
Miklos Szeredi 2018-07-18 15:44:41 +02:00
parent 4f3572954a
commit 5812160eb5

View file

@ -39,10 +39,27 @@ int ovl_setattr(struct dentry *dentry, struct iattr *attr)
if (err)
goto out;
if (attr->ia_valid & ATTR_SIZE) {
struct inode *realinode = d_inode(ovl_dentry_real(dentry));
err = -ETXTBSY;
if (atomic_read(&realinode->i_writecount) < 0)
goto out_drop_write;
}
err = ovl_copy_up(dentry);
if (!err) {
struct inode *winode = NULL;
upperdentry = ovl_dentry_upper(dentry);
if (attr->ia_valid & ATTR_SIZE) {
winode = d_inode(upperdentry);
err = get_write_access(winode);
if (err)
goto out_drop_write;
}
if (attr->ia_valid & (ATTR_KILL_SUID|ATTR_KILL_SGID))
attr->ia_valid &= ~ATTR_MODE;
@ -53,7 +70,11 @@ int ovl_setattr(struct dentry *dentry, struct iattr *attr)
if (!err)
ovl_copyattr(upperdentry->d_inode, dentry->d_inode);
inode_unlock(upperdentry->d_inode);
if (winode)
put_write_access(winode);
}
out_drop_write:
ovl_drop_write(dentry);
out:
return err;