Commit df0e91d4 authored by Miklos Szeredi's avatar Miklos Szeredi

fuse: atomic_o_trunc should truncate pagecache

Fuse has an "atomic_o_trunc" mode, where userspace filesystem uses the
O_TRUNC flag in the OPEN request to truncate the file atomically with the
open.

In this mode there's no need to send a SETATTR request to userspace after
the open, so fuse_do_setattr() checks this mode and returns.  But this
misses the important step of truncating the pagecache.

Add the missing parts of truncation to the ATTR_OPEN branch.
Reported-by: default avatarChad Austin <chadaustin@fb.com>
Fixes: 6ff958ed ("fuse: add atomic open+truncate support")
Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
Cc: <stable@vger.kernel.org>
parent c698ca52
......@@ -1629,8 +1629,19 @@ int fuse_do_setattr(struct dentry *dentry, struct iattr *attr,
return err;
if (attr->ia_valid & ATTR_OPEN) {
if (fc->atomic_o_trunc)
/* This is coming from open(..., ... | O_TRUNC); */
WARN_ON(!(attr->ia_valid & ATTR_SIZE));
WARN_ON(attr->ia_size != 0);
if (fc->atomic_o_trunc) {
/*
* No need to send request to userspace, since actual
* truncation has already been done by OPEN. But still
* need to truncate page cache.
*/
i_size_write(inode, 0);
truncate_pagecache(inode, 0);
return 0;
}
file = NULL;
}
......
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