diff options
author | David Howells <dhowells@redhat.com> | 2009-11-19 18:11:52 +0000 |
---|---|---|
committer | David Howells <dhowells@redhat.com> | 2009-11-19 18:11:52 +0000 |
commit | a17754fb8c28af19cd70dcbec6d5b0773b94e0c1 (patch) | |
tree | d7c25b217c684153eadbac78ab9b1bbff08b75f6 /arch | |
parent | 868411be3f445a83fafbd734f3e426400138add5 (diff) |
CacheFiles: Don't write a full page if there's only a partial page to cache
cachefiles_write_page() writes a full page to the backing file for the last
page of the netfs file, even if the netfs file's last page is only a partial
page.
This causes the EOF on the backing file to be extended beyond the EOF of the
netfs, and thus the backing file will be truncated by cachefiles_attr_changed()
called from cachefiles_lookup_object().
So we need to limit the write we make to the backing file on that last page
such that it doesn't push the EOF too far.
Also, if a backing file that has a partial page at the end is expanded, we
discard the partial page and refetch it on the basis that we then have a hole
in the file with invalid data, and should the power go out... A better way to
deal with this could be to record a note that the partial page contains invalid
data until the correct data is written into it.
This isn't a problem for netfs's that discard the whole backing file if the
file size changes (such as NFS).
Signed-off-by: David Howells <dhowells@redhat.com>
Diffstat (limited to 'arch')
0 files changed, 0 insertions, 0 deletions