Skip to content

Fixing OOM created by the admission hook #4

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
Patrick-Pataky wants to merge 1 commit into
base: admit_hook
Choose a base branch
from
Open

Fixing OOM created by the admission hook #4

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
18 changes: 6 additions & 12 deletions mm/filemap.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2598,21 +2598,21 @@ static int __cache_ext_dio(struct file *file, struct address_space *mapping,
if (!folio) {
if (i == index)
return -ENOMEM;
// We added some folios that we want to copy and then
// free, so this could fix our OOM
return 1;
}

filemap_invalidate_lock_shared(mapping);
__folio_set_locked(folio);

folio_ref_add(folio, folio_nr_pages(folio));
folio->mapping = mapping;
folio->index = i;
error = filemap_read_folio_cache_ext(
file, mapping->a_ops->read_folio, folio);
filemap_invalidate_unlock_shared(mapping);
folio->mapping = NULL;
if (error) {
folio_put(folio);

if (i == index)
return error;
return 1;
Expand Down Expand Up @@ -2797,7 +2797,7 @@ ssize_t filemap_read(struct kiocb *iocb, struct iov_iter *iter,
* mark it as accessed the first time.
*/
if (!pos_same_folio(iocb->ki_pos, last_pos - 1,
fbatch.folios[0]))
fbatch.folios[0]) && !cache_ext_flag)
folio_mark_accessed(fbatch.folios[0]);

for (i = 0; i < folio_batch_count(&fbatch); i++) {
Expand All @@ -2818,7 +2818,6 @@ ssize_t filemap_read(struct kiocb *iocb, struct iov_iter *iter,
* before reading the folio on the kernel side.
*/

// TODO: investigate
if (writably_mapped)
flush_dcache_folio(folio);

Expand All @@ -2832,15 +2831,10 @@ ssize_t filemap_read(struct kiocb *iocb, struct iov_iter *iter,
error = -EFAULT;
break;
}

// TODO: drop reference count before freeing?
if (cache_ext_flag)
filemap_free_folio(mapping, folio);
}
put_folios:
if (!cache_ext_flag)
for (i = 0; i < folio_batch_count(&fbatch); i++)
folio_put(fbatch.folios[i]);
for (i = 0; i < folio_batch_count(&fbatch); i++)
folio_put(fbatch.folios[i]);

cache_ext_flag = 0;
folio_batch_init(&fbatch);
Expand Down