From: Ackerley Tng <ackerleytng@google.com>
To: akpm@linux-foundation.org, linux-fsdevel@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
mike.kravetz@oracle.com, muchun.song@linux.dev,
willy@infradead.org, sidhartha.kumar@oracle.com,
jhubbard@nvidia.com
Cc: vannapurve@google.com, erdemaktas@google.com,
Ackerley Tng <ackerleytng@google.com>
Subject: [PATCH 0/2] Fix fallocate error in hugetlbfs when fallocating again
Date: Tue, 2 May 2023 23:56:01 +0000 [thread overview]
Message-ID: <cover.1683069252.git.ackerleytng@google.com> (raw)
When fallocate() is used twice on the same offset, it should succeed
and return 0 to userspace. The second fallocate() in
test_multiple_fallocates() in the following code will return -EEXIST
for hugetlbfs, but not tmpfs/shmem.
#define _GNU_SOURCE
#include <fcntl.h>
#include <linux/falloc.h>
#include <linux/memfd.h>
#include <sys/mman.h>
#include <stdio.h>
#include <unistd.h>
void test_multiple_fallocates(unsigned int flags)
{
int fd = memfd_create("foo", flags);
if (fallocate(fd, 0, 0, 0x1000))
printf("error with fallocate %m\n");
if (fallocate(fd, 0, 0, 0x1000))
printf("error with second fallocate %m\n");
}
int main(void) {
printf("Testing tmpfs:\n");
test_multiple_fallocates(0);
printf("Testing hugetlbfs:\n");
test_multiple_fallocates(MFD_HUGETLB | MFD_HUGE_2MB);
}
This patch series replaces page_cache_next_miss(), used to determine a
page cache hit, with a more direct filemap_has_folio() (a new
function).
I hope that this is also the desired refactoring as mentioned in [1].
[1] https://lore.kernel.org/all/Y8oqEOICcNV762IA@casper.infradead.org/
---
Ackerley Tng (2):
mm: filemap: Add filemap_has_folio function
fs: hugetlbfs: Fix logic to skip allocation on hit in page cache
fs/hugetlbfs/inode.c | 6 +-----
include/linux/pagemap.h | 1 +
mm/filemap.c | 17 +++++++++++++++++
3 files changed, 19 insertions(+), 5 deletions(-)
--
2.40.1.495.gc816e09b53d-goog
next reply other threads:[~2023-05-02 23:56 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-02 23:56 Ackerley Tng [this message]
2023-05-02 23:56 ` [PATCH 1/2] mm: filemap: Add filemap_has_folio function Ackerley Tng
2023-05-02 23:56 ` [PATCH 2/2] fs: hugetlbfs: Fix logic to skip allocation on hit in page cache Ackerley Tng
2023-05-03 3:05 ` Mike Kravetz
2023-05-04 0:14 ` Mike Kravetz
2023-05-08 16:29 ` Ackerley Tng
2023-05-08 20:40 ` Ackerley Tng
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=cover.1683069252.git.ackerleytng@google.com \
--to=ackerleytng@google.com \
--cc=akpm@linux-foundation.org \
--cc=erdemaktas@google.com \
--cc=jhubbard@nvidia.com \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mike.kravetz@oracle.com \
--cc=muchun.song@linux.dev \
--cc=sidhartha.kumar@oracle.com \
--cc=vannapurve@google.com \
--cc=willy@infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).