From: Hugh Dickins <hughd@google.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Hugh Dickins <hughd@google.com>,
Shakeel Butt <shakeelb@google.com>,
"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
Yang Shi <shy828301@gmail.com>, Miaohe Lin <linmiaohe@huawei.com>,
Mike Kravetz <mike.kravetz@oracle.com>,
Michal Hocko <mhocko@suse.com>, Rik van Riel <riel@surriel.com>,
Christoph Hellwig <hch@infradead.org>,
Matthew Wilcox <willy@infradead.org>,
"Eric W. Biederman" <ebiederm@xmission.com>,
Alexey Gladkov <legion@kernel.org>,
Chris Wilson <chris@chris-wilson.co.uk>,
Matthew Auld <matthew.auld@intel.com>,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-api@vger.kernel.org, linux-mm@kvack.org
Subject: [PATCH 11/16] tmpfs: fcntl(fd, F_MEM_LOCKED) to test if memlocked
Date: Fri, 30 Jul 2021 00:57:56 -0700 (PDT) [thread overview]
Message-ID: <a4f03e42-14a3-8e1b-387e-6f18b57f1eb@google.com> (raw)
In-Reply-To: <2862852d-badd-7486-3a8e-c5ea9666d6fb@google.com>
Though we have not yet found a compelling need to make the locked status
of a tmpfs file visible, and offer no tool to show it, the kernel ought
to be able to support such a tool: add the F_MEM_LOCKED fcntl, returning
-1 on failure (not tmpfs), 0 when not F_MEM_LOCKED, 1 when F_MEM_LOCKED.
Signed-off-by: Hugh Dickins <hughd@google.com>
---
fs/fcntl.c | 1 +
include/uapi/linux/fcntl.h | 1 +
mm/shmem.c | 4 ++++
3 files changed, 6 insertions(+)
diff --git a/fs/fcntl.c b/fs/fcntl.c
index a3534764b50e..0d8dc723732d 100644
--- a/fs/fcntl.c
+++ b/fs/fcntl.c
@@ -439,6 +439,7 @@ static long do_fcntl(int fd, unsigned int cmd, unsigned long arg,
case F_NOHUGEPAGE:
case F_MEM_LOCK:
case F_MEM_UNLOCK:
+ case F_MEM_LOCKED:
err = shmem_fcntl(filp, cmd, arg);
break;
default:
diff --git a/include/uapi/linux/fcntl.h b/include/uapi/linux/fcntl.h
index 21dc969df0fd..012585e8c9ab 100644
--- a/include/uapi/linux/fcntl.h
+++ b/include/uapi/linux/fcntl.h
@@ -88,6 +88,7 @@
*/
#define F_MEM_LOCK (F_LINUX_SPECIFIC_BASE + 17)
#define F_MEM_UNLOCK (F_LINUX_SPECIFIC_BASE + 18)
+#define F_MEM_LOCKED (F_LINUX_SPECIFIC_BASE + 19)
/*
* Types of directory notifications that may be requested.
diff --git a/mm/shmem.c b/mm/shmem.c
index ba9b9900287b..6e53dabe658b 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -2299,6 +2299,9 @@ static int shmem_memlock_fcntl(struct file *file, unsigned int cmd)
bool cleanup_mapping = false;
int retval = 0;
+ if (cmd == F_MEM_LOCKED)
+ return !!info->mlock_ucounts;
+
inode_lock(inode);
if (cmd == F_MEM_LOCK) {
if (!info->mlock_ucounts) {
@@ -2762,6 +2765,7 @@ long shmem_fcntl(struct file *file, unsigned int cmd, unsigned long arg)
break;
case F_MEM_LOCK:
case F_MEM_UNLOCK:
+ case F_MEM_LOCKED:
error = shmem_memlock_fcntl(file, cmd);
break;
}
--
2.26.2
next prev parent reply other threads:[~2021-07-30 7:58 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-30 7:22 [PATCH 00/16] tmpfs: HUGEPAGE and MEM_LOCK fcntls and memfds Hugh Dickins
2021-07-30 7:25 ` [PATCH 01/16] huge tmpfs: fix fallocate(vanilla) advance over huge pages Hugh Dickins
2021-07-30 21:36 ` Yang Shi
2021-08-01 3:38 ` Hugh Dickins
2021-08-02 20:36 ` Yang Shi
2021-07-30 7:28 ` [PATCH 02/16] huge tmpfs: fix split_huge_page() after FALLOC_FL_KEEP_SIZE Hugh Dickins
2021-07-30 23:48 ` Yang Shi
2021-07-30 7:30 ` [PATCH 03/16] huge tmpfs: remove shrinklist addition from shmem_setattr() Hugh Dickins
2021-07-30 21:50 ` Yang Shi
2021-07-30 7:36 ` [PATCH 04/16] huge tmpfs: revert shmem's use of transhuge_vma_enabled() Hugh Dickins
2021-07-30 21:56 ` Yang Shi
2021-08-01 4:01 ` Hugh Dickins
2021-08-02 20:39 ` Yang Shi
2021-07-30 7:39 ` [PATCH 05/16] huge tmpfs: move shmem_huge_enabled() upwards Hugh Dickins
2021-07-30 21:57 ` Yang Shi
2021-07-30 7:42 ` [PATCH 06/16] huge tmpfs: shmem_is_huge(vma, inode, index) Hugh Dickins
2021-07-30 23:34 ` Yang Shi
2021-08-01 5:22 ` Hugh Dickins
2021-08-01 5:37 ` Hugh Dickins
2021-08-02 21:14 ` Yang Shi
2021-08-04 8:28 ` Hugh Dickins
2021-08-04 19:01 ` Yang Shi
2021-08-06 5:21 ` Hugh Dickins
2021-08-06 17:41 ` Yang Shi
2021-08-05 23:04 ` Yang Shi
2021-08-06 5:43 ` Hugh Dickins
2021-08-06 17:57 ` Yang Shi
2021-08-12 18:19 ` Yang Shi
2021-07-30 7:45 ` [PATCH 07/16] memfd: memfd_create(name, MFD_HUGEPAGE) for shmem huge pages Hugh Dickins
2021-08-04 14:03 ` Kirill A. Shutemov
2021-08-06 3:33 ` Hugh Dickins
2021-07-30 7:48 ` [PATCH 08/16] huge tmpfs: fcntl(fd, F_HUGEPAGE) and fcntl(fd, F_NOHUGEPAGE) Hugh Dickins
2021-08-04 14:08 ` Kirill A. Shutemov
2021-08-06 4:34 ` Hugh Dickins
2021-07-30 7:51 ` [PATCH 09/16] huge tmpfs: decide stat.st_blksize by shmem_is_huge() Hugh Dickins
2021-07-30 23:40 ` Yang Shi
2021-07-30 7:55 ` [PATCH 10/16] tmpfs: fcntl(fd, F_MEM_LOCK) to memlock a tmpfs file Hugh Dickins
2021-08-03 1:38 ` Matthew Wilcox
2021-08-04 9:15 ` Hugh Dickins
2021-07-30 7:57 ` Hugh Dickins [this message]
2021-07-30 8:00 ` [PATCH 12/16] tmpfs: refuse memlock when fallocated beyond i_size Hugh Dickins
2021-07-30 8:03 ` [PATCH 13/16] mm: bool user_shm_lock(loff_t size, struct ucounts *) Hugh Dickins
2021-07-30 8:06 ` [PATCH 14/16] mm: user_shm_lock(,,getuc) and user_shm_unlock(,,putuc) Hugh Dickins
2021-07-30 8:09 ` [PATCH 15/16] tmpfs: permit changing size of memlocked file Hugh Dickins
2021-07-30 8:13 ` [PATCH 16/16] memfd: memfd_create(name, MFD_MEM_LOCK) for memlocked shmem Hugh Dickins
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=a4f03e42-14a3-8e1b-387e-6f18b57f1eb@google.com \
--to=hughd@google.com \
--cc=akpm@linux-foundation.org \
--cc=chris@chris-wilson.co.uk \
--cc=ebiederm@xmission.com \
--cc=hch@infradead.org \
--cc=kirill.shutemov@linux.intel.com \
--cc=legion@kernel.org \
--cc=linmiaohe@huawei.com \
--cc=linux-api@vger.kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=matthew.auld@intel.com \
--cc=mhocko@suse.com \
--cc=mike.kravetz@oracle.com \
--cc=riel@surriel.com \
--cc=shakeelb@google.com \
--cc=shy828301@gmail.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).