The patch titled
Subject: hugetlbfs: add O_TMPFILE support
has been added to the -mm tree. Its filename is
hugetlbfs-add-o_tmpfile-support.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/hugetlbfs-add-o_tmpfile-support.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/hugetlbfs-add-o_tmpfile-support.patch
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The -mm tree is included into linux-next and is updated
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------------------------------------------------------
From: Piotr Sarna <p.sarna@xxxxxxx>
Subject: hugetlbfs: add O_TMPFILE support
O_TMPFILE is an option used to create an unnamed temporary regular file.
Currently, libhugetlbfs and Seastar use a combination of mkstemp and
unlink to accomplish similar functionality on hugetlbfs. Add O_TMPFILE
support to hugetlbfs so that it can potentially be used by existing users
(Seastar) and new users (Oracle DB). Support is added by simply using the
d_tmpfile utility function to instantiate the dcache entry for a temporary
file.
Tested manually by successfully creating a temporary file by opening it
with (O_TMPFILE|O_RDWR) on mounted hugetlbfs and successfully mapping 2M
huge pages with it. Without the patch, trying to open a file with
O_TMPFILE results in -ENOSUP.
[mike.kravetz@xxxxxxxxxx: changelog updates]
Link: http://lkml.kernel.org/r/22c29acf9c51dae17802e1b05c9e5e4051448c5c.1571129593.git.p.sarna@xxxxxxx
Signed-off-by: Piotr Sarna <p.sarna@xxxxxxx>
Reviewed-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/hugetlbfs/inode.c | 25 ++++++++++++++++++++++---
1 file changed, 22 insertions(+), 3 deletions(-)
--- a/fs/hugetlbfs/inode.c~hugetlbfs-add-o_tmpfile-support
+++ a/fs/hugetlbfs/inode.c
@@ -815,8 +815,11 @@ static struct inode *hugetlbfs_get_inode
/*
* File creation. Allocate an inode, and we're done..
*/
-static int hugetlbfs_mknod(struct inode *dir,
- struct dentry *dentry, umode_t mode, dev_t dev)
+static int do_hugetlbfs_mknod(struct inode *dir,
+ struct dentry *dentry,
+ umode_t mode,
+ dev_t dev,
+ bool tmpfile)
{
struct inode *inode;
int error = -ENOSPC;
@@ -824,13 +827,22 @@ static int hugetlbfs_mknod(struct inode
inode = hugetlbfs_get_inode(dir->i_sb, dir, mode, dev);
if (inode) {
dir->i_ctime = dir->i_mtime = current_time(dir);
- d_instantiate(dentry, inode);
+ if (tmpfile)
+ d_tmpfile(dentry, inode);
+ else
+ d_instantiate(dentry, inode);
dget(dentry); /* Extra count - pin the dentry in core */
error = 0;
}
return error;
}
+static int hugetlbfs_mknod(struct inode *dir,
+ struct dentry *dentry, umode_t mode, dev_t dev)
+{
+ return do_hugetlbfs_mknod(dir, dentry, mode, dev, false);
+}
+
static int hugetlbfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
{
int retval = hugetlbfs_mknod(dir, dentry, mode | S_IFDIR, 0);
@@ -844,6 +856,12 @@ static int hugetlbfs_create(struct inode
return hugetlbfs_mknod(dir, dentry, mode | S_IFREG, 0);
}
+static int hugetlbfs_tmpfile(struct inode *dir,
+ struct dentry *dentry, umode_t mode)
+{
+ return do_hugetlbfs_mknod(dir, dentry, mode | S_IFREG, 0, true);
+}
+
static int hugetlbfs_symlink(struct inode *dir,
struct dentry *dentry, const char *symname)
{
@@ -1102,6 +1120,7 @@ static const struct inode_operations hug
.mknod = hugetlbfs_mknod,
.rename = simple_rename,
.setattr = hugetlbfs_setattr,
+ .tmpfile = hugetlbfs_tmpfile,
};
static const struct inode_operations hugetlbfs_inode_operations = {
_
Patches currently in -mm which might be from p.sarna@xxxxxxx are
hugetlbfs-add-o_tmpfile-support.patch
