diff options
| author | Piotr Sarna | 2019-11-30 17:56:43 -0800 |
|---|---|---|
| committer | Linus Torvalds | 2019-12-01 12:59:08 -0800 |
| commit | 1ab5b82f540b31852fbf4a3c975f3c16e0e76b9f (patch) | |
| tree | 9f1583419c12a50e52437d00f10dd159854c821e /fs | |
| parent | 1f9dccb25b8fb48778149a002bb25d4ac2899633 (diff) | |
hugetlbfs: add O_TMPFILE support
With hugetlbfs, a common pattern for mapping anonymous huge pages is to
create a temporary file first. Currently libraries like libhugetlbfs
and seastar create these with a standard mkstemp+unlink trick, but it
would be more robust to be able to simply pass the O_TMPFILE flag to
open(). O_TMPFILE is already supported by several file systems like
ext4 and xfs. The implementation simply uses the existi= ng d_tmpfile
utility function to instantiate the dcache entry for the 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.
Link: http://lkml.kernel.org/r/bc9383eff6e1374d79f3a92257ae829ba1e6ae60.1573285189.git.p.sarna@tlen.pl
Signed-off-by: Piotr Sarna <p.sarna@tlen.pl>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/hugetlbfs/inode.c | 28 |
1 files changed, 24 insertions, 4 deletions
diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c index 0cacf99922cc..c978061c3893 100644 --- a/fs/hugetlbfs/inode.c +++ b/fs/hugetlbfs/inode.c @@ -815,8 +815,11 @@ static struct inode *hugetlbfs_get_inode(struct super_block *sb, /* * 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 +827,23 @@ static int hugetlbfs_mknod(struct inode *dir, 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); - dget(dentry); /* Extra count - pin the dentry in core */ + 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 +857,12 @@ static int hugetlbfs_create(struct inode *dir, struct dentry *dentry, umode_t mo 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 +1121,7 @@ static const struct inode_operations hugetlbfs_dir_inode_operations = { .mknod = hugetlbfs_mknod, .rename = simple_rename, .setattr = hugetlbfs_setattr, + .tmpfile = hugetlbfs_tmpfile, }; static const struct inode_operations hugetlbfs_inode_operations = { |