[PATCH v2] tmpfs: support for file creation time

Xavier Roche
2022-02-11T21:36:37Z

Various filesystems (including ext4) now support file creation time.
This patch adds such support for tmpfs-based filesystems.

Signed-off-by: Xavier Roche <xavier.roche@algolia.com>
Tested-by: Jean Delvare <jdelvare@suse.de>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
---
include/linux/shmem_fs.h | 1 +
mm/shmem.c | 11 +++++++++++
2 files changed, 12 insertions(+)

diff --git a/include/linux/shmem_fs.h b/include/linux/shmem_fs.h
index e65b80ed09e7..29787767c3b9 100644
--- a/include/linux/shmem_fs.h
+++ b/include/linux/shmem_fs.h
@@ -25,6 +25,7 @@ struct shmem_inode_info {
struct simple_xattrs xattrs; /* list of xattrs */
atomic_t stop_eviction; /* hold when working on inode */
struct inode vfs_inode;
+ struct timespec64 i_crtime; /* file creation time */
};

struct shmem_sb_info {
diff --git a/mm/shmem.c b/mm/shmem.c
index a09b29ec2b45..5a3907712c4f 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1061,6 +1061,12 @@ static int shmem_getattr(struct user_namespace *mnt_userns,
if (shmem_is_huge(NULL, inode, 0))
stat->blksize = HPAGE_PMD_SIZE;

+ if ((request_mask & STATX_BTIME)) {
+ stat->result_mask |= STATX_BTIME;
+ stat->btime.tv_sec = info->i_crtime.tv_sec;
+ stat->btime.tv_nsec = info->i_crtime.tv_nsec;
+ }
+
return 0;
}

@@ -2265,6 +2271,7 @@ static struct inode *shmem_get_inode(struct super_block *sb, const struct inode
atomic_set(&info->stop_eviction, 0);
info->seals = F_SEAL_SEAL;
info->flags = flags & VM_NORESERVE;
+ info->i_crtime = inode->i_mtime;
INIT_LIST_HEAD(&info->shrinklist);
INIT_LIST_HEAD(&info->swaplist);
simple_xattrs_init(&info->xattrs);
@@ -3196,6 +3203,7 @@ static ssize_t shmem_listxattr(struct dentry *dentry, char *buffer, size_t size)
#endif /* CONFIG_TMPFS_XATTR */

static const struct inode_operations shmem_short_symlink_operations = {
+ .getattr = shmem_getattr,
.get_link = simple_get_link,
#ifdef CONFIG_TMPFS_XATTR
.listxattr = shmem_listxattr,
@@ -3203,6 +3211,7 @@ static const struct inode_operations shmem_short_symlink_operations = {
};

static const struct inode_operations shmem_symlink_inode_operations = {
+ .getattr = shmem_getattr,
.get_link = shmem_get_link,
#ifdef CONFIG_TMPFS_XATTR
.listxattr = shmem_listxattr,
@@ -3790,6 +3799,7 @@ static const struct inode_operations shmem_inode_operations = {

static const struct inode_operations shmem_dir_inode_operations = {
#ifdef CONFIG_TMPFS
+ .getattr = shmem_getattr,
.create = shmem_create,
.lookup = simple_lookup,
.link = shmem_link,
@@ -3811,6 +3821,7 @@ static const struct inode_operations shmem_dir_inode_operations = {
};

static const struct inode_operations shmem_special_inode_operations = {
+ .getattr = shmem_getattr,
#ifdef CONFIG_TMPFS_XATTR
.listxattr = shmem_listxattr,
#endif
--
2.25.1