[RFC PATCH 5/6] f2fs: add support for setting btime

[Omar Sandoval]

From: Omar Sandoval <osan...@fb.com>

The f2fs inode format includes btime (under the name crtime) if the
feature was enabled at mkfs time.

Signed-off-by: Omar Sandoval <osan...@fb.com>
---
 fs/f2fs/file.c  | 19 +++++++++++++++----
 fs/f2fs/super.c |  2 +-
 2 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index bba56b39dcc5..6064d3e42987 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -690,17 +690,23 @@ int f2fs_truncate(struct inode *inode)
        return 0;
 }
 
+static bool f2fs_inode_has_crtime(struct inode *inode)
+{
+       struct f2fs_inode *ri;
+
+       return (f2fs_has_extra_attr(inode) &&
+               f2fs_sb_has_inode_crtime(F2FS_I_SB(inode)) &&
+               F2FS_FITS_IN_INODE(ri, F2FS_I(inode)->i_extra_isize, i_crtime));
+}
+
 int f2fs_getattr(const struct path *path, struct kstat *stat,
                 u32 request_mask, unsigned int query_flags)
 {
        struct inode *inode = d_inode(path->dentry);
        struct f2fs_inode_info *fi = F2FS_I(inode);
-       struct f2fs_inode *ri;
        unsigned int flags;
 
-       if (f2fs_has_extra_attr(inode) &&
-                       f2fs_sb_has_inode_crtime(F2FS_I_SB(inode)) &&
-                       F2FS_FITS_IN_INODE(ri, fi->i_extra_isize, i_crtime)) {
+       if (f2fs_inode_has_crtime(inode)) {
                stat->result_mask |= STATX_BTIME;
                stat->btime.tv_sec = fi->i_crtime.tv_sec;
                stat->btime.tv_nsec = fi->i_crtime.tv_nsec;
@@ -770,6 +776,9 @@ int f2fs_setattr(struct dentry *dentry, struct iattr *attr)
        int err;
        bool size_changed = false;
 
+       if ((attr->ia_valid & ATTR_BTIME) && !f2fs_inode_has_crtime(inode))
+               return -EOPNOTSUPP;
+
        if (unlikely(f2fs_cp_error(F2FS_I_SB(inode))))
                return -EIO;
 
@@ -848,6 +857,8 @@ int f2fs_setattr(struct dentry *dentry, struct iattr *attr)
        }
 
        __setattr_copy(inode, attr);
+       if (attr->ia_valid & ATTR_BTIME)
+               F2FS_I(inode)->i_crtime = attr->ia_btime;
 
        if (attr->ia_valid & ATTR_MODE) {
                err = posix_acl_chmod(inode, f2fs_get_inode_mode(inode));
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index c46a1d4318d4..e32070c8cb27 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -3485,7 +3485,7 @@ static struct file_system_type f2fs_fs_type = {
        .name           = "f2fs",
        .mount          = f2fs_mount,
        .kill_sb        = kill_f2fs_super,
-       .fs_flags       = FS_REQUIRES_DEV,
+       .fs_flags       = FS_REQUIRES_DEV | FS_HAS_BTIME,
 };
 MODULE_ALIAS_FS("f2fs");
 
-- 
2.20.1