[RFC PATCH 4/6] ext4: add support for setting btime

Omar Sandoval
2019-02-14T10:01:05Z

From: Omar Sandoval <osandov@fb.com>

The ext4 inode format includes btime (under the name crtime) if the
inode is large enough (256 bytes).

Signed-off-by: Omar Sandoval <osandov@fb.com>
---
fs/ext4/inode.c | 15 +++++++++++++--
fs/ext4/super.c | 2 +-
2 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 34d7e0703cc6..7f4f83ef539d 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -5489,6 +5489,13 @@ static void ext4_wait_for_tail_page_commit(struct inode *inode)
}
}

+static bool ext4_inode_has_crtime(struct inode *inode)
+{
+ struct ext4_inode *raw_inode;
+
+ return EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), i_crtime);
+}
+
/*
* ext4_setattr()
*
@@ -5520,6 +5527,9 @@ int ext4_setattr(struct dentry *dentry, struct iattr *attr)
int orphan = 0;
const unsigned int ia_valid = attr->ia_valid;

+ if ((ia_valid & ATTR_BTIME) && !ext4_inode_has_crtime(inode))
+ return -EOPNOTSUPP;
+
if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
return -EIO;

@@ -5671,6 +5681,8 @@ int ext4_setattr(struct dentry *dentry, struct iattr *attr)

if (!error) {
setattr_copy(inode, attr);
+ if (ia_valid & ATTR_BTIME)
+ EXT4_I(inode)->i_crtime = attr->ia_btime;
mark_inode_dirty(inode);
}

@@ -5695,11 +5707,10 @@ int ext4_getattr(const struct path *path, struct kstat *stat,
u32 request_mask, unsigned int query_flags)
{
struct inode *inode = d_inode(path->dentry);
- struct ext4_inode *raw_inode;
struct ext4_inode_info *ei = EXT4_I(inode);
unsigned int flags;

- if (EXT4_FITS_IN_INODE(raw_inode, ei, i_crtime)) {
+ if (ext4_inode_has_crtime(inode)) {
stat->result_mask |= STATX_BTIME;
stat->btime.tv_sec = ei->i_crtime.tv_sec;
stat->btime.tv_nsec = ei->i_crtime.tv_nsec;
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index fb12d3c17c1b..cdd3975de130 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -5976,7 +5976,7 @@ static struct file_system_type ext4_fs_type = {
.name = "ext4",
.mount = ext4_mount,
.kill_sb = kill_block_super,
- .fs_flags = FS_REQUIRES_DEV,
+ .fs_flags = FS_REQUIRES_DEV | FS_HAS_BTIME,
};
MODULE_ALIAS_FS("ext4");

--
2.20.1