[PATCH] ext4: Add statx support

From: David Howells
Date: Thu Mar 16 2017 - 07:35:39 EST


Return enhanced file attributes from the Ext4 filesystem. This includes
the following:

(1) The inode creation time (i_crtime) as stx_btime, setting STATX_BTIME.

(2) Certain FS_xxx_FL flags are mapped to stx_attribute flags.

This requires that all ext4 inodes have a getattr call, not just some of
them, so to this end, split the ext4_getattr() function and only call part
of it where appropriate.

Example output:

[root@andromeda ~]# touch foo
[root@andromeda ~]# chattr +ai foo
[root@andromeda ~]# /tmp/test-statx foo
statx(foo) = 0
results=fff
Size: 0 Blocks: 0 IO Block: 4096 regular file
Device: 08:12 Inode: 2101950 Links: 1
Access: (0644/-rw-r--r--) Uid: 0 Gid: 0
Access: 2016-02-11 17:08:29.031795451+0000
Modify: 2016-02-11 17:08:29.031795451+0000
Change: 2016-02-11 17:11:11.987790114+0000
Birth: 2016-02-11 17:08:29.031795451+0000
Attributes: 0000000000000030 (-------- -------- -------- -------- -------- -------- -------- --ai----)

Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
---

fs/ext4/ext4.h | 1 +
fs/ext4/file.c | 2 +-
fs/ext4/inode.c | 36 +++++++++++++++++++++++++++++++++---
fs/ext4/namei.c | 2 ++
fs/ext4/symlink.c | 2 ++
5 files changed, 39 insertions(+), 4 deletions(-)

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index f493af666591..fb69ee2388db 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -2466,6 +2466,7 @@ extern int ext4_setattr(struct dentry *, struct iattr *);
extern int ext4_getattr(const struct path *, struct kstat *, u32, unsigned int);
extern void ext4_evict_inode(struct inode *);
extern void ext4_clear_inode(struct inode *);
+extern int ext4_file_getattr(const struct path *, struct kstat *, u32, unsigned int);
extern int ext4_sync_inode(handle_t *, struct inode *);
extern void ext4_dirty_inode(struct inode *, int);
extern int ext4_change_inode_journal_flag(struct inode *, int);
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 8210c1f43556..cefa9835f275 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -744,7 +744,7 @@ const struct file_operations ext4_file_operations = {

const struct inode_operations ext4_file_inode_operations = {
.setattr = ext4_setattr,
- .getattr = ext4_getattr,
+ .getattr = ext4_file_getattr,
.listxattr = ext4_listxattr,
.get_acl = ext4_get_acl,
.set_acl = ext4_set_acl,
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 7385e6a6b6cb..5450e1eade1d 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -5390,11 +5390,41 @@ int ext4_setattr(struct dentry *dentry, struct iattr *attr)
int ext4_getattr(const struct path *path, struct kstat *stat,
u32 request_mask, unsigned int query_flags)
{
- struct inode *inode;
- unsigned long long delalloc_blocks;
+ 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)) {
+ stat->result_mask |= STATX_BTIME;
+ stat->btime.tv_sec = ei->i_crtime.tv_sec;
+ stat->btime.tv_nsec = ei->i_crtime.tv_nsec;
+ }
+
+ ext4_get_inode_flags(ei);
+ flags = ei->i_flags & EXT4_FL_USER_VISIBLE;
+ if (flags & EXT4_APPEND_FL)
+ stat->attributes |= STATX_ATTR_APPEND;
+ if (flags & EXT4_COMPR_FL)
+ stat->attributes |= STATX_ATTR_COMPRESSED;
+ if (flags & EXT4_ENCRYPT_FL)
+ stat->attributes |= STATX_ATTR_ENCRYPTED;
+ if (flags & EXT4_IMMUTABLE_FL)
+ stat->attributes |= STATX_ATTR_IMMUTABLE;
+ if (flags & EXT4_NODUMP_FL)
+ stat->attributes |= STATX_ATTR_NODUMP;

- inode = d_inode(path->dentry);
generic_fillattr(inode, stat);
+ return 0;
+}
+
+int ext4_file_getattr(const struct path *path, struct kstat *stat,
+ u32 request_mask, unsigned int query_flags)
+{
+ struct inode *inode = d_inode(path->dentry);
+ u64 delalloc_blocks;
+
+ ext4_getattr(path, stat, request_mask, query_flags);

/*
* If there is inline data in the inode, the inode will normally not
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 6ad612c576fc..07e5e1405771 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -3912,6 +3912,7 @@ const struct inode_operations ext4_dir_inode_operations = {
.tmpfile = ext4_tmpfile,
.rename = ext4_rename2,
.setattr = ext4_setattr,
+ .getattr = ext4_getattr,
.listxattr = ext4_listxattr,
.get_acl = ext4_get_acl,
.set_acl = ext4_set_acl,
@@ -3920,6 +3921,7 @@ const struct inode_operations ext4_dir_inode_operations = {

const struct inode_operations ext4_special_inode_operations = {
.setattr = ext4_setattr,
+ .getattr = ext4_getattr,
.listxattr = ext4_listxattr,
.get_acl = ext4_get_acl,
.set_acl = ext4_set_acl,
diff --git a/fs/ext4/symlink.c b/fs/ext4/symlink.c
index 73b184d161fc..4c6b23a0603e 100644
--- a/fs/ext4/symlink.c
+++ b/fs/ext4/symlink.c
@@ -91,11 +91,13 @@ const struct inode_operations ext4_encrypted_symlink_inode_operations = {
const struct inode_operations ext4_symlink_inode_operations = {
.get_link = page_get_link,
.setattr = ext4_setattr,
+ .getattr = ext4_getattr,
.listxattr = ext4_listxattr,
};

const struct inode_operations ext4_fast_symlink_inode_operations = {
.get_link = simple_get_link,
.setattr = ext4_setattr,
+ .getattr = ext4_getattr,
.listxattr = ext4_listxattr,
};