Re: [PATCH 2/4] statx: Ext4: Return enhanced file attributes

[Andreas Dilger]

On Nov 17, 2016, at 6:35 AM, David Howells <dhowells@xxxxxxxxxx> wrote:
> 
> 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) The inode i_version as stx_version if a file with I_VERSION set or a
>     directory, setting STATX_VERSION.
> 
> (3) Certain FS_xxx_FL flags are copied 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----)
> 	IO-blocksize: blksize=4096
> 
> Signed-off-by: David Howells <dhowells@xxxxxxxxxx>

Reviewed-by: Andreas Dilger <adilger@xxxxxxxxx>

> ---
> 
> fs/ext4/ext4.h    |    2 ++
> fs/ext4/file.c    |    2 +-
> fs/ext4/inode.c   |   38 +++++++++++++++++++++++++++++++++++---
> fs/ext4/namei.c   |    2 ++
> fs/ext4/symlink.c |    2 ++
> 5 files changed, 42 insertions(+), 4 deletions(-)
> 
> diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
> index 282a51b07c57..f65e4a560c4c 100644
> --- a/fs/ext4/ext4.h
> +++ b/fs/ext4/ext4.h
> @@ -2485,6 +2485,8 @@ extern int  ext4_getattr(struct vfsmount *mnt, struct dentry *dentry,
> 				struct kstat *stat);
> extern void ext4_evict_inode(struct inode *);
> extern void ext4_clear_inode(struct inode *);
> +extern int  ext4_file_getattr(struct vfsmount *mnt, struct dentry *dentry,
> +			      struct kstat *stat);
> 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 2a822d30e73f..20bab4b0d6fc 100644
> --- a/fs/ext4/file.c
> +++ b/fs/ext4/file.c
> @@ -705,7 +705,7 @@ 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 9c064727ed62..91a49cbc4c63 100644
> --- a/fs/ext4/inode.c
> +++ b/fs/ext4/inode.c
> @@ -5229,11 +5229,43 @@ int ext4_setattr(struct dentry *dentry, struct iattr *attr)
> int ext4_getattr(struct vfsmount *mnt, struct dentry *dentry,
> 		 struct kstat *stat)
> {
> -	struct inode *inode;
> -	unsigned long long delalloc_blocks;
> +	struct inode *inode = d_inode(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;
> +	}
> +
> +	if (S_ISDIR(inode->i_mode) || IS_I_VERSION(inode)) {
> +		stat->result_mask |= STATX_VERSION;
> +		stat->version = inode->i_version;
> +	}
> +
> +	ext4_get_inode_flags(ei);
> +	flags = ei->i_flags & EXT4_FL_USER_VISIBLE;
> +	stat->attributes |= flags & (EXT4_IMMUTABLE_FL | EXT4_NODUMP_FL);
> +	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;
> 
> -	inode = d_inode(dentry);
> 	generic_fillattr(inode, stat);
> +	return 0;
> +}
> +
> +int ext4_file_getattr(struct vfsmount *mnt, struct dentry *dentry,
> +		      struct kstat *stat)
> +{
> +	struct inode *inode = dentry->d_inode;
> +	u64 delalloc_blocks;
> +
> +	ext4_getattr(mnt, dentry, stat);
> 
> 	/*
> 	 * 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 104f8bfba718..e115281fb8c5 100644
> --- a/fs/ext4/namei.c
> +++ b/fs/ext4/namei.c
> @@ -3882,6 +3882,7 @@ 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,
> @@ -3890,6 +3891,7 @@ 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 557b3b0d668c..209b833633e2 100644
> --- a/fs/ext4/symlink.c
> +++ b/fs/ext4/symlink.c
> @@ -93,6 +93,7 @@ const struct inode_operations ext4_symlink_inode_operations = {
> 	.readlink	= generic_readlink,
> 	.get_link	= page_get_link,
> 	.setattr	= ext4_setattr,
> +	.getattr	= ext4_getattr,
> 	.listxattr	= ext4_listxattr,
> };
> 
> @@ -100,5 +101,6 @@ const struct inode_operations ext4_fast_symlink_inode_operations = {
> 	.readlink	= generic_readlink,
> 	.get_link	= simple_get_link,
> 	.setattr	= ext4_setattr,
> +	.getattr	= ext4_getattr,
> 	.listxattr	= ext4_listxattr,
> };
> 
> --
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Cheers, Andreas

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