Btrfs: add statx support

Return enhanced file attributes from the btrfs, including:
  (1). inode creation time as stx_btime, and
  (2). Certain BTRFS_INODE_xxx flags are mapped to stx_attributes flags.

Example output:
	[root@localhost ~]# cat t.sh
	touch t
	chattr +aic t
	~/linux/samples/statx/test-statx t
	chattr -aic t
	touch t
	echo "========================================"
	~/linux/samples/statx/test-statx t
	/bin/rm t
	[root@localhost ~]# ./t.sh
	statx(t) = 0
	results=fff
  	  Size: 0               Blocks: 0          IO Block: 4096    regular file
	Device: 00:1c           Inode: 63962       Links: 1
	Access: (0644/-rw-r--r--)  Uid:     0   Gid:     0
	Access: 2017-05-11 16:03:13.999856591-0700
	Modify: 2017-05-11 16:03:13.999856591-0700
	Change: 2017-05-11 16:03:14.000856663-0700
 	 Birth: 2017-05-11 16:03:13.999856591-0700
	Attributes: 0000000000000034 (........ ........ ........ ........ ........ ........ ........ .-ai.c..)
	========================================
	statx(t) = 0
	results=fff
	  Size: 0               Blocks: 0          IO Block: 4096    regular file
	Device: 00:1c           Inode: 63962       Links: 1
	Access: (0644/-rw-r--r--)  Uid:     0   Gid:     0
	Access: 2017-05-11 16:03:14.006857097-0700
	Modify: 2017-05-11 16:03:14.006857097-0700
	Change: 2017-05-11 16:03:14.006857097-0700
 	Birth: 2017-05-11 16:03:13.999856591-0700
	Attributes: 0000000000000000 (........ ........ ........ ........ ........ ........ ........ .---.-..)
	[root@localhost ~]#

Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 222d33d78092263fc0466911146286872605b1d5..6b8d34136044ca193f10f1ab0f2f113c42134c84 100644 (file)
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -9563,6 +9563,24 @@ static int btrfs_getattr(const struct path *path, struct kstat *stat,
        u64 delalloc_bytes;
        struct inode *inode = d_inode(path->dentry);
        u32 blocksize = inode->i_sb->s_blocksize;
+       u32 bi_flags = BTRFS_I(inode)->flags;
+
+       stat->result_mask |= STATX_BTIME;
+       stat->btime.tv_sec = BTRFS_I(inode)->i_otime.tv_sec;
+       stat->btime.tv_nsec = BTRFS_I(inode)->i_otime.tv_nsec;
+       if (bi_flags & BTRFS_INODE_APPEND)
+               stat->attributes |= STATX_ATTR_APPEND;
+       if (bi_flags & BTRFS_INODE_COMPRESS)
+               stat->attributes |= STATX_ATTR_COMPRESSED;
+       if (bi_flags & BTRFS_INODE_IMMUTABLE)
+               stat->attributes |= STATX_ATTR_IMMUTABLE;
+       if (bi_flags & BTRFS_INODE_NODUMP)
+               stat->attributes |= STATX_ATTR_NODUMP;
+
+       stat->attributes_mask |= (STATX_ATTR_APPEND |
+                                 STATX_ATTR_COMPRESSED |
+                                 STATX_ATTR_IMMUTABLE |
+                                 STATX_ATTR_NODUMP);
 
        generic_fillattr(inode, stat);
        stat->dev = BTRFS_I(inode)->root->anon_dev;