[PATCH 2/6] statx: AFS: Return enhanced file attributes

David Howells
2016-04-29T12:57:51Z

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

(1) The data version number as st_version, setting STATX_VERSION.

(2) STATX_INFO_AUTOMOUNT will be set on automount directories by virtue of
S_AUTOMOUNT being set on the inode. These are referrals to other
volumes or other cells.

(3) STATX_INFO_AUTODIR on a directory that does cell lookup for
non-existent names and mounts them (typically mounted on /afs with -o
autocell). The resulting directories are marked STATX_INFO_FABRICATED
as they do not actually exist in the mounted AFS directory.

(4) Files, directories and symlinks accessed over AFS are marked
STATX_INFO_REMOTE. Local fake directories are marked
STATX_INFO_FABRICATED.

(5) STATX_INFO_NONSYSTEM_OWNERSHIP is set as the UID and GID retrieved
from an AFS share may not be applicable on the system.

STATX_ATIME, STATX_CTIME and STATX_BLOCKS are cleared as AFS does not
support them.

Example output:

[root@andromeda ~]# ./samples/statx/test-statx /afs
statx(/afs) = 0
results=7ef
Size: 2048 Blocks: 0 IO Block: 4096 directory
Device: 00:25 Inode: 1 Links: 2
Access: (0777/drwxrwxrwx) Uid: 0 Gid: 0
Access: 2006-05-07 00:21:15.000000000+0100
Modify: 2006-05-07 00:21:15.000000000+0100
Change: 2006-05-07 00:21:15.000000000+0100
IO-blocksize: blksize=4096

Signed-off-by: David Howells <dhowells@redhat.com>
---

fs/afs/inode.c | 24 +++++++++++++++++++-----
1 file changed, 19 insertions(+), 5 deletions(-)

diff --git a/fs/afs/inode.c b/fs/afs/inode.c
index 86cc7264c21c..e9958d5e267e 100644
--- a/fs/afs/inode.c
+++ b/fs/afs/inode.c
@@ -72,9 +72,9 @@ static int afs_inode_map_status(struct afs_vnode *vnode, struct key *key)
inode->i_uid = vnode->status.owner;
inode->i_gid = GLOBAL_ROOT_GID;
inode->i_size = vnode->status.size;
- inode->i_ctime.tv_sec = vnode->status.mtime_server;
- inode->i_ctime.tv_nsec = 0;
- inode->i_atime = inode->i_mtime = inode->i_ctime;
+ inode->i_mtime.tv_sec = vnode->status.mtime_server;
+ inode->i_mtime.tv_nsec = 0;
+ inode->i_atime = inode->i_ctime = inode->i_mtime;
inode->i_blocks = 0;
inode->i_generation = vnode->fid.unique;
inode->i_version = vnode->status.data_version;
@@ -375,8 +375,7 @@ error_unlock:
/*
* read the attributes of an inode
*/
-int afs_getattr(struct vfsmount *mnt, struct dentry *dentry,
- struct kstat *stat)
+int afs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
{
struct inode *inode;

@@ -385,6 +384,21 @@ int afs_getattr(struct vfsmount *mnt, struct dentry *dentry,
_enter("{ ino=%lu v=%u }", inode->i_ino, inode->i_generation);

generic_fillattr(inode, stat);
+
+ stat->result_mask &= ~(STATX_ATIME | STATX_CTIME | STATX_BLOCKS);
+ stat->result_mask |= STATX_VERSION | STATX_GEN;
+ stat->version = inode->i_version;
+ stat->gen = inode->i_generation;
+
+ if (test_bit(AFS_VNODE_AUTOCELL, &AFS_FS_I(inode)->flags))
+ stat->information |= STATX_INFO_AUTODIR;
+
+ if (test_bit(AFS_VNODE_PSEUDODIR, &AFS_FS_I(inode)->flags))
+ stat->information |= STATX_INFO_FABRICATED;
+ else
+ stat->information |= STATX_INFO_REMOTE;
+
+ stat->information |= STATX_INFO_NONSYSTEM_OWNERSHIP;
return 0;
}