[PATCH review 16/85] afs: Support interacting with multiple user namespaces

From: Eric W. Biederman
Date: Wed Feb 13 2013 - 13:00:30 EST


From: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>

Modify struct afs_file_status to store owner as a kuid_t and group as
a kgid_t.

In xdr_decode_AFSFetchStatus as owner is now a kuid_t and group is now
a kgid_t don't use the EXTRACT macro. Instead perform the work of
the extract macro explicitly. Read the value with ntohl and
convert it to the appropriate type with make_kuid or make_kgid.
Test if the value is different from what is stored in status and
update changed. Update the value in status.

In xdr_encode_AFS_StoreStatus call from_kuid or from_kgid as
we are computing the on the wire encoding.

Initialize uids with GLOBAL_ROOT_UID instead of 0.
Initialize gids with GLOBAL_ROOT_GID instead of 0.

Cc: David Howells <dhowells@xxxxxxxxxx>
Acked-by: Serge Hallyn <serge.hallyn@xxxxxxxxxxxxx>
Signed-off-by: Eric W. Biederman <ebiederm@xxxxxxxxxxxx>
---
fs/afs/afs.h | 4 ++--
fs/afs/fsclient.c | 14 ++++++++++----
fs/afs/inode.c | 6 +++---
init/Kconfig | 1 -
4 files changed, 15 insertions(+), 10 deletions(-)

diff --git a/fs/afs/afs.h b/fs/afs/afs.h
index 3d8fd35..3c462ff 100644
--- a/fs/afs/afs.h
+++ b/fs/afs/afs.h
@@ -119,8 +119,8 @@ struct afs_file_status {
u64 size; /* file size */
afs_dataversion_t data_version; /* current data version */
u32 author; /* author ID */
- u32 owner; /* owner ID */
- u32 group; /* group ID */
+ kuid_t owner; /* owner ID */
+ kgid_t group; /* group ID */
afs_access_t caller_access; /* access rights for authenticated caller */
afs_access_t anon_access; /* access rights for unauthenticated caller */
umode_t mode; /* UNIX mode */
diff --git a/fs/afs/fsclient.c b/fs/afs/fsclient.c
index b960ff0..c2e930e 100644
--- a/fs/afs/fsclient.c
+++ b/fs/afs/fsclient.c
@@ -42,6 +42,8 @@ static void xdr_decode_AFSFetchStatus(const __be32 **_bp,
umode_t mode;
u64 data_version, size;
u32 changed = 0; /* becomes non-zero if ctime-type changes seen */
+ kuid_t owner;
+ kgid_t group;

#define EXTRACT(DST) \
do { \
@@ -56,7 +58,9 @@ static void xdr_decode_AFSFetchStatus(const __be32 **_bp,
size = ntohl(*bp++);
data_version = ntohl(*bp++);
EXTRACT(status->author);
- EXTRACT(status->owner);
+ owner = make_kuid(&init_user_ns, ntohl(*bp++));
+ changed |= !uid_eq(owner, status->owner);
+ status->owner = owner;
EXTRACT(status->caller_access); /* call ticket dependent */
EXTRACT(status->anon_access);
EXTRACT(status->mode);
@@ -65,7 +69,9 @@ static void xdr_decode_AFSFetchStatus(const __be32 **_bp,
bp++; /* seg size */
status->mtime_client = ntohl(*bp++);
status->mtime_server = ntohl(*bp++);
- EXTRACT(status->group);
+ group = make_kgid(&init_user_ns, ntohl(*bp++));
+ changed |= !gid_eq(group, status->group);
+ status->group = group;
bp++; /* sync counter */
data_version |= (u64) ntohl(*bp++) << 32;
EXTRACT(status->lock_count);
@@ -181,12 +187,12 @@ static void xdr_encode_AFS_StoreStatus(__be32 **_bp, struct iattr *attr)

if (attr->ia_valid & ATTR_UID) {
mask |= AFS_SET_OWNER;
- owner = attr->ia_uid;
+ owner = from_kuid(&init_user_ns, attr->ia_uid);
}

if (attr->ia_valid & ATTR_GID) {
mask |= AFS_SET_GROUP;
- group = attr->ia_gid;
+ group = from_kgid(&init_user_ns, attr->ia_gid);
}

if (attr->ia_valid & ATTR_MODE) {
diff --git a/fs/afs/inode.c b/fs/afs/inode.c
index 95cffd3..789bc25 100644
--- a/fs/afs/inode.c
+++ b/fs/afs/inode.c
@@ -69,7 +69,7 @@ static int afs_inode_map_status(struct afs_vnode *vnode, struct key *key)

set_nlink(inode, vnode->status.nlink);
inode->i_uid = vnode->status.owner;
- inode->i_gid = 0;
+ 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;
@@ -175,8 +175,8 @@ struct inode *afs_iget_autocell(struct inode *dir, const char *dev_name,
inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO;
inode->i_op = &afs_autocell_inode_operations;
set_nlink(inode, 2);
- inode->i_uid = 0;
- inode->i_gid = 0;
+ inode->i_uid = GLOBAL_ROOT_UID;
+ inode->i_gid = GLOBAL_ROOT_GID;
inode->i_ctime.tv_sec = get_seconds();
inode->i_ctime.tv_nsec = 0;
inode->i_atime = inode->i_mtime = inode->i_ctime;
diff --git a/init/Kconfig b/init/Kconfig
index 394d24f..4570b02 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1071,7 +1071,6 @@ config UIDGID_CONVERTED
default y

# Filesystems
- depends on AFS_FS = n
depends on CIFS = n
depends on CODA_FS = n
depends on GFS2_FS = n
--
1.7.5.4

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