afs: implement acl setting

Implements the setting of ACLs in AFS by means of setting the
afs.acl extended attribute on the file.

Signed-off-by: Joe Gorse <jhgorse@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>

5 files changed, 110 insertions, 6 deletions

diff --git a/fs/afs/afs_fs.h b/fs/afs/afs_fs.h
index 4df1f1eec0ab..18a54ca422f8 100644
--- a/fs/afs/afs_fs.h
+++ b/fs/afs/afs_fs.h
@@ -20,6 +20,7 @@ enum AFS_FS_Operations {
         FSFETCHACL              = 131,  /* AFS Fetch file ACL */
         FSFETCHSTATUS           = 132,  /* AFS Fetch file status */
         FSSTOREDATA             = 133,  /* AFS Store file data */
+        FSSTOREACL              = 134,  /* AFS Store file ACL */
         FSSTORESTATUS           = 135,  /* AFS Store file status */
         FSREMOVEFILE            = 136,  /* AFS Remove a file */
         FSCREATEFILE            = 137,  /* AFS Create a file */
diff --git a/fs/afs/fsclient.c b/fs/afs/fsclient.c
index 283f486c59f4..7f1722b9e432 100644
--- a/fs/afs/fsclient.c
+++ b/fs/afs/fsclient.c
@@ -836,9 +836,10 @@ int afs_fs_create(struct afs_fs_cursor *fc,
 }
 
 /*
- * deliver reply data to an FS.RemoveFile or FS.RemoveDir
+ * Deliver reply data to any operation that returns file status and volume
+ * sync.
  */
-static int afs_deliver_fs_remove(struct afs_call *call)
+static int afs_deliver_fs_status_and_vol(struct afs_call *call)
 {
         struct afs_vnode *vnode = call->reply[0];
         const __be32 *bp;
@@ -868,14 +869,14 @@ static int afs_deliver_fs_remove(struct afs_call *call)
 static const struct afs_call_type afs_RXFSRemoveFile = {
         .name           = "FS.RemoveFile",
         .op             = afs_FS_RemoveFile,
-        .deliver        = afs_deliver_fs_remove,
+        .deliver        = afs_deliver_fs_status_and_vol,
         .destructor     = afs_flat_call_destructor,
 };
 
 static const struct afs_call_type afs_RXFSRemoveDir = {
         .name           = "FS.RemoveDir",
         .op             = afs_FS_RemoveDir,
-        .deliver        = afs_deliver_fs_remove,
+        .deliver        = afs_deliver_fs_status_and_vol,
         .destructor     = afs_flat_call_destructor,
 };
 
@@ -2513,3 +2514,55 @@ struct afs_acl *afs_fs_fetch_acl(struct afs_fs_cursor *fc)
         afs_make_call(&fc->ac, call, GFP_KERNEL);
         return (struct afs_acl *)afs_wait_for_call_to_complete(call, &fc->ac);
 }
+
+/*
+ * FS.StoreACL operation type
+ */
+static const struct afs_call_type afs_RXFSStoreACL = {
+        .name           = "FS.StoreACL",
+        .op             = afs_FS_StoreACL,
+        .deliver        = afs_deliver_fs_status_and_vol,
+        .destructor     = afs_flat_call_destructor,
+};
+
+/*
+ * Fetch the ACL for a file.
+ */
+int afs_fs_store_acl(struct afs_fs_cursor *fc, const struct afs_acl *acl)
+{
+        struct afs_vnode *vnode = fc->vnode;
+        struct afs_call *call;
+        struct afs_net *net = afs_v2net(vnode);
+        size_t size;
+        __be32 *bp;
+
+        _enter(",%x,{%llx:%llu},,",
+               key_serial(fc->key), vnode->fid.vid, vnode->fid.vnode);
+
+        size = round_up(acl->size, 4);
+        call = afs_alloc_flat_call(net, &afs_RXFSStoreACL,
+                                   5 * 4 + size, (21 + 6) * 4);
+        if (!call) {
+                fc->ac.error = -ENOMEM;
+                return -ENOMEM;
+        }
+
+        call->key = fc->key;
+        call->reply[0] = vnode;
+        call->reply[2] = NULL; /* volsync */
+
+        /* marshall the parameters */
+        bp = call->request;
+        bp[0] = htonl(FSSTOREACL);
+        bp[1] = htonl(vnode->fid.vid);
+        bp[2] = htonl(vnode->fid.vnode);
+        bp[3] = htonl(vnode->fid.unique);
+        bp[4] = htonl(acl->size);
+        memcpy(&bp[5], acl->data, acl->size);
+        if (acl->size != size)
+                memset((void *)&bp[5] + acl->size, 0, size - acl->size);
+
+        trace_afs_make_fs_call(call, &vnode->fid);
+        afs_make_call(&fc->ac, call, GFP_KERNEL);
+        return afs_wait_for_call_to_complete(call, &fc->ac);
+}
diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index 683b802c20ea..5269824244c6 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -983,6 +983,7 @@ struct afs_acl {
 };
 
 extern struct afs_acl *afs_fs_fetch_acl(struct afs_fs_cursor *);
+extern int afs_fs_store_acl(struct afs_fs_cursor *, const struct afs_acl *);
 
 /*
  * fs_probe.c
diff --git a/fs/afs/xattr.c b/fs/afs/xattr.c
index b7d3d714d8ff..31db360947a6 100644
--- a/fs/afs/xattr.c
+++ b/fs/afs/xattr.c
@@ -80,9 +80,57 @@ static int afs_xattr_get_acl(const struct xattr_handler *handler,
         return ret;
 }
 
+/*
+ * Set a file's AFS3 ACL.
+ */
+static int afs_xattr_set_acl(const struct xattr_handler *handler,
+                             struct dentry *dentry,
+                             struct inode *inode, const char *name,
+                             const void *buffer, size_t size, int flags)
+{
+        struct afs_fs_cursor fc;
+        struct afs_vnode *vnode = AFS_FS_I(inode);
+        struct afs_acl *acl = NULL;
+        struct key *key;
+        int ret;
+
+        if (flags == XATTR_CREATE)
+                return -EINVAL;
+
+        key = afs_request_key(vnode->volume->cell);
+        if (IS_ERR(key))
+                return PTR_ERR(key);
+
+        acl = kmalloc(sizeof(*acl) + size, GFP_KERNEL);
+        if (!acl) {
+                key_put(key);
+                return -ENOMEM;
+        }
+
+        acl->size = size;
+        memcpy(acl->data, buffer, size);
+
+        ret = -ERESTARTSYS;
+        if (afs_begin_vnode_operation(&fc, vnode, key)) {
+                while (afs_select_fileserver(&fc)) {
+                        fc.cb_break = afs_calc_vnode_cb_break(vnode);
+                        afs_fs_store_acl(&fc, acl);
+                }
+
+                afs_check_for_remote_deletion(&fc, fc.vnode);
+                afs_vnode_commit_status(&fc, vnode, fc.cb_break);
+                ret = afs_end_vnode_operation(&fc);
+        }
+
+        kfree(acl);
+        key_put(key);
+        return ret;
+}
+
 static const struct xattr_handler afs_xattr_afs_acl_handler = {
-        .name   = "afs.acl",
-        .get    = afs_xattr_get_acl,
+        .name   = "afs.acl",
+        .get    = afs_xattr_get_acl,
+        .set    = afs_xattr_set_acl,
 };
 
 /*
diff --git a/include/trace/events/afs.h b/include/trace/events/afs.h
index 25c2e089c6ea..562f854ac4bf 100644
--- a/include/trace/events/afs.h
+++ b/include/trace/events/afs.h
@@ -36,6 +36,7 @@ enum afs_fs_operation {
         afs_FS_FetchACL                 = 131,  /* AFS Fetch file ACL */
         afs_FS_FetchStatus              = 132,  /* AFS Fetch file status */
         afs_FS_StoreData                = 133,  /* AFS Store file data */
+        afs_FS_StoreACL                 = 134,  /* AFS Store file ACL */
         afs_FS_StoreStatus              = 135,  /* AFS Store file status */
         afs_FS_RemoveFile               = 136,  /* AFS Remove a file */
         afs_FS_CreateFile               = 137,  /* AFS Create a file */