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authorDavid Howells <dhowells@redhat.com>2019-04-25 14:26:52 +0100
committerDavid Howells <dhowells@redhat.com>2019-05-07 16:48:44 +0100
commit260f082bae6dcf70aeae2cc3e24aecb55bdb1c99 (patch)
tree128a02382c0b98b01f8c1fce97347a41a2507e40 /fs
parenta2f611a3dc317d8ea1c98ad6c54b911cf7f93193 (diff)
downloadlinux-260f082bae6dcf70aeae2cc3e24aecb55bdb1c99.tar.bz2
afs: Get an AFS3 ACL as an xattr
Implement an xattr on AFS files called "afs.acl" that retrieves a file's ACL. It returns the raw AFS3 ACL from the result of calling FS.FetchACL, leaving any interpretation to userspace. Note that whilst YFS servers will respond to FS.FetchACL, this will render a more-advanced YFS ACL down. Use "afs.yfs.acl" instead for that. Signed-off-by: David Howells <dhowells@redhat.com>
Diffstat (limited to 'fs')
-rw-r--r--fs/afs/afs_fs.h1
-rw-r--r--fs/afs/fsclient.c122
-rw-r--r--fs/afs/internal.h7
-rw-r--r--fs/afs/xattr.c53
4 files changed, 183 insertions, 0 deletions
diff --git a/fs/afs/afs_fs.h b/fs/afs/afs_fs.h
index ddfa88a7a9c0..4df1f1eec0ab 100644
--- a/fs/afs/afs_fs.h
+++ b/fs/afs/afs_fs.h
@@ -17,6 +17,7 @@
enum AFS_FS_Operations {
FSFETCHDATA = 130, /* AFS Fetch file data */
+ FSFETCHACL = 131, /* AFS Fetch file ACL */
FSFETCHSTATUS = 132, /* AFS Fetch file status */
FSSTOREDATA = 133, /* AFS Store file data */
FSSTORESTATUS = 135, /* AFS Store file status */
diff --git a/fs/afs/fsclient.c b/fs/afs/fsclient.c
index 9b73a57aa5cb..283f486c59f4 100644
--- a/fs/afs/fsclient.c
+++ b/fs/afs/fsclient.c
@@ -2391,3 +2391,125 @@ int afs_fs_inline_bulk_status(struct afs_fs_cursor *fc,
afs_make_call(&fc->ac, call, GFP_NOFS);
return afs_wait_for_call_to_complete(call, &fc->ac);
}
+
+/*
+ * deliver reply data to an FS.FetchACL
+ */
+static int afs_deliver_fs_fetch_acl(struct afs_call *call)
+{
+ struct afs_vnode *vnode = call->reply[1];
+ struct afs_acl *acl;
+ const __be32 *bp;
+ unsigned int size;
+ int ret;
+
+ _enter("{%u}", call->unmarshall);
+
+ switch (call->unmarshall) {
+ case 0:
+ afs_extract_to_tmp(call);
+ call->unmarshall++;
+
+ /* extract the returned data length */
+ case 1:
+ ret = afs_extract_data(call, true);
+ if (ret < 0)
+ return ret;
+
+ size = call->count2 = ntohl(call->tmp);
+ size = round_up(size, 4);
+
+ acl = kmalloc(struct_size(acl, data, size), GFP_KERNEL);
+ if (!acl)
+ return -ENOMEM;
+ call->reply[0] = acl;
+ acl->size = call->count2;
+ afs_extract_begin(call, acl->data, size);
+ call->unmarshall++;
+
+ /* extract the returned data */
+ case 2:
+ ret = afs_extract_data(call, true);
+ if (ret < 0)
+ return ret;
+
+ afs_extract_to_buf(call, (21 + 6) * 4);
+ call->unmarshall++;
+
+ /* extract the metadata */
+ case 3:
+ ret = afs_extract_data(call, false);
+ if (ret < 0)
+ return ret;
+
+ bp = call->buffer;
+ ret = afs_decode_status(call, &bp, &vnode->status, vnode,
+ &vnode->status.data_version, NULL);
+ if (ret < 0)
+ return ret;
+ xdr_decode_AFSVolSync(&bp, call->reply[2]);
+
+ call->unmarshall++;
+
+ case 4:
+ break;
+ }
+
+ _leave(" = 0 [done]");
+ return 0;
+}
+
+static void afs_destroy_fs_fetch_acl(struct afs_call *call)
+{
+ kfree(call->reply[0]);
+ afs_flat_call_destructor(call);
+}
+
+/*
+ * FS.FetchACL operation type
+ */
+static const struct afs_call_type afs_RXFSFetchACL = {
+ .name = "FS.FetchACL",
+ .op = afs_FS_FetchACL,
+ .deliver = afs_deliver_fs_fetch_acl,
+ .destructor = afs_destroy_fs_fetch_acl,
+};
+
+/*
+ * Fetch the ACL for a file.
+ */
+struct afs_acl *afs_fs_fetch_acl(struct afs_fs_cursor *fc)
+{
+ struct afs_vnode *vnode = fc->vnode;
+ struct afs_call *call;
+ struct afs_net *net = afs_v2net(vnode);
+ __be32 *bp;
+
+ _enter(",%x,{%llx:%llu},,",
+ key_serial(fc->key), vnode->fid.vid, vnode->fid.vnode);
+
+ call = afs_alloc_flat_call(net, &afs_RXFSFetchACL, 16, (21 + 6) * 4);
+ if (!call) {
+ fc->ac.error = -ENOMEM;
+ return ERR_PTR(-ENOMEM);
+ }
+
+ call->key = fc->key;
+ call->reply[0] = NULL;
+ call->reply[1] = vnode;
+ call->reply[2] = NULL; /* volsync */
+ call->ret_reply0 = true;
+
+ /* marshall the parameters */
+ bp = call->request;
+ bp[0] = htonl(FSFETCHACL);
+ bp[1] = htonl(vnode->fid.vid);
+ bp[2] = htonl(vnode->fid.vnode);
+ bp[3] = htonl(vnode->fid.unique);
+
+ call->cb_break = fc->cb_break;
+ afs_use_fs_server(call, fc->cbi);
+ trace_afs_make_fs_call(call, &vnode->fid);
+ afs_make_call(&fc->ac, call, GFP_KERNEL);
+ return (struct afs_acl *)afs_wait_for_call_to_complete(call, &fc->ac);
+}
diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index 585a5952f608..683b802c20ea 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -977,6 +977,13 @@ extern int afs_fs_fetch_status(struct afs_fs_cursor *, struct afs_net *,
struct afs_fid *, struct afs_file_status *,
struct afs_callback *, struct afs_volsync *);
+struct afs_acl {
+ u32 size;
+ u8 data[];
+};
+
+extern struct afs_acl *afs_fs_fetch_acl(struct afs_fs_cursor *);
+
/*
* fs_probe.c
*/
diff --git a/fs/afs/xattr.c b/fs/afs/xattr.c
index e729ee3d4b02..b7d3d714d8ff 100644
--- a/fs/afs/xattr.c
+++ b/fs/afs/xattr.c
@@ -16,6 +16,7 @@
#include "internal.h"
static const char afs_xattr_list[] =
+ "afs.acl\0"
"afs.cell\0"
"afs.fid\0"
"afs.volume";
@@ -34,6 +35,57 @@ ssize_t afs_listxattr(struct dentry *dentry, char *buffer, size_t size)
}
/*
+ * Get a file's ACL.
+ */
+static int afs_xattr_get_acl(const struct xattr_handler *handler,
+ struct dentry *dentry,
+ struct inode *inode, const char *name,
+ void *buffer, size_t size)
+{
+ struct afs_fs_cursor fc;
+ struct afs_vnode *vnode = AFS_FS_I(inode);
+ struct afs_acl *acl = NULL;
+ struct key *key;
+ int ret;
+
+ key = afs_request_key(vnode->volume->cell);
+ if (IS_ERR(key))
+ return PTR_ERR(key);
+
+ ret = -ERESTARTSYS;
+ if (afs_begin_vnode_operation(&fc, vnode, key)) {
+ while (afs_select_fileserver(&fc)) {
+ fc.cb_break = afs_calc_vnode_cb_break(vnode);
+ acl = afs_fs_fetch_acl(&fc);
+ }
+
+ afs_check_for_remote_deletion(&fc, fc.vnode);
+ afs_vnode_commit_status(&fc, vnode, fc.cb_break);
+ ret = afs_end_vnode_operation(&fc);
+ }
+
+ if (ret == 0) {
+ ret = acl->size;
+ if (size > 0) {
+ ret = -ERANGE;
+ if (acl->size > size)
+ return -ERANGE;
+ memcpy(buffer, acl->data, acl->size);
+ ret = acl->size;
+ }
+ 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,
+};
+
+/*
* Get the name of the cell on which a file resides.
*/
static int afs_xattr_get_cell(const struct xattr_handler *handler,
@@ -123,6 +175,7 @@ static const struct xattr_handler afs_xattr_afs_volume_handler = {
};
const struct xattr_handler *afs_xattr_handlers[] = {
+ &afs_xattr_afs_acl_handler,
&afs_xattr_afs_cell_handler,
&afs_xattr_afs_fid_handler,
&afs_xattr_afs_volume_handler,