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authorDavid Howells <dhowells@redhat.com>2020-04-10 22:51:51 +0300
committerDavid Howells <dhowells@redhat.com>2020-06-04 17:37:17 +0300
commite49c7b2f6de7ff81ca34c56e4eeb4fa740c099f2 (patch)
treeaf62a4222f25fdc713dc5dff570aa874596102b1 /fs/afs/server.c
parenta310082f6d0afe28797e148726cd52118a8a4428 (diff)
downloadlinux-e49c7b2f6de7ff81ca34c56e4eeb4fa740c099f2.tar.xz
afs: Build an abstraction around an "operation" concept
Turn the afs_operation struct into the main way that most fileserver operations are managed. Various things are added to the struct, including the following: (1) All the parameters and results of the relevant operations are moved into it, removing corresponding fields from the afs_call struct. afs_call gets a pointer to the op. (2) The target volume is made the main focus of the operation, rather than the target vnode(s), and a bunch of op->vnode->volume are made op->volume instead. (3) Two vnode records are defined (op->file[]) for the vnode(s) involved in most operations. The vnode record (struct afs_vnode_param) contains: - The vnode pointer. - The fid of the vnode to be included in the parameters or that was returned in the reply (eg. FS.MakeDir). - The status and callback information that may be returned in the reply about the vnode. - Callback break and data version tracking for detecting simultaneous third-parth changes. (4) Pointers to dentries to be updated with new inodes. (5) An operations table pointer. The table includes pointers to functions for issuing AFS and YFS-variant RPCs, handling the success and abort of an operation and handling post-I/O-lock local editing of a directory. To make this work, the following function restructuring is made: (A) The rotation loop that issues calls to fileservers that can be found in each function that wants to issue an RPC (such as afs_mkdir()) is extracted out into common code, in a new file called fs_operation.c. (B) The rotation loops, such as the one in afs_mkdir(), are replaced with a much smaller piece of code that allocates an operation, sets the parameters and then calls out to the common code to do the actual work. (C) The code for handling the success and failure of an operation are moved into operation functions (as (5) above) and these are called from the core code at appropriate times. (D) The pseudo inode getting stuff used by the dynamic root code is moved over into dynroot.c. (E) struct afs_iget_data is absorbed into the operation struct and afs_iget() expects to be given an op pointer and a vnode record. (F) Point (E) doesn't work for the root dir of a volume, but we know the FID in advance (it's always vnode 1, unique 1), so a separate inode getter, afs_root_iget(), is provided to special-case that. (G) The inode status init/update functions now also take an op and a vnode record. (H) The RPC marshalling functions now, for the most part, just take an afs_operation struct as their only argument. All the data they need is held there. The result delivery functions write their answers there as well. (I) The call is attached to the operation and then the operation core does the waiting. And then the new operation code is, for the moment, made to just initialise the operation, get the appropriate vnode I/O locks and do the same rotation loop as before. This lays the foundation for the following changes in the future: (*) Overhauling the rotation (again). (*) Support for asynchronous I/O, where the fileserver rotation must be done asynchronously also. Signed-off-by: David Howells <dhowells@redhat.com>
Diffstat (limited to 'fs/afs/server.c')
-rw-r--r--fs/afs/server.c37
1 files changed, 21 insertions, 16 deletions
diff --git a/fs/afs/server.c b/fs/afs/server.c
index 3008f2ecfeee..1c1e315094ae 100644
--- a/fs/afs/server.c
+++ b/fs/afs/server.c
@@ -424,10 +424,7 @@ static void __afs_put_server(struct afs_net *net, struct afs_server *server)
afs_dec_servers_outstanding(net);
}
-/*
- * destroy a dead server
- */
-static void afs_destroy_server(struct afs_net *net, struct afs_server *server)
+static void afs_give_up_callbacks(struct afs_net *net, struct afs_server *server)
{
struct afs_addr_list *alist = rcu_access_pointer(server->addresses);
struct afs_addr_cursor ac = {
@@ -436,8 +433,16 @@ static void afs_destroy_server(struct afs_net *net, struct afs_server *server)
.error = 0,
};
+ afs_fs_give_up_all_callbacks(net, server, &ac, NULL);
+}
+
+/*
+ * destroy a dead server
+ */
+static void afs_destroy_server(struct afs_net *net, struct afs_server *server)
+{
if (test_bit(AFS_SERVER_FL_MAY_HAVE_CB, &server->flags))
- afs_fs_give_up_all_callbacks(net, server, &ac, NULL);
+ afs_give_up_callbacks(net, server);
afs_put_server(net, server, afs_server_trace_destroy);
}
@@ -571,7 +576,8 @@ void afs_purge_servers(struct afs_net *net)
/*
* Get an update for a server's address list.
*/
-static noinline bool afs_update_server_record(struct afs_operation *fc, struct afs_server *server)
+static noinline bool afs_update_server_record(struct afs_operation *op,
+ struct afs_server *server)
{
struct afs_addr_list *alist, *discard;
@@ -580,18 +586,17 @@ static noinline bool afs_update_server_record(struct afs_operation *fc, struct a
trace_afs_server(server, atomic_read(&server->ref), atomic_read(&server->active),
afs_server_trace_update);
- alist = afs_vl_lookup_addrs(fc->vnode->volume->cell, fc->key,
- &server->uuid);
+ alist = afs_vl_lookup_addrs(op->volume->cell, op->key, &server->uuid);
if (IS_ERR(alist)) {
if ((PTR_ERR(alist) == -ERESTARTSYS ||
PTR_ERR(alist) == -EINTR) &&
- !(fc->flags & AFS_OPERATION_INTR) &&
+ (op->flags & AFS_OPERATION_UNINTR) &&
server->addresses) {
_leave(" = t [intr]");
return true;
}
- fc->error = PTR_ERR(alist);
- _leave(" = f [%d]", fc->error);
+ op->error = PTR_ERR(alist);
+ _leave(" = f [%d]", op->error);
return false;
}
@@ -613,7 +618,7 @@ static noinline bool afs_update_server_record(struct afs_operation *fc, struct a
/*
* See if a server's address list needs updating.
*/
-bool afs_check_server_record(struct afs_operation *fc, struct afs_server *server)
+bool afs_check_server_record(struct afs_operation *op, struct afs_server *server)
{
bool success;
int ret, retries = 0;
@@ -633,7 +638,7 @@ retry:
update:
if (!test_and_set_bit_lock(AFS_SERVER_FL_UPDATING, &server->flags)) {
clear_bit(AFS_SERVER_FL_NEEDS_UPDATE, &server->flags);
- success = afs_update_server_record(fc, server);
+ success = afs_update_server_record(op, server);
clear_bit_unlock(AFS_SERVER_FL_UPDATING, &server->flags);
wake_up_bit(&server->flags, AFS_SERVER_FL_UPDATING);
_leave(" = %d", success);
@@ -642,10 +647,10 @@ update:
wait:
ret = wait_on_bit(&server->flags, AFS_SERVER_FL_UPDATING,
- (fc->flags & AFS_OPERATION_INTR) ?
- TASK_INTERRUPTIBLE : TASK_UNINTERRUPTIBLE);
+ (op->flags & AFS_OPERATION_UNINTR) ?
+ TASK_UNINTERRUPTIBLE : TASK_INTERRUPTIBLE);
if (ret == -ERESTARTSYS) {
- fc->error = ret;
+ op->error = ret;
_leave(" = f [intr]");
return false;
}