[PATCH 05/10] afs: Better tracing of protocol errors

From: David Howells
Date: Thu Sep 13 2018 - 11:52:26 EST


Include the site of detection of AFS protocol errors in trace lines to
better be able to determine what went wrong.

Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
---

fs/afs/cmservice.c | 6 ++
fs/afs/fsclient.c | 117 +++++++++++++++++++++++++++-----------------
fs/afs/inode.c | 2 -
fs/afs/internal.h | 2 -
fs/afs/rxrpc.c | 5 +-
fs/afs/vlclient.c | 30 ++++++++---
include/trace/events/afs.h | 54 +++++++++++++++++---
7 files changed, 146 insertions(+), 70 deletions(-)

diff --git a/fs/afs/cmservice.c b/fs/afs/cmservice.c
index 9e51d6fe7e8f..58f79301a716 100644
--- a/fs/afs/cmservice.c
+++ b/fs/afs/cmservice.c
@@ -189,7 +189,8 @@ static int afs_deliver_cb_callback(struct afs_call *call)
call->count = ntohl(call->tmp);
_debug("FID count: %u", call->count);
if (call->count > AFSCBMAX)
- return afs_protocol_error(call, -EBADMSG);
+ return afs_protocol_error(call, -EBADMSG,
+ afs_eproto_cb_fid_count);

call->buffer = kmalloc(array3_size(call->count, 3, 4),
GFP_KERNEL);
@@ -234,7 +235,8 @@ static int afs_deliver_cb_callback(struct afs_call *call)
call->count2 = ntohl(call->tmp);
_debug("CB count: %u", call->count2);
if (call->count2 != call->count && call->count2 != 0)
- return afs_protocol_error(call, -EBADMSG);
+ return afs_protocol_error(call, -EBADMSG,
+ afs_eproto_cb_count);
call->offset = 0;
call->unmarshall++;

diff --git a/fs/afs/fsclient.c b/fs/afs/fsclient.c
index 50929cb91732..d9a5815945dc 100644
--- a/fs/afs/fsclient.c
+++ b/fs/afs/fsclient.c
@@ -233,7 +233,7 @@ static int xdr_decode_AFSFetchStatus(struct afs_call *call,

bad:
xdr_dump_bad(*_bp);
- return afs_protocol_error(call, -EBADMSG);
+ return afs_protocol_error(call, -EBADMSG, afs_eproto_bad_status);
}

/*
@@ -399,9 +399,10 @@ static int afs_deliver_fs_fetch_status_vnode(struct afs_call *call)

/* unmarshall the reply once we've received all of it */
bp = call->buffer;
- if (afs_decode_status(call, &bp, &vnode->status, vnode,
- &call->expected_version, NULL) < 0)
- return afs_protocol_error(call, -EBADMSG);
+ ret = afs_decode_status(call, &bp, &vnode->status, vnode,
+ &call->expected_version, NULL);
+ if (ret < 0)
+ return ret;
xdr_decode_AFSCallBack(call, vnode, &bp);
if (call->reply[1])
xdr_decode_AFSVolSync(&bp, call->reply[1]);
@@ -580,9 +581,10 @@ static int afs_deliver_fs_fetch_data(struct afs_call *call)
return ret;

bp = call->buffer;
- if (afs_decode_status(call, &bp, &vnode->status, vnode,
- &vnode->status.data_version, req) < 0)
- return afs_protocol_error(call, -EBADMSG);
+ ret = afs_decode_status(call, &bp, &vnode->status, vnode,
+ &vnode->status.data_version, req);
+ if (ret < 0)
+ return ret;
xdr_decode_AFSCallBack(call, vnode, &bp);
if (call->reply[1])
xdr_decode_AFSVolSync(&bp, call->reply[1]);
@@ -733,10 +735,13 @@ static int afs_deliver_fs_create_vnode(struct afs_call *call)
/* unmarshall the reply once we've received all of it */
bp = call->buffer;
xdr_decode_AFSFid(&bp, call->reply[1]);
- if (afs_decode_status(call, &bp, call->reply[2], NULL, NULL, NULL) < 0 ||
- afs_decode_status(call, &bp, &vnode->status, vnode,
- &call->expected_version, NULL) < 0)
- return afs_protocol_error(call, -EBADMSG);
+ ret = afs_decode_status(call, &bp, call->reply[2], NULL, NULL, NULL);
+ if (ret < 0)
+ return ret;
+ ret = afs_decode_status(call, &bp, &vnode->status, vnode,
+ &call->expected_version, NULL);
+ if (ret < 0)
+ return ret;
xdr_decode_AFSCallBack_raw(&bp, call->reply[3]);
/* xdr_decode_AFSVolSync(&bp, call->reply[X]); */

@@ -839,9 +844,10 @@ static int afs_deliver_fs_remove(struct afs_call *call)

/* unmarshall the reply once we've received all of it */
bp = call->buffer;
- if (afs_decode_status(call, &bp, &vnode->status, vnode,
- &call->expected_version, NULL) < 0)
- return afs_protocol_error(call, -EBADMSG);
+ ret = afs_decode_status(call, &bp, &vnode->status, vnode,
+ &call->expected_version, NULL);
+ if (ret < 0)
+ return ret;
/* xdr_decode_AFSVolSync(&bp, call->reply[X]); */

_leave(" = 0 [done]");
@@ -929,10 +935,13 @@ static int afs_deliver_fs_link(struct afs_call *call)

/* unmarshall the reply once we've received all of it */
bp = call->buffer;
- if (afs_decode_status(call, &bp, &vnode->status, vnode, NULL, NULL) < 0 ||
- afs_decode_status(call, &bp, &dvnode->status, dvnode,
- &call->expected_version, NULL) < 0)
- return afs_protocol_error(call, -EBADMSG);
+ ret = afs_decode_status(call, &bp, &vnode->status, vnode, NULL, NULL);
+ if (ret < 0)
+ return ret;
+ ret = afs_decode_status(call, &bp, &dvnode->status, dvnode,
+ &call->expected_version, NULL);
+ if (ret < 0)
+ return ret;
/* xdr_decode_AFSVolSync(&bp, call->reply[X]); */

_leave(" = 0 [done]");
@@ -1016,10 +1025,13 @@ static int afs_deliver_fs_symlink(struct afs_call *call)
/* unmarshall the reply once we've received all of it */
bp = call->buffer;
xdr_decode_AFSFid(&bp, call->reply[1]);
- if (afs_decode_status(call, &bp, call->reply[2], NULL, NULL, NULL) ||
- afs_decode_status(call, &bp, &vnode->status, vnode,
- &call->expected_version, NULL) < 0)
- return afs_protocol_error(call, -EBADMSG);
+ ret = afs_decode_status(call, &bp, call->reply[2], NULL, NULL, NULL);
+ if (ret < 0)
+ return ret;
+ ret = afs_decode_status(call, &bp, &vnode->status, vnode,
+ &call->expected_version, NULL);
+ if (ret < 0)
+ return ret;
/* xdr_decode_AFSVolSync(&bp, call->reply[X]); */

_leave(" = 0 [done]");
@@ -1122,13 +1134,16 @@ static int afs_deliver_fs_rename(struct afs_call *call)

/* unmarshall the reply once we've received all of it */
bp = call->buffer;
- if (afs_decode_status(call, &bp, &orig_dvnode->status, orig_dvnode,
- &call->expected_version, NULL) < 0)
- return afs_protocol_error(call, -EBADMSG);
- if (new_dvnode != orig_dvnode &&
- afs_decode_status(call, &bp, &new_dvnode->status, new_dvnode,
- &call->expected_version_2, NULL) < 0)
- return afs_protocol_error(call, -EBADMSG);
+ ret = afs_decode_status(call, &bp, &orig_dvnode->status, orig_dvnode,
+ &call->expected_version, NULL);
+ if (ret < 0)
+ return ret;
+ if (new_dvnode != orig_dvnode) {
+ ret = afs_decode_status(call, &bp, &new_dvnode->status, new_dvnode,
+ &call->expected_version_2, NULL);
+ if (ret < 0)
+ return ret;
+ }
/* xdr_decode_AFSVolSync(&bp, call->reply[X]); */

_leave(" = 0 [done]");
@@ -1231,9 +1246,10 @@ static int afs_deliver_fs_store_data(struct afs_call *call)

/* unmarshall the reply once we've received all of it */
bp = call->buffer;
- if (afs_decode_status(call, &bp, &vnode->status, vnode,
- &call->expected_version, NULL) < 0)
- return afs_protocol_error(call, -EBADMSG);
+ ret = afs_decode_status(call, &bp, &vnode->status, vnode,
+ &call->expected_version, NULL);
+ if (ret < 0)
+ return ret;
/* xdr_decode_AFSVolSync(&bp, call->reply[X]); */

afs_pages_written_back(vnode, call);
@@ -1407,9 +1423,10 @@ static int afs_deliver_fs_store_status(struct afs_call *call)

/* unmarshall the reply once we've received all of it */
bp = call->buffer;
- if (afs_decode_status(call, &bp, &vnode->status, vnode,
- &call->expected_version, NULL) < 0)
- return afs_protocol_error(call, -EBADMSG);
+ ret = afs_decode_status(call, &bp, &vnode->status, vnode,
+ &call->expected_version, NULL);
+ if (ret < 0)
+ return ret;
/* xdr_decode_AFSVolSync(&bp, call->reply[X]); */

_leave(" = 0 [done]");
@@ -1612,7 +1629,8 @@ static int afs_deliver_fs_get_volume_status(struct afs_call *call)
call->count = ntohl(call->tmp);
_debug("volname length: %u", call->count);
if (call->count >= AFSNAMEMAX)
- return afs_protocol_error(call, -EBADMSG);
+ return afs_protocol_error(call, -EBADMSG,
+ afs_eproto_volname_len);
call->offset = 0;
call->unmarshall++;

@@ -1659,7 +1677,8 @@ static int afs_deliver_fs_get_volume_status(struct afs_call *call)
call->count = ntohl(call->tmp);
_debug("offline msg length: %u", call->count);
if (call->count >= AFSNAMEMAX)
- return afs_protocol_error(call, -EBADMSG);
+ return afs_protocol_error(call, -EBADMSG,
+ afs_eproto_offline_msg_len);
call->offset = 0;
call->unmarshall++;

@@ -1706,7 +1725,8 @@ static int afs_deliver_fs_get_volume_status(struct afs_call *call)
call->count = ntohl(call->tmp);
_debug("motd length: %u", call->count);
if (call->count >= AFSNAMEMAX)
- return afs_protocol_error(call, -EBADMSG);
+ return afs_protocol_error(call, -EBADMSG,
+ afs_eproto_motd_len);
call->offset = 0;
call->unmarshall++;

@@ -2109,8 +2129,10 @@ static int afs_deliver_fs_fetch_status(struct afs_call *call)

/* unmarshall the reply once we've received all of it */
bp = call->buffer;
- afs_decode_status(call, &bp, status, vnode,
- &call->expected_version, NULL);
+ ret = afs_decode_status(call, &bp, status, vnode,
+ &call->expected_version, NULL);
+ if (ret < 0)
+ return ret;
callback[call->count].version = ntohl(bp[0]);
callback[call->count].expiry = ntohl(bp[1]);
callback[call->count].type = ntohl(bp[2]);
@@ -2206,7 +2228,8 @@ static int afs_deliver_fs_inline_bulk_status(struct afs_call *call)
tmp = ntohl(call->tmp);
_debug("status count: %u/%u", tmp, call->count2);
if (tmp != call->count2)
- return afs_protocol_error(call, -EBADMSG);
+ return afs_protocol_error(call, -EBADMSG,
+ afs_eproto_ibulkst_count);

call->count = 0;
call->unmarshall++;
@@ -2221,10 +2244,11 @@ static int afs_deliver_fs_inline_bulk_status(struct afs_call *call)

bp = call->buffer;
statuses = call->reply[1];
- if (afs_decode_status(call, &bp, &statuses[call->count],
- call->count == 0 ? vnode : NULL,
- NULL, NULL) < 0)
- return afs_protocol_error(call, -EBADMSG);
+ ret = afs_decode_status(call, &bp, &statuses[call->count],
+ call->count == 0 ? vnode : NULL,
+ NULL, NULL);
+ if (ret < 0)
+ return ret;

call->count++;
if (call->count < call->count2)
@@ -2244,7 +2268,8 @@ static int afs_deliver_fs_inline_bulk_status(struct afs_call *call)
tmp = ntohl(call->tmp);
_debug("CB count: %u", tmp);
if (tmp != call->count2)
- return afs_protocol_error(call, -EBADMSG);
+ return afs_protocol_error(call, -EBADMSG,
+ afs_eproto_ibulkst_cb_count);
call->count = 0;
call->unmarshall++;
more_cbs:
diff --git a/fs/afs/inode.c b/fs/afs/inode.c
index 479b7fdda124..ab4e7a15c205 100644
--- a/fs/afs/inode.c
+++ b/fs/afs/inode.c
@@ -82,7 +82,7 @@ static int afs_inode_init_from_status(struct afs_vnode *vnode, struct key *key)
default:
printk("kAFS: AFS vnode with undefined type\n");
read_sequnlock_excl(&vnode->cb_lock);
- return afs_protocol_error(NULL, -EBADMSG);
+ return afs_protocol_error(NULL, -EBADMSG, afs_eproto_file_type);
}

inode->i_blocks = 0;
diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index 871a228d7f37..457a8f76b6a2 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -929,7 +929,7 @@ extern void afs_flat_call_destructor(struct afs_call *);
extern void afs_send_empty_reply(struct afs_call *);
extern void afs_send_simple_reply(struct afs_call *, const void *, size_t);
extern int afs_extract_data(struct afs_call *, void *, size_t, bool);
-extern int afs_protocol_error(struct afs_call *, int);
+extern int afs_protocol_error(struct afs_call *, int, enum afs_eproto_cause);

static inline int afs_transfer_reply(struct afs_call *call)
{
diff --git a/fs/afs/rxrpc.c b/fs/afs/rxrpc.c
index ad947f8c63f1..20199f2b2c31 100644
--- a/fs/afs/rxrpc.c
+++ b/fs/afs/rxrpc.c
@@ -941,8 +941,9 @@ int afs_extract_data(struct afs_call *call, void *buf, size_t count,
/*
* Log protocol error production.
*/
-noinline int afs_protocol_error(struct afs_call *call, int error)
+noinline int afs_protocol_error(struct afs_call *call, int error,
+ enum afs_eproto_cause cause)
{
- trace_afs_protocol_error(call, error, __builtin_return_address(0));
+ trace_afs_protocol_error(call, error, cause);
return error;
}
diff --git a/fs/afs/vlclient.c b/fs/afs/vlclient.c
index c3b740813fc7..d0f95c4ab05e 100644
--- a/fs/afs/vlclient.c
+++ b/fs/afs/vlclient.c
@@ -451,7 +451,8 @@ static int afs_deliver_yfsvl_get_endpoints(struct afs_call *call)
call->count2 = ntohl(*bp); /* Type or next count */

if (call->count > YFS_MAXENDPOINTS)
- return afs_protocol_error(call, -EBADMSG);
+ return afs_protocol_error(call, -EBADMSG,
+ afs_eproto_yvl_fsendpt_num);

alist = afs_alloc_addrlist(call->count, FS_SERVICE, AFS_FS_PORT);
if (!alist)
@@ -475,7 +476,8 @@ static int afs_deliver_yfsvl_get_endpoints(struct afs_call *call)
size = sizeof(__be32) * (1 + 4 + 1);
break;
default:
- return afs_protocol_error(call, -EBADMSG);
+ return afs_protocol_error(call, -EBADMSG,
+ afs_eproto_yvl_fsendpt_type);
}

size += sizeof(__be32);
@@ -488,18 +490,21 @@ static int afs_deliver_yfsvl_get_endpoints(struct afs_call *call)
switch (call->count2) {
case YFS_ENDPOINT_IPV4:
if (ntohl(bp[0]) != sizeof(__be32) * 2)
- return afs_protocol_error(call, -EBADMSG);
+ return afs_protocol_error(call, -EBADMSG,
+ afs_eproto_yvl_fsendpt4_len);
afs_merge_fs_addr4(alist, bp[1], ntohl(bp[2]));
bp += 3;
break;
case YFS_ENDPOINT_IPV6:
if (ntohl(bp[0]) != sizeof(__be32) * 5)
- return afs_protocol_error(call, -EBADMSG);
+ return afs_protocol_error(call, -EBADMSG,
+ afs_eproto_yvl_fsendpt6_len);
afs_merge_fs_addr6(alist, bp + 1, ntohl(bp[5]));
bp += 6;
break;
default:
- return afs_protocol_error(call, -EBADMSG);
+ return afs_protocol_error(call, -EBADMSG,
+ afs_eproto_yvl_fsendpt_type);
}

/* Got either the type of the next entry or the count of
@@ -518,7 +523,8 @@ static int afs_deliver_yfsvl_get_endpoints(struct afs_call *call)
if (!call->count)
goto end;
if (call->count > YFS_MAXENDPOINTS)
- return afs_protocol_error(call, -EBADMSG);
+ return afs_protocol_error(call, -EBADMSG,
+ afs_eproto_yvl_vlendpt_type);

call->unmarshall = 3;

@@ -546,7 +552,8 @@ static int afs_deliver_yfsvl_get_endpoints(struct afs_call *call)
size = sizeof(__be32) * (1 + 4 + 1);
break;
default:
- return afs_protocol_error(call, -EBADMSG);
+ return afs_protocol_error(call, -EBADMSG,
+ afs_eproto_yvl_vlendpt_type);
}

if (call->count > 1)
@@ -559,16 +566,19 @@ static int afs_deliver_yfsvl_get_endpoints(struct afs_call *call)
switch (call->count2) {
case YFS_ENDPOINT_IPV4:
if (ntohl(bp[0]) != sizeof(__be32) * 2)
- return afs_protocol_error(call, -EBADMSG);
+ return afs_protocol_error(call, -EBADMSG,
+ afs_eproto_yvl_vlendpt4_len);
bp += 3;
break;
case YFS_ENDPOINT_IPV6:
if (ntohl(bp[0]) != sizeof(__be32) * 5)
- return afs_protocol_error(call, -EBADMSG);
+ return afs_protocol_error(call, -EBADMSG,
+ afs_eproto_yvl_vlendpt6_len);
bp += 6;
break;
default:
- return afs_protocol_error(call, -EBADMSG);
+ return afs_protocol_error(call, -EBADMSG,
+ afs_eproto_yvl_vlendpt_type);
}

/* Got either the type of the next entry or the count of
diff --git a/include/trace/events/afs.h b/include/trace/events/afs.h
index d0a341bc4540..5c60ade2c7d8 100644
--- a/include/trace/events/afs.h
+++ b/include/trace/events/afs.h
@@ -84,6 +84,25 @@ enum afs_edit_dir_reason {
afs_edit_dir_for_unlink,
};

+enum afs_eproto_cause {
+ afs_eproto_bad_status,
+ afs_eproto_cb_count,
+ afs_eproto_cb_fid_count,
+ afs_eproto_file_type,
+ afs_eproto_ibulkst_cb_count,
+ afs_eproto_ibulkst_count,
+ afs_eproto_motd_len,
+ afs_eproto_offline_msg_len,
+ afs_eproto_volname_len,
+ afs_eproto_yvl_fsendpt4_len,
+ afs_eproto_yvl_fsendpt6_len,
+ afs_eproto_yvl_fsendpt_num,
+ afs_eproto_yvl_fsendpt_type,
+ afs_eproto_yvl_vlendpt4_len,
+ afs_eproto_yvl_vlendpt6_len,
+ afs_eproto_yvl_vlendpt_type,
+};
+
#endif /* end __AFS_DECLARE_TRACE_ENUMS_ONCE_ONLY */

/*
@@ -146,6 +165,24 @@ enum afs_edit_dir_reason {
EM(afs_edit_dir_for_symlink, "Symlnk") \
E_(afs_edit_dir_for_unlink, "Unlink")

+#define afs_eproto_causes \
+ EM(afs_eproto_bad_status, "BadStatus") \
+ EM(afs_eproto_cb_count, "CbCount") \
+ EM(afs_eproto_cb_fid_count, "CbFidCount") \
+ EM(afs_eproto_file_type, "FileTYpe") \
+ EM(afs_eproto_ibulkst_cb_count, "IBS.CbCount") \
+ EM(afs_eproto_ibulkst_count, "IBS.FidCount") \
+ EM(afs_eproto_motd_len, "MotdLen") \
+ EM(afs_eproto_offline_msg_len, "OfflineMsgLen") \
+ EM(afs_eproto_volname_len, "VolNameLen") \
+ EM(afs_eproto_yvl_fsendpt4_len, "YVL.FsEnd4Len") \
+ EM(afs_eproto_yvl_fsendpt6_len, "YVL.FsEnd6Len") \
+ EM(afs_eproto_yvl_fsendpt_num, "YVL.FsEndCount") \
+ EM(afs_eproto_yvl_fsendpt_type, "YVL.FsEndType") \
+ EM(afs_eproto_yvl_vlendpt4_len, "YVL.VlEnd4Len") \
+ EM(afs_eproto_yvl_vlendpt6_len, "YVL.VlEnd6Len") \
+ E_(afs_eproto_yvl_vlendpt_type, "YVL.VlEndType")
+

/*
* Export enum symbols via userspace.
@@ -555,24 +592,25 @@ TRACE_EVENT(afs_edit_dir,
);

TRACE_EVENT(afs_protocol_error,
- TP_PROTO(struct afs_call *call, int error, const void *where),
+ TP_PROTO(struct afs_call *call, int error, enum afs_eproto_cause cause),

- TP_ARGS(call, error, where),
+ TP_ARGS(call, error, cause),

TP_STRUCT__entry(
- __field(unsigned int, call )
- __field(int, error )
- __field(const void *, where )
+ __field(unsigned int, call )
+ __field(int, error )
+ __field(enum afs_eproto_cause, cause )
),

TP_fast_assign(
__entry->call = call ? call->debug_id : 0;
__entry->error = error;
- __entry->where = where;
+ __entry->cause = cause;
),

- TP_printk("c=%08x r=%d sp=%pSR",
- __entry->call, __entry->error, __entry->where)
+ TP_printk("c=%08x r=%d %s",
+ __entry->call, __entry->error,
+ __print_symbolic(__entry->cause, afs_eproto_causes))
);

TRACE_EVENT(afs_cm_no_server,