[PATCH 09/10] afs: Add a couple of tracepoints to log I/O errors

From: David Howells
Date: Thu Sep 13 2018 - 11:52:56 EST


Add a couple of tracepoints to log the production of I/O errors within the AFS
filesystem.

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

fs/afs/cmservice.c | 10 +++--
fs/afs/dir.c | 23 ++++++++----
fs/afs/internal.h | 11 ++++++
fs/afs/mntpt.c | 6 +++
fs/afs/rxrpc.c | 2 +
fs/afs/server.c | 4 +-
fs/afs/volume.c | 2 +
fs/afs/write.c | 1 +
include/trace/events/afs.h | 81 ++++++++++++++++++++++++++++++++++++++++++++
9 files changed, 122 insertions(+), 18 deletions(-)

diff --git a/fs/afs/cmservice.c b/fs/afs/cmservice.c
index 4db62ae8dc1a..186f621f8722 100644
--- a/fs/afs/cmservice.c
+++ b/fs/afs/cmservice.c
@@ -260,7 +260,7 @@ static int afs_deliver_cb_callback(struct afs_call *call)
}

if (!afs_check_call_state(call, AFS_CALL_SV_REPLYING))
- return -EIO;
+ return afs_io_error(call, afs_io_error_cm_reply);

/* we'll need the file server record as that tells us which set of
* vnodes to operate upon */
@@ -368,7 +368,7 @@ static int afs_deliver_cb_init_call_back_state3(struct afs_call *call)
}

if (!afs_check_call_state(call, AFS_CALL_SV_REPLYING))
- return -EIO;
+ return afs_io_error(call, afs_io_error_cm_reply);

/* we'll need the file server record as that tells us which set of
* vnodes to operate upon */
@@ -409,7 +409,7 @@ static int afs_deliver_cb_probe(struct afs_call *call)
return ret;

if (!afs_check_call_state(call, AFS_CALL_SV_REPLYING))
- return -EIO;
+ return afs_io_error(call, afs_io_error_cm_reply);

return afs_queue_call_work(call);
}
@@ -490,7 +490,7 @@ static int afs_deliver_cb_probe_uuid(struct afs_call *call)
}

if (!afs_check_call_state(call, AFS_CALL_SV_REPLYING))
- return -EIO;
+ return afs_io_error(call, afs_io_error_cm_reply);

return afs_queue_call_work(call);
}
@@ -573,7 +573,7 @@ static int afs_deliver_cb_tell_me_about_yourself(struct afs_call *call)
return ret;

if (!afs_check_call_state(call, AFS_CALL_SV_REPLYING))
- return -EIO;
+ return afs_io_error(call, afs_io_error_cm_reply);

return afs_queue_call_work(call);
}
diff --git a/fs/afs/dir.c b/fs/afs/dir.c
index c36b54b7450b..15f740b910fb 100644
--- a/fs/afs/dir.c
+++ b/fs/afs/dir.c
@@ -172,6 +172,7 @@ static bool afs_dir_check_page(struct afs_vnode *dvnode, struct page *page,
ntohs(dbuf->blocks[tmp].hdr.magic));
trace_afs_dir_check_failed(dvnode, off, i_size);
kunmap(page);
+ trace_afs_file_error(dvnode, -EIO, afs_file_error_dir_bad_magic);
goto error;
}

@@ -271,12 +272,15 @@ static struct afs_read *afs_read_dir(struct afs_vnode *dvnode, struct key *key)

expand:
i_size = i_size_read(&dvnode->vfs_inode);
- ret = -EIO;
- if (i_size < 2048)
+ if (i_size < 2048) {
+ ret = afs_bad(dvnode, afs_file_error_dir_small);
goto error;
- ret = -EFBIG;
- if (i_size > 2048 * 1024)
+ }
+ if (i_size > 2048 * 1024) {
+ trace_afs_file_error(dvnode, -EFBIG, afs_file_error_dir_big);
+ ret = -EFBIG;
goto error;
+ }

nr_pages = (i_size + PAGE_SIZE - 1) / PAGE_SIZE;

@@ -381,7 +385,8 @@ static struct afs_read *afs_read_dir(struct afs_vnode *dvnode, struct key *key)
/*
* deal with one block in an AFS directory
*/
-static int afs_dir_iterate_block(struct dir_context *ctx,
+static int afs_dir_iterate_block(struct afs_vnode *dvnode,
+ struct dir_context *ctx,
union afs_xdr_dir_block *block,
unsigned blkoff)
{
@@ -431,7 +436,7 @@ static int afs_dir_iterate_block(struct dir_context *ctx,
" (len %u/%zu)",
blkoff / sizeof(union afs_xdr_dir_block),
offset, next, tmp, nlen);
- return -EIO;
+ return afs_bad(dvnode, afs_file_error_dir_over_end);
}
if (!(block->hdr.bitmap[next / 8] &
(1 << (next % 8)))) {
@@ -439,7 +444,7 @@ static int afs_dir_iterate_block(struct dir_context *ctx,
" %u unmarked extension (len %u/%zu)",
blkoff / sizeof(union afs_xdr_dir_block),
offset, next, tmp, nlen);
- return -EIO;
+ return afs_bad(dvnode, afs_file_error_dir_unmarked_ext);
}

_debug("ENT[%zu.%u]: ext %u/%zu",
@@ -515,7 +520,7 @@ static int afs_dir_iterate(struct inode *dir, struct dir_context *ctx,
page = radix_tree_deref_slot(slot);
rcu_read_unlock();
if (!page) {
- ret = -EIO;
+ ret = afs_bad(dvnode, afs_file_error_dir_missing_page);
break;
}
mark_page_accessed(page);
@@ -528,7 +533,7 @@ static int afs_dir_iterate(struct inode *dir, struct dir_context *ctx,
do {
dblock = &dbuf->blocks[(blkoff % PAGE_SIZE) /
sizeof(union afs_xdr_dir_block)];
- ret = afs_dir_iterate_block(ctx, dblock, blkoff);
+ ret = afs_dir_iterate_block(dvnode, ctx, dblock, blkoff);
if (ret != 1) {
kunmap(page);
goto out;
diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index 38b48382db52..3dd502e55720 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -1150,6 +1150,17 @@ static inline void afs_check_for_remote_deletion(struct afs_fs_cursor *fc,
}
}

+static inline int afs_io_error(struct afs_call *call, enum afs_io_error where)
+{
+ trace_afs_io_error(call->debug_id, -EIO, where);
+ return -EIO;
+}
+
+static inline int afs_bad(struct afs_vnode *vnode, enum afs_file_error where)
+{
+ trace_afs_file_error(vnode, -EIO, where);
+ return -EIO;
+}

/*****************************************************************************/
/*
diff --git a/fs/afs/mntpt.c b/fs/afs/mntpt.c
index 99fd13500a97..4238bb63931d 100644
--- a/fs/afs/mntpt.c
+++ b/fs/afs/mntpt.c
@@ -130,6 +130,12 @@ static struct vfsmount *afs_mntpt_do_automount(struct dentry *mntpt)
goto error_no_page;
}

+ if (PageError(page)) {
+ put_page(page);
+ ret = afs_bad(AFS_FS_I(d_inode(mntpt)), afs_file_error_mntpt);
+ goto error_no_page;
+ }
+
ret = -EIO;
if (PageError(page))
goto error;
diff --git a/fs/afs/rxrpc.c b/fs/afs/rxrpc.c
index 6138c12c74a3..748b37b130a2 100644
--- a/fs/afs/rxrpc.c
+++ b/fs/afs/rxrpc.c
@@ -845,7 +845,7 @@ int afs_extract_data(struct afs_call *call, bool want_more)
break;
case AFS_CALL_COMPLETE:
kdebug("prem complete %d", call->error);
- return -EIO;
+ return afs_io_error(call, afs_io_error_extract);
default:
break;
}
diff --git a/fs/afs/server.c b/fs/afs/server.c
index 1d329e6981d5..b7874bf9402e 100644
--- a/fs/afs/server.c
+++ b/fs/afs/server.c
@@ -274,7 +274,7 @@ static struct afs_addr_list *afs_vl_lookup_addrs(struct afs_cell *cell,
case -ECONNREFUSED:
break;
default:
- ac.error = -EIO;
+ ac.error = afs_io_error(NULL, afs_io_error_vl_lookup_fail);
goto error;
}
}
@@ -560,7 +560,7 @@ static bool afs_do_probe_fileserver(struct afs_fs_cursor *fc)
case -ETIME:
break;
default:
- fc->ac.error = -EIO;
+ fc->ac.error = afs_io_error(NULL, afs_io_error_fs_probe_fail);
goto error;
}
}
diff --git a/fs/afs/volume.c b/fs/afs/volume.c
index 3037bd01f617..7bd4fc784c38 100644
--- a/fs/afs/volume.c
+++ b/fs/afs/volume.c
@@ -116,7 +116,7 @@ static struct afs_vldb_entry *afs_vl_lookup_vldb(struct afs_cell *cell,
case -ECONNREFUSED:
break;
default:
- ac.error = -EIO;
+ ac.error = afs_io_error(NULL, afs_io_error_vl_lookup_fail);
goto error;
}
}
diff --git a/fs/afs/write.c b/fs/afs/write.c
index 46a3a911c682..1dfca4b722da 100644
--- a/fs/afs/write.c
+++ b/fs/afs/write.c
@@ -537,6 +537,7 @@ static int afs_write_back_from_locked_page(struct address_space *mapping,
case -ENOENT:
case -ENOMEDIUM:
case -ENXIO:
+ trace_afs_file_error(vnode, ret, afs_file_error_writeback_fail);
afs_kill_pages(mapping, first, last);
mapping_set_error(mapping, ret);
break;
diff --git a/include/trace/events/afs.h b/include/trace/events/afs.h
index 9c44245987b3..d9c99c423fd9 100644
--- a/include/trace/events/afs.h
+++ b/include/trace/events/afs.h
@@ -103,6 +103,24 @@ enum afs_eproto_cause {
afs_eproto_yvl_vlendpt_type,
};

+enum afs_io_error {
+ afs_io_error_cm_reply,
+ afs_io_error_extract,
+ afs_io_error_fs_probe_fail,
+ afs_io_error_vl_lookup_fail,
+};
+
+enum afs_file_error {
+ afs_file_error_dir_bad_magic,
+ afs_file_error_dir_big,
+ afs_file_error_dir_missing_page,
+ afs_file_error_dir_over_end,
+ afs_file_error_dir_small,
+ afs_file_error_dir_unmarked_ext,
+ afs_file_error_mntpt,
+ afs_file_error_writeback_fail,
+};
+
#endif /* end __AFS_DECLARE_TRACE_ENUMS_ONCE_ONLY */

/*
@@ -183,6 +201,21 @@ enum afs_eproto_cause {
EM(afs_eproto_yvl_vlendpt6_len, "YVL.VlEnd6Len") \
E_(afs_eproto_yvl_vlendpt_type, "YVL.VlEndType")

+#define afs_io_errors \
+ EM(afs_io_error_cm_reply, "CM_REPLY") \
+ EM(afs_io_error_extract, "EXTRACT") \
+ EM(afs_io_error_fs_probe_fail, "FS_PROBE_FAIL") \
+ E_(afs_io_error_vl_lookup_fail, "VL_LOOKUP_FAIL")
+
+#define afs_file_errors \
+ EM(afs_file_error_dir_bad_magic, "DIR_BAD_MAGIC") \
+ EM(afs_file_error_dir_big, "DIR_BIG") \
+ EM(afs_file_error_dir_missing_page, "DIR_MISSING_PAGE") \
+ EM(afs_file_error_dir_over_end, "DIR_ENT_OVER_END") \
+ EM(afs_file_error_dir_small, "DIR_SMALL") \
+ EM(afs_file_error_dir_unmarked_ext, "DIR_UNMARKED_EXT") \
+ EM(afs_file_error_mntpt, "MNTPT_READ_FAILED") \
+ E_(afs_file_error_writeback_fail, "WRITEBACK_FAILED")

/*
* Export enum symbols via userspace.
@@ -197,6 +230,9 @@ afs_fs_operations;
afs_vl_operations;
afs_edit_dir_ops;
afs_edit_dir_reasons;
+afs_eproto_causes;
+afs_io_errors;
+afs_file_errors;

/*
* Now redefine the EM() and E_() macros to map the enums to the strings that
@@ -600,6 +636,51 @@ TRACE_EVENT(afs_protocol_error,
__print_symbolic(__entry->cause, afs_eproto_causes))
);

+TRACE_EVENT(afs_io_error,
+ TP_PROTO(unsigned int call, int error, enum afs_io_error where),
+
+ TP_ARGS(call, error, where),
+
+ TP_STRUCT__entry(
+ __field(unsigned int, call )
+ __field(int, error )
+ __field(enum afs_io_error, where )
+ ),
+
+ TP_fast_assign(
+ __entry->call = call;
+ __entry->error = error;
+ __entry->where = where;
+ ),
+
+ TP_printk("c=%08x r=%d %s",
+ __entry->call, __entry->error,
+ __print_symbolic(__entry->where, afs_io_errors))
+ );
+
+TRACE_EVENT(afs_file_error,
+ TP_PROTO(struct afs_vnode *vnode, int error, enum afs_file_error where),
+
+ TP_ARGS(vnode, error, where),
+
+ TP_STRUCT__entry(
+ __field_struct(struct afs_fid, fid )
+ __field(int, error )
+ __field(enum afs_file_error, where )
+ ),
+
+ TP_fast_assign(
+ __entry->fid = vnode->fid;
+ __entry->error = error;
+ __entry->where = where;
+ ),
+
+ TP_printk("%x:%x:%x r=%d %s",
+ __entry->fid.vid, __entry->fid.vnode, __entry->fid.unique,
+ __entry->error,
+ __print_symbolic(__entry->where, afs_file_errors))
+ );
+
TRACE_EVENT(afs_cm_no_server,
TP_PROTO(struct afs_call *call, struct sockaddr_rxrpc *srx),