cachefiles: Make some tracepoint adjustments

Make some adjustments to tracepoints to make the tracing a bit more
followable:

 (1) Standardise on displaying the backing inode number as "B=<hex>" with
     no leading zeros.

 (2) Make the cachefiles_lookup tracepoint log the directory inode number
     as well as the looked-up inode number.

 (3) Add a cachefiles_lookup tracepoint into cachefiles_get_directory() to
     log directory lookup.

 (4) Add a new cachefiles_mkdir tracepoint and use that to log a successful
     mkdir from cachefiles_get_directory().

 (5) Make the cachefiles_unlink and cachefiles_rename tracepoints log the
     inode number of the affected file/dir rather than dentry struct
     pointers.

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
Link: https://lore.kernel.org/r/164251403694.3435901.9797725381831316715.stgit@warthog.procyon.org.uk/

diff --git a/fs/cachefiles/namei.c b/fs/cachefiles/namei.c
index 9bd692870617c4cd108845aae0b1891f94584323..52c9f0864a877901cc651f86c6cd7de27844fd69 100644 (file)
--- a/fs/cachefiles/namei.c
+++ b/fs/cachefiles/namei.c
@@ -101,6 +101,7 @@ retry:
                subdir = lookup_one_len(dirname, dir, strlen(dirname));
        else
                subdir = ERR_PTR(ret);
+       trace_cachefiles_lookup(NULL, dir, subdir);
        if (IS_ERR(subdir)) {
                trace_cachefiles_vfs_error(NULL, d_backing_inode(dir),
                                           PTR_ERR(subdir),
@@ -135,6 +136,7 @@ retry:
                                                   cachefiles_trace_mkdir_error);
                        goto mkdir_error;
                }
+               trace_cachefiles_mkdir(dir, subdir);
 
                if (unlikely(d_unhashed(subdir))) {
                        cachefiles_put_directory(subdir);
@@ -233,7 +235,7 @@ static int cachefiles_unlink(struct cachefiles_cache *cache,
        };
        int ret;
 
-       trace_cachefiles_unlink(object, dentry, why);
+       trace_cachefiles_unlink(object, d_inode(dentry)->i_ino, why);
        ret = security_path_unlink(&path, dentry);
        if (ret < 0) {
                cachefiles_io_error(cache, "Unlink security error");
@@ -386,7 +388,7 @@ try_again:
                        .new_dir        = d_inode(cache->graveyard),
                        .new_dentry     = grave,
                };
-               trace_cachefiles_rename(object, rep, grave, why);
+               trace_cachefiles_rename(object, d_inode(rep)->i_ino, why);
                ret = cachefiles_inject_read_error();
                if (ret == 0)
                        ret = vfs_rename(&rd);
@@ -617,7 +619,7 @@ bool cachefiles_look_up_object(struct cachefiles_object *object)
                                                  object->d_name_len);
        else
                dentry = ERR_PTR(ret);
-       trace_cachefiles_lookup(object, dentry);
+       trace_cachefiles_lookup(object, fan, dentry);
        if (IS_ERR(dentry)) {
                if (dentry == ERR_PTR(-ENOENT))
                        goto new_file;

diff --git a/include/trace/events/cachefiles.h b/include/trace/events/cachefiles.h
index 1172529b5b4945367c9487f8e2c7932bf404caea..093c4acb7a3a602475bd75f6eca0748dcea76937 100644 (file)
--- a/include/trace/events/cachefiles.h
+++ b/include/trace/events/cachefiles.h
@@ -233,25 +233,48 @@ TRACE_EVENT(cachefiles_ref,
 
 TRACE_EVENT(cachefiles_lookup,
            TP_PROTO(struct cachefiles_object *obj,
+                    struct dentry *dir,
                     struct dentry *de),
 
-           TP_ARGS(obj, de),
+           TP_ARGS(obj, dir, de),
 
            TP_STRUCT__entry(
                    __field(unsigned int,               obj     )
                    __field(short,                      error   )
+                   __field(unsigned long,              dino    )
                    __field(unsigned long,              ino     )
                             ),
 
            TP_fast_assign(
-                   __entry->obj        = obj->debug_id;
+                   __entry->obj        = obj ? obj->debug_id : 0;
+                   __entry->dino       = d_backing_inode(dir)->i_ino;
                    __entry->ino        = (!IS_ERR(de) && d_backing_inode(de) ?
                                           d_backing_inode(de)->i_ino : 0);
                    __entry->error      = IS_ERR(de) ? PTR_ERR(de) : 0;
                           ),
 
-           TP_printk("o=%08x i=%lx e=%d",
-                     __entry->obj, __entry->ino, __entry->error)
+           TP_printk("o=%08x dB=%lx B=%lx e=%d",
+                     __entry->obj, __entry->dino, __entry->ino, __entry->error)
+           );
+
+TRACE_EVENT(cachefiles_mkdir,
+           TP_PROTO(struct dentry *dir, struct dentry *subdir),
+
+           TP_ARGS(dir, subdir),
+
+           TP_STRUCT__entry(
+                   __field(unsigned int,                       dir     )
+                   __field(unsigned int,                       subdir  )
+                            ),
+
+           TP_fast_assign(
+                   __entry->dir        = d_backing_inode(dir)->i_ino;
+                   __entry->subdir     = d_backing_inode(subdir)->i_ino;
+                          ),
+
+           TP_printk("dB=%x sB=%x",
+                     __entry->dir,
+                     __entry->subdir)
            );
 
 TRACE_EVENT(cachefiles_tmpfile,
@@ -269,7 +292,7 @@ TRACE_EVENT(cachefiles_tmpfile,
                    __entry->backer     = backer->i_ino;
                           ),
 
-           TP_printk("o=%08x b=%08x",
+           TP_printk("o=%08x B=%x",
                      __entry->obj,
                      __entry->backer)
            );
@@ -289,61 +312,58 @@ TRACE_EVENT(cachefiles_link,
                    __entry->backer     = backer->i_ino;
                           ),
 
-           TP_printk("o=%08x b=%08x",
+           TP_printk("o=%08x B=%x",
                      __entry->obj,
                      __entry->backer)
            );
 
 TRACE_EVENT(cachefiles_unlink,
            TP_PROTO(struct cachefiles_object *obj,
-                    struct dentry *de,
+                    ino_t ino,
                     enum fscache_why_object_killed why),
 
-           TP_ARGS(obj, de, why),
+           TP_ARGS(obj, ino, why),
 
            /* Note that obj may be NULL */
            TP_STRUCT__entry(
                    __field(unsigned int,               obj             )
-                   __field(struct dentry *,            de              )
+                   __field(unsigned int,               ino             )
                    __field(enum fscache_why_object_killed, why         )
                             ),
 
            TP_fast_assign(
                    __entry->obj        = obj ? obj->debug_id : UINT_MAX;
-                   __entry->de         = de;
+                   __entry->ino        = ino;
                    __entry->why        = why;
                           ),
 
-           TP_printk("o=%08x d=%p w=%s",
-                     __entry->obj, __entry->de,
+           TP_printk("o=%08x B=%x w=%s",
+                     __entry->obj, __entry->ino,
                      __print_symbolic(__entry->why, cachefiles_obj_kill_traces))
            );
 
 TRACE_EVENT(cachefiles_rename,
            TP_PROTO(struct cachefiles_object *obj,
-                    struct dentry *de,
-                    struct dentry *to,
+                    ino_t ino,
                     enum fscache_why_object_killed why),
 
-           TP_ARGS(obj, de, to, why),
+           TP_ARGS(obj, ino, why),
 
            /* Note that obj may be NULL */
            TP_STRUCT__entry(
                    __field(unsigned int,               obj             )
-                   __field(struct dentry *,            de              )
-                   __field(struct dentry *,            to              )
+                   __field(unsigned int,               ino             )
                    __field(enum fscache_why_object_killed, why         )
                             ),
 
            TP_fast_assign(
                    __entry->obj        = obj ? obj->debug_id : UINT_MAX;
-                   __entry->de         = de;
-                   __entry->to         = to;
+                   __entry->ino        = ino;
                    __entry->why        = why;
                           ),
 
-           TP_printk("o=%08x d=%p t=%p w=%s",
-                     __entry->obj, __entry->de, __entry->to,
+           TP_printk("o=%08x B=%x w=%s",
+                     __entry->obj, __entry->ino,
                      __print_symbolic(__entry->why, cachefiles_obj_kill_traces))
            );
 
@@ -370,7 +390,7 @@ TRACE_EVENT(cachefiles_coherency,
                    __entry->ino        = ino;
                           ),
 
-           TP_printk("o=%08x %s i=%llx c=%u",
+           TP_printk("o=%08x %s B=%llx c=%u",
                      __entry->obj,
                      __print_symbolic(__entry->why, cachefiles_coherency_traces),
                      __entry->ino,
@@ -397,7 +417,7 @@ TRACE_EVENT(cachefiles_vol_coherency,
                    __entry->ino        = ino;
                           ),
 
-           TP_printk("V=%08x %s i=%llx",
+           TP_printk("V=%08x %s B=%llx",
                      __entry->vol,
                      __print_symbolic(__entry->why, cachefiles_coherency_traces),
                      __entry->ino)
@@ -435,7 +455,7 @@ TRACE_EVENT(cachefiles_prep_read,
                    __entry->cache_inode = cache_inode;
                           ),
 
-           TP_printk("R=%08x[%u] %s %s f=%02x s=%llx %zx ni=%x b=%x",
+           TP_printk("R=%08x[%u] %s %s f=%02x s=%llx %zx ni=%x B=%x",
                      __entry->rreq, __entry->index,
                      __print_symbolic(__entry->source, netfs_sreq_sources),
                      __print_symbolic(__entry->why, cachefiles_prepare_read_traces),
@@ -466,7 +486,7 @@ TRACE_EVENT(cachefiles_read,
                    __entry->len        = len;
                           ),
 
-           TP_printk("o=%08x b=%08x s=%llx l=%zx",
+           TP_printk("o=%08x B=%x s=%llx l=%zx",
                      __entry->obj,
                      __entry->backer,
                      __entry->start,
@@ -495,7 +515,7 @@ TRACE_EVENT(cachefiles_write,
                    __entry->len        = len;
                           ),
 
-           TP_printk("o=%08x b=%08x s=%llx l=%zx",
+           TP_printk("o=%08x B=%x s=%llx l=%zx",
                      __entry->obj,
                      __entry->backer,
                      __entry->start,
@@ -524,7 +544,7 @@ TRACE_EVENT(cachefiles_trunc,
                    __entry->why        = why;
                           ),
 
-           TP_printk("o=%08x b=%08x %s l=%llx->%llx",
+           TP_printk("o=%08x B=%x %s l=%llx->%llx",
                      __entry->obj,
                      __entry->backer,
                      __print_symbolic(__entry->why, cachefiles_trunc_traces),
@@ -549,7 +569,7 @@ TRACE_EVENT(cachefiles_mark_active,
                    __entry->inode      = inode->i_ino;
                           ),
 
-           TP_printk("o=%08x i=%lx",
+           TP_printk("o=%08x B=%lx",
                      __entry->obj, __entry->inode)
            );
 
@@ -570,7 +590,7 @@ TRACE_EVENT(cachefiles_mark_inactive,
                    __entry->inode      = inode->i_ino;
                           ),
 
-           TP_printk("o=%08x i=%lx",
+           TP_printk("o=%08x B=%lx",
                      __entry->obj, __entry->inode)
            );
 
@@ -594,7 +614,7 @@ TRACE_EVENT(cachefiles_vfs_error,
                    __entry->where      = where;
                           ),
 
-           TP_printk("o=%08x b=%08x %s e=%d",
+           TP_printk("o=%08x B=%x %s e=%d",
                      __entry->obj,
                      __entry->backer,
                      __print_symbolic(__entry->where, cachefiles_error_traces),
@@ -621,7 +641,7 @@ TRACE_EVENT(cachefiles_io_error,
                    __entry->where      = where;
                           ),
 
-           TP_printk("o=%08x b=%08x %s e=%d",
+           TP_printk("o=%08x B=%x %s e=%d",
                      __entry->obj,
                      __entry->backer,
                      __print_symbolic(__entry->where, cachefiles_error_traces),