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authorDavid Howells <dhowells@redhat.com>2020-02-10 13:00:22 +0300
committerDavid Howells <dhowells@redhat.com>2021-08-27 15:24:46 +0300
commit2908f5e101e3fb1d478cff1c556966e1af816641 (patch)
tree3bfc51416024a1b1f2043872a00d6a36d45625b3 /fs/fscache/cookie.c
parent185981958c920dd28e35cba7cda69486c8551781 (diff)
downloadlinux-2908f5e101e3fb1d478cff1c556966e1af816641.tar.xz
fscache: Add a cookie debug ID and use that in traces
Add a cookie debug ID and use that in traces and in procfiles rather than displaying the (hashed) pointer to the cookie. This is easier to correlate and we don't lose anything when interpreting oops output since that shows unhashed addresses and registers that aren't comparable to the hashed values. Changes: ver #2: - Fix the fscache_op tracepoint to handle a NULL cookie pointer. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@redhat.com> cc: linux-cachefs@redhat.com Link: https://lore.kernel.org/r/158861210988.340223.11688464116498247790.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/159465769844.1376105.14119502774019865432.stgit@warthog.procyon.org.uk/ Link: https://lore.kernel.org/r/160588459097.3465195.1273313637721852165.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/162431193544.2908479.17556704572948300790.stgit@warthog.procyon.org.uk/
Diffstat (limited to 'fs/fscache/cookie.c')
-rw-r--r--fs/fscache/cookie.c29
1 files changed, 20 insertions, 9 deletions
diff --git a/fs/fscache/cookie.c b/fs/fscache/cookie.c
index 751bc5b1cddf..f2be98d2c64d 100644
--- a/fs/fscache/cookie.c
+++ b/fs/fscache/cookie.c
@@ -29,21 +29,29 @@ static int fscache_attach_object(struct fscache_cookie *cookie,
static void fscache_print_cookie(struct fscache_cookie *cookie, char prefix)
{
- struct hlist_node *object;
+ struct fscache_object *object;
+ struct hlist_node *o;
const u8 *k;
unsigned loop;
- pr_err("%c-cookie c=%p [p=%p fl=%lx nc=%u na=%u]\n",
- prefix, cookie, cookie->parent, cookie->flags,
+ pr_err("%c-cookie c=%08x [p=%08x fl=%lx nc=%u na=%u]\n",
+ prefix,
+ cookie->debug_id,
+ cookie->parent ? cookie->parent->debug_id : 0,
+ cookie->flags,
atomic_read(&cookie->n_children),
atomic_read(&cookie->n_active));
- pr_err("%c-cookie d=%p n=%p\n",
- prefix, cookie->def, cookie->netfs_data);
+ pr_err("%c-cookie d=%p{%s} n=%p\n",
+ prefix,
+ cookie->def,
+ cookie->def ? cookie->def->name : "?",
+ cookie->netfs_data);
- object = READ_ONCE(cookie->backing_objects.first);
- if (object)
- pr_err("%c-cookie o=%p\n",
- prefix, hlist_entry(object, struct fscache_object, cookie_link));
+ o = READ_ONCE(cookie->backing_objects.first);
+ if (o) {
+ object = hlist_entry(o, struct fscache_object, cookie_link);
+ pr_err("%c-cookie o=%u\n", prefix, object->debug_id);
+ }
pr_err("%c-key=[%u] '", prefix, cookie->key_len);
k = (cookie->key_len <= sizeof(cookie->inline_key)) ?
@@ -129,6 +137,8 @@ static long fscache_compare_cookie(const struct fscache_cookie *a,
return memcmp(ka, kb, a->key_len);
}
+static atomic_t fscache_cookie_debug_id = ATOMIC_INIT(1);
+
/*
* Allocate a cookie.
*/
@@ -163,6 +173,7 @@ struct fscache_cookie *fscache_alloc_cookie(
atomic_set(&cookie->usage, 1);
atomic_set(&cookie->n_children, 0);
+ cookie->debug_id = atomic_inc_return(&fscache_cookie_debug_id);
/* We keep the active count elevated until relinquishment to prevent an
* attempt to wake up every time the object operations queue quiesces.