[PATCH 18/67] cachefiles: Remove tree of active files and use S_CACHE_FILE inode flag

David Howells
2021-10-18T14:55:39Z

Remove the tree of active dentries from the cachefiles_cache struct and
instead set a flag, S_CACHE_FILE, on the backing inode to indicate that
this file is in use by the kernel so as to ward off other kernel users.

This simplifies the code a lot and also prevents two overlain caches from
fighting with each other.

Signed-off-by: David Howells <dhowells@redhat.com>
---

fs/cachefiles/daemon.c | 4
fs/cachefiles/interface.c | 20 --
fs/cachefiles/internal.h | 10 -
fs/cachefiles/namei.c | 378 +++++++------------------------------
include/trace/events/cachefiles.h | 54 -----
5 files changed, 79 insertions(+), 387 deletions(-)

diff --git a/fs/cachefiles/daemon.c b/fs/cachefiles/daemon.c
index 752c1e43416f..8a937d6d5e22 100644
--- a/fs/cachefiles/daemon.c
+++ b/fs/cachefiles/daemon.c
@@ -102,8 +102,6 @@ static int cachefiles_daemon_open(struct inode *inode, struct file *file)
}

mutex_init(&cache->daemon_mutex);
- cache->active_nodes = RB_ROOT;
- rwlock_init(&cache->active_lock);
init_waitqueue_head(&cache->daemon_pollwq);

/* set default caching limits
@@ -138,8 +136,6 @@ static int cachefiles_daemon_release(struct inode *inode, struct file *file)

cachefiles_daemon_unbind(cache);

- ASSERT(!cache->active_nodes.rb_node);
-
/* clean up the control file interface */
cache->cachefilesd = NULL;
file->private_data = NULL;
diff --git a/fs/cachefiles/interface.c b/fs/cachefiles/interface.c
index a84adf638737..bc28bb6c7ef5 100644
--- a/fs/cachefiles/interface.c
+++ b/fs/cachefiles/interface.c
@@ -36,7 +36,6 @@ static struct fscache_object *cachefiles_alloc_object(

ASSERTCMP(object->backer, ==, NULL);

- BUG_ON(test_bit(CACHEFILES_OBJECT_ACTIVE, &object->flags));
atomic_set(&object->usage, 1);

fscache_object_init(&object->fscache, cookie, &cache->cache);
@@ -74,7 +73,6 @@ static struct fscache_object *cachefiles_alloc_object(
nomem_key:
kfree(buffer);
nomem_buffer:
- BUG_ON(test_bit(CACHEFILES_OBJECT_ACTIVE, &object->flags));
kmem_cache_free(cachefiles_object_jar, object);
fscache_object_destroyed(&cache->cache);
nomem_object:
@@ -190,8 +188,6 @@ static void cachefiles_drop_object(struct fscache_object *_object)
struct cachefiles_object *object;
struct cachefiles_cache *cache;
const struct cred *saved_cred;
- struct inode *inode;
- blkcnt_t i_blocks = 0;

ASSERT(_object);

@@ -218,10 +214,6 @@ static void cachefiles_drop_object(struct fscache_object *_object)
_object != cache->cache.fsdef
) {
_debug("- retire object OBJ%x", object->fscache.debug_id);
- inode = d_backing_inode(object->dentry);
- if (inode)
- i_blocks = inode->i_blocks;
-
cachefiles_begin_secure(cache, &saved_cred);
cachefiles_delete_object(cache, object);
cachefiles_end_secure(cache, saved_cred);
@@ -231,14 +223,11 @@ static void cachefiles_drop_object(struct fscache_object *_object)
if (object->backer != object->dentry)
dput(object->backer);
object->backer = NULL;
- }

- /* note that the object is now inactive */
- if (test_bit(CACHEFILES_OBJECT_ACTIVE, &object->flags))
- cachefiles_mark_object_inactive(cache, object, i_blocks);
-
- dput(object->dentry);
- object->dentry = NULL;
+ cachefiles_unmark_inode_in_use(object, object->dentry);
+ dput(object->dentry);
+ object->dentry = NULL;
+ }

_leave("");
}
@@ -274,7 +263,6 @@ void cachefiles_put_object(struct fscache_object *_object,
if (u == 0) {
_debug("- kill object OBJ%x", object->fscache.debug_id);

- ASSERT(!test_bit(CACHEFILES_OBJECT_ACTIVE, &object->flags));
ASSERTCMP(object->fscache.parent, ==, NULL);
ASSERTCMP(object->backer, ==, NULL);
ASSERTCMP(object->dentry, ==, NULL);
diff --git a/fs/cachefiles/internal.h b/fs/cachefiles/internal.h
index fbe43e1aa517..0515add2b7e8 100644
--- a/fs/cachefiles/internal.h
+++ b/fs/cachefiles/internal.h
@@ -38,12 +38,9 @@ struct cachefiles_object {
struct dentry *dentry; /* the file/dir representing this object */
struct dentry *backer; /* backing file */
loff_t i_size; /* object size */
- unsigned long flags;
-#define CACHEFILES_OBJECT_ACTIVE 0 /* T if marked active */
atomic_t usage; /* object usage count */
uint8_t type; /* object type */
uint8_t new; /* T if object new */
- struct rb_node active_node; /* link in active tree (dentry is key) */
};

extern struct kmem_cache *cachefiles_object_jar;
@@ -59,8 +56,6 @@ struct cachefiles_cache {
const struct cred *cache_cred; /* security override for accessing cache */
struct mutex daemon_mutex; /* command serialisation mutex */
wait_queue_head_t daemon_pollwq; /* poll waitqueue for daemon */
- struct rb_root active_nodes; /* active nodes (can't be culled) */
- rwlock_t active_lock; /* lock for active_nodes */
atomic_t gravecounter; /* graveyard uniquifier */
atomic_t f_released; /* number of objects released lately */
atomic_long_t b_released; /* number of blocks released lately */
@@ -129,9 +124,8 @@ extern char *cachefiles_cook_key(const u8 *raw, int keylen, uint8_t type);
/*
* namei.c
*/
-extern void cachefiles_mark_object_inactive(struct cachefiles_cache *cache,
- struct cachefiles_object *object,
- blkcnt_t i_blocks);
+extern void cachefiles_unmark_inode_in_use(struct cachefiles_object *object,
+ struct dentry *dentry);
extern int cachefiles_delete_object(struct cachefiles_cache *cache,
struct cachefiles_object *object);
extern int cachefiles_walk_to_object(struct cachefiles_object *parent,
diff --git a/fs/cachefiles/namei.c b/fs/cachefiles/namei.c
index 548aac544293..4bd31be3be30 100644
--- a/fs/cachefiles/namei.c
+++ b/fs/cachefiles/namei.c
@@ -21,251 +21,51 @@
#define CACHEFILES_KEYBUF_SIZE 512

/*
- * dump debugging info about an object
+ * Mark the backing file as being a cache file if it's not already in use so.
*/
-static noinline
-void __cachefiles_printk_object(struct cachefiles_object *object,
- const char *prefix)
+static bool cachefiles_mark_inode_in_use(struct cachefiles_object *object,
+ struct dentry *dentry)
{
- struct fscache_cookie *cookie;
- const u8 *k;
- unsigned loop;
-
- pr_err("%sobject: OBJ%x\n", prefix, object->fscache.debug_id);
- pr_err("%sobjstate=%s fl=%lx wbusy=%x ev=%lx[%lx]\n",
- prefix, object->fscache.state->name,
- object->fscache.flags, work_busy(&object->fscache.work),
- object->fscache.events, object->fscache.event_mask);
- pr_err("%sops=%u\n",
- prefix, object->fscache.n_ops);
- pr_err("%sparent=%x\n",
- prefix, object->fscache.parent ? object->fscache.parent->debug_id : 0);
-
- spin_lock(&object->fscache.lock);
- cookie = object->fscache.cookie;
- if (cookie) {
- pr_err("%scookie=%x [pr=%x fl=%lx]\n",
- prefix,
- cookie->debug_id,
- cookie->parent ? cookie->parent->debug_id : 0,
- cookie->flags);
- pr_err("%skey=[%u] '", prefix, cookie->key_len);
- k = (cookie->key_len <= sizeof(cookie->inline_key)) ?
- cookie->inline_key : cookie->key;
- for (loop = 0; loop < cookie->key_len; loop++)
- pr_cont("%02x", k[loop]);
- pr_cont("'\n");
- } else {
- pr_err("%scookie=NULL\n", prefix);
- }
- spin_unlock(&object->fscache.lock);
-}
-
-/*
- * dump debugging info about a pair of objects
- */
-static noinline void cachefiles_printk_object(struct cachefiles_object *object,
- struct cachefiles_object *xobject)
-{
- if (object)
- __cachefiles_printk_object(object, "");
- if (xobject)
- __cachefiles_printk_object(xobject, "x");
-}
-
-/*
- * mark the owner of a dentry, if there is one, to indicate that that dentry
- * has been preemptively deleted
- * - the caller must hold the i_mutex on the dentry's parent as required to
- * call vfs_unlink(), vfs_rmdir() or vfs_rename()
- */
-static void cachefiles_mark_object_buried(struct cachefiles_cache *cache,
- struct dentry *dentry,
- enum fscache_why_object_killed why)
-{
- struct cachefiles_object *object;
- struct rb_node *p;
-
- _enter(",'%pd'", dentry);
-
- write_lock(&cache->active_lock);
-
- p = cache->active_nodes.rb_node;
- while (p) {
- object = rb_entry(p, struct cachefiles_object, active_node);
- if (object->dentry > dentry)
- p = p->rb_left;
- else if (object->dentry < dentry)
- p = p->rb_right;
- else
- goto found_dentry;
- }
-
- write_unlock(&cache->active_lock);
- trace_cachefiles_mark_buried(NULL, dentry, why);
- _leave(" [no owner]");
- return;
+ struct inode *inode = d_backing_inode(dentry);
+ bool can_use = false;

- /* found the dentry for */
-found_dentry:
- kdebug("preemptive burial: OBJ%x [%s] %pd",
- object->fscache.debug_id,
- object->fscache.state->name,
- dentry);
+ _enter(",%x", object->fscache.debug_id);

- trace_cachefiles_mark_buried(object, dentry, why);
+ inode_lock(inode);

- if (fscache_object_is_live(&object->fscache)) {
- pr_err("\n");
- pr_err("Error: Can't preemptively bury live object\n");
- cachefiles_printk_object(object, NULL);
+ if (!(inode->i_flags & S_KERNEL_FILE)) {
+ inode->i_flags |= S_KERNEL_FILE;
+ trace_cachefiles_mark_active(object, dentry);
+ can_use = true;
} else {
- if (why != FSCACHE_OBJECT_IS_STALE)
- fscache_object_mark_killed(&object->fscache, why);
+ pr_notice("cachefiles: Inode already in use: %pd\n", dentry);
}

- write_unlock(&cache->active_lock);
- _leave(" [owner marked]");
+ inode_unlock(inode);
+ return can_use;
}

/*
- * record the fact that an object is now active
+ * Unmark a backing inode.
*/
-static int cachefiles_mark_object_active(struct cachefiles_cache *cache,
- struct cachefiles_object *object)
+void cachefiles_unmark_inode_in_use(struct cachefiles_object *object,
+ struct dentry *dentry)
{
- struct cachefiles_object *xobject;
- struct rb_node **_p, *_parent = NULL;
- struct dentry *dentry;
-
- _enter(",%x", object->fscache.debug_id);
-
-try_again:
- write_lock(&cache->active_lock);
-
- dentry = object->dentry;
- trace_cachefiles_mark_active(object, dentry);
-
- if (test_and_set_bit(CACHEFILES_OBJECT_ACTIVE, &object->flags)) {
- pr_err("Error: Object already active\n");
- cachefiles_printk_object(object, NULL);
- BUG();
- }
-
- _p = &cache->active_nodes.rb_node;
- while (*_p) {
- _parent = *_p;
- xobject = rb_entry(_parent,
- struct cachefiles_object, active_node);
-
- ASSERT(xobject != object);
-
- if (xobject->dentry > dentry)
- _p = &(*_p)->rb_left;
- else if (xobject->dentry < dentry)
- _p = &(*_p)->rb_right;
- else
- goto wait_for_old_object;
- }
-
- rb_link_node(&object->active_node, _parent, _p);
- rb_insert_color(&object->active_node, &cache->active_nodes);
-
- write_unlock(&cache->active_lock);
- _leave(" = 0");
- return 0;
-
- /* an old object from a previous incarnation is hogging the slot - we
- * need to wait for it to be destroyed */
-wait_for_old_object:
- trace_cachefiles_wait_active(object, dentry, xobject);
- clear_bit(CACHEFILES_OBJECT_ACTIVE, &object->flags);
-
- if (fscache_object_is_live(&xobject->fscache)) {
- pr_err("\n");
- pr_err("Error: Unexpected object collision\n");
- cachefiles_printk_object(object, xobject);
- }
- atomic_inc(&xobject->usage);
- write_unlock(&cache->active_lock);
-
- if (test_bit(CACHEFILES_OBJECT_ACTIVE, &xobject->flags)) {
- wait_queue_head_t *wq;
-
- signed long timeout = 60 * HZ;
- wait_queue_entry_t wait;
- bool requeue;
-
- /* if the object we're waiting for is queued for processing,
- * then just put ourselves on the queue behind it */
- if (work_pending(&xobject->fscache.work)) {
- _debug("queue OBJ%x behind OBJ%x immediately",
- object->fscache.debug_id,
- xobject->fscache.debug_id);
- goto requeue;
- }
-
- /* otherwise we sleep until either the object we're waiting for
- * is done, or the fscache_object is congested */
- wq = bit_waitqueue(&xobject->flags, CACHEFILES_OBJECT_ACTIVE);
- init_wait(&wait);
- requeue = false;
- do {
- prepare_to_wait(wq, &wait, TASK_UNINTERRUPTIBLE);
- if (!test_bit(CACHEFILES_OBJECT_ACTIVE, &xobject->flags))
- break;
-
- requeue = fscache_object_sleep_till_congested(&timeout);
- } while (timeout > 0 && !requeue);
- finish_wait(wq, &wait);
-
- if (requeue &&
- test_bit(CACHEFILES_OBJECT_ACTIVE, &xobject->flags)) {
- _debug("queue OBJ%x behind OBJ%x after wait",
- object->fscache.debug_id,
- xobject->fscache.debug_id);
- goto requeue;
- }
-
- if (timeout <= 0) {
- pr_err("\n");
- pr_err("Error: Overlong wait for old active object to go away\n");
- cachefiles_printk_object(object, xobject);
- goto requeue;
- }
- }
-
- ASSERT(!test_bit(CACHEFILES_OBJECT_ACTIVE, &xobject->flags));
-
- cache->cache.ops->put_object(&xobject->fscache,
- (enum fscache_obj_ref_trace)cachefiles_obj_put_wait_retry);
- goto try_again;
+ struct inode *inode = d_backing_inode(dentry);

-requeue:
- cache->cache.ops->put_object(&xobject->fscache,
- (enum fscache_obj_ref_trace)cachefiles_obj_put_wait_timeo);
- _leave(" = -ETIMEDOUT");
- return -ETIMEDOUT;
+ inode_lock(inode);
+ inode->i_flags &= ~S_KERNEL_FILE;
+ inode_unlock(inode);
+ trace_cachefiles_mark_inactive(object, dentry, inode);
}

/*
* Mark an object as being inactive.
*/
-void cachefiles_mark_object_inactive(struct cachefiles_cache *cache,
- struct cachefiles_object *object,
- blkcnt_t i_blocks)
+static void cachefiles_mark_object_inactive(struct cachefiles_cache *cache,
+ struct cachefiles_object *object)
{
- struct dentry *dentry = object->dentry;
- struct inode *inode = d_backing_inode(dentry);
-
- trace_cachefiles_mark_inactive(object, dentry, inode);
-
- write_lock(&cache->active_lock);
- rb_erase(&object->active_node, &cache->active_nodes);
- clear_bit(CACHEFILES_OBJECT_ACTIVE, &object->flags);
- write_unlock(&cache->active_lock);
-
- wake_up_bit(&object->flags, CACHEFILES_OBJECT_ACTIVE);
+ blkcnt_t i_blocks = d_backing_inode(object->dentry)->i_blocks;

/* This object can now be culled, so we need to let the daemon know
* that there is something it can remove if it needs to.
@@ -286,7 +86,6 @@ static int cachefiles_bury_object(struct cachefiles_cache *cache,
struct cachefiles_object *object,
struct dentry *dir,
struct dentry *rep,
- bool preemptive,
enum fscache_why_object_killed why)
{
struct dentry *grave, *trap;
@@ -307,11 +106,7 @@ static int cachefiles_bury_object(struct cachefiles_cache *cache,
cachefiles_io_error(cache, "Unlink security error");
} else {
trace_cachefiles_unlink(object, rep, why);
- ret = vfs_unlink(&init_user_ns, d_inode(dir), rep,
- NULL);
-
- if (preemptive)
- cachefiles_mark_object_buried(cache, rep, why);
+ ret = vfs_unlink(&init_user_ns, d_inode(dir), rep, NULL);
}

inode_unlock(d_inode(dir));
@@ -372,8 +167,7 @@ static int cachefiles_bury_object(struct cachefiles_cache *cache,
return -ENOMEM;
}

- cachefiles_io_error(cache, "Lookup error %ld",
- PTR_ERR(grave));
+ cachefiles_io_error(cache, "Lookup error %ld", PTR_ERR(grave));
return -EIO;
}

@@ -422,9 +216,6 @@ static int cachefiles_bury_object(struct cachefiles_cache *cache,
if (ret != 0 && ret != -ENOMEM)
cachefiles_io_error(cache,
"Rename failed with error %d", ret);
-
- if (preemptive)
- cachefiles_mark_object_buried(cache, rep, why);
}

unlock_rename(cache->graveyard, dir);
@@ -452,26 +243,18 @@ int cachefiles_delete_object(struct cachefiles_cache *cache,

inode_lock_nested(d_inode(dir), I_MUTEX_PARENT);

- if (test_bit(FSCACHE_OBJECT_KILLED_BY_CACHE, &object->fscache.flags)) {
- /* object allocation for the same key preemptively deleted this
- * object's file so that it could create its own file */
- _debug("object preemptively buried");
+ /* We need to check that our parent is _still_ our parent - it may have
+ * been renamed.
+ */
+ if (dir == object->dentry->d_parent) {
+ ret = cachefiles_bury_object(cache, object, dir, object->dentry,
+ FSCACHE_OBJECT_WAS_RETIRED);
+ } else {
+ /* It got moved, presumably by cachefilesd culling it, so it's
+ * no longer in the key path and we can ignore it.
+ */
inode_unlock(d_inode(dir));
ret = 0;
- } else {
- /* we need to check that our parent is _still_ our parent - it
- * may have been renamed */
- if (dir == object->dentry->d_parent) {
- ret = cachefiles_bury_object(cache, object, dir,
- object->dentry, false,
- FSCACHE_OBJECT_WAS_RETIRED);
- } else {
- /* it got moved, presumably by cachefilesd culling it,
- * so it's no longer in the key path and we can ignore
- * it */
- inode_unlock(d_inode(dir));
- ret = 0;
- }
}

dput(dir);
@@ -492,6 +275,7 @@ int cachefiles_walk_to_object(struct cachefiles_object *parent,
struct inode *inode;
struct path path;
const char *name;
+ bool marked = false;
int ret, nlen;

_enter("OBJ%x{%pd},OBJ%x,%s,",
@@ -532,6 +316,7 @@ int cachefiles_walk_to_object(struct cachefiles_object *parent,
next = lookup_one_len(name, dir, nlen);
if (IS_ERR(next)) {
trace_cachefiles_lookup(object, next, NULL);
+ ret = PTR_ERR(next);
goto lookup_error;
}

@@ -628,6 +413,13 @@ int cachefiles_walk_to_object(struct cachefiles_object *parent,
/* we've found the object we were looking for */
object->dentry = next;

+ /* note that we're now using this object */
+ if (!cachefiles_mark_inode_in_use(object, object->dentry)) {
+ ret = -EBUSY;
+ goto check_error_unlock;
+ }
+ marked = true;
+
/* if we've found that the terminal object exists, then we need to
* check its attributes and delete it if it's out of date */
if (!object->new) {
@@ -640,13 +432,12 @@ int cachefiles_walk_to_object(struct cachefiles_object *parent,
object->dentry = NULL;

ret = cachefiles_bury_object(cache, object, dir, next,
- true,
FSCACHE_OBJECT_IS_STALE);
dput(next);
next = NULL;

if (ret < 0)
- goto delete_error;
+ goto error_out2;

_debug("redo lookup");
fscache_object_retrying_stale(&object->fscache);
@@ -654,16 +445,10 @@ int cachefiles_walk_to_object(struct cachefiles_object *parent,
}
}

- /* note that we're now using this object */
- ret = cachefiles_mark_object_active(cache, object);
-
inode_unlock(d_inode(dir));
dput(dir);
dir = NULL;

- if (ret == -ETIMEDOUT)
- goto mark_active_timed_out;
-
_debug("=== OBTAINED_OBJECT ===");

if (object->new) {
@@ -712,26 +497,19 @@ int cachefiles_walk_to_object(struct cachefiles_object *parent,
cachefiles_io_error(cache, "Create/mkdir failed");
goto error;

-mark_active_timed_out:
- _debug("mark active timed out");
- goto release_dentry;
-
+check_error_unlock:
+ inode_unlock(d_inode(dir));
+ dput(dir);
check_error:
- _debug("check error %d", ret);
- cachefiles_mark_object_inactive(
- cache, object, d_backing_inode(object->dentry)->i_blocks);
-release_dentry:
+ if (marked)
+ cachefiles_unmark_inode_in_use(object, object->dentry);
+ cachefiles_mark_object_inactive(cache, object);
dput(object->dentry);
object->dentry = NULL;
goto error_out;

-delete_error:
- _debug("delete error %d", ret);
- goto error_out2;
-
lookup_error:
- _debug("lookup error %ld", PTR_ERR(next));
- ret = PTR_ERR(next);
+ _debug("lookup error %d", ret);
if (ret == -EIO)
cachefiles_io_error(cache, "Lookup failed");
next = NULL;
@@ -856,8 +634,6 @@ static struct dentry *cachefiles_check_active(struct cachefiles_cache *cache,
struct dentry *dir,
char *filename)
{
- struct cachefiles_object *object;
- struct rb_node *_n;
struct dentry *victim;
int ret;

@@ -884,34 +660,9 @@ static struct dentry *cachefiles_check_active(struct cachefiles_cache *cache,
return ERR_PTR(-ENOENT);
}

- /* check to see if we're using this object */
- read_lock(&cache->active_lock);
-
- _n = cache->active_nodes.rb_node;
-
- while (_n) {
- object = rb_entry(_n, struct cachefiles_object, active_node);
-
- if (object->dentry > victim)
- _n = _n->rb_left;
- else if (object->dentry < victim)
- _n = _n->rb_right;
- else
- goto object_in_use;
- }
-
- read_unlock(&cache->active_lock);
-
//_leave(" = %pd", victim);
return victim;

-object_in_use:
- read_unlock(&cache->active_lock);
- inode_unlock(d_inode(dir));
- dput(victim);
- //_leave(" = -EBUSY [in use]");
- return ERR_PTR(-EBUSY);
-
lookup_error:
inode_unlock(d_inode(dir));
ret = PTR_ERR(victim);
@@ -940,6 +691,7 @@ int cachefiles_cull(struct cachefiles_cache *cache, struct dentry *dir,
char *filename)
{
struct dentry *victim;
+ struct inode *inode;
int ret;

_enter(",%pd/,%s", dir, filename);
@@ -948,6 +700,19 @@ int cachefiles_cull(struct cachefiles_cache *cache, struct dentry *dir,
if (IS_ERR(victim))
return PTR_ERR(victim);

+ /* check to see if someone is using this object */
+ inode = d_inode(victim);
+ inode_lock(inode);
+ if (inode->i_flags & S_KERNEL_FILE) {
+ ret = -EBUSY;
+ } else {
+ inode->i_flags |= S_KERNEL_FILE;
+ ret = 0;
+ }
+ inode_unlock(inode);
+ if (ret < 0)
+ goto error_unlock;
+
_debug("victim -> %pd %s",
victim, d_backing_inode(victim) ? "positive" : "negative");

@@ -963,7 +728,7 @@ int cachefiles_cull(struct cachefiles_cache *cache, struct dentry *dir,
/* actually remove the victim (drops the dir mutex) */
_debug("bury");

- ret = cachefiles_bury_object(cache, NULL, dir, victim, false,
+ ret = cachefiles_bury_object(cache, NULL, dir, victim,
FSCACHE_OBJECT_WAS_CULLED);
if (ret < 0)
goto error;
@@ -1000,6 +765,7 @@ int cachefiles_check_in_use(struct cachefiles_cache *cache, struct dentry *dir,
char *filename)
{
struct dentry *victim;
+ int ret = 0;

//_enter(",%pd/,%s",
// dir, filename);
@@ -1009,7 +775,9 @@ int cachefiles_check_in_use(struct cachefiles_cache *cache, struct dentry *dir,
return PTR_ERR(victim);

inode_unlock(d_inode(dir));
+ if (d_inode(victim)->i_flags & S_KERNEL_FILE)
+ ret = -EBUSY;
dput(victim);
//_leave(" = 0");
- return 0;
+ return ret;
}
diff --git a/include/trace/events/cachefiles.h b/include/trace/events/cachefiles.h
index 920b6a303d60..57d811718953 100644
--- a/include/trace/events/cachefiles.h
+++ b/include/trace/events/cachefiles.h
@@ -237,35 +237,6 @@ TRACE_EVENT(cachefiles_mark_active,
__entry->obj, __entry->de)
);

-TRACE_EVENT(cachefiles_wait_active,
- TP_PROTO(struct cachefiles_object *obj,
- struct dentry *de,
- struct cachefiles_object *xobj),
-
- TP_ARGS(obj, de, xobj),
-
- /* Note that obj may be NULL */
- TP_STRUCT__entry(
- __field(unsigned int, obj )
- __field(unsigned int, xobj )
- __field(struct dentry *, de )
- __field(u16, flags )
- __field(u16, fsc_flags )
- ),
-
- TP_fast_assign(
- __entry->obj = obj->fscache.debug_id;
- __entry->de = de;
- __entry->xobj = xobj->fscache.debug_id;
- __entry->flags = xobj->flags;
- __entry->fsc_flags = xobj->fscache.flags;
- ),
-
- TP_printk("o=%08x d=%p wo=%08x wf=%x wff=%x",
- __entry->obj, __entry->de, __entry->xobj,
- __entry->flags, __entry->fsc_flags)
- );
-
TRACE_EVENT(cachefiles_mark_inactive,
TP_PROTO(struct cachefiles_object *obj,
struct dentry *de,
@@ -290,31 +261,6 @@ TRACE_EVENT(cachefiles_mark_inactive,
__entry->obj, __entry->de, __entry->inode)
);

-TRACE_EVENT(cachefiles_mark_buried,
- TP_PROTO(struct cachefiles_object *obj,
- struct dentry *de,
- enum fscache_why_object_killed why),
-
- TP_ARGS(obj, de, why),
-
- /* Note that obj may be NULL */
- TP_STRUCT__entry(
- __field(unsigned int, obj )
- __field(struct dentry *, de )
- __field(enum fscache_why_object_killed, why )
- ),
-
- TP_fast_assign(
- __entry->obj = obj ? obj->fscache.debug_id : UINT_MAX;
- __entry->de = de;
- __entry->why = why;
- ),
-
- TP_printk("o=%08x d=%p w=%s",
- __entry->obj, __entry->de,
- __print_symbolic(__entry->why, cachefiles_obj_kill_traces))
- );
-
#endif /* _TRACE_CACHEFILES_H */

/* This part must be outside protection */