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-rw-r--r--fs/tracefs/event_inode.c87
-rw-r--r--kernel/trace/ring_buffer.c28
2 files changed, 85 insertions, 30 deletions
diff --git a/fs/tracefs/event_inode.c b/fs/tracefs/event_inode.c
index 9f64e7332796..5f1714089884 100644
--- a/fs/tracefs/event_inode.c
+++ b/fs/tracefs/event_inode.c
@@ -70,6 +70,7 @@ static struct dentry *eventfs_root_lookup(struct inode *dir,
struct dentry *dentry,
unsigned int flags);
static int dcache_dir_open_wrapper(struct inode *inode, struct file *file);
+static int dcache_readdir_wrapper(struct file *file, struct dir_context *ctx);
static int eventfs_release(struct inode *inode, struct file *file);
static const struct inode_operations eventfs_root_dir_inode_operations = {
@@ -79,7 +80,7 @@ static const struct inode_operations eventfs_root_dir_inode_operations = {
static const struct file_operations eventfs_file_operations = {
.open = dcache_dir_open_wrapper,
.read = generic_read_dir,
- .iterate_shared = dcache_readdir,
+ .iterate_shared = dcache_readdir_wrapper,
.llseek = generic_file_llseek,
.release = eventfs_release,
};
@@ -396,6 +397,11 @@ static struct dentry *eventfs_root_lookup(struct inode *dir,
return ret;
}
+struct dentry_list {
+ void *cursor;
+ struct dentry **dentries;
+};
+
/**
* eventfs_release - called to release eventfs file/dir
* @inode: inode to be released
@@ -404,26 +410,25 @@ static struct dentry *eventfs_root_lookup(struct inode *dir,
static int eventfs_release(struct inode *inode, struct file *file)
{
struct tracefs_inode *ti;
- struct eventfs_inode *ei;
- struct eventfs_file *ef;
- struct dentry *dentry;
- int idx;
+ struct dentry_list *dlist = file->private_data;
+ void *cursor;
+ int i;
ti = get_tracefs(inode);
if (!(ti->flags & TRACEFS_EVENT_INODE))
return -EINVAL;
- ei = ti->private;
- idx = srcu_read_lock(&eventfs_srcu);
- list_for_each_entry_srcu(ef, &ei->e_top_files, list,
- srcu_read_lock_held(&eventfs_srcu)) {
- mutex_lock(&eventfs_mutex);
- dentry = ef->dentry;
- mutex_unlock(&eventfs_mutex);
- if (dentry)
- dput(dentry);
+ if (WARN_ON_ONCE(!dlist))
+ return -EINVAL;
+
+ for (i = 0; dlist->dentries[i]; i++) {
+ dput(dlist->dentries[i]);
}
- srcu_read_unlock(&eventfs_srcu, idx);
+
+ cursor = dlist->cursor;
+ kfree(dlist->dentries);
+ kfree(dlist);
+ file->private_data = cursor;
return dcache_dir_close(inode, file);
}
@@ -442,22 +447,70 @@ static int dcache_dir_open_wrapper(struct inode *inode, struct file *file)
struct tracefs_inode *ti;
struct eventfs_inode *ei;
struct eventfs_file *ef;
+ struct dentry_list *dlist;
+ struct dentry **dentries = NULL;
struct dentry *dentry = file_dentry(file);
+ struct dentry *d;
struct inode *f_inode = file_inode(file);
+ int cnt = 0;
int idx;
+ int ret;
ti = get_tracefs(f_inode);
if (!(ti->flags & TRACEFS_EVENT_INODE))
return -EINVAL;
+ if (WARN_ON_ONCE(file->private_data))
+ return -EINVAL;
+
+ dlist = kmalloc(sizeof(*dlist), GFP_KERNEL);
+ if (!dlist)
+ return -ENOMEM;
+
ei = ti->private;
idx = srcu_read_lock(&eventfs_srcu);
list_for_each_entry_srcu(ef, &ei->e_top_files, list,
srcu_read_lock_held(&eventfs_srcu)) {
- create_dentry(ef, dentry, false);
+ d = create_dentry(ef, dentry, false);
+ if (d) {
+ struct dentry **tmp;
+
+ tmp = krealloc(dentries, sizeof(d) * (cnt + 2), GFP_KERNEL);
+ if (!tmp)
+ break;
+ tmp[cnt] = d;
+ tmp[cnt + 1] = NULL;
+ cnt++;
+ dentries = tmp;
+ }
}
srcu_read_unlock(&eventfs_srcu, idx);
- return dcache_dir_open(inode, file);
+ ret = dcache_dir_open(inode, file);
+
+ /*
+ * dcache_dir_open() sets file->private_data to a dentry cursor.
+ * Need to save that but also save all the dentries that were
+ * opened by this function.
+ */
+ dlist->cursor = file->private_data;
+ dlist->dentries = dentries;
+ file->private_data = dlist;
+ return ret;
+}
+
+/*
+ * This just sets the file->private_data back to the cursor and back.
+ */
+static int dcache_readdir_wrapper(struct file *file, struct dir_context *ctx)
+{
+ struct dentry_list *dlist = file->private_data;
+ int ret;
+
+ file->private_data = dlist->cursor;
+ ret = dcache_readdir(file, ctx);
+ dlist->cursor = file->private_data;
+ file->private_data = dlist;
+ return ret;
}
/**
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index a1651edc48d5..28daf0ce95c5 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -354,6 +354,11 @@ static void rb_init_page(struct buffer_data_page *bpage)
local_set(&bpage->commit, 0);
}
+static __always_inline unsigned int rb_page_commit(struct buffer_page *bpage)
+{
+ return local_read(&bpage->page->commit);
+}
+
static void free_buffer_page(struct buffer_page *bpage)
{
free_page((unsigned long)bpage->page);
@@ -2003,7 +2008,7 @@ rb_remove_pages(struct ring_buffer_per_cpu *cpu_buffer, unsigned long nr_pages)
* Increment overrun to account for the lost events.
*/
local_add(page_entries, &cpu_buffer->overrun);
- local_sub(BUF_PAGE_SIZE, &cpu_buffer->entries_bytes);
+ local_sub(rb_page_commit(to_remove_page), &cpu_buffer->entries_bytes);
local_inc(&cpu_buffer->pages_lost);
}
@@ -2367,11 +2372,6 @@ rb_reader_event(struct ring_buffer_per_cpu *cpu_buffer)
cpu_buffer->reader_page->read);
}
-static __always_inline unsigned rb_page_commit(struct buffer_page *bpage)
-{
- return local_read(&bpage->page->commit);
-}
-
static struct ring_buffer_event *
rb_iter_head_event(struct ring_buffer_iter *iter)
{
@@ -2517,7 +2517,7 @@ rb_handle_head_page(struct ring_buffer_per_cpu *cpu_buffer,
* the counters.
*/
local_add(entries, &cpu_buffer->overrun);
- local_sub(BUF_PAGE_SIZE, &cpu_buffer->entries_bytes);
+ local_sub(rb_page_commit(next_page), &cpu_buffer->entries_bytes);
local_inc(&cpu_buffer->pages_lost);
/*
@@ -2660,9 +2660,6 @@ rb_reset_tail(struct ring_buffer_per_cpu *cpu_buffer,
event = __rb_page_index(tail_page, tail);
- /* account for padding bytes */
- local_add(BUF_PAGE_SIZE - tail, &cpu_buffer->entries_bytes);
-
/*
* Save the original length to the meta data.
* This will be used by the reader to add lost event
@@ -2676,7 +2673,8 @@ rb_reset_tail(struct ring_buffer_per_cpu *cpu_buffer,
* write counter enough to allow another writer to slip
* in on this page.
* We put in a discarded commit instead, to make sure
- * that this space is not used again.
+ * that this space is not used again, and this space will
+ * not be accounted into 'entries_bytes'.
*
* If we are less than the minimum size, we don't need to
* worry about it.
@@ -2701,6 +2699,9 @@ rb_reset_tail(struct ring_buffer_per_cpu *cpu_buffer,
/* time delta must be non zero */
event->time_delta = 1;
+ /* account for padding bytes */
+ local_add(BUF_PAGE_SIZE - tail, &cpu_buffer->entries_bytes);
+
/* Make sure the padding is visible before the tail_page->write update */
smp_wmb();
@@ -4215,7 +4216,7 @@ u64 ring_buffer_oldest_event_ts(struct trace_buffer *buffer, int cpu)
EXPORT_SYMBOL_GPL(ring_buffer_oldest_event_ts);
/**
- * ring_buffer_bytes_cpu - get the number of bytes consumed in a cpu buffer
+ * ring_buffer_bytes_cpu - get the number of bytes unconsumed in a cpu buffer
* @buffer: The ring buffer
* @cpu: The per CPU buffer to read from.
*/
@@ -4723,6 +4724,7 @@ static void rb_advance_reader(struct ring_buffer_per_cpu *cpu_buffer)
length = rb_event_length(event);
cpu_buffer->reader_page->read += length;
+ cpu_buffer->read_bytes += length;
}
static void rb_advance_iter(struct ring_buffer_iter *iter)
@@ -5816,7 +5818,7 @@ int ring_buffer_read_page(struct trace_buffer *buffer,
} else {
/* update the entry counter */
cpu_buffer->read += rb_page_entries(reader);
- cpu_buffer->read_bytes += BUF_PAGE_SIZE;
+ cpu_buffer->read_bytes += rb_page_commit(reader);
/* swap the pages */
rb_init_page(bpage);