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-rw-r--r--fs/debugfs/inode.c110
1 files changed, 89 insertions, 21 deletions
diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c
index bece948b363d..4bc1f68243c1 100644
--- a/fs/debugfs/inode.c
+++ b/fs/debugfs/inode.c
@@ -27,9 +27,14 @@
#include <linux/parser.h>
#include <linux/magic.h>
#include <linux/slab.h>
+#include <linux/srcu.h>
+
+#include "internal.h"
#define DEBUGFS_DEFAULT_MODE 0700
+DEFINE_SRCU(debugfs_srcu);
+
static struct vfsmount *debugfs_mount;
static int debugfs_mount_count;
static bool debugfs_registered;
@@ -39,7 +44,8 @@ static struct inode *debugfs_get_inode(struct super_block *sb)
struct inode *inode = new_inode(sb);
if (inode) {
inode->i_ino = get_next_ino();
- inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+ inode->i_atime = inode->i_mtime =
+ inode->i_ctime = current_fs_time(sb);
}
return inode;
}
@@ -294,6 +300,37 @@ static struct dentry *end_creating(struct dentry *dentry)
return dentry;
}
+static struct dentry *__debugfs_create_file(const char *name, umode_t mode,
+ struct dentry *parent, void *data,
+ const struct file_operations *proxy_fops,
+ const struct file_operations *real_fops)
+{
+ struct dentry *dentry;
+ struct inode *inode;
+
+ if (!(mode & S_IFMT))
+ mode |= S_IFREG;
+ BUG_ON(!S_ISREG(mode));
+ dentry = start_creating(name, parent);
+
+ if (IS_ERR(dentry))
+ return NULL;
+
+ inode = debugfs_get_inode(dentry->d_sb);
+ if (unlikely(!inode))
+ return failed_creating(dentry);
+
+ inode->i_mode = mode;
+ inode->i_private = data;
+
+ inode->i_fop = proxy_fops;
+ dentry->d_fsdata = (void *)real_fops;
+
+ d_instantiate(dentry, inode);
+ fsnotify_create(d_inode(dentry->d_parent), dentry);
+ return end_creating(dentry);
+}
+
/**
* debugfs_create_file - create a file in the debugfs filesystem
* @name: a pointer to a string containing the name of the file to create.
@@ -324,29 +361,52 @@ struct dentry *debugfs_create_file(const char *name, umode_t mode,
struct dentry *parent, void *data,
const struct file_operations *fops)
{
- struct dentry *dentry;
- struct inode *inode;
- if (!(mode & S_IFMT))
- mode |= S_IFREG;
- BUG_ON(!S_ISREG(mode));
- dentry = start_creating(name, parent);
-
- if (IS_ERR(dentry))
- return NULL;
+ return __debugfs_create_file(name, mode, parent, data,
+ fops ? &debugfs_full_proxy_file_operations :
+ &debugfs_noop_file_operations,
+ fops);
+}
+EXPORT_SYMBOL_GPL(debugfs_create_file);
- inode = debugfs_get_inode(dentry->d_sb);
- if (unlikely(!inode))
- return failed_creating(dentry);
+/**
+ * debugfs_create_file_unsafe - create a file in the debugfs filesystem
+ * @name: a pointer to a string containing the name of the file to create.
+ * @mode: the permission that the file should have.
+ * @parent: a pointer to the parent dentry for this file. This should be a
+ * directory dentry if set. If this parameter is NULL, then the
+ * file will be created in the root of the debugfs filesystem.
+ * @data: a pointer to something that the caller will want to get to later
+ * on. The inode.i_private pointer will point to this value on
+ * the open() call.
+ * @fops: a pointer to a struct file_operations that should be used for
+ * this file.
+ *
+ * debugfs_create_file_unsafe() is completely analogous to
+ * debugfs_create_file(), the only difference being that the fops
+ * handed it will not get protected against file removals by the
+ * debugfs core.
+ *
+ * It is your responsibility to protect your struct file_operation
+ * methods against file removals by means of debugfs_use_file_start()
+ * and debugfs_use_file_finish(). ->open() is still protected by
+ * debugfs though.
+ *
+ * Any struct file_operations defined by means of
+ * DEFINE_DEBUGFS_ATTRIBUTE() is protected against file removals and
+ * thus, may be used here.
+ */
+struct dentry *debugfs_create_file_unsafe(const char *name, umode_t mode,
+ struct dentry *parent, void *data,
+ const struct file_operations *fops)
+{
- inode->i_mode = mode;
- inode->i_fop = fops ? fops : &debugfs_file_operations;
- inode->i_private = data;
- d_instantiate(dentry, inode);
- fsnotify_create(d_inode(dentry->d_parent), dentry);
- return end_creating(dentry);
+ return __debugfs_create_file(name, mode, parent, data,
+ fops ? &debugfs_open_proxy_file_operations :
+ &debugfs_noop_file_operations,
+ fops);
}
-EXPORT_SYMBOL_GPL(debugfs_create_file);
+EXPORT_SYMBOL_GPL(debugfs_create_file_unsafe);
/**
* debugfs_create_file_size - create a file in the debugfs filesystem
@@ -457,11 +517,15 @@ struct dentry *debugfs_create_automount(const char *name,
if (unlikely(!inode))
return failed_creating(dentry);
- inode->i_mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO;
+ make_empty_dir_inode(inode);
inode->i_flags |= S_AUTOMOUNT;
inode->i_private = data;
dentry->d_fsdata = (void *)f;
+ /* directory inodes start off with i_nlink == 2 (for "." entry) */
+ inc_nlink(inode);
d_instantiate(dentry, inode);
+ inc_nlink(d_inode(dentry->d_parent));
+ fsnotify_mkdir(d_inode(dentry->d_parent), dentry);
return end_creating(dentry);
}
EXPORT_SYMBOL(debugfs_create_automount);
@@ -565,6 +629,8 @@ void debugfs_remove(struct dentry *dentry)
inode_unlock(d_inode(parent));
if (!ret)
simple_release_fs(&debugfs_mount, &debugfs_mount_count);
+
+ synchronize_srcu(&debugfs_srcu);
}
EXPORT_SYMBOL_GPL(debugfs_remove);
@@ -642,6 +708,8 @@ void debugfs_remove_recursive(struct dentry *dentry)
if (!__debugfs_remove(child, parent))
simple_release_fs(&debugfs_mount, &debugfs_mount_count);
inode_unlock(d_inode(parent));
+
+ synchronize_srcu(&debugfs_srcu);
}
EXPORT_SYMBOL_GPL(debugfs_remove_recursive);
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