lkml.org 
[lkml]   [2019]   [Nov]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH next 3/3] debugfs: introduce debugfs_create_seq[,_data]
Date
Like proc_create_seq[,_data] in procfs, introduce a similar
debugfs_create_seq[,_data] function, which could drastically
reduces the boilerplate code.

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
---
fs/debugfs/file.c | 62 ++++++++++++++++++++++++++++++++++++++++-
include/linux/debugfs.h | 16 +++++++++++
2 files changed, 77 insertions(+), 1 deletion(-)

diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c
index 68f0c4b19bef..77522717c9fb 100644
--- a/fs/debugfs/file.c
+++ b/fs/debugfs/file.c
@@ -1107,7 +1107,10 @@ EXPORT_SYMBOL_GPL(debugfs_create_regset32);
#endif /* CONFIG_HAS_IOMEM */

struct debugfs_entry {
- int (*read)(struct seq_file *seq, void *data);
+ union {
+ const struct seq_operations *seq_ops;
+ int (*read)(struct seq_file *seq, void *data);
+ };
void *data;
};

@@ -1196,3 +1199,60 @@ struct dentry *debugfs_create_single_data(const char *name, umode_t mode,
&debugfs_entry_ops);
}
EXPORT_SYMBOL_GPL(debugfs_create_single_data);
+
+static int debugfs_entry_seq_open(struct inode *inode, struct file *file)
+{
+ struct debugfs_entry *entry = inode->i_private;
+ int ret;
+
+ entry = debugfs_clear_lowest_bit(entry);
+
+ ret = seq_open(file, entry->seq_ops);
+ if (!ret && entry->data) {
+ struct seq_file *seq = file->private_data;
+ seq->private = entry->data;
+ }
+
+ return ret;
+}
+
+static const struct file_operations debugfs_seq_fops = {
+ .open = debugfs_entry_seq_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
+
+/**
+ * debugfs_create_seq_data - 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.
+ * @seq_ops: seq_operations pointer of the seqfile.
+ *
+ * This function creates a file in debugfs with the extra data and a seq_ops.
+ */
+struct dentry *debugfs_create_seq_data(const char *name, umode_t mode,
+ struct dentry *parent, void *data,
+ const struct seq_operations *seq_ops)
+{
+ struct debugfs_entry *entry;
+
+ entry = kzalloc(sizeof(*entry), GFP_KERNEL);
+ if (!entry)
+ return ERR_PTR(-ENOMEM);
+
+ entry->seq_ops = seq_ops;
+ entry->data = data;
+
+ entry = debugfs_set_lowest_bit(entry);
+
+ return debugfs_create_file(name, mode, parent, entry,
+ &debugfs_seq_fops);
+}
+EXPORT_SYMBOL_GPL(debugfs_create_seq_data);
diff --git a/include/linux/debugfs.h b/include/linux/debugfs.h
index 82171f183e93..d32d49983547 100644
--- a/include/linux/debugfs.h
+++ b/include/linux/debugfs.h
@@ -147,6 +147,10 @@ struct dentry *debugfs_create_single_data(const char *name, umode_t mode,
int (*read_fn)(struct seq_file *s,
void *data));

+struct dentry *debugfs_create_seq_data(const char *name, umode_t mode,
+ struct dentry *parent, void *data,
+ const struct seq_operations *seq_ops);
+
bool debugfs_initialized(void);

ssize_t debugfs_read_file_bool(struct file *file, char __user *user_buf,
@@ -351,6 +355,15 @@ static inline struct dentry *debugfs_create_single_data(const char *name,
return ERR_PTR(-ENODEV);
}

+static inline struct dentry *debugfs_create_seq_data(const char *name,
+ umode_t mode,
+ struct dentry *parent,
+ void *data,
+ const struct seq_operations *seq_ops)
+{
+ return ERR_PTR(-ENODEV);
+}
+
static inline ssize_t debugfs_read_file_bool(struct file *file,
char __user *user_buf,
size_t count, loff_t *ppos)
@@ -370,6 +383,9 @@ static inline ssize_t debugfs_write_file_bool(struct file *file,
#define debugfs_create_single(name, mode, parent, read) \
debugfs_create_single_data(name, mode, parent, NULL, read)

+#define debugfs_create_seq(name, mode, parent, ops) \
+ debugfs_create_seq_data(name, mode, parent, NULL, ops)
+
/**
* debugfs_create_xul - create a debugfs file that is used to read and write an
* unsigned long value, formatted in hexadecimal
--
2.20.1
\
 
 \ /
  Last update: 2019-11-29 10:31    [W:0.054 / U:2.792 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site