Messages in this thread Patch in this message |  | | From | Kefeng Wang <> | Subject | [PATCH next 3/3] debugfs: introduce debugfs_create_seq[,_data] | Date | Fri, 29 Nov 2019 17:27:52 +0800 |
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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
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