Commit b829a0f0 authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle) Committed by Linus Torvalds
Browse files

seq_file: remove m->version 



The process maps file was the only user of version (introduced back in
2005).  Now that it uses ppos instead, we can remove it.

Signed-off-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: default avatarAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20200317193201.9924-4-adobriyan@gmail.com


Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 4781f2c3

fs/seq_file.c

+0 −28
Original line number Diff line number Diff line
@@ -67,13 +67,6 @@ int seq_open(struct file *file, const struct seq_operations *op) 
	// to the lifetime of the file.

	p->file = file;



	/*

	 * Wrappers around seq_open(e.g. swaps_open) need to be

	 * aware of this. If they set f_version themselves, they

	 * should call seq_open first and then set f_version.

	 */

	file->f_version = 0;



	/*

	 * seq_files support lseek() and pread().  They do not implement

	 * write() at all, but we clear FMODE_PWRITE here for historical
@@ -94,7 +87,6 @@ static int traverse(struct seq_file *m, loff_t offset) 
	int error = 0;

	void *p;



	m->version = 0;

	m->index = 0;

	m->count = m->from = 0;

	if (!offset)
@@ -160,26 +152,12 @@ ssize_t seq_read(struct file *file, char __user *buf, size_t size, loff_t *ppos) 


	mutex_lock(&m->lock);



	/*

	 * seq_file->op->..m_start/m_stop/m_next may do special actions

	 * or optimisations based on the file->f_version, so we want to

	 * pass the file->f_version to those methods.

	 *

	 * seq_file->version is just copy of f_version, and seq_file

	 * methods can treat it simply as file version.

	 * It is copied in first and copied out after all operations.

	 * It is convenient to have it as  part of structure to avoid the

	 * need of passing another argument to all the seq_file methods.

	 */

	m->version = file->f_version;



	/*

	 * if request is to read from zero offset, reset iterator to first

	 * record as it might have been already advanced by previous requests

	 */

	if (*ppos == 0) {

		m->index = 0;

		m->version = 0;

		m->count = 0;

	}
@@ -190,7 +168,6 @@ ssize_t seq_read(struct file *file, char __user *buf, size_t size, loff_t *ppos) 
		if (err) {

			/* With prejudice... */

			m->read_pos = 0;

			m->version = 0;

			m->index = 0;

			m->count = 0;

			goto Done;
@@ -243,7 +220,6 @@ ssize_t seq_read(struct file *file, char __user *buf, size_t size, loff_t *ppos) 
		m->buf = seq_buf_alloc(m->size <<= 1);

		if (!m->buf)

			goto Enomem;

		m->version = 0;

		p = m->op->start(m, &m->index);

	}

	m->op->stop(m, p);
@@ -287,7 +263,6 @@ ssize_t seq_read(struct file *file, char __user *buf, size_t size, loff_t *ppos) 
		*ppos += copied;

		m->read_pos += copied;

	}

	file->f_version = m->version;

	mutex_unlock(&m->lock);

	return copied;

Enomem:
@@ -313,7 +288,6 @@ loff_t seq_lseek(struct file *file, loff_t offset, int whence) 
	loff_t retval = -EINVAL;



	mutex_lock(&m->lock);

	m->version = file->f_version;

	switch (whence) {

	case SEEK_CUR:

		offset += file->f_pos;
@@ -329,7 +303,6 @@ loff_t seq_lseek(struct file *file, loff_t offset, int whence) 
				/* with extreme prejudice... */

				file->f_pos = 0;

				m->read_pos = 0;

				m->version = 0;

				m->index = 0;

				m->count = 0;

			} else {
@@ -340,7 +313,6 @@ loff_t seq_lseek(struct file *file, loff_t offset, int whence) 
			file->f_pos = offset;

		}

	}

	file->f_version = m->version;

	mutex_unlock(&m->lock);

	return retval;

}

include/linux/seq_file.h

+0 −1
Original line number Diff line number Diff line
@@ -21,7 +21,6 @@ struct seq_file { 
	size_t pad_until;

	loff_t index;

	loff_t read_pos;

	u64 version;

	struct mutex lock;

	const struct seq_operations *op;

	int poll_event;