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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: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20200317193201.9924-4-adobriyan@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Matthew Wilcox (Oracle) 2020-04-06 20:09:17 -07:00 committed by Linus Torvalds
parent 4781f2c3ab
commit b829a0f0f2
2 changed files with 0 additions and 29 deletions
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28
fs/seq_file.c
View File

@ -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;
}

1
include/linux/seq_file.h
View File

@ -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;