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-rw-r--r--fs/seq_file.c54
1 files changed, 21 insertions, 33 deletions
diff --git a/fs/seq_file.c b/fs/seq_file.c
index 4cc090b50cc5..1dea7a8a5255 100644
--- a/fs/seq_file.c
+++ b/fs/seq_file.c
@@ -90,23 +90,22 @@ EXPORT_SYMBOL(seq_open);
static int traverse(struct seq_file *m, loff_t offset)
{
- loff_t pos = 0, index;
+ loff_t pos = 0;
int error = 0;
void *p;
m->version = 0;
- index = 0;
+ m->index = 0;
m->count = m->from = 0;
- if (!offset) {
- m->index = index;
+ if (!offset)
return 0;
- }
+
if (!m->buf) {
m->buf = seq_buf_alloc(m->size = PAGE_SIZE);
if (!m->buf)
return -ENOMEM;
}
- p = m->op->start(m, &index);
+ p = m->op->start(m, &m->index);
while (p) {
error = PTR_ERR(p);
if (IS_ERR(p))
@@ -123,20 +122,15 @@ static int traverse(struct seq_file *m, loff_t offset)
if (pos + m->count > offset) {
m->from = offset - pos;
m->count -= m->from;
- m->index = index;
break;
}
pos += m->count;
m->count = 0;
- if (pos == offset) {
- index++;
- m->index = index;
+ p = m->op->next(m, p, &m->index);
+ if (pos == offset)
break;
- }
- p = m->op->next(m, p, &index);
}
m->op->stop(m, p);
- m->index = index;
return error;
Eoverflow:
@@ -160,7 +154,6 @@ ssize_t seq_read(struct file *file, char __user *buf, size_t size, loff_t *ppos)
{
struct seq_file *m = file->private_data;
size_t copied = 0;
- loff_t pos;
size_t n;
void *p;
int err = 0;
@@ -223,16 +216,12 @@ ssize_t seq_read(struct file *file, char __user *buf, size_t size, loff_t *ppos)
size -= n;
buf += n;
copied += n;
- if (!m->count) {
- m->from = 0;
- m->index++;
- }
if (!size)
goto Done;
}
/* we need at least one record in buffer */
- pos = m->index;
- p = m->op->start(m, &pos);
+ m->from = 0;
+ p = m->op->start(m, &m->index);
while (1) {
err = PTR_ERR(p);
if (!p || IS_ERR(p))
@@ -243,8 +232,7 @@ ssize_t seq_read(struct file *file, char __user *buf, size_t size, loff_t *ppos)
if (unlikely(err))
m->count = 0;
if (unlikely(!m->count)) {
- p = m->op->next(m, p, &pos);
- m->index = pos;
+ p = m->op->next(m, p, &m->index);
continue;
}
if (m->count < m->size)
@@ -256,29 +244,33 @@ ssize_t seq_read(struct file *file, char __user *buf, size_t size, loff_t *ppos)
if (!m->buf)
goto Enomem;
m->version = 0;
- pos = m->index;
- p = m->op->start(m, &pos);
+ p = m->op->start(m, &m->index);
}
m->op->stop(m, p);
m->count = 0;
goto Done;
Fill:
/* they want more? let's try to get some more */
- while (m->count < size) {
+ while (1) {
size_t offs = m->count;
- loff_t next = pos;
- p = m->op->next(m, p, &next);
+ loff_t pos = m->index;
+
+ p = m->op->next(m, p, &m->index);
+ if (pos == m->index)
+ /* Buggy ->next function */
+ m->index++;
if (!p || IS_ERR(p)) {
err = PTR_ERR(p);
break;
}
+ if (m->count >= size)
+ break;
err = m->op->show(m, p);
if (seq_has_overflowed(m) || err) {
m->count = offs;
if (likely(err <= 0))
break;
}
- pos = next;
}
m->op->stop(m, p);
n = min(m->count, size);
@@ -287,11 +279,7 @@ Fill:
goto Efault;
copied += n;
m->count -= n;
- if (m->count)
- m->from = n;
- else
- pos++;
- m->index = pos;
+ m->from = n;
Done:
if (!copied)
copied = err;