* into the buffer. In case of error ->start() and ->next() return
* ERR_PTR(error). In the end of sequence they return %NULL. ->show()
* returns 0 in case of success and negative number in case of error.
+ * Returning SEQ_SKIP means "discard this element and move on".
*/
-int seq_open(struct file *file, struct seq_operations *op)
+int seq_open(struct file *file, const struct seq_operations *op)
{
struct seq_file *p = file->private_data;
*/
file->f_version = 0;
- /* SEQ files support lseek, but not pread/pwrite */
- file->f_mode &= ~(FMODE_PREAD | FMODE_PWRITE);
+ /*
+ * seq_files support lseek() and pread(). They do not implement
+ * write() at all, but we clear FMODE_PWRITE here for historical
+ * reasons.
+ *
+ * If a client of seq_files a) implements file.write() and b) wishes to
+ * support pwrite() then that client will need to implement its own
+ * file.open() which calls seq_open() and then sets FMODE_PWRITE.
+ */
+ file->f_mode &= ~FMODE_PWRITE;
return 0;
}
EXPORT_SYMBOL(seq_open);
+static int traverse(struct seq_file *m, loff_t offset)
+{
+ loff_t pos = 0, index;
+ int error = 0;
+ void *p;
+
+ m->version = 0;
+ index = 0;
+ m->count = m->from = 0;
+ if (!offset) {
+ m->index = index;
+ return 0;
+ }
+ if (!m->buf) {
+ m->buf = kmalloc(m->size = PAGE_SIZE, GFP_KERNEL);
+ if (!m->buf)
+ return -ENOMEM;
+ }
+ p = m->op->start(m, &index);
+ while (p) {
+ error = PTR_ERR(p);
+ if (IS_ERR(p))
+ break;
+ error = m->op->show(m, p);
+ if (error < 0)
+ break;
+ if (unlikely(error)) {
+ error = 0;
+ m->count = 0;
+ }
+ if (m->count == m->size)
+ goto Eoverflow;
+ 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;
+ break;
+ }
+ p = m->op->next(m, p, &index);
+ }
+ m->op->stop(m, p);
+ m->index = index;
+ return error;
+
+Eoverflow:
+ m->op->stop(m, p);
+ kfree(m->buf);
+ m->buf = kmalloc(m->size <<= 1, GFP_KERNEL);
+ return !m->buf ? -ENOMEM : -EAGAIN;
+}
+
/**
* seq_read - ->read() method for sequential files.
* @file: the file to read from
int err = 0;
mutex_lock(&m->lock);
+
+ /* Don't assume *ppos is where we left it */
+ if (unlikely(*ppos != m->read_pos)) {
+ m->read_pos = *ppos;
+ while ((err = traverse(m, *ppos)) == -EAGAIN)
+ ;
+ if (err) {
+ /* With prejudice... */
+ m->read_pos = 0;
+ m->version = 0;
+ m->index = 0;
+ m->count = 0;
+ goto Done;
+ }
+ }
+
/*
* 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
goto Done;
}
/* we need at least one record in buffer */
+ pos = m->index;
+ p = m->op->start(m, &pos);
while (1) {
- pos = m->index;
- p = m->op->start(m, &pos);
err = PTR_ERR(p);
if (!p || IS_ERR(p))
break;
err = m->op->show(m, p);
- if (err)
+ if (err < 0)
break;
+ if (unlikely(err))
+ m->count = 0;
+ if (unlikely(!m->count)) {
+ p = m->op->next(m, p, &pos);
+ m->index = pos;
+ continue;
+ }
if (m->count < m->size)
goto Fill;
m->op->stop(m, p);
goto Enomem;
m->count = 0;
m->version = 0;
+ pos = m->index;
+ p = m->op->start(m, &pos);
}
m->op->stop(m, p);
m->count = 0;
break;
}
err = m->op->show(m, p);
- if (err || m->count == m->size) {
+ if (m->count == m->size || err) {
m->count = offs;
- break;
+ if (likely(err <= 0))
+ break;
}
pos = next;
}
Done:
if (!copied)
copied = err;
- else
+ else {
*ppos += copied;
+ m->read_pos += copied;
+ }
file->f_version = m->version;
mutex_unlock(&m->lock);
return copied;
}
EXPORT_SYMBOL(seq_read);
-static int traverse(struct seq_file *m, loff_t offset)
-{
- loff_t pos = 0;
- int error = 0;
- void *p;
-
- m->version = 0;
- m->index = 0;
- m->count = m->from = 0;
- if (!offset)
- return 0;
- if (!m->buf) {
- m->buf = kmalloc(m->size = PAGE_SIZE, GFP_KERNEL);
- if (!m->buf)
- return -ENOMEM;
- }
- p = m->op->start(m, &m->index);
- while (p) {
- error = PTR_ERR(p);
- if (IS_ERR(p))
- break;
- error = m->op->show(m, p);
- if (error)
- break;
- if (m->count == m->size)
- goto Eoverflow;
- if (pos + m->count > offset) {
- m->from = offset - pos;
- m->count -= m->from;
- break;
- }
- pos += m->count;
- m->count = 0;
- if (pos == offset) {
- m->index++;
- break;
- }
- p = m->op->next(m, p, &m->index);
- }
- m->op->stop(m, p);
- return error;
-
-Eoverflow:
- m->op->stop(m, p);
- kfree(m->buf);
- m->buf = kmalloc(m->size <<= 1, GFP_KERNEL);
- return !m->buf ? -ENOMEM : -EAGAIN;
-}
-
/**
* seq_lseek - ->llseek() method for sequential files.
* @file: the file in question
loff_t seq_lseek(struct file *file, loff_t offset, int origin)
{
struct seq_file *m = (struct seq_file *)file->private_data;
- long long retval = -EINVAL;
+ loff_t retval = -EINVAL;
mutex_lock(&m->lock);
m->version = file->f_version;
if (offset < 0)
break;
retval = offset;
- if (offset != file->f_pos) {
+ if (offset != m->read_pos) {
while ((retval=traverse(m, offset)) == -EAGAIN)
;
if (retval) {
/* with extreme prejudice... */
file->f_pos = 0;
+ m->read_pos = 0;
m->version = 0;
m->index = 0;
m->count = 0;
} else {
+ m->read_pos = offset;
retval = file->f_pos = offset;
}
}
}
- mutex_unlock(&m->lock);
file->f_version = m->version;
+ mutex_unlock(&m->lock);
return retval;
}
EXPORT_SYMBOL(seq_lseek);
/**
* seq_release - free the structures associated with sequential file.
* @file: file in question
- * @inode: file->f_dentry->d_inode
+ * @inode: file->f_path.dentry->d_inode
*
* Frees the structures associated with sequential file; can be used
* as ->f_op->release() if you don't have private data to destroy.
}
EXPORT_SYMBOL(seq_printf);
-int seq_path(struct seq_file *m,
- struct vfsmount *mnt, struct dentry *dentry,
- char *esc)
+/**
+ * mangle_path - mangle and copy path to buffer beginning
+ * @s: buffer start
+ * @p: beginning of path in above buffer
+ * @esc: set of characters that need escaping
+ *
+ * Copy the path from @p to @s, replacing each occurrence of character from
+ * @esc with usual octal escape.
+ * Returns pointer past last written character in @s, or NULL in case of
+ * failure.
+ */
+char *mangle_path(char *s, char *p, char *esc)
{
- if (m->count < m->size) {
- char *s = m->buf + m->count;
- char *p = d_path(dentry, mnt, s, m->size - m->count);
+ while (s <= p) {
+ char c = *p++;
+ if (!c) {
+ return s;
+ } else if (!strchr(esc, c)) {
+ *s++ = c;
+ } else if (s + 4 > p) {
+ break;
+ } else {
+ *s++ = '\\';
+ *s++ = '0' + ((c & 0300) >> 6);
+ *s++ = '0' + ((c & 070) >> 3);
+ *s++ = '0' + (c & 07);
+ }
+ }
+ return NULL;
+}
+EXPORT_SYMBOL(mangle_path);
+
+/**
+ * seq_path - seq_file interface to print a pathname
+ * @m: the seq_file handle
+ * @path: the struct path to print
+ * @esc: set of characters to escape in the output
+ *
+ * return the absolute path of 'path', as represented by the
+ * dentry / mnt pair in the path parameter.
+ */
+int seq_path(struct seq_file *m, struct path *path, char *esc)
+{
+ char *buf;
+ size_t size = seq_get_buf(m, &buf);
+ int res = -1;
+
+ if (size) {
+ char *p = d_path(path, buf, size);
if (!IS_ERR(p)) {
- while (s <= p) {
- char c = *p++;
- if (!c) {
- p = m->buf + m->count;
- m->count = s - m->buf;
- return s - p;
- } else if (!strchr(esc, c)) {
- *s++ = c;
- } else if (s + 4 > p) {
- break;
- } else {
- *s++ = '\\';
- *s++ = '0' + ((c & 0300) >> 6);
- *s++ = '0' + ((c & 070) >> 3);
- *s++ = '0' + (c & 07);
- }
- }
+ char *end = mangle_path(buf, p, esc);
+ if (end)
+ res = end - buf;
+ }
+ }
+ seq_commit(m, res);
+
+ return res;
+}
+EXPORT_SYMBOL(seq_path);
+
+/*
+ * Same as seq_path, but relative to supplied root.
+ *
+ * root may be changed, see __d_path().
+ */
+int seq_path_root(struct seq_file *m, struct path *path, struct path *root,
+ char *esc)
+{
+ char *buf;
+ size_t size = seq_get_buf(m, &buf);
+ int res = -ENAMETOOLONG;
+
+ if (size) {
+ char *p;
+
+ spin_lock(&dcache_lock);
+ p = __d_path(path, root, buf, size);
+ spin_unlock(&dcache_lock);
+ res = PTR_ERR(p);
+ if (!IS_ERR(p)) {
+ char *end = mangle_path(buf, p, esc);
+ if (end)
+ res = end - buf;
+ else
+ res = -ENAMETOOLONG;
+ }
+ }
+ seq_commit(m, res);
+
+ return res < 0 ? res : 0;
+}
+
+/*
+ * returns the path of the 'dentry' from the root of its filesystem.
+ */
+int seq_dentry(struct seq_file *m, struct dentry *dentry, char *esc)
+{
+ char *buf;
+ size_t size = seq_get_buf(m, &buf);
+ int res = -1;
+
+ if (size) {
+ char *p = dentry_path(dentry, buf, size);
+ if (!IS_ERR(p)) {
+ char *end = mangle_path(buf, p, esc);
+ if (end)
+ res = end - buf;
+ }
+ }
+ seq_commit(m, res);
+
+ return res;
+}
+
+int seq_bitmap(struct seq_file *m, const unsigned long *bits,
+ unsigned int nr_bits)
+{
+ if (m->count < m->size) {
+ int len = bitmap_scnprintf(m->buf + m->count,
+ m->size - m->count, bits, nr_bits);
+ if (m->count + len < m->size) {
+ m->count += len;
+ return 0;
}
}
m->count = m->size;
return -1;
}
-EXPORT_SYMBOL(seq_path);
+EXPORT_SYMBOL(seq_bitmap);
+
+int seq_bitmap_list(struct seq_file *m, const unsigned long *bits,
+ unsigned int nr_bits)
+{
+ if (m->count < m->size) {
+ int len = bitmap_scnlistprintf(m->buf + m->count,
+ m->size - m->count, bits, nr_bits);
+ if (m->count + len < m->size) {
+ m->count += len;
+ return 0;
+ }
+ }
+ m->count = m->size;
+ return -1;
+}
+EXPORT_SYMBOL(seq_bitmap_list);
static void *single_start(struct seq_file *p, loff_t *pos)
{
int single_release(struct inode *inode, struct file *file)
{
- struct seq_operations *op = ((struct seq_file *)file->private_data)->op;
+ const struct seq_operations *op = ((struct seq_file *)file->private_data)->op;
int res = seq_release(inode, file);
kfree(op);
return res;
}
EXPORT_SYMBOL(seq_release_private);
+void *__seq_open_private(struct file *f, const struct seq_operations *ops,
+ int psize)
+{
+ int rc;
+ void *private;
+ struct seq_file *seq;
+
+ private = kzalloc(psize, GFP_KERNEL);
+ if (private == NULL)
+ goto out;
+
+ rc = seq_open(f, ops);
+ if (rc < 0)
+ goto out_free;
+
+ seq = f->private_data;
+ seq->private = private;
+ return private;
+
+out_free:
+ kfree(private);
+out:
+ return NULL;
+}
+EXPORT_SYMBOL(__seq_open_private);
+
+int seq_open_private(struct file *filp, const struct seq_operations *ops,
+ int psize)
+{
+ return __seq_open_private(filp, ops, psize) ? 0 : -ENOMEM;
+}
+EXPORT_SYMBOL(seq_open_private);
+
int seq_putc(struct seq_file *m, char c)
{
if (m->count < m->size) {
return -1;
}
EXPORT_SYMBOL(seq_puts);
+
+/**
+ * seq_write - write arbitrary data to buffer
+ * @seq: seq_file identifying the buffer to which data should be written
+ * @data: data address
+ * @len: number of bytes
+ *
+ * Return 0 on success, non-zero otherwise.
+ */
+int seq_write(struct seq_file *seq, const void *data, size_t len)
+{
+ if (seq->count + len < seq->size) {
+ memcpy(seq->buf + seq->count, data, len);
+ seq->count += len;
+ return 0;
+ }
+ seq->count = seq->size;
+ return -1;
+}
+EXPORT_SYMBOL(seq_write);
+
+struct list_head *seq_list_start(struct list_head *head, loff_t pos)
+{
+ struct list_head *lh;
+
+ list_for_each(lh, head)
+ if (pos-- == 0)
+ return lh;
+
+ return NULL;
+}
+EXPORT_SYMBOL(seq_list_start);
+
+struct list_head *seq_list_start_head(struct list_head *head, loff_t pos)
+{
+ if (!pos)
+ return head;
+
+ return seq_list_start(head, pos - 1);
+}
+EXPORT_SYMBOL(seq_list_start_head);
+
+struct list_head *seq_list_next(void *v, struct list_head *head, loff_t *ppos)
+{
+ struct list_head *lh;
+
+ lh = ((struct list_head *)v)->next;
+ ++*ppos;
+ return lh == head ? NULL : lh;
+}
+EXPORT_SYMBOL(seq_list_next);
+
+/**
+ * seq_hlist_start - start an iteration of a hlist
+ * @head: the head of the hlist
+ * @pos: the start position of the sequence
+ *
+ * Called at seq_file->op->start().
+ */
+struct hlist_node *seq_hlist_start(struct hlist_head *head, loff_t pos)
+{
+ struct hlist_node *node;
+
+ hlist_for_each(node, head)
+ if (pos-- == 0)
+ return node;
+ return NULL;
+}
+EXPORT_SYMBOL(seq_hlist_start);
+
+/**
+ * seq_hlist_start_head - start an iteration of a hlist
+ * @head: the head of the hlist
+ * @pos: the start position of the sequence
+ *
+ * Called at seq_file->op->start(). Call this function if you want to
+ * print a header at the top of the output.
+ */
+struct hlist_node *seq_hlist_start_head(struct hlist_head *head, loff_t pos)
+{
+ if (!pos)
+ return SEQ_START_TOKEN;
+
+ return seq_hlist_start(head, pos - 1);
+}
+EXPORT_SYMBOL(seq_hlist_start_head);
+
+/**
+ * seq_hlist_next - move to the next position of the hlist
+ * @v: the current iterator
+ * @head: the head of the hlist
+ * @pos: the current posision
+ *
+ * Called at seq_file->op->next().
+ */
+struct hlist_node *seq_hlist_next(void *v, struct hlist_head *head,
+ loff_t *ppos)
+{
+ struct hlist_node *node = v;
+
+ ++*ppos;
+ if (v == SEQ_START_TOKEN)
+ return head->first;
+ else
+ return node->next;
+}
+EXPORT_SYMBOL(seq_hlist_next);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff