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f36108c462
When calling debugfs functions, there is no need to ever check the return value. The function can work or not, but the code logic should never do something different based on this. Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: linux-s390@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
101 lines
2 KiB
C
101 lines
2 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Hypervisor filesystem for Linux on s390 - debugfs interface
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*
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* Copyright IBM Corp. 2010
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* Author(s): Michael Holzheu <holzheu@linux.vnet.ibm.com>
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*/
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#include <linux/slab.h>
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#include "hypfs.h"
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static struct dentry *dbfs_dir;
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static struct hypfs_dbfs_data *hypfs_dbfs_data_alloc(struct hypfs_dbfs_file *f)
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{
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struct hypfs_dbfs_data *data;
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data = kmalloc(sizeof(*data), GFP_KERNEL);
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if (!data)
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return NULL;
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data->dbfs_file = f;
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return data;
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}
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static void hypfs_dbfs_data_free(struct hypfs_dbfs_data *data)
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{
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data->dbfs_file->data_free(data->buf_free_ptr);
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kfree(data);
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}
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static ssize_t dbfs_read(struct file *file, char __user *buf,
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size_t size, loff_t *ppos)
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{
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struct hypfs_dbfs_data *data;
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struct hypfs_dbfs_file *df;
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ssize_t rc;
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if (*ppos != 0)
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return 0;
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df = file_inode(file)->i_private;
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mutex_lock(&df->lock);
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data = hypfs_dbfs_data_alloc(df);
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if (!data) {
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mutex_unlock(&df->lock);
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return -ENOMEM;
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}
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rc = df->data_create(&data->buf, &data->buf_free_ptr, &data->size);
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if (rc) {
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mutex_unlock(&df->lock);
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kfree(data);
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return rc;
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}
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mutex_unlock(&df->lock);
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rc = simple_read_from_buffer(buf, size, ppos, data->buf, data->size);
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hypfs_dbfs_data_free(data);
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return rc;
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}
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static long dbfs_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
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{
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struct hypfs_dbfs_file *df = file_inode(file)->i_private;
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long rc;
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mutex_lock(&df->lock);
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if (df->unlocked_ioctl)
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rc = df->unlocked_ioctl(file, cmd, arg);
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else
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rc = -ENOTTY;
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mutex_unlock(&df->lock);
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return rc;
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}
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static const struct file_operations dbfs_ops = {
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.read = dbfs_read,
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.llseek = no_llseek,
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.unlocked_ioctl = dbfs_ioctl,
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};
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void hypfs_dbfs_create_file(struct hypfs_dbfs_file *df)
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{
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df->dentry = debugfs_create_file(df->name, 0400, dbfs_dir, df,
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&dbfs_ops);
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mutex_init(&df->lock);
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}
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void hypfs_dbfs_remove_file(struct hypfs_dbfs_file *df)
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{
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debugfs_remove(df->dentry);
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}
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void hypfs_dbfs_init(void)
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{
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dbfs_dir = debugfs_create_dir("s390_hypfs", NULL);
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}
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void hypfs_dbfs_exit(void)
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{
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debugfs_remove(dbfs_dir);
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}
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