Contributors: 12
| Author |
Tokens |
Token Proportion |
Commits |
Commit Proportion |
| David Howells |
226 |
60.43% |
2 |
10.53% |
| Bob Liu |
40 |
10.70% |
1 |
5.26% |
| Christoph Hellwig |
32 |
8.56% |
1 |
5.26% |
| Artem B. Bityutskiy |
27 |
7.22% |
3 |
15.79% |
| Greg Ungerer |
22 |
5.88% |
1 |
5.26% |
| Linus Torvalds (pre-git) |
8 |
2.14% |
3 |
15.79% |
| Al Viro |
5 |
1.34% |
2 |
10.53% |
| Andrew Morton |
5 |
1.34% |
2 |
10.53% |
| David Hildenbrand |
3 |
0.80% |
1 |
5.26% |
| David Brownell |
2 |
0.53% |
1 |
5.26% |
| Thomas Gleixner |
2 |
0.53% |
1 |
5.26% |
| Linus Torvalds |
2 |
0.53% |
1 |
5.26% |
| Total |
374 |
|
19 |
|
// SPDX-License-Identifier: GPL-2.0-or-later
/* NOMMU mmap support for RomFS on MTD devices
*
* Copyright © 2007 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*/
#include <linux/mm.h>
#include <linux/mtd/super.h>
#include "internal.h"
/*
* try to determine where a shared mapping can be made
* - only supported for NOMMU at the moment (MMU can't doesn't copy private
* mappings)
* - attempts to map through to the underlying MTD device
*/
static unsigned long romfs_get_unmapped_area(struct file *file,
unsigned long addr,
unsigned long len,
unsigned long pgoff,
unsigned long flags)
{
struct inode *inode = file->f_mapping->host;
struct mtd_info *mtd = inode->i_sb->s_mtd;
unsigned long isize, offset, maxpages, lpages;
int ret;
if (!mtd)
return (unsigned long) -ENOSYS;
/* the mapping mustn't extend beyond the EOF */
lpages = (len + PAGE_SIZE - 1) >> PAGE_SHIFT;
isize = i_size_read(inode);
offset = pgoff << PAGE_SHIFT;
maxpages = (isize + PAGE_SIZE - 1) >> PAGE_SHIFT;
if ((pgoff >= maxpages) || (maxpages - pgoff < lpages))
return (unsigned long) -EINVAL;
if (addr != 0)
return (unsigned long) -EINVAL;
if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
return (unsigned long) -EINVAL;
offset += ROMFS_I(inode)->i_dataoffset;
if (offset >= mtd->size)
return (unsigned long) -EINVAL;
/* the mapping mustn't extend beyond the EOF */
if ((offset + len) > mtd->size)
len = mtd->size - offset;
ret = mtd_get_unmapped_area(mtd, len, offset, flags);
if (ret == -EOPNOTSUPP)
ret = -ENOSYS;
return (unsigned long) ret;
}
/*
* permit a R/O mapping to be made directly through onto an MTD device if
* possible
*/
static int romfs_mmap(struct file *file, struct vm_area_struct *vma)
{
return is_nommu_shared_mapping(vma->vm_flags) ? 0 : -ENOSYS;
}
static unsigned romfs_mmap_capabilities(struct file *file)
{
struct mtd_info *mtd = file_inode(file)->i_sb->s_mtd;
if (!mtd)
return NOMMU_MAP_COPY;
return mtd_mmap_capabilities(mtd);
}
const struct file_operations romfs_ro_fops = {
.llseek = generic_file_llseek,
.read_iter = generic_file_read_iter,
.splice_read = filemap_splice_read,
.mmap = romfs_mmap,
.get_unmapped_area = romfs_get_unmapped_area,
.mmap_capabilities = romfs_mmap_capabilities,
};