mirror of
https://github.com/torvalds/linux.git
synced 2024-12-05 02:23:16 +00:00
25985edced
Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
279 lines
6.6 KiB
C
279 lines
6.6 KiB
C
/*
|
|
* fs/logfs/dev_mtd.c - Device access methods for MTD
|
|
*
|
|
* As should be obvious for Linux kernel code, license is GPLv2
|
|
*
|
|
* Copyright (c) 2005-2008 Joern Engel <joern@logfs.org>
|
|
*/
|
|
#include "logfs.h"
|
|
#include <linux/completion.h>
|
|
#include <linux/mount.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/slab.h>
|
|
|
|
#define PAGE_OFS(ofs) ((ofs) & (PAGE_SIZE-1))
|
|
|
|
static int mtd_read(struct super_block *sb, loff_t ofs, size_t len, void *buf)
|
|
{
|
|
struct mtd_info *mtd = logfs_super(sb)->s_mtd;
|
|
size_t retlen;
|
|
int ret;
|
|
|
|
ret = mtd->read(mtd, ofs, len, &retlen, buf);
|
|
BUG_ON(ret == -EINVAL);
|
|
if (ret)
|
|
return ret;
|
|
|
|
/* Not sure if we should loop instead. */
|
|
if (retlen != len)
|
|
return -EIO;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int mtd_write(struct super_block *sb, loff_t ofs, size_t len, void *buf)
|
|
{
|
|
struct logfs_super *super = logfs_super(sb);
|
|
struct mtd_info *mtd = super->s_mtd;
|
|
size_t retlen;
|
|
loff_t page_start, page_end;
|
|
int ret;
|
|
|
|
if (super->s_flags & LOGFS_SB_FLAG_RO)
|
|
return -EROFS;
|
|
|
|
BUG_ON((ofs >= mtd->size) || (len > mtd->size - ofs));
|
|
BUG_ON(ofs != (ofs >> super->s_writeshift) << super->s_writeshift);
|
|
BUG_ON(len > PAGE_CACHE_SIZE);
|
|
page_start = ofs & PAGE_CACHE_MASK;
|
|
page_end = PAGE_CACHE_ALIGN(ofs + len) - 1;
|
|
ret = mtd->write(mtd, ofs, len, &retlen, buf);
|
|
if (ret || (retlen != len))
|
|
return -EIO;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* For as long as I can remember (since about 2001) mtd->erase has been an
|
|
* asynchronous interface lacking the first driver to actually use the
|
|
* asynchronous properties. So just to prevent the first implementor of such
|
|
* a thing from breaking logfs in 2350, we do the usual pointless dance to
|
|
* declare a completion variable and wait for completion before returning
|
|
* from mtd_erase(). What an exercise in futility!
|
|
*/
|
|
static void logfs_erase_callback(struct erase_info *ei)
|
|
{
|
|
complete((struct completion *)ei->priv);
|
|
}
|
|
|
|
static int mtd_erase_mapping(struct super_block *sb, loff_t ofs, size_t len)
|
|
{
|
|
struct logfs_super *super = logfs_super(sb);
|
|
struct address_space *mapping = super->s_mapping_inode->i_mapping;
|
|
struct page *page;
|
|
pgoff_t index = ofs >> PAGE_SHIFT;
|
|
|
|
for (index = ofs >> PAGE_SHIFT; index < (ofs + len) >> PAGE_SHIFT; index++) {
|
|
page = find_get_page(mapping, index);
|
|
if (!page)
|
|
continue;
|
|
memset(page_address(page), 0xFF, PAGE_SIZE);
|
|
page_cache_release(page);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int mtd_erase(struct super_block *sb, loff_t ofs, size_t len,
|
|
int ensure_write)
|
|
{
|
|
struct mtd_info *mtd = logfs_super(sb)->s_mtd;
|
|
struct erase_info ei;
|
|
DECLARE_COMPLETION_ONSTACK(complete);
|
|
int ret;
|
|
|
|
BUG_ON(len % mtd->erasesize);
|
|
if (logfs_super(sb)->s_flags & LOGFS_SB_FLAG_RO)
|
|
return -EROFS;
|
|
|
|
memset(&ei, 0, sizeof(ei));
|
|
ei.mtd = mtd;
|
|
ei.addr = ofs;
|
|
ei.len = len;
|
|
ei.callback = logfs_erase_callback;
|
|
ei.priv = (long)&complete;
|
|
ret = mtd->erase(mtd, &ei);
|
|
if (ret)
|
|
return -EIO;
|
|
|
|
wait_for_completion(&complete);
|
|
if (ei.state != MTD_ERASE_DONE)
|
|
return -EIO;
|
|
return mtd_erase_mapping(sb, ofs, len);
|
|
}
|
|
|
|
static void mtd_sync(struct super_block *sb)
|
|
{
|
|
struct mtd_info *mtd = logfs_super(sb)->s_mtd;
|
|
|
|
if (mtd->sync)
|
|
mtd->sync(mtd);
|
|
}
|
|
|
|
static int mtd_readpage(void *_sb, struct page *page)
|
|
{
|
|
struct super_block *sb = _sb;
|
|
int err;
|
|
|
|
err = mtd_read(sb, page->index << PAGE_SHIFT, PAGE_SIZE,
|
|
page_address(page));
|
|
if (err == -EUCLEAN || err == -EBADMSG) {
|
|
/* -EBADMSG happens regularly on power failures */
|
|
err = 0;
|
|
/* FIXME: force GC this segment */
|
|
}
|
|
if (err) {
|
|
ClearPageUptodate(page);
|
|
SetPageError(page);
|
|
} else {
|
|
SetPageUptodate(page);
|
|
ClearPageError(page);
|
|
}
|
|
unlock_page(page);
|
|
return err;
|
|
}
|
|
|
|
static struct page *mtd_find_first_sb(struct super_block *sb, u64 *ofs)
|
|
{
|
|
struct logfs_super *super = logfs_super(sb);
|
|
struct address_space *mapping = super->s_mapping_inode->i_mapping;
|
|
filler_t *filler = mtd_readpage;
|
|
struct mtd_info *mtd = super->s_mtd;
|
|
|
|
if (!mtd->block_isbad)
|
|
return NULL;
|
|
|
|
*ofs = 0;
|
|
while (mtd->block_isbad(mtd, *ofs)) {
|
|
*ofs += mtd->erasesize;
|
|
if (*ofs >= mtd->size)
|
|
return NULL;
|
|
}
|
|
BUG_ON(*ofs & ~PAGE_MASK);
|
|
return read_cache_page(mapping, *ofs >> PAGE_SHIFT, filler, sb);
|
|
}
|
|
|
|
static struct page *mtd_find_last_sb(struct super_block *sb, u64 *ofs)
|
|
{
|
|
struct logfs_super *super = logfs_super(sb);
|
|
struct address_space *mapping = super->s_mapping_inode->i_mapping;
|
|
filler_t *filler = mtd_readpage;
|
|
struct mtd_info *mtd = super->s_mtd;
|
|
|
|
if (!mtd->block_isbad)
|
|
return NULL;
|
|
|
|
*ofs = mtd->size - mtd->erasesize;
|
|
while (mtd->block_isbad(mtd, *ofs)) {
|
|
*ofs -= mtd->erasesize;
|
|
if (*ofs <= 0)
|
|
return NULL;
|
|
}
|
|
*ofs = *ofs + mtd->erasesize - 0x1000;
|
|
BUG_ON(*ofs & ~PAGE_MASK);
|
|
return read_cache_page(mapping, *ofs >> PAGE_SHIFT, filler, sb);
|
|
}
|
|
|
|
static int __mtd_writeseg(struct super_block *sb, u64 ofs, pgoff_t index,
|
|
size_t nr_pages)
|
|
{
|
|
struct logfs_super *super = logfs_super(sb);
|
|
struct address_space *mapping = super->s_mapping_inode->i_mapping;
|
|
struct page *page;
|
|
int i, err;
|
|
|
|
for (i = 0; i < nr_pages; i++) {
|
|
page = find_lock_page(mapping, index + i);
|
|
BUG_ON(!page);
|
|
|
|
err = mtd_write(sb, page->index << PAGE_SHIFT, PAGE_SIZE,
|
|
page_address(page));
|
|
unlock_page(page);
|
|
page_cache_release(page);
|
|
if (err)
|
|
return err;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static void mtd_writeseg(struct super_block *sb, u64 ofs, size_t len)
|
|
{
|
|
struct logfs_super *super = logfs_super(sb);
|
|
int head;
|
|
|
|
if (super->s_flags & LOGFS_SB_FLAG_RO)
|
|
return;
|
|
|
|
if (len == 0) {
|
|
/* This can happen when the object fit perfectly into a
|
|
* segment, the segment gets written per sync and subsequently
|
|
* closed.
|
|
*/
|
|
return;
|
|
}
|
|
head = ofs & (PAGE_SIZE - 1);
|
|
if (head) {
|
|
ofs -= head;
|
|
len += head;
|
|
}
|
|
len = PAGE_ALIGN(len);
|
|
__mtd_writeseg(sb, ofs, ofs >> PAGE_SHIFT, len >> PAGE_SHIFT);
|
|
}
|
|
|
|
static void mtd_put_device(struct logfs_super *s)
|
|
{
|
|
put_mtd_device(s->s_mtd);
|
|
}
|
|
|
|
static int mtd_can_write_buf(struct super_block *sb, u64 ofs)
|
|
{
|
|
struct logfs_super *super = logfs_super(sb);
|
|
void *buf;
|
|
int err;
|
|
|
|
buf = kmalloc(super->s_writesize, GFP_KERNEL);
|
|
if (!buf)
|
|
return -ENOMEM;
|
|
err = mtd_read(sb, ofs, super->s_writesize, buf);
|
|
if (err)
|
|
goto out;
|
|
if (memchr_inv(buf, 0xff, super->s_writesize))
|
|
err = -EIO;
|
|
kfree(buf);
|
|
out:
|
|
return err;
|
|
}
|
|
|
|
static const struct logfs_device_ops mtd_devops = {
|
|
.find_first_sb = mtd_find_first_sb,
|
|
.find_last_sb = mtd_find_last_sb,
|
|
.readpage = mtd_readpage,
|
|
.writeseg = mtd_writeseg,
|
|
.erase = mtd_erase,
|
|
.can_write_buf = mtd_can_write_buf,
|
|
.sync = mtd_sync,
|
|
.put_device = mtd_put_device,
|
|
};
|
|
|
|
int logfs_get_sb_mtd(struct logfs_super *s, int mtdnr)
|
|
{
|
|
struct mtd_info *mtd = get_mtd_device(NULL, mtdnr);
|
|
if (IS_ERR(mtd))
|
|
return PTR_ERR(mtd);
|
|
|
|
s->s_bdev = NULL;
|
|
s->s_mtd = mtd;
|
|
s->s_devops = &mtd_devops;
|
|
return 0;
|
|
}
|