Release 4.7 fs/logfs/dev_mtd.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 logfs_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;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
joern engel | joern engel | 82 | 97.62% | 1 | 33.33% |
artem bityutskiy | artem bityutskiy | 2 | 2.38% | 2 | 66.67% |
| Total | 84 | 100.00% | 3 | 100.00% |
static int loffs_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_SIZE);
page_start = ofs & PAGE_MASK;
page_end = PAGE_ALIGN(ofs + len) - 1;
ret = mtd_write(mtd, ofs, len, &retlen, buf);
if (ret || (retlen != len))
return -EIO;
return 0;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
joern engel | joern engel | 153 | 96.84% | 1 | 25.00% |
kirill a. shutemov | kirill a. shutemov | 3 | 1.90% | 1 | 25.00% |
artem bityutskiy | artem bityutskiy | 2 | 1.27% | 2 | 50.00% |
| Total | 158 | 100.00% | 4 | 100.00% |
/*
* 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 logfs_mtd_erase(). What an exercise in futility!
*/
static void logfs_erase_callback(struct erase_info *ei)
{
complete((struct completion *)ei->priv);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
joern engel | joern engel | 23 | 100.00% | 1 | 100.00% |
| Total | 23 | 100.00% | 1 | 100.00% |
static int logfs_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);
put_page(page);
}
return 0;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
joern engel | joern engel | 106 | 98.15% | 1 | 33.33% |
artem bityutskiy | artem bityutskiy | 1 | 0.93% | 1 | 33.33% |
kirill a. shutemov | kirill a. shutemov | 1 | 0.93% | 1 | 33.33% |
| Total | 108 | 100.00% | 3 | 100.00% |
static int logfs_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 logfs_mtd_erase_mapping(sb, ofs, len);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
joern engel | joern engel | 158 | 98.14% | 2 | 50.00% |
artem bityutskiy | artem bityutskiy | 3 | 1.86% | 2 | 50.00% |
| Total | 161 | 100.00% | 4 | 100.00% |
static void logfs_mtd_sync(struct super_block *sb)
{
struct mtd_info *mtd = logfs_super(sb)->s_mtd;
mtd_sync(mtd);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
joern engel | joern engel | 26 | 92.86% | 1 | 33.33% |
artem bityutskiy | artem bityutskiy | 2 | 7.14% | 2 | 66.67% |
| Total | 28 | 100.00% | 3 | 100.00% |
static int logfs_mtd_readpage(void *_sb, struct page *page)
{
struct super_block *sb = _sb;
int err;
err = logfs_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;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
joern engel | joern engel | 100 | 98.04% | 2 | 66.67% |
artem bityutskiy | artem bityutskiy | 2 | 1.96% | 1 | 33.33% |
| Total | 102 | 100.00% | 3 | 100.00% |
static struct page *logfs_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 = logfs_mtd_readpage;
struct mtd_info *mtd = super->s_mtd;
*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);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
joern engel | joern engel | 110 | 97.35% | 1 | 33.33% |
artem bityutskiy | artem bityutskiy | 3 | 2.65% | 2 | 66.67% |
| Total | 113 | 100.00% | 3 | 100.00% |
static struct page *logfs_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 = logfs_mtd_readpage;
struct mtd_info *mtd = super->s_mtd;
*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);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
joern engel | joern engel | 126 | 97.67% | 1 | 33.33% |
artem bityutskiy | artem bityutskiy | 3 | 2.33% | 2 | 66.67% |
| Total | 129 | 100.00% | 3 | 100.00% |
static int __logfs_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 = loffs_mtd_write(sb, page->index << PAGE_SHIFT, PAGE_SIZE,
page_address(page));
unlock_page(page);
put_page(page);
if (err)
return err;
}
return 0;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
joern engel | joern engel | 120 | 97.56% | 1 | 33.33% |
artem bityutskiy | artem bityutskiy | 2 | 1.63% | 1 | 33.33% |
kirill a. shutemov | kirill a. shutemov | 1 | 0.81% | 1 | 33.33% |
| Total | 123 | 100.00% | 3 | 100.00% |
static void logfs_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);
__logfs_mtd_writeseg(sb, ofs, ofs >> PAGE_SHIFT, len >> PAGE_SHIFT);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
joern engel | joern engel | 93 | 97.89% | 1 | 50.00% |
artem bityutskiy | artem bityutskiy | 2 | 2.11% | 1 | 50.00% |
| Total | 95 | 100.00% | 2 | 100.00% |
static void logfs_mtd_put_device(struct logfs_super *s)
{
put_mtd_device(s->s_mtd);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
joern engel | joern engel | 14 | 77.78% | 1 | 33.33% |
al viro | al viro | 3 | 16.67% | 1 | 33.33% |
artem bityutskiy | artem bityutskiy | 1 | 5.56% | 1 | 33.33% |
| Total | 18 | 100.00% | 3 | 100.00% |
static int logfs_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 = logfs_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;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
joern engel | joern engel | 99 | 98.02% | 1 | 50.00% |
artem bityutskiy | artem bityutskiy | 2 | 1.98% | 1 | 50.00% |
| Total | 101 | 100.00% | 2 | 100.00% |
static const struct logfs_device_ops mtd_devops = {
.find_first_sb = logfs_mtd_find_first_sb,
.find_last_sb = logfs_mtd_find_last_sb,
.readpage = logfs_mtd_readpage,
.writeseg = logfs_mtd_writeseg,
.erase = logfs_mtd_erase,
.can_write_buf = logfs_mtd_can_write_buf,
.sync = logfs_mtd_sync,
.put_device = logfs_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;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
al viro | al viro | 25 | 41.67% | 3 | 60.00% |
joern engel | joern engel | 22 | 36.67% | 1 | 20.00% |
dan carpenter | dan carpenter | 13 | 21.67% | 1 | 20.00% |
| Total | 60 | 100.00% | 5 | 100.00% |
Overall Contributors
| Person | Tokens | Prop | Commits | CommitProp |
joern engel | joern engel | 1295 | 94.18% | 3 | 20.00% |
artem bityutskiy | artem bityutskiy | 34 | 2.47% | 6 | 40.00% |
al viro | al viro | 28 | 2.04% | 4 | 26.67% |
dan carpenter | dan carpenter | 13 | 0.95% | 1 | 6.67% |
kirill a. shutemov | kirill a. shutemov | 5 | 0.36% | 1 | 6.67% |
| Total | 1375 | 100.00% | 15 | 100.00% |
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