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Diffstat (limited to 'fs/logfs/dev_mtd.c')
-rw-r--r--fs/logfs/dev_mtd.c274
1 files changed, 0 insertions, 274 deletions
diff --git a/fs/logfs/dev_mtd.c b/fs/logfs/dev_mtd.c
deleted file mode 100644
index b76a62b1978f..000000000000
--- a/fs/logfs/dev_mtd.c
+++ /dev/null
@@ -1,274 +0,0 @@
-/*
- * 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;
-}
-
-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;
-}
-
-/*
- * 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);
-}
-
-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;
-}
-
-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);
-}
-
-static void logfs_mtd_sync(struct super_block *sb)
-{
- struct mtd_info *mtd = logfs_super(sb)->s_mtd;
-
- mtd_sync(mtd);
-}
-
-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;
-}
-
-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);
-}
-
-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);
-}
-
-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;
-}
-
-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);
-}
-
-static void logfs_mtd_put_device(struct logfs_super *s)
-{
- put_mtd_device(s->s_mtd);
-}
-
-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;
-}
-
-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;
-}