From 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 Mon Sep 17 00:00:00 2001 From: Yunhong Jiang Date: Tue, 4 Aug 2015 12:17:53 -0700 Subject: Add the rt linux 4.1.3-rt3 as base Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang --- kernel/fs/logfs/dev_mtd.c | 274 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 274 insertions(+) create mode 100644 kernel/fs/logfs/dev_mtd.c (limited to 'kernel/fs/logfs/dev_mtd.c') diff --git a/kernel/fs/logfs/dev_mtd.c b/kernel/fs/logfs/dev_mtd.c new file mode 100644 index 000000000..9c5014494 --- /dev/null +++ b/kernel/fs/logfs/dev_mtd.c @@ -0,0 +1,274 @@ +/* + * 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 + */ +#include "logfs.h" +#include +#include +#include +#include + +#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_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 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); + page_cache_release(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); + page_cache_release(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; +} -- cgit 1.2.3-korg