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_bdev.c | 321 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 321 insertions(+) create mode 100644 kernel/fs/logfs/dev_bdev.c (limited to 'kernel/fs/logfs/dev_bdev.c') diff --git a/kernel/fs/logfs/dev_bdev.c b/kernel/fs/logfs/dev_bdev.c new file mode 100644 index 000000000..76279e119 --- /dev/null +++ b/kernel/fs/logfs/dev_bdev.c @@ -0,0 +1,321 @@ +/* + * fs/logfs/dev_bdev.c - Device access methods for block devices + * + * As should be obvious for Linux kernel code, license is GPLv2 + * + * Copyright (c) 2005-2008 Joern Engel + */ +#include "logfs.h" +#include +#include +#include +#include +#include + +#define PAGE_OFS(ofs) ((ofs) & (PAGE_SIZE-1)) + +static int sync_request(struct page *page, struct block_device *bdev, int rw) +{ + struct bio bio; + struct bio_vec bio_vec; + + bio_init(&bio); + bio.bi_max_vecs = 1; + bio.bi_io_vec = &bio_vec; + bio_vec.bv_page = page; + bio_vec.bv_len = PAGE_SIZE; + bio_vec.bv_offset = 0; + bio.bi_vcnt = 1; + bio.bi_bdev = bdev; + bio.bi_iter.bi_sector = page->index * (PAGE_SIZE >> 9); + bio.bi_iter.bi_size = PAGE_SIZE; + + return submit_bio_wait(rw, &bio); +} + +static int bdev_readpage(void *_sb, struct page *page) +{ + struct super_block *sb = _sb; + struct block_device *bdev = logfs_super(sb)->s_bdev; + int err; + + err = sync_request(page, bdev, READ); + if (err) { + ClearPageUptodate(page); + SetPageError(page); + } else { + SetPageUptodate(page); + ClearPageError(page); + } + unlock_page(page); + return err; +} + +static DECLARE_WAIT_QUEUE_HEAD(wq); + +static void writeseg_end_io(struct bio *bio, int err) +{ + const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); + struct bio_vec *bvec; + int i; + struct super_block *sb = bio->bi_private; + struct logfs_super *super = logfs_super(sb); + + BUG_ON(!uptodate); /* FIXME: Retry io or write elsewhere */ + BUG_ON(err); + + bio_for_each_segment_all(bvec, bio, i) { + end_page_writeback(bvec->bv_page); + page_cache_release(bvec->bv_page); + } + bio_put(bio); + if (atomic_dec_and_test(&super->s_pending_writes)) + wake_up(&wq); +} + +static int __bdev_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 bio *bio; + struct page *page; + unsigned int max_pages; + int i; + + max_pages = min(nr_pages, (size_t) bio_get_nr_vecs(super->s_bdev)); + + bio = bio_alloc(GFP_NOFS, max_pages); + BUG_ON(!bio); + + for (i = 0; i < nr_pages; i++) { + if (i >= max_pages) { + /* Block layer cannot split bios :( */ + bio->bi_vcnt = i; + bio->bi_iter.bi_size = i * PAGE_SIZE; + bio->bi_bdev = super->s_bdev; + bio->bi_iter.bi_sector = ofs >> 9; + bio->bi_private = sb; + bio->bi_end_io = writeseg_end_io; + atomic_inc(&super->s_pending_writes); + submit_bio(WRITE, bio); + + ofs += i * PAGE_SIZE; + index += i; + nr_pages -= i; + i = 0; + + bio = bio_alloc(GFP_NOFS, max_pages); + BUG_ON(!bio); + } + page = find_lock_page(mapping, index + i); + BUG_ON(!page); + bio->bi_io_vec[i].bv_page = page; + bio->bi_io_vec[i].bv_len = PAGE_SIZE; + bio->bi_io_vec[i].bv_offset = 0; + + BUG_ON(PageWriteback(page)); + set_page_writeback(page); + unlock_page(page); + } + bio->bi_vcnt = nr_pages; + bio->bi_iter.bi_size = nr_pages * PAGE_SIZE; + bio->bi_bdev = super->s_bdev; + bio->bi_iter.bi_sector = ofs >> 9; + bio->bi_private = sb; + bio->bi_end_io = writeseg_end_io; + atomic_inc(&super->s_pending_writes); + submit_bio(WRITE, bio); + return 0; +} + +static void bdev_writeseg(struct super_block *sb, u64 ofs, size_t len) +{ + struct logfs_super *super = logfs_super(sb); + int head; + + BUG_ON(super->s_flags & LOGFS_SB_FLAG_RO); + + 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); + __bdev_writeseg(sb, ofs, ofs >> PAGE_SHIFT, len >> PAGE_SHIFT); +} + + +static void erase_end_io(struct bio *bio, int err) +{ + const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); + struct super_block *sb = bio->bi_private; + struct logfs_super *super = logfs_super(sb); + + BUG_ON(!uptodate); /* FIXME: Retry io or write elsewhere */ + BUG_ON(err); + BUG_ON(bio->bi_vcnt == 0); + bio_put(bio); + if (atomic_dec_and_test(&super->s_pending_writes)) + wake_up(&wq); +} + +static int do_erase(struct super_block *sb, u64 ofs, pgoff_t index, + size_t nr_pages) +{ + struct logfs_super *super = logfs_super(sb); + struct bio *bio; + unsigned int max_pages; + int i; + + max_pages = min(nr_pages, (size_t) bio_get_nr_vecs(super->s_bdev)); + + bio = bio_alloc(GFP_NOFS, max_pages); + BUG_ON(!bio); + + for (i = 0; i < nr_pages; i++) { + if (i >= max_pages) { + /* Block layer cannot split bios :( */ + bio->bi_vcnt = i; + bio->bi_iter.bi_size = i * PAGE_SIZE; + bio->bi_bdev = super->s_bdev; + bio->bi_iter.bi_sector = ofs >> 9; + bio->bi_private = sb; + bio->bi_end_io = erase_end_io; + atomic_inc(&super->s_pending_writes); + submit_bio(WRITE, bio); + + ofs += i * PAGE_SIZE; + index += i; + nr_pages -= i; + i = 0; + + bio = bio_alloc(GFP_NOFS, max_pages); + BUG_ON(!bio); + } + bio->bi_io_vec[i].bv_page = super->s_erase_page; + bio->bi_io_vec[i].bv_len = PAGE_SIZE; + bio->bi_io_vec[i].bv_offset = 0; + } + bio->bi_vcnt = nr_pages; + bio->bi_iter.bi_size = nr_pages * PAGE_SIZE; + bio->bi_bdev = super->s_bdev; + bio->bi_iter.bi_sector = ofs >> 9; + bio->bi_private = sb; + bio->bi_end_io = erase_end_io; + atomic_inc(&super->s_pending_writes); + submit_bio(WRITE, bio); + return 0; +} + +static int bdev_erase(struct super_block *sb, loff_t to, size_t len, + int ensure_write) +{ + struct logfs_super *super = logfs_super(sb); + + BUG_ON(to & (PAGE_SIZE - 1)); + BUG_ON(len & (PAGE_SIZE - 1)); + + if (super->s_flags & LOGFS_SB_FLAG_RO) + return -EROFS; + + if (ensure_write) { + /* + * Object store doesn't care whether erases happen or not. + * But for the journal they are required. Otherwise a scan + * can find an old commit entry and assume it is the current + * one, travelling back in time. + */ + do_erase(sb, to, to >> PAGE_SHIFT, len >> PAGE_SHIFT); + } + + return 0; +} + +static void bdev_sync(struct super_block *sb) +{ + struct logfs_super *super = logfs_super(sb); + + wait_event(wq, atomic_read(&super->s_pending_writes) == 0); +} + +static struct page *bdev_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 = bdev_readpage; + + *ofs = 0; + return read_cache_page(mapping, 0, filler, sb); +} + +static struct page *bdev_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 = bdev_readpage; + u64 pos = (super->s_bdev->bd_inode->i_size & ~0xfffULL) - 0x1000; + pgoff_t index = pos >> PAGE_SHIFT; + + *ofs = pos; + return read_cache_page(mapping, index, filler, sb); +} + +static int bdev_write_sb(struct super_block *sb, struct page *page) +{ + struct block_device *bdev = logfs_super(sb)->s_bdev; + + /* Nothing special to do for block devices. */ + return sync_request(page, bdev, WRITE); +} + +static void bdev_put_device(struct logfs_super *s) +{ + blkdev_put(s->s_bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL); +} + +static int bdev_can_write_buf(struct super_block *sb, u64 ofs) +{ + return 0; +} + +static const struct logfs_device_ops bd_devops = { + .find_first_sb = bdev_find_first_sb, + .find_last_sb = bdev_find_last_sb, + .write_sb = bdev_write_sb, + .readpage = bdev_readpage, + .writeseg = bdev_writeseg, + .erase = bdev_erase, + .can_write_buf = bdev_can_write_buf, + .sync = bdev_sync, + .put_device = bdev_put_device, +}; + +int logfs_get_sb_bdev(struct logfs_super *p, struct file_system_type *type, + const char *devname) +{ + struct block_device *bdev; + + bdev = blkdev_get_by_path(devname, FMODE_READ|FMODE_WRITE|FMODE_EXCL, + type); + if (IS_ERR(bdev)) + return PTR_ERR(bdev); + + if (MAJOR(bdev->bd_dev) == MTD_BLOCK_MAJOR) { + int mtdnr = MINOR(bdev->bd_dev); + blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL); + return logfs_get_sb_mtd(p, mtdnr); + } + + p->s_bdev = bdev; + p->s_mtd = NULL; + p->s_devops = &bd_devops; + return 0; +} -- cgit 1.2.3-korg