From: NeilBrown Date: Tue, 22 May 2012 03:55:08 +0000 (+1000) Subject: md/bitmap: centralise allocation of bitmap file pages. X-Git-Tag: upstream/snapshot3+hdmi~7404^2~28 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=27581e5ae01f77b5472dc5c2368b41063fed7f37;p=platform%2Fadaptation%2Frenesas_rcar%2Frenesas_kernel.git md/bitmap: centralise allocation of bitmap file pages. Instead of allocating pages in read_sb_page, read_page and bitmap_read_sb, allocate them all in bitmap_init_from disk. Also replace the hack of calling "attach_page_buffers(page, NULL)" to ensure that free_buffer() won't complain, by putting a test for PagePrivate in free_buffer(). Signed-off-by: NeilBrown --- diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c index c042efd..324a198 100644 --- a/drivers/md/bitmap.c +++ b/drivers/md/bitmap.c @@ -130,22 +130,14 @@ static void bitmap_checkfree(struct bitmap *bitmap, unsigned long page) */ /* IO operations when bitmap is stored near all superblocks */ -static struct page *read_sb_page(struct mddev *mddev, loff_t offset, - struct page *page, - unsigned long index, int size) +static int read_sb_page(struct mddev *mddev, loff_t offset, + struct page *page, + unsigned long index, int size) { /* choose a good rdev and read the page from there */ struct md_rdev *rdev; sector_t target; - int did_alloc = 0; - - if (!page) { - page = alloc_page(GFP_KERNEL); - if (!page) - return ERR_PTR(-ENOMEM); - did_alloc = 1; - } rdev_for_each(rdev, mddev) { if (! test_bit(In_sync, &rdev->flags) @@ -158,15 +150,10 @@ static struct page *read_sb_page(struct mddev *mddev, loff_t offset, roundup(size, bdev_logical_block_size(rdev->bdev)), page, READ, true)) { page->index = index; - attach_page_buffers(page, NULL); /* so that free_buffer will - * quietly no-op */ - return page; + return 0; } } - if (did_alloc) - put_page(page); - return ERR_PTR(-EIO); - + return -EIO; } static struct md_rdev *next_active_rdev(struct md_rdev *rdev, struct mddev *mddev) @@ -325,8 +312,12 @@ __clear_page_buffers(struct page *page) } static void free_buffers(struct page *page) { - struct buffer_head *bh = page_buffers(page); + struct buffer_head *bh; + if (!PagePrivate(page)) + return; + + bh = page_buffers(page); while (bh) { struct buffer_head *next = bh->b_this_page; free_buffer_head(bh); @@ -343,11 +334,12 @@ static void free_buffers(struct page *page) * This usage is similar to how swap files are handled, and allows us * to write to a file with no concerns of memory allocation failing. */ -static struct page *read_page(struct file *file, unsigned long index, - struct bitmap *bitmap, - unsigned long count) +static int read_page(struct file *file, unsigned long index, + struct bitmap *bitmap, + unsigned long count, + struct page *page) { - struct page *page = NULL; + int ret = 0; struct inode *inode = file->f_path.dentry->d_inode; struct buffer_head *bh; sector_t block; @@ -355,16 +347,9 @@ static struct page *read_page(struct file *file, unsigned long index, pr_debug("read bitmap file (%dB @ %llu)\n", (int)PAGE_SIZE, (unsigned long long)index << PAGE_SHIFT); - page = alloc_page(GFP_KERNEL); - if (!page) - page = ERR_PTR(-ENOMEM); - if (IS_ERR(page)) - goto out; - bh = alloc_page_buffers(page, 1<i_blkbits, 0); if (!bh) { - put_page(page); - page = ERR_PTR(-ENOMEM); + ret = -ENOMEM; goto out; } attach_page_buffers(page, bh); @@ -376,8 +361,7 @@ static struct page *read_page(struct file *file, unsigned long index, bh->b_blocknr = bmap(inode, block); if (bh->b_blocknr == 0) { /* Cannot use this file! */ - free_buffers(page); - page = ERR_PTR(-EINVAL); + ret = -EINVAL; goto out; } bh->b_bdev = inode->i_sb->s_bdev; @@ -400,17 +384,15 @@ static struct page *read_page(struct file *file, unsigned long index, wait_event(bitmap->write_wait, atomic_read(&bitmap->pending_writes)==0); - if (bitmap->flags & BITMAP_WRITE_ERROR) { - free_buffers(page); - page = ERR_PTR(-EIO); - } + if (bitmap->flags & BITMAP_WRITE_ERROR) + ret = -EIO; out: - if (IS_ERR(page)) - printk(KERN_ALERT "md: bitmap read error: (%dB @ %llu): %ld\n", + if (ret) + printk(KERN_ALERT "md: bitmap read error: (%dB @ %llu): %d\n", (int)PAGE_SIZE, (unsigned long long)index << PAGE_SHIFT, - PTR_ERR(page)); - return page; + ret); + return ret; } /* @@ -552,6 +534,7 @@ static int bitmap_read_sb(struct bitmap *bitmap) unsigned long chunksize, daemon_sleep, write_behind; unsigned long long events; int err = -EINVAL; + struct page *sb_page; if (!bitmap->file && !bitmap->mddev->bitmap_info.offset) { chunksize = 128 * 1024 * 1024; @@ -562,24 +545,27 @@ static int bitmap_read_sb(struct bitmap *bitmap) goto out_no_sb; } /* page 0 is the superblock, read it... */ + sb_page = alloc_page(GFP_KERNEL); + if (!sb_page) + return -ENOMEM; + bitmap->sb_page = sb_page; + if (bitmap->file) { loff_t isize = i_size_read(bitmap->file->f_mapping->host); int bytes = isize > PAGE_SIZE ? PAGE_SIZE : isize; - bitmap->sb_page = read_page(bitmap->file, 0, bitmap, bytes); + err = read_page(bitmap->file, 0, + bitmap, bytes, sb_page); } else { - bitmap->sb_page = read_sb_page(bitmap->mddev, - bitmap->mddev->bitmap_info.offset, - NULL, - 0, sizeof(bitmap_super_t)); + err = read_sb_page(bitmap->mddev, + bitmap->mddev->bitmap_info.offset, + sb_page, + 0, sizeof(bitmap_super_t)); } - if (IS_ERR(bitmap->sb_page)) { - err = PTR_ERR(bitmap->sb_page); - bitmap->sb_page = NULL; + if (err) return err; - } - sb = kmap_atomic(bitmap->sb_page); + sb = kmap_atomic(sb_page); chunksize = le32_to_cpu(sb->chunksize); daemon_sleep = le32_to_cpu(sb->daemon_sleep) * HZ; @@ -948,7 +934,8 @@ static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int n static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start) { unsigned long i, chunks, index, oldindex, bit; - struct page *page = NULL, *oldpage = NULL; + int pnum; + struct page *page = NULL; unsigned long num_pages, bit_cnt = 0; struct file *file; unsigned long bytes, offset; @@ -999,6 +986,22 @@ static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start) if (!bitmap->filemap) goto err; + pnum = 0; + offset = 0; + if (bitmap->sb_page) { + bitmap->filemap[0] = bitmap->sb_page; + pnum = 1; + offset = sizeof(bitmap_super_t); + } + for ( ; pnum < num_pages; pnum++) { + bitmap->filemap[pnum] = alloc_page(GFP_KERNEL); + if (!bitmap->filemap[pnum]) { + bitmap->file_pages = pnum; + goto err; + } + } + bitmap->file_pages = pnum; + /* We need 4 bits per page, rounded up to a multiple of sizeof(unsigned long) */ bitmap->filemap_attr = kzalloc( roundup(DIV_ROUND_UP(num_pages*4, 8), sizeof(unsigned long)), @@ -1019,39 +1022,22 @@ static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start) count = bytes - index * PAGE_SIZE; else count = PAGE_SIZE; - if (index == 0 && bitmap->sb_page) { - /* - * if we're here then the superblock page - * contains some bits (PAGE_SIZE != sizeof sb) - * we've already read it in, so just use it - */ - page = bitmap->sb_page; - offset = sizeof(bitmap_super_t); - if (!file) - page = read_sb_page( - bitmap->mddev, - bitmap->mddev->bitmap_info.offset, - page, - index, count); - } else if (file) { - page = read_page(file, index, bitmap, count); - offset = 0; - } else { - page = read_sb_page(bitmap->mddev, - bitmap->mddev->bitmap_info.offset, - NULL, - index, count); - offset = 0; - } - if (IS_ERR(page)) { /* read error */ - ret = PTR_ERR(page); + page = bitmap->filemap[index]; + if (file) + ret = read_page(file, index, bitmap, + count, page); + else + ret = read_sb_page( + bitmap->mddev, + bitmap->mddev->bitmap_info.offset, + page, + index, count); + + if (ret) goto err; - } oldindex = index; - oldpage = page; - bitmap->filemap[bitmap->file_pages++] = page; bitmap->last_page_size = count; if (outofdate) { @@ -1085,6 +1071,7 @@ static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start) needed); bit_cnt++; } + offset = 0; } printk(KERN_INFO "%s: bitmap initialized from disk: "