[PATCH] md: allow md intent bitmap to be stored near the superblock.
This provides an alternate to storing the bitmap in a separate file. The bitmap can be stored at a given offset from the superblock. Obviously the creator of the array must make sure this doesn't intersect with data.... After is good for version-0.90 superblocks. Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
NeilBrown
Linus Torvalds
parent
3d310eb7b3
commit
a654b9d8f8
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@ -116,7 +116,7 @@ static unsigned char *bitmap_alloc_page(struct bitmap *bitmap)
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if (!page)
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printk("%s: bitmap_alloc_page FAILED\n", bmname(bitmap));
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else
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printk("%s: bitmap_alloc_page: allocated page at %p\n",
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PRINTK("%s: bitmap_alloc_page: allocated page at %p\n",
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bmname(bitmap), page);
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return page;
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}
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@ -258,13 +258,61 @@ char *file_path(struct file *file, char *buf, int count)
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* basic page I/O operations
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*/
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/* IO operations when bitmap is stored near all superblocks */
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static struct page *read_sb_page(mddev_t *mddev, long offset, unsigned long index)
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{
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/* choose a good rdev and read the page from there */
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mdk_rdev_t *rdev;
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struct list_head *tmp;
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struct page *page = alloc_page(GFP_KERNEL);
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sector_t target;
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if (!page)
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return ERR_PTR(-ENOMEM);
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do {
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ITERATE_RDEV(mddev, rdev, tmp)
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if (rdev->in_sync && !rdev->faulty)
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goto found;
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return ERR_PTR(-EIO);
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found:
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target = (rdev->sb_offset << 1) + offset + index * (PAGE_SIZE/512);
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} while (!sync_page_io(rdev->bdev, target, PAGE_SIZE, page, READ));
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page->index = index;
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return page;
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}
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static int write_sb_page(mddev_t *mddev, long offset, struct page *page, int wait)
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{
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mdk_rdev_t *rdev;
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struct list_head *tmp;
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ITERATE_RDEV(mddev, rdev, tmp)
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if (rdev->in_sync && !rdev->faulty)
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md_super_write(mddev, rdev,
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(rdev->sb_offset<<1) + offset
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+ page->index * (PAGE_SIZE/512),
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PAGE_SIZE,
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page);
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if (wait)
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wait_event(mddev->sb_wait, atomic_read(&mddev->pending_writes)==0);
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return 0;
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}
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/*
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* write out a page
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* write out a page to a file
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*/
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static int write_page(struct bitmap *bitmap, struct page *page, int wait)
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{
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int ret = -ENOMEM;
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if (bitmap->file == NULL)
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return write_sb_page(bitmap->mddev, bitmap->offset, page, wait);
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lock_page(page);
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ret = page->mapping->a_ops->prepare_write(NULL, page, 0, PAGE_SIZE);
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@ -394,7 +442,12 @@ static int bitmap_read_sb(struct bitmap *bitmap)
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int err = -EINVAL;
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/* page 0 is the superblock, read it... */
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if (bitmap->file)
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bitmap->sb_page = read_page(bitmap->file, 0, &bytes_read);
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else {
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bitmap->sb_page = read_sb_page(bitmap->mddev, bitmap->offset, 0);
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bytes_read = PAGE_SIZE;
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}
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if (IS_ERR(bitmap->sb_page)) {
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err = PTR_ERR(bitmap->sb_page);
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bitmap->sb_page = NULL;
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@ -625,6 +678,7 @@ static void bitmap_file_kick(struct bitmap *bitmap)
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bitmap_mask_state(bitmap, BITMAP_STALE, MASK_SET);
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bitmap_update_sb(bitmap);
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if (bitmap->file) {
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path = kmalloc(PAGE_SIZE, GFP_KERNEL);
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if (path)
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ptr = file_path(bitmap->file, path, PAGE_SIZE);
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@ -633,6 +687,7 @@ static void bitmap_file_kick(struct bitmap *bitmap)
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bmname(bitmap), ptr ? ptr : "");
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kfree(path);
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}
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bitmap_file_put(bitmap);
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@ -676,7 +731,7 @@ static void bitmap_file_set_bit(struct bitmap *bitmap, sector_t block)
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void *kaddr;
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unsigned long chunk = block >> CHUNK_BLOCK_SHIFT(bitmap);
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if (!bitmap->file || !bitmap->filemap) {
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if (!bitmap->filemap) {
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return;
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}
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@ -715,7 +770,7 @@ int bitmap_unplug(struct bitmap *bitmap)
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* flushed out to disk */
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for (i = 0; i < bitmap->file_pages; i++) {
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spin_lock_irqsave(&bitmap->lock, flags);
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if (!bitmap->file || !bitmap->filemap) {
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if (!bitmap->filemap) {
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spin_unlock_irqrestore(&bitmap->lock, flags);
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return 0;
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}
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@ -732,11 +787,15 @@ int bitmap_unplug(struct bitmap *bitmap)
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return 1;
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}
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if (wait) { /* if any writes were performed, we need to wait on them */
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if (bitmap->file) {
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spin_lock_irq(&bitmap->write_lock);
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wait_event_lock_irq(bitmap->write_wait,
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list_empty(&bitmap->complete_pages), bitmap->write_lock,
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wake_up_process(bitmap->writeback_daemon->tsk));
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spin_unlock_irq(&bitmap->write_lock);
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} else
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wait_event(bitmap->mddev->sb_wait,
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atomic_read(&bitmap->mddev->pending_writes)==0);
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}
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return 0;
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}
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@ -764,7 +823,7 @@ static int bitmap_init_from_disk(struct bitmap *bitmap, int in_sync)
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chunks = bitmap->chunks;
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file = bitmap->file;
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BUG_ON(!file);
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BUG_ON(!file && !bitmap->offset);
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#if INJECT_FAULTS_3
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outofdate = 1;
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@ -779,7 +838,7 @@ static int bitmap_init_from_disk(struct bitmap *bitmap, int in_sync)
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num_pages = (bytes + sizeof(bitmap_super_t) + PAGE_SIZE - 1) / PAGE_SIZE;
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if (i_size_read(file->f_mapping->host) < bytes + sizeof(bitmap_super_t)) {
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if (file && i_size_read(file->f_mapping->host) < bytes + sizeof(bitmap_super_t)) {
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printk(KERN_INFO "%s: bitmap file too short %lu < %lu\n",
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bmname(bitmap),
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(unsigned long) i_size_read(file->f_mapping->host),
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@ -816,14 +875,18 @@ static int bitmap_init_from_disk(struct bitmap *bitmap, int in_sync)
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*/
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page = bitmap->sb_page;
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offset = sizeof(bitmap_super_t);
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} else {
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} else if (file) {
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page = read_page(file, index, &dummy);
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offset = 0;
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} else {
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page = read_sb_page(bitmap->mddev, bitmap->offset, index);
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offset = 0;
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}
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if (IS_ERR(page)) { /* read error */
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ret = PTR_ERR(page);
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goto out;
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}
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offset = 0;
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}
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oldindex = index;
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oldpage = page;
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kmap(page);
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@ -874,6 +937,19 @@ out:
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return ret;
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}
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void bitmap_write_all(struct bitmap *bitmap)
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{
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/* We don't actually write all bitmap blocks here,
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* just flag them as needing to be written
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*/
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unsigned long chunks = bitmap->chunks;
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unsigned long bytes = (chunks+7)/8 + sizeof(bitmap_super_t);
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unsigned long num_pages = (bytes + PAGE_SIZE-1) / PAGE_SIZE;
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while (num_pages--)
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bitmap->filemap_attr[num_pages] |= BITMAP_PAGE_NEEDWRITE;
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}
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static void bitmap_count_page(struct bitmap *bitmap, sector_t offset, int inc)
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{
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@ -913,7 +989,7 @@ int bitmap_daemon_work(struct bitmap *bitmap)
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for (j = 0; j < bitmap->chunks; j++) {
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bitmap_counter_t *bmc;
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spin_lock_irqsave(&bitmap->lock, flags);
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if (!bitmap->file || !bitmap->filemap) {
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if (!bitmap->filemap) {
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/* error or shutdown */
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spin_unlock_irqrestore(&bitmap->lock, flags);
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break;
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@ -1072,6 +1148,7 @@ static int bitmap_start_daemon(struct bitmap *bitmap, mdk_thread_t **ptr,
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spin_lock_irqsave(&bitmap->lock, flags);
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*ptr = NULL;
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if (!bitmap->file) /* no need for daemon if there's no backing file */
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goto out_unlock;
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@ -1416,9 +1493,11 @@ int bitmap_create(mddev_t *mddev)
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BUG_ON(sizeof(bitmap_super_t) != 256);
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if (!file) /* bitmap disabled, nothing to do */
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if (!file && !mddev->bitmap_offset) /* bitmap disabled, nothing to do */
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return 0;
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BUG_ON(file && mddev->bitmap_offset);
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bitmap = kmalloc(sizeof(*bitmap), GFP_KERNEL);
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if (!bitmap)
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return -ENOMEM;
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@ -1438,7 +1517,8 @@ int bitmap_create(mddev_t *mddev)
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return -ENOMEM;
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bitmap->file = file;
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get_file(file);
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bitmap->offset = mddev->bitmap_offset;
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if (file) get_file(file);
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/* read superblock from bitmap file (this sets bitmap->chunksize) */
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err = bitmap_read_sb(bitmap);
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if (err)
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@ -337,7 +337,7 @@ static int bi_complete(struct bio *bio, unsigned int bytes_done, int error)
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return 0;
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}
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static int sync_page_io(struct block_device *bdev, sector_t sector, int size,
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int sync_page_io(struct block_device *bdev, sector_t sector, int size,
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struct page *page, int rw)
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{
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struct bio *bio = bio_alloc(GFP_NOIO, 1);
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@ -609,6 +609,17 @@ static int super_90_validate(mddev_t *mddev, mdk_rdev_t *rdev)
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memcpy(mddev->uuid+12,&sb->set_uuid3, 4);
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mddev->max_disks = MD_SB_DISKS;
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if (sb->state & (1<<MD_SB_BITMAP_PRESENT) &&
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mddev->bitmap_file == NULL) {
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if (mddev->level != 1) {
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/* FIXME use a better test */
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printk(KERN_WARNING "md: bitmaps only support for raid1\n");
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return -EINVAL;
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}
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mddev->bitmap_offset = (MD_SB_BYTES >> 9);
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}
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} else if (mddev->pers == NULL) {
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/* Insist on good event counter while assembling */
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__u64 ev1 = md_event(sb);
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@ -702,6 +713,9 @@ static void super_90_sync(mddev_t *mddev, mdk_rdev_t *rdev)
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sb->layout = mddev->layout;
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sb->chunk_size = mddev->chunk_size;
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if (mddev->bitmap && mddev->bitmap_file == NULL)
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sb->state |= (1<<MD_SB_BITMAP_PRESENT);
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sb->disks[0].state = (1<<MD_DISK_REMOVED);
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ITERATE_RDEV(mddev,rdev2,tmp) {
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mdp_disk_t *d;
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@ -898,6 +912,15 @@ static int super_1_validate(mddev_t *mddev, mdk_rdev_t *rdev)
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memcpy(mddev->uuid, sb->set_uuid, 16);
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mddev->max_disks = (4096-256)/2;
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if ((le32_to_cpu(sb->feature_map) & 1) &&
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mddev->bitmap_file == NULL ) {
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if (mddev->level != 1) {
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printk(KERN_WARNING "md: bitmaps only supported for raid1\n");
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return -EINVAL;
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}
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mddev->bitmap_offset = (__s32)le32_to_cpu(sb->bitmap_offset);
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}
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} else if (mddev->pers == NULL) {
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/* Insist of good event counter while assembling */
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__u64 ev1 = le64_to_cpu(sb->events);
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@ -960,6 +983,11 @@ static void super_1_sync(mddev_t *mddev, mdk_rdev_t *rdev)
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else
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sb->resync_offset = cpu_to_le64(0);
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if (mddev->bitmap && mddev->bitmap_file == NULL) {
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sb->bitmap_offset = cpu_to_le32((__u32)mddev->bitmap_offset);
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sb->feature_map = cpu_to_le32(1);
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}
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max_dev = 0;
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ITERATE_RDEV(mddev,rdev2,tmp)
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if (rdev2->desc_nr+1 > max_dev)
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@ -2406,7 +2434,8 @@ static int set_bitmap_file(mddev_t *mddev, int fd)
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mdname(mddev));
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fput(mddev->bitmap_file);
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mddev->bitmap_file = NULL;
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}
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} else
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mddev->bitmap_offset = 0; /* file overrides offset */
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return err;
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}
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@ -3774,6 +3803,13 @@ void md_check_recovery(mddev_t *mddev)
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set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
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if (!spares)
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set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
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if (spares && mddev->bitmap && ! mddev->bitmap->file) {
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/* We are adding a device or devices to an array
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* which has the bitmap stored on all devices.
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* So make sure all bitmap pages get written
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*/
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bitmap_write_all(mddev->bitmap);
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}
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mddev->sync_thread = md_register_thread(md_do_sync,
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mddev,
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"%s_resync");
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@ -217,6 +217,7 @@ struct bitmap {
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/* bitmap spinlock */
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spinlock_t lock;
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long offset; /* offset from superblock if file is NULL */
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struct file *file; /* backing disk file */
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struct page *sb_page; /* cached copy of the bitmap file superblock */
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struct page **filemap; /* list of cache pages for the file */
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@ -255,6 +256,7 @@ void bitmap_print_sb(struct bitmap *bitmap);
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int bitmap_update_sb(struct bitmap *bitmap);
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int bitmap_setallbits(struct bitmap *bitmap);
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void bitmap_write_all(struct bitmap *bitmap);
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/* these are exported */
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int bitmap_startwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors);
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@ -60,7 +60,14 @@
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*/
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#define MD_MAJOR_VERSION 0
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#define MD_MINOR_VERSION 90
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#define MD_PATCHLEVEL_VERSION 1
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/*
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* MD_PATCHLEVEL_VERSION indicates kernel functionality.
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* >=1 means different superblock formats are selectable using SET_ARRAY_INFO
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* and major_version/minor_version accordingly
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* >=2 means that Internal bitmaps are supported by setting MD_SB_BITMAP_PRESENT
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* in the super status byte
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*/
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#define MD_PATCHLEVEL_VERSION 2
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extern int register_md_personality (int p_num, mdk_personality_t *p);
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extern int unregister_md_personality (int p_num);
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@ -78,6 +85,12 @@ extern void md_unplug_mddev(mddev_t *mddev);
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extern void md_print_devices (void);
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extern void md_super_write(mddev_t *mddev, mdk_rdev_t *rdev,
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sector_t sector, int size, struct page *page);
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extern int sync_page_io(struct block_device *bdev, sector_t sector, int size,
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struct page *page, int rw);
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#define MD_BUG(x...) { printk("md: bug in file %s, line %d\n", __FILE__, __LINE__); md_print_devices(); }
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#endif
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@ -273,6 +273,10 @@ struct mddev_s
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struct bitmap *bitmap; /* the bitmap for the device */
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struct file *bitmap_file; /* the bitmap file */
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long bitmap_offset; /* offset from superblock of
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* start of bitmap. May be
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* negative, but not '0'
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*/
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struct list_head all_mddevs;
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};
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@ -96,6 +96,7 @@ typedef struct mdp_device_descriptor_s {
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#define MD_SB_CLEAN 0
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#define MD_SB_ERRORS 1
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#define MD_SB_BITMAP_PRESENT 8 /* bitmap may be present nearby */
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typedef struct mdp_superblock_s {
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/*
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* Constant generic information
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@ -184,7 +185,7 @@ struct mdp_superblock_1 {
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/* constant array information - 128 bytes */
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__u32 magic; /* MD_SB_MAGIC: 0xa92b4efc - little endian */
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__u32 major_version; /* 1 */
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__u32 feature_map; /* 0 for now */
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__u32 feature_map; /* bit 0 set if 'bitmap_offset' is meaningful */
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__u32 pad0; /* always set to 0 when writing */
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__u8 set_uuid[16]; /* user-space generated. */
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@ -197,6 +198,10 @@ struct mdp_superblock_1 {
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__u32 chunksize; /* in 512byte sectors */
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__u32 raid_disks;
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__u32 bitmap_offset; /* sectors after start of superblock that bitmap starts
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* NOTE: signed, so bitmap can be before superblock
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* only meaningful of feature_map[0] is set.
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*/
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__u8 pad1[128-96]; /* set to 0 when written */
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/* constant this-device information - 64 bytes */
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