[T106][ZXW-22]7520V3SCV2.01.01.02P42U09_VEC_V0.8_AP_VEC origin source commit
Change-Id: Ic6e05d89ecd62fc34f82b23dcf306c93764aec4b
diff --git a/ap/os/linux/linux-3.4.x/drivers/md/bitmap.c b/ap/os/linux/linux-3.4.x/drivers/md/bitmap.c
new file mode 100644
index 0000000..17e2b47
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/drivers/md/bitmap.c
@@ -0,0 +1,2113 @@
+/*
+ * bitmap.c two-level bitmap (C) Peter T. Breuer (ptb@ot.uc3m.es) 2003
+ *
+ * bitmap_create - sets up the bitmap structure
+ * bitmap_destroy - destroys the bitmap structure
+ *
+ * additions, Copyright (C) 2003-2004, Paul Clements, SteelEye Technology, Inc.:
+ * - added disk storage for bitmap
+ * - changes to allow various bitmap chunk sizes
+ */
+
+/*
+ * Still to do:
+ *
+ * flush after percent set rather than just time based. (maybe both).
+ */
+
+#include <linux/blkdev.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/timer.h>
+#include <linux/sched.h>
+#include <linux/list.h>
+#include <linux/file.h>
+#include <linux/mount.h>
+#include <linux/buffer_head.h>
+#include <linux/seq_file.h>
+#include "md.h"
+#include "bitmap.h"
+
+static inline char *bmname(struct bitmap *bitmap)
+{
+ return bitmap->mddev ? mdname(bitmap->mddev) : "mdX";
+}
+
+/*
+ * check a page and, if necessary, allocate it (or hijack it if the alloc fails)
+ *
+ * 1) check to see if this page is allocated, if it's not then try to alloc
+ * 2) if the alloc fails, set the page's hijacked flag so we'll use the
+ * page pointer directly as a counter
+ *
+ * if we find our page, we increment the page's refcount so that it stays
+ * allocated while we're using it
+ */
+static int bitmap_checkpage(struct bitmap *bitmap,
+ unsigned long page, int create)
+__releases(bitmap->lock)
+__acquires(bitmap->lock)
+{
+ unsigned char *mappage;
+
+ if (page >= bitmap->pages) {
+ /* This can happen if bitmap_start_sync goes beyond
+ * End-of-device while looking for a whole page.
+ * It is harmless.
+ */
+ return -EINVAL;
+ }
+
+ if (bitmap->bp[page].hijacked) /* it's hijacked, don't try to alloc */
+ return 0;
+
+ if (bitmap->bp[page].map) /* page is already allocated, just return */
+ return 0;
+
+ if (!create)
+ return -ENOENT;
+
+ /* this page has not been allocated yet */
+
+ spin_unlock_irq(&bitmap->lock);
+ mappage = kzalloc(PAGE_SIZE, GFP_NOIO);
+ spin_lock_irq(&bitmap->lock);
+
+ if (mappage == NULL) {
+ pr_debug("%s: bitmap map page allocation failed, hijacking\n",
+ bmname(bitmap));
+ /* failed - set the hijacked flag so that we can use the
+ * pointer as a counter */
+ if (!bitmap->bp[page].map)
+ bitmap->bp[page].hijacked = 1;
+ } else if (bitmap->bp[page].map ||
+ bitmap->bp[page].hijacked) {
+ /* somebody beat us to getting the page */
+ kfree(mappage);
+ return 0;
+ } else {
+
+ /* no page was in place and we have one, so install it */
+
+ bitmap->bp[page].map = mappage;
+ bitmap->missing_pages--;
+ }
+ return 0;
+}
+
+/* if page is completely empty, put it back on the free list, or dealloc it */
+/* if page was hijacked, unmark the flag so it might get alloced next time */
+/* Note: lock should be held when calling this */
+static void bitmap_checkfree(struct bitmap *bitmap, unsigned long page)
+{
+ char *ptr;
+
+ if (bitmap->bp[page].count) /* page is still busy */
+ return;
+
+ /* page is no longer in use, it can be released */
+
+ if (bitmap->bp[page].hijacked) { /* page was hijacked, undo this now */
+ bitmap->bp[page].hijacked = 0;
+ bitmap->bp[page].map = NULL;
+ } else {
+ /* normal case, free the page */
+ ptr = bitmap->bp[page].map;
+ bitmap->bp[page].map = NULL;
+ bitmap->missing_pages++;
+ kfree(ptr);
+ }
+}
+
+/*
+ * bitmap file handling - read and write the bitmap file and its superblock
+ */
+
+/*
+ * basic page I/O operations
+ */
+
+/* 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)
+{
+ /* 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)
+ || test_bit(Faulty, &rdev->flags))
+ continue;
+
+ target = offset + index * (PAGE_SIZE/512);
+
+ if (sync_page_io(rdev, target,
+ 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;
+ }
+ }
+ if (did_alloc)
+ put_page(page);
+ return ERR_PTR(-EIO);
+
+}
+
+static struct md_rdev *next_active_rdev(struct md_rdev *rdev, struct mddev *mddev)
+{
+ /* Iterate the disks of an mddev, using rcu to protect access to the
+ * linked list, and raising the refcount of devices we return to ensure
+ * they don't disappear while in use.
+ * As devices are only added or removed when raid_disk is < 0 and
+ * nr_pending is 0 and In_sync is clear, the entries we return will
+ * still be in the same position on the list when we re-enter
+ * list_for_each_continue_rcu.
+ */
+ struct list_head *pos;
+ rcu_read_lock();
+ if (rdev == NULL)
+ /* start at the beginning */
+ pos = &mddev->disks;
+ else {
+ /* release the previous rdev and start from there. */
+ rdev_dec_pending(rdev, mddev);
+ pos = &rdev->same_set;
+ }
+ list_for_each_continue_rcu(pos, &mddev->disks) {
+ rdev = list_entry(pos, struct md_rdev, same_set);
+ if (rdev->raid_disk >= 0 &&
+ !test_bit(Faulty, &rdev->flags)) {
+ /* this is a usable devices */
+ atomic_inc(&rdev->nr_pending);
+ rcu_read_unlock();
+ return rdev;
+ }
+ }
+ rcu_read_unlock();
+ return NULL;
+}
+
+static int write_sb_page(struct bitmap *bitmap, struct page *page, int wait)
+{
+ struct md_rdev *rdev = NULL;
+ struct block_device *bdev;
+ struct mddev *mddev = bitmap->mddev;
+
+ while ((rdev = next_active_rdev(rdev, mddev)) != NULL) {
+ int size = PAGE_SIZE;
+ loff_t offset = mddev->bitmap_info.offset;
+
+ bdev = (rdev->meta_bdev) ? rdev->meta_bdev : rdev->bdev;
+
+ if (page->index == bitmap->file_pages-1)
+ size = roundup(bitmap->last_page_size,
+ bdev_logical_block_size(bdev));
+ /* Just make sure we aren't corrupting data or
+ * metadata
+ */
+ if (mddev->external) {
+ /* Bitmap could be anywhere. */
+ if (rdev->sb_start + offset + (page->index
+ * (PAGE_SIZE/512))
+ > rdev->data_offset
+ &&
+ rdev->sb_start + offset
+ < (rdev->data_offset + mddev->dev_sectors
+ + (PAGE_SIZE/512)))
+ goto bad_alignment;
+ } else if (offset < 0) {
+ /* DATA BITMAP METADATA */
+ if (offset
+ + (long)(page->index * (PAGE_SIZE/512))
+ + size/512 > 0)
+ /* bitmap runs in to metadata */
+ goto bad_alignment;
+ if (rdev->data_offset + mddev->dev_sectors
+ > rdev->sb_start + offset)
+ /* data runs in to bitmap */
+ goto bad_alignment;
+ } else if (rdev->sb_start < rdev->data_offset) {
+ /* METADATA BITMAP DATA */
+ if (rdev->sb_start
+ + offset
+ + page->index*(PAGE_SIZE/512) + size/512
+ > rdev->data_offset)
+ /* bitmap runs in to data */
+ goto bad_alignment;
+ } else {
+ /* DATA METADATA BITMAP - no problems */
+ }
+ md_super_write(mddev, rdev,
+ rdev->sb_start + offset
+ + page->index * (PAGE_SIZE/512),
+ size,
+ page);
+ }
+
+ if (wait)
+ md_super_wait(mddev);
+ return 0;
+
+ bad_alignment:
+ return -EINVAL;
+}
+
+static void bitmap_file_kick(struct bitmap *bitmap);
+/*
+ * write out a page to a file
+ */
+static void write_page(struct bitmap *bitmap, struct page *page, int wait)
+{
+ struct buffer_head *bh;
+
+ if (bitmap->file == NULL) {
+ switch (write_sb_page(bitmap, page, wait)) {
+ case -EINVAL:
+ bitmap->flags |= BITMAP_WRITE_ERROR;
+ }
+ } else {
+
+ bh = page_buffers(page);
+
+ while (bh && bh->b_blocknr) {
+ atomic_inc(&bitmap->pending_writes);
+ set_buffer_locked(bh);
+ set_buffer_mapped(bh);
+ submit_bh(WRITE | REQ_SYNC, bh);
+ bh = bh->b_this_page;
+ }
+
+ if (wait)
+ wait_event(bitmap->write_wait,
+ atomic_read(&bitmap->pending_writes)==0);
+ }
+ if (bitmap->flags & BITMAP_WRITE_ERROR)
+ bitmap_file_kick(bitmap);
+}
+
+static void end_bitmap_write(struct buffer_head *bh, int uptodate)
+{
+ struct bitmap *bitmap = bh->b_private;
+ unsigned long flags;
+
+ if (!uptodate) {
+ spin_lock_irqsave(&bitmap->lock, flags);
+ bitmap->flags |= BITMAP_WRITE_ERROR;
+ spin_unlock_irqrestore(&bitmap->lock, flags);
+ }
+ if (atomic_dec_and_test(&bitmap->pending_writes))
+ wake_up(&bitmap->write_wait);
+}
+
+/* copied from buffer.c */
+static void
+__clear_page_buffers(struct page *page)
+{
+ ClearPagePrivate(page);
+ set_page_private(page, 0);
+ page_cache_release(page);
+}
+static void free_buffers(struct page *page)
+{
+ struct buffer_head *bh = page_buffers(page);
+
+ while (bh) {
+ struct buffer_head *next = bh->b_this_page;
+ free_buffer_head(bh);
+ bh = next;
+ }
+ __clear_page_buffers(page);
+ put_page(page);
+}
+
+/* read a page from a file.
+ * We both read the page, and attach buffers to the page to record the
+ * address of each block (using bmap). These addresses will be used
+ * to write the block later, completely bypassing the filesystem.
+ * 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)
+{
+ struct page *page = NULL;
+ struct inode *inode = file->f_path.dentry->d_inode;
+ struct buffer_head *bh;
+ sector_t block;
+
+ 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<<inode->i_blkbits, 0);
+ if (!bh) {
+ put_page(page);
+ page = ERR_PTR(-ENOMEM);
+ goto out;
+ }
+ attach_page_buffers(page, bh);
+ block = index << (PAGE_SHIFT - inode->i_blkbits);
+ while (bh) {
+ if (count == 0)
+ bh->b_blocknr = 0;
+ else {
+ bh->b_blocknr = bmap(inode, block);
+ if (bh->b_blocknr == 0) {
+ /* Cannot use this file! */
+ free_buffers(page);
+ page = ERR_PTR(-EINVAL);
+ goto out;
+ }
+ bh->b_bdev = inode->i_sb->s_bdev;
+ if (count < (1<<inode->i_blkbits))
+ count = 0;
+ else
+ count -= (1<<inode->i_blkbits);
+
+ bh->b_end_io = end_bitmap_write;
+ bh->b_private = bitmap;
+ atomic_inc(&bitmap->pending_writes);
+ set_buffer_locked(bh);
+ set_buffer_mapped(bh);
+ submit_bh(READ, bh);
+ }
+ block++;
+ bh = bh->b_this_page;
+ }
+ page->index = 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);
+ }
+out:
+ if (IS_ERR(page))
+ printk(KERN_ALERT "md: bitmap read error: (%dB @ %llu): %ld\n",
+ (int)PAGE_SIZE,
+ (unsigned long long)index << PAGE_SHIFT,
+ PTR_ERR(page));
+ return page;
+}
+
+/*
+ * bitmap file superblock operations
+ */
+
+/* update the event counter and sync the superblock to disk */
+void bitmap_update_sb(struct bitmap *bitmap)
+{
+ bitmap_super_t *sb;
+
+ if (!bitmap || !bitmap->mddev) /* no bitmap for this array */
+ return;
+ if (bitmap->mddev->bitmap_info.external)
+ return;
+ if (!bitmap->sb_page) /* no superblock */
+ return;
+ sb = kmap_atomic(bitmap->sb_page);
+ sb->events = cpu_to_le64(bitmap->mddev->events);
+ if (bitmap->mddev->events < bitmap->events_cleared)
+ /* rocking back to read-only */
+ bitmap->events_cleared = bitmap->mddev->events;
+ sb->events_cleared = cpu_to_le64(bitmap->events_cleared);
+ sb->state = cpu_to_le32(bitmap->flags);
+ /* Just in case these have been changed via sysfs: */
+ sb->daemon_sleep = cpu_to_le32(bitmap->mddev->bitmap_info.daemon_sleep/HZ);
+ sb->write_behind = cpu_to_le32(bitmap->mddev->bitmap_info.max_write_behind);
+ kunmap_atomic(sb);
+ write_page(bitmap, bitmap->sb_page, 1);
+}
+
+/* print out the bitmap file superblock */
+void bitmap_print_sb(struct bitmap *bitmap)
+{
+ bitmap_super_t *sb;
+
+ if (!bitmap || !bitmap->sb_page)
+ return;
+ sb = kmap_atomic(bitmap->sb_page);
+ printk(KERN_DEBUG "%s: bitmap file superblock:\n", bmname(bitmap));
+ printk(KERN_DEBUG " magic: %08x\n", le32_to_cpu(sb->magic));
+ printk(KERN_DEBUG " version: %d\n", le32_to_cpu(sb->version));
+ printk(KERN_DEBUG " uuid: %08x.%08x.%08x.%08x\n",
+ *(__u32 *)(sb->uuid+0),
+ *(__u32 *)(sb->uuid+4),
+ *(__u32 *)(sb->uuid+8),
+ *(__u32 *)(sb->uuid+12));
+ printk(KERN_DEBUG " events: %llu\n",
+ (unsigned long long) le64_to_cpu(sb->events));
+ printk(KERN_DEBUG "events cleared: %llu\n",
+ (unsigned long long) le64_to_cpu(sb->events_cleared));
+ printk(KERN_DEBUG " state: %08x\n", le32_to_cpu(sb->state));
+ printk(KERN_DEBUG " chunksize: %d B\n", le32_to_cpu(sb->chunksize));
+ printk(KERN_DEBUG " daemon sleep: %ds\n", le32_to_cpu(sb->daemon_sleep));
+ printk(KERN_DEBUG " sync size: %llu KB\n",
+ (unsigned long long)le64_to_cpu(sb->sync_size)/2);
+ printk(KERN_DEBUG "max write behind: %d\n", le32_to_cpu(sb->write_behind));
+ kunmap_atomic(sb);
+}
+
+/*
+ * bitmap_new_disk_sb
+ * @bitmap
+ *
+ * This function is somewhat the reverse of bitmap_read_sb. bitmap_read_sb
+ * reads and verifies the on-disk bitmap superblock and populates bitmap_info.
+ * This function verifies 'bitmap_info' and populates the on-disk bitmap
+ * structure, which is to be written to disk.
+ *
+ * Returns: 0 on success, -Exxx on error
+ */
+static int bitmap_new_disk_sb(struct bitmap *bitmap)
+{
+ bitmap_super_t *sb;
+ unsigned long chunksize, daemon_sleep, write_behind;
+ int err = -EINVAL;
+
+ bitmap->sb_page = alloc_page(GFP_KERNEL);
+ if (IS_ERR(bitmap->sb_page)) {
+ err = PTR_ERR(bitmap->sb_page);
+ bitmap->sb_page = NULL;
+ return err;
+ }
+ bitmap->sb_page->index = 0;
+
+ sb = kmap_atomic(bitmap->sb_page);
+
+ sb->magic = cpu_to_le32(BITMAP_MAGIC);
+ sb->version = cpu_to_le32(BITMAP_MAJOR_HI);
+
+ chunksize = bitmap->mddev->bitmap_info.chunksize;
+ BUG_ON(!chunksize);
+ if (!is_power_of_2(chunksize)) {
+ kunmap_atomic(sb);
+ printk(KERN_ERR "bitmap chunksize not a power of 2\n");
+ return -EINVAL;
+ }
+ sb->chunksize = cpu_to_le32(chunksize);
+
+ daemon_sleep = bitmap->mddev->bitmap_info.daemon_sleep;
+ if (!daemon_sleep ||
+ (daemon_sleep < 1) || (daemon_sleep > MAX_SCHEDULE_TIMEOUT)) {
+ printk(KERN_INFO "Choosing daemon_sleep default (5 sec)\n");
+ daemon_sleep = 5 * HZ;
+ }
+ sb->daemon_sleep = cpu_to_le32(daemon_sleep);
+ bitmap->mddev->bitmap_info.daemon_sleep = daemon_sleep;
+
+ /*
+ * FIXME: write_behind for RAID1. If not specified, what
+ * is a good choice? We choose COUNTER_MAX / 2 arbitrarily.
+ */
+ write_behind = bitmap->mddev->bitmap_info.max_write_behind;
+ if (write_behind > COUNTER_MAX)
+ write_behind = COUNTER_MAX / 2;
+ sb->write_behind = cpu_to_le32(write_behind);
+ bitmap->mddev->bitmap_info.max_write_behind = write_behind;
+
+ /* keep the array size field of the bitmap superblock up to date */
+ sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors);
+
+ memcpy(sb->uuid, bitmap->mddev->uuid, 16);
+
+ bitmap->flags |= BITMAP_STALE;
+ sb->state |= cpu_to_le32(BITMAP_STALE);
+ bitmap->events_cleared = bitmap->mddev->events;
+ sb->events_cleared = cpu_to_le64(bitmap->mddev->events);
+
+ kunmap_atomic(sb);
+
+ return 0;
+}
+
+/* read the superblock from the bitmap file and initialize some bitmap fields */
+static int bitmap_read_sb(struct bitmap *bitmap)
+{
+ char *reason = NULL;
+ bitmap_super_t *sb;
+ unsigned long chunksize, daemon_sleep, write_behind;
+ unsigned long long events;
+ int err = -EINVAL;
+
+ /* page 0 is the superblock, read it... */
+ 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);
+ } else {
+ bitmap->sb_page = read_sb_page(bitmap->mddev,
+ bitmap->mddev->bitmap_info.offset,
+ NULL,
+ 0, sizeof(bitmap_super_t));
+ }
+ if (IS_ERR(bitmap->sb_page)) {
+ err = PTR_ERR(bitmap->sb_page);
+ bitmap->sb_page = NULL;
+ return err;
+ }
+
+ sb = kmap_atomic(bitmap->sb_page);
+
+ chunksize = le32_to_cpu(sb->chunksize);
+ daemon_sleep = le32_to_cpu(sb->daemon_sleep) * HZ;
+ write_behind = le32_to_cpu(sb->write_behind);
+
+ /* verify that the bitmap-specific fields are valid */
+ if (sb->magic != cpu_to_le32(BITMAP_MAGIC))
+ reason = "bad magic";
+ else if (le32_to_cpu(sb->version) < BITMAP_MAJOR_LO ||
+ le32_to_cpu(sb->version) > BITMAP_MAJOR_HI)
+ reason = "unrecognized superblock version";
+ else if (chunksize < 512)
+ reason = "bitmap chunksize too small";
+ else if (!is_power_of_2(chunksize))
+ reason = "bitmap chunksize not a power of 2";
+ else if (daemon_sleep < 1 || daemon_sleep > MAX_SCHEDULE_TIMEOUT)
+ reason = "daemon sleep period out of range";
+ else if (write_behind > COUNTER_MAX)
+ reason = "write-behind limit out of range (0 - 16383)";
+ if (reason) {
+ printk(KERN_INFO "%s: invalid bitmap file superblock: %s\n",
+ bmname(bitmap), reason);
+ goto out;
+ }
+
+ /* keep the array size field of the bitmap superblock up to date */
+ sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors);
+
+ if (bitmap->mddev->persistent) {
+ /*
+ * We have a persistent array superblock, so compare the
+ * bitmap's UUID and event counter to the mddev's
+ */
+ if (memcmp(sb->uuid, bitmap->mddev->uuid, 16)) {
+ printk(KERN_INFO
+ "%s: bitmap superblock UUID mismatch\n",
+ bmname(bitmap));
+ goto out;
+ }
+ events = le64_to_cpu(sb->events);
+ if (events < bitmap->mddev->events) {
+ printk(KERN_INFO
+ "%s: bitmap file is out of date (%llu < %llu) "
+ "-- forcing full recovery\n",
+ bmname(bitmap), events,
+ (unsigned long long) bitmap->mddev->events);
+ sb->state |= cpu_to_le32(BITMAP_STALE);
+ }
+ }
+
+ /* assign fields using values from superblock */
+ bitmap->mddev->bitmap_info.chunksize = chunksize;
+ bitmap->mddev->bitmap_info.daemon_sleep = daemon_sleep;
+ bitmap->mddev->bitmap_info.max_write_behind = write_behind;
+ bitmap->flags |= le32_to_cpu(sb->state);
+ if (le32_to_cpu(sb->version) == BITMAP_MAJOR_HOSTENDIAN)
+ bitmap->flags |= BITMAP_HOSTENDIAN;
+ bitmap->events_cleared = le64_to_cpu(sb->events_cleared);
+ if (bitmap->flags & BITMAP_STALE)
+ bitmap->events_cleared = bitmap->mddev->events;
+ err = 0;
+out:
+ kunmap_atomic(sb);
+ if (err)
+ bitmap_print_sb(bitmap);
+ return err;
+}
+
+enum bitmap_mask_op {
+ MASK_SET,
+ MASK_UNSET
+};
+
+/* record the state of the bitmap in the superblock. Return the old value */
+static int bitmap_mask_state(struct bitmap *bitmap, enum bitmap_state bits,
+ enum bitmap_mask_op op)
+{
+ bitmap_super_t *sb;
+ int old;
+
+ if (!bitmap->sb_page) /* can't set the state */
+ return 0;
+ sb = kmap_atomic(bitmap->sb_page);
+ old = le32_to_cpu(sb->state) & bits;
+ switch (op) {
+ case MASK_SET:
+ sb->state |= cpu_to_le32(bits);
+ bitmap->flags |= bits;
+ break;
+ case MASK_UNSET:
+ sb->state &= cpu_to_le32(~bits);
+ bitmap->flags &= ~bits;
+ break;
+ default:
+ BUG();
+ }
+ kunmap_atomic(sb);
+ return old;
+}
+
+/*
+ * general bitmap file operations
+ */
+
+/*
+ * on-disk bitmap:
+ *
+ * Use one bit per "chunk" (block set). We do the disk I/O on the bitmap
+ * file a page at a time. There's a superblock at the start of the file.
+ */
+/* calculate the index of the page that contains this bit */
+static inline unsigned long file_page_index(struct bitmap *bitmap, unsigned long chunk)
+{
+ if (!bitmap->mddev->bitmap_info.external)
+ chunk += sizeof(bitmap_super_t) << 3;
+ return chunk >> PAGE_BIT_SHIFT;
+}
+
+/* calculate the (bit) offset of this bit within a page */
+static inline unsigned long file_page_offset(struct bitmap *bitmap, unsigned long chunk)
+{
+ if (!bitmap->mddev->bitmap_info.external)
+ chunk += sizeof(bitmap_super_t) << 3;
+ return chunk & (PAGE_BITS - 1);
+}
+
+/*
+ * return a pointer to the page in the filemap that contains the given bit
+ *
+ * this lookup is complicated by the fact that the bitmap sb might be exactly
+ * 1 page (e.g., x86) or less than 1 page -- so the bitmap might start on page
+ * 0 or page 1
+ */
+static inline struct page *filemap_get_page(struct bitmap *bitmap,
+ unsigned long chunk)
+{
+ if (file_page_index(bitmap, chunk) >= bitmap->file_pages)
+ return NULL;
+ return bitmap->filemap[file_page_index(bitmap, chunk)
+ - file_page_index(bitmap, 0)];
+}
+
+static void bitmap_file_unmap(struct bitmap *bitmap)
+{
+ struct page **map, *sb_page;
+ unsigned long *attr;
+ int pages;
+ unsigned long flags;
+
+ spin_lock_irqsave(&bitmap->lock, flags);
+ map = bitmap->filemap;
+ bitmap->filemap = NULL;
+ attr = bitmap->filemap_attr;
+ bitmap->filemap_attr = NULL;
+ pages = bitmap->file_pages;
+ bitmap->file_pages = 0;
+ sb_page = bitmap->sb_page;
+ bitmap->sb_page = NULL;
+ spin_unlock_irqrestore(&bitmap->lock, flags);
+
+ while (pages--)
+ if (map[pages] != sb_page) /* 0 is sb_page, release it below */
+ free_buffers(map[pages]);
+ kfree(map);
+ kfree(attr);
+
+ if (sb_page)
+ free_buffers(sb_page);
+}
+
+static void bitmap_file_put(struct bitmap *bitmap)
+{
+ struct file *file;
+ unsigned long flags;
+
+ spin_lock_irqsave(&bitmap->lock, flags);
+ file = bitmap->file;
+ bitmap->file = NULL;
+ spin_unlock_irqrestore(&bitmap->lock, flags);
+
+ if (file)
+ wait_event(bitmap->write_wait,
+ atomic_read(&bitmap->pending_writes)==0);
+ bitmap_file_unmap(bitmap);
+
+ if (file) {
+ struct inode *inode = file->f_path.dentry->d_inode;
+ invalidate_mapping_pages(inode->i_mapping, 0, -1);
+ fput(file);
+ }
+}
+
+/*
+ * bitmap_file_kick - if an error occurs while manipulating the bitmap file
+ * then it is no longer reliable, so we stop using it and we mark the file
+ * as failed in the superblock
+ */
+static void bitmap_file_kick(struct bitmap *bitmap)
+{
+ char *path, *ptr = NULL;
+
+ if (bitmap_mask_state(bitmap, BITMAP_STALE, MASK_SET) == 0) {
+ bitmap_update_sb(bitmap);
+
+ if (bitmap->file) {
+ path = kmalloc(PAGE_SIZE, GFP_KERNEL);
+ if (path)
+ ptr = d_path(&bitmap->file->f_path, path,
+ PAGE_SIZE);
+
+ printk(KERN_ALERT
+ "%s: kicking failed bitmap file %s from array!\n",
+ bmname(bitmap), IS_ERR(ptr) ? "" : ptr);
+
+ kfree(path);
+ } else
+ printk(KERN_ALERT
+ "%s: disabling internal bitmap due to errors\n",
+ bmname(bitmap));
+ }
+
+ bitmap_file_put(bitmap);
+
+ return;
+}
+
+enum bitmap_page_attr {
+ BITMAP_PAGE_DIRTY = 0, /* there are set bits that need to be synced */
+ BITMAP_PAGE_PENDING = 1, /* there are bits that are being cleaned.
+ * i.e. counter is 1 or 2. */
+ BITMAP_PAGE_NEEDWRITE = 2, /* there are cleared bits that need to be synced */
+};
+
+static inline void set_page_attr(struct bitmap *bitmap, struct page *page,
+ enum bitmap_page_attr attr)
+{
+ __set_bit((page->index<<2) + attr, bitmap->filemap_attr);
+}
+
+static inline void clear_page_attr(struct bitmap *bitmap, struct page *page,
+ enum bitmap_page_attr attr)
+{
+ __clear_bit((page->index<<2) + attr, bitmap->filemap_attr);
+}
+
+static inline unsigned long test_page_attr(struct bitmap *bitmap, struct page *page,
+ enum bitmap_page_attr attr)
+{
+ return test_bit((page->index<<2) + attr, bitmap->filemap_attr);
+}
+
+/*
+ * bitmap_file_set_bit -- called before performing a write to the md device
+ * to set (and eventually sync) a particular bit in the bitmap file
+ *
+ * we set the bit immediately, then we record the page number so that
+ * when an unplug occurs, we can flush the dirty pages out to disk
+ */
+static void bitmap_file_set_bit(struct bitmap *bitmap, sector_t block)
+{
+ unsigned long bit;
+ struct page *page;
+ void *kaddr;
+ unsigned long chunk = block >> bitmap->chunkshift;
+
+ if (!bitmap->filemap)
+ return;
+
+ page = filemap_get_page(bitmap, chunk);
+ if (!page)
+ return;
+ bit = file_page_offset(bitmap, chunk);
+
+ /* set the bit */
+ kaddr = kmap_atomic(page);
+ if (bitmap->flags & BITMAP_HOSTENDIAN)
+ set_bit(bit, kaddr);
+ else
+ __set_bit_le(bit, kaddr);
+ kunmap_atomic(kaddr);
+ pr_debug("set file bit %lu page %lu\n", bit, page->index);
+ /* record page number so it gets flushed to disk when unplug occurs */
+ set_page_attr(bitmap, page, BITMAP_PAGE_DIRTY);
+}
+
+/* this gets called when the md device is ready to unplug its underlying
+ * (slave) device queues -- before we let any writes go down, we need to
+ * sync the dirty pages of the bitmap file to disk */
+void bitmap_unplug(struct bitmap *bitmap)
+{
+ unsigned long i, flags;
+ int dirty, need_write;
+ struct page *page;
+ int wait = 0;
+
+ if (!bitmap)
+ return;
+
+ /* look at each page to see if there are any set bits that need to be
+ * flushed out to disk */
+ for (i = 0; i < bitmap->file_pages; i++) {
+ spin_lock_irqsave(&bitmap->lock, flags);
+ if (!bitmap->filemap) {
+ spin_unlock_irqrestore(&bitmap->lock, flags);
+ return;
+ }
+ page = bitmap->filemap[i];
+ dirty = test_page_attr(bitmap, page, BITMAP_PAGE_DIRTY);
+ need_write = test_page_attr(bitmap, page, BITMAP_PAGE_NEEDWRITE);
+ clear_page_attr(bitmap, page, BITMAP_PAGE_DIRTY);
+ clear_page_attr(bitmap, page, BITMAP_PAGE_NEEDWRITE);
+ if (dirty)
+ wait = 1;
+ spin_unlock_irqrestore(&bitmap->lock, flags);
+
+ if (dirty || need_write)
+ write_page(bitmap, page, 0);
+ }
+ if (wait) { /* if any writes were performed, we need to wait on them */
+ if (bitmap->file)
+ wait_event(bitmap->write_wait,
+ atomic_read(&bitmap->pending_writes)==0);
+ else
+ md_super_wait(bitmap->mddev);
+ }
+ if (bitmap->flags & BITMAP_WRITE_ERROR)
+ bitmap_file_kick(bitmap);
+}
+EXPORT_SYMBOL(bitmap_unplug);
+
+static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed);
+/* * bitmap_init_from_disk -- called at bitmap_create time to initialize
+ * the in-memory bitmap from the on-disk bitmap -- also, sets up the
+ * memory mapping of the bitmap file
+ * Special cases:
+ * if there's no bitmap file, or if the bitmap file had been
+ * previously kicked from the array, we mark all the bits as
+ * 1's in order to cause a full resync.
+ *
+ * We ignore all bits for sectors that end earlier than 'start'.
+ * This is used when reading an out-of-date bitmap...
+ */
+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;
+ unsigned long num_pages, bit_cnt = 0;
+ struct file *file;
+ unsigned long bytes, offset;
+ int outofdate;
+ int ret = -ENOSPC;
+ void *paddr;
+
+ chunks = bitmap->chunks;
+ file = bitmap->file;
+
+ BUG_ON(!file && !bitmap->mddev->bitmap_info.offset);
+
+ outofdate = bitmap->flags & BITMAP_STALE;
+ if (outofdate)
+ printk(KERN_INFO "%s: bitmap file is out of date, doing full "
+ "recovery\n", bmname(bitmap));
+
+ bytes = DIV_ROUND_UP(bitmap->chunks, 8);
+ if (!bitmap->mddev->bitmap_info.external)
+ bytes += sizeof(bitmap_super_t);
+
+ num_pages = DIV_ROUND_UP(bytes, PAGE_SIZE);
+
+ if (file && i_size_read(file->f_mapping->host) < bytes) {
+ printk(KERN_INFO "%s: bitmap file too short %lu < %lu\n",
+ bmname(bitmap),
+ (unsigned long) i_size_read(file->f_mapping->host),
+ bytes);
+ goto err;
+ }
+
+ ret = -ENOMEM;
+
+ bitmap->filemap = kmalloc(sizeof(struct page *) * num_pages, GFP_KERNEL);
+ if (!bitmap->filemap)
+ goto err;
+
+ /* 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)),
+ GFP_KERNEL);
+ if (!bitmap->filemap_attr)
+ goto err;
+
+ oldindex = ~0L;
+
+ for (i = 0; i < chunks; i++) {
+ int b;
+ index = file_page_index(bitmap, i);
+ bit = file_page_offset(bitmap, i);
+ if (index != oldindex) { /* this is a new page, read it in */
+ int count;
+ /* unmap the old page, we're done with it */
+ if (index == num_pages-1)
+ 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);
+ goto err;
+ }
+
+ oldindex = index;
+ oldpage = page;
+
+ bitmap->filemap[bitmap->file_pages++] = page;
+ bitmap->last_page_size = count;
+
+ if (outofdate) {
+ /*
+ * if bitmap is out of date, dirty the
+ * whole page and write it out
+ */
+ paddr = kmap_atomic(page);
+ memset(paddr + offset, 0xff,
+ PAGE_SIZE - offset);
+ kunmap_atomic(paddr);
+ write_page(bitmap, page, 1);
+
+ ret = -EIO;
+ if (bitmap->flags & BITMAP_WRITE_ERROR)
+ goto err;
+ }
+ }
+ paddr = kmap_atomic(page);
+ if (bitmap->flags & BITMAP_HOSTENDIAN)
+ b = test_bit(bit, paddr);
+ else
+ b = test_bit_le(bit, paddr);
+ kunmap_atomic(paddr);
+ if (b) {
+ /* if the disk bit is set, set the memory bit */
+ int needed = ((sector_t)(i+1) << bitmap->chunkshift
+ >= start);
+ bitmap_set_memory_bits(bitmap,
+ (sector_t)i << bitmap->chunkshift,
+ needed);
+ bit_cnt++;
+ }
+ }
+
+ /* everything went OK */
+ ret = 0;
+ bitmap_mask_state(bitmap, BITMAP_STALE, MASK_UNSET);
+
+ if (bit_cnt) { /* Kick recovery if any bits were set */
+ set_bit(MD_RECOVERY_NEEDED, &bitmap->mddev->recovery);
+ md_wakeup_thread(bitmap->mddev->thread);
+ }
+
+ printk(KERN_INFO "%s: bitmap initialized from disk: "
+ "read %lu/%lu pages, set %lu of %lu bits\n",
+ bmname(bitmap), bitmap->file_pages, num_pages, bit_cnt, chunks);
+
+ return 0;
+
+ err:
+ printk(KERN_INFO "%s: bitmap initialisation failed: %d\n",
+ bmname(bitmap), ret);
+ return ret;
+}
+
+void bitmap_write_all(struct bitmap *bitmap)
+{
+ /* We don't actually write all bitmap blocks here,
+ * just flag them as needing to be written
+ */
+ int i;
+
+ spin_lock_irq(&bitmap->lock);
+ for (i = 0; i < bitmap->file_pages; i++)
+ set_page_attr(bitmap, bitmap->filemap[i],
+ BITMAP_PAGE_NEEDWRITE);
+ bitmap->allclean = 0;
+ spin_unlock_irq(&bitmap->lock);
+}
+
+static void bitmap_count_page(struct bitmap *bitmap, sector_t offset, int inc)
+{
+ sector_t chunk = offset >> bitmap->chunkshift;
+ unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
+ bitmap->bp[page].count += inc;
+ bitmap_checkfree(bitmap, page);
+}
+static bitmap_counter_t *bitmap_get_counter(struct bitmap *bitmap,
+ sector_t offset, sector_t *blocks,
+ int create);
+
+/*
+ * bitmap daemon -- periodically wakes up to clean bits and flush pages
+ * out to disk
+ */
+
+void bitmap_daemon_work(struct mddev *mddev)
+{
+ struct bitmap *bitmap;
+ unsigned long j;
+ unsigned long flags;
+ struct page *page = NULL, *lastpage = NULL;
+ sector_t blocks;
+ void *paddr;
+
+ /* Use a mutex to guard daemon_work against
+ * bitmap_destroy.
+ */
+ mutex_lock(&mddev->bitmap_info.mutex);
+ bitmap = mddev->bitmap;
+ if (bitmap == NULL) {
+ mutex_unlock(&mddev->bitmap_info.mutex);
+ return;
+ }
+ if (time_before(jiffies, bitmap->daemon_lastrun
+ + mddev->bitmap_info.daemon_sleep))
+ goto done;
+
+ bitmap->daemon_lastrun = jiffies;
+ if (bitmap->allclean) {
+ mddev->thread->timeout = MAX_SCHEDULE_TIMEOUT;
+ goto done;
+ }
+ bitmap->allclean = 1;
+
+ spin_lock_irqsave(&bitmap->lock, flags);
+ for (j = 0; j < bitmap->chunks; j++) {
+ bitmap_counter_t *bmc;
+ if (!bitmap->filemap)
+ /* error or shutdown */
+ break;
+
+ page = filemap_get_page(bitmap, j);
+
+ if (page != lastpage) {
+ /* skip this page unless it's marked as needing cleaning */
+ if (!test_page_attr(bitmap, page, BITMAP_PAGE_PENDING)) {
+ int need_write = test_page_attr(bitmap, page,
+ BITMAP_PAGE_NEEDWRITE);
+ if (need_write)
+ clear_page_attr(bitmap, page, BITMAP_PAGE_NEEDWRITE);
+
+ spin_unlock_irqrestore(&bitmap->lock, flags);
+ if (need_write)
+ write_page(bitmap, page, 0);
+ spin_lock_irqsave(&bitmap->lock, flags);
+ j |= (PAGE_BITS - 1);
+ continue;
+ }
+
+ /* grab the new page, sync and release the old */
+ if (lastpage != NULL) {
+ if (test_page_attr(bitmap, lastpage,
+ BITMAP_PAGE_NEEDWRITE)) {
+ clear_page_attr(bitmap, lastpage,
+ BITMAP_PAGE_NEEDWRITE);
+ spin_unlock_irqrestore(&bitmap->lock, flags);
+ write_page(bitmap, lastpage, 0);
+ } else {
+ set_page_attr(bitmap, lastpage,
+ BITMAP_PAGE_NEEDWRITE);
+ bitmap->allclean = 0;
+ spin_unlock_irqrestore(&bitmap->lock, flags);
+ }
+ } else
+ spin_unlock_irqrestore(&bitmap->lock, flags);
+ lastpage = page;
+
+ /* We are possibly going to clear some bits, so make
+ * sure that events_cleared is up-to-date.
+ */
+ if (bitmap->need_sync &&
+ mddev->bitmap_info.external == 0) {
+ bitmap_super_t *sb;
+ bitmap->need_sync = 0;
+ sb = kmap_atomic(bitmap->sb_page);
+ sb->events_cleared =
+ cpu_to_le64(bitmap->events_cleared);
+ kunmap_atomic(sb);
+ write_page(bitmap, bitmap->sb_page, 1);
+ }
+ spin_lock_irqsave(&bitmap->lock, flags);
+ if (!bitmap->need_sync)
+ clear_page_attr(bitmap, page, BITMAP_PAGE_PENDING);
+ else
+ bitmap->allclean = 0;
+ }
+ bmc = bitmap_get_counter(bitmap,
+ (sector_t)j << bitmap->chunkshift,
+ &blocks, 0);
+ if (!bmc)
+ j |= PAGE_COUNTER_MASK;
+ else if (*bmc) {
+ if (*bmc == 1 && !bitmap->need_sync) {
+ /* we can clear the bit */
+ *bmc = 0;
+ bitmap_count_page(bitmap,
+ (sector_t)j << bitmap->chunkshift,
+ -1);
+
+ /* clear the bit */
+ paddr = kmap_atomic(page);
+ if (bitmap->flags & BITMAP_HOSTENDIAN)
+ clear_bit(file_page_offset(bitmap, j),
+ paddr);
+ else
+ __clear_bit_le(
+ file_page_offset(bitmap,
+ j),
+ paddr);
+ kunmap_atomic(paddr);
+ } else if (*bmc <= 2) {
+ *bmc = 1; /* maybe clear the bit next time */
+ set_page_attr(bitmap, page, BITMAP_PAGE_PENDING);
+ bitmap->allclean = 0;
+ }
+ }
+ }
+ spin_unlock_irqrestore(&bitmap->lock, flags);
+
+ /* now sync the final page */
+ if (lastpage != NULL) {
+ spin_lock_irqsave(&bitmap->lock, flags);
+ if (test_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE)) {
+ clear_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
+ spin_unlock_irqrestore(&bitmap->lock, flags);
+ write_page(bitmap, lastpage, 0);
+ } else {
+ set_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
+ bitmap->allclean = 0;
+ spin_unlock_irqrestore(&bitmap->lock, flags);
+ }
+ }
+
+ done:
+ if (bitmap->allclean == 0)
+ mddev->thread->timeout =
+ mddev->bitmap_info.daemon_sleep;
+ mutex_unlock(&mddev->bitmap_info.mutex);
+}
+
+static bitmap_counter_t *bitmap_get_counter(struct bitmap *bitmap,
+ sector_t offset, sector_t *blocks,
+ int create)
+__releases(bitmap->lock)
+__acquires(bitmap->lock)
+{
+ /* If 'create', we might release the lock and reclaim it.
+ * The lock must have been taken with interrupts enabled.
+ * If !create, we don't release the lock.
+ */
+ sector_t chunk = offset >> bitmap->chunkshift;
+ unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
+ unsigned long pageoff = (chunk & PAGE_COUNTER_MASK) << COUNTER_BYTE_SHIFT;
+ sector_t csize;
+ int err;
+
+ err = bitmap_checkpage(bitmap, page, create);
+
+ if (bitmap->bp[page].hijacked ||
+ bitmap->bp[page].map == NULL)
+ csize = ((sector_t)1) << (bitmap->chunkshift +
+ PAGE_COUNTER_SHIFT - 1);
+ else
+ csize = ((sector_t)1) << bitmap->chunkshift;
+ *blocks = csize - (offset & (csize - 1));
+
+ if (err < 0)
+ return NULL;
+
+ /* now locked ... */
+
+ if (bitmap->bp[page].hijacked) { /* hijacked pointer */
+ /* should we use the first or second counter field
+ * of the hijacked pointer? */
+ int hi = (pageoff > PAGE_COUNTER_MASK);
+ return &((bitmap_counter_t *)
+ &bitmap->bp[page].map)[hi];
+ } else /* page is allocated */
+ return (bitmap_counter_t *)
+ &(bitmap->bp[page].map[pageoff]);
+}
+
+int bitmap_startwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors, int behind)
+{
+ if (!bitmap)
+ return 0;
+
+ if (behind) {
+ int bw;
+ atomic_inc(&bitmap->behind_writes);
+ bw = atomic_read(&bitmap->behind_writes);
+ if (bw > bitmap->behind_writes_used)
+ bitmap->behind_writes_used = bw;
+
+ pr_debug("inc write-behind count %d/%lu\n",
+ bw, bitmap->mddev->bitmap_info.max_write_behind);
+ }
+
+ while (sectors) {
+ sector_t blocks;
+ bitmap_counter_t *bmc;
+
+ spin_lock_irq(&bitmap->lock);
+ bmc = bitmap_get_counter(bitmap, offset, &blocks, 1);
+ if (!bmc) {
+ spin_unlock_irq(&bitmap->lock);
+ return 0;
+ }
+
+ if (unlikely(COUNTER(*bmc) == COUNTER_MAX)) {
+ DEFINE_WAIT(__wait);
+ /* note that it is safe to do the prepare_to_wait
+ * after the test as long as we do it before dropping
+ * the spinlock.
+ */
+ prepare_to_wait(&bitmap->overflow_wait, &__wait,
+ TASK_UNINTERRUPTIBLE);
+ spin_unlock_irq(&bitmap->lock);
+ io_schedule();
+ finish_wait(&bitmap->overflow_wait, &__wait);
+ continue;
+ }
+
+ switch (*bmc) {
+ case 0:
+ bitmap_file_set_bit(bitmap, offset);
+ bitmap_count_page(bitmap, offset, 1);
+ /* fall through */
+ case 1:
+ *bmc = 2;
+ }
+
+ (*bmc)++;
+
+ spin_unlock_irq(&bitmap->lock);
+
+ offset += blocks;
+ if (sectors > blocks)
+ sectors -= blocks;
+ else
+ sectors = 0;
+ }
+ return 0;
+}
+EXPORT_SYMBOL(bitmap_startwrite);
+
+void bitmap_endwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors,
+ int success, int behind)
+{
+ if (!bitmap)
+ return;
+ if (behind) {
+ if (atomic_dec_and_test(&bitmap->behind_writes))
+ wake_up(&bitmap->behind_wait);
+ pr_debug("dec write-behind count %d/%lu\n",
+ atomic_read(&bitmap->behind_writes),
+ bitmap->mddev->bitmap_info.max_write_behind);
+ }
+
+ while (sectors) {
+ sector_t blocks;
+ unsigned long flags;
+ bitmap_counter_t *bmc;
+
+ spin_lock_irqsave(&bitmap->lock, flags);
+ bmc = bitmap_get_counter(bitmap, offset, &blocks, 0);
+ if (!bmc) {
+ spin_unlock_irqrestore(&bitmap->lock, flags);
+ return;
+ }
+
+ if (success && !bitmap->mddev->degraded &&
+ bitmap->events_cleared < bitmap->mddev->events) {
+ bitmap->events_cleared = bitmap->mddev->events;
+ bitmap->need_sync = 1;
+ sysfs_notify_dirent_safe(bitmap->sysfs_can_clear);
+ }
+
+ if (!success && !NEEDED(*bmc))
+ *bmc |= NEEDED_MASK;
+
+ if (COUNTER(*bmc) == COUNTER_MAX)
+ wake_up(&bitmap->overflow_wait);
+
+ (*bmc)--;
+ if (*bmc <= 2) {
+ set_page_attr(bitmap,
+ filemap_get_page(
+ bitmap,
+ offset >> bitmap->chunkshift),
+ BITMAP_PAGE_PENDING);
+ bitmap->allclean = 0;
+ }
+ spin_unlock_irqrestore(&bitmap->lock, flags);
+ offset += blocks;
+ if (sectors > blocks)
+ sectors -= blocks;
+ else
+ sectors = 0;
+ }
+}
+EXPORT_SYMBOL(bitmap_endwrite);
+
+static int __bitmap_start_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks,
+ int degraded)
+{
+ bitmap_counter_t *bmc;
+ int rv;
+ if (bitmap == NULL) {/* FIXME or bitmap set as 'failed' */
+ *blocks = 1024;
+ return 1; /* always resync if no bitmap */
+ }
+ spin_lock_irq(&bitmap->lock);
+ bmc = bitmap_get_counter(bitmap, offset, blocks, 0);
+ rv = 0;
+ if (bmc) {
+ /* locked */
+ if (RESYNC(*bmc))
+ rv = 1;
+ else if (NEEDED(*bmc)) {
+ rv = 1;
+ if (!degraded) { /* don't set/clear bits if degraded */
+ *bmc |= RESYNC_MASK;
+ *bmc &= ~NEEDED_MASK;
+ }
+ }
+ }
+ spin_unlock_irq(&bitmap->lock);
+ return rv;
+}
+
+int bitmap_start_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks,
+ int degraded)
+{
+ /* bitmap_start_sync must always report on multiples of whole
+ * pages, otherwise resync (which is very PAGE_SIZE based) will
+ * get confused.
+ * So call __bitmap_start_sync repeatedly (if needed) until
+ * At least PAGE_SIZE>>9 blocks are covered.
+ * Return the 'or' of the result.
+ */
+ int rv = 0;
+ sector_t blocks1;
+
+ *blocks = 0;
+ while (*blocks < (PAGE_SIZE>>9)) {
+ rv |= __bitmap_start_sync(bitmap, offset,
+ &blocks1, degraded);
+ offset += blocks1;
+ *blocks += blocks1;
+ }
+ return rv;
+}
+EXPORT_SYMBOL(bitmap_start_sync);
+
+void bitmap_end_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks, int aborted)
+{
+ bitmap_counter_t *bmc;
+ unsigned long flags;
+
+ if (bitmap == NULL) {
+ *blocks = 1024;
+ return;
+ }
+ spin_lock_irqsave(&bitmap->lock, flags);
+ bmc = bitmap_get_counter(bitmap, offset, blocks, 0);
+ if (bmc == NULL)
+ goto unlock;
+ /* locked */
+ if (RESYNC(*bmc)) {
+ *bmc &= ~RESYNC_MASK;
+
+ if (!NEEDED(*bmc) && aborted)
+ *bmc |= NEEDED_MASK;
+ else {
+ if (*bmc <= 2) {
+ set_page_attr(bitmap,
+ filemap_get_page(bitmap, offset >> bitmap->chunkshift),
+ BITMAP_PAGE_PENDING);
+ bitmap->allclean = 0;
+ }
+ }
+ }
+ unlock:
+ spin_unlock_irqrestore(&bitmap->lock, flags);
+}
+EXPORT_SYMBOL(bitmap_end_sync);
+
+void bitmap_close_sync(struct bitmap *bitmap)
+{
+ /* Sync has finished, and any bitmap chunks that weren't synced
+ * properly have been aborted. It remains to us to clear the
+ * RESYNC bit wherever it is still on
+ */
+ sector_t sector = 0;
+ sector_t blocks;
+ if (!bitmap)
+ return;
+ while (sector < bitmap->mddev->resync_max_sectors) {
+ bitmap_end_sync(bitmap, sector, &blocks, 0);
+ sector += blocks;
+ }
+}
+EXPORT_SYMBOL(bitmap_close_sync);
+
+void bitmap_cond_end_sync(struct bitmap *bitmap, sector_t sector)
+{
+ sector_t s = 0;
+ sector_t blocks;
+
+ if (!bitmap)
+ return;
+ if (sector == 0) {
+ bitmap->last_end_sync = jiffies;
+ return;
+ }
+ if (time_before(jiffies, (bitmap->last_end_sync
+ + bitmap->mddev->bitmap_info.daemon_sleep)))
+ return;
+ wait_event(bitmap->mddev->recovery_wait,
+ atomic_read(&bitmap->mddev->recovery_active) == 0);
+
+ bitmap->mddev->curr_resync_completed = sector;
+ set_bit(MD_CHANGE_CLEAN, &bitmap->mddev->flags);
+ sector &= ~((1ULL << bitmap->chunkshift) - 1);
+ s = 0;
+ while (s < sector && s < bitmap->mddev->resync_max_sectors) {
+ bitmap_end_sync(bitmap, s, &blocks, 0);
+ s += blocks;
+ }
+ bitmap->last_end_sync = jiffies;
+ sysfs_notify(&bitmap->mddev->kobj, NULL, "sync_completed");
+}
+EXPORT_SYMBOL(bitmap_cond_end_sync);
+
+static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed)
+{
+ /* For each chunk covered by any of these sectors, set the
+ * counter to 1 and set resync_needed. They should all
+ * be 0 at this point
+ */
+
+ sector_t secs;
+ bitmap_counter_t *bmc;
+ spin_lock_irq(&bitmap->lock);
+ bmc = bitmap_get_counter(bitmap, offset, &secs, 1);
+ if (!bmc) {
+ spin_unlock_irq(&bitmap->lock);
+ return;
+ }
+ if (!*bmc) {
+ struct page *page;
+ *bmc = 2 | (needed ? NEEDED_MASK : 0);
+ bitmap_count_page(bitmap, offset, 1);
+ page = filemap_get_page(bitmap, offset >> bitmap->chunkshift);
+ set_page_attr(bitmap, page, BITMAP_PAGE_PENDING);
+ bitmap->allclean = 0;
+ }
+ spin_unlock_irq(&bitmap->lock);
+}
+
+/* dirty the memory and file bits for bitmap chunks "s" to "e" */
+void bitmap_dirty_bits(struct bitmap *bitmap, unsigned long s, unsigned long e)
+{
+ unsigned long chunk;
+
+ for (chunk = s; chunk <= e; chunk++) {
+ sector_t sec = (sector_t)chunk << bitmap->chunkshift;
+ bitmap_set_memory_bits(bitmap, sec, 1);
+ spin_lock_irq(&bitmap->lock);
+ bitmap_file_set_bit(bitmap, sec);
+ spin_unlock_irq(&bitmap->lock);
+ if (sec < bitmap->mddev->recovery_cp)
+ /* We are asserting that the array is dirty,
+ * so move the recovery_cp address back so
+ * that it is obvious that it is dirty
+ */
+ bitmap->mddev->recovery_cp = sec;
+ }
+}
+
+/*
+ * flush out any pending updates
+ */
+void bitmap_flush(struct mddev *mddev)
+{
+ struct bitmap *bitmap = mddev->bitmap;
+ long sleep;
+
+ if (!bitmap) /* there was no bitmap */
+ return;
+
+ /* run the daemon_work three time to ensure everything is flushed
+ * that can be
+ */
+ sleep = mddev->bitmap_info.daemon_sleep * 2;
+ bitmap->daemon_lastrun -= sleep;
+ bitmap_daemon_work(mddev);
+ bitmap->daemon_lastrun -= sleep;
+ bitmap_daemon_work(mddev);
+ bitmap->daemon_lastrun -= sleep;
+ bitmap_daemon_work(mddev);
+ bitmap_update_sb(bitmap);
+}
+
+/*
+ * free memory that was allocated
+ */
+static void bitmap_free(struct bitmap *bitmap)
+{
+ unsigned long k, pages;
+ struct bitmap_page *bp;
+
+ if (!bitmap) /* there was no bitmap */
+ return;
+
+ /* release the bitmap file and kill the daemon */
+ bitmap_file_put(bitmap);
+
+ bp = bitmap->bp;
+ pages = bitmap->pages;
+
+ /* free all allocated memory */
+
+ if (bp) /* deallocate the page memory */
+ for (k = 0; k < pages; k++)
+ if (bp[k].map && !bp[k].hijacked)
+ kfree(bp[k].map);
+ kfree(bp);
+ kfree(bitmap);
+}
+
+void bitmap_destroy(struct mddev *mddev)
+{
+ struct bitmap *bitmap = mddev->bitmap;
+
+ if (!bitmap) /* there was no bitmap */
+ return;
+
+ mutex_lock(&mddev->bitmap_info.mutex);
+ mddev->bitmap = NULL; /* disconnect from the md device */
+ mutex_unlock(&mddev->bitmap_info.mutex);
+ if (mddev->thread)
+ mddev->thread->timeout = MAX_SCHEDULE_TIMEOUT;
+
+ if (bitmap->sysfs_can_clear)
+ sysfs_put(bitmap->sysfs_can_clear);
+
+ bitmap_free(bitmap);
+}
+
+/*
+ * initialize the bitmap structure
+ * if this returns an error, bitmap_destroy must be called to do clean up
+ */
+int bitmap_create(struct mddev *mddev)
+{
+ struct bitmap *bitmap;
+ sector_t blocks = mddev->resync_max_sectors;
+ unsigned long chunks;
+ unsigned long pages;
+ struct file *file = mddev->bitmap_info.file;
+ int err;
+ struct sysfs_dirent *bm = NULL;
+
+ BUILD_BUG_ON(sizeof(bitmap_super_t) != 256);
+
+ if (!file
+ && !mddev->bitmap_info.offset) /* bitmap disabled, nothing to do */
+ return 0;
+
+ BUG_ON(file && mddev->bitmap_info.offset);
+
+ bitmap = kzalloc(sizeof(*bitmap), GFP_KERNEL);
+ if (!bitmap)
+ return -ENOMEM;
+
+ spin_lock_init(&bitmap->lock);
+ atomic_set(&bitmap->pending_writes, 0);
+ init_waitqueue_head(&bitmap->write_wait);
+ init_waitqueue_head(&bitmap->overflow_wait);
+ init_waitqueue_head(&bitmap->behind_wait);
+
+ bitmap->mddev = mddev;
+
+ if (mddev->kobj.sd)
+ bm = sysfs_get_dirent(mddev->kobj.sd, NULL, "bitmap");
+ if (bm) {
+ bitmap->sysfs_can_clear = sysfs_get_dirent(bm, NULL, "can_clear");
+ sysfs_put(bm);
+ } else
+ bitmap->sysfs_can_clear = NULL;
+
+ bitmap->file = file;
+ if (file) {
+ get_file(file);
+ /* As future accesses to this file will use bmap,
+ * and bypass the page cache, we must sync the file
+ * first.
+ */
+ vfs_fsync(file, 1);
+ }
+ /* read superblock from bitmap file (this sets mddev->bitmap_info.chunksize) */
+ if (!mddev->bitmap_info.external) {
+ /*
+ * If 'MD_ARRAY_FIRST_USE' is set, then device-mapper is
+ * instructing us to create a new on-disk bitmap instance.
+ */
+ if (test_and_clear_bit(MD_ARRAY_FIRST_USE, &mddev->flags))
+ err = bitmap_new_disk_sb(bitmap);
+ else
+ err = bitmap_read_sb(bitmap);
+ } else {
+ err = 0;
+ if (mddev->bitmap_info.chunksize == 0 ||
+ mddev->bitmap_info.daemon_sleep == 0)
+ /* chunksize and time_base need to be
+ * set first. */
+ err = -EINVAL;
+ }
+ if (err)
+ goto error;
+
+ bitmap->daemon_lastrun = jiffies;
+ bitmap->chunkshift = (ffz(~mddev->bitmap_info.chunksize)
+ - BITMAP_BLOCK_SHIFT);
+
+ chunks = (blocks + (1 << bitmap->chunkshift) - 1) >>
+ bitmap->chunkshift;
+ pages = (chunks + PAGE_COUNTER_RATIO - 1) / PAGE_COUNTER_RATIO;
+
+ BUG_ON(!pages);
+
+ bitmap->chunks = chunks;
+ bitmap->pages = pages;
+ bitmap->missing_pages = pages;
+
+ bitmap->bp = kzalloc(pages * sizeof(*bitmap->bp), GFP_KERNEL);
+
+ err = -ENOMEM;
+ if (!bitmap->bp)
+ goto error;
+
+ printk(KERN_INFO "created bitmap (%lu pages) for device %s\n",
+ pages, bmname(bitmap));
+
+ mddev->bitmap = bitmap;
+
+
+ return (bitmap->flags & BITMAP_WRITE_ERROR) ? -EIO : 0;
+
+ error:
+ bitmap_free(bitmap);
+ return err;
+}
+
+int bitmap_load(struct mddev *mddev)
+{
+ int err = 0;
+ sector_t start = 0;
+ sector_t sector = 0;
+ struct bitmap *bitmap = mddev->bitmap;
+
+ if (!bitmap)
+ goto out;
+
+ /* Clear out old bitmap info first: Either there is none, or we
+ * are resuming after someone else has possibly changed things,
+ * so we should forget old cached info.
+ * All chunks should be clean, but some might need_sync.
+ */
+ while (sector < mddev->resync_max_sectors) {
+ sector_t blocks;
+ bitmap_start_sync(bitmap, sector, &blocks, 0);
+ sector += blocks;
+ }
+ bitmap_close_sync(bitmap);
+
+ if (mddev->degraded == 0
+ || bitmap->events_cleared == mddev->events)
+ /* no need to keep dirty bits to optimise a
+ * re-add of a missing device */
+ start = mddev->recovery_cp;
+
+ mutex_lock(&mddev->bitmap_info.mutex);
+ err = bitmap_init_from_disk(bitmap, start);
+ mutex_unlock(&mddev->bitmap_info.mutex);
+
+ if (err)
+ goto out;
+
+ mddev->thread->timeout = mddev->bitmap_info.daemon_sleep;
+ md_wakeup_thread(mddev->thread);
+
+ bitmap_update_sb(bitmap);
+
+ if (bitmap->flags & BITMAP_WRITE_ERROR)
+ err = -EIO;
+out:
+ return err;
+}
+EXPORT_SYMBOL_GPL(bitmap_load);
+
+void bitmap_status(struct seq_file *seq, struct bitmap *bitmap)
+{
+ unsigned long chunk_kb;
+ unsigned long flags;
+
+ if (!bitmap)
+ return;
+
+ spin_lock_irqsave(&bitmap->lock, flags);
+ chunk_kb = bitmap->mddev->bitmap_info.chunksize >> 10;
+ seq_printf(seq, "bitmap: %lu/%lu pages [%luKB], "
+ "%lu%s chunk",
+ bitmap->pages - bitmap->missing_pages,
+ bitmap->pages,
+ (bitmap->pages - bitmap->missing_pages)
+ << (PAGE_SHIFT - 10),
+ chunk_kb ? chunk_kb : bitmap->mddev->bitmap_info.chunksize,
+ chunk_kb ? "KB" : "B");
+ if (bitmap->file) {
+ seq_printf(seq, ", file: ");
+ seq_path(seq, &bitmap->file->f_path, " \t\n");
+ }
+
+ seq_printf(seq, "\n");
+ spin_unlock_irqrestore(&bitmap->lock, flags);
+}
+
+static ssize_t
+location_show(struct mddev *mddev, char *page)
+{
+ ssize_t len;
+ if (mddev->bitmap_info.file)
+ len = sprintf(page, "file");
+ else if (mddev->bitmap_info.offset)
+ len = sprintf(page, "%+lld", (long long)mddev->bitmap_info.offset);
+ else
+ len = sprintf(page, "none");
+ len += sprintf(page+len, "\n");
+ return len;
+}
+
+static ssize_t
+location_store(struct mddev *mddev, const char *buf, size_t len)
+{
+
+ if (mddev->pers) {
+ if (!mddev->pers->quiesce)
+ return -EBUSY;
+ if (mddev->recovery || mddev->sync_thread)
+ return -EBUSY;
+ }
+
+ if (mddev->bitmap || mddev->bitmap_info.file ||
+ mddev->bitmap_info.offset) {
+ /* bitmap already configured. Only option is to clear it */
+ if (strncmp(buf, "none", 4) != 0)
+ return -EBUSY;
+ if (mddev->pers) {
+ mddev->pers->quiesce(mddev, 1);
+ bitmap_destroy(mddev);
+ mddev->pers->quiesce(mddev, 0);
+ }
+ mddev->bitmap_info.offset = 0;
+ if (mddev->bitmap_info.file) {
+ struct file *f = mddev->bitmap_info.file;
+ mddev->bitmap_info.file = NULL;
+ restore_bitmap_write_access(f);
+ fput(f);
+ }
+ } else {
+ /* No bitmap, OK to set a location */
+ long long offset;
+ if (strncmp(buf, "none", 4) == 0)
+ /* nothing to be done */;
+ else if (strncmp(buf, "file:", 5) == 0) {
+ /* Not supported yet */
+ return -EINVAL;
+ } else {
+ int rv;
+ if (buf[0] == '+')
+ rv = strict_strtoll(buf+1, 10, &offset);
+ else
+ rv = strict_strtoll(buf, 10, &offset);
+ if (rv)
+ return rv;
+ if (offset == 0)
+ return -EINVAL;
+ if (mddev->bitmap_info.external == 0 &&
+ mddev->major_version == 0 &&
+ offset != mddev->bitmap_info.default_offset)
+ return -EINVAL;
+ mddev->bitmap_info.offset = offset;
+ if (mddev->pers) {
+ mddev->pers->quiesce(mddev, 1);
+ rv = bitmap_create(mddev);
+ if (!rv)
+ rv = bitmap_load(mddev);
+ if (rv) {
+ bitmap_destroy(mddev);
+ mddev->bitmap_info.offset = 0;
+ }
+ mddev->pers->quiesce(mddev, 0);
+ if (rv)
+ return rv;
+ }
+ }
+ }
+ if (!mddev->external) {
+ /* Ensure new bitmap info is stored in
+ * metadata promptly.
+ */
+ set_bit(MD_CHANGE_DEVS, &mddev->flags);
+ md_wakeup_thread(mddev->thread);
+ }
+ return len;
+}
+
+static struct md_sysfs_entry bitmap_location =
+__ATTR(location, S_IRUGO|S_IWUSR, location_show, location_store);
+
+static ssize_t
+timeout_show(struct mddev *mddev, char *page)
+{
+ ssize_t len;
+ unsigned long secs = mddev->bitmap_info.daemon_sleep / HZ;
+ unsigned long jifs = mddev->bitmap_info.daemon_sleep % HZ;
+
+ len = sprintf(page, "%lu", secs);
+ if (jifs)
+ len += sprintf(page+len, ".%03u", jiffies_to_msecs(jifs));
+ len += sprintf(page+len, "\n");
+ return len;
+}
+
+static ssize_t
+timeout_store(struct mddev *mddev, const char *buf, size_t len)
+{
+ /* timeout can be set at any time */
+ unsigned long timeout;
+ int rv = strict_strtoul_scaled(buf, &timeout, 4);
+ if (rv)
+ return rv;
+
+ /* just to make sure we don't overflow... */
+ if (timeout >= LONG_MAX / HZ)
+ return -EINVAL;
+
+ timeout = timeout * HZ / 10000;
+
+ if (timeout >= MAX_SCHEDULE_TIMEOUT)
+ timeout = MAX_SCHEDULE_TIMEOUT-1;
+ if (timeout < 1)
+ timeout = 1;
+ mddev->bitmap_info.daemon_sleep = timeout;
+ if (mddev->thread) {
+ /* if thread->timeout is MAX_SCHEDULE_TIMEOUT, then
+ * the bitmap is all clean and we don't need to
+ * adjust the timeout right now
+ */
+ if (mddev->thread->timeout < MAX_SCHEDULE_TIMEOUT) {
+ mddev->thread->timeout = timeout;
+ md_wakeup_thread(mddev->thread);
+ }
+ }
+ return len;
+}
+
+static struct md_sysfs_entry bitmap_timeout =
+__ATTR(time_base, S_IRUGO|S_IWUSR, timeout_show, timeout_store);
+
+static ssize_t
+backlog_show(struct mddev *mddev, char *page)
+{
+ return sprintf(page, "%lu\n", mddev->bitmap_info.max_write_behind);
+}
+
+static ssize_t
+backlog_store(struct mddev *mddev, const char *buf, size_t len)
+{
+ unsigned long backlog;
+ int rv = strict_strtoul(buf, 10, &backlog);
+ if (rv)
+ return rv;
+ if (backlog > COUNTER_MAX)
+ return -EINVAL;
+ mddev->bitmap_info.max_write_behind = backlog;
+ return len;
+}
+
+static struct md_sysfs_entry bitmap_backlog =
+__ATTR(backlog, S_IRUGO|S_IWUSR, backlog_show, backlog_store);
+
+static ssize_t
+chunksize_show(struct mddev *mddev, char *page)
+{
+ return sprintf(page, "%lu\n", mddev->bitmap_info.chunksize);
+}
+
+static ssize_t
+chunksize_store(struct mddev *mddev, const char *buf, size_t len)
+{
+ /* Can only be changed when no bitmap is active */
+ int rv;
+ unsigned long csize;
+ if (mddev->bitmap)
+ return -EBUSY;
+ rv = strict_strtoul(buf, 10, &csize);
+ if (rv)
+ return rv;
+ if (csize < 512 ||
+ !is_power_of_2(csize))
+ return -EINVAL;
+ mddev->bitmap_info.chunksize = csize;
+ return len;
+}
+
+static struct md_sysfs_entry bitmap_chunksize =
+__ATTR(chunksize, S_IRUGO|S_IWUSR, chunksize_show, chunksize_store);
+
+static ssize_t metadata_show(struct mddev *mddev, char *page)
+{
+ return sprintf(page, "%s\n", (mddev->bitmap_info.external
+ ? "external" : "internal"));
+}
+
+static ssize_t metadata_store(struct mddev *mddev, const char *buf, size_t len)
+{
+ if (mddev->bitmap ||
+ mddev->bitmap_info.file ||
+ mddev->bitmap_info.offset)
+ return -EBUSY;
+ if (strncmp(buf, "external", 8) == 0)
+ mddev->bitmap_info.external = 1;
+ else if (strncmp(buf, "internal", 8) == 0)
+ mddev->bitmap_info.external = 0;
+ else
+ return -EINVAL;
+ return len;
+}
+
+static struct md_sysfs_entry bitmap_metadata =
+__ATTR(metadata, S_IRUGO|S_IWUSR, metadata_show, metadata_store);
+
+static ssize_t can_clear_show(struct mddev *mddev, char *page)
+{
+ int len;
+ if (mddev->bitmap)
+ len = sprintf(page, "%s\n", (mddev->bitmap->need_sync ?
+ "false" : "true"));
+ else
+ len = sprintf(page, "\n");
+ return len;
+}
+
+static ssize_t can_clear_store(struct mddev *mddev, const char *buf, size_t len)
+{
+ if (mddev->bitmap == NULL)
+ return -ENOENT;
+ if (strncmp(buf, "false", 5) == 0)
+ mddev->bitmap->need_sync = 1;
+ else if (strncmp(buf, "true", 4) == 0) {
+ if (mddev->degraded)
+ return -EBUSY;
+ mddev->bitmap->need_sync = 0;
+ } else
+ return -EINVAL;
+ return len;
+}
+
+static struct md_sysfs_entry bitmap_can_clear =
+__ATTR(can_clear, S_IRUGO|S_IWUSR, can_clear_show, can_clear_store);
+
+static ssize_t
+behind_writes_used_show(struct mddev *mddev, char *page)
+{
+ if (mddev->bitmap == NULL)
+ return sprintf(page, "0\n");
+ return sprintf(page, "%lu\n",
+ mddev->bitmap->behind_writes_used);
+}
+
+static ssize_t
+behind_writes_used_reset(struct mddev *mddev, const char *buf, size_t len)
+{
+ if (mddev->bitmap)
+ mddev->bitmap->behind_writes_used = 0;
+ return len;
+}
+
+static struct md_sysfs_entry max_backlog_used =
+__ATTR(max_backlog_used, S_IRUGO | S_IWUSR,
+ behind_writes_used_show, behind_writes_used_reset);
+
+static struct attribute *md_bitmap_attrs[] = {
+ &bitmap_location.attr,
+ &bitmap_timeout.attr,
+ &bitmap_backlog.attr,
+ &bitmap_chunksize.attr,
+ &bitmap_metadata.attr,
+ &bitmap_can_clear.attr,
+ &max_backlog_used.attr,
+ NULL
+};
+struct attribute_group md_bitmap_group = {
+ .name = "bitmap",
+ .attrs = md_bitmap_attrs,
+};
+