diff options
Diffstat (limited to 'drivers/md/bitmap.c')
| -rw-r--r-- | drivers/md/bitmap.c | 2113 |
1 files changed, 2113 insertions, 0 deletions
diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c new file mode 100644 index 00000000..17e2b472 --- /dev/null +++ b/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, +}; + |