diff options
Diffstat (limited to 'drivers/md/bitmap.c')
| -rw-r--r-- | drivers/md/bitmap.c | 1586 |
1 files changed, 1586 insertions, 0 deletions
diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c new file mode 100644 index 000000000000..95980ad6b27b --- /dev/null +++ b/drivers/md/bitmap.c @@ -0,0 +1,1586 @@ +/* + * 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 + * - added bitmap daemon (to asynchronously clear bitmap bits from disk) + */ + +/* + * Still to do: + * + * flush after percent set rather than just time based. (maybe both). + * wait if count gets too high, wake when it drops to half. + * allow bitmap to be mirrored with superblock (before or after...) + * allow hot-add to re-instate a current device. + * allow hot-add of bitmap after quiessing device + */ + +#include <linux/module.h> +#include <linux/version.h> +#include <linux/errno.h> +#include <linux/slab.h> +#include <linux/init.h> +#include <linux/config.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/raid/md.h> +#include <linux/raid/bitmap.h> + +/* debug macros */ + +#define DEBUG 0 + +#if DEBUG +/* these are for debugging purposes only! */ + +/* define one and only one of these */ +#define INJECT_FAULTS_1 0 /* cause bitmap_alloc_page to fail always */ +#define INJECT_FAULTS_2 0 /* cause bitmap file to be kicked when first bit set*/ +#define INJECT_FAULTS_3 0 /* treat bitmap file as kicked at init time */ +#define INJECT_FAULTS_4 0 /* undef */ +#define INJECT_FAULTS_5 0 /* undef */ +#define INJECT_FAULTS_6 0 + +/* if these are defined, the driver will fail! debug only */ +#define INJECT_FATAL_FAULT_1 0 /* fail kmalloc, causing bitmap_create to fail */ +#define INJECT_FATAL_FAULT_2 0 /* undef */ +#define INJECT_FATAL_FAULT_3 0 /* undef */ +#endif + +//#define DPRINTK PRINTK /* set this NULL to avoid verbose debug output */ +#define DPRINTK(x...) do { } while(0) + +#ifndef PRINTK +# if DEBUG > 0 +# define PRINTK(x...) printk(KERN_DEBUG x) +# else +# define PRINTK(x...) +# endif +#endif + +static inline char * bmname(struct bitmap *bitmap) +{ + return bitmap->mddev ? mdname(bitmap->mddev) : "mdX"; +} + + +/* + * test if the bitmap is active + */ +int bitmap_active(struct bitmap *bitmap) +{ + unsigned long flags; + int res = 0; + + if (!bitmap) + return res; + spin_lock_irqsave(&bitmap->lock, flags); + res = bitmap->flags & BITMAP_ACTIVE; + spin_unlock_irqrestore(&bitmap->lock, flags); + return res; +} + +#define WRITE_POOL_SIZE 256 +/* mempool for queueing pending writes on the bitmap file */ +static void *write_pool_alloc(unsigned int gfp_flags, void *data) +{ + return kmalloc(sizeof(struct page_list), gfp_flags); +} + +static void write_pool_free(void *ptr, void *data) +{ + kfree(ptr); +} + +/* + * just a placeholder - calls kmalloc for bitmap pages + */ +static unsigned char *bitmap_alloc_page(struct bitmap *bitmap) +{ + unsigned char *page; + +#if INJECT_FAULTS_1 + page = NULL; +#else + page = kmalloc(PAGE_SIZE, GFP_NOIO); +#endif + if (!page) + printk("%s: bitmap_alloc_page FAILED\n", bmname(bitmap)); + else + PRINTK("%s: bitmap_alloc_page: allocated page at %p\n", + bmname(bitmap), page); + return page; +} + +/* + * for now just a placeholder -- just calls kfree for bitmap pages + */ +static void bitmap_free_page(struct bitmap *bitmap, unsigned char *page) +{ + PRINTK("%s: bitmap_free_page: free page %p\n", bmname(bitmap), page); + kfree(page); +} + +/* + * 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) +{ + unsigned char *mappage; + + if (page >= bitmap->pages) { + printk(KERN_ALERT + "%s: invalid bitmap page request: %lu (> %lu)\n", + bmname(bitmap), page, bitmap->pages-1); + 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; + + spin_unlock_irq(&bitmap->lock); + + /* this page has not been allocated yet */ + + if ((mappage = bitmap_alloc_page(bitmap)) == NULL) { + PRINTK("%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 */ + spin_lock_irq(&bitmap->lock); + if (!bitmap->bp[page].map) + bitmap->bp[page].hijacked = 1; + goto out; + } + + /* got a page */ + + spin_lock_irq(&bitmap->lock); + + /* recheck the page */ + + if (bitmap->bp[page].map || bitmap->bp[page].hijacked) { + /* somebody beat us to getting the page */ + bitmap_free_page(bitmap, mappage); + return 0; + } + + /* no page was in place and we have one, so install it */ + + memset(mappage, 0, PAGE_SIZE); + bitmap->bp[page].map = mappage; + bitmap->missing_pages--; +out: + 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 inline 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; + return; + } + + /* normal case, free the page */ + +#if 0 +/* actually ... let's not. We will probably need the page again exactly when + * memory is tight and we are flusing to disk + */ + return; +#else + ptr = bitmap->bp[page].map; + bitmap->bp[page].map = NULL; + bitmap->missing_pages++; + bitmap_free_page(bitmap, ptr); + return; +#endif +} + + +/* + * bitmap file handling - read and write the bitmap file and its superblock + */ + +/* copy the pathname of a file to a buffer */ +char *file_path(struct file *file, char *buf, int count) +{ + struct dentry *d; + struct vfsmount *v; + + if (!buf) + return NULL; + + d = file->f_dentry; + v = file->f_vfsmnt; + + buf = d_path(d, v, buf, count); + + return IS_ERR(buf) ? NULL : buf; +} + +/* + * basic page I/O operations + */ + +/* IO operations when bitmap is stored near all superblocks */ +static struct page *read_sb_page(mddev_t *mddev, long offset, unsigned long index) +{ + /* choose a good rdev and read the page from there */ + + mdk_rdev_t *rdev; + struct list_head *tmp; + struct page *page = alloc_page(GFP_KERNEL); + sector_t target; + + if (!page) + return ERR_PTR(-ENOMEM); + do { + ITERATE_RDEV(mddev, rdev, tmp) + if (rdev->in_sync && !rdev->faulty) + goto found; + return ERR_PTR(-EIO); + + found: + target = (rdev->sb_offset << 1) + offset + index * (PAGE_SIZE/512); + + } while (!sync_page_io(rdev->bdev, target, PAGE_SIZE, page, READ)); + + page->index = index; + return page; +} + +static int write_sb_page(mddev_t *mddev, long offset, struct page *page, int wait) +{ + mdk_rdev_t *rdev; + struct list_head *tmp; + + ITERATE_RDEV(mddev, rdev, tmp) + if (rdev->in_sync && !rdev->faulty) + md_super_write(mddev, rdev, + (rdev->sb_offset<<1) + offset + + page->index * (PAGE_SIZE/512), + PAGE_SIZE, + page); + + if (wait) + wait_event(mddev->sb_wait, atomic_read(&mddev->pending_writes)==0); + return 0; +} + +/* + * write out a page to a file + */ +static int write_page(struct bitmap *bitmap, struct page *page, int wait) +{ + int ret = -ENOMEM; + + if (bitmap->file == NULL) + return write_sb_page(bitmap->mddev, bitmap->offset, page, wait); + + if (wait) + lock_page(page); + else { + if (TestSetPageLocked(page)) + return -EAGAIN; /* already locked */ + if (PageWriteback(page)) { + unlock_page(page); + return -EAGAIN; + } + } + + ret = page->mapping->a_ops->prepare_write(NULL, page, 0, PAGE_SIZE); + if (!ret) + ret = page->mapping->a_ops->commit_write(NULL, page, 0, + PAGE_SIZE); + if (ret) { + unlock_page(page); + return ret; + } + + set_page_dirty(page); /* force it to be written out */ + + if (!wait) { + /* add to list to be waited for by daemon */ + struct page_list *item = mempool_alloc(bitmap->write_pool, GFP_NOIO); + item->page = page; + page_cache_get(page); + spin_lock(&bitmap->write_lock); + list_add(&item->list, &bitmap->complete_pages); + spin_unlock(&bitmap->write_lock); + md_wakeup_thread(bitmap->writeback_daemon); + } + return write_one_page(page, wait); +} + +/* read a page from a file, pinning it into cache, and return bytes_read */ +static struct page *read_page(struct file *file, unsigned long index, + unsigned long *bytes_read) +{ + struct inode *inode = file->f_mapping->host; + struct page *page = NULL; + loff_t isize = i_size_read(inode); + unsigned long end_index = isize >> PAGE_CACHE_SHIFT; + + PRINTK("read bitmap file (%dB @ %Lu)\n", (int)PAGE_CACHE_SIZE, + (unsigned long long)index << PAGE_CACHE_SHIFT); + + page = read_cache_page(inode->i_mapping, index, + (filler_t *)inode->i_mapping->a_ops->readpage, file); + if (IS_ERR(page)) + goto out; + wait_on_page_locked(page); + if (!PageUptodate(page) || PageError(page)) { + page_cache_release(page); + page = ERR_PTR(-EIO); + goto out; + } + + if (index > end_index) /* we have read beyond EOF */ + *bytes_read = 0; + else if (index == end_index) /* possible short read */ + *bytes_read = isize & ~PAGE_CACHE_MASK; + else + *bytes_read = PAGE_CACHE_SIZE; /* got a full page */ +out: + if (IS_ERR(page)) + printk(KERN_ALERT "md: bitmap read error: (%dB @ %Lu): %ld\n", + (int)PAGE_CACHE_SIZE, + (unsigned long long)index << PAGE_CACHE_SHIFT, + PTR_ERR(page)); + return page; +} + +/* + * bitmap file superblock operations + */ + +/* update the event counter and sync the superblock to disk */ +int bitmap_update_sb(struct bitmap *bitmap) +{ + bitmap_super_t *sb; + unsigned long flags; + + if (!bitmap || !bitmap->mddev) /* no bitmap for this array */ + return 0; + spin_lock_irqsave(&bitmap->lock, flags); + if (!bitmap->sb_page) { /* no superblock */ + spin_unlock_irqrestore(&bitmap->lock, flags); + return 0; + } + spin_unlock_irqrestore(&bitmap->lock, flags); + sb = (bitmap_super_t *)kmap(bitmap->sb_page); + sb->events = cpu_to_le64(bitmap->mddev->events); + if (!bitmap->mddev->degraded) + sb->events_cleared = cpu_to_le64(bitmap->mddev->events); + kunmap(bitmap->sb_page); + return 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 = (bitmap_super_t *)kmap(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); + kunmap(bitmap->sb_page); +} + +/* 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; + unsigned long bytes_read; + unsigned long long events; + int err = -EINVAL; + + /* page 0 is the superblock, read it... */ + if (bitmap->file) + bitmap->sb_page = read_page(bitmap->file, 0, &bytes_read); + else { + bitmap->sb_page = read_sb_page(bitmap->mddev, bitmap->offset, 0); + bytes_read = PAGE_SIZE; + } + if (IS_ERR(bitmap->sb_page)) { + err = PTR_ERR(bitmap->sb_page); + bitmap->sb_page = NULL; + return err; + } + + sb = (bitmap_super_t *)kmap(bitmap->sb_page); + + if (bytes_read < sizeof(*sb)) { /* short read */ + printk(KERN_INFO "%s: bitmap file superblock truncated\n", + bmname(bitmap)); + err = -ENOSPC; + goto out; + } + + chunksize = le32_to_cpu(sb->chunksize); + daemon_sleep = le32_to_cpu(sb->daemon_sleep); + + /* verify that the bitmap-specific fields are valid */ + if (sb->magic != cpu_to_le32(BITMAP_MAGIC)) + reason = "bad magic"; + else if (sb->version != cpu_to_le32(BITMAP_MAJOR)) + reason = "unrecognized superblock version"; + else if (chunksize < 512 || chunksize > (1024 * 1024 * 4)) + reason = "bitmap chunksize out of range (512B - 4MB)"; + else if ((1 << ffz(~chunksize)) != chunksize) + reason = "bitmap chunksize not a power of 2"; + else if (daemon_sleep < 1 || daemon_sleep > 15) + reason = "daemon sleep period out of range"; + 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) + goto success; + + /* + * if we have a persistent array superblock, 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 |= BITMAP_STALE; + } +success: + /* assign fields using values from superblock */ + bitmap->chunksize = chunksize; + bitmap->daemon_sleep = daemon_sleep; + bitmap->flags |= sb->state; + bitmap->events_cleared = le64_to_cpu(sb->events_cleared); + err = 0; +out: + kunmap(bitmap->sb_page); + 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 */ +static void bitmap_mask_state(struct bitmap *bitmap, enum bitmap_state bits, + enum bitmap_mask_op op) +{ + bitmap_super_t *sb; + unsigned long flags; + + spin_lock_irqsave(&bitmap->lock, flags); + if (!bitmap || !bitmap->sb_page) { /* can't set the state */ + spin_unlock_irqrestore(&bitmap->lock, flags); + return; + } + page_cache_get(bitmap->sb_page); + spin_unlock_irqrestore(&bitmap->lock, flags); + sb = (bitmap_super_t *)kmap(bitmap->sb_page); + switch (op) { + case MASK_SET: sb->state |= bits; + break; + case MASK_UNSET: sb->state &= ~bits; + break; + default: BUG(); + } + kunmap(bitmap->sb_page); + page_cache_release(bitmap->sb_page); +} + +/* + * general bitmap file operations + */ + +/* calculate the index of the page that contains this bit */ +static inline unsigned long file_page_index(unsigned long chunk) +{ + return CHUNK_BIT_OFFSET(chunk) >> PAGE_BIT_SHIFT; +} + +/* calculate the (bit) offset of this bit within a page */ +static inline unsigned long file_page_offset(unsigned long chunk) +{ + return CHUNK_BIT_OFFSET(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) +{ + return bitmap->filemap[file_page_index(chunk) - file_page_index(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]->index != 0) /* 0 is sb_page, release it below */ + page_cache_release(map[pages]); + kfree(map); + kfree(attr); + + if (sb_page) + page_cache_release(sb_page); +} + +static void bitmap_stop_daemons(struct bitmap *bitmap); + +/* dequeue the next item in a page list -- don't call from irq context */ +static struct page_list *dequeue_page(struct bitmap *bitmap) +{ + struct page_list *item = NULL; + struct list_head *head = &bitmap->complete_pages; + + spin_lock(&bitmap->write_lock); + if (list_empty(head)) + goto out; + item = list_entry(head->prev, struct page_list, list); + list_del(head->prev); +out: + spin_unlock(&bitmap->write_lock); + return item; +} + +static void drain_write_queues(struct bitmap *bitmap) +{ + struct page_list *item; + + while ((item = dequeue_page(bitmap))) { + /* don't bother to wait */ + page_cache_release(item->page); + mempool_free(item, bitmap->write_pool); + } + + wake_up(&bitmap->write_wait); +} + +static void bitmap_file_put(struct bitmap *bitmap) +{ + struct file *file; + struct inode *inode; + unsigned long flags; + + spin_lock_irqsave(&bitmap->lock, flags); + file = bitmap->file; + bitmap->file = NULL; + spin_unlock_irqrestore(&bitmap->lock, flags); + + bitmap_stop_daemons(bitmap); + + drain_write_queues(bitmap); + + bitmap_file_unmap(bitmap); + + if (file) { + inode = file->f_mapping->host; + spin_lock(&inode->i_lock); + atomic_set(&inode->i_writecount, 1); /* allow writes again */ + spin_unlock(&inode->i_lock); + 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; + + bitmap_mask_state(bitmap, BITMAP_STALE, MASK_SET); + bitmap_update_sb(bitmap); + + if (bitmap->file) { + path = kmalloc(PAGE_SIZE, GFP_KERNEL); + if (path) + ptr = file_path(bitmap->file, path, PAGE_SIZE); + + printk(KERN_ALERT "%s: kicking failed bitmap file %s from array!\n", + bmname(bitmap), ptr ? ptr : ""); + + kfree(path); + } + + bitmap_file_put(bitmap); + + return; +} + +enum bitmap_page_attr { + BITMAP_PAGE_DIRTY = 1, // there are set bits that need to be synced + BITMAP_PAGE_CLEAN = 2, // there are bits that might need to be cleared + BITMAP_PAGE_NEEDWRITE=4, // 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) +{ + bitmap->filemap_attr[page->index] |= attr; +} + +static inline void clear_page_attr(struct bitmap *bitmap, struct page *page, + enum bitmap_page_attr attr) +{ + bitmap->filemap_attr[page->index] &= ~attr; +} + +static inline unsigned long get_page_attr(struct bitmap *bitmap, struct page *page) +{ + return bitmap->filemap_attr[page->index]; +} + +/* + * 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 >> CHUNK_BLOCK_SHIFT(bitmap); + + if (!bitmap->filemap) { + return; + } + + page = filemap_get_page(bitmap, chunk); + bit = file_page_offset(chunk); + + + /* make sure the page stays cached until it gets written out */ + if (! (get_page_attr(bitmap, page) & BITMAP_PAGE_DIRTY)) + page_cache_get(page); + + /* set the bit */ + kaddr = kmap_atomic(page, KM_USER0); + set_bit(bit, kaddr); + kunmap_atomic(kaddr, KM_USER0); + PRINTK("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 */ +int bitmap_unplug(struct bitmap *bitmap) +{ + unsigned long i, attr, flags; + struct page *page; + int wait = 0; + int err; + + if (!bitmap) + return 0; + + /* 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 0; + } + page = bitmap->filemap[i]; + attr = get_page_attr(bitmap, page); + clear_page_attr(bitmap, page, BITMAP_PAGE_DIRTY); + clear_page_attr(bitmap, page, BITMAP_PAGE_NEEDWRITE); + if ((attr & BITMAP_PAGE_DIRTY)) + wait = 1; + spin_unlock_irqrestore(&bitmap->lock, flags); + + if (attr & (BITMAP_PAGE_DIRTY | BITMAP_PAGE_NEEDWRITE)) { + err = write_page(bitmap, page, 0); + if (err == -EAGAIN) { + if (attr & BITMAP_PAGE_DIRTY) + err = write_page(bitmap, page, 1); + else + err = 0; + } + if (err) + return 1; + } + } + if (wait) { /* if any writes were performed, we need to wait on them */ + if (bitmap->file) { + spin_lock_irq(&bitmap->write_lock); + wait_event_lock_irq(bitmap->write_wait, + list_empty(&bitmap->complete_pages), bitmap->write_lock, + wake_up_process(bitmap->writeback_daemon->tsk)); + spin_unlock_irq(&bitmap->write_lock); + } else + wait_event(bitmap->mddev->sb_wait, + atomic_read(&bitmap->mddev->pending_writes)==0); + } + return 0; +} + +static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, + unsigned long sectors, int in_sync); +/* * 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. + */ +static int bitmap_init_from_disk(struct bitmap *bitmap, int in_sync) +{ + 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, dummy; + int outofdate; + int ret = -ENOSPC; + + chunks = bitmap->chunks; + file = bitmap->file; + + BUG_ON(!file && !bitmap->offset); + +#if INJECT_FAULTS_3 + outofdate = 1; +#else + outofdate = bitmap->flags & BITMAP_STALE; +#endif + if (outofdate) + printk(KERN_INFO "%s: bitmap file is out of date, doing full " + "recovery\n", bmname(bitmap)); + + bytes = (chunks + 7) / 8; + + num_pages = (bytes + sizeof(bitmap_super_t) + PAGE_SIZE - 1) / PAGE_SIZE; + + if (file && i_size_read(file->f_mapping->host) < bytes + sizeof(bitmap_super_t)) { + printk(KERN_INFO "%s: bitmap file too short %lu < %lu\n", + bmname(bitmap), + (unsigned long) i_size_read(file->f_mapping->host), + bytes + sizeof(bitmap_super_t)); + goto out; + } + + ret = -ENOMEM; + + bitmap->filemap = kmalloc(sizeof(struct page *) * num_pages, GFP_KERNEL); + if (!bitmap->filemap) + goto out; + + bitmap->filemap_attr = kmalloc(sizeof(long) * num_pages, GFP_KERNEL); + if (!bitmap->filemap_attr) + goto out; + + memset(bitmap->filemap_attr, 0, sizeof(long) * num_pages); + + oldindex = ~0L; + + for (i = 0; i < chunks; i++) { + index = file_page_index(i); + bit = file_page_offset(i); + if (index != oldindex) { /* this is a new page, read it in */ + /* unmap the old page, we're done with it */ + if (oldpage != NULL) + kunmap(oldpage); + if (index == 0) { + /* + * 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); + } else if (file) { + page = read_page(file, index, &dummy); + offset = 0; + } else { + page = read_sb_page(bitmap->mddev, bitmap->offset, index); + offset = 0; + } + if (IS_ERR(page)) { /* read error */ + ret = PTR_ERR(page); + goto out; + } + + oldindex = index; + oldpage = page; + kmap(page); + + if (outofdate) { + /* + * if bitmap is out of date, dirty the + * whole page and write it out + */ + memset(page_address(page) + offset, 0xff, + PAGE_SIZE - offset); + ret = write_page(bitmap, page, 1); + if (ret) { + kunmap(page); + /* release, page not in filemap yet */ + page_cache_release(page); + goto out; + } + } + + bitmap->filemap[bitmap->file_pages++] = page; + } + if (test_bit(bit, page_address(page))) { + /* if the disk bit is set, set the memory bit */ + bitmap_set_memory_bits(bitmap, + i << CHUNK_BLOCK_SHIFT(bitmap), 1, in_sync); + bit_cnt++; + } + } + + /* everything went OK */ + ret = 0; + bitmap_mask_state(bitmap, BITMAP_STALE, MASK_UNSET); + + if (page) /* unmap the last page */ + kunmap(page); + + if (bit_cnt) { /* Kick recovery if any bits were set */ + set_bit(MD_RECOVERY_NEEDED, &bitmap->mddev->recovery); + md_wakeup_thread(bitmap->mddev->thread); + } + +out: + printk(KERN_INFO "%s: bitmap initialized from disk: " + "read %lu/%lu pages, set %lu bits, status: %d\n", + bmname(bitmap), bitmap->file_pages, num_pages, bit_cnt, 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 + */ + + unsigned long chunks = bitmap->chunks; + unsigned long bytes = (chunks+7)/8 + sizeof(bitmap_super_t); + unsigned long num_pages = (bytes + PAGE_SIZE-1) / PAGE_SIZE; + while (num_pages--) + bitmap->filemap_attr[num_pages] |= BITMAP_PAGE_NEEDWRITE; +} + + +static void bitmap_count_page(struct bitmap *bitmap, sector_t offset, int inc) +{ + sector_t chunk = offset >> CHUNK_BLOCK_SHIFT(bitmap); + unsigned long page = chunk >> PAGE_COUNTER_SHIFT; + bitmap->bp[page].count += inc; +/* + if (page == 0) printk("count page 0, offset %llu: %d gives %d\n", + (unsigned long long)offset, inc, bitmap->bp[page].count); +*/ + bitmap_checkfree(bitmap, page); +} +static bitmap_counter_t *bitmap_get_counter(struct bitmap *bitmap, + sector_t offset, int *blocks, + int create); + +/* + * bitmap daemon -- periodically wakes up to clean bits and flush pages + * out to disk + */ + +int bitmap_daemon_work(struct bitmap *bitmap) +{ + unsigned long j; + unsigned long flags; + struct page *page = NULL, *lastpage = NULL; + int err = 0; + int blocks; + int attr; + + if (bitmap == NULL) + return 0; + if (time_before(jiffies, bitmap->daemon_lastrun + bitmap->daemon_sleep*HZ)) + return 0; + bitmap->daemon_lastrun = jiffies; + + for (j = 0; j < bitmap->chunks; j++) { + bitmap_counter_t *bmc; + spin_lock_irqsave(&bitmap->lock, flags); + if (!bitmap->filemap) { + /* error or shutdown */ + spin_unlock_irqrestore(&bitmap->lock, flags); + break; + } + + page = filemap_get_page(bitmap, j); + + if (page != lastpage) { + /* skip this page unless it's marked as needing cleaning */ + if (!((attr=get_page_attr(bitmap, page)) & BITMAP_PAGE_CLEAN)) { + if (attr & BITMAP_PAGE_NEEDWRITE) { + page_cache_get(page); + clear_page_attr(bitmap, page, BITMAP_PAGE_NEEDWRITE); + } + spin_unlock_irqrestore(&bitmap->lock, flags); + if (attr & BITMAP_PAGE_NEEDWRITE) { + switch (write_page(bitmap, page, 0)) { + case -EAGAIN: + set_page_attr(bitmap, page, BITMAP_PAGE_NEEDWRITE); + break; + case 0: + break; + default: + bitmap_file_kick(bitmap); + } + page_cache_release(page); + } + continue; + } + + /* grab the new page, sync and release the old */ + page_cache_get(page); + if (lastpage != NULL) { + if (get_page_attr(bitmap, lastpage) & BITMAP_PAGE_NEEDWRITE) { + clear_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE); + spin_unlock_irqrestore(&bitmap->lock, flags); + err = write_page(bitmap, lastpage, 0); + if (err == -EAGAIN) { + err = 0; + set_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE); + } + } else { + set_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE); + spin_unlock_irqrestore(&bitmap->lock, flags); + } + kunmap(lastpage); + page_cache_release(lastpage); + if (err) + bitmap_file_kick(bitmap); + } else + spin_unlock_irqrestore(&bitmap->lock, flags); + lastpage = page; + kmap(page); +/* + printk("bitmap clean at page %lu\n", j); +*/ + spin_lock_irqsave(&bitmap->lock, flags); + clear_page_attr(bitmap, page, BITMAP_PAGE_CLEAN); + } + bmc = bitmap_get_counter(bitmap, j << CHUNK_BLOCK_SHIFT(bitmap), + &blocks, 0); + if (bmc) { +/* + if (j < 100) printk("bitmap: j=%lu, *bmc = 0x%x\n", j, *bmc); +*/ + if (*bmc == 2) { + *bmc=1; /* maybe clear the bit next time */ + set_page_attr(bitmap, page, BITMAP_PAGE_CLEAN); + } else if (*bmc == 1) { + /* we can clear the bit */ + *bmc = 0; + bitmap_count_page(bitmap, j << CHUNK_BLOCK_SHIFT(bitmap), + -1); + + /* clear the bit */ + clear_bit(file_page_offset(j), page_address(page)); + } + } + spin_unlock_irqrestore(&bitmap->lock, flags); + } + + /* now sync the final page */ + if (lastpage != NULL) { + kunmap(lastpage); + spin_lock_irqsave(&bitmap->lock, flags); + if (get_page_attr(bitmap, lastpage) &BITMAP_PAGE_NEEDWRITE) { + clear_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE); + spin_unlock_irqrestore(&bitmap->lock, flags); + err = write_page(bitmap, lastpage, 0); + if (err == -EAGAIN) { + set_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE); + err = 0; + } + } else { + set_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE); + spin_unlock_irqrestore(&bitmap->lock, flags); + } + + page_cache_release(lastpage); + } + + return err; +} + +static void daemon_exit(struct bitmap *bitmap, mdk_thread_t **daemon) +{ + mdk_thread_t *dmn; + unsigned long flags; + + /* if no one is waiting on us, we'll free the md thread struct + * and exit, otherwise we let the waiter clean things up */ + spin_lock_irqsave(&bitmap->lock, flags); + if ((dmn = *daemon)) { /* no one is waiting, cleanup and exit */ + *daemon = NULL; + spin_unlock_irqrestore(&bitmap->lock, flags); + kfree(dmn); + complete_and_exit(NULL, 0); /* do_exit not exported */ + } + spin_unlock_irqrestore(&bitmap->lock, flags); +} + +static void bitmap_writeback_daemon(mddev_t *mddev) +{ + struct bitmap *bitmap = mddev->bitmap; + struct page *page; + struct page_list *item; + int err = 0; + + if (signal_pending(current)) { + printk(KERN_INFO + "%s: bitmap writeback daemon got signal, exiting...\n", + bmname(bitmap)); + err = -EINTR; + goto out; + } + + PRINTK("%s: bitmap writeback daemon woke up...\n", bmname(bitmap)); + /* wait on bitmap page writebacks */ + while ((item = dequeue_page(bitmap))) { + page = item->page; + mempool_free(item, bitmap->write_pool); + PRINTK("wait on page writeback: %p\n", page); + wait_on_page_writeback(page); + PRINTK("finished page writeback: %p\n", page); + + err = PageError(page); + page_cache_release(page); + if (err) { + printk(KERN_WARNING "%s: bitmap file writeback " + "failed (page %lu): %d\n", + bmname(bitmap), page->index, err); + bitmap_file_kick(bitmap); + goto out; + } + } + out: + wake_up(&bitmap->write_wait); + if (err) { + printk(KERN_INFO "%s: bitmap writeback daemon exiting (%d)\n", + bmname(bitmap), err); + daemon_exit(bitmap, &bitmap->writeback_daemon); + } +} + +static int bitmap_start_daemon(struct bitmap *bitmap, mdk_thread_t **ptr, + void (*func)(mddev_t *), char *name) +{ + mdk_thread_t *daemon; + unsigned long flags; + char namebuf[32]; + + spin_lock_irqsave(&bitmap->lock, flags); + *ptr = NULL; + + if (!bitmap->file) /* no need for daemon if there's no backing file */ + goto out_unlock; + + spin_unlock_irqrestore(&bitmap->lock, flags); + +#if INJECT_FATAL_FAULT_2 + daemon = NULL; +#else + sprintf(namebuf, "%%s_%s", name); + daemon = md_register_thread(func, bitmap->mddev, namebuf); +#endif + if (!daemon) { + printk(KERN_ERR "%s: failed to start bitmap daemon\n", + bmname(bitmap)); + return -ECHILD; + } + + spin_lock_irqsave(&bitmap->lock, flags); + *ptr = daemon; + + md_wakeup_thread(daemon); /* start it running */ + + PRINTK("%s: %s daemon (pid %d) started...\n", + bmname(bitmap), name, daemon->tsk->pid); +out_unlock: + spin_unlock_irqrestore(&bitmap->lock, flags); + return 0; +} + +static int bitmap_start_daemons(struct bitmap *bitmap) +{ + int err = bitmap_start_daemon(bitmap, &bitmap->writeback_daemon, + bitmap_writeback_daemon, "bitmap_wb"); + return err; +} + +static void bitmap_stop_daemon(struct bitmap *bitmap, mdk_thread_t **ptr) +{ + mdk_thread_t *daemon; + unsigned long flags; + + spin_lock_irqsave(&bitmap->lock, flags); + daemon = *ptr; + *ptr = NULL; + spin_unlock_irqrestore(&bitmap->lock, flags); + if (daemon) + md_unregister_thread(daemon); /* destroy the thread */ +} + +static void bitmap_stop_daemons(struct bitmap *bitmap) +{ + /* the daemons can't stop themselves... they'll just exit instead... */ + if (bitmap->writeback_daemon && + current->pid != bitmap->writeback_daemon->tsk->pid) + bitmap_stop_daemon(bitmap, &bitmap->writeback_daemon); +} + +static bitmap_counter_t *bitmap_get_counter(struct bitmap *bitmap, + sector_t offset, int *blocks, + int create) +{ + /* 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 >> CHUNK_BLOCK_SHIFT(bitmap); + unsigned long page = chunk >> PAGE_COUNTER_SHIFT; + unsigned long pageoff = (chunk & PAGE_COUNTER_MASK) << COUNTER_BYTE_SHIFT; + sector_t csize; + + if (bitmap_checkpage(bitmap, page, create) < 0) { + csize = ((sector_t)1) << (CHUNK_BLOCK_SHIFT(bitmap)); + *blocks = csize - (offset & (csize- 1)); + 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); + csize = ((sector_t)1) << (CHUNK_BLOCK_SHIFT(bitmap) + + PAGE_COUNTER_SHIFT - 1); + *blocks = csize - (offset & (csize- 1)); + return &((bitmap_counter_t *) + &bitmap->bp[page].map)[hi]; + } else { /* page is allocated */ + csize = ((sector_t)1) << (CHUNK_BLOCK_SHIFT(bitmap)); + *blocks = csize - (offset & (csize- 1)); + return (bitmap_counter_t *) + &(bitmap->bp[page].map[pageoff]); + } +} + +int bitmap_startwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors) +{ + if (!bitmap) return 0; + while (sectors) { + int 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; + } + + switch(*bmc) { + case 0: + bitmap_file_set_bit(bitmap, offset); + bitmap_count_page(bitmap,offset, 1); + blk_plug_device(bitmap->mddev->queue); + /* fall through */ + case 1: + *bmc = 2; + } + if ((*bmc & COUNTER_MAX) == COUNTER_MAX) BUG(); + (*bmc)++; + + spin_unlock_irq(&bitmap->lock); + + offset += blocks; + if (sectors > blocks) + sectors -= blocks; + else sectors = 0; + } + return 0; +} + +void bitmap_endwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors, + int success) +{ + if (!bitmap) return; + while (sectors) { + int 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 && ! (*bmc & NEEDED_MASK)) + *bmc |= NEEDED_MASK; + + (*bmc)--; + if (*bmc <= 2) { + set_page_attr(bitmap, + filemap_get_page(bitmap, offset >> CHUNK_BLOCK_SHIFT(bitmap)), + BITMAP_PAGE_CLEAN); + } + spin_unlock_irqrestore(&bitmap->lock, flags); + offset += blocks; + if (sectors > blocks) + sectors -= blocks; + else sectors = 0; + } +} + +int bitmap_start_sync(struct bitmap *bitmap, sector_t offset, int *blocks) +{ + 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; + *bmc |= RESYNC_MASK; + *bmc &= ~NEEDED_MASK; + } + } + spin_unlock_irq(&bitmap->lock); + return rv; +} + +void bitmap_end_sync(struct bitmap *bitmap, sector_t offset, int *blocks, int aborted) +{ + bitmap_counter_t *bmc; + unsigned long flags; +/* + if (offset == 0) printk("bitmap_end_sync 0 (%d)\n", aborted); +*/ 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 (offset == 0) printk("bitmap_end sync found 0x%x, blocks %d\n", *bmc, *blocks); +*/ + 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 >> CHUNK_BLOCK_SHIFT(bitmap)), + BITMAP_PAGE_CLEAN); + } + } + } + unlock: + spin_unlock_irqrestore(&bitmap->lock, flags); +} + +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; + int blocks; + if (!bitmap) return; + while (sector < bitmap->mddev->resync_max_sectors) { + bitmap_end_sync(bitmap, sector, &blocks, 0); +/* + if (sector < 500) printk("bitmap_close_sync: sec %llu blks %d\n", + (unsigned long long)sector, blocks); +*/ sector += blocks; + } +} + +static void bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, + unsigned long sectors, int in_sync) +{ + /* For each chunk covered by any of these sectors, set the + * counter to 1 and set resync_needed unless in_sync. They should all + * be 0 at this point + */ + while (sectors) { + int 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 = 1 | (in_sync? 0 : NEEDED_MASK); + bitmap_count_page(bitmap, offset, 1); + page = filemap_get_page(bitmap, offset >> CHUNK_BLOCK_SHIFT(bitmap)); + set_page_attr(bitmap, page, BITMAP_PAGE_CLEAN); + } + spin_unlock_irq(&bitmap->lock); + if (sectors > secs) + sectors -= secs; + else + sectors = 0; + } +} + +/* + * free memory that was allocated + */ +void bitmap_destroy(mddev_t *mddev) +{ + unsigned long k, pages; + struct bitmap_page *bp; + struct bitmap *bitmap = mddev->bitmap; + + if (!bitmap) /* there was no bitmap */ + return; + + mddev->bitmap = NULL; /* disconnect from the md device */ + + /* release the bitmap file and kill the daemon */ + bitmap_file_put(bitmap); + + bp = bitmap->bp; + pages = bitmap->pages; + + /* free all allocated memory */ + + mempool_destroy(bitmap->write_pool); + + 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); +} + +/* + * initialize the bitmap structure + * if this returns an error, bitmap_destroy must be called to do clean up + */ +int bitmap_create(mddev_t *mddev) +{ + struct bitmap *bitmap; + unsigned long blocks = mddev->resync_max_sectors; + unsigned long chunks; + unsigned long pages; + struct file *file = mddev->bitmap_file; + int err; + + BUG_ON(sizeof(bitmap_super_t) != 256); + + if (!file && !mddev->bitmap_offset) /* bitmap disabled, nothing to do */ + return 0; + + BUG_ON(file && mddev->bitmap_offset); + + bitmap = kmalloc(sizeof(*bitmap), GFP_KERNEL); + if (!bitmap) + return -ENOMEM; + + memset(bitmap, 0, sizeof(*bitmap)); + + spin_lock_init(&bitmap->lock); + bitmap->mddev = mddev; + mddev->bitmap = bitmap; + + spin_lock_init(&bitmap->write_lock); + INIT_LIST_HEAD(&bitmap->complete_pages); + init_waitqueue_head(&bitmap->write_wait); + bitmap->write_pool = mempool_create(WRITE_POOL_SIZE, write_pool_alloc, + write_pool_free, NULL); + if (!bitmap->write_pool) + return -ENOMEM; + + bitmap->file = file; + bitmap->offset = mddev->bitmap_offset; + if (file) get_file(file); + /* read superblock from bitmap file (this sets bitmap->chunksize) */ + err = bitmap_read_sb(bitmap); + if (err) + return err; + + bitmap->chunkshift = find_first_bit(&bitmap->chunksize, + sizeof(bitmap->chunksize)); + + /* now that chunksize and chunkshift are set, we can use these macros */ + chunks = (blocks + CHUNK_BLOCK_RATIO(bitmap) - 1) / + CHUNK_BLOCK_RATIO(bitmap); + pages = (chunks + PAGE_COUNTER_RATIO - 1) / PAGE_COUNTER_RATIO; + + BUG_ON(!pages); + + bitmap->chunks = chunks; + bitmap->pages = pages; + bitmap->missing_pages = pages; + bitmap->counter_bits = COUNTER_BITS; + + bitmap->syncchunk = ~0UL; + +#if INJECT_FATAL_FAULT_1 + bitmap->bp = NULL; +#else + bitmap->bp = kmalloc(pages * sizeof(*bitmap->bp), GFP_KERNEL); +#endif + if (!bitmap->bp) + return -ENOMEM; + memset(bitmap->bp, 0, pages * sizeof(*bitmap->bp)); + + bitmap->flags |= BITMAP_ACTIVE; + + /* now that we have some pages available, initialize the in-memory + * bitmap from the on-disk bitmap */ + err = bitmap_init_from_disk(bitmap, mddev->recovery_cp == MaxSector); + if (err) + return err; + + printk(KERN_INFO "created bitmap (%lu pages) for device %s\n", + pages, bmname(bitmap)); + + /* kick off the bitmap daemons */ + err = bitmap_start_daemons(bitmap); + if (err) + return err; + return bitmap_update_sb(bitmap); +} + +/* the bitmap API -- for raid personalities */ +EXPORT_SYMBOL(bitmap_startwrite); +EXPORT_SYMBOL(bitmap_endwrite); +EXPORT_SYMBOL(bitmap_start_sync); +EXPORT_SYMBOL(bitmap_end_sync); +EXPORT_SYMBOL(bitmap_unplug); +EXPORT_SYMBOL(bitmap_close_sync); +EXPORT_SYMBOL(bitmap_daemon_work); |