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OpenCloudOS-Kernel/drivers/md/bitmap.c

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/*
* 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;
#ifdef 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);
ITERATE_RDEV(mddev, rdev, tmp) {
if (! rdev->in_sync || rdev->faulty)
continue;
target = (rdev->sb_offset << 1) + offset + index * (PAGE_SIZE/512);
if (sync_page_io(rdev->bdev, target, PAGE_SIZE, page, READ)) {
page->index = index;
return page;
}
}
return ERR_PTR(-EIO);
}
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);
printk(KERN_DEBUG "max write behind: %d\n", le32_to_cpu(sb->write_behind));
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, write_behind;
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);
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 (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 (1-15s)";
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)
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->daemon_lastrun = jiffies;
bitmap->max_write_behind = write_behind;
bitmap->flags |= sb->state;
bitmap->events_cleared = le64_to_cpu(sb->events_cleared);
if (sb->state & BITMAP_STALE)
bitmap->events_cleared = bitmap->mddev->events;
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_daemon(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_daemon(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, 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, dummy;
int outofdate;
int ret = -ENOSPC;
chunks = bitmap->chunks;
file = bitmap->file;
BUG_ON(!file && !bitmap->offset);
#ifdef 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),
((i+1) << (CHUNK_BLOCK_SHIFT(bitmap)) >= start)
);
bit_cnt++;
set_page_attr(bitmap, page, BITMAP_PAGE_CLEAN);
}
}
/* 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;
}
if (bitmap == NULL)
/* about to be stopped. */
return;
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 mdk_thread_t *bitmap_start_daemon(struct bitmap *bitmap,
void (*func)(mddev_t *), char *name)
{
mdk_thread_t *daemon;
char namebuf[32];
#ifdef 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 ERR_PTR(-ECHILD);
}
md_wakeup_thread(daemon); /* start it running */
PRINTK("%s: %s daemon (pid %d) started...\n",
bmname(bitmap), name, daemon->tsk->pid);
return daemon;
}
static void bitmap_stop_daemon(struct bitmap *bitmap)
{
/* the daemon can't stop itself... it'll just exit instead... */
if (bitmap->writeback_daemon && ! IS_ERR(bitmap->writeback_daemon) &&
current->pid != bitmap->writeback_daemon->tsk->pid) {
mdk_thread_t *daemon;
unsigned long flags;
spin_lock_irqsave(&bitmap->lock, flags);
daemon = bitmap->writeback_daemon;
bitmap->writeback_daemon = NULL;
spin_unlock_irqrestore(&bitmap->lock, flags);
if (daemon && ! IS_ERR(daemon))
md_unregister_thread(daemon); /* destroy the thread */
}
}
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, int behind)
{
if (!bitmap) return 0;
if (behind) {
atomic_inc(&bitmap->behind_writes);
PRINTK(KERN_DEBUG "inc write-behind count %d/%d\n",
atomic_read(&bitmap->behind_writes), bitmap->max_write_behind);
}
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, int behind)
{
if (!bitmap) return;
if (behind) {
atomic_dec(&bitmap->behind_writes);
PRINTK(KERN_DEBUG "dec write-behind count %d/%d\n",
atomic_read(&bitmap->behind_writes), bitmap->max_write_behind);
}
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,
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;
}
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, 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
*/
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 | (needed?NEEDED_MASK:0);
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);
}
/*
* flush out any pending updates
*/
void bitmap_flush(mddev_t *mddev)
{
struct bitmap *bitmap = mddev->bitmap;
int sleep;
if (!bitmap) /* there was no bitmap */
return;
/* run the daemon_work three time to ensure everything is flushed
* that can be
*/
sleep = bitmap->daemon_sleep;
bitmap->daemon_sleep = 0;
bitmap_daemon_work(bitmap);
bitmap_daemon_work(bitmap);
bitmap_daemon_work(bitmap);
bitmap->daemon_sleep = sleep;
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 */
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);
}
void bitmap_destroy(mddev_t *mddev)
{
struct bitmap *bitmap = mddev->bitmap;
if (!bitmap) /* there was no bitmap */
return;
mddev->bitmap = NULL; /* disconnect from the md device */
bitmap_free(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;
sector_t start;
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;
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);
err = -ENOMEM;
if (!bitmap->write_pool)
goto error;
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)
goto error;
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;
#ifdef INJECT_FATAL_FAULT_1
bitmap->bp = NULL;
#else
bitmap->bp = kmalloc(pages * sizeof(*bitmap->bp), GFP_KERNEL);
#endif
err = -ENOMEM;
if (!bitmap->bp)
goto error;
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 */
start = 0;
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;
err = bitmap_init_from_disk(bitmap, start);
if (err)
goto error;
printk(KERN_INFO "created bitmap (%lu pages) for device %s\n",
pages, bmname(bitmap));
mddev->bitmap = bitmap;
if (file)
/* kick off the bitmap writeback daemon */
bitmap->writeback_daemon =
bitmap_start_daemon(bitmap,
bitmap_writeback_daemon,
"bitmap_wb");
if (IS_ERR(bitmap->writeback_daemon))
return PTR_ERR(bitmap->writeback_daemon);
return bitmap_update_sb(bitmap);
error:
bitmap_free(bitmap);
return err;
}
/* 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);
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