*
* 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>
}
-/*
- * 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
-
/*
* just a placeholder - calls kmalloc for bitmap pages
*/
if (sync_page_io(rdev->bdev, target, PAGE_SIZE, page, READ)) {
page->index = index;
+ attach_page_buffers(page, NULL); /* so that free_buffer will
+ * quietly no-op */
return page;
}
}
*/
static int write_page(struct bitmap *bitmap, struct page *page, int wait)
{
- int ret = -ENOMEM;
+ struct buffer_head *bh;
if (bitmap->file == NULL)
return write_sb_page(bitmap->mddev, bitmap->offset, page, wait);
- flush_dcache_page(page); /* make sure visible to anyone reading the file */
+ bh = page_buffers(page);
- if (wait)
- lock_page(page);
- else {
- if (TestSetPageLocked(page))
- return -EAGAIN; /* already locked */
- if (PageWriteback(page)) {
- unlock_page(page);
- return -EAGAIN;
- }
+ while (bh && bh->b_blocknr) {
+ atomic_inc(&bitmap->pending_writes);
+ set_buffer_locked(bh);
+ set_buffer_mapped(bh);
+ submit_bh(WRITE, bh);
+ bh = bh->b_this_page;
}
- ret = page->mapping->a_ops->prepare_write(bitmap->file, page, 0, PAGE_SIZE);
- if (!ret)
- ret = page->mapping->a_ops->commit_write(bitmap->file, page, 0,
- PAGE_SIZE);
- if (ret) {
- unlock_page(page);
- return ret;
+ if (wait) {
+ wait_event(bitmap->write_wait,
+ atomic_read(&bitmap->pending_writes)==0);
+ return (bitmap->flags & BITMAP_WRITE_ERROR) ? -EIO : 0;
+ }
+ return 0;
+}
+
+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);
+}
- set_page_dirty(page); /* force it to be written out */
+/* 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);
- if (!wait) {
- /* add to list to be waited for */
- struct page_list *item = mempool_alloc(bitmap->write_pool, GFP_NOIO);
- item->page = page;
- get_page(page);
- spin_lock(&bitmap->write_lock);
- list_add(&item->list, &bitmap->complete_pages);
- spin_unlock(&bitmap->write_lock);
+ while (bh) {
+ struct buffer_head *next = bh->b_this_page;
+ free_buffer_head(bh);
+ bh = next;
}
- return write_one_page(page, wait);
+ __clear_page_buffers(page);
+ put_page(page);
}
-/* read a page from a file, pinning it into cache, and return bytes_read */
+/* 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,
- unsigned long *bytes_read)
+ struct bitmap *bitmap,
+ unsigned long count)
{
- struct inode *inode = file->f_mapping->host;
struct page *page = NULL;
- loff_t isize = i_size_read(inode);
- unsigned long end_index = isize >> PAGE_SHIFT;
+ struct inode *inode = file->f_dentry->d_inode;
+ struct buffer_head *bh;
+ sector_t block;
PRINTK("read bitmap file (%dB @ %Lu)\n", (int)PAGE_SIZE,
(unsigned long long)index << PAGE_SHIFT);
- page = read_cache_page(inode->i_mapping, index,
- (filler_t *)inode->i_mapping->a_ops->readpage, file);
+ page = alloc_page(GFP_KERNEL);
+ if (!page)
+ page = ERR_PTR(-ENOMEM);
if (IS_ERR(page))
goto out;
- wait_on_page_locked(page);
- if (!PageUptodate(page) || PageError(page)) {
+
+ bh = alloc_page_buffers(page, 1<<inode->i_blkbits, 0);
+ if (!bh) {
put_page(page);
- page = ERR_PTR(-EIO);
+ 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;
- if (index > end_index) /* we have read beyond EOF */
- *bytes_read = 0;
- else if (index == end_index) /* possible short read */
- *bytes_read = isize & ~PAGE_MASK;
- else
- *bytes_read = PAGE_SIZE; /* got a full page */
+ 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 @ %Lu): %ld\n",
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);
+ bitmap->sb_page = read_page(bitmap->file, 0, bitmap, PAGE_SIZE);
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);
sb = (bitmap_super_t *)kmap_atomic(bitmap->sb_page, KM_USER0);
- 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);
spin_unlock_irqrestore(&bitmap->lock, flags);
return;
}
- get_page(bitmap->sb_page);
spin_unlock_irqrestore(&bitmap->lock, flags);
sb = (bitmap_super_t *)kmap_atomic(bitmap->sb_page, KM_USER0);
switch (op) {
default: BUG();
}
kunmap_atomic(sb, KM_USER0);
- put_page(bitmap->sb_page);
}
/*
while (pages--)
if (map[pages]->index != 0) /* 0 is sb_page, release it below */
- put_page(map[pages]);
+ free_buffers(map[pages]);
kfree(map);
kfree(attr);
- safe_put_page(sb_page);
-}
-
-/* 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 */
- put_page(item->page);
- mempool_free(item, bitmap->write_pool);
- }
+ if (sb_page)
+ free_buffers(sb_page);
}
static void bitmap_file_put(struct bitmap *bitmap)
{
struct file *file;
- struct inode *inode;
unsigned long flags;
spin_lock_irqsave(&bitmap->lock, flags);
bitmap->file = NULL;
spin_unlock_irqrestore(&bitmap->lock, flags);
- drain_write_queues(bitmap);
-
+ if (file)
+ wait_event(bitmap->write_wait,
+ atomic_read(&bitmap->pending_writes)==0);
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);
+ struct inode *inode = file->f_dentry->d_inode;
+ invalidate_inode_pages(inode->i_mapping);
fput(file);
}
}
}
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
+ BITMAP_PAGE_DIRTY = 0, // there are set bits that need to be synced
+ BITMAP_PAGE_CLEAN = 1, // there are bits that might need to be cleared
+ 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)
{
- bitmap->filemap_attr[page->index] |= 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)
{
- bitmap->filemap_attr[page->index] &= ~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 bitmap->filemap_attr[page->index] & attr;
+ return test_bit((page->index<<2) + attr, bitmap->filemap_attr);
}
/*
page = filemap_get_page(bitmap, chunk);
bit = file_page_offset(chunk);
-
- /* make sure the page stays cached until it gets written out */
- if (! test_page_attr(bitmap, page, BITMAP_PAGE_DIRTY))
- get_page(page);
-
/* set the bit */
kaddr = kmap_atomic(page, KM_USER0);
if (bitmap->flags & BITMAP_HOSTENDIAN)
}
-static void bitmap_writeback(struct bitmap *bitmap);
-
/* 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 */
wait = 1;
spin_unlock_irqrestore(&bitmap->lock, flags);
- if (dirty | need_write) {
+ if (dirty | need_write)
err = write_page(bitmap, page, 0);
- if (err == -EAGAIN) {
- if (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)
- bitmap_writeback(bitmap);
+ 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);
return 0;
}
struct page *page = NULL, *oldpage = NULL;
unsigned long num_pages, bit_cnt = 0;
struct file *file;
- unsigned long bytes, offset, dummy;
+ unsigned long bytes, offset;
int outofdate;
int ret = -ENOSPC;
void *paddr;
if (!bitmap->filemap)
goto out;
- bitmap->filemap_attr = kzalloc(sizeof(long) * num_pages, GFP_KERNEL);
+ /* We need 4 bits per page, rounded up to a multiple of sizeof(unsigned long) */
+ bitmap->filemap_attr = kzalloc(
+ (((num_pages*4/8)+sizeof(unsigned long)-1)
+ /sizeof(unsigned long))
+ *sizeof(unsigned long),
+ GFP_KERNEL);
if (!bitmap->filemap_attr)
goto out;
index = file_page_index(i);
bit = file_page_offset(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) {
/*
* if we're here then the superblock page
page = bitmap->sb_page;
offset = sizeof(bitmap_super_t);
} else if (file) {
- page = read_page(file, index, &dummy);
+ page = read_page(file, index, bitmap, count);
offset = 0;
} else {
page = read_sb_page(bitmap->mddev, bitmap->offset, index);
if (!test_page_attr(bitmap, page, BITMAP_PAGE_CLEAN)) {
int need_write = test_page_attr(bitmap, page,
BITMAP_PAGE_NEEDWRITE);
- if (need_write) {
- get_page(page);
+ if (need_write)
clear_page_attr(bitmap, page, BITMAP_PAGE_NEEDWRITE);
- }
+
spin_unlock_irqrestore(&bitmap->lock, flags);
if (need_write) {
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);
}
- put_page(page);
}
continue;
}
/* grab the new page, sync and release the old */
- get_page(page);
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);
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);
}
- put_page(lastpage);
if (err)
bitmap_file_kick(bitmap);
} else
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);
}
-
- put_page(lastpage);
}
return err;
}
-static void bitmap_writeback(struct bitmap *bitmap)
-{
- struct page *page;
- struct page_list *item;
- int err = 0;
-
- 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);
- put_page(page);
- if (err) {
- printk(KERN_WARNING "%s: bitmap file writeback "
- "failed (page %lu): %d\n",
- bmname(bitmap), page->index, err);
- bitmap_file_kick(bitmap);
- break;
- }
- }
-}
-
static bitmap_counter_t *bitmap_get_counter(struct bitmap *bitmap,
sector_t offset, int *blocks,
int create)
/* 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)
return -ENOMEM;
spin_lock_init(&bitmap->lock);
- bitmap->mddev = mddev;
+ atomic_set(&bitmap->pending_writes, 0);
+ init_waitqueue_head(&bitmap->write_wait);
- spin_lock_init(&bitmap->write_lock);
- INIT_LIST_HEAD(&bitmap->complete_pages);
- bitmap->write_pool = mempool_create_kmalloc_pool(WRITE_POOL_SIZE,
- sizeof(struct page_list));
- err = -ENOMEM;
- if (!bitmap->write_pool)
- goto error;
+ bitmap->mddev = mddev;
bitmap->file = file;
bitmap->offset = mddev->bitmap_offset;
- if (file) get_file(file);
+ if (file) {
+ get_file(file);
+ do_sync_file_range(file, 0, LLONG_MAX,
+ SYNC_FILE_RANGE_WAIT_BEFORE |
+ SYNC_FILE_RANGE_WRITE |
+ SYNC_FILE_RANGE_WAIT_AFTER);
+ }
/* read superblock from bitmap file (this sets bitmap->chunksize) */
err = bitmap_read_sb(bitmap);
if (err)
if (!bitmap->bp)
goto error;
- bitmap->flags |= BITMAP_ACTIVE;
-
/* now that we have some pages available, initialize the in-memory
* bitmap from the on-disk bitmap */
start = 0;
EXPORT_SYMBOL(bitmap_end_sync);
EXPORT_SYMBOL(bitmap_unplug);
EXPORT_SYMBOL(bitmap_close_sync);
-EXPORT_SYMBOL(bitmap_daemon_work);