#include <linux/bitops.h>
#include <linux/mpage.h>
#include <linux/bit_spinlock.h>
+#include <linux/pagevec.h>
#include <trace/events/block.h>
static int fsync_buffers_list(spinlock_t *lock, struct list_head *list);
}
EXPORT_SYMBOL(create_empty_buffers);
-/*
- * We are taking a block for data and we don't want any output from any
- * buffer-cache aliases starting from return from that function and
- * until the moment when something will explicitly mark the buffer
- * dirty (hopefully that will not happen until we will free that block ;-)
- * We don't even need to mark it not-uptodate - nobody can expect
- * anything from a newly allocated buffer anyway. We used to used
- * unmap_buffer() for such invalidation, but that was wrong. We definitely
- * don't want to mark the alias unmapped, for example - it would confuse
- * anyone who might pick it with bread() afterwards...
- *
- * Also.. Note that bforget() doesn't lock the buffer. So there can
- * be writeout I/O going on against recently-freed buffers. We don't
- * wait on that I/O in bforget() - it's more efficient to wait on the I/O
- * only if we really need to. That happens here.
- */
-void unmap_underlying_metadata(struct block_device *bdev, sector_t block)
+/**
+ * clean_bdev_aliases: clean a range of buffers in block device
+ * @bdev: Block device to clean buffers in
+ * @block: Start of a range of blocks to clean
+ * @len: Number of blocks to clean
+ *
+ * We are taking a range of blocks for data and we don't want writeback of any
+ * buffer-cache aliases starting from return from this function and until the
+ * moment when something will explicitly mark the buffer dirty (hopefully that
+ * will not happen until we will free that block ;-) We don't even need to mark
+ * it not-uptodate - nobody can expect anything from a newly allocated buffer
+ * anyway. We used to use unmap_buffer() for such invalidation, but that was
+ * wrong. We definitely don't want to mark the alias unmapped, for example - it
+ * would confuse anyone who might pick it with bread() afterwards...
+ *
+ * Also.. Note that bforget() doesn't lock the buffer. So there can be
+ * writeout I/O going on against recently-freed buffers. We don't wait on that
+ * I/O in bforget() - it's more efficient to wait on the I/O only if we really
+ * need to. That happens here.
+ */
+void clean_bdev_aliases(struct block_device *bdev, sector_t block, sector_t len)
{
- struct buffer_head *old_bh;
+ struct inode *bd_inode = bdev->bd_inode;
+ struct address_space *bd_mapping = bd_inode->i_mapping;
+ struct pagevec pvec;
+ pgoff_t index = block >> (PAGE_SHIFT - bd_inode->i_blkbits);
+ pgoff_t end;
+ int i;
+ struct buffer_head *bh;
+ struct buffer_head *head;
- might_sleep();
+ end = (block + len - 1) >> (PAGE_SHIFT - bd_inode->i_blkbits);
+ pagevec_init(&pvec, 0);
+ while (index <= end && pagevec_lookup(&pvec, bd_mapping, index,
+ min(end - index, (pgoff_t)PAGEVEC_SIZE - 1) + 1)) {
+ for (i = 0; i < pagevec_count(&pvec); i++) {
+ struct page *page = pvec.pages[i];
- old_bh = __find_get_block_slow(bdev, block);
- if (old_bh) {
- clear_buffer_dirty(old_bh);
- wait_on_buffer(old_bh);
- clear_buffer_req(old_bh);
- __brelse(old_bh);
+ index = page->index;
+ if (index > end)
+ break;
+ if (!page_has_buffers(page))
+ continue;
+ /*
+ * We use page lock instead of bd_mapping->private_lock
+ * to pin buffers here since we can afford to sleep and
+ * it scales better than a global spinlock lock.
+ */
+ lock_page(page);
+ /* Recheck when the page is locked which pins bhs */
+ if (!page_has_buffers(page))
+ goto unlock_page;
+ head = page_buffers(page);
+ bh = head;
+ do {
+ if (!buffer_mapped(bh))
+ goto next;
+ if (bh->b_blocknr >= block + len)
+ break;
+ clear_buffer_dirty(bh);
+ wait_on_buffer(bh);
+ clear_buffer_req(bh);
+next:
+ bh = bh->b_this_page;
+ } while (bh != head);
+unlock_page:
+ unlock_page(page);
+ }
+ pagevec_release(&pvec);
+ cond_resched();
+ index++;
}
}
-EXPORT_SYMBOL(unmap_underlying_metadata);
+EXPORT_SYMBOL(clean_bdev_aliases);
/*
* Size is a power-of-two in the range 512..PAGE_SIZE,
if (buffer_new(bh)) {
/* blockdev mappings never come here */
clear_buffer_new(bh);
- unmap_underlying_metadata(bh->b_bdev,
- bh->b_blocknr);
+ clean_bdev_bh_alias(bh);
}
}
bh = bh->b_this_page;
}
if (buffer_new(bh)) {
- unmap_underlying_metadata(bh->b_bdev,
- bh->b_blocknr);
+ clean_bdev_bh_alias(bh);
if (PageUptodate(page)) {
clear_buffer_new(bh);
set_buffer_uptodate(bh);
if (!buffer_mapped(bh))
is_mapped_to_disk = 0;
if (buffer_new(bh))
- unmap_underlying_metadata(bh->b_bdev, bh->b_blocknr);
+ clean_bdev_bh_alias(bh);
if (PageUptodate(page)) {
set_buffer_uptodate(bh);
continue;
projects / platform / kernel / linux-starfive.git / blobdiff