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cac06d843f
For sectorsize < page size support, we need a structure to record extra status info for each sector of a page. Introduce the skeleton structure, all subpage related code would go to subpage.[ch]. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
44 lines
1.0 KiB
C
44 lines
1.0 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <linux/slab.h>
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#include "ctree.h"
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#include "subpage.h"
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int btrfs_attach_subpage(const struct btrfs_fs_info *fs_info,
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struct page *page, enum btrfs_subpage_type type)
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{
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struct btrfs_subpage *subpage;
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/*
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* We have cases like a dummy extent buffer page, which is not mappped
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* and doesn't need to be locked.
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*/
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if (page->mapping)
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ASSERT(PageLocked(page));
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/* Either not subpage, or the page already has private attached */
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if (fs_info->sectorsize == PAGE_SIZE || PagePrivate(page))
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return 0;
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subpage = kzalloc(sizeof(struct btrfs_subpage), GFP_NOFS);
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if (!subpage)
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return -ENOMEM;
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spin_lock_init(&subpage->lock);
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attach_page_private(page, subpage);
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return 0;
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}
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void btrfs_detach_subpage(const struct btrfs_fs_info *fs_info,
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struct page *page)
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{
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struct btrfs_subpage *subpage;
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/* Either not subpage, or already detached */
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if (fs_info->sectorsize == PAGE_SIZE || !PagePrivate(page))
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return;
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subpage = (struct btrfs_subpage *)detach_page_private(page);
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ASSERT(subpage);
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kfree(subpage);
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}
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