Qu Wenruo | cac06d8 | 2021-01-26 16:33:47 +0800 | [diff] [blame] | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
| 2 | |
| 3 | #ifndef BTRFS_SUBPAGE_H |
| 4 | #define BTRFS_SUBPAGE_H |
| 5 | |
| 6 | #include <linux/spinlock.h> |
| 7 | |
| 8 | /* |
Qu Wenruo | 8481dd8 | 2021-08-17 17:38:51 +0800 | [diff] [blame] | 9 | * Extra info for subpapge bitmap. |
| 10 | * |
Christoph Hellwig | 2b2553f | 2023-05-31 08:04:57 +0200 | [diff] [blame] | 11 | * For subpage we pack all uptodate/dirty/writeback/ordered bitmaps into |
Qu Wenruo | 8481dd8 | 2021-08-17 17:38:51 +0800 | [diff] [blame] | 12 | * one larger bitmap. |
| 13 | * |
| 14 | * This structure records how they are organized in the bitmap: |
| 15 | * |
Christoph Hellwig | 2b2553f | 2023-05-31 08:04:57 +0200 | [diff] [blame] | 16 | * /- uptodate_offset /- dirty_offset /- ordered_offset |
Qu Wenruo | 8481dd8 | 2021-08-17 17:38:51 +0800 | [diff] [blame] | 17 | * | | | |
| 18 | * v v v |
Christoph Hellwig | 2b2553f | 2023-05-31 08:04:57 +0200 | [diff] [blame] | 19 | * |u|u|u|u|........|u|u|d|d|.......|d|d|o|o|.......|o|o| |
Qu Wenruo | 8481dd8 | 2021-08-17 17:38:51 +0800 | [diff] [blame] | 20 | * |<- bitmap_nr_bits ->| |
Christoph Hellwig | 2b2553f | 2023-05-31 08:04:57 +0200 | [diff] [blame] | 21 | * |<----------------- total_nr_bits ------------------>| |
Qu Wenruo | 8481dd8 | 2021-08-17 17:38:51 +0800 | [diff] [blame] | 22 | */ |
| 23 | struct btrfs_subpage_info { |
| 24 | /* Number of bits for each bitmap */ |
| 25 | unsigned int bitmap_nr_bits; |
| 26 | |
| 27 | /* Total number of bits for the whole bitmap */ |
| 28 | unsigned int total_nr_bits; |
| 29 | |
| 30 | /* |
| 31 | * *_start indicates where the bitmap starts, the length is always |
| 32 | * @bitmap_size, which is calculated from PAGE_SIZE / sectorsize. |
| 33 | */ |
| 34 | unsigned int uptodate_offset; |
Qu Wenruo | 8481dd8 | 2021-08-17 17:38:51 +0800 | [diff] [blame] | 35 | unsigned int dirty_offset; |
| 36 | unsigned int writeback_offset; |
| 37 | unsigned int ordered_offset; |
Qu Wenruo | e4f9434 | 2021-09-27 15:21:49 +0800 | [diff] [blame] | 38 | unsigned int checked_offset; |
Qu Wenruo | 8481dd8 | 2021-08-17 17:38:51 +0800 | [diff] [blame] | 39 | }; |
| 40 | |
| 41 | /* |
Qu Wenruo | cac06d8 | 2021-01-26 16:33:47 +0800 | [diff] [blame] | 42 | * Structure to trace status of each sector inside a page, attached to |
| 43 | * page::private for both data and metadata inodes. |
| 44 | */ |
| 45 | struct btrfs_subpage { |
| 46 | /* Common members for both data and metadata pages */ |
| 47 | spinlock_t lock; |
Qu Wenruo | 3d078ef | 2021-06-07 17:02:58 +0800 | [diff] [blame] | 48 | /* |
| 49 | * Both data and metadata needs to track how many readers are for the |
| 50 | * page. |
| 51 | * Data relies on @readers to unlock the page when last reader finished. |
| 52 | * While metadata doesn't need page unlock, it needs to prevent |
| 53 | * page::private get cleared before the last end_page_read(). |
| 54 | */ |
| 55 | atomic_t readers; |
Qu Wenruo | 760f991 | 2021-01-26 16:33:48 +0800 | [diff] [blame] | 56 | union { |
Qu Wenruo | 8ff8466 | 2021-01-26 16:33:50 +0800 | [diff] [blame] | 57 | /* |
| 58 | * Structures only used by metadata |
| 59 | * |
| 60 | * @eb_refs should only be operated under private_lock, as it |
| 61 | * manages whether the subpage can be detached. |
| 62 | */ |
| 63 | atomic_t eb_refs; |
Qu Wenruo | 6f17400 | 2021-05-31 16:50:45 +0800 | [diff] [blame] | 64 | |
Qu Wenruo | 72a69cd | 2021-08-17 17:38:52 +0800 | [diff] [blame] | 65 | /* Structures only used by data */ |
| 66 | atomic_t writers; |
Qu Wenruo | 760f991 | 2021-01-26 16:33:48 +0800 | [diff] [blame] | 67 | }; |
Qu Wenruo | 72a69cd | 2021-08-17 17:38:52 +0800 | [diff] [blame] | 68 | unsigned long bitmaps[]; |
Qu Wenruo | cac06d8 | 2021-01-26 16:33:47 +0800 | [diff] [blame] | 69 | }; |
| 70 | |
| 71 | enum btrfs_subpage_type { |
| 72 | BTRFS_SUBPAGE_METADATA, |
| 73 | BTRFS_SUBPAGE_DATA, |
| 74 | }; |
| 75 | |
Qu Wenruo | fbca46e | 2022-01-13 13:22:09 +0800 | [diff] [blame] | 76 | bool btrfs_is_subpage(const struct btrfs_fs_info *fs_info, struct page *page); |
| 77 | |
Qu Wenruo | 8481dd8 | 2021-08-17 17:38:51 +0800 | [diff] [blame] | 78 | void btrfs_init_subpage_info(struct btrfs_subpage_info *subpage_info, u32 sectorsize); |
Qu Wenruo | cac06d8 | 2021-01-26 16:33:47 +0800 | [diff] [blame] | 79 | int btrfs_attach_subpage(const struct btrfs_fs_info *fs_info, |
| 80 | struct page *page, enum btrfs_subpage_type type); |
| 81 | void btrfs_detach_subpage(const struct btrfs_fs_info *fs_info, |
| 82 | struct page *page); |
| 83 | |
Qu Wenruo | 760f991 | 2021-01-26 16:33:48 +0800 | [diff] [blame] | 84 | /* Allocate additional data where page represents more than one sector */ |
Qu Wenruo | 651fb41 | 2021-08-17 17:38:50 +0800 | [diff] [blame] | 85 | struct btrfs_subpage *btrfs_alloc_subpage(const struct btrfs_fs_info *fs_info, |
| 86 | enum btrfs_subpage_type type); |
Qu Wenruo | 760f991 | 2021-01-26 16:33:48 +0800 | [diff] [blame] | 87 | void btrfs_free_subpage(struct btrfs_subpage *subpage); |
| 88 | |
Qu Wenruo | 8ff8466 | 2021-01-26 16:33:50 +0800 | [diff] [blame] | 89 | void btrfs_page_inc_eb_refs(const struct btrfs_fs_info *fs_info, |
| 90 | struct page *page); |
| 91 | void btrfs_page_dec_eb_refs(const struct btrfs_fs_info *fs_info, |
| 92 | struct page *page); |
| 93 | |
Qu Wenruo | 92082d4 | 2021-02-02 10:28:36 +0800 | [diff] [blame] | 94 | void btrfs_subpage_start_reader(const struct btrfs_fs_info *fs_info, |
| 95 | struct page *page, u64 start, u32 len); |
| 96 | void btrfs_subpage_end_reader(const struct btrfs_fs_info *fs_info, |
| 97 | struct page *page, u64 start, u32 len); |
| 98 | |
Qu Wenruo | 1e1de38 | 2021-05-31 16:50:44 +0800 | [diff] [blame] | 99 | void btrfs_subpage_start_writer(const struct btrfs_fs_info *fs_info, |
| 100 | struct page *page, u64 start, u32 len); |
| 101 | bool btrfs_subpage_end_and_test_writer(const struct btrfs_fs_info *fs_info, |
| 102 | struct page *page, u64 start, u32 len); |
| 103 | int btrfs_page_start_writer_lock(const struct btrfs_fs_info *fs_info, |
| 104 | struct page *page, u64 start, u32 len); |
| 105 | void btrfs_page_end_writer_lock(const struct btrfs_fs_info *fs_info, |
| 106 | struct page *page, u64 start, u32 len); |
| 107 | |
Qu Wenruo | a1d767c | 2021-01-26 16:33:52 +0800 | [diff] [blame] | 108 | /* |
| 109 | * Template for subpage related operations. |
| 110 | * |
| 111 | * btrfs_subpage_*() are for call sites where the page has subpage attached and |
| 112 | * the range is ensured to be inside the page. |
| 113 | * |
| 114 | * btrfs_page_*() are for call sites where the page can either be subpage |
| 115 | * specific or regular page. The function will handle both cases. |
| 116 | * But the range still needs to be inside the page. |
Qu Wenruo | 60e2d25 | 2021-05-31 16:50:39 +0800 | [diff] [blame] | 117 | * |
| 118 | * btrfs_page_clamp_*() are similar to btrfs_page_*(), except the range doesn't |
| 119 | * need to be inside the page. Those functions will truncate the range |
| 120 | * automatically. |
Qu Wenruo | a1d767c | 2021-01-26 16:33:52 +0800 | [diff] [blame] | 121 | */ |
| 122 | #define DECLARE_BTRFS_SUBPAGE_OPS(name) \ |
| 123 | void btrfs_subpage_set_##name(const struct btrfs_fs_info *fs_info, \ |
| 124 | struct page *page, u64 start, u32 len); \ |
| 125 | void btrfs_subpage_clear_##name(const struct btrfs_fs_info *fs_info, \ |
| 126 | struct page *page, u64 start, u32 len); \ |
| 127 | bool btrfs_subpage_test_##name(const struct btrfs_fs_info *fs_info, \ |
| 128 | struct page *page, u64 start, u32 len); \ |
| 129 | void btrfs_page_set_##name(const struct btrfs_fs_info *fs_info, \ |
| 130 | struct page *page, u64 start, u32 len); \ |
| 131 | void btrfs_page_clear_##name(const struct btrfs_fs_info *fs_info, \ |
| 132 | struct page *page, u64 start, u32 len); \ |
| 133 | bool btrfs_page_test_##name(const struct btrfs_fs_info *fs_info, \ |
Qu Wenruo | 60e2d25 | 2021-05-31 16:50:39 +0800 | [diff] [blame] | 134 | struct page *page, u64 start, u32 len); \ |
| 135 | void btrfs_page_clamp_set_##name(const struct btrfs_fs_info *fs_info, \ |
| 136 | struct page *page, u64 start, u32 len); \ |
| 137 | void btrfs_page_clamp_clear_##name(const struct btrfs_fs_info *fs_info, \ |
| 138 | struct page *page, u64 start, u32 len); \ |
| 139 | bool btrfs_page_clamp_test_##name(const struct btrfs_fs_info *fs_info, \ |
Qu Wenruo | a1d767c | 2021-01-26 16:33:52 +0800 | [diff] [blame] | 140 | struct page *page, u64 start, u32 len); |
| 141 | |
| 142 | DECLARE_BTRFS_SUBPAGE_OPS(uptodate); |
Qu Wenruo | d8a5713 | 2021-03-25 15:14:37 +0800 | [diff] [blame] | 143 | DECLARE_BTRFS_SUBPAGE_OPS(dirty); |
Qu Wenruo | 3470da3 | 2021-03-25 15:14:38 +0800 | [diff] [blame] | 144 | DECLARE_BTRFS_SUBPAGE_OPS(writeback); |
Qu Wenruo | 6f17400 | 2021-05-31 16:50:45 +0800 | [diff] [blame] | 145 | DECLARE_BTRFS_SUBPAGE_OPS(ordered); |
Qu Wenruo | e4f9434 | 2021-09-27 15:21:49 +0800 | [diff] [blame] | 146 | DECLARE_BTRFS_SUBPAGE_OPS(checked); |
Qu Wenruo | d8a5713 | 2021-03-25 15:14:37 +0800 | [diff] [blame] | 147 | |
| 148 | bool btrfs_subpage_clear_and_test_dirty(const struct btrfs_fs_info *fs_info, |
| 149 | struct page *page, u64 start, u32 len); |
Qu Wenruo | a1d767c | 2021-01-26 16:33:52 +0800 | [diff] [blame] | 150 | |
Qu Wenruo | cc1d0d9 | 2021-07-26 14:34:58 +0800 | [diff] [blame] | 151 | void btrfs_page_assert_not_dirty(const struct btrfs_fs_info *fs_info, |
| 152 | struct page *page); |
Qu Wenruo | e55a0de | 2021-09-27 15:22:05 +0800 | [diff] [blame] | 153 | void btrfs_page_unlock_writer(struct btrfs_fs_info *fs_info, struct page *page, |
| 154 | u64 start, u32 len); |
Qu Wenruo | 75258f2 | 2023-05-26 20:30:53 +0800 | [diff] [blame] | 155 | void __cold btrfs_subpage_dump_bitmap(const struct btrfs_fs_info *fs_info, |
| 156 | struct page *page, u64 start, u32 len); |
Qu Wenruo | cc1d0d9 | 2021-07-26 14:34:58 +0800 | [diff] [blame] | 157 | |
Qu Wenruo | cac06d8 | 2021-01-26 16:33:47 +0800 | [diff] [blame] | 158 | #endif |