diff options
| -rw-r--r-- | fs/btrfs/btrfs_inode.h | 1 | ||||
| -rw-r--r-- | fs/btrfs/disk-io.c | 28 | ||||
| -rw-r--r-- | fs/btrfs/extent_io.c | 113 | ||||
| -rw-r--r-- | fs/btrfs/fs.h | 12 | ||||
| -rw-r--r-- | fs/btrfs/inode.c | 217 | ||||
| -rw-r--r-- | fs/btrfs/subpage.c | 216 | ||||
| -rw-r--r-- | fs/btrfs/subpage.h | 41 | ||||
| -rw-r--r-- | include/trace/events/btrfs.h | 35 |
8 files changed, 651 insertions, 12 deletions
diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h index 7fdc6c3fd066..1082fa92c145 100644 --- a/fs/btrfs/btrfs_inode.h +++ b/fs/btrfs/btrfs_inode.h @@ -600,6 +600,7 @@ int btrfs_prealloc_file_range_trans(struct inode *inode, loff_t actual_len, u64 *alloc_hint); int btrfs_run_delalloc_range(struct btrfs_inode *inode, struct folio *locked_folio, u64 start, u64 end, struct writeback_control *wbc); +void btrfs_queue_writepage_fixup(struct btrfs_inode *inode, struct folio *folio); int btrfs_encoded_io_compression_from_extent(struct btrfs_fs_info *fs_info, int compress_type); int btrfs_encoded_read_regular_fill_pages(struct btrfs_inode *inode, diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 50228c2e66c0..2f1666d9544e 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -1760,6 +1760,8 @@ static int read_backup_root(struct btrfs_fs_info *fs_info, u8 priority) /* helper to cleanup workers */ static void btrfs_stop_all_workers(struct btrfs_fs_info *fs_info) { + if (fs_info->fixup_workers) + destroy_workqueue(fs_info->fixup_workers); btrfs_destroy_workqueue(fs_info->delalloc_workers); btrfs_destroy_workqueue(fs_info->workers); if (fs_info->endio_workers) @@ -1967,6 +1969,9 @@ static int btrfs_init_workqueues(struct btrfs_fs_info *fs_info) fs_info->caching_workers = btrfs_alloc_workqueue(fs_info, "cache", flags, max_active, 0); + fs_info->fixup_workers = + alloc_ordered_workqueue("btrfs-fixup", ordered_flags); + fs_info->endio_workers = alloc_workqueue("btrfs-endio", flags, max_active); fs_info->endio_meta_workers = @@ -1992,7 +1997,7 @@ static int btrfs_init_workqueues(struct btrfs_fs_info *fs_info) fs_info->endio_workers && fs_info->endio_meta_workers && fs_info->endio_write_workers && fs_info->endio_freespace_worker && fs_info->rmw_workers && - fs_info->caching_workers && + fs_info->caching_workers && fs_info->fixup_workers && fs_info->delayed_workers && fs_info->qgroup_rescan_workers && fs_info->discard_ctl.discard_workers)) { return -ENOMEM; @@ -4365,6 +4370,18 @@ void __cold close_ctree(struct btrfs_fs_info *fs_info) btrfs_cleanup_defrag_inodes(fs_info); /* + * Before the unmount, we sync down all the writeback which can + * generate fixup work. We are about to run delalloc for autodefrag so + * piggy back on that by also flushing the fixup work which can also + * generate delalloc we would like to get run. + * + * After this, it is still possible that some thread doing writeback is + * in btrfs_queue_writepage_fixup() and might finish queueing some final + * work, racing the btrfs_fs_closing() check there. + */ + flush_workqueue(fs_info->fixup_workers); + + /* * Handle the error fs first, as it will flush and wait for all ordered * extents. This will generate delayed iputs, thus we want to handle * it first. @@ -4442,6 +4459,15 @@ void __cold close_ctree(struct btrfs_fs_info *fs_info) cancel_work_sync(&fs_info->em_shrinker_work); /* + * Reclaim workers can run writeback which can queue fixup. + * After the above cancel_work_sync() calls, any such queueing attempts are + * guaranteed to see btrfs_fs_closing(), so at this point we can genuinely fully + * flush the fixup workqueue. This relies on the belief that *now* no thread can + * still be sitting in btrfs_queue_writepage_fixup(). + */ + flush_workqueue(fs_info->fixup_workers); + + /* * Run delayed iputs again because an async reclaim worker may have * added new ones if it was flushing delalloc: * diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index de5785117a47..f032f0858f40 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -1441,6 +1441,115 @@ static bool find_next_delalloc_bitmap(struct folio *folio, } /* + * Debug checks for fixup selection logic to help ensure the invariants + * we expect for fixup marking hold in practice. + * + * - A dirty block without a fixup bit is covered by delalloc or a running + * ordered extent (it was dirtied by a reserving write path). + * - A block with a fixup bit is never covered by delalloc: every delalloc + * setter holds the folio lock and cancels the fixup state of the blocks + * it covers (btrfs_folio_set_dirty()) before releasing it. + */ +static void debug_check_writepage_fixup(struct btrfs_inode *inode, u64 start, + u32 len, bool needs_fixup) +{ + struct btrfs_ordered_extent *ordered; + bool delalloc; + + if (!IS_ENABLED(CONFIG_BTRFS_DEBUG)) + return; + + delalloc = btrfs_test_range_bit_exists(&inode->io_tree, start, + start + len - 1, EXTENT_DELALLOC); + if (needs_fixup) { + if (unlikely(delalloc)) + DEBUG_WARN("writeback: delalloc and fixup conflict. ino %llu start %llu", + btrfs_ino(inode), start); + } else { + if (delalloc) + return; + + ordered = btrfs_lookup_ordered_range(inode, start, len); + if (unlikely(!ordered)) + DEBUG_WARN("dirty block, no delalloc, fixup, ordered. ino %llu start %llu", + btrfs_ino(inode), start); + else + btrfs_put_ordered_extent(ordered); + } +} + +/* + * Handle folios dirtied without a delalloc reservation, e.g. + * O_DIRECT read into a MAP_SHARED mapping dirtying via set_page_dirty_lock(). + * + * btrfs_data_dirty_folio() records the affected blocks in the fixup bitmap + * and the folio fixup flag and we check them here in writeback. + * + * Don't submit such blocks and queue work for the fixup worker to reserve + * space for them so that they can be submitted properly by writeback. + * + * Return 1 if the folio needed fixup, 0 if not, and a negative error code + * on error. + */ +static noinline_for_stack int writepage_fixup(struct btrfs_inode *inode, + struct folio *folio, + struct btrfs_bio_ctrl *bio_ctrl) +{ + struct btrfs_fs_info *fs_info = inode_to_fs_info(&inode->vfs_inode); + const unsigned int blocks_per_folio = btrfs_blocks_per_folio(fs_info, folio); + const u32 sectorsize = fs_info->sectorsize; + const u64 page_start = folio_pos(folio); + bool found_fixup = false; + unsigned int bit; + + /* + * A folio was dirtied without calling aops->dirty_folio() which we + * explicitly assert is not allowed. + */ + if (unlikely(bitmap_empty(bio_ctrl->submit_bitmap, blocks_per_folio))) { + DEBUG_WARN(); + btrfs_err_rl(fs_info, + "root %lld ino %llu folio %llu is dirty with an empty dirty bitmap", + btrfs_root_id(inode->root), btrfs_ino(inode), + folio_pos(folio)); + return -EUCLEAN; + } + + /* Cheap check on the folio flag. Set iff the fixup bitmap is non-empty. */ + if (likely(!folio_test_fixup_pending(folio))) + return 0; + + for_each_set_bit(bit, bio_ctrl->submit_bitmap, blocks_per_folio) { + const u64 start = page_start + (bit << fs_info->sectorsize_bits); + const bool needs_fixup = btrfs_folio_test_fixup(fs_info, folio, + start, sectorsize); + + debug_check_writepage_fixup(inode, start, sectorsize, needs_fixup); + if (needs_fixup) { + bitmap_clear(bio_ctrl->submit_bitmap, bit, 1); + found_fixup = true; + } + } + if (likely(found_fixup)) { + btrfs_queue_writepage_fixup(inode, folio); + folio_redirty_for_writepage(bio_ctrl->wbc, folio); + if (bitmap_empty(bio_ctrl->submit_bitmap, blocks_per_folio)) { + folio_unlock(folio); + return 1; + } + return 0; + } + /* We should always find fixup if the folio fixup flag was set. */ + DEBUG_WARN(); + btrfs_err_rl(fs_info, + "root %lld ino %llu folio %llu is fixup with an empty fixup bitmap", + btrfs_root_id(inode->root), btrfs_ino(inode), + folio_pos(folio)); + + return -EUCLEAN; +} + +/* * Do all of the delayed allocation setup. * * Return >0 if all the dirty blocks are submitted async (compression) or inlined. @@ -1492,6 +1601,10 @@ static noinline_for_stack int writepage_delalloc(struct btrfs_inode *inode, /* Save the dirty bitmap as our submission bitmap will be a subset of it. */ btrfs_copy_subpage_dirty_bitmap(fs_info, folio, bio_ctrl->submit_bitmap); + ret = writepage_fixup(inode, folio, bio_ctrl); + if (ret) + return ret; + for_each_set_bitrange(start_bit, end_bit, bio_ctrl->submit_bitmap, blocks_per_folio) { u64 start = page_start + (start_bit << fs_info->sectorsize_bits); diff --git a/fs/btrfs/fs.h b/fs/btrfs/fs.h index 7ee9ec2b0efb..f7f343fbe732 100644 --- a/fs/btrfs/fs.h +++ b/fs/btrfs/fs.h @@ -713,6 +713,8 @@ struct btrfs_fs_info { struct btrfs_workqueue *endio_write_workers; struct btrfs_workqueue *endio_freespace_worker; struct btrfs_workqueue *caching_workers; + + struct workqueue_struct *fixup_workers; struct btrfs_workqueue *delayed_workers; struct task_struct *transaction_kthread; @@ -1200,6 +1202,16 @@ static inline void btrfs_wake_unfinished_drop(struct btrfs_fs_info *fs_info) clear_and_wake_up_bit(BTRFS_FS_UNFINISHED_DROPS, &fs_info->flags); } +/* + * We use the folio owner_2 flag to indicate the folio has blocks that were + * dirtied without a space reservation and need the writepage fixup before + * writeback. For bs < folio_size the fixup bitmap tracks the affected + * blocks. + */ +#define folio_test_fixup_pending(folio) folio_test_owner_2(folio) +#define folio_set_fixup_pending(folio) folio_set_owner_2(folio) +#define folio_clear_fixup_pending(folio) folio_clear_owner_2(folio) + #define BTRFS_FS_ERROR(fs_info) (READ_ONCE((fs_info)->fs_error)) #define BTRFS_FS_LOG_CLEANUP_ERROR(fs_info) \ diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index d7b5a05fae00..2534cd9284d5 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -2812,6 +2812,180 @@ int btrfs_set_extent_delalloc(struct btrfs_inode *inode, u64 start, u64 end, EXTENT_DELALLOC | extra_bits, cached_state); } +struct btrfs_writepage_fixup { + struct folio *folio; + struct btrfs_inode *inode; + struct work_struct work; +}; + +/* + * Do the real fixup work of reserving space for the blocks a folio's fixup + * state records. Queued by writepage_fixup() when writeback found the bits set. + * + * Since the fixup can be cancelled by a task dirtying with a reservation, we must + * re-check the state of fixup under the folio lock. + */ +static void btrfs_writepage_fixup_worker(struct work_struct *work) +{ + struct btrfs_writepage_fixup *fixup = + container_of(work, struct btrfs_writepage_fixup, work); + struct extent_state *cached_state = NULL; + struct extent_changeset *data_reserved = NULL; + unsigned long delalloc_bitmap[BITS_TO_LONGS(BTRFS_MAX_BLOCKS_PER_FOLIO)] = { 0 }; + struct folio *folio = fixup->folio; + struct btrfs_inode *inode = fixup->inode; + struct btrfs_fs_info *fs_info = inode->root->fs_info; + const unsigned int blocks_per_folio = btrfs_blocks_per_folio(fs_info, folio); + const u32 sectorsize = fs_info->sectorsize; + const u64 page_start = folio_pos(folio); + const u64 page_end = folio_next_pos(folio) - 1; + unsigned int start_bit; + unsigned int end_bit; + unsigned int bit; + bool reserved; + int ret; + + /* + * We would prefer to reserve under the folio lock when we know exactly + * which blocks need a reservation. Unfortunately, since the reservation + * can go into flushers which can go into writeback, which takes folio + * locks, that is not possible. Therefore, we have to reserve for the + * whole folio here, then release what we didn't end up needing once we + * figure it out. + * + * Also note the slightly strange error checking. If fixup is actually + * not set, we don't need to mark an error on the mapping. So hang on to + * ret until after we lock and find out if we actually care. + */ + ret = btrfs_delalloc_reserve_space(inode, &data_reserved, page_start, + folio_size(folio)); + reserved = (ret == 0); +again: + folio_lock(folio); + + if (!folio->mapping || !folio_test_fixup_pending(folio)) { + ret = 0; + goto out; + } + if (ret) + goto out; + + btrfs_lock_extent(&inode->io_tree, page_start, page_end, &cached_state); + + for (bit = 0; bit < blocks_per_folio; bit++) { + struct btrfs_ordered_extent *ordered; + const u64 start = page_start + (bit << fs_info->sectorsize_bits); + + if (test_bit(bit, delalloc_bitmap)) + continue; + if (!btrfs_folio_test_fixup(fs_info, folio, start, sectorsize)) + continue; + /* + * Any task that sets EXTENT_DELALLOC clears the fixup bits + * under the folio lock, so it should be impossible to observe + * both under the lock. Setting delalloc twice would wrongly + * double account the space. + */ + if (IS_ENABLED(CONFIG_BTRFS_DEBUG) && + unlikely(btrfs_test_range_bit_exists(&inode->io_tree, start, + start + sectorsize - 1, + EXTENT_DELALLOC))) { + DEBUG_WARN("fixup worker: delalloc and fixup conflict. ino %llu start %llu", + btrfs_ino(inode), start); + btrfs_folio_clear_fixup(fs_info, folio, start, sectorsize); + continue; + } + ordered = btrfs_lookup_ordered_range(inode, start, sectorsize); + if (ordered) { + trace_btrfs_writepage_fixup_defer(inode, ordered); + btrfs_unlock_extent(&inode->io_tree, page_start, + page_end, &cached_state); + folio_unlock(folio); + btrfs_start_ordered_extent(ordered); + btrfs_put_ordered_extent(ordered); + goto again; + } + ret = btrfs_set_extent_delalloc(inode, start, + start + sectorsize - 1, 0, + &cached_state); + if (ret) + break; + trace_btrfs_writepage_fixup_reserve(inode, start, sectorsize); + btrfs_folio_clear_fixup(fs_info, folio, start, sectorsize); + set_bit(bit, delalloc_bitmap); + } + + btrfs_unlock_extent(&inode->io_tree, page_start, page_end, &cached_state); +out: + if (ret < 0) { + /* Failure here is analogous to failure in writeback. */ + mapping_set_error(folio->mapping, ret); + btrfs_folio_clear_fixup_dirty(fs_info, folio, page_start, + folio_size(folio)); + } + if (reserved) { + btrfs_delalloc_release_extents(inode, folio_size(folio)); + for_each_clear_bitrange(start_bit, end_bit, delalloc_bitmap, + blocks_per_folio) + btrfs_delalloc_release_space(inode, data_reserved, + page_start + (start_bit << fs_info->sectorsize_bits), + (end_bit - start_bit) << fs_info->sectorsize_bits, + true); + } + folio_unlock(folio); + folio_put(folio); + kfree(fixup); + extent_changeset_free(data_reserved); + btrfs_add_delayed_iput(inode); +} + +/* + * Queue space reservation fixup work for blocks dirtied without a space reservation. + * + * Should be used by writeback while holding the folio locked. + * + * If we fail to queue fixup, then the folio state is unchanged and a future + * writeback pass will still see it. + */ +void btrfs_queue_writepage_fixup(struct btrfs_inode *inode, struct folio *folio) +{ + struct btrfs_fs_info *fs_info = inode->root->fs_info; + struct btrfs_writepage_fixup *fixup; + + /* + * Disallow queueing more fixup during unmount to break the cycle + * of writeback queuing fixup queuing writeback etc. + * + * If it actually hit, then something which was fixup wasn't written + * which we should warn about. + */ + if (btrfs_fs_closing(fs_info)) { + btrfs_warn_rl(fs_info, + "dropping unqueued fixup blocks at unmount. root %lld ino %llu folio %llu", + btrfs_root_id(inode->root), btrfs_ino(inode), + folio_pos(folio)); + btrfs_folio_clear_fixup_dirty(fs_info, folio, + folio_pos(folio), folio_size(folio)); + return; + } + + fixup = kzalloc_obj(*fixup, GFP_NOFS); + if (!fixup) + return; + + /* + * This is called from within extent_write_cache_pages() which + * has successfully done an igrab(). But that will be released at the + * end of the writeback pass. We need to extend it for the worker as well. + */ + ihold(&inode->vfs_inode); + folio_get(folio); + INIT_WORK(&fixup->work, btrfs_writepage_fixup_worker); + fixup->folio = folio; + fixup->inode = inode; + queue_work(fs_info->fixup_workers, &fixup->work); +} + /* * Clear the old accounting flags and set EXTENT_DELALLOC for the range. * @@ -7509,6 +7683,12 @@ static void btrfs_invalidate_folio(struct folio *folio, size_t offset, wait_subpage_spinlock(folio); /* + * The invalidated blocks are going away; drop any fixup blocks among + * them, data included, as they have no space reservation. + */ + btrfs_folio_clear_fixup_dirty(fs_info, folio, page_start + offset, length); + + /* * For subpage case, we have call sites like * btrfs_punch_hole_lock_range() which passes range not aligned to * sectorsize. @@ -10551,6 +10731,41 @@ static const struct file_operations btrfs_dir_file_operations = { }; /* + * The folio is going dirty without a btrfs delalloc space reservation. + * This requires a fixup before writeback which we might sleep so cannot + * run in this context, so we merely set state on the folio indicating it + * needs fixup before writeback. + * + * Note that there is no range in the input, so the whole folio is marked + * dirty and fixup. + * + * We believe that all callers of dirty_folio either: + * - take the folio lock (e.g. pinned folio release notification). + * - take the pte lock but must be running on a dirty pte which means + * page_mkwrite() ran on it and reserved the space. zap_pte_range() cannot + * race with writeback cleaning the folio because writeback runs + * folio_mkclean() which also uses the pte lock and revokes outstanding + * writable mappings. + * Therefore, an additional folio private lock (a la bfs->lock for all cases, + * not just subpage) is not necessary. + */ +static bool btrfs_data_dirty_folio(struct address_space *mapping, + struct folio *folio) +{ + struct btrfs_inode *inode = BTRFS_I(mapping->host); + struct btrfs_fs_info *fs_info = inode->root->fs_info; + const u64 page_start = folio_pos(folio); + const u64 range_end = min_t(u64, folio_next_pos(folio), + round_up(i_size_read(&inode->vfs_inode), + fs_info->sectorsize)); + + if (range_end > page_start) + btrfs_folio_set_fixup_dirty(fs_info, folio, page_start, + range_end - page_start); + return filemap_dirty_folio(mapping, folio); +} + +/* * btrfs doesn't support the bmap operation because swapfiles * use bmap to make a mapping of extents in the file. They assume * these extents won't change over the life of the file and they @@ -10570,7 +10785,7 @@ static const struct address_space_operations btrfs_aops = { .launder_folio = btrfs_launder_folio, .release_folio = btrfs_release_folio, .migrate_folio = btrfs_migrate_folio, - .dirty_folio = filemap_dirty_folio, + .dirty_folio = btrfs_data_dirty_folio, .error_remove_folio = generic_error_remove_folio, .swap_activate = btrfs_swap_activate, .swap_deactivate = btrfs_swap_deactivate, diff --git a/fs/btrfs/subpage.c b/fs/btrfs/subpage.c index 2a9397be8116..27dd677ca687 100644 --- a/fs/btrfs/subpage.c +++ b/fs/btrfs/subpage.c @@ -345,18 +345,57 @@ void btrfs_subpage_clear_uptodate(const struct btrfs_fs_info *fs_info, spin_unlock_irqrestore(&bfs->lock, flags); } +/* + * folio_mark_dirty() for a folio we are dirtying with a space reservation. + * + * Dirtiers without a reservation use btrfs_data_dirty_folio(). + */ +static void btrfs_folio_mark_dirty(struct folio *folio) +{ + struct address_space *mapping = folio_mapping(folio); + + if (!mapping || !mapping->host || !is_data_inode(BTRFS_I(mapping->host))) { + folio_mark_dirty(folio); + return; + } + if (folio_test_reclaim(folio)) + folio_clear_reclaim(folio); + filemap_dirty_folio(mapping, folio); +} + +/* + * The set helper of the dirty ops, so it only runs for folios without a + * fixup bitmap: for those the folio flag is the whole fixup state, and this + * reserving write covers the block, so retire it. Metadata never has the + * flag set and only pays the test. + */ +static void btrfs_folio_mark_dirty_reserved(struct folio *folio) +{ + if (folio_test_fixup_pending(folio)) + folio_clear_fixup_pending(folio); + btrfs_folio_mark_dirty(folio); +} + void btrfs_subpage_set_dirty(const struct btrfs_fs_info *fs_info, struct folio *folio, u64 start, u32 len) { struct btrfs_folio_state *bfs = folio_get_private(folio); - unsigned int start_bit = subpage_calc_start_bit(fs_info, folio, + unsigned int dirty_bit = subpage_calc_start_bit(fs_info, folio, dirty, start, len); + unsigned int fixup_bit = subpage_calc_start_bit(fs_info, folio, + fixup, start, len); + const unsigned int nbits = len >> fs_info->sectorsize_bits; unsigned long flags; spin_lock_irqsave(&bfs->lock, flags); - bitmap_set(bfs->bitmaps, start_bit, len >> fs_info->sectorsize_bits); + bitmap_set(bfs->bitmaps, dirty_bit, nbits); + /* Proper dirtying obviates the need for fixup. */ + bitmap_clear(bfs->bitmaps, fixup_bit, nbits); + if (folio_test_fixup_pending(folio) && + subpage_test_bitmap_all_zero(fs_info, folio, fixup)) + folio_clear_fixup_pending(folio); spin_unlock_irqrestore(&bfs->lock, flags); - folio_mark_dirty(folio); + btrfs_folio_mark_dirty(folio); } static void folio_clear_tags(struct folio *folio) @@ -457,6 +496,172 @@ void btrfs_subpage_clear_writeback(const struct btrfs_fs_info *fs_info, spin_unlock_irqrestore(&bfs->lock, flags); } +void btrfs_subpage_clear_fixup(const struct btrfs_fs_info *fs_info, + struct folio *folio, u64 start, u32 len) +{ + struct btrfs_folio_state *bfs = folio_get_private(folio); + unsigned int start_bit = subpage_calc_start_bit(fs_info, folio, + fixup, start, len); + unsigned long flags; + + spin_lock_irqsave(&bfs->lock, flags); + bitmap_clear(bfs->bitmaps, start_bit, len >> fs_info->sectorsize_bits); + if (subpage_test_bitmap_all_zero(fs_info, folio, fixup)) + folio_clear_fixup_pending(folio); + spin_unlock_irqrestore(&bfs->lock, flags); +} + +/* + * In one pass under bfs->lock, mark every block with a clear dirty bit in the + * range both dirty and needing fixup. + * + * Only called from the dirty_folio callback, which owns the folio-level + * dirty flag; calling folio_mark_dirty() here would recurse. + * + * The folio fixup flag and bits are both set under bfs->lock so that a + * writeback pass observing the new bits also observes the flag. + */ +static void btrfs_subpage_set_fixup_dirty(const struct btrfs_fs_info *fs_info, + struct folio *folio, u64 start, u32 len) +{ + struct btrfs_folio_state *bfs = folio_get_private(folio); + unsigned int dirty_bit = subpage_calc_start_bit(fs_info, folio, + dirty, start, len); + unsigned int fixup_bit = subpage_calc_start_bit(fs_info, folio, + fixup, start, len); + const unsigned int nbits = len >> fs_info->sectorsize_bits; + unsigned long flags; + bool marked = false; + + spin_lock_irqsave(&bfs->lock, flags); + for (unsigned int i = 0; i < nbits; i++) { + if (test_bit(dirty_bit + i, bfs->bitmaps)) + continue; + set_bit(dirty_bit + i, bfs->bitmaps); + set_bit(fixup_bit + i, bfs->bitmaps); + marked = true; + } + if (marked) + folio_set_fixup_pending(folio); + spin_unlock_irqrestore(&bfs->lock, flags); +} + +/* + * Mark the still-clean blocks of a folio dirty and needing fixup, for + * btrfs_data_dirty_folio(). + * + * A subpage block size folio that is not uptodate is left alone: its clean + * blocks may hold content that was never read in, which must not be marked + * dirty. + */ +void btrfs_folio_set_fixup_dirty(const struct btrfs_fs_info *fs_info, + struct folio *folio, u64 start, u32 len) +{ + if (!btrfs_is_subpage(fs_info, folio)) { + if (!folio_test_dirty(folio)) + folio_set_fixup_pending(folio); + return; + } + if (!folio_test_uptodate(folio)) + return; + btrfs_subpage_set_fixup_dirty(fs_info, folio, start, len); +} + +/* + * Drop the fixup blocks inside the range: clear both their fixup and dirty + * bits. + * + * Fixup blocks carry no space reservation, so their fixup and dirty bits + * must be dropped together. Clearing only the fixup bit would leave a + * dirty block without a reservation which is not a valid state. + * + * Returns true if the folio has no dirty blocks left. + */ +static bool btrfs_subpage_clear_fixup_dirty(const struct btrfs_fs_info *fs_info, + struct folio *folio, u64 start, u32 len) +{ + struct btrfs_folio_state *bfs = folio_get_private(folio); + unsigned int dirty_bit = subpage_calc_start_bit(fs_info, folio, + dirty, start, len); + unsigned int fixup_bit = subpage_calc_start_bit(fs_info, folio, + fixup, start, len); + const unsigned int nbits = len >> fs_info->sectorsize_bits; + unsigned long flags; + bool last; + + spin_lock_irqsave(&bfs->lock, flags); + for (unsigned int i = 0; i < nbits; i++) { + if (!test_bit(fixup_bit + i, bfs->bitmaps)) + continue; + clear_bit(fixup_bit + i, bfs->bitmaps); + clear_bit(dirty_bit + i, bfs->bitmaps); + } + if (subpage_test_bitmap_all_zero(fs_info, folio, fixup)) + folio_clear_fixup_pending(folio); + last = subpage_test_bitmap_all_zero(fs_info, folio, dirty); + spin_unlock_irqrestore(&bfs->lock, flags); + return last; +} + +/* + * Drop the fixup blocks inside the range, for callers discarding their data: + * btrfs_invalidate_folio() and the writepage fixup worker's error path. + * + * Callers that have just reserved space for a block want + * btrfs_folio_clear_fixup() instead - there the block stays dirty and gets + * written. + * + * The range can be byte-granular (an unaligned truncate through + * btrfs_invalidate_folio()); only blocks fully inside it are dropped, as a + * partially covered block still holds live data outside the range. For + * single-block folios the folio flag is the fixup state, so it is dropped + * only when the range covers the whole folio. + */ +void btrfs_folio_clear_fixup_dirty(const struct btrfs_fs_info *fs_info, + struct folio *folio, u64 start, u32 len) +{ + u64 aligned_start; + u64 aligned_end; + + /* The folio flag is set whenever any fixup bitmap bit is. */ + if (!folio_test_fixup_pending(folio)) + return; + if (!btrfs_is_subpage(fs_info, folio)) { + if (start <= folio_pos(folio) && + start + len >= folio_next_pos(folio)) { + folio_clear_fixup_pending(folio); + folio_clear_dirty_for_io(folio); + } + return; + } + btrfs_subpage_clamp_range(folio, &start, &len); + aligned_start = round_up(start, fs_info->sectorsize); + aligned_end = round_down(start + len, fs_info->sectorsize); + if (aligned_end <= aligned_start) + return; + if (btrfs_subpage_clear_fixup_dirty(fs_info, folio, aligned_start, + aligned_end - aligned_start)) + folio_clear_dirty_for_io(folio); +} + +bool btrfs_folio_test_fixup(const struct btrfs_fs_info *fs_info, + struct folio *folio, u64 start, u32 len) +{ + if (!btrfs_is_subpage(fs_info, folio)) + return folio_test_fixup_pending(folio); + return btrfs_subpage_test_fixup(fs_info, folio, start, len); +} + +void btrfs_folio_clear_fixup(const struct btrfs_fs_info *fs_info, + struct folio *folio, u64 start, u32 len) +{ + if (!btrfs_is_subpage(fs_info, folio)) { + folio_clear_fixup_pending(folio); + return; + } + btrfs_subpage_clear_fixup(fs_info, folio, start, len); +} + /* * Unlike set/clear which is dependent on each page status, for test all bits * are tested in the same way. @@ -480,6 +685,7 @@ bool btrfs_subpage_test_##name(const struct btrfs_fs_info *fs_info, \ IMPLEMENT_BTRFS_SUBPAGE_TEST_OP(uptodate); IMPLEMENT_BTRFS_SUBPAGE_TEST_OP(dirty); IMPLEMENT_BTRFS_SUBPAGE_TEST_OP(writeback); +IMPLEMENT_BTRFS_SUBPAGE_TEST_OP(fixup); /* * Note that, in selftests (extent-io-tests), we can have empty fs_info passed @@ -571,8 +777,8 @@ bool btrfs_meta_folio_test_##name(struct folio *folio, const struct extent_buffe } IMPLEMENT_BTRFS_PAGE_OPS(uptodate, folio_mark_uptodate, folio_clear_uptodate, folio_test_uptodate); -IMPLEMENT_BTRFS_PAGE_OPS(dirty, folio_mark_dirty, folio_clear_dirty_for_io, - folio_test_dirty); +IMPLEMENT_BTRFS_PAGE_OPS(dirty, btrfs_folio_mark_dirty_reserved, + folio_clear_dirty_for_io, folio_test_dirty); IMPLEMENT_BTRFS_PAGE_OPS(writeback, folio_start_writeback, folio_end_writeback, folio_test_writeback); diff --git a/fs/btrfs/subpage.h b/fs/btrfs/subpage.h index c6d7394e6418..9aceba93c818 100644 --- a/fs/btrfs/subpage.h +++ b/fs/btrfs/subpage.h @@ -14,15 +14,15 @@ struct folio; /* * Extra info for subpage bitmap. * - * For subpage we pack all uptodate/dirty/writeback bitmaps into + * For subpage we pack all uptodate/dirty/writeback/fixup bitmaps into * one larger bitmap. * * This structure records how they are organized in the bitmap: * - * /- uptodate /- dirty /- writeback - * | | | - * v v v - * |u|u|u|u|........|u|u|d|d|.......|d|d|w|w|.......|w|w| + * /- uptodate /- dirty /- writeback /- fixup + * | | | | + * v v v v + * |u|u|u|u|........|u|u|d|d|.......|d|d|w|w|.....|w|w|f|f|.....|f|f| * |< sectors_per_page >| * * Unlike regular macro-like enums, here we do not go upper-case names, as @@ -40,6 +40,14 @@ enum { */ btrfs_bitmap_nr_writeback, + /* + * Blocks dirtied by the dirty_folio callback instead of a reserving + * write path (e.g. set_page_dirty_lock() on a GUP pin). They have + * no space reservation and need the writepage fixup before they can + * be submitted. + */ + btrfs_bitmap_nr_fixup, + btrfs_bitmap_nr_max }; @@ -166,6 +174,29 @@ DECLARE_BTRFS_SUBPAGE_OPS(dirty); DECLARE_BTRFS_SUBPAGE_OPS(writeback); /* + * Fixup bit helpers. + * + * The fixup bit is data-only and has no plain set helper (setting happens + * together with dirtying in btrfs_subpage_set_fixup_dirty()), so it does not + * go through DECLARE_BTRFS_SUBPAGE_OPS(). For single-block folios the + * folio_*_fixup_pending() flag takes the place of the bitmap. + */ +void btrfs_subpage_clear_fixup(const struct btrfs_fs_info *fs_info, + struct folio *folio, u64 start, u32 len); +bool btrfs_subpage_test_fixup(const struct btrfs_fs_info *fs_info, + struct folio *folio, u64 start, u32 len); +bool btrfs_folio_test_fixup(const struct btrfs_fs_info *fs_info, + struct folio *folio, u64 start, u32 len); +void btrfs_folio_set_fixup_dirty(const struct btrfs_fs_info *fs_info, + struct folio *folio, u64 start, u32 len); +/* For a block that just got its space reserved; it stays dirty. */ +void btrfs_folio_clear_fixup(const struct btrfs_fs_info *fs_info, + struct folio *folio, u64 start, u32 len); +/* For callers discarding the data; clears the dirty bits too. */ +void btrfs_folio_clear_fixup_dirty(const struct btrfs_fs_info *fs_info, + struct folio *folio, u64 start, u32 len); + +/* * Helper for error cleanup, where a folio will have its dirty flag cleared, * with writeback started and finished. */ diff --git a/include/trace/events/btrfs.h b/include/trace/events/btrfs.h index 4c5c47c5edb7..6c1438f6a4d3 100644 --- a/include/trace/events/btrfs.h +++ b/include/trace/events/btrfs.h @@ -689,6 +689,41 @@ DEFINE_EVENT(btrfs__ordered_extent, btrfs_ordered_extent_lookup_first, TP_ARGS(inode, ordered) ); +/* + * The writepage fixup worker deferred a block because this still-running + * ordered extent covers it. + */ +DEFINE_EVENT(btrfs__ordered_extent, btrfs_writepage_fixup_defer, + + TP_PROTO(const struct btrfs_inode *inode, + const struct btrfs_ordered_extent *ordered), + + TP_ARGS(inode, ordered) +); + +/* The writepage fixup worker reserved space for a block and set delalloc. */ +TRACE_EVENT(btrfs_writepage_fixup_reserve, + + TP_PROTO(const struct btrfs_inode *inode, u64 start, u32 len), + + TP_ARGS(inode, start, len), + + TP_STRUCT__entry_btrfs( + __field( u64, ino ) + __field( u64, start ) + __field( u32, len ) + ), + + TP_fast_assign_btrfs(inode->root->fs_info, + __entry->ino = btrfs_ino(inode); + __entry->start = start; + __entry->len = len; + ), + + TP_printk_btrfs("ino=%llu start=%llu len=%u", + __entry->ino, __entry->start, __entry->len) +); + DEFINE_EVENT(btrfs__ordered_extent, btrfs_ordered_extent_split, TP_PROTO(const struct btrfs_inode *inode, |