new file mode 100644
@@ -0,0 +1,2953 @@
+// SPDX-License-Identifier: BSD-3-Clause-Clear
+/*
+ * SSDFS -- SSD-oriented File System.
+ *
+ * fs/ssdfs/peb_gc_thread.c - GC thread functionality.
+ *
+ * Copyright (c) 2014-2019 HGST, a Western Digital Company.
+ * http://www.hgst.com/
+ * Copyright (c) 2014-2023 Viacheslav Dubeyko <slava@dubeyko.com>
+ * http://www.ssdfs.org/
+ *
+ * (C) Copyright 2014-2019, HGST, Inc., All rights reserved.
+ *
+ * Created by HGST, San Jose Research Center, Storage Architecture Group
+ *
+ * Authors: Viacheslav Dubeyko <slava@dubeyko.com>
+ *
+ * Acknowledgement: Cyril Guyot
+ * Zvonimir Bandic
+ */
+
+#include <linux/pagemap.h>
+#include <linux/slab.h>
+#include <linux/kthread.h>
+#include <linux/pagevec.h>
+
+#include "peb_mapping_queue.h"
+#include "peb_mapping_table_cache.h"
+#include "ssdfs.h"
+#include "offset_translation_table.h"
+#include "compression.h"
+#include "page_vector.h"
+#include "block_bitmap.h"
+#include "page_array.h"
+#include "peb.h"
+#include "peb_container.h"
+#include "peb_mapping_table.h"
+#include "segment_bitmap.h"
+#include "segment.h"
+#include "segment_tree.h"
+
+#include <trace/events/ssdfs.h>
+
+#ifdef CONFIG_SSDFS_MEMORY_LEAKS_ACCOUNTING
+atomic64_t ssdfs_gc_page_leaks;
+atomic64_t ssdfs_gc_memory_leaks;
+atomic64_t ssdfs_gc_cache_leaks;
+#endif /* CONFIG_SSDFS_MEMORY_LEAKS_ACCOUNTING */
+
+/*
+ * void ssdfs_gc_cache_leaks_increment(void *kaddr)
+ * void ssdfs_gc_cache_leaks_decrement(void *kaddr)
+ * void *ssdfs_gc_kmalloc(size_t size, gfp_t flags)
+ * void *ssdfs_gc_kzalloc(size_t size, gfp_t flags)
+ * void *ssdfs_gc_kcalloc(size_t n, size_t size, gfp_t flags)
+ * void ssdfs_gc_kfree(void *kaddr)
+ * struct page *ssdfs_gc_alloc_page(gfp_t gfp_mask)
+ * struct page *ssdfs_gc_add_pagevec_page(struct pagevec *pvec)
+ * void ssdfs_gc_free_page(struct page *page)
+ * void ssdfs_gc_pagevec_release(struct pagevec *pvec)
+ */
+#ifdef CONFIG_SSDFS_MEMORY_LEAKS_ACCOUNTING
+ SSDFS_MEMORY_LEAKS_CHECKER_FNS(gc)
+#else
+ SSDFS_MEMORY_ALLOCATOR_FNS(gc)
+#endif /* CONFIG_SSDFS_MEMORY_LEAKS_ACCOUNTING */
+
+void ssdfs_gc_memory_leaks_init(void)
+{
+#ifdef CONFIG_SSDFS_MEMORY_LEAKS_ACCOUNTING
+ atomic64_set(&ssdfs_gc_page_leaks, 0);
+ atomic64_set(&ssdfs_gc_memory_leaks, 0);
+ atomic64_set(&ssdfs_gc_cache_leaks, 0);
+#endif /* CONFIG_SSDFS_MEMORY_LEAKS_ACCOUNTING */
+}
+
+void ssdfs_gc_check_memory_leaks(void)
+{
+#ifdef CONFIG_SSDFS_MEMORY_LEAKS_ACCOUNTING
+ if (atomic64_read(&ssdfs_gc_page_leaks) != 0) {
+ SSDFS_ERR("GC: "
+ "memory leaks include %lld pages\n",
+ atomic64_read(&ssdfs_gc_page_leaks));
+ }
+
+ if (atomic64_read(&ssdfs_gc_memory_leaks) != 0) {
+ SSDFS_ERR("GC: "
+ "memory allocator suffers from %lld leaks\n",
+ atomic64_read(&ssdfs_gc_memory_leaks));
+ }
+
+ if (atomic64_read(&ssdfs_gc_cache_leaks) != 0) {
+ SSDFS_ERR("GC: "
+ "caches suffers from %lld leaks\n",
+ atomic64_read(&ssdfs_gc_cache_leaks));
+ }
+#endif /* CONFIG_SSDFS_MEMORY_LEAKS_ACCOUNTING */
+}
+
+/******************************************************************************
+ * GC THREAD FUNCTIONALITY *
+ ******************************************************************************/
+
+static
+struct ssdfs_thread_descriptor thread_desc[SSDFS_GC_THREAD_TYPE_MAX] = {
+ {.threadfn = ssdfs_using_seg_gc_thread_func,
+ .fmt = "ssdfs-gc-using-seg",},
+ {.threadfn = ssdfs_used_seg_gc_thread_func,
+ .fmt = "ssdfs-gc-used-seg",},
+ {.threadfn = ssdfs_pre_dirty_seg_gc_thread_func,
+ .fmt = "ssdfs-gc-pre-dirty-seg",},
+ {.threadfn = ssdfs_dirty_seg_gc_thread_func,
+ .fmt = "ssdfs-gc-dirty-seg",},
+};
+
+/*
+ * __ssdfs_peb_define_extent() - define extent for request
+ * @fsi: pointer on shared file system object
+ * @pebi: pointer on PEB object
+ * @desc_off: physical offset descriptor
+ * @desc_array: array of metadata descriptors
+ * @pos: position offset
+ * @req: request
+ *
+ * This function tries to define extent for request.
+ *
+ * RETURN:
+ * [success]
+ * [failure] - error code:
+ *
+ * %-ERANGE - internal error.
+ * %-EAGAIN - unable to extract the whole range.
+ */
+static
+int __ssdfs_peb_define_extent(struct ssdfs_fs_info *fsi,
+ struct ssdfs_peb_info *pebi,
+ struct ssdfs_phys_offset_descriptor *desc_off,
+ struct ssdfs_metadata_descriptor *desc_array,
+ struct ssdfs_offset_position *pos,
+ struct ssdfs_segment_request *req)
+{
+ struct ssdfs_block_descriptor *blk_desc = NULL;
+ int err = 0;
+
+#ifdef CONFIG_SSDFS_DEBUG
+ BUG_ON(!fsi || !pebi || !desc_off || !req);
+ BUG_ON(!desc_array);
+
+ SSDFS_DBG("peb %llu, "
+ "class %#x, cmd %#x, type %#x\n",
+ pebi->peb_id,
+ req->private.class, req->private.cmd, req->private.type);
+ SSDFS_DBG("ino %llu, seg %llu, peb %llu, logical_offset %llu, "
+ "processed_blks %d, logical_block %u, data_bytes %u, "
+ "cno %llu, parent_snapshot %llu, cmd %#x, type %#x\n",
+ req->extent.ino, req->place.start.seg_id,
+ pebi->peb_id,
+ req->extent.logical_offset,
+ req->result.processed_blks,
+ req->place.start.blk_index,
+ req->extent.data_bytes, req->extent.cno,
+ req->extent.parent_snapshot,
+ req->private.cmd, req->private.type);
+#endif /* CONFIG_SSDFS_DEBUG */
+
+ err = ssdfs_blk_desc_buffer_init(pebi->pebc, req, desc_off, pos,
+ desc_array,
+ SSDFS_SEG_HDR_DESC_MAX);
+ if (unlikely(err)) {
+ SSDFS_ERR("fail to init blk desc buffer: err %d\n",
+ err);
+ goto finish_define_extent;
+ }
+
+ blk_desc = &pos->blk_desc.buf;
+
+ if (req->extent.ino >= U64_MAX) {
+ req->extent.ino = le64_to_cpu(blk_desc->ino);
+ req->extent.logical_offset =
+ le32_to_cpu(blk_desc->logical_offset);
+ req->extent.logical_offset *= fsi->pagesize;
+ } else if (req->extent.ino != le64_to_cpu(blk_desc->ino)) {
+ err = -EAGAIN;
+ req->place.len = req->result.processed_blks;
+
+#ifdef CONFIG_SSDFS_DEBUG
+ SSDFS_DBG("OFFSET DESCRIPTOR: "
+ "logical_offset %u, logical_blk %u, "
+ "peb_page %u, log_start_page %u, "
+ "log_area %u, peb_migration_id %u, "
+ "byte_offset %u\n",
+ le32_to_cpu(desc_off->page_desc.logical_offset),
+ le16_to_cpu(desc_off->page_desc.logical_blk),
+ le16_to_cpu(desc_off->page_desc.peb_page),
+ le16_to_cpu(desc_off->blk_state.log_start_page),
+ desc_off->blk_state.log_area,
+ desc_off->blk_state.peb_migration_id,
+ le32_to_cpu(desc_off->blk_state.byte_offset));
+ SSDFS_DBG("BLOCK DECRIPTOR: "
+ "ino %llu, logical_offset %u, "
+ "peb_index %u, peb_page %u, "
+ "log_start_page %u, "
+ "log_area %u, peb_migration_id %u, "
+ "byte_offset %u\n",
+ le64_to_cpu(blk_desc->ino),
+ le32_to_cpu(blk_desc->logical_offset),
+ le16_to_cpu(blk_desc->peb_index),
+ le16_to_cpu(blk_desc->peb_page),
+ le16_to_cpu(blk_desc->state[0].log_start_page),
+ blk_desc->state[0].log_area,
+ blk_desc->state[0].peb_migration_id,
+ le32_to_cpu(blk_desc->state[0].byte_offset));
+ SSDFS_DBG("ino %llu, seg %llu, peb %llu, logical_offset %llu, "
+ "processed_blks %d, logical_block %u, "
+ "data_bytes %u, blks %u, "
+ "cno %llu, parent_snapshot %llu, cmd %#x, type %#x\n",
+ req->extent.ino, req->place.start.seg_id,
+ pebi->peb_id,
+ req->extent.logical_offset,
+ req->result.processed_blks,
+ req->place.start.blk_index,
+ req->place.len,
+ req->extent.data_bytes, req->extent.cno,
+ req->extent.parent_snapshot,
+ req->private.cmd, req->private.type);
+ SSDFS_DBG("ino1 %llu != ino2 %llu, peb %llu\n",
+ req->extent.ino,
+ le64_to_cpu(blk_desc->ino),
+ pebi->peb_id);
+#endif /* CONFIG_SSDFS_DEBUG */
+
+ goto finish_define_extent;
+ }
+
+ req->extent.data_bytes += fsi->pagesize;
+
+finish_define_extent:
+ return err;
+}
+
+/*
+ * __ssdfs_peb_copy_page() - copy page from PEB into buffer
+ * @pebc: pointer on PEB container
+ * @desc_off: physical offset descriptor
+ * @pos: position offset
+ * @req: request
+ *
+ * This function tries to copy PEB's page into the buffer.
+ *
+ * RETURN:
+ * [success]
+ * [failure] - error code:
+ *
+ * %-ERANGE - internal error.
+ * %-EAGAIN - unable to extract the whole range.
+ */
+static
+int __ssdfs_peb_copy_page(struct ssdfs_peb_container *pebc,
+ struct ssdfs_phys_offset_descriptor *desc_off,
+ struct ssdfs_offset_position *pos,
+ struct ssdfs_segment_request *req)
+{
+ struct ssdfs_fs_info *fsi;
+ struct ssdfs_peb_info *pebi = NULL;
+ struct ssdfs_metadata_descriptor desc_array[SSDFS_SEG_HDR_DESC_MAX];
+ int err = 0;
+
+#ifdef CONFIG_SSDFS_DEBUG
+ BUG_ON(!pebc || !pebc->parent_si || !pebc->parent_si->fsi);
+ BUG_ON(!desc_off || !pos || !req);
+
+ SSDFS_DBG("seg %llu, peb_index %u, "
+ "class %#x, cmd %#x, type %#x\n",
+ pebc->parent_si->seg_id, pebc->peb_index,
+ req->private.class, req->private.cmd, req->private.type);
+#endif /* CONFIG_SSDFS_DEBUG */
+
+ fsi = pebc->parent_si->fsi;
+
+ down_read(&pebc->lock);
+
+ pebi = pebc->src_peb;
+
+ if (!pebi) {
+ err = -ERANGE;
+ SSDFS_ERR("invalid source peb: "
+ "src_peb %p, dst_peb %p\n",
+ pebc->src_peb, pebc->dst_peb);
+ goto finish_copy_page;
+ }
+
+ if (pagevec_space(&req->result.pvec) == 0) {
+ err = -EAGAIN;
+ SSDFS_DBG("request's pagevec is full\n");
+ goto finish_copy_page;
+ }
+
+ err = __ssdfs_peb_define_extent(fsi, pebi, desc_off,
+ desc_array, pos, req);
+ if (err == -EAGAIN) {
+ SSDFS_DBG("unable to add block of another inode\n");
+ goto finish_copy_page;
+ } else if (unlikely(err)) {
+ SSDFS_ERR("fail to define extent: "
+ "seg %llu, peb_index %u, peb %llu, err %d\n",
+ pebc->parent_si->seg_id, pebc->peb_index,
+ pebi->peb_id, err);
+ goto finish_copy_page;
+ }
+
+ err = ssdfs_request_add_allocated_page_locked(req);
+ if (unlikely(err)) {
+ SSDFS_ERR("fail to allocate memory page: "
+ "err %d\n", err);
+ goto finish_copy_page;
+ }
+
+ err = ssdfs_peb_read_block_state(pebc, req, desc_off, pos,
+ desc_array,
+ SSDFS_SEG_HDR_DESC_MAX);
+ if (unlikely(err)) {
+ SSDFS_ERR("fail to read block state: err %d\n",
+ err);
+ goto finish_copy_page;
+ }
+
+finish_copy_page:
+ up_read(&pebc->lock);
+
+ return err;
+}
+
+/*
+ * ssdfs_peb_define_extent() - define extent for request
+ * @pebc: pointer on PEB container
+ * @desc_off: physical offset descriptor
+ * @req: request
+ *
+ * This function tries to define extent for request.
+ *
+ * RETURN:
+ * [success]
+ * [failure] - error code:
+ *
+ * %-ERANGE - internal error.
+ * %-EAGAIN - unable to extract the whole range.
+ */
+#ifdef CONFIG_SSDFS_UNDER_DEVELOPMENT_FUNC
+static
+int ssdfs_peb_define_extent(struct ssdfs_peb_container *pebc,
+ struct ssdfs_phys_offset_descriptor *desc_off,
+ struct ssdfs_segment_request *req)
+{
+ struct ssdfs_fs_info *fsi;
+ struct ssdfs_peb_info *pebi = NULL;
+ struct ssdfs_metadata_descriptor desc_array[SSDFS_SEG_HDR_DESC_MAX];
+ struct ssdfs_block_descriptor blk_desc = {0};
+ int err = 0;
+
+#ifdef CONFIG_SSDFS_DEBUG
+ BUG_ON(!pebc || !pebc->parent_si || !pebc->parent_si->fsi);
+ BUG_ON(!desc_off || !req);
+
+ SSDFS_DBG("seg %llu, peb_index %u, "
+ "class %#x, cmd %#x, type %#x\n",
+ pebc->parent_si->seg_id, pebc->peb_index,
+ req->private.class, req->private.cmd, req->private.type);
+#endif /* CONFIG_SSDFS_DEBUG */
+
+ fsi = pebc->parent_si->fsi;
+
+ down_read(&pebc->lock);
+
+ pebi = pebc->src_peb;
+
+ if (!pebi) {
+ err = -ERANGE;
+ SSDFS_ERR("invalid source peb: "
+ "src_peb %p, dst_peb %p\n",
+ pebc->src_peb, pebc->dst_peb);
+ goto finish_define_extent;
+ }
+
+ err = __ssdfs_peb_define_extent(fsi, pebi, desc_off,
+ desc_array, &blk_desc, req);
+ if (err == -EAGAIN) {
+ SSDFS_DBG("unable to add block of another inode\n");
+ goto finish_define_extent;
+ } else if (unlikely(err)) {
+ SSDFS_ERR("fail to define extent: "
+ "seg %llu, peb_index %u, peb %llu, err %d\n",
+ pebc->parent_si->seg_id, pebc->peb_index,
+ pebi->peb_id, err);
+ goto finish_define_extent;
+ }
+
+finish_define_extent:
+ up_read(&pebc->lock);
+
+ return err;
+}
+#endif /* CONFIG_SSDFS_UNDER_DEVELOPMENT_FUNC */
+
+/*
+ * ssdfs_peb_copy_pre_alloc_page() - copy pre-alloc page into buffer
+ * @pebc: pointer on PEB container
+ * @logical_blk: logical block
+ * @req: request
+ *
+ * This function tries to copy PEB's page into the buffer.
+ *
+ * RETURN:
+ * [success]
+ * [failure] - error code:
+ *
+ * %-ERANGE - internal error.
+ * %-ENODATA - pre-allocated block hasn't content.
+ * %-EAGAIN - unable to extract the whole range.
+ */
+int ssdfs_peb_copy_pre_alloc_page(struct ssdfs_peb_container *pebc,
+ u32 logical_blk,
+ struct ssdfs_segment_request *req)
+{
+ struct ssdfs_fs_info *fsi;
+ struct ssdfs_blk2off_table *table;
+ struct ssdfs_phys_offset_descriptor *desc_off = NULL;
+ struct ssdfs_offset_position pos = {0};
+ u16 peb_index;
+ bool has_data = false;
+ int err = 0;
+
+#ifdef CONFIG_SSDFS_DEBUG
+ BUG_ON(!pebc || !pebc->parent_si || !pebc->parent_si->fsi);
+ BUG_ON(!req);
+
+ SSDFS_DBG("seg %llu, peb_index %u, "
+ "class %#x, cmd %#x, type %#x, "
+ "logical_blk %u\n",
+ pebc->parent_si->seg_id, pebc->peb_index,
+ req->private.class, req->private.cmd, req->private.type,
+ logical_blk);
+#endif /* CONFIG_SSDFS_DEBUG */
+
+ fsi = pebc->parent_si->fsi;
+
+ if (logical_blk >= U32_MAX) {
+ SSDFS_ERR("invalid logical_blk %u\n",
+ logical_blk);
+ return -EINVAL;
+ }
+
+ table = pebc->parent_si->blk2off_table;
+
+ desc_off = ssdfs_blk2off_table_convert(table, logical_blk,
+ &peb_index, NULL,
+ &pos);
+ if (IS_ERR(desc_off) && PTR_ERR(desc_off) == -EAGAIN) {
+ struct completion *end = &table->full_init_end;
+
+ err = SSDFS_WAIT_COMPLETION(end);
+ if (unlikely(err)) {
+ SSDFS_ERR("blk2off init failed: "
+ "err %d\n", err);
+ return err;
+ }
+
+ desc_off = ssdfs_blk2off_table_convert(table, logical_blk,
+ &peb_index, NULL,
+ &pos);
+ }
+
+ if (IS_ERR_OR_NULL(desc_off)) {
+ err = (desc_off == NULL ? -ERANGE : PTR_ERR(desc_off));
+ SSDFS_ERR("fail to convert: "
+ "logical_blk %u, err %d\n",
+ logical_blk, err);
+ return err;
+ }
+
+ has_data = (desc_off->blk_state.log_area < SSDFS_LOG_AREA_MAX) &&
+ (le32_to_cpu(desc_off->blk_state.byte_offset) < U32_MAX);
+
+ if (has_data) {
+ ssdfs_peb_read_request_cno(pebc);
+
+ err = __ssdfs_peb_copy_page(pebc, desc_off, &pos, req);
+ if (err == -EAGAIN) {
+ SSDFS_DBG("unable to add block of another inode\n");
+ goto finish_copy_page;
+ } else if (unlikely(err)) {
+ SSDFS_ERR("fail to copy page: "
+ "logical_blk %u, err %d\n",
+ logical_blk, err);
+ goto finish_copy_page;
+ }
+
+ err = ssdfs_blk2off_table_set_block_migration(table,
+ logical_blk,
+ peb_index,
+ req);
+ if (unlikely(err)) {
+ SSDFS_ERR("fail to set migration state: "
+ "logical_blk %u, peb_index %u, err %d\n",
+ logical_blk, peb_index, err);
+ goto finish_copy_page;
+ }
+
+finish_copy_page:
+ ssdfs_peb_finish_read_request_cno(pebc);
+ } else {
+ if (req->extent.logical_offset >= U64_MAX)
+ req->extent.logical_offset = 0;
+
+ req->extent.data_bytes += fsi->pagesize;
+
+ err = -ENODATA;
+ req->result.processed_blks = 1;
+ req->result.err = err;
+ }
+
+ return err;
+}
+
+/*
+ * ssdfs_peb_copy_page() - copy valid page from PEB into buffer
+ * @pebc: pointer on PEB container
+ * @logical_blk: logical block
+ * @req: request
+ *
+ * This function tries to copy PEB's page into the buffer.
+ *
+ * RETURN:
+ * [success]
+ * [failure] - error code:
+ *
+ * %-ERANGE - internal error.
+ * %-EAGAIN - unable to extract the whole range.
+ */
+int ssdfs_peb_copy_page(struct ssdfs_peb_container *pebc,
+ u32 logical_blk,
+ struct ssdfs_segment_request *req)
+{
+ struct ssdfs_fs_info *fsi;
+ struct ssdfs_blk2off_table *table;
+ struct ssdfs_phys_offset_descriptor *desc_off = NULL;
+ struct ssdfs_offset_position pos = {0};
+ u16 peb_index;
+ int err = 0;
+
+#ifdef CONFIG_SSDFS_DEBUG
+ BUG_ON(!pebc || !pebc->parent_si || !pebc->parent_si->fsi);
+ BUG_ON(!req);
+
+ SSDFS_DBG("seg %llu, peb_index %u, "
+ "class %#x, cmd %#x, type %#x, "
+ "logical_blk %u\n",
+ pebc->parent_si->seg_id, pebc->peb_index,
+ req->private.class, req->private.cmd, req->private.type,
+ logical_blk);
+#endif /* CONFIG_SSDFS_DEBUG */
+
+ fsi = pebc->parent_si->fsi;
+
+ if (logical_blk >= U32_MAX) {
+ SSDFS_ERR("invalid logical_blk %u\n",
+ logical_blk);
+ return -EINVAL;
+ }
+
+ table = pebc->parent_si->blk2off_table;
+
+ desc_off = ssdfs_blk2off_table_convert(table, logical_blk,
+ &peb_index, NULL,
+ &pos);
+ if (IS_ERR(desc_off) && PTR_ERR(desc_off) == -EAGAIN) {
+ struct completion *end = &table->full_init_end;
+
+ err = SSDFS_WAIT_COMPLETION(end);
+ if (unlikely(err)) {
+ SSDFS_ERR("blk2off init failed: "
+ "err %d\n", err);
+ return err;
+ }
+
+ desc_off = ssdfs_blk2off_table_convert(table, logical_blk,
+ &peb_index, NULL,
+ &pos);
+ }
+
+ if (IS_ERR_OR_NULL(desc_off)) {
+ err = (desc_off == NULL ? -ERANGE : PTR_ERR(desc_off));
+ SSDFS_ERR("fail to convert: "
+ "logical_blk %u, err %d\n",
+ logical_blk, err);
+ return err;
+ }
+
+ ssdfs_peb_read_request_cno(pebc);
+
+ err = __ssdfs_peb_copy_page(pebc, desc_off, &pos, req);
+ if (err == -EAGAIN) {
+#ifdef CONFIG_SSDFS_DEBUG
+ SSDFS_DBG("unable to copy the whole range: "
+ "logical_blk %u, peb_index %u\n",
+ logical_blk, peb_index);
+#endif /* CONFIG_SSDFS_DEBUG */
+ goto finish_copy_page;
+ } else if (unlikely(err)) {
+ SSDFS_ERR("fail to copy page: "
+ "logical_blk %u, peb_index %u, err %d\n",
+ logical_blk, peb_index, err);
+ goto finish_copy_page;
+ }
+
+ err = ssdfs_blk2off_table_set_block_migration(table,
+ logical_blk,
+ peb_index,
+ req);
+ if (unlikely(err)) {
+ SSDFS_ERR("fail to set migration state: "
+ "logical_blk %u, peb_index %u, err %d\n",
+ logical_blk, peb_index, err);
+ goto finish_copy_page;
+ }
+
+finish_copy_page:
+ ssdfs_peb_finish_read_request_cno(pebc);
+
+ return err;
+}
+
+/*
+ * ssdfs_peb_copy_pages_range() - copy pages' range into buffer
+ * @pebc: pointer on PEB container
+ * @range: range of logical blocks
+ * @req: request
+ *
+ * This function tries to copy PEB's page into the buffer.
+ *
+ * RETURN:
+ * [success]
+ * [failure] - error code:
+ *
+ * %-ERANGE - internal error.
+ * %-EAGAIN - unable to extract the whole range.
+ */
+int ssdfs_peb_copy_pages_range(struct ssdfs_peb_container *pebc,
+ struct ssdfs_block_bmap_range *range,
+ struct ssdfs_segment_request *req)
+{
+ u32 logical_blk;
+ int i;
+ int err;
+
+#ifdef CONFIG_SSDFS_DEBUG
+ BUG_ON(!pebc || !pebc->parent_si || !pebc->parent_si->fsi);
+ BUG_ON(!range || !req);
+
+ SSDFS_DBG("seg %llu, peb_index %u, "
+ "class %#x, cmd %#x, type %#x, "
+ "range->start %u, range->len %u\n",
+ pebc->parent_si->seg_id, pebc->peb_index,
+ req->private.class, req->private.cmd, req->private.type,
+ range->start, range->len);
+#endif /* CONFIG_SSDFS_DEBUG */
+
+ if (range->len == 0) {
+ SSDFS_WARN("empty pages range request\n");
+ return 0;
+ }
+
+ req->extent.ino = U64_MAX;
+ req->extent.logical_offset = U64_MAX;
+ req->extent.data_bytes = 0;
+
+ req->place.start.seg_id = pebc->parent_si->seg_id;
+ req->place.start.blk_index = range->start;
+ req->place.len = 0;
+
+ req->result.processed_blks = 0;
+
+ for (i = 0; i < range->len; i++) {
+ logical_blk = range->start + i;
+ req->place.len++;
+
+ err = ssdfs_peb_copy_page(pebc, logical_blk, req);
+ if (err == -EAGAIN) {
+ req->place.len = req->result.processed_blks;
+#ifdef CONFIG_SSDFS_DEBUG
+ SSDFS_DBG("unable to copy the whole range: "
+ "seg %llu, logical_blk %u, len %u\n",
+ pebc->parent_si->seg_id,
+ logical_blk, req->place.len);
+#endif /* CONFIG_SSDFS_DEBUG */
+ return err;
+ } else if (unlikely(err)) {
+ SSDFS_ERR("fail to copy page: "
+ "seg %llu, logical_blk %u, err %d\n",
+ pebc->parent_si->seg_id,
+ logical_blk, err);
+ return err;
+ }
+ }
+
+ return 0;
+}
+
+/* TODO: add condition of presence of items for processing */
+#define GC_THREAD_WAKE_CONDITION(pebi) \
+ (kthread_should_stop())
+
+/*
+ * ssdfs_peb_gc_thread_func() - main fuction of GC thread
+ * @data: pointer on data object
+ *
+ * This function is main fuction of GC thread.
+ *
+ * RETURN:
+ * [success]
+ * [failure] - error code:
+ *
+ * %-EINVAL - invalid input.
+ */
+int ssdfs_peb_gc_thread_func(void *data)
+{
+ struct ssdfs_peb_container *pebc = data;
+ wait_queue_head_t *wait_queue;
+
+#ifdef CONFIG_SSDFS_DEBUG
+ if (!pebc) {
+ SSDFS_ERR("pointer on PEB container is NULL\n");
+ return -EINVAL;
+ }
+
+ SSDFS_DBG("GC thread: seg %llu, peb_index %u\n",
+ pebc->parent_si->seg_id, pebc->peb_index);
+#endif /* CONFIG_SSDFS_DEBUG */
+
+ wait_queue = &pebc->parent_si->wait_queue[SSDFS_PEB_GC_THREAD];
+
+repeat:
+ if (kthread_should_stop()) {
+ complete_all(&pebc->thread[SSDFS_PEB_GC_THREAD].full_stop);
+ return 0;
+ }
+
+ /* TODO: collect garbage */
+ SSDFS_DBG("TODO: implement %s\n", __func__);
+ goto sleep_gc_thread;
+ /*return -ENOSYS;*/
+
+sleep_gc_thread:
+ wait_event_interruptible(*wait_queue, GC_THREAD_WAKE_CONDITION(pebi));
+ goto repeat;
+}
+
+/*
+ * ssdfs_gc_find_next_seg_id() - find next victim segment ID
+ * @fsi: pointer on shared file system object
+ * @start_seg_id: starting segment ID
+ * @max_seg_id: upper bound value for the search
+ * @seg_type: type of segment
+ * @type_mask: segment types' mask
+ * @seg_id: found segment ID [out]
+ *
+ * This function tries to find the next victim
+ * segement ID for the requested type.
+ *
+ * RETURN:
+ * [success]
+ * [failure] - error code:
+ *
+ * %-EINVAL - invalid input.
+ * %-ERANGE - internal error.
+ * %-ENODATA - no segment for requested state was found.
+ */
+static
+int ssdfs_gc_find_next_seg_id(struct ssdfs_fs_info *fsi,
+ u64 start_seg_id, u64 max_seg_id,
+ int seg_type, int type_mask,
+ u64 *seg_id)
+{
+ struct ssdfs_segment_bmap *segbmap;
+ struct completion *init_end;
+ int res;
+ int err;
+
+#ifdef CONFIG_SSDFS_DEBUG
+ BUG_ON(!fsi || !fsi->segbmap || !seg_id);
+
+ SSDFS_DBG("fsi %p, start_seg_id %llu, max_seg_id %llu, "
+ "seg_type %#x, type_mask %#x\n",
+ fsi, start_seg_id, max_seg_id,
+ seg_type, type_mask);
+#endif /* CONFIG_SSDFS_DEBUG */
+
+ segbmap = fsi->segbmap;
+ *seg_id = U64_MAX;
+
+try_to_find_victim:
+ res = ssdfs_segbmap_find(segbmap,
+ start_seg_id, max_seg_id,
+ seg_type, type_mask,
+ seg_id, &init_end);
+ if (res >= 0) {
+check_segment_state:
+ switch (res) {
+ case SSDFS_SEG_DATA_USING:
+ case SSDFS_SEG_LEAF_NODE_USING:
+ case SSDFS_SEG_HYBRID_NODE_USING:
+ case SSDFS_SEG_INDEX_NODE_USING:
+ /* do nothing */
+ break;
+
+ default:
+ if (res != seg_type) {
+ if (*seg_id >= max_seg_id) {
+ res = -ENODATA;
+ goto finish_search_segments;
+ } else {
+ start_seg_id = *seg_id + 1;
+ *seg_id = U64_MAX;
+#ifdef CONFIG_SSDFS_DEBUG
+ SSDFS_DBG("res %#x != seg_type %#x\n",
+ res, seg_type);
+#endif /* CONFIG_SSDFS_DEBUG */
+ goto try_to_find_victim;
+ }
+ }
+ break;
+ }
+
+#ifdef CONFIG_SSDFS_DEBUG
+ SSDFS_DBG("found segment: "
+ "seg_id %llu, state %#x\n",
+ *seg_id, res);
+#endif /* CONFIG_SSDFS_DEBUG */
+ } else if (res == -EAGAIN) {
+ err = SSDFS_WAIT_COMPLETION(init_end);
+ if (unlikely(err)) {
+ SSDFS_ERR("segbmap init failed: "
+ "err %d\n", err);
+ return err;
+ }
+
+ res = ssdfs_segbmap_find(segbmap,
+ start_seg_id, max_seg_id,
+ seg_type, type_mask,
+ seg_id, &init_end);
+ if (res >= 0)
+ goto check_segment_state;
+ else if (res == -ENODATA)
+ goto finish_search_segments;
+ else if (res == -EAGAIN) {
+ res = -ENODATA;
+ goto finish_search_segments;
+ } else
+ goto fail_find_segment;
+ } else if (res == -ENODATA) {
+finish_search_segments:
+#ifdef CONFIG_SSDFS_DEBUG
+ SSDFS_DBG("no more victim segments: "
+ "start_seg_id %llu, max_seg_id %llu\n",
+ start_seg_id, max_seg_id);
+#endif /* CONFIG_SSDFS_DEBUG */
+ return res;
+ } else {
+fail_find_segment:
+ SSDFS_ERR("fail to find segment number: "
+ "start_seg_id %llu, max_seg_id %llu, "
+ "err %d\n",
+ start_seg_id, max_seg_id, res);
+ return res;
+ }
+
+ return 0;
+}
+
+/*
+ * ssdfs_gc_convert_leb2peb() - convert LEB ID into PEB ID
+ * @fsi: pointer on shared file system object
+ * @leb_id: LEB ID number
+ * @pebr: pointer on PEBs association container [out]
+ *
+ * This method tries to convert LEB ID into PEB ID.
+ *
+ * RETURN:
+ * [success]
+ * [failure] - error code:
+ *
+ * %-ENODATA - can't convert LEB to PEB.
+ * %-ERANGE - internal error.
+ */
+static
+int ssdfs_gc_convert_leb2peb(struct ssdfs_fs_info *fsi,
+ u64 leb_id,
+ struct ssdfs_maptbl_peb_relation *pebr)
+{
+ struct completion *init_end;
+#ifdef CONFIG_SSDFS_DEBUG
+ struct ssdfs_maptbl_peb_descriptor *ptr;
+#endif /* CONFIG_SSDFS_DEBUG */
+ u8 peb_type = SSDFS_MAPTBL_UNKNOWN_PEB_TYPE;
+ int err;
+
+#ifdef CONFIG_SSDFS_DEBUG
+ BUG_ON(!fsi || !pebr);
+
+ SSDFS_DBG("fsi %p, leb_id %llu, pebr %p\n",
+ fsi, leb_id, pebr);
+#endif /* CONFIG_SSDFS_DEBUG */
+
+ err = ssdfs_maptbl_convert_leb2peb(fsi, leb_id,
+ peb_type, pebr,
+ &init_end);
+ if (err == -EAGAIN) {
+ err = SSDFS_WAIT_COMPLETION(init_end);
+ if (unlikely(err)) {
+ SSDFS_ERR("maptbl init failed: "
+ "err %d\n", err);
+ return err;
+ }
+
+ err = ssdfs_maptbl_convert_leb2peb(fsi, leb_id,
+ peb_type, pebr,
+ &init_end);
+ }
+
+ if (err == -ENODATA) {
+#ifdef CONFIG_SSDFS_DEBUG
+ SSDFS_DBG("LEB is not mapped: leb_id %llu\n",
+ leb_id);
+#endif /* CONFIG_SSDFS_DEBUG */
+ return err;
+ } else if (unlikely(err)) {
+ SSDFS_ERR("fail to convert LEB to PEB: "
+ "leb_id %llu, peb_type %#x, err %d\n",
+ leb_id, peb_type, err);
+ return err;
+ }
+
+#ifdef CONFIG_SSDFS_DEBUG
+ SSDFS_DBG("LEB %llu\n", leb_id);
+
+ ptr = &pebr->pebs[SSDFS_MAPTBL_MAIN_INDEX];
+ SSDFS_DBG("MAIN: peb_id %llu, shared_peb_index %u, "
+ "erase_cycles %u, type %#x, state %#x, "
+ "flags %#x\n",
+ ptr->peb_id, ptr->shared_peb_index,
+ ptr->erase_cycles, ptr->type,
+ ptr->state, ptr->flags);
+ ptr = &pebr->pebs[SSDFS_MAPTBL_RELATION_INDEX];
+ SSDFS_DBG("RELATION: peb_id %llu, shared_peb_index %u, "
+ "erase_cycles %u, type %#x, state %#x, "
+ "flags %#x\n",
+ ptr->peb_id, ptr->shared_peb_index,
+ ptr->erase_cycles, ptr->type,
+ ptr->state, ptr->flags);
+#endif /* CONFIG_SSDFS_DEBUG */
+
+ return 0;
+}
+
+/*
+ * should_ssdfs_segment_be_destroyed() - check necessity to destroy a segment
+ * @si: pointer on segment object
+ *
+ * This method tries to check the necessity to destroy
+ * a segment object.
+ */
+static
+bool should_ssdfs_segment_be_destroyed(struct ssdfs_segment_info *si)
+{
+ struct ssdfs_peb_container *pebc;
+ struct ssdfs_peb_info *pebi;
+ u64 peb_id;
+ bool is_rq_empty;
+ bool is_fq_empty;
+ bool peb_has_dirty_pages = false;
+ bool is_blk_bmap_dirty = false;
+ bool dont_touch = false;
+ int i;
+
+#ifdef CONFIG_SSDFS_DEBUG
+ BUG_ON(!si);
+
+ SSDFS_DBG("seg_id %llu, refs_count %d\n",
+ si->seg_id,
+ atomic_read(&si->refs_count));
+#endif /* CONFIG_SSDFS_DEBUG */
+
+ if (atomic_read(&si->refs_count) > 0)
+ return false;
+
+ dont_touch = should_gc_doesnt_touch_segment(si);
+ if (dont_touch)
+ return false;
+
+ for (i = 0; i < si->pebs_count; i++) {
+ pebc = &si->peb_array[i];
+
+ is_rq_empty = is_ssdfs_requests_queue_empty(READ_RQ_PTR(pebc));
+ is_fq_empty = !have_flush_requests(pebc);
+
+ is_blk_bmap_dirty =
+ is_ssdfs_segment_blk_bmap_dirty(&si->blk_bmap, i);
+
+ pebi = ssdfs_get_current_peb_locked(pebc);
+ if (IS_ERR_OR_NULL(pebi))
+ return false;
+
+ ssdfs_peb_current_log_lock(pebi);
+ peb_has_dirty_pages = ssdfs_peb_has_dirty_pages(pebi);
+ peb_id = pebi->peb_id;
+ ssdfs_peb_current_log_unlock(pebi);
+ ssdfs_unlock_current_peb(pebc);
+
+#ifdef CONFIG_SSDFS_DEBUG
+ SSDFS_DBG("seg_id %llu, peb_id %llu, refs_count %d, "
+ "peb_has_dirty_pages %#x, "
+ "not empty: (read %#x, flush %#x), "
+ "dont_touch %#x, is_blk_bmap_dirty %#x\n",
+ si->seg_id, peb_id,
+ atomic_read(&si->refs_count),
+ peb_has_dirty_pages,
+ !is_rq_empty, !is_fq_empty,
+ dont_touch, is_blk_bmap_dirty);
+#endif /* CONFIG_SSDFS_DEBUG */
+
+ if (!is_rq_empty || !is_fq_empty ||
+ peb_has_dirty_pages || is_blk_bmap_dirty)
+ return false;
+ }
+
+ return true;
+}
+
+/*
+ * should_gc_work() - check that GC should fulfill some activity
+ * @fsi: pointer on shared file system object
+ * @type: thread type
+ */
+static inline
+bool should_gc_work(struct ssdfs_fs_info *fsi, int type)
+{
+ return atomic_read(&fsi->gc_should_act[type]) > 0;
+}
+
+#define GLOBAL_GC_THREAD_WAKE_CONDITION(fsi, type) \
+ (kthread_should_stop() || should_gc_work(fsi, type))
+#define GLOBAL_GC_FAILED_THREAD_WAKE_CONDITION() \
+ (kthread_should_stop())
+
+#define SSDFS_GC_LOW_BOUND_THRESHOLD (50)
+#define SSDFS_GC_UPPER_BOUND_THRESHOLD (1000)
+#define SSDFS_GC_DISTANCE_THRESHOLD (5)
+#define SSDFS_GC_DEFAULT_SEARCH_STEP (100)
+#define SSDFS_GC_DIRTY_SEG_SEARCH_STEP (1000)
+#define SSDFS_GC_DIRTY_SEG_DEFAULT_OPS (50)
+
+/*
+ * GC possible states
+ */
+enum {
+ SSDFS_UNDEFINED_GC_STATE,
+ SSDFS_COLLECT_GARBAGE_NOW,
+ SSDFS_WAIT_IDLE_STATE,
+ SSDFS_STOP_GC_ACTIVITY_NOW,
+ SSDFS_GC_STATE_MAX
+};
+
+/*
+ * struct ssdfs_io_load_stats - I/O load estimation
+ * @measurements: number of executed measurements
+ * @reqs_count: number of I/O requests for every measurement
+ */
+struct ssdfs_io_load_stats {
+ u32 measurements;
+#define SSDFS_MEASUREMENTS_MAX (10)
+ s64 reqs_count[SSDFS_MEASUREMENTS_MAX];
+};
+
+/*
+ * is_time_collect_garbage() - check that it's good time for GC activity
+ * @fsi: pointer on shared file system object
+ * @io_stats: I/O load estimation [in|out]
+ *
+ * This method tries to estimate the I/O load with
+ * the goal to define the good time for GC activity.
+ */
+static
+int is_time_collect_garbage(struct ssdfs_fs_info *fsi,
+ struct ssdfs_io_load_stats *io_stats)
+{
+ int state;
+ s64 reqs_count;
+ s64 average_diff;
+ s64 cur_diff;
+ u64 distance;
+ u32 i;
+
+#ifdef CONFIG_SSDFS_DEBUG
+ BUG_ON(!fsi || !io_stats);
+
+ SSDFS_DBG("fsi %p, io_stats %p, measurements %u\n",
+ fsi, io_stats, io_stats->measurements);
+#endif /* CONFIG_SSDFS_DEBUG */
+
+ if (io_stats->measurements > SSDFS_MEASUREMENTS_MAX) {
+ SSDFS_ERR("invalid count: "
+ "measurements %u\n",
+ io_stats->measurements);
+ return SSDFS_UNDEFINED_GC_STATE;
+ }
+
+ reqs_count = atomic64_read(&fsi->flush_reqs);
+
+ if (reqs_count < 0) {
+ SSDFS_WARN("unexpected reqs_count %lld\n",
+ reqs_count);
+ }
+
+ if (io_stats->measurements < SSDFS_MEASUREMENTS_MAX) {
+ io_stats->reqs_count[io_stats->measurements] = reqs_count;
+ io_stats->measurements++;
+ }
+
+ state = atomic_read(&fsi->global_fs_state);
+ switch (state) {
+ case SSDFS_METADATA_GOING_FLUSHING:
+ case SSDFS_METADATA_UNDER_FLUSH:
+ /*
+ * Thread that is trying to flush metadata
+ * waits the end of user data flush requests.
+ * So, GC should not add any requests,
+ * otherwise, the metadata flush could
+ * never happened.
+ */
+ SSDFS_DBG("don't add request before metadata flush\n");
+ return SSDFS_WAIT_IDLE_STATE;
+
+ default:
+ /* continue logic */
+ break;
+ }
+
+ if (reqs_count <= SSDFS_GC_LOW_BOUND_THRESHOLD) {
+#ifdef CONFIG_SSDFS_DEBUG
+ SSDFS_DBG("reqs_count %lld\n", reqs_count);
+#endif /* CONFIG_SSDFS_DEBUG */
+ return SSDFS_COLLECT_GARBAGE_NOW;
+ }
+
+ if (reqs_count >= SSDFS_GC_UPPER_BOUND_THRESHOLD) {
+#ifdef CONFIG_SSDFS_DEBUG
+ SSDFS_DBG("reqs_count %lld\n", reqs_count);
+#endif /* CONFIG_SSDFS_DEBUG */
+ return SSDFS_STOP_GC_ACTIVITY_NOW;
+ }
+
+ if (io_stats->measurements < 3) {
+#ifdef CONFIG_SSDFS_DEBUG
+ SSDFS_DBG("measurement %u, reqs_count %lld\n",
+ io_stats->measurements,
+ reqs_count);
+#endif /* CONFIG_SSDFS_DEBUG */
+ return SSDFS_WAIT_IDLE_STATE;
+ }
+
+ average_diff = 0;
+
+ for (i = 1; i < io_stats->measurements; i++) {
+ cur_diff = io_stats->reqs_count[i] -
+ io_stats->reqs_count[i - 1];
+ average_diff += cur_diff;
+ }
+
+ if (average_diff < 0) {
+ /*
+ * I/O load is decreasing.
+ */
+ cur_diff = io_stats->reqs_count[io_stats->measurements - 1];
+ distance = div_u64((u64)cur_diff, abs(average_diff));
+
+ if (distance < SSDFS_GC_DISTANCE_THRESHOLD) {
+#ifdef CONFIG_SSDFS_DEBUG
+ SSDFS_DBG("I/O load is decreasing: "
+ "average_diff %lld : "
+ "Start GC activity.\n",
+ average_diff);
+#endif /* CONFIG_SSDFS_DEBUG */
+ return SSDFS_COLLECT_GARBAGE_NOW;
+ }
+ } else {
+ /*
+ * I/O load is increasing.
+ */
+ if (io_stats->measurements >= SSDFS_MEASUREMENTS_MAX) {
+#ifdef CONFIG_SSDFS_DEBUG
+ SSDFS_DBG("I/O load is increasing: "
+ "average_diff %lld : "
+ "Stop GC activity.\n",
+ average_diff);
+#endif /* CONFIG_SSDFS_DEBUG */
+ return SSDFS_STOP_GC_ACTIVITY_NOW;
+ }
+ }
+
+ return SSDFS_WAIT_IDLE_STATE;
+}
+
+#define SSDFS_SEG2REQ_PAIR_CAPACITY (10)
+
+/*
+ * struct ssdfs_seg2req_pair_array - segment/request pairs array
+ * @items_count: items count in the array
+ * @pairs: pairs array
+ */
+struct ssdfs_seg2req_pair_array {
+ u32 items_count;
+ struct ssdfs_seg2req_pair pairs[SSDFS_SEG2REQ_PAIR_CAPACITY];
+};
+
+/*
+ * is_seg2req_pair_array_exhausted() - is seg2req pairs array exhausted?
+ * @array: pairs array
+ */
+static inline
+bool is_seg2req_pair_array_exhausted(struct ssdfs_seg2req_pair_array *array)
+{
+ bool is_exhausted;
+
+#ifdef CONFIG_SSDFS_DEBUG
+ BUG_ON(!array);
+#endif /* CONFIG_SSDFS_DEBUG */
+
+ is_exhausted = array->items_count >= SSDFS_SEG2REQ_PAIR_CAPACITY;
+
+#ifdef CONFIG_SSDFS_DEBUG
+ SSDFS_DBG("is_exhausted %#x\n", is_exhausted);
+#endif /* CONFIG_SSDFS_DEBUG */
+
+ return is_exhausted;
+}
+
+/*
+ * ssdfs_gc_check_request() - check request
+ * @req: segment request
+ *
+ * This method tries to check the state of request.
+ *
+ * RETURN:
+ * [success]
+ * [failure] - error code:
+ *
+ * %-ERANGE - internal error.
+ */
+static
+int ssdfs_gc_check_request(struct ssdfs_segment_request *req)
+{
+ wait_queue_head_t *wq = NULL;
+ int err;
+
+#ifdef CONFIG_SSDFS_DEBUG
+ BUG_ON(!req);
+
+ SSDFS_DBG("req %p\n", req);
+#endif /* CONFIG_SSDFS_DEBUG */
+
+check_req_state:
+ switch (atomic_read(&req->result.state)) {
+ case SSDFS_REQ_CREATED:
+ case SSDFS_REQ_STARTED:
+ wq = &req->private.wait_queue;
+
+ err = wait_event_killable_timeout(*wq,
+ has_request_been_executed(req),
+ SSDFS_DEFAULT_TIMEOUT);
+ if (err < 0)
+ WARN_ON(err < 0);
+ else
+ err = 0;
+
+ goto check_req_state;
+ break;
+
+ case SSDFS_REQ_FINISHED:
+ /* do nothing */
+ break;
+
+ case SSDFS_REQ_FAILED:
+ err = req->result.err;
+
+ if (!err) {
+ SSDFS_ERR("error code is absent: "
+ "req %p, err %d\n",
+ req, err);
+ err = -ERANGE;
+ }
+
+ SSDFS_ERR("flush request is failed: "
+ "err %d\n", err);
+ return err;
+
+ default:
+ SSDFS_ERR("invalid result's state %#x\n",
+ atomic_read(&req->result.state));
+ return -ERANGE;
+ }
+
+ return 0;
+}
+
+/*
+ * ssdfs_gc_wait_commit_logs_end() - wait commit logs ending
+ * @fsi: pointer on shared file system object
+ * @array: seg2req pairs array
+ *
+ * This method is waiting the end of commit logs operation.
+ */
+static
+void ssdfs_gc_wait_commit_logs_end(struct ssdfs_fs_info *fsi,
+ struct ssdfs_seg2req_pair_array *array)
+{
+ u32 items_count;
+ int refs_count;
+ int i;
+ int err;
+
+#ifdef CONFIG_SSDFS_DEBUG
+ BUG_ON(!array);
+
+ SSDFS_DBG("items_count %u\n", array->items_count);
+#endif /* CONFIG_SSDFS_DEBUG */
+
+ items_count = min_t(u32, array->items_count,
+ SSDFS_SEG2REQ_PAIR_CAPACITY);
+
+ for (i = 0; i < items_count; i++) {
+ struct ssdfs_seg2req_pair *pair;
+
+ pair = &array->pairs[i];
+
+ if (pair->req != NULL) {
+ err = ssdfs_gc_check_request(pair->req);
+ if (unlikely(err)) {
+ SSDFS_ERR("flush request failed: "
+ "err %d\n", err);
+ }
+
+ refs_count =
+ atomic_read(&pair->req->private.refs_count);
+ if (refs_count != 0) {
+ SSDFS_WARN("unexpected refs_count %d\n",
+ refs_count);
+ }
+
+ ssdfs_request_free(pair->req);
+ } else {
+ SSDFS_ERR("request is NULL: "
+ "item_index %d\n", i);
+ }
+
+ if (pair->si != NULL) {
+ struct ssdfs_segment_info *si = pair->si;
+
+ ssdfs_segment_put_object(si);
+
+ if (should_ssdfs_segment_be_destroyed(si)) {
+ err = ssdfs_segment_tree_remove(fsi, si);
+ if (unlikely(err)) {
+ SSDFS_WARN("fail to remove segment: "
+ "seg %llu, err %d\n",
+ si->seg_id, err);
+ } else {
+ err = ssdfs_segment_destroy_object(si);
+ if (err) {
+ SSDFS_WARN("fail to destroy: "
+ "seg %llu, err %d\n",
+ si->seg_id, err);
+ }
+ }
+ }
+ } else {
+ SSDFS_ERR("segment is NULL: "
+ "item_index %d\n", i);
+ }
+ }
+
+ memset(array, 0, sizeof(struct ssdfs_seg2req_pair_array));
+}
+
+/*
+ * ssdfs_gc_stimulate_migration() - stimulate migration
+ * @si: pointer on segment object
+ * @pebc: pointer on PEB container object
+ * @array: seg2req pairs array
+ *
+ * This method tries to stimulate the PEB's migration.
+ *
+ * RETURN:
+ * [success]
+ * [failure] - error code:
+ *
+ * %-ERANGE - internal error.
+ */
+static
+int ssdfs_gc_stimulate_migration(struct ssdfs_segment_info *si,
+ struct ssdfs_peb_container *pebc,
+ struct ssdfs_seg2req_pair_array *array)
+{
+ struct ssdfs_peb_info *pebi;
+ struct ssdfs_seg2req_pair *pair;
+ u32 index;
+ int count;
+ int err = 0;
+
+#ifdef CONFIG_SSDFS_DEBUG
+ BUG_ON(!si || !pebc || !array);
+
+ SSDFS_DBG("seg %llu, peb_index %u\n",
+ si->seg_id, pebc->peb_index);
+#endif /* CONFIG_SSDFS_DEBUG */
+
+ if (have_flush_requests(pebc)) {
+#ifdef CONFIG_SSDFS_DEBUG
+ SSDFS_DBG("Do nothing: request queue is not empty: "
+ "seg %llu, peb_index %u\n",
+ si->seg_id, pebc->peb_index);
+#endif /* CONFIG_SSDFS_DEBUG */
+ return 0;
+ }
+
+ if (is_seg2req_pair_array_exhausted(array)) {
+ SSDFS_ERR("seg2req pair array is exhausted\n");
+ return -ERANGE;
+ }
+
+ index = array->items_count;
+ pair = &array->pairs[index];
+
+ if (pair->req || pair->si) {
+ SSDFS_ERR("invalid pair state: index %u\n",
+ index);
+ return -ERANGE;
+ }
+
+ if (!is_peb_under_migration(pebc)) {
+ SSDFS_ERR("invalid PEB state: "
+ "seg %llu, peb_index %u\n",
+ si->seg_id, pebc->peb_index);
+ return -ERANGE;
+ }
+
+ pebi = ssdfs_get_current_peb_locked(pebc);
+ if (IS_ERR_OR_NULL(pebi)) {
+ err = pebi == NULL ? -ERANGE : PTR_ERR(pebi);
+ SSDFS_ERR("fail to get PEB object: "
+ "seg %llu, peb_index %u, err %d\n",
+ pebc->parent_si->seg_id,
+ pebc->peb_index, err);
+ return err;
+ }
+
+ /*
+ * The ssdfs_get_current_peb_locked() defines
+ * migration phase. It should be set properly
+ * before the ssdfs_peb_prepare_range_migration()
+ * call.
+ */
+
+ ssdfs_unlock_current_peb(pebc);
+
+ mutex_lock(&pebc->migration_lock);
+
+ for (count = 0; count < 2; count++) {
+ int err1, err2;
+
+ err1 = ssdfs_peb_prepare_range_migration(pebc, 1,
+ SSDFS_BLK_PRE_ALLOCATED);
+ if (err1 && err1 != -ENODATA) {
+ err = err1;
+ break;
+ }
+
+ err2 = ssdfs_peb_prepare_range_migration(pebc, 1,
+ SSDFS_BLK_VALID);
+ if (err2 && err2 != -ENODATA) {
+ err = err2;
+ break;
+ }
+
+ if (err1 == -ENODATA && err2 == -ENODATA) {
+ err = 0;
+ break;
+ }
+ }
+
+ if (unlikely(err)) {
+ SSDFS_ERR("fail to prepare range migration: "
+ "err %d\n", err);
+ } else if (count == 0) {
+ err = -ENODATA;
+#ifdef CONFIG_SSDFS_DEBUG
+ SSDFS_DBG("no data for migration: "
+ "seg %llu, peb_index %u\n",
+ si->seg_id, pebc->peb_index);
+#endif /* CONFIG_SSDFS_DEBUG */
+ }
+
+ mutex_unlock(&pebc->migration_lock);
+
+ if (unlikely(err))
+ return err;
+
+ pair->req = ssdfs_request_alloc();
+ if (IS_ERR_OR_NULL(pair->req)) {
+ err = (pair->req == NULL ? -ENOMEM : PTR_ERR(pair->req));
+ SSDFS_ERR("fail to allocate request: err %d\n",
+ err);
+ return err;
+ }
+
+ ssdfs_request_init(pair->req);
+ ssdfs_get_request(pair->req);
+
+ err = ssdfs_segment_commit_log_async2(si, SSDFS_REQ_ASYNC_NO_FREE,
+ pebc->peb_index, pair->req);
+ if (unlikely(err)) {
+ SSDFS_ERR("commit log request failed: "
+ "err %d\n", err);
+ ssdfs_put_request(pair->req);
+ ssdfs_request_free(pair->req);
+ pair->req = NULL;
+ return err;
+ }
+
+ pair->si = si;
+ array->items_count++;
+
+ return 0;
+}
+
+/*
+ * ssdfs_gc_finish_migration() - finish migration
+ * @si: pointer on segment object
+ * @pebc: pointer on PEB container object
+ * @array: seg2req pairs array
+ *
+ * This method tries to finish the PEB's migration.
+ *
+ * RETURN:
+ * [success]
+ * [failure] - error code:
+ *
+ * %-ERANGE - internal error.
+ */
+static
+int ssdfs_gc_finish_migration(struct ssdfs_segment_info *si,
+ struct ssdfs_peb_container *pebc,
+ struct ssdfs_seg2req_pair_array *array)
+{
+ struct ssdfs_seg2req_pair *pair;
+ struct ssdfs_peb_info *pebi;
+ u32 index;
+ int err;
+
+#ifdef CONFIG_SSDFS_DEBUG
+ BUG_ON(!si || !pebc || !array);
+
+ SSDFS_DBG("seg %llu, peb_index %u\n",
+ si->seg_id, pebc->peb_index);
+#endif /* CONFIG_SSDFS_DEBUG */
+
+ if (have_flush_requests(pebc)) {
+#ifdef CONFIG_SSDFS_DEBUG
+ SSDFS_DBG("Do nothing: request queue is not empty: "
+ "seg %llu, peb_index %u\n",
+ si->seg_id, pebc->peb_index);
+#endif /* CONFIG_SSDFS_DEBUG */
+ return 0;
+ }
+
+ if (is_seg2req_pair_array_exhausted(array)) {
+ SSDFS_ERR("seg2req pair array is exhausted\n");
+ return -ERANGE;
+ }
+
+ index = array->items_count;
+ pair = &array->pairs[index];
+
+ if (pair->req || pair->si) {
+ SSDFS_ERR("invalid pair state: index %u\n",
+ index);
+ return -ERANGE;
+ }
+
+ if (!is_peb_under_migration(pebc)) {
+ SSDFS_ERR("invalid PEB state: "
+ "seg %llu, peb_index %u\n",
+ si->seg_id, pebc->peb_index);
+ return -ERANGE;
+ }
+
+ err = ssdfs_peb_finish_migration(pebc);
+ if (unlikely(err)) {
+ SSDFS_ERR("fail to finish migration: "
+ "seg %llu, peb_index %u, "
+ "err %d\n",
+ pebc->parent_si->seg_id,
+ pebc->peb_index, err);
+ return err;
+ }
+
+ pebi = ssdfs_get_current_peb_locked(pebc);
+ if (IS_ERR_OR_NULL(pebi)) {
+ err = pebi == NULL ? -ERANGE : PTR_ERR(pebi);
+ SSDFS_ERR("fail to get PEB object: "
+ "seg %llu, peb_index %u, err %d\n",
+ pebc->parent_si->seg_id,
+ pebc->peb_index, err);
+ return err;
+ }
+
+ if (is_ssdfs_maptbl_going_to_be_destroyed(si->fsi->maptbl)) {
+ SSDFS_WARN("seg %llu, peb_index %u\n",
+ si->seg_id, pebc->peb_index);
+ }
+
+ err = ssdfs_peb_container_change_state(pebc);
+ if (unlikely(err)) {
+ ssdfs_unlock_current_peb(pebc);
+ SSDFS_ERR("fail to change peb state: "
+ "err %d\n", err);
+ return err;
+ }
+
+ ssdfs_unlock_current_peb(pebc);
+
+ pair->req = ssdfs_request_alloc();
+ if (IS_ERR_OR_NULL(pair->req)) {
+ err = (pair->req == NULL ? -ENOMEM : PTR_ERR(pair->req));
+ SSDFS_ERR("fail to allocate request: err %d\n",
+ err);
+ return err;
+ }
+
+ ssdfs_request_init(pair->req);
+ ssdfs_get_request(pair->req);
+
+ err = ssdfs_segment_commit_log_async2(si, SSDFS_REQ_ASYNC_NO_FREE,
+ pebc->peb_index, pair->req);
+ if (unlikely(err)) {
+ SSDFS_ERR("commit log request failed: "
+ "err %d\n", err);
+ ssdfs_put_request(pair->req);
+ ssdfs_request_free(pair->req);
+ pair->req = NULL;
+ return err;
+ }
+
+ pair->si = si;
+ array->items_count++;
+
+ return 0;
+}
+
+static inline
+int ssdfs_mark_segment_under_gc_activity(struct ssdfs_segment_info *si)
+{
+ int activity_type;
+
+ activity_type = atomic_cmpxchg(&si->activity_type,
+ SSDFS_SEG_OBJECT_REGULAR_ACTIVITY,
+ SSDFS_SEG_UNDER_GC_ACTIVITY);
+ if (activity_type < SSDFS_SEG_OBJECT_REGULAR_ACTIVITY ||
+ activity_type >= SSDFS_SEG_UNDER_GC_ACTIVITY) {
+#ifdef CONFIG_SSDFS_DEBUG
+ SSDFS_DBG("segment %llu is busy under activity %#x\n",
+ si->seg_id, activity_type);
+#endif /* CONFIG_SSDFS_DEBUG */
+ return -EBUSY;
+ }
+
+#ifdef CONFIG_SSDFS_DEBUG
+ SSDFS_DBG("segment %llu is under GC activity\n",
+ si->seg_id);
+#endif /* CONFIG_SSDFS_DEBUG */
+
+ return 0;
+}
+
+static inline
+int ssdfs_revert_segment_to_regular_activity(struct ssdfs_segment_info *si)
+{
+ int activity_type;
+
+ activity_type = atomic_cmpxchg(&si->activity_type,
+ SSDFS_SEG_UNDER_GC_ACTIVITY,
+ SSDFS_SEG_OBJECT_REGULAR_ACTIVITY);
+ if (activity_type != SSDFS_SEG_UNDER_GC_ACTIVITY) {
+ SSDFS_WARN("segment %llu is under activity %#x\n",
+ si->seg_id, activity_type);
+ return -EFAULT;
+ }
+
+#ifdef CONFIG_SSDFS_DEBUG
+ SSDFS_DBG("segment %llu has been reverted from GC activity\n",
+ si->seg_id);
+#endif /* CONFIG_SSDFS_DEBUG */
+
+ return 0;
+}
+
+/*
+ * ssdfs_generic_seg_gc_thread_func() - generic function of GC thread
+ * @fsi: pointer on shared file system object
+ * @thread_type: thread type
+ * @seg_state: type of segment
+ * @seg_state_mask: segment types' mask
+ *
+ * This function is the key logic of GC thread.
+ *
+ * RETURN:
+ * [success]
+ * [failure] - error code:
+ *
+ * %-ERANGE - internal error.
+ */
+static
+int ssdfs_generic_seg_gc_thread_func(struct ssdfs_fs_info *fsi,
+ int thread_type,
+ int seg_state, int seg_state_mask)
+{
+ struct ssdfs_segment_info *si;
+ struct ssdfs_peb_container *pebc;
+ struct ssdfs_maptbl_peb_relation pebr;
+ struct ssdfs_maptbl_peb_descriptor *pebd;
+ struct ssdfs_io_load_stats io_stats;
+ size_t io_stats_size = sizeof(struct ssdfs_io_load_stats);
+ wait_queue_head_t *wq;
+ struct ssdfs_segment_blk_bmap *seg_blkbmap;
+ struct ssdfs_peb_blk_bmap *peb_blkbmap;
+ struct ssdfs_seg2req_pair_array reqs_array;
+ u8 peb_type = SSDFS_MAPTBL_UNKNOWN_PEB_TYPE;
+ int seg_type = SSDFS_UNKNOWN_SEG_TYPE;
+ u64 seg_id = 0;
+ u64 max_seg_id;
+ u64 seg_id_step = SSDFS_GC_DEFAULT_SEARCH_STEP;
+ u64 nsegs;
+ u64 cur_leb_id;
+ u32 lebs_per_segment;
+ int gc_strategy;
+ int used_pages;
+ u32 i;
+ int err = 0;
+
+#ifdef CONFIG_SSDFS_DEBUG
+ BUG_ON(!fsi);
+
+ SSDFS_DBG("GC thread: thread_type %#x, "
+ "seg_state %#x, seg_state_mask %#x\n",
+ thread_type, seg_state, seg_state_mask);
+#endif /* CONFIG_SSDFS_DEBUG */
+
+ wq = &fsi->gc_wait_queue[thread_type];
+ lebs_per_segment = fsi->pebs_per_seg;
+ memset(&reqs_array, 0, sizeof(struct ssdfs_seg2req_pair_array));
+
+repeat:
+ if (kthread_should_stop()) {
+ complete_all(&fsi->gc_thread[thread_type].full_stop);
+ return err;
+ } else if (unlikely(err))
+ goto sleep_failed_gc_thread;
+
+ mutex_lock(&fsi->resize_mutex);
+ nsegs = fsi->nsegs;
+ mutex_unlock(&fsi->resize_mutex);
+
+ if (seg_id >= nsegs)
+ seg_id = 0;
+
+ while (seg_id < nsegs) {
+ peb_type = SSDFS_MAPTBL_UNKNOWN_PEB_TYPE;
+ seg_type = SSDFS_UNKNOWN_SEG_TYPE;
+
+ max_seg_id = seg_id + seg_id_step;
+ max_seg_id = min_t(u64, max_seg_id, nsegs);
+
+ err = ssdfs_gc_find_next_seg_id(fsi, seg_id, max_seg_id,
+ seg_state, seg_state_mask,
+ &seg_id);
+ if (err == -ENODATA) {
+ err = 0;
+
+ if (max_seg_id >= nsegs) {
+ seg_id = 0;
+ SSDFS_DBG("GC hasn't found any victim\n");
+ goto finish_seg_processing;
+ }
+
+ seg_id = max_seg_id;
+
+ wait_event_interruptible_timeout(*wq,
+ kthread_should_stop(), HZ);
+
+ if (kthread_should_stop())
+ goto finish_seg_processing;
+ else
+ continue;
+ } else if (unlikely(err)) {
+ SSDFS_ERR("fail to find segment: "
+ "seg_id %llu, nsegs %llu, err %d\n",
+ seg_id, nsegs, err);
+ goto sleep_failed_gc_thread;
+ }
+
+#ifdef CONFIG_SSDFS_DEBUG
+ SSDFS_DBG("found segment: "
+ "seg_id %llu, seg_state %#x\n",
+ seg_id, seg_state);
+#endif /* CONFIG_SSDFS_DEBUG */
+
+ if (kthread_should_stop())
+ goto finish_seg_processing;
+
+ i = 0;
+
+ for (; i < lebs_per_segment; i++) {
+ cur_leb_id = ssdfs_get_leb_id_for_peb_index(fsi,
+ seg_id,
+ i);
+ if (cur_leb_id >= U64_MAX) {
+#ifdef CONFIG_SSDFS_DEBUG
+ SSDFS_DBG("unexpected leb_id: "
+ "seg_id %llu, peb_index %u\n",
+ seg_id, i);
+#endif /* CONFIG_SSDFS_DEBUG */
+ continue;
+ }
+
+ if (kthread_should_stop())
+ goto finish_seg_processing;
+
+ err = ssdfs_gc_convert_leb2peb(fsi, cur_leb_id, &pebr);
+ if (err == -ENODATA) {
+#ifdef CONFIG_SSDFS_DEBUG
+ SSDFS_DBG("LEB is not mapped: leb_id %llu\n",
+ cur_leb_id);
+#endif /* CONFIG_SSDFS_DEBUG */
+ continue;
+ } else if (unlikely(err)) {
+ SSDFS_ERR("fail to convert LEB to PEB: "
+ "leb_id %llu, peb_type %#x, err %d\n",
+ cur_leb_id, peb_type, err);
+ goto sleep_failed_gc_thread;
+ }
+
+ pebd = &pebr.pebs[SSDFS_MAPTBL_MAIN_INDEX];
+
+ switch (pebd->state) {
+ case SSDFS_MAPTBL_MIGRATION_SRC_USED_STATE:
+ case SSDFS_MAPTBL_MIGRATION_SRC_PRE_DIRTY_STATE:
+ /* PEB is under migration */
+ break;
+
+ case SSDFS_MAPTBL_MIGRATION_SRC_DIRTY_STATE:
+#ifdef CONFIG_SSDFS_DEBUG
+ SSDFS_DBG("SRC PEB %llu is dirty\n",
+ pebd->peb_id);
+#endif /* CONFIG_SSDFS_DEBUG */
+ continue;
+
+ default:
+#ifdef CONFIG_SSDFS_DEBUG
+ SSDFS_DBG("LEB %llu is not migrating\n",
+ cur_leb_id);
+#endif /* CONFIG_SSDFS_DEBUG */
+ continue;
+ }
+
+ pebd = &pebr.pebs[SSDFS_MAPTBL_RELATION_INDEX];
+
+ switch (pebd->state) {
+ case SSDFS_MAPTBL_MIGRATION_DST_CLEAN_STATE:
+ case SSDFS_MAPTBL_MIGRATION_DST_USING_STATE:
+ /* stimulate migration */
+ break;
+
+ default:
+ continue;
+ }
+
+ if (kthread_should_stop())
+ goto finish_seg_processing;
+
+ peb_type = pebd->type;
+ seg_type = PEB2SEG_TYPE(peb_type);
+
+ goto try_to_find_seg_object;
+ }
+
+ if (i >= lebs_per_segment) {
+ /* segment hasn't valid blocks for migration */
+ goto check_next_segment;
+ }
+
+try_to_find_seg_object:
+ si = ssdfs_segment_tree_find(fsi, seg_id);
+ if (IS_ERR_OR_NULL(si)) {
+ err = PTR_ERR(si);
+
+ if (err == -ENODATA) {
+ /*
+ * It needs to create the segment.
+ */
+ err = 0;
+ goto try_create_seg_object;
+ } else if (err == 0) {
+ err = -ERANGE;
+ SSDFS_ERR("seg tree returns NULL\n");
+ goto finish_seg_processing;
+ } else {
+ SSDFS_ERR("fail to find segment: "
+ "seg %llu, err %d\n",
+ seg_id, err);
+ goto sleep_failed_gc_thread;
+ }
+ } else if (should_ssdfs_segment_be_destroyed(si)) {
+ /*
+ * Segment hasn't requests in the queues.
+ * But it is under migration.
+ * Try to collect the garbage.
+ */
+ ssdfs_segment_get_object(si);
+ goto try_collect_garbage;
+ } else
+ goto check_next_segment;
+
+try_create_seg_object:
+ si = ssdfs_grab_segment(fsi, seg_type, seg_id, U64_MAX);
+ if (unlikely(IS_ERR_OR_NULL(si))) {
+ err = PTR_ERR(si);
+ SSDFS_ERR("fail to grab segment object: "
+ "seg %llu, err %d\n",
+ seg_id, err);
+ goto sleep_failed_gc_thread;
+ }
+
+try_collect_garbage:
+ for (; i < lebs_per_segment; i++) {
+ cur_leb_id = ssdfs_get_leb_id_for_peb_index(fsi,
+ seg_id,
+ i);
+ if (cur_leb_id >= U64_MAX) {
+#ifdef CONFIG_SSDFS_DEBUG
+ SSDFS_DBG("unexpected leb_id: "
+ "seg_id %llu, peb_index %u\n",
+ seg_id, i);
+#endif /* CONFIG_SSDFS_DEBUG */
+ continue;
+ }
+
+ if (kthread_should_stop()) {
+ ssdfs_segment_put_object(si);
+ goto finish_seg_processing;
+ }
+
+ err = ssdfs_gc_convert_leb2peb(fsi, cur_leb_id, &pebr);
+ if (err == -ENODATA) {
+#ifdef CONFIG_SSDFS_DEBUG
+ SSDFS_DBG("LEB is not mapped: leb_id %llu\n",
+ cur_leb_id);
+#endif /* CONFIG_SSDFS_DEBUG */
+ continue;
+ } else if (unlikely(err)) {
+ SSDFS_ERR("fail to convert LEB to PEB: "
+ "leb_id %llu, peb_type %#x, err %d\n",
+ cur_leb_id, peb_type, err);
+ ssdfs_segment_put_object(si);
+ goto sleep_failed_gc_thread;
+ }
+
+ pebd = &pebr.pebs[SSDFS_MAPTBL_MAIN_INDEX];
+
+ switch (pebd->state) {
+ case SSDFS_MAPTBL_MIGRATION_SRC_USED_STATE:
+ case SSDFS_MAPTBL_MIGRATION_SRC_PRE_DIRTY_STATE:
+ case SSDFS_MAPTBL_MIGRATION_SRC_DIRTY_STATE:
+ /* PEB is under migration */
+ break;
+
+ default:
+#ifdef CONFIG_SSDFS_DEBUG
+ SSDFS_DBG("LEB %llu is not migrating\n",
+ cur_leb_id);
+#endif /* CONFIG_SSDFS_DEBUG */
+ continue;
+ }
+
+ pebd = &pebr.pebs[SSDFS_MAPTBL_RELATION_INDEX];
+
+ switch (pebd->state) {
+ case SSDFS_MAPTBL_MIGRATION_DST_CLEAN_STATE:
+ case SSDFS_MAPTBL_MIGRATION_DST_USING_STATE:
+ /* stimulate migration */
+ break;
+
+ default:
+ continue;
+ }
+
+ memset(&io_stats, 0, io_stats_size);
+ gc_strategy = SSDFS_UNDEFINED_GC_STATE;
+
+ do {
+ gc_strategy = is_time_collect_garbage(fsi,
+ &io_stats);
+
+ switch (gc_strategy) {
+ case SSDFS_COLLECT_GARBAGE_NOW:
+ goto collect_garbage_now;
+
+ case SSDFS_STOP_GC_ACTIVITY_NOW:
+ ssdfs_segment_put_object(si);
+ goto finish_seg_processing;
+
+ case SSDFS_WAIT_IDLE_STATE:
+ wait_event_interruptible_timeout(*wq,
+ kthread_should_stop(),
+ HZ);
+
+ if (kthread_should_stop()) {
+ ssdfs_segment_put_object(si);
+ goto finish_seg_processing;
+ }
+ break;
+
+ default:
+ err = -ERANGE;
+ SSDFS_ERR("unexpected strategy %#x\n",
+ gc_strategy);
+ ssdfs_segment_put_object(si);
+ goto finish_seg_processing;
+ }
+ } while (gc_strategy == SSDFS_WAIT_IDLE_STATE);
+
+collect_garbage_now:
+ if (kthread_should_stop()) {
+ ssdfs_segment_put_object(si);
+ goto finish_seg_processing;
+ }
+
+ pebc = &si->peb_array[i];
+
+ seg_blkbmap = &si->blk_bmap;
+ peb_blkbmap = &seg_blkbmap->peb[pebc->peb_index];
+
+ if (is_seg2req_pair_array_exhausted(&reqs_array))
+ ssdfs_gc_wait_commit_logs_end(fsi, &reqs_array);
+
+ used_pages =
+ ssdfs_src_blk_bmap_get_used_pages(peb_blkbmap);
+ if (used_pages < 0) {
+ err = used_pages;
+ SSDFS_ERR("fail to get used pages: err %d\n",
+ err);
+ ssdfs_segment_put_object(si);
+ goto sleep_failed_gc_thread;
+ }
+
+ err = ssdfs_mark_segment_under_gc_activity(si);
+ if (err) {
+#ifdef CONFIG_SSDFS_DEBUG
+ SSDFS_DBG("segment %llu is busy\n",
+ si->seg_id);
+#endif /* CONFIG_SSDFS_DEBUG */
+ goto check_next_segment;
+ }
+
+ if (used_pages == 0) {
+ SSDFS_WARN("needs to finish migration: "
+ "seg %llu, leb_id %llu, "
+ "used_pages %d\n",
+ seg_id, cur_leb_id, used_pages);
+ } else if (used_pages <= SSDFS_GC_FINISH_MIGRATION) {
+ ssdfs_segment_get_object(si);
+
+ err = ssdfs_gc_finish_migration(si, pebc,
+ &reqs_array);
+ if (unlikely(err)) {
+ SSDFS_ERR("fail to finish migration: "
+ "seg %llu, leb_id %llu, "
+ "err %d\n",
+ seg_id, cur_leb_id, err);
+ err = 0;
+ ssdfs_segment_put_object(si);
+ }
+ } else {
+ ssdfs_segment_get_object(si);
+
+ err = ssdfs_gc_stimulate_migration(si, pebc,
+ &reqs_array);
+ if (err == -ENODATA) {
+#ifdef CONFIG_SSDFS_DEBUG
+ SSDFS_DBG("no data for migration: "
+ "seg %llu, leb_id %llu, "
+ "err %d\n",
+ seg_id, cur_leb_id, err);
+#endif /* CONFIG_SSDFS_DEBUG */
+ err = 0;
+ ssdfs_segment_put_object(si);
+ } else if (unlikely(err)) {
+ SSDFS_ERR("fail to stimulate migration: "
+ "seg %llu, leb_id %llu, "
+ "err %d\n",
+ seg_id, cur_leb_id, err);
+ err = 0;
+ ssdfs_segment_put_object(si);
+ }
+ }
+ }
+
+ ssdfs_segment_put_object(si);
+
+ if (is_seg2req_pair_array_exhausted(&reqs_array))
+ ssdfs_gc_wait_commit_logs_end(fsi, &reqs_array);
+
+ err = ssdfs_revert_segment_to_regular_activity(si);
+ if (unlikely(err)) {
+ SSDFS_ERR("segment %llu is under unexpected activity\n",
+ si->seg_id);
+ goto sleep_failed_gc_thread;
+ }
+
+ if (should_ssdfs_segment_be_destroyed(si)) {
+ err = ssdfs_segment_tree_remove(fsi, si);
+ if (unlikely(err)) {
+ SSDFS_WARN("fail to remove segment: "
+ "seg %llu, err %d\n",
+ si->seg_id, err);
+ } else {
+ err = ssdfs_segment_destroy_object(si);
+ if (err) {
+ SSDFS_WARN("fail to destroy: "
+ "seg %llu, err %d\n",
+ si->seg_id, err);
+ }
+ }
+ }
+
+check_next_segment:
+ seg_id++;
+
+ atomic_dec(&fsi->gc_should_act[thread_type]);
+
+ if (kthread_should_stop())
+ goto finish_seg_processing;
+
+ if (atomic_read(&fsi->gc_should_act[thread_type]) > 0) {
+ wait_event_interruptible_timeout(*wq,
+ kthread_should_stop(),
+ HZ);
+ } else
+ goto finish_seg_processing;
+
+ if (kthread_should_stop())
+ goto finish_seg_processing;
+ }
+
+finish_seg_processing:
+ atomic_set(&fsi->gc_should_act[thread_type], 0);
+
+ ssdfs_gc_wait_commit_logs_end(fsi, &reqs_array);
+
+ wait_event_interruptible(*wq,
+ GLOBAL_GC_THREAD_WAKE_CONDITION(fsi, thread_type));
+ goto repeat;
+
+sleep_failed_gc_thread:
+ atomic_set(&fsi->gc_should_act[thread_type], 0);
+
+ ssdfs_gc_wait_commit_logs_end(fsi, &reqs_array);
+
+ wait_event_interruptible(*wq,
+ GLOBAL_GC_FAILED_THREAD_WAKE_CONDITION());
+ goto repeat;
+}
+
+/*
+ * should_continue_processing() - should continue processing?
+ */
+static inline
+bool should_continue_processing(int mandatory_ops)
+{
+ if (kthread_should_stop()) {
+ if (mandatory_ops > 0)
+ return true;
+ else
+ return false;
+ } else
+ return true;
+}
+
+/*
+ * __ssdfs_dirty_seg_gc_thread_func() - GC thread's function for dirty segments
+ * @fsi: pointer on shared file system object
+ * @thread_type: thread type
+ * @seg_state: type of segment
+ * @seg_state_mask: segment types' mask
+ *
+ * This function is the logic of GC thread for dirty segments.
+ *
+ * RETURN:
+ * [success]
+ * [failure] - error code:
+ *
+ * %-ERANGE - internal error.
+ */
+static
+int __ssdfs_dirty_seg_gc_thread_func(struct ssdfs_fs_info *fsi,
+ int thread_type,
+ int seg_state, int seg_state_mask)
+{
+ struct ssdfs_segment_info *si;
+ struct ssdfs_maptbl_peb_relation pebr;
+ struct ssdfs_maptbl_peb_descriptor *pebd;
+ struct ssdfs_segment_bmap *segbmap;
+ struct completion *end = NULL;
+ wait_queue_head_t *wq;
+ u64 seg_id = 0;
+ u64 max_seg_id;
+ u64 nsegs;
+ u64 cur_leb_id;
+ u32 lebs_per_segment;
+ int mandatory_ops = SSDFS_GC_DIRTY_SEG_DEFAULT_OPS;
+ u32 i;
+ int err = 0;
+
+#ifdef CONFIG_SSDFS_DEBUG
+ BUG_ON(!fsi);
+
+ SSDFS_DBG("GC thread: thread_type %#x, "
+ "seg_state %#x, seg_state_mask %#x\n",
+ thread_type, seg_state, seg_state_mask);
+#endif /* CONFIG_SSDFS_DEBUG */
+
+ segbmap = fsi->segbmap;
+ wq = &fsi->gc_wait_queue[thread_type];
+ lebs_per_segment = fsi->pebs_per_seg;
+
+repeat:
+ if (kthread_should_stop()) {
+ complete_all(&fsi->gc_thread[thread_type].full_stop);
+ return err;
+ } else if (unlikely(err))
+ goto sleep_failed_gc_thread;
+
+ mutex_lock(&fsi->resize_mutex);
+ nsegs = fsi->nsegs;
+ mutex_unlock(&fsi->resize_mutex);
+
+ if (seg_id >= nsegs)
+ seg_id = 0;
+
+ while (seg_id < nsegs) {
+ max_seg_id = nsegs;
+
+ err = ssdfs_gc_find_next_seg_id(fsi, seg_id, max_seg_id,
+ seg_state, seg_state_mask,
+ &seg_id);
+ if (err == -ENODATA) {
+ err = 0;
+ seg_id = 0;
+ SSDFS_DBG("GC hasn't found any victim\n");
+ goto finish_seg_processing;
+ } else if (unlikely(err)) {
+ SSDFS_ERR("fail to find segment: "
+ "seg_id %llu, nsegs %llu, err %d\n",
+ seg_id, nsegs, err);
+ goto sleep_failed_gc_thread;
+ }
+
+#ifdef CONFIG_SSDFS_DEBUG
+ SSDFS_DBG("found segment: "
+ "seg_id %llu, seg_state %#x\n",
+ seg_id, seg_state);
+#endif /* CONFIG_SSDFS_DEBUG */
+
+ if (!should_continue_processing(mandatory_ops))
+ goto finish_seg_processing;
+
+ i = 0;
+
+ for (; i < lebs_per_segment; i++) {
+ cur_leb_id = ssdfs_get_leb_id_for_peb_index(fsi,
+ seg_id,
+ i);
+ if (cur_leb_id >= U64_MAX) {
+#ifdef CONFIG_SSDFS_DEBUG
+ SSDFS_DBG("unexpected leb_id: "
+ "seg_id %llu, peb_index %u\n",
+ seg_id, i);
+#endif /* CONFIG_SSDFS_DEBUG */
+ continue;
+ }
+
+ err = ssdfs_gc_convert_leb2peb(fsi, cur_leb_id, &pebr);
+ if (err == -ENODATA) {
+#ifdef CONFIG_SSDFS_DEBUG
+ SSDFS_DBG("LEB doesn't mapped: leb_id %llu\n",
+ cur_leb_id);
+#endif /* CONFIG_SSDFS_DEBUG */
+ continue;
+ } else if (unlikely(err)) {
+ SSDFS_ERR("fail to convert LEB to PEB: "
+ "leb_id %llu, err %d\n",
+ cur_leb_id, err);
+ goto sleep_failed_gc_thread;
+ }
+
+ pebd = &pebr.pebs[SSDFS_MAPTBL_MAIN_INDEX];
+
+ switch (pebd->state) {
+ case SSDFS_MAPTBL_DIRTY_PEB_STATE:
+ /* PEB is dirty */
+ break;
+
+ default:
+#ifdef CONFIG_SSDFS_DEBUG
+ SSDFS_DBG("LEB %llu is not dirty: "
+ "pebd->state %u\n",
+ cur_leb_id, pebd->state);
+#endif /* CONFIG_SSDFS_DEBUG */
+ goto check_next_segment;
+ }
+
+ if (!should_continue_processing(mandatory_ops))
+ goto finish_seg_processing;
+
+ goto try_to_find_seg_object;
+ }
+
+try_to_find_seg_object:
+ si = ssdfs_segment_tree_find(fsi, seg_id);
+ if (IS_ERR_OR_NULL(si)) {
+ err = PTR_ERR(si);
+
+ if (err == -ENODATA) {
+ err = 0;
+ goto try_set_pre_erase_state;
+ } else if (err == 0) {
+ err = -ERANGE;
+ SSDFS_ERR("seg tree returns NULL\n");
+ goto finish_seg_processing;
+ } else {
+ SSDFS_ERR("fail to find segment: "
+ "seg %llu, err %d\n",
+ seg_id, err);
+ goto sleep_failed_gc_thread;
+ }
+ } else if (should_ssdfs_segment_be_destroyed(si)) {
+ err = ssdfs_segment_tree_remove(fsi, si);
+ if (unlikely(err)) {
+ SSDFS_WARN("fail to remove segment: "
+ "seg %llu, err %d\n",
+ si->seg_id, err);
+ } else {
+ err = ssdfs_segment_destroy_object(si);
+ if (err) {
+ SSDFS_WARN("fail to destroy: "
+ "seg %llu, err %d\n",
+ si->seg_id, err);
+ }
+ }
+ } else
+ goto check_next_segment;
+
+try_set_pre_erase_state:
+ for (; i < lebs_per_segment; i++) {
+ cur_leb_id = ssdfs_get_leb_id_for_peb_index(fsi,
+ seg_id,
+ i);
+ if (cur_leb_id >= U64_MAX) {
+#ifdef CONFIG_SSDFS_DEBUG
+ SSDFS_DBG("unexpected leb_id: "
+ "seg_id %llu, peb_index %u\n",
+ seg_id, i);
+#endif /* CONFIG_SSDFS_DEBUG */
+ continue;
+ }
+
+ err = ssdfs_gc_convert_leb2peb(fsi, cur_leb_id, &pebr);
+ if (err == -ENODATA) {
+#ifdef CONFIG_SSDFS_DEBUG
+ SSDFS_DBG("LEB doesn't mapped: leb_id %llu\n",
+ cur_leb_id);
+#endif /* CONFIG_SSDFS_DEBUG */
+ continue;
+ } else if (unlikely(err)) {
+ SSDFS_ERR("fail to convert LEB to PEB: "
+ "leb_id %llu, err %d\n",
+ cur_leb_id, err);
+ goto sleep_failed_gc_thread;
+ }
+
+ pebd = &pebr.pebs[SSDFS_MAPTBL_MAIN_INDEX];
+
+ switch (pebd->state) {
+ case SSDFS_MAPTBL_DIRTY_PEB_STATE:
+ /* PEB is dirty */
+ break;
+
+ default:
+#ifdef CONFIG_SSDFS_DEBUG
+ SSDFS_DBG("LEB %llu is not dirty: "
+ "pebd->state %u\n",
+ cur_leb_id, pebd->state);
+#endif /* CONFIG_SSDFS_DEBUG */
+ goto check_next_segment;
+ }
+
+ err = ssdfs_maptbl_prepare_pre_erase_state(fsi,
+ cur_leb_id,
+ pebd->type,
+ &end);
+ if (err == -EAGAIN) {
+ err = SSDFS_WAIT_COMPLETION(end);
+ if (unlikely(err)) {
+ SSDFS_ERR("maptbl init failed: "
+ "err %d\n", err);
+ goto sleep_failed_gc_thread;
+ }
+
+ err = ssdfs_maptbl_prepare_pre_erase_state(fsi,
+ cur_leb_id,
+ pebd->type,
+ &end);
+ }
+
+ if (err == -EBUSY) {
+ err = 0;
+#ifdef CONFIG_SSDFS_DEBUG
+ SSDFS_DBG("unable to prepare pre-erase state: "
+ "leb_id %llu\n",
+ cur_leb_id);
+#endif /* CONFIG_SSDFS_DEBUG */
+ goto finish_seg_processing;
+ } else if (unlikely(err)) {
+ SSDFS_ERR("fail to prepare pre-erase state: "
+ "leb_id %llu, err %d\n",
+ cur_leb_id, err);
+ goto sleep_failed_gc_thread;
+ }
+ }
+
+ err = ssdfs_segbmap_change_state(segbmap, seg_id,
+ SSDFS_SEG_CLEAN, &end);
+ if (err == -EAGAIN) {
+ err = SSDFS_WAIT_COMPLETION(end);
+ if (unlikely(err)) {
+ SSDFS_ERR("segbmap init failed: "
+ "err %d\n", err);
+ goto sleep_failed_gc_thread;
+ }
+
+ err = ssdfs_segbmap_change_state(segbmap, seg_id,
+ SSDFS_SEG_CLEAN, &end);
+ }
+
+ if (unlikely(err)) {
+ SSDFS_ERR("fail to change segment state: "
+ "seg %llu, state %#x, err %d\n",
+ seg_id, SSDFS_SEG_CLEAN, err);
+ goto sleep_failed_gc_thread;
+ }
+
+check_next_segment:
+ mandatory_ops--;
+ seg_id++;
+
+ if (!should_continue_processing(mandatory_ops))
+ goto finish_seg_processing;
+ }
+
+finish_seg_processing:
+ atomic_set(&fsi->gc_should_act[thread_type], 0);
+
+ wait_event_interruptible(*wq,
+ GLOBAL_GC_THREAD_WAKE_CONDITION(fsi, thread_type));
+ goto repeat;
+
+sleep_failed_gc_thread:
+ atomic_set(&fsi->gc_should_act[thread_type], 0);
+
+ wait_event_interruptible(*wq,
+ GLOBAL_GC_FAILED_THREAD_WAKE_CONDITION());
+ goto repeat;
+}
+
+/*
+ * ssdfs_collect_dirty_segments_now() - collect dirty segments now
+ * @fsi: pointer on shared file system object
+ *
+ * This function tries to collect the dirty segments.
+ *
+ * RETURN:
+ * [success]
+ * [failure] - error code:
+ *
+ * %-ERANGE - internal error.
+ */
+int ssdfs_collect_dirty_segments_now(struct ssdfs_fs_info *fsi)
+{
+ struct ssdfs_segment_info *si;
+ struct ssdfs_maptbl_peb_relation pebr;
+ struct ssdfs_maptbl_peb_descriptor *pebd;
+ struct ssdfs_segment_bmap *segbmap;
+ struct completion *end = NULL;
+ int seg_state = SSDFS_SEG_DIRTY;
+ int seg_state_mask = SSDFS_SEG_DIRTY_STATE_FLAG;
+ u64 seg_id = 0;
+ u64 max_seg_id;
+ u64 nsegs;
+ u64 cur_leb_id;
+ u32 lebs_per_segment;
+ u32 i;
+ int err = 0;
+
+#ifdef CONFIG_SSDFS_DEBUG
+ BUG_ON(!fsi);
+
+ SSDFS_DBG("fsi %p\n", fsi);
+#endif /* CONFIG_SSDFS_DEBUG */
+
+ segbmap = fsi->segbmap;
+ lebs_per_segment = fsi->pebs_per_seg;
+
+ mutex_lock(&fsi->resize_mutex);
+ nsegs = fsi->nsegs;
+ mutex_unlock(&fsi->resize_mutex);
+
+ while (seg_id < nsegs) {
+ max_seg_id = nsegs;
+
+ err = ssdfs_gc_find_next_seg_id(fsi, seg_id, max_seg_id,
+ seg_state, seg_state_mask,
+ &seg_id);
+ if (err == -ENODATA) {
+ SSDFS_DBG("GC hasn't found any victim\n");
+ return err;
+ } else if (unlikely(err)) {
+ SSDFS_ERR("fail to find segment: "
+ "seg_id %llu, nsegs %llu, err %d\n",
+ seg_id, nsegs, err);
+ return err;
+ }
+
+#ifdef CONFIG_SSDFS_DEBUG
+ SSDFS_DBG("found segment: "
+ "seg_id %llu, seg_state %#x\n",
+ seg_id, seg_state);
+#endif /* CONFIG_SSDFS_DEBUG */
+
+ i = 0;
+
+ for (; i < lebs_per_segment; i++) {
+ cur_leb_id = ssdfs_get_leb_id_for_peb_index(fsi,
+ seg_id,
+ i);
+ if (cur_leb_id >= U64_MAX) {
+#ifdef CONFIG_SSDFS_DEBUG
+ SSDFS_DBG("unexpected leb_id: "
+ "seg_id %llu, peb_index %u\n",
+ seg_id, i);
+#endif /* CONFIG_SSDFS_DEBUG */
+ continue;
+ }
+
+ err = ssdfs_gc_convert_leb2peb(fsi, cur_leb_id, &pebr);
+ if (err == -ENODATA) {
+#ifdef CONFIG_SSDFS_DEBUG
+ SSDFS_DBG("LEB is not mapped: leb_id %llu\n",
+ cur_leb_id);
+#endif /* CONFIG_SSDFS_DEBUG */
+ continue;
+ } else if (unlikely(err)) {
+ SSDFS_ERR("fail to convert LEB to PEB: "
+ "leb_id %llu, err %d\n",
+ cur_leb_id, err);
+ return err;
+ }
+
+ pebd = &pebr.pebs[SSDFS_MAPTBL_MAIN_INDEX];
+
+ switch (pebd->state) {
+ case SSDFS_MAPTBL_DIRTY_PEB_STATE:
+ /* PEB is dirty */
+ break;
+
+ default:
+#ifdef CONFIG_SSDFS_DEBUG
+ SSDFS_DBG("LEB %llu is not dirty: "
+ "pebd->state %u\n",
+ cur_leb_id, pebd->state);
+#endif /* CONFIG_SSDFS_DEBUG */
+ goto check_next_segment;
+ }
+
+ goto try_to_find_seg_object;
+ }
+
+try_to_find_seg_object:
+ si = ssdfs_segment_tree_find(fsi, seg_id);
+ if (IS_ERR_OR_NULL(si)) {
+ err = PTR_ERR(si);
+
+ if (err == -ENODATA) {
+ err = 0;
+ goto try_set_pre_erase_state;
+ } else if (err == 0) {
+ err = -ERANGE;
+ SSDFS_ERR("seg tree returns NULL\n");
+ return err;
+ } else {
+ SSDFS_ERR("fail to find segment: "
+ "seg %llu, err %d\n",
+ seg_id, err);
+ return err;
+ }
+ } else if (should_ssdfs_segment_be_destroyed(si)) {
+ err = ssdfs_segment_tree_remove(fsi, si);
+ if (unlikely(err)) {
+ SSDFS_WARN("fail to remove segment: "
+ "seg %llu, err %d\n",
+ si->seg_id, err);
+ } else {
+ err = ssdfs_segment_destroy_object(si);
+ if (err) {
+ SSDFS_WARN("fail to destroy: "
+ "seg %llu, err %d\n",
+ si->seg_id, err);
+ }
+ }
+ } else
+ goto check_next_segment;
+
+try_set_pre_erase_state:
+ for (; i < lebs_per_segment; i++) {
+ cur_leb_id = ssdfs_get_leb_id_for_peb_index(fsi,
+ seg_id,
+ i);
+ if (cur_leb_id >= U64_MAX) {
+#ifdef CONFIG_SSDFS_DEBUG
+ SSDFS_DBG("unexpected leb_id: "
+ "seg_id %llu, peb_index %u\n",
+ seg_id, i);
+#endif /* CONFIG_SSDFS_DEBUG */
+ continue;
+ }
+
+ err = ssdfs_gc_convert_leb2peb(fsi, cur_leb_id, &pebr);
+ if (err == -ENODATA) {
+#ifdef CONFIG_SSDFS_DEBUG
+ SSDFS_DBG("LEB is not mapped: leb_id %llu\n",
+ cur_leb_id);
+#endif /* CONFIG_SSDFS_DEBUG */
+ continue;
+ } else if (unlikely(err)) {
+ SSDFS_ERR("fail to convert LEB to PEB: "
+ "leb_id %llu, err %d\n",
+ cur_leb_id, err);
+ return err;
+ }
+
+ pebd = &pebr.pebs[SSDFS_MAPTBL_MAIN_INDEX];
+
+ switch (pebd->state) {
+ case SSDFS_MAPTBL_DIRTY_PEB_STATE:
+ /* PEB is dirty */
+ break;
+
+ default:
+#ifdef CONFIG_SSDFS_DEBUG
+ SSDFS_DBG("LEB %llu is not dirty: "
+ "pebd->state %u\n",
+ cur_leb_id, pebd->state);
+#endif /* CONFIG_SSDFS_DEBUG */
+ goto check_next_segment;
+ }
+
+ err = ssdfs_maptbl_prepare_pre_erase_state(fsi,
+ cur_leb_id,
+ pebd->type,
+ &end);
+ if (err == -EAGAIN) {
+ err = SSDFS_WAIT_COMPLETION(end);
+ if (unlikely(err)) {
+ SSDFS_ERR("maptbl init failed: "
+ "err %d\n", err);
+ return err;
+ }
+
+ err = ssdfs_maptbl_prepare_pre_erase_state(fsi,
+ cur_leb_id,
+ pebd->type,
+ &end);
+ }
+
+ if (err == -EBUSY) {
+ err = 0;
+#ifdef CONFIG_SSDFS_DEBUG
+ SSDFS_DBG("unable to prepare pre-erase state: "
+ "leb_id %llu\n",
+ cur_leb_id);
+#endif /* CONFIG_SSDFS_DEBUG */
+ goto check_next_segment;
+ } else if (unlikely(err)) {
+ SSDFS_ERR("fail to prepare pre-erase state: "
+ "leb_id %llu, err %d\n",
+ cur_leb_id, err);
+ return err;
+ }
+ }
+
+ err = ssdfs_segbmap_change_state(segbmap, seg_id,
+ SSDFS_SEG_CLEAN, &end);
+ if (err == -EAGAIN) {
+ err = SSDFS_WAIT_COMPLETION(end);
+ if (unlikely(err)) {
+ SSDFS_ERR("segbmap init failed: "
+ "err %d\n", err);
+ return err;
+ }
+
+ err = ssdfs_segbmap_change_state(segbmap, seg_id,
+ SSDFS_SEG_CLEAN, &end);
+ }
+
+ if (unlikely(err)) {
+ SSDFS_ERR("fail to change segment state: "
+ "seg %llu, state %#x, err %d\n",
+ seg_id, SSDFS_SEG_CLEAN, err);
+ return err;
+ }
+
+check_next_segment:
+ seg_id++;
+ }
+
+ return 0;
+}
+
+int ssdfs_using_seg_gc_thread_func(void *data)
+{
+ struct ssdfs_fs_info *fsi = data;
+
+#ifdef CONFIG_SSDFS_DEBUG
+ if (!fsi) {
+ SSDFS_ERR("invalid shared FS object\n");
+ return -EINVAL;
+ }
+
+ SSDFS_DBG("GC thread: using segments\n");
+#endif /* CONFIG_SSDFS_DEBUG */
+
+ return ssdfs_generic_seg_gc_thread_func(fsi,
+ SSDFS_SEG_USING_GC_THREAD,
+ SSDFS_SEG_DATA_USING,
+ SSDFS_SEG_DATA_USING_STATE_FLAG |
+ SSDFS_SEG_LEAF_NODE_USING_STATE_FLAG |
+ SSDFS_SEG_HYBRID_NODE_USING_STATE_FLAG |
+ SSDFS_SEG_INDEX_NODE_USING_STATE_FLAG);
+}
+
+int ssdfs_used_seg_gc_thread_func(void *data)
+{
+ struct ssdfs_fs_info *fsi = data;
+
+#ifdef CONFIG_SSDFS_DEBUG
+ if (!fsi) {
+ SSDFS_ERR("invalid shared FS object\n");
+ return -EINVAL;
+ }
+
+ SSDFS_DBG("GC thread: used segments\n");
+#endif /* CONFIG_SSDFS_DEBUG */
+
+ return ssdfs_generic_seg_gc_thread_func(fsi,
+ SSDFS_SEG_USED_GC_THREAD,
+ SSDFS_SEG_USED,
+ SSDFS_SEG_USED_STATE_FLAG);
+}
+
+int ssdfs_pre_dirty_seg_gc_thread_func(void *data)
+{
+ struct ssdfs_fs_info *fsi = data;
+
+#ifdef CONFIG_SSDFS_DEBUG
+ if (!fsi) {
+ SSDFS_ERR("invalid shared FS object\n");
+ return -EINVAL;
+ }
+
+ SSDFS_DBG("GC thread: pre-dirty segments\n");
+#endif /* CONFIG_SSDFS_DEBUG */
+
+ return ssdfs_generic_seg_gc_thread_func(fsi,
+ SSDFS_SEG_PRE_DIRTY_GC_THREAD,
+ SSDFS_SEG_PRE_DIRTY,
+ SSDFS_SEG_PRE_DIRTY_STATE_FLAG);
+}
+
+int ssdfs_dirty_seg_gc_thread_func(void *data)
+{
+ struct ssdfs_fs_info *fsi = data;
+
+#ifdef CONFIG_SSDFS_DEBUG
+ if (!fsi) {
+ SSDFS_ERR("invalid shared FS object\n");
+ return -EINVAL;
+ }
+
+ SSDFS_DBG("GC thread: dirty segments\n");
+#endif /* CONFIG_SSDFS_DEBUG */
+
+ return __ssdfs_dirty_seg_gc_thread_func(fsi,
+ SSDFS_SEG_DIRTY_GC_THREAD,
+ SSDFS_SEG_DIRTY,
+ SSDFS_SEG_DIRTY_STATE_FLAG);
+}
+
+/*
+ * ssdfs_start_gc_thread() - start GC thread
+ * @fsi: pointer on shared file system object
+ * @type: thread type
+ *
+ * This function tries to start GC thread of @type.
+ *
+ * RETURN:
+ * [success] - GC thread has been started.
+ * [failure] - error code:
+ *
+ * %-EINVAL - invalid input.
+ */
+int ssdfs_start_gc_thread(struct ssdfs_fs_info *fsi, int type)
+{
+ ssdfs_threadfn threadfn;
+ const char *fmt;
+ int err;
+
+#ifdef CONFIG_SSDFS_DEBUG
+ BUG_ON(!fsi);
+
+ if (type >= SSDFS_GC_THREAD_TYPE_MAX) {
+ SSDFS_ERR("invalid GC thread type %d\n", type);
+ return -EINVAL;
+ }
+
+ SSDFS_DBG("thread_type %d\n", type);
+#endif /* CONFIG_SSDFS_DEBUG */
+
+ threadfn = thread_desc[type].threadfn;
+ fmt = thread_desc[type].fmt;
+
+ fsi->gc_thread[type].task = kthread_create(threadfn, fsi, fmt);
+ if (IS_ERR_OR_NULL(fsi->gc_thread[type].task)) {
+ err = PTR_ERR(fsi->gc_thread[type].task);
+ if (err == -EINTR) {
+ /*
+ * Ignore this error.
+ */
+ } else {
+ if (err == 0)
+ err = -ERANGE;
+ SSDFS_ERR("fail to start GC thread: "
+ "thread_type %d, err %d\n",
+ type, err);
+ }
+
+ return err;
+ }
+
+ init_waitqueue_entry(&fsi->gc_thread[type].wait,
+ fsi->gc_thread[type].task);
+ add_wait_queue(&fsi->gc_wait_queue[type],
+ &fsi->gc_thread[type].wait);
+ init_completion(&fsi->gc_thread[type].full_stop);
+
+ wake_up_process(fsi->gc_thread[type].task);
+
+ return 0;
+}
+
+/*
+ * ssdfs_stop_gc_thread() - stop GC thread
+ * @fsi: pointer on shared file system object
+ * @type: thread type
+ *
+ * This function tries to stop GC thread of @type.
+ *
+ * RETURN:
+ * [success] - GC thread has been stopped.
+ * [failure] - error code:
+ *
+ * %-EINVAL - invalid input.
+ */
+int ssdfs_stop_gc_thread(struct ssdfs_fs_info *fsi, int type)
+{
+ int err;
+
+#ifdef CONFIG_SSDFS_DEBUG
+ BUG_ON(!fsi);
+
+ if (type >= SSDFS_GC_THREAD_TYPE_MAX) {
+ SSDFS_ERR("invalid GC thread type %d\n", type);
+ return -EINVAL;
+ }
+
+ SSDFS_DBG("type %#x, task %p\n",
+ type, fsi->gc_thread[type].task);
+#endif /* CONFIG_SSDFS_DEBUG */
+
+ if (!fsi->gc_thread[type].task)
+ return 0;
+
+ err = kthread_stop(fsi->gc_thread[type].task);
+ if (err == -EINTR) {
+ /*
+ * Ignore this error.
+ * The wake_up_process() was never called.
+ */
+ return 0;
+ } else if (unlikely(err)) {
+ SSDFS_WARN("thread function had some issue: err %d\n",
+ err);
+ return err;
+ }
+
+ finish_wait(&fsi->gc_wait_queue[type],
+ &fsi->gc_thread[type].wait);
+
+ fsi->gc_thread[type].task = NULL;
+
+ err = SSDFS_WAIT_COMPLETION(&fsi->gc_thread[type].full_stop);
+ if (unlikely(err)) {
+ SSDFS_ERR("stop thread fails: err %d\n", err);
+ return err;
+ }
+
+ return 0;
+}
SSDFS implements a migration scheme. Migration scheme is a fundamental technique of GC overhead management. The key responsibility of the migration scheme is to guarantee the presence of data in the same segment for any update operations. Generally speaking, the migration scheme’s model is implemented on the basis of association an exhausted "Physical" Erase Block (PEB) with a clean one. The goal such association of two PEBs is to implement the gradual migration of data by means of the update operations in the initial (exhausted) PEB. As a result, the old, exhausted PEB becomes invalidated after complete data migration and it will be possible to apply the erase operation to convert it in the clean state. Moreover, the destination PEB in the association changes the initial PEB for some index in the segment and, finally, it becomes the only PEB for this position. Namely such technique implements the concept of logical extent with the goal to decrease the write amplification issue and to manage the GC overhead. Because the logical extent concept excludes the necessity to update metadata is tracking the position of user data on the file system’s volume. Generally speaking, the migration scheme is capable to decrease the GC activity significantly by means of excluding the necessity to update metadata and by means of self-migration of data between of PEBs is triggered by regular update operations. Generally speaking, SSDFS doesn't need in classical model of garbage collection that is used in NILFS2 or F2FS. However, SSDFS has several global GC threads (dirty, pre-dirty, used, using segment states) and segment bitmap. The main responsibility of global GC threads is: (1) find segment in a particular state, (2) check that segment object is constructed and initialized by file system driver logic, (3) check the necessity to stimulate or finish the migration (if segment is under update operations or has update operations recently, then migration stimulation is not necessary), (4) define valid blocks that require migration, (5) add recommended migration request to PEB update queue, (6) destroy in-core segment object if no migration is necessary and no create/update requests have been received by segment object recently. Global GC threads are used to recommend migration stimulation for particular PEBs and to destroy in-core segment objects that have no requests for processing. Signed-off-by: Viacheslav Dubeyko <slava@dubeyko.com> CC: Viacheslav Dubeyko <viacheslav.dubeyko@bytedance.com> CC: Luka Perkov <luka.perkov@sartura.hr> CC: Bruno Banelli <bruno.banelli@sartura.hr> --- fs/ssdfs/peb_gc_thread.c | 2953 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 2953 insertions(+) create mode 100644 fs/ssdfs/peb_gc_thread.c