// SPDX-License-Identifier: GPL-2.0-only/* * This file is part of UBIFS. * * Copyright (C) 2006-2008 Nokia Corporation. * * Authors: Adrian Hunter * Artem Bityutskiy (Битюцкий Артём) */ /* * This file implements functions that manage the running of the commit process. * Each affected module has its own functions to accomplish their part in the * commit and those functions are called here. * * The commit is the process whereby all updates to the index and LEB properties * are written out together and the journal becomes empty. This keeps the * file system consistent - at all times the state can be recreated by reading * the index and LEB properties and then replaying the journal. * * The commit is split into two parts named "commit start" and "commit end". * During commit start, the commit process has exclusive access to the journal * by holding the commit semaphore down for writing. As few I/O operations as * possible are performed during commit start, instead the nodes that are to be * written are merely identified. During commit end, the commit semaphore is no * longer held and the journal is again in operation, allowing users to continue * to use the file system while the bulk of the commit I/O is performed. The * purpose of this two-step approach is to prevent the commit from causing any * latency blips. Note that in any case, the commit does not prevent lookups * (as permitted by the TNC mutex), or access to VFS data structures e.g. page * cache. */ #include <linux/freezer.h>#include <linux/kthread.h>#include <linux/slab.h>#include "ubifs.h" /* * nothing_to_commit - check if there is nothing to commit. * @c: UBIFS file-system description object * * This is a helper function which checks if there is anything to commit. It is * used as an optimization to avoid starting the commit if it is not really * necessary. Indeed, the commit operation always assumes flash I/O (e.g., * writing the commit start node to the log), and it is better to avoid doing * this unnecessarily. E.g., 'ubifs_sync_fs()' runs the commit, but if there is * nothing to commit, it is more optimal to avoid any flash I/O. * * This function has to be called with @c->commit_sem locked for writing - * this function does not take LPT/TNC locks because the @c->commit_sem * guarantees that we have exclusive access to the TNC and LPT data structures. * * This function returns %1 if there is nothing to commit and %0 otherwise. */static int nothing_to_commit(struct ubifs_info *c){ /* * During mounting or remounting from R/O mode to R/W mode we may * commit for various recovery-related reasons. */ if (c->mounting || c->remounting_rw) return 0; /* * If the root TNC node is dirty, we definitely have something to * commit. */ if (c->zroot.znode && ubifs_zn_dirty(c->zroot.znode)) return 0; /* * Increasing @c->dirty_pn_cnt/@c->dirty_nn_cnt and marking * nnodes/pnodes as dirty in run_gc() could race with following * checking, which leads inconsistent states between @c->nroot * and @c->dirty_pn_cnt/@c->dirty_nn_cnt, holding @c->lp_mutex * to avoid that. */ mutex_lock(&c->lp_mutex); /* * Even though the TNC is clean, the LPT tree may have dirty nodes. For * example, this may happen if the budgeting subsystem invoked GC to * make some free space, and the GC found an LEB with only dirty and * free space. In this case GC would just change the lprops of this * LEB (by turning all space into free space) and unmap it. */ if (c->nroot && test_bit(DIRTY_CNODE, &c->nroot->flags)) { mutex_unlock(&c->lp_mutex); return 0; } ubifs_assert(c, atomic_long_read(&c->dirty_zn_cnt) == 0); ubifs_assert(c, c->dirty_pn_cnt == 0); ubifs_assert(c, c->dirty_nn_cnt == 0); mutex_unlock(&c->lp_mutex); return 1;} /** * do_commit - commit the journal. * @c: UBIFS file-system description object * * This function implements UBIFS commit. It has to be called with commit lock * locked. Returns zero in case of success and a negative error code in case of * failure. */static int do_commit(struct ubifs_info *c){ int err, new_ltail_lnum, old_ltail_lnum, i; struct ubifs_zbranch zroot; struct ubifs_lp_stats lst; dbg_cmt("start"); ubifs_assert(c, !c->ro_media && !c->ro_mount); if (c->ro_error) { err = -EROFS; goto out_up; } if (nothing_to_commit(c)) { up_write(&c->commit_sem); err = 0; goto out_cancel; } /* Sync all write buffers (necessary for recovery) */ for (i = 0; i < c->jhead_cnt; i++) { err = ubifs_wbuf_sync(&c->jheads[i].wbuf); if (err) goto out_up; } c->cmt_no += 1; err = ubifs_gc_start_commit(c); if (err) goto out_up; err = dbg_check_lprops(c); if (err) goto out_up; err = ubifs_log_start_commit(c, &new_ltail_lnum); if (err) goto out_up; err = ubifs_tnc_start_commit(c, &zroot); if (err) goto out_up; err = ubifs_lpt_start_commit(c); if (err) goto out_up; err = ubifs_orphan_start_commit(c); if (err) goto out_up; ubifs_get_lp_stats(c, &lst); up_write(&c->commit_sem); err = ubifs_tnc_end_commit(c); if (err) goto out; err = ubifs_lpt_end_commit(c); if (err) goto out; err = ubifs_orphan_end_commit(c); if (err) goto out; err = dbg_check_old_index(c, &zroot); if (err) goto out; c->mst_node->cmt_no = cpu_to_le64(c->cmt_no); c->mst_node->log_lnum = cpu_to_le32(new_ltail_lnum); c->mst_node->root_lnum = cpu_to_le32(zroot.lnum); c->mst_node->root_offs = cpu_to_le32(zroot.offs); c->mst_node->root_len = cpu_to_le32(zroot.len); c->mst_node->ihead_lnum = cpu_to_le32(c->ihead_lnum); c->mst_node->ihead_offs = cpu_to_le32(c->ihead_offs); c->mst_node->index_size = cpu_to_le64(c->bi.old_idx_sz); c->mst_node->lpt_lnum = cpu_to_le32(c->lpt_lnum); c->mst_node->lpt_offs = cpu_to_le32(c->lpt_offs); c->mst_node->nhead_lnum = cpu_to_le32(c->nhead_lnum); c->mst_node->nhead_offs = cpu_to_le32(c->nhead_offs); c->mst_node->ltab_lnum = cpu_to_le32(c->ltab_lnum); c->mst_node->ltab_offs = cpu_to_le32(c->ltab_offs); c->mst_node->lsave_lnum = cpu_to_le32(c->lsave_lnum); c->mst_node->lsave_offs = cpu_to_le32(c->lsave_offs); c->mst_node->lscan_lnum = cpu_to_le32(c->lscan_lnum); c->mst_node->empty_lebs = cpu_to_le32(lst.empty_lebs); c->mst_node->idx_lebs = cpu_to_le32(lst.idx_lebs); c->mst_node->total_free = cpu_to_le64(lst.total_free); c->mst_node->total_dirty = cpu_to_le64(lst.total_dirty); c->mst_node->total_used = cpu_to_le64(lst.total_used); c->mst_node->total_dead = cpu_to_le64(lst.total_dead); c->mst_node->total_dark = cpu_to_le64(lst.total_dark); if (c->no_orphs) c->mst_node->flags |= cpu_to_le32(UBIFS_MST_NO_ORPHS); else c->mst_node->flags &= ~cpu_to_le32(UBIFS_MST_NO_ORPHS); old_ltail_lnum = c->ltail_lnum; err = ubifs_log_end_commit(c, new_ltail_lnum); if (err) goto out; err = ubifs_log_post_commit(c, old_ltail_lnum); if (err) goto out; err = ubifs_gc_end_commit(c); if (err) goto out; err = ubifs_lpt_post_commit(c); if (err) goto out; out_cancel: spin_lock(&c->cs_lock); c->cmt_state = COMMIT_RESTING; wake_up(&c->cmt_wq); dbg_cmt("commit end"); spin_unlock(&c->cs_lock); return 0; out_up: up_write(&c->commit_sem);out: ubifs_err(c, "commit failed, error %d", err); spin_lock(&c->cs_lock); c->cmt_state = COMMIT_BROKEN; wake_up(&c->cmt_wq); spin_unlock(&c->cs_lock); ubifs_ro_mode(c, err); return err;} /** * run_bg_commit - run background commit if it is needed. * @c: UBIFS file-system description object * * This function runs background commit if it is needed. Returns zero in case * of success and a negative error code in case of failure. */static int run_bg_commit(struct ubifs_info *c){ spin_lock(&c->cs_lock); /* * Run background commit only if background commit was requested or if * commit is required. */ if (c->cmt_state != COMMIT_BACKGROUND && c->cmt_state != COMMIT_REQUIRED) goto out; spin_unlock(&c->cs_lock); down_write(&c->commit_sem); spin_lock(&c->cs_lock); if (c->cmt_state == COMMIT_REQUIRED) c->cmt_state = COMMIT_RUNNING_REQUIRED; else if (c->cmt_state == COMMIT_BACKGROUND) c->cmt_state = COMMIT_RUNNING_BACKGROUND; else goto out_cmt_unlock; spin_unlock(&c->cs_lock); return do_commit(c); out_cmt_unlock: up_write(&c->commit_sem);out: spin_unlock(&c->cs_lock); return 0;} /** * ubifs_bg_thread - UBIFS background thread function. * @info: points to the file-system description object * * This function implements various file-system background activities: * o when a write-buffer timer expires it synchronizes the appropriate * write-buffer; * o when the journal is about to be full, it starts in-advance commit. * * Note, other stuff like background garbage collection may be added here in * future. */int ubifs_bg_thread(void *info){ int err; struct ubifs_info *c = info; ubifs_msg(c, "background thread \"%s\" started, PID %d", c->bgt_name, current->pid); set_freezable(); while (1) { if (kthread_should_stop()) break; if (try_to_freeze()) continue; set_current_state(TASK_INTERRUPTIBLE); /* Check if there is something to do */ if (!c->need_bgt) { /* * Nothing prevents us from going sleep now and * be never woken up and block the task which * could wait in 'kthread_stop()' forever. */ if (kthread_should_stop()) break; schedule(); continue; } else __set_current_state(TASK_RUNNING); c->need_bgt = 0; err = ubifs_bg_wbufs_sync(c); if (err) ubifs_ro_mode(c, err); run_bg_commit(c); cond_resched(); } ubifs_msg(c, "background thread \"%s\" stops", c->bgt_name); return 0;} /** * ubifs_commit_required - set commit state to "required". * @c: UBIFS file-system description object * * This function is called if a commit is required but cannot be done from the * calling function, so it is just flagged instead. */void ubifs_commit_required(struct ubifs_info *c){ spin_lock(&c->cs_lock); switch (c->cmt_state) { case COMMIT_RESTING: case COMMIT_BACKGROUND: dbg_cmt("old: %s, new: %s", dbg_cstate(c->cmt_state), dbg_cstate(COMMIT_REQUIRED)); c->cmt_state = COMMIT_REQUIRED; break; case COMMIT_RUNNING_BACKGROUND: dbg_cmt("old: %s, new: %s", dbg_cstate(c->cmt_state), dbg_cstate(COMMIT_RUNNING_REQUIRED)); c->cmt_state = COMMIT_RUNNING_REQUIRED; break; case COMMIT_REQUIRED: case COMMIT_RUNNING_REQUIRED: case COMMIT_BROKEN: break; } spin_unlock(&c->cs_lock);} /** * ubifs_request_bg_commit - notify the background thread to do a commit. * @c: UBIFS file-system description object * * This function is called if the journal is full enough to make a commit * worthwhile, so background thread is kicked to start it. */void ubifs_request_bg_commit(struct ubifs_info *c){ spin_lock(&c->cs_lock); if (c->cmt_state == COMMIT_RESTING) { dbg_cmt("old: %s, new: %s", dbg_cstate(c->cmt_state), dbg_cstate(COMMIT_BACKGROUND)); c->cmt_state = COMMIT_BACKGROUND; spin_unlock(&c->cs_lock); ubifs_wake_up_bgt(c); } else spin_unlock(&c->cs_lock);} /** * wait_for_commit - wait for commit. * @c: UBIFS file-system description object * * This function sleeps until the commit operation is no longer running. */static int wait_for_commit(struct ubifs_info *c){ dbg_cmt("pid %d goes sleep", current->pid); /* * The following sleeps if the condition is false, and will be woken * when the commit ends. It is possible, although very unlikely, that we * will wake up and see the subsequent commit running, rather than the * one we were waiting for, and go back to sleep. However, we will be * woken again, so there is no danger of sleeping forever. */ wait_event(c->cmt_wq, c->cmt_state != COMMIT_RUNNING_BACKGROUND && c->cmt_state != COMMIT_RUNNING_REQUIRED); dbg_cmt("commit finished, pid %d woke up", current->pid); return 0;} /** * ubifs_run_commit - run or wait for commit. * @c: UBIFS file-system description object * * This function runs commit and returns zero in case of success and a negative * error code in case of failure. */int ubifs_run_commit(struct ubifs_info *c){ int err = 0; spin_lock(&c->cs_lock); if (c->cmt_state == COMMIT_BROKEN) { err = -EROFS; goto out; } if (c->cmt_state == COMMIT_RUNNING_BACKGROUND) /* * We set the commit state to 'running required' to indicate * that we want it to complete as quickly as possible. */ c->cmt_state = COMMIT_RUNNING_REQUIRED; if (c->cmt_state == COMMIT_RUNNING_REQUIRED) { spin_unlock(&c->cs_lock); return wait_for_commit(c); } spin_unlock(&c->cs_lock); /* Ok, the commit is indeed needed */ down_write(&c->commit_sem); spin_lock(&c->cs_lock); /* * Since we unlocked 'c->cs_lock', the state may have changed, so * re-check it. */ if (c->cmt_state == COMMIT_BROKEN) { err = -EROFS; goto out_cmt_unlock; } if (c->cmt_state == COMMIT_RUNNING_BACKGROUND) c->cmt_state = COMMIT_RUNNING_REQUIRED; if (c->cmt_state == COMMIT_RUNNING_REQUIRED) { up_write(&c->commit_sem); spin_unlock(&c->cs_lock); return wait_for_commit(c); } c->cmt_state = COMMIT_RUNNING_REQUIRED; spin_unlock(&c->cs_lock); err = do_commit(c); return err; out_cmt_unlock: up_write(&c->commit_sem);out: spin_unlock(&c->cs_lock); return err;} /** * ubifs_gc_should_commit - determine if it is time for GC to run commit. * @c: UBIFS file-system description object * * This function is called by garbage collection to determine if commit should * be run. If commit state is @COMMIT_BACKGROUND, which means that the journal * is full enough to start commit, this function returns true. It is not * absolutely necessary to commit yet, but it feels like this should be better * then to keep doing GC. This function returns %1 if GC has to initiate commit * and %0 if not. */int ubifs_gc_should_commit(struct ubifs_info *c){ int ret = 0; spin_lock(&c->cs_lock); if (c->cmt_state == COMMIT_BACKGROUND) { dbg_cmt("commit required now"); c->cmt_state = COMMIT_REQUIRED; } else dbg_cmt("commit not requested"); if (c->cmt_state == COMMIT_REQUIRED) ret = 1; spin_unlock(&c->cs_lock); return ret;} /* * Everything below is related to debugging. */ /** * struct idx_node - hold index nodes during index tree traversal. * @list: listLines 1–500 of 733. Load more
// SPDX-License-Identifier: GPL-2.0-only /* * This file is part of UBIFS. * * Copyright (C) 2006-2008 Nokia Corporation. * * Authors: Adrian Hunter * Artem Bityutskiy (Битюцкий Артём) */ /* * This file implements functions that manage the running of the commit process. * Each affected module has its own functions to accomplish their part in the * commit and those functions are called here. * * The commit is the process whereby all updates to the index and LEB properties * are written out together and the journal becomes empty. This keeps the * file system consistent - at all times the state can be recreated by reading * the index and LEB properties and then replaying the journal. * * The commit is split into two parts named "commit start" and "commit end". * During commit start, the commit process has exclusive access to the journal * by holding the commit semaphore down for writing. As few I/O operations as * possible are performed during commit start, instead the nodes that are to be * written are merely identified. During commit end, the commit semaphore is no * longer held and the journal is again in operation, allowing users to continue * to use the file system while the bulk of the commit I/O is performed. The * purpose of this two-step approach is to prevent the commit from causing any * latency blips. Note that in any case, the commit does not prevent lookups * (as permitted by the TNC mutex), or access to VFS data structures e.g. page * cache. */ #include <linux/freezer.h> #include <linux/kthread.h> #include <linux/slab.h> #include "ubifs.h" /* * nothing_to_commit - check if there is nothing to commit. * @c: UBIFS file-system description object * * This is a helper function which checks if there is anything to commit. It is * used as an optimization to avoid starting the commit if it is not really * necessary. Indeed, the commit operation always assumes flash I/O (e.g., * writing the commit start node to the log), and it is better to avoid doing * this unnecessarily. E.g., 'ubifs_sync_fs()' runs the commit, but if there is * nothing to commit, it is more optimal to avoid any flash I/O. * * This function has to be called with @c->commit_sem locked for writing - * this function does not take LPT/TNC locks because the @c->commit_sem * guarantees that we have exclusive access to the TNC and LPT data structures. * * This function returns %1 if there is nothing to commit and %0 otherwise. */ static int nothing_to_commit(struct ubifs_info *c) { /* * During mounting or remounting from R/O mode to R/W mode we may * commit for various recovery-related reasons. */ if (c->mounting || c->remounting_rw) return 0; /* * If the root TNC node is dirty, we definitely have something to * commit. */ if (c->zroot.znode && ubifs_zn_dirty(c->zroot.znode)) return 0; /* * Increasing @c->dirty_pn_cnt/@c->dirty_nn_cnt and marking * nnodes/pnodes as dirty in run_gc() could race with following * checking, which leads inconsistent states between @c->nroot * and @c->dirty_pn_cnt/@c->dirty_nn_cnt, holding @c->lp_mutex * to avoid that. */ mutex_lock(&c->lp_mutex); /* * Even though the TNC is clean, the LPT tree may have dirty nodes. For * example, this may happen if the budgeting subsystem invoked GC to * make some free space, and the GC found an LEB with only dirty and * free space. In this case GC would just change the lprops of this * LEB (by turning all space into free space) and unmap it. */ if (c->nroot && test_bit(DIRTY_CNODE, &c->nroot->flags)) { mutex_unlock(&c->lp_mutex); return 0; } ubifs_assert(c, atomic_long_read(&c->dirty_zn_cnt) == 0); ubifs_assert(c, c->dirty_pn_cnt == 0); ubifs_assert(c, c->dirty_nn_cnt == 0); mutex_unlock(&c->lp_mutex); return 1; } /** * do_commit - commit the journal. * @c: UBIFS file-system description object * * This function implements UBIFS commit. It has to be called with commit lock * locked. Returns zero in case of success and a negative error code in case of * failure. */ static int do_commit(struct ubifs_info *c) { int err, new_ltail_lnum, old_ltail_lnum, i; struct ubifs_zbranch zroot; struct ubifs_lp_stats lst; dbg_cmt("start"); ubifs_assert(c, !c->ro_media && !c->ro_mount); if (c->ro_error) { err = -EROFS; goto out_up; } if (nothing_to_commit(c)) { up_write(&c->commit_sem); err = 0; goto out_cancel; } /* Sync all write buffers (necessary for recovery) */ for (i = 0; i < c->jhead_cnt; i++) { err = ubifs_wbuf_sync(&c->jheads[i].wbuf); if (err) goto out_up; } c->cmt_no += 1; err = ubifs_gc_start_commit(c); if (err) goto out_up; err = dbg_check_lprops(c); if (err) goto out_up; err = ubifs_log_start_commit(c, &new_ltail_lnum); if (err) goto out_up; err = ubifs_tnc_start_commit(c, &zroot); if (err) goto out_up; err = ubifs_lpt_start_commit(c); if (err) goto out_up; err = ubifs_orphan_start_commit(c); if (err) goto out_up; ubifs_get_lp_stats(c, &lst); up_write(&c->commit_sem); err = ubifs_tnc_end_commit(c); if (err) goto out; err = ubifs_lpt_end_commit(c); if (err) goto out; err = ubifs_orphan_end_commit(c); if (err) goto out; err = dbg_check_old_index(c, &zroot); if (err) goto out; c->mst_node->cmt_no = cpu_to_le64(c->cmt_no); c->mst_node->log_lnum = cpu_to_le32(new_ltail_lnum); c->mst_node->root_lnum = cpu_to_le32(zroot.lnum); c->mst_node->root_offs = cpu_to_le32(zroot.offs); c->mst_node->root_len = cpu_to_le32(zroot.len); c->mst_node->ihead_lnum = cpu_to_le32(c->ihead_lnum); c->mst_node->ihead_offs = cpu_to_le32(c->ihead_offs); c->mst_node->index_size = cpu_to_le64(c->bi.old_idx_sz); c->mst_node->lpt_lnum = cpu_to_le32(c->lpt_lnum); c->mst_node->lpt_offs = cpu_to_le32(c->lpt_offs); c->mst_node->nhead_lnum = cpu_to_le32(c->nhead_lnum); c->mst_node->nhead_offs = cpu_to_le32(c->nhead_offs); c->mst_node->ltab_lnum = cpu_to_le32(c->ltab_lnum); c->mst_node->ltab_offs = cpu_to_le32(c->ltab_offs); c->mst_node->lsave_lnum = cpu_to_le32(c->lsave_lnum); c->mst_node->lsave_offs = cpu_to_le32(c->lsave_offs); c->mst_node->lscan_lnum = cpu_to_le32(c->lscan_lnum); c->mst_node->empty_lebs = cpu_to_le32(lst.empty_lebs); c->mst_node->idx_lebs = cpu_to_le32(lst.idx_lebs); c->mst_node->total_free = cpu_to_le64(lst.total_free); c->mst_node->total_dirty = cpu_to_le64(lst.total_dirty); c->mst_node->total_used = cpu_to_le64(lst.total_used); c->mst_node->total_dead = cpu_to_le64(lst.total_dead); c->mst_node->total_dark = cpu_to_le64(lst.total_dark); if (c->no_orphs) c->mst_node->flags |= cpu_to_le32(UBIFS_MST_NO_ORPHS); else c->mst_node->flags &= ~cpu_to_le32(UBIFS_MST_NO_ORPHS); old_ltail_lnum = c->ltail_lnum; err = ubifs_log_end_commit(c, new_ltail_lnum); if (err) goto out; err = ubifs_log_post_commit(c, old_ltail_lnum); if (err) goto out; err = ubifs_gc_end_commit(c); if (err) goto out; err = ubifs_lpt_post_commit(c); if (err) goto out; out_cancel: spin_lock(&c->cs_lock); c->cmt_state = COMMIT_RESTING; wake_up(&c->cmt_wq); dbg_cmt("commit end"); spin_unlock(&c->cs_lock); return 0; out_up: up_write(&c->commit_sem); out: ubifs_err(c, "commit failed, error %d", err); spin_lock(&c->cs_lock); c->cmt_state = COMMIT_BROKEN; wake_up(&c->cmt_wq); spin_unlock(&c->cs_lock); ubifs_ro_mode(c, err); return err; } /** * run_bg_commit - run background commit if it is needed. * @c: UBIFS file-system description object * * This function runs background commit if it is needed. Returns zero in case * of success and a negative error code in case of failure. */ static int run_bg_commit(struct ubifs_info *c) { spin_lock(&c->cs_lock); /* * Run background commit only if background commit was requested or if * commit is required. */ if (c->cmt_state != COMMIT_BACKGROUND && c->cmt_state != COMMIT_REQUIRED) goto out; spin_unlock(&c->cs_lock); down_write(&c->commit_sem); spin_lock(&c->cs_lock); if (c->cmt_state == COMMIT_REQUIRED) c->cmt_state = COMMIT_RUNNING_REQUIRED; else if (c->cmt_state == COMMIT_BACKGROUND) c->cmt_state = COMMIT_RUNNING_BACKGROUND; else goto out_cmt_unlock; spin_unlock(&c->cs_lock); return do_commit(c); out_cmt_unlock: up_write(&c->commit_sem); out: spin_unlock(&c->cs_lock); return 0; } /** * ubifs_bg_thread - UBIFS background thread function. * @info: points to the file-system description object * * This function implements various file-system background activities: * o when a write-buffer timer expires it synchronizes the appropriate * write-buffer; * o when the journal is about to be full, it starts in-advance commit. * * Note, other stuff like background garbage collection may be added here in * future. */ int ubifs_bg_thread(void *info) { int err; struct ubifs_info *c = info; ubifs_msg(c, "background thread \"%s\" started, PID %d", c->bgt_name, current->pid); set_freezable(); while (1) { if (kthread_should_stop()) break; if (try_to_freeze()) continue; set_current_state(TASK_INTERRUPTIBLE); /* Check if there is something to do */ if (!c->need_bgt) { /* * Nothing prevents us from going sleep now and * be never woken up and block the task which * could wait in 'kthread_stop()' forever. */ if (kthread_should_stop()) break; schedule(); continue; } else __set_current_state(TASK_RUNNING); c->need_bgt = 0; err = ubifs_bg_wbufs_sync(c); if (err) ubifs_ro_mode(c, err); run_bg_commit(c); cond_resched(); } ubifs_msg(c, "background thread \"%s\" stops", c->bgt_name); return 0; } /** * ubifs_commit_required - set commit state to "required". * @c: UBIFS file-system description object * * This function is called if a commit is required but cannot be done from the * calling function, so it is just flagged instead. */ void ubifs_commit_required(struct ubifs_info *c) { spin_lock(&c->cs_lock); switch (c->cmt_state) { case COMMIT_RESTING: case COMMIT_BACKGROUND: dbg_cmt("old: %s, new: %s", dbg_cstate(c->cmt_state), dbg_cstate(COMMIT_REQUIRED)); c->cmt_state = COMMIT_REQUIRED; break; case COMMIT_RUNNING_BACKGROUND: dbg_cmt("old: %s, new: %s", dbg_cstate(c->cmt_state), dbg_cstate(COMMIT_RUNNING_REQUIRED)); c->cmt_state = COMMIT_RUNNING_REQUIRED; break; case COMMIT_REQUIRED: case COMMIT_RUNNING_REQUIRED: case COMMIT_BROKEN: break; } spin_unlock(&c->cs_lock); } /** * ubifs_request_bg_commit - notify the background thread to do a commit. * @c: UBIFS file-system description object * * This function is called if the journal is full enough to make a commit * worthwhile, so background thread is kicked to start it. */ void ubifs_request_bg_commit(struct ubifs_info *c) { spin_lock(&c->cs_lock); if (c->cmt_state == COMMIT_RESTING) { dbg_cmt("old: %s, new: %s", dbg_cstate(c->cmt_state), dbg_cstate(COMMIT_BACKGROUND)); c->cmt_state = COMMIT_BACKGROUND; spin_unlock(&c->cs_lock); ubifs_wake_up_bgt(c); } else spin_unlock(&c->cs_lock); } /** * wait_for_commit - wait for commit. * @c: UBIFS file-system description object * * This function sleeps until the commit operation is no longer running. */ static int wait_for_commit(struct ubifs_info *c) { dbg_cmt("pid %d goes sleep", current->pid); /* * The following sleeps if the condition is false, and will be woken * when the commit ends. It is possible, although very unlikely, that we * will wake up and see the subsequent commit running, rather than the * one we were waiting for, and go back to sleep. However, we will be * woken again, so there is no danger of sleeping forever. */ wait_event(c->cmt_wq, c->cmt_state != COMMIT_RUNNING_BACKGROUND && c->cmt_state != COMMIT_RUNNING_REQUIRED); dbg_cmt("commit finished, pid %d woke up", current->pid); return 0; } /** * ubifs_run_commit - run or wait for commit. * @c: UBIFS file-system description object * * This function runs commit and returns zero in case of success and a negative * error code in case of failure. */ int ubifs_run_commit(struct ubifs_info *c) { int err = 0; spin_lock(&c->cs_lock); if (c->cmt_state == COMMIT_BROKEN) { err = -EROFS; goto out; } if (c->cmt_state == COMMIT_RUNNING_BACKGROUND) /* * We set the commit state to 'running required' to indicate * that we want it to complete as quickly as possible. */ c->cmt_state = COMMIT_RUNNING_REQUIRED; if (c->cmt_state == COMMIT_RUNNING_REQUIRED) { spin_unlock(&c->cs_lock); return wait_for_commit(c); } spin_unlock(&c->cs_lock); /* Ok, the commit is indeed needed */ down_write(&c->commit_sem); spin_lock(&c->cs_lock); /* * Since we unlocked 'c->cs_lock', the state may have changed, so * re-check it. */ if (c->cmt_state == COMMIT_BROKEN) { err = -EROFS; goto out_cmt_unlock; } if (c->cmt_state == COMMIT_RUNNING_BACKGROUND) c->cmt_state = COMMIT_RUNNING_REQUIRED; if (c->cmt_state == COMMIT_RUNNING_REQUIRED) { up_write(&c->commit_sem); spin_unlock(&c->cs_lock); return wait_for_commit(c); } c->cmt_state = COMMIT_RUNNING_REQUIRED; spin_unlock(&c->cs_lock); err = do_commit(c); return err; out_cmt_unlock: up_write(&c->commit_sem); out: spin_unlock(&c->cs_lock); return err; } /** * ubifs_gc_should_commit - determine if it is time for GC to run commit. * @c: UBIFS file-system description object * * This function is called by garbage collection to determine if commit should * be run. If commit state is @COMMIT_BACKGROUND, which means that the journal * is full enough to start commit, this function returns true. It is not * absolutely necessary to commit yet, but it feels like this should be better * then to keep doing GC. This function returns %1 if GC has to initiate commit * and %0 if not. */ int ubifs_gc_should_commit(struct ubifs_info *c) { int ret = 0; spin_lock(&c->cs_lock); if (c->cmt_state == COMMIT_BACKGROUND) { dbg_cmt("commit required now"); c->cmt_state = COMMIT_REQUIRED; } else dbg_cmt("commit not requested"); if (c->cmt_state == COMMIT_REQUIRED) ret = 1; spin_unlock(&c->cs_lock); return ret; } /* * Everything below is related to debugging. */ /** * struct idx_node - hold index nodes during index tree traversal. * @list: list