Something went wrong. Try again.
Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Something went wrong. Try again.
123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462463464465466467468469470471472473474475476477478479480481482483484485486487488489490491492493494495496497498499500501502503504505506507508509510511512513514515516517518519520521522523524525526527528529530531532533534535536537538539540541542543544545546547548549550551552553554555556557558559560561562563564565566567568569570571572573574575576577578579580581582583584585586587588589590591592593594595596597598599600601602603604605606607608609610611612613614615616617618619620621622623624625626627628629630631632633634635636637638639640641642643644645646647648649650651652653654655656657658659660661662663664665666667668669670671672673674675676677678679680681682683684685686687688689690691692693694695696697698699700701702703704705706707708709710711712713714715716717718719720721722723724725726727728729730731732733734// 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 * @iip: index in parent (slot number of this indexing node in the parent * indexing node) * @upper_key: all keys in this indexing node have to be less or equivalent to * this key * @idx: index node (8-byte aligned because all node structures must be 8-byte * aligned) */struct idx_node { struct list_head list; int iip; union ubifs_key upper_key; struct ubifs_idx_node idx __aligned(8);};
/** * dbg_old_index_check_init - get information for the next old index check. * @c: UBIFS file-system description object * @zroot: root of the index * * This function records information about the index that will be needed for the * next old index check i.e. 'dbg_check_old_index()'. * * This function returns %0 on success and a negative error code on failure. */int dbg_old_index_check_init(struct ubifs_info *c, struct ubifs_zbranch *zroot){ struct ubifs_idx_node *idx; int lnum, offs, len, err = 0; struct ubifs_debug_info *d = c->dbg;
d->old_zroot = *zroot; lnum = d->old_zroot.lnum; offs = d->old_zroot.offs; len = d->old_zroot.len;
idx = kmalloc(c->max_idx_node_sz, GFP_NOFS); if (!idx) return -ENOMEM;
err = ubifs_read_node(c, idx, UBIFS_IDX_NODE, len, lnum, offs); if (err) goto out;
d->old_zroot_level = le16_to_cpu(idx->level); d->old_zroot_sqnum = le64_to_cpu(idx->ch.sqnum);out: kfree(idx); return err;}
/** * dbg_check_old_index - check the old copy of the index. * @c: UBIFS file-system description object * @zroot: root of the new index * * In order to be able to recover from an unclean unmount, a complete copy of * the index must exist on flash. This is the "old" index. The commit process * must write the "new" index to flash without overwriting or destroying any * part of the old index. This function is run at commit end in order to check * that the old index does indeed exist completely intact. * * This function returns %0 on success and a negative error code on failure. */int dbg_check_old_index(struct ubifs_info *c, struct ubifs_zbranch *zroot){ int lnum, offs, len, err = 0, last_level, child_cnt; int first = 1, iip; struct ubifs_debug_info *d = c->dbg; union ubifs_key lower_key, upper_key, l_key, u_key; unsigned long long last_sqnum; struct ubifs_idx_node *idx; struct list_head list; struct idx_node *i; size_t sz;
if (!dbg_is_chk_index(c)) return 0;
INIT_LIST_HEAD(&list);
sz = sizeof(struct idx_node) + ubifs_idx_node_sz(c, c->fanout) - UBIFS_IDX_NODE_SZ;
/* Start at the old zroot */ lnum = d->old_zroot.lnum; offs = d->old_zroot.offs; len = d->old_zroot.len; iip = 0;
/* * Traverse the index tree preorder depth-first i.e. do a node and then * its subtrees from left to right. */ while (1) { struct ubifs_branch *br;
/* Get the next index node */ i = kmalloc(sz, GFP_NOFS); if (!i) { err = -ENOMEM; goto out_free; } i->iip = iip; /* Keep the index nodes on our path in a linked list */ list_add_tail(&i->list, &list); /* Read the index node */ idx = &i->idx; err = ubifs_read_node(c, idx, UBIFS_IDX_NODE, len, lnum, offs); if (err) goto out_free; /* Validate index node */ child_cnt = le16_to_cpu(idx->child_cnt); if (child_cnt < 1 || child_cnt > c->fanout) { err = 1; goto out_dump; } if (first) { first = 0; /* Check root level and sqnum */ if (le16_to_cpu(idx->level) != d->old_zroot_level) { err = 2; goto out_dump; } if (le64_to_cpu(idx->ch.sqnum) != d->old_zroot_sqnum) { err = 3; goto out_dump; } /* Set last values as though root had a parent */ last_level = le16_to_cpu(idx->level) + 1; last_sqnum = le64_to_cpu(idx->ch.sqnum) + 1; key_read(c, ubifs_idx_key(c, idx), &lower_key); highest_ino_key(c, &upper_key, INUM_WATERMARK); } key_copy(c, &upper_key, &i->upper_key); if (le16_to_cpu(idx->level) != last_level - 1) { err = 3; goto out_dump; } /* * The index is always written bottom up hence a child's sqnum * is always less than the parents. */ if (le64_to_cpu(idx->ch.sqnum) >= last_sqnum) { err = 4; goto out_dump; } /* Check key range */ key_read(c, ubifs_idx_key(c, idx), &l_key); br = ubifs_idx_branch(c, idx, child_cnt - 1); key_read(c, &br->key, &u_key); if (keys_cmp(c, &lower_key, &l_key) > 0) { err = 5; goto out_dump; } if (keys_cmp(c, &upper_key, &u_key) < 0) { err = 6; goto out_dump; } if (keys_cmp(c, &upper_key, &u_key) == 0) if (!is_hash_key(c, &u_key)) { err = 7; goto out_dump; } /* Go to next index node */ if (le16_to_cpu(idx->level) == 0) { /* At the bottom, so go up until can go right */ while (1) { /* Drop the bottom of the list */ list_del(&i->list); kfree(i); /* No more list means we are done */ if (list_empty(&list)) goto out; /* Look at the new bottom */ i = list_entry(list.prev, struct idx_node, list); idx = &i->idx; /* Can we go right */ if (iip + 1 < le16_to_cpu(idx->child_cnt)) { iip = iip + 1; break; } else /* Nope, so go up again */ iip = i->iip; } } else /* Go down left */ iip = 0; /* * We have the parent in 'idx' and now we set up for reading the * child pointed to by slot 'iip'. */ last_level = le16_to_cpu(idx->level); last_sqnum = le64_to_cpu(idx->ch.sqnum); br = ubifs_idx_branch(c, idx, iip); lnum = le32_to_cpu(br->lnum); offs = le32_to_cpu(br->offs); len = le32_to_cpu(br->len); key_read(c, &br->key, &lower_key); if (iip + 1 < le16_to_cpu(idx->child_cnt)) { br = ubifs_idx_branch(c, idx, iip + 1); key_read(c, &br->key, &upper_key); } else key_copy(c, &i->upper_key, &upper_key); }out: err = dbg_old_index_check_init(c, zroot); if (err) goto out_free;
return 0;
out_dump: ubifs_err(c, "dumping index node (iip=%d)", i->iip); ubifs_dump_node(c, idx, ubifs_idx_node_sz(c, c->fanout)); list_del(&i->list); kfree(i); if (!list_empty(&list)) { i = list_entry(list.prev, struct idx_node, list); ubifs_err(c, "dumping parent index node"); ubifs_dump_node(c, &i->idx, ubifs_idx_node_sz(c, c->fanout)); }out_free: while (!list_empty(&list)) { i = list_entry(list.next, struct idx_node, list); list_del(&i->list); kfree(i); } ubifs_err(c, "failed, error %d", err); if (err > 0) err = -EINVAL; return err;}