| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Dave Kleikamp | 4319 | 36.86% | 2 | 0.95% |
| zhangyi (F) | 1569 | 13.39% | 22 | 10.43% |
| Theodore Y. Ts'o | 1110 | 9.47% | 31 | 14.69% |
| Jan Kara | 1017 | 8.68% | 32 | 15.17% |
| Harshad Shirwadkar | 896 | 7.65% | 9 | 4.27% |
| Johann Lombardi | 841 | 7.18% | 2 | 0.95% |
| Darrick J. Wong | 455 | 3.88% | 12 | 5.69% |
| Mingming Cao | 158 | 1.35% | 6 | 2.84% |
| Leah Rumancik | 140 | 1.19% | 1 | 0.47% |
| Dmitriy Monakhov | 130 | 1.11% | 3 | 1.42% |
| Paul Gortmaker | 87 | 0.74% | 1 | 0.47% |
| Thomas Gleixner | 82 | 0.70% | 3 | 1.42% |
| Geliang Tang | 80 | 0.68% | 1 | 0.47% |
| Joseph Qi | 78 | 0.67% | 2 | 0.95% |
| Qi Zheng | 56 | 0.48% | 1 | 0.47% |
| Chengguang Xu | 44 | 0.38% | 1 | 0.47% |
| Hidehiro Kawai | 43 | 0.37% | 1 | 0.47% |
| Matthew Wilcox | 35 | 0.30% | 3 | 1.42% |
| Eryu Guan | 33 | 0.28% | 2 | 0.95% |
| Guoqing Cai | 32 | 0.27% | 1 | 0.47% |
| Ding Dinghua | 31 | 0.26% | 1 | 0.47% |
| Michal Hocko | 29 | 0.25% | 4 | 1.90% |
| Eric Sandeen | 28 | 0.24% | 2 | 0.95% |
| Ye Bin | 25 | 0.21% | 2 | 0.95% |
| Girish Shilamkar | 25 | 0.21% | 1 | 0.47% |
| Pavel Emelyanov | 25 | 0.21% | 1 | 0.47% |
| Carlos Maiolino | 23 | 0.20% | 1 | 0.47% |
| Joel Becker | 21 | 0.18% | 1 | 0.47% |
| Kees Cook | 19 | 0.16% | 1 | 0.47% |
| Ross Zwisler | 18 | 0.15% | 1 | 0.47% |
| Christoph Hellwig | 18 | 0.15% | 4 | 1.90% |
| Zach Brown | 15 | 0.13% | 1 | 0.47% |
| Sheng Yang | 14 | 0.12% | 1 | 0.47% |
| Duane Griffin | 14 | 0.12% | 2 | 0.95% |
| Li Zetao | 13 | 0.11% | 1 | 0.47% |
| Mauro Carvalho Chehab | 13 | 0.11% | 1 | 0.47% |
| Eric Biggers | 13 | 0.11% | 1 | 0.47% |
| Wang Long | 11 | 0.09% | 1 | 0.47% |
| OGAWA Hirofumi | 11 | 0.09% | 1 | 0.47% |
| Yongqiang Yang | 10 | 0.09% | 2 | 0.95% |
| Jose R. Santos | 10 | 0.09% | 3 | 1.42% |
| Kai Li | 8 | 0.07% | 1 | 0.47% |
| Roman Gushchin | 8 | 0.07% | 1 | 0.47% |
| Alexey Dobriyan | 8 | 0.07% | 2 | 0.95% |
| Daeho Jeong | 7 | 0.06% | 1 | 0.47% |
| Tejun Heo | 7 | 0.06% | 2 | 0.95% |
| Jiufei (Joyce) Xue | 7 | 0.06% | 1 | 0.47% |
| Gaowei Pu | 7 | 0.06% | 1 | 0.47% |
| Vasily Averin | 6 | 0.05% | 1 | 0.47% |
| Harvey Harrison | 5 | 0.04% | 1 | 0.47% |
| Mauricio Faria de Oliveira | 5 | 0.04% | 1 | 0.47% |
| Christoph Lameter | 4 | 0.03% | 1 | 0.47% |
| Al Viro | 4 | 0.03% | 1 | 0.47% |
| Tao Ma | 4 | 0.03% | 1 | 0.47% |
| Nigel Cunningham | 4 | 0.03% | 2 | 0.95% |
| Simon Holm Thögersen | 4 | 0.03% | 1 | 0.47% |
| Denis V. Lunev | 4 | 0.03% | 1 | 0.47% |
| Bart Van Assche | 4 | 0.03% | 1 | 0.47% |
| Andy Shevchenko | 3 | 0.03% | 1 | 0.47% |
| Brian King | 3 | 0.03% | 1 | 0.47% |
| Xin Yin | 2 | 0.02% | 1 | 0.47% |
| Li Yang | 2 | 0.02% | 1 | 0.47% |
| Patrick J. LoPresti | 2 | 0.02% | 1 | 0.47% |
| Ingo Molnar | 2 | 0.02% | 1 | 0.47% |
| Zheng Liu | 2 | 0.02% | 1 | 0.47% |
| Randy Dunlap | 1 | 0.01% | 1 | 0.47% |
| Linus Torvalds | 1 | 0.01% | 1 | 0.47% |
| Xiaoguang Wang | 1 | 0.01% | 1 | 0.47% |
| Ritesh Harjani | 1 | 0.01% | 1 | 0.47% |
| James Morris | 1 | 0.01% | 1 | 0.47% |
| Bill Pemberton | 1 | 0.01% | 1 | 0.47% |
| Andrea Gelmini | 1 | 0.01% | 1 | 0.47% |
| Artem B. Bityutskiy | 1 | 0.01% | 1 | 0.47% |
| Rasmus Villemoes | 1 | 0.01% | 1 | 0.47% |
| Kirill A. Shutemov | 1 | 0.01% | 1 | 0.47% |
| Josef Bacik | 1 | 0.01% | 1 | 0.47% |
| Shilong Wang | 1 | 0.01% | 1 | 0.47% |
| Paul Mundt | 1 | 0.01% | 1 | 0.47% |
| Song Muchun | 1 | 0.01% | 1 | 0.47% |
| Paul E. McKenney | 1 | 0.01% | 1 | 0.47% |
| Total | 11718 | 211 |
// SPDX-License-Identifier: GPL-2.0+ /* * linux/fs/jbd2/journal.c * * Written by Stephen C. Tweedie <sct@redhat.com>, 1998 * * Copyright 1998 Red Hat corp --- All Rights Reserved * * Generic filesystem journal-writing code; part of the ext2fs * journaling system. * * This file manages journals: areas of disk reserved for logging * transactional updates. This includes the kernel journaling thread * which is responsible for scheduling updates to the log. * * We do not actually manage the physical storage of the journal in this * file: that is left to a per-journal policy function, which allows us * to store the journal within a filesystem-specified area for ext2 * journaling (ext2 can use a reserved inode for storing the log). */ #include <linux/module.h> #include <linux/time.h> #include <linux/fs.h> #include <linux/jbd2.h> #include <linux/errno.h> #include <linux/slab.h> #include <linux/init.h> #include <linux/mm.h> #include <linux/freezer.h> #include <linux/pagemap.h> #include <linux/kthread.h> #include <linux/poison.h> #include <linux/proc_fs.h> #include <linux/seq_file.h> #include <linux/math64.h> #include <linux/hash.h> #include <linux/log2.h> #include <linux/vmalloc.h> #include <linux/backing-dev.h> #include <linux/bitops.h> #include <linux/ratelimit.h> #include <linux/sched/mm.h> #define CREATE_TRACE_POINTS #include <trace/events/jbd2.h> #include <linux/uaccess.h> #include <asm/page.h> #ifdef CONFIG_JBD2_DEBUG static ushort jbd2_journal_enable_debug __read_mostly; module_param_named(jbd2_debug, jbd2_journal_enable_debug, ushort, 0644); MODULE_PARM_DESC(jbd2_debug, "Debugging level for jbd2"); #endif EXPORT_SYMBOL(jbd2_journal_extend); EXPORT_SYMBOL(jbd2_journal_stop); EXPORT_SYMBOL(jbd2_journal_lock_updates); EXPORT_SYMBOL(jbd2_journal_unlock_updates); EXPORT_SYMBOL(jbd2_journal_get_write_access); EXPORT_SYMBOL(jbd2_journal_get_create_access); EXPORT_SYMBOL(jbd2_journal_get_undo_access); EXPORT_SYMBOL(jbd2_journal_set_triggers); EXPORT_SYMBOL(jbd2_journal_dirty_metadata); EXPORT_SYMBOL(jbd2_journal_forget); EXPORT_SYMBOL(jbd2_journal_flush); EXPORT_SYMBOL(jbd2_journal_revoke); EXPORT_SYMBOL(jbd2_journal_init_dev); EXPORT_SYMBOL(jbd2_journal_init_inode); EXPORT_SYMBOL(jbd2_journal_check_used_features); EXPORT_SYMBOL(jbd2_journal_check_available_features); EXPORT_SYMBOL(jbd2_journal_set_features); EXPORT_SYMBOL(jbd2_journal_load); EXPORT_SYMBOL(jbd2_journal_destroy); EXPORT_SYMBOL(jbd2_journal_abort); EXPORT_SYMBOL(jbd2_journal_errno); EXPORT_SYMBOL(jbd2_journal_ack_err); EXPORT_SYMBOL(jbd2_journal_clear_err); EXPORT_SYMBOL(jbd2_log_wait_commit); EXPORT_SYMBOL(jbd2_journal_start_commit); EXPORT_SYMBOL(jbd2_journal_force_commit_nested); EXPORT_SYMBOL(jbd2_journal_wipe); EXPORT_SYMBOL(jbd2_journal_blocks_per_page); EXPORT_SYMBOL(jbd2_journal_invalidate_folio); EXPORT_SYMBOL(jbd2_journal_try_to_free_buffers); EXPORT_SYMBOL(jbd2_journal_force_commit); EXPORT_SYMBOL(jbd2_journal_inode_ranged_write); EXPORT_SYMBOL(jbd2_journal_inode_ranged_wait); EXPORT_SYMBOL(jbd2_journal_finish_inode_data_buffers); EXPORT_SYMBOL(jbd2_journal_init_jbd_inode); EXPORT_SYMBOL(jbd2_journal_release_jbd_inode); EXPORT_SYMBOL(jbd2_journal_begin_ordered_truncate); EXPORT_SYMBOL(jbd2_inode_cache); static int jbd2_journal_create_slab(size_t slab_size); #ifdef CONFIG_JBD2_DEBUG void __jbd2_debug(int level, const char *file, const char *func, unsigned int line, const char *fmt, ...) { struct va_format vaf; va_list args; if (level > jbd2_journal_enable_debug) return; va_start(args, fmt); vaf.fmt = fmt; vaf.va = &args; printk(KERN_DEBUG "%s: (%s, %u): %pV", file, func, line, &vaf); va_end(args); } #endif /* Checksumming functions */ static __be32 jbd2_superblock_csum(journal_t *j, journal_superblock_t *sb) { __u32 csum; __be32 old_csum; old_csum = sb->s_checksum; sb->s_checksum = 0; csum = jbd2_chksum(j, ~0, (char *)sb, sizeof(journal_superblock_t)); sb->s_checksum = old_csum; return cpu_to_be32(csum); } /* * Helper function used to manage commit timeouts */ static void commit_timeout(struct timer_list *t) { journal_t *journal = from_timer(journal, t, j_commit_timer); wake_up_process(journal->j_task); } /* * kjournald2: The main thread function used to manage a logging device * journal. * * This kernel thread is responsible for two things: * * 1) COMMIT: Every so often we need to commit the current state of the * filesystem to disk. The journal thread is responsible for writing * all of the metadata buffers to disk. If a fast commit is ongoing * journal thread waits until it's done and then continues from * there on. * * 2) CHECKPOINT: We cannot reuse a used section of the log file until all * of the data in that part of the log has been rewritten elsewhere on * the disk. Flushing these old buffers to reclaim space in the log is * known as checkpointing, and this thread is responsible for that job. */ static int kjournald2(void *arg) { journal_t *journal = arg; transaction_t *transaction; /* * Set up an interval timer which can be used to trigger a commit wakeup * after the commit interval expires */ timer_setup(&journal->j_commit_timer, commit_timeout, 0); set_freezable(); /* Record that the journal thread is running */ journal->j_task = current; wake_up(&journal->j_wait_done_commit); /* * Make sure that no allocations from this kernel thread will ever * recurse to the fs layer because we are responsible for the * transaction commit and any fs involvement might get stuck waiting for * the trasn. commit. */ memalloc_nofs_save(); /* * And now, wait forever for commit wakeup events. */ write_lock(&journal->j_state_lock); loop: if (journal->j_flags & JBD2_UNMOUNT) goto end_loop; jbd2_debug(1, "commit_sequence=%u, commit_request=%u\n", journal->j_commit_sequence, journal->j_commit_request); if (journal->j_commit_sequence != journal->j_commit_request) { jbd2_debug(1, "OK, requests differ\n"); write_unlock(&journal->j_state_lock); del_timer_sync(&journal->j_commit_timer); jbd2_journal_commit_transaction(journal); write_lock(&journal->j_state_lock); goto loop; } wake_up(&journal->j_wait_done_commit); if (freezing(current)) { /* * The simpler the better. Flushing journal isn't a * good idea, because that depends on threads that may * be already stopped. */ jbd2_debug(1, "Now suspending kjournald2\n"); write_unlock(&journal->j_state_lock); try_to_freeze(); write_lock(&journal->j_state_lock); } else { /* * We assume on resume that commits are already there, * so we don't sleep */ DEFINE_WAIT(wait); int should_sleep = 1; prepare_to_wait(&journal->j_wait_commit, &wait, TASK_INTERRUPTIBLE); if (journal->j_commit_sequence != journal->j_commit_request) should_sleep = 0; transaction = journal->j_running_transaction; if (transaction && time_after_eq(jiffies, transaction->t_expires)) should_sleep = 0; if (journal->j_flags & JBD2_UNMOUNT) should_sleep = 0; if (should_sleep) { write_unlock(&journal->j_state_lock); schedule(); write_lock(&journal->j_state_lock); } finish_wait(&journal->j_wait_commit, &wait); } jbd2_debug(1, "kjournald2 wakes\n"); /* * Were we woken up by a commit wakeup event? */ transaction = journal->j_running_transaction; if (transaction && time_after_eq(jiffies, transaction->t_expires)) { journal->j_commit_request = transaction->t_tid; jbd2_debug(1, "woke because of timeout\n"); } goto loop; end_loop: del_timer_sync(&journal->j_commit_timer); journal->j_task = NULL; wake_up(&journal->j_wait_done_commit); jbd2_debug(1, "Journal thread exiting.\n"); write_unlock(&journal->j_state_lock); return 0; } static int jbd2_journal_start_thread(journal_t *journal) { struct task_struct *t; t = kthread_run(kjournald2, journal, "jbd2/%s", journal->j_devname); if (IS_ERR(t)) return PTR_ERR(t); wait_event(journal->j_wait_done_commit, journal->j_task != NULL); return 0; } static void journal_kill_thread(journal_t *journal) { write_lock(&journal->j_state_lock); journal->j_flags |= JBD2_UNMOUNT; while (journal->j_task) { write_unlock(&journal->j_state_lock); wake_up(&journal->j_wait_commit); wait_event(journal->j_wait_done_commit, journal->j_task == NULL); write_lock(&journal->j_state_lock); } write_unlock(&journal->j_state_lock); } /* * jbd2_journal_write_metadata_buffer: write a metadata buffer to the journal. * * Writes a metadata buffer to a given disk block. The actual IO is not * performed but a new buffer_head is constructed which labels the data * to be written with the correct destination disk block. * * Any magic-number escaping which needs to be done will cause a * copy-out here. If the buffer happens to start with the * JBD2_MAGIC_NUMBER, then we can't write it to the log directly: the * magic number is only written to the log for descripter blocks. In * this case, we copy the data and replace the first word with 0, and we * return a result code which indicates that this buffer needs to be * marked as an escaped buffer in the corresponding log descriptor * block. The missing word can then be restored when the block is read * during recovery. * * If the source buffer has already been modified by a new transaction * since we took the last commit snapshot, we use the frozen copy of * that data for IO. If we end up using the existing buffer_head's data * for the write, then we have to make sure nobody modifies it while the * IO is in progress. do_get_write_access() handles this. * * The function returns a pointer to the buffer_head to be used for IO. * * * Return value: * <0: Error * >=0: Finished OK * * On success: * Bit 0 set == escape performed on the data * Bit 1 set == buffer copy-out performed (kfree the data after IO) */ int jbd2_journal_write_metadata_buffer(transaction_t *transaction, struct journal_head *jh_in, struct buffer_head **bh_out, sector_t blocknr) { int need_copy_out = 0; int done_copy_out = 0; int do_escape = 0; char *mapped_data; struct buffer_head *new_bh; struct folio *new_folio; unsigned int new_offset; struct buffer_head *bh_in = jh2bh(jh_in); journal_t *journal = transaction->t_journal; /* * The buffer really shouldn't be locked: only the current committing * transaction is allowed to write it, so nobody else is allowed * to do any IO. * * akpm: except if we're journalling data, and write() output is * also part of a shared mapping, and another thread has * decided to launch a writepage() against this buffer. */ J_ASSERT_BH(bh_in, buffer_jbddirty(bh_in)); new_bh = alloc_buffer_head(GFP_NOFS|__GFP_NOFAIL); /* keep subsequent assertions sane */ atomic_set(&new_bh->b_count, 1); spin_lock(&jh_in->b_state_lock); repeat: /* * If a new transaction has already done a buffer copy-out, then * we use that version of the data for the commit. */ if (jh_in->b_frozen_data) { done_copy_out = 1; new_folio = virt_to_folio(jh_in->b_frozen_data); new_offset = offset_in_folio(new_folio, jh_in->b_frozen_data); } else { new_folio = jh2bh(jh_in)->b_folio; new_offset = offset_in_folio(new_folio, jh2bh(jh_in)->b_data); } mapped_data = kmap_local_folio(new_folio, new_offset); /* * Fire data frozen trigger if data already wasn't frozen. Do this * before checking for escaping, as the trigger may modify the magic * offset. If a copy-out happens afterwards, it will have the correct * data in the buffer. */ if (!done_copy_out) jbd2_buffer_frozen_trigger(jh_in, mapped_data, jh_in->b_triggers); /* * Check for escaping */ if (*((__be32 *)mapped_data) == cpu_to_be32(JBD2_MAGIC_NUMBER)) { need_copy_out = 1; do_escape = 1; } kunmap_local(mapped_data); /* * Do we need to do a data copy? */ if (need_copy_out && !done_copy_out) { char *tmp; spin_unlock(&jh_in->b_state_lock); tmp = jbd2_alloc(bh_in->b_size, GFP_NOFS); if (!tmp) { brelse(new_bh); return -ENOMEM; } spin_lock(&jh_in->b_state_lock); if (jh_in->b_frozen_data) { jbd2_free(tmp, bh_in->b_size); goto repeat; } jh_in->b_frozen_data = tmp; memcpy_from_folio(tmp, new_folio, new_offset, bh_in->b_size); new_folio = virt_to_folio(tmp); new_offset = offset_in_folio(new_folio, tmp); done_copy_out = 1; /* * This isn't strictly necessary, as we're using frozen * data for the escaping, but it keeps consistency with * b_frozen_data usage. */ jh_in->b_frozen_triggers = jh_in->b_triggers; } /* * Did we need to do an escaping? Now we've done all the * copying, we can finally do so. */ if (do_escape) { mapped_data = kmap_local_folio(new_folio, new_offset); *((unsigned int *)mapped_data) = 0; kunmap_local(mapped_data); } folio_set_bh(new_bh, new_folio, new_offset); new_bh->b_size = bh_in->b_size; new_bh->b_bdev = journal->j_dev; new_bh->b_blocknr = blocknr; new_bh->b_private = bh_in; set_buffer_mapped(new_bh); set_buffer_dirty(new_bh); *bh_out = new_bh; /* * The to-be-written buffer needs to get moved to the io queue, * and the original buffer whose contents we are shadowing or * copying is moved to the transaction's shadow queue. */ JBUFFER_TRACE(jh_in, "file as BJ_Shadow"); spin_lock(&journal->j_list_lock); __jbd2_journal_file_buffer(jh_in, transaction, BJ_Shadow); spin_unlock(&journal->j_list_lock); set_buffer_shadow(bh_in); spin_unlock(&jh_in->b_state_lock); return do_escape | (done_copy_out << 1); } /* * Allocation code for the journal file. Manage the space left in the * journal, so that we can begin checkpointing when appropriate. */ /* * Called with j_state_lock locked for writing. * Returns true if a transaction commit was started. */ static int __jbd2_log_start_commit(journal_t *journal, tid_t target) { /* Return if the txn has already requested to be committed */ if (journal->j_commit_request == target) return 0; /* * The only transaction we can possibly wait upon is the * currently running transaction (if it exists). Otherwise, * the target tid must be an old one. */ if (journal->j_running_transaction && journal->j_running_transaction->t_tid == target) { /* * We want a new commit: OK, mark the request and wakeup the * commit thread. We do _not_ do the commit ourselves. */ journal->j_commit_request = target; jbd2_debug(1, "JBD2: requesting commit %u/%u\n", journal->j_commit_request, journal->j_commit_sequence); journal->j_running_transaction->t_requested = jiffies; wake_up(&journal->j_wait_commit); return 1; } else if (!tid_geq(journal->j_commit_request, target)) /* This should never happen, but if it does, preserve the evidence before kjournald goes into a loop and increments j_commit_sequence beyond all recognition. */ WARN_ONCE(1, "JBD2: bad log_start_commit: %u %u %u %u\n", journal->j_commit_request, journal->j_commit_sequence, target, journal->j_running_transaction ? journal->j_running_transaction->t_tid : 0); return 0; } int jbd2_log_start_commit(journal_t *journal, tid_t tid) { int ret; write_lock(&journal->j_state_lock); ret = __jbd2_log_start_commit(journal, tid); write_unlock(&journal->j_state_lock); return ret; } /* * Force and wait any uncommitted transactions. We can only force the running * transaction if we don't have an active handle, otherwise, we will deadlock. * Returns: <0 in case of error, * 0 if nothing to commit, * 1 if transaction was successfully committed. */ static int __jbd2_journal_force_commit(journal_t *journal) { transaction_t *transaction = NULL; tid_t tid; int need_to_start = 0, ret = 0; read_lock(&journal->j_state_lock); if (journal->j_running_transaction && !current->journal_info) { transaction = journal->j_running_transaction; if (!tid_geq(journal->j_commit_request, transaction->t_tid)) need_to_start = 1; } else if (journal->j_committing_transaction) transaction = journal->j_committing_transaction; if (!transaction) { /* Nothing to commit */ read_unlock(&journal->j_state_lock); return 0; } tid = transaction->t_tid; read_unlock(&journal->j_state_lock); if (need_to_start) jbd2_log_start_commit(journal, tid); ret = jbd2_log_wait_commit(journal, tid); if (!ret) ret = 1; return ret; } /** * jbd2_journal_force_commit_nested - Force and wait upon a commit if the * calling process is not within transaction. * * @journal: journal to force * Returns true if progress was made. * * This is used for forcing out undo-protected data which contains * bitmaps, when the fs is running out of space. */ int jbd2_journal_force_commit_nested(journal_t *journal) { int ret; ret = __jbd2_journal_force_commit(journal); return ret > 0; } /** * jbd2_journal_force_commit() - force any uncommitted transactions * @journal: journal to force * * Caller want unconditional commit. We can only force the running transaction * if we don't have an active handle, otherwise, we will deadlock. */ int jbd2_journal_force_commit(journal_t *journal) { int ret; J_ASSERT(!current->journal_info); ret = __jbd2_journal_force_commit(journal); if (ret > 0) ret = 0; return ret; } /* * Start a commit of the current running transaction (if any). Returns true * if a transaction is going to be committed (or is currently already * committing), and fills its tid in at *ptid */ int jbd2_journal_start_commit(journal_t *journal, tid_t *ptid) { int ret = 0; write_lock(&journal->j_state_lock); if (journal->j_running_transaction) { tid_t tid = journal->j_running_transaction->t_tid; __jbd2_log_start_commit(journal, tid); /* There's a running transaction and we've just made sure * it's commit has been scheduled. */ if (ptid) *ptid = tid; ret = 1; } else if (journal->j_committing_transaction) { /* * If commit has been started, then we have to wait for * completion of that transaction. */ if (ptid) *ptid = journal->j_committing_transaction->t_tid; ret = 1; } write_unlock(&journal->j_state_lock); return ret; } /* * Return 1 if a given transaction has not yet sent barrier request * connected with a transaction commit. If 0 is returned, transaction * may or may not have sent the barrier. Used to avoid sending barrier * twice in common cases. */ int jbd2_trans_will_send_data_barrier(journal_t *journal, tid_t tid) { int ret = 0; transaction_t *commit_trans; if (!(journal->j_flags & JBD2_BARRIER)) return 0; read_lock(&journal->j_state_lock); /* Transaction already committed? */ if (tid_geq(journal->j_commit_sequence, tid)) goto out; commit_trans = journal->j_committing_transaction; if (!commit_trans || commit_trans->t_tid != tid) { ret = 1; goto out; } /* * Transaction is being committed and we already proceeded to * submitting a flush to fs partition? */ if (journal->j_fs_dev != journal->j_dev) { if (!commit_trans->t_need_data_flush || commit_trans->t_state >= T_COMMIT_DFLUSH) goto out; } else { if (commit_trans->t_state >= T_COMMIT_JFLUSH) goto out; } ret = 1; out: read_unlock(&journal->j_state_lock); return ret; } EXPORT_SYMBOL(jbd2_trans_will_send_data_barrier); /* * Wait for a specified commit to complete. * The caller may not hold the journal lock. */ int jbd2_log_wait_commit(journal_t *journal, tid_t tid) { int err = 0; read_lock(&journal->j_state_lock); #ifdef CONFIG_PROVE_LOCKING /* * Some callers make sure transaction is already committing and in that * case we cannot block on open handles anymore. So don't warn in that * case. */ if (tid_gt(tid, journal->j_commit_sequence) && (!journal->j_committing_transaction || journal->j_committing_transaction->t_tid != tid)) { read_unlock(&journal->j_state_lock); jbd2_might_wait_for_commit(journal); read_lock(&journal->j_state_lock); } #endif #ifdef CONFIG_JBD2_DEBUG if (!tid_geq(journal->j_commit_request, tid)) { printk(KERN_ERR "%s: error: j_commit_request=%u, tid=%u\n", __func__, journal->j_commit_request, tid); } #endif while (tid_gt(tid, journal->j_commit_sequence)) { jbd2_debug(1, "JBD2: want %u, j_commit_sequence=%u\n", tid, journal->j_commit_sequence); read_unlock(&journal->j_state_lock); wake_up(&journal->j_wait_commit); wait_event(journal->j_wait_done_commit, !tid_gt(tid, journal->j_commit_sequence)); read_lock(&journal->j_state_lock); } read_unlock(&journal->j_state_lock); if (unlikely(is_journal_aborted(journal))) err = -EIO; return err; } /* * Start a fast commit. If there's an ongoing fast or full commit wait for * it to complete. Returns 0 if a new fast commit was started. Returns -EALREADY * if a fast commit is not needed, either because there's an already a commit * going on or this tid has already been committed. Returns -EINVAL if no jbd2 * commit has yet been performed. */ int jbd2_fc_begin_commit(journal_t *journal, tid_t tid) { if (unlikely(is_journal_aborted(journal))) return -EIO; /* * Fast commits only allowed if at least one full commit has * been processed. */ if (!journal->j_stats.ts_tid) return -EINVAL; write_lock(&journal->j_state_lock); if (tid <= journal->j_commit_sequence) { write_unlock(&journal->j_state_lock); return -EALREADY; } if (journal->j_flags & JBD2_FULL_COMMIT_ONGOING || (journal->j_flags & JBD2_FAST_COMMIT_ONGOING)) { DEFINE_WAIT(wait); prepare_to_wait(&journal->j_fc_wait, &wait, TASK_UNINTERRUPTIBLE); write_unlock(&journal->j_state_lock); schedule(); finish_wait(&journal->j_fc_wait, &wait); return -EALREADY; } journal->j_flags |= JBD2_FAST_COMMIT_ONGOING; write_unlock(&journal->j_state_lock); jbd2_journal_lock_updates(journal); return 0; } EXPORT_SYMBOL(jbd2_fc_begin_commit); /* * Stop a fast commit. If fallback is set, this function starts commit of * TID tid before any other fast commit can start. */ static int __jbd2_fc_end_commit(journal_t *journal, tid_t tid, bool fallback) { jbd2_journal_unlock_updates(journal); if (journal->j_fc_cleanup_callback) journal->j_fc_cleanup_callback(journal, 0, tid); write_lock(&journal->j_state_lock); journal->j_flags &= ~JBD2_FAST_COMMIT_ONGOING; if (fallback) journal->j_flags |= JBD2_FULL_COMMIT_ONGOING; write_unlock(&journal->j_state_lock); wake_up(&journal->j_fc_wait); if (fallback) return jbd2_complete_transaction(journal, tid); return 0; } int jbd2_fc_end_commit(journal_t *journal) { return __jbd2_fc_end_commit(journal, 0, false); } EXPORT_SYMBOL(jbd2_fc_end_commit); int jbd2_fc_end_commit_fallback(journal_t *journal) { tid_t tid; read_lock(&journal->j_state_lock); tid = journal->j_running_transaction ? journal->j_running_transaction->t_tid : 0; read_unlock(&journal->j_state_lock); return __jbd2_fc_end_commit(journal, tid, true); } EXPORT_SYMBOL(jbd2_fc_end_commit_fallback); /* Return 1 when transaction with given tid has already committed. */ int jbd2_transaction_committed(journal_t *journal, tid_t tid) { int ret = 1; read_lock(&journal->j_state_lock); if (journal->j_running_transaction && journal->j_running_transaction->t_tid == tid) ret = 0; if (journal->j_committing_transaction && journal->j_committing_transaction->t_tid == tid) ret = 0; read_unlock(&journal->j_state_lock); return ret; } EXPORT_SYMBOL(jbd2_transaction_committed); /* * When this function returns the transaction corresponding to tid * will be completed. If the transaction has currently running, start * committing that transaction before waiting for it to complete. If * the transaction id is stale, it is by definition already completed, * so just return SUCCESS. */ int jbd2_complete_transaction(journal_t *journal, tid_t tid) { int need_to_wait = 1; read_lock(&journal->j_state_lock); if (journal->j_running_transaction && journal->j_running_transaction->t_tid == tid) { if (journal->j_commit_request != tid) { /* transaction not yet started, so request it */ read_unlock(&journal->j_state_lock); jbd2_log_start_commit(journal, tid); goto wait_commit; } } else if (!(journal->j_committing_transaction && journal->j_committing_transaction->t_tid == tid)) need_to_wait = 0; read_unlock(&journal->j_state_lock); if (!need_to_wait) return 0; wait_commit: return jbd2_log_wait_commit(journal, tid); } EXPORT_SYMBOL(jbd2_complete_transaction); /* * Log buffer allocation routines: */ int jbd2_journal_next_log_block(journal_t *journal, unsigned long long *retp) { unsigned long blocknr; write_lock(&journal->j_state_lock); J_ASSERT(journal->j_free > 1); blocknr = journal->j_head; journal->j_head++; journal->j_free--; if (journal->j_head == journal->j_last) journal->j_head = journal->j_first; write_unlock(&journal->j_state_lock); return jbd2_journal_bmap(journal, blocknr, retp); } /* Map one fast commit buffer for use by the file system */ int jbd2_fc_get_buf(journal_t *journal, struct buffer_head **bh_out) { unsigned long long pblock; unsigned long blocknr; int ret = 0; struct buffer_head *bh; int fc_off; *bh_out = NULL; if (journal->j_fc_off + journal->j_fc_first < journal->j_fc_last) { fc_off = journal->j_fc_off; blocknr = journal->j_fc_first + fc_off; journal->j_fc_off++; } else { ret = -EINVAL; } if (ret) return ret; ret = jbd2_journal_bmap(journal, blocknr, &pblock); if (ret) return ret; bh = __getblk(journal->j_dev, pblock, journal->j_blocksize); if (!bh) return -ENOMEM; journal->j_fc_wbuf[fc_off] = bh; *bh_out = bh; return 0; } EXPORT_SYMBOL(jbd2_fc_get_buf); /* * Wait on fast commit buffers that were allocated by jbd2_fc_get_buf * for completion. */ int jbd2_fc_wait_bufs(journal_t *journal, int num_blks) { struct buffer_head *bh; int i, j_fc_off; j_fc_off = journal->j_fc_off; /* * Wait in reverse order to minimize chances of us being woken up before * all IOs have completed */ for (i = j_fc_off - 1; i >= j_fc_off - num_blks; i--) { bh = journal->j_fc_wbuf[i]; wait_on_buffer(bh); /* * Update j_fc_off so jbd2_fc_release_bufs can release remain * buffer head. */ if (unlikely(!buffer_uptodate(bh))) { journal->j_fc_off = i + 1; return -EIO; } put_bh(bh); journal->j_fc_wbuf[i] = NULL; } return 0; } EXPORT_SYMBOL(jbd2_fc_wait_bufs); int jbd2_fc_release_bufs(journal_t *journal) { struct buffer_head *bh; int i, j_fc_off; j_fc_off = journal->j_fc_off; for (i = j_fc_off - 1; i >= 0; i--) { bh = journal->j_fc_wbuf[i]; if (!bh) break; put_bh(bh); journal->j_fc_wbuf[i] = NULL; } return 0; } EXPORT_SYMBOL(jbd2_fc_release_bufs); /* * Conversion of logical to physical block numbers for the journal * * On external journals the journal blocks are identity-mapped, so * this is a no-op. If needed, we can use j_blk_offset - everything is * ready. */ int jbd2_journal_bmap(journal_t *journal, unsigned long blocknr, unsigned long long *retp) { int err = 0; unsigned long long ret; sector_t block = blocknr; if (journal->j_bmap) { err = journal->j_bmap(journal, &block); if (err == 0) *retp = block; } else if (journal->j_inode) { ret = bmap(journal->j_inode, &block); if (ret || !block) { printk(KERN_ALERT "%s: journal block not found " "at offset %lu on %s\n", __func__, blocknr, journal->j_devname); err = -EIO; jbd2_journal_abort(journal, err); } else { *retp = block; } } else { *retp = blocknr; /* +journal->j_blk_offset */ } return err; } /* * We play buffer_head aliasing tricks to write data/metadata blocks to * the journal without copying their contents, but for journal * descriptor blocks we do need to generate bona fide buffers. * * After the caller of jbd2_journal_get_descriptor_buffer() has finished modifying * the buffer's contents they really should run flush_dcache_page(bh->b_page). * But we don't bother doing that, so there will be coherency problems with * mmaps of blockdevs which hold live JBD-controlled filesystems. */ struct buffer_head * jbd2_journal_get_descriptor_buffer(transaction_t *transaction, int type) { journal_t *journal = transaction->t_journal; struct buffer_head *bh; unsigned long long blocknr; journal_header_t *header; int err; err = jbd2_journal_next_log_block(journal, &blocknr); if (err) return NULL; bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize); if (!bh) return NULL; atomic_dec(&transaction->t_outstanding_credits); lock_buffer(bh); memset(bh->b_data, 0, journal->j_blocksize); header = (journal_header_t *)bh->b_data; header->h_magic = cpu_to_be32(JBD2_MAGIC_NUMBER); header->h_blocktype = cpu_to_be32(type); header->h_sequence = cpu_to_be32(transaction->t_tid); set_buffer_uptodate(bh); unlock_buffer(bh); BUFFER_TRACE(bh, "return this buffer"); return bh; } void jbd2_descriptor_block_csum_set(journal_t *j, struct buffer_head *bh) { struct jbd2_journal_block_tail *tail; __u32 csum; if (!jbd2_journal_has_csum_v2or3(j)) return; tail = (struct jbd2_journal_block_tail *)(bh->b_data + j->j_blocksize - sizeof(struct jbd2_journal_block_tail)); tail->t_checksum = 0; csum = jbd2_chksum(j, j->j_csum_seed, bh->b_data, j->j_blocksize); tail->t_checksum = cpu_to_be32(csum); } /* * Return tid of the oldest transaction in the journal and block in the journal * where the transaction starts. * * If the journal is now empty, return which will be the next transaction ID * we will write and where will that transaction start. * * The return value is 0 if journal tail cannot be pushed any further, 1 if * it can. */ int jbd2_journal_get_log_tail(journal_t *journal, tid_t *tid, unsigned long *block) { transaction_t *transaction; int ret; read_lock(&journal->j_state_lock); spin_lock(&journal->j_list_lock); transaction = journal->j_checkpoint_transactions; if (transaction) { *tid = transaction->t_tid; *block = transaction->t_log_start; } else if ((transaction = journal->j_committing_transaction) != NULL) { *tid = transaction->t_tid; *block = transaction->t_log_start; } else if ((transaction = journal->j_running_transaction) != NULL) { *tid = transaction->t_tid; *block = journal->j_head; } else { *tid = journal->j_transaction_sequence; *block = journal->j_head; } ret = tid_gt(*tid, journal->j_tail_sequence); spin_unlock(&journal->j_list_lock); read_unlock(&journal->j_state_lock); return ret; } /* * Update information in journal structure and in on disk journal superblock * about log tail. This function does not check whether information passed in * really pushes log tail further. It's responsibility of the caller to make * sure provided log tail information is valid (e.g. by holding * j_checkpoint_mutex all the time between computing log tail and calling this * function as is the case with jbd2_cleanup_journal_tail()). * * Requires j_checkpoint_mutex */ int __jbd2_update_log_tail(journal_t *journal, tid_t tid, unsigned long block) { unsigned long freed; int ret; BUG_ON(!mutex_is_locked(&journal->j_checkpoint_mutex)); /* * We cannot afford for write to remain in drive's caches since as * soon as we update j_tail, next transaction can start reusing journal * space and if we lose sb update during power failure we'd replay * old transaction with possibly newly overwritten data. */ ret = jbd2_journal_update_sb_log_tail(journal, tid, block, REQ_FUA); if (ret) goto out; write_lock(&journal->j_state_lock); freed = block - journal->j_tail; if (block < journal->j_tail) freed += journal->j_last - journal->j_first; trace_jbd2_update_log_tail(journal, tid, block, freed); jbd2_debug(1, "Cleaning journal tail from %u to %u (offset %lu), " "freeing %lu\n", journal->j_tail_sequence, tid, block, freed); journal->j_free += freed; journal->j_tail_sequence = tid; journal->j_tail = block; write_unlock(&journal->j_state_lock); out: return ret; } /* * This is a variation of __jbd2_update_log_tail which checks for validity of * provided log tail and locks j_checkpoint_mutex. So it is safe against races * with other threads updating log tail. */ void jbd2_update_log_tail(journal_t *journal, tid_t tid, unsigned long block) { mutex_lock_io(&journal->j_checkpoint_mutex); if (tid_gt(tid, journal->j_tail_sequence)) __jbd2_update_log_tail(journal, tid, block); mutex_unlock(&journal->j_checkpoint_mutex); } struct jbd2_stats_proc_session { journal_t *journal; struct transaction_stats_s *stats; int start; int max; }; static void *jbd2_seq_info_start(struct seq_file *seq, loff_t *pos) { return *pos ? NULL : SEQ_START_TOKEN; } static void *jbd2_seq_info_next(struct seq_file *seq, void *v, loff_t *pos) { (*pos)++; return NULL; } static int jbd2_seq_info_show(struct seq_file *seq, void *v) { struct jbd2_stats_proc_session *s = seq->private; if (v != SEQ_START_TOKEN) return 0; seq_printf(seq, "%lu transactions (%lu requested), " "each up to %u blocks\n", s->stats->ts_tid, s->stats->ts_requested, s->journal->j_max_transaction_buffers); if (s->stats->ts_tid == 0) return 0; seq_printf(seq, "average: \n %ums waiting for transaction\n", jiffies_to_msecs(s->stats->run.rs_wait / s->stats->ts_tid)); seq_printf(seq, " %ums request delay\n", (s->stats->ts_requested == 0) ? 0 : jiffies_to_msecs(s->stats->run.rs_request_delay / s->stats->ts_requested)); seq_printf(seq, " %ums running transaction\n", jiffies_to_msecs(s->stats->run.rs_running / s->stats->ts_tid)); seq_printf(seq, " %ums transaction was being locked\n", jiffies_to_msecs(s->stats->run.rs_locked / s->stats->ts_tid)); seq_printf(seq, " %ums flushing data (in ordered mode)\n", jiffies_to_msecs(s->stats->run.rs_flushing / s->stats->ts_tid)); seq_printf(seq, " %ums logging transaction\n", jiffies_to_msecs(s->stats->run.rs_logging / s->stats->ts_tid)); seq_printf(seq, " %lluus average transaction commit time\n", div_u64(s->journal->j_average_commit_time, 1000)); seq_printf(seq, " %lu handles per transaction\n", s->stats->run.rs_handle_count / s->stats->ts_tid); seq_printf(seq, " %lu blocks per transaction\n", s->stats->run.rs_blocks / s->stats->ts_tid); seq_printf(seq, " %lu logged blocks per transaction\n", s->stats->run.rs_blocks_logged / s->stats->ts_tid); return 0; } static void jbd2_seq_info_stop(struct seq_file *seq, void *v) { } static const struct seq_operations jbd2_seq_info_ops = { .start = jbd2_seq_info_start, .next = jbd2_seq_info_next, .stop = jbd2_seq_info_stop, .show = jbd2_seq_info_show, }; static int jbd2_seq_info_open(struct inode *inode, struct file *file) { journal_t *journal = pde_data(inode); struct jbd2_stats_proc_session *s; int rc, size; s = kmalloc(sizeof(*s), GFP_KERNEL); if (s == NULL) return -ENOMEM; size = sizeof(struct transaction_stats_s); s->stats = kmalloc(size, GFP_KERNEL); if (s->stats == NULL) { kfree(s); return -ENOMEM; } spin_lock(&journal->j_history_lock); memcpy(s->stats, &journal->j_stats, size); s->journal = journal; spin_unlock(&journal->j_history_lock); rc = seq_open(file, &jbd2_seq_info_ops); if (rc == 0) { struct seq_file *m = file->private_data; m->private = s; } else { kfree(s->stats); kfree(s); } return rc; } static int jbd2_seq_info_release(struct inode *inode, struct file *file) { struct seq_file *seq = file->private_data; struct jbd2_stats_proc_session *s = seq->private; kfree(s->stats); kfree(s); return seq_release(inode, file); } static const struct proc_ops jbd2_info_proc_ops = { .proc_open = jbd2_seq_info_open, .proc_read = seq_read, .proc_lseek = seq_lseek, .proc_release = jbd2_seq_info_release, }; static struct proc_dir_entry *proc_jbd2_stats; static void jbd2_stats_proc_init(journal_t *journal) { journal->j_proc_entry = proc_mkdir(journal->j_devname, proc_jbd2_stats); if (journal->j_proc_entry) { proc_create_data("info", S_IRUGO, journal->j_proc_entry, &jbd2_info_proc_ops, journal); } } static void jbd2_stats_proc_exit(journal_t *journal) { remove_proc_entry("info", journal->j_proc_entry); remove_proc_entry(journal->j_devname, proc_jbd2_stats); } /* Minimum size of descriptor tag */ static int jbd2_min_tag_size(void) { /* * Tag with 32-bit block numbers does not use last four bytes of the * structure */ return sizeof(journal_block_tag_t) - 4; } /** * jbd2_journal_shrink_scan() * @shrink: shrinker to work on * @sc: reclaim request to process * * Scan the checkpointed buffer on the checkpoint list and release the * journal_head. */ static unsigned long jbd2_journal_shrink_scan(struct shrinker *shrink, struct shrink_control *sc) { journal_t *journal = shrink->private_data; unsigned long nr_to_scan = sc->nr_to_scan; unsigned long nr_shrunk; unsigned long count; count = percpu_counter_read_positive(&journal->j_checkpoint_jh_count); trace_jbd2_shrink_scan_enter(journal, sc->nr_to_scan, count); nr_shrunk = jbd2_journal_shrink_checkpoint_list(journal, &nr_to_scan); count = percpu_counter_read_positive(&journal->j_checkpoint_jh_count); trace_jbd2_shrink_scan_exit(journal, nr_to_scan, nr_shrunk, count); return nr_shrunk; } /** * jbd2_journal_shrink_count() * @shrink: shrinker to work on * @sc: reclaim request to process * * Count the number of checkpoint buffers on the checkpoint list. */ static unsigned long jbd2_journal_shrink_count(struct shrinker *shrink, struct shrink_control *sc) { journal_t *journal = shrink->private_data; unsigned long count; count = percpu_counter_read_positive(&journal->j_checkpoint_jh_count); trace_jbd2_shrink_count(journal, sc->nr_to_scan, count); return count; } /* * If the journal init or create aborts, we need to mark the journal * superblock as being NULL to prevent the journal destroy from writing * back a bogus superblock. */ static void journal_fail_superblock(journal_t *journal) { struct buffer_head *bh = journal->j_sb_buffer; brelse(bh); journal->j_sb_buffer = NULL; } /* * Check the superblock for a given journal, performing initial * validation of the format. */ static int journal_check_superblock(journal_t *journal) { journal_superblock_t *sb = journal->j_superblock; int num_fc_blks; int err = -EINVAL; if (sb->s_header.h_magic != cpu_to_be32(JBD2_MAGIC_NUMBER) || sb->s_blocksize != cpu_to_be32(journal->j_blocksize)) { printk(KERN_WARNING "JBD2: no valid journal superblock found\n"); return err; } if (be32_to_cpu(sb->s_header.h_blocktype) != JBD2_SUPERBLOCK_V1 && be32_to_cpu(sb->s_header.h_blocktype) != JBD2_SUPERBLOCK_V2) { printk(KERN_WARNING "JBD2: unrecognised superblock format ID\n"); return err; } if (be32_to_cpu(sb->s_maxlen) > journal->j_total_len) { printk(KERN_WARNING "JBD2: journal file too short\n"); return err; } if (be32_to_cpu(sb->s_first) == 0 || be32_to_cpu(sb->s_first) >= journal->j_total_len) { printk(KERN_WARNING "JBD2: Invalid start block of journal: %u\n", be32_to_cpu(sb->s_first)); return err; } /* * If this is a V2 superblock, then we have to check the * features flags on it. */ if (!jbd2_format_support_feature(journal)) return 0; if ((sb->s_feature_ro_compat & ~cpu_to_be32(JBD2_KNOWN_ROCOMPAT_FEATURES)) || (sb->s_feature_incompat & ~cpu_to_be32(JBD2_KNOWN_INCOMPAT_FEATURES))) { printk(KERN_WARNING "JBD2: Unrecognised features on journal\n"); return err; } num_fc_blks = jbd2_has_feature_fast_commit(journal) ? jbd2_journal_get_num_fc_blks(sb) : 0; if (be32_to_cpu(sb->s_maxlen) < JBD2_MIN_JOURNAL_BLOCKS || be32_to_cpu(sb->s_maxlen) - JBD2_MIN_JOURNAL_BLOCKS < num_fc_blks) { printk(KERN_ERR "JBD2: journal file too short %u,%d\n", be32_to_cpu(sb->s_maxlen), num_fc_blks); return err; } if (jbd2_has_feature_csum2(journal) && jbd2_has_feature_csum3(journal)) { /* Can't have checksum v2 and v3 at the same time! */ printk(KERN_ERR "JBD2: Can't enable checksumming v2 and v3 " "at the same time!\n"); return err; } if (jbd2_journal_has_csum_v2or3_feature(journal) && jbd2_has_feature_checksum(journal)) { /* Can't have checksum v1 and v2 on at the same time! */ printk(KERN_ERR "JBD2: Can't enable checksumming v1 and v2/3 " "at the same time!\n"); return err; } /* Load the checksum driver */ if (jbd2_journal_has_csum_v2or3_feature(journal)) { if (sb->s_checksum_type != JBD2_CRC32C_CHKSUM) { printk(KERN_ERR "JBD2: Unknown checksum type\n"); return err; } journal->j_chksum_driver = crypto_alloc_shash("crc32c", 0, 0); if (IS_ERR(journal->j_chksum_driver)) { printk(KERN_ERR "JBD2: Cannot load crc32c driver.\n"); err = PTR_ERR(journal->j_chksum_driver); journal->j_chksum_driver = NULL; return err; } /* Check superblock checksum */ if (sb->s_checksum != jbd2_superblock_csum(journal, sb)) { printk(KERN_ERR "JBD2: journal checksum error\n"); err = -EFSBADCRC; return err; } } return 0; } static int journal_revoke_records_per_block(journal_t *journal) { int record_size; int space = journal->j_blocksize - sizeof(jbd2_journal_revoke_header_t); if (jbd2_has_feature_64bit(journal)) record_size = 8; else record_size = 4; if (jbd2_journal_has_csum_v2or3(journal)) space -= sizeof(struct jbd2_journal_block_tail); return space / record_size; } /* * Load the on-disk journal superblock and read the key fields into the * journal_t. */ static int journal_load_superblock(journal_t *journal) { int err; struct buffer_head *bh; journal_superblock_t *sb; bh = getblk_unmovable(journal->j_dev, journal->j_blk_offset, journal->j_blocksize); if (bh) err = bh_read(bh, 0); if (!bh || err < 0) { pr_err("%s: Cannot read journal superblock\n", __func__); brelse(bh); return -EIO; } journal->j_sb_buffer = bh; sb = (journal_superblock_t *)bh->b_data; journal->j_superblock = sb; err = journal_check_superblock(journal); if (err) { journal_fail_superblock(journal); return err; } journal->j_tail_sequence = be32_to_cpu(sb->s_sequence); journal->j_tail = be32_to_cpu(sb->s_start); journal->j_first = be32_to_cpu(sb->s_first); journal->j_errno = be32_to_cpu(sb->s_errno); journal->j_last = be32_to_cpu(sb->s_maxlen); if (be32_to_cpu(sb->s_maxlen) < journal->j_total_len) journal->j_total_len = be32_to_cpu(sb->s_maxlen); /* Precompute checksum seed for all metadata */ if (jbd2_journal_has_csum_v2or3(journal)) journal->j_csum_seed = jbd2_chksum(journal, ~0, sb->s_uuid, sizeof(sb->s_uuid)); journal->j_revoke_records_per_block = journal_revoke_records_per_block(journal); if (jbd2_has_feature_fast_commit(journal)) { journal->j_fc_last = be32_to_cpu(sb->s_maxlen); journal->j_last = journal->j_fc_last - jbd2_journal_get_num_fc_blks(sb); journal->j_fc_first = journal->j_last + 1; journal->j_fc_off = 0; } return 0; } /* * Management for journal control blocks: functions to create and * destroy journal_t structures, and to initialise and read existing * journal blocks from disk. */ /* First: create and setup a journal_t object in memory. We initialise * very few fields yet: that has to wait until we have created the * journal structures from from scratch, or loaded them from disk. */ static journal_t *journal_init_common(struct block_device *bdev, struct block_device *fs_dev, unsigned long long start, int len, int blocksize) { static struct lock_class_key jbd2_trans_commit_key; journal_t *journal; int err; int n; journal = kzalloc(sizeof(*journal), GFP_KERNEL); if (!journal) return ERR_PTR(-ENOMEM); journal->j_blocksize = blocksize; journal->j_dev = bdev; journal->j_fs_dev = fs_dev; journal->j_blk_offset = start; journal->j_total_len = len; err = journal_load_superblock(journal); if (err) goto err_cleanup; init_waitqueue_head(&journal->j_wait_transaction_locked); init_waitqueue_head(&journal->j_wait_done_commit); init_waitqueue_head(&journal->j_wait_commit); init_waitqueue_head(&journal->j_wait_updates); init_waitqueue_head(&journal->j_wait_reserved); init_waitqueue_head(&journal->j_fc_wait); mutex_init(&journal->j_abort_mutex); mutex_init(&journal->j_barrier); mutex_init(&journal->j_checkpoint_mutex); spin_lock_init(&journal->j_revoke_lock); spin_lock_init(&journal->j_list_lock); spin_lock_init(&journal->j_history_lock); rwlock_init(&journal->j_state_lock); journal->j_commit_interval = (HZ * JBD2_DEFAULT_MAX_COMMIT_AGE); journal->j_min_batch_time = 0; journal->j_max_batch_time = 15000; /* 15ms */ atomic_set(&journal->j_reserved_credits, 0); lockdep_init_map(&journal->j_trans_commit_map, "jbd2_handle", &jbd2_trans_commit_key, 0); /* The journal is marked for error until we succeed with recovery! */ journal->j_flags = JBD2_ABORT; /* Set up a default-sized revoke table for the new mount. */ err = jbd2_journal_init_revoke(journal, JOURNAL_REVOKE_DEFAULT_HASH); if (err) goto err_cleanup; /* * journal descriptor can store up to n blocks, we need enough * buffers to write out full descriptor block. */ err = -ENOMEM; n = journal->j_blocksize / jbd2_min_tag_size(); journal->j_wbufsize = n; journal->j_fc_wbuf = NULL; journal->j_wbuf = kmalloc_array(n, sizeof(struct buffer_head *), GFP_KERNEL); if (!journal->j_wbuf) goto err_cleanup; err = percpu_counter_init(&journal->j_checkpoint_jh_count, 0, GFP_KERNEL); if (err) goto err_cleanup; journal->j_shrink_transaction = NULL; journal->j_shrinker = shrinker_alloc(0, "jbd2-journal:(%u:%u)", MAJOR(bdev->bd_dev), MINOR(bdev->bd_dev)); if (!journal->j_shrinker) { err = -ENOMEM; goto err_cleanup; } journal->j_shrinker->scan_objects = jbd2_journal_shrink_scan; journal->j_shrinker->count_objects = jbd2_journal_shrink_count; journal->j_shrinker->batch = journal->j_max_transaction_buffers; journal->j_shrinker->private_data = journal; shrinker_register(journal->j_shrinker); return journal; err_cleanup: percpu_counter_destroy(&journal->j_checkpoint_jh_count); if (journal->j_chksum_driver) crypto_free_shash(journal->j_chksum_driver); kfree(journal->j_wbuf); jbd2_journal_destroy_revoke(journal); journal_fail_superblock(journal); kfree(journal); return ERR_PTR(err); } /* jbd2_journal_init_dev and jbd2_journal_init_inode: * * Create a journal structure assigned some fixed set of disk blocks to * the journal. We don't actually touch those disk blocks yet, but we * need to set up all of the mapping information to tell the journaling * system where the journal blocks are. * */ /** * journal_t * jbd2_journal_init_dev() - creates and initialises a journal structure * @bdev: Block device on which to create the journal * @fs_dev: Device which hold journalled filesystem for this journal. * @start: Block nr Start of journal. * @len: Length of the journal in blocks. * @blocksize: blocksize of journalling device * * Returns: a newly created journal_t * * * jbd2_journal_init_dev creates a journal which maps a fixed contiguous * range of blocks on an arbitrary block device. * */ journal_t *jbd2_journal_init_dev(struct block_device *bdev, struct block_device *fs_dev, unsigned long long start, int len, int blocksize) { journal_t *journal; journal = journal_init_common(bdev, fs_dev, start, len, blocksize); if (IS_ERR(journal)) return ERR_CAST(journal); snprintf(journal->j_devname, sizeof(journal->j_devname), "%pg", journal->j_dev); strreplace(journal->j_devname, '/', '!'); jbd2_stats_proc_init(journal); return journal; } /** * journal_t * jbd2_journal_init_inode () - creates a journal which maps to a inode. * @inode: An inode to create the journal in * * jbd2_journal_init_inode creates a journal which maps an on-disk inode as * the journal. The inode must exist already, must support bmap() and * must have all data blocks preallocated. */ journal_t *jbd2_journal_init_inode(struct inode *inode) { journal_t *journal; sector_t blocknr; int err = 0; blocknr = 0; err = bmap(inode, &blocknr); if (err || !blocknr) { pr_err("%s: Cannot locate journal superblock\n", __func__); return err ? ERR_PTR(err) : ERR_PTR(-EINVAL); } jbd2_debug(1, "JBD2: inode %s/%ld, size %lld, bits %d, blksize %ld\n", inode->i_sb->s_id, inode->i_ino, (long long) inode->i_size, inode->i_sb->s_blocksize_bits, inode->i_sb->s_blocksize); journal = journal_init_common(inode->i_sb->s_bdev, inode->i_sb->s_bdev, blocknr, inode->i_size >> inode->i_sb->s_blocksize_bits, inode->i_sb->s_blocksize); if (IS_ERR(journal)) return ERR_CAST(journal); journal->j_inode = inode; snprintf(journal->j_devname, sizeof(journal->j_devname), "%pg-%lu", journal->j_dev, journal->j_inode->i_ino); strreplace(journal->j_devname, '/', '!'); jbd2_stats_proc_init(journal); return journal; } /* * Given a journal_t structure, initialise the various fields for * startup of a new journaling session. We use this both when creating * a journal, and after recovering an old journal to reset it for * subsequent use. */ static int journal_reset(journal_t *journal) { journal_superblock_t *sb = journal->j_superblock; unsigned long long first, last; first = be32_to_cpu(sb->s_first); last = be32_to_cpu(sb->s_maxlen); if (first + JBD2_MIN_JOURNAL_BLOCKS > last + 1) { printk(KERN_ERR "JBD2: Journal too short (blocks %llu-%llu).\n", first, last); journal_fail_superblock(journal); return -EINVAL; } journal->j_first = first; journal->j_last = last; if (journal->j_head != 0 && journal->j_flags & JBD2_CYCLE_RECORD) { /* * Disable the cycled recording mode if the journal head block * number is not correct. */ if (journal->j_head < first || journal->j_head >= last) { printk(KERN_WARNING "JBD2: Incorrect Journal head block %lu, " "disable journal_cycle_record\n", journal->j_head); journal->j_head = journal->j_first; } } else { journal->j_head = journal->j_first; } journal->j_tail = journal->j_head; journal->j_free = journal->j_last - journal->j_first; journal->j_tail_sequence = journal->j_transaction_sequence; journal->j_commit_sequence = journal->j_transaction_sequence - 1; journal->j_commit_request = journal->j_commit_sequence; journal->j_max_transaction_buffers = jbd2_journal_get_max_txn_bufs(journal); /* * Now that journal recovery is done, turn fast commits off here. This * way, if fast commit was enabled before the crash but if now FS has * disabled it, we don't enable fast commits. */ jbd2_clear_feature_fast_commit(journal); /* * As a special case, if the on-disk copy is already marked as needing * no recovery (s_start == 0), then we can safely defer the superblock * update until the next commit by setting JBD2_FLUSHED. This avoids * attempting a write to a potential-readonly device. */ if (sb->s_start == 0) { jbd2_debug(1, "JBD2: Skipping superblock update on recovered sb " "(start %ld, seq %u, errno %d)\n", journal->j_tail, journal->j_tail_sequence, journal->j_errno); journal->j_flags |= JBD2_FLUSHED; } else { /* Lock here to make assertions happy... */ mutex_lock_io(&journal->j_checkpoint_mutex); /* * Update log tail information. We use REQ_FUA since new * transaction will start reusing journal space and so we * must make sure information about current log tail is on * disk before that. */ jbd2_journal_update_sb_log_tail(journal, journal->j_tail_sequence, journal->j_tail, REQ_FUA); mutex_unlock(&journal->j_checkpoint_mutex); } return jbd2_journal_start_thread(journal); } /* * This function expects that the caller will have locked the journal * buffer head, and will return with it unlocked */ static int jbd2_write_superblock(journal_t *journal, blk_opf_t write_flags) { struct buffer_head *bh = journal->j_sb_buffer; journal_superblock_t *sb = journal->j_superblock; int ret = 0; /* Buffer got discarded which means block device got invalidated */ if (!buffer_mapped(bh)) { unlock_buffer(bh); return -EIO; } /* * Always set high priority flags to exempt from block layer's * QOS policies, e.g. writeback throttle. */ write_flags |= JBD2_JOURNAL_REQ_FLAGS; if (!(journal->j_flags & JBD2_BARRIER)) write_flags &= ~(REQ_FUA | REQ_PREFLUSH); trace_jbd2_write_superblock(journal, write_flags); if (buffer_write_io_error(bh)) { /* * Oh, dear. A previous attempt to write the journal * superblock failed. This could happen because the * USB device was yanked out. Or it could happen to * be a transient write error and maybe the block will * be remapped. Nothing we can do but to retry the * write and hope for the best. */ printk(KERN_ERR "JBD2: previous I/O error detected " "for journal superblock update for %s.\n", journal->j_devname); clear_buffer_write_io_error(bh); set_buffer_uptodate(bh); } if (jbd2_journal_has_csum_v2or3(journal)) sb->s_checksum = jbd2_superblock_csum(journal, sb); get_bh(bh); bh->b_end_io = end_buffer_write_sync; submit_bh(REQ_OP_WRITE | write_flags, bh); wait_on_buffer(bh); if (buffer_write_io_error(bh)) { clear_buffer_write_io_error(bh); set_buffer_uptodate(bh); ret = -EIO; } if (ret) { printk(KERN_ERR "JBD2: I/O error when updating journal superblock for %s.\n", journal->j_devname); if (!is_journal_aborted(journal)) jbd2_journal_abort(journal, ret); } return ret; } /** * jbd2_journal_update_sb_log_tail() - Update log tail in journal sb on disk. * @journal: The journal to update. * @tail_tid: TID of the new transaction at the tail of the log * @tail_block: The first block of the transaction at the tail of the log * @write_flags: Flags for the journal sb write operation * * Update a journal's superblock information about log tail and write it to * disk, waiting for the IO to complete. */ int jbd2_journal_update_sb_log_tail(journal_t *journal, tid_t tail_tid, unsigned long tail_block, blk_opf_t write_flags) { journal_superblock_t *sb = journal->j_superblock; int ret; if (is_journal_aborted(journal)) return -EIO; if (test_bit(JBD2_CHECKPOINT_IO_ERROR, &journal->j_atomic_flags)) { jbd2_journal_abort(journal, -EIO); return -EIO; } BUG_ON(!mutex_is_locked(&journal->j_checkpoint_mutex)); jbd2_debug(1, "JBD2: updating superblock (start %lu, seq %u)\n", tail_block, tail_tid); lock_buffer(journal->j_sb_buffer); sb->s_sequence = cpu_to_be32(tail_tid); sb->s_start = cpu_to_be32(tail_block); ret = jbd2_write_superblock(journal, write_flags); if (ret) goto out; /* Log is no longer empty */ write_lock(&journal->j_state_lock); WARN_ON(!sb->s_sequence); journal->j_flags &= ~JBD2_FLUSHED; write_unlock(&journal->j_state_lock); out: return ret; } /** * jbd2_mark_journal_empty() - Mark on disk journal as empty. * @journal: The journal to update. * @write_flags: Flags for the journal sb write operation * * Update a journal's dynamic superblock fields to show that journal is empty. * Write updated superblock to disk waiting for IO to complete. */ static void jbd2_mark_journal_empty(journal_t *journal, blk_opf_t write_flags) { journal_superblock_t *sb = journal->j_superblock; bool had_fast_commit = false; BUG_ON(!mutex_is_locked(&journal->j_checkpoint_mutex)); lock_buffer(journal->j_sb_buffer); if (sb->s_start == 0) { /* Is it already empty? */ unlock_buffer(journal->j_sb_buffer); return; } jbd2_debug(1, "JBD2: Marking journal as empty (seq %u)\n", journal->j_tail_sequence); sb->s_sequence = cpu_to_be32(journal->j_tail_sequence); sb->s_start = cpu_to_be32(0); sb->s_head = cpu_to_be32(journal->j_head); if (jbd2_has_feature_fast_commit(journal)) { /* * When journal is clean, no need to commit fast commit flag and * make file system incompatible with older kernels. */ jbd2_clear_feature_fast_commit(journal); had_fast_commit = true; } jbd2_write_superblock(journal, write_flags); if (had_fast_commit) jbd2_set_feature_fast_commit(journal); /* Log is no longer empty */ write_lock(&journal->j_state_lock); journal->j_flags |= JBD2_FLUSHED; write_unlock(&journal->j_state_lock); } /** * __jbd2_journal_erase() - Discard or zeroout journal blocks (excluding superblock) * @journal: The journal to erase. * @flags: A discard/zeroout request is sent for each physically contigous * region of the journal. Either JBD2_JOURNAL_FLUSH_DISCARD or * JBD2_JOURNAL_FLUSH_ZEROOUT must be set to determine which operation * to perform. * * Note: JBD2_JOURNAL_FLUSH_ZEROOUT attempts to use hardware offload. Zeroes * will be explicitly written if no hardware offload is available, see * blkdev_issue_zeroout for more details. */ static int __jbd2_journal_erase(journal_t *journal, unsigned int flags) { int err = 0; unsigned long block, log_offset; /* logical */ unsigned long long phys_block, block_start, block_stop; /* physical */ loff_t byte_start, byte_stop, byte_count; /* flags must be set to either discard or zeroout */ if ((flags & ~JBD2_JOURNAL_FLUSH_VALID) || !flags || ((flags & JBD2_JOURNAL_FLUSH_DISCARD) && (flags & JBD2_JOURNAL_FLUSH_ZEROOUT))) return -EINVAL; if ((flags & JBD2_JOURNAL_FLUSH_DISCARD) && !bdev_max_discard_sectors(journal->j_dev)) return -EOPNOTSUPP; /* * lookup block mapping and issue discard/zeroout for each * contiguous region */ log_offset = be32_to_cpu(journal->j_superblock->s_first); block_start = ~0ULL; for (block = log_offset; block < journal->j_total_len; block++) { err = jbd2_journal_bmap(journal, block, &phys_block); if (err) { pr_err("JBD2: bad block at offset %lu", block); return err; } if (block_start == ~0ULL) { block_start = phys_block; block_stop = block_start - 1; } /* * last block not contiguous with current block, * process last contiguous region and return to this block on * next loop */ if (phys_block != block_stop + 1) { block--; } else { block_stop++; /* * if this isn't the last block of journal, * no need to process now because next block may also * be part of this contiguous region */ if (block != journal->j_total_len - 1) continue; } /* * end of contiguous region or this is last block of journal, * take care of the region */ byte_start = block_start * journal->j_blocksize; byte_stop = block_stop * journal->j_blocksize; byte_count = (block_stop - block_start + 1) * journal->j_blocksize; truncate_inode_pages_range(journal->j_dev->bd_inode->i_mapping, byte_start, byte_stop); if (flags & JBD2_JOURNAL_FLUSH_DISCARD) { err = blkdev_issue_discard(journal->j_dev, byte_start >> SECTOR_SHIFT, byte_count >> SECTOR_SHIFT, GFP_NOFS); } else if (flags & JBD2_JOURNAL_FLUSH_ZEROOUT) { err = blkdev_issue_zeroout(journal->j_dev, byte_start >> SECTOR_SHIFT, byte_count >> SECTOR_SHIFT, GFP_NOFS, 0); } if (unlikely(err != 0)) { pr_err("JBD2: (error %d) unable to wipe journal at physical blocks %llu - %llu", err, block_start, block_stop); return err; } /* reset start and stop after processing a region */ block_start = ~0ULL; } return blkdev_issue_flush(journal->j_dev); } /** * jbd2_journal_update_sb_errno() - Update error in the journal. * @journal: The journal to update. * * Update a journal's errno. Write updated superblock to disk waiting for IO * to complete. */ void jbd2_journal_update_sb_errno(journal_t *journal) { journal_superblock_t *sb = journal->j_superblock; int errcode; lock_buffer(journal->j_sb_buffer); errcode = journal->j_errno; if (errcode == -ESHUTDOWN) errcode = 0; jbd2_debug(1, "JBD2: updating superblock error (errno %d)\n", errcode); sb->s_errno = cpu_to_be32(errcode); jbd2_write_superblock(journal, REQ_FUA); } EXPORT_SYMBOL(jbd2_journal_update_sb_errno); /** * jbd2_journal_load() - Read journal from disk. * @journal: Journal to act on. * * Given a journal_t structure which tells us which disk blocks contain * a journal, read the journal from disk to initialise the in-memory * structures. */ int jbd2_journal_load(journal_t *journal) { int err; journal_superblock_t *sb = journal->j_superblock; /* * Create a slab for this blocksize */ err = jbd2_journal_create_slab(be32_to_cpu(sb->s_blocksize)); if (err) return err; /* Let the recovery code check whether it needs to recover any * data from the journal. */ err = jbd2_journal_recover(journal); if (err) { pr_warn("JBD2: journal recovery failed\n"); return err; } if (journal->j_failed_commit) { printk(KERN_ERR "JBD2: journal transaction %u on %s " "is corrupt.\n", journal->j_failed_commit, journal->j_devname); return -EFSCORRUPTED; } /* * clear JBD2_ABORT flag initialized in journal_init_common * here to update log tail information with the newest seq. */ journal->j_flags &= ~JBD2_ABORT; /* OK, we've finished with the dynamic journal bits: * reinitialise the dynamic contents of the superblock in memory * and reset them on disk. */ err = journal_reset(journal); if (err) { pr_warn("JBD2: journal reset failed\n"); return err; } journal->j_flags |= JBD2_LOADED; return 0; } /** * jbd2_journal_destroy() - Release a journal_t structure. * @journal: Journal to act on. * * Release a journal_t structure once it is no longer in use by the * journaled object. * Return <0 if we couldn't clean up the journal. */ int jbd2_journal_destroy(journal_t *journal) { int err = 0; /* Wait for the commit thread to wake up and die. */ journal_kill_thread(journal); /* Force a final log commit */ if (journal->j_running_transaction) jbd2_journal_commit_transaction(journal); /* Force any old transactions to disk */ /* Totally anal locking here... */ spin_lock(&journal->j_list_lock); while (journal->j_checkpoint_transactions != NULL) { spin_unlock(&journal->j_list_lock); mutex_lock_io(&journal->j_checkpoint_mutex); err = jbd2_log_do_checkpoint(journal); mutex_unlock(&journal->j_checkpoint_mutex); /* * If checkpointing failed, just free the buffers to avoid * looping forever */ if (err) { jbd2_journal_destroy_checkpoint(journal); spin_lock(&journal->j_list_lock); break; } spin_lock(&journal->j_list_lock); } J_ASSERT(journal->j_running_transaction == NULL); J_ASSERT(journal->j_committing_transaction == NULL); J_ASSERT(journal->j_checkpoint_transactions == NULL); spin_unlock(&journal->j_list_lock); /* * OK, all checkpoint transactions have been checked, now check the * write out io error flag and abort the journal if some buffer failed * to write back to the original location, otherwise the filesystem * may become inconsistent. */ if (!is_journal_aborted(journal) && test_bit(JBD2_CHECKPOINT_IO_ERROR, &journal->j_atomic_flags)) jbd2_journal_abort(journal, -EIO); if (journal->j_sb_buffer) { if (!is_journal_aborted(journal)) { mutex_lock_io(&journal->j_checkpoint_mutex); write_lock(&journal->j_state_lock); journal->j_tail_sequence = ++journal->j_transaction_sequence; write_unlock(&journal->j_state_lock); jbd2_mark_journal_empty(journal, REQ_PREFLUSH | REQ_FUA); mutex_unlock(&journal->j_checkpoint_mutex); } else err = -EIO; brelse(journal->j_sb_buffer); } if (journal->j_shrinker) { percpu_counter_destroy(&journal->j_checkpoint_jh_count); shrinker_free(journal->j_shrinker); } if (journal->j_proc_entry) jbd2_stats_proc_exit(journal); iput(journal->j_inode); if (journal->j_revoke) jbd2_journal_destroy_revoke(journal); if (journal->j_chksum_driver) crypto_free_shash(journal->j_chksum_driver); kfree(journal->j_fc_wbuf); kfree(journal->j_wbuf); kfree(journal); return err; } /** * jbd2_journal_check_used_features() - Check if features specified are used. * @journal: Journal to check. * @compat: bitmask of compatible features * @ro: bitmask of features that force read-only mount * @incompat: bitmask of incompatible features * * Check whether the journal uses all of a given set of * features. Return true (non-zero) if it does. **/ int jbd2_journal_check_used_features(journal_t *journal, unsigned long compat, unsigned long ro, unsigned long incompat) { journal_superblock_t *sb; if (!compat && !ro && !incompat) return 1; if (!jbd2_format_support_feature(journal)) return 0; sb = journal->j_superblock; if (((be32_to_cpu(sb->s_feature_compat) & compat) == compat) && ((be32_to_cpu(sb->s_feature_ro_compat) & ro) == ro) && ((be32_to_cpu(sb->s_feature_incompat) & incompat) == incompat)) return 1; return 0; } /** * jbd2_journal_check_available_features() - Check feature set in journalling layer * @journal: Journal to check. * @compat: bitmask of compatible features * @ro: bitmask of features that force read-only mount * @incompat: bitmask of incompatible features * * Check whether the journaling code supports the use of * all of a given set of features on this journal. Return true * (non-zero) if it can. */ int jbd2_journal_check_available_features(journal_t *journal, unsigned long compat, unsigned long ro, unsigned long incompat) { if (!compat && !ro && !incompat) return 1; if (!jbd2_format_support_feature(journal)) return 0; if ((compat & JBD2_KNOWN_COMPAT_FEATURES) == compat && (ro & JBD2_KNOWN_ROCOMPAT_FEATURES) == ro && (incompat & JBD2_KNOWN_INCOMPAT_FEATURES) == incompat) return 1; return 0; } static int jbd2_journal_initialize_fast_commit(journal_t *journal) { journal_superblock_t *sb = journal->j_superblock; unsigned long long num_fc_blks; num_fc_blks = jbd2_journal_get_num_fc_blks(sb); if (journal->j_last - num_fc_blks < JBD2_MIN_JOURNAL_BLOCKS) return -ENOSPC; /* Are we called twice? */ WARN_ON(journal->j_fc_wbuf != NULL); journal->j_fc_wbuf = kmalloc_array(num_fc_blks, sizeof(struct buffer_head *), GFP_KERNEL); if (!journal->j_fc_wbuf) return -ENOMEM; journal->j_fc_wbufsize = num_fc_blks; journal->j_fc_last = journal->j_last; journal->j_last = journal->j_fc_last - num_fc_blks; journal->j_fc_first = journal->j_last + 1; journal->j_fc_off = 0; journal->j_free = journal->j_last - journal->j_first; journal->j_max_transaction_buffers = jbd2_journal_get_max_txn_bufs(journal); return 0; } /** * jbd2_journal_set_features() - Mark a given journal feature in the superblock * @journal: Journal to act on. * @compat: bitmask of compatible features * @ro: bitmask of features that force read-only mount * @incompat: bitmask of incompatible features * * Mark a given journal feature as present on the * superblock. Returns true if the requested features could be set. * */ int jbd2_journal_set_features(journal_t *journal, unsigned long compat, unsigned long ro, unsigned long incompat) { #define INCOMPAT_FEATURE_ON(f) \ ((incompat & (f)) && !(sb->s_feature_incompat & cpu_to_be32(f))) #define COMPAT_FEATURE_ON(f) \ ((compat & (f)) && !(sb->s_feature_compat & cpu_to_be32(f))) journal_superblock_t *sb; if (jbd2_journal_check_used_features(journal, compat, ro, incompat)) return 1; if (!jbd2_journal_check_available_features(journal, compat, ro, incompat)) return 0; /* If enabling v2 checksums, turn on v3 instead */ if (incompat & JBD2_FEATURE_INCOMPAT_CSUM_V2) { incompat &= ~JBD2_FEATURE_INCOMPAT_CSUM_V2; incompat |= JBD2_FEATURE_INCOMPAT_CSUM_V3; } /* Asking for checksumming v3 and v1? Only give them v3. */ if (incompat & JBD2_FEATURE_INCOMPAT_CSUM_V3 && compat & JBD2_FEATURE_COMPAT_CHECKSUM) compat &= ~JBD2_FEATURE_COMPAT_CHECKSUM; jbd2_debug(1, "Setting new features 0x%lx/0x%lx/0x%lx\n", compat, ro, incompat); sb = journal->j_superblock; if (incompat & JBD2_FEATURE_INCOMPAT_FAST_COMMIT) { if (jbd2_journal_initialize_fast_commit(journal)) { pr_err("JBD2: Cannot enable fast commits.\n"); return 0; } } /* Load the checksum driver if necessary */ if ((journal->j_chksum_driver == NULL) && INCOMPAT_FEATURE_ON(JBD2_FEATURE_INCOMPAT_CSUM_V3)) { journal->j_chksum_driver = crypto_alloc_shash("crc32c", 0, 0); if (IS_ERR(journal->j_chksum_driver)) { printk(KERN_ERR "JBD2: Cannot load crc32c driver.\n"); journal->j_chksum_driver = NULL; return 0; } /* Precompute checksum seed for all metadata */ journal->j_csum_seed = jbd2_chksum(journal, ~0, sb->s_uuid, sizeof(sb->s_uuid)); } lock_buffer(journal->j_sb_buffer); /* If enabling v3 checksums, update superblock */ if (INCOMPAT_FEATURE_ON(JBD2_FEATURE_INCOMPAT_CSUM_V3)) { sb->s_checksum_type = JBD2_CRC32C_CHKSUM; sb->s_feature_compat &= ~cpu_to_be32(JBD2_FEATURE_COMPAT_CHECKSUM); } /* If enabling v1 checksums, downgrade superblock */ if (COMPAT_FEATURE_ON(JBD2_FEATURE_COMPAT_CHECKSUM)) sb->s_feature_incompat &= ~cpu_to_be32(JBD2_FEATURE_INCOMPAT_CSUM_V2 | JBD2_FEATURE_INCOMPAT_CSUM_V3); sb->s_feature_compat |= cpu_to_be32(compat); sb->s_feature_ro_compat |= cpu_to_be32(ro); sb->s_feature_incompat |= cpu_to_be32(incompat); unlock_buffer(journal->j_sb_buffer); journal->j_revoke_records_per_block = journal_revoke_records_per_block(journal); return 1; #undef COMPAT_FEATURE_ON #undef INCOMPAT_FEATURE_ON } /* * jbd2_journal_clear_features() - Clear a given journal feature in the * superblock * @journal: Journal to act on. * @compat: bitmask of compatible features * @ro: bitmask of features that force read-only mount * @incompat: bitmask of incompatible features * * Clear a given journal feature as present on the * superblock. */ void jbd2_journal_clear_features(journal_t *journal, unsigned long compat, unsigned long ro, unsigned long incompat) { journal_superblock_t *sb; jbd2_debug(1, "Clear features 0x%lx/0x%lx/0x%lx\n", compat, ro, incompat); sb = journal->j_superblock; sb->s_feature_compat &= ~cpu_to_be32(compat); sb->s_feature_ro_compat &= ~cpu_to_be32(ro); sb->s_feature_incompat &= ~cpu_to_be32(incompat); journal->j_revoke_records_per_block = journal_revoke_records_per_block(journal); } EXPORT_SYMBOL(jbd2_journal_clear_features); /** * jbd2_journal_flush() - Flush journal * @journal: Journal to act on. * @flags: optional operation on the journal blocks after the flush (see below) * * Flush all data for a given journal to disk and empty the journal. * Filesystems can use this when remounting readonly to ensure that * recovery does not need to happen on remount. Optionally, a discard or zeroout * can be issued on the journal blocks after flushing. * * flags: * JBD2_JOURNAL_FLUSH_DISCARD: issues discards for the journal blocks * JBD2_JOURNAL_FLUSH_ZEROOUT: issues zeroouts for the journal blocks */ int jbd2_journal_flush(journal_t *journal, unsigned int flags) { int err = 0; transaction_t *transaction = NULL; write_lock(&journal->j_state_lock); /* Force everything buffered to the log... */ if (journal->j_running_transaction) { transaction = journal->j_running_transaction; __jbd2_log_start_commit(journal, transaction->t_tid); } else if (journal->j_committing_transaction) transaction = journal->j_committing_transaction; /* Wait for the log commit to complete... */ if (transaction) { tid_t tid = transaction->t_tid; write_unlock(&journal->j_state_lock); jbd2_log_wait_commit(journal, tid); } else { write_unlock(&journal->j_state_lock); } /* ...and flush everything in the log out to disk. */ spin_lock(&journal->j_list_lock); while (!err && journal->j_checkpoint_transactions != NULL) { spin_unlock(&journal->j_list_lock); mutex_lock_io(&journal->j_checkpoint_mutex); err = jbd2_log_do_checkpoint(journal); mutex_unlock(&journal->j_checkpoint_mutex); spin_lock(&journal->j_list_lock); } spin_unlock(&journal->j_list_lock); if (is_journal_aborted(journal)) return -EIO; mutex_lock_io(&journal->j_checkpoint_mutex); if (!err) { err = jbd2_cleanup_journal_tail(journal); if (err < 0) { mutex_unlock(&journal->j_checkpoint_mutex); goto out; } err = 0; } /* Finally, mark the journal as really needing no recovery. * This sets s_start==0 in the underlying superblock, which is * the magic code for a fully-recovered superblock. Any future * commits of data to the journal will restore the current * s_start value. */ jbd2_mark_journal_empty(journal, REQ_FUA); if (flags) err = __jbd2_journal_erase(journal, flags); mutex_unlock(&journal->j_checkpoint_mutex); write_lock(&journal->j_state_lock); J_ASSERT(!journal->j_running_transaction); J_ASSERT(!journal->j_committing_transaction); J_ASSERT(!journal->j_checkpoint_transactions); J_ASSERT(journal->j_head == journal->j_tail); J_ASSERT(journal->j_tail_sequence == journal->j_transaction_sequence); write_unlock(&journal->j_state_lock); out: return err; } /** * jbd2_journal_wipe() - Wipe journal contents * @journal: Journal to act on. * @write: flag (see below) * * Wipe out all of the contents of a journal, safely. This will produce * a warning if the journal contains any valid recovery information. * Must be called between journal_init_*() and jbd2_journal_load(). * * If 'write' is non-zero, then we wipe out the journal on disk; otherwise * we merely suppress recovery. */ int jbd2_journal_wipe(journal_t *journal, int write) { int err; J_ASSERT (!(journal->j_flags & JBD2_LOADED)); if (!journal->j_tail) return 0; printk(KERN_WARNING "JBD2: %s recovery information on journal\n", write ? "Clearing" : "Ignoring"); err = jbd2_journal_skip_recovery(journal); if (write) { /* Lock to make assertions happy... */ mutex_lock_io(&journal->j_checkpoint_mutex); jbd2_mark_journal_empty(journal, REQ_FUA); mutex_unlock(&journal->j_checkpoint_mutex); } return err; } /** * jbd2_journal_abort () - Shutdown the journal immediately. * @journal: the journal to shutdown. * @errno: an error number to record in the journal indicating * the reason for the shutdown. * * Perform a complete, immediate shutdown of the ENTIRE * journal (not of a single transaction). This operation cannot be * undone without closing and reopening the journal. * * The jbd2_journal_abort function is intended to support higher level error * recovery mechanisms such as the ext2/ext3 remount-readonly error * mode. * * Journal abort has very specific semantics. Any existing dirty, * unjournaled buffers in the main filesystem will still be written to * disk by bdflush, but the journaling mechanism will be suspended * immediately and no further transaction commits will be honoured. * * Any dirty, journaled buffers will be written back to disk without * hitting the journal. Atomicity cannot be guaranteed on an aborted * filesystem, but we _do_ attempt to leave as much data as possible * behind for fsck to use for cleanup. * * Any attempt to get a new transaction handle on a journal which is in * ABORT state will just result in an -EROFS error return. A * jbd2_journal_stop on an existing handle will return -EIO if we have * entered abort state during the update. * * Recursive transactions are not disturbed by journal abort until the * final jbd2_journal_stop, which will receive the -EIO error. * * Finally, the jbd2_journal_abort call allows the caller to supply an errno * which will be recorded (if possible) in the journal superblock. This * allows a client to record failure conditions in the middle of a * transaction without having to complete the transaction to record the * failure to disk. ext3_error, for example, now uses this * functionality. * */ void jbd2_journal_abort(journal_t *journal, int errno) { transaction_t *transaction; /* * Lock the aborting procedure until everything is done, this avoid * races between filesystem's error handling flow (e.g. ext4_abort()), * ensure panic after the error info is written into journal's * superblock. */ mutex_lock(&journal->j_abort_mutex); /* * ESHUTDOWN always takes precedence because a file system check * caused by any other journal abort error is not required after * a shutdown triggered. */ write_lock(&journal->j_state_lock); if (journal->j_flags & JBD2_ABORT) { int old_errno = journal->j_errno; write_unlock(&journal->j_state_lock); if (old_errno != -ESHUTDOWN && errno == -ESHUTDOWN) { journal->j_errno = errno; jbd2_journal_update_sb_errno(journal); } mutex_unlock(&journal->j_abort_mutex); return; } /* * Mark the abort as occurred and start current running transaction * to release all journaled buffer. */ pr_err("Aborting journal on device %s.\n", journal->j_devname); journal->j_flags |= JBD2_ABORT; journal->j_errno = errno; transaction = journal->j_running_transaction; if (transaction) __jbd2_log_start_commit(journal, transaction->t_tid); write_unlock(&journal->j_state_lock); /* * Record errno to the journal super block, so that fsck and jbd2 * layer could realise that a filesystem check is needed. */ jbd2_journal_update_sb_errno(journal); mutex_unlock(&journal->j_abort_mutex); } /** * jbd2_journal_errno() - returns the journal's error state. * @journal: journal to examine. * * This is the errno number set with jbd2_journal_abort(), the last * time the journal was mounted - if the journal was stopped * without calling abort this will be 0. * * If the journal has been aborted on this mount time -EROFS will * be returned. */ int jbd2_journal_errno(journal_t *journal) { int err; read_lock(&journal->j_state_lock); if (journal->j_flags & JBD2_ABORT) err = -EROFS; else err = journal->j_errno; read_unlock(&journal->j_state_lock); return err; } /** * jbd2_journal_clear_err() - clears the journal's error state * @journal: journal to act on. * * An error must be cleared or acked to take a FS out of readonly * mode. */ int jbd2_journal_clear_err(journal_t *journal) { int err = 0; write_lock(&journal->j_state_lock); if (journal->j_flags & JBD2_ABORT) err = -EROFS; else journal->j_errno = 0; write_unlock(&journal->j_state_lock); return err; } /** * jbd2_journal_ack_err() - Ack journal err. * @journal: journal to act on. * * An error must be cleared or acked to take a FS out of readonly * mode. */ void jbd2_journal_ack_err(journal_t *journal) { write_lock(&journal->j_state_lock); if (journal->j_errno) journal->j_flags |= JBD2_ACK_ERR; write_unlock(&journal->j_state_lock); } int jbd2_journal_blocks_per_page(struct inode *inode) { return 1 << (PAGE_SHIFT - inode->i_sb->s_blocksize_bits); } /* * helper functions to deal with 32 or 64bit block numbers. */ size_t journal_tag_bytes(journal_t *journal) { size_t sz; if (jbd2_has_feature_csum3(journal)) return sizeof(journal_block_tag3_t); sz = sizeof(journal_block_tag_t); if (jbd2_has_feature_csum2(journal)) sz += sizeof(__u16); if (jbd2_has_feature_64bit(journal)) return sz; else return sz - sizeof(__u32); } /* * JBD memory management * * These functions are used to allocate block-sized chunks of memory * used for making copies of buffer_head data. Very often it will be * page-sized chunks of data, but sometimes it will be in * sub-page-size chunks. (For example, 16k pages on Power systems * with a 4k block file system.) For blocks smaller than a page, we * use a SLAB allocator. There are slab caches for each block size, * which are allocated at mount time, if necessary, and we only free * (all of) the slab caches when/if the jbd2 module is unloaded. For * this reason we don't need to a mutex to protect access to * jbd2_slab[] allocating or releasing memory; only in * jbd2_journal_create_slab(). */ #define JBD2_MAX_SLABS 8 static struct kmem_cache *jbd2_slab[JBD2_MAX_SLABS]; static const char *jbd2_slab_names[JBD2_MAX_SLABS] = { "jbd2_1k", "jbd2_2k", "jbd2_4k", "jbd2_8k", "jbd2_16k", "jbd2_32k", "jbd2_64k", "jbd2_128k" }; static void jbd2_journal_destroy_slabs(void) { int i; for (i = 0; i < JBD2_MAX_SLABS; i++) { kmem_cache_destroy(jbd2_slab[i]); jbd2_slab[i] = NULL; } } static int jbd2_journal_create_slab(size_t size) { static DEFINE_MUTEX(jbd2_slab_create_mutex); int i = order_base_2(size) - 10; size_t slab_size; if (size == PAGE_SIZE) return 0; if (i >= JBD2_MAX_SLABS) return -EINVAL; if (unlikely(i < 0)) i = 0; mutex_lock(&jbd2_slab_create_mutex); if (jbd2_slab[i]) { mutex_unlock(&jbd2_slab_create_mutex); return 0; /* Already created */ } slab_size = 1 << (i+10); jbd2_slab[i] = kmem_cache_create(jbd2_slab_names[i], slab_size, slab_size, 0, NULL); mutex_unlock(&jbd2_slab_create_mutex); if (!jbd2_slab[i]) { printk(KERN_EMERG "JBD2: no memory for jbd2_slab cache\n"); return -ENOMEM; } return 0; } static struct kmem_cache *get_slab(size_t size) { int i = order_base_2(size) - 10; BUG_ON(i >= JBD2_MAX_SLABS); if (unlikely(i < 0)) i = 0; BUG_ON(jbd2_slab[i] == NULL); return jbd2_slab[i]; } void *jbd2_alloc(size_t size, gfp_t flags) { void *ptr; BUG_ON(size & (size-1)); /* Must be a power of 2 */ if (size < PAGE_SIZE) ptr = kmem_cache_alloc(get_slab(size), flags); else ptr = (void *)__get_free_pages(flags, get_order(size)); /* Check alignment; SLUB has gotten this wrong in the past, * and this can lead to user data corruption! */ BUG_ON(((unsigned long) ptr) & (size-1)); return ptr; } void jbd2_free(void *ptr, size_t size) { if (size < PAGE_SIZE) kmem_cache_free(get_slab(size), ptr); else free_pages((unsigned long)ptr, get_order(size)); }; /* * Journal_head storage management */ static struct kmem_cache *jbd2_journal_head_cache; #ifdef CONFIG_JBD2_DEBUG static atomic_t nr_journal_heads = ATOMIC_INIT(0); #endif static int __init jbd2_journal_init_journal_head_cache(void) { J_ASSERT(!jbd2_journal_head_cache); jbd2_journal_head_cache = kmem_cache_create("jbd2_journal_head", sizeof(struct journal_head), 0, /* offset */ SLAB_TEMPORARY | SLAB_TYPESAFE_BY_RCU, NULL); /* ctor */ if (!jbd2_journal_head_cache) { printk(KERN_EMERG "JBD2: no memory for journal_head cache\n"); return -ENOMEM; } return 0; } static void jbd2_journal_destroy_journal_head_cache(void) { kmem_cache_destroy(jbd2_journal_head_cache); jbd2_journal_head_cache = NULL; } /* * journal_head splicing and dicing */ static struct journal_head *journal_alloc_journal_head(void) { struct journal_head *ret; #ifdef CONFIG_JBD2_DEBUG atomic_inc(&nr_journal_heads); #endif ret = kmem_cache_zalloc(jbd2_journal_head_cache, GFP_NOFS); if (!ret) { jbd2_debug(1, "out of memory for journal_head\n"); pr_notice_ratelimited("ENOMEM in %s, retrying.\n", __func__); ret = kmem_cache_zalloc(jbd2_journal_head_cache, GFP_NOFS | __GFP_NOFAIL); } if (ret) spin_lock_init(&ret->b_state_lock); return ret; } static void journal_free_journal_head(struct journal_head *jh) { #ifdef CONFIG_JBD2_DEBUG atomic_dec(&nr_journal_heads); memset(jh, JBD2_POISON_FREE, sizeof(*jh)); #endif kmem_cache_free(jbd2_journal_head_cache, jh); } /* * A journal_head is attached to a buffer_head whenever JBD has an * interest in the buffer. * * Whenever a buffer has an attached journal_head, its ->b_state:BH_JBD bit * is set. This bit is tested in core kernel code where we need to take * JBD-specific actions. Testing the zeroness of ->b_private is not reliable * there. * * When a buffer has its BH_JBD bit set, its ->b_count is elevated by one. * * When a buffer has its BH_JBD bit set it is immune from being released by * core kernel code, mainly via ->b_count. * * A journal_head is detached from its buffer_head when the journal_head's * b_jcount reaches zero. Running transaction (b_transaction) and checkpoint * transaction (b_cp_transaction) hold their references to b_jcount. * * Various places in the kernel want to attach a journal_head to a buffer_head * _before_ attaching the journal_head to a transaction. To protect the * journal_head in this situation, jbd2_journal_add_journal_head elevates the * journal_head's b_jcount refcount by one. The caller must call * jbd2_journal_put_journal_head() to undo this. * * So the typical usage would be: * * (Attach a journal_head if needed. Increments b_jcount) * struct journal_head *jh = jbd2_journal_add_journal_head(bh); * ... * (Get another reference for transaction) * jbd2_journal_grab_journal_head(bh); * jh->b_transaction = xxx; * (Put original reference) * jbd2_journal_put_journal_head(jh); */ /* * Give a buffer_head a journal_head. * * May sleep. */ struct journal_head *jbd2_journal_add_journal_head(struct buffer_head *bh) { struct journal_head *jh; struct journal_head *new_jh = NULL; repeat: if (!buffer_jbd(bh)) new_jh = journal_alloc_journal_head(); jbd_lock_bh_journal_head(bh); if (buffer_jbd(bh)) { jh = bh2jh(bh); } else { J_ASSERT_BH(bh, (atomic_read(&bh->b_count) > 0) || (bh->b_folio && bh->b_folio->mapping)); if (!new_jh) { jbd_unlock_bh_journal_head(bh); goto repeat; } jh = new_jh; new_jh = NULL; /* We consumed it */ set_buffer_jbd(bh); bh->b_private = jh; jh->b_bh = bh; get_bh(bh); BUFFER_TRACE(bh, "added journal_head"); } jh->b_jcount++; jbd_unlock_bh_journal_head(bh); if (new_jh) journal_free_journal_head(new_jh); return bh->b_private; } /* * Grab a ref against this buffer_head's journal_head. If it ended up not * having a journal_head, return NULL */ struct journal_head *jbd2_journal_grab_journal_head(struct buffer_head *bh) { struct journal_head *jh = NULL; jbd_lock_bh_journal_head(bh); if (buffer_jbd(bh)) { jh = bh2jh(bh); jh->b_jcount++; } jbd_unlock_bh_journal_head(bh); return jh; } EXPORT_SYMBOL(jbd2_journal_grab_journal_head); static void __journal_remove_journal_head(struct buffer_head *bh) { struct journal_head *jh = bh2jh(bh); J_ASSERT_JH(jh, jh->b_transaction == NULL); J_ASSERT_JH(jh, jh->b_next_transaction == NULL); J_ASSERT_JH(jh, jh->b_cp_transaction == NULL); J_ASSERT_JH(jh, jh->b_jlist == BJ_None); J_ASSERT_BH(bh, buffer_jbd(bh)); J_ASSERT_BH(bh, jh2bh(jh) == bh); BUFFER_TRACE(bh, "remove journal_head"); /* Unlink before dropping the lock */ bh->b_private = NULL; jh->b_bh = NULL; /* debug, really */ clear_buffer_jbd(bh); } static void journal_release_journal_head(struct journal_head *jh, size_t b_size) { if (jh->b_frozen_data) { printk(KERN_WARNING "%s: freeing b_frozen_data\n", __func__); jbd2_free(jh->b_frozen_data, b_size); } if (jh->b_committed_data) { printk(KERN_WARNING "%s: freeing b_committed_data\n", __func__); jbd2_free(jh->b_committed_data, b_size); } journal_free_journal_head(jh); } /* * Drop a reference on the passed journal_head. If it fell to zero then * release the journal_head from the buffer_head. */ void jbd2_journal_put_journal_head(struct journal_head *jh) { struct buffer_head *bh = jh2bh(jh); jbd_lock_bh_journal_head(bh); J_ASSERT_JH(jh, jh->b_jcount > 0); --jh->b_jcount; if (!jh->b_jcount) { __journal_remove_journal_head(bh); jbd_unlock_bh_journal_head(bh); journal_release_journal_head(jh, bh->b_size); __brelse(bh); } else { jbd_unlock_bh_journal_head(bh); } } EXPORT_SYMBOL(jbd2_journal_put_journal_head); /* * Initialize jbd inode head */ void jbd2_journal_init_jbd_inode(struct jbd2_inode *jinode, struct inode *inode) { jinode->i_transaction = NULL; jinode->i_next_transaction = NULL; jinode->i_vfs_inode = inode; jinode->i_flags = 0; jinode->i_dirty_start = 0; jinode->i_dirty_end = 0; INIT_LIST_HEAD(&jinode->i_list); } /* * Function to be called before we start removing inode from memory (i.e., * clear_inode() is a fine place to be called from). It removes inode from * transaction's lists. */ void jbd2_journal_release_jbd_inode(journal_t *journal, struct jbd2_inode *jinode) { if (!journal) return; restart: spin_lock(&journal->j_list_lock); /* Is commit writing out inode - we have to wait */ if (jinode->i_flags & JI_COMMIT_RUNNING) { wait_queue_head_t *wq; DEFINE_WAIT_BIT(wait, &jinode->i_flags, __JI_COMMIT_RUNNING); wq = bit_waitqueue(&jinode->i_flags, __JI_COMMIT_RUNNING); prepare_to_wait(wq, &wait.wq_entry, TASK_UNINTERRUPTIBLE); spin_unlock(&journal->j_list_lock); schedule(); finish_wait(wq, &wait.wq_entry); goto restart; } if (jinode->i_transaction) { list_del(&jinode->i_list); jinode->i_transaction = NULL; } spin_unlock(&journal->j_list_lock); } #ifdef CONFIG_PROC_FS #define JBD2_STATS_PROC_NAME "fs/jbd2" static void __init jbd2_create_jbd_stats_proc_entry(void) { proc_jbd2_stats = proc_mkdir(JBD2_STATS_PROC_NAME, NULL); } static void __exit jbd2_remove_jbd_stats_proc_entry(void) { if (proc_jbd2_stats) remove_proc_entry(JBD2_STATS_PROC_NAME, NULL); } #else #define jbd2_create_jbd_stats_proc_entry() do {} while (0) #define jbd2_remove_jbd_stats_proc_entry() do {} while (0) #endif struct kmem_cache *jbd2_handle_cache, *jbd2_inode_cache; static int __init jbd2_journal_init_inode_cache(void) { J_ASSERT(!jbd2_inode_cache); jbd2_inode_cache = KMEM_CACHE(jbd2_inode, 0); if (!jbd2_inode_cache) { pr_emerg("JBD2: failed to create inode cache\n"); return -ENOMEM; } return 0; } static int __init jbd2_journal_init_handle_cache(void) { J_ASSERT(!jbd2_handle_cache); jbd2_handle_cache = KMEM_CACHE(jbd2_journal_handle, SLAB_TEMPORARY); if (!jbd2_handle_cache) { printk(KERN_EMERG "JBD2: failed to create handle cache\n"); return -ENOMEM; } return 0; } static void jbd2_journal_destroy_inode_cache(void) { kmem_cache_destroy(jbd2_inode_cache); jbd2_inode_cache = NULL; } static void jbd2_journal_destroy_handle_cache(void) { kmem_cache_destroy(jbd2_handle_cache); jbd2_handle_cache = NULL; } /* * Module startup and shutdown */ static int __init journal_init_caches(void) { int ret; ret = jbd2_journal_init_revoke_record_cache(); if (ret == 0) ret = jbd2_journal_init_revoke_table_cache(); if (ret == 0) ret = jbd2_journal_init_journal_head_cache(); if (ret == 0) ret = jbd2_journal_init_handle_cache(); if (ret == 0) ret = jbd2_journal_init_inode_cache(); if (ret == 0) ret = jbd2_journal_init_transaction_cache(); return ret; } static void jbd2_journal_destroy_caches(void) { jbd2_journal_destroy_revoke_record_cache(); jbd2_journal_destroy_revoke_table_cache(); jbd2_journal_destroy_journal_head_cache(); jbd2_journal_destroy_handle_cache(); jbd2_journal_destroy_inode_cache(); jbd2_journal_destroy_transaction_cache(); jbd2_journal_destroy_slabs(); } static int __init journal_init(void) { int ret; BUILD_BUG_ON(sizeof(struct journal_superblock_s) != 1024); ret = journal_init_caches(); if (ret == 0) { jbd2_create_jbd_stats_proc_entry(); } else { jbd2_journal_destroy_caches(); } return ret; } static void __exit journal_exit(void) { #ifdef CONFIG_JBD2_DEBUG int n = atomic_read(&nr_journal_heads); if (n) printk(KERN_ERR "JBD2: leaked %d journal_heads!\n", n); #endif jbd2_remove_jbd_stats_proc_entry(); jbd2_journal_destroy_caches(); } MODULE_LICENSE("GPL"); module_init(journal_init); module_exit(journal_exit);
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