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authorSrikant Patnaik2015-01-11 12:28:04 +0530
committerSrikant Patnaik2015-01-11 12:28:04 +0530
commit871480933a1c28f8a9fed4c4d34d06c439a7a422 (patch)
tree8718f573808810c2a1e8cb8fb6ac469093ca2784 /ANDROID_3.4.5/fs/jbd2/checkpoint.c
parent9d40ac5867b9aefe0722bc1f110b965ff294d30d (diff)
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Moved, renamed, and deleted files
The original directory structure was scattered and unorganized. Changes are basically to make it look like kernel structure.
Diffstat (limited to 'ANDROID_3.4.5/fs/jbd2/checkpoint.c')
-rw-r--r--ANDROID_3.4.5/fs/jbd2/checkpoint.c705
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diff --git a/ANDROID_3.4.5/fs/jbd2/checkpoint.c b/ANDROID_3.4.5/fs/jbd2/checkpoint.c
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--- a/ANDROID_3.4.5/fs/jbd2/checkpoint.c
+++ /dev/null
@@ -1,705 +0,0 @@
-/*
- * linux/fs/jbd2/checkpoint.c
- *
- * Written by Stephen C. Tweedie <sct@redhat.com>, 1999
- *
- * Copyright 1999 Red Hat Software --- All Rights Reserved
- *
- * This file is part of the Linux kernel and is made available under
- * the terms of the GNU General Public License, version 2, or at your
- * option, any later version, incorporated herein by reference.
- *
- * Checkpoint routines for the generic filesystem journaling code.
- * Part of the ext2fs journaling system.
- *
- * Checkpointing is the process of ensuring that a section of the log is
- * committed fully to disk, so that that portion of the log can be
- * reused.
- */
-
-#include <linux/time.h>
-#include <linux/fs.h>
-#include <linux/jbd2.h>
-#include <linux/errno.h>
-#include <linux/slab.h>
-#include <linux/blkdev.h>
-#include <trace/events/jbd2.h>
-
-/*
- * Unlink a buffer from a transaction checkpoint list.
- *
- * Called with j_list_lock held.
- */
-static inline void __buffer_unlink_first(struct journal_head *jh)
-{
- transaction_t *transaction = jh->b_cp_transaction;
-
- jh->b_cpnext->b_cpprev = jh->b_cpprev;
- jh->b_cpprev->b_cpnext = jh->b_cpnext;
- if (transaction->t_checkpoint_list == jh) {
- transaction->t_checkpoint_list = jh->b_cpnext;
- if (transaction->t_checkpoint_list == jh)
- transaction->t_checkpoint_list = NULL;
- }
-}
-
-/*
- * Unlink a buffer from a transaction checkpoint(io) list.
- *
- * Called with j_list_lock held.
- */
-static inline void __buffer_unlink(struct journal_head *jh)
-{
- transaction_t *transaction = jh->b_cp_transaction;
-
- __buffer_unlink_first(jh);
- if (transaction->t_checkpoint_io_list == jh) {
- transaction->t_checkpoint_io_list = jh->b_cpnext;
- if (transaction->t_checkpoint_io_list == jh)
- transaction->t_checkpoint_io_list = NULL;
- }
-}
-
-/*
- * Move a buffer from the checkpoint list to the checkpoint io list
- *
- * Called with j_list_lock held
- */
-static inline void __buffer_relink_io(struct journal_head *jh)
-{
- transaction_t *transaction = jh->b_cp_transaction;
-
- __buffer_unlink_first(jh);
-
- if (!transaction->t_checkpoint_io_list) {
- jh->b_cpnext = jh->b_cpprev = jh;
- } else {
- jh->b_cpnext = transaction->t_checkpoint_io_list;
- jh->b_cpprev = transaction->t_checkpoint_io_list->b_cpprev;
- jh->b_cpprev->b_cpnext = jh;
- jh->b_cpnext->b_cpprev = jh;
- }
- transaction->t_checkpoint_io_list = jh;
-}
-
-/*
- * Try to release a checkpointed buffer from its transaction.
- * Returns 1 if we released it and 2 if we also released the
- * whole transaction.
- *
- * Requires j_list_lock
- */
-static int __try_to_free_cp_buf(struct journal_head *jh)
-{
- int ret = 0;
- struct buffer_head *bh = jh2bh(jh);
-
- if (jh->b_transaction == NULL && !buffer_locked(bh) &&
- !buffer_dirty(bh) && !buffer_write_io_error(bh)) {
- /*
- * Get our reference so that bh cannot be freed before
- * we unlock it
- */
- get_bh(bh);
- JBUFFER_TRACE(jh, "remove from checkpoint list");
- ret = __jbd2_journal_remove_checkpoint(jh) + 1;
- BUFFER_TRACE(bh, "release");
- __brelse(bh);
- }
- return ret;
-}
-
-/*
- * __jbd2_log_wait_for_space: wait until there is space in the journal.
- *
- * Called under j-state_lock *only*. It will be unlocked if we have to wait
- * for a checkpoint to free up some space in the log.
- */
-void __jbd2_log_wait_for_space(journal_t *journal)
-{
- int nblocks, space_left;
- /* assert_spin_locked(&journal->j_state_lock); */
-
- nblocks = jbd_space_needed(journal);
- while (__jbd2_log_space_left(journal) < nblocks) {
- if (journal->j_flags & JBD2_ABORT)
- return;
- write_unlock(&journal->j_state_lock);
- mutex_lock(&journal->j_checkpoint_mutex);
-
- /*
- * Test again, another process may have checkpointed while we
- * were waiting for the checkpoint lock. If there are no
- * transactions ready to be checkpointed, try to recover
- * journal space by calling cleanup_journal_tail(), and if
- * that doesn't work, by waiting for the currently committing
- * transaction to complete. If there is absolutely no way
- * to make progress, this is either a BUG or corrupted
- * filesystem, so abort the journal and leave a stack
- * trace for forensic evidence.
- */
- write_lock(&journal->j_state_lock);
- spin_lock(&journal->j_list_lock);
- nblocks = jbd_space_needed(journal);
- space_left = __jbd2_log_space_left(journal);
- if (space_left < nblocks) {
- int chkpt = journal->j_checkpoint_transactions != NULL;
- tid_t tid = 0;
-
- if (journal->j_committing_transaction)
- tid = journal->j_committing_transaction->t_tid;
- spin_unlock(&journal->j_list_lock);
- write_unlock(&journal->j_state_lock);
- if (chkpt) {
- jbd2_log_do_checkpoint(journal);
- } else if (jbd2_cleanup_journal_tail(journal) == 0) {
- /* We were able to recover space; yay! */
- ;
- } else if (tid) {
- jbd2_log_wait_commit(journal, tid);
- } else {
- printk(KERN_ERR "%s: needed %d blocks and "
- "only had %d space available\n",
- __func__, nblocks, space_left);
- printk(KERN_ERR "%s: no way to get more "
- "journal space in %s\n", __func__,
- journal->j_devname);
- WARN_ON(1);
- jbd2_journal_abort(journal, 0);
- }
- write_lock(&journal->j_state_lock);
- } else {
- spin_unlock(&journal->j_list_lock);
- }
- mutex_unlock(&journal->j_checkpoint_mutex);
- }
-}
-
-/*
- * Clean up transaction's list of buffers submitted for io.
- * We wait for any pending IO to complete and remove any clean
- * buffers. Note that we take the buffers in the opposite ordering
- * from the one in which they were submitted for IO.
- *
- * Return 0 on success, and return <0 if some buffers have failed
- * to be written out.
- *
- * Called with j_list_lock held.
- */
-static int __wait_cp_io(journal_t *journal, transaction_t *transaction)
-{
- struct journal_head *jh;
- struct buffer_head *bh;
- tid_t this_tid;
- int released = 0;
- int ret = 0;
-
- this_tid = transaction->t_tid;
-restart:
- /* Did somebody clean up the transaction in the meanwhile? */
- if (journal->j_checkpoint_transactions != transaction ||
- transaction->t_tid != this_tid)
- return ret;
- while (!released && transaction->t_checkpoint_io_list) {
- jh = transaction->t_checkpoint_io_list;
- bh = jh2bh(jh);
- get_bh(bh);
- if (buffer_locked(bh)) {
- spin_unlock(&journal->j_list_lock);
- wait_on_buffer(bh);
- /* the journal_head may have gone by now */
- BUFFER_TRACE(bh, "brelse");
- __brelse(bh);
- spin_lock(&journal->j_list_lock);
- goto restart;
- }
- if (unlikely(buffer_write_io_error(bh)))
- ret = -EIO;
-
- /*
- * Now in whatever state the buffer currently is, we know that
- * it has been written out and so we can drop it from the list
- */
- released = __jbd2_journal_remove_checkpoint(jh);
- __brelse(bh);
- }
-
- return ret;
-}
-
-static void
-__flush_batch(journal_t *journal, int *batch_count)
-{
- int i;
- struct blk_plug plug;
-
- blk_start_plug(&plug);
- for (i = 0; i < *batch_count; i++)
- write_dirty_buffer(journal->j_chkpt_bhs[i], WRITE_SYNC);
- blk_finish_plug(&plug);
-
- for (i = 0; i < *batch_count; i++) {
- struct buffer_head *bh = journal->j_chkpt_bhs[i];
- BUFFER_TRACE(bh, "brelse");
- __brelse(bh);
- }
- *batch_count = 0;
-}
-
-/*
- * Try to flush one buffer from the checkpoint list to disk.
- *
- * Return 1 if something happened which requires us to abort the current
- * scan of the checkpoint list. Return <0 if the buffer has failed to
- * be written out.
- *
- * Called with j_list_lock held and drops it if 1 is returned
- */
-static int __process_buffer(journal_t *journal, struct journal_head *jh,
- int *batch_count, transaction_t *transaction)
-{
- struct buffer_head *bh = jh2bh(jh);
- int ret = 0;
-
- if (buffer_locked(bh)) {
- get_bh(bh);
- spin_unlock(&journal->j_list_lock);
- wait_on_buffer(bh);
- /* the journal_head may have gone by now */
- BUFFER_TRACE(bh, "brelse");
- __brelse(bh);
- ret = 1;
- } else if (jh->b_transaction != NULL) {
- transaction_t *t = jh->b_transaction;
- tid_t tid = t->t_tid;
-
- transaction->t_chp_stats.cs_forced_to_close++;
- spin_unlock(&journal->j_list_lock);
- if (unlikely(journal->j_flags & JBD2_UNMOUNT))
- /*
- * The journal thread is dead; so starting and
- * waiting for a commit to finish will cause
- * us to wait for a _very_ long time.
- */
- printk(KERN_ERR "JBD2: %s: "
- "Waiting for Godot: block %llu\n",
- journal->j_devname,
- (unsigned long long) bh->b_blocknr);
- jbd2_log_start_commit(journal, tid);
- jbd2_log_wait_commit(journal, tid);
- ret = 1;
- } else if (!buffer_dirty(bh)) {
- ret = 1;
- if (unlikely(buffer_write_io_error(bh)))
- ret = -EIO;
- get_bh(bh);
- BUFFER_TRACE(bh, "remove from checkpoint");
- __jbd2_journal_remove_checkpoint(jh);
- spin_unlock(&journal->j_list_lock);
- __brelse(bh);
- } else {
- /*
- * Important: we are about to write the buffer, and
- * possibly block, while still holding the journal lock.
- * We cannot afford to let the transaction logic start
- * messing around with this buffer before we write it to
- * disk, as that would break recoverability.
- */
- BUFFER_TRACE(bh, "queue");
- get_bh(bh);
- J_ASSERT_BH(bh, !buffer_jwrite(bh));
- journal->j_chkpt_bhs[*batch_count] = bh;
- __buffer_relink_io(jh);
- transaction->t_chp_stats.cs_written++;
- (*batch_count)++;
- if (*batch_count == JBD2_NR_BATCH) {
- spin_unlock(&journal->j_list_lock);
- __flush_batch(journal, batch_count);
- ret = 1;
- }
- }
- return ret;
-}
-
-/*
- * Perform an actual checkpoint. We take the first transaction on the
- * list of transactions to be checkpointed and send all its buffers
- * to disk. We submit larger chunks of data at once.
- *
- * The journal should be locked before calling this function.
- * Called with j_checkpoint_mutex held.
- */
-int jbd2_log_do_checkpoint(journal_t *journal)
-{
- transaction_t *transaction;
- tid_t this_tid;
- int result;
-
- jbd_debug(1, "Start checkpoint\n");
-
- /*
- * First thing: if there are any transactions in the log which
- * don't need checkpointing, just eliminate them from the
- * journal straight away.
- */
- result = jbd2_cleanup_journal_tail(journal);
- trace_jbd2_checkpoint(journal, result);
- jbd_debug(1, "cleanup_journal_tail returned %d\n", result);
- if (result <= 0)
- return result;
-
- /*
- * OK, we need to start writing disk blocks. Take one transaction
- * and write it.
- */
- result = 0;
- spin_lock(&journal->j_list_lock);
- if (!journal->j_checkpoint_transactions)
- goto out;
- transaction = journal->j_checkpoint_transactions;
- if (transaction->t_chp_stats.cs_chp_time == 0)
- transaction->t_chp_stats.cs_chp_time = jiffies;
- this_tid = transaction->t_tid;
-restart:
- /*
- * If someone cleaned up this transaction while we slept, we're
- * done (maybe it's a new transaction, but it fell at the same
- * address).
- */
- if (journal->j_checkpoint_transactions == transaction &&
- transaction->t_tid == this_tid) {
- int batch_count = 0;
- struct journal_head *jh;
- int retry = 0, err;
-
- while (!retry && transaction->t_checkpoint_list) {
- jh = transaction->t_checkpoint_list;
- retry = __process_buffer(journal, jh, &batch_count,
- transaction);
- if (retry < 0 && !result)
- result = retry;
- if (!retry && (need_resched() ||
- spin_needbreak(&journal->j_list_lock))) {
- spin_unlock(&journal->j_list_lock);
- retry = 1;
- break;
- }
- }
-
- if (batch_count) {
- if (!retry) {
- spin_unlock(&journal->j_list_lock);
- retry = 1;
- }
- __flush_batch(journal, &batch_count);
- }
-
- if (retry) {
- spin_lock(&journal->j_list_lock);
- goto restart;
- }
- /*
- * Now we have cleaned up the first transaction's checkpoint
- * list. Let's clean up the second one
- */
- err = __wait_cp_io(journal, transaction);
- if (!result)
- result = err;
- }
-out:
- spin_unlock(&journal->j_list_lock);
- if (result < 0)
- jbd2_journal_abort(journal, result);
- else
- result = jbd2_cleanup_journal_tail(journal);
-
- return (result < 0) ? result : 0;
-}
-
-/*
- * Check the list of checkpoint transactions for the journal to see if
- * we have already got rid of any since the last update of the log tail
- * in the journal superblock. If so, we can instantly roll the
- * superblock forward to remove those transactions from the log.
- *
- * Return <0 on error, 0 on success, 1 if there was nothing to clean up.
- *
- * Called with the journal lock held.
- *
- * This is the only part of the journaling code which really needs to be
- * aware of transaction aborts. Checkpointing involves writing to the
- * main filesystem area rather than to the journal, so it can proceed
- * even in abort state, but we must not update the super block if
- * checkpointing may have failed. Otherwise, we would lose some metadata
- * buffers which should be written-back to the filesystem.
- */
-
-int jbd2_cleanup_journal_tail(journal_t *journal)
-{
- tid_t first_tid;
- unsigned long blocknr;
-
- if (is_journal_aborted(journal))
- return 1;
-
- if (!jbd2_journal_get_log_tail(journal, &first_tid, &blocknr))
- return 1;
- J_ASSERT(blocknr != 0);
-
- /*
- * We need to make sure that any blocks that were recently written out
- * --- perhaps by jbd2_log_do_checkpoint() --- are flushed out before
- * we drop the transactions from the journal. It's unlikely this will
- * be necessary, especially with an appropriately sized journal, but we
- * need this to guarantee correctness. Fortunately
- * jbd2_cleanup_journal_tail() doesn't get called all that often.
- */
- if (journal->j_flags & JBD2_BARRIER)
- blkdev_issue_flush(journal->j_fs_dev, GFP_KERNEL, NULL);
-
- __jbd2_update_log_tail(journal, first_tid, blocknr);
- return 0;
-}
-
-
-/* Checkpoint list management */
-
-/*
- * journal_clean_one_cp_list
- *
- * Find all the written-back checkpoint buffers in the given list and
- * release them.
- *
- * Called with the journal locked.
- * Called with j_list_lock held.
- * Returns number of buffers reaped (for debug)
- */
-
-static int journal_clean_one_cp_list(struct journal_head *jh, int *released)
-{
- struct journal_head *last_jh;
- struct journal_head *next_jh = jh;
- int ret, freed = 0;
-
- *released = 0;
- if (!jh)
- return 0;
-
- last_jh = jh->b_cpprev;
- do {
- jh = next_jh;
- next_jh = jh->b_cpnext;
- ret = __try_to_free_cp_buf(jh);
- if (ret) {
- freed++;
- if (ret == 2) {
- *released = 1;
- return freed;
- }
- }
- /*
- * This function only frees up some memory
- * if possible so we dont have an obligation
- * to finish processing. Bail out if preemption
- * requested:
- */
- if (need_resched())
- return freed;
- } while (jh != last_jh);
-
- return freed;
-}
-
-/*
- * journal_clean_checkpoint_list
- *
- * Find all the written-back checkpoint buffers in the journal and release them.
- *
- * Called with the journal locked.
- * Called with j_list_lock held.
- * Returns number of buffers reaped (for debug)
- */
-
-int __jbd2_journal_clean_checkpoint_list(journal_t *journal)
-{
- transaction_t *transaction, *last_transaction, *next_transaction;
- int ret = 0;
- int released;
-
- transaction = journal->j_checkpoint_transactions;
- if (!transaction)
- goto out;
-
- last_transaction = transaction->t_cpprev;
- next_transaction = transaction;
- do {
- transaction = next_transaction;
- next_transaction = transaction->t_cpnext;
- ret += journal_clean_one_cp_list(transaction->
- t_checkpoint_list, &released);
- /*
- * This function only frees up some memory if possible so we
- * dont have an obligation to finish processing. Bail out if
- * preemption requested:
- */
- if (need_resched())
- goto out;
- if (released)
- continue;
- /*
- * It is essential that we are as careful as in the case of
- * t_checkpoint_list with removing the buffer from the list as
- * we can possibly see not yet submitted buffers on io_list
- */
- ret += journal_clean_one_cp_list(transaction->
- t_checkpoint_io_list, &released);
- if (need_resched())
- goto out;
- } while (transaction != last_transaction);
-out:
- return ret;
-}
-
-/*
- * journal_remove_checkpoint: called after a buffer has been committed
- * to disk (either by being write-back flushed to disk, or being
- * committed to the log).
- *
- * We cannot safely clean a transaction out of the log until all of the
- * buffer updates committed in that transaction have safely been stored
- * elsewhere on disk. To achieve this, all of the buffers in a
- * transaction need to be maintained on the transaction's checkpoint
- * lists until they have been rewritten, at which point this function is
- * called to remove the buffer from the existing transaction's
- * checkpoint lists.
- *
- * The function returns 1 if it frees the transaction, 0 otherwise.
- * The function can free jh and bh.
- *
- * This function is called with j_list_lock held.
- */
-int __jbd2_journal_remove_checkpoint(struct journal_head *jh)
-{
- struct transaction_chp_stats_s *stats;
- transaction_t *transaction;
- journal_t *journal;
- int ret = 0;
-
- JBUFFER_TRACE(jh, "entry");
-
- if ((transaction = jh->b_cp_transaction) == NULL) {
- JBUFFER_TRACE(jh, "not on transaction");
- goto out;
- }
- journal = transaction->t_journal;
-
- JBUFFER_TRACE(jh, "removing from transaction");
- __buffer_unlink(jh);
- jh->b_cp_transaction = NULL;
- jbd2_journal_put_journal_head(jh);
-
- if (transaction->t_checkpoint_list != NULL ||
- transaction->t_checkpoint_io_list != NULL)
- goto out;
-
- /*
- * There is one special case to worry about: if we have just pulled the
- * buffer off a running or committing transaction's checkpoing list,
- * then even if the checkpoint list is empty, the transaction obviously
- * cannot be dropped!
- *
- * The locking here around t_state is a bit sleazy.
- * See the comment at the end of jbd2_journal_commit_transaction().
- */
- if (transaction->t_state != T_FINISHED)
- goto out;
-
- /* OK, that was the last buffer for the transaction: we can now
- safely remove this transaction from the log */
- stats = &transaction->t_chp_stats;
- if (stats->cs_chp_time)
- stats->cs_chp_time = jbd2_time_diff(stats->cs_chp_time,
- jiffies);
- trace_jbd2_checkpoint_stats(journal->j_fs_dev->bd_dev,
- transaction->t_tid, stats);
-
- __jbd2_journal_drop_transaction(journal, transaction);
- jbd2_journal_free_transaction(transaction);
-
- /* Just in case anybody was waiting for more transactions to be
- checkpointed... */
- wake_up(&journal->j_wait_logspace);
- ret = 1;
-out:
- return ret;
-}
-
-/*
- * journal_insert_checkpoint: put a committed buffer onto a checkpoint
- * list so that we know when it is safe to clean the transaction out of
- * the log.
- *
- * Called with the journal locked.
- * Called with j_list_lock held.
- */
-void __jbd2_journal_insert_checkpoint(struct journal_head *jh,
- transaction_t *transaction)
-{
- JBUFFER_TRACE(jh, "entry");
- J_ASSERT_JH(jh, buffer_dirty(jh2bh(jh)) || buffer_jbddirty(jh2bh(jh)));
- J_ASSERT_JH(jh, jh->b_cp_transaction == NULL);
-
- /* Get reference for checkpointing transaction */
- jbd2_journal_grab_journal_head(jh2bh(jh));
- jh->b_cp_transaction = transaction;
-
- if (!transaction->t_checkpoint_list) {
- jh->b_cpnext = jh->b_cpprev = jh;
- } else {
- jh->b_cpnext = transaction->t_checkpoint_list;
- jh->b_cpprev = transaction->t_checkpoint_list->b_cpprev;
- jh->b_cpprev->b_cpnext = jh;
- jh->b_cpnext->b_cpprev = jh;
- }
- transaction->t_checkpoint_list = jh;
-}
-
-/*
- * We've finished with this transaction structure: adios...
- *
- * The transaction must have no links except for the checkpoint by this
- * point.
- *
- * Called with the journal locked.
- * Called with j_list_lock held.
- */
-
-void __jbd2_journal_drop_transaction(journal_t *journal, transaction_t *transaction)
-{
- assert_spin_locked(&journal->j_list_lock);
- if (transaction->t_cpnext) {
- transaction->t_cpnext->t_cpprev = transaction->t_cpprev;
- transaction->t_cpprev->t_cpnext = transaction->t_cpnext;
- if (journal->j_checkpoint_transactions == transaction)
- journal->j_checkpoint_transactions =
- transaction->t_cpnext;
- if (journal->j_checkpoint_transactions == transaction)
- journal->j_checkpoint_transactions = NULL;
- }
-
- J_ASSERT(transaction->t_state == T_FINISHED);
- J_ASSERT(transaction->t_buffers == NULL);
- J_ASSERT(transaction->t_forget == NULL);
- J_ASSERT(transaction->t_iobuf_list == NULL);
- J_ASSERT(transaction->t_shadow_list == NULL);
- J_ASSERT(transaction->t_log_list == NULL);
- J_ASSERT(transaction->t_checkpoint_list == NULL);
- J_ASSERT(transaction->t_checkpoint_io_list == NULL);
- J_ASSERT(atomic_read(&transaction->t_updates) == 0);
- J_ASSERT(journal->j_committing_transaction != transaction);
- J_ASSERT(journal->j_running_transaction != transaction);
-
- trace_jbd2_drop_transaction(journal, transaction);
-
- jbd_debug(1, "Dropping transaction %d, all done\n", transaction->t_tid);
-}