Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: Fix NULL dereference in ext4_ext_migrate()'s error handling
  ext4: Implement range_cyclic in ext4_da_writepages instead of write_cache_pages
  ext4: Initialize preallocation list_head's properly
  ext4: Fix lockdep warning
  ext4: Fix to read empty directory blocks correctly in 64k
  jbd2: Avoid possible NULL dereference in jbd2_journal_begin_ordered_truncate()
  Revert "ext4: wait on all pending commits in ext4_sync_fs()"
  jbd2: Fix return value of jbd2_journal_start_commit()

8 files changed, 99 insertions, 46 deletions

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index aafc9eba1c25..b0c87dce66a3 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -868,7 +868,7 @@ static inline unsigned ext4_rec_len_from_disk(__le16 dlen)
 {
         unsigned len = le16_to_cpu(dlen);
 
-        if (len == EXT4_MAX_REC_LEN)
+        if (len == EXT4_MAX_REC_LEN || len == 0)
                 return 1 << 16;
         return len;
 }
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 03ba20be1329..cbd2ca99d113 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -47,8 +47,10 @@
 static inline int ext4_begin_ordered_truncate(struct inode *inode,
                                               loff_t new_size)
 {
-        return jbd2_journal_begin_ordered_truncate(&EXT4_I(inode)->jinode,
-                                                   new_size);
+        return jbd2_journal_begin_ordered_truncate(
+                                        EXT4_SB(inode->i_sb)->s_journal,
+                                        &EXT4_I(inode)->jinode,
+                                        new_size);
 }
 
 static void ext4_invalidatepage(struct page *page, unsigned long offset);
@@ -2437,6 +2439,7 @@ static int ext4_da_writepages(struct address_space *mapping,
         int no_nrwrite_index_update;
         int pages_written = 0;
         long pages_skipped;
+        int range_cyclic, cycled = 1, io_done = 0;
         int needed_blocks, ret = 0, nr_to_writebump = 0;
         struct ext4_sb_info *sbi = EXT4_SB(mapping->host->i_sb);
 
@@ -2488,9 +2491,15 @@ static int ext4_da_writepages(struct address_space *mapping,
         if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
                 range_whole = 1;
 
-        if (wbc->range_cyclic)
+        range_cyclic = wbc->range_cyclic;
+        if (wbc->range_cyclic) {
                 index = mapping->writeback_index;
-        else
+                if (index)
+                        cycled = 0;
+                wbc->range_start = index << PAGE_CACHE_SHIFT;
+                wbc->range_end  = LLONG_MAX;
+                wbc->range_cyclic = 0;
+        } else
                 index = wbc->range_start >> PAGE_CACHE_SHIFT;
 
         mpd.wbc = wbc;
@@ -2504,6 +2513,7 @@ static int ext4_da_writepages(struct address_space *mapping,
         wbc->no_nrwrite_index_update = 1;
         pages_skipped = wbc->pages_skipped;
 
+retry:
         while (!ret && wbc->nr_to_write > 0) {
 
                 /*
@@ -2546,6 +2556,7 @@ static int ext4_da_writepages(struct address_space *mapping,
                         pages_written += mpd.pages_written;
                         wbc->pages_skipped = pages_skipped;
                         ret = 0;
+                        io_done = 1;
                 } else if (wbc->nr_to_write)
                         /*
                          * There is no more writeout needed
@@ -2554,6 +2565,13 @@ static int ext4_da_writepages(struct address_space *mapping,
                          */
                         break;
         }
+        if (!io_done && !cycled) {
+                cycled = 1;
+                index = 0;
+                wbc->range_start = index << PAGE_CACHE_SHIFT;
+                wbc->range_end  = mapping->writeback_index - 1;
+                goto retry;
+        }
         if (pages_skipped != wbc->pages_skipped)
                 printk(KERN_EMERG "This should not happen leaving %s "
                                 "with nr_to_write = %ld ret = %d\n",
@@ -2561,6 +2579,7 @@ static int ext4_da_writepages(struct address_space *mapping,
 
         /* Update index */
         index += pages_written;
+        wbc->range_cyclic = range_cyclic;
         if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
                 /*
                  * set the writeback_index so that range_cyclic
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index deba54f6cbed..4415beeb0b62 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -3693,6 +3693,8 @@ ext4_mb_new_inode_pa(struct ext4_allocation_context *ac)
         pa->pa_free = pa->pa_len;
         atomic_set(&pa->pa_count, 1);
         spin_lock_init(&pa->pa_lock);
+        INIT_LIST_HEAD(&pa->pa_inode_list);
+        INIT_LIST_HEAD(&pa->pa_group_list);
         pa->pa_deleted = 0;
         pa->pa_linear = 0;
 
@@ -3755,6 +3757,7 @@ ext4_mb_new_group_pa(struct ext4_allocation_context *ac)
         atomic_set(&pa->pa_count, 1);
         spin_lock_init(&pa->pa_lock);
         INIT_LIST_HEAD(&pa->pa_inode_list);
+        INIT_LIST_HEAD(&pa->pa_group_list);
         pa->pa_deleted = 0;
         pa->pa_linear = 1;
 
@@ -4476,23 +4479,26 @@ static int ext4_mb_release_context(struct ext4_allocation_context *ac)
                         pa->pa_free -= ac->ac_b_ex.fe_len;
                         pa->pa_len -= ac->ac_b_ex.fe_len;
                         spin_unlock(&pa->pa_lock);
-                        /*
-                         * We want to add the pa to the right bucket.
-                         * Remove it from the list and while adding
-                         * make sure the list to which we are adding
-                         * doesn't grow big.
-                         */
-                        if (likely(pa->pa_free)) {
-                                spin_lock(pa->pa_obj_lock);
-                                list_del_rcu(&pa->pa_inode_list);
-                                spin_unlock(pa->pa_obj_lock);
-                                ext4_mb_add_n_trim(ac);
-                        }
                 }
-                ext4_mb_put_pa(ac, ac->ac_sb, pa);
         }
         if (ac->alloc_semp)
                 up_read(ac->alloc_semp);
+        if (pa) {
+                /*
+                 * We want to add the pa to the right bucket.
+                 * Remove it from the list and while adding
+                 * make sure the list to which we are adding
+                 * doesn't grow big.  We need to release
+                 * alloc_semp before calling ext4_mb_add_n_trim()
+                 */
+                if (pa->pa_linear && likely(pa->pa_free)) {
+                        spin_lock(pa->pa_obj_lock);
+                        list_del_rcu(&pa->pa_inode_list);
+                        spin_unlock(pa->pa_obj_lock);
+                        ext4_mb_add_n_trim(ac);
+                }
+                ext4_mb_put_pa(ac, ac->ac_sb, pa);
+        }
         if (ac->ac_bitmap_page)
                 page_cache_release(ac->ac_bitmap_page);
         if (ac->ac_buddy_page)
diff --git a/fs/ext4/migrate.c b/fs/ext4/migrate.c
index 734abca25e35..fe64d9f79852 100644
--- a/fs/ext4/migrate.c
+++ b/fs/ext4/migrate.c
@@ -481,7 +481,7 @@ int ext4_ext_migrate(struct inode *inode)
                                         + 1);
         if (IS_ERR(handle)) {
                 retval = PTR_ERR(handle);
-                goto err_out;
+                return retval;
         }
         tmp_inode = ext4_new_inode(handle,
                                 inode->i_sb->s_root->d_inode,
@@ -489,8 +489,7 @@ int ext4_ext_migrate(struct inode *inode)
         if (IS_ERR(tmp_inode)) {
                 retval = -ENOMEM;
                 ext4_journal_stop(handle);
-                tmp_inode = NULL;
-                goto err_out;
+                return retval;
         }
         i_size_write(tmp_inode, i_size_read(inode));
         /*
@@ -618,8 +617,7 @@ err_out:
 
         ext4_journal_stop(handle);
 
-        if (tmp_inode)
-                iput(tmp_inode);
+        iput(tmp_inode);
 
         return retval;
 }
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index e5f06a5f045e..a5732c58f676 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -3046,14 +3046,17 @@ static void ext4_write_super(struct super_block *sb)
 static int ext4_sync_fs(struct super_block *sb, int wait)
 {
         int ret = 0;
+        tid_t target;
 
         trace_mark(ext4_sync_fs, "dev %s wait %d", sb->s_id, wait);
         sb->s_dirt = 0;
         if (EXT4_SB(sb)->s_journal) {
-                if (wait)
-                        ret = ext4_force_commit(sb);
-                else
-                        jbd2_journal_start_commit(EXT4_SB(sb)->s_journal, NULL);
+                if (jbd2_journal_start_commit(EXT4_SB(sb)->s_journal,
+                                              &target)) {
+                        if (wait)
+                                jbd2_log_wait_commit(EXT4_SB(sb)->s_journal,
+                                                     target);
+                }
         } else {
                 ext4_commit_super(sb, EXT4_SB(sb)->s_es, wait);
         }
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index eb343008eded..58144102bf25 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -450,7 +450,7 @@ int __jbd2_log_space_left(journal_t *journal)
 }
 
 /*
- * Called under j_state_lock.  Returns true if a transaction was started.
+ * Called under j_state_lock.  Returns true if a transaction commit was started.
  */
 int __jbd2_log_start_commit(journal_t *journal, tid_t target)
 {
@@ -518,7 +518,8 @@ int jbd2_journal_force_commit_nested(journal_t *journal)
 
 /*
  * Start a commit of the current running transaction (if any).  Returns true
- * if a transaction was started, and fills its tid in at *ptid
+ * 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)
 {
@@ -528,15 +529,19 @@ int jbd2_journal_start_commit(journal_t *journal, tid_t *ptid)
         if (journal->j_running_transaction) {
                 tid_t tid = journal->j_running_transaction->t_tid;
 
-                ret = __jbd2_log_start_commit(journal, tid);
-                if (ret && ptid)
+                __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;
-        } else if (journal->j_committing_transaction && ptid) {
+                ret = 1;
+        } else if (journal->j_committing_transaction) {
                 /*
                  * If ext3_write_super() recently started a commit, then we
                  * have to wait for completion of that transaction
                  */
-                *ptid = journal->j_committing_transaction->t_tid;
+                if (ptid)
+                        *ptid = journal->j_committing_transaction->t_tid;
                 ret = 1;
         }
         spin_unlock(&journal->j_state_lock);
diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c
index 46b4e347ed7d..28ce21d8598e 100644
--- a/fs/jbd2/transaction.c
+++ b/fs/jbd2/transaction.c
@@ -2129,26 +2129,46 @@ done:
 }
 
 /*
- * This function must be called when inode is journaled in ordered mode
- * before truncation happens. It starts writeout of truncated part in
- * case it is in the committing transaction so that we stand to ordered
- * mode consistency guarantees.
+ * File truncate and transaction commit interact with each other in a
+ * non-trivial way.  If a transaction writing data block A is
+ * committing, we cannot discard the data by truncate until we have
+ * written them.  Otherwise if we crashed after the transaction with
+ * write has committed but before the transaction with truncate has
+ * committed, we could see stale data in block A.  This function is a
+ * helper to solve this problem.  It starts writeout of the truncated
+ * part in case it is in the committing transaction.
+ *
+ * Filesystem code must call this function when inode is journaled in
+ * ordered mode before truncation happens and after the inode has been
+ * placed on orphan list with the new inode size. The second condition
+ * avoids the race that someone writes new data and we start
+ * committing the transaction after this function has been called but
+ * before a transaction for truncate is started (and furthermore it
+ * allows us to optimize the case where the addition to orphan list
+ * happens in the same transaction as write --- we don't have to write
+ * any data in such case).
  */
-int jbd2_journal_begin_ordered_truncate(struct jbd2_inode *inode,
+int jbd2_journal_begin_ordered_truncate(journal_t *journal,
+                                        struct jbd2_inode *jinode,
                                         loff_t new_size)
 {
-        journal_t *journal;
-        transaction_t *commit_trans;
+        transaction_t *inode_trans, *commit_trans;
         int ret = 0;
 
-        if (!inode->i_transaction && !inode->i_next_transaction)
+        /* This is a quick check to avoid locking if not necessary */
+        if (!jinode->i_transaction)
                 goto out;
-        journal = inode->i_transaction->t_journal;
+        /* Locks are here just to force reading of recent values, it is
+         * enough that the transaction was not committing before we started
+         * a transaction adding the inode to orphan list */
         spin_lock(&journal->j_state_lock);
         commit_trans = journal->j_committing_transaction;
         spin_unlock(&journal->j_state_lock);
-        if (inode->i_transaction == commit_trans) {
-                ret = filemap_fdatawrite_range(inode->i_vfs_inode->i_mapping,
+        spin_lock(&journal->j_list_lock);
+        inode_trans = jinode->i_transaction;
+        spin_unlock(&journal->j_list_lock);
+        if (inode_trans == commit_trans) {
+                ret = filemap_fdatawrite_range(jinode->i_vfs_inode->i_mapping,
                         new_size, LLONG_MAX);
                 if (ret)
                         jbd2_journal_abort(journal, ret);
diff --git a/fs/ocfs2/journal.h b/fs/ocfs2/journal.h
index 3c3532e1307c..172850a9a12a 100644
--- a/fs/ocfs2/journal.h
+++ b/fs/ocfs2/journal.h
@@ -513,8 +513,10 @@ static inline int ocfs2_jbd2_file_inode(handle_t *handle, struct inode *inode)
 static inline int ocfs2_begin_ordered_truncate(struct inode *inode,
                                                loff_t new_size)
 {
-        return jbd2_journal_begin_ordered_truncate(&OCFS2_I(inode)->ip_jinode,
-                                                   new_size);
+        return jbd2_journal_begin_ordered_truncate(
+                                OCFS2_SB(inode->i_sb)->journal->j_journal,
+                                &OCFS2_I(inode)->ip_jinode,
+                                new_size);
 }
 
 #endif /* OCFS2_JOURNAL_H */