[PATCH] OCFS2: The Second Oracle Cluster Filesystem

The OCFS2 file system module.

Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Signed-off-by: Kurt Hackel <kurt.hackel@oracle.com>

1 files changed, 457 insertions, 0 deletions

diff --git a/fs/ocfs2/journal.h b/fs/ocfs2/journal.h
new file mode 100644
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+++ b/fs/ocfs2/journal.h
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+/* -*- mode: c; c-basic-offset: 8; -*-
+ * vim: noexpandtab sw=8 ts=8 sts=0:
+ *
+ * journal.h
+ *
+ * Defines journalling api and structures.
+ *
+ * Copyright (C) 2003, 2005 Oracle.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#ifndef OCFS2_JOURNAL_H
+#define OCFS2_JOURNAL_H
+
+#include <linux/fs.h>
+#include <linux/jbd.h>
+
+#define OCFS2_CHECKPOINT_INTERVAL        (8 * HZ)
+
+enum ocfs2_journal_state {
+        OCFS2_JOURNAL_FREE = 0,
+        OCFS2_JOURNAL_LOADED,
+        OCFS2_JOURNAL_IN_SHUTDOWN,
+};
+
+struct ocfs2_super;
+struct ocfs2_dinode;
+struct ocfs2_journal_handle;
+
+struct ocfs2_journal {
+        enum ocfs2_journal_state   j_state;    /* Journals current state   */
+
+        journal_t                 *j_journal; /* The kernels journal type */
+        struct inode              *j_inode;   /* Kernel inode pointing to
+                                               * this journal             */
+        struct ocfs2_super        *j_osb;     /* pointer to the super
+                                               * block for the node
+                                               * we're currently
+                                               * running on -- not
+                                               * necessarily the super
+                                               * block from the node
+                                               * which we usually run
+                                               * from (recovery,
+                                               * etc)                     */
+        struct buffer_head        *j_bh;      /* Journal disk inode block */
+        atomic_t                  j_num_trans; /* Number of transactions
+                                                * currently in the system. */
+        unsigned long             j_trans_id;
+        struct rw_semaphore       j_trans_barrier;
+        wait_queue_head_t         j_checkpointed;
+
+        spinlock_t                j_lock;
+        struct list_head          j_la_cleanups;
+        struct work_struct        j_recovery_work;
+};
+
+extern spinlock_t trans_inc_lock;
+
+/* wrap j_trans_id so we never have it equal to zero. */
+static inline unsigned long ocfs2_inc_trans_id(struct ocfs2_journal *j)
+{
+        unsigned long old_id;
+        spin_lock(&trans_inc_lock);
+        old_id = j->j_trans_id++;
+        if (unlikely(!j->j_trans_id))
+                j->j_trans_id = 1;
+        spin_unlock(&trans_inc_lock);
+        return old_id;
+}
+
+static inline void ocfs2_set_inode_lock_trans(struct ocfs2_journal *journal,
+                                              struct inode *inode)
+{
+        spin_lock(&trans_inc_lock);
+        OCFS2_I(inode)->ip_last_trans = journal->j_trans_id;
+        spin_unlock(&trans_inc_lock);
+}
+
+/* Used to figure out whether it's safe to drop a metadata lock on an
+ * inode. Returns true if all the inodes changes have been
+ * checkpointed to disk. You should be holding the spinlock on the
+ * metadata lock while calling this to be sure that nobody can take
+ * the lock and put it on another transaction. */
+static inline int ocfs2_inode_fully_checkpointed(struct inode *inode)
+{
+        int ret;
+        struct ocfs2_journal *journal = OCFS2_SB(inode->i_sb)->journal;
+
+        spin_lock(&trans_inc_lock);
+        ret = time_after(journal->j_trans_id, OCFS2_I(inode)->ip_last_trans);
+        spin_unlock(&trans_inc_lock);
+        return ret;
+}
+
+/* convenience function to check if an inode is still new (has never
+ * hit disk) Will do you a favor and set created_trans = 0 when you've
+ * been checkpointed.  returns '1' if the inode is still new. */
+static inline int ocfs2_inode_is_new(struct inode *inode)
+{
+        int ret;
+
+        /* System files are never "new" as they're written out by
+         * mkfs. This helps us early during mount, before we have the
+         * journal open and j_trans_id could be junk. */
+        if (OCFS2_I(inode)->ip_flags & OCFS2_INODE_SYSTEM_FILE)
+                return 0;
+        spin_lock(&trans_inc_lock);
+        ret = !(time_after(OCFS2_SB(inode->i_sb)->journal->j_trans_id,
+                           OCFS2_I(inode)->ip_created_trans));
+        if (!ret)
+                OCFS2_I(inode)->ip_created_trans = 0;
+        spin_unlock(&trans_inc_lock);
+        return ret;
+}
+
+static inline void ocfs2_inode_set_new(struct ocfs2_super *osb,
+                                       struct inode *inode)
+{
+        spin_lock(&trans_inc_lock);
+        OCFS2_I(inode)->ip_created_trans = osb->journal->j_trans_id;
+        spin_unlock(&trans_inc_lock);
+}
+
+extern kmem_cache_t *ocfs2_lock_cache;
+
+struct ocfs2_journal_lock {
+        struct inode     *jl_inode;
+        struct list_head  jl_lock_list;
+};
+
+struct ocfs2_journal_handle {
+        handle_t            *k_handle; /* kernel handle.                */
+        struct ocfs2_journal        *journal;
+        u32                 flags;     /* see flags below.              */
+        int                 max_buffs; /* Buffs reserved by this handle */
+
+        /* The following two fields are for ocfs2_handle_add_lock */
+        int                 num_locks;
+        struct list_head    locks;     /* A bunch of locks to
+                                        * release on commit. This
+                                        * should be a list_head */
+
+        struct list_head     inode_list;
+};
+
+#define OCFS2_HANDLE_STARTED                    1
+/* should we sync-commit this handle? */
+#define OCFS2_HANDLE_SYNC                       2
+static inline int ocfs2_handle_started(struct ocfs2_journal_handle *handle)
+{
+        return handle->flags & OCFS2_HANDLE_STARTED;
+}
+
+static inline void ocfs2_handle_set_sync(struct ocfs2_journal_handle *handle, int sync)
+{
+        if (sync)
+                handle->flags |= OCFS2_HANDLE_SYNC;
+        else
+                handle->flags &= ~OCFS2_HANDLE_SYNC;
+}
+
+/* Exported only for the journal struct init code in super.c. Do not call. */
+void ocfs2_complete_recovery(void *data);
+
+/*
+ *  Journal Control:
+ *  Initialize, Load, Shutdown, Wipe a journal.
+ *
+ *  ocfs2_journal_init     - Initialize journal structures in the OSB.
+ *  ocfs2_journal_load     - Load the given journal off disk. Replay it if
+ *                          there's transactions still in there.
+ *  ocfs2_journal_shutdown - Shutdown a journal, this will flush all
+ *                          uncommitted, uncheckpointed transactions.
+ *  ocfs2_journal_wipe     - Wipe transactions from a journal. Optionally
+ *                          zero out each block.
+ *  ocfs2_recovery_thread  - Perform recovery on a node. osb is our own osb.
+ *  ocfs2_mark_dead_nodes - Start recovery on nodes we won't get a heartbeat
+ *                          event on.
+ *  ocfs2_start_checkpoint - Kick the commit thread to do a checkpoint.
+ */
+void   ocfs2_set_journal_params(struct ocfs2_super *osb);
+int    ocfs2_journal_init(struct ocfs2_journal *journal,
+                          int *dirty);
+void   ocfs2_journal_shutdown(struct ocfs2_super *osb);
+int    ocfs2_journal_wipe(struct ocfs2_journal *journal,
+                          int full);
+int    ocfs2_journal_load(struct ocfs2_journal *journal);
+int    ocfs2_check_journals_nolocks(struct ocfs2_super *osb);
+void   ocfs2_recovery_thread(struct ocfs2_super *osb,
+                             int node_num);
+int    ocfs2_mark_dead_nodes(struct ocfs2_super *osb);
+void   ocfs2_complete_mount_recovery(struct ocfs2_super *osb);
+
+static inline void ocfs2_start_checkpoint(struct ocfs2_super *osb)
+{
+        atomic_set(&osb->needs_checkpoint, 1);
+        wake_up(&osb->checkpoint_event);
+}
+
+static inline void ocfs2_checkpoint_inode(struct inode *inode)
+{
+        struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+
+        if (!ocfs2_inode_fully_checkpointed(inode)) {
+                /* WARNING: This only kicks off a single
+                 * checkpoint. If someone races you and adds more
+                 * metadata to the journal, you won't know, and will
+                 * wind up waiting *alot* longer than necessary. Right
+                 * now we only use this in clear_inode so that's
+                 * OK. */
+                ocfs2_start_checkpoint(osb);
+
+                wait_event(osb->journal->j_checkpointed,
+                           ocfs2_inode_fully_checkpointed(inode));
+        }
+}
+
+/*
+ *  Transaction Handling:
+ *  Manage the lifetime of a transaction handle.
+ *
+ *  ocfs2_alloc_handle     - Only allocate a handle so we can start putting
+ *                          cluster locks on it. To actually change blocks,
+ *                          call ocfs2_start_trans with the handle returned
+ *                          from this function. You may call ocfs2_commit_trans
+ *                           at any time in the lifetime of a handle.
+ *  ocfs2_start_trans      - Begin a transaction. Give it an upper estimate of
+ *                          the number of blocks that will be changed during
+ *                          this handle.
+ *  ocfs2_commit_trans     - Complete a handle.
+ *  ocfs2_extend_trans     - Extend a handle by nblocks credits. This may
+ *                          commit the handle to disk in the process, but will
+ *                          not release any locks taken during the transaction.
+ *  ocfs2_journal_access   - Notify the handle that we want to journal this
+ *                          buffer. Will have to call ocfs2_journal_dirty once
+ *                          we've actually dirtied it. Type is one of . or .
+ *  ocfs2_journal_dirty    - Mark a journalled buffer as having dirty data.
+ *  ocfs2_journal_dirty_data - Indicate that a data buffer should go out before
+ *                             the current handle commits.
+ *  ocfs2_handle_add_lock  - Sometimes we need to delay lock release
+ *                          until after a transaction has been completed. Use
+ *                          ocfs2_handle_add_lock to indicate that a lock needs
+ *                          to be released at the end of that handle. Locks
+ *                          will be released in the order that they are added.
+ *  ocfs2_handle_add_inode - Add a locked inode to a transaction.
+ */
+
+/* You must always start_trans with a number of buffs > 0, but it's
+ * perfectly legal to go through an entire transaction without having
+ * dirtied any buffers. */
+struct ocfs2_journal_handle *ocfs2_alloc_handle(struct ocfs2_super *osb);
+struct ocfs2_journal_handle *ocfs2_start_trans(struct ocfs2_super *osb,
+                                               struct ocfs2_journal_handle *handle,
+                                               int max_buffs);
+void                         ocfs2_commit_trans(struct ocfs2_journal_handle *handle);
+int                          ocfs2_extend_trans(struct ocfs2_journal_handle *handle,
+                                                int nblocks);
+
+/*
+ * Create access is for when we get a newly created buffer and we're
+ * not gonna read it off disk, but rather fill it ourselves.  Right
+ * now, we don't do anything special with this (it turns into a write
+ * request), but this is a good placeholder in case we do...
+ *
+ * Write access is for when we read a block off disk and are going to
+ * modify it. This way the journalling layer knows it may need to make
+ * a copy of that block (if it's part of another, uncommitted
+ * transaction) before we do so.
+ */
+#define OCFS2_JOURNAL_ACCESS_CREATE 0
+#define OCFS2_JOURNAL_ACCESS_WRITE  1
+#define OCFS2_JOURNAL_ACCESS_UNDO   2
+
+int                  ocfs2_journal_access(struct ocfs2_journal_handle *handle,
+                                          struct inode *inode,
+                                          struct buffer_head *bh,
+                                          int type);
+/*
+ * A word about the journal_access/journal_dirty "dance". It is
+ * entirely legal to journal_access a buffer more than once (as long
+ * as the access type is the same -- I'm not sure what will happen if
+ * access type is different but this should never happen anyway) It is
+ * also legal to journal_dirty a buffer more than once. In fact, you
+ * can even journal_access a buffer after you've done a
+ * journal_access/journal_dirty pair. The only thing you cannot do
+ * however, is journal_dirty a buffer which you haven't yet passed to
+ * journal_access at least once.
+ *
+ * That said, 99% of the time this doesn't matter and this is what the
+ * path looks like:
+ *
+ *      <read a bh>
+ *      ocfs2_journal_access(handle, bh,        OCFS2_JOURNAL_ACCESS_WRITE);
+ *      <modify the bh>
+ *      ocfs2_journal_dirty(handle, bh);
+ */
+int                  ocfs2_journal_dirty(struct ocfs2_journal_handle *handle,
+                                         struct buffer_head *bh);
+int                  ocfs2_journal_dirty_data(handle_t *handle,
+                                              struct buffer_head *bh);
+int                  ocfs2_handle_add_lock(struct ocfs2_journal_handle *handle,
+                                           struct inode *inode);
+/*
+ * Use this to protect from other processes reading buffer state while
+ * it's in flight.
+ */
+void                 ocfs2_handle_add_inode(struct ocfs2_journal_handle *handle,
+                                            struct inode *inode);
+
+/*
+ *  Credit Macros:
+ *  Convenience macros to calculate number of credits needed.
+ *
+ *  For convenience sake, I have a set of macros here which calculate
+ *  the *maximum* number of sectors which will be changed for various
+ *  metadata updates.
+ */
+
+/* simple file updates like chmod, etc. */
+#define OCFS2_INODE_UPDATE_CREDITS 1
+
+/* get one bit out of a suballocator: dinode + group descriptor +
+ * prev. group desc. if we relink. */
+#define OCFS2_SUBALLOC_ALLOC (3)
+
+/* dinode + group descriptor update. We don't relink on free yet. */
+#define OCFS2_SUBALLOC_FREE  (2)
+
+#define OCFS2_TRUNCATE_LOG_UPDATE OCFS2_INODE_UPDATE_CREDITS
+#define OCFS2_TRUNCATE_LOG_FLUSH_ONE_REC (OCFS2_SUBALLOC_FREE                 \
+                                         + OCFS2_TRUNCATE_LOG_UPDATE)
+
+/* data block for new dir/symlink, 2 for bitmap updates (bitmap fe +
+ * bitmap block for the new bit) */
+#define OCFS2_DIR_LINK_ADDITIONAL_CREDITS (1 + 2)
+
+/* parent fe, parent block, new file entry, inode alloc fe, inode alloc
+ * group descriptor + mkdir/symlink blocks */
+#define OCFS2_MKNOD_CREDITS (3 + OCFS2_SUBALLOC_ALLOC                         \
+                            + OCFS2_DIR_LINK_ADDITIONAL_CREDITS)
+
+/* local alloc metadata change + main bitmap updates */
+#define OCFS2_WINDOW_MOVE_CREDITS (OCFS2_INODE_UPDATE_CREDITS                 \
+                                  + OCFS2_SUBALLOC_ALLOC + OCFS2_SUBALLOC_FREE)
+
+/* used when we don't need an allocation change for a dir extend. One
+ * for the dinode, one for the new block. */
+#define OCFS2_SIMPLE_DIR_EXTEND_CREDITS (2)
+
+/* file update (nlink, etc) + dir entry block */
+#define OCFS2_LINK_CREDITS  (OCFS2_INODE_UPDATE_CREDITS + 1)
+
+/* inode + dir inode (if we unlink a dir), + dir entry block + orphan
+ * dir inode link */
+#define OCFS2_UNLINK_CREDITS  (2 * OCFS2_INODE_UPDATE_CREDITS + 1             \
+                              + OCFS2_LINK_CREDITS)
+
+/* dinode + orphan dir dinode + inode alloc dinode + orphan dir entry +
+ * inode alloc group descriptor */
+#define OCFS2_DELETE_INODE_CREDITS (3 * OCFS2_INODE_UPDATE_CREDITS + 1 + 1)
+
+/* dinode update, old dir dinode update, new dir dinode update, old
+ * dir dir entry, new dir dir entry, dir entry update for renaming
+ * directory + target unlink */
+#define OCFS2_RENAME_CREDITS (3 * OCFS2_INODE_UPDATE_CREDITS + 3              \
+                             + OCFS2_UNLINK_CREDITS)
+
+static inline int ocfs2_calc_extend_credits(struct super_block *sb,
+                                            struct ocfs2_dinode *fe,
+                                            u32 bits_wanted)
+{
+        int bitmap_blocks, sysfile_bitmap_blocks, dinode_blocks;
+
+        /* bitmap dinode, group desc. + relinked group. */
+        bitmap_blocks = OCFS2_SUBALLOC_ALLOC;
+
+        /* we might need to shift tree depth so lets assume an
+         * absolute worst case of complete fragmentation.  Even with
+         * that, we only need one update for the dinode, and then
+         * however many metadata chunks needed * a remaining suballoc
+         * alloc. */
+        sysfile_bitmap_blocks = 1 +
+                (OCFS2_SUBALLOC_ALLOC - 1) * ocfs2_extend_meta_needed(fe);
+
+        /* this does not include *new* metadata blocks, which are
+         * accounted for in sysfile_bitmap_blocks. fe +
+         * prev. last_eb_blk + blocks along edge of tree.
+         * calc_symlink_credits passes because we just need 1
+         * credit for the dinode there. */
+        dinode_blocks = 1 + 1 + le16_to_cpu(fe->id2.i_list.l_tree_depth);
+
+        return bitmap_blocks + sysfile_bitmap_blocks + dinode_blocks;
+}
+
+static inline int ocfs2_calc_symlink_credits(struct super_block *sb)
+{
+        int blocks = OCFS2_MKNOD_CREDITS;
+
+        /* links can be longer than one block so we may update many
+         * within our single allocated extent. */
+        blocks += ocfs2_clusters_to_blocks(sb, 1);
+
+        return blocks;
+}
+
+static inline int ocfs2_calc_group_alloc_credits(struct super_block *sb,
+                                                 unsigned int cpg)
+{
+        int blocks;
+        int bitmap_blocks = OCFS2_SUBALLOC_ALLOC + 1;
+        /* parent inode update + new block group header + bitmap inode update
+           + bitmap blocks affected */
+        blocks = 1 + 1 + 1 + bitmap_blocks;
+        return blocks;
+}
+
+static inline int ocfs2_calc_tree_trunc_credits(struct super_block *sb,
+                                                unsigned int clusters_to_del,
+                                                struct ocfs2_dinode *fe,
+                                                struct ocfs2_extent_list *last_el)
+{
+        /* for dinode + all headers in this pass + update to next leaf */
+        u16 next_free = le16_to_cpu(last_el->l_next_free_rec);
+        u16 tree_depth = le16_to_cpu(fe->id2.i_list.l_tree_depth);
+        int credits = 1 + tree_depth + 1;
+        int i;
+
+        i = next_free - 1;
+        BUG_ON(i < 0);
+
+        /* We may be deleting metadata blocks, so metadata alloc dinode +
+           one desc. block for each possible delete. */
+        if (tree_depth && next_free == 1 &&
+            le32_to_cpu(last_el->l_recs[i].e_clusters) == clusters_to_del)
+                credits += 1 + tree_depth;
+
+        /* update to the truncate log. */
+        credits += OCFS2_TRUNCATE_LOG_UPDATE;
+
+        return credits;
+}
+
+#endif /* OCFS2_JOURNAL_H */