1 files changed, 336 insertions, 0 deletions
diff --git a/fs/gfs2/trans.c b/fs/gfs2/trans.c
new file mode 100644
index 000000000..7e835be70
--- /dev/null
+++ b/fs/gfs2/trans.c
@@ -0,0 +1,336 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
+ * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/completion.h>
+#include <linux/buffer_head.h>
+#include <linux/kallsyms.h>
+#include <linux/gfs2_ondisk.h>
+
+#include "gfs2.h"
+#include "incore.h"
+#include "glock.h"
+#include "inode.h"
+#include "log.h"
+#include "lops.h"
+#include "meta_io.h"
+#include "trans.h"
+#include "util.h"
+#include "trace_gfs2.h"
+
+static void gfs2_print_trans(struct gfs2_sbd *sdp, const struct gfs2_trans *tr)
+{
+	fs_warn(sdp, "Transaction created at: %pSR\n", (void *)tr->tr_ip);
+	fs_warn(sdp, "blocks=%u revokes=%u reserved=%u touched=%u\n",
+		tr->tr_blocks, tr->tr_revokes, tr->tr_reserved,
+		test_bit(TR_TOUCHED, &tr->tr_flags));
+	fs_warn(sdp, "Buf %u/%u Databuf %u/%u Revoke %u\n",
+		tr->tr_num_buf_new, tr->tr_num_buf_rm,
+		tr->tr_num_databuf_new, tr->tr_num_databuf_rm,
+		tr->tr_num_revoke);
+}
+
+int __gfs2_trans_begin(struct gfs2_trans *tr, struct gfs2_sbd *sdp,
+		       unsigned int blocks, unsigned int revokes,
+		       unsigned long ip)
+{
+	unsigned int extra_revokes;
+
+	if (current->journal_info) {
+		gfs2_print_trans(sdp, current->journal_info);
+		BUG();
+	}
+	BUG_ON(blocks == 0 && revokes == 0);
+
+	if (!test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags))
+		return -EROFS;
+
+	tr->tr_ip = ip;
+	tr->tr_blocks = blocks;
+	tr->tr_revokes = revokes;
+	tr->tr_reserved = GFS2_LOG_FLUSH_MIN_BLOCKS;
+	if (blocks) {
+		/*
+		 * The reserved blocks are either used for data or metadata.
+		 * We can have mixed data and metadata, each with its own log
+		 * descriptor block; see calc_reserved().
+		 */
+		tr->tr_reserved += blocks + 1 + DIV_ROUND_UP(blocks - 1, databuf_limit(sdp));
+	}
+	INIT_LIST_HEAD(&tr->tr_databuf);
+	INIT_LIST_HEAD(&tr->tr_buf);
+	INIT_LIST_HEAD(&tr->tr_list);
+	INIT_LIST_HEAD(&tr->tr_ail1_list);
+	INIT_LIST_HEAD(&tr->tr_ail2_list);
+
+	if (gfs2_assert_warn(sdp, tr->tr_reserved <= sdp->sd_jdesc->jd_blocks))
+		return -EINVAL;
+
+	sb_start_intwrite(sdp->sd_vfs);
+
+	/*
+	 * Try the reservations under sd_log_flush_lock to prevent log flushes
+	 * from creating inconsistencies between the number of allocated and
+	 * reserved revokes.  If that fails, do a full-block allocation outside
+	 * of the lock to avoid stalling log flushes.  Then, allot the
+	 * appropriate number of blocks to revokes, use as many revokes locally
+	 * as needed, and "release" the surplus into the revokes pool.
+	 */
+
+	down_read(&sdp->sd_log_flush_lock);
+	if (gfs2_log_try_reserve(sdp, tr, &extra_revokes))
+		goto reserved;
+	up_read(&sdp->sd_log_flush_lock);
+	gfs2_log_reserve(sdp, tr, &extra_revokes);
+	down_read(&sdp->sd_log_flush_lock);
+
+reserved:
+	gfs2_log_release_revokes(sdp, extra_revokes);
+	if (unlikely(!test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags))) {
+		gfs2_log_release_revokes(sdp, tr->tr_revokes);
+		up_read(&sdp->sd_log_flush_lock);
+		gfs2_log_release(sdp, tr->tr_reserved);
+		sb_end_intwrite(sdp->sd_vfs);
+		return -EROFS;
+	}
+
+	current->journal_info = tr;
+
+	return 0;
+}
+
+int gfs2_trans_begin(struct gfs2_sbd *sdp, unsigned int blocks,
+		     unsigned int revokes)
+{
+	struct gfs2_trans *tr;
+	int error;
+
+	tr = kmem_cache_zalloc(gfs2_trans_cachep, GFP_NOFS);
+	if (!tr)
+		return -ENOMEM;
+	error = __gfs2_trans_begin(tr, sdp, blocks, revokes, _RET_IP_);
+	if (error)
+		kmem_cache_free(gfs2_trans_cachep, tr);
+	return error;
+}
+
+void gfs2_trans_end(struct gfs2_sbd *sdp)
+{
+	struct gfs2_trans *tr = current->journal_info;
+	s64 nbuf;
+
+	current->journal_info = NULL;
+
+	if (!test_bit(TR_TOUCHED, &tr->tr_flags)) {
+		gfs2_log_release_revokes(sdp, tr->tr_revokes);
+		up_read(&sdp->sd_log_flush_lock);
+		gfs2_log_release(sdp, tr->tr_reserved);
+		if (!test_bit(TR_ONSTACK, &tr->tr_flags))
+			gfs2_trans_free(sdp, tr);
+		sb_end_intwrite(sdp->sd_vfs);
+		return;
+	}
+
+	gfs2_log_release_revokes(sdp, tr->tr_revokes - tr->tr_num_revoke);
+
+	nbuf = tr->tr_num_buf_new + tr->tr_num_databuf_new;
+	nbuf -= tr->tr_num_buf_rm;
+	nbuf -= tr->tr_num_databuf_rm;
+
+	if (gfs2_assert_withdraw(sdp, nbuf <= tr->tr_blocks) ||
+	    gfs2_assert_withdraw(sdp, tr->tr_num_revoke <= tr->tr_revokes))
+		gfs2_print_trans(sdp, tr);
+
+	gfs2_log_commit(sdp, tr);
+	if (!test_bit(TR_ONSTACK, &tr->tr_flags) &&
+	    !test_bit(TR_ATTACHED, &tr->tr_flags))
+		gfs2_trans_free(sdp, tr);
+	up_read(&sdp->sd_log_flush_lock);
+
+	if (sdp->sd_vfs->s_flags & SB_SYNCHRONOUS)
+		gfs2_log_flush(sdp, NULL, GFS2_LOG_HEAD_FLUSH_NORMAL |
+			       GFS2_LFC_TRANS_END);
+	sb_end_intwrite(sdp->sd_vfs);
+}
+
+static struct gfs2_bufdata *gfs2_alloc_bufdata(struct gfs2_glock *gl,
+					       struct buffer_head *bh)
+{
+	struct gfs2_bufdata *bd;
+
+	bd = kmem_cache_zalloc(gfs2_bufdata_cachep, GFP_NOFS | __GFP_NOFAIL);
+	bd->bd_bh = bh;
+	bd->bd_gl = gl;
+	INIT_LIST_HEAD(&bd->bd_list);
+	INIT_LIST_HEAD(&bd->bd_ail_st_list);
+	INIT_LIST_HEAD(&bd->bd_ail_gl_list);
+	bh->b_private = bd;
+	return bd;
+}
+
+/**
+ * gfs2_trans_add_data - Add a databuf to the transaction.
+ * @gl: The inode glock associated with the buffer
+ * @bh: The buffer to add
+ *
+ * This is used in journaled data mode.
+ * We need to journal the data block in the same way as metadata in
+ * the functions above. The difference is that here we have a tag
+ * which is two __be64's being the block number (as per meta data)
+ * and a flag which says whether the data block needs escaping or
+ * not. This means we need a new log entry for each 251 or so data
+ * blocks, which isn't an enormous overhead but twice as much as
+ * for normal metadata blocks.
+ */
+void gfs2_trans_add_data(struct gfs2_glock *gl, struct buffer_head *bh)
+{
+	struct gfs2_trans *tr = current->journal_info;
+	struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
+	struct gfs2_bufdata *bd;
+
+	lock_buffer(bh);
+	if (buffer_pinned(bh)) {
+		set_bit(TR_TOUCHED, &tr->tr_flags);
+		goto out;
+	}
+	gfs2_log_lock(sdp);
+	bd = bh->b_private;
+	if (bd == NULL) {
+		gfs2_log_unlock(sdp);
+		unlock_buffer(bh);
+		if (bh->b_private == NULL)
+			bd = gfs2_alloc_bufdata(gl, bh);
+		else
+			bd = bh->b_private;
+		lock_buffer(bh);
+		gfs2_log_lock(sdp);
+	}
+	gfs2_assert(sdp, bd->bd_gl == gl);
+	set_bit(TR_TOUCHED, &tr->tr_flags);
+	if (list_empty(&bd->bd_list)) {
+		set_bit(GLF_LFLUSH, &bd->bd_gl->gl_flags);
+		set_bit(GLF_DIRTY, &bd->bd_gl->gl_flags);
+		gfs2_pin(sdp, bd->bd_bh);
+		tr->tr_num_databuf_new++;
+		list_add_tail(&bd->bd_list, &tr->tr_databuf);
+	}
+	gfs2_log_unlock(sdp);
+out:
+	unlock_buffer(bh);
+}
+
+void gfs2_trans_add_meta(struct gfs2_glock *gl, struct buffer_head *bh)
+{
+
+	struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
+	struct super_block *sb = sdp->sd_vfs;
+	struct gfs2_bufdata *bd;
+	struct gfs2_meta_header *mh;
+	struct gfs2_trans *tr = current->journal_info;
+	bool withdraw = false;
+
+	lock_buffer(bh);
+	if (buffer_pinned(bh)) {
+		set_bit(TR_TOUCHED, &tr->tr_flags);
+		goto out;
+	}
+	gfs2_log_lock(sdp);
+	bd = bh->b_private;
+	if (bd == NULL) {
+		gfs2_log_unlock(sdp);
+		unlock_buffer(bh);
+		lock_page(bh->b_page);
+		if (bh->b_private == NULL)
+			bd = gfs2_alloc_bufdata(gl, bh);
+		else
+			bd = bh->b_private;
+		unlock_page(bh->b_page);
+		lock_buffer(bh);
+		gfs2_log_lock(sdp);
+	}
+	gfs2_assert(sdp, bd->bd_gl == gl);
+	set_bit(TR_TOUCHED, &tr->tr_flags);
+	if (!list_empty(&bd->bd_list))
+		goto out_unlock;
+	set_bit(GLF_LFLUSH, &bd->bd_gl->gl_flags);
+	set_bit(GLF_DIRTY, &bd->bd_gl->gl_flags);
+	mh = (struct gfs2_meta_header *)bd->bd_bh->b_data;
+	if (unlikely(mh->mh_magic != cpu_to_be32(GFS2_MAGIC))) {
+		fs_err(sdp, "Attempting to add uninitialised block to "
+		       "journal (inplace block=%lld)\n",
+		       (unsigned long long)bd->bd_bh->b_blocknr);
+		BUG();
+	}
+	if (unlikely(gfs2_withdrawn(sdp))) {
+		fs_info(sdp, "GFS2:adding buf while withdrawn! 0x%llx\n",
+			(unsigned long long)bd->bd_bh->b_blocknr);
+		goto out_unlock;
+	}
+	if (unlikely(sb->s_writers.frozen == SB_FREEZE_COMPLETE)) {
+		fs_info(sdp, "GFS2:adding buf while frozen\n");
+		withdraw = true;
+		goto out_unlock;
+	}
+	gfs2_pin(sdp, bd->bd_bh);
+	mh->__pad0 = cpu_to_be64(0);
+	mh->mh_jid = cpu_to_be32(sdp->sd_jdesc->jd_jid);
+	list_add(&bd->bd_list, &tr->tr_buf);
+	tr->tr_num_buf_new++;
+out_unlock:
+	gfs2_log_unlock(sdp);
+	if (withdraw)
+		gfs2_assert_withdraw(sdp, 0);
+out:
+	unlock_buffer(bh);
+}
+
+void gfs2_trans_add_revoke(struct gfs2_sbd *sdp, struct gfs2_bufdata *bd)
+{
+	struct gfs2_trans *tr = current->journal_info;
+
+	BUG_ON(!list_empty(&bd->bd_list));
+	gfs2_add_revoke(sdp, bd);
+	set_bit(TR_TOUCHED, &tr->tr_flags);
+	tr->tr_num_revoke++;
+}
+
+void gfs2_trans_remove_revoke(struct gfs2_sbd *sdp, u64 blkno, unsigned int len)
+{
+	struct gfs2_bufdata *bd, *tmp;
+	unsigned int n = len;
+
+	gfs2_log_lock(sdp);
+	list_for_each_entry_safe(bd, tmp, &sdp->sd_log_revokes, bd_list) {
+		if ((bd->bd_blkno >= blkno) && (bd->bd_blkno < (blkno + len))) {
+			list_del_init(&bd->bd_list);
+			gfs2_assert_withdraw(sdp, sdp->sd_log_num_revoke);
+			sdp->sd_log_num_revoke--;
+			if (bd->bd_gl)
+				gfs2_glock_remove_revoke(bd->bd_gl);
+			kmem_cache_free(gfs2_bufdata_cachep, bd);
+			gfs2_log_release_revokes(sdp, 1);
+			if (--n == 0)
+				break;
+		}
+	}
+	gfs2_log_unlock(sdp);
+}
+
+void gfs2_trans_free(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
+{
+	if (tr == NULL)
+		return;
+
+	gfs2_assert_warn(sdp, list_empty(&tr->tr_ail1_list));
+	gfs2_assert_warn(sdp, list_empty(&tr->tr_ail2_list));
+	gfs2_assert_warn(sdp, list_empty(&tr->tr_databuf));
+	gfs2_assert_warn(sdp, list_empty(&tr->tr_buf));
+	kmem_cache_free(gfs2_trans_cachep, tr);
+}