Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1128 insertions, 0 deletions

diff --git a/fs/gfs2/lops.c b/fs/gfs2/lops.c
new file mode 100644
index 0000000000..483f698070
--- /dev/null
+++ b/fs/gfs2/lops.c
@@ -0,0 +1,1128 @@
+// 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.
+ */
+
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/completion.h>
+#include <linux/buffer_head.h>
+#include <linux/mempool.h>
+#include <linux/gfs2_ondisk.h>
+#include <linux/bio.h>
+#include <linux/fs.h>
+#include <linux/list_sort.h>
+#include <linux/blkdev.h>
+
+#include "bmap.h"
+#include "dir.h"
+#include "gfs2.h"
+#include "incore.h"
+#include "inode.h"
+#include "glock.h"
+#include "glops.h"
+#include "log.h"
+#include "lops.h"
+#include "meta_io.h"
+#include "recovery.h"
+#include "rgrp.h"
+#include "trans.h"
+#include "util.h"
+#include "trace_gfs2.h"
+
+/**
+ * gfs2_pin - Pin a buffer in memory
+ * @sdp: The superblock
+ * @bh: The buffer to be pinned
+ *
+ * The log lock must be held when calling this function
+ */
+void gfs2_pin(struct gfs2_sbd *sdp, struct buffer_head *bh)
+{
+	struct gfs2_bufdata *bd;
+
+	BUG_ON(!current->journal_info);
+
+	clear_buffer_dirty(bh);
+	if (test_set_buffer_pinned(bh))
+		gfs2_assert_withdraw(sdp, 0);
+	if (!buffer_uptodate(bh))
+		gfs2_io_error_bh_wd(sdp, bh);
+	bd = bh->b_private;
+	/* If this buffer is in the AIL and it has already been written
+	 * to in-place disk block, remove it from the AIL.
+	 */
+	spin_lock(&sdp->sd_ail_lock);
+	if (bd->bd_tr)
+		list_move(&bd->bd_ail_st_list, &bd->bd_tr->tr_ail2_list);
+	spin_unlock(&sdp->sd_ail_lock);
+	get_bh(bh);
+	atomic_inc(&sdp->sd_log_pinned);
+	trace_gfs2_pin(bd, 1);
+}
+
+static bool buffer_is_rgrp(const struct gfs2_bufdata *bd)
+{
+	return bd->bd_gl->gl_name.ln_type == LM_TYPE_RGRP;
+}
+
+static void maybe_release_space(struct gfs2_bufdata *bd)
+{
+	struct gfs2_glock *gl = bd->bd_gl;
+	struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
+	struct gfs2_rgrpd *rgd = gfs2_glock2rgrp(gl);
+	unsigned int index = bd->bd_bh->b_blocknr - gl->gl_name.ln_number;
+	struct gfs2_bitmap *bi = rgd->rd_bits + index;
+
+	rgrp_lock_local(rgd);
+	if (bi->bi_clone == NULL)
+		goto out;
+	if (sdp->sd_args.ar_discard)
+		gfs2_rgrp_send_discards(sdp, rgd->rd_data0, bd->bd_bh, bi, 1, NULL);
+	memcpy(bi->bi_clone + bi->bi_offset,
+	       bd->bd_bh->b_data + bi->bi_offset, bi->bi_bytes);
+	clear_bit(GBF_FULL, &bi->bi_flags);
+	rgd->rd_free_clone = rgd->rd_free;
+	BUG_ON(rgd->rd_free_clone < rgd->rd_reserved);
+	rgd->rd_extfail_pt = rgd->rd_free;
+
+out:
+	rgrp_unlock_local(rgd);
+}
+
+/**
+ * gfs2_unpin - Unpin a buffer
+ * @sdp: the filesystem the buffer belongs to
+ * @bh: The buffer to unpin
+ * @tr: The system transaction being flushed
+ */
+
+static void gfs2_unpin(struct gfs2_sbd *sdp, struct buffer_head *bh,
+		       struct gfs2_trans *tr)
+{
+	struct gfs2_bufdata *bd = bh->b_private;
+
+	BUG_ON(!buffer_uptodate(bh));
+	BUG_ON(!buffer_pinned(bh));
+
+	lock_buffer(bh);
+	mark_buffer_dirty(bh);
+	clear_buffer_pinned(bh);
+
+	if (buffer_is_rgrp(bd))
+		maybe_release_space(bd);
+
+	spin_lock(&sdp->sd_ail_lock);
+	if (bd->bd_tr) {
+		list_del(&bd->bd_ail_st_list);
+		brelse(bh);
+	} else {
+		struct gfs2_glock *gl = bd->bd_gl;
+		list_add(&bd->bd_ail_gl_list, &gl->gl_ail_list);
+		atomic_inc(&gl->gl_ail_count);
+	}
+	bd->bd_tr = tr;
+	list_add(&bd->bd_ail_st_list, &tr->tr_ail1_list);
+	spin_unlock(&sdp->sd_ail_lock);
+
+	clear_bit(GLF_LFLUSH, &bd->bd_gl->gl_flags);
+	trace_gfs2_pin(bd, 0);
+	unlock_buffer(bh);
+	atomic_dec(&sdp->sd_log_pinned);
+}
+
+void gfs2_log_incr_head(struct gfs2_sbd *sdp)
+{
+	BUG_ON((sdp->sd_log_flush_head == sdp->sd_log_tail) &&
+	       (sdp->sd_log_flush_head != sdp->sd_log_head));
+
+	if (++sdp->sd_log_flush_head == sdp->sd_jdesc->jd_blocks)
+		sdp->sd_log_flush_head = 0;
+}
+
+u64 gfs2_log_bmap(struct gfs2_jdesc *jd, unsigned int lblock)
+{
+	struct gfs2_journal_extent *je;
+
+	list_for_each_entry(je, &jd->extent_list, list) {
+		if (lblock >= je->lblock && lblock < je->lblock + je->blocks)
+			return je->dblock + lblock - je->lblock;
+	}
+
+	return -1;
+}
+
+/**
+ * gfs2_end_log_write_bh - end log write of pagecache data with buffers
+ * @sdp: The superblock
+ * @bvec: The bio_vec
+ * @error: The i/o status
+ *
+ * This finds the relevant buffers and unlocks them and sets the
+ * error flag according to the status of the i/o request. This is
+ * used when the log is writing data which has an in-place version
+ * that is pinned in the pagecache.
+ */
+
+static void gfs2_end_log_write_bh(struct gfs2_sbd *sdp,
+				  struct bio_vec *bvec,
+				  blk_status_t error)
+{
+	struct buffer_head *bh, *next;
+	struct page *page = bvec->bv_page;
+	unsigned size;
+
+	bh = page_buffers(page);
+	size = bvec->bv_len;
+	while (bh_offset(bh) < bvec->bv_offset)
+		bh = bh->b_this_page;
+	do {
+		if (error)
+			mark_buffer_write_io_error(bh);
+		unlock_buffer(bh);
+		next = bh->b_this_page;
+		size -= bh->b_size;
+		brelse(bh);
+		bh = next;
+	} while(bh && size);
+}
+
+/**
+ * gfs2_end_log_write - end of i/o to the log
+ * @bio: The bio
+ *
+ * Each bio_vec contains either data from the pagecache or data
+ * relating to the log itself. Here we iterate over the bio_vec
+ * array, processing both kinds of data.
+ *
+ */
+
+static void gfs2_end_log_write(struct bio *bio)
+{
+	struct gfs2_sbd *sdp = bio->bi_private;
+	struct bio_vec *bvec;
+	struct page *page;
+	struct bvec_iter_all iter_all;
+
+	if (bio->bi_status) {
+		if (!cmpxchg(&sdp->sd_log_error, 0, (int)bio->bi_status))
+			fs_err(sdp, "Error %d writing to journal, jid=%u\n",
+			       bio->bi_status, sdp->sd_jdesc->jd_jid);
+		gfs2_withdraw_delayed(sdp);
+		/* prevent more writes to the journal */
+		clear_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags);
+		wake_up(&sdp->sd_logd_waitq);
+	}
+
+	bio_for_each_segment_all(bvec, bio, iter_all) {
+		page = bvec->bv_page;
+		if (page_has_buffers(page))
+			gfs2_end_log_write_bh(sdp, bvec, bio->bi_status);
+		else
+			mempool_free(page, gfs2_page_pool);
+	}
+
+	bio_put(bio);
+	if (atomic_dec_and_test(&sdp->sd_log_in_flight))
+		wake_up(&sdp->sd_log_flush_wait);
+}
+
+/**
+ * gfs2_log_submit_bio - Submit any pending log bio
+ * @biop: Address of the bio pointer
+ * @opf: REQ_OP | op_flags
+ *
+ * Submit any pending part-built or full bio to the block device. If
+ * there is no pending bio, then this is a no-op.
+ */
+
+void gfs2_log_submit_bio(struct bio **biop, blk_opf_t opf)
+{
+	struct bio *bio = *biop;
+	if (bio) {
+		struct gfs2_sbd *sdp = bio->bi_private;
+		atomic_inc(&sdp->sd_log_in_flight);
+		bio->bi_opf = opf;
+		submit_bio(bio);
+		*biop = NULL;
+	}
+}
+
+/**
+ * gfs2_log_alloc_bio - Allocate a bio
+ * @sdp: The super block
+ * @blkno: The device block number we want to write to
+ * @end_io: The bi_end_io callback
+ *
+ * Allocate a new bio, initialize it with the given parameters and return it.
+ *
+ * Returns: The newly allocated bio
+ */
+
+static struct bio *gfs2_log_alloc_bio(struct gfs2_sbd *sdp, u64 blkno,
+				      bio_end_io_t *end_io)
+{
+	struct super_block *sb = sdp->sd_vfs;
+	struct bio *bio = bio_alloc(sb->s_bdev, BIO_MAX_VECS, 0, GFP_NOIO);
+
+	bio->bi_iter.bi_sector = blkno << sdp->sd_fsb2bb_shift;
+	bio->bi_end_io = end_io;
+	bio->bi_private = sdp;
+
+	return bio;
+}
+
+/**
+ * gfs2_log_get_bio - Get cached log bio, or allocate a new one
+ * @sdp: The super block
+ * @blkno: The device block number we want to write to
+ * @biop: The bio to get or allocate
+ * @op: REQ_OP
+ * @end_io: The bi_end_io callback
+ * @flush: Always flush the current bio and allocate a new one?
+ *
+ * If there is a cached bio, then if the next block number is sequential
+ * with the previous one, return it, otherwise flush the bio to the
+ * device. If there is no cached bio, or we just flushed it, then
+ * allocate a new one.
+ *
+ * Returns: The bio to use for log writes
+ */
+
+static struct bio *gfs2_log_get_bio(struct gfs2_sbd *sdp, u64 blkno,
+				    struct bio **biop, enum req_op op,
+				    bio_end_io_t *end_io, bool flush)
+{
+	struct bio *bio = *biop;
+
+	if (bio) {
+		u64 nblk;
+
+		nblk = bio_end_sector(bio);
+		nblk >>= sdp->sd_fsb2bb_shift;
+		if (blkno == nblk && !flush)
+			return bio;
+		gfs2_log_submit_bio(biop, op);
+	}
+
+	*biop = gfs2_log_alloc_bio(sdp, blkno, end_io);
+	return *biop;
+}
+
+/**
+ * gfs2_log_write - write to log
+ * @sdp: the filesystem
+ * @jd: The journal descriptor
+ * @page: the page to write
+ * @size: the size of the data to write
+ * @offset: the offset within the page 
+ * @blkno: block number of the log entry
+ *
+ * Try and add the page segment to the current bio. If that fails,
+ * submit the current bio to the device and create a new one, and
+ * then add the page segment to that.
+ */
+
+void gfs2_log_write(struct gfs2_sbd *sdp, struct gfs2_jdesc *jd,
+		    struct page *page, unsigned size, unsigned offset,
+		    u64 blkno)
+{
+	struct bio *bio;
+	int ret;
+
+	bio = gfs2_log_get_bio(sdp, blkno, &jd->jd_log_bio, REQ_OP_WRITE,
+			       gfs2_end_log_write, false);
+	ret = bio_add_page(bio, page, size, offset);
+	if (ret == 0) {
+		bio = gfs2_log_get_bio(sdp, blkno, &jd->jd_log_bio,
+				       REQ_OP_WRITE, gfs2_end_log_write, true);
+		ret = bio_add_page(bio, page, size, offset);
+		WARN_ON(ret == 0);
+	}
+}
+
+/**
+ * gfs2_log_write_bh - write a buffer's content to the log
+ * @sdp: The super block
+ * @bh: The buffer pointing to the in-place location
+ * 
+ * This writes the content of the buffer to the next available location
+ * in the log. The buffer will be unlocked once the i/o to the log has
+ * completed.
+ */
+
+static void gfs2_log_write_bh(struct gfs2_sbd *sdp, struct buffer_head *bh)
+{
+	u64 dblock;
+
+	dblock = gfs2_log_bmap(sdp->sd_jdesc, sdp->sd_log_flush_head);
+	gfs2_log_incr_head(sdp);
+	gfs2_log_write(sdp, sdp->sd_jdesc, bh->b_page, bh->b_size,
+		       bh_offset(bh), dblock);
+}
+
+/**
+ * gfs2_log_write_page - write one block stored in a page, into the log
+ * @sdp: The superblock
+ * @page: The struct page
+ *
+ * This writes the first block-sized part of the page into the log. Note
+ * that the page must have been allocated from the gfs2_page_pool mempool
+ * and that after this has been called, ownership has been transferred and
+ * the page may be freed at any time.
+ */
+
+static void gfs2_log_write_page(struct gfs2_sbd *sdp, struct page *page)
+{
+	struct super_block *sb = sdp->sd_vfs;
+	u64 dblock;
+
+	dblock = gfs2_log_bmap(sdp->sd_jdesc, sdp->sd_log_flush_head);
+	gfs2_log_incr_head(sdp);
+	gfs2_log_write(sdp, sdp->sd_jdesc, page, sb->s_blocksize, 0, dblock);
+}
+
+/**
+ * gfs2_end_log_read - end I/O callback for reads from the log
+ * @bio: The bio
+ *
+ * Simply unlock the pages in the bio. The main thread will wait on them and
+ * process them in order as necessary.
+ */
+
+static void gfs2_end_log_read(struct bio *bio)
+{
+	struct page *page;
+	struct bio_vec *bvec;
+	struct bvec_iter_all iter_all;
+
+	bio_for_each_segment_all(bvec, bio, iter_all) {
+		page = bvec->bv_page;
+		if (bio->bi_status) {
+			int err = blk_status_to_errno(bio->bi_status);
+
+			SetPageError(page);
+			mapping_set_error(page->mapping, err);
+		}
+		unlock_page(page);
+	}
+
+	bio_put(bio);
+}
+
+/**
+ * gfs2_jhead_pg_srch - Look for the journal head in a given page.
+ * @jd: The journal descriptor
+ * @head: The journal head to start from
+ * @page: The page to look in
+ *
+ * Returns: 1 if found, 0 otherwise.
+ */
+
+static bool gfs2_jhead_pg_srch(struct gfs2_jdesc *jd,
+			      struct gfs2_log_header_host *head,
+			      struct page *page)
+{
+	struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
+	struct gfs2_log_header_host lh;
+	void *kaddr;
+	unsigned int offset;
+	bool ret = false;
+
+	kaddr = kmap_local_page(page);
+	for (offset = 0; offset < PAGE_SIZE; offset += sdp->sd_sb.sb_bsize) {
+		if (!__get_log_header(sdp, kaddr + offset, 0, &lh)) {
+			if (lh.lh_sequence >= head->lh_sequence)
+				*head = lh;
+			else {
+				ret = true;
+				break;
+			}
+		}
+	}
+	kunmap_local(kaddr);
+	return ret;
+}
+
+/**
+ * gfs2_jhead_process_page - Search/cleanup a page
+ * @jd: The journal descriptor
+ * @index: Index of the page to look into
+ * @head: The journal head to start from
+ * @done: If set, perform only cleanup, else search and set if found.
+ *
+ * Find the folio with 'index' in the journal's mapping. Search the folio for
+ * the journal head if requested (cleanup == false). Release refs on the
+ * folio so the page cache can reclaim it. We grabbed a
+ * reference on this folio twice, first when we did a grab_cache_page()
+ * to obtain the folio to add it to the bio and second when we do a
+ * filemap_get_folio() here to get the folio to wait on while I/O on it is being
+ * completed.
+ * This function is also used to free up a folio we might've grabbed but not
+ * used. Maybe we added it to a bio, but not submitted it for I/O. Or we
+ * submitted the I/O, but we already found the jhead so we only need to drop
+ * our references to the folio.
+ */
+
+static void gfs2_jhead_process_page(struct gfs2_jdesc *jd, unsigned long index,
+				    struct gfs2_log_header_host *head,
+				    bool *done)
+{
+	struct folio *folio;
+
+	folio = filemap_get_folio(jd->jd_inode->i_mapping, index);
+
+	folio_wait_locked(folio);
+	if (folio_test_error(folio))
+		*done = true;
+
+	if (!*done)
+		*done = gfs2_jhead_pg_srch(jd, head, &folio->page);
+
+	/* filemap_get_folio() and the earlier grab_cache_page() */
+	folio_put_refs(folio, 2);
+}
+
+static struct bio *gfs2_chain_bio(struct bio *prev, unsigned int nr_iovecs)
+{
+	struct bio *new;
+
+	new = bio_alloc(prev->bi_bdev, nr_iovecs, prev->bi_opf, GFP_NOIO);
+	bio_clone_blkg_association(new, prev);
+	new->bi_iter.bi_sector = bio_end_sector(prev);
+	bio_chain(new, prev);
+	submit_bio(prev);
+	return new;
+}
+
+/**
+ * gfs2_find_jhead - find the head of a log
+ * @jd: The journal descriptor
+ * @head: The log descriptor for the head of the log is returned here
+ * @keep_cache: If set inode pages will not be truncated
+ *
+ * Do a search of a journal by reading it in large chunks using bios and find
+ * the valid log entry with the highest sequence number.  (i.e. the log head)
+ *
+ * Returns: 0 on success, errno otherwise
+ */
+int gfs2_find_jhead(struct gfs2_jdesc *jd, struct gfs2_log_header_host *head,
+		    bool keep_cache)
+{
+	struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
+	struct address_space *mapping = jd->jd_inode->i_mapping;
+	unsigned int block = 0, blocks_submitted = 0, blocks_read = 0;
+	unsigned int bsize = sdp->sd_sb.sb_bsize, off;
+	unsigned int bsize_shift = sdp->sd_sb.sb_bsize_shift;
+	unsigned int shift = PAGE_SHIFT - bsize_shift;
+	unsigned int max_blocks = 2 * 1024 * 1024 >> bsize_shift;
+	struct gfs2_journal_extent *je;
+	int sz, ret = 0;
+	struct bio *bio = NULL;
+	struct page *page = NULL;
+	bool done = false;
+	errseq_t since;
+
+	memset(head, 0, sizeof(*head));
+	if (list_empty(&jd->extent_list))
+		gfs2_map_journal_extents(sdp, jd);
+
+	since = filemap_sample_wb_err(mapping);
+	list_for_each_entry(je, &jd->extent_list, list) {
+		u64 dblock = je->dblock;
+
+		for (; block < je->lblock + je->blocks; block++, dblock++) {
+			if (!page) {
+				page = grab_cache_page(mapping, block >> shift);
+				if (!page) {
+					ret = -ENOMEM;
+					done = true;
+					goto out;
+				}
+				off = 0;
+			}
+
+			if (bio && (off || block < blocks_submitted + max_blocks)) {
+				sector_t sector = dblock << sdp->sd_fsb2bb_shift;
+
+				if (bio_end_sector(bio) == sector) {
+					sz = bio_add_page(bio, page, bsize, off);
+					if (sz == bsize)
+						goto block_added;
+				}
+				if (off) {
+					unsigned int blocks =
+						(PAGE_SIZE - off) >> bsize_shift;
+
+					bio = gfs2_chain_bio(bio, blocks);
+					goto add_block_to_new_bio;
+				}
+			}
+
+			if (bio) {
+				blocks_submitted = block;
+				submit_bio(bio);
+			}
+
+			bio = gfs2_log_alloc_bio(sdp, dblock, gfs2_end_log_read);
+			bio->bi_opf = REQ_OP_READ;
+add_block_to_new_bio:
+			sz = bio_add_page(bio, page, bsize, off);
+			BUG_ON(sz != bsize);
+block_added:
+			off += bsize;
+			if (off == PAGE_SIZE)
+				page = NULL;
+			if (blocks_submitted <= blocks_read + max_blocks) {
+				/* Keep at least one bio in flight */
+				continue;
+			}
+
+			gfs2_jhead_process_page(jd, blocks_read >> shift, head, &done);
+			blocks_read += PAGE_SIZE >> bsize_shift;
+			if (done)
+				goto out;  /* found */
+		}
+	}
+
+out:
+	if (bio)
+		submit_bio(bio);
+	while (blocks_read < block) {
+		gfs2_jhead_process_page(jd, blocks_read >> shift, head, &done);
+		blocks_read += PAGE_SIZE >> bsize_shift;
+	}
+
+	if (!ret)
+		ret = filemap_check_wb_err(mapping, since);
+
+	if (!keep_cache)
+		truncate_inode_pages(mapping, 0);
+
+	return ret;
+}
+
+static struct page *gfs2_get_log_desc(struct gfs2_sbd *sdp, u32 ld_type,
+				      u32 ld_length, u32 ld_data1)
+{
+	struct page *page = mempool_alloc(gfs2_page_pool, GFP_NOIO);
+	struct gfs2_log_descriptor *ld = page_address(page);
+	clear_page(ld);
+	ld->ld_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
+	ld->ld_header.mh_type = cpu_to_be32(GFS2_METATYPE_LD);
+	ld->ld_header.mh_format = cpu_to_be32(GFS2_FORMAT_LD);
+	ld->ld_type = cpu_to_be32(ld_type);
+	ld->ld_length = cpu_to_be32(ld_length);
+	ld->ld_data1 = cpu_to_be32(ld_data1);
+	ld->ld_data2 = 0;
+	return page;
+}
+
+static void gfs2_check_magic(struct buffer_head *bh)
+{
+	void *kaddr;
+	__be32 *ptr;
+
+	clear_buffer_escaped(bh);
+	kaddr = kmap_local_page(bh->b_page);
+	ptr = kaddr + bh_offset(bh);
+	if (*ptr == cpu_to_be32(GFS2_MAGIC))
+		set_buffer_escaped(bh);
+	kunmap_local(kaddr);
+}
+
+static int blocknr_cmp(void *priv, const struct list_head *a,
+		       const struct list_head *b)
+{
+	struct gfs2_bufdata *bda, *bdb;
+
+	bda = list_entry(a, struct gfs2_bufdata, bd_list);
+	bdb = list_entry(b, struct gfs2_bufdata, bd_list);
+
+	if (bda->bd_bh->b_blocknr < bdb->bd_bh->b_blocknr)
+		return -1;
+	if (bda->bd_bh->b_blocknr > bdb->bd_bh->b_blocknr)
+		return 1;
+	return 0;
+}
+
+static void gfs2_before_commit(struct gfs2_sbd *sdp, unsigned int limit,
+				unsigned int total, struct list_head *blist,
+				bool is_databuf)
+{
+	struct gfs2_log_descriptor *ld;
+	struct gfs2_bufdata *bd1 = NULL, *bd2;
+	struct page *page;
+	unsigned int num;
+	unsigned n;
+	__be64 *ptr;
+
+	gfs2_log_lock(sdp);
+	list_sort(NULL, blist, blocknr_cmp);
+	bd1 = bd2 = list_prepare_entry(bd1, blist, bd_list);
+	while(total) {
+		num = total;
+		if (total > limit)
+			num = limit;
+		gfs2_log_unlock(sdp);
+		page = gfs2_get_log_desc(sdp,
+					 is_databuf ? GFS2_LOG_DESC_JDATA :
+					 GFS2_LOG_DESC_METADATA, num + 1, num);
+		ld = page_address(page);
+		gfs2_log_lock(sdp);
+		ptr = (__be64 *)(ld + 1);
+
+		n = 0;
+		list_for_each_entry_continue(bd1, blist, bd_list) {
+			*ptr++ = cpu_to_be64(bd1->bd_bh->b_blocknr);
+			if (is_databuf) {
+				gfs2_check_magic(bd1->bd_bh);
+				*ptr++ = cpu_to_be64(buffer_escaped(bd1->bd_bh) ? 1 : 0);
+			}
+			if (++n >= num)
+				break;
+		}
+
+		gfs2_log_unlock(sdp);
+		gfs2_log_write_page(sdp, page);
+		gfs2_log_lock(sdp);
+
+		n = 0;
+		list_for_each_entry_continue(bd2, blist, bd_list) {
+			get_bh(bd2->bd_bh);
+			gfs2_log_unlock(sdp);
+			lock_buffer(bd2->bd_bh);
+
+			if (buffer_escaped(bd2->bd_bh)) {
+				void *p;
+
+				page = mempool_alloc(gfs2_page_pool, GFP_NOIO);
+				p = page_address(page);
+				memcpy_from_page(p, page, bh_offset(bd2->bd_bh), bd2->bd_bh->b_size);
+				*(__be32 *)p = 0;
+				clear_buffer_escaped(bd2->bd_bh);
+				unlock_buffer(bd2->bd_bh);
+				brelse(bd2->bd_bh);
+				gfs2_log_write_page(sdp, page);
+			} else {
+				gfs2_log_write_bh(sdp, bd2->bd_bh);
+			}
+			gfs2_log_lock(sdp);
+			if (++n >= num)
+				break;
+		}
+
+		BUG_ON(total < num);
+		total -= num;
+	}
+	gfs2_log_unlock(sdp);
+}
+
+static void buf_lo_before_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
+{
+	unsigned int limit = buf_limit(sdp); /* 503 for 4k blocks */
+	unsigned int nbuf;
+	if (tr == NULL)
+		return;
+	nbuf = tr->tr_num_buf_new - tr->tr_num_buf_rm;
+	gfs2_before_commit(sdp, limit, nbuf, &tr->tr_buf, 0);
+}
+
+static void buf_lo_after_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
+{
+	struct list_head *head;
+	struct gfs2_bufdata *bd;
+
+	if (tr == NULL)
+		return;
+
+	head = &tr->tr_buf;
+	while (!list_empty(head)) {
+		bd = list_first_entry(head, struct gfs2_bufdata, bd_list);
+		list_del_init(&bd->bd_list);
+		gfs2_unpin(sdp, bd->bd_bh, tr);
+	}
+}
+
+static void buf_lo_before_scan(struct gfs2_jdesc *jd,
+			       struct gfs2_log_header_host *head, int pass)
+{
+	if (pass != 0)
+		return;
+
+	jd->jd_found_blocks = 0;
+	jd->jd_replayed_blocks = 0;
+}
+
+#define obsolete_rgrp_replay \
+"Replaying 0x%llx from jid=%d/0x%llx but we already have a bh!\n"
+#define obsolete_rgrp_replay2 \
+"busy:%d, pinned:%d rg_gen:0x%llx, j_gen:0x%llx\n"
+
+static void obsolete_rgrp(struct gfs2_jdesc *jd, struct buffer_head *bh_log,
+			  u64 blkno)
+{
+	struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
+	struct gfs2_rgrpd *rgd;
+	struct gfs2_rgrp *jrgd = (struct gfs2_rgrp *)bh_log->b_data;
+
+	rgd = gfs2_blk2rgrpd(sdp, blkno, false);
+	if (rgd && rgd->rd_addr == blkno &&
+	    rgd->rd_bits && rgd->rd_bits->bi_bh) {
+		fs_info(sdp, obsolete_rgrp_replay, (unsigned long long)blkno,
+			jd->jd_jid, bh_log->b_blocknr);
+		fs_info(sdp, obsolete_rgrp_replay2,
+			buffer_busy(rgd->rd_bits->bi_bh) ? 1 : 0,
+			buffer_pinned(rgd->rd_bits->bi_bh),
+			rgd->rd_igeneration,
+			be64_to_cpu(jrgd->rg_igeneration));
+		gfs2_dump_glock(NULL, rgd->rd_gl, true);
+	}
+}
+
+static int buf_lo_scan_elements(struct gfs2_jdesc *jd, u32 start,
+				struct gfs2_log_descriptor *ld, __be64 *ptr,
+				int pass)
+{
+	struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
+	struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
+	struct gfs2_glock *gl = ip->i_gl;
+	unsigned int blks = be32_to_cpu(ld->ld_data1);
+	struct buffer_head *bh_log, *bh_ip;
+	u64 blkno;
+	int error = 0;
+
+	if (pass != 1 || be32_to_cpu(ld->ld_type) != GFS2_LOG_DESC_METADATA)
+		return 0;
+
+	gfs2_replay_incr_blk(jd, &start);
+
+	for (; blks; gfs2_replay_incr_blk(jd, &start), blks--) {
+		blkno = be64_to_cpu(*ptr++);
+
+		jd->jd_found_blocks++;
+
+		if (gfs2_revoke_check(jd, blkno, start))
+			continue;
+
+		error = gfs2_replay_read_block(jd, start, &bh_log);
+		if (error)
+			return error;
+
+		bh_ip = gfs2_meta_new(gl, blkno);
+		memcpy(bh_ip->b_data, bh_log->b_data, bh_log->b_size);
+
+		if (gfs2_meta_check(sdp, bh_ip))
+			error = -EIO;
+		else {
+			struct gfs2_meta_header *mh =
+				(struct gfs2_meta_header *)bh_ip->b_data;
+
+			if (mh->mh_type == cpu_to_be32(GFS2_METATYPE_RG))
+				obsolete_rgrp(jd, bh_log, blkno);
+
+			mark_buffer_dirty(bh_ip);
+		}
+		brelse(bh_log);
+		brelse(bh_ip);
+
+		if (error)
+			break;
+
+		jd->jd_replayed_blocks++;
+	}
+
+	return error;
+}
+
+static void buf_lo_after_scan(struct gfs2_jdesc *jd, int error, int pass)
+{
+	struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
+	struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
+
+	if (error) {
+		gfs2_inode_metasync(ip->i_gl);
+		return;
+	}
+	if (pass != 1)
+		return;
+
+	gfs2_inode_metasync(ip->i_gl);
+
+	fs_info(sdp, "jid=%u: Replayed %u of %u blocks\n",
+	        jd->jd_jid, jd->jd_replayed_blocks, jd->jd_found_blocks);
+}
+
+static void revoke_lo_before_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
+{
+	struct gfs2_meta_header *mh;
+	unsigned int offset;
+	struct list_head *head = &sdp->sd_log_revokes;
+	struct gfs2_bufdata *bd;
+	struct page *page;
+	unsigned int length;
+
+	gfs2_flush_revokes(sdp);
+	if (!sdp->sd_log_num_revoke)
+		return;
+
+	length = gfs2_struct2blk(sdp, sdp->sd_log_num_revoke);
+	page = gfs2_get_log_desc(sdp, GFS2_LOG_DESC_REVOKE, length, sdp->sd_log_num_revoke);
+	offset = sizeof(struct gfs2_log_descriptor);
+
+	list_for_each_entry(bd, head, bd_list) {
+		sdp->sd_log_num_revoke--;
+
+		if (offset + sizeof(u64) > sdp->sd_sb.sb_bsize) {
+			gfs2_log_write_page(sdp, page);
+			page = mempool_alloc(gfs2_page_pool, GFP_NOIO);
+			mh = page_address(page);
+			clear_page(mh);
+			mh->mh_magic = cpu_to_be32(GFS2_MAGIC);
+			mh->mh_type = cpu_to_be32(GFS2_METATYPE_LB);
+			mh->mh_format = cpu_to_be32(GFS2_FORMAT_LB);
+			offset = sizeof(struct gfs2_meta_header);
+		}
+
+		*(__be64 *)(page_address(page) + offset) = cpu_to_be64(bd->bd_blkno);
+		offset += sizeof(u64);
+	}
+	gfs2_assert_withdraw(sdp, !sdp->sd_log_num_revoke);
+
+	gfs2_log_write_page(sdp, page);
+}
+
+void gfs2_drain_revokes(struct gfs2_sbd *sdp)
+{
+	struct list_head *head = &sdp->sd_log_revokes;
+	struct gfs2_bufdata *bd;
+	struct gfs2_glock *gl;
+
+	while (!list_empty(head)) {
+		bd = list_first_entry(head, struct gfs2_bufdata, bd_list);
+		list_del_init(&bd->bd_list);
+		gl = bd->bd_gl;
+		gfs2_glock_remove_revoke(gl);
+		kmem_cache_free(gfs2_bufdata_cachep, bd);
+	}
+}
+
+static void revoke_lo_after_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
+{
+	gfs2_drain_revokes(sdp);
+}
+
+static void revoke_lo_before_scan(struct gfs2_jdesc *jd,
+				  struct gfs2_log_header_host *head, int pass)
+{
+	if (pass != 0)
+		return;
+
+	jd->jd_found_revokes = 0;
+	jd->jd_replay_tail = head->lh_tail;
+}
+
+static int revoke_lo_scan_elements(struct gfs2_jdesc *jd, u32 start,
+				   struct gfs2_log_descriptor *ld, __be64 *ptr,
+				   int pass)
+{
+	struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
+	unsigned int blks = be32_to_cpu(ld->ld_length);
+	unsigned int revokes = be32_to_cpu(ld->ld_data1);
+	struct buffer_head *bh;
+	unsigned int offset;
+	u64 blkno;
+	int first = 1;
+	int error;
+
+	if (pass != 0 || be32_to_cpu(ld->ld_type) != GFS2_LOG_DESC_REVOKE)
+		return 0;
+
+	offset = sizeof(struct gfs2_log_descriptor);
+
+	for (; blks; gfs2_replay_incr_blk(jd, &start), blks--) {
+		error = gfs2_replay_read_block(jd, start, &bh);
+		if (error)
+			return error;
+
+		if (!first)
+			gfs2_metatype_check(sdp, bh, GFS2_METATYPE_LB);
+
+		while (offset + sizeof(u64) <= sdp->sd_sb.sb_bsize) {
+			blkno = be64_to_cpu(*(__be64 *)(bh->b_data + offset));
+
+			error = gfs2_revoke_add(jd, blkno, start);
+			if (error < 0) {
+				brelse(bh);
+				return error;
+			}
+			else if (error)
+				jd->jd_found_revokes++;
+
+			if (!--revokes)
+				break;
+			offset += sizeof(u64);
+		}
+
+		brelse(bh);
+		offset = sizeof(struct gfs2_meta_header);
+		first = 0;
+	}
+
+	return 0;
+}
+
+static void revoke_lo_after_scan(struct gfs2_jdesc *jd, int error, int pass)
+{
+	struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
+
+	if (error) {
+		gfs2_revoke_clean(jd);
+		return;
+	}
+	if (pass != 1)
+		return;
+
+	fs_info(sdp, "jid=%u: Found %u revoke tags\n",
+	        jd->jd_jid, jd->jd_found_revokes);
+
+	gfs2_revoke_clean(jd);
+}
+
+/**
+ * databuf_lo_before_commit - Scan the data buffers, writing as we go
+ * @sdp: The filesystem
+ * @tr: The system transaction being flushed
+ */
+
+static void databuf_lo_before_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
+{
+	unsigned int limit = databuf_limit(sdp);
+	unsigned int nbuf;
+	if (tr == NULL)
+		return;
+	nbuf = tr->tr_num_databuf_new - tr->tr_num_databuf_rm;
+	gfs2_before_commit(sdp, limit, nbuf, &tr->tr_databuf, 1);
+}
+
+static int databuf_lo_scan_elements(struct gfs2_jdesc *jd, u32 start,
+				    struct gfs2_log_descriptor *ld,
+				    __be64 *ptr, int pass)
+{
+	struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
+	struct gfs2_glock *gl = ip->i_gl;
+	unsigned int blks = be32_to_cpu(ld->ld_data1);
+	struct buffer_head *bh_log, *bh_ip;
+	u64 blkno;
+	u64 esc;
+	int error = 0;
+
+	if (pass != 1 || be32_to_cpu(ld->ld_type) != GFS2_LOG_DESC_JDATA)
+		return 0;
+
+	gfs2_replay_incr_blk(jd, &start);
+	for (; blks; gfs2_replay_incr_blk(jd, &start), blks--) {
+		blkno = be64_to_cpu(*ptr++);
+		esc = be64_to_cpu(*ptr++);
+
+		jd->jd_found_blocks++;
+
+		if (gfs2_revoke_check(jd, blkno, start))
+			continue;
+
+		error = gfs2_replay_read_block(jd, start, &bh_log);
+		if (error)
+			return error;
+
+		bh_ip = gfs2_meta_new(gl, blkno);
+		memcpy(bh_ip->b_data, bh_log->b_data, bh_log->b_size);
+
+		/* Unescape */
+		if (esc) {
+			__be32 *eptr = (__be32 *)bh_ip->b_data;
+			*eptr = cpu_to_be32(GFS2_MAGIC);
+		}
+		mark_buffer_dirty(bh_ip);
+
+		brelse(bh_log);
+		brelse(bh_ip);
+
+		jd->jd_replayed_blocks++;
+	}
+
+	return error;
+}
+
+/* FIXME: sort out accounting for log blocks etc. */
+
+static void databuf_lo_after_scan(struct gfs2_jdesc *jd, int error, int pass)
+{
+	struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
+	struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
+
+	if (error) {
+		gfs2_inode_metasync(ip->i_gl);
+		return;
+	}
+	if (pass != 1)
+		return;
+
+	/* data sync? */
+	gfs2_inode_metasync(ip->i_gl);
+
+	fs_info(sdp, "jid=%u: Replayed %u of %u data blocks\n",
+		jd->jd_jid, jd->jd_replayed_blocks, jd->jd_found_blocks);
+}
+
+static void databuf_lo_after_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
+{
+	struct list_head *head;
+	struct gfs2_bufdata *bd;
+
+	if (tr == NULL)
+		return;
+
+	head = &tr->tr_databuf;
+	while (!list_empty(head)) {
+		bd = list_first_entry(head, struct gfs2_bufdata, bd_list);
+		list_del_init(&bd->bd_list);
+		gfs2_unpin(sdp, bd->bd_bh, tr);
+	}
+}
+
+
+static const struct gfs2_log_operations gfs2_buf_lops = {
+	.lo_before_commit = buf_lo_before_commit,
+	.lo_after_commit = buf_lo_after_commit,
+	.lo_before_scan = buf_lo_before_scan,
+	.lo_scan_elements = buf_lo_scan_elements,
+	.lo_after_scan = buf_lo_after_scan,
+	.lo_name = "buf",
+};
+
+static const struct gfs2_log_operations gfs2_revoke_lops = {
+	.lo_before_commit = revoke_lo_before_commit,
+	.lo_after_commit = revoke_lo_after_commit,
+	.lo_before_scan = revoke_lo_before_scan,
+	.lo_scan_elements = revoke_lo_scan_elements,
+	.lo_after_scan = revoke_lo_after_scan,
+	.lo_name = "revoke",
+};
+
+static const struct gfs2_log_operations gfs2_databuf_lops = {
+	.lo_before_commit = databuf_lo_before_commit,
+	.lo_after_commit = databuf_lo_after_commit,
+	.lo_scan_elements = databuf_lo_scan_elements,
+	.lo_after_scan = databuf_lo_after_scan,
+	.lo_name = "databuf",
+};
+
+const struct gfs2_log_operations *gfs2_log_ops[] = {
+	&gfs2_databuf_lops,
+	&gfs2_buf_lops,
+	&gfs2_revoke_lops,
+	NULL,
+};
+