1 files changed, 590 insertions, 0 deletions
diff --git a/fs/gfs2/meta_io.c b/fs/gfs2/meta_io.c
new file mode 100644
index 000000000000..3912d6a4b1e6
--- /dev/null
+++ b/fs/gfs2/meta_io.c
@@ -0,0 +1,590 @@
+/*
+ * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
+ * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
+ *
+ * This copyrighted material is made available to anyone wishing to use,
+ * modify, copy, or redistribute it subject to the terms and conditions
+ * of the GNU General Public License version 2.
+ */
+
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/completion.h>
+#include <linux/buffer_head.h>
+#include <linux/mm.h>
+#include <linux/pagemap.h>
+#include <linux/writeback.h>
+#include <linux/swap.h>
+#include <linux/delay.h>
+#include <linux/bio.h>
+#include <linux/gfs2_ondisk.h>
+#include <linux/lm_interface.h>
+
+#include "gfs2.h"
+#include "incore.h"
+#include "glock.h"
+#include "glops.h"
+#include "inode.h"
+#include "log.h"
+#include "lops.h"
+#include "meta_io.h"
+#include "rgrp.h"
+#include "trans.h"
+#include "util.h"
+#include "ops_address.h"
+
+static int aspace_get_block(struct inode *inode, sector_t lblock,
+			    struct buffer_head *bh_result, int create)
+{
+	gfs2_assert_warn(inode->i_sb->s_fs_info, 0);
+	return -EOPNOTSUPP;
+}
+
+static int gfs2_aspace_writepage(struct page *page,
+				 struct writeback_control *wbc)
+{
+	return block_write_full_page(page, aspace_get_block, wbc);
+}
+
+static const struct address_space_operations aspace_aops = {
+	.writepage = gfs2_aspace_writepage,
+	.releasepage = gfs2_releasepage,
+};
+
+/**
+ * gfs2_aspace_get - Create and initialize a struct inode structure
+ * @sdp: the filesystem the aspace is in
+ *
+ * Right now a struct inode is just a struct inode.  Maybe Linux
+ * will supply a more lightweight address space construct (that works)
+ * in the future.
+ *
+ * Make sure pages/buffers in this aspace aren't in high memory.
+ *
+ * Returns: the aspace
+ */
+
+struct inode *gfs2_aspace_get(struct gfs2_sbd *sdp)
+{
+	struct inode *aspace;
+
+	aspace = new_inode(sdp->sd_vfs);
+	if (aspace) {
+		mapping_set_gfp_mask(aspace->i_mapping, GFP_NOFS);
+		aspace->i_mapping->a_ops = &aspace_aops;
+		aspace->i_size = ~0ULL;
+		aspace->i_private = NULL;
+		insert_inode_hash(aspace);
+	}
+	return aspace;
+}
+
+void gfs2_aspace_put(struct inode *aspace)
+{
+	remove_inode_hash(aspace);
+	iput(aspace);
+}
+
+/**
+ * gfs2_meta_inval - Invalidate all buffers associated with a glock
+ * @gl: the glock
+ *
+ */
+
+void gfs2_meta_inval(struct gfs2_glock *gl)
+{
+	struct gfs2_sbd *sdp = gl->gl_sbd;
+	struct inode *aspace = gl->gl_aspace;
+	struct address_space *mapping = gl->gl_aspace->i_mapping;
+
+	gfs2_assert_withdraw(sdp, !atomic_read(&gl->gl_ail_count));
+
+	atomic_inc(&aspace->i_writecount);
+	truncate_inode_pages(mapping, 0);
+	atomic_dec(&aspace->i_writecount);
+
+	gfs2_assert_withdraw(sdp, !mapping->nrpages);
+}
+
+/**
+ * gfs2_meta_sync - Sync all buffers associated with a glock
+ * @gl: The glock
+ *
+ */
+
+void gfs2_meta_sync(struct gfs2_glock *gl)
+{
+	struct address_space *mapping = gl->gl_aspace->i_mapping;
+	int error;
+
+	filemap_fdatawrite(mapping);
+	error = filemap_fdatawait(mapping);
+
+	if (error)
+		gfs2_io_error(gl->gl_sbd);
+}
+
+/**
+ * getbuf - Get a buffer with a given address space
+ * @sdp: the filesystem
+ * @aspace: the address space
+ * @blkno: the block number (filesystem scope)
+ * @create: 1 if the buffer should be created
+ *
+ * Returns: the buffer
+ */
+
+static struct buffer_head *getbuf(struct gfs2_sbd *sdp, struct inode *aspace,
+				  u64 blkno, int create)
+{
+	struct page *page;
+	struct buffer_head *bh;
+	unsigned int shift;
+	unsigned long index;
+	unsigned int bufnum;
+
+	shift = PAGE_CACHE_SHIFT - sdp->sd_sb.sb_bsize_shift;
+	index = blkno >> shift;             /* convert block to page */
+	bufnum = blkno - (index << shift);  /* block buf index within page */
+
+	if (create) {
+		for (;;) {
+			page = grab_cache_page(aspace->i_mapping, index);
+			if (page)
+				break;
+			yield();
+		}
+	} else {
+		page = find_lock_page(aspace->i_mapping, index);
+		if (!page)
+			return NULL;
+	}
+
+	if (!page_has_buffers(page))
+		create_empty_buffers(page, sdp->sd_sb.sb_bsize, 0);
+
+	/* Locate header for our buffer within our page */
+	for (bh = page_buffers(page); bufnum--; bh = bh->b_this_page)
+		/* Do nothing */;
+	get_bh(bh);
+
+	if (!buffer_mapped(bh))
+		map_bh(bh, sdp->sd_vfs, blkno);
+
+	unlock_page(page);
+	mark_page_accessed(page);
+	page_cache_release(page);
+
+	return bh;
+}
+
+static void meta_prep_new(struct buffer_head *bh)
+{
+	struct gfs2_meta_header *mh = (struct gfs2_meta_header *)bh->b_data;
+
+	lock_buffer(bh);
+	clear_buffer_dirty(bh);
+	set_buffer_uptodate(bh);
+	unlock_buffer(bh);
+
+	mh->mh_magic = cpu_to_be32(GFS2_MAGIC);
+}
+
+/**
+ * gfs2_meta_new - Get a block
+ * @gl: The glock associated with this block
+ * @blkno: The block number
+ *
+ * Returns: The buffer
+ */
+
+struct buffer_head *gfs2_meta_new(struct gfs2_glock *gl, u64 blkno)
+{
+	struct buffer_head *bh;
+	bh = getbuf(gl->gl_sbd, gl->gl_aspace, blkno, CREATE);
+	meta_prep_new(bh);
+	return bh;
+}
+
+/**
+ * gfs2_meta_read - Read a block from disk
+ * @gl: The glock covering the block
+ * @blkno: The block number
+ * @flags: flags
+ * @bhp: the place where the buffer is returned (NULL on failure)
+ *
+ * Returns: errno
+ */
+
+int gfs2_meta_read(struct gfs2_glock *gl, u64 blkno, int flags,
+		   struct buffer_head **bhp)
+{
+	*bhp = getbuf(gl->gl_sbd, gl->gl_aspace, blkno, CREATE);
+	if (!buffer_uptodate(*bhp))
+		ll_rw_block(READ_META, 1, bhp);
+	if (flags & DIO_WAIT) {
+		int error = gfs2_meta_wait(gl->gl_sbd, *bhp);
+		if (error) {
+			brelse(*bhp);
+			return error;
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * gfs2_meta_wait - Reread a block from disk
+ * @sdp: the filesystem
+ * @bh: The block to wait for
+ *
+ * Returns: errno
+ */
+
+int gfs2_meta_wait(struct gfs2_sbd *sdp, struct buffer_head *bh)
+{
+	if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
+		return -EIO;
+
+	wait_on_buffer(bh);
+
+	if (!buffer_uptodate(bh)) {
+		struct gfs2_trans *tr = current->journal_info;
+		if (tr && tr->tr_touched)
+			gfs2_io_error_bh(sdp, bh);
+		return -EIO;
+	}
+	if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
+		return -EIO;
+
+	return 0;
+}
+
+/**
+ * gfs2_attach_bufdata - attach a struct gfs2_bufdata structure to a buffer
+ * @gl: the glock the buffer belongs to
+ * @bh: The buffer to be attached to
+ * @meta: Flag to indicate whether its metadata or not
+ */
+
+void gfs2_attach_bufdata(struct gfs2_glock *gl, struct buffer_head *bh,
+			 int meta)
+{
+	struct gfs2_bufdata *bd;
+
+	if (meta)
+		lock_page(bh->b_page);
+
+	if (bh->b_private) {
+		if (meta)
+			unlock_page(bh->b_page);
+		return;
+	}
+
+	bd = kmem_cache_alloc(gfs2_bufdata_cachep, GFP_NOFS | __GFP_NOFAIL),
+	memset(bd, 0, sizeof(struct gfs2_bufdata));
+	bd->bd_bh = bh;
+	bd->bd_gl = gl;
+
+	INIT_LIST_HEAD(&bd->bd_list_tr);
+	if (meta)
+		lops_init_le(&bd->bd_le, &gfs2_buf_lops);
+	else
+		lops_init_le(&bd->bd_le, &gfs2_databuf_lops);
+	bh->b_private = bd;
+
+	if (meta)
+		unlock_page(bh->b_page);
+}
+
+/**
+ * gfs2_pin - Pin a buffer in memory
+ * @sdp: the filesystem the buffer belongs to
+ * @bh: The buffer to be pinned
+ *
+ */
+
+void gfs2_pin(struct gfs2_sbd *sdp, struct buffer_head *bh)
+{
+	struct gfs2_bufdata *bd = bh->b_private;
+
+	gfs2_assert_withdraw(sdp, test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags));
+
+	if (test_set_buffer_pinned(bh))
+		gfs2_assert_withdraw(sdp, 0);
+
+	wait_on_buffer(bh);
+
+	/* If this buffer is in the AIL and it has already been written
+	   to in-place disk block, remove it from the AIL. */
+
+	gfs2_log_lock(sdp);
+	if (bd->bd_ail && !buffer_in_io(bh))
+		list_move(&bd->bd_ail_st_list, &bd->bd_ail->ai_ail2_list);
+	gfs2_log_unlock(sdp);
+
+	clear_buffer_dirty(bh);
+	wait_on_buffer(bh);
+
+	if (!buffer_uptodate(bh))
+		gfs2_io_error_bh(sdp, bh);
+
+	get_bh(bh);
+}
+
+/**
+ * gfs2_unpin - Unpin a buffer
+ * @sdp: the filesystem the buffer belongs to
+ * @bh: The buffer to unpin
+ * @ai:
+ *
+ */
+
+void gfs2_unpin(struct gfs2_sbd *sdp, struct buffer_head *bh,
+	        struct gfs2_ail *ai)
+{
+	struct gfs2_bufdata *bd = bh->b_private;
+
+	gfs2_assert_withdraw(sdp, buffer_uptodate(bh));
+
+	if (!buffer_pinned(bh))
+		gfs2_assert_withdraw(sdp, 0);
+
+	mark_buffer_dirty(bh);
+	clear_buffer_pinned(bh);
+
+	gfs2_log_lock(sdp);
+	if (bd->bd_ail) {
+		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_ail = ai;
+	list_add(&bd->bd_ail_st_list, &ai->ai_ail1_list);
+	gfs2_log_unlock(sdp);
+}
+
+/**
+ * gfs2_meta_wipe - make inode's buffers so they aren't dirty/pinned anymore
+ * @ip: the inode who owns the buffers
+ * @bstart: the first buffer in the run
+ * @blen: the number of buffers in the run
+ *
+ */
+
+void gfs2_meta_wipe(struct gfs2_inode *ip, u64 bstart, u32 blen)
+{
+	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
+	struct inode *aspace = ip->i_gl->gl_aspace;
+	struct buffer_head *bh;
+
+	while (blen) {
+		bh = getbuf(sdp, aspace, bstart, NO_CREATE);
+		if (bh) {
+			struct gfs2_bufdata *bd = bh->b_private;
+
+			if (test_clear_buffer_pinned(bh)) {
+				struct gfs2_trans *tr = current->journal_info;
+				gfs2_log_lock(sdp);
+				list_del_init(&bd->bd_le.le_list);
+				gfs2_assert_warn(sdp, sdp->sd_log_num_buf);
+				sdp->sd_log_num_buf--;
+				gfs2_log_unlock(sdp);
+				tr->tr_num_buf_rm++;
+				brelse(bh);
+			}
+			if (bd) {
+				gfs2_log_lock(sdp);
+				if (bd->bd_ail) {
+					u64 blkno = bh->b_blocknr;
+					bd->bd_ail = NULL;
+					list_del(&bd->bd_ail_st_list);
+					list_del(&bd->bd_ail_gl_list);
+					atomic_dec(&bd->bd_gl->gl_ail_count);
+					brelse(bh);
+					gfs2_log_unlock(sdp);
+					gfs2_trans_add_revoke(sdp, blkno);
+				} else
+					gfs2_log_unlock(sdp);
+			}
+
+			lock_buffer(bh);
+			clear_buffer_dirty(bh);
+			clear_buffer_uptodate(bh);
+			unlock_buffer(bh);
+
+			brelse(bh);
+		}
+
+		bstart++;
+		blen--;
+	}
+}
+
+/**
+ * gfs2_meta_cache_flush - get rid of any references on buffers for this inode
+ * @ip: The GFS2 inode
+ *
+ * This releases buffers that are in the most-recently-used array of
+ * blocks used for indirect block addressing for this inode.
+ */
+
+void gfs2_meta_cache_flush(struct gfs2_inode *ip)
+{
+	struct buffer_head **bh_slot;
+	unsigned int x;
+
+	spin_lock(&ip->i_spin);
+
+	for (x = 0; x < GFS2_MAX_META_HEIGHT; x++) {
+		bh_slot = &ip->i_cache[x];
+		if (!*bh_slot)
+			break;
+		brelse(*bh_slot);
+		*bh_slot = NULL;
+	}
+
+	spin_unlock(&ip->i_spin);
+}
+
+/**
+ * gfs2_meta_indirect_buffer - Get a metadata buffer
+ * @ip: The GFS2 inode
+ * @height: The level of this buf in the metadata (indir addr) tree (if any)
+ * @num: The block number (device relative) of the buffer
+ * @new: Non-zero if we may create a new buffer
+ * @bhp: the buffer is returned here
+ *
+ * Try to use the gfs2_inode's MRU metadata tree cache.
+ *
+ * Returns: errno
+ */
+
+int gfs2_meta_indirect_buffer(struct gfs2_inode *ip, int height, u64 num,
+			      int new, struct buffer_head **bhp)
+{
+	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
+	struct gfs2_glock *gl = ip->i_gl;
+	struct buffer_head *bh = NULL, **bh_slot = ip->i_cache + height;
+	int in_cache = 0;
+
+	spin_lock(&ip->i_spin);
+	if (*bh_slot && (*bh_slot)->b_blocknr == num) {
+		bh = *bh_slot;
+		get_bh(bh);
+		in_cache = 1;
+	}
+	spin_unlock(&ip->i_spin);
+
+	if (!bh)
+		bh = getbuf(gl->gl_sbd, gl->gl_aspace, num, CREATE);
+
+	if (!bh)
+		return -ENOBUFS;
+
+	if (new) {
+		if (gfs2_assert_warn(sdp, height))
+			goto err;
+		meta_prep_new(bh);
+		gfs2_trans_add_bh(ip->i_gl, bh, 1);
+		gfs2_metatype_set(bh, GFS2_METATYPE_IN, GFS2_FORMAT_IN);
+		gfs2_buffer_clear_tail(bh, sizeof(struct gfs2_meta_header));
+	} else {
+		u32 mtype = height ? GFS2_METATYPE_IN : GFS2_METATYPE_DI;
+		if (!buffer_uptodate(bh)) {
+			ll_rw_block(READ_META, 1, &bh);
+			if (gfs2_meta_wait(sdp, bh))
+				goto err;
+		}
+		if (gfs2_metatype_check(sdp, bh, mtype))
+			goto err;
+	}
+
+	if (!in_cache) {
+		spin_lock(&ip->i_spin);
+		if (*bh_slot)
+			brelse(*bh_slot);
+		*bh_slot = bh;
+		get_bh(bh);
+		spin_unlock(&ip->i_spin);
+	}
+
+	*bhp = bh;
+	return 0;
+err:
+	brelse(bh);
+	return -EIO;
+}
+
+/**
+ * gfs2_meta_ra - start readahead on an extent of a file
+ * @gl: the glock the blocks belong to
+ * @dblock: the starting disk block
+ * @extlen: the number of blocks in the extent
+ *
+ * returns: the first buffer in the extent
+ */
+
+struct buffer_head *gfs2_meta_ra(struct gfs2_glock *gl, u64 dblock, u32 extlen)
+{
+	struct gfs2_sbd *sdp = gl->gl_sbd;
+	struct inode *aspace = gl->gl_aspace;
+	struct buffer_head *first_bh, *bh;
+	u32 max_ra = gfs2_tune_get(sdp, gt_max_readahead) >>
+			  sdp->sd_sb.sb_bsize_shift;
+
+	BUG_ON(!extlen);
+
+	if (max_ra < 1)
+		max_ra = 1;
+	if (extlen > max_ra)
+		extlen = max_ra;
+
+	first_bh = getbuf(sdp, aspace, dblock, CREATE);
+
+	if (buffer_uptodate(first_bh))
+		goto out;
+	if (!buffer_locked(first_bh))
+		ll_rw_block(READ_META, 1, &first_bh);
+
+	dblock++;
+	extlen--;
+
+	while (extlen) {
+		bh = getbuf(sdp, aspace, dblock, CREATE);
+
+		if (!buffer_uptodate(bh) && !buffer_locked(bh))
+			ll_rw_block(READA, 1, &bh);
+		brelse(bh);
+		dblock++;
+		extlen--;
+		if (!buffer_locked(first_bh) && buffer_uptodate(first_bh))
+			goto out;
+	}
+
+	wait_on_buffer(first_bh);
+out:
+	return first_bh;
+}
+
+/**
+ * gfs2_meta_syncfs - sync all the buffers in a filesystem
+ * @sdp: the filesystem
+ *
+ */
+
+void gfs2_meta_syncfs(struct gfs2_sbd *sdp)
+{
+	gfs2_log_flush(sdp, NULL);
+	for (;;) {
+		gfs2_ail1_start(sdp, DIO_ALL);
+		if (gfs2_ail1_empty(sdp, DIO_ALL))
+			break;
+		msleep(10);
+	}
+}
+