Merge tag 'gfs2-merge-window' of git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-3.0-nmw

Pull GFS2 updates from Steven Whitehouse:
 "This is possibly the smallest ever set of GFS2 patches for a merge
  window.  Also, most of them are bug fixes this time.

  Two of my three patches (moving gfs2_sync_meta and merging the two
  writepage implementations) are clean ups with the third (taking the
  glock ref in examine_bucket) being a fix for a difficult to hit race
  condition.

  The removal of an unused memory barrier is a clean up from Bob
  Peterson, and the "spectator" relates to a rarely used mount option.
  Ben Marzinski's patch fixes a corner case where the incorrect inode
  flags were being set, resulting in incorrect behaviour on fsync"

* tag 'gfs2-merge-window' of git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-3.0-nmw:
  GFS2: dirty inode correctly in gfs2_write_end
  GFS2: Don't flag consistency error if first mounter is a spectator
  GFS2: Remove unnecessary memory barrier
  GFS2: Merge ordered and writeback writepage
  GFS2: Take glock reference in examine_bucket()
  GFS2: Move gfs2_sync_meta to lops.c

7 files changed, 99 insertions, 77 deletions

diff --git a/fs/gfs2/aops.c b/fs/gfs2/aops.c
index ee48ad37d9c..1f7d8057ea6 100644
--- a/fs/gfs2/aops.c
+++ b/fs/gfs2/aops.c
@@ -122,14 +122,13 @@ out:
 }
 
 /**
- * gfs2_writeback_writepage - Write page for writeback mappings
+ * gfs2_writepage - Write page for writeback mappings
  * @page: The page
  * @wbc: The writeback control
  *
  */
 
-static int gfs2_writeback_writepage(struct page *page,
-				    struct writeback_control *wbc)
+static int gfs2_writepage(struct page *page, struct writeback_control *wbc)
 {
 	int ret;
 
@@ -141,32 +140,6 @@ static int gfs2_writeback_writepage(struct page *page,
 }
 
 /**
- * gfs2_ordered_writepage - Write page for ordered data files
- * @page: The page to write
- * @wbc: The writeback control
- *
- */
-
-static int gfs2_ordered_writepage(struct page *page,
-				  struct writeback_control *wbc)
-{
-	struct inode *inode = page->mapping->host;
-	struct gfs2_inode *ip = GFS2_I(inode);
-	int ret;
-
-	ret = gfs2_writepage_common(page, wbc);
-	if (ret <= 0)
-		return ret;
-
-	if (!page_has_buffers(page)) {
-		create_empty_buffers(page, inode->i_sb->s_blocksize,
-				     (1 << BH_Dirty)|(1 << BH_Uptodate));
-	}
-	gfs2_page_add_databufs(ip, page, 0, inode->i_sb->s_blocksize-1);
-	return block_write_full_page(page, gfs2_get_block_noalloc, wbc);
-}
-
-/**
  * __gfs2_jdata_writepage - The core of jdata writepage
  * @page: The page to write
  * @wbc: The writeback control
@@ -842,6 +815,8 @@ static int gfs2_write_end(struct file *file, struct address_space *mapping,
 	unsigned int from = pos & (PAGE_CACHE_SIZE - 1);
 	unsigned int to = from + len;
 	int ret;
+	struct gfs2_trans *tr = current->journal_info;
+	BUG_ON(!tr);
 
 	BUG_ON(gfs2_glock_is_locked_by_me(ip->i_gl) == NULL);
 
@@ -852,8 +827,6 @@ static int gfs2_write_end(struct file *file, struct address_space *mapping,
 		goto failed;
 	}
 
-	gfs2_trans_add_meta(ip->i_gl, dibh);
-
 	if (gfs2_is_stuffed(ip))
 		return gfs2_stuffed_write_end(inode, dibh, pos, len, copied, page);
 
@@ -861,6 +834,11 @@ static int gfs2_write_end(struct file *file, struct address_space *mapping,
 		gfs2_page_add_databufs(ip, page, from, to);
 
 	ret = generic_write_end(file, mapping, pos, len, copied, page, fsdata);
+	if (tr->tr_num_buf_new)
+		__mark_inode_dirty(inode, I_DIRTY_DATASYNC);
+	else
+		gfs2_trans_add_meta(ip->i_gl, dibh);
+
 
 	if (inode == sdp->sd_rindex) {
 		adjust_fs_space(inode);
@@ -1107,7 +1085,7 @@ cannot_release:
 }
 
 static const struct address_space_operations gfs2_writeback_aops = {
-	.writepage = gfs2_writeback_writepage,
+	.writepage = gfs2_writepage,
 	.writepages = gfs2_writepages,
 	.readpage = gfs2_readpage,
 	.readpages = gfs2_readpages,
@@ -1123,7 +1101,7 @@ static const struct address_space_operations gfs2_writeback_aops = {
 };
 
 static const struct address_space_operations gfs2_ordered_aops = {
-	.writepage = gfs2_ordered_writepage,
+	.writepage = gfs2_writepage,
 	.writepages = gfs2_writepages,
 	.readpage = gfs2_readpage,
 	.readpages = gfs2_readpages,
diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c
index 72c3866a732..0621b46d474 100644
--- a/fs/gfs2/file.c
+++ b/fs/gfs2/file.c
@@ -650,7 +650,7 @@ static int gfs2_fsync(struct file *file, loff_t start, loff_t end,
 {
 	struct address_space *mapping = file->f_mapping;
 	struct inode *inode = mapping->host;
-	int sync_state = inode->i_state & (I_DIRTY_SYNC|I_DIRTY_DATASYNC);
+	int sync_state = inode->i_state & I_DIRTY;
 	struct gfs2_inode *ip = GFS2_I(inode);
 	int ret = 0, ret1 = 0;
 
@@ -660,6 +660,8 @@ static int gfs2_fsync(struct file *file, loff_t start, loff_t end,
 			return ret1;
 	}
 
+	if (!gfs2_is_jdata(ip))
+		sync_state &= ~I_DIRTY_PAGES;
 	if (datasync)
 		sync_state &= ~I_DIRTY_SYNC;
 
diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
index 544a809819c..722329cac98 100644
--- a/fs/gfs2/glock.c
+++ b/fs/gfs2/glock.c
@@ -1411,7 +1411,6 @@ __acquires(&lru_lock)
 		if (demote_ok(gl))
 			handle_callback(gl, LM_ST_UNLOCKED, 0, false);
 		WARN_ON(!test_and_clear_bit(GLF_LOCK, &gl->gl_flags));
-		smp_mb__after_clear_bit();
 		if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
 			gfs2_glock_put_nolock(gl);
 		spin_unlock(&gl->gl_spin);
@@ -1488,7 +1487,7 @@ static void examine_bucket(glock_examiner examiner, const struct gfs2_sbd *sdp,
 
 	rcu_read_lock();
 	hlist_bl_for_each_entry_rcu(gl, pos, head, gl_list) {
-		if ((gl->gl_sbd == sdp) && atomic_read(&gl->gl_ref))
+		if ((gl->gl_sbd == sdp) && atomic_inc_not_zero(&gl->gl_ref))
 			examiner(gl);
 	}
 	rcu_read_unlock();
@@ -1508,18 +1507,17 @@ static void glock_hash_walk(glock_examiner examiner, const struct gfs2_sbd *sdp)
  * thaw_glock - thaw out a glock which has an unprocessed reply waiting
  * @gl: The glock to thaw
  *
- * N.B. When we freeze a glock, we leave a ref to the glock outstanding,
- * so this has to result in the ref count being dropped by one.
  */
 
 static void thaw_glock(struct gfs2_glock *gl)
 {
 	if (!test_and_clear_bit(GLF_FROZEN, &gl->gl_flags))
-		return;
+		goto out;
 	set_bit(GLF_REPLY_PENDING, &gl->gl_flags);
-	gfs2_glock_hold(gl);
-	if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
+	if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0) {
+out:
 		gfs2_glock_put(gl);
+	}
 }
 
 /**
@@ -1536,7 +1534,6 @@ static void clear_glock(struct gfs2_glock *gl)
 	if (gl->gl_state != LM_ST_UNLOCKED)
 		handle_callback(gl, LM_ST_UNLOCKED, 0, false);
 	spin_unlock(&gl->gl_spin);
-	gfs2_glock_hold(gl);
 	if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
 		gfs2_glock_put(gl);
 }
diff --git a/fs/gfs2/lops.c b/fs/gfs2/lops.c
index 17c5b5d7dc8..010b9fb9fec 100644
--- a/fs/gfs2/lops.c
+++ b/fs/gfs2/lops.c
@@ -579,6 +579,24 @@ static int buf_lo_scan_elements(struct gfs2_jdesc *jd, unsigned int start,
 	return error;
 }
 
+/**
+ * gfs2_meta_sync - Sync all buffers associated with a glock
+ * @gl: The glock
+ *
+ */
+
+static void gfs2_meta_sync(struct gfs2_glock *gl)
+{
+	struct address_space *mapping = gfs2_glock2aspace(gl);
+	int error;
+
+	filemap_fdatawrite(mapping);
+	error = filemap_fdatawait(mapping);
+
+	if (error)
+		gfs2_io_error(gl->gl_sbd);
+}
+
 static void buf_lo_after_scan(struct gfs2_jdesc *jd, int error, int pass)
 {
 	struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
diff --git a/fs/gfs2/meta_io.c b/fs/gfs2/meta_io.c
index 0da390686c0..93241505054 100644
--- a/fs/gfs2/meta_io.c
+++ b/fs/gfs2/meta_io.c
@@ -98,24 +98,6 @@ const struct address_space_operations gfs2_meta_aops = {
 };
 
 /**
- * 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 = gfs2_glock2aspace(gl);
-	int error;
-
-	filemap_fdatawrite(mapping);
-	error = filemap_fdatawait(mapping);
-
-	if (error)
-		gfs2_io_error(gl->gl_sbd);
-}
-
-/**
  * gfs2_getbuf - Get a buffer with a given address space
  * @gl: the glock
  * @blkno: the block number (filesystem scope)
diff --git a/fs/gfs2/meta_io.h b/fs/gfs2/meta_io.h
index 0d4c843b6f8..4823b934208 100644
--- a/fs/gfs2/meta_io.h
+++ b/fs/gfs2/meta_io.h
@@ -48,21 +48,17 @@ static inline struct gfs2_sbd *gfs2_mapping2sbd(struct address_space *mapping)
 		return inode->i_sb->s_fs_info;
 }
 
-void gfs2_meta_sync(struct gfs2_glock *gl);
-
-struct buffer_head *gfs2_meta_new(struct gfs2_glock *gl, u64 blkno);
-int gfs2_meta_read(struct gfs2_glock *gl, u64 blkno,
-		   int flags, struct buffer_head **bhp);
-int gfs2_meta_wait(struct gfs2_sbd *sdp, struct buffer_head *bh);
-struct buffer_head *gfs2_getbuf(struct gfs2_glock *gl, u64 blkno, int create);
-
-void gfs2_remove_from_journal(struct buffer_head *bh, struct gfs2_trans *tr,
-			      int meta);
-
-void gfs2_meta_wipe(struct gfs2_inode *ip, u64 bstart, u32 blen);
-
-int gfs2_meta_indirect_buffer(struct gfs2_inode *ip, int height, u64 num,
-			      struct buffer_head **bhp);
+extern struct buffer_head *gfs2_meta_new(struct gfs2_glock *gl, u64 blkno);
+extern int gfs2_meta_read(struct gfs2_glock *gl, u64 blkno, int flags,
+			  struct buffer_head **bhp);
+extern int gfs2_meta_wait(struct gfs2_sbd *sdp, struct buffer_head *bh);
+extern struct buffer_head *gfs2_getbuf(struct gfs2_glock *gl, u64 blkno,
+				       int create);
+extern void gfs2_remove_from_journal(struct buffer_head *bh,
+				     struct gfs2_trans *tr, int meta);
+extern void gfs2_meta_wipe(struct gfs2_inode *ip, u64 bstart, u32 blen);
+extern int gfs2_meta_indirect_buffer(struct gfs2_inode *ip, int height, u64 num,
+				     struct buffer_head **bhp);
 
 static inline int gfs2_meta_inode_buffer(struct gfs2_inode *ip,
 					 struct buffer_head **bhp)
diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c
index 0262c190b6f..19ff5e8c285 100644
--- a/fs/gfs2/ops_fstype.c
+++ b/fs/gfs2/ops_fstype.c
@@ -646,6 +646,48 @@ static int gfs2_jindex_hold(struct gfs2_sbd *sdp, struct gfs2_holder *ji_gh)
 	return error;
 }
 
+/**
+ * check_journal_clean - Make sure a journal is clean for a spectator mount
+ * @sdp: The GFS2 superblock
+ * @jd: The journal descriptor
+ *
+ * Returns: 0 if the journal is clean or locked, else an error
+ */
+static int check_journal_clean(struct gfs2_sbd *sdp, struct gfs2_jdesc *jd)
+{
+	int error;
+	struct gfs2_holder j_gh;
+	struct gfs2_log_header_host head;
+	struct gfs2_inode *ip;
+
+	ip = GFS2_I(jd->jd_inode);
+	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_NOEXP |
+				   GL_EXACT | GL_NOCACHE, &j_gh);
+	if (error) {
+		fs_err(sdp, "Error locking journal for spectator mount.\n");
+		return -EPERM;
+	}
+	error = gfs2_jdesc_check(jd);
+	if (error) {
+		fs_err(sdp, "Error checking journal for spectator mount.\n");
+		goto out_unlock;
+	}
+	error = gfs2_find_jhead(jd, &head);
+	if (error) {
+		fs_err(sdp, "Error parsing journal for spectator mount.\n");
+		goto out_unlock;
+	}
+	if (!(head.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
+		error = -EPERM;
+		fs_err(sdp, "jid=%u: Journal is dirty, so the first mounter "
+		       "must not be a spectator.\n", jd->jd_jid);
+	}
+
+out_unlock:
+	gfs2_glock_dq_uninit(&j_gh);
+	return error;
+}
+
 static int init_journal(struct gfs2_sbd *sdp, int undo)
 {
 	struct inode *master = sdp->sd_master_dir->d_inode;
@@ -732,8 +774,15 @@ static int init_journal(struct gfs2_sbd *sdp, int undo)
 	if (sdp->sd_lockstruct.ls_first) {
 		unsigned int x;
 		for (x = 0; x < sdp->sd_journals; x++) {
-			error = gfs2_recover_journal(gfs2_jdesc_find(sdp, x),
-						     true);
+			struct gfs2_jdesc *jd = gfs2_jdesc_find(sdp, x);
+
+			if (sdp->sd_args.ar_spectator) {
+				error = check_journal_clean(sdp, jd);
+				if (error)
+					goto fail_jinode_gh;
+				continue;
+			}
+			error = gfs2_recover_journal(jd, true);
 			if (error) {
 				fs_err(sdp, "error recovering journal %u: %d\n",
 				       x, error);