Commit 4fd1a579 authored by Andreas Gruenbacher's avatar Andreas Gruenbacher Committed by Bob Peterson
Browse files

gfs2: Get rid of flush_delayed_work in gfs2_evict_inode 



So far, gfs2_evict_inode clears gl->gl_object and then flushes the glock
work queue to make sure that inode glops which dereference gl->gl_object
have finished running before the inode is destroyed.  However, flushing
the work queue may do more work than needed, and in particular, it may
call into DLM, which we want to avoid here.  Use a bit lock
(GIF_GLOP_PENDING) to synchronize between the inode glops and
gfs2_evict_inode instead to get rid of the flushing.

In addition, flush the work queues of existing glocks before reusing
them for new inodes to get those glocks into a known state: the glock
state engine currently doesn't handle glock re-appropriation correctly.
(We may be able to fix the glock state engine instead later.)

Based on a patch by Steven Whitehouse <swhiteho@redhat.com>.

Signed-off-by: default avatarAndreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: default avatarBob Peterson <rpeterso@redhat.com>
parent 722f6f62

fs/gfs2/glock.h

+7 −0
Original line number Diff line number Diff line
@@ -257,4 +257,11 @@ static inline bool gfs2_holder_initialized(struct gfs2_holder *gh) 
	return gh->gh_gl;

}



static inline void glock_set_object(struct gfs2_glock *gl, void *object)

{

	spin_lock(&gl->gl_lockref.lock);

	gl->gl_object = object;

	spin_unlock(&gl->gl_lockref.lock);

}



#endif /* __GLOCK_DOT_H__ */

fs/gfs2/glops.c

+32 −7
Original line number Diff line number Diff line
@@ -197,6 +197,27 @@ static void rgrp_go_inval(struct gfs2_glock *gl, int flags) 
		rgd->rd_flags &= ~GFS2_RDF_UPTODATE;

}



static struct gfs2_inode *gfs2_glock2inode(struct gfs2_glock *gl)

{

	struct gfs2_inode *ip;



	spin_lock(&gl->gl_lockref.lock);

	ip = gl->gl_object;

	if (ip)

		set_bit(GIF_GLOP_PENDING, &ip->i_flags);

	spin_unlock(&gl->gl_lockref.lock);

	return ip;

}



static void gfs2_clear_glop_pending(struct gfs2_inode *ip)

{

	if (!ip)

		return;



	clear_bit_unlock(GIF_GLOP_PENDING, &ip->i_flags);

	wake_up_bit(&ip->i_flags, GIF_GLOP_PENDING);

}



/**

 * inode_go_sync - Sync the dirty data and/or metadata for an inode glock

 * @gl: the glock protecting the inode
@@ -205,25 +226,24 @@ static void rgrp_go_inval(struct gfs2_glock *gl, int flags) 


static void inode_go_sync(struct gfs2_glock *gl)

{

	struct gfs2_inode *ip = gl->gl_object;

	struct gfs2_inode *ip = gfs2_glock2inode(gl);

	int isreg = ip && S_ISREG(ip->i_inode.i_mode);

	struct address_space *metamapping = gfs2_glock2aspace(gl);

	int error;



	if (ip && !S_ISREG(ip->i_inode.i_mode))

		ip = NULL;

	if (ip) {

	if (isreg) {

		if (test_and_clear_bit(GIF_SW_PAGED, &ip->i_flags))

			unmap_shared_mapping_range(ip->i_inode.i_mapping, 0, 0);

		inode_dio_wait(&ip->i_inode);

	}

	if (!test_and_clear_bit(GLF_DIRTY, &gl->gl_flags))

		return;

		goto out;



	GLOCK_BUG_ON(gl, gl->gl_state != LM_ST_EXCLUSIVE);



	gfs2_log_flush(gl->gl_name.ln_sbd, gl, NORMAL_FLUSH);

	filemap_fdatawrite(metamapping);

	if (ip) {

	if (isreg) {

		struct address_space *mapping = ip->i_inode.i_mapping;

		filemap_fdatawrite(mapping);

		error = filemap_fdatawait(mapping);
@@ -238,6 +258,9 @@ static void inode_go_sync(struct gfs2_glock *gl) 
	 */

	smp_mb__before_atomic();

	clear_bit(GLF_DIRTY, &gl->gl_flags);



out:

	gfs2_clear_glop_pending(ip);

}



/**
@@ -253,7 +276,7 @@ static void inode_go_sync(struct gfs2_glock *gl) 


static void inode_go_inval(struct gfs2_glock *gl, int flags)

{

	struct gfs2_inode *ip = gl->gl_object;

	struct gfs2_inode *ip = gfs2_glock2inode(gl);



	gfs2_assert_withdraw(gl->gl_name.ln_sbd, !atomic_read(&gl->gl_ail_count));
@@ -274,6 +297,8 @@ static void inode_go_inval(struct gfs2_glock *gl, int flags) 
	}

	if (ip && S_ISREG(ip->i_inode.i_mode))

		truncate_inode_pages(ip->i_inode.i_mapping, 0);



	gfs2_clear_glop_pending(ip);

}



/**

fs/gfs2/incore.h

+1 −0
Original line number Diff line number Diff line
@@ -385,6 +385,7 @@ enum { 
	GIF_SW_PAGED		= 3,

	GIF_ORDERED		= 4,

	GIF_FREE_VFS_INODE      = 5,

	GIF_GLOP_PENDING	= 6,

};



struct gfs2_inode {

fs/gfs2/inode.c

+4 −3
Original line number Diff line number Diff line
@@ -144,7 +144,8 @@ struct inode *gfs2_inode_lookup(struct super_block *sb, unsigned int type, 
		error = gfs2_glock_get(sdp, no_addr, &gfs2_inode_glops, CREATE, &ip->i_gl);

		if (unlikely(error))

			goto fail;

		ip->i_gl->gl_object = ip;

		flush_delayed_work(&ip->i_gl->gl_work);

		glock_set_object(ip->i_gl, ip);



		error = gfs2_glock_get(sdp, no_addr, &gfs2_iopen_glops, CREATE, &io_gl);

		if (unlikely(error))
@@ -173,8 +174,8 @@ struct inode *gfs2_inode_lookup(struct super_block *sb, unsigned int type, 
		error = gfs2_glock_nq_init(io_gl, LM_ST_SHARED, GL_EXACT, &ip->i_iopen_gh);

		if (unlikely(error))

			goto fail_put;



		ip->i_iopen_gh.gh_gl->gl_object = ip;

		flush_delayed_work(&ip->i_iopen_gh.gh_gl->gl_work);

		glock_set_object(ip->i_iopen_gh.gh_gl, ip);

		gfs2_glock_put(io_gl);

		io_gl = NULL;

fs/gfs2/super.c

+2 −2
Original line number Diff line number Diff line
@@ -1631,8 +1631,8 @@ out: 
	gfs2_ordered_del_inode(ip);

	clear_inode(inode);

	gfs2_dir_hash_inval(ip);

	ip->i_gl->gl_object = NULL;

	flush_delayed_work(&ip->i_gl->gl_work);

	glock_set_object(ip->i_gl, NULL);

	wait_on_bit_io(&ip->i_flags, GIF_GLOP_PENDING, TASK_UNINTERRUPTIBLE);

	gfs2_glock_add_to_lru(ip->i_gl);

	gfs2_glock_put(ip->i_gl);

	ip->i_gl = NULL;

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