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Commit 9b9107a5 authored by Steven Whitehouse's avatar Steven Whitehouse
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[GFS2] Move pin/unpin into lops.c, clean up locking 



gfs2_pin and gfs2_unpin are only used in lops.c, despite being
defined in meta_io.c, so this patch moves them into lops.c and
makes them static. At the same time, its possible to clean up
the locking in the buf and databuf _lo_add() functions so that
we only need to grab the spinlock once. Also we have to move
lock_buffer() around the _lo_add() functions since we can't
do that in gfs2_pin() any more since we hold the spinlock
for the duration of that function.

As a result, the code shrinks by 12 lines and we do far fewer
operations when adding buffers to the log. It also makes the
code somewhat easier to read & understand.

Signed-off-by: default avatarSteven Whitehouse <swhiteho@redhat.com>
parent eaf96527

fs/gfs2/lops.c

+89 −28
Original line number Diff line number Diff line
@@ -27,7 +27,71 @@ 
#include "trans.h"

#include "util.h"



static void glock_lo_add(struct gfs2_sbd *sdp, struct gfs2_log_element *le)

/**

 * 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

 */

static void gfs2_pin(struct gfs2_sbd *sdp, struct buffer_head *bh)

{

	struct gfs2_bufdata *bd;



	gfs2_assert_withdraw(sdp, test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags));



	clear_buffer_dirty(bh);

	if (test_set_buffer_pinned(bh))

		gfs2_assert_withdraw(sdp, 0);

	if (!buffer_uptodate(bh))

		gfs2_io_error_bh(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.

	 */

	if (bd->bd_ail)

		list_move(&bd->bd_ail_st_list, &bd->bd_ail->ai_ail2_list);

	get_bh(bh);

}



/**

 * gfs2_unpin - Unpin a buffer

 * @sdp: the filesystem the buffer belongs to

 * @bh: The buffer to unpin

 * @ai:

 *

 */



static 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);



	lock_buffer(bh);

	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);

	unlock_buffer(bh);

}



static void __glock_lo_add(struct gfs2_sbd *sdp, struct gfs2_log_element *le)

{

	struct gfs2_glock *gl;

	struct gfs2_trans *tr = current->journal_info;
@@ -38,15 +102,19 @@ static void glock_lo_add(struct gfs2_sbd *sdp, struct gfs2_log_element *le) 
	if (gfs2_assert_withdraw(sdp, gfs2_glock_is_held_excl(gl)))

		return;



	gfs2_log_lock(sdp);

	if (!list_empty(&le->le_list)){

		gfs2_log_unlock(sdp);

	if (!list_empty(&le->le_list))

		return;

	}



	gfs2_glock_hold(gl);

	set_bit(GLF_DIRTY, &gl->gl_flags);

	sdp->sd_log_num_gl++;

	list_add(&le->le_list, &sdp->sd_log_le_gl);

}



static void glock_lo_add(struct gfs2_sbd *sdp, struct gfs2_log_element *le)

{

	gfs2_log_lock(sdp);

	__glock_lo_add(sdp, le);

	gfs2_log_unlock(sdp);

}
@@ -71,30 +139,25 @@ static void buf_lo_add(struct gfs2_sbd *sdp, struct gfs2_log_element *le) 
	struct gfs2_bufdata *bd = container_of(le, struct gfs2_bufdata, bd_le);

	struct gfs2_trans *tr;



	lock_buffer(bd->bd_bh);

	gfs2_log_lock(sdp);

	if (!list_empty(&bd->bd_list_tr)) {

		gfs2_log_unlock(sdp);

		return;

	}

	if (!list_empty(&bd->bd_list_tr))

		goto out;

	tr = current->journal_info;

	tr->tr_touched = 1;

	tr->tr_num_buf++;

	list_add(&bd->bd_list_tr, &tr->tr_list_buf);

	gfs2_log_unlock(sdp);



	if (!list_empty(&le->le_list))

		return;



	gfs2_trans_add_gl(bd->bd_gl);



		goto out;

	__glock_lo_add(sdp, &bd->bd_gl->gl_le);

	gfs2_meta_check(sdp, bd->bd_bh);

	gfs2_pin(sdp, bd->bd_bh);

	gfs2_log_lock(sdp);

	sdp->sd_log_num_buf++;

	list_add(&le->le_list, &sdp->sd_log_le_buf);

	gfs2_log_unlock(sdp);



	tr->tr_num_buf_new++;

out:

	gfs2_log_unlock(sdp);

	unlock_buffer(bd->bd_bh);

}



static void buf_lo_incore_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
@@ -476,31 +539,29 @@ static void databuf_lo_add(struct gfs2_sbd *sdp, struct gfs2_log_element *le) 
	struct address_space *mapping = bd->bd_bh->b_page->mapping;

	struct gfs2_inode *ip = GFS2_I(mapping->host);



	lock_buffer(bd->bd_bh);

	gfs2_log_lock(sdp);

	if (!list_empty(&bd->bd_list_tr)) {

		gfs2_log_unlock(sdp);

		return;

	}

	if (!list_empty(&bd->bd_list_tr))

		goto out;

	tr->tr_touched = 1;

	if (gfs2_is_jdata(ip)) {

		tr->tr_num_buf++;

		list_add(&bd->bd_list_tr, &tr->tr_list_buf);

	}

	gfs2_log_unlock(sdp);

	if (!list_empty(&le->le_list))

		return;

		goto out;



	gfs2_trans_add_gl(bd->bd_gl);

	__glock_lo_add(sdp, &bd->bd_gl->gl_le);

	if (gfs2_is_jdata(ip)) {

		gfs2_pin(sdp, bd->bd_bh);

		tr->tr_num_databuf_new++;

	}

	gfs2_log_lock(sdp);

	if (gfs2_is_jdata(ip))

		sdp->sd_log_num_jdata++;

	}

	sdp->sd_log_num_databuf++;

	list_add(&le->le_list, &sdp->sd_log_le_databuf);

out:

	gfs2_log_unlock(sdp);

	unlock_buffer(bd->bd_bh);

}



static int gfs2_check_magic(struct buffer_head *bh)

fs/gfs2/meta_io.c

+0 −70
Original line number Diff line number Diff line
@@ -297,76 +297,6 @@ void gfs2_attach_bufdata(struct gfs2_glock *gl, struct buffer_head *bh, 
		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

fs/gfs2/meta_io.h

+0 −3
Original line number Diff line number Diff line
@@ -50,9 +50,6 @@ int gfs2_meta_wait(struct gfs2_sbd *sdp, struct buffer_head *bh); 


void gfs2_attach_bufdata(struct gfs2_glock *gl, struct buffer_head *bh,

			 int meta);

void gfs2_pin(struct gfs2_sbd *sdp, struct buffer_head *bh);

void gfs2_unpin(struct gfs2_sbd *sdp, struct buffer_head *bh,

		struct gfs2_ail *ai);



void gfs2_meta_wipe(struct gfs2_inode *ip, u64 bstart, u32 blen);