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[GFS2] Move pin/unpin into lops.c, clean up locking
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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: Steven Whitehouse <swhiteho@redhat.com>
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Steven Whitehouse committed Oct 10, 2007
1 parent eaf9652 commit 9b9107a
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Showing 3 changed files with 89 additions and 101 deletions.
117 changes: 89 additions & 28 deletions fs/gfs2/lops.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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;
Expand All @@ -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);
}

Expand All @@ -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)
Expand Down Expand Up @@ -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)
Expand Down
70 changes: 0 additions & 70 deletions fs/gfs2/meta_io.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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
Expand Down
3 changes: 0 additions & 3 deletions fs/gfs2/meta_io.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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);

Expand Down

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