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authorSteven Whitehouse <swhiteho@redhat.com>2007-08-27 13:54:05 +0100
committerSteven Whitehouse <swhiteho@redhat.com>2007-10-10 08:56:00 +0100
commit9b9107a5a8b190e6cf09bbdf893869c6a9c482cc (patch)
tree77016dd5476f6ba72605ac0cdcbccec3ce794057 /fs/gfs2/lops.c
parenteaf965270ffff3086ef929e660ace45e862cfd2d (diff)
downloadlwn-9b9107a5a8b190e6cf09bbdf893869c6a9c482cc.tar.gz
lwn-9b9107a5a8b190e6cf09bbdf893869c6a9c482cc.zip
[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: Steven Whitehouse <swhiteho@redhat.com>
Diffstat (limited to 'fs/gfs2/lops.c')
-rw-r--r--fs/gfs2/lops.c117
1 files changed, 89 insertions, 28 deletions
diff --git a/fs/gfs2/lops.c b/fs/gfs2/lops.c
index 7ef335623373..3ec587135d46 100644
--- a/fs/gfs2/lops.c
+++ b/fs/gfs2/lops.c
@@ -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)