GFS2: Improve tracing support (adds two flags)

This adds support for two new flags. One keeps track of whether
the glock is on the LRU list or not. The other isn't really a
flag as such, but an indication of whether the glock has an
attached object or not. This indication is reported without
any locking, which is ok since we do not dereference the object
pointer but merely report whether it is NULL or not.

Also, this fixes one place where a tracepoint was missing, which
was at the point we remove deallocated blocks from the journal.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
index 1019183232fe08ef1230e09886359e13103cb230..0c6c690901406436d2fd5e0e1c5fc2d83cac7931 100644 (file)
--- a/fs/gfs2/glock.c
+++ b/fs/gfs2/glock.c
@@ -170,6 +170,7 @@ void gfs2_glock_add_to_lru(struct gfs2_glock *gl)
                atomic_inc(&lru_count);
 
        list_add_tail(&gl->gl_lru, &lru_list);
+       set_bit(GLF_LRU, &gl->gl_flags);
        spin_unlock(&lru_lock);
 }
 
@@ -1364,6 +1365,7 @@ static int gfs2_shrink_glock_memory(struct shrinker *shrink, int nr, gfp_t gfp_m
        while(nr && !list_empty(&lru_list)) {
                gl = list_entry(lru_list.next, struct gfs2_glock, gl_lru);
                list_del_init(&gl->gl_lru);
+               clear_bit(GLF_LRU, &gl->gl_flags);
                atomic_dec(&lru_count);
 
                /* Test for being demotable */
@@ -1386,6 +1388,7 @@ static int gfs2_shrink_glock_memory(struct shrinker *shrink, int nr, gfp_t gfp_m
                }
                nr_skipped++;
                list_add(&gl->gl_lru, &skipped);
+               set_bit(GLF_LRU, &gl->gl_flags);
        }
        list_splice(&skipped, &lru_list);
        atomic_add(nr_skipped, &lru_count);
@@ -1598,9 +1601,11 @@ static int dump_holder(struct seq_file *seq, const struct gfs2_holder *gh)
        return 0;
 }
 
-static const char *gflags2str(char *buf, const unsigned long *gflags)
+static const char *gflags2str(char *buf, const struct gfs2_glock *gl)
 {
+       const unsigned long *gflags = &gl->gl_flags;
        char *p = buf;
+
        if (test_bit(GLF_LOCK, gflags))
                *p++ = 'l';
        if (test_bit(GLF_DEMOTE, gflags))
@@ -1623,6 +1628,10 @@ static const char *gflags2str(char *buf, const unsigned long *gflags)
                *p++ = 'F';
        if (test_bit(GLF_QUEUED, gflags))
                *p++ = 'q';
+       if (test_bit(GLF_LRU, gflags))
+               *p++ = 'L';
+       if (gl->gl_object)
+               *p++ = 'o';
        *p = 0;
        return buf;
 }
@@ -1661,7 +1670,7 @@ static int __dump_glock(struct seq_file *seq, const struct gfs2_glock *gl)
                  state2str(gl->gl_state),
                  gl->gl_name.ln_type,
                  (unsigned long long)gl->gl_name.ln_number,
-                 gflags2str(gflags_buf, &gl->gl_flags),
+                 gflags2str(gflags_buf, gl),
                  state2str(gl->gl_target),
                  state2str(gl->gl_demote_state), dtime,
                  atomic_read(&gl->gl_ail_count),

diff --git a/fs/gfs2/incore.h b/fs/gfs2/incore.h
index 870a89d6d4dcb6d74accba494f1393f2df2a6f7f..48eb1eed51b5d59714236ef57bd058f841452527 100644 (file)
--- a/fs/gfs2/incore.h
+++ b/fs/gfs2/incore.h
@@ -200,6 +200,8 @@ enum {
        GLF_INITIAL                     = 10,
        GLF_FROZEN                      = 11,
        GLF_QUEUED                      = 12,
+       GLF_LRU                         = 13,
+       GLF_OBJECT                      = 14, /* Used only for tracing */
 };
 
 struct gfs2_glock {

diff --git a/fs/gfs2/meta_io.c b/fs/gfs2/meta_io.c
index 675349b5a1335de5e7c8f4ef22730fbed46b7463..747238cd9f96dfeefffc380a2802e28c4bf5a404 100644 (file)
--- a/fs/gfs2/meta_io.c
+++ b/fs/gfs2/meta_io.c
@@ -31,6 +31,7 @@
 #include "rgrp.h"
 #include "trans.h"
 #include "util.h"
+#include "trace_gfs2.h"
 
 static int gfs2_aspace_writepage(struct page *page, struct writeback_control *wbc)
 {
@@ -310,6 +311,7 @@ void gfs2_remove_from_journal(struct buffer_head *bh, struct gfs2_trans *tr, int
        struct gfs2_bufdata *bd = bh->b_private;
 
        if (test_clear_buffer_pinned(bh)) {
+               trace_gfs2_pin(bd, 0);
                atomic_dec(&sdp->sd_log_pinned);
                list_del_init(&bd->bd_le.le_list);
                if (meta) {

diff --git a/fs/gfs2/trace_gfs2.h b/fs/gfs2/trace_gfs2.h
index cedb0bb96d968414d14e6eca3e5b934b68ee606e..9133d0aaac2672cf0d620a608a96824a58b51cb8 100644 (file)
--- a/fs/gfs2/trace_gfs2.h
+++ b/fs/gfs2/trace_gfs2.h
@@ -40,7 +40,9 @@
        {(1UL << GLF_REPLY_PENDING),            "r" },          \
        {(1UL << GLF_INITIAL),                  "I" },          \
        {(1UL << GLF_FROZEN),                   "F" },          \
-       {(1UL << GLF_QUEUED),                   "q" })
+       {(1UL << GLF_QUEUED),                   "q" },          \
+       {(1UL << GLF_LRU),                      "L" },          \
+       {(1UL << GLF_OBJECT),                   "o" })
 
 #ifndef NUMPTY
 #define NUMPTY
@@ -94,7 +96,7 @@ TRACE_EVENT(gfs2_glock_state_change,
                __entry->new_state      = glock_trace_state(new_state);
                __entry->tgt_state      = glock_trace_state(gl->gl_target);
                __entry->dmt_state      = glock_trace_state(gl->gl_demote_state);
-               __entry->flags          = gl->gl_flags;
+               __entry->flags          = gl->gl_flags | (gl->gl_object ? (1UL<<GLF_OBJECT) : 0);
        ),
 
        TP_printk("%u,%u glock %d:%lld state %s to %s tgt:%s dmt:%s flags:%s",
@@ -127,7 +129,7 @@ TRACE_EVENT(gfs2_glock_put,
                __entry->gltype         = gl->gl_name.ln_type;
                __entry->glnum          = gl->gl_name.ln_number;
                __entry->cur_state      = glock_trace_state(gl->gl_state);
-               __entry->flags          = gl->gl_flags;
+               __entry->flags          = gl->gl_flags  | (gl->gl_object ? (1UL<<GLF_OBJECT) : 0);
        ),
 
        TP_printk("%u,%u glock %d:%lld state %s => %s flags:%s",
@@ -161,7 +163,7 @@ TRACE_EVENT(gfs2_demote_rq,
                __entry->glnum          = gl->gl_name.ln_number;
                __entry->cur_state      = glock_trace_state(gl->gl_state);
                __entry->dmt_state      = glock_trace_state(gl->gl_demote_state);
-               __entry->flags          = gl->gl_flags;
+               __entry->flags          = gl->gl_flags  | (gl->gl_object ? (1UL<<GLF_OBJECT) : 0);
        ),
 
        TP_printk("%u,%u glock %d:%lld demote %s to %s flags:%s",