[GFS2] Don't do recursive locking in glock layer
This patch changes the last user of recursive locking so that
it no longer needs this feature and removes it from the glock
layer. This makes the glock code a lot simpler and easier to
understand. Its also a prerequsite to adding support for the
AOP_TRUNCATED_PAGE return code (or at least it is if you don't
want your brain to melt in the process)
I've left in a couple of checks just in case there is some place
else in the code which is still using this feature that I didn't
spot yet, but they can probably be removed long term.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
index 32cc400..0f31715 100644
--- a/fs/gfs2/glock.c
+++ b/fs/gfs2/glock.c
@@ -450,86 +450,6 @@
}
/**
- * handle_recurse - put other holder structures (marked recursive)
- * into the holders list
- * @gh: the holder structure
- *
- */
-
-static void handle_recurse(struct gfs2_holder *gh)
-{
- struct gfs2_glock *gl = gh->gh_gl;
- struct gfs2_sbd *sdp = gl->gl_sbd;
- struct gfs2_holder *tmp_gh, *safe;
- int found = 0;
-
- BUG_ON(!spin_is_locked(&gl->gl_spin));
-
- printk(KERN_INFO "recursion %016llx, %u\n", gl->gl_name.ln_number,
- gl->gl_name.ln_type);
-
- if (gfs2_assert_warn(sdp, gh->gh_owner))
- return;
-
- list_for_each_entry_safe(tmp_gh, safe, &gl->gl_waiters3, gh_list) {
- if (tmp_gh->gh_owner != gh->gh_owner)
- continue;
-
- gfs2_assert_warn(sdp,
- test_bit(HIF_RECURSE, &tmp_gh->gh_iflags));
-
- list_move_tail(&tmp_gh->gh_list, &gl->gl_holders);
- tmp_gh->gh_error = 0;
- set_bit(HIF_HOLDER, &tmp_gh->gh_iflags);
-
- complete(&tmp_gh->gh_wait);
-
- found = 1;
- }
-
- gfs2_assert_warn(sdp, found);
-}
-
-/**
- * do_unrecurse - a recursive holder was just dropped of the waiters3 list
- * @gh: the holder
- *
- * If there is only one other recursive holder, clear its HIF_RECURSE bit.
- * If there is more than one, leave them alone.
- *
- */
-
-static void do_unrecurse(struct gfs2_holder *gh)
-{
- struct gfs2_glock *gl = gh->gh_gl;
- struct gfs2_sbd *sdp = gl->gl_sbd;
- struct gfs2_holder *tmp_gh, *last_gh = NULL;
- int found = 0;
-
- BUG_ON(!spin_is_locked(&gl->gl_spin));
-
- if (gfs2_assert_warn(sdp, gh->gh_owner))
- return;
-
- list_for_each_entry(tmp_gh, &gl->gl_waiters3, gh_list) {
- if (tmp_gh->gh_owner != gh->gh_owner)
- continue;
-
- gfs2_assert_warn(sdp,
- test_bit(HIF_RECURSE, &tmp_gh->gh_iflags));
-
- if (found)
- return;
-
- found = 1;
- last_gh = tmp_gh;
- }
-
- if (!gfs2_assert_warn(sdp, found))
- clear_bit(HIF_RECURSE, &last_gh->gh_iflags);
-}
-
-/**
* rq_mutex - process a mutex request in the queue
* @gh: the glock holder
*
@@ -562,7 +482,6 @@
struct gfs2_glock *gl = gh->gh_gl;
struct gfs2_sbd *sdp = gl->gl_sbd;
struct gfs2_glock_operations *glops = gl->gl_ops;
- int recurse;
if (!relaxed_state_ok(gl->gl_state, gh->gh_state, gh->gh_flags)) {
if (list_empty(&gl->gl_holders)) {
@@ -588,7 +507,6 @@
if (list_empty(&gl->gl_holders)) {
set_bit(HIF_FIRST, &gh->gh_iflags);
set_bit(GLF_LOCK, &gl->gl_flags);
- recurse = 0;
} else {
struct gfs2_holder *next_gh;
if (gh->gh_flags & GL_LOCAL_EXCL)
@@ -597,16 +515,12 @@
gh_list);
if (next_gh->gh_flags & GL_LOCAL_EXCL)
return 1;
- recurse = test_bit(HIF_RECURSE, &gh->gh_iflags);
}
list_move_tail(&gh->gh_list, &gl->gl_holders);
gh->gh_error = 0;
set_bit(HIF_HOLDER, &gh->gh_iflags);
- if (recurse)
- handle_recurse(gh);
-
complete(&gh->gh_wait);
return 0;
@@ -897,8 +811,6 @@
spin_lock(&gl->gl_spin);
list_del_init(&gh->gh_list);
gh->gh_error = -EIO;
- if (test_bit(HIF_RECURSE, &gh->gh_iflags))
- do_unrecurse(gh);
spin_unlock(&gl->gl_spin);
} else if (test_bit(HIF_DEMOTE, &gh->gh_iflags)) {
@@ -922,8 +834,6 @@
spin_lock(&gl->gl_spin);
list_del_init(&gh->gh_list);
gh->gh_error = GLR_CANCELED;
- if (test_bit(HIF_RECURSE, &gh->gh_iflags))
- do_unrecurse(gh);
spin_unlock(&gl->gl_spin);
} else if (relaxed_state_ok(gl->gl_state, gh->gh_state, gh->gh_flags)) {
@@ -941,8 +851,6 @@
spin_lock(&gl->gl_spin);
list_del_init(&gh->gh_list);
gh->gh_error = GLR_TRYFAILED;
- if (test_bit(HIF_RECURSE, &gh->gh_iflags))
- do_unrecurse(gh);
spin_unlock(&gl->gl_spin);
} else {
@@ -1161,8 +1069,6 @@
!list_empty(&gh->gh_list)) {
list_del_init(&gh->gh_list);
gh->gh_error = GLR_TRYFAILED;
- if (test_bit(HIF_RECURSE, &gh->gh_iflags))
- do_unrecurse(gh);
run_queue(gl);
spin_unlock(&gl->gl_spin);
return gh->gh_error;
@@ -1191,9 +1097,6 @@
if (gh->gh_error) {
spin_lock(&gl->gl_spin);
list_del_init(&gh->gh_list);
- if (test_and_clear_bit(HIF_RECURSE,
- &gh->gh_iflags))
- do_unrecurse(gh);
spin_unlock(&gl->gl_spin);
}
}
@@ -1202,8 +1105,6 @@
gl->gl_req_gh = NULL;
gl->gl_req_bh = NULL;
clear_bit(GLF_LOCK, &gl->gl_flags);
- if (test_bit(HIF_RECURSE, &gh->gh_iflags))
- handle_recurse(gh);
run_queue(gl);
spin_unlock(&gl->gl_spin);
}
@@ -1225,40 +1126,6 @@
}
/**
- * recurse_check -
- *
- * Make sure the new holder is compatible with the pre-existing one.
- *
- */
-
-static int recurse_check(struct gfs2_holder *existing, struct gfs2_holder *new,
- unsigned int state)
-{
- struct gfs2_sbd *sdp = existing->gh_gl->gl_sbd;
-
- if (gfs2_assert_warn(sdp, (new->gh_flags & LM_FLAG_ANY) ||
- !(existing->gh_flags & LM_FLAG_ANY)))
- goto fail;
-
- if (gfs2_assert_warn(sdp, (existing->gh_flags & GL_LOCAL_EXCL) ||
- !(new->gh_flags & GL_LOCAL_EXCL)))
- goto fail;
-
- if (gfs2_assert_warn(sdp, relaxed_state_ok(state, new->gh_state,
- new->gh_flags)))
- goto fail;
-
- return 0;
-
-fail:
- print_symbol(KERN_WARNING "GFS2: Existing holder from %s\n",
- existing->gh_ip);
- print_symbol(KERN_WARNING "GFS2: New holder from %s\n", new->gh_ip);
- set_bit(HIF_ABORTED, &new->gh_iflags);
- return -EINVAL;
-}
-
-/**
* add_to_queue - Add a holder to the wait queue (but look for recursion)
* @gh: the holder structure to add
*
@@ -1271,37 +1138,20 @@
BUG_ON(!gh->gh_owner);
- if (!gh->gh_owner)
- goto out;
-
existing = find_holder_by_owner(&gl->gl_holders, gh->gh_owner);
if (existing) {
- if (recurse_check(existing, gh, gl->gl_state))
- return;
-
- list_add_tail(&gh->gh_list, &gl->gl_holders);
- set_bit(HIF_HOLDER, &gh->gh_iflags);
-
- gh->gh_error = 0;
- complete(&gh->gh_wait);
-
- return;
+ print_symbol(KERN_WARNING "original: %s\n", existing->gh_ip);
+ print_symbol(KERN_WARNING "new: %s\n", gh->gh_ip);
+ BUG();
}
existing = find_holder_by_owner(&gl->gl_waiters3, gh->gh_owner);
if (existing) {
- if (recurse_check(existing, gh, existing->gh_state))
- return;
-
- set_bit(HIF_RECURSE, &gh->gh_iflags);
- set_bit(HIF_RECURSE, &existing->gh_iflags);
-
- list_add_tail(&gh->gh_list, &gl->gl_waiters3);
-
- return;
+ print_symbol(KERN_WARNING "original: %s\n", existing->gh_ip);
+ print_symbol(KERN_WARNING "new: %s\n", gh->gh_ip);
+ BUG();
}
- out:
if (gh->gh_flags & LM_FLAG_PRIORITY)
list_add(&gh->gh_list, &gl->gl_waiters3);
else
diff --git a/fs/gfs2/incore.h b/fs/gfs2/incore.h
index 761f001..84dd2f5 100644
--- a/fs/gfs2/incore.h
+++ b/fs/gfs2/incore.h
@@ -146,7 +146,6 @@
HIF_DEALLOC = 5,
HIF_HOLDER = 6,
HIF_FIRST = 7,
- HIF_RECURSE = 8,
HIF_ABORTED = 9,
};
diff --git a/fs/gfs2/recovery.c b/fs/gfs2/recovery.c
index e91c2bd..7d46796 100644
--- a/fs/gfs2/recovery.c
+++ b/fs/gfs2/recovery.c
@@ -436,30 +436,35 @@
unsigned int pass;
int error;
- fs_info(sdp, "jid=%u: Trying to acquire journal lock...\n", jd->jd_jid);
+ if (jd->jd_jid != sdp->sd_lockstruct.ls_jid) {
+ fs_info(sdp, "jid=%u: Trying to acquire journal lock...\n",
+ jd->jd_jid);
- /* Aquire the journal lock so we can do recovery */
+ /* Aquire the journal lock so we can do recovery */
- error = gfs2_glock_nq_num(sdp, jd->jd_jid, &gfs2_journal_glops,
- LM_ST_EXCLUSIVE,
- LM_FLAG_NOEXP | LM_FLAG_TRY | GL_NOCACHE,
- &j_gh);
- switch (error) {
- case 0:
- break;
+ error = gfs2_glock_nq_num(sdp, jd->jd_jid, &gfs2_journal_glops,
+ LM_ST_EXCLUSIVE,
+ LM_FLAG_NOEXP | LM_FLAG_TRY | GL_NOCACHE,
+ &j_gh);
+ switch (error) {
+ case 0:
+ break;
+
+ case GLR_TRYFAILED:
+ fs_info(sdp, "jid=%u: Busy\n", jd->jd_jid);
+ error = 0;
+
+ default:
+ goto fail;
+ };
- case GLR_TRYFAILED:
- fs_info(sdp, "jid=%u: Busy\n", jd->jd_jid);
- error = 0;
-
- default:
- goto fail;
- };
-
- error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED,
- LM_FLAG_NOEXP, &ji_gh);
- if (error)
- goto fail_gunlock_j;
+ error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED,
+ LM_FLAG_NOEXP, &ji_gh);
+ if (error)
+ goto fail_gunlock_j;
+ } else {
+ fs_info(sdp, "jid=%u, already locked for use\n", jd->jd_jid);
+ }
fs_info(sdp, "jid=%u: Looking at journal...\n", jd->jd_jid);
@@ -481,10 +486,8 @@
error = gfs2_glock_nq_init(sdp->sd_trans_gl,
LM_ST_SHARED,
- LM_FLAG_NOEXP |
- LM_FLAG_PRIORITY |
- GL_NEVER_RECURSE |
- GL_NOCANCEL |
+ LM_FLAG_NOEXP | LM_FLAG_PRIORITY |
+ GL_NEVER_RECURSE | GL_NOCANCEL |
GL_NOCACHE,
&t_gh);
if (error)
@@ -521,37 +524,35 @@
goto fail_gunlock_tr;
gfs2_glock_dq_uninit(&t_gh);
-
t = DIV_ROUND_UP(jiffies - t, HZ);
-
fs_info(sdp, "jid=%u: Journal replayed in %lus\n",
jd->jd_jid, t);
}
- gfs2_glock_dq_uninit(&ji_gh);
+ if (jd->jd_jid != sdp->sd_lockstruct.ls_jid)
+ gfs2_glock_dq_uninit(&ji_gh);
gfs2_lm_recovery_done(sdp, jd->jd_jid, LM_RD_SUCCESS);
- gfs2_glock_dq_uninit(&j_gh);
+ if (jd->jd_jid != sdp->sd_lockstruct.ls_jid)
+ gfs2_glock_dq_uninit(&j_gh);
fs_info(sdp, "jid=%u: Done\n", jd->jd_jid);
-
return 0;
- fail_gunlock_tr:
+fail_gunlock_tr:
gfs2_glock_dq_uninit(&t_gh);
-
- fail_gunlock_ji:
- gfs2_glock_dq_uninit(&ji_gh);
-
- fail_gunlock_j:
- gfs2_glock_dq_uninit(&j_gh);
+fail_gunlock_ji:
+ if (jd->jd_jid != sdp->sd_lockstruct.ls_jid) {
+ gfs2_glock_dq_uninit(&ji_gh);
+fail_gunlock_j:
+ gfs2_glock_dq_uninit(&j_gh);
+ }
fs_info(sdp, "jid=%u: %s\n", jd->jd_jid, (error) ? "Failed" : "Done");
- fail:
+fail:
gfs2_lm_recovery_done(sdp, jd->jd_jid, LM_RD_GAVEUP);
-
return error;
}