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-rw-r--r--fs/gfs2/glock.c316
1 files changed, 75 insertions, 241 deletions
diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
index 4381469..6618c11 100644
--- a/fs/gfs2/glock.c
+++ b/fs/gfs2/glock.c
@@ -19,6 +19,8 @@
#include <linux/gfs2_ondisk.h>
#include <linux/list.h>
#include <linux/lm_interface.h>
+#include <linux/wait.h>
+#include <linux/rwsem.h>
#include <asm/uaccess.h>
#include "gfs2.h"
@@ -33,11 +35,6 @@
#include "super.h"
#include "util.h"
-struct greedy {
- struct gfs2_holder gr_gh;
- struct delayed_work gr_work;
-};
-
struct gfs2_gl_hash_bucket {
struct hlist_head hb_list;
};
@@ -47,6 +44,9 @@ typedef void (*glock_examiner) (struct gfs2_glock * gl);
static int gfs2_dump_lockstate(struct gfs2_sbd *sdp);
static int dump_glock(struct gfs2_glock *gl);
static int dump_inode(struct gfs2_inode *ip);
+static void gfs2_glock_xmote_th(struct gfs2_holder *gh);
+static void gfs2_glock_drop_th(struct gfs2_glock *gl);
+static DECLARE_RWSEM(gfs2_umount_flush_sem);
#define GFS2_GL_HASH_SHIFT 15
#define GFS2_GL_HASH_SIZE (1 << GFS2_GL_HASH_SHIFT)
@@ -213,30 +213,6 @@ out:
}
/**
- * queue_empty - check to see if a glock's queue is empty
- * @gl: the glock
- * @head: the head of the queue to check
- *
- * This function protects the list in the event that a process already
- * has a holder on the list and is adding a second holder for itself.
- * The glmutex lock is what generally prevents processes from working
- * on the same glock at once, but the special case of adding a second
- * holder for yourself ("recursive" locking) doesn't involve locking
- * glmutex, making the spin lock necessary.
- *
- * Returns: 1 if the queue is empty
- */
-
-static inline int queue_empty(struct gfs2_glock *gl, struct list_head *head)
-{
- int empty;
- spin_lock(&gl->gl_spin);
- empty = list_empty(head);
- spin_unlock(&gl->gl_spin);
- return empty;
-}
-
-/**
* search_bucket() - Find struct gfs2_glock by lock number
* @bucket: the bucket to search
* @name: The lock name
@@ -395,11 +371,6 @@ void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, unsigned flags,
gh->gh_flags = flags;
gh->gh_error = 0;
gh->gh_iflags = 0;
- init_completion(&gh->gh_wait);
-
- if (gh->gh_state == LM_ST_EXCLUSIVE)
- gh->gh_flags |= GL_LOCAL_EXCL;
-
gfs2_glock_hold(gl);
}
@@ -417,9 +388,6 @@ void gfs2_holder_reinit(unsigned int state, unsigned flags, struct gfs2_holder *
{
gh->gh_state = state;
gh->gh_flags = flags;
- if (gh->gh_state == LM_ST_EXCLUSIVE)
- gh->gh_flags |= GL_LOCAL_EXCL;
-
gh->gh_iflags &= 1 << HIF_ALLOCED;
gh->gh_ip = (unsigned long)__builtin_return_address(0);
}
@@ -479,6 +447,29 @@ static void gfs2_holder_put(struct gfs2_holder *gh)
kfree(gh);
}
+static void gfs2_holder_dispose_or_wake(struct gfs2_holder *gh)
+{
+ if (test_bit(HIF_DEALLOC, &gh->gh_iflags)) {
+ gfs2_holder_put(gh);
+ return;
+ }
+ clear_bit(HIF_WAIT, &gh->gh_iflags);
+ smp_mb();
+ wake_up_bit(&gh->gh_iflags, HIF_WAIT);
+}
+
+static int holder_wait(void *word)
+{
+ schedule();
+ return 0;
+}
+
+static void wait_on_holder(struct gfs2_holder *gh)
+{
+ might_sleep();
+ wait_on_bit(&gh->gh_iflags, HIF_WAIT, holder_wait, TASK_UNINTERRUPTIBLE);
+}
+
/**
* rq_mutex - process a mutex request in the queue
* @gh: the glock holder
@@ -493,7 +484,9 @@ static int rq_mutex(struct gfs2_holder *gh)
list_del_init(&gh->gh_list);
/* gh->gh_error never examined. */
set_bit(GLF_LOCK, &gl->gl_flags);
- complete(&gh->gh_wait);
+ clear_bit(HIF_WAIT, &gh->gh_iflags);
+ smp_mb();
+ wake_up_bit(&gh->gh_iflags, HIF_WAIT);
return 1;
}
@@ -511,7 +504,6 @@ static int rq_promote(struct gfs2_holder *gh)
{
struct gfs2_glock *gl = gh->gh_gl;
struct gfs2_sbd *sdp = gl->gl_sbd;
- const struct gfs2_glock_operations *glops = gl->gl_ops;
if (!relaxed_state_ok(gl->gl_state, gh->gh_state, gh->gh_flags)) {
if (list_empty(&gl->gl_holders)) {
@@ -526,7 +518,7 @@ static int rq_promote(struct gfs2_holder *gh)
gfs2_reclaim_glock(sdp);
}
- glops->go_xmote_th(gl, gh->gh_state, gh->gh_flags);
+ gfs2_glock_xmote_th(gh);
spin_lock(&gl->gl_spin);
}
return 1;
@@ -537,11 +529,11 @@ static int rq_promote(struct gfs2_holder *gh)
set_bit(GLF_LOCK, &gl->gl_flags);
} else {
struct gfs2_holder *next_gh;
- if (gh->gh_flags & GL_LOCAL_EXCL)
+ if (gh->gh_state == LM_ST_EXCLUSIVE)
return 1;
next_gh = list_entry(gl->gl_holders.next, struct gfs2_holder,
gh_list);
- if (next_gh->gh_flags & GL_LOCAL_EXCL)
+ if (next_gh->gh_state == LM_ST_EXCLUSIVE)
return 1;
}
@@ -549,7 +541,7 @@ static int rq_promote(struct gfs2_holder *gh)
gh->gh_error = 0;
set_bit(HIF_HOLDER, &gh->gh_iflags);
- complete(&gh->gh_wait);
+ gfs2_holder_dispose_or_wake(gh);
return 0;
}
@@ -564,7 +556,6 @@ static int rq_promote(struct gfs2_holder *gh)
static int rq_demote(struct gfs2_holder *gh)
{
struct gfs2_glock *gl = gh->gh_gl;
- const struct gfs2_glock_operations *glops = gl->gl_ops;
if (!list_empty(&gl->gl_holders))
return 1;
@@ -573,10 +564,7 @@ static int rq_demote(struct gfs2_holder *gh)
list_del_init(&gh->gh_list);
gh->gh_error = 0;
spin_unlock(&gl->gl_spin);
- if (test_bit(HIF_DEALLOC, &gh->gh_iflags))
- gfs2_holder_put(gh);
- else
- complete(&gh->gh_wait);
+ gfs2_holder_dispose_or_wake(gh);
spin_lock(&gl->gl_spin);
} else {
gl->gl_req_gh = gh;
@@ -585,9 +573,9 @@ static int rq_demote(struct gfs2_holder *gh)
if (gh->gh_state == LM_ST_UNLOCKED ||
gl->gl_state != LM_ST_EXCLUSIVE)
- glops->go_drop_th(gl);
+ gfs2_glock_drop_th(gl);
else
- glops->go_xmote_th(gl, gh->gh_state, gh->gh_flags);
+ gfs2_glock_xmote_th(gh);
spin_lock(&gl->gl_spin);
}
@@ -596,30 +584,6 @@ static int rq_demote(struct gfs2_holder *gh)
}
/**
- * rq_greedy - process a queued request to drop greedy status
- * @gh: the glock holder
- *
- * Returns: 1 if the queue is blocked
- */
-
-static int rq_greedy(struct gfs2_holder *gh)
-{
- struct gfs2_glock *gl = gh->gh_gl;
-
- list_del_init(&gh->gh_list);
- /* gh->gh_error never examined. */
- clear_bit(GLF_GREEDY, &gl->gl_flags);
- spin_unlock(&gl->gl_spin);
-
- gfs2_holder_uninit(gh);
- kfree(container_of(gh, struct greedy, gr_gh));
-
- spin_lock(&gl->gl_spin);
-
- return 0;
-}
-
-/**
* run_queue - process holder structures on a glock
* @gl: the glock
*
@@ -649,8 +613,6 @@ static void run_queue(struct gfs2_glock *gl)
if (test_bit(HIF_DEMOTE, &gh->gh_iflags))
blocked = rq_demote(gh);
- else if (test_bit(HIF_GREEDY, &gh->gh_iflags))
- blocked = rq_greedy(gh);
else
gfs2_assert_warn(gl->gl_sbd, 0);
@@ -684,6 +646,8 @@ static void gfs2_glmutex_lock(struct gfs2_glock *gl)
gfs2_holder_init(gl, 0, 0, &gh);
set_bit(HIF_MUTEX, &gh.gh_iflags);
+ if (test_and_set_bit(HIF_WAIT, &gh.gh_iflags))
+ BUG();
spin_lock(&gl->gl_spin);
if (test_and_set_bit(GLF_LOCK, &gl->gl_flags)) {
@@ -691,11 +655,13 @@ static void gfs2_glmutex_lock(struct gfs2_glock *gl)
} else {
gl->gl_owner = current;
gl->gl_ip = (unsigned long)__builtin_return_address(0);
- complete(&gh.gh_wait);
+ clear_bit(HIF_WAIT, &gh.gh_iflags);
+ smp_mb();
+ wake_up_bit(&gh.gh_iflags, HIF_WAIT);
}
spin_unlock(&gl->gl_spin);
- wait_for_completion(&gh.gh_wait);
+ wait_on_holder(&gh);
gfs2_holder_uninit(&gh);
}
@@ -774,6 +740,7 @@ restart:
return;
set_bit(HIF_DEMOTE, &new_gh->gh_iflags);
set_bit(HIF_DEALLOC, &new_gh->gh_iflags);
+ set_bit(HIF_WAIT, &new_gh->gh_iflags);
goto restart;
}
@@ -825,7 +792,7 @@ static void xmote_bh(struct gfs2_glock *gl, unsigned int ret)
int op_done = 1;
gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags));
- gfs2_assert_warn(sdp, queue_empty(gl, &gl->gl_holders));
+ gfs2_assert_warn(sdp, list_empty(&gl->gl_holders));
gfs2_assert_warn(sdp, !(ret & LM_OUT_ASYNC));
state_change(gl, ret & LM_OUT_ST_MASK);
@@ -908,12 +875,8 @@ static void xmote_bh(struct gfs2_glock *gl, unsigned int ret)
gfs2_glock_put(gl);
- if (gh) {
- if (test_bit(HIF_DEALLOC, &gh->gh_iflags))
- gfs2_holder_put(gh);
- else
- complete(&gh->gh_wait);
- }
+ if (gh)
+ gfs2_holder_dispose_or_wake(gh);
}
/**
@@ -924,23 +887,26 @@ static void xmote_bh(struct gfs2_glock *gl, unsigned int ret)
*
*/
-void gfs2_glock_xmote_th(struct gfs2_glock *gl, unsigned int state, int flags)
+void gfs2_glock_xmote_th(struct gfs2_holder *gh)
{
+ struct gfs2_glock *gl = gh->gh_gl;
struct gfs2_sbd *sdp = gl->gl_sbd;
+ int flags = gh->gh_flags;
+ unsigned state = gh->gh_state;
const struct gfs2_glock_operations *glops = gl->gl_ops;
int lck_flags = flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB |
LM_FLAG_NOEXP | LM_FLAG_ANY |
LM_FLAG_PRIORITY);
unsigned int lck_ret;
+ if (glops->go_xmote_th)
+ glops->go_xmote_th(gl);
+
gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags));
- gfs2_assert_warn(sdp, queue_empty(gl, &gl->gl_holders));
+ gfs2_assert_warn(sdp, list_empty(&gl->gl_holders));
gfs2_assert_warn(sdp, state != LM_ST_UNLOCKED);
gfs2_assert_warn(sdp, state != gl->gl_state);
- if (gl->gl_state == LM_ST_EXCLUSIVE && glops->go_sync)
- glops->go_sync(gl);
-
gfs2_glock_hold(gl);
gl->gl_req_bh = xmote_bh;
@@ -971,10 +937,8 @@ static void drop_bh(struct gfs2_glock *gl, unsigned int ret)
const struct gfs2_glock_operations *glops = gl->gl_ops;
struct gfs2_holder *gh = gl->gl_req_gh;
- clear_bit(GLF_PREFETCH, &gl->gl_flags);
-
gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags));
- gfs2_assert_warn(sdp, queue_empty(gl, &gl->gl_holders));
+ gfs2_assert_warn(sdp, list_empty(&gl->gl_holders));
gfs2_assert_warn(sdp, !ret);
state_change(gl, LM_ST_UNLOCKED);
@@ -1001,12 +965,8 @@ static void drop_bh(struct gfs2_glock *gl, unsigned int ret)
gfs2_glock_put(gl);
- if (gh) {
- if (test_bit(HIF_DEALLOC, &gh->gh_iflags))
- gfs2_holder_put(gh);
- else
- complete(&gh->gh_wait);
- }
+ if (gh)
+ gfs2_holder_dispose_or_wake(gh);
}
/**
@@ -1015,19 +975,19 @@ static void drop_bh(struct gfs2_glock *gl, unsigned int ret)
*
*/
-void gfs2_glock_drop_th(struct gfs2_glock *gl)
+static void gfs2_glock_drop_th(struct gfs2_glock *gl)
{
struct gfs2_sbd *sdp = gl->gl_sbd;
const struct gfs2_glock_operations *glops = gl->gl_ops;
unsigned int ret;
+ if (glops->go_drop_th)
+ glops->go_drop_th(gl);
+
gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags));
- gfs2_assert_warn(sdp, queue_empty(gl, &gl->gl_holders));
+ gfs2_assert_warn(sdp, list_empty(&gl->gl_holders));
gfs2_assert_warn(sdp, gl->gl_state != LM_ST_UNLOCKED);
- if (gl->gl_state == LM_ST_EXCLUSIVE && glops->go_sync)
- glops->go_sync(gl);
-
gfs2_glock_hold(gl);
gl->gl_req_bh = drop_bh;
@@ -1107,8 +1067,7 @@ static int glock_wait_internal(struct gfs2_holder *gh)
if (gh->gh_flags & LM_FLAG_PRIORITY)
do_cancels(gh);
- wait_for_completion(&gh->gh_wait);
-
+ wait_on_holder(gh);
if (gh->gh_error)
return gh->gh_error;
@@ -1164,6 +1123,8 @@ static void add_to_queue(struct gfs2_holder *gh)
struct gfs2_holder *existing;
BUG_ON(!gh->gh_owner);
+ if (test_and_set_bit(HIF_WAIT, &gh->gh_iflags))
+ BUG();
existing = find_holder_by_owner(&gl->gl_holders, gh->gh_owner);
if (existing) {
@@ -1227,8 +1188,6 @@ restart:
}
}
- clear_bit(GLF_PREFETCH, &gl->gl_flags);
-
return error;
}
@@ -1321,98 +1280,6 @@ void gfs2_glock_dq(struct gfs2_holder *gh)
}
/**
- * gfs2_glock_prefetch - Try to prefetch a glock
- * @gl: the glock
- * @state: the state to prefetch in
- * @flags: flags passed to go_xmote_th()
- *
- */
-
-static void gfs2_glock_prefetch(struct gfs2_glock *gl, unsigned int state,
- int flags)
-{
- const struct gfs2_glock_operations *glops = gl->gl_ops;
-
- spin_lock(&gl->gl_spin);
-
- if (test_bit(GLF_LOCK, &gl->gl_flags) || !list_empty(&gl->gl_holders) ||
- !list_empty(&gl->gl_waiters1) || !list_empty(&gl->gl_waiters2) ||
- !list_empty(&gl->gl_waiters3) ||
- relaxed_state_ok(gl->gl_state, state, flags)) {
- spin_unlock(&gl->gl_spin);
- return;
- }
-
- set_bit(GLF_PREFETCH, &gl->gl_flags);
- set_bit(GLF_LOCK, &gl->gl_flags);
- spin_unlock(&gl->gl_spin);
-
- glops->go_xmote_th(gl, state, flags);
-}
-
-static void greedy_work(struct work_struct *work)
-{
- struct greedy *gr = container_of(work, struct greedy, gr_work.work);
- struct gfs2_holder *gh = &gr->gr_gh;
- struct gfs2_glock *gl = gh->gh_gl;
- const struct gfs2_glock_operations *glops = gl->gl_ops;
-
- clear_bit(GLF_SKIP_WAITERS2, &gl->gl_flags);
-
- if (glops->go_greedy)
- glops->go_greedy(gl);
-
- spin_lock(&gl->gl_spin);
-
- if (list_empty(&gl->gl_waiters2)) {
- clear_bit(GLF_GREEDY, &gl->gl_flags);
- spin_unlock(&gl->gl_spin);
- gfs2_holder_uninit(gh);
- kfree(gr);
- } else {
- gfs2_glock_hold(gl);
- list_add_tail(&gh->gh_list, &gl->gl_waiters2);
- run_queue(gl);
- spin_unlock(&gl->gl_spin);
- gfs2_glock_put(gl);
- }
-}
-
-/**
- * gfs2_glock_be_greedy -
- * @gl:
- * @time:
- *
- * Returns: 0 if go_greedy will be called, 1 otherwise
- */
-
-int gfs2_glock_be_greedy(struct gfs2_glock *gl, unsigned int time)
-{
- struct greedy *gr;
- struct gfs2_holder *gh;
-
- if (!time || gl->gl_sbd->sd_args.ar_localcaching ||
- test_and_set_bit(GLF_GREEDY, &gl->gl_flags))
- return 1;
-
- gr = kmalloc(sizeof(struct greedy), GFP_KERNEL);
- if (!gr) {
- clear_bit(GLF_GREEDY, &gl->gl_flags);
- return 1;
- }
- gh = &gr->gr_gh;
-
- gfs2_holder_init(gl, 0, 0, gh);
- set_bit(HIF_GREEDY, &gh->gh_iflags);
- INIT_DELAYED_WORK(&gr->gr_work, greedy_work);
-
- set_bit(GLF_SKIP_WAITERS2, &gl->gl_flags);
- schedule_delayed_work(&gr->gr_work, time);
-
- return 0;
-}
-
-/**
* gfs2_glock_dq_uninit - dequeue a holder from a glock and initialize it
* @gh: the holder structure
*
@@ -1470,10 +1337,7 @@ static int glock_compare(const void *arg_a, const void *arg_b)
return 1;
if (a->ln_number < b->ln_number)
return -1;
- if (gh_a->gh_state == LM_ST_SHARED && gh_b->gh_state == LM_ST_EXCLUSIVE)
- return 1;
- if (!(gh_a->gh_flags & GL_LOCAL_EXCL) && (gh_b->gh_flags & GL_LOCAL_EXCL))
- return 1;
+ BUG_ON(gh_a->gh_gl->gl_ops->go_type == gh_b->gh_gl->gl_ops->go_type);
return 0;
}
@@ -1618,34 +1482,6 @@ void gfs2_glock_dq_uninit_m(unsigned int num_gh, struct gfs2_holder *ghs)
}
/**
- * gfs2_glock_prefetch_num - prefetch a glock based on lock number
- * @sdp: the filesystem
- * @number: the lock number
- * @glops: the glock operations for the type of glock
- * @state: the state to acquire the glock in
- * @flags: modifier flags for the aquisition
- *
- * Returns: errno
- */
-
-void gfs2_glock_prefetch_num(struct gfs2_sbd *sdp, u64 number,
- const struct gfs2_glock_operations *glops,
- unsigned int state, int flags)
-{
- struct gfs2_glock *gl;
- int error;
-
- if (atomic_read(&sdp->sd_reclaim_count) <
- gfs2_tune_get(sdp, gt_reclaim_limit)) {
- error = gfs2_glock_get(sdp, number, glops, CREATE, &gl);
- if (!error) {
- gfs2_glock_prefetch(gl, state, flags);
- gfs2_glock_put(gl);
- }
- }
-}
-
-/**
* gfs2_lvb_hold - attach a LVB from a glock
* @gl: The glock in question
*
@@ -1703,8 +1539,6 @@ static void blocking_cb(struct gfs2_sbd *sdp, struct lm_lockname *name,
if (!gl)
return;
- if (gl->gl_ops->go_callback)
- gl->gl_ops->go_callback(gl, state);
handle_callback(gl, state);
spin_lock(&gl->gl_spin);
@@ -1746,12 +1580,14 @@ void gfs2_glock_cb(void *cb_data, unsigned int type, void *data)
struct lm_async_cb *async = data;
struct gfs2_glock *gl;
+ down_read(&gfs2_umount_flush_sem);
gl = gfs2_glock_find(sdp, &async->lc_name);
if (gfs2_assert_warn(sdp, gl))
return;
if (!gfs2_assert_warn(sdp, gl->gl_req_bh))
gl->gl_req_bh(gl, async->lc_ret);
gfs2_glock_put(gl);
+ up_read(&gfs2_umount_flush_sem);
return;
}
@@ -1781,15 +1617,11 @@ void gfs2_glock_cb(void *cb_data, unsigned int type, void *data)
static int demote_ok(struct gfs2_glock *gl)
{
- struct gfs2_sbd *sdp = gl->gl_sbd;
const struct gfs2_glock_operations *glops = gl->gl_ops;
int demote = 1;
if (test_bit(GLF_STICKY, &gl->gl_flags))
demote = 0;
- else if (test_bit(GLF_PREFETCH, &gl->gl_flags))
- demote = time_after_eq(jiffies, gl->gl_stamp +
- gfs2_tune_get(sdp, gt_prefetch_secs) * HZ);
else if (glops->go_demote_ok)
demote = glops->go_demote_ok(gl);
@@ -1845,7 +1677,7 @@ void gfs2_reclaim_glock(struct gfs2_sbd *sdp)
atomic_inc(&sdp->sd_reclaimed);
if (gfs2_glmutex_trylock(gl)) {
- if (queue_empty(gl, &gl->gl_holders) &&
+ if (list_empty(&gl->gl_holders) &&
gl->gl_state != LM_ST_UNLOCKED && demote_ok(gl))
handle_callback(gl, LM_ST_UNLOCKED);
gfs2_glmutex_unlock(gl);
@@ -1909,7 +1741,7 @@ static void scan_glock(struct gfs2_glock *gl)
return;
if (gfs2_glmutex_trylock(gl)) {
- if (queue_empty(gl, &gl->gl_holders) &&
+ if (list_empty(&gl->gl_holders) &&
gl->gl_state != LM_ST_UNLOCKED && demote_ok(gl))
goto out_schedule;
gfs2_glmutex_unlock(gl);
@@ -1958,7 +1790,7 @@ static void clear_glock(struct gfs2_glock *gl)
}
if (gfs2_glmutex_trylock(gl)) {
- if (queue_empty(gl, &gl->gl_holders) &&
+ if (list_empty(&gl->gl_holders) &&
gl->gl_state != LM_ST_UNLOCKED)
handle_callback(gl, LM_ST_UNLOCKED);
gfs2_glmutex_unlock(gl);
@@ -2000,7 +1832,9 @@ void gfs2_gl_hash_clear(struct gfs2_sbd *sdp, int wait)
t = jiffies;
}
+ down_write(&gfs2_umount_flush_sem);
invalidate_inodes(sdp->sd_vfs);
+ up_write(&gfs2_umount_flush_sem);
msleep(10);
}
}
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