diff options
Diffstat (limited to 'fs/gfs2/glock.c')
-rw-r--r-- | fs/gfs2/glock.c | 316 |
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); } } |