Re: [PATCH/RFC] SCHED: allow wait_on_bit functions to support a timeout.

From: NeilBrown
Date: Tue Apr 29 2014 - 22:29:46 EST

On Tue, 29 Apr 2014 12:32:17 +0200 Peter Zijlstra <peterz@xxxxxxxxxxxxx>
wrote:

> So I'm sure I'm not getting it; but why is all the wait_bit crap so
> entirely different from the normal wait stuff?
>
> Surely something like:
>
> wait_event_timeout(&wq, test_bit(bit, word), timeout);
>
> Is pretty much the same, no? The only thing that's different is the wake
> function, but surely we can thread that into there somehow without all
> this silly repetition.
>
> Furthermore, I count about 23 action functions, of which there appear to
> be only like 4 actual variants. Surely such repetition sucks arse and
> should be avoided?
>


What do you think of the following as a cleanup prior to my patch. It will
make my patch a lot smaller and removes a lot of the duplication that you
don't like.

It renames the current wait_on_bit{_lock} function to have a "_cmd" suffix
and introduces versions which are not passed an action function (maybe it
should be an "_action" suffix...).

wait_on_bit() and wait_on_bit_lock() use schedule(),
wait_on_bit_io() and wait_on_bit_lock_io() use io_schedule().

The bit_wait() and bit_wait_io() function that these pass through use
signal_pending_state() to determine if they should abort or [io_]schedule().
I think the code is right, but it is the bit I would particularly like you
to check.

The return value from wait_on_bit{,_lock} is 0 or non-zero.
Functions which wanted a particular error code need to interpolate that
themselves.

(somewhat amusingly, fs/fscache/cookie.c currently has

wait_on_bit(&cookie->flags, FSCACHE_COOKIE_INVALIDATING,
fscache_wait_bit_interruptible,
TASK_UNINTERRUPTIBLE);

which is a little bit interruptible, but mostly not...)

If you think it is a good cleanup I'll post a proper patch with all the right
Cc:s.

Thanks,
NeilBrown

diff --git a/include/linux/wait.h b/include/linux/wait.h
index 559044c79232..13e6fd9acf09 100644
--- a/include/linux/wait.h
+++ b/include/linux/wait.h
@@ -854,7 +854,7 @@ int wake_bit_function(wait_queue_t *wait, unsigned mode, int sync, void *key);
} while (0)

/**
- * wait_on_bit - wait for a bit to be cleared
+ * wait_on_bit_cmd - wait for a bit to be cleared
* @word: the word being waited on, a kernel virtual address
* @bit: the bit of the word being waited on
* @action: the function used to sleep, which may take special actions
@@ -868,15 +868,51 @@ int wake_bit_function(wait_queue_t *wait, unsigned mode, int sync, void *key);
* but has no intention of setting it.
*/
static inline int
-wait_on_bit(void *word, int bit, int (*action)(void *), unsigned mode)
+wait_on_bit_cmd(void *word, int bit, int (*action)(void *), unsigned mode)
{
if (!test_bit(bit, word))
return 0;
return out_of_line_wait_on_bit(word, bit, action, mode);
}

+extern int bit_wait(void *);
+extern int bit_wait_io(void *);
+
/**
- * wait_on_bit_lock - wait for a bit to be cleared, when wanting to set it
+ * wait_on_bit - wait for a bit to be cleared
+ * @word: the word being waited on, a kernel virtual address
+ * @bit: the bit of the word being waited on
+ * @mode: the task state to sleep in
+ *
+ * There is a standard hashed waitqueue table for generic use. This
+ * is the part of the hashtable's accessor API that waits on a bit.
+ * For instance, if one were to have waiters on a bitflag, one would
+ * call wait_on_bit() in threads waiting for the bit to clear.
+ * One uses wait_on_bit() where one is waiting for the bit to clear,
+ * but has no intention of setting it.
+ */
+static inline int
+wait_on_bit(void *word, int bit, unsigned mode)
+{
+ if (!test_bit(bit, word))
+ return 0;
+ return out_of_line_wait_on_bit(word, bit,
+ bit_wait,
+ mode & 65535);
+}
+
+static inline int
+wait_on_bit_io(void *word, int bit, unsigned mode)
+{
+ if (!test_bit(bit, word))
+ return 0;
+ return out_of_line_wait_on_bit(word, bit,
+ bit_wait_io,
+ mode & 65535);
+}
+
+/**
+ * wait_on_bit_lock_cmd - wait for a bit to be cleared, when wanting to set it
* @word: the word being waited on, a kernel virtual address
* @bit: the bit of the word being waited on
* @action: the function used to sleep, which may take special actions
@@ -892,7 +928,7 @@ wait_on_bit(void *word, int bit, int (*action)(void *), unsigned mode)
* clear with the intention of setting it, and when done, clearing it.
*/
static inline int
-wait_on_bit_lock(void *word, int bit, int (*action)(void *), unsigned mode)
+wait_on_bit_lock_cmd(void *word, int bit, int (*action)(void *), unsigned mode)
{
if (!test_and_set_bit(bit, word))
return 0;
@@ -900,6 +936,41 @@ wait_on_bit_lock(void *word, int bit, int (*action)(void *), unsigned mode)
}

/**
+ * wait_on_bit_lock - wait for a bit to be cleared, when wanting to set it
+ * @word: the word being waited on, a kernel virtual address
+ * @bit: the bit of the word being waited on
+ * @mode: the task state to sleep in
+ *
+ * There is a standard hashed waitqueue table for generic use. This
+ * is the part of the hashtable's accessor API that waits on a bit
+ * when one intends to set it, for instance, trying to lock bitflags.
+ * For instance, if one were to have waiters trying to set bitflag
+ * and waiting for it to clear before setting it, one would call
+ * wait_on_bit() in threads waiting to be able to set the bit.
+ * One uses wait_on_bit_lock() where one is waiting for the bit to
+ * clear with the intention of setting it, and when done, clearing it.
+ */
+static inline int
+wait_on_bit_lock(void *word, int bit, unsigned mode)
+{
+ if (!test_and_set_bit(bit, word))
+ return 0;
+ return out_of_line_wait_on_bit_lock(word, bit,
+ bit_wait,
+ mode & 65536);
+}
+
+static inline int
+wait_on_bit_lock_io(void *word, int bit, unsigned mode)
+{
+ if (!test_and_set_bit(bit, word))
+ return 0;
+ return out_of_line_wait_on_bit_lock(word, bit,
+ bit_wait_io,
+ mode & 65536);
+}
+
+/**
* wait_on_atomic_t - Wait for an atomic_t to become 0
* @val: The atomic value being waited on, a kernel virtual address
* @action: the function used to sleep, which may take special actions
diff --git a/kernel/sched/wait.c b/kernel/sched/wait.c
index 7d50f794e248..0c0795002f56 100644
--- a/kernel/sched/wait.c
+++ b/kernel/sched/wait.c
@@ -502,3 +502,21 @@ void wake_up_atomic_t(atomic_t *p)
__wake_up_bit(atomic_t_waitqueue(p), p, WAIT_ATOMIC_T_BIT_NR);
}
EXPORT_SYMBOL(wake_up_atomic_t);
+
+__sched int bit_wait(void *word)
+{
+ if (signal_pending_state(current->state, current))
+ return 1;
+ schedule();
+ return 0;
+}
+EXPORT_SYMBOL(bit_wait);
+
+__sched int bit_wait_io(void *word)
+{
+ if (signal_pending_state(current->state, current))
+ return 1;
+ io_schedule();
+ return 0;
+}
+EXPORT_SYMBOL(bit_wait_io);
diff --git a/Documentation/filesystems/caching/operations.txt b/Documentation/filesystems/caching/operations.txt
index bee2a5f93d60..a1c052cbba35 100644
--- a/Documentation/filesystems/caching/operations.txt
+++ b/Documentation/filesystems/caching/operations.txt
@@ -90,7 +90,7 @@ operations:
to be cleared before proceeding:

wait_on_bit(&op->flags, FSCACHE_OP_WAITING,
- fscache_wait_bit, TASK_UNINTERRUPTIBLE);
+ TASK_UNINTERRUPTIBLE);


(2) The operation may be fast asynchronous (FSCACHE_OP_FAST), in which case it
diff --git a/drivers/md/dm-bufio.c b/drivers/md/dm-bufio.c
index 66c5d130c8c2..c6b692dd3b88 100644
--- a/drivers/md/dm-bufio.c
+++ b/drivers/md/dm-bufio.c
@@ -615,16 +615,6 @@ static void write_endio(struct bio *bio, int error)
}

/*
- * This function is called when wait_on_bit is actually waiting.
- */
-static int do_io_schedule(void *word)
-{
- io_schedule();
-
- return 0;
-}
-
-/*
* Initiate a write on a dirty buffer, but don't wait for it.
*
* - If the buffer is not dirty, exit.
@@ -640,8 +630,8 @@ static void __write_dirty_buffer(struct dm_buffer *b,
return;

clear_bit(B_DIRTY, &b->state);
- wait_on_bit_lock(&b->state, B_WRITING,
- do_io_schedule, TASK_UNINTERRUPTIBLE);
+ wait_on_bit_lock_io(&b->state, B_WRITING,
+ TASK_UNINTERRUPTIBLE);

if (!write_list)
submit_io(b, WRITE, b->block, write_endio);
@@ -675,9 +665,9 @@ static void __make_buffer_clean(struct dm_buffer *b)
if (!b->state) /* fast case */
return;

- wait_on_bit(&b->state, B_READING, do_io_schedule, TASK_UNINTERRUPTIBLE);
+ wait_on_bit_io(&b->state, B_READING, TASK_UNINTERRUPTIBLE);
__write_dirty_buffer(b, NULL);
- wait_on_bit(&b->state, B_WRITING, do_io_schedule, TASK_UNINTERRUPTIBLE);
+ wait_on_bit_io(&b->state, B_WRITING, TASK_UNINTERRUPTIBLE);
}

/*
@@ -1030,7 +1020,7 @@ static void *new_read(struct dm_bufio_client *c, sector_t block,
if (need_submit)
submit_io(b, READ, b->block, read_endio);

- wait_on_bit(&b->state, B_READING, do_io_schedule, TASK_UNINTERRUPTIBLE);
+ wait_on_bit_io(&b->state, B_READING, TASK_UNINTERRUPTIBLE);

if (b->read_error) {
int error = b->read_error;
@@ -1209,15 +1199,13 @@ again:
dropped_lock = 1;
b->hold_count++;
dm_bufio_unlock(c);
- wait_on_bit(&b->state, B_WRITING,
- do_io_schedule,
- TASK_UNINTERRUPTIBLE);
+ wait_on_bit_io(&b->state, B_WRITING,
+ TASK_UNINTERRUPTIBLE);
dm_bufio_lock(c);
b->hold_count--;
} else
- wait_on_bit(&b->state, B_WRITING,
- do_io_schedule,
- TASK_UNINTERRUPTIBLE);
+ wait_on_bit_io(&b->state, B_WRITING,
+ TASK_UNINTERRUPTIBLE);
}

if (!test_bit(B_DIRTY, &b->state) &&
@@ -1321,15 +1309,15 @@ retry:

__write_dirty_buffer(b, NULL);
if (b->hold_count == 1) {
- wait_on_bit(&b->state, B_WRITING,
- do_io_schedule, TASK_UNINTERRUPTIBLE);
+ wait_on_bit_io(&b->state, B_WRITING,
+ TASK_UNINTERRUPTIBLE);
set_bit(B_DIRTY, &b->state);
__unlink_buffer(b);
__link_buffer(b, new_block, LIST_DIRTY);
} else {
sector_t old_block;
- wait_on_bit_lock(&b->state, B_WRITING,
- do_io_schedule, TASK_UNINTERRUPTIBLE);
+ wait_on_bit_lock_io(&b->state, B_WRITING,
+ TASK_UNINTERRUPTIBLE);
/*
* Relink buffer to "new_block" so that write_callback
* sees "new_block" as a block number.
@@ -1341,8 +1329,8 @@ retry:
__unlink_buffer(b);
__link_buffer(b, new_block, b->list_mode);
submit_io(b, WRITE, new_block, write_endio);
- wait_on_bit(&b->state, B_WRITING,
- do_io_schedule, TASK_UNINTERRUPTIBLE);
+ wait_on_bit_io(&b->state, B_WRITING,
+ TASK_UNINTERRUPTIBLE);
__unlink_buffer(b);
__link_buffer(b, old_block, b->list_mode);
}
diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c
index ebddef5237e4..172ba0d6e4e0 100644
--- a/drivers/md/dm-snap.c
+++ b/drivers/md/dm-snap.c
@@ -1032,20 +1032,13 @@ static void start_merge(struct dm_snapshot *s)
snapshot_merge_next_chunks(s);
}

-static int wait_schedule(void *ptr)
-{
- schedule();
-
- return 0;
-}
-
/*
* Stop the merging process and wait until it finishes.
*/
static void stop_merge(struct dm_snapshot *s)
{
set_bit(SHUTDOWN_MERGE, &s->state_bits);
- wait_on_bit(&s->state_bits, RUNNING_MERGE, wait_schedule,
+ wait_on_bit(&s->state_bits, RUNNING_MERGE,
TASK_UNINTERRUPTIBLE);
clear_bit(SHUTDOWN_MERGE, &s->state_bits);
}
diff --git a/drivers/media/usb/dvb-usb-v2/dvb_usb_core.c b/drivers/media/usb/dvb-usb-v2/dvb_usb_core.c
index 8a054d66e708..f65ecdc79cbb 100644
--- a/drivers/media/usb/dvb-usb-v2/dvb_usb_core.c
+++ b/drivers/media/usb/dvb-usb-v2/dvb_usb_core.c
@@ -253,13 +253,6 @@ static int dvb_usbv2_adapter_stream_exit(struct dvb_usb_adapter *adap)
return usb_urb_exitv2(&adap->stream);
}

-static int wait_schedule(void *ptr)
-{
- schedule();
-
- return 0;
-}
-
static int dvb_usb_start_feed(struct dvb_demux_feed *dvbdmxfeed)
{
struct dvb_usb_adapter *adap = dvbdmxfeed->demux->priv;
@@ -273,7 +266,7 @@ static int dvb_usb_start_feed(struct dvb_demux_feed *dvbdmxfeed)
dvbdmxfeed->pid, dvbdmxfeed->index);

/* wait init is done */
- wait_on_bit(&adap->state_bits, ADAP_INIT, wait_schedule,
+ wait_on_bit(&adap->state_bits, ADAP_INIT,
TASK_UNINTERRUPTIBLE);

if (adap->active_fe == -1)
@@ -568,7 +561,7 @@ static int dvb_usb_fe_sleep(struct dvb_frontend *fe)

if (!adap->suspend_resume_active) {
set_bit(ADAP_SLEEP, &adap->state_bits);
- wait_on_bit(&adap->state_bits, ADAP_STREAMING, wait_schedule,
+ wait_on_bit(&adap->state_bits, ADAP_STREAMING,
TASK_UNINTERRUPTIBLE);
}

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 85bbd01f1271..34011f6be939 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -3366,16 +3366,10 @@ done_unlocked:
return 0;
}

-static int eb_wait(void *word)
-{
- io_schedule();
- return 0;
-}
-
void wait_on_extent_buffer_writeback(struct extent_buffer *eb)
{
- wait_on_bit(&eb->bflags, EXTENT_BUFFER_WRITEBACK, eb_wait,
- TASK_UNINTERRUPTIBLE);
+ wait_on_bit_io(&eb->bflags, EXTENT_BUFFER_WRITEBACK,
+ TASK_UNINTERRUPTIBLE);
}

static int lock_extent_buffer_for_io(struct extent_buffer *eb,
diff --git a/fs/buffer.c b/fs/buffer.c
index 27265a8b43c1..a92a1f51716a 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -61,16 +61,9 @@ inline void touch_buffer(struct buffer_head *bh)
}
EXPORT_SYMBOL(touch_buffer);

-static int sleep_on_buffer(void *word)
-{
- io_schedule();
- return 0;
-}
-
void __lock_buffer(struct buffer_head *bh)
{
- wait_on_bit_lock(&bh->b_state, BH_Lock, sleep_on_buffer,
- TASK_UNINTERRUPTIBLE);
+ wait_on_bit_lock_io(&bh->b_state, BH_Lock, TASK_UNINTERRUPTIBLE);
}
EXPORT_SYMBOL(__lock_buffer);

@@ -123,7 +116,7 @@ EXPORT_SYMBOL(buffer_check_dirty_writeback);
*/
void __wait_on_buffer(struct buffer_head * bh)
{
- wait_on_bit(&bh->b_state, BH_Lock, sleep_on_buffer, TASK_UNINTERRUPTIBLE);
+ wait_on_bit_io(&bh->b_state, BH_Lock, TASK_UNINTERRUPTIBLE);
}
EXPORT_SYMBOL(__wait_on_buffer);

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 8813ff776ba3..d4a24ef95647 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -3931,13 +3931,6 @@ cifs_sb_master_tcon(struct cifs_sb_info *cifs_sb)
return tlink_tcon(cifs_sb_master_tlink(cifs_sb));
}

-static int
-cifs_sb_tcon_pending_wait(void *unused)
-{
- schedule();
- return signal_pending(current) ? -ERESTARTSYS : 0;
-}
-
/* find and return a tlink with given uid */
static struct tcon_link *
tlink_rb_search(struct rb_root *root, kuid_t uid)
@@ -4036,11 +4029,10 @@ cifs_sb_tlink(struct cifs_sb_info *cifs_sb)
} else {
wait_for_construction:
ret = wait_on_bit(&tlink->tl_flags, TCON_LINK_PENDING,
- cifs_sb_tcon_pending_wait,
TASK_INTERRUPTIBLE);
if (ret) {
cifs_put_tlink(tlink);
- return ERR_PTR(ret);
+ return ERR_PTR(-ERESTARTSYS);
}

/* if it's good, return it */
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index d754e3cf99a8..268e25885d96 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -327,7 +327,8 @@ static void __inode_wait_for_writeback(struct inode *inode)
wqh = bit_waitqueue(&inode->i_state, __I_SYNC);
while (inode->i_state & I_SYNC) {
spin_unlock(&inode->i_lock);
- __wait_on_bit(wqh, &wq, inode_wait, TASK_UNINTERRUPTIBLE);
+ __wait_on_bit(wqh, &wq, bit_wait,
+ TASK_UNINTERRUPTIBLE);
spin_lock(&inode->i_lock);
}
}
diff --git a/fs/fscache/cookie.c b/fs/fscache/cookie.c
index 29d7feb62cf7..9a494d8e1f1b 100644
--- a/fs/fscache/cookie.c
+++ b/fs/fscache/cookie.c
@@ -160,7 +160,7 @@ void __fscache_enable_cookie(struct fscache_cookie *cookie,
_enter("%p", cookie);

wait_on_bit_lock(&cookie->flags, FSCACHE_COOKIE_ENABLEMENT_LOCK,
- fscache_wait_bit, TASK_UNINTERRUPTIBLE);
+ TASK_UNINTERRUPTIBLE);

if (test_bit(FSCACHE_COOKIE_ENABLED, &cookie->flags))
goto out_unlock;
@@ -255,7 +255,7 @@ static int fscache_acquire_non_index_cookie(struct fscache_cookie *cookie)
if (!fscache_defer_lookup) {
_debug("non-deferred lookup %p", &cookie->flags);
wait_on_bit(&cookie->flags, FSCACHE_COOKIE_LOOKING_UP,
- fscache_wait_bit, TASK_UNINTERRUPTIBLE);
+ TASK_UNINTERRUPTIBLE);
_debug("complete");
if (test_bit(FSCACHE_COOKIE_UNAVAILABLE, &cookie->flags))
goto unavailable;
@@ -463,8 +463,7 @@ void __fscache_wait_on_invalidate(struct fscache_cookie *cookie)
_enter("%p", cookie);

wait_on_bit(&cookie->flags, FSCACHE_COOKIE_INVALIDATING,
- fscache_wait_bit_interruptible,
- TASK_UNINTERRUPTIBLE);
+ TASK_INTERRUPTIBLE);

_leave("");
}
@@ -525,7 +524,7 @@ void __fscache_disable_cookie(struct fscache_cookie *cookie, bool invalidate)
}

wait_on_bit_lock(&cookie->flags, FSCACHE_COOKIE_ENABLEMENT_LOCK,
- fscache_wait_bit, TASK_UNINTERRUPTIBLE);
+ TASK_UNINTERRUPTIBLE);
if (!test_and_clear_bit(FSCACHE_COOKIE_ENABLED, &cookie->flags))
goto out_unlock_enable;

diff --git a/fs/fscache/main.c b/fs/fscache/main.c
index 7c27907e650c..818057de05c6 100644
--- a/fs/fscache/main.c
+++ b/fs/fscache/main.c
@@ -198,24 +198,6 @@ static void __exit fscache_exit(void)
module_exit(fscache_exit);

/*
- * wait_on_bit() sleep function for uninterruptible waiting
- */
-int fscache_wait_bit(void *flags)
-{
- schedule();
- return 0;
-}
-
-/*
- * wait_on_bit() sleep function for interruptible waiting
- */
-int fscache_wait_bit_interruptible(void *flags)
-{
- schedule();
- return signal_pending(current);
-}
-
-/*
* wait_on_atomic_t() sleep function for uninterruptible waiting
*/
int fscache_wait_atomic_t(atomic_t *p)
diff --git a/fs/fscache/page.c b/fs/fscache/page.c
index 7f5c658af755..e9bb50c391db 100644
--- a/fs/fscache/page.c
+++ b/fs/fscache/page.c
@@ -298,7 +298,6 @@ int fscache_wait_for_deferred_lookup(struct fscache_cookie *cookie)

jif = jiffies;
if (wait_on_bit(&cookie->flags, FSCACHE_COOKIE_LOOKING_UP,
- fscache_wait_bit_interruptible,
TASK_INTERRUPTIBLE) != 0) {
fscache_stat(&fscache_n_retrievals_intr);
_leave(" = -ERESTARTSYS");
@@ -342,7 +341,6 @@ int fscache_wait_for_operation_activation(struct fscache_object *object,
if (stat_op_waits)
fscache_stat(stat_op_waits);
if (wait_on_bit(&op->flags, FSCACHE_OP_WAITING,
- fscache_wait_bit_interruptible,
TASK_INTERRUPTIBLE) != 0) {
ret = fscache_cancel_op(op, do_cancel);
if (ret == 0)
@@ -351,7 +349,7 @@ int fscache_wait_for_operation_activation(struct fscache_object *object,
/* it's been removed from the pending queue by another party,
* so we should get to run shortly */
wait_on_bit(&op->flags, FSCACHE_OP_WAITING,
- fscache_wait_bit, TASK_UNINTERRUPTIBLE);
+ TASK_UNINTERRUPTIBLE);
}
_debug("<<< GO");

diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
index ca0be6c69a26..43a54163d99e 100644
--- a/fs/gfs2/glock.c
+++ b/fs/gfs2/glock.c
@@ -854,27 +854,6 @@ void gfs2_holder_uninit(struct gfs2_holder *gh)
}

/**
- * gfs2_glock_holder_wait
- * @word: unused
- *
- * This function and gfs2_glock_demote_wait both show up in the WCHAN
- * field. Thus I've separated these otherwise identical functions in
- * order to be more informative to the user.
- */
-
-static int gfs2_glock_holder_wait(void *word)
-{
- schedule();
- return 0;
-}
-
-static int gfs2_glock_demote_wait(void *word)
-{
- schedule();
- return 0;
-}
-
-/**
* gfs2_glock_wait - wait on a glock acquisition
* @gh: the glock holder
*
@@ -886,7 +865,7 @@ int gfs2_glock_wait(struct gfs2_holder *gh)
unsigned long time1 = jiffies;

might_sleep();
- wait_on_bit(&gh->gh_iflags, HIF_WAIT, gfs2_glock_holder_wait, TASK_UNINTERRUPTIBLE);
+ wait_on_bit(&gh->gh_iflags, HIF_WAIT, TASK_UNINTERRUPTIBLE);
if (time_after(jiffies, time1 + HZ)) /* have we waited > a second? */
/* Lengthen the minimum hold time. */
gh->gh_gl->gl_hold_time = min(gh->gh_gl->gl_hold_time +
@@ -1122,7 +1101,7 @@ void gfs2_glock_dq_wait(struct gfs2_holder *gh)
struct gfs2_glock *gl = gh->gh_gl;
gfs2_glock_dq(gh);
might_sleep();
- wait_on_bit(&gl->gl_flags, GLF_DEMOTE, gfs2_glock_demote_wait, TASK_UNINTERRUPTIBLE);
+ wait_on_bit(&gl->gl_flags, GLF_DEMOTE, TASK_UNINTERRUPTIBLE);
}

/**
diff --git a/fs/gfs2/lock_dlm.c b/fs/gfs2/lock_dlm.c
index 2a6ba06bee6f..e7b029356355 100644
--- a/fs/gfs2/lock_dlm.c
+++ b/fs/gfs2/lock_dlm.c
@@ -934,12 +934,6 @@ fail:
return error;
}

-static int dlm_recovery_wait(void *word)
-{
- schedule();
- return 0;
-}
-
static int control_first_done(struct gfs2_sbd *sdp)
{
struct lm_lockstruct *ls = &sdp->sd_lockstruct;
@@ -974,7 +968,7 @@ restart:
fs_info(sdp, "control_first_done wait gen %u\n", start_gen);

wait_on_bit(&ls->ls_recover_flags, DFL_DLM_RECOVERY,
- dlm_recovery_wait, TASK_UNINTERRUPTIBLE);
+ TASK_UNINTERRUPTIBLE);
goto restart;
}

diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c
index c6872d09561a..0a086acf0835 100644
--- a/fs/gfs2/ops_fstype.c
+++ b/fs/gfs2/ops_fstype.c
@@ -1071,20 +1071,13 @@ void gfs2_lm_unmount(struct gfs2_sbd *sdp)
lm->lm_unmount(sdp);
}

-static int gfs2_journalid_wait(void *word)
-{
- if (signal_pending(current))
- return -EINTR;
- schedule();
- return 0;
-}
-
static int wait_on_journal(struct gfs2_sbd *sdp)
{
if (sdp->sd_lockstruct.ls_ops->lm_mount == NULL)
return 0;

- return wait_on_bit(&sdp->sd_flags, SDF_NOJOURNALID, gfs2_journalid_wait, TASK_INTERRUPTIBLE);
+ return wait_on_bit(&sdp->sd_flags, SDF_NOJOURNALID, TASK_INTERRUPTIBLE)
+ ? -EINTR : 0;
}

void gfs2_online_uevent(struct gfs2_sbd *sdp)
diff --git a/fs/gfs2/recovery.c b/fs/gfs2/recovery.c
index 963b2d75200c..da8853f49609 100644
--- a/fs/gfs2/recovery.c
+++ b/fs/gfs2/recovery.c
@@ -591,12 +591,6 @@ done:
wake_up_bit(&jd->jd_flags, JDF_RECOVERY);
}

-static int gfs2_recovery_wait(void *word)
-{
- schedule();
- return 0;
-}
-
int gfs2_recover_journal(struct gfs2_jdesc *jd, bool wait)
{
int rv;
@@ -609,7 +603,7 @@ int gfs2_recover_journal(struct gfs2_jdesc *jd, bool wait)
BUG_ON(!rv);

if (wait)
- wait_on_bit(&jd->jd_flags, JDF_RECOVERY, gfs2_recovery_wait,
+ wait_on_bit(&jd->jd_flags, JDF_RECOVERY,
TASK_UNINTERRUPTIBLE);

return wait ? jd->jd_recover_error : 0;
diff --git a/fs/gfs2/super.c b/fs/gfs2/super.c
index 60f60f6181f3..58c22af73967 100644
--- a/fs/gfs2/super.c
+++ b/fs/gfs2/super.c
@@ -858,12 +858,6 @@ static int gfs2_make_fs_ro(struct gfs2_sbd *sdp)
return error;
}

-static int gfs2_umount_recovery_wait(void *word)
-{
- schedule();
- return 0;
-}
-
/**
* gfs2_put_super - Unmount the filesystem
* @sb: The VFS superblock
@@ -888,7 +882,7 @@ restart:
continue;
spin_unlock(&sdp->sd_jindex_spin);
wait_on_bit(&jd->jd_flags, JDF_RECOVERY,
- gfs2_umount_recovery_wait, TASK_UNINTERRUPTIBLE);
+ TASK_UNINTERRUPTIBLE);
goto restart;
}
spin_unlock(&sdp->sd_jindex_spin);
diff --git a/fs/inode.c b/fs/inode.c
index 4bcdad3c9361..e5b968ddf79e 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -1696,13 +1696,6 @@ int inode_needs_sync(struct inode *inode)
}
EXPORT_SYMBOL(inode_needs_sync);

-int inode_wait(void *word)
-{
- schedule();
- return 0;
-}
-EXPORT_SYMBOL(inode_wait);
-
/*
* If we try to find an inode in the inode hash while it is being
* deleted, we have to wait until the filesystem completes its
diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c
index 60bb365f54a5..02a675b5d815 100644
--- a/fs/jbd2/transaction.c
+++ b/fs/jbd2/transaction.c
@@ -763,12 +763,6 @@ static void warn_dirty_buffer(struct buffer_head *bh)
bdevname(bh->b_bdev, b), (unsigned long long)bh->b_blocknr);
}

-static int sleep_on_shadow_bh(void *word)
-{
- io_schedule();
- return 0;
-}
-
/*
* If the buffer is already part of the current transaction, then there
* is nothing we need to do. If it is already part of a prior
@@ -906,8 +900,8 @@ repeat:
if (buffer_shadow(bh)) {
JBUFFER_TRACE(jh, "on shadow: sleep");
jbd_unlock_bh_state(bh);
- wait_on_bit(&bh->b_state, BH_Shadow,
- sleep_on_shadow_bh, TASK_UNINTERRUPTIBLE);
+ wait_on_bit_io(&bh->b_state, BH_Shadow,
+ TASK_UNINTERRUPTIBLE);
goto repeat;
}

diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 5bb790a69c71..d470019fddfa 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -362,8 +362,8 @@ start:
* Prevent starvation issues if someone is doing a consistency
* sync-to-disk
*/
- ret = wait_on_bit(&NFS_I(mapping->host)->flags, NFS_INO_FLUSHING,
- nfs_wait_bit_killable, TASK_KILLABLE);
+ ret = wait_on_bit_cmd(&NFS_I(mapping->host)->flags, NFS_INO_FLUSHING,
+ nfs_wait_bit_killable, TASK_KILLABLE);
if (ret)
return ret;

diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index 91c4746fdab1..82444eb25785 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -1050,8 +1050,8 @@ int nfs_revalidate_mapping(struct inode *inode, struct address_space *mapping)
* the bit lock here if it looks like we're going to be doing that.
*/
for (;;) {
- ret = wait_on_bit(bitlock, NFS_INO_INVALIDATING,
- nfs_wait_bit_killable, TASK_KILLABLE);
+ ret = wait_on_bit_cmd(bitlock, NFS_INO_INVALIDATING,
+ nfs_wait_bit_killable, TASK_KILLABLE);
if (ret)
goto out;
spin_lock(&inode->i_lock);
diff --git a/fs/nfs/nfs4filelayoutdev.c b/fs/nfs/nfs4filelayoutdev.c
index efac602edb37..8a2346f4e598 100644
--- a/fs/nfs/nfs4filelayoutdev.c
+++ b/fs/nfs/nfs4filelayoutdev.c
@@ -783,7 +783,7 @@ nfs4_fl_select_ds_fh(struct pnfs_layout_segment *lseg, u32 j)
static void nfs4_wait_ds_connect(struct nfs4_pnfs_ds *ds)
{
might_sleep();
- wait_on_bit(&ds->ds_state, NFS4DS_CONNECTING,
+ wait_on_bit_cmd(&ds->ds_state, NFS4DS_CONNECTING,
nfs_wait_bit_killable, TASK_KILLABLE);
}

diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
index 0deb32105ccf..1a7a8da9cde8 100644
--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c
@@ -1251,8 +1251,8 @@ int nfs4_wait_clnt_recover(struct nfs_client *clp)
might_sleep();

atomic_inc(&clp->cl_count);
- res = wait_on_bit(&clp->cl_state, NFS4CLNT_MANAGER_RUNNING,
- nfs_wait_bit_killable, TASK_KILLABLE);
+ res = wait_on_bit_cmd(&clp->cl_state, NFS4CLNT_MANAGER_RUNNING,
+ nfs_wait_bit_killable, TASK_KILLABLE);
if (res)
goto out;
if (clp->cl_cons_state < 0)
diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index 2ffebf2081ce..f369a74f2b31 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -258,12 +258,6 @@ void nfs_release_request(struct nfs_page *req)
kref_put(&req->wb_kref, nfs_free_request);
}

-static int nfs_wait_bit_uninterruptible(void *word)
-{
- io_schedule();
- return 0;
-}
-
/**
* nfs_wait_on_request - Wait for a request to complete.
* @req: request to wait upon.
@@ -274,9 +268,8 @@ static int nfs_wait_bit_uninterruptible(void *word)
int
nfs_wait_on_request(struct nfs_page *req)
{
- return wait_on_bit(&req->wb_flags, PG_BUSY,
- nfs_wait_bit_uninterruptible,
- TASK_UNINTERRUPTIBLE);
+ return wait_on_bit_io(&req->wb_flags, PG_BUSY,
+ TASK_UNINTERRUPTIBLE);
}

bool nfs_generic_pg_test(struct nfs_pageio_descriptor *desc, struct nfs_page *prev, struct nfs_page *req)
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 4755858e37a0..c1536c503649 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -1898,7 +1898,7 @@ pnfs_layoutcommit_inode(struct inode *inode, bool sync)
if (test_and_set_bit(NFS_INO_LAYOUTCOMMITTING, &nfsi->flags)) {
if (!sync)
goto out;
- status = wait_on_bit_lock(&nfsi->flags,
+ status = wait_on_bit_lock_cmd(&nfsi->flags,
NFS_INO_LAYOUTCOMMITTING,
nfs_wait_bit_killable,
TASK_KILLABLE);
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 9a3b6a4cd6b9..790f94514793 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -393,7 +393,7 @@ int nfs_writepages(struct address_space *mapping, struct writeback_control *wbc)
int err;

/* Stop dirtying of new pages while we sync */
- err = wait_on_bit_lock(bitlock, NFS_INO_FLUSHING,
+ err = wait_on_bit_lock_cmd(bitlock, NFS_INO_FLUSHING,
nfs_wait_bit_killable, TASK_KILLABLE);
if (err)
goto out_err;
@@ -1694,7 +1694,7 @@ int nfs_commit_inode(struct inode *inode, int how)
return error;
if (!may_wait)
goto out_mark_dirty;
- error = wait_on_bit(&NFS_I(inode)->flags,
+ error = wait_on_bit_cmd(&NFS_I(inode)->flags,
NFS_INO_COMMIT,
nfs_wait_bit_killable,
TASK_KILLABLE);
diff --git a/include/linux/writeback.h b/include/linux/writeback.h
index 021b8a319b9e..f1bc4fd07b2f 100644
--- a/include/linux/writeback.h
+++ b/include/linux/writeback.h
@@ -90,7 +90,6 @@ struct writeback_control {
* fs/fs-writeback.c
*/
struct bdi_writeback;
-int inode_wait(void *);
void writeback_inodes_sb(struct super_block *, enum wb_reason reason);
void writeback_inodes_sb_nr(struct super_block *, unsigned long nr,
enum wb_reason reason);
@@ -105,7 +104,7 @@ void inode_wait_for_writeback(struct inode *inode);
static inline void wait_on_inode(struct inode *inode)
{
might_sleep();
- wait_on_bit(&inode->i_state, __I_NEW, inode_wait, TASK_UNINTERRUPTIBLE);
+ wait_on_bit(&inode->i_state, __I_NEW, TASK_UNINTERRUPTIBLE);
}

/*
diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index 1f4bcb3cc21c..23acf4b4e421 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -28,12 +28,6 @@
#include <linux/compat.h>


-static int ptrace_trapping_sleep_fn(void *flags)
-{
- schedule();
- return 0;
-}
-
/*
* ptrace a task: make the debugger its new parent and
* move it to the ptrace list.
@@ -371,7 +365,7 @@ unlock_creds:
out:
if (!retval) {
wait_on_bit(&task->jobctl, JOBCTL_TRAPPING_BIT,
- ptrace_trapping_sleep_fn, TASK_UNINTERRUPTIBLE);
+ TASK_UNINTERRUPTIBLE);
proc_ptrace_connector(task, PTRACE_ATTACH);
}

diff --git a/mm/ksm.c b/mm/ksm.c
index 68710e80994a..33c8b475df65 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -1979,18 +1979,12 @@ void ksm_migrate_page(struct page *newpage, struct page *oldpage)
#endif /* CONFIG_MIGRATION */

#ifdef CONFIG_MEMORY_HOTREMOVE
-static int just_wait(void *word)
-{
- schedule();
- return 0;
-}
-
static void wait_while_offlining(void)
{
while (ksm_run & KSM_RUN_OFFLINE) {
mutex_unlock(&ksm_thread_mutex);
wait_on_bit(&ksm_run, ilog2(KSM_RUN_OFFLINE),
- just_wait, TASK_UNINTERRUPTIBLE);
+ TASK_UNINTERRUPTIBLE);
mutex_lock(&ksm_thread_mutex);
}
}
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index 5e8663c194c1..29bd326d1a0f 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -1753,12 +1753,6 @@ static void hci_inq_req(struct hci_request *req, unsigned long opt)
hci_req_add(req, HCI_OP_INQUIRY, sizeof(cp), &cp);
}

-static int wait_inquiry(void *word)
-{
- schedule();
- return signal_pending(current);
-}
-
int hci_inquiry(void __user *arg)
{
__u8 __user *ptr = arg;
@@ -1809,7 +1803,7 @@ int hci_inquiry(void __user *arg)
/* Wait until Inquiry procedure finishes (HCI_INQUIRY flag is
* cleared). If it is interrupted by a signal, return -EINTR.
*/
- if (wait_on_bit(&hdev->flags, HCI_INQUIRY, wait_inquiry,
+ if (wait_on_bit(&hdev->flags, HCI_INQUIRY,
TASK_INTERRUPTIBLE))
return -EINTR;
}
diff --git a/security/keys/gc.c b/security/keys/gc.c
index d3222b6d7d59..9609a7f0faea 100644
--- a/security/keys/gc.c
+++ b/security/keys/gc.c
@@ -92,15 +92,6 @@ static void key_gc_timer_func(unsigned long data)
}

/*
- * wait_on_bit() sleep function for uninterruptible waiting
- */
-static int key_gc_wait_bit(void *flags)
-{
- schedule();
- return 0;
-}
-
-/*
* Reap keys of dead type.
*
* We use three flags to make sure we see three complete cycles of the garbage
@@ -123,7 +114,7 @@ void key_gc_keytype(struct key_type *ktype)
schedule_work(&key_gc_work);

kdebug("sleep");
- wait_on_bit(&key_gc_flags, KEY_GC_REAPING_KEYTYPE, key_gc_wait_bit,
+ wait_on_bit(&key_gc_flags, KEY_GC_REAPING_KEYTYPE,
TASK_UNINTERRUPTIBLE);

key_gc_dead_keytype = NULL;
diff --git a/security/keys/request_key.c b/security/keys/request_key.c
index 381411941cc1..26a94f18af94 100644
--- a/security/keys/request_key.c
+++ b/security/keys/request_key.c
@@ -21,24 +21,6 @@

#define key_negative_timeout 60 /* default timeout on a negative key's existence */

-/*
- * wait_on_bit() sleep function for uninterruptible waiting
- */
-static int key_wait_bit(void *flags)
-{
- schedule();
- return 0;
-}
-
-/*
- * wait_on_bit() sleep function for interruptible waiting
- */
-static int key_wait_bit_intr(void *flags)
-{
- schedule();
- return signal_pending(current) ? -ERESTARTSYS : 0;
-}
-
/**
* complete_request_key - Complete the construction of a key.
* @cons: The key construction record.
@@ -592,10 +574,9 @@ int wait_for_key_construction(struct key *key, bool intr)
int ret;

ret = wait_on_bit(&key->flags, KEY_FLAG_USER_CONSTRUCT,
- intr ? key_wait_bit_intr : key_wait_bit,
intr ? TASK_INTERRUPTIBLE : TASK_UNINTERRUPTIBLE);
- if (ret < 0)
- return ret;
+ if (ret)
+ return -ERESTARTSYS;
if (test_bit(KEY_FLAG_NEGATIVE, &key->flags)) {
smp_rmb();
return key->type_data.reject_error;

Attachment: signature.asc
Description: PGP signature