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-rw-r--r--block/blk-cgroup.c37
-rw-r--r--block/blk-core.c15
-rw-r--r--block/blk-softirq.c2
-rw-r--r--block/blk-sysfs.c10
-rw-r--r--block/cfq-iosched.c20
-rw-r--r--drivers/block/floppy.c8
-rw-r--r--drivers/block/xen-blkback/common.h2
-rw-r--r--drivers/block/xen-blkback/xenbus.c6
-rw-r--r--drivers/mmc/card/block.c3
-rw-r--r--fs/ext3/inode.c4
-rw-r--r--fs/ext3/namei.c3
-rw-r--r--fs/ext4/inode.c4
-rw-r--r--fs/ext4/namei.c3
-rw-r--r--fs/gfs2/log.c4
-rw-r--r--fs/gfs2/meta_io.c6
-rw-r--r--fs/gfs2/ops_fstype.c2
-rw-r--r--fs/gfs2/quota.c2
-rw-r--r--include/linux/blk_types.h6
-rw-r--r--include/linux/blkdev.h1
-rw-r--r--include/linux/fs.h2
-rw-r--r--mm/backing-dev.c30
21 files changed, 92 insertions, 78 deletions
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index bcaf16e..b596e54 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -785,10 +785,10 @@ static int blkio_policy_parse_and_set(char *buf,
{
char *s[4], *p, *major_s = NULL, *minor_s = NULL;
int ret;
- unsigned long major, minor, temp;
+ unsigned long major, minor;
int i = 0;
dev_t dev;
- u64 bps, iops;
+ u64 temp;
memset(s, 0, sizeof(s));
@@ -826,20 +826,23 @@ static int blkio_policy_parse_and_set(char *buf,
dev = MKDEV(major, minor);
- ret = blkio_check_dev_num(dev);
+ ret = strict_strtoull(s[1], 10, &temp);
if (ret)
- return ret;
+ return -EINVAL;
- newpn->dev = dev;
+ /* For rule removal, do not check for device presence. */
+ if (temp) {
+ ret = blkio_check_dev_num(dev);
+ if (ret)
+ return ret;
+ }
- if (s[1] == NULL)
- return -EINVAL;
+ newpn->dev = dev;
switch (plid) {
case BLKIO_POLICY_PROP:
- ret = strict_strtoul(s[1], 10, &temp);
- if (ret || (temp < BLKIO_WEIGHT_MIN && temp > 0) ||
- temp > BLKIO_WEIGHT_MAX)
+ if ((temp < BLKIO_WEIGHT_MIN && temp > 0) ||
+ temp > BLKIO_WEIGHT_MAX)
return -EINVAL;
newpn->plid = plid;
@@ -850,26 +853,18 @@ static int blkio_policy_parse_and_set(char *buf,
switch(fileid) {
case BLKIO_THROTL_read_bps_device:
case BLKIO_THROTL_write_bps_device:
- ret = strict_strtoull(s[1], 10, &bps);
- if (ret)
- return -EINVAL;
-
newpn->plid = plid;
newpn->fileid = fileid;
- newpn->val.bps = bps;
+ newpn->val.bps = temp;
break;
case BLKIO_THROTL_read_iops_device:
case BLKIO_THROTL_write_iops_device:
- ret = strict_strtoull(s[1], 10, &iops);
- if (ret)
- return -EINVAL;
-
- if (iops > THROTL_IOPS_MAX)
+ if (temp > THROTL_IOPS_MAX)
return -EINVAL;
newpn->plid = plid;
newpn->fileid = fileid;
- newpn->val.iops = (unsigned int)iops;
+ newpn->val.iops = (unsigned int)temp;
break;
}
break;
diff --git a/block/blk-core.c b/block/blk-core.c
index 90e1ffd..b2ed78a 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1167,7 +1167,7 @@ static bool bio_attempt_front_merge(struct request_queue *q,
* true if merge was successful, otherwise false.
*/
static bool attempt_plug_merge(struct task_struct *tsk, struct request_queue *q,
- struct bio *bio)
+ struct bio *bio, unsigned int *request_count)
{
struct blk_plug *plug;
struct request *rq;
@@ -1176,10 +1176,13 @@ static bool attempt_plug_merge(struct task_struct *tsk, struct request_queue *q,
plug = tsk->plug;
if (!plug)
goto out;
+ *request_count = 0;
list_for_each_entry_reverse(rq, &plug->list, queuelist) {
int el_ret;
+ (*request_count)++;
+
if (rq->q != q)
continue;
@@ -1219,6 +1222,7 @@ static int __make_request(struct request_queue *q, struct bio *bio)
struct blk_plug *plug;
int el_ret, rw_flags, where = ELEVATOR_INSERT_SORT;
struct request *req;
+ unsigned int request_count = 0;
/*
* low level driver can indicate that it wants pages above a
@@ -1237,7 +1241,7 @@ static int __make_request(struct request_queue *q, struct bio *bio)
* Check if we can merge with the plugged list before grabbing
* any locks.
*/
- if (attempt_plug_merge(current, q, bio))
+ if (attempt_plug_merge(current, q, bio, &request_count))
goto out;
spin_lock_irq(q->queue_lock);
@@ -1302,11 +1306,10 @@ get_rq:
if (__rq->q != q)
plug->should_sort = 1;
}
+ if (request_count >= BLK_MAX_REQUEST_COUNT)
+ blk_flush_plug_list(plug, false);
list_add_tail(&req->queuelist, &plug->list);
- plug->count++;
drive_stat_acct(req, 1);
- if (plug->count >= BLK_MAX_REQUEST_COUNT)
- blk_flush_plug_list(plug, false);
} else {
spin_lock_irq(q->queue_lock);
add_acct_request(q, req, where);
@@ -2634,7 +2637,6 @@ void blk_start_plug(struct blk_plug *plug)
INIT_LIST_HEAD(&plug->list);
INIT_LIST_HEAD(&plug->cb_list);
plug->should_sort = 0;
- plug->count = 0;
/*
* If this is a nested plug, don't actually assign it. It will be
@@ -2718,7 +2720,6 @@ void blk_flush_plug_list(struct blk_plug *plug, bool from_schedule)
return;
list_splice_init(&plug->list, &list);
- plug->count = 0;
if (plug->should_sort) {
list_sort(NULL, &list, plug_rq_cmp);
diff --git a/block/blk-softirq.c b/block/blk-softirq.c
index 58340d0..1366a89 100644
--- a/block/blk-softirq.c
+++ b/block/blk-softirq.c
@@ -115,7 +115,7 @@ void __blk_complete_request(struct request *req)
/*
* Select completion CPU
*/
- if (test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags) && req->cpu != -1) {
+ if (req->cpu != -1) {
ccpu = req->cpu;
if (!test_bit(QUEUE_FLAG_SAME_FORCE, &q->queue_flags)) {
ccpu = blk_cpu_to_group(ccpu);
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 0ee17b5..e681805 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -258,11 +258,13 @@ queue_rq_affinity_store(struct request_queue *q, const char *page, size_t count)
ret = queue_var_store(&val, page, count);
spin_lock_irq(q->queue_lock);
- if (val) {
+ if (val == 2) {
queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
- if (val == 2)
- queue_flag_set(QUEUE_FLAG_SAME_FORCE, q);
- } else {
+ queue_flag_set(QUEUE_FLAG_SAME_FORCE, q);
+ } else if (val == 1) {
+ queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
+ queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q);
+ } else if (val == 0) {
queue_flag_clear(QUEUE_FLAG_SAME_COMP, q);
queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q);
}
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index a33bd43..16ace89 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -130,8 +130,8 @@ struct cfq_queue {
unsigned long slice_end;
long slice_resid;
- /* pending metadata requests */
- int meta_pending;
+ /* pending priority requests */
+ int prio_pending;
/* number of requests that are on the dispatch list or inside driver */
int dispatched;
@@ -684,8 +684,8 @@ cfq_choose_req(struct cfq_data *cfqd, struct request *rq1, struct request *rq2,
if (rq_is_sync(rq1) != rq_is_sync(rq2))
return rq_is_sync(rq1) ? rq1 : rq2;
- if ((rq1->cmd_flags ^ rq2->cmd_flags) & REQ_META)
- return rq1->cmd_flags & REQ_META ? rq1 : rq2;
+ if ((rq1->cmd_flags ^ rq2->cmd_flags) & REQ_PRIO)
+ return rq1->cmd_flags & REQ_PRIO ? rq1 : rq2;
s1 = blk_rq_pos(rq1);
s2 = blk_rq_pos(rq2);
@@ -1612,9 +1612,9 @@ static void cfq_remove_request(struct request *rq)
cfqq->cfqd->rq_queued--;
cfq_blkiocg_update_io_remove_stats(&(RQ_CFQG(rq))->blkg,
rq_data_dir(rq), rq_is_sync(rq));
- if (rq->cmd_flags & REQ_META) {
- WARN_ON(!cfqq->meta_pending);
- cfqq->meta_pending--;
+ if (rq->cmd_flags & REQ_PRIO) {
+ WARN_ON(!cfqq->prio_pending);
+ cfqq->prio_pending--;
}
}
@@ -3372,7 +3372,7 @@ cfq_should_preempt(struct cfq_data *cfqd, struct cfq_queue *new_cfqq,
* So both queues are sync. Let the new request get disk time if
* it's a metadata request and the current queue is doing regular IO.
*/
- if ((rq->cmd_flags & REQ_META) && !cfqq->meta_pending)
+ if ((rq->cmd_flags & REQ_PRIO) && !cfqq->prio_pending)
return true;
/*
@@ -3439,8 +3439,8 @@ cfq_rq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq,
struct cfq_io_context *cic = RQ_CIC(rq);
cfqd->rq_queued++;
- if (rq->cmd_flags & REQ_META)
- cfqq->meta_pending++;
+ if (rq->cmd_flags & REQ_PRIO)
+ cfqq->prio_pending++;
cfq_update_io_thinktime(cfqd, cfqq, cic);
cfq_update_io_seektime(cfqd, cfqq, rq);
diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c
index 98de8f4..9955a53 100644
--- a/drivers/block/floppy.c
+++ b/drivers/block/floppy.c
@@ -4250,7 +4250,7 @@ static int __init floppy_init(void)
use_virtual_dma = can_use_virtual_dma & 1;
fdc_state[0].address = FDC1;
if (fdc_state[0].address == -1) {
- del_timer(&fd_timeout);
+ del_timer_sync(&fd_timeout);
err = -ENODEV;
goto out_unreg_region;
}
@@ -4261,7 +4261,7 @@ static int __init floppy_init(void)
fdc = 0; /* reset fdc in case of unexpected interrupt */
err = floppy_grab_irq_and_dma();
if (err) {
- del_timer(&fd_timeout);
+ del_timer_sync(&fd_timeout);
err = -EBUSY;
goto out_unreg_region;
}
@@ -4318,7 +4318,7 @@ static int __init floppy_init(void)
user_reset_fdc(-1, FD_RESET_ALWAYS, false);
}
fdc = 0;
- del_timer(&fd_timeout);
+ del_timer_sync(&fd_timeout);
current_drive = 0;
initialized = true;
if (have_no_fdc) {
@@ -4368,7 +4368,7 @@ out_unreg_blkdev:
unregister_blkdev(FLOPPY_MAJOR, "fd");
out_put_disk:
while (dr--) {
- del_timer(&motor_off_timer[dr]);
+ del_timer_sync(&motor_off_timer[dr]);
if (disks[dr]->queue)
blk_cleanup_queue(disks[dr]->queue);
put_disk(disks[dr]);
diff --git a/drivers/block/xen-blkback/common.h b/drivers/block/xen-blkback/common.h
index 9e40b28..00c57c9 100644
--- a/drivers/block/xen-blkback/common.h
+++ b/drivers/block/xen-blkback/common.h
@@ -46,7 +46,7 @@
#define DRV_PFX "xen-blkback:"
#define DPRINTK(fmt, args...) \
- pr_debug(DRV_PFX "(%s:%d) " fmt ".\n", \
+ pr_debug(DRV_PFX "(%s:%d) " fmt ".\n", \
__func__, __LINE__, ##args)
diff --git a/drivers/block/xen-blkback/xenbus.c b/drivers/block/xen-blkback/xenbus.c
index 3f129b4..5fd2010 100644
--- a/drivers/block/xen-blkback/xenbus.c
+++ b/drivers/block/xen-blkback/xenbus.c
@@ -590,7 +590,7 @@ static void frontend_changed(struct xenbus_device *dev,
/*
* Enforce precondition before potential leak point.
- * blkif_disconnect() is idempotent.
+ * xen_blkif_disconnect() is idempotent.
*/
xen_blkif_disconnect(be->blkif);
@@ -601,17 +601,17 @@ static void frontend_changed(struct xenbus_device *dev,
break;
case XenbusStateClosing:
- xen_blkif_disconnect(be->blkif);
xenbus_switch_state(dev, XenbusStateClosing);
break;
case XenbusStateClosed:
+ xen_blkif_disconnect(be->blkif);
xenbus_switch_state(dev, XenbusStateClosed);
if (xenbus_dev_is_online(dev))
break;
/* fall through if not online */
case XenbusStateUnknown:
- /* implies blkif_disconnect() via blkback_remove() */
+ /* implies xen_blkif_disconnect() via xen_blkbk_remove() */
device_unregister(&dev->dev);
break;
diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index 1ff5486..4c1a648 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -926,6 +926,9 @@ static void mmc_blk_rw_rq_prep(struct mmc_queue_req *mqrq,
/*
* Reliable writes are used to implement Forced Unit Access and
* REQ_META accesses, and are supported only on MMCs.
+ *
+ * XXX: this really needs a good explanation of why REQ_META
+ * is treated special.
*/
bool do_rel_wr = ((req->cmd_flags & REQ_FUA) ||
(req->cmd_flags & REQ_META)) &&
diff --git a/fs/ext3/inode.c b/fs/ext3/inode.c
index 04da6ac..12661e1 100644
--- a/fs/ext3/inode.c
+++ b/fs/ext3/inode.c
@@ -1134,7 +1134,7 @@ struct buffer_head *ext3_bread(handle_t *handle, struct inode *inode,
return bh;
if (buffer_uptodate(bh))
return bh;
- ll_rw_block(READ_META, 1, &bh);
+ ll_rw_block(READ | REQ_META | REQ_PRIO, 1, &bh);
wait_on_buffer(bh);
if (buffer_uptodate(bh))
return bh;
@@ -2807,7 +2807,7 @@ make_io:
trace_ext3_load_inode(inode);
get_bh(bh);
bh->b_end_io = end_buffer_read_sync;
- submit_bh(READ_META, bh);
+ submit_bh(READ | REQ_META | REQ_PRIO, bh);
wait_on_buffer(bh);
if (!buffer_uptodate(bh)) {
ext3_error(inode->i_sb, "ext3_get_inode_loc",
diff --git a/fs/ext3/namei.c b/fs/ext3/namei.c
index 5571708..0629e09 100644
--- a/fs/ext3/namei.c
+++ b/fs/ext3/namei.c
@@ -922,7 +922,8 @@ restart:
bh = ext3_getblk(NULL, dir, b++, 0, &err);
bh_use[ra_max] = bh;
if (bh)
- ll_rw_block(READ_META, 1, &bh);
+ ll_rw_block(READ | REQ_META | REQ_PRIO,
+ 1, &bh);
}
}
if ((bh = bh_use[ra_ptr++]) == NULL)
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 18d2558..986e238 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -647,7 +647,7 @@ struct buffer_head *ext4_bread(handle_t *handle, struct inode *inode,
return bh;
if (buffer_uptodate(bh))
return bh;
- ll_rw_block(READ_META, 1, &bh);
+ ll_rw_block(READ | REQ_META | REQ_PRIO, 1, &bh);
wait_on_buffer(bh);
if (buffer_uptodate(bh))
return bh;
@@ -3298,7 +3298,7 @@ make_io:
trace_ext4_load_inode(inode);
get_bh(bh);
bh->b_end_io = end_buffer_read_sync;
- submit_bh(READ_META, bh);
+ submit_bh(READ | REQ_META | REQ_PRIO, bh);
wait_on_buffer(bh);
if (!buffer_uptodate(bh)) {
EXT4_ERROR_INODE_BLOCK(inode, block,
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index f8068c7..1c924fa 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -922,7 +922,8 @@ restart:
bh = ext4_getblk(NULL, dir, b++, 0, &err);
bh_use[ra_max] = bh;
if (bh)
- ll_rw_block(READ_META, 1, &bh);
+ ll_rw_block(READ | REQ_META | REQ_PRIO,
+ 1, &bh);
}
}
if ((bh = bh_use[ra_ptr++]) == NULL)
diff --git a/fs/gfs2/log.c b/fs/gfs2/log.c
index 85c6292..5986464 100644
--- a/fs/gfs2/log.c
+++ b/fs/gfs2/log.c
@@ -624,9 +624,9 @@ static void log_write_header(struct gfs2_sbd *sdp, u32 flags, int pull)
bh->b_end_io = end_buffer_write_sync;
get_bh(bh);
if (test_bit(SDF_NOBARRIERS, &sdp->sd_flags))
- submit_bh(WRITE_SYNC | REQ_META, bh);
+ submit_bh(WRITE_SYNC | REQ_META | REQ_PRIO, bh);
else
- submit_bh(WRITE_FLUSH_FUA | REQ_META, bh);
+ submit_bh(WRITE_FLUSH_FUA | REQ_META | REQ_PRIO, bh);
wait_on_buffer(bh);
if (!buffer_uptodate(bh))
diff --git a/fs/gfs2/meta_io.c b/fs/gfs2/meta_io.c
index 747238c..be29858 100644
--- a/fs/gfs2/meta_io.c
+++ b/fs/gfs2/meta_io.c
@@ -37,7 +37,7 @@ static int gfs2_aspace_writepage(struct page *page, struct writeback_control *wb
{
struct buffer_head *bh, *head;
int nr_underway = 0;
- int write_op = REQ_META |
+ int write_op = REQ_META | REQ_PRIO |
(wbc->sync_mode == WB_SYNC_ALL ? WRITE_SYNC : WRITE);
BUG_ON(!PageLocked(page));
@@ -225,7 +225,7 @@ int gfs2_meta_read(struct gfs2_glock *gl, u64 blkno, int flags,
}
bh->b_end_io = end_buffer_read_sync;
get_bh(bh);
- submit_bh(READ_SYNC | REQ_META, bh);
+ submit_bh(READ_SYNC | REQ_META | REQ_PRIO, bh);
if (!(flags & DIO_WAIT))
return 0;
@@ -435,7 +435,7 @@ struct buffer_head *gfs2_meta_ra(struct gfs2_glock *gl, u64 dblock, u32 extlen)
if (buffer_uptodate(first_bh))
goto out;
if (!buffer_locked(first_bh))
- ll_rw_block(READ_SYNC | REQ_META, 1, &first_bh);
+ ll_rw_block(READ_SYNC | REQ_META | REQ_PRIO, 1, &first_bh);
dblock++;
extlen--;
diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c
index 3bc073a..079587e 100644
--- a/fs/gfs2/ops_fstype.c
+++ b/fs/gfs2/ops_fstype.c
@@ -224,7 +224,7 @@ static int gfs2_read_super(struct gfs2_sbd *sdp, sector_t sector, int silent)
bio->bi_end_io = end_bio_io_page;
bio->bi_private = page;
- submit_bio(READ_SYNC | REQ_META, bio);
+ submit_bio(READ_SYNC | REQ_META | REQ_PRIO, bio);
wait_on_page_locked(page);
bio_put(bio);
if (!PageUptodate(page)) {
diff --git a/fs/gfs2/quota.c b/fs/gfs2/quota.c
index 42e8d23..0e8bb13 100644
--- a/fs/gfs2/quota.c
+++ b/fs/gfs2/quota.c
@@ -709,7 +709,7 @@ get_a_page:
set_buffer_uptodate(bh);
if (!buffer_uptodate(bh)) {
- ll_rw_block(READ_META, 1, &bh);
+ ll_rw_block(READ | REQ_META | REQ_PRIO, 1, &bh);
wait_on_buffer(bh);
if (!buffer_uptodate(bh))
goto unlock_out;
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index 32f0076..71fc53b 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -124,6 +124,7 @@ enum rq_flag_bits {
__REQ_SYNC, /* request is sync (sync write or read) */
__REQ_META, /* metadata io request */
+ __REQ_PRIO, /* boost priority in cfq */
__REQ_DISCARD, /* request to discard sectors */
__REQ_SECURE, /* secure discard (used with __REQ_DISCARD) */
@@ -161,14 +162,15 @@ enum rq_flag_bits {
#define REQ_FAILFAST_DRIVER (1 << __REQ_FAILFAST_DRIVER)
#define REQ_SYNC (1 << __REQ_SYNC)
#define REQ_META (1 << __REQ_META)
+#define REQ_PRIO (1 << __REQ_PRIO)
#define REQ_DISCARD (1 << __REQ_DISCARD)
#define REQ_NOIDLE (1 << __REQ_NOIDLE)
#define REQ_FAILFAST_MASK \
(REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | REQ_FAILFAST_DRIVER)
#define REQ_COMMON_MASK \
- (REQ_WRITE | REQ_FAILFAST_MASK | REQ_SYNC | REQ_META | REQ_DISCARD | \
- REQ_NOIDLE | REQ_FLUSH | REQ_FUA | REQ_SECURE)
+ (REQ_WRITE | REQ_FAILFAST_MASK | REQ_SYNC | REQ_META | REQ_PRIO | \
+ REQ_DISCARD | REQ_NOIDLE | REQ_FLUSH | REQ_FUA | REQ_SECURE)
#define REQ_CLONE_MASK REQ_COMMON_MASK
#define REQ_RAHEAD (1 << __REQ_RAHEAD)
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 84b15d5..7fbaa91 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -873,7 +873,6 @@ struct blk_plug {
struct list_head list;
struct list_head cb_list;
unsigned int should_sort;
- unsigned int count;
};
#define BLK_MAX_REQUEST_COUNT 16
diff --git a/include/linux/fs.h b/include/linux/fs.h
index c2bd68f..277f497 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -162,10 +162,8 @@ struct inodes_stat_t {
#define READA RWA_MASK
#define READ_SYNC (READ | REQ_SYNC)
-#define READ_META (READ | REQ_META)
#define WRITE_SYNC (WRITE | REQ_SYNC | REQ_NOIDLE)
#define WRITE_ODIRECT (WRITE | REQ_SYNC)
-#define WRITE_META (WRITE | REQ_META)
#define WRITE_FLUSH (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_FLUSH)
#define WRITE_FUA (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_FUA)
#define WRITE_FLUSH_FUA (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_FLUSH | REQ_FUA)
diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index d6edf8d..a87da52 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -359,6 +359,17 @@ static unsigned long bdi_longest_inactive(void)
return max(5UL * 60 * HZ, interval);
}
+/*
+ * Clear pending bit and wakeup anybody waiting for flusher thread creation or
+ * shutdown
+ */
+static void bdi_clear_pending(struct backing_dev_info *bdi)
+{
+ clear_bit(BDI_pending, &bdi->state);
+ smp_mb__after_clear_bit();
+ wake_up_bit(&bdi->state, BDI_pending);
+}
+
static int bdi_forker_thread(void *ptr)
{
struct bdi_writeback *me = ptr;
@@ -390,6 +401,13 @@ static int bdi_forker_thread(void *ptr)
}
spin_lock_bh(&bdi_lock);
+ /*
+ * In the following loop we are going to check whether we have
+ * some work to do without any synchronization with tasks
+ * waking us up to do work for them. So we have to set task
+ * state already here so that we don't miss wakeups coming
+ * after we verify some condition.
+ */
set_current_state(TASK_INTERRUPTIBLE);
list_for_each_entry(bdi, &bdi_list, bdi_list) {
@@ -469,11 +487,13 @@ static int bdi_forker_thread(void *ptr)
spin_unlock_bh(&bdi->wb_lock);
wake_up_process(task);
}
+ bdi_clear_pending(bdi);
break;
case KILL_THREAD:
__set_current_state(TASK_RUNNING);
kthread_stop(task);
+ bdi_clear_pending(bdi);
break;
case NO_ACTION:
@@ -489,16 +509,8 @@ static int bdi_forker_thread(void *ptr)
else
schedule_timeout(msecs_to_jiffies(dirty_writeback_interval * 10));
try_to_freeze();
- /* Back to the main loop */
- continue;
+ break;
}
-
- /*
- * Clear pending bit and wakeup anybody waiting to tear us down.
- */
- clear_bit(BDI_pending, &bdi->state);
- smp_mb__after_clear_bit();
- wake_up_bit(&bdi->state, BDI_pending);
}
return 0;
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