Since kobj->name can be freed by bdi_unregister(), we try to copy
the name into buffer rather than return name pointer. This patch
is prepare for following patch to fix use-after-free for bdi->dev.
Signed-off-by: Yufen Yu <yuyufen@xxxxxxxxxx>
---
block/bfq-iosched.c | 7 +++---
block/blk-cgroup-rwstat.c | 6 +++--
block/blk-cgroup.c | 19 +++++-----------
block/blk-iocost.c | 14 +++++++-----
block/blk-iolatency.c | 5 +++--
block/blk-throttle.c | 6 +++--
fs/fs-writeback.c | 4 +++-
include/linux/blk-cgroup.h | 1 -
include/trace/events/wbt.h | 8 +++----
include/trace/events/writeback.h | 38 ++++++++++++++------------------
10 files changed, 53 insertions(+), 55 deletions(-)
diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
index 94261b7d7181..a8a67a95006e 100644
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -4971,6 +4971,7 @@ bfq_set_next_ioprio_data(struct bfq_queue *bfqq, struct bfq_io_cq *bic)
struct task_struct *tsk = current;
int ioprio_class;
struct bfq_data *bfqd = bfqq->bfqd;
+ char dname[BDI_DEV_NAME_LEN];
if (!bfqd)
return;
@@ -4978,9 +4979,9 @@ bfq_set_next_ioprio_data(struct bfq_queue *bfqq, struct bfq_io_cq *bic)
ioprio_class = IOPRIO_PRIO_CLASS(bic->ioprio);
switch (ioprio_class) {
default:
- pr_err("bdi %s: bfq: bad prio class %d\n",
- bdi_dev_name(bfqq->bfqd->queue->backing_dev_info),
- ioprio_class);
+ bdi_get_dev_name(bfqq->bfqd->queue->backing_dev_info, dname,
+ BDI_DEV_NAME_LEN);
+ pr_err("bdi %s: bfq: bad prio class %d\n", dname, ioprio_class);
/* fall through */
case IOPRIO_CLASS_NONE:
/*
diff --git a/block/blk-cgroup-rwstat.c b/block/blk-cgroup-rwstat.c
index 85d5790ac49b..2dc260802228 100644
--- a/block/blk-cgroup-rwstat.c
+++ b/block/blk-cgroup-rwstat.c
@@ -4,6 +4,7 @@
* Do not use in new code.
*/
#include "blk-cgroup-rwstat.h"
+#include <linux/backing-dev.h>
int blkg_rwstat_init(struct blkg_rwstat *rwstat, gfp_t gfp)
{
@@ -49,11 +50,12 @@ u64 __blkg_prfill_rwstat(struct seq_file *sf, struct blkg_policy_data *pd,
[BLKG_RWSTAT_ASYNC] = "Async",
[BLKG_RWSTAT_DISCARD] = "Discard",
};
- const char *dname = blkg_dev_name(pd->blkg);
+ char dname[BDI_DEV_NAME_LEN];
u64 v;
int i;
- if (!dname)
+ if (!bdi_get_dev_name(pd->blkg->q->backing_dev_info, dname,
+ BDI_DEV_NAME_LEN))
return 0;
for (i = 0; i < BLKG_RWSTAT_NR; i++)
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index be92405c6547..a072ca6141ca 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -492,14 +492,6 @@ static int blkcg_reset_stats(struct cgroup_subsys_state *css,
return 0;
}
-const char *blkg_dev_name(struct blkcg_gq *blkg)
-{
- /* some drivers (floppy) instantiate a queue w/o disk registered */
- if (blkg->q->backing_dev_info->dev)
- return bdi_dev_name(blkg->q->backing_dev_info);
- return NULL;
-}
-
/**
* blkcg_print_blkgs - helper for printing per-blkg data
* @sf: seq_file to print to
@@ -551,9 +543,10 @@ EXPORT_SYMBOL_GPL(blkcg_print_blkgs);
*/
u64 __blkg_prfill_u64(struct seq_file *sf, struct blkg_policy_data *pd, u64 v)
{
- const char *dname = blkg_dev_name(pd->blkg);
+ char dname[BDI_DEV_NAME_LEN];
- if (!dname)
+ if (!bdi_get_dev_name(pd->blkg->q->backing_dev_info, dname,
+ BDI_DEV_NAME_LEN))
return 0;
seq_printf(sf, "%s %llu\n", dname, (unsigned long long)v);
@@ -749,7 +742,7 @@ static int blkcg_print_stat(struct seq_file *sf, void *v)
hlist_for_each_entry_rcu(blkg, &blkcg->blkg_list, blkcg_node) {
struct blkg_iostat_set *bis = &blkg->iostat;
- const char *dname;
+ char dname[BDI_DEV_NAME_LEN];
char *buf;
u64 rbytes, wbytes, rios, wios, dbytes, dios;
size_t size = seq_get_buf(sf, &buf), off = 0;
@@ -762,8 +755,8 @@ static int blkcg_print_stat(struct seq_file *sf, void *v)
if (!blkg->online)
goto skip;
- dname = blkg_dev_name(blkg);
- if (!dname)
+ if (!bdi_get_dev_name(blkg->q->backing_dev_info, dname,
+ BDI_DEV_NAME_LEN))
goto skip;
/*
diff --git a/block/blk-iocost.c b/block/blk-iocost.c
index 27ca68621137..4231d65915c8 100644
--- a/block/blk-iocost.c
+++ b/block/blk-iocost.c
@@ -2047,10 +2047,11 @@ static void ioc_pd_free(struct blkg_policy_data *pd)
static u64 ioc_weight_prfill(struct seq_file *sf, struct blkg_policy_data *pd,
int off)
{
- const char *dname = blkg_dev_name(pd->blkg);
+ char dname[BDI_DEV_NAME_LEN];
struct ioc_gq *iocg = pd_to_iocg(pd);
- if (dname && iocg->cfg_weight)
+ if (bdi_get_dev_name(pd->blkg, dname, BDI_DEV_NAME_LEN) &&
+ iocg->cfg_weight)
seq_printf(sf, "%s %u\n", dname, iocg->cfg_weight);
return 0;
}
@@ -2133,10 +2134,11 @@ static ssize_t ioc_weight_write(struct kernfs_open_file *of, char *buf,
static u64 ioc_qos_prfill(struct seq_file *sf, struct blkg_policy_data *pd,
int off)
{
- const char *dname = blkg_dev_name(pd->blkg);
+ char dname[BDI_DEV_NAME_LEN];
struct ioc *ioc = pd_to_iocg(pd)->ioc;
- if (!dname)
+ if (!bdi_get_dev_name(pd->blkg->q->backing_dev_info, dname,
+ BDI_DEV_NAME_LEN))
return 0;
seq_printf(sf, "%s enable=%d ctrl=%s rpct=%u.%02u rlat=%u wpct=%u.%02u wlat=%u min=%u.%02u max=%u.%02u\n",
@@ -2304,11 +2306,11 @@ static ssize_t ioc_qos_write(struct kernfs_open_file *of, char *input,
static u64 ioc_cost_model_prfill(struct seq_file *sf,
struct blkg_policy_data *pd, int off)
{
- const char *dname = blkg_dev_name(pd->blkg);
+ char dname[BDI_DEV_NAME_LEN];
struct ioc *ioc = pd_to_iocg(pd)->ioc;
u64 *u = ioc->params.i_lcoefs;
- if (!dname)
+ if (!bdi_get_dev_name(pd->blkg, dname, BDI_DEV_NAME_LEN))
return 0;
seq_printf(sf, "%s ctrl=%s model=linear "
diff --git a/block/blk-iolatency.c b/block/blk-iolatency.c
index c128d50cb410..2ab49167aea1 100644
--- a/block/blk-iolatency.c
+++ b/block/blk-iolatency.c
@@ -868,9 +868,10 @@ static u64 iolatency_prfill_limit(struct seq_file *sf,
struct blkg_policy_data *pd, int off)
{
struct iolatency_grp *iolat = pd_to_lat(pd);
- const char *dname = blkg_dev_name(pd->blkg);
+ char dname[BDI_DEV_NAME_LEN];
- if (!dname || !iolat->min_lat_nsec)
+ if (!bdi_get_dev_name(pd->blkg, dname, BDI_DEV_NAME_LEN)
+ || !iolat->min_lat_nsec)
return 0;
seq_printf(sf, "%s target=%llu\n",
dname, div_u64(iolat->min_lat_nsec, NSEC_PER_USEC));
diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index 98233c9c65a8..f77dc93d4e83 100644
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -13,6 +13,7 @@
#include <linux/blk-cgroup.h>
#include "blk.h"
#include "blk-cgroup-rwstat.h"
+#include <linux/backing-dev.h>
/* Max dispatch from a group in 1 round */
static int throtl_grp_quantum = 8;
@@ -1560,14 +1561,15 @@ static u64 tg_prfill_limit(struct seq_file *sf, struct blkg_policy_data *pd,
int off)
{
struct throtl_grp *tg = pd_to_tg(pd);
- const char *dname = blkg_dev_name(pd->blkg);
+ char dname[BDI_DEV_NAME_LEN];
char bufs[4][21] = { "max", "max", "max", "max" };
u64 bps_dft;
unsigned int iops_dft;
char idle_time[26] = "";
char latency_time[26] = "";
- if (!dname)
+ if (!bdi_get_dev_name(pd->blkg->q->backing_dev_info, dname,
+ BDI_DEV_NAME_LEN))
return 0;
if (off == LIMIT_LOW) {
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index 76ac9c7d32ec..8d36c256560c 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -2062,8 +2062,10 @@ void wb_workfn(struct work_struct *work)
struct bdi_writeback *wb = container_of(to_delayed_work(work),
struct bdi_writeback, dwork);
long pages_written;
+ char dname[BDI_DEV_NAME_LEN];
- set_worker_desc("flush-%s", bdi_dev_name(wb->bdi));
+ set_worker_desc("flush-%s",
+ bdi_get_dev_name(wb->bdi, dname, BDI_DEV_NAME_LEN));
current->flags |= PF_SWAPWRITE;
if (likely(!current_is_workqueue_rescuer() ||
diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h
index e4a6949fd171..384b3343d5f4 100644
--- a/include/linux/blk-cgroup.h
+++ b/include/linux/blk-cgroup.h
@@ -198,7 +198,6 @@ int blkcg_activate_policy(struct request_queue *q,
void blkcg_deactivate_policy(struct request_queue *q,
const struct blkcg_policy *pol);
-const char *blkg_dev_name(struct blkcg_gq *blkg);
void blkcg_print_blkgs(struct seq_file *sf, struct blkcg *blkcg,
u64 (*prfill)(struct seq_file *,
struct blkg_policy_data *, int),
diff --git a/include/trace/events/wbt.h b/include/trace/events/wbt.h
index 9996420d7ec4..3fbf15565962 100644
--- a/include/trace/events/wbt.h
+++ b/include/trace/events/wbt.h
@@ -33,7 +33,7 @@ TRACE_EVENT(wbt_stat,
),
TP_fast_assign(
- strlcpy(__entry->name, bdi_dev_name(bdi),
+ bdi_get_dev_name(bdi, __entry->name,
ARRAY_SIZE(__entry->name));
__entry->rmean = stat[0].mean;
__entry->rmin = stat[0].min;
@@ -68,7 +68,7 @@ TRACE_EVENT(wbt_lat,
),
TP_fast_assign(
- strlcpy(__entry->name, bdi_dev_name(bdi),
+ bdi_get_dev_name(bdi, __entry->name,
ARRAY_SIZE(__entry->name));
__entry->lat = div_u64(lat, 1000);
),
@@ -105,7 +105,7 @@ TRACE_EVENT(wbt_step,
),
TP_fast_assign(
- strlcpy(__entry->name, bdi_dev_name(bdi),
+ bdi_get_dev_name(bdi, __entry->name,
ARRAY_SIZE(__entry->name));
__entry->msg = msg;
__entry->step = step;
@@ -141,7 +141,7 @@ TRACE_EVENT(wbt_timer,
),
TP_fast_assign(
- strlcpy(__entry->name, bdi_dev_name(bdi),
+ bdi_get_dev_name(bdi, __entry->name,
ARRAY_SIZE(__entry->name));
__entry->status = status;
__entry->step = step;
diff --git a/include/trace/events/writeback.h b/include/trace/events/writeback.h
index d94def25e4dc..4767a5ab5e36 100644
--- a/include/trace/events/writeback.h
+++ b/include/trace/events/writeback.h
@@ -66,9 +66,8 @@ DECLARE_EVENT_CLASS(writeback_page_template,
),
TP_fast_assign(
- strscpy_pad(__entry->name,
- bdi_dev_name(mapping ? inode_to_bdi(mapping->host) :
- NULL), 32);
+ bdi_get_dev_name(mapping ? inode_to_bdi(mapping->host) : NULL,
+ __entry->name, 32);
__entry->ino = mapping ? mapping->host->i_ino : 0;
__entry->index = page->index;
),
@@ -111,7 +110,7 @@ DECLARE_EVENT_CLASS(writeback_dirty_inode_template,
struct backing_dev_info *bdi = inode_to_bdi(inode);
/* may be called for files on pseudo FSes w/ unregistered bdi */
- strscpy_pad(__entry->name, bdi_dev_name(bdi), 32);
+ bdi_get_dev_name(bdi, __entry->name, 32);
__entry->ino = inode->i_ino;
__entry->state = inode->i_state;
__entry->flags = flags;
@@ -192,7 +191,7 @@ TRACE_EVENT(inode_foreign_history,
),
TP_fast_assign(
- strncpy(__entry->name, bdi_dev_name(inode_to_bdi(inode)), 32);
+ bdi_get_dev_name(inode_to_bdi(inode), __entry->name, 32);
__entry->ino = inode->i_ino;
__entry->cgroup_ino = __trace_wbc_assign_cgroup(wbc);
__entry->history = history;
@@ -221,7 +220,7 @@ TRACE_EVENT(inode_switch_wbs,
),
TP_fast_assign(
- strncpy(__entry->name, bdi_dev_name(old_wb->bdi), 32);
+ bdi_get_dev_name(old_wb->bdi, __entry->name, 32);
__entry->ino = inode->i_ino;
__entry->old_cgroup_ino = __trace_wb_assign_cgroup(old_wb);
__entry->new_cgroup_ino = __trace_wb_assign_cgroup(new_wb);
@@ -254,7 +253,7 @@ TRACE_EVENT(track_foreign_dirty,
struct address_space *mapping = page_mapping(page);
struct inode *inode = mapping ? mapping->host : NULL;
- strncpy(__entry->name, bdi_dev_name(wb->bdi), 32);
+ bdi_get_dev_name(wb->bdi, __entry->name, 32);
__entry->bdi_id = wb->bdi->id;
__entry->ino = inode ? inode->i_ino : 0;
__entry->memcg_id = wb->memcg_css->id;
@@ -287,7 +286,7 @@ TRACE_EVENT(flush_foreign,
),
TP_fast_assign(
- strncpy(__entry->name, bdi_dev_name(wb->bdi), 32);
+ bdi_get_dev_name(wb->bdi, __entry->name, 32);
__entry->cgroup_ino = __trace_wb_assign_cgroup(wb);
__entry->frn_bdi_id = frn_bdi_id;
__entry->frn_memcg_id = frn_memcg_id;
@@ -316,8 +315,7 @@ DECLARE_EVENT_CLASS(writeback_write_inode_template,
),
TP_fast_assign(
- strscpy_pad(__entry->name,
- bdi_dev_name(inode_to_bdi(inode)), 32);
+ bdi_get_dev_name(inode_to_bdi(inode), __entry->name, 32);
__entry->ino = inode->i_ino;
__entry->sync_mode = wbc->sync_mode;
__entry->cgroup_ino = __trace_wbc_assign_cgroup(wbc);
@@ -360,7 +358,7 @@ DECLARE_EVENT_CLASS(writeback_work_class,
__field(ino_t, cgroup_ino)
),
TP_fast_assign(
- strscpy_pad(__entry->name, bdi_dev_name(wb->bdi), 32);
+ bdi_get_dev_name(wb->bdi, __entry->name, 32);
__entry->nr_pages = work->nr_pages;
__entry->sb_dev = work->sb ? work->sb->s_dev : 0;
__entry->sync_mode = work->sync_mode;
@@ -413,7 +411,7 @@ DECLARE_EVENT_CLASS(writeback_class,
__field(ino_t, cgroup_ino)
),
TP_fast_assign(
- strscpy_pad(__entry->name, bdi_dev_name(wb->bdi), 32);
+ bdi_get_dev_name(wb->bdi, __entry->name, 32);
__entry->cgroup_ino = __trace_wb_assign_cgroup(wb);
),
TP_printk("bdi %s: cgroup_ino=%lu",
@@ -435,7 +433,7 @@ TRACE_EVENT(writeback_bdi_register,
__array(char, name, 32)
),
TP_fast_assign(
- strscpy_pad(__entry->name, bdi_dev_name(bdi), 32);
+ bdi_get_dev_name(bdi, __entry->name, 32);
),
TP_printk("bdi %s",
__entry->name
@@ -460,7 +458,7 @@ DECLARE_EVENT_CLASS(wbc_class,
),
TP_fast_assign(
- strscpy_pad(__entry->name, bdi_dev_name(bdi), 32);
+ bdi_get_dev_name(bdi, __entry->name, 32);
__entry->nr_to_write = wbc->nr_to_write;
__entry->pages_skipped = wbc->pages_skipped;
__entry->sync_mode = wbc->sync_mode;
@@ -511,7 +509,7 @@ TRACE_EVENT(writeback_queue_io,
),
TP_fast_assign(
unsigned long *older_than_this = work->older_than_this;
- strscpy_pad(__entry->name, bdi_dev_name(wb->bdi), 32);
+ bdi_get_dev_name(wb->bdi, __entry->name, 32);
__entry->older = older_than_this ? *older_than_this : 0;
__entry->age = older_than_this ?
(jiffies - *older_than_this) * 1000 / HZ : -1;
@@ -597,7 +595,7 @@ TRACE_EVENT(bdi_dirty_ratelimit,
),
TP_fast_assign(
- strscpy_pad(__entry->bdi, bdi_dev_name(wb->bdi), 32);
+ bdi_get_dev_name(wb->bdi, __entry->bdi, 32);
__entry->write_bw = KBps(wb->write_bandwidth);
__entry->avg_write_bw = KBps(wb->avg_write_bandwidth);
__entry->dirty_rate = KBps(dirty_rate);
@@ -662,7 +660,7 @@ TRACE_EVENT(balance_dirty_pages,
TP_fast_assign(
unsigned long freerun = (thresh + bg_thresh) / 2;
- strscpy_pad(__entry->bdi, bdi_dev_name(wb->bdi), 32);
+ bdi_get_dev_name(wb->bdi, __entry->bdi, 32);
__entry->limit = global_wb_domain.dirty_limit;
__entry->setpoint = (global_wb_domain.dirty_limit +
@@ -722,8 +720,7 @@ TRACE_EVENT(writeback_sb_inodes_requeue,
),
TP_fast_assign(
- strscpy_pad(__entry->name,
- bdi_dev_name(inode_to_bdi(inode)), 32);
+ bdi_get_dev_name(inode_to_bdi(inode), __entry->name, 32);
__entry->ino = inode->i_ino;
__entry->state = inode->i_state;
__entry->dirtied_when = inode->dirtied_when;
@@ -796,8 +793,7 @@ DECLARE_EVENT_CLASS(writeback_single_inode_template,
),
TP_fast_assign(
- strscpy_pad(__entry->name,
- bdi_dev_name(inode_to_bdi(inode)), 32);
+ bdi_get_dev_name(inode_to_bdi(inode), __entry->name, 32);
__entry->ino = inode->i_ino;
__entry->state = inode->i_state;
__entry->dirtied_when = inode->dirtied_when;
--
2.17.2
