Skip to content

Commit 7e0adbf

Browse files
author
Christoph Hellwig
committed
md: rewrite md_setup_drive to avoid ioctls
md_setup_drive knows it works with md devices, so it is rather pointless to open a file descriptor and issue ioctls. Just call directly into the relevant low-level md routines after getting a handle to the device using blkdev_get_by_dev instead. Signed-off-by: Christoph Hellwig <[email protected]> Reviewed-by: NeilBrown <[email protected]> Acked-by: Song Liu <[email protected]> Acked-by: Linus Torvalds <[email protected]>
1 parent d110048 commit 7e0adbf

File tree

3 files changed

+81
-85
lines changed

3 files changed

+81
-85
lines changed

‎drivers/md/md-autodetect.c

Lines changed: 63 additions & 71 deletions
Original file line numberDiff line numberDiff line change
@@ -2,7 +2,6 @@
22
#include <linux/kernel.h>
33
#include <linux/blkdev.h>
44
#include <linux/init.h>
5-
#include <linux/syscalls.h>
65
#include <linux/mount.h>
76
#include <linux/major.h>
87
#include <linux/delay.h>
@@ -120,37 +119,29 @@ static int __init md_setup(char *str)
120119
return 1;
121120
}
122121

123-
static inline int create_dev(char *name, dev_t dev)
124-
{
125-
ksys_unlink(name);
126-
return ksys_mknod(name, S_IFBLK|0600, new_encode_dev(dev));
127-
}
128-
129122
static void __init md_setup_drive(struct md_setup_args *args)
130123
{
131-
int minor, i, partitioned;
132-
dev_t dev;
133-
dev_t devices[MD_SB_DISKS+1];
134-
int fd;
135-
int err = 0;
136-
char *devname;
137-
mdu_disk_info_t dinfo;
124+
char *devname = args->device_names;
125+
dev_t devices[MD_SB_DISKS + 1], mdev;
126+
struct mdu_array_info_s ainfo = { };
127+
struct block_device *bdev;
128+
struct mddev *mddev;
129+
int err = 0, i;
138130
char name[16];
139131

140-
minor = args->minor;
141-
partitioned = args->partitioned;
142-
devname = args->device_names;
132+
if (args->partitioned) {
133+
mdev = MKDEV(mdp_major, args->minor << MdpMinorShift);
134+
sprintf(name, "md_d%d", args->minor);
135+
} else {
136+
mdev = MKDEV(MD_MAJOR, args->minor);
137+
sprintf(name, "md%d", args->minor);
138+
}
143139

144-
sprintf(name, "/dev/md%s%d", partitioned?"_d":"", minor);
145-
if (partitioned)
146-
dev = MKDEV(mdp_major, minor << MdpMinorShift);
147-
else
148-
dev = MKDEV(MD_MAJOR, minor);
149-
create_dev(name, dev);
150140
for (i = 0; i < MD_SB_DISKS && devname != NULL; i++) {
151141
struct kstat stat;
152142
char *p;
153143
char comp_name[64];
144+
dev_t dev;
154145

155146
p = strchr(devname, ',');
156147
if (p)
@@ -163,7 +154,7 @@ static void __init md_setup_drive(struct md_setup_args *args)
163154
if (vfs_stat(comp_name, &stat) == 0 && S_ISBLK(stat.mode))
164155
dev = new_decode_dev(stat.rdev);
165156
if (!dev) {
166-
printk(KERN_WARNING "md: Unknown device name: %s\n", devname);
157+
pr_warn("md: Unknown device name: %s\n", devname);
167158
break;
168159
}
169160

@@ -175,68 +166,71 @@ static void __init md_setup_drive(struct md_setup_args *args)
175166
if (!i)
176167
return;
177168

178-
printk(KERN_INFO "md: Loading md%s%d: %s\n",
179-
partitioned ? "_d" : "", minor,
180-
args->device_names);
169+
pr_info("md: Loading %s: %s\n", name, args->device_names);
181170

182-
fd = ksys_open(name, 0, 0);
183-
if (fd < 0) {
184-
printk(KERN_ERR "md: open failed - cannot start "
185-
"array %s\n", name);
171+
bdev = blkdev_get_by_dev(mdev, FMODE_READ, NULL);
172+
if (IS_ERR(bdev)) {
173+
pr_err("md: open failed - cannot start array %s\n", name);
186174
return;
187175
}
188-
if (ksys_ioctl(fd, SET_ARRAY_INFO, 0) == -EBUSY) {
189-
printk(KERN_WARNING
190-
"md: Ignoring md=%d, already autodetected. (Use raid=noautodetect)\n",
191-
minor);
192-
ksys_close(fd);
193-
return;
176+
177+
err = -EIO;
178+
if (WARN(bdev->bd_disk->fops != &md_fops,
179+
"Opening block device %x resulted in non-md device\n",
180+
mdev))
181+
goto out_blkdev_put;
182+
183+
mddev = bdev->bd_disk->private_data;
184+
185+
err = mddev_lock(mddev);
186+
if (err) {
187+
pr_err("md: failed to lock array %s\n", name);
188+
goto out_blkdev_put;
189+
}
190+
191+
if (!list_empty(&mddev->disks) || mddev->raid_disks) {
192+
pr_warn("md: Ignoring %s, already autodetected. (Use raid=noautodetect)\n",
193+
name);
194+
goto out_unlock;
194195
}
195196

196197
if (args->level != LEVEL_NONE) {
197198
/* non-persistent */
198-
mdu_array_info_t ainfo;
199199
ainfo.level = args->level;
200-
ainfo.size = 0;
201-
ainfo.nr_disks =0;
202-
ainfo.raid_disks =0;
203-
while (devices[ainfo.raid_disks])
204-
ainfo.raid_disks++;
205-
ainfo.md_minor =minor;
200+
ainfo.md_minor = args->minor;
206201
ainfo.not_persistent = 1;
207-
208202
ainfo.state = (1 << MD_SB_CLEAN);
209-
ainfo.layout = 0;
210203
ainfo.chunk_size = args->chunk;
211-
err = ksys_ioctl(fd, SET_ARRAY_INFO, (long)&ainfo);
212-
for (i = 0; !err && i <= MD_SB_DISKS; i++) {
213-
dev = devices[i];
214-
if (!dev)
215-
break;
204+
while (devices[ainfo.raid_disks])
205+
ainfo.raid_disks++;
206+
}
207+
208+
err = md_set_array_info(mddev, &ainfo);
209+
210+
for (i = 0; i <= MD_SB_DISKS && devices[i]; i++) {
211+
struct mdu_disk_info_s dinfo = {
212+
.major = MAJOR(devices[i]),
213+
.minor = MINOR(devices[i]),
214+
};
215+
216+
if (args->level != LEVEL_NONE) {
216217
dinfo.number = i;
217218
dinfo.raid_disk = i;
218-
dinfo.state = (1<<MD_DISK_ACTIVE)|(1<<MD_DISK_SYNC);
219-
dinfo.major = MAJOR(dev);
220-
dinfo.minor = MINOR(dev);
221-
err = ksys_ioctl(fd, ADD_NEW_DISK,
222-
(long)&dinfo);
223-
}
224-
} else {
225-
/* persistent */
226-
for (i = 0; i <= MD_SB_DISKS; i++) {
227-
dev = devices[i];
228-
if (!dev)
229-
break;
230-
dinfo.major = MAJOR(dev);
231-
dinfo.minor = MINOR(dev);
232-
ksys_ioctl(fd, ADD_NEW_DISK, (long)&dinfo);
219+
dinfo.state =
220+
(1 << MD_DISK_ACTIVE) | (1 << MD_DISK_SYNC);
233221
}
222+
223+
md_add_new_disk(mddev, &dinfo);
234224
}
225+
235226
if (!err)
236-
err = ksys_ioctl(fd, RUN_ARRAY, 0);
227+
err = do_md_run(mddev);
237228
if (err)
238-
printk(KERN_WARNING "md: starting md%d failed\n", minor);
239-
ksys_close(fd);
229+
pr_warn("md: starting %s failed\n", name);
230+
out_unlock:
231+
mddev_unlock(mddev);
232+
out_blkdev_put:
233+
blkdev_put(bdev, FMODE_READ);
240234
}
241235

242236
static int __init raid_setup(char *str)
@@ -286,8 +280,6 @@ void __init md_run_setup(void)
286280
{
287281
int ent;
288282

289-
create_dev("/dev/md0", MKDEV(MD_MAJOR, 0));
290-
291283
if (raid_noautodetect)
292284
printk(KERN_INFO "md: Skipping autodetection of RAID arrays. (raid=autodetect will force)\n");
293285
else

‎drivers/md/md.c

Lines changed: 10 additions & 14 deletions
Original file line numberDiff line numberDiff line change
@@ -326,8 +326,6 @@ static struct ctl_table raid_root_table[] = {
326326
{ }
327327
};
328328

329-
static const struct block_device_operations md_fops;
330-
331329
static int start_readonly;
332330

333331
/*
@@ -4368,7 +4366,6 @@ array_state_show(struct mddev *mddev, char *page)
43684366

43694367
static int do_md_stop(struct mddev *mddev, int ro, struct block_device *bdev);
43704368
static int md_set_readonly(struct mddev *mddev, struct block_device *bdev);
4371-
static int do_md_run(struct mddev *mddev);
43724369
static int restart_array(struct mddev *mddev);
43734370

43744371
static ssize_t
@@ -6015,7 +6012,7 @@ int md_run(struct mddev *mddev)
60156012
}
60166013
EXPORT_SYMBOL_GPL(md_run);
60176014

6018-
static int do_md_run(struct mddev *mddev)
6015+
int do_md_run(struct mddev *mddev)
60196016
{
60206017
int err;
60216018

@@ -6651,7 +6648,7 @@ static int get_disk_info(struct mddev *mddev, void __user * arg)
66516648
return 0;
66526649
}
66536650

6654-
static int add_new_disk(struct mddev *mddev, mdu_disk_info_t *info)
6651+
int md_add_new_disk(struct mddev *mddev, struct mdu_disk_info_s *info)
66556652
{
66566653
char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
66576654
struct md_rdev *rdev;
@@ -6697,7 +6694,7 @@ static int add_new_disk(struct mddev *mddev, mdu_disk_info_t *info)
66976694
}
66986695

66996696
/*
6700-
* add_new_disk can be used once the array is assembled
6697+
* md_add_new_disk can be used once the array is assembled
67016698
* to add "hot spares". They must already have a superblock
67026699
* written
67036700
*/
@@ -6810,7 +6807,7 @@ static int add_new_disk(struct mddev *mddev, mdu_disk_info_t *info)
68106807
return err;
68116808
}
68126809

6813-
/* otherwise, add_new_disk is only allowed
6810+
/* otherwise, md_add_new_disk is only allowed
68146811
* for major_version==0 superblocks
68156812
*/
68166813
if (mddev->major_version != 0) {
@@ -7055,7 +7052,7 @@ static int set_bitmap_file(struct mddev *mddev, int fd)
70557052
}
70567053

70577054
/*
7058-
* set_array_info is used two different ways
7055+
* md_set_array_info is used two different ways
70597056
* The original usage is when creating a new array.
70607057
* In this usage, raid_disks is > 0 and it together with
70617058
* level, size, not_persistent,layout,chunksize determine the
@@ -7067,9 +7064,8 @@ static int set_bitmap_file(struct mddev *mddev, int fd)
70677064
* The minor and patch _version numbers are also kept incase the
70687065
* super_block handler wishes to interpret them.
70697066
*/
7070-
static int set_array_info(struct mddev *mddev, mdu_array_info_t *info)
7067+
int md_set_array_info(struct mddev *mddev, struct mdu_array_info_s *info)
70717068
{
7072-
70737069
if (info->raid_disks == 0) {
70747070
/* just setting version number for superblock loading */
70757071
if (info->major_version < 0 ||
@@ -7560,7 +7556,7 @@ static int md_ioctl(struct block_device *bdev, fmode_t mode,
75607556
err = -EBUSY;
75617557
goto unlock;
75627558
}
7563-
err = set_array_info(mddev, &info);
7559+
err = md_set_array_info(mddev, &info);
75647560
if (err) {
75657561
pr_warn("md: couldn't set array info. %d\n", err);
75667562
goto unlock;
@@ -7614,7 +7610,7 @@ static int md_ioctl(struct block_device *bdev, fmode_t mode,
76147610
/* Need to clear read-only for this */
76157611
break;
76167612
else
7617-
err = add_new_disk(mddev, &info);
7613+
err = md_add_new_disk(mddev, &info);
76187614
goto unlock;
76197615
}
76207616
break;
@@ -7682,7 +7678,7 @@ static int md_ioctl(struct block_device *bdev, fmode_t mode,
76827678
if (copy_from_user(&info, argp, sizeof(info)))
76837679
err = -EFAULT;
76847680
else
7685-
err = add_new_disk(mddev, &info);
7681+
err = md_add_new_disk(mddev, &info);
76867682
goto unlock;
76877683
}
76887684

@@ -7808,7 +7804,7 @@ static int md_revalidate(struct gendisk *disk)
78087804
mddev->changed = 0;
78097805
return 0;
78107806
}
7811-
static const struct block_device_operations md_fops =
7807+
const struct block_device_operations md_fops =
78127808
{
78137809
.owner = THIS_MODULE,
78147810
.open = md_open,

‎drivers/md/md.h

Lines changed: 8 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -801,7 +801,15 @@ static inline void mddev_check_write_zeroes(struct mddev *mddev, struct bio *bio
801801
mddev->queue->limits.max_write_zeroes_sectors = 0;
802802
}
803803

804+
struct mdu_array_info_s;
805+
struct mdu_disk_info_s;
806+
804807
extern int mdp_major;
805808
void md_autostart_arrays(int part);
809+
int md_set_array_info(struct mddev *mddev, struct mdu_array_info_s *info);
810+
int md_add_new_disk(struct mddev *mddev, struct mdu_disk_info_s *info);
811+
int do_md_run(struct mddev *mddev);
812+
813+
extern const struct block_device_operations md_fops;
806814

807815
#endif /* _MD_MD_H */

0 commit comments

Comments
 (0)