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-rw-r--r--drivers/md/md.c59
1 files changed, 51 insertions, 8 deletions
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 8238c1c0ec0..d002b8301fc 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -131,6 +131,8 @@ static ctl_table raid_root_table[] = {
static struct block_device_operations md_fops;
+static int start_readonly;
+
/*
* Enables to iterate over all existing md arrays
* all_mddevs_lock protects this list.
@@ -2029,6 +2031,9 @@ static int do_md_run(mddev_t * mddev)
mddev->resync_max_sectors = mddev->size << 1; /* may be over-ridden by personality */
mddev->barriers_work = 1;
+ if (start_readonly)
+ mddev->ro = 2; /* read-only, but switch on first write */
+
/* before we start the array running, initialise the bitmap */
err = bitmap_create(mddev);
if (err)
@@ -2141,7 +2146,7 @@ static int do_md_stop(mddev_t * mddev, int ro)
if (ro) {
err = -ENXIO;
- if (mddev->ro)
+ if (mddev->ro==1)
goto out;
mddev->ro = 1;
} else {
@@ -3258,12 +3263,22 @@ static int md_ioctl(struct inode *inode, struct file *file,
/*
* The remaining ioctls are changing the state of the
- * superblock, so we do not allow read-only arrays
- * here:
+ * superblock, so we do not allow them on read-only arrays.
+ * However non-MD ioctls (e.g. get-size) will still come through
+ * here and hit the 'default' below, so only disallow
+ * 'md' ioctls, and switch to rw mode if started auto-readonly.
*/
- if (mddev->ro) {
- err = -EROFS;
- goto abort_unlock;
+ if (_IOC_TYPE(cmd) == MD_MAJOR &&
+ mddev->ro && mddev->pers) {
+ if (mddev->ro == 2) {
+ mddev->ro = 0;
+ set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
+ md_wakeup_thread(mddev->thread);
+
+ } else {
+ err = -EROFS;
+ goto abort_unlock;
+ }
}
switch (cmd)
@@ -3651,8 +3666,10 @@ static int md_seq_show(struct seq_file *seq, void *v)
seq_printf(seq, "%s : %sactive", mdname(mddev),
mddev->pers ? "" : "in");
if (mddev->pers) {
- if (mddev->ro)
+ if (mddev->ro==1)
seq_printf(seq, " (read-only)");
+ if (mddev->ro==2)
+ seq_printf(seq, "(auto-read-only)");
seq_printf(seq, " %s", mddev->pers->name);
}
@@ -3696,7 +3713,9 @@ static int md_seq_show(struct seq_file *seq, void *v)
status_resync (seq, mddev);
seq_printf(seq, "\n ");
} else if (mddev->curr_resync == 1 || mddev->curr_resync == 2)
- seq_printf(seq, " resync=DELAYED\n ");
+ seq_printf(seq, "\tresync=DELAYED\n ");
+ else if (mddev->recovery_cp < MaxSector)
+ seq_printf(seq, "\tresync=PENDING\n ");
} else
seq_printf(seq, "\n ");
@@ -3833,6 +3852,13 @@ void md_write_start(mddev_t *mddev, struct bio *bi)
if (bio_data_dir(bi) != WRITE)
return;
+ BUG_ON(mddev->ro == 1);
+ if (mddev->ro == 2) {
+ /* need to switch to read/write */
+ mddev->ro = 0;
+ set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
+ md_wakeup_thread(mddev->thread);
+ }
atomic_inc(&mddev->writes_pending);
if (mddev->in_sync) {
spin_lock_irq(&mddev->write_lock);
@@ -4431,6 +4457,23 @@ static __exit void md_exit(void)
module_init(md_init)
module_exit(md_exit)
+static int get_ro(char *buffer, struct kernel_param *kp)
+{
+ return sprintf(buffer, "%d", start_readonly);
+}
+static int set_ro(const char *val, struct kernel_param *kp)
+{
+ char *e;
+ int num = simple_strtoul(val, &e, 10);
+ if (*val && (*e == '\0' || *e == '\n')) {
+ start_readonly = num;
+ return 0;;
+ }
+ return -EINVAL;
+}
+
+module_param_call(start_ro, set_ro, get_ro, NULL, 0600);
+
EXPORT_SYMBOL(register_md_personality);
EXPORT_SYMBOL(unregister_md_personality);
EXPORT_SYMBOL(md_error);