diff options
| -rw-r--r-- | drivers/md/md.c | 81 |
1 files changed, 76 insertions, 5 deletions
diff --git a/drivers/md/md.c b/drivers/md/md.c index 1364a1c97e6..6101879a730 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -42,6 +42,7 @@ #include <linux/devfs_fs_kernel.h> #include <linux/buffer_head.h> /* for invalidate_bdev */ #include <linux/suspend.h> +#include <linux/poll.h> #include <linux/init.h> @@ -134,6 +135,24 @@ static struct block_device_operations md_fops; static int start_readonly; /* + * We have a system wide 'event count' that is incremented + * on any 'interesting' event, and readers of /proc/mdstat + * can use 'poll' or 'select' to find out when the event + * count increases. + * + * Events are: + * start array, stop array, error, add device, remove device, + * start build, activate spare + */ +DECLARE_WAIT_QUEUE_HEAD(md_event_waiters); +static atomic_t md_event_count; +void md_new_event(mddev_t *mddev) +{ + atomic_inc(&md_event_count); + wake_up(&md_event_waiters); +} + +/* * Enables to iterate over all existing md arrays * all_mddevs_lock protects this list. */ @@ -2111,6 +2130,7 @@ static int do_md_run(mddev_t * mddev) mddev->queue->make_request_fn = mddev->pers->make_request; mddev->changed = 1; + md_new_event(mddev); return 0; } @@ -2238,6 +2258,7 @@ static int do_md_stop(mddev_t * mddev, int ro) printk(KERN_INFO "md: %s switched to read-only mode.\n", mdname(mddev)); err = 0; + md_new_event(mddev); out: return err; } @@ -2712,6 +2733,7 @@ static int hot_remove_disk(mddev_t * mddev, dev_t dev) kick_rdev_from_array(rdev); md_update_sb(mddev); + md_new_event(mddev); return 0; busy: @@ -2802,7 +2824,7 @@ static int hot_add_disk(mddev_t * mddev, dev_t dev) */ set_bit(MD_RECOVERY_NEEDED, &mddev->recovery); md_wakeup_thread(mddev->thread); - + md_new_event(mddev); return 0; abort_unbind_export: @@ -3531,6 +3553,7 @@ void md_error(mddev_t *mddev, mdk_rdev_t *rdev) set_bit(MD_RECOVERY_INTR, &mddev->recovery); set_bit(MD_RECOVERY_NEEDED, &mddev->recovery); md_wakeup_thread(mddev->thread); + md_new_event(mddev); } /* seq_file implementation /proc/mdstat */ @@ -3671,12 +3694,17 @@ static void md_seq_stop(struct seq_file *seq, void *v) mddev_put(mddev); } +struct mdstat_info { + int event; +}; + static int md_seq_show(struct seq_file *seq, void *v) { mddev_t *mddev = v; sector_t size; struct list_head *tmp2; mdk_rdev_t *rdev; + struct mdstat_info *mi = seq->private; int i; struct bitmap *bitmap; @@ -3689,6 +3717,7 @@ static int md_seq_show(struct seq_file *seq, void *v) spin_unlock(&pers_lock); seq_printf(seq, "\n"); + mi->event = atomic_read(&md_event_count); return 0; } if (v == (void*)2) { @@ -3797,16 +3826,52 @@ static struct seq_operations md_seq_ops = { static int md_seq_open(struct inode *inode, struct file *file) { int error; + struct mdstat_info *mi = kmalloc(sizeof(*mi), GFP_KERNEL); + if (mi == NULL) + return -ENOMEM; error = seq_open(file, &md_seq_ops); + if (error) + kfree(mi); + else { + struct seq_file *p = file->private_data; + p->private = mi; + mi->event = atomic_read(&md_event_count); + } return error; } +static int md_seq_release(struct inode *inode, struct file *file) +{ + struct seq_file *m = file->private_data; + struct mdstat_info *mi = m->private; + m->private = NULL; + kfree(mi); + return seq_release(inode, file); +} + +static unsigned int mdstat_poll(struct file *filp, poll_table *wait) +{ + struct seq_file *m = filp->private_data; + struct mdstat_info *mi = m->private; + int mask; + + poll_wait(filp, &md_event_waiters, wait); + + /* always allow read */ + mask = POLLIN | POLLRDNORM; + + if (mi->event != atomic_read(&md_event_count)) + mask |= POLLERR | POLLPRI; + return mask; +} + static struct file_operations md_seq_fops = { .open = md_seq_open, .read = seq_read, .llseek = seq_lseek, - .release = seq_release, + .release = md_seq_release, + .poll = mdstat_poll, }; int register_md_personality(int pnum, mdk_personality_t *p) @@ -4076,7 +4141,11 @@ static void md_do_sync(mddev_t *mddev) j += sectors; if (j>1) mddev->curr_resync = j; - + if (last_check == 0) + /* this is the earliers that rebuilt will be + * visible in /proc/mdstat + */ + md_new_event(mddev); if (last_check + window > io_sectors || j == max_sectors) continue; @@ -4262,6 +4331,7 @@ void md_check_recovery(mddev_t *mddev) mddev->recovery = 0; /* flag recovery needed just to double check */ set_bit(MD_RECOVERY_NEEDED, &mddev->recovery); + md_new_event(mddev); goto unlock; } /* Clear some bits that don't mean anything, but @@ -4299,6 +4369,7 @@ void md_check_recovery(mddev_t *mddev) sprintf(nm, "rd%d", rdev->raid_disk); sysfs_create_link(&mddev->kobj, &rdev->kobj, nm); spares++; + md_new_event(mddev); } else break; } @@ -4331,9 +4402,9 @@ void md_check_recovery(mddev_t *mddev) mdname(mddev)); /* leave the spares where they are, it shouldn't hurt */ mddev->recovery = 0; - } else { + } else md_wakeup_thread(mddev->sync_thread); - } + md_new_event(mddev); } unlock: mddev_unlock(mddev); |