md: introduce md_ro_state

[ Upstream commit f97a5528b21eb175d90dce2df9960c8d08e1be82 ]

Introduce md_ro_state for mddev->ro, so it is easy to understand.

Signed-off-by: Ye Bin <yebin10@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Stable-dep-of: c9f7cb5b2bc9 ("md: don't leave 'MD_RECOVERY_FROZEN' in error path of md_set_readonly()")
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 20f67ed..246af78 100644 (file)
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -93,6 +93,18 @@ static int remove_and_add_spares(struct mddev *mddev,
                                 struct md_rdev *this);
 static void mddev_detach(struct mddev *mddev);
 
+enum md_ro_state {
+       MD_RDWR,
+       MD_RDONLY,
+       MD_AUTO_READ,
+       MD_MAX_STATE
+};
+
+static bool md_is_rdwr(struct mddev *mddev)
+{
+       return (mddev->ro == MD_RDWR);
+}
+
 /*
  * Default number of read corrections we'll attempt on an rdev
  * before ejecting it from the array. We divide the read error
@@ -444,7 +456,7 @@ static void md_submit_bio(struct bio *bio)
        if (!bio)
                return;
 
-       if (mddev->ro == 1 && unlikely(rw == WRITE)) {
+       if (mddev->ro == MD_RDONLY && unlikely(rw == WRITE)) {
                if (bio_sectors(bio) != 0)
                        bio->bi_status = BLK_STS_IOERR;
                bio_endio(bio);
@@ -2643,7 +2655,7 @@ void md_update_sb(struct mddev *mddev, int force_change)
        int any_badblocks_changed = 0;
        int ret = -1;
 
-       if (mddev->ro) {
+       if (!md_is_rdwr(mddev)) {
                if (force_change)
                        set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
                return;
@@ -3909,7 +3921,7 @@ level_store(struct mddev *mddev, const char *buf, size_t len)
                goto out_unlock;
        }
        rv = -EROFS;
-       if (mddev->ro)
+       if (!md_is_rdwr(mddev))
                goto out_unlock;
 
        /* request to change the personality.  Need to ensure:
@@ -4115,7 +4127,7 @@ layout_store(struct mddev *mddev, const char *buf, size_t len)
        if (mddev->pers) {
                if (mddev->pers->check_reshape == NULL)
                        err = -EBUSY;
-               else if (mddev->ro)
+               else if (!md_is_rdwr(mddev))
                        err = -EROFS;
                else {
                        mddev->new_layout = n;
@@ -4224,7 +4236,7 @@ chunk_size_store(struct mddev *mddev, const char *buf, size_t len)
        if (mddev->pers) {
                if (mddev->pers->check_reshape == NULL)
                        err = -EBUSY;
-               else if (mddev->ro)
+               else if (!md_is_rdwr(mddev))
                        err = -EROFS;
                else {
                        mddev->new_chunk_sectors = n >> 9;
@@ -4347,13 +4359,13 @@ array_state_show(struct mddev *mddev, char *page)
 
        if (mddev->pers && !test_bit(MD_NOT_READY, &mddev->flags)) {
                switch(mddev->ro) {
-               case 1:
+               case MD_RDONLY:
                        st = readonly;
                        break;
-               case 2:
+               case MD_AUTO_READ:
                        st = read_auto;
                        break;
-               case 0:
+               case MD_RDWR:
                        spin_lock(&mddev->lock);
                        if (test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags))
                                st = write_pending;
@@ -4389,7 +4401,8 @@ array_state_store(struct mddev *mddev, const char *buf, size_t len)
        int err = 0;
        enum array_state st = match_word(buf, array_states);
 
-       if (mddev->pers && (st == active || st == clean) && mddev->ro != 1) {
+       if (mddev->pers && (st == active || st == clean) &&
+           mddev->ro != MD_RDONLY) {
                /* don't take reconfig_mutex when toggling between
                 * clean and active
                 */
@@ -4433,23 +4446,23 @@ array_state_store(struct mddev *mddev, const char *buf, size_t len)
                if (mddev->pers)
                        err = md_set_readonly(mddev, NULL);
                else {
-                       mddev->ro = 1;
+                       mddev->ro = MD_RDONLY;
                        set_disk_ro(mddev->gendisk, 1);
                        err = do_md_run(mddev);
                }
                break;
        case read_auto:
                if (mddev->pers) {
-                       if (mddev->ro == 0)
+                       if (md_is_rdwr(mddev))
                                err = md_set_readonly(mddev, NULL);
-                       else if (mddev->ro == 1)
+                       else if (mddev->ro == MD_RDONLY)
                                err = restart_array(mddev);
                        if (err == 0) {
-                               mddev->ro = 2;
+                               mddev->ro = MD_AUTO_READ;
                                set_disk_ro(mddev->gendisk, 0);
                        }
                } else {
-                       mddev->ro = 2;
+                       mddev->ro = MD_AUTO_READ;
                        err = do_md_run(mddev);
                }
                break;
@@ -4474,7 +4487,7 @@ array_state_store(struct mddev *mddev, const char *buf, size_t len)
                        wake_up(&mddev->sb_wait);
                        err = 0;
                } else {
-                       mddev->ro = 0;
+                       mddev->ro = MD_RDWR;
                        set_disk_ro(mddev->gendisk, 0);
                        err = do_md_run(mddev);
                }
@@ -4775,7 +4788,7 @@ action_show(struct mddev *mddev, char *page)
        if (test_bit(MD_RECOVERY_FROZEN, &recovery))
                type = "frozen";
        else if (test_bit(MD_RECOVERY_RUNNING, &recovery) ||
-           (!mddev->ro && test_bit(MD_RECOVERY_NEEDED, &recovery))) {
+           (md_is_rdwr(mddev) && test_bit(MD_RECOVERY_NEEDED, &recovery))) {
                if (test_bit(MD_RECOVERY_RESHAPE, &recovery))
                        type = "reshape";
                else if (test_bit(MD_RECOVERY_SYNC, &recovery)) {
@@ -4861,11 +4874,11 @@ action_store(struct mddev *mddev, const char *page, size_t len)
                set_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
                set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
        }
-       if (mddev->ro == 2) {
+       if (mddev->ro == MD_AUTO_READ) {
                /* A write to sync_action is enough to justify
                 * canceling read-auto mode
                 */
-               mddev->ro = 0;
+               mddev->ro = MD_RDWR;
                md_wakeup_thread(mddev->sync_thread);
        }
        set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
@@ -5093,8 +5106,7 @@ max_sync_store(struct mddev *mddev, const char *buf, size_t len)
                        goto out_unlock;
 
                err = -EBUSY;
-               if (max < mddev->resync_max &&
-                   mddev->ro == 0 &&
+               if (max < mddev->resync_max && md_is_rdwr(mddev) &&
                    test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
                        goto out_unlock;
 
@@ -5829,8 +5841,8 @@ int md_run(struct mddev *mddev)
                        continue;
                sync_blockdev(rdev->bdev);
                invalidate_bdev(rdev->bdev);
-               if (mddev->ro != 1 && rdev_read_only(rdev)) {
-                       mddev->ro = 1;
+               if (mddev->ro != MD_RDONLY && rdev_read_only(rdev)) {
+                       mddev->ro = MD_RDONLY;
                        if (mddev->gendisk)
                                set_disk_ro(mddev->gendisk, 1);
                }
@@ -5938,8 +5950,8 @@ int md_run(struct mddev *mddev)
 
        mddev->ok_start_degraded = start_dirty_degraded;
 
-       if (start_readonly && mddev->ro == 0)
-               mddev->ro = 2; /* read-only, but switch on first write */
+       if (start_readonly && md_is_rdwr(mddev))
+               mddev->ro = MD_AUTO_READ; /* read-only, but switch on first write */
 
        err = pers->run(mddev);
        if (err)
@@ -6017,8 +6029,8 @@ int md_run(struct mddev *mddev)
                mddev->sysfs_action = sysfs_get_dirent_safe(mddev->kobj.sd, "sync_action");
                mddev->sysfs_completed = sysfs_get_dirent_safe(mddev->kobj.sd, "sync_completed");
                mddev->sysfs_degraded = sysfs_get_dirent_safe(mddev->kobj.sd, "degraded");
-       } else if (mddev->ro == 2) /* auto-readonly not meaningful */
-               mddev->ro = 0;
+       } else if (mddev->ro == MD_AUTO_READ)
+               mddev->ro = MD_RDWR;
 
        atomic_set(&mddev->max_corr_read_errors,
                   MD_DEFAULT_MAX_CORRECTED_READ_ERRORS);
@@ -6036,7 +6048,7 @@ int md_run(struct mddev *mddev)
                if (rdev->raid_disk >= 0)
                        sysfs_link_rdev(mddev, rdev); /* failure here is OK */
 
-       if (mddev->degraded && !mddev->ro)
+       if (mddev->degraded && md_is_rdwr(mddev))
                /* This ensures that recovering status is reported immediately
                 * via sysfs - until a lack of spares is confirmed.
                 */
@@ -6128,7 +6140,7 @@ static int restart_array(struct mddev *mddev)
                return -ENXIO;
        if (!mddev->pers)
                return -EINVAL;
-       if (!mddev->ro)
+       if (md_is_rdwr(mddev))
                return -EBUSY;
 
        rcu_read_lock();
@@ -6147,7 +6159,7 @@ static int restart_array(struct mddev *mddev)
                return -EROFS;
 
        mddev->safemode = 0;
-       mddev->ro = 0;
+       mddev->ro = MD_RDWR;
        set_disk_ro(disk, 0);
        pr_debug("md: %s switched to read-write mode.\n", mdname(mddev));
        /* Kick recovery or resync if necessary */
@@ -6174,7 +6186,7 @@ static void md_clean(struct mddev *mddev)
        mddev->clevel[0] = 0;
        mddev->flags = 0;
        mddev->sb_flags = 0;
-       mddev->ro = 0;
+       mddev->ro = MD_RDWR;
        mddev->metadata_type[0] = 0;
        mddev->chunk_sectors = 0;
        mddev->ctime = mddev->utime = 0;
@@ -6226,7 +6238,7 @@ static void __md_stop_writes(struct mddev *mddev)
        }
        md_bitmap_flush(mddev);
 
-       if (mddev->ro == 0 &&
+       if (md_is_rdwr(mddev) &&
            ((!mddev->in_sync && !mddev_is_clustered(mddev)) ||
             mddev->sb_flags)) {
                /* mark array as shutdown cleanly */
@@ -6340,9 +6352,9 @@ static int md_set_readonly(struct mddev *mddev, struct block_device *bdev)
                __md_stop_writes(mddev);
 
                err  = -ENXIO;
-               if (mddev->ro==1)
+               if (mddev->ro == MD_RDONLY)
                        goto out;
-               mddev->ro = 1;
+               mddev->ro = MD_RDONLY;
                set_disk_ro(mddev->gendisk, 1);
                clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
                set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
@@ -6399,7 +6411,7 @@ static int do_md_stop(struct mddev *mddev, int mode,
                return -EBUSY;
        }
        if (mddev->pers) {
-               if (mddev->ro)
+               if (!md_is_rdwr(mddev))
                        set_disk_ro(disk, 0);
 
                __md_stop_writes(mddev);
@@ -6416,8 +6428,8 @@ static int do_md_stop(struct mddev *mddev, int mode,
                mutex_unlock(&mddev->open_mutex);
                mddev->changed = 1;
 
-               if (mddev->ro)
-                       mddev->ro = 0;
+               if (!md_is_rdwr(mddev))
+                       mddev->ro = MD_RDWR;
        } else
                mutex_unlock(&mddev->open_mutex);
        /*
@@ -7232,7 +7244,7 @@ static int update_size(struct mddev *mddev, sector_t num_sectors)
        if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
            mddev->sync_thread)
                return -EBUSY;
-       if (mddev->ro)
+       if (!md_is_rdwr(mddev))
                return -EROFS;
 
        rdev_for_each(rdev, mddev) {
@@ -7262,7 +7274,7 @@ static int update_raid_disks(struct mddev *mddev, int raid_disks)
        /* change the number of raid disks */
        if (mddev->pers->check_reshape == NULL)
                return -EINVAL;
-       if (mddev->ro)
+       if (!md_is_rdwr(mddev))
                return -EROFS;
        if (raid_disks <= 0 ||
            (mddev->max_disks && raid_disks >= mddev->max_disks))
@@ -7686,26 +7698,25 @@ static int md_ioctl(struct block_device *bdev, fmode_t mode,
         * The remaining ioctls are changing the state of the
         * superblock, so we do not allow them on read-only arrays.
         */
-       if (mddev->ro && mddev->pers) {
-               if (mddev->ro == 2) {
-                       mddev->ro = 0;
-                       sysfs_notify_dirent_safe(mddev->sysfs_state);
-                       set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
-                       /* mddev_unlock will wake thread */
-                       /* If a device failed while we were read-only, we
-                        * need to make sure the metadata is updated now.
-                        */
-                       if (test_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags)) {
-                               mddev_unlock(mddev);
-                               wait_event(mddev->sb_wait,
-                                          !test_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags) &&
-                                          !test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags));
-                               mddev_lock_nointr(mddev);
-                       }
-               } else {
+       if (!md_is_rdwr(mddev) && mddev->pers) {
+               if (mddev->ro != MD_AUTO_READ) {
                        err = -EROFS;
                        goto unlock;
                }
+               mddev->ro = MD_RDWR;
+               sysfs_notify_dirent_safe(mddev->sysfs_state);
+               set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
+               /* mddev_unlock will wake thread */
+               /* If a device failed while we were read-only, we
+                * need to make sure the metadata is updated now.
+                */
+               if (test_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags)) {
+                       mddev_unlock(mddev);
+                       wait_event(mddev->sb_wait,
+                                  !test_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags) &&
+                                  !test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags));
+                       mddev_lock_nointr(mddev);
+               }
        }
 
        switch (cmd) {
@@ -7791,11 +7802,11 @@ static int md_set_read_only(struct block_device *bdev, bool ro)
         * Transitioning to read-auto need only happen for arrays that call
         * md_write_start and which are not ready for writes yet.
         */
-       if (!ro && mddev->ro == 1 && mddev->pers) {
+       if (!ro && mddev->ro == MD_RDONLY && mddev->pers) {
                err = restart_array(mddev);
                if (err)
                        goto out_unlock;
-               mddev->ro = 2;
+               mddev->ro = MD_AUTO_READ;
        }
 
 out_unlock:
@@ -8269,9 +8280,9 @@ 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==1)
+                       if (mddev->ro == MD_RDONLY)
                                seq_printf(seq, " (read-only)");
-                       if (mddev->ro==2)
+                       if (mddev->ro == MD_AUTO_READ)
                                seq_printf(seq, " (auto-read-only)");
                        seq_printf(seq, " %s", mddev->pers->name);
                }
@@ -8530,10 +8541,10 @@ bool md_write_start(struct mddev *mddev, struct bio *bi)
        if (bio_data_dir(bi) != WRITE)
                return true;
 
-       BUG_ON(mddev->ro == 1);
-       if (mddev->ro == 2) {
+       BUG_ON(mddev->ro == MD_RDONLY);
+       if (mddev->ro == MD_AUTO_READ) {
                /* need to switch to read/write */
-               mddev->ro = 0;
+               mddev->ro = MD_RDWR;
                set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
                md_wakeup_thread(mddev->thread);
                md_wakeup_thread(mddev->sync_thread);
@@ -8584,7 +8595,7 @@ void md_write_inc(struct mddev *mddev, struct bio *bi)
 {
        if (bio_data_dir(bi) != WRITE)
                return;
-       WARN_ON_ONCE(mddev->in_sync || mddev->ro);
+       WARN_ON_ONCE(mddev->in_sync || !md_is_rdwr(mddev));
        percpu_ref_get(&mddev->writes_pending);
 }
 EXPORT_SYMBOL(md_write_inc);
@@ -8690,7 +8701,7 @@ void md_allow_write(struct mddev *mddev)
 {
        if (!mddev->pers)
                return;
-       if (mddev->ro)
+       if (!md_is_rdwr(mddev))
                return;
        if (!mddev->pers->sync_request)
                return;
@@ -8738,7 +8749,7 @@ void md_do_sync(struct md_thread *thread)
        if (test_bit(MD_RECOVERY_DONE, &mddev->recovery) ||
            test_bit(MD_RECOVERY_WAIT, &mddev->recovery))
                return;
-       if (mddev->ro) {/* never try to sync a read-only array */
+       if (!md_is_rdwr(mddev)) {/* never try to sync a read-only array */
                set_bit(MD_RECOVERY_INTR, &mddev->recovery);
                return;
        }
@@ -9207,9 +9218,9 @@ static int remove_and_add_spares(struct mddev *mddev,
                if (test_bit(Faulty, &rdev->flags))
                        continue;
                if (!test_bit(Journal, &rdev->flags)) {
-                       if (mddev->ro &&
-                           ! (rdev->saved_raid_disk >= 0 &&
-                              !test_bit(Bitmap_sync, &rdev->flags)))
+                       if (!md_is_rdwr(mddev) &&
+                           !(rdev->saved_raid_disk >= 0 &&
+                             !test_bit(Bitmap_sync, &rdev->flags)))
                                continue;
 
                        rdev->recovery_offset = 0;
@@ -9307,7 +9318,8 @@ void md_check_recovery(struct mddev *mddev)
                flush_signals(current);
        }
 
-       if (mddev->ro && !test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))
+       if (!md_is_rdwr(mddev) &&
+           !test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))
                return;
        if ( ! (
                (mddev->sb_flags & ~ (1<<MD_SB_CHANGE_PENDING)) ||
@@ -9326,7 +9338,7 @@ void md_check_recovery(struct mddev *mddev)
                if (!mddev->external && mddev->safemode == 1)
                        mddev->safemode = 0;
 
-               if (mddev->ro) {
+               if (!md_is_rdwr(mddev)) {
                        struct md_rdev *rdev;
                        if (!mddev->external && mddev->in_sync)
                                /* 'Blocked' flag not needed as failed devices