diff options
author | Lars Ellenberg <lars.ellenberg@linbit.com> | 2015-03-26 19:53:55 (GMT) |
---|---|---|
committer | Jens Axboe <axboe@fb.com> | 2015-11-25 16:22:02 (GMT) |
commit | 63a7c8ad92af5f57d4a2c5be223d6ca424c3670b (patch) | |
tree | 4c9232f769b3fda758633add5d4ee5f559cf98a5 /drivers/block/drbd/drbd_nl.c | |
parent | 088b70526d5b4080010147e4a6ae1252c3fc2228 (diff) | |
download | linux-63a7c8ad92af5f57d4a2c5be223d6ca424c3670b.tar.xz |
drbd: make drbd known to lsblk: use bd_link_disk_holder
lsblk should be able to pick up stacking device driver relations
involving DRBD conveniently.
Even though upstream kernel since 2011 says
"DON'T USE THIS UNLESS YOU'RE ALREADY USING IT."
a new user has been added since (bcache),
which sets the precedences for us to use it as well.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'drivers/block/drbd/drbd_nl.c')
-rw-r--r-- | drivers/block/drbd/drbd_nl.c | 121 |
1 files changed, 86 insertions, 35 deletions
diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c index 4703f1a..ee34739 100644 --- a/drivers/block/drbd/drbd_nl.c +++ b/drivers/block/drbd/drbd_nl.c @@ -1471,6 +1471,88 @@ success: return 0; } +static struct block_device *open_backing_dev(struct drbd_device *device, + const char *bdev_path, void *claim_ptr, bool do_bd_link) +{ + struct block_device *bdev; + int err = 0; + + bdev = blkdev_get_by_path(bdev_path, + FMODE_READ | FMODE_WRITE | FMODE_EXCL, claim_ptr); + if (IS_ERR(bdev)) { + drbd_err(device, "open(\"%s\") failed with %ld\n", + bdev_path, PTR_ERR(bdev)); + return bdev; + } + + if (!do_bd_link) + return bdev; + + err = bd_link_disk_holder(bdev, device->vdisk); + if (err) { + blkdev_put(bdev, FMODE_READ | FMODE_WRITE | FMODE_EXCL); + drbd_err(device, "bd_link_disk_holder(\"%s\", ...) failed with %d\n", + bdev_path, err); + bdev = ERR_PTR(err); + } + return bdev; +} + +static int open_backing_devices(struct drbd_device *device, + struct disk_conf *new_disk_conf, + struct drbd_backing_dev *nbc) +{ + struct block_device *bdev; + + bdev = open_backing_dev(device, new_disk_conf->backing_dev, device, true); + if (IS_ERR(bdev)) + return ERR_OPEN_DISK; + nbc->backing_bdev = bdev; + + /* + * meta_dev_idx >= 0: external fixed size, possibly multiple + * drbd sharing one meta device. TODO in that case, paranoia + * check that [md_bdev, meta_dev_idx] is not yet used by some + * other drbd minor! (if you use drbd.conf + drbdadm, that + * should check it for you already; but if you don't, or + * someone fooled it, we need to double check here) + */ + bdev = open_backing_dev(device, new_disk_conf->meta_dev, + /* claim ptr: device, if claimed exclusively; shared drbd_m_holder, + * if potentially shared with other drbd minors */ + (new_disk_conf->meta_dev_idx < 0) ? (void*)device : (void*)drbd_m_holder, + /* avoid double bd_claim_by_disk() for the same (source,target) tuple, + * as would happen with internal metadata. */ + (new_disk_conf->meta_dev_idx != DRBD_MD_INDEX_FLEX_INT && + new_disk_conf->meta_dev_idx != DRBD_MD_INDEX_INTERNAL)); + if (IS_ERR(bdev)) + return ERR_OPEN_MD_DISK; + nbc->md_bdev = bdev; + return NO_ERROR; +} + +static void close_backing_dev(struct drbd_device *device, struct block_device *bdev, + bool do_bd_unlink) +{ + if (!bdev) + return; + if (do_bd_unlink) + bd_unlink_disk_holder(bdev, device->vdisk); + blkdev_put(bdev, FMODE_READ | FMODE_WRITE | FMODE_EXCL); +} + +void drbd_backing_dev_free(struct drbd_device *device, struct drbd_backing_dev *ldev) +{ + if (ldev == NULL) + return; + + close_backing_dev(device, ldev->md_bdev, ldev->md_bdev != ldev->backing_bdev); + close_backing_dev(device, ldev->backing_bdev, true); + + kfree(ldev->disk_conf); + kfree(ldev); +} + int drbd_adm_attach(struct sk_buff *skb, struct genl_info *info) { struct drbd_config_context adm_ctx; @@ -1484,7 +1566,6 @@ int drbd_adm_attach(struct sk_buff *skb, struct genl_info *info) sector_t min_md_device_sectors; struct drbd_backing_dev *nbc = NULL; /* new_backing_conf */ struct disk_conf *new_disk_conf = NULL; - struct block_device *bdev; struct lru_cache *resync_lru = NULL; struct fifo_buffer *new_plan = NULL; union drbd_state ns, os; @@ -1572,35 +1653,9 @@ int drbd_adm_attach(struct sk_buff *skb, struct genl_info *info) } rcu_read_unlock(); - bdev = blkdev_get_by_path(new_disk_conf->backing_dev, - FMODE_READ | FMODE_WRITE | FMODE_EXCL, device); - if (IS_ERR(bdev)) { - drbd_err(device, "open(\"%s\") failed with %ld\n", new_disk_conf->backing_dev, - PTR_ERR(bdev)); - retcode = ERR_OPEN_DISK; - goto fail; - } - nbc->backing_bdev = bdev; - - /* - * meta_dev_idx >= 0: external fixed size, possibly multiple - * drbd sharing one meta device. TODO in that case, paranoia - * check that [md_bdev, meta_dev_idx] is not yet used by some - * other drbd minor! (if you use drbd.conf + drbdadm, that - * should check it for you already; but if you don't, or - * someone fooled it, we need to double check here) - */ - bdev = blkdev_get_by_path(new_disk_conf->meta_dev, - FMODE_READ | FMODE_WRITE | FMODE_EXCL, - (new_disk_conf->meta_dev_idx < 0) ? - (void *)device : (void *)drbd_m_holder); - if (IS_ERR(bdev)) { - drbd_err(device, "open(\"%s\") failed with %ld\n", new_disk_conf->meta_dev, - PTR_ERR(bdev)); - retcode = ERR_OPEN_MD_DISK; + retcode = open_backing_devices(device, new_disk_conf, nbc); + if (retcode != NO_ERROR) goto fail; - } - nbc->md_bdev = bdev; if ((nbc->backing_bdev == nbc->md_bdev) != (new_disk_conf->meta_dev_idx == DRBD_MD_INDEX_INTERNAL || @@ -1900,12 +1955,8 @@ int drbd_adm_attach(struct sk_buff *skb, struct genl_info *info) fail: conn_reconfig_done(connection); if (nbc) { - if (nbc->backing_bdev) - blkdev_put(nbc->backing_bdev, - FMODE_READ | FMODE_WRITE | FMODE_EXCL); - if (nbc->md_bdev) - blkdev_put(nbc->md_bdev, - FMODE_READ | FMODE_WRITE | FMODE_EXCL); + close_backing_dev(device, nbc->md_bdev, nbc->md_bdev != nbc->backing_bdev); + close_backing_dev(device, nbc->backing_bdev, true); kfree(nbc); } kfree(new_disk_conf); |