f3aa3b93df
Partitions for a zvol device were not appearing in /dev/zvol/<pool>/ at module load time for a couple of reasons. 1) The Linux block layer expects a block device to have a non-zero capacity during add_disk(). If the capacity is zero it does not attempt to open the device which means we never trigger a partition scan. The device capacity was just being set during the first open. 2) Because we expect to be adding a block device to the zvol_state_list during zvol_create_minor() the zvol_state_lock() is held. This can result in a deadlock in add_disk() when it attempts to open the block device via zvol_open() which also takes this same lock. To avoid this issue special handling has been added to zvol_open() and zvol_release() to allow the mutex owner to enter these functions without retaking the lock. 3) In __zvol_create_minor() the call to dmu_objset_disown() must occur before the call to add_disk(). As mentioned above add_disk() results in a call to zvol_open() which will attempt to call dmu_objset_own() again on the objset. If the objset is already open it will fail resulting in a failed open. This in turn means the kernel will be unable to read the partition information from the device. |
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| .. | ||
| avl | ||
| nvpair | ||
| unicode | ||
| zcommon | ||
| zfs | ||
| .gitignore | ||
| Makefile.in | ||