3937ab20f3
Restructure the zfsdev_state_list to allow for lock-free reading by converting to a simple singly-linked list from which items are never deleted and over which only forward iterations are performed. It depends on, among other things, the atomicity of accessing the zs_minor integer and zs_next pointer. This fixes a lock inversion in which the zfsdev_state_lock is used by both the sync task (txg_sync) and indirectly by any user program which uses /dev/zfs; the zfsdev_release method uses the same lock and then blocks on the sync task. The most typical failure scenerio occurs when the sync task is cleaning up a user hold while various concurrent "zfs" commands are in progress. Neither Illumos nor Solaris are affected by this issue because they use DDI interface which provides lock-free reading of device state via the ddi_get_soft_state() function. Signed-off-by: Tim Chase <tim@chase2k.com> Signed-off-by: Chunwei Chen <tuxoko@gmail.com> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes #2301 |
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| avl | ||
| nvpair | ||
| unicode | ||
| zcommon | ||
| zfs | ||
| zpios | ||
| .gitignore | ||
| Makefile.in | ||