2ebc7b72b3
There exists a lock inversion between the z_xattr_lock and the
z_teardown_lock. Resolve this by taking the z_teardown_lock in
all registered xattr callbacks prior to taking the z_xattr_lock.
This ensures the locks are always taken is the same order thus
preventing a deadlock. Note the z_teardown_lock is taken again
in zfs_lookup() and this is safe because the z_teardown lock is
a re-entrant read reader/writer lock.
* process-1
zpl_xattr_get -> Takes zp->z_xattr_lock
__zpl_xattr_get
zfs_lookup -> Takes zsb->z_teardown_lock in ZFS_ENTER macro
* process-2
zfs_ioc_recv -> Takes zsb->z_teardown_lock in zfs_suspend_fs()
zfs_resume_fs
zfs_rezget -> Takes zp->z_xattr_lock
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Chunwei Chen <tuxoko@gmail.com>
Closes #3943
Closes #3969
Closes #4121
Native ZFS for Linux!
ZFS is an advanced file system and volume manager which was originally developed for Solaris and is now maintained by the Illumos community.
ZFS on Linux, which is also known as ZoL, is currently feature complete. It includes fully functional and stable SPA, DMU, ZVOL, and ZPL layers.
Full documentation for installing ZoL on your favorite Linux distribution can be found at: http://zfsonlinux.org