20.3. CB_LAYOUTRECALL
"LAYOUTRECALL4_FSID and LAYOUTRECALL4_ALL specify that all the storage device ID to storage device address mappings in the affected file system(s) are also recalled."
pnfs_file_layout_recall() now takes a nfs41_client instead of just the pnfs_file_layout_list, because both the layout list and device list are accessible from nfs41_client. for bulk recalls, calls new function pnfs_file_device_list_invalidate(). each device with layout_count=0 is removed and freed, and devices in use are flagged as REVOKED and freed when layout_count->0
layout_recall_return() now takes a pnfs_file_layout instead of pnfs_layout for access to pnfs_file_layout.device. pnfs_layout_io_start() and pnfs_layout_io_finish() do the same, because pnfs_layout_io_finish() calls layout_recall_return(). layout_recall_return() calls pnfs_file_device_put() to release its reference on the device
Signed-off-by: Casey Bodley <cbodley@citi.umich.edu>
pnfs_device.status remembers whether a given device has been GRANTED/REVOKED
pnfs_device.layout_count tracks the number of layouts using the device, incremented by pnfs_file_device_get() and decremented by pnfs_file_device_put(). when pnfs_file_device_put() takes layout_count to 0, remove and free the device only if it's flagged as REVOKED
because pnfs_file_device_get() modifies pnfs_device.layout_count, we can no longer use a shared lock; changed pnfs_file_device.lock from SRWLOCK to CRITICAL_SECTION, and moved to pnfs_device.lock to document the fact that it's used for pnfs_device.status and pnfs_device.layout_count
Signed-off-by: Casey Bodley <cbodley@citi.umich.edu>
operations that require a stateid now take stateid_arg for recovery information. these operations include close, setattr, lock/unlock, layoutget, and read/write (including pnfs)
nfs41_open_stateid_arg() locks nfs41_open_state and copies its stateid into a stateid_arg
nfs41_lock_stateid_arg() locks nfs41_open_state.last_lock and copies its stateid into a stateid_arg; if there is no lock state, it falls back to nfs41_open_stateid_arg()
pnfs_read/write() now take nfs41_open_state so they can generate stateid_args
Signed-off-by: Casey Bodley <cbodley@citi.umich.edu>
