the thread-by-server model breaks down when using dense layouts, because multiple stripes could be mapped to a single data server, and the per-data-server thread would have to send a COMMIT for each stripe
Signed-off-by: Casey Bodley <cbodley@citi.umich.edu>
sorry, earlier Casey, but the patch 'threading by io unit instead of stripe' from 6/20/2010 was nuts! with PNFS_THREAD_BY_SERVER disabled, we definitely -don't- want to create a separate thread for each io unit (each READ/WRITE request to a ds). we just want the one per stripe, as the intended alternative to PNFS_THREAD_BY_SERVER
Signed-off-by: Casey Bodley <cbodley@citi.umich.edu>
added 2011 year to the copyright line
added authors info to the license
added UofM license to libtirpc files that we modified
(but i probably missed some)
exclusive locks are no longer held over LAYOUTGET, LAYOUTRETURN, or GETDEVICEINFO rpcs. this prevents a deadlock when CB_LAYOUTRECALL needs an exclusive lock while another operation is on the wire
introduced a 'pending' condition variable to protect access to state->layout while the layout's lock is not held
updated file_layout_recall() to compare the stateid sequence numbers to determine if the server has processed an outstanding LAYOUTGET or LAYOUTRETURN, where we're required to reply with NFS4ERR_DELAY
LAYOUTGET, LAYOUTRETURN, and GETDEVICEINFO can now be sent with try_recovery=TRUE because they no longer hold an exclusive lock. this makes it possible for recover_client_state() to recall all of the client's layouts without deadlocking
Signed-off-by: Casey Bodley <cbodley@citi.umich.edu>
nfs41_lock_stateid_arg() is now called only once in handle_read()/handle_write(), and pnfs_read()/pnfs_write() no longer depend on nfs41_open_state
Signed-off-by: Casey Bodley <cbodley@citi.umich.edu>
on a successful LAYOUTGET, file_layout_fetch() calls layout_update() to copy the first layout segment returned and update the layout stateid
on a successful LAYOUTRETURN, file_layout_return() frees the layout segment and updates/clears the stateid
Signed-off-by: Casey Bodley <cbodley@citi.umich.edu>
moved state data (stateid, flags, locks, and reference counts) out of struct pnfs_layout, which should represent a layout segment returned by LAYOUTGET
struct pnfs_layout_state now holds this state, along with a pointer to a single pnfs_file_layout
struct pnfs_file_layout_list is now a list of pnfs_layout_states, and was renamed to pnfs_layout_list
Signed-off-by: Casey Bodley <cbodley@citi.umich.edu>
added pnfs_layout.open_count to count open references, and only return the layout when pnfs_open_state_close() takes the open_count to 0
use InterlockedIncrement/Decrement to avoid an exclusive lock on the layout
Signed-off-by: Casey Bodley <cbodley@citi.umich.edu>
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>
fixed a few cases of warning 4242: possible loss of data
wincrypt.h appears to come with windows.h in later versions of the ddk, but nfs41_client.c fails to compile in WDK 6001 without #include <wincrypt.h>
Signed-off-by: Casey Bodley <cbodley@citi.umich.edu>
