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183d9e7b11
There are several problems in the way a stateid is selected for a LAYOUTGET operation: We pick a stateid to use in the RPC prepare op, but that makes it difficult to serialize LAYOUTGETs that use the open stateid. That serialization is done in pnfs_update_layout, which occurs well before the rpc_prepare operation. Between those two events, the i_lock is dropped and reacquired. pnfs_update_layout can find that the list has lsegs in it and not do any serialization, but then later pnfs_choose_layoutget_stateid ends up choosing the open stateid. This patch changes the client to select the stateid to use in the LAYOUTGET earlier, when we're searching for a usable layout segment. This way we can do it all while holding the i_lock the first time, and ensure that we serialize any LAYOUTGET call that uses a non-layout stateid. This also means a rework of how LAYOUTGET replies are handled, as we must now get the latest stateid if we want to retransmit in response to a retryable error. Most of those errors boil down to the fact that the layout state has changed in some fashion. Thus, what we really want to do is to re-search for a layout when it fails with a retryable error, so that we can avoid reissuing the RPC at all if possible. While the LAYOUTGET RPC is async, the initiating thread always waits for it to complete, so it's effectively synchronous anyway. Currently, when we need to retry a LAYOUTGET because of an error, we drive that retry via the rpc state machine. This means that once the call has been submitted, it runs until it completes. So, we must move the error handling for this RPC out of the rpc_call_done operation and into the caller. In order to handle errors like NFS4ERR_DELAY properly, we must also pass a pointer to the sliding timeout, which is now moved to the stack in pnfs_update_layout. The complicating errors are -NFS4ERR_RECALLCONFLICT and -NFS4ERR_LAYOUTTRYLATER, as those involve a timeout after which we give up and return NULL back to the caller. So, there is some special handling for those errors to ensure that the layers driving the retries can handle that appropriately. Signed-off-by: Jeff Layton <jeff.layton@primarydata.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
34 lines
1.3 KiB
C
34 lines
1.3 KiB
C
#ifndef _LINUX_ERRNO_H
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#define _LINUX_ERRNO_H
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#include <uapi/linux/errno.h>
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/*
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* These should never be seen by user programs. To return one of ERESTART*
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* codes, signal_pending() MUST be set. Note that ptrace can observe these
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* at syscall exit tracing, but they will never be left for the debugged user
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* process to see.
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*/
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#define ERESTARTSYS 512
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#define ERESTARTNOINTR 513
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#define ERESTARTNOHAND 514 /* restart if no handler.. */
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#define ENOIOCTLCMD 515 /* No ioctl command */
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#define ERESTART_RESTARTBLOCK 516 /* restart by calling sys_restart_syscall */
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#define EPROBE_DEFER 517 /* Driver requests probe retry */
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#define EOPENSTALE 518 /* open found a stale dentry */
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/* Defined for the NFSv3 protocol */
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#define EBADHANDLE 521 /* Illegal NFS file handle */
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#define ENOTSYNC 522 /* Update synchronization mismatch */
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#define EBADCOOKIE 523 /* Cookie is stale */
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#define ENOTSUPP 524 /* Operation is not supported */
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#define ETOOSMALL 525 /* Buffer or request is too small */
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#define ESERVERFAULT 526 /* An untranslatable error occurred */
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#define EBADTYPE 527 /* Type not supported by server */
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#define EJUKEBOX 528 /* Request initiated, but will not complete before timeout */
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#define EIOCBQUEUED 529 /* iocb queued, will get completion event */
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#define ERECALLCONFLICT 530 /* conflict with recalled state */
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#endif
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