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path: root/fs/nfs/pnfs.c
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2011-08-04pnfs: let layoutcommit handle a list of lsegPeng Tao
commit a9bae5666d0510ad69bdb437371c9a3e6b770705 upstream. There can be multiple lseg per file, so layoutcommit should be able to handle it. [Needed in v3.0] Signed-off-by: Peng Tao <peng_tao@emc.com> Signed-off-by: Boaz Harrosh <bharrosh@panasas.com> Signed-off-by: Jim Rees <rees@umich.edu> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-08-04pnfs: save layoutcommit cred at layout header initPeng Tao
commit 9fa4075878a5faac872a63f4a97ce79c776264e9 upstream. No need to save it for every lseg. No need to save it at every pnfs_set_layoutcommit. [Needed in v3.0] Signed-off-by: Peng Tao <peng_tao@emc.com> Signed-off-by: Boaz Harrosh <bharrosh@panasas.com> Signed-off-by: Jim Rees <rees@umich.edu> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-08-04pnfs: save layoutcommit lwb at layout headerPeng Tao
commit acff5880539fe33897d016c0f3dcf062e67c61b6 upstream. No need to save it for every lseg. [Needed in v3.0] Signed-off-by: Peng Tao <peng_tao@emc.com> Signed-off-by: Jim Rees <rees@umich.edu> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-06-21NFSv4.1: Fix an off-by-one error in pnfs_generic_pg_testTrond Myklebust
And document what is going on there... Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-06-21NFSv4.1: Fix some issues with pnfs_generic_pg_testTrond Myklebust
1. If the intention is to coalesce requests 'prev' and 'req' then we have to ensure at least that we have a layout starting at req_offset(prev). 2. If we're only requesting a minimal layout of length desc->pg_count, we need to test the length actually returned by the server before we allow the coalescing to occur. 3. We need to deal correctly with (pgio->lseg == NULL) 4. Fixup the test guarding the pnfs_update_layout. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-06-15nfs4.1: mark layout as bad on error path in _pnfs_return_layoutFred Isaman
Signed-off-by: Fred Isaman <iisaman@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-06-15nfs4.1: prevent race that allowed use of freed layout in _pnfs_return_layoutFred Isaman
mark_matching_lsegs_invalid could put the last ref to the layout, so the get_layout_hdr needs to be called first. Signed-off-by: Fred Isaman <iisaman@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-06-15NFSv4.1: need to put_layout_hdr on _pnfs_return_layout error pathBenny Halevy
We always get a reference on the layout header and we rely on nfs4_layoutreturn_release to put it. If we hit an allocation error before starting the rpc proc we bail out early without dereferncing the layout header properly. Signed-off-by: Benny Halevy <benny@tonian.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-06-15NFSv4.1: fix break condition in pnfs_find_lsegBenny Halevy
The break condition to skip out of the loop got broken when cmp_layout was change. Essentially, we want to stop looking once we know no layout on the remainder of the list can match the first byte of the looked-up range. Reported-by: Peng Tao <peng_tao@emc.com> Signed-off-by: Benny Halevy <benny@tonian.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-06-15nfs4.1: fix several problems with _pnfs_return_layoutFred Isaman
_pnfs_return_layout had the following problems: - it did not call pnfs_free_lseg_list on all paths - it unintentionally did a forgetful return when there was no outstanding io - it raced with concurrent LAYOUTGETS Signed-off-by: Fred Isaman <iisaman@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-05-29Merge branch 'pnfs-submit' of git://git.open-osd.org/linux-open-osdLinus Torvalds
* 'pnfs-submit' of git://git.open-osd.org/linux-open-osd: (32 commits) pnfs-obj: pg_test check for max_io_size NFSv4.1: define nfs_generic_pg_test NFSv4.1: use pnfs_generic_pg_test directly by layout driver NFSv4.1: change pg_test return type to bool NFSv4.1: unify pnfs_pageio_init functions pnfs-obj: objlayout_encode_layoutcommit implementation pnfs: encode_layoutcommit pnfs-obj: report errors and .encode_layoutreturn Implementation. pnfs: encode_layoutreturn pnfs: layoutret_on_setattr pnfs: layoutreturn pnfs-obj: osd raid engine read/write implementation pnfs: support for non-rpc layout drivers pnfs-obj: define per-inode private structure pnfs: alloc and free layout_hdr layoutdriver methods pnfs-obj: objio_osd device information retrieval and caching pnfs-obj: decode layout, alloc/free lseg pnfs-obj: pnfs_osd XDR client implementation pnfs-obj: pnfs_osd XDR definitions pnfs-obj: objlayoutdriver module skeleton ...
2011-05-29NFSv4.1: use pnfs_generic_pg_test directly by layout driverBenny Halevy
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
2011-05-29NFSv4.1: change pg_test return type to boolBenny Halevy
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
2011-05-29NFSv4.1: unify pnfs_pageio_init functionsBenny Halevy
Use common code for pnfs_pageio_init_{read,write} and use a common generic pg_test function. Note that this function always assumes the the layout driver's pg_test method is implemented. [Fix BUG] Signed-off-by: Boaz Harrosh <bharrosh@panasas.com> Signed-off-by: Benny Halevy <bhalevy@panasas.com>
2011-05-29pnfs: layoutreturnBenny Halevy
NFSv4.1 LAYOUTRETURN implementation Currently, does not support layout-type payload encoding. Signed-off-by: Alexandros Batsakis <batsakis@netapp.com> Signed-off-by: Andy Adamson <andros@citi.umich.edu> Signed-off-by: Andy Adamson <andros@netapp.com> Signed-off-by: Dean Hildebrand <dhildeb@us.ibm.com> Signed-off-by: Fred Isaman <iisaman@citi.umich.edu> Signed-off-by: Fred Isaman <iisaman@netapp.com> Signed-off-by: Marc Eshel <eshel@almaden.ibm.com> Signed-off-by: Zhang Jingwang <zhangjingwang@nrchpc.ac.cn> [call pnfs_return_layout right before pnfs_destroy_layout] [remove assert_spin_locked from pnfs_clear_lseg_list] [remove wait parameter from the layoutreturn path.] [remove return_type field from nfs4_layoutreturn_args] [remove range from nfs4_layoutreturn_args] [no need to send layoutcommit from _pnfs_return_layout] [don't wait on sync layoutreturn] [fix layout stateid in layoutreturn args] [fixed NULL deref in _pnfs_return_layout] [removed recaim member of nfs4_layoutreturn_args] Signed-off-by: Benny Halevy <bhalevy@panasas.com>
2011-05-29pnfs: support for non-rpc layout driversBenny Halevy
Non-rpc layout driver such as for objects and blocks implement their own I/O path and error handling logic. Therefore bypass NFS-based error handling for these layout drivers. [fix lseg ref-count bugs, and null de-refs] [Fall out from: non-rpc layout drivers] Signed-off-by: Boaz Harrosh <bharrosh@panasas.com> [get rid of PNFS_USE_RPC_CODE] [get rid of __nfs4_write_done_cb] [revert useless change in nfs4_write_done_cb] Signed-off-by: Benny Halevy <bhalevy@panasas.com>
2011-05-29pnfs: alloc and free layout_hdr layoutdriver methodsBenny Halevy
[gfp_flags] Signed-off-by: Benny Halevy <bhalevy@panasas.com>
2011-05-29pnfs: Use byte-range for cb_layoutrecallBenny Halevy
Use recalled range to invalidate particular layout segments in the layout cache. Signed-off-by: Benny Halevy <bhalevy@panasas.com>
2011-05-29pnfs: align layoutget requests on page boundariesBenny Halevy
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
2011-05-29pnfs: Use byte-range for layoutgetBenny Halevy
Add offset and count parameters to pnfs_update_layout and use them to get the layout in the pageio path. Order cache layout segments in the following order: * offset (ascending) * length (descending) * iomode (RW before READ) Test byte range against the layout segment in use in pnfs_{read,write}_pg_test so not to coalesce pages not using the same layout segment. [fix lseg ordering] [clean up pnfs_find_lseg lseg arg] [remove unnecessary FIXME] [fix ordering in pnfs_insert_layout] [clean up pnfs_insert_layout] Signed-off-by: Benny Halevy <bhalevy@panasas.com>
2011-05-27nfs41: Correct offset for LAYOUTCOMMITVitaliy Gusev
A client sends offset to MDS as it was seen by DS. As result, file size after copy is only half of original file size in case of 2 DS. Signed-off-by: Vitaliy Gusev <gusev.vitaliy@nexenta.com> Cc: stable@kernel.org [2.6.39] Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-05-11NFSv4.1: Ensure that layoutget uses the correct gfp modesTrond Myklebust
Currently, writebacks may end up recursing back into the filesystem due to GFP_KERNEL direct reclaims in the pnfs subsystem. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-05-11NFSv4.1: remove pnfs_layout_hdr from pnfs_destroy_all_layouts tmp_listAndy Adamson
Prevents an infinite loop as list was never emptied. Signed-off-by: Andy Adamson <andros@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-04-13Don't mark_inode_dirty_sync() while holding lockWeston Andros Adamson
mark_inode_dirty_sync() grabs the same inode lock! race conditions between holding the lock in pnfs_set_layoutcommit() and in mark_inode_dirty_sync() can result in a second call to pnfs_layoutcommit_inode(), but this will be a noop as NFS_INO_LAYOUTCOMMIT won't be set in the second call Signed-off-by: Weston Andros Adamson <dros@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-24Cleanup XDR parsing for LAYOUTGET, GETDEVICEINFOWeston Andros Adamson
changes LAYOUTGET and GETDEVICEINFO XDR parsing to: - not use vmap, which doesn't work on incoherent archs - use xdr_stream parsing for all xdr Signed-off-by: Weston Andros Adamson <dros@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-24NFSv4.1 convert layoutcommit sync to booleanAndy Adamson
Signed-off-by: Andy Adamson <andros@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-24NFSv4.1 pnfs_layoutcommit_inode fixesAndy Adamson
Test NFS_INO_LAYOUTCOMMIT before kzalloc Mark inode dirty to retry LAYOUTCOMMIT on kzalloc failure. Add comments. Signed-off-by: Andy Adamson <andros@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-23NFSv4.1: layoutcommitAndy Adamson
The filelayout driver sends LAYOUTCOMMIT only when COMMIT goes to the data server (as opposed to the MDS) and the data server WRITE is not NFS_FILE_SYNC. Only whole file layout support means that there is only one IOMODE_RW layout segment. Signed-off-by: Andy Adamson <andros@netapp.com> Signed-off-by: Alexandros Batsakis <batsakis@netapp.com> Signed-off-by: Boaz Harrosh <bharrosh@panasas.com> Signed-off-by: Dean Hildebrand <dhildeb@us.ibm.com> Signed-off-by: Fred Isaman <iisaman@citi.umich.edu> Signed-off-by: Mingyang Guo <guomingyang@nrchpc.ac.cn> Signed-off-by: Tao Guo <guotao@nrchpc.ac.cn> Signed-off-by: Zhang Jingwang <zhangjingwang@nrchpc.ac.cn> Tested-by: Boaz Harrosh <bharrosh@panasas.com> Signed-off-by: Benny Halevy <bhalevy@panasas.com> Signed-off-by: Fred Isaman <iisaman@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-23NFSv4.1: filelayout driver specific code for COMMITFred Isaman
Implement all the hooks created in the previous patches. This requires exporting quite a few functions and adding a few structure fields. Signed-off-by: Fred Isaman <iisaman@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11NFSv4.1: implement generic pnfs layer write switchAndy Adamson
Signed-off-by: Andy Adamson <andros@citi.umich.edu> Signed-off-by: Boaz Harrosh <bharrosh@panasas.com> Signed-off-by: Dean Hildebrand <dhildeb@us.ibm.com> Signed-off-by: Fred Isaman <iisaman@citi.umich.edu> Signed-off-by: J. Bruce Fields <bfields@fieldses.org> Signed-off-by: Mike Sager <sager@netapp.com> Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com> Signed-off-by: Tao Guo <guotao@nrchpc.ac.cn> Signed-off-by: Andy Adamson <andros@netapp.com> Signed-off-by: Benny Halevy <bhalevy@panasas.com> Signed-off-by: Fred Isaman <iisaman@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11NFSv4.1: trigger LAYOUTGET for writesFred Isaman
Signed-off-by: Fred Isaman <iisaman@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11NFSv4.1: turn off pNFS on ds connection failureAndy Adamson
If a data server is unavailable, go through MDS. Mark the deviceid containing the data server as a negative cache entry. Do not try to connect to any data server on a deviceid marked as a negative cache entry. Mark any layout that tries to use the marked deviceid as failed. Inodes with a layout marked as fails will not use the layout for I/O, and will not perform any more layoutgets. Inodes without a layout will still do layoutget, but the layout will get marked immediately. Signed-off-by: Andy Adamson <andros@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11NFSv4.1 move deviceid cache to filelayout driverChristoph Hellwig
No need for generic cache with only one user. Keep a simple hash of deviceids in the filelayout driver. Signed-off-by: Christoph Hellwig <hch@infradead.org> Acked-by: Andy Adamson <andros@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11NFSv4.1: generic readAndy Adamson
Separate the rpc run portion of nfs_read_rpcsetup into a new function nfs_initiate_read that is called for normal NFS I/O. Add a pNFS read_pagelist function that is called instead of nfs_intitate_read for pNFS reads. Signed-off-by: Andy Adamson <andros@citi.umich.edu> Signed-off-by: Boaz Harrosh <bharrosh@panasas.com> Signed-off-by: Dean Hildebrand <dhildeb@us.ibm.com> Signed-off-by: Fred Isaman <iisaman@citi.umich.edu> Signed-off-by: Fred Isaman <iisaman@netapp.com> Signed-off-by: Mike Sager <sager@netapp.com> Signed-off-by: Mingyang Guo <guomingyang@nrchpc.ac.cn> Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com> Signed-off-by: Tao Guo <guotao@nrchpc.ac.cn> Signed-off-by: Andy Adamson <andros@netapp.com> Signed-off-by: Benny Halevy <bhalevy@panasas.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11NFSv4.1: shift pnfs_update_layout locationsFred Isaman
Move the pnfs_update_layout call location to nfs_pageio_do_add_request(). Grab the lseg sent in the doio function to nfs_read_rpcsetup and attach it to each nfs_read_data so it can be sent to the layout driver. Signed-off-by: Andy Adamson <andros@netapp.com> Signed-off-by: Andy Adamson <andros@citi.umich.edu> Signed-off-by: Dean Hildebrand <dhildeb@us.ibm.com> Signed-off-by: Fred Isaman <iisaman@citi.umich.edu> Signed-off-by: Fred Isaman <iisaman@netapp.com> Signed-off-by: Benny Halevy <bhalevy@panasas.com> Signed-off-by: Boaz Harrosh <bharrosh@panasas.com> Signed-off-by: Oleg Drokin <green@linuxhacker.ru> Signed-off-by: Tao Guo <guotao@nrchpc.ac.cn> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11NFSv4.1: coelesce across layout stripesFred Isaman
Add a pg_test layout driver hook which is used to avoid coelescing I/O across layout stripes. Signed-off-by: Andy Adamson <andros@netapp.com> Signed-off-by: Andy Adamson <andros@citi.umich.edu> Signed-off-by: Dean Hildebrand <dhildeb@us.ibm.com> Signed-off-by: Fred Isaman <iisaman@citi.umich.edu> Signed-off-by: Fred Isaman <iisaman@netapp.com> Signed-off-by: Benny Halevy <bhalevy@panasas.com> Signed-off-by: Boaz Harrosh <bharrosh@panasas.com> Signed-off-by: Oleg Drokin <green@linuxhacker.ru> Signed-off-by: Tao Guo <guotao@nrchpc.ac.cn> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11NFSv4.1: lseg refcountingFred Isaman
Prepare put_lseg and get_lseg to be called from the pNFS I/O code. Pull common code from pnfs_lseg_locked to call from pnfs_lseg. Inline pnfs_lseg_locked into it's only caller. Signed-off-by: Fred Isaman <iisaman@netapp.com> Signed-off-by: Benny Halevy <bhalevy@panasas.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11NFSv4.1: put_layout_hdr can remove nfsi->layoutAndy Adamson
Prevents an Oops triggered by CB_LAYOUTRECALL and LAYOUTGET race on a pnfs_layout_hdr first pnfs_layout_segment. Signed-off-by: Andy Adamson <andros@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11pnfs: fix pnfs lock inversion of i_lock and cl_lockFred Isaman
The pnfs code was using throughout the lock order i_lock, cl_lock. This conflicts with the nfs delegation code. Rework the pnfs code to avoid taking both locks simultaneously. Currently the code takes the double lock to add/remove the layout to a nfs_client list, while atomically checking that the list of lsegs is empty. To avoid this, we rely on existing serializations. When a layout is initialized with lseg count equal zero, LAYOUTGET's openstateid serialization is in effect, making it safe to assume it stays zero unless we change it. And once a layout's lseg count drops to zero, it is set as DESTROYED and so will stay at zero. Signed-off-by: Fred Isaman <iisaman@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11pnfs: do not need to clear NFS_LAYOUT_BULK_RECALL flagFred Isaman
We do not need to clear the NFS_LAYOUT_BULK_RECALL, as setting it guarantees that NFS_LAYOUT_DESTROYED will be set once any outstanding io is finished. Signed-off-by: Fred Isaman <iisaman@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-03-11pnfs: avoid incorrect use of layout stateidFred Isaman
The code could violate the following from RFC5661, section 12.5.3: "Once a client has no more layouts on a file, the layout stateid is no longer valid and MUST NOT be used." This can occur when a layout already has a lseg, starts another non-everlapping LAYOUTGET, and a CB_LAYOUTRECALL for the existing lseg is processed before we hit pnfs_layout_process(). Solve by setting, each time the client has no more lsegs for a file, a flag which blocks further use of the layout and triggers its removal. This also fixes a second bug which occurs in the same instance as above. If we actually use pnfs_layout_process, we add the new lseg to the layout, but the layout has been removed from the nfs_client list by the intervening CB_LAYOUTRECALL and will not be added back. Thus the newly acquired lseg will not be properly returned in the event of a subsequent CB_LAYOUTRECALL. Signed-off-by: Fred Isaman <iisaman@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-01-25NFS improve pnfs_put_deviceid_cache debug printAndy Adamson
What we really want to know is the ref count. Signed-off-by: Andy Adamson <andros@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-01-06pnfs: layout roc codeFred Isaman
A layout can request return-on-close. How this interacts with the forgetful model of never sending LAYOUTRETURNS is a bit ambiguous. We forget any layouts marked roc, and wait for them to be completely forgotten before continuing with the close. In addition, to compensate for races with any inflight LAYOUTGETs, and the fact that we do not get any layout stateid back from the server, we set the barrier to the worst case scenario of current_seqid + number of outstanding LAYOUTGETS. Signed-off-by: Fred Isaman <iisaman@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-01-06pnfs: add CB_LAYOUTRECALL handlingFred Isaman
This is the heart of the wave 2 submission. Add the code to trigger drain and forget of any afected layouts. In addition, we set a "barrier", below which any LAYOUTGET reply is ignored. This is to compensate for the fact that we do not wait for outstanding LAYOUTGETs to complete as per section 12.5.5.2.1 of RFC 5661. Signed-off-by: Fred Isaman <iisaman@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-01-06pnfs: change lo refcounting to atomic_tFred Isaman
This will be required to allow us to grab reference outside of i_lock. While we are at it, make put_layout_hdr take the same argument as all the related functions. Signed-off-by: Fred Isaman <iisaman@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-01-06pnfs: check that partial LAYOUTGET return is ignoredFred Isaman
Either a bad server reply, or our ignoring of multiple array segments in a reply, can cause a reply to not meet our requirements. Ensure that we ignore such replies. Signed-off-by: Fred Isaman <iisaman@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-01-06pnfs: add layout to client list before sending rpcFred Isaman
Since this list will be used to search for layouts to recall, this is necessary to avoid a race where the recall comes in, sees there is nothing in the client list, and prepares to return NOMATCHING, while the LAYOUTGET gets processed before the recall updates the stateid. Signed-off-by: Fred Isaman <iisaman@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-01-06pnfs: serialize LAYOUTGET(openstateid)Fred Isaman
We shouldn't send a LAYOUTGET(openstateid) unless all outstanding RPCs using the previous stateid are completed. This requires choosing the stateid to encode earlier, so we can abort if one is not available (we want to use the open stateid, but a LAYOUTGET is already out using it), and adding a count of the number of outstanding rpc calls using layout state (which for now consist solely of LAYOUTGETs). Signed-off-by: Fred Isaman <iisaman@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-01-06pnfs: change how lsegs are removed from layout listFred Isaman
This is to prepare the way for sensible io draining. Instead of just removing the lseg from the list, we instead clear the VALID flag (preventing new io from grabbing references to the lseg) and remove the reference holding it in the list. Thus the lseg will be removed once any io in progress completes and any references still held are dropped. Signed-off-by: Fred Isaman <iisaman@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-01-06pnfs: change layout state seqlock to a spinlockFred Isaman
This prepares for future changes, where the layout state needs to change atomically with several other variables. In particular, it will need to know if lo->segs is empty, as we test that instead of manipulating the NFS_LAYOUT_STATEID_SET bit. Moreover, the layoutstateid is not really a read-mostly structure, as it is written almost as often as it is read. The behavior of pnfs_get_layout_stateid is also slightly changed, so that it no longer changes the stateid. Its name is changed to +pnfs_choose_layoutget_stateid. Signed-off-by: Fred Isaman <iisaman@netapp.com> Signed-off-by: Benny Halevy <bhalevy@panasas.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
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