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| author | Fred Isaman <iisaman@netapp.com> | 2011-01-06 11:36:22 +0000 |
|---|---|---|
| committer | Trond Myklebust <Trond.Myklebust@netapp.com> | 2011-01-06 14:46:31 -0500 |
| commit | fd6002e9b8a93220d5f53b93d9624caf73cdc8a2 (patch) | |
| tree | f45c22c9ec855949b1ec0488162229df4eb3f5ed /fs/nfs/pnfs.h | |
| parent | b7edfaa1983362842351e425adeb8e297b4c11fb (diff) | |
| download | lwn-fd6002e9b8a93220d5f53b93d9624caf73cdc8a2.tar.gz lwn-fd6002e9b8a93220d5f53b93d9624caf73cdc8a2.zip | |
pnfs: change layout state seqlock to a spinlock
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>
Diffstat (limited to 'fs/nfs/pnfs.h')
| -rw-r--r-- | fs/nfs/pnfs.h | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h index c2f108640fc4..10937203d236 100644 --- a/fs/nfs/pnfs.h +++ b/fs/nfs/pnfs.h @@ -44,7 +44,6 @@ struct pnfs_layout_segment { enum { NFS_LAYOUT_RO_FAILED = 0, /* get ro layout failed stop trying */ NFS_LAYOUT_RW_FAILED, /* get rw layout failed stop trying */ - NFS_LAYOUT_STATEID_SET, /* have a valid layout stateid */ }; /* Per-layout driver specific registration structure */ @@ -63,7 +62,6 @@ struct pnfs_layout_hdr { unsigned long plh_refcount; struct list_head plh_layouts; /* other client layouts */ struct list_head plh_segs; /* layout segments list */ - seqlock_t plh_seqlock; /* Protects the stateid */ nfs4_stateid plh_stateid; unsigned long plh_flags; struct inode *plh_inode; @@ -143,8 +141,9 @@ int pnfs_layout_process(struct nfs4_layoutget *lgp); void pnfs_destroy_layout(struct nfs_inode *); void pnfs_destroy_all_layouts(struct nfs_client *); void put_layout_hdr(struct inode *inode); -void pnfs_get_layout_stateid(nfs4_stateid *dst, struct pnfs_layout_hdr *lo, - struct nfs4_state *open_state); +int pnfs_choose_layoutget_stateid(nfs4_stateid *dst, + struct pnfs_layout_hdr *lo, + struct nfs4_state *open_state); static inline int lo_fail_bit(u32 iomode) |