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linux-next/include/linux/nfs_fs.h
Peter Staubach 64672d55d9 optimize attribute timeouts for "noac" and "actimeo=0"
Hi.

I've been looking at a bugzilla which describes a problem where
a customer was advised to use either the "noac" or "actimeo=0"
mount options to solve a consistency problem that they were
seeing in the file attributes.  It turned out that this solution
did not work reliably for them because sometimes, the local
attribute cache was believed to be valid and not timed out.
(With an attribute cache timeout of 0, the cache should always
appear to be timed out.)

In looking at this situation, it appears to me that the problem
is that the attribute cache timeout code has an off-by-one
error in it.  It is assuming that the cache is valid in the
region, [read_cache_jiffies, read_cache_jiffies + attrtimeo].  The
cache should be considered valid only in the region,
[read_cache_jiffies, read_cache_jiffies + attrtimeo).  With this
change, the options, "noac" and "actimeo=0", work as originally
expected.

This problem was previously addressed by special casing the
attrtimeo == 0 case.  However, since the problem is only an off-
by-one error, the cleaner solution is address the off-by-one
error and thus, not require the special case.

    Thanx...

        ps

Signed-off-by: Peter Staubach <staubach@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-12-23 15:21:56 -05:00

607 lines
16 KiB
C

/*
* linux/include/linux/nfs_fs.h
*
* Copyright (C) 1992 Rick Sladkey
*
* OS-specific nfs filesystem definitions and declarations
*/
#ifndef _LINUX_NFS_FS_H
#define _LINUX_NFS_FS_H
#include <linux/magic.h>
/* Default timeout values */
#define NFS_DEF_UDP_TIMEO (11)
#define NFS_DEF_UDP_RETRANS (3)
#define NFS_DEF_TCP_TIMEO (600)
#define NFS_DEF_TCP_RETRANS (2)
#define NFS_MAX_UDP_TIMEOUT (60*HZ)
#define NFS_MAX_TCP_TIMEOUT (600*HZ)
#define NFS_DEF_ACREGMIN (3)
#define NFS_DEF_ACREGMAX (60)
#define NFS_DEF_ACDIRMIN (30)
#define NFS_DEF_ACDIRMAX (60)
/*
* When flushing a cluster of dirty pages, there can be different
* strategies:
*/
#define FLUSH_SYNC 1 /* file being synced, or contention */
#define FLUSH_STABLE 4 /* commit to stable storage */
#define FLUSH_LOWPRI 8 /* low priority background flush */
#define FLUSH_HIGHPRI 16 /* high priority memory reclaim flush */
#define FLUSH_NOCOMMIT 32 /* Don't send the NFSv3/v4 COMMIT */
#define FLUSH_INVALIDATE 64 /* Invalidate the page cache */
#define FLUSH_NOWRITEPAGE 128 /* Don't call writepage() */
#ifdef __KERNEL__
#include <linux/in.h>
#include <linux/kref.h>
#include <linux/mm.h>
#include <linux/pagemap.h>
#include <linux/rbtree.h>
#include <linux/rwsem.h>
#include <linux/wait.h>
#include <linux/sunrpc/debug.h>
#include <linux/sunrpc/auth.h>
#include <linux/sunrpc/clnt.h>
#include <linux/nfs.h>
#include <linux/nfs2.h>
#include <linux/nfs3.h>
#include <linux/nfs4.h>
#include <linux/nfs_xdr.h>
#include <linux/nfs_fs_sb.h>
#include <linux/mempool.h>
/*
* These are the default flags for swap requests
*/
#define NFS_RPC_SWAPFLAGS (RPC_TASK_SWAPPER|RPC_TASK_ROOTCREDS)
/*
* NFSv3/v4 Access mode cache entry
*/
struct nfs_access_entry {
struct rb_node rb_node;
struct list_head lru;
unsigned long jiffies;
struct rpc_cred * cred;
int mask;
};
struct nfs4_state;
struct nfs_open_context {
atomic_t count;
struct path path;
struct rpc_cred *cred;
struct nfs4_state *state;
fl_owner_t lockowner;
fmode_t mode;
unsigned long flags;
#define NFS_CONTEXT_ERROR_WRITE (0)
int error;
struct list_head list;
__u64 dir_cookie;
};
/*
* NFSv4 delegation
*/
struct nfs_delegation;
struct posix_acl;
/*
* nfs fs inode data in memory
*/
struct nfs_inode {
/*
* The 64bit 'inode number'
*/
__u64 fileid;
/*
* NFS file handle
*/
struct nfs_fh fh;
/*
* Various flags
*/
unsigned long flags; /* atomic bit ops */
unsigned long cache_validity; /* bit mask */
/*
* read_cache_jiffies is when we started read-caching this inode.
* attrtimeo is for how long the cached information is assumed
* to be valid. A successful attribute revalidation doubles
* attrtimeo (up to acregmax/acdirmax), a failure resets it to
* acregmin/acdirmin.
*
* We need to revalidate the cached attrs for this inode if
*
* jiffies - read_cache_jiffies >= attrtimeo
*
* Please note the comparison is greater than or equal
* so that zero timeout values can be specified.
*/
unsigned long read_cache_jiffies;
unsigned long attrtimeo;
unsigned long attrtimeo_timestamp;
__u64 change_attr; /* v4 only */
unsigned long attr_gencount;
/* "Generation counter" for the attribute cache. This is
* bumped whenever we update the metadata on the
* server.
*/
unsigned long cache_change_attribute;
struct rb_root access_cache;
struct list_head access_cache_entry_lru;
struct list_head access_cache_inode_lru;
#ifdef CONFIG_NFS_V3_ACL
struct posix_acl *acl_access;
struct posix_acl *acl_default;
#endif
/*
* This is the cookie verifier used for NFSv3 readdir
* operations
*/
__be32 cookieverf[2];
/*
* This is the list of dirty unwritten pages.
*/
struct radix_tree_root nfs_page_tree;
unsigned long ncommit,
npages;
/* Open contexts for shared mmap writes */
struct list_head open_files;
/* Number of in-flight sillydelete RPC calls */
atomic_t silly_count;
/* List of deferred sillydelete requests */
struct hlist_head silly_list;
wait_queue_head_t waitqueue;
#ifdef CONFIG_NFS_V4
struct nfs4_cached_acl *nfs4_acl;
/* NFSv4 state */
struct list_head open_states;
struct nfs_delegation *delegation;
fmode_t delegation_state;
struct rw_semaphore rwsem;
#endif /* CONFIG_NFS_V4*/
struct inode vfs_inode;
};
/*
* Cache validity bit flags
*/
#define NFS_INO_INVALID_ATTR 0x0001 /* cached attrs are invalid */
#define NFS_INO_INVALID_DATA 0x0002 /* cached data is invalid */
#define NFS_INO_INVALID_ATIME 0x0004 /* cached atime is invalid */
#define NFS_INO_INVALID_ACCESS 0x0008 /* cached access cred invalid */
#define NFS_INO_INVALID_ACL 0x0010 /* cached acls are invalid */
#define NFS_INO_REVAL_PAGECACHE 0x0020 /* must revalidate pagecache */
#define NFS_INO_REVAL_FORCED 0x0040 /* force revalidation ignoring a delegation */
/*
* Bit offsets in flags field
*/
#define NFS_INO_ADVISE_RDPLUS (0) /* advise readdirplus */
#define NFS_INO_STALE (1) /* possible stale inode */
#define NFS_INO_ACL_LRU_SET (2) /* Inode is on the LRU list */
#define NFS_INO_MOUNTPOINT (3) /* inode is remote mountpoint */
static inline struct nfs_inode *NFS_I(const struct inode *inode)
{
return container_of(inode, struct nfs_inode, vfs_inode);
}
static inline struct nfs_server *NFS_SB(const struct super_block *s)
{
return (struct nfs_server *)(s->s_fs_info);
}
static inline struct nfs_fh *NFS_FH(const struct inode *inode)
{
return &NFS_I(inode)->fh;
}
static inline struct nfs_server *NFS_SERVER(const struct inode *inode)
{
return NFS_SB(inode->i_sb);
}
static inline struct rpc_clnt *NFS_CLIENT(const struct inode *inode)
{
return NFS_SERVER(inode)->client;
}
static inline const struct nfs_rpc_ops *NFS_PROTO(const struct inode *inode)
{
return NFS_SERVER(inode)->nfs_client->rpc_ops;
}
static inline __be32 *NFS_COOKIEVERF(const struct inode *inode)
{
return NFS_I(inode)->cookieverf;
}
static inline unsigned NFS_MINATTRTIMEO(const struct inode *inode)
{
struct nfs_server *nfss = NFS_SERVER(inode);
return S_ISDIR(inode->i_mode) ? nfss->acdirmin : nfss->acregmin;
}
static inline unsigned NFS_MAXATTRTIMEO(const struct inode *inode)
{
struct nfs_server *nfss = NFS_SERVER(inode);
return S_ISDIR(inode->i_mode) ? nfss->acdirmax : nfss->acregmax;
}
static inline int NFS_STALE(const struct inode *inode)
{
return test_bit(NFS_INO_STALE, &NFS_I(inode)->flags);
}
static inline __u64 NFS_FILEID(const struct inode *inode)
{
return NFS_I(inode)->fileid;
}
static inline void set_nfs_fileid(struct inode *inode, __u64 fileid)
{
NFS_I(inode)->fileid = fileid;
}
static inline void nfs_mark_for_revalidate(struct inode *inode)
{
struct nfs_inode *nfsi = NFS_I(inode);
spin_lock(&inode->i_lock);
nfsi->cache_validity |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ACCESS;
if (S_ISDIR(inode->i_mode))
nfsi->cache_validity |= NFS_INO_REVAL_PAGECACHE|NFS_INO_INVALID_DATA;
spin_unlock(&inode->i_lock);
}
static inline int nfs_server_capable(struct inode *inode, int cap)
{
return NFS_SERVER(inode)->caps & cap;
}
static inline int NFS_USE_READDIRPLUS(struct inode *inode)
{
return test_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(inode)->flags);
}
static inline void nfs_set_verifier(struct dentry * dentry, unsigned long verf)
{
dentry->d_time = verf;
}
/**
* nfs_save_change_attribute - Returns the inode attribute change cookie
* @dir - pointer to parent directory inode
* The "change attribute" is updated every time we finish an operation
* that will result in a metadata change on the server.
*/
static inline unsigned long nfs_save_change_attribute(struct inode *dir)
{
return NFS_I(dir)->cache_change_attribute;
}
/**
* nfs_verify_change_attribute - Detects NFS remote directory changes
* @dir - pointer to parent directory inode
* @chattr - previously saved change attribute
* Return "false" if the verifiers doesn't match the change attribute.
* This would usually indicate that the directory contents have changed on
* the server, and that any dentries need revalidating.
*/
static inline int nfs_verify_change_attribute(struct inode *dir, unsigned long chattr)
{
return chattr == NFS_I(dir)->cache_change_attribute;
}
/*
* linux/fs/nfs/inode.c
*/
extern int nfs_sync_mapping(struct address_space *mapping);
extern void nfs_zap_mapping(struct inode *inode, struct address_space *mapping);
extern void nfs_zap_caches(struct inode *);
extern void nfs_invalidate_atime(struct inode *);
extern struct inode *nfs_fhget(struct super_block *, struct nfs_fh *,
struct nfs_fattr *);
extern int nfs_refresh_inode(struct inode *, struct nfs_fattr *);
extern int nfs_post_op_update_inode(struct inode *inode, struct nfs_fattr *fattr);
extern int nfs_post_op_update_inode_force_wcc(struct inode *inode, struct nfs_fattr *fattr);
extern int nfs_getattr(struct vfsmount *, struct dentry *, struct kstat *);
extern int nfs_permission(struct inode *, int);
extern int nfs_open(struct inode *, struct file *);
extern int nfs_release(struct inode *, struct file *);
extern int nfs_attribute_timeout(struct inode *inode);
extern int nfs_revalidate_inode(struct nfs_server *server, struct inode *inode);
extern int __nfs_revalidate_inode(struct nfs_server *, struct inode *);
extern int nfs_revalidate_mapping(struct inode *inode, struct address_space *mapping);
extern int nfs_revalidate_mapping_nolock(struct inode *inode, struct address_space *mapping);
extern int nfs_setattr(struct dentry *, struct iattr *);
extern void nfs_setattr_update_inode(struct inode *inode, struct iattr *attr);
extern struct nfs_open_context *get_nfs_open_context(struct nfs_open_context *ctx);
extern void put_nfs_open_context(struct nfs_open_context *ctx);
extern struct nfs_open_context *nfs_find_open_context(struct inode *inode, struct rpc_cred *cred, fmode_t mode);
extern u64 nfs_compat_user_ino64(u64 fileid);
extern void nfs_fattr_init(struct nfs_fattr *fattr);
/* linux/net/ipv4/ipconfig.c: trims ip addr off front of name, too. */
extern __be32 root_nfs_parse_addr(char *name); /*__init*/
extern unsigned long nfs_inc_attr_generation_counter(void);
/*
* linux/fs/nfs/file.c
*/
extern const struct inode_operations nfs_file_inode_operations;
#ifdef CONFIG_NFS_V3
extern const struct inode_operations nfs3_file_inode_operations;
#endif /* CONFIG_NFS_V3 */
extern const struct file_operations nfs_file_operations;
extern const struct address_space_operations nfs_file_aops;
static inline struct nfs_open_context *nfs_file_open_context(struct file *filp)
{
return filp->private_data;
}
static inline struct rpc_cred *nfs_file_cred(struct file *file)
{
if (file != NULL) {
struct nfs_open_context *ctx =
nfs_file_open_context(file);
if (ctx)
return ctx->cred;
}
return NULL;
}
/*
* linux/fs/nfs/xattr.c
*/
#ifdef CONFIG_NFS_V3_ACL
extern ssize_t nfs3_listxattr(struct dentry *, char *, size_t);
extern ssize_t nfs3_getxattr(struct dentry *, const char *, void *, size_t);
extern int nfs3_setxattr(struct dentry *, const char *,
const void *, size_t, int);
extern int nfs3_removexattr (struct dentry *, const char *name);
#else
# define nfs3_listxattr NULL
# define nfs3_getxattr NULL
# define nfs3_setxattr NULL
# define nfs3_removexattr NULL
#endif
/*
* linux/fs/nfs/direct.c
*/
extern ssize_t nfs_direct_IO(int, struct kiocb *, const struct iovec *, loff_t,
unsigned long);
extern ssize_t nfs_file_direct_read(struct kiocb *iocb,
const struct iovec *iov, unsigned long nr_segs,
loff_t pos);
extern ssize_t nfs_file_direct_write(struct kiocb *iocb,
const struct iovec *iov, unsigned long nr_segs,
loff_t pos);
/*
* linux/fs/nfs/dir.c
*/
extern const struct inode_operations nfs_dir_inode_operations;
#ifdef CONFIG_NFS_V3
extern const struct inode_operations nfs3_dir_inode_operations;
#endif /* CONFIG_NFS_V3 */
extern const struct file_operations nfs_dir_operations;
extern struct dentry_operations nfs_dentry_operations;
extern void nfs_force_lookup_revalidate(struct inode *dir);
extern int nfs_instantiate(struct dentry *dentry, struct nfs_fh *fh, struct nfs_fattr *fattr);
extern int nfs_may_open(struct inode *inode, struct rpc_cred *cred, int openflags);
extern void nfs_access_zap_cache(struct inode *inode);
/*
* linux/fs/nfs/symlink.c
*/
extern const struct inode_operations nfs_symlink_inode_operations;
/*
* linux/fs/nfs/sysctl.c
*/
#ifdef CONFIG_SYSCTL
extern int nfs_register_sysctl(void);
extern void nfs_unregister_sysctl(void);
#else
#define nfs_register_sysctl() 0
#define nfs_unregister_sysctl() do { } while(0)
#endif
/*
* linux/fs/nfs/namespace.c
*/
extern const struct inode_operations nfs_mountpoint_inode_operations;
extern const struct inode_operations nfs_referral_inode_operations;
extern int nfs_mountpoint_expiry_timeout;
extern void nfs_release_automount_timer(void);
/*
* linux/fs/nfs/unlink.c
*/
extern int nfs_async_unlink(struct inode *dir, struct dentry *dentry);
extern void nfs_complete_unlink(struct dentry *dentry, struct inode *);
extern void nfs_block_sillyrename(struct dentry *dentry);
extern void nfs_unblock_sillyrename(struct dentry *dentry);
/*
* linux/fs/nfs/write.c
*/
extern int nfs_congestion_kb;
extern int nfs_writepage(struct page *page, struct writeback_control *wbc);
extern int nfs_writepages(struct address_space *, struct writeback_control *);
extern int nfs_flush_incompatible(struct file *file, struct page *page);
extern int nfs_updatepage(struct file *, struct page *, unsigned int, unsigned int);
extern int nfs_writeback_done(struct rpc_task *, struct nfs_write_data *);
extern void nfs_writedata_release(void *);
/*
* Try to write back everything synchronously (but check the
* return value!)
*/
extern long nfs_sync_mapping_wait(struct address_space *, struct writeback_control *, int);
extern int nfs_wb_all(struct inode *inode);
extern int nfs_wb_nocommit(struct inode *inode);
extern int nfs_wb_page(struct inode *inode, struct page* page);
extern int nfs_wb_page_cancel(struct inode *inode, struct page* page);
#if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
extern int nfs_commit_inode(struct inode *, int);
extern struct nfs_write_data *nfs_commitdata_alloc(void);
extern void nfs_commit_free(struct nfs_write_data *wdata);
extern void nfs_commitdata_release(void *wdata);
#else
static inline int
nfs_commit_inode(struct inode *inode, int how)
{
return 0;
}
#endif
static inline int
nfs_have_writebacks(struct inode *inode)
{
return NFS_I(inode)->npages != 0;
}
/*
* Allocate nfs_write_data structures
*/
extern struct nfs_write_data *nfs_writedata_alloc(unsigned int npages);
/*
* linux/fs/nfs/read.c
*/
extern int nfs_readpage(struct file *, struct page *);
extern int nfs_readpages(struct file *, struct address_space *,
struct list_head *, unsigned);
extern int nfs_readpage_result(struct rpc_task *, struct nfs_read_data *);
extern void nfs_readdata_release(void *data);
/*
* Allocate nfs_read_data structures
*/
extern struct nfs_read_data *nfs_readdata_alloc(unsigned int npages);
/*
* linux/fs/nfs3proc.c
*/
#ifdef CONFIG_NFS_V3_ACL
extern struct posix_acl *nfs3_proc_getacl(struct inode *inode, int type);
extern int nfs3_proc_setacl(struct inode *inode, int type,
struct posix_acl *acl);
extern int nfs3_proc_set_default_acl(struct inode *dir, struct inode *inode,
mode_t mode);
extern void nfs3_forget_cached_acls(struct inode *inode);
#else
static inline int nfs3_proc_set_default_acl(struct inode *dir,
struct inode *inode,
mode_t mode)
{
return 0;
}
static inline void nfs3_forget_cached_acls(struct inode *inode)
{
}
#endif /* CONFIG_NFS_V3_ACL */
/*
* inline functions
*/
static inline loff_t nfs_size_to_loff_t(__u64 size)
{
if (size > (__u64) OFFSET_MAX - 1)
return OFFSET_MAX - 1;
return (loff_t) size;
}
static inline ino_t
nfs_fileid_to_ino_t(u64 fileid)
{
ino_t ino = (ino_t) fileid;
if (sizeof(ino_t) < sizeof(u64))
ino ^= fileid >> (sizeof(u64)-sizeof(ino_t)) * 8;
return ino;
}
/* NFS root */
extern void * nfs_root_data(void);
#define nfs_wait_event(clnt, wq, condition) \
({ \
int __retval = wait_event_killable(wq, condition); \
__retval; \
})
#define NFS_JUKEBOX_RETRY_TIME (5 * HZ)
#endif /* __KERNEL__ */
/*
* NFS debug flags
*/
#define NFSDBG_VFS 0x0001
#define NFSDBG_DIRCACHE 0x0002
#define NFSDBG_LOOKUPCACHE 0x0004
#define NFSDBG_PAGECACHE 0x0008
#define NFSDBG_PROC 0x0010
#define NFSDBG_XDR 0x0020
#define NFSDBG_FILE 0x0040
#define NFSDBG_ROOT 0x0080
#define NFSDBG_CALLBACK 0x0100
#define NFSDBG_CLIENT 0x0200
#define NFSDBG_MOUNT 0x0400
#define NFSDBG_ALL 0xFFFF
#ifdef __KERNEL__
/*
* Enable debugging support for nfs client.
* Requires RPC_DEBUG.
*/
#ifdef RPC_DEBUG
# define NFS_DEBUG
#endif
# undef ifdebug
# ifdef NFS_DEBUG
# define ifdebug(fac) if (unlikely(nfs_debug & NFSDBG_##fac))
# else
# define ifdebug(fac) if (0)
# endif
#endif /* __KERNEL */
#endif