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linux-stable/include/linux/nfs_fs.h
NeilBrown 3db63daabe NFSv3: handle out-of-order write replies. 
NFSv3 includes pre/post wcc attributes which allow the client to
determine if all changes to the file have been made by the client
itself, or if any might have been made by some other client.

If there are gaps in the pre/post ctime sequence it must be assumed that
some other client changed the file in that gap and the local cache must
be suspect.  The next time the file is opened the cache should be
invalidated.

Since Commit 1c341b7775 ("NFS: Add deferred cache invalidation for
close-to-open consistency violations") in linux 5.3 the Linux client has
been triggering this invalidation.  The chunk in nfs_update_inode() in
particularly triggers.

Unfortunately Linux NFS assumes that all replies will be processed in
the order sent, and will arrive in the order processed.  This is not
true in general.  Consequently Linux NFS might ignore the wcc info in a
WRITE reply because the reply is in response to a WRITE that was sent
before some other request for which a reply has already been seen.  This
is detected by Linux using the gencount tests in nfs_inode_attr_cmp().

Also, when the gencount tests pass it is still possible that the request
were processed on the server in a different order, and a gap seen in
the ctime sequence might be filled in by a subsequent reply, so gaps
should not immediately trigger delayed invalidation.

The net result is that writing to a server and then reading the file
back can result in going to the server for the read rather than serving
it from cache - all because a couple of replies arrived out-of-order.
This is a performance regression over kernels before 5.3, though the
change in 5.3 is a correctness improvement.

This has been seen with Linux writing to a Netapp server which
occasionally re-orders requests.  In testing the majority of requests
were in-order, but a few (maybe 2 or three at a time) could be
re-ordered.

This patch addresses the problem by recording any gaps seen in the
pre/post ctime sequence and not triggering invalidation until either
there are too many gaps to fit in the table, or until there are no more
active writes and the remaining gaps cannot be resolved.

We allocate a table of 16 gaps on demand.  If the allocation fails we
revert to current behaviour which is of little cost as we are unlikely
to be able to cache the writes anyway.

In the table we store "start->end" pair when iversion is updated and
"end<-start" pairs pre/post pairs reported by the server.  Usually these
exactly cancel out and so nothing is stored.  When there are
out-of-order replies we do store gaps and these will eventually be
cancelled against later replies when this client is the only writer.

If the final write is out-of-order there may be one gap remaining when
the file is closed.  This will be noticed and if there is precisely on
gap and if the iversion can be advanced to match it, then we do so.

This patch makes no attempt to handle directories correctly.  The same
problem potentially exists in the out-of-order replies to create/unlink
requests can cause future lookup requires to be sent to the server
unnecessarily.  A similar scheme using the same primitives could be used
to notice and handle out-of-order replies.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2023-04-11 16:13:21 -04:00

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/* SPDX-License-Identifier: GPL-2.0 */
/*
* 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 <uapi/linux/nfs_fs.h>
/*
* Enable dprintk() debugging support for nfs client.
*/
#ifdef CONFIG_NFS_DEBUG
# define NFS_DEBUG
#endif
#include <linux/in.h>
#include <linux/mm.h>
#include <linux/pagemap.h>
#include <linux/rbtree.h>
#include <linux/refcount.h>
#include <linux/rwsem.h>
#include <linux/wait.h>
#include <linux/sunrpc/debug.h>
#include <linux/sunrpc/auth.h>
#include <linux/sunrpc/clnt.h>
#ifdef CONFIG_NFS_FSCACHE
#include <linux/netfs.h>
#endif
#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 for number of transports to different server IPs
*/
#define NFS_MAX_TRANSPORTS 16
/*
* Size of the NFS directory verifier
*/
#define NFS_DIR_VERIFIER_SIZE 2
/*
* NFSv3/v4 Access mode cache entry
*/
struct nfs_access_entry {
struct rb_node rb_node;
struct list_head lru;
kuid_t fsuid;
kgid_t fsgid;
struct group_info *group_info;
u64 timestamp;
__u32 mask;
struct rcu_head rcu_head;
};
struct nfs_lock_context {
refcount_t count;
struct list_head list;
struct nfs_open_context *open_context;
fl_owner_t lockowner;
atomic_t io_count;
struct rcu_head rcu_head;
};
struct nfs4_state;
struct nfs_open_context {
struct nfs_lock_context lock_context;
fl_owner_t flock_owner;
struct dentry *dentry;
const struct cred *cred;
struct rpc_cred __rcu *ll_cred; /* low-level cred - use to check for expiry */
struct nfs4_state *state;
fmode_t mode;
unsigned long flags;
#define NFS_CONTEXT_BAD (2)
#define NFS_CONTEXT_UNLOCK (3)
#define NFS_CONTEXT_FILE_OPEN (4)
int error;
struct list_head list;
struct nfs4_threshold *mdsthreshold;
struct rcu_head rcu_head;
};
struct nfs_open_dir_context {
struct list_head list;
atomic_t cache_hits;
atomic_t cache_misses;
unsigned long attr_gencount;
__be32 verf[NFS_DIR_VERIFIER_SIZE];
__u64 dir_cookie;
__u64 last_cookie;
pgoff_t page_index;
unsigned int dtsize;
bool force_clear;
bool eof;
struct rcu_head rcu_head;
};
/*
* NFSv4 delegation
*/
struct nfs_delegation;
struct posix_acl;
struct nfs4_xattr_cache;
/*
* 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;
unsigned long attr_gencount;
struct rb_root access_cache;
struct list_head access_cache_entry_lru;
struct list_head access_cache_inode_lru;
union {
/* Directory */
struct {
/* "Generation counter" for the attribute cache.
* This is bumped whenever we update the metadata
* on the server.
*/
unsigned long cache_change_attribute;
/*
* This is the cookie verifier used for NFSv3 readdir
* operations
*/
__be32 cookieverf[NFS_DIR_VERIFIER_SIZE];
/* Readers: in-flight sillydelete RPC calls */
/* Writers: rmdir */
struct rw_semaphore rmdir_sem;
};
/* Regular file */
struct {
atomic_long_t nrequests;
atomic_long_t redirtied_pages;
struct nfs_mds_commit_info commit_info;
struct mutex commit_mutex;
};
};
/* Open contexts for shared mmap writes */
struct list_head open_files;
/* Keep track of out-of-order replies.
* The ooo array contains start/end pairs of
* numbers from the changeid sequence when
* the inode's iversion has been updated.
* It also contains end/start pair (i.e. reverse order)
* of sections of the changeid sequence that have
* been seen in replies from the server.
* Normally these should match and when both
* A:B and B:A are found in ooo, they are both removed.
* And if a reply with A:B causes an iversion update
* of A:B, then neither are added.
* When a reply has pre_change that doesn't match
* iversion, then the changeid pair and any consequent
* change in iversion ARE added. Later replies
* might fill in the gaps, or possibly a gap is caused
* by a change from another client.
* When a file or directory is opened, if the ooo table
* is not empty, then we assume the gaps were due to
* another client and we invalidate the cached data.
*
* We can only track a limited number of concurrent gaps.
* Currently that limit is 16.
* We allocate the table on demand. If there is insufficient
* memory, then we probably cannot cache the file anyway
* so there is no loss.
*/
struct {
int cnt;
struct {
u64 start, end;
} gap[16];
} *ooo;
#if IS_ENABLED(CONFIG_NFS_V4)
struct nfs4_cached_acl *nfs4_acl;
/* NFSv4 state */
struct list_head open_states;
struct nfs_delegation __rcu *delegation;
struct rw_semaphore rwsem;
/* pNFS layout information */
struct pnfs_layout_hdr *layout;
#endif /* CONFIG_NFS_V4*/
/* how many bytes have been written/read and how many bytes queued up */
__u64 write_io;
__u64 read_io;
#ifdef CONFIG_NFS_V4_2
struct nfs4_xattr_cache *xattr_cache;
#endif
union {
struct inode vfs_inode;
#ifdef CONFIG_NFS_FSCACHE
struct netfs_inode netfs; /* netfs context and VFS inode */
#endif
};
};
struct nfs4_copy_state {
struct list_head copies;
struct list_head src_copies;
nfs4_stateid stateid;
struct completion completion;
uint64_t count;
struct nfs_writeverf verf;
int error;
int flags;
struct nfs4_state *parent_src_state;
struct nfs4_state *parent_dst_state;
};
/*
* Access bit flags
*/
#define NFS_ACCESS_READ 0x0001
#define NFS_ACCESS_LOOKUP 0x0002
#define NFS_ACCESS_MODIFY 0x0004
#define NFS_ACCESS_EXTEND 0x0008
#define NFS_ACCESS_DELETE 0x0010
#define NFS_ACCESS_EXECUTE 0x0020
#define NFS_ACCESS_XAREAD 0x0040
#define NFS_ACCESS_XAWRITE 0x0080
#define NFS_ACCESS_XALIST 0x0100
/*
* Cache validity bit flags
*/
#define NFS_INO_INVALID_DATA BIT(1) /* cached data is invalid */
#define NFS_INO_INVALID_ATIME BIT(2) /* cached atime is invalid */
#define NFS_INO_INVALID_ACCESS BIT(3) /* cached access cred invalid */
#define NFS_INO_INVALID_ACL BIT(4) /* cached acls are invalid */
#define NFS_INO_REVAL_FORCED BIT(6) /* force revalidation ignoring a delegation */
#define NFS_INO_INVALID_LABEL BIT(7) /* cached label is invalid */
#define NFS_INO_INVALID_CHANGE BIT(8) /* cached change is invalid */
#define NFS_INO_INVALID_CTIME BIT(9) /* cached ctime is invalid */
#define NFS_INO_INVALID_MTIME BIT(10) /* cached mtime is invalid */
#define NFS_INO_INVALID_SIZE BIT(11) /* cached size is invalid */
#define NFS_INO_INVALID_OTHER BIT(12) /* other attrs are invalid */
#define NFS_INO_DATA_INVAL_DEFER \
BIT(13) /* Deferred cache invalidation */
#define NFS_INO_INVALID_BLOCKS BIT(14) /* cached blocks are invalid */
#define NFS_INO_INVALID_XATTR BIT(15) /* xattrs are invalid */
#define NFS_INO_INVALID_NLINK BIT(16) /* cached nlinks is invalid */
#define NFS_INO_INVALID_MODE BIT(17) /* cached mode is invalid */
#define NFS_INO_INVALID_ATTR (NFS_INO_INVALID_CHANGE \
| NFS_INO_INVALID_CTIME \
| NFS_INO_INVALID_MTIME \
| NFS_INO_INVALID_SIZE \
| NFS_INO_INVALID_NLINK \
| NFS_INO_INVALID_MODE \
| NFS_INO_INVALID_OTHER) /* inode metadata is invalid */
/*
* Bit offsets in flags field
*/
#define NFS_INO_STALE (1) /* possible stale inode */
#define NFS_INO_ACL_LRU_SET (2) /* Inode is on the LRU list */
#define NFS_INO_INVALIDATING (3) /* inode is being invalidated */
#define NFS_INO_PRESERVE_UNLINKED (4) /* preserve file if removed while open */
#define NFS_INO_LAYOUTCOMMIT (9) /* layoutcommit required */
#define NFS_INO_LAYOUTCOMMITTING (10) /* layoutcommit inflight */
#define NFS_INO_LAYOUTSTATS (11) /* layoutstats inflight */
#define NFS_INO_ODIRECT (12) /* I/O setting is O_DIRECT */
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 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_ACCESS | NFS_INO_INVALID_ACL |
NFS_INO_INVALID_CHANGE | NFS_INO_INVALID_CTIME |
NFS_INO_INVALID_SIZE;
if (S_ISDIR(inode->i_mode))
nfsi->cache_validity |= NFS_INO_INVALID_DATA;
spin_unlock(&inode->i_lock);
}
static inline int nfs_server_capable(const struct inode *inode, int cap)
{
return NFS_SERVER(inode)->caps & cap;
}
/**
* nfs_save_change_attribute - Returns the inode attribute change cookie
* @dir - pointer to parent directory inode
* The "cache change attribute" is updated when we need to revalidate
* our dentry cache after a directory was seen to change on the server.
*/
static inline unsigned long nfs_save_change_attribute(struct inode *dir)
{
return 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_set_inode_stale(struct inode *inode);
extern void nfs_invalidate_atime(struct inode *);
extern struct inode *nfs_fhget(struct super_block *, struct nfs_fh *,
struct nfs_fattr *);
struct inode *nfs_ilookup(struct super_block *sb, struct nfs_fattr *, struct nfs_fh *);
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_post_op_update_inode_force_wcc_locked(struct inode *inode, struct nfs_fattr *fattr);
extern int nfs_getattr(struct mnt_idmap *, const struct path *,
struct kstat *, u32, unsigned int);
extern void nfs_access_add_cache(struct inode *, struct nfs_access_entry *, const struct cred *);
extern void nfs_access_set_mask(struct nfs_access_entry *, u32);
extern int nfs_permission(struct mnt_idmap *, struct inode *, int);
extern int nfs_open(struct inode *, struct file *);
extern int nfs_attribute_cache_expired(struct inode *inode);
extern int nfs_revalidate_inode(struct inode *inode, unsigned long flags);
extern int __nfs_revalidate_inode(struct nfs_server *, struct inode *);
extern int nfs_clear_invalid_mapping(struct address_space *mapping);
extern bool nfs_mapping_need_revalidate_inode(struct inode *inode);
extern int nfs_revalidate_mapping(struct inode *inode, struct address_space *mapping);
extern int nfs_revalidate_mapping_rcu(struct inode *inode);
extern int nfs_setattr(struct mnt_idmap *, struct dentry *, struct iattr *);
extern void nfs_setattr_update_inode(struct inode *inode, struct iattr *attr, struct nfs_fattr *);
extern void nfs_setsecurity(struct inode *inode, struct nfs_fattr *fattr);
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, const struct cred *cred, fmode_t mode);
extern struct nfs_open_context *alloc_nfs_open_context(struct dentry *dentry, fmode_t f_mode, struct file *filp);
extern void nfs_inode_attach_open_context(struct nfs_open_context *ctx);
extern void nfs_file_set_open_context(struct file *filp, struct nfs_open_context *ctx);
extern void nfs_file_clear_open_context(struct file *flip);
extern struct nfs_lock_context *nfs_get_lock_context(struct nfs_open_context *ctx);
extern void nfs_put_lock_context(struct nfs_lock_context *l_ctx);
extern u64 nfs_compat_user_ino64(u64 fileid);
extern void nfs_fattr_init(struct nfs_fattr *fattr);
extern void nfs_fattr_set_barrier(struct nfs_fattr *fattr);
extern unsigned long nfs_inc_attr_generation_counter(void);
extern struct nfs_fattr *nfs_alloc_fattr(void);
extern struct nfs_fattr *nfs_alloc_fattr_with_label(struct nfs_server *server);
static inline void nfs4_label_free(struct nfs4_label *label)
{
#ifdef CONFIG_NFS_V4_SECURITY_LABEL
if (label) {
kfree(label->label);
kfree(label);
}
#endif
}
static inline void nfs_free_fattr(const struct nfs_fattr *fattr)
{
if (fattr)
nfs4_label_free(fattr->label);
kfree(fattr);
}
extern struct nfs_fh *nfs_alloc_fhandle(void);
static inline void nfs_free_fhandle(const struct nfs_fh *fh)
{
kfree(fh);
}
#ifdef NFS_DEBUG
extern u32 _nfs_display_fhandle_hash(const struct nfs_fh *fh);
static inline u32 nfs_display_fhandle_hash(const struct nfs_fh *fh)
{
return _nfs_display_fhandle_hash(fh);
}
extern void _nfs_display_fhandle(const struct nfs_fh *fh, const char *caption);
#define nfs_display_fhandle(fh, caption) \
do { \
if (unlikely(nfs_debug & NFSDBG_FACILITY)) \
_nfs_display_fhandle(fh, caption); \
} while (0)
#else
static inline u32 nfs_display_fhandle_hash(const struct nfs_fh *fh)
{
return 0;
}
static inline void nfs_display_fhandle(const struct nfs_fh *fh,
const char *caption)
{
}
#endif
/*
* linux/fs/nfs/nfsroot.c
*/
extern int nfs_root_data(char **root_device, char **root_data); /*__init*/
/* linux/net/ipv4/ipconfig.c: trims ip addr off front of name, too. */
extern __be32 root_nfs_parse_addr(char *name); /*__init*/
/*
* linux/fs/nfs/file.c
*/
extern const struct file_operations nfs_file_operations;
#if IS_ENABLED(CONFIG_NFS_V4)
extern const struct file_operations nfs4_file_operations;
#endif /* CONFIG_NFS_V4 */
extern const struct address_space_operations nfs_file_aops;
extern const struct address_space_operations nfs_dir_aops;
static inline struct nfs_open_context *nfs_file_open_context(struct file *filp)
{
return filp->private_data;
}
static inline const struct 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/direct.c
*/
int nfs_swap_rw(struct kiocb *iocb, struct iov_iter *iter);
ssize_t nfs_file_direct_read(struct kiocb *iocb,
struct iov_iter *iter, bool swap);
ssize_t nfs_file_direct_write(struct kiocb *iocb,
struct iov_iter *iter, bool swap);
/*
* linux/fs/nfs/dir.c
*/
extern const struct file_operations nfs_dir_operations;
extern const struct dentry_operations nfs_dentry_operations;
extern void nfs_force_lookup_revalidate(struct inode *dir);
extern void nfs_set_verifier(struct dentry * dentry, unsigned long verf);
#if IS_ENABLED(CONFIG_NFS_V4)
extern void nfs_clear_verifier_delegated(struct inode *inode);
#endif /* IS_ENABLED(CONFIG_NFS_V4) */
extern struct dentry *nfs_add_or_obtain(struct dentry *dentry,
struct nfs_fh *fh, struct nfs_fattr *fattr);
extern int nfs_instantiate(struct dentry *dentry, struct nfs_fh *fh,
struct nfs_fattr *fattr);
extern int nfs_may_open(struct inode *inode, const struct cred *cred, int openflags);
extern void nfs_access_zap_cache(struct inode *inode);
extern int nfs_access_get_cached(struct inode *inode, const struct cred *cred,
u32 *mask, bool may_block);
/*
* 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 void nfs_complete_unlink(struct dentry *dentry, struct inode *);
/*
* 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 folio *folio);
extern int nfs_update_folio(struct file *file, struct folio *folio,
unsigned int offset, unsigned int count);
/*
* Try to write back everything synchronously (but check the
* return value!)
*/
extern int nfs_sync_inode(struct inode *inode);
extern int nfs_wb_all(struct inode *inode);
extern int nfs_wb_folio(struct inode *inode, struct folio *folio);
int nfs_wb_folio_cancel(struct inode *inode, struct folio *folio);
extern int nfs_commit_inode(struct inode *, int);
extern struct nfs_commit_data *nfs_commitdata_alloc(void);
extern void nfs_commit_free(struct nfs_commit_data *data);
bool nfs_commit_end(struct nfs_mds_commit_info *cinfo);
static inline bool nfs_have_writebacks(const struct inode *inode)
{
if (S_ISREG(inode->i_mode))
return atomic_long_read(&NFS_I(inode)->nrequests) != 0;
return false;
}
/*
* linux/fs/nfs/read.c
*/
int nfs_read_folio(struct file *, struct folio *);
void nfs_readahead(struct readahead_control *);
/*
* inline functions
*/
static inline loff_t nfs_size_to_loff_t(__u64 size)
{
return min_t(u64, size, OFFSET_MAX);
}
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;
}
static inline void nfs_ooo_clear(struct nfs_inode *nfsi)
{
nfsi->cache_validity &= ~NFS_INO_DATA_INVAL_DEFER;
kfree(nfsi->ooo);
nfsi->ooo = NULL;
}
static inline bool nfs_ooo_test(struct nfs_inode *nfsi)
{
return (nfsi->cache_validity & NFS_INO_DATA_INVAL_DEFER) ||
(nfsi->ooo && nfsi->ooo->cnt > 0);
}
#define NFS_JUKEBOX_RETRY_TIME (5 * HZ)
/* We need to block new opens while a file is being unlinked.
* If it is opened *before* we decide to unlink, we will silly-rename
* instead. If it is opened *after*, then we need to create or will fail.
* If we allow the two to race, we could end up with a file that is open
* but deleted on the server resulting in ESTALE.
* So use ->d_fsdata to record when the unlink is happening
* and block dentry revalidation while it is set.
*/
#define NFS_FSDATA_BLOCKED ((void*)1)
# undef ifdebug
# ifdef NFS_DEBUG
# define ifdebug(fac) if (unlikely(nfs_debug & NFSDBG_##fac))
# define NFS_IFDEBUG(x) x
# else
# define ifdebug(fac) if (0)
# define NFS_IFDEBUG(x)
# endif
#endif
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