fs/nfs/fscache.h

Source file repositories/reference/linux-study-clean/fs/nfs/fscache.h

File Facts

System
Linux kernel
Corpus path
fs/nfs/fscache.h
Extension
.h
Size
6700 bytes
Lines
203
Domain
Core OS
Bucket
VFS And Filesystem Core
Inferred role
Core OS: implementation source
Status
source implementation candidate

Why This File Exists

Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.

Dependency Surface

Detected Declarations

Annotated Snippet

struct nfs_fscache_inode_auxdata {
	s64	mtime_sec;
	s64	mtime_nsec;
	s64	ctime_sec;
	s64	ctime_nsec;
	u64	change_attr;
};

struct nfs_netfs_io_data {
	/*
	 * NFS may split a netfs_io_subrequest into multiple RPCs, each
	 * with their own read completion.  In netfs, we can only call
	 * netfs_subreq_terminated() once for each subrequest.  Use the
	 * refcount here to double as a marker of the last RPC completion,
	 * and only call netfs via netfs_subreq_terminated() once.
	 */
	refcount_t			refcount;
	struct netfs_io_subrequest	*sreq;

	/*
	 * Final disposition of the netfs_io_subrequest, sent in
	 * netfs_subreq_terminated()
	 */
	atomic64_t	transferred;
	int		error;
};

static inline void nfs_netfs_get(struct nfs_netfs_io_data *netfs)
{
	refcount_inc(&netfs->refcount);
}

static inline void nfs_netfs_put(struct nfs_netfs_io_data *netfs)
{
	/* Only the last RPC completion should call netfs_subreq_terminated() */
	if (!refcount_dec_and_test(&netfs->refcount))
		return;

	/*
	 * The NFS pageio interface may read a complete page, even when netfs
	 * only asked for a partial page.  Specifically, this may be seen when
	 * one thread is truncating a file while another one is reading the last
	 * page of the file.
	 * Correct the final length here to be no larger than the netfs subrequest
	 * length, and thus avoid netfs's "Subreq overread" warning message.
	 */
	netfs->sreq->transferred = min_t(s64, netfs->sreq->len,
					 atomic64_read(&netfs->transferred));
	netfs->sreq->error = netfs->error;
	netfs_read_subreq_terminated(netfs->sreq);
	kfree(netfs);
}
static inline void nfs_netfs_inode_init(struct nfs_inode *nfsi)
{
	netfs_inode_init(&nfsi->netfs, &nfs_netfs_ops, false);
}
extern void nfs_netfs_initiate_read(struct nfs_pgio_header *hdr);
extern void nfs_netfs_read_completion(struct nfs_pgio_header *hdr);
extern int nfs_netfs_folio_unlock(struct folio *folio);

/*
 * fscache.c
 */
extern int nfs_fscache_get_super_cookie(struct super_block *, const char *, int);
extern void nfs_fscache_release_super_cookie(struct super_block *);

extern void nfs_fscache_init_inode(struct inode *);
extern void nfs_fscache_clear_inode(struct inode *);
extern void nfs_fscache_open_file(struct inode *, struct file *);
extern void nfs_fscache_release_file(struct inode *, struct file *);
extern int nfs_netfs_readahead(struct readahead_control *ractl);
extern int nfs_netfs_read_folio(struct file *file, struct folio *folio);

static inline bool nfs_fscache_release_folio(struct folio *folio, gfp_t gfp)
{
	if (folio_test_private_2(folio)) { /* [DEPRECATED] */
		if (current_is_kswapd() || !(gfp & __GFP_FS))
			return false;
		folio_wait_private_2(folio);
	}
	fscache_note_page_release(netfs_i_cookie(netfs_inode(folio->mapping->host)));
	return true;
}

static inline void nfs_fscache_update_auxdata(struct nfs_fscache_inode_auxdata *auxdata,
					      struct inode *inode)
{
	memset(auxdata, 0, sizeof(*auxdata));
	auxdata->mtime_sec  = inode_get_mtime(inode).tv_sec;
	auxdata->mtime_nsec = inode_get_mtime(inode).tv_nsec;

Annotation

Implementation Notes