mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-28 20:02:17 +00:00
![David Howells](/assets/img/avatar_default.png)
Move netfs_extract_iter_to_sg() to lib/scatterlist.c as it's going to be used by more than just network filesystems (AF_ALG, for example). Signed-off-by: David Howells <dhowells@redhat.com> cc: Jeff Layton <jlayton@kernel.org> cc: Steve French <sfrench@samba.org> cc: Shyam Prasad N <nspmangalore@gmail.com> cc: Rohith Surabattula <rohiths.msft@gmail.com> cc: Jens Axboe <axboe@kernel.dk> cc: Herbert Xu <herbert@gondor.apana.org.au> cc: "David S. Miller" <davem@davemloft.net> cc: Eric Dumazet <edumazet@google.com> cc: Jakub Kicinski <kuba@kernel.org> cc: Paolo Abeni <pabeni@redhat.com> cc: Matthew Wilcox <willy@infradead.org> cc: linux-crypto@vger.kernel.org cc: linux-cachefs@redhat.com cc: linux-cifs@vger.kernel.org cc: linux-fsdevel@vger.kernel.org cc: netdev@vger.kernel.org Signed-off-by: Paolo Abeni <pabeni@redhat.com>
361 lines
12 KiB
C
361 lines
12 KiB
C
/* SPDX-License-Identifier: GPL-2.0-or-later */
|
|
/* Network filesystem support services.
|
|
*
|
|
* Copyright (C) 2021 Red Hat, Inc. All Rights Reserved.
|
|
* Written by David Howells (dhowells@redhat.com)
|
|
*
|
|
* See:
|
|
*
|
|
* Documentation/filesystems/netfs_library.rst
|
|
*
|
|
* for a description of the network filesystem interface declared here.
|
|
*/
|
|
|
|
#ifndef _LINUX_NETFS_H
|
|
#define _LINUX_NETFS_H
|
|
|
|
#include <linux/workqueue.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/pagemap.h>
|
|
#include <linux/uio.h>
|
|
|
|
enum netfs_sreq_ref_trace;
|
|
|
|
/*
|
|
* Overload PG_private_2 to give us PG_fscache - this is used to indicate that
|
|
* a page is currently backed by a local disk cache
|
|
*/
|
|
#define folio_test_fscache(folio) folio_test_private_2(folio)
|
|
#define PageFsCache(page) PagePrivate2((page))
|
|
#define SetPageFsCache(page) SetPagePrivate2((page))
|
|
#define ClearPageFsCache(page) ClearPagePrivate2((page))
|
|
#define TestSetPageFsCache(page) TestSetPagePrivate2((page))
|
|
#define TestClearPageFsCache(page) TestClearPagePrivate2((page))
|
|
|
|
/**
|
|
* folio_start_fscache - Start an fscache write on a folio.
|
|
* @folio: The folio.
|
|
*
|
|
* Call this function before writing a folio to a local cache. Starting a
|
|
* second write before the first one finishes is not allowed.
|
|
*/
|
|
static inline void folio_start_fscache(struct folio *folio)
|
|
{
|
|
VM_BUG_ON_FOLIO(folio_test_private_2(folio), folio);
|
|
folio_get(folio);
|
|
folio_set_private_2(folio);
|
|
}
|
|
|
|
/**
|
|
* folio_end_fscache - End an fscache write on a folio.
|
|
* @folio: The folio.
|
|
*
|
|
* Call this function after the folio has been written to the local cache.
|
|
* This will wake any sleepers waiting on this folio.
|
|
*/
|
|
static inline void folio_end_fscache(struct folio *folio)
|
|
{
|
|
folio_end_private_2(folio);
|
|
}
|
|
|
|
/**
|
|
* folio_wait_fscache - Wait for an fscache write on this folio to end.
|
|
* @folio: The folio.
|
|
*
|
|
* If this folio is currently being written to a local cache, wait for
|
|
* the write to finish. Another write may start after this one finishes,
|
|
* unless the caller holds the folio lock.
|
|
*/
|
|
static inline void folio_wait_fscache(struct folio *folio)
|
|
{
|
|
folio_wait_private_2(folio);
|
|
}
|
|
|
|
/**
|
|
* folio_wait_fscache_killable - Wait for an fscache write on this folio to end.
|
|
* @folio: The folio.
|
|
*
|
|
* If this folio is currently being written to a local cache, wait
|
|
* for the write to finish or for a fatal signal to be received.
|
|
* Another write may start after this one finishes, unless the caller
|
|
* holds the folio lock.
|
|
*
|
|
* Return:
|
|
* - 0 if successful.
|
|
* - -EINTR if a fatal signal was encountered.
|
|
*/
|
|
static inline int folio_wait_fscache_killable(struct folio *folio)
|
|
{
|
|
return folio_wait_private_2_killable(folio);
|
|
}
|
|
|
|
static inline void set_page_fscache(struct page *page)
|
|
{
|
|
folio_start_fscache(page_folio(page));
|
|
}
|
|
|
|
static inline void end_page_fscache(struct page *page)
|
|
{
|
|
folio_end_private_2(page_folio(page));
|
|
}
|
|
|
|
static inline void wait_on_page_fscache(struct page *page)
|
|
{
|
|
folio_wait_private_2(page_folio(page));
|
|
}
|
|
|
|
static inline int wait_on_page_fscache_killable(struct page *page)
|
|
{
|
|
return folio_wait_private_2_killable(page_folio(page));
|
|
}
|
|
|
|
enum netfs_io_source {
|
|
NETFS_FILL_WITH_ZEROES,
|
|
NETFS_DOWNLOAD_FROM_SERVER,
|
|
NETFS_READ_FROM_CACHE,
|
|
NETFS_INVALID_READ,
|
|
} __mode(byte);
|
|
|
|
typedef void (*netfs_io_terminated_t)(void *priv, ssize_t transferred_or_error,
|
|
bool was_async);
|
|
|
|
/*
|
|
* Per-inode context. This wraps the VFS inode.
|
|
*/
|
|
struct netfs_inode {
|
|
struct inode inode; /* The VFS inode */
|
|
const struct netfs_request_ops *ops;
|
|
#if IS_ENABLED(CONFIG_FSCACHE)
|
|
struct fscache_cookie *cache;
|
|
#endif
|
|
loff_t remote_i_size; /* Size of the remote file */
|
|
};
|
|
|
|
/*
|
|
* Resources required to do operations on a cache.
|
|
*/
|
|
struct netfs_cache_resources {
|
|
const struct netfs_cache_ops *ops;
|
|
void *cache_priv;
|
|
void *cache_priv2;
|
|
unsigned int debug_id; /* Cookie debug ID */
|
|
unsigned int inval_counter; /* object->inval_counter at begin_op */
|
|
};
|
|
|
|
/*
|
|
* Descriptor for a single component subrequest.
|
|
*/
|
|
struct netfs_io_subrequest {
|
|
struct netfs_io_request *rreq; /* Supervising I/O request */
|
|
struct list_head rreq_link; /* Link in rreq->subrequests */
|
|
loff_t start; /* Where to start the I/O */
|
|
size_t len; /* Size of the I/O */
|
|
size_t transferred; /* Amount of data transferred */
|
|
refcount_t ref;
|
|
short error; /* 0 or error that occurred */
|
|
unsigned short debug_index; /* Index in list (for debugging output) */
|
|
enum netfs_io_source source; /* Where to read from/write to */
|
|
unsigned long flags;
|
|
#define NETFS_SREQ_COPY_TO_CACHE 0 /* Set if should copy the data to the cache */
|
|
#define NETFS_SREQ_CLEAR_TAIL 1 /* Set if the rest of the read should be cleared */
|
|
#define NETFS_SREQ_SHORT_IO 2 /* Set if the I/O was short */
|
|
#define NETFS_SREQ_SEEK_DATA_READ 3 /* Set if ->read() should SEEK_DATA first */
|
|
#define NETFS_SREQ_NO_PROGRESS 4 /* Set if we didn't manage to read any data */
|
|
#define NETFS_SREQ_ONDEMAND 5 /* Set if it's from on-demand read mode */
|
|
};
|
|
|
|
enum netfs_io_origin {
|
|
NETFS_READAHEAD, /* This read was triggered by readahead */
|
|
NETFS_READPAGE, /* This read is a synchronous read */
|
|
NETFS_READ_FOR_WRITE, /* This read is to prepare a write */
|
|
} __mode(byte);
|
|
|
|
/*
|
|
* Descriptor for an I/O helper request. This is used to make multiple I/O
|
|
* operations to a variety of data stores and then stitch the result together.
|
|
*/
|
|
struct netfs_io_request {
|
|
struct work_struct work;
|
|
struct inode *inode; /* The file being accessed */
|
|
struct address_space *mapping; /* The mapping being accessed */
|
|
struct netfs_cache_resources cache_resources;
|
|
struct list_head subrequests; /* Contributory I/O operations */
|
|
void *netfs_priv; /* Private data for the netfs */
|
|
unsigned int debug_id;
|
|
atomic_t nr_outstanding; /* Number of ops in progress */
|
|
atomic_t nr_copy_ops; /* Number of copy-to-cache ops in progress */
|
|
size_t submitted; /* Amount submitted for I/O so far */
|
|
size_t len; /* Length of the request */
|
|
short error; /* 0 or error that occurred */
|
|
enum netfs_io_origin origin; /* Origin of the request */
|
|
loff_t i_size; /* Size of the file */
|
|
loff_t start; /* Start position */
|
|
pgoff_t no_unlock_folio; /* Don't unlock this folio after read */
|
|
refcount_t ref;
|
|
unsigned long flags;
|
|
#define NETFS_RREQ_INCOMPLETE_IO 0 /* Some ioreqs terminated short or with error */
|
|
#define NETFS_RREQ_COPY_TO_CACHE 1 /* Need to write to the cache */
|
|
#define NETFS_RREQ_NO_UNLOCK_FOLIO 2 /* Don't unlock no_unlock_folio on completion */
|
|
#define NETFS_RREQ_DONT_UNLOCK_FOLIOS 3 /* Don't unlock the folios on completion */
|
|
#define NETFS_RREQ_FAILED 4 /* The request failed */
|
|
#define NETFS_RREQ_IN_PROGRESS 5 /* Unlocked when the request completes */
|
|
const struct netfs_request_ops *netfs_ops;
|
|
};
|
|
|
|
/*
|
|
* Operations the network filesystem can/must provide to the helpers.
|
|
*/
|
|
struct netfs_request_ops {
|
|
int (*init_request)(struct netfs_io_request *rreq, struct file *file);
|
|
void (*free_request)(struct netfs_io_request *rreq);
|
|
int (*begin_cache_operation)(struct netfs_io_request *rreq);
|
|
|
|
void (*expand_readahead)(struct netfs_io_request *rreq);
|
|
bool (*clamp_length)(struct netfs_io_subrequest *subreq);
|
|
void (*issue_read)(struct netfs_io_subrequest *subreq);
|
|
bool (*is_still_valid)(struct netfs_io_request *rreq);
|
|
int (*check_write_begin)(struct file *file, loff_t pos, unsigned len,
|
|
struct folio **foliop, void **_fsdata);
|
|
void (*done)(struct netfs_io_request *rreq);
|
|
};
|
|
|
|
/*
|
|
* How to handle reading from a hole.
|
|
*/
|
|
enum netfs_read_from_hole {
|
|
NETFS_READ_HOLE_IGNORE,
|
|
NETFS_READ_HOLE_CLEAR,
|
|
NETFS_READ_HOLE_FAIL,
|
|
};
|
|
|
|
/*
|
|
* Table of operations for access to a cache. This is obtained by
|
|
* rreq->ops->begin_cache_operation().
|
|
*/
|
|
struct netfs_cache_ops {
|
|
/* End an operation */
|
|
void (*end_operation)(struct netfs_cache_resources *cres);
|
|
|
|
/* Read data from the cache */
|
|
int (*read)(struct netfs_cache_resources *cres,
|
|
loff_t start_pos,
|
|
struct iov_iter *iter,
|
|
enum netfs_read_from_hole read_hole,
|
|
netfs_io_terminated_t term_func,
|
|
void *term_func_priv);
|
|
|
|
/* Write data to the cache */
|
|
int (*write)(struct netfs_cache_resources *cres,
|
|
loff_t start_pos,
|
|
struct iov_iter *iter,
|
|
netfs_io_terminated_t term_func,
|
|
void *term_func_priv);
|
|
|
|
/* Expand readahead request */
|
|
void (*expand_readahead)(struct netfs_cache_resources *cres,
|
|
loff_t *_start, size_t *_len, loff_t i_size);
|
|
|
|
/* Prepare a read operation, shortening it to a cached/uncached
|
|
* boundary as appropriate.
|
|
*/
|
|
enum netfs_io_source (*prepare_read)(struct netfs_io_subrequest *subreq,
|
|
loff_t i_size);
|
|
|
|
/* Prepare a write operation, working out what part of the write we can
|
|
* actually do.
|
|
*/
|
|
int (*prepare_write)(struct netfs_cache_resources *cres,
|
|
loff_t *_start, size_t *_len, loff_t i_size,
|
|
bool no_space_allocated_yet);
|
|
|
|
/* Prepare an on-demand read operation, shortening it to a cached/uncached
|
|
* boundary as appropriate.
|
|
*/
|
|
enum netfs_io_source (*prepare_ondemand_read)(struct netfs_cache_resources *cres,
|
|
loff_t start, size_t *_len,
|
|
loff_t i_size,
|
|
unsigned long *_flags, ino_t ino);
|
|
|
|
/* Query the occupancy of the cache in a region, returning where the
|
|
* next chunk of data starts and how long it is.
|
|
*/
|
|
int (*query_occupancy)(struct netfs_cache_resources *cres,
|
|
loff_t start, size_t len, size_t granularity,
|
|
loff_t *_data_start, size_t *_data_len);
|
|
};
|
|
|
|
struct readahead_control;
|
|
void netfs_readahead(struct readahead_control *);
|
|
int netfs_read_folio(struct file *, struct folio *);
|
|
int netfs_write_begin(struct netfs_inode *, struct file *,
|
|
struct address_space *, loff_t pos, unsigned int len,
|
|
struct folio **, void **fsdata);
|
|
|
|
void netfs_subreq_terminated(struct netfs_io_subrequest *, ssize_t, bool);
|
|
void netfs_get_subrequest(struct netfs_io_subrequest *subreq,
|
|
enum netfs_sreq_ref_trace what);
|
|
void netfs_put_subrequest(struct netfs_io_subrequest *subreq,
|
|
bool was_async, enum netfs_sreq_ref_trace what);
|
|
void netfs_stats_show(struct seq_file *);
|
|
ssize_t netfs_extract_user_iter(struct iov_iter *orig, size_t orig_len,
|
|
struct iov_iter *new,
|
|
iov_iter_extraction_t extraction_flags);
|
|
|
|
/**
|
|
* netfs_inode - Get the netfs inode context from the inode
|
|
* @inode: The inode to query
|
|
*
|
|
* Get the netfs lib inode context from the network filesystem's inode. The
|
|
* context struct is expected to directly follow on from the VFS inode struct.
|
|
*/
|
|
static inline struct netfs_inode *netfs_inode(struct inode *inode)
|
|
{
|
|
return container_of(inode, struct netfs_inode, inode);
|
|
}
|
|
|
|
/**
|
|
* netfs_inode_init - Initialise a netfslib inode context
|
|
* @ctx: The netfs inode to initialise
|
|
* @ops: The netfs's operations list
|
|
*
|
|
* Initialise the netfs library context struct. This is expected to follow on
|
|
* directly from the VFS inode struct.
|
|
*/
|
|
static inline void netfs_inode_init(struct netfs_inode *ctx,
|
|
const struct netfs_request_ops *ops)
|
|
{
|
|
ctx->ops = ops;
|
|
ctx->remote_i_size = i_size_read(&ctx->inode);
|
|
#if IS_ENABLED(CONFIG_FSCACHE)
|
|
ctx->cache = NULL;
|
|
#endif
|
|
}
|
|
|
|
/**
|
|
* netfs_resize_file - Note that a file got resized
|
|
* @ctx: The netfs inode being resized
|
|
* @new_i_size: The new file size
|
|
*
|
|
* Inform the netfs lib that a file got resized so that it can adjust its state.
|
|
*/
|
|
static inline void netfs_resize_file(struct netfs_inode *ctx, loff_t new_i_size)
|
|
{
|
|
ctx->remote_i_size = new_i_size;
|
|
}
|
|
|
|
/**
|
|
* netfs_i_cookie - Get the cache cookie from the inode
|
|
* @ctx: The netfs inode to query
|
|
*
|
|
* Get the caching cookie (if enabled) from the network filesystem's inode.
|
|
*/
|
|
static inline struct fscache_cookie *netfs_i_cookie(struct netfs_inode *ctx)
|
|
{
|
|
#if IS_ENABLED(CONFIG_FSCACHE)
|
|
return ctx->cache;
|
|
#else
|
|
return NULL;
|
|
#endif
|
|
}
|
|
|
|
#endif /* _LINUX_NETFS_H */
|