Commit a06fac15 authored by Jeffle Xu's avatar Jeffle Xu Committed by Gao Xiang
Browse files

cachefiles: extract write routine 



Extract the generic routine of writing data to cache files, and make it
generally available.

This will be used by the following patch implementing on-demand read
mode. Since it's called inside CacheFiles module, make the interface
generic and unrelated to netfs_cache_resources.

It is worth noting that, ki->inval_counter is not initialized after
this cleanup. It shall not make any visible difference, since
inval_counter is no longer used in the write completion routine, i.e.
cachefiles_write_complete().

Signed-off-by: default avatarJeffle Xu <jefflexu@linux.alibaba.com>
Acked-by: default avatarDavid Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20220425122143.56815-2-jefflexu@linux.alibaba.com


Signed-off-by: default avatarGao Xiang <hsiangkao@linux.alibaba.com>
parent 6c459b78

fs/cachefiles/internal.h

+10 −0
Original line number Diff line number Diff line
@@ -201,6 +201,16 @@ extern void cachefiles_put_object(struct cachefiles_object *object, 
 */

extern bool cachefiles_begin_operation(struct netfs_cache_resources *cres,

				       enum fscache_want_state want_state);

extern int __cachefiles_prepare_write(struct cachefiles_object *object,

				      struct file *file,

				      loff_t *_start, size_t *_len,

				      bool no_space_allocated_yet);

extern int __cachefiles_write(struct cachefiles_object *object,

			      struct file *file,

			      loff_t start_pos,

			      struct iov_iter *iter,

			      netfs_io_terminated_t term_func,

			      void *term_func_priv);



/*

 * key.c

fs/cachefiles/io.c

+35 −26
Original line number Diff line number Diff line
@@ -277,36 +277,33 @@ static void cachefiles_write_complete(struct kiocb *iocb, long ret) 
/*

 * Initiate a write to the cache.

 */

static int cachefiles_write(struct netfs_cache_resources *cres,

int __cachefiles_write(struct cachefiles_object *object,

		       struct file *file,

		       loff_t start_pos,

		       struct iov_iter *iter,

		       netfs_io_terminated_t term_func,

		       void *term_func_priv)

{

	struct cachefiles_object *object;

	struct cachefiles_cache *cache;

	struct cachefiles_kiocb *ki;

	struct inode *inode;

	struct file *file;

	unsigned int old_nofs;

	ssize_t ret = -ENOBUFS;

	ssize_t ret;

	size_t len = iov_iter_count(iter);



	if (!fscache_wait_for_operation(cres, FSCACHE_WANT_WRITE))

		goto presubmission_error;

	fscache_count_write();

	object = cachefiles_cres_object(cres);

	cache = object->volume->cache;

	file = cachefiles_cres_file(cres);



	_enter("%pD,%li,%llx,%zx/%llx",

	       file, file_inode(file)->i_ino, start_pos, len,

	       i_size_read(file_inode(file)));



	ret = -ENOMEM;

	ki = kzalloc(sizeof(struct cachefiles_kiocb), GFP_KERNEL);

	if (!ki)

		goto presubmission_error;

	if (!ki) {

		if (term_func)

			term_func(term_func_priv, -ENOMEM, false);

		return -ENOMEM;

	}



	refcount_set(&ki->ki_refcnt, 2);

	ki->iocb.ki_filp	= file;
@@ -314,7 +311,6 @@ static int cachefiles_write(struct netfs_cache_resources *cres, 
	ki->iocb.ki_flags	= IOCB_DIRECT | IOCB_WRITE;

	ki->iocb.ki_ioprio	= get_current_ioprio();

	ki->object		= object;

	ki->inval_counter	= cres->inval_counter;

	ki->start		= start_pos;

	ki->len			= len;

	ki->term_func		= term_func;
@@ -369,11 +365,24 @@ static int cachefiles_write(struct netfs_cache_resources *cres, 
	cachefiles_put_kiocb(ki);

	_leave(" = %zd", ret);

	return ret;

}



presubmission_error:

static int cachefiles_write(struct netfs_cache_resources *cres,

			    loff_t start_pos,

			    struct iov_iter *iter,

			    netfs_io_terminated_t term_func,

			    void *term_func_priv)

{

	if (!fscache_wait_for_operation(cres, FSCACHE_WANT_WRITE)) {

		if (term_func)

		term_func(term_func_priv, ret, false);

	return ret;

			term_func(term_func_priv, -ENOBUFS, false);

		return -ENOBUFS;

	}



	return __cachefiles_write(cachefiles_cres_object(cres),

				  cachefiles_cres_file(cres),

				  start_pos, iter,

				  term_func, term_func_priv);

}



/*
@@ -484,13 +493,12 @@ static enum netfs_io_source cachefiles_prepare_read(struct netfs_io_subrequest * 
/*

 * Prepare for a write to occur.

 */

static int __cachefiles_prepare_write(struct netfs_cache_resources *cres,

				      loff_t *_start, size_t *_len, loff_t i_size,

int __cachefiles_prepare_write(struct cachefiles_object *object,

			       struct file *file,

			       loff_t *_start, size_t *_len,

			       bool no_space_allocated_yet)

{

	struct cachefiles_object *object = cachefiles_cres_object(cres);

	struct cachefiles_cache *cache = object->volume->cache;

	struct file *file = cachefiles_cres_file(cres);

	loff_t start = *_start, pos;

	size_t len = *_len, down;

	int ret;
@@ -577,7 +585,8 @@ static int cachefiles_prepare_write(struct netfs_cache_resources *cres, 
	}



	cachefiles_begin_secure(cache, &saved_cred);

	ret = __cachefiles_prepare_write(cres, _start, _len, i_size,

	ret = __cachefiles_prepare_write(object, cachefiles_cres_file(cres),

					 _start, _len,

					 no_space_allocated_yet);

	cachefiles_end_secure(cache, saved_cred);

	return ret;