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Commit 56698236 authored by Suresh Jayaraman's avatar Suresh Jayaraman Committed by Steve French
Browse files

cifs: read pages from FS-Cache 



Read pages from a FS-Cache data storage object into a CIFS inode.

Signed-off-by: default avatarSuresh Jayaraman <sjayaraman@suse.de>
Acked-by: default avatarDavid Howells <dhowells@redhat.com>
Signed-off-by: default avatarSteve French <sfrench@us.ibm.com>
parent 9dc06558

fs/cifs/file.c

+17 −0
Original line number Diff line number Diff line
@@ -1977,6 +1977,15 @@ static int cifs_readpages(struct file *file, struct address_space *mapping, 
	cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);

	pTcon = cifs_sb->tcon;



	/*

	 * Reads as many pages as possible from fscache. Returns -ENOBUFS

	 * immediately if the cookie is negative

	 */

	rc = cifs_readpages_from_fscache(mapping->host, mapping, page_list,

					 &num_pages);

	if (rc == 0)

		goto read_complete;



	cFYI(DBG2, "rpages: num pages %d", num_pages);

	for (i = 0; i < num_pages; ) {

		unsigned contig_pages;
@@ -2087,6 +2096,7 @@ static int cifs_readpages(struct file *file, struct address_space *mapping, 
		smb_read_data = NULL;

	}



read_complete:

	FreeXid(xid);

	return rc;

}
@@ -2097,6 +2107,11 @@ static int cifs_readpage_worker(struct file *file, struct page *page, 
	char *read_data;

	int rc;



	/* Is the page cached? */

	rc = cifs_readpage_from_fscache(file->f_path.dentry->d_inode, page);

	if (rc == 0)

		goto read_complete;



	page_cache_get(page);

	read_data = kmap(page);

	/* for reads over a certain size could initiate async read ahead */
@@ -2125,6 +2140,8 @@ static int cifs_readpage_worker(struct file *file, struct page *page, 
io_error:

	kunmap(page);

	page_cache_release(page);



read_complete:

	return rc;

}

fs/cifs/fscache.c

+73 −0
Original line number Diff line number Diff line
@@ -140,6 +140,79 @@ int cifs_fscache_release_page(struct page *page, gfp_t gfp) 
	return 1;

}



static void cifs_readpage_from_fscache_complete(struct page *page, void *ctx,

						int error)

{

	cFYI(1, "CFS: readpage_from_fscache_complete (0x%p/%d)",

			page, error);

	if (!error)

		SetPageUptodate(page);

	unlock_page(page);

}



/*

 * Retrieve a page from FS-Cache

 */

int __cifs_readpage_from_fscache(struct inode *inode, struct page *page)

{

	int ret;



	cFYI(1, "CIFS: readpage_from_fscache(fsc:%p, p:%p, i:0x%p",

			CIFS_I(inode)->fscache, page, inode);

	ret = fscache_read_or_alloc_page(CIFS_I(inode)->fscache, page,

					 cifs_readpage_from_fscache_complete,

					 NULL,

					 GFP_KERNEL);

	switch (ret) {



	case 0: /* page found in fscache, read submitted */

		cFYI(1, "CIFS: readpage_from_fscache: submitted");

		return ret;

	case -ENOBUFS:	/* page won't be cached */

	case -ENODATA:	/* page not in cache */

		cFYI(1, "CIFS: readpage_from_fscache %d", ret);

		return 1;



	default:

		cERROR(1, "unknown error ret = %d", ret);

	}

	return ret;

}



/*

 * Retrieve a set of pages from FS-Cache

 */

int __cifs_readpages_from_fscache(struct inode *inode,

				struct address_space *mapping,

				struct list_head *pages,

				unsigned *nr_pages)

{

	int ret;



	cFYI(1, "CIFS: __cifs_readpages_from_fscache (0x%p/%u/0x%p)",

			CIFS_I(inode)->fscache, *nr_pages, inode);

	ret = fscache_read_or_alloc_pages(CIFS_I(inode)->fscache, mapping,

					  pages, nr_pages,

					  cifs_readpage_from_fscache_complete,

					  NULL,

					  mapping_gfp_mask(mapping));

	switch (ret) {

	case 0:	/* read submitted to the cache for all pages */

		cFYI(1, "CIFS: readpages_from_fscache: submitted");

		return ret;



	case -ENOBUFS:	/* some pages are not cached and can't be */

	case -ENODATA:	/* some pages are not cached */

		cFYI(1, "CIFS: readpages_from_fscache: no page");

		return 1;



	default:

		cFYI(1, "unknown error ret = %d", ret);

	}



	return ret;

}



void __cifs_readpage_to_fscache(struct inode *inode, struct page *page)

{

	int ret;

fs/cifs/fscache.h

+39 −1
Original line number Diff line number Diff line
@@ -32,7 +32,6 @@ extern const struct fscache_cookie_def cifs_fscache_server_index_def; 
extern const struct fscache_cookie_def cifs_fscache_super_index_def;

extern const struct fscache_cookie_def cifs_fscache_inode_object_def;





extern int cifs_fscache_register(void);

extern void cifs_fscache_unregister(void);
@@ -50,6 +49,11 @@ extern void cifs_fscache_reset_inode_cookie(struct inode *); 


extern void __cifs_fscache_invalidate_page(struct page *, struct inode *);

extern int cifs_fscache_release_page(struct page *page, gfp_t gfp);

extern int __cifs_readpage_from_fscache(struct inode *, struct page *);

extern int __cifs_readpages_from_fscache(struct inode *,

					 struct address_space *,

					 struct list_head *,

					 unsigned *);



extern void __cifs_readpage_to_fscache(struct inode *, struct page *);
@@ -60,6 +64,26 @@ static inline void cifs_fscache_invalidate_page(struct page *page, 
		__cifs_fscache_invalidate_page(page, inode);

}



static inline int cifs_readpage_from_fscache(struct inode *inode,

					     struct page *page)

{

	if (CIFS_I(inode)->fscache)

		return __cifs_readpage_from_fscache(inode, page);



	return -ENOBUFS;

}



static inline int cifs_readpages_from_fscache(struct inode *inode,

					      struct address_space *mapping,

					      struct list_head *pages,

					      unsigned *nr_pages)

{

	if (CIFS_I(inode)->fscache)

		return __cifs_readpages_from_fscache(inode, mapping, pages,

						     nr_pages);

	return -ENOBUFS;

}



static inline void cifs_readpage_to_fscache(struct inode *inode,

					    struct page *page)

{
@@ -90,6 +114,20 @@ static inline void cifs_fscache_release_page(struct page *page, gfp_t gfp) 


static inline int cifs_fscache_invalidate_page(struct page *page,

			struct inode *) {}

static inline int

cifs_readpage_from_fscache(struct inode *inode, struct page *page)

{

	return -ENOBUFS;

}



static inline int cifs_readpages_from_fscache(struct inode *inode,

					      struct address_space *mapping,

					      struct list_head *pages,

					      unsigned *nr_pages)

{

	return -ENOBUFS;

}



static inline void cifs_readpage_to_fscache(struct inode *inode,

			struct page *page) {}