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cifs: read pages from FS-Cache

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

Signed-off-by: Suresh Jayaraman <sjayaraman@suse.de>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
This commit is contained in:
Suresh Jayaraman 2010-07-05 18:13:25 +05:30 committed by Steve French
parent 9dc06558c2
commit 56698236e1
3 changed files with 129 additions and 1 deletions
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17
fs/cifs/file.c
View File

@ -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;
}

73
fs/cifs/fscache.c
View File

@ -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;

40
fs/cifs/fscache.h
View File

@ -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) {}