[RFC PATCH 09/79] fs: add struct address_space to read_cache_page() callback argument

[jglisse]

From: Jérôme Glisse 

Add struct address_space to callback arguments of read_cache_page()
and read_cache_pages(). Note this patch only add arguments and modify
callback function signature, it does not make use of the new argument
and thus it should be regression free.

One step toward dropping reliance on page->mapping.

Signed-off-by: Jérôme Glisse 
Cc: Alexander Viro 
Cc: linux-fsde...@vger.kernel.org
Cc: Tejun Heo 
Cc: Jan Kara 
Cc: Josef Bacik 
Cc: Mel Gorman 
Cc: Jeff Layton 
---
 drivers/staging/lustre/lustre/mdc/mdc_request.c |  3 ++-
 fs/9p/vfs_addr.c| 13 -
 fs/afs/file.c   |  7 ---
 fs/afs/internal.h   |  2 +-
 fs/exofs/inode.c|  5 +++--
 fs/fuse/file.c  |  3 ++-
 fs/gfs2/aops.c  |  5 +++--
 fs/jffs2/file.c |  6 --
 fs/jffs2/fs.c   |  2 +-
 fs/jffs2/os-linux.h |  3 ++-
 fs/nfs/dir.c|  3 ++-
 fs/nfs/read.c   |  3 ++-
 fs/nfs/symlink.c|  6 --
 include/linux/pagemap.h |  8 ++--
 mm/filemap.c| 14 +++---
 mm/readahead.c  |  4 ++--
 16 files changed, 61 insertions(+), 26 deletions(-)

diff --git a/drivers/staging/lustre/lustre/mdc/mdc_request.c 
b/drivers/staging/lustre/lustre/mdc/mdc_request.c
index 03e55bca4ada..4814ef083824 100644
--- a/drivers/staging/lustre/lustre/mdc/mdc_request.c
+++ b/drivers/staging/lustre/lustre/mdc/mdc_request.c
@@ -1122,7 +1122,8 @@ struct readpage_param {
  * in PAGE_SIZE (if PAGE_SIZE greater than LU_PAGE_SIZE), and the
  * lu_dirpage for this integrated page will be adjusted.
  **/
-static int mdc_read_page_remote(void *data, struct page *page0)
+static int mdc_read_page_remote(void *data, struct address_space *mapping,
+   struct page *page0)
 {
struct readpage_param *rp = data;
struct page **page_pool;
diff --git a/fs/9p/vfs_addr.c b/fs/9p/vfs_addr.c
index e1cbdfdb7c68..61f70e63a525 100644
--- a/fs/9p/vfs_addr.c
+++ b/fs/9p/vfs_addr.c
@@ -99,6 +99,17 @@ static int v9fs_vfs_readpage(struct file *filp, struct page 
*page)
return v9fs_fid_readpage(filp->private_data, page);
 }
 
+/*
+ * This wrapper is needed to avoid forcing callback cast on read_cache_pages()
+ * and defeating compiler figuring out we are doing something wrong.
+ */
+static int v9fs_vfs_readpage_filler(void *data, struct address_space *mapping,
+   struct page *page)
+{
+   return v9fs_vfs_readpage(data, page);
+}
+
+
 /**
  * v9fs_vfs_readpages - read a set of pages from 9P
  *
@@ -122,7 +133,7 @@ static int v9fs_vfs_readpages(struct file *filp, struct 
address_space *mapping,
if (ret == 0)
return ret;
 
-   ret = read_cache_pages(mapping, pages, (void *)v9fs_vfs_readpage, filp);
+   ret = read_cache_pages(mapping, pages, v9fs_vfs_readpage_filler, filp);
p9_debug(P9_DEBUG_VFS, "  = %d\n", ret);
return ret;
 }
diff --git a/fs/afs/file.c b/fs/afs/file.c
index a39192ced99e..f457b0144946 100644
--- a/fs/afs/file.c
+++ b/fs/afs/file.c
@@ -247,7 +247,8 @@ int afs_fetch_data(struct afs_vnode *vnode, struct key 
*key, struct afs_read *de
 /*
  * read page from file, directory or symlink, given a key to use
  */
-int afs_page_filler(void *data, struct page *page)
+int afs_page_filler(void *data, struct address_space *mapping,
+   struct page *page)
 {
struct inode *inode = page->mapping->host;
struct afs_vnode *vnode = AFS_FS_I(inode);
@@ -373,14 +374,14 @@ static int afs_readpage(struct file *file, struct page 
*page)
if (file) {
key = afs_file_key(file);
ASSERT(key != NULL);
-   ret = afs_page_filler(key, page);
+   ret = afs_page_filler(key, page->mapping, page);
} else {
struct inode *inode = page->mapping->host;
key = afs_request_key(AFS_FS_S(inode->i_sb)->cell);
if (IS_ERR(key)) {
ret = PTR_ERR(key);
} else {
-   ret = afs_page_filler(key, page);
+   ret = afs_page_filler(key, page->mapping, page);
key_put(key);
}
}
diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index f38d6a561a84..4c449145f668 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -656,7 +656,7 @@ extern void afs_put_wb_key(struct afs_wb_key *);
 extern int 

[RFC PATCH 09/79] fs: add struct address_space to read_cache_page() callback argument

[jglisse]

From: Jérôme Glisse 

Add struct address_space to callback arguments of read_cache_page()
and read_cache_pages(). Note this patch only add arguments and modify
callback function signature, it does not make use of the new argument
and thus it should be regression free.

One step toward dropping reliance on page->mapping.

Signed-off-by: Jérôme Glisse 
Cc: Alexander Viro 
Cc: linux-fsde...@vger.kernel.org
Cc: Tejun Heo 
Cc: Jan Kara 
Cc: Josef Bacik 
Cc: Mel Gorman 
Cc: Jeff Layton 
---
 drivers/staging/lustre/lustre/mdc/mdc_request.c |  3 ++-
 fs/9p/vfs_addr.c| 13 -
 fs/afs/file.c   |  7 ---
 fs/afs/internal.h   |  2 +-
 fs/exofs/inode.c|  5 +++--
 fs/fuse/file.c  |  3 ++-
 fs/gfs2/aops.c  |  5 +++--
 fs/jffs2/file.c |  6 --
 fs/jffs2/fs.c   |  2 +-
 fs/jffs2/os-linux.h |  3 ++-
 fs/nfs/dir.c|  3 ++-
 fs/nfs/read.c   |  3 ++-
 fs/nfs/symlink.c|  6 --
 include/linux/pagemap.h |  8 ++--
 mm/filemap.c| 14 +++---
 mm/readahead.c  |  4 ++--
 16 files changed, 61 insertions(+), 26 deletions(-)

diff --git a/drivers/staging/lustre/lustre/mdc/mdc_request.c 
b/drivers/staging/lustre/lustre/mdc/mdc_request.c
index 03e55bca4ada..4814ef083824 100644
--- a/drivers/staging/lustre/lustre/mdc/mdc_request.c
+++ b/drivers/staging/lustre/lustre/mdc/mdc_request.c
@@ -1122,7 +1122,8 @@ struct readpage_param {
  * in PAGE_SIZE (if PAGE_SIZE greater than LU_PAGE_SIZE), and the
  * lu_dirpage for this integrated page will be adjusted.
  **/
-static int mdc_read_page_remote(void *data, struct page *page0)
+static int mdc_read_page_remote(void *data, struct address_space *mapping,
+   struct page *page0)
 {
struct readpage_param *rp = data;
struct page **page_pool;
diff --git a/fs/9p/vfs_addr.c b/fs/9p/vfs_addr.c
index e1cbdfdb7c68..61f70e63a525 100644
--- a/fs/9p/vfs_addr.c
+++ b/fs/9p/vfs_addr.c
@@ -99,6 +99,17 @@ static int v9fs_vfs_readpage(struct file *filp, struct page 
*page)
return v9fs_fid_readpage(filp->private_data, page);
 }
 
+/*
+ * This wrapper is needed to avoid forcing callback cast on read_cache_pages()
+ * and defeating compiler figuring out we are doing something wrong.
+ */
+static int v9fs_vfs_readpage_filler(void *data, struct address_space *mapping,
+   struct page *page)
+{
+   return v9fs_vfs_readpage(data, page);
+}
+
+
 /**
  * v9fs_vfs_readpages - read a set of pages from 9P
  *
@@ -122,7 +133,7 @@ static int v9fs_vfs_readpages(struct file *filp, struct 
address_space *mapping,
if (ret == 0)
return ret;
 
-   ret = read_cache_pages(mapping, pages, (void *)v9fs_vfs_readpage, filp);
+   ret = read_cache_pages(mapping, pages, v9fs_vfs_readpage_filler, filp);
p9_debug(P9_DEBUG_VFS, "  = %d\n", ret);
return ret;
 }
diff --git a/fs/afs/file.c b/fs/afs/file.c
index a39192ced99e..f457b0144946 100644
--- a/fs/afs/file.c
+++ b/fs/afs/file.c
@@ -247,7 +247,8 @@ int afs_fetch_data(struct afs_vnode *vnode, struct key 
*key, struct afs_read *de
 /*
  * read page from file, directory or symlink, given a key to use
  */
-int afs_page_filler(void *data, struct page *page)
+int afs_page_filler(void *data, struct address_space *mapping,
+   struct page *page)
 {
struct inode *inode = page->mapping->host;
struct afs_vnode *vnode = AFS_FS_I(inode);
@@ -373,14 +374,14 @@ static int afs_readpage(struct file *file, struct page 
*page)
if (file) {
key = afs_file_key(file);
ASSERT(key != NULL);
-   ret = afs_page_filler(key, page);
+   ret = afs_page_filler(key, page->mapping, page);
} else {
struct inode *inode = page->mapping->host;
key = afs_request_key(AFS_FS_S(inode->i_sb)->cell);
if (IS_ERR(key)) {
ret = PTR_ERR(key);
} else {
-   ret = afs_page_filler(key, page);
+   ret = afs_page_filler(key, page->mapping, page);
key_put(key);
}
}
diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index f38d6a561a84..4c449145f668 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -656,7 +656,7 @@ extern void afs_put_wb_key(struct afs_wb_key *);
 extern int afs_open(struct inode *, struct file *);
 extern int afs_release(struct inode *, struct file *);
 extern int afs_fetch_data(struct afs_vnode *, struct key *, struct