[PATCH] read_mapping_page for address space

Add read_mapping_page() which is used for callers that pass
mapping->a_ops->readpage as the filler for read_cache_page.  This removes
some duplication from filesystem code.

Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

22 files changed, 38 insertions, 56 deletions

diff --git a/fs/afs/dir.c b/fs/afs/dir.c
index a6dff6a4f204..2fc99877cb0d 100644
--- a/fs/afs/dir.c
+++ b/fs/afs/dir.c
@@ -185,9 +185,7 @@ static struct page *afs_dir_get_page(struct inode *dir, unsigned long index)
 
         _enter("{%lu},%lu", dir->i_ino, index);
 
-        page = read_cache_page(dir->i_mapping,index,
-                               (filler_t *) dir->i_mapping->a_ops->readpage,
-                               NULL);
+        page = read_mapping_page(dir->i_mapping, index, NULL);
         if (!IS_ERR(page)) {
                 wait_on_page_locked(page);
                 kmap(page);
diff --git a/fs/afs/mntpt.c b/fs/afs/mntpt.c
index 4e6eeb59b83c..b5cf9e1205ad 100644
--- a/fs/afs/mntpt.c
+++ b/fs/afs/mntpt.c
@@ -63,7 +63,6 @@ unsigned long afs_mntpt_expiry_timeout = 20;
 int afs_mntpt_check_symlink(struct afs_vnode *vnode)
 {
         struct page *page;
-        filler_t *filler;
         size_t size;
         char *buf;
         int ret;
@@ -71,10 +70,7 @@ int afs_mntpt_check_symlink(struct afs_vnode *vnode)
         _enter("{%u,%u}", vnode->fid.vnode, vnode->fid.unique);
 
         /* read the contents of the symlink into the pagecache */
-        filler = (filler_t *) AFS_VNODE_TO_I(vnode)->i_mapping->a_ops->readpage;
-
-        page = read_cache_page(AFS_VNODE_TO_I(vnode)->i_mapping, 0,
-                               filler, NULL);
+        page = read_mapping_page(AFS_VNODE_TO_I(vnode)->i_mapping, 0, NULL);
         if (IS_ERR(page)) {
                 ret = PTR_ERR(page);
                 goto out;
@@ -160,7 +156,6 @@ static struct vfsmount *afs_mntpt_do_automount(struct dentry *mntpt)
         struct page *page = NULL;
         size_t size;
         char *buf, *devname = NULL, *options = NULL;
-        filler_t *filler;
         int ret;
 
         kenter("{%s}", mntpt->d_name.name);
@@ -182,9 +177,7 @@ static struct vfsmount *afs_mntpt_do_automount(struct dentry *mntpt)
                 goto error;
 
         /* read the contents of the AFS special symlink */
-        filler = (filler_t *)mntpt->d_inode->i_mapping->a_ops->readpage;
-
-        page = read_cache_page(mntpt->d_inode->i_mapping, 0, filler, NULL);
+        page = read_mapping_page(mntpt->d_inode->i_mapping, 0, NULL);
         if (IS_ERR(page)) {
                 ret = PTR_ERR(page);
                 goto error;
diff --git a/fs/cramfs/inode.c b/fs/cramfs/inode.c
index 8a9d5d3b3262..c45d73860803 100644
--- a/fs/cramfs/inode.c
+++ b/fs/cramfs/inode.c
@@ -181,9 +181,7 @@ static void *cramfs_read(struct super_block *sb, unsigned int offset, unsigned i
                 struct page *page = NULL;
 
                 if (blocknr + i < devsize) {
-                        page = read_cache_page(mapping, blocknr + i,
-                                (filler_t *)mapping->a_ops->readpage,
-                                NULL);
+                        page = read_mapping_page(mapping, blocknr + i, NULL);
                         /* synchronous error? */
                         if (IS_ERR(page))
                                 page = NULL;
diff --git a/fs/ext2/dir.c b/fs/ext2/dir.c
index d672aa9f4061..3c1c9aaaca6b 100644
--- a/fs/ext2/dir.c
+++ b/fs/ext2/dir.c
@@ -159,8 +159,7 @@ fail:
 static struct page * ext2_get_page(struct inode *dir, unsigned long n)
 {
         struct address_space *mapping = dir->i_mapping;
-        struct page *page = read_cache_page(mapping, n,
-                                (filler_t*)mapping->a_ops->readpage, NULL);
+        struct page *page = read_mapping_page(mapping, n, NULL);
         if (!IS_ERR(page)) {
                 wait_on_page_locked(page);
                 kmap(page);
diff --git a/fs/freevxfs/vxfs_subr.c b/fs/freevxfs/vxfs_subr.c
index 50aae77651b2..c1be118fc067 100644
--- a/fs/freevxfs/vxfs_subr.c
+++ b/fs/freevxfs/vxfs_subr.c
@@ -71,8 +71,7 @@ vxfs_get_page(struct address_space *mapping, u_long n)
 {
         struct page *                   pp;
 
-        pp = read_cache_page(mapping, n,
-                        (filler_t*)mapping->a_ops->readpage, NULL);
+        pp = read_mapping_page(mapping, n, NULL);
 
         if (!IS_ERR(pp)) {
                 wait_on_page_locked(pp);
diff --git a/fs/hfs/bnode.c b/fs/hfs/bnode.c
index 1e44dcfe49c4..13231dd5ce66 100644
--- a/fs/hfs/bnode.c
+++ b/fs/hfs/bnode.c
@@ -280,7 +280,7 @@ static struct hfs_bnode *__hfs_bnode_create(struct hfs_btree *tree, u32 cnid)
         block = off >> PAGE_CACHE_SHIFT;
         node->page_offset = off & ~PAGE_CACHE_MASK;
         for (i = 0; i < tree->pages_per_bnode; i++) {
-                page = read_cache_page(mapping, block++, (filler_t *)mapping->a_ops->readpage, NULL);
+                page = read_mapping_page(mapping, block++, NULL);
                 if (IS_ERR(page))
                         goto fail;
                 if (PageError(page)) {
diff --git a/fs/hfs/btree.c b/fs/hfs/btree.c
index d20131ce4b95..400357994319 100644
--- a/fs/hfs/btree.c
+++ b/fs/hfs/btree.c
@@ -59,7 +59,7 @@ struct hfs_btree *hfs_btree_open(struct super_block *sb, u32 id, btree_keycmp ke
         unlock_new_inode(tree->inode);
 
         mapping = tree->inode->i_mapping;
-        page = read_cache_page(mapping, 0, (filler_t *)mapping->a_ops->readpage, NULL);
+        page = read_mapping_page(mapping, 0, NULL);
         if (IS_ERR(page))
                 goto free_tree;
 
diff --git a/fs/hfsplus/bitmap.c b/fs/hfsplus/bitmap.c
index 9fb51632303c..d128a25b74d2 100644
--- a/fs/hfsplus/bitmap.c
+++ b/fs/hfsplus/bitmap.c
@@ -31,8 +31,7 @@ int hfsplus_block_allocate(struct super_block *sb, u32 size, u32 offset, u32 *ma
         dprint(DBG_BITMAP, "block_allocate: %u,%u,%u\n", size, offset, len);
         mutex_lock(&HFSPLUS_SB(sb).alloc_file->i_mutex);
         mapping = HFSPLUS_SB(sb).alloc_file->i_mapping;
-        page = read_cache_page(mapping, offset / PAGE_CACHE_BITS,
-                               (filler_t *)mapping->a_ops->readpage, NULL);
+        page = read_mapping_page(mapping, offset / PAGE_CACHE_BITS, NULL);
         pptr = kmap(page);
         curr = pptr + (offset & (PAGE_CACHE_BITS - 1)) / 32;
         i = offset % 32;
@@ -72,8 +71,8 @@ int hfsplus_block_allocate(struct super_block *sb, u32 size, u32 offset, u32 *ma
                 offset += PAGE_CACHE_BITS;
                 if (offset >= size)
                         break;
-                page = read_cache_page(mapping, offset / PAGE_CACHE_BITS,
-                                       (filler_t *)mapping->a_ops->readpage, NULL);
+                page = read_mapping_page(mapping, offset / PAGE_CACHE_BITS,
+                                         NULL);
                 curr = pptr = kmap(page);
                 if ((size ^ offset) / PAGE_CACHE_BITS)
                         end = pptr + PAGE_CACHE_BITS / 32;
@@ -119,8 +118,8 @@ found:
                 set_page_dirty(page);
                 kunmap(page);
                 offset += PAGE_CACHE_BITS;
-                page = read_cache_page(mapping, offset / PAGE_CACHE_BITS,
-                                       (filler_t *)mapping->a_ops->readpage, NULL);
+                page = read_mapping_page(mapping, offset / PAGE_CACHE_BITS,
+                                         NULL);
                 pptr = kmap(page);
                 curr = pptr;
                 end = pptr + PAGE_CACHE_BITS / 32;
@@ -167,7 +166,7 @@ int hfsplus_block_free(struct super_block *sb, u32 offset, u32 count)
         mutex_lock(&HFSPLUS_SB(sb).alloc_file->i_mutex);
         mapping = HFSPLUS_SB(sb).alloc_file->i_mapping;
         pnr = offset / PAGE_CACHE_BITS;
-        page = read_cache_page(mapping, pnr, (filler_t *)mapping->a_ops->readpage, NULL);
+        page = read_mapping_page(mapping, pnr, NULL);
         pptr = kmap(page);
         curr = pptr + (offset & (PAGE_CACHE_BITS - 1)) / 32;
         end = pptr + PAGE_CACHE_BITS / 32;
@@ -199,7 +198,7 @@ int hfsplus_block_free(struct super_block *sb, u32 offset, u32 count)
                         break;
                 set_page_dirty(page);
                 kunmap(page);
-                page = read_cache_page(mapping, ++pnr, (filler_t *)mapping->a_ops->readpage, NULL);
+                page = read_mapping_page(mapping, ++pnr, NULL);
                 pptr = kmap(page);
                 curr = pptr;
                 end = pptr + PAGE_CACHE_BITS / 32;
diff --git a/fs/hfsplus/bnode.c b/fs/hfsplus/bnode.c
index 746abc9ecf70..77bf434da679 100644
--- a/fs/hfsplus/bnode.c
+++ b/fs/hfsplus/bnode.c
@@ -440,7 +440,7 @@ static struct hfs_bnode *__hfs_bnode_create(struct hfs_btree *tree, u32 cnid)
         block = off >> PAGE_CACHE_SHIFT;
         node->page_offset = off & ~PAGE_CACHE_MASK;
         for (i = 0; i < tree->pages_per_bnode; block++, i++) {
-                page = read_cache_page(mapping, block, (filler_t *)mapping->a_ops->readpage, NULL);
+                page = read_mapping_page(mapping, block, NULL);
                 if (IS_ERR(page))
                         goto fail;
                 if (PageError(page)) {
diff --git a/fs/hfsplus/btree.c b/fs/hfsplus/btree.c
index effa8991999c..cfc852fdd1b5 100644
--- a/fs/hfsplus/btree.c
+++ b/fs/hfsplus/btree.c
@@ -38,7 +38,7 @@ struct hfs_btree *hfs_btree_open(struct super_block *sb, u32 id)
                 goto free_tree;
 
         mapping = tree->inode->i_mapping;
-        page = read_cache_page(mapping, 0, (filler_t *)mapping->a_ops->readpage, NULL);
+        page = read_mapping_page(mapping, 0, NULL);
         if (IS_ERR(page))
                 goto free_tree;
 
diff --git a/fs/jfs/jfs_metapage.c b/fs/jfs/jfs_metapage.c
index 2b220dd6b4e7..7f6e88039700 100644
--- a/fs/jfs/jfs_metapage.c
+++ b/fs/jfs/jfs_metapage.c
@@ -632,10 +632,9 @@ struct metapage *__get_metapage(struct inode *inode, unsigned long lblock,
                 }
                 SetPageUptodate(page);
         } else {
-                page = read_cache_page(mapping, page_index,
-                            (filler_t *)mapping->a_ops->readpage, NULL);
+                page = read_mapping_page(mapping, page_index, NULL);
                 if (IS_ERR(page) || !PageUptodate(page)) {
-                        jfs_err("read_cache_page failed!");
+                        jfs_err("read_mapping_page failed!");
                         return NULL;
                 }
                 lock_page(page);
diff --git a/fs/minix/dir.c b/fs/minix/dir.c
index 69224d1fe043..2b0a389d1987 100644
--- a/fs/minix/dir.c
+++ b/fs/minix/dir.c
@@ -60,8 +60,7 @@ static int dir_commit_chunk(struct page *page, unsigned from, unsigned to)
 static struct page * dir_get_page(struct inode *dir, unsigned long n)
 {
         struct address_space *mapping = dir->i_mapping;
-        struct page *page = read_cache_page(mapping, n,
-                                (filler_t*)mapping->a_ops->readpage, NULL);
+        struct page *page = read_mapping_page(mapping, n, NULL);
         if (!IS_ERR(page)) {
                 wait_on_page_locked(page);
                 kmap(page);
diff --git a/fs/namei.c b/fs/namei.c
index 184fe4acf824..bb4a3e40e432 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2577,8 +2577,7 @@ static char *page_getlink(struct dentry * dentry, struct page **ppage)
 {
         struct page * page;
         struct address_space *mapping = dentry->d_inode->i_mapping;
-        page = read_cache_page(mapping, 0, (filler_t *)mapping->a_ops->readpage,
-                                NULL);
+        page = read_mapping_page(mapping, 0, NULL);
         if (IS_ERR(page))
                 goto sync_fail;
         wait_on_page_locked(page);
diff --git a/fs/ntfs/aops.h b/fs/ntfs/aops.h
index 3b74e66ca2ff..325ce261a107 100644
--- a/fs/ntfs/aops.h
+++ b/fs/ntfs/aops.h
@@ -86,8 +86,7 @@ static inline void ntfs_unmap_page(struct page *page)
 static inline struct page *ntfs_map_page(struct address_space *mapping,
                 unsigned long index)
 {
-        struct page *page = read_cache_page(mapping, index,
-                        (filler_t*)mapping->a_ops->readpage, NULL);
+        struct page *page = read_mapping_page(mapping, index, NULL);
 
         if (!IS_ERR(page)) {
                 wait_on_page_locked(page);
diff --git a/fs/ntfs/attrib.c b/fs/ntfs/attrib.c
index 1663f5c3c6aa..6708e1d68a9e 100644
--- a/fs/ntfs/attrib.c
+++ b/fs/ntfs/attrib.c
@@ -2529,8 +2529,7 @@ int ntfs_attr_set(ntfs_inode *ni, const s64 ofs, const s64 cnt, const u8 val)
         end >>= PAGE_CACHE_SHIFT;
         /* If there is a first partial page, need to do it the slow way. */
         if (start_ofs) {
-                page = read_cache_page(mapping, idx,
-                                (filler_t*)mapping->a_ops->readpage, NULL);
+                page = read_mapping_page(mapping, idx, NULL);
                 if (IS_ERR(page)) {
                         ntfs_error(vol->sb, "Failed to read first partial "
                                         "page (sync error, index 0x%lx).", idx);
@@ -2600,8 +2599,7 @@ int ntfs_attr_set(ntfs_inode *ni, const s64 ofs, const s64 cnt, const u8 val)
         }
         /* If there is a last partial page, need to do it the slow way. */
         if (end_ofs) {
-                page = read_cache_page(mapping, idx,
-                                (filler_t*)mapping->a_ops->readpage, NULL);
+                page = read_mapping_page(mapping, idx, NULL);
                 if (IS_ERR(page)) {
                         ntfs_error(vol->sb, "Failed to read last partial page "
                                         "(sync error, index 0x%lx).", idx);
diff --git a/fs/ntfs/file.c b/fs/ntfs/file.c
index 36e1e136bb0c..88292f9e4b9b 100644
--- a/fs/ntfs/file.c
+++ b/fs/ntfs/file.c
@@ -231,8 +231,7 @@ do_non_resident_extend:
                  * Read the page.  If the page is not present, this will zero
                  * the uninitialized regions for us.
                  */
-                page = read_cache_page(mapping, index,
-                                (filler_t*)mapping->a_ops->readpage, NULL);
+                page = read_mapping_page(mapping, index, NULL);
                 if (IS_ERR(page)) {
                         err = PTR_ERR(page);
                         goto init_err_out;
diff --git a/fs/ocfs2/symlink.c b/fs/ocfs2/symlink.c
index f6986bd79e75..0c8a1294ec96 100644
--- a/fs/ocfs2/symlink.c
+++ b/fs/ocfs2/symlink.c
@@ -64,8 +64,7 @@ static char *ocfs2_page_getlink(struct dentry * dentry,
 {
         struct page * page;
         struct address_space *mapping = dentry->d_inode->i_mapping;
-        page = read_cache_page(mapping, 0,
-                               (filler_t *)mapping->a_ops->readpage, NULL);
+        page = read_mapping_page(mapping, 0, NULL);
         if (IS_ERR(page))
                 goto sync_fail;
         wait_on_page_locked(page);
diff --git a/fs/partitions/check.c b/fs/partitions/check.c
index 8851b81e7c5a..cd885b23cb5c 100644
--- a/fs/partitions/check.c
+++ b/fs/partitions/check.c
@@ -499,8 +499,8 @@ unsigned char *read_dev_sector(struct block_device *bdev, sector_t n, Sector *p)
         struct address_space *mapping = bdev->bd_inode->i_mapping;
         struct page *page;
 
-        page = read_cache_page(mapping, (pgoff_t)(n >> (PAGE_CACHE_SHIFT-9)),
-                        (filler_t *)mapping->a_ops->readpage, NULL);
+        page = read_mapping_page(mapping, (pgoff_t)(n >> (PAGE_CACHE_SHIFT-9)),
+                                 NULL);
         if (!IS_ERR(page)) {
                 wait_on_page_locked(page);
                 if (!PageUptodate(page))
diff --git a/fs/reiserfs/xattr.c b/fs/reiserfs/xattr.c
index ffb79c48c5bf..39fedaa88a0c 100644
--- a/fs/reiserfs/xattr.c
+++ b/fs/reiserfs/xattr.c
@@ -452,8 +452,7 @@ static struct page *reiserfs_get_page(struct inode *dir, unsigned long n)
         /* We can deadlock if we try to free dentries,
            and an unlink/rmdir has just occured - GFP_NOFS avoids this */
         mapping_set_gfp_mask(mapping, GFP_NOFS);
-        page = read_cache_page(mapping, n,
-                               (filler_t *) mapping->a_ops->readpage, NULL);
+        page = read_mapping_page(mapping, n, NULL);
         if (!IS_ERR(page)) {
                 wait_on_page_locked(page);
                 kmap(page);
diff --git a/fs/sysv/dir.c b/fs/sysv/dir.c
index d7074341ee87..f2bef962d309 100644
--- a/fs/sysv/dir.c
+++ b/fs/sysv/dir.c
@@ -53,8 +53,7 @@ static int dir_commit_chunk(struct page *page, unsigned from, unsigned to)
 static struct page * dir_get_page(struct inode *dir, unsigned long n)
 {
         struct address_space *mapping = dir->i_mapping;
-        struct page *page = read_cache_page(mapping, n,
-                                (filler_t*)mapping->a_ops->readpage, NULL);
+        struct page *page = read_mapping_page(mapping, n, NULL);
         if (!IS_ERR(page)) {
                 wait_on_page_locked(page);
                 kmap(page);
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 7a1af574dedf..1245df7141aa 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -99,6 +99,13 @@ extern struct page * read_cache_page(struct address_space *mapping,
 extern int read_cache_pages(struct address_space *mapping,
                 struct list_head *pages, filler_t *filler, void *data);
 
+static inline struct page *read_mapping_page(struct address_space *mapping,
+                                             unsigned long index, void *data)
+{
+        filler_t *filler = (filler_t *)mapping->a_ops->readpage;
+        return read_cache_page(mapping, index, filler, data);
+}
+
 int add_to_page_cache(struct page *page, struct address_space *mapping,
                                 unsigned long index, gfp_t gfp_mask);
 int add_to_page_cache_lru(struct page *page, struct address_space *mapping,
diff --git a/mm/swapfile.c b/mm/swapfile.c
index f2824c3c31b4..cc367f7e75d8 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -1477,8 +1477,7 @@ asmlinkage long sys_swapon(const char __user * specialfile, int swap_flags)
                 error = -EINVAL;
                 goto bad_swap;
         }
-        page = read_cache_page(mapping, 0,
-                        (filler_t *)mapping->a_ops->readpage, swap_file);
+        page = read_mapping_page(mapping, 0, swap_file);
         if (IS_ERR(page)) {
                 error = PTR_ERR(page);
                 goto bad_swap;