8 files changed, 126 insertions, 132 deletions

diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c
index b8a2990bab83..687023bdfd1e 100644
--- a/fs/ext2/inode.c
+++ b/fs/ext2/inode.c
@@ -796,7 +796,7 @@ const struct address_space_operations ext2_aops = {
 
 const struct address_space_operations ext2_aops_xip = {
         .bmap                   = ext2_bmap,
-        .get_xip_page           = ext2_get_xip_page,
+        .get_xip_mem            = ext2_get_xip_mem,
 };
 
 const struct address_space_operations ext2_nobh_aops = {
diff --git a/fs/ext2/xip.c b/fs/ext2/xip.c
index 430b4c8ee971..233f7fdbe31d 100644
--- a/fs/ext2/xip.c
+++ b/fs/ext2/xip.c
@@ -15,26 +15,28 @@
 #include "xip.h"
 
 static inline int
-__inode_direct_access(struct inode *inode, sector_t sector,
+__inode_direct_access(struct inode *inode, sector_t block,
                       void **kaddr, unsigned long *pfn)
 {
         struct block_device *bdev = inode->i_sb->s_bdev;
         struct block_device_operations *ops = bdev->bd_disk->fops;
+        sector_t sector;
+
+        sector = block * (PAGE_SIZE / 512); /* ext2 block to bdev sector */
 
         BUG_ON(!ops->direct_access);
         return ops->direct_access(bdev, sector, kaddr, pfn);
 }
 
 static inline int
-__ext2_get_sector(struct inode *inode, sector_t offset, int create,
+__ext2_get_block(struct inode *inode, pgoff_t pgoff, int create,
                    sector_t *result)
 {
         struct buffer_head tmp;
         int rc;
 
         memset(&tmp, 0, sizeof(struct buffer_head));
-        rc = ext2_get_block(inode, offset/ (PAGE_SIZE/512), &tmp,
-                            create);
+        rc = ext2_get_block(inode, pgoff, &tmp, create);
         *result = tmp.b_blocknr;
 
         /* did we get a sparse block (hole in the file)? */
@@ -47,14 +49,13 @@ __ext2_get_sector(struct inode *inode, sector_t offset, int create,
 }
 
 int
-ext2_clear_xip_target(struct inode *inode, int block)
+ext2_clear_xip_target(struct inode *inode, sector_t block)
 {
-        sector_t sector = block * (PAGE_SIZE/512);
         void *kaddr;
         unsigned long pfn;
         int rc;
 
-        rc = __inode_direct_access(inode, sector, &kaddr, &pfn);
+        rc = __inode_direct_access(inode, block, &kaddr, &pfn);
         if (!rc)
                 clear_page(kaddr);
         return rc;
@@ -72,26 +73,18 @@ void ext2_xip_verify_sb(struct super_block *sb)
         }
 }
 
-struct page *
-ext2_get_xip_page(struct address_space *mapping, sector_t offset,
-                   int create)
+int ext2_get_xip_mem(struct address_space *mapping, pgoff_t pgoff, int create,
+                                void **kmem, unsigned long *pfn)
 {
         int rc;
-        void *kaddr;
-        unsigned long pfn;
-        sector_t sector;
+        sector_t block;
 
         /* first, retrieve the sector number */
-        rc = __ext2_get_sector(mapping->host, offset, create, &sector);
+        rc = __ext2_get_block(mapping->host, pgoff, create, &block);
         if (rc)
-                goto error;
+                return rc;
 
         /* retrieve address of the target data */
-        rc = __inode_direct_access
-                (mapping->host, sector * (PAGE_SIZE/512), &kaddr, &pfn);
-        if (!rc)
-                return pfn_to_page(pfn);
-
- error:
-        return ERR_PTR(rc);
+        rc = __inode_direct_access(mapping->host, block, kmem, pfn);
+        return rc;
 }
diff --git a/fs/ext2/xip.h b/fs/ext2/xip.h
index aa85331d6c56..18b34d2f31b3 100644
--- a/fs/ext2/xip.h
+++ b/fs/ext2/xip.h
@@ -7,19 +7,20 @@
 
 #ifdef CONFIG_EXT2_FS_XIP
 extern void ext2_xip_verify_sb (struct super_block *);
-extern int ext2_clear_xip_target (struct inode *, int);
+extern int ext2_clear_xip_target (struct inode *, sector_t);
 
 static inline int ext2_use_xip (struct super_block *sb)
 {
         struct ext2_sb_info *sbi = EXT2_SB(sb);
         return (sbi->s_mount_opt & EXT2_MOUNT_XIP);
 }
-struct page* ext2_get_xip_page (struct address_space *, sector_t, int);
-#define mapping_is_xip(map) unlikely(map->a_ops->get_xip_page)
+int ext2_get_xip_mem(struct address_space *, pgoff_t, int,
+                                void **, unsigned long *);
+#define mapping_is_xip(map) unlikely(map->a_ops->get_xip_mem)
 #else
 #define mapping_is_xip(map)                     0
 #define ext2_xip_verify_sb(sb)                  do { } while (0)
 #define ext2_use_xip(sb)                        0
 #define ext2_clear_xip_target(inode, chain)     0
-#define ext2_get_xip_page                       NULL
+#define ext2_get_xip_mem                        NULL
 #endif
diff --git a/fs/open.c b/fs/open.c
index b70e7666bb2c..7af1f05d5978 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -837,7 +837,7 @@ static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt,
         if (f->f_flags & O_DIRECT) {
                 if (!f->f_mapping->a_ops ||
                     ((!f->f_mapping->a_ops->direct_IO) &&
-                    (!f->f_mapping->a_ops->get_xip_page))) {
+                    (!f->f_mapping->a_ops->get_xip_mem))) {
                         fput(f);
                         f = ERR_PTR(-EINVAL);
                 }
diff --git a/include/linux/fs.h b/include/linux/fs.h
index bd05f5678045..2c925747bc49 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -474,8 +474,8 @@ struct address_space_operations {
         int (*releasepage) (struct page *, gfp_t);
         ssize_t (*direct_IO)(int, struct kiocb *, const struct iovec *iov,
                         loff_t offset, unsigned long nr_segs);
-        struct page* (*get_xip_page)(struct address_space *, sector_t,
-                        int);
+        int (*get_xip_mem)(struct address_space *, pgoff_t, int,
+                                                void **, unsigned long *);
         /* migrate the contents of a page to the specified target */
         int (*migratepage) (struct address_space *,
                         struct page *, struct page *);
diff --git a/mm/fadvise.c b/mm/fadvise.c
index 3c0f1e99f5e4..343cfdfebd9e 100644
--- a/mm/fadvise.c
+++ b/mm/fadvise.c
@@ -49,7 +49,7 @@ asmlinkage long sys_fadvise64_64(int fd, loff_t offset, loff_t len, int advice)
                 goto out;
         }
 
-        if (mapping->a_ops->get_xip_page) {
+        if (mapping->a_ops->get_xip_mem) {
                 switch (advice) {
                 case POSIX_FADV_NORMAL:
                 case POSIX_FADV_RANDOM:
diff --git a/mm/filemap_xip.c b/mm/filemap_xip.c
index 5e598c42afd7..3e744abcce9d 100644
--- a/mm/filemap_xip.c
+++ b/mm/filemap_xip.c
@@ -15,6 +15,7 @@
 #include <linux/rmap.h>
 #include <linux/sched.h>
 #include <asm/tlbflush.h>
+#include <asm/io.h>
 
 /*
  * We do use our own empty page to avoid interference with other users
@@ -42,37 +43,41 @@ static struct page *xip_sparse_page(void)
 
 /*
  * This is a file read routine for execute in place files, and uses
- * the mapping->a_ops->get_xip_page() function for the actual low-level
+ * the mapping->a_ops->get_xip_mem() function for the actual low-level
  * stuff.
  *
  * Note the struct file* is not used at all.  It may be NULL.
  */
-static void
+static ssize_t
 do_xip_mapping_read(struct address_space *mapping,
                     struct file_ra_state *_ra,
                     struct file *filp,
-                    loff_t *ppos,
-                    read_descriptor_t *desc,
-                    read_actor_t actor)
+                    char __user *buf,
+                    size_t len,
+                    loff_t *ppos)
 {
         struct inode *inode = mapping->host;
         pgoff_t index, end_index;
         unsigned long offset;
-        loff_t isize;
+        loff_t isize, pos;
+        size_t copied = 0, error = 0;
 
-        BUG_ON(!mapping->a_ops->get_xip_page);
+        BUG_ON(!mapping->a_ops->get_xip_mem);
 
-        index = *ppos >> PAGE_CACHE_SHIFT;
-        offset = *ppos & ~PAGE_CACHE_MASK;
+        pos = *ppos;
+        index = pos >> PAGE_CACHE_SHIFT;
+        offset = pos & ~PAGE_CACHE_MASK;
 
         isize = i_size_read(inode);
         if (!isize)
                 goto out;
 
         end_index = (isize - 1) >> PAGE_CACHE_SHIFT;
-        for (;;) {
-                struct page *page;
-                unsigned long nr, ret;
+        do {
+                unsigned long nr, left;
+                void *xip_mem;
+                unsigned long xip_pfn;
+                int zero = 0;
 
                 /* nr is the maximum number of bytes to copy from this page */
                 nr = PAGE_CACHE_SIZE;
@@ -85,19 +90,17 @@ do_xip_mapping_read(struct address_space *mapping,
                         }
                 }
                 nr = nr - offset;
+                if (nr > len)
+                        nr = len;
 
-                page = mapping->a_ops->get_xip_page(mapping,
-                        index*(PAGE_SIZE/512), 0);
-                if (!page)
-                        goto no_xip_page;
-                if (unlikely(IS_ERR(page))) {
-                        if (PTR_ERR(page) == -ENODATA) {
+                error = mapping->a_ops->get_xip_mem(mapping, index, 0,
+                                                        &xip_mem, &xip_pfn);
+                if (unlikely(error)) {
+                        if (error == -ENODATA) {
                                 /* sparse */
-                                page = ZERO_PAGE(0);
-                        } else {
-                                desc->error = PTR_ERR(page);
+                                zero = 1;
+                        } else
                                 goto out;
-                        }
                 }
 
                 /* If users can be writing to this page using arbitrary
@@ -105,10 +108,10 @@ do_xip_mapping_read(struct address_space *mapping,
                  * before reading the page on the kernel side.
                  */
                 if (mapping_writably_mapped(mapping))
-                        flush_dcache_page(page);
+                        /* address based flush */ ;
 
                 /*
-                 * Ok, we have the page, so now we can copy it to user space...
+                 * Ok, we have the mem, so now we can copy it to user space...
                  *
                  * The actor routine returns how many bytes were actually used..
                  * NOTE! This may not be the same as how much of a user buffer
@@ -116,47 +119,38 @@ do_xip_mapping_read(struct address_space *mapping,
                  * "pos" here (the actor routine has to update the user buffer
                  * pointers and the remaining count).
                  */
-                ret = actor(desc, page, offset, nr);
-                offset += ret;
-                index += offset >> PAGE_CACHE_SHIFT;
-                offset &= ~PAGE_CACHE_MASK;
+                if (!zero)
+                        left = __copy_to_user(buf+copied, xip_mem+offset, nr);
+                else
+                        left = __clear_user(buf + copied, nr);
 
-                if (ret == nr && desc->count)
-                        continue;
-                goto out;
+                if (left) {
+                        error = -EFAULT;
+                        goto out;
+                }
 
-no_xip_page:
-                /* Did not get the page. Report it */
-                desc->error = -EIO;
-                goto out;
-        }
+                copied += (nr - left);
+                offset += (nr - left);
+                index += offset >> PAGE_CACHE_SHIFT;
+                offset &= ~PAGE_CACHE_MASK;
+        } while (copied < len);
 
 out:
-        *ppos = ((loff_t) index << PAGE_CACHE_SHIFT) + offset;
+        *ppos = pos + copied;
         if (filp)
                 file_accessed(filp);
+
+        return (copied ? copied : error);
 }
 
 ssize_t
 xip_file_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos)
 {
-        read_descriptor_t desc;
-
         if (!access_ok(VERIFY_WRITE, buf, len))
                 return -EFAULT;
 
-        desc.written = 0;
-        desc.arg.buf = buf;
-        desc.count = len;
-        desc.error = 0;
-
-        do_xip_mapping_read(filp->f_mapping, &filp->f_ra, filp,
-                            ppos, &desc, file_read_actor);
-
-        if (desc.written)
-                return desc.written;
-        else
-                return desc.error;
+        return do_xip_mapping_read(filp->f_mapping, &filp->f_ra, filp,
+                            buf, len, ppos);
 }
 EXPORT_SYMBOL_GPL(xip_file_read);
 
@@ -211,13 +205,16 @@ __xip_unmap (struct address_space * mapping,
  *
  * This function is derived from filemap_fault, but used for execute in place
  */
-static int xip_file_fault(struct vm_area_struct *area, struct vm_fault *vmf)
+static int xip_file_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
-        struct file *file = area->vm_file;
+        struct file *file = vma->vm_file;
         struct address_space *mapping = file->f_mapping;
         struct inode *inode = mapping->host;
-        struct page *page;
         pgoff_t size;
+        void *xip_mem;
+        unsigned long xip_pfn;
+        struct page *page;
+        int error;
 
         /* XXX: are VM_FAULT_ codes OK? */
 
@@ -225,35 +222,44 @@ static int xip_file_fault(struct vm_area_struct *area, struct vm_fault *vmf)
         if (vmf->pgoff >= size)
                 return VM_FAULT_SIGBUS;
 
-        page = mapping->a_ops->get_xip_page(mapping,
-                                        vmf->pgoff*(PAGE_SIZE/512), 0);
-        if (!IS_ERR(page))
-                goto out;
-        if (PTR_ERR(page) != -ENODATA)
+        error = mapping->a_ops->get_xip_mem(mapping, vmf->pgoff, 0,
+                                                &xip_mem, &xip_pfn);
+        if (likely(!error))
+                goto found;
+        if (error != -ENODATA)
                 return VM_FAULT_OOM;
 
         /* sparse block */
-        if ((area->vm_flags & (VM_WRITE | VM_MAYWRITE)) &&
-            (area->vm_flags & (VM_SHARED| VM_MAYSHARE)) &&
+        if ((vma->vm_flags & (VM_WRITE | VM_MAYWRITE)) &&
+            (vma->vm_flags & (VM_SHARED | VM_MAYSHARE)) &&
             (!(mapping->host->i_sb->s_flags & MS_RDONLY))) {
+                int err;
+
                 /* maybe shared writable, allocate new block */
-                page = mapping->a_ops->get_xip_page(mapping,
-                                        vmf->pgoff*(PAGE_SIZE/512), 1);
-                if (IS_ERR(page))
+                error = mapping->a_ops->get_xip_mem(mapping, vmf->pgoff, 1,
+                                                        &xip_mem, &xip_pfn);
+                if (error)
                         return VM_FAULT_SIGBUS;
-                /* unmap page at pgoff from all other vmas */
+                /* unmap sparse mappings at pgoff from all other vmas */
                 __xip_unmap(mapping, vmf->pgoff);
+
+found:
+                err = vm_insert_mixed(vma, (unsigned long)vmf->virtual_address,
+                                                        xip_pfn);
+                if (err == -ENOMEM)
+                        return VM_FAULT_OOM;
+                BUG_ON(err);
+                return VM_FAULT_NOPAGE;
         } else {
                 /* not shared and writable, use xip_sparse_page() */
                 page = xip_sparse_page();
                 if (!page)
                         return VM_FAULT_OOM;
-        }
 
-out:
-        page_cache_get(page);
-        vmf->page = page;
-        return 0;
+                page_cache_get(page);
+                vmf->page = page;
+                return 0;
+        }
 }
 
 static struct vm_operations_struct xip_file_vm_ops = {
@@ -262,11 +268,11 @@ static struct vm_operations_struct xip_file_vm_ops = {
 
 int xip_file_mmap(struct file * file, struct vm_area_struct * vma)
 {
-        BUG_ON(!file->f_mapping->a_ops->get_xip_page);
+        BUG_ON(!file->f_mapping->a_ops->get_xip_mem);
 
         file_accessed(file);
         vma->vm_ops = &xip_file_vm_ops;
-        vma->vm_flags |= VM_CAN_NONLINEAR;
+        vma->vm_flags |= VM_CAN_NONLINEAR | VM_MIXEDMAP;
         return 0;
 }
 EXPORT_SYMBOL_GPL(xip_file_mmap);
@@ -279,17 +285,17 @@ __xip_file_write(struct file *filp, const char __user *buf,
         const struct address_space_operations *a_ops = mapping->a_ops;
         struct inode    *inode = mapping->host;
         long            status = 0;
-        struct page     *page;
         size_t          bytes;
         ssize_t         written = 0;
 
-        BUG_ON(!mapping->a_ops->get_xip_page);
+        BUG_ON(!mapping->a_ops->get_xip_mem);
 
         do {
                 unsigned long index;
                 unsigned long offset;
                 size_t copied;
-                char *kaddr;
+                void *xip_mem;
+                unsigned long xip_pfn;
 
                 offset = (pos & (PAGE_CACHE_SIZE -1)); /* Within page */
                 index = pos >> PAGE_CACHE_SHIFT;
@@ -297,28 +303,22 @@ __xip_file_write(struct file *filp, const char __user *buf,
                 if (bytes > count)
                         bytes = count;
 
-                page = a_ops->get_xip_page(mapping,
-                                           index*(PAGE_SIZE/512), 0);
-                if (IS_ERR(page) && (PTR_ERR(page) == -ENODATA)) {
+                status = a_ops->get_xip_mem(mapping, index, 0,
+                                                &xip_mem, &xip_pfn);
+                if (status == -ENODATA) {
                         /* we allocate a new page unmap it */
-                        page = a_ops->get_xip_page(mapping,
-                                                   index*(PAGE_SIZE/512), 1);
-                        if (!IS_ERR(page))
+                        status = a_ops->get_xip_mem(mapping, index, 1,
+                                                        &xip_mem, &xip_pfn);
+                        if (!status)
                                 /* unmap page at pgoff from all other vmas */
                                 __xip_unmap(mapping, index);
                 }
 
-                if (IS_ERR(page)) {
-                        status = PTR_ERR(page);
+                if (status)
                         break;
-                }
 
-                fault_in_pages_readable(buf, bytes);
-                kaddr = kmap_atomic(page, KM_USER0);
                 copied = bytes -
-                        __copy_from_user_inatomic_nocache(kaddr + offset, buf, bytes);
-                kunmap_atomic(kaddr, KM_USER0);
-                flush_dcache_page(page);
+                        __copy_from_user_nocache(xip_mem + offset, buf, bytes);
 
                 if (likely(copied > 0)) {
                         status = copied;
@@ -398,7 +398,7 @@ EXPORT_SYMBOL_GPL(xip_file_write);
 
 /*
  * truncate a page used for execute in place
- * functionality is analog to block_truncate_page but does use get_xip_page
+ * functionality is analog to block_truncate_page but does use get_xip_mem
  * to get the page instead of page cache
  */
 int
@@ -408,9 +408,11 @@ xip_truncate_page(struct address_space *mapping, loff_t from)
         unsigned offset = from & (PAGE_CACHE_SIZE-1);
         unsigned blocksize;
         unsigned length;
-        struct page *page;
+        void *xip_mem;
+        unsigned long xip_pfn;
+        int err;
 
-        BUG_ON(!mapping->a_ops->get_xip_page);
+        BUG_ON(!mapping->a_ops->get_xip_mem);
 
         blocksize = 1 << mapping->host->i_blkbits;
         length = offset & (blocksize - 1);
@@ -421,18 +423,16 @@ xip_truncate_page(struct address_space *mapping, loff_t from)
 
         length = blocksize - length;
 
-        page = mapping->a_ops->get_xip_page(mapping,
-                                            index*(PAGE_SIZE/512), 0);
-        if (!page)
-                return -ENOMEM;
-        if (unlikely(IS_ERR(page))) {
-                if (PTR_ERR(page) == -ENODATA)
+        err = mapping->a_ops->get_xip_mem(mapping, index, 0,
+                                                &xip_mem, &xip_pfn);
+        if (unlikely(err)) {
+                if (err == -ENODATA)
                         /* Hole? No need to truncate */
                         return 0;
                 else
-                        return PTR_ERR(page);
+                        return err;
         }
-        zero_user(page, offset, length);
+        memset(xip_mem + offset, 0, length);
         return 0;
 }
 EXPORT_SYMBOL_GPL(xip_truncate_page);
diff --git a/mm/madvise.c b/mm/madvise.c
index 93ee375b38e7..23a0ec3e0ea0 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -112,7 +112,7 @@ static long madvise_willneed(struct vm_area_struct * vma,
         if (!file)
                 return -EBADF;
 
-        if (file->f_mapping->a_ops->get_xip_page) {
+        if (file->f_mapping->a_ops->get_xip_mem) {
                 /* no bad return value, but ignore advice */
                 return 0;
         }