hugetlb: modular state for hugetlb page size

The goal of this patchset is to support multiple hugetlb page sizes.  This
is achieved by introducing a new struct hstate structure, which
encapsulates the important hugetlb state and constants (eg.  huge page
size, number of huge pages currently allocated, etc).

The hstate structure is then passed around the code which requires these
fields, they will do the right thing regardless of the exact hstate they
are operating on.

This patch adds the hstate structure, with a single global instance of it
(default_hstate), and does the basic work of converting hugetlb to use the
hstate.

Future patches will add more hstate structures to allow for different
hugetlbfs mounts to have different page sizes.

[akpm@linux-foundation.org: coding-style fixes]
Acked-by: Adam Litke <agl@us.ibm.com>
Acked-by: Nishanth Aravamudan <nacc@us.ibm.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 30 insertions, 22 deletions

diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index 428eff5b73f3..516c581b5371 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -80,6 +80,7 @@ static int hugetlbfs_file_mmap(struct file *file, struct vm_area_struct *vma)
 	struct inode *inode = file->f_path.dentry->d_inode;
 	loff_t len, vma_len;
 	int ret;
+	struct hstate *h = hstate_file(file);
 
 	/*
 	 * vma address alignment (but not the pgoff alignment) has
@@ -92,7 +93,7 @@ static int hugetlbfs_file_mmap(struct file *file, struct vm_area_struct *vma)
 	vma->vm_flags |= VM_HUGETLB | VM_RESERVED;
 	vma->vm_ops = &hugetlb_vm_ops;
 
-	if (vma->vm_pgoff & ~(HPAGE_MASK >> PAGE_SHIFT))
+	if (vma->vm_pgoff & ~(huge_page_mask(h) >> PAGE_SHIFT))
 		return -EINVAL;
 
 	vma_len = (loff_t)(vma->vm_end - vma->vm_start);
@@ -104,8 +105,8 @@ static int hugetlbfs_file_mmap(struct file *file, struct vm_area_struct *vma)
 	len = vma_len + ((loff_t)vma->vm_pgoff << PAGE_SHIFT);
 
 	if (hugetlb_reserve_pages(inode,
-				vma->vm_pgoff >> (HPAGE_SHIFT-PAGE_SHIFT),
-				len >> HPAGE_SHIFT, vma))
+				vma->vm_pgoff >> huge_page_order(h),
+				len >> huge_page_shift(h), vma))
 		goto out;
 
 	ret = 0;
@@ -130,20 +131,21 @@ hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
 	struct mm_struct *mm = current->mm;
 	struct vm_area_struct *vma;
 	unsigned long start_addr;
+	struct hstate *h = hstate_file(file);
 
-	if (len & ~HPAGE_MASK)
+	if (len & ~huge_page_mask(h))
 		return -EINVAL;
 	if (len > TASK_SIZE)
 		return -ENOMEM;
 
 	if (flags & MAP_FIXED) {
-		if (prepare_hugepage_range(addr, len))
+		if (prepare_hugepage_range(file, addr, len))
 			return -EINVAL;
 		return addr;
 	}
 
 	if (addr) {
-		addr = ALIGN(addr, HPAGE_SIZE);
+		addr = ALIGN(addr, huge_page_size(h));
 		vma = find_vma(mm, addr);
 		if (TASK_SIZE - len >= addr &&
 		    (!vma || addr + len <= vma->vm_start))
@@ -156,7 +158,7 @@ hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
 		start_addr = TASK_UNMAPPED_BASE;
 
 full_search:
-	addr = ALIGN(start_addr, HPAGE_SIZE);
+	addr = ALIGN(start_addr, huge_page_size(h));
 
 	for (vma = find_vma(mm, addr); ; vma = vma->vm_next) {
 		/* At this point:  (!vma || addr < vma->vm_end). */
@@ -174,7 +176,7 @@ full_search:
 
 		if (!vma || addr + len <= vma->vm_start)
 			return addr;
-		addr = ALIGN(vma->vm_end, HPAGE_SIZE);
+		addr = ALIGN(vma->vm_end, huge_page_size(h));
 	}
 }
 #endif
@@ -225,10 +227,11 @@ hugetlbfs_read_actor(struct page *page, unsigned long offset,
 static ssize_t hugetlbfs_read(struct file *filp, char __user *buf,
 			      size_t len, loff_t *ppos)
 {
+	struct hstate *h = hstate_file(filp);
 	struct address_space *mapping = filp->f_mapping;
 	struct inode *inode = mapping->host;
-	unsigned long index = *ppos >> HPAGE_SHIFT;
-	unsigned long offset = *ppos & ~HPAGE_MASK;
+	unsigned long index = *ppos >> huge_page_shift(h);
+	unsigned long offset = *ppos & ~huge_page_mask(h);
 	unsigned long end_index;
 	loff_t isize;
 	ssize_t retval = 0;
@@ -243,17 +246,17 @@ static ssize_t hugetlbfs_read(struct file *filp, char __user *buf,
 	if (!isize)
 		goto out;
 
-	end_index = (isize - 1) >> HPAGE_SHIFT;
+	end_index = (isize - 1) >> huge_page_shift(h);
 	for (;;) {
 		struct page *page;
-		int nr, ret;
+		unsigned long nr, ret;
 
 		/* nr is the maximum number of bytes to copy from this page */
-		nr = HPAGE_SIZE;
+		nr = huge_page_size(h);
 		if (index >= end_index) {
 			if (index > end_index)
 				goto out;
-			nr = ((isize - 1) & ~HPAGE_MASK) + 1;
+			nr = ((isize - 1) & ~huge_page_mask(h)) + 1;
 			if (nr <= offset) {
 				goto out;
 			}
@@ -287,8 +290,8 @@ static ssize_t hugetlbfs_read(struct file *filp, char __user *buf,
 		offset += ret;
 		retval += ret;
 		len -= ret;
-		index += offset >> HPAGE_SHIFT;
-		offset &= ~HPAGE_MASK;
+		index += offset >> huge_page_shift(h);
+		offset &= ~huge_page_mask(h);
 
 		if (page)
 			page_cache_release(page);
@@ -298,7 +301,7 @@ static ssize_t hugetlbfs_read(struct file *filp, char __user *buf,
 			break;
 	}
 out:
-	*ppos = ((loff_t)index << HPAGE_SHIFT) + offset;
+	*ppos = ((loff_t)index << huge_page_shift(h)) + offset;
 	mutex_unlock(&inode->i_mutex);
 	return retval;
 }
@@ -339,8 +342,9 @@ static void truncate_huge_page(struct page *page)
 
 static void truncate_hugepages(struct inode *inode, loff_t lstart)
 {
+	struct hstate *h = hstate_inode(inode);
 	struct address_space *mapping = &inode->i_data;
-	const pgoff_t start = lstart >> HPAGE_SHIFT;
+	const pgoff_t start = lstart >> huge_page_shift(h);
 	struct pagevec pvec;
 	pgoff_t next;
 	int i, freed = 0;
@@ -449,8 +453,9 @@ static int hugetlb_vmtruncate(struct inode *inode, loff_t offset)
 {
 	pgoff_t pgoff;
 	struct address_space *mapping = inode->i_mapping;
+	struct hstate *h = hstate_inode(inode);
 
-	BUG_ON(offset & ~HPAGE_MASK);
+	BUG_ON(offset & ~huge_page_mask(h));
 	pgoff = offset >> PAGE_SHIFT;
 
 	i_size_write(inode, offset);
@@ -465,6 +470,7 @@ static int hugetlb_vmtruncate(struct inode *inode, loff_t offset)
 static int hugetlbfs_setattr(struct dentry *dentry, struct iattr *attr)
 {
 	struct inode *inode = dentry->d_inode;
+	struct hstate *h = hstate_inode(inode);
 	int error;
 	unsigned int ia_valid = attr->ia_valid;
 
@@ -476,7 +482,7 @@ static int hugetlbfs_setattr(struct dentry *dentry, struct iattr *attr)
 
 	if (ia_valid & ATTR_SIZE) {
 		error = -EINVAL;
-		if (!(attr->ia_size & ~HPAGE_MASK))
+		if (!(attr->ia_size & ~huge_page_mask(h)))
 			error = hugetlb_vmtruncate(inode, attr->ia_size);
 		if (error)
 			goto out;
@@ -610,9 +616,10 @@ static int hugetlbfs_set_page_dirty(struct page *page)
 static int hugetlbfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 {
 	struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(dentry->d_sb);
+	struct hstate *h = hstate_inode(dentry->d_inode);
 
 	buf->f_type = HUGETLBFS_MAGIC;
-	buf->f_bsize = HPAGE_SIZE;
+	buf->f_bsize = huge_page_size(h);
 	if (sbinfo) {
 		spin_lock(&sbinfo->stat_lock);
 		/* If no limits set, just report 0 for max/free/used
@@ -942,7 +949,8 @@ struct file *hugetlb_file_setup(const char *name, size_t size)
 		goto out_dentry;
 
 	error = -ENOMEM;
-	if (hugetlb_reserve_pages(inode, 0, size >> HPAGE_SHIFT, NULL))
+	if (hugetlb_reserve_pages(inode, 0,
+			size >> huge_page_shift(hstate_inode(inode)), NULL))
 		goto out_inode;
 
 	d_instantiate(dentry, inode);