inode.c 34.3 KB
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/*
 * hugetlbpage-backed filesystem.  Based on ramfs.
 *
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 * Nadia Yvette Chambers, 2002
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 *
 * Copyright (C) 2002 Linus Torvalds.
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 * License: GPL
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 */

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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

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#include <linux/thread_info.h>
#include <asm/current.h>
#include <linux/sched.h>		/* remove ASAP */
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#include <linux/falloc.h>
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#include <linux/fs.h>
#include <linux/mount.h>
#include <linux/file.h>
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#include <linux/kernel.h>
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#include <linux/writeback.h>
#include <linux/pagemap.h>
#include <linux/highmem.h>
#include <linux/init.h>
#include <linux/string.h>
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#include <linux/capability.h>
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#include <linux/ctype.h>
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#include <linux/backing-dev.h>
#include <linux/hugetlb.h>
#include <linux/pagevec.h>
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#include <linux/parser.h>
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#include <linux/mman.h>
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#include <linux/slab.h>
#include <linux/dnotify.h>
#include <linux/statfs.h>
#include <linux/security.h>
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#include <linux/magic.h>
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#include <linux/migrate.h>
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#include <linux/uio.h>
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#include <asm/uaccess.h>

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static const struct super_operations hugetlbfs_ops;
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static const struct address_space_operations hugetlbfs_aops;
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const struct file_operations hugetlbfs_file_operations;
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static const struct inode_operations hugetlbfs_dir_inode_operations;
static const struct inode_operations hugetlbfs_inode_operations;
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struct hugetlbfs_config {
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	kuid_t   uid;
	kgid_t   gid;
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	umode_t mode;
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	long	max_hpages;
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	long	nr_inodes;
	struct hstate *hstate;
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	long    min_hpages;
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};

struct hugetlbfs_inode_info {
	struct shared_policy policy;
	struct inode vfs_inode;
};

static inline struct hugetlbfs_inode_info *HUGETLBFS_I(struct inode *inode)
{
	return container_of(inode, struct hugetlbfs_inode_info, vfs_inode);
}

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int sysctl_hugetlb_shm_group;

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enum {
	Opt_size, Opt_nr_inodes,
	Opt_mode, Opt_uid, Opt_gid,
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	Opt_pagesize, Opt_min_size,
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	Opt_err,
};

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static const match_table_t tokens = {
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	{Opt_size,	"size=%s"},
	{Opt_nr_inodes,	"nr_inodes=%s"},
	{Opt_mode,	"mode=%o"},
	{Opt_uid,	"uid=%u"},
	{Opt_gid,	"gid=%u"},
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	{Opt_pagesize,	"pagesize=%s"},
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	{Opt_min_size,	"min_size=%s"},
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	{Opt_err,	NULL},
};

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#ifdef CONFIG_NUMA
static inline void hugetlb_set_vma_policy(struct vm_area_struct *vma,
					struct inode *inode, pgoff_t index)
{
	vma->vm_policy = mpol_shared_policy_lookup(&HUGETLBFS_I(inode)->policy,
							index);
}

static inline void hugetlb_drop_vma_policy(struct vm_area_struct *vma)
{
	mpol_cond_put(vma->vm_policy);
}
#else
static inline void hugetlb_set_vma_policy(struct vm_area_struct *vma,
					struct inode *inode, pgoff_t index)
{
}

static inline void hugetlb_drop_vma_policy(struct vm_area_struct *vma)
{
}
#endif

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static void huge_pagevec_release(struct pagevec *pvec)
{
	int i;

	for (i = 0; i < pagevec_count(pvec); ++i)
		put_page(pvec->pages[i]);

	pagevec_reinit(pvec);
}

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static int hugetlbfs_file_mmap(struct file *file, struct vm_area_struct *vma)
{
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	struct inode *inode = file_inode(file);
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	loff_t len, vma_len;
	int ret;
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	struct hstate *h = hstate_file(file);
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	/*
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	 * vma address alignment (but not the pgoff alignment) has
	 * already been checked by prepare_hugepage_range.  If you add
	 * any error returns here, do so after setting VM_HUGETLB, so
	 * is_vm_hugetlb_page tests below unmap_region go the right
	 * way when do_mmap_pgoff unwinds (may be important on powerpc
	 * and ia64).
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	 */
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	vma->vm_flags |= VM_HUGETLB | VM_DONTEXPAND;
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	vma->vm_ops = &hugetlb_vm_ops;
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	if (vma->vm_pgoff & (~huge_page_mask(h) >> PAGE_SHIFT))
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		return -EINVAL;

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	vma_len = (loff_t)(vma->vm_end - vma->vm_start);

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	mutex_lock(&inode->i_mutex);
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	file_accessed(file);

	ret = -ENOMEM;
	len = vma_len + ((loff_t)vma->vm_pgoff << PAGE_SHIFT);

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	if (hugetlb_reserve_pages(inode,
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				vma->vm_pgoff >> huge_page_order(h),
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				len >> huge_page_shift(h), vma,
				vma->vm_flags))
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		goto out;
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	ret = 0;
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	if (vma->vm_flags & VM_WRITE && inode->i_size < len)
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		inode->i_size = len;
out:
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	mutex_unlock(&inode->i_mutex);
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	return ret;
}

/*
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 * Called under down_write(mmap_sem).
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 */

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#ifndef HAVE_ARCH_HUGETLB_UNMAPPED_AREA
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static unsigned long
hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
		unsigned long len, unsigned long pgoff, unsigned long flags)
{
	struct mm_struct *mm = current->mm;
	struct vm_area_struct *vma;
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	struct hstate *h = hstate_file(file);
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	struct vm_unmapped_area_info info;
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	if (len & ~huge_page_mask(h))
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		return -EINVAL;
	if (len > TASK_SIZE)
		return -ENOMEM;

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	if (flags & MAP_FIXED) {
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		if (prepare_hugepage_range(file, addr, len))
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			return -EINVAL;
		return addr;
	}

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	if (addr) {
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		addr = ALIGN(addr, huge_page_size(h));
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		vma = find_vma(mm, addr);
		if (TASK_SIZE - len >= addr &&
		    (!vma || addr + len <= vma->vm_start))
			return addr;
	}

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	info.flags = 0;
	info.length = len;
	info.low_limit = TASK_UNMAPPED_BASE;
	info.high_limit = TASK_SIZE;
	info.align_mask = PAGE_MASK & ~huge_page_mask(h);
	info.align_offset = 0;
	return vm_unmapped_area(&info);
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}
#endif

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static size_t
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hugetlbfs_read_actor(struct page *page, unsigned long offset,
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			struct iov_iter *to, unsigned long size)
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{
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	size_t copied = 0;
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	int i, chunksize;

	/* Find which 4k chunk and offset with in that chunk */
	i = offset >> PAGE_CACHE_SHIFT;
	offset = offset & ~PAGE_CACHE_MASK;

	while (size) {
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		size_t n;
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		chunksize = PAGE_CACHE_SIZE;
		if (offset)
			chunksize -= offset;
		if (chunksize > size)
			chunksize = size;
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		n = copy_page_to_iter(&page[i], offset, chunksize, to);
		copied += n;
		if (n != chunksize)
			return copied;
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		offset = 0;
		size -= chunksize;
		i++;
	}
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	return copied;
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}

/*
 * Support for read() - Find the page attached to f_mapping and copy out the
 * data. Its *very* similar to do_generic_mapping_read(), we can't use that
 * since it has PAGE_CACHE_SIZE assumptions.
 */
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static ssize_t hugetlbfs_read_iter(struct kiocb *iocb, struct iov_iter *to)
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{
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	struct file *file = iocb->ki_filp;
	struct hstate *h = hstate_file(file);
	struct address_space *mapping = file->f_mapping;
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	struct inode *inode = mapping->host;
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	unsigned long index = iocb->ki_pos >> huge_page_shift(h);
	unsigned long offset = iocb->ki_pos & ~huge_page_mask(h);
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	unsigned long end_index;
	loff_t isize;
	ssize_t retval = 0;

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	while (iov_iter_count(to)) {
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		struct page *page;
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		size_t nr, copied;
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		/* nr is the maximum number of bytes to copy from this page */
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		nr = huge_page_size(h);
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		isize = i_size_read(inode);
		if (!isize)
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			break;
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		end_index = (isize - 1) >> huge_page_shift(h);
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		if (index > end_index)
			break;
		if (index == end_index) {
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			nr = ((isize - 1) & ~huge_page_mask(h)) + 1;
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			if (nr <= offset)
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				break;
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		}
		nr = nr - offset;

		/* Find the page */
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		page = find_lock_page(mapping, index);
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		if (unlikely(page == NULL)) {
			/*
			 * We have a HOLE, zero out the user-buffer for the
			 * length of the hole or request.
			 */
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			copied = iov_iter_zero(nr, to);
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		} else {
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			unlock_page(page);

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			/*
			 * We have the page, copy it to user space buffer.
			 */
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			copied = hugetlbfs_read_actor(page, offset, to, nr);
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			page_cache_release(page);
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		}
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		offset += copied;
		retval += copied;
		if (copied != nr && iov_iter_count(to)) {
			if (!retval)
				retval = -EFAULT;
			break;
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		}
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		index += offset >> huge_page_shift(h);
		offset &= ~huge_page_mask(h);
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	}
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	iocb->ki_pos = ((loff_t)index << huge_page_shift(h)) + offset;
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	return retval;
}

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static int hugetlbfs_write_begin(struct file *file,
			struct address_space *mapping,
			loff_t pos, unsigned len, unsigned flags,
			struct page **pagep, void **fsdata)
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{
	return -EINVAL;
}

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static int hugetlbfs_write_end(struct file *file, struct address_space *mapping,
			loff_t pos, unsigned len, unsigned copied,
			struct page *page, void *fsdata)
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{
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	BUG();
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	return -EINVAL;
}

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static void remove_huge_page(struct page *page)
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{
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	ClearPageDirty(page);
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	ClearPageUptodate(page);
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	delete_from_page_cache(page);
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}

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/*
 * remove_inode_hugepages handles two distinct cases: truncation and hole
 * punch.  There are subtle differences in operation for each case.

 * truncation is indicated by end of range being LLONG_MAX
 *	In this case, we first scan the range and release found pages.
 *	After releasing pages, hugetlb_unreserve_pages cleans up region/reserv
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 *	maps and global counts.  Page faults can not race with truncation
 *	in this routine.  hugetlb_no_page() prevents page faults in the
 *	truncated range.  It checks i_size before allocation, and again after
 *	with the page table lock for the page held.  The same lock must be
 *	acquired to unmap a page.
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 * hole punch is indicated if end is not LLONG_MAX
 *	In the hole punch case we scan the range and release found pages.
 *	Only when releasing a page is the associated region/reserv map
 *	deleted.  The region/reserv map for ranges without associated
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 *	pages are not modified.  Page faults can race with hole punch.
 *	This is indicated if we find a mapped page.
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 * Note: If the passed end of range value is beyond the end of file, but
 * not LLONG_MAX this routine still performs a hole punch operation.
 */
static void remove_inode_hugepages(struct inode *inode, loff_t lstart,
				   loff_t lend)
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{
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	struct hstate *h = hstate_inode(inode);
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	struct address_space *mapping = &inode->i_data;
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	const pgoff_t start = lstart >> huge_page_shift(h);
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	const pgoff_t end = lend >> huge_page_shift(h);
	struct vm_area_struct pseudo_vma;
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	struct pagevec pvec;
	pgoff_t next;
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	int i, freed = 0;
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	long lookup_nr = PAGEVEC_SIZE;
	bool truncate_op = (lend == LLONG_MAX);
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	memset(&pseudo_vma, 0, sizeof(struct vm_area_struct));
	pseudo_vma.vm_flags = (VM_HUGETLB | VM_MAYSHARE | VM_SHARED);
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	pagevec_init(&pvec, 0);
	next = start;
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	while (next < end) {
		/*
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		 * Don't grab more pages than the number left in the range.
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		 */
		if (end - next < lookup_nr)
			lookup_nr = end - next;

		/*
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		 * When no more pages are found, we are done.
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		 */
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		if (!pagevec_lookup(&pvec, mapping, next, lookup_nr))
			break;
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		for (i = 0; i < pagevec_count(&pvec); ++i) {
			struct page *page = pvec.pages[i];
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			u32 hash;

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			/*
			 * The page (index) could be beyond end.  This is
			 * only possible in the punch hole case as end is
			 * max page offset in the truncate case.
			 */
			next = page->index;
			if (next >= end)
				break;

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			hash = hugetlb_fault_mutex_hash(h, current->mm,
							&pseudo_vma,
							mapping, next, 0);
			mutex_lock(&hugetlb_fault_mutex_table[hash]);
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			lock_page(page);
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			if (likely(!page_mapped(page))) {
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				bool rsv_on_error = !PagePrivate(page);
				/*
				 * We must free the huge page and remove
				 * from page cache (remove_huge_page) BEFORE
				 * removing the region/reserve map
				 * (hugetlb_unreserve_pages).  In rare out
				 * of memory conditions, removal of the
				 * region/reserve map could fail.  Before
				 * free'ing the page, note PagePrivate which
				 * is used in case of error.
				 */
				remove_huge_page(page);
				freed++;
				if (!truncate_op) {
					if (unlikely(hugetlb_unreserve_pages(
							inode, next,
							next + 1, 1)))
						hugetlb_fix_reserve_counts(
							inode, rsv_on_error);
				}
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			} else {
				/*
				 * If page is mapped, it was faulted in after
				 * being unmapped.  It indicates a race between
				 * hole punch and page fault.  Do nothing in
				 * this case.  Getting here in a truncate
				 * operation is a bug.
				 */
				BUG_ON(truncate_op);
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			}

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			unlock_page(page);
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			mutex_unlock(&hugetlb_fault_mutex_table[hash]);
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		}
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		++next;
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		huge_pagevec_release(&pvec);
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		cond_resched();
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	}
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	if (truncate_op)
		(void)hugetlb_unreserve_pages(inode, start, LONG_MAX, freed);
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}

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static void hugetlbfs_evict_inode(struct inode *inode)
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{
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	struct resv_map *resv_map;

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	remove_inode_hugepages(inode, 0, LLONG_MAX);
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	resv_map = (struct resv_map *)inode->i_mapping->private_data;
	/* root inode doesn't have the resv_map, so we should check it */
	if (resv_map)
		resv_map_release(&resv_map->refs);
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	clear_inode(inode);
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}

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static inline void
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hugetlb_vmdelete_list(struct rb_root *root, pgoff_t start, pgoff_t end)
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{
	struct vm_area_struct *vma;

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	/*
	 * end == 0 indicates that the entire range after
	 * start should be unmapped.
	 */
	vma_interval_tree_foreach(vma, root, start, end ? end : ULONG_MAX) {
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		unsigned long v_offset;
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		unsigned long v_end;
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		/*
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		 * Can the expression below overflow on 32-bit arches?
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		 * No, because the interval tree returns us only those vmas
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		 * which overlap the truncated area starting at pgoff,
		 * and no vma on a 32-bit arch can span beyond the 4GB.
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		 */
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		if (vma->vm_pgoff < start)
			v_offset = (start - vma->vm_pgoff) << PAGE_SHIFT;
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		else
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			v_offset = 0;

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		if (!end)
			v_end = vma->vm_end;
		else {
			v_end = ((end - vma->vm_pgoff) << PAGE_SHIFT)
							+ vma->vm_start;
			if (v_end > vma->vm_end)
				v_end = vma->vm_end;
		}
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		unmap_hugepage_range(vma, vma->vm_start + v_offset, v_end,
									NULL);
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	}
}

static int hugetlb_vmtruncate(struct inode *inode, loff_t offset)
{
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	pgoff_t pgoff;
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	struct address_space *mapping = inode->i_mapping;
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	struct hstate *h = hstate_inode(inode);
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	BUG_ON(offset & ~huge_page_mask(h));
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	pgoff = offset >> PAGE_SHIFT;
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	i_size_write(inode, offset);
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	i_mmap_lock_write(mapping);
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	if (!RB_EMPTY_ROOT(&mapping->i_mmap))
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		hugetlb_vmdelete_list(&mapping->i_mmap, pgoff, 0);
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	i_mmap_unlock_write(mapping);
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	remove_inode_hugepages(inode, offset, LLONG_MAX);
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	return 0;
}

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static long hugetlbfs_punch_hole(struct inode *inode, loff_t offset, loff_t len)
{
	struct hstate *h = hstate_inode(inode);
	loff_t hpage_size = huge_page_size(h);
	loff_t hole_start, hole_end;

	/*
	 * For hole punch round up the beginning offset of the hole and
	 * round down the end.
	 */
	hole_start = round_up(offset, hpage_size);
	hole_end = round_down(offset + len, hpage_size);

	if (hole_end > hole_start) {
		struct address_space *mapping = inode->i_mapping;

		mutex_lock(&inode->i_mutex);
		i_mmap_lock_write(mapping);
		if (!RB_EMPTY_ROOT(&mapping->i_mmap))
			hugetlb_vmdelete_list(&mapping->i_mmap,
						hole_start >> PAGE_SHIFT,
						hole_end  >> PAGE_SHIFT);
		i_mmap_unlock_write(mapping);
		remove_inode_hugepages(inode, hole_start, hole_end);
		mutex_unlock(&inode->i_mutex);
	}

	return 0;
}

static long hugetlbfs_fallocate(struct file *file, int mode, loff_t offset,
				loff_t len)
{
	struct inode *inode = file_inode(file);
	struct address_space *mapping = inode->i_mapping;
	struct hstate *h = hstate_inode(inode);
	struct vm_area_struct pseudo_vma;
	struct mm_struct *mm = current->mm;
	loff_t hpage_size = huge_page_size(h);
	unsigned long hpage_shift = huge_page_shift(h);
	pgoff_t start, index, end;
	int error;
	u32 hash;

	if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
		return -EOPNOTSUPP;

	if (mode & FALLOC_FL_PUNCH_HOLE)
		return hugetlbfs_punch_hole(inode, offset, len);

	/*
	 * Default preallocate case.
	 * For this range, start is rounded down and end is rounded up
	 * as well as being converted to page offsets.
	 */
	start = offset >> hpage_shift;
	end = (offset + len + hpage_size - 1) >> hpage_shift;

	mutex_lock(&inode->i_mutex);

	/* We need to check rlimit even when FALLOC_FL_KEEP_SIZE */
	error = inode_newsize_ok(inode, offset + len);
	if (error)
		goto out;

	/*
	 * Initialize a pseudo vma as this is required by the huge page
	 * allocation routines.  If NUMA is configured, use page index
	 * as input to create an allocation policy.
	 */
	memset(&pseudo_vma, 0, sizeof(struct vm_area_struct));
	pseudo_vma.vm_flags = (VM_HUGETLB | VM_MAYSHARE | VM_SHARED);
	pseudo_vma.vm_file = file;

	for (index = start; index < end; index++) {
		/*
		 * This is supposed to be the vaddr where the page is being
		 * faulted in, but we have no vaddr here.
		 */
		struct page *page;
		unsigned long addr;
		int avoid_reserve = 0;

		cond_resched();

		/*
		 * fallocate(2) manpage permits EINTR; we may have been
		 * interrupted because we are using up too much memory.
		 */
		if (signal_pending(current)) {
			error = -EINTR;
			break;
		}

		/* Set numa allocation policy based on index */
		hugetlb_set_vma_policy(&pseudo_vma, inode, index);

		/* addr is the offset within the file (zero based) */
		addr = index * hpage_size;

		/* mutex taken here, fault path and hole punch */
		hash = hugetlb_fault_mutex_hash(h, mm, &pseudo_vma, mapping,
						index, addr);
		mutex_lock(&hugetlb_fault_mutex_table[hash]);

		/* See if already present in mapping to avoid alloc/free */
		page = find_get_page(mapping, index);
		if (page) {
			put_page(page);
			mutex_unlock(&hugetlb_fault_mutex_table[hash]);
			hugetlb_drop_vma_policy(&pseudo_vma);
			continue;
		}

		/* Allocate page and add to page cache */
		page = alloc_huge_page(&pseudo_vma, addr, avoid_reserve);
		hugetlb_drop_vma_policy(&pseudo_vma);
		if (IS_ERR(page)) {
			mutex_unlock(&hugetlb_fault_mutex_table[hash]);
			error = PTR_ERR(page);
			goto out;
		}
		clear_huge_page(page, addr, pages_per_huge_page(h));
		__SetPageUptodate(page);
		error = huge_add_to_page_cache(page, mapping, index);
		if (unlikely(error)) {
			put_page(page);
			mutex_unlock(&hugetlb_fault_mutex_table[hash]);
			goto out;
		}

		mutex_unlock(&hugetlb_fault_mutex_table[hash]);

		/*
		 * page_put due to reference from alloc_huge_page()
		 * unlock_page because locked by add_to_page_cache()
		 */
		put_page(page);
		unlock_page(page);
	}

	if (!(mode & FALLOC_FL_KEEP_SIZE) && offset + len > inode->i_size)
		i_size_write(inode, offset + len);
	inode->i_ctime = CURRENT_TIME;
out:
	mutex_unlock(&inode->i_mutex);
	return error;
}

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static int hugetlbfs_setattr(struct dentry *dentry, struct iattr *attr)
{
662
	struct inode *inode = d_inode(dentry);
663
	struct hstate *h = hstate_inode(inode);
L
Linus Torvalds 已提交
664 665 666 667 668 669 670
	int error;
	unsigned int ia_valid = attr->ia_valid;

	BUG_ON(!inode);

	error = inode_change_ok(inode, attr);
	if (error)
C
Christoph Hellwig 已提交
671
		return error;
L
Linus Torvalds 已提交
672 673 674

	if (ia_valid & ATTR_SIZE) {
		error = -EINVAL;
C
Christoph Hellwig 已提交
675 676 677
		if (attr->ia_size & ~huge_page_mask(h))
			return -EINVAL;
		error = hugetlb_vmtruncate(inode, attr->ia_size);
L
Linus Torvalds 已提交
678
		if (error)
C
Christoph Hellwig 已提交
679
			return error;
L
Linus Torvalds 已提交
680
	}
C
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681 682 683 684

	setattr_copy(inode, attr);
	mark_inode_dirty(inode);
	return 0;
L
Linus Torvalds 已提交
685 686
}

687 688
static struct inode *hugetlbfs_get_root(struct super_block *sb,
					struct hugetlbfs_config *config)
L
Linus Torvalds 已提交
689 690 691 692 693 694
{
	struct inode *inode;

	inode = new_inode(sb);
	if (inode) {
		struct hugetlbfs_inode_info *info;
695
		inode->i_ino = get_next_ino();
696 697 698 699 700 701 702 703 704 705
		inode->i_mode = S_IFDIR | config->mode;
		inode->i_uid = config->uid;
		inode->i_gid = config->gid;
		inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
		info = HUGETLBFS_I(inode);
		mpol_shared_policy_init(&info->policy, NULL);
		inode->i_op = &hugetlbfs_dir_inode_operations;
		inode->i_fop = &simple_dir_operations;
		/* directory inodes start off with i_nlink == 2 (for "." entry) */
		inc_nlink(inode);
706
		lockdep_annotate_inode_mutex_key(inode);
707 708 709 710
	}
	return inode;
}

711
/*
712
 * Hugetlbfs is not reclaimable; therefore its i_mmap_rwsem will never
713
 * be taken from reclaim -- unlike regular filesystems. This needs an
714
 * annotation because huge_pmd_share() does an allocation under hugetlb's
715
 * i_mmap_rwsem.
716
 */
717
static struct lock_class_key hugetlbfs_i_mmap_rwsem_key;
718

719 720
static struct inode *hugetlbfs_get_inode(struct super_block *sb,
					struct inode *dir,
A
Al Viro 已提交
721
					umode_t mode, dev_t dev)
722 723
{
	struct inode *inode;
724 725 726 727 728
	struct resv_map *resv_map;

	resv_map = resv_map_alloc();
	if (!resv_map)
		return NULL;
729 730 731 732 733 734

	inode = new_inode(sb);
	if (inode) {
		struct hugetlbfs_inode_info *info;
		inode->i_ino = get_next_ino();
		inode_init_owner(inode, dir, mode);
735 736
		lockdep_set_class(&inode->i_mapping->i_mmap_rwsem,
				&hugetlbfs_i_mmap_rwsem_key);
L
Linus Torvalds 已提交
737 738
		inode->i_mapping->a_ops = &hugetlbfs_aops;
		inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
739
		inode->i_mapping->private_data = resv_map;
L
Linus Torvalds 已提交
740
		info = HUGETLBFS_I(inode);
741 742 743
		/*
		 * The policy is initialized here even if we are creating a
		 * private inode because initialization simply creates an
744
		 * an empty rb tree and calls rwlock_init(), later when we
745 746 747
		 * call mpol_free_shared_policy() it will just return because
		 * the rb tree will still be empty.
		 */
748
		mpol_shared_policy_init(&info->policy, NULL);
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749 750 751 752 753 754 755 756 757 758 759 760 761
		switch (mode & S_IFMT) {
		default:
			init_special_inode(inode, mode, dev);
			break;
		case S_IFREG:
			inode->i_op = &hugetlbfs_inode_operations;
			inode->i_fop = &hugetlbfs_file_operations;
			break;
		case S_IFDIR:
			inode->i_op = &hugetlbfs_dir_inode_operations;
			inode->i_fop = &simple_dir_operations;

			/* directory inodes start off with i_nlink == 2 (for "." entry) */
762
			inc_nlink(inode);
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Linus Torvalds 已提交
763 764 765
			break;
		case S_IFLNK:
			inode->i_op = &page_symlink_inode_operations;
766
			inode_nohighmem(inode);
L
Linus Torvalds 已提交
767 768
			break;
		}
769
		lockdep_annotate_inode_mutex_key(inode);
770 771 772
	} else
		kref_put(&resv_map->refs, resv_map_release);

L
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773 774 775 776 777 778 779
	return inode;
}

/*
 * File creation. Allocate an inode, and we're done..
 */
static int hugetlbfs_mknod(struct inode *dir,
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780
			struct dentry *dentry, umode_t mode, dev_t dev)
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781 782 783
{
	struct inode *inode;
	int error = -ENOSPC;
784 785

	inode = hugetlbfs_get_inode(dir->i_sb, dir, mode, dev);
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786 787 788 789 790 791 792 793 794
	if (inode) {
		dir->i_ctime = dir->i_mtime = CURRENT_TIME;
		d_instantiate(dentry, inode);
		dget(dentry);	/* Extra count - pin the dentry in core */
		error = 0;
	}
	return error;
}

795
static int hugetlbfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
L
Linus Torvalds 已提交
796 797 798
{
	int retval = hugetlbfs_mknod(dir, dentry, mode | S_IFDIR, 0);
	if (!retval)
799
		inc_nlink(dir);
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	return retval;
}

A
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803
static int hugetlbfs_create(struct inode *dir, struct dentry *dentry, umode_t mode, bool excl)
L
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804 805 806 807 808 809 810 811 812 813
{
	return hugetlbfs_mknod(dir, dentry, mode | S_IFREG, 0);
}

static int hugetlbfs_symlink(struct inode *dir,
			struct dentry *dentry, const char *symname)
{
	struct inode *inode;
	int error = -ENOSPC;

814
	inode = hugetlbfs_get_inode(dir->i_sb, dir, S_IFLNK|S_IRWXUGO, 0);
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815 816 817 818 819 820 821 822 823 824 825 826 827 828 829
	if (inode) {
		int l = strlen(symname)+1;
		error = page_symlink(inode, symname, l);
		if (!error) {
			d_instantiate(dentry, inode);
			dget(dentry);
		} else
			iput(inode);
	}
	dir->i_ctime = dir->i_mtime = CURRENT_TIME;

	return error;
}

/*
830
 * mark the head page dirty
L
Linus Torvalds 已提交
831 832 833
 */
static int hugetlbfs_set_page_dirty(struct page *page)
{
834
	struct page *head = compound_head(page);
835 836

	SetPageDirty(head);
L
Linus Torvalds 已提交
837 838 839
	return 0;
}

N
Naoya Horiguchi 已提交
840
static int hugetlbfs_migrate_page(struct address_space *mapping,
841
				struct page *newpage, struct page *page,
842
				enum migrate_mode mode)
N
Naoya Horiguchi 已提交
843 844 845 846
{
	int rc;

	rc = migrate_huge_page_move_mapping(mapping, newpage, page);
847
	if (rc != MIGRATEPAGE_SUCCESS)
N
Naoya Horiguchi 已提交
848 849 850
		return rc;
	migrate_page_copy(newpage, page);

851
	return MIGRATEPAGE_SUCCESS;
N
Naoya Horiguchi 已提交
852 853
}

854
static int hugetlbfs_statfs(struct dentry *dentry, struct kstatfs *buf)
L
Linus Torvalds 已提交
855
{
856
	struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(dentry->d_sb);
857
	struct hstate *h = hstate_inode(d_inode(dentry));
L
Linus Torvalds 已提交
858 859

	buf->f_type = HUGETLBFS_MAGIC;
860
	buf->f_bsize = huge_page_size(h);
L
Linus Torvalds 已提交
861 862
	if (sbinfo) {
		spin_lock(&sbinfo->stat_lock);
863 864
		/* If no limits set, just report 0 for max/free/used
		 * blocks, like simple_statfs() */
865 866 867 868 869 870 871 872 873
		if (sbinfo->spool) {
			long free_pages;

			spin_lock(&sbinfo->spool->lock);
			buf->f_blocks = sbinfo->spool->max_hpages;
			free_pages = sbinfo->spool->max_hpages
				- sbinfo->spool->used_hpages;
			buf->f_bavail = buf->f_bfree = free_pages;
			spin_unlock(&sbinfo->spool->lock);
874 875 876
			buf->f_files = sbinfo->max_inodes;
			buf->f_ffree = sbinfo->free_inodes;
		}
L
Linus Torvalds 已提交
877 878 879 880 881 882 883 884 885 886 887 888
		spin_unlock(&sbinfo->stat_lock);
	}
	buf->f_namelen = NAME_MAX;
	return 0;
}

static void hugetlbfs_put_super(struct super_block *sb)
{
	struct hugetlbfs_sb_info *sbi = HUGETLBFS_SB(sb);

	if (sbi) {
		sb->s_fs_info = NULL;
889 890 891 892

		if (sbi->spool)
			hugepage_put_subpool(sbi->spool);

L
Linus Torvalds 已提交
893 894 895 896
		kfree(sbi);
	}
}

897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921
static inline int hugetlbfs_dec_free_inodes(struct hugetlbfs_sb_info *sbinfo)
{
	if (sbinfo->free_inodes >= 0) {
		spin_lock(&sbinfo->stat_lock);
		if (unlikely(!sbinfo->free_inodes)) {
			spin_unlock(&sbinfo->stat_lock);
			return 0;
		}
		sbinfo->free_inodes--;
		spin_unlock(&sbinfo->stat_lock);
	}

	return 1;
}

static void hugetlbfs_inc_free_inodes(struct hugetlbfs_sb_info *sbinfo)
{
	if (sbinfo->free_inodes >= 0) {
		spin_lock(&sbinfo->stat_lock);
		sbinfo->free_inodes++;
		spin_unlock(&sbinfo->stat_lock);
	}
}


922
static struct kmem_cache *hugetlbfs_inode_cachep;
L
Linus Torvalds 已提交
923 924 925

static struct inode *hugetlbfs_alloc_inode(struct super_block *sb)
{
926
	struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(sb);
L
Linus Torvalds 已提交
927 928
	struct hugetlbfs_inode_info *p;

929 930
	if (unlikely(!hugetlbfs_dec_free_inodes(sbinfo)))
		return NULL;
931
	p = kmem_cache_alloc(hugetlbfs_inode_cachep, GFP_KERNEL);
932 933
	if (unlikely(!p)) {
		hugetlbfs_inc_free_inodes(sbinfo);
L
Linus Torvalds 已提交
934
		return NULL;
935
	}
L
Linus Torvalds 已提交
936 937 938
	return &p->vfs_inode;
}

N
Nick Piggin 已提交
939 940 941 942 943 944
static void hugetlbfs_i_callback(struct rcu_head *head)
{
	struct inode *inode = container_of(head, struct inode, i_rcu);
	kmem_cache_free(hugetlbfs_inode_cachep, HUGETLBFS_I(inode));
}

L
Linus Torvalds 已提交
945 946
static void hugetlbfs_destroy_inode(struct inode *inode)
{
947
	hugetlbfs_inc_free_inodes(HUGETLBFS_SB(inode->i_sb));
L
Linus Torvalds 已提交
948
	mpol_free_shared_policy(&HUGETLBFS_I(inode)->policy);
N
Nick Piggin 已提交
949
	call_rcu(&inode->i_rcu, hugetlbfs_i_callback);
L
Linus Torvalds 已提交
950 951
}

952
static const struct address_space_operations hugetlbfs_aops = {
N
Nick Piggin 已提交
953 954
	.write_begin	= hugetlbfs_write_begin,
	.write_end	= hugetlbfs_write_end,
L
Linus Torvalds 已提交
955
	.set_page_dirty	= hugetlbfs_set_page_dirty,
N
Naoya Horiguchi 已提交
956
	.migratepage    = hugetlbfs_migrate_page,
L
Linus Torvalds 已提交
957 958
};

959

960
static void init_once(void *foo)
961 962 963
{
	struct hugetlbfs_inode_info *ei = (struct hugetlbfs_inode_info *)foo;

C
Christoph Lameter 已提交
964
	inode_init_once(&ei->vfs_inode);
965 966
}

967
const struct file_operations hugetlbfs_file_operations = {
A
Al Viro 已提交
968
	.read_iter		= hugetlbfs_read_iter,
L
Linus Torvalds 已提交
969
	.mmap			= hugetlbfs_file_mmap,
970
	.fsync			= noop_fsync,
L
Linus Torvalds 已提交
971
	.get_unmapped_area	= hugetlb_get_unmapped_area,
972 973
	.llseek			= default_llseek,
	.fallocate		= hugetlbfs_fallocate,
L
Linus Torvalds 已提交
974 975
};

976
static const struct inode_operations hugetlbfs_dir_inode_operations = {
L
Linus Torvalds 已提交
977 978 979 980 981 982 983 984 985 986 987 988
	.create		= hugetlbfs_create,
	.lookup		= simple_lookup,
	.link		= simple_link,
	.unlink		= simple_unlink,
	.symlink	= hugetlbfs_symlink,
	.mkdir		= hugetlbfs_mkdir,
	.rmdir		= simple_rmdir,
	.mknod		= hugetlbfs_mknod,
	.rename		= simple_rename,
	.setattr	= hugetlbfs_setattr,
};

989
static const struct inode_operations hugetlbfs_inode_operations = {
L
Linus Torvalds 已提交
990 991 992
	.setattr	= hugetlbfs_setattr,
};

993
static const struct super_operations hugetlbfs_ops = {
L
Linus Torvalds 已提交
994 995
	.alloc_inode    = hugetlbfs_alloc_inode,
	.destroy_inode  = hugetlbfs_destroy_inode,
A
Al Viro 已提交
996
	.evict_inode	= hugetlbfs_evict_inode,
L
Linus Torvalds 已提交
997 998
	.statfs		= hugetlbfs_statfs,
	.put_super	= hugetlbfs_put_super,
M
Miklos Szeredi 已提交
999
	.show_options	= generic_show_options,
L
Linus Torvalds 已提交
1000 1001
};

1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025
enum { NO_SIZE, SIZE_STD, SIZE_PERCENT };

/*
 * Convert size option passed from command line to number of huge pages
 * in the pool specified by hstate.  Size option could be in bytes
 * (val_type == SIZE_STD) or percentage of the pool (val_type == SIZE_PERCENT).
 */
static long long
hugetlbfs_size_to_hpages(struct hstate *h, unsigned long long size_opt,
								int val_type)
{
	if (val_type == NO_SIZE)
		return -1;

	if (val_type == SIZE_PERCENT) {
		size_opt <<= huge_page_shift(h);
		size_opt *= h->max_huge_pages;
		do_div(size_opt, 100);
	}

	size_opt >>= huge_page_shift(h);
	return size_opt;
}

L
Linus Torvalds 已提交
1026 1027 1028
static int
hugetlbfs_parse_options(char *options, struct hugetlbfs_config *pconfig)
{
1029 1030 1031
	char *p, *rest;
	substring_t args[MAX_OPT_ARGS];
	int option;
1032 1033
	unsigned long long max_size_opt = 0, min_size_opt = 0;
	int max_val_type = NO_SIZE, min_val_type = NO_SIZE;
L
Linus Torvalds 已提交
1034 1035 1036 1037

	if (!options)
		return 0;

1038 1039
	while ((p = strsep(&options, ",")) != NULL) {
		int token;
1040 1041
		if (!*p)
			continue;
1042 1043 1044 1045 1046 1047

		token = match_token(p, tokens, args);
		switch (token) {
		case Opt_uid:
			if (match_int(&args[0], &option))
 				goto bad_val;
1048 1049 1050
			pconfig->uid = make_kuid(current_user_ns(), option);
			if (!uid_valid(pconfig->uid))
				goto bad_val;
1051 1052 1053 1054 1055
			break;

		case Opt_gid:
			if (match_int(&args[0], &option))
 				goto bad_val;
1056 1057 1058
			pconfig->gid = make_kgid(current_user_ns(), option);
			if (!gid_valid(pconfig->gid))
				goto bad_val;
1059 1060 1061 1062 1063
			break;

		case Opt_mode:
			if (match_octal(&args[0], &option))
 				goto bad_val;
1064
			pconfig->mode = option & 01777U;
1065 1066 1067 1068 1069 1070
			break;

		case Opt_size: {
			/* memparse() will accept a K/M/G without a digit */
			if (!isdigit(*args[0].from))
				goto bad_val;
1071 1072
			max_size_opt = memparse(args[0].from, &rest);
			max_val_type = SIZE_STD;
1073
			if (*rest == '%')
1074
				max_val_type = SIZE_PERCENT;
1075 1076
			break;
		}
L
Linus Torvalds 已提交
1077

1078 1079 1080 1081 1082 1083 1084
		case Opt_nr_inodes:
			/* memparse() will accept a K/M/G without a digit */
			if (!isdigit(*args[0].from))
				goto bad_val;
			pconfig->nr_inodes = memparse(args[0].from, &rest);
			break;

1085 1086 1087 1088 1089
		case Opt_pagesize: {
			unsigned long ps;
			ps = memparse(args[0].from, &rest);
			pconfig->hstate = size_to_hstate(ps);
			if (!pconfig->hstate) {
1090
				pr_err("Unsupported page size %lu MB\n",
1091 1092 1093 1094 1095 1096
					ps >> 20);
				return -EINVAL;
			}
			break;
		}

1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107
		case Opt_min_size: {
			/* memparse() will accept a K/M/G without a digit */
			if (!isdigit(*args[0].from))
				goto bad_val;
			min_size_opt = memparse(args[0].from, &rest);
			min_val_type = SIZE_STD;
			if (*rest == '%')
				min_val_type = SIZE_PERCENT;
			break;
		}

1108
		default:
1109
			pr_err("Bad mount option: \"%s\"\n", p);
1110
			return -EINVAL;
1111 1112
			break;
		}
L
Linus Torvalds 已提交
1113
	}
1114

1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130
	/*
	 * Use huge page pool size (in hstate) to convert the size
	 * options to number of huge pages.  If NO_SIZE, -1 is returned.
	 */
	pconfig->max_hpages = hugetlbfs_size_to_hpages(pconfig->hstate,
						max_size_opt, max_val_type);
	pconfig->min_hpages = hugetlbfs_size_to_hpages(pconfig->hstate,
						min_size_opt, min_val_type);

	/*
	 * If max_size was specified, then min_size must be smaller
	 */
	if (max_val_type > NO_SIZE &&
	    pconfig->min_hpages > pconfig->max_hpages) {
		pr_err("minimum size can not be greater than maximum size\n");
		return -EINVAL;
1131 1132
	}

L
Linus Torvalds 已提交
1133
	return 0;
1134 1135

bad_val:
1136
	pr_err("Bad value '%s' for mount option '%s'\n", args[0].from, p);
1137
 	return -EINVAL;
L
Linus Torvalds 已提交
1138 1139 1140 1141 1142 1143 1144 1145 1146
}

static int
hugetlbfs_fill_super(struct super_block *sb, void *data, int silent)
{
	int ret;
	struct hugetlbfs_config config;
	struct hugetlbfs_sb_info *sbinfo;

M
Miklos Szeredi 已提交
1147 1148
	save_mount_options(sb, data);

1149
	config.max_hpages = -1; /* No limit on size by default */
L
Linus Torvalds 已提交
1150
	config.nr_inodes = -1; /* No limit on number of inodes by default */
1151 1152
	config.uid = current_fsuid();
	config.gid = current_fsgid();
L
Linus Torvalds 已提交
1153
	config.mode = 0755;
1154
	config.hstate = &default_hstate;
1155
	config.min_hpages = -1; /* No default minimum size */
L
Linus Torvalds 已提交
1156 1157 1158 1159 1160 1161 1162 1163
	ret = hugetlbfs_parse_options(data, &config);
	if (ret)
		return ret;

	sbinfo = kmalloc(sizeof(struct hugetlbfs_sb_info), GFP_KERNEL);
	if (!sbinfo)
		return -ENOMEM;
	sb->s_fs_info = sbinfo;
1164
	sbinfo->hstate = config.hstate;
L
Linus Torvalds 已提交
1165 1166 1167
	spin_lock_init(&sbinfo->stat_lock);
	sbinfo->max_inodes = config.nr_inodes;
	sbinfo->free_inodes = config.nr_inodes;
1168
	sbinfo->spool = NULL;
1169 1170 1171 1172 1173 1174 1175 1176 1177
	/*
	 * Allocate and initialize subpool if maximum or minimum size is
	 * specified.  Any needed reservations (for minimim size) are taken
	 * taken when the subpool is created.
	 */
	if (config.max_hpages != -1 || config.min_hpages != -1) {
		sbinfo->spool = hugepage_new_subpool(config.hstate,
							config.max_hpages,
							config.min_hpages);
1178 1179 1180
		if (!sbinfo->spool)
			goto out_free;
	}
L
Linus Torvalds 已提交
1181
	sb->s_maxbytes = MAX_LFS_FILESIZE;
1182 1183
	sb->s_blocksize = huge_page_size(config.hstate);
	sb->s_blocksize_bits = huge_page_shift(config.hstate);
L
Linus Torvalds 已提交
1184 1185 1186
	sb->s_magic = HUGETLBFS_MAGIC;
	sb->s_op = &hugetlbfs_ops;
	sb->s_time_gran = 1;
1187 1188
	sb->s_root = d_make_root(hugetlbfs_get_root(sb, &config));
	if (!sb->s_root)
L
Linus Torvalds 已提交
1189 1190 1191
		goto out_free;
	return 0;
out_free:
1192
	kfree(sbinfo->spool);
L
Linus Torvalds 已提交
1193 1194 1195 1196
	kfree(sbinfo);
	return -ENOMEM;
}

A
Al Viro 已提交
1197 1198
static struct dentry *hugetlbfs_mount(struct file_system_type *fs_type,
	int flags, const char *dev_name, void *data)
L
Linus Torvalds 已提交
1199
{
A
Al Viro 已提交
1200
	return mount_nodev(fs_type, flags, data, hugetlbfs_fill_super);
L
Linus Torvalds 已提交
1201 1202 1203 1204
}

static struct file_system_type hugetlbfs_fs_type = {
	.name		= "hugetlbfs",
A
Al Viro 已提交
1205
	.mount		= hugetlbfs_mount,
L
Linus Torvalds 已提交
1206 1207 1208
	.kill_sb	= kill_litter_super,
};

1209
static struct vfsmount *hugetlbfs_vfsmount[HUGE_MAX_HSTATE];
L
Linus Torvalds 已提交
1210

1211
static int can_do_hugetlb_shm(void)
L
Linus Torvalds 已提交
1212
{
1213 1214 1215
	kgid_t shm_group;
	shm_group = make_kgid(&init_user_ns, sysctl_hugetlb_shm_group);
	return capable(CAP_IPC_LOCK) || in_group_p(shm_group);
L
Linus Torvalds 已提交
1216 1217
}

1218 1219
static int get_hstate_idx(int page_size_log)
{
1220
	struct hstate *h = hstate_sizelog(page_size_log);
1221 1222 1223 1224 1225 1226

	if (!h)
		return -1;
	return h - hstates;
}

1227
static const struct dentry_operations anon_ops = {
1228
	.d_dname = simple_dname
1229 1230
};

1231 1232 1233 1234 1235 1236
/*
 * Note that size should be aligned to proper hugepage size in caller side,
 * otherwise hugetlb_reserve_pages reserves one less hugepages than intended.
 */
struct file *hugetlb_file_setup(const char *name, size_t size,
				vm_flags_t acctflag, struct user_struct **user,
1237
				int creat_flags, int page_size_log)
L
Linus Torvalds 已提交
1238
{
1239
	struct file *file = ERR_PTR(-ENOMEM);
L
Linus Torvalds 已提交
1240
	struct inode *inode;
1241
	struct path path;
1242
	struct super_block *sb;
L
Linus Torvalds 已提交
1243
	struct qstr quick_string;
1244 1245 1246 1247 1248
	int hstate_idx;

	hstate_idx = get_hstate_idx(page_size_log);
	if (hstate_idx < 0)
		return ERR_PTR(-ENODEV);
L
Linus Torvalds 已提交
1249

1250
	*user = NULL;
1251
	if (!hugetlbfs_vfsmount[hstate_idx])
1252 1253
		return ERR_PTR(-ENOENT);

1254
	if (creat_flags == HUGETLB_SHMFS_INODE && !can_do_hugetlb_shm()) {
1255 1256
		*user = current_user();
		if (user_shm_lock(size, *user)) {
1257
			task_lock(current);
1258
			pr_warn_once("%s (%d): Using mlock ulimits for SHM_HUGETLB is deprecated\n",
1259 1260
				current->comm, current->pid);
			task_unlock(current);
1261 1262
		} else {
			*user = NULL;
1263
			return ERR_PTR(-EPERM);
1264
		}
1265
	}
L
Linus Torvalds 已提交
1266

1267
	sb = hugetlbfs_vfsmount[hstate_idx]->mnt_sb;
1268
	quick_string.name = name;
L
Linus Torvalds 已提交
1269 1270
	quick_string.len = strlen(quick_string.name);
	quick_string.hash = 0;
1271
	path.dentry = d_alloc_pseudo(sb, &quick_string);
1272
	if (!path.dentry)
L
Linus Torvalds 已提交
1273 1274
		goto out_shm_unlock;

1275
	d_set_d_op(path.dentry, &anon_ops);
1276
	path.mnt = mntget(hugetlbfs_vfsmount[hstate_idx]);
1277
	file = ERR_PTR(-ENOSPC);
1278
	inode = hugetlbfs_get_inode(sb, NULL, S_IFREG | S_IRWXUGO, 0);
L
Linus Torvalds 已提交
1279
	if (!inode)
1280
		goto out_dentry;
1281 1282
	if (creat_flags == HUGETLB_SHMFS_INODE)
		inode->i_flags |= S_PRIVATE;
L
Linus Torvalds 已提交
1283

1284
	file = ERR_PTR(-ENOMEM);
1285 1286 1287
	if (hugetlb_reserve_pages(inode, 0,
			size >> huge_page_shift(hstate_inode(inode)), NULL,
			acctflag))
1288 1289
		goto out_inode;

1290
	d_instantiate(path.dentry, inode);
L
Linus Torvalds 已提交
1291
	inode->i_size = size;
1292
	clear_nlink(inode);
1293

1294
	file = alloc_file(&path, FMODE_WRITE | FMODE_READ,
1295
			&hugetlbfs_file_operations);
1296
	if (IS_ERR(file))
1297
		goto out_dentry; /* inode is already attached */
1298

L
Linus Torvalds 已提交
1299 1300
	return file;

1301 1302
out_inode:
	iput(inode);
L
Linus Torvalds 已提交
1303
out_dentry:
1304
	path_put(&path);
L
Linus Torvalds 已提交
1305
out_shm_unlock:
1306 1307 1308 1309
	if (*user) {
		user_shm_unlock(size, *user);
		*user = NULL;
	}
1310
	return file;
L
Linus Torvalds 已提交
1311 1312 1313 1314
}

static int __init init_hugetlbfs_fs(void)
{
1315
	struct hstate *h;
L
Linus Torvalds 已提交
1316
	int error;
1317
	int i;
L
Linus Torvalds 已提交
1318

1319
	if (!hugepages_supported()) {
1320
		pr_info("disabling because there are no supported hugepage sizes\n");
1321 1322 1323
		return -ENOTSUPP;
	}

1324
	error = -ENOMEM;
L
Linus Torvalds 已提交
1325 1326
	hugetlbfs_inode_cachep = kmem_cache_create("hugetlbfs_inode_cache",
					sizeof(struct hugetlbfs_inode_info),
1327
					0, SLAB_ACCOUNT, init_once);
L
Linus Torvalds 已提交
1328
	if (hugetlbfs_inode_cachep == NULL)
P
Peter Zijlstra 已提交
1329
		goto out2;
L
Linus Torvalds 已提交
1330 1331 1332 1333 1334

	error = register_filesystem(&hugetlbfs_fs_type);
	if (error)
		goto out;

1335 1336 1337 1338
	i = 0;
	for_each_hstate(h) {
		char buf[50];
		unsigned ps_kb = 1U << (h->order + PAGE_SHIFT - 10);
L
Linus Torvalds 已提交
1339

1340 1341 1342
		snprintf(buf, sizeof(buf), "pagesize=%uK", ps_kb);
		hugetlbfs_vfsmount[i] = kern_mount_data(&hugetlbfs_fs_type,
							buf);
L
Linus Torvalds 已提交
1343

1344
		if (IS_ERR(hugetlbfs_vfsmount[i])) {
1345
			pr_err("Cannot mount internal hugetlbfs for "
1346 1347 1348 1349 1350 1351 1352 1353 1354
				"page size %uK", ps_kb);
			error = PTR_ERR(hugetlbfs_vfsmount[i]);
			hugetlbfs_vfsmount[i] = NULL;
		}
		i++;
	}
	/* Non default hstates are optional */
	if (!IS_ERR_OR_NULL(hugetlbfs_vfsmount[default_hstate_idx]))
		return 0;
L
Linus Torvalds 已提交
1355 1356

 out:
1357
	kmem_cache_destroy(hugetlbfs_inode_cachep);
P
Peter Zijlstra 已提交
1358
 out2:
L
Linus Torvalds 已提交
1359 1360
	return error;
}
1361
fs_initcall(init_hugetlbfs_fs)